T ermin " mechatronics"Introduced by Tetsuro Moria (Tetsuro Mori) engineer of the Japanese company Yaskawa Electric (Yaskawa electrician) in 1969. Term consists of two parts - "fur", from the word mechanics, and "tronics", from the word electronics. In Russia, before the term "mechatronics" appeared, devices with the name "mechanotrons" were used.
Mechatronics is a progressive direction in the development of science and technology, focused on the creation and operation of automatic and automated machines and systems with computer (microprocessor) control of their movement. The main task of mechatronics is the development and creation of high-precision, highly reliable and multifunctional control systems for complex dynamic objects. The simplest examples of mechatronics are the braking system of a car with ABS (anti-lock braking system) and industrial CNC machines.
The largest developer and manufacturer of mechatronic devices in the world bearing industry is the companySNR. The company is known as a pioneer in the field of "sensor" bearings, c who created the "know-how" technology c using multi-pole magnetic rings and measuring components integrated into mechanical parts. ExactlySNRpioneered the use of wheel bearings with an integrated rotation speed sensor based on a unique magnetic technology –ASB® (Active Sensor Bearing), which is now the standard recognized and used by almost all major car manufacturers in Europe and Japan. More than 82 million such devices have already been produced, and by 2010 almost 50% of all wheel bearings in the world produced by various manufacturers will use the technologyASB®. Such widespread useASB®once again proves the reliability of these solutions, providing high accuracy of measurement and transmission of digital information in the most aggressive environments (vibrations, dirt, large temperature differences, etc.).
Illustration : SNR
Bearing structure ASB®
The main advantages of technologyASB®used in the automotive industry are:
it is a compact and economical solution that can be used on vehicles of the lower price range, and not only on expensive cars, unlike many other competitive technologies,
it is a progressive technology in the study of automotive comfort and safety,
this is the main element in the concept of “total chassis control”,
it is an open standard that provides the lowest licensing costs for manufacturers of bearings and electronic components.
Technology ASB®in 1997 at the exhibition EquipAuto in Paris received the first Grand Prix in the nomination "New technologies for original (conveyor) production".
In 2005 EquipAuto SNRsuggested further developmentASB®– a special system with a rotation angle sensorASB® Steering System, designed to measure the angle of rotation of the steering wheel, which will optimize the operation of the car's electronic systems and increase the level of safety and comfort. The development of this system began in 2003, with the efforts ofCONTINENTAL TEVES And SNR Routines. In 2004, the first prototypes were ready. Field testASB® Steering Systemwere held in March 2005 in Sweden on cars Mercedes C -class and showed excellent results. In serial productionASB® Steering Systemshould enter in 2008.
Illustration : SNR
ASB® Steering System
Key BenefitsASB® Steering System will become:
simpler design,
ensuring a low noise level,
lower cost,
size optimization…
With more than 15 years of experience in the development and manufacture of mechatronic devices, the company offers customers not only from the automotive industry, but also from industry and aerospace - “mechatronic” bearingsSensor Line. These bearings have inherited unsurpassed reliabilityASB®, full integration and compliance with international standards ISO.
Located in the very center of movement, the sensorSensor Linetransmits information about the angular displacement and rotational speed for more than 32 periods per revolution. Thus, the functions of the bearing and the measuring device are combined, which has a positive effect on the compactness of the bearing and the equipment as a whole, while providing a competitive price in relation to standard solutions (based on optical sensors).
Photo : SNR
includes:
Patented multi-track and multi-pole magnetic ring that generates a magnetic field of a certain shape;
Special electronic component MPS 32 XF converts information about the change in the magnetic field into a digital signal.
Photo : Torrington
MPS 32 XF component
Sensor Line Encodercan achieve a resolution of 4096 pulses per revolution with a reading radius of only 15 mm, providing a positioning accuracy of more than 0.1°! Thus,Sensor Line Encoderin many cases can replace the standard optical encoder, while givingadditional functions.
Device Sensor Line Encodercan provide the following data with high accuracy and reliability:
angular position,
Speed,
direction of rotation
Number of turns
temperature.
Unique properties of the new deviceSNRwere recognized in the world of electronics at the stage of prototypes. Special sensor MPS 32 XF won the grand prize Gold Award at Sensor Expo 2001 in Chicago (USA).
CurrentlySensor Line Encoderfinds its application:
in mechanical transmissions;
in conveyors;
in robotics;
in vehicles;
in forklifts;
in control, measurement and positioning systems.
Photo : SNR
One of the further projects, which should finish in 2010-11, isASB®3– a bearing with an integrated torque sensor based on the use of tunnel magnetoresistance. The use of tunnel magnetoresistance technology makes it possible to provide:
high sensitivity of the sensor,
low energy consumption,
the best signal in relation to the noise level,
wider temperature range.
ASB®4, which is scheduled for release in 2012-15, will complete the opening of the era of information technology for the bearing industry. For the first time, a self-diagnostic system will be integrated, which will allow, for example, the bearing lubrication temperature or its vibration to find out the condition of the bearing.
Mechatronic modules are increasingly being used in various transport systems.
A modern car as a whole is a mechatronic system that includes mechanics, electronics, various sensors, an on-board computer that monitors and regulates the activity of all car systems, informs the user and brings control from the user to all systems. The automotive industry at the present stage of its development is one of the most promising areas for the introduction of mechatronic systems due to increased demand and increasing motorization of the population, as well as due to the presence of competition between individual manufacturers.
If we classify a modern car according to the principle of control, it belongs to anthropomorphic devices, because. its movement is controlled by man. Already now we can say that in the foreseeable future of the automotive industry, we should expect the appearance of cars with the possibility of autonomous control, i.e. with an intelligent traffic control system.
Fierce competition in the automotive market forces specialists in this field to search for new advanced technologies. Today, one of the main problems for developers is to create "smart" electronic devices that can reduce the number of road traffic accidents (RTA). The result of work in this area was the creation of an integrated vehicle security system (SCBA), which is able to automatically maintain a given distance, stop the car at a red traffic light, and warn the driver that he overcomes a turn at a speed higher than is permissible by the laws of physics. Even shock sensors with a radio signaling device have been developed, which, when a car hits an obstacle or a collision, calls an ambulance.
All these electronic accident prevention devices fall into two categories. The first includes devices in the car that operate independently of any signals from external sources of information (other cars, infrastructure). They process information coming from the airborne radar (radar). The second category is systems based on data received from information sources located near the road, in particular from beacons, which collect traffic information and transmit it via infrared rays to passing cars.
SKBA has brought together a new generation of the devices listed above. It receives both radar signals and the infrared rays of "thinking" beacons, and in addition to the main functions, it provides non-stop and calm traffic for the driver at unregulated intersections of roads and streets, limits the speed of movement on bends and in residential areas within the established speed limits. Like all autonomous systems, SCBA requires the vehicle to be equipped with an anti-lock brake system (ABS) and an automatic transmission.
SKBA includes a laser rangefinder that constantly measures the distance between the car and any obstacle along the way - moving or stationary. If a collision is likely, and the driver does not slow down, the microprocessor instructs to relieve pressure on the accelerator pedal, apply the brakes. A small screen on the instrument panel flashes a warning of danger. At the request of the driver, the on-board computer can set a safe distance depending on the road surface - wet or dry.
SCBA (Fig. 5.22) is able to drive a car, focusing on the white lines of the road surface markings. But for this it is necessary that they be clear, since they are constantly “read” by the video camera on board. The image processing then determines the position of the machine in relation to the lines, and the electronic system acts on the steering accordingly.
On-board receivers of infrared rays of the SCBA operate in the presence of transmitters placed at certain intervals along the carriageway. The beams propagate in a straight line and over a short distance (up to about 120 m), and the data transmitted by coded signals cannot be either jammed or distorted.
Rice. 5.22. Integrated vehicle security system: 1 - infrared receiver; 2 - weather sensor (rain, humidity); 3 - throttle actuator of the power supply system; 4 - computer; 5 - auxiliary solenoid valve in the brake drive; 6 - ABS; 7 - rangefinder; 8 - automatic transmission; 9 - vehicle speed sensor; 10 - auxiliary steering solenoid valve; 11 - accelerator sensor; 12 - steering sensor; 13 - signal table; 14 - electronic vision computer; 15 - television camera; 16 - screen.
On fig. 5.23 shows the Boch weather sensor. Depending on the model, an infrared LED and one or three photodetectors are placed inside. The LED emits an invisible beam at an acute angle to the surface of the windshield. If it is dry outside, all the light is reflected back and hits the photodetector (this is how the optical system is designed). Since the beam is modulated by pulses, the sensor will not react to extraneous light. But if there are drops or a layer of water on the glass, the refraction conditions change, and part of the light escapes into space. This is detected by the sensor and the controller calculates the appropriate wiper operation. Along the way, this device can close the electric sunroof, raise the windows. The sensor has 2 more photodetectors, which are integrated into a common housing with a weather sensor. The first is designed to automatically turn on the headlights when it gets dark or the car enters the tunnel. The second, switches the "distant" and "dipped" light. Whether these functions are enabled depends on the particular vehicle model.
Fig.5.23. The principle of operation of the weather sensor
Anti-lock braking system (ABS), its required components are wheel speed sensors, an electronic processor (control unit), servo valves, an electrically driven hydraulic pump and a pressure accumulator. Some early ABSs were "tri-channel", ie. controlled the front brake mechanisms individually, but completely released all the rear brake mechanisms at the beginning of blocking of any of the rear wheels. This saved some amount of cost and complexity, but resulted in lower efficiency compared to a full four-channel system in which each brake mechanism is individually controlled.
ABS has much in common with the traction control system (SBS), whose action could be considered as "ABS in reverse", since the SBS works on the principle of detecting the moment when one of the wheels begins to rapidly rotate compared to the other (the moment when slippage begins) and giving a signal to brake this wheel. Wheel speed sensors can be shared, and therefore the most effective way to prevent the drive wheel from spinning by reducing its speed is to apply a momentary (and if necessary, repeated) brake action, braking impulses can be received from the ABS valve block. In fact, if ABS is present, this is all that is required to provide the EBS as well - plus some additional software and an additional control unit to reduce engine torque or reduce the amount of fuel supplied if necessary, or to directly intervene in the accelerator pedal control system. .
On fig. 5.24 shows a diagram of the car's electronic power system: 1 - ignition relay; 2 - central switch; 3 - battery; 4 - exhaust gas converter; 5 - oxygen sensor; 6 - air filter; 7 - mass air flow sensor; 8 - diagnostic block; 9 - idle speed regulator; 10 - throttle position sensor; 11 - throttle pipe; 12 - ignition module; 13 - phase sensor; 14 - nozzle; 15 - fuel pressure regulator; 16 - coolant temperature sensor; 17 - candle; 18 - crankshaft position sensor; 19 - knock sensor; 20 - fuel filter; 21 - controller; 22 - speed sensor; 23 - fuel pump; 24 - relay for turning on the fuel pump; 25 - gas tank.
Rice. 5.24. Simplified diagram of the injection system
One of the components of the SCBA is an airbag (see Fig. 5.25.), The elements of which are located in different parts of the car. Inertial sensors located in the bumper, at the engine shield, in the racks or in the armrest area (depending on the car model), in the event of an accident, send a signal to the electronic control unit. In most modern SCBAs, frontal sensors are designed for impact force at speeds of 50 km/h or more. The side ones work with weaker impacts. From the electronic control unit, the signal follows to the main module, which consists of a compactly laid pillow connected to the gas generator. The latter is a tablet with a diameter of about 10 cm and a thickness of about 1 cm with a crystalline nitrogen-generating substance. An electrical impulse ignites a squib in the “tablet” or melts the wire, and the crystals turn into gas with the speed of an explosion. The entire process described is very fast. The “medium” pillow inflates in 25 ms. The surface of the European standard pillow rushes towards the chest and face at a speed of about 200 km / h, and the American one - about 300. Therefore, in cars equipped with an airbag, manufacturers strongly advise you to buckle up and not sit close to the steering wheel or dashboard. In the most "advanced" systems, there are devices that identify the presence of a passenger or a child seat and, accordingly, either turn off or correct the degree of inflation.
Fig.5.25 Car airbag:
1 - seat belt tensioner; 2 - airbag; 3 - airbag; for the driver; 4 - control unit and central sensor; 5 – executive module; 6 - inertial sensors
More details on modern automotive MS can be found in the manual.
In addition to conventional cars, much attention is paid to the creation of light vehicles (LTV) with electric drive (sometimes they are called non-traditional). This group of vehicles includes electric bicycles, scooters, wheelchairs, electric vehicles with autonomous power sources. The development of such mechatronic systems is carried out by the Scientific and Engineering Center "Mechatronika" in cooperation with a number of organizations. LTS are an alternative to vehicles with internal combustion engines and are currently used in environmentally friendly areas (health, tourism, exhibition, park complexes), as well as in retail and storage facilities. Technical characteristics of the prototype electric bike:
Maximum speed 20 km/h,
Rated drive power 160 W,
Rated speed 160 rpm,
Maximum torque 18 Nm,
Engine weight 4.7 kg,
Rechargeable battery 36V, 6 Ah,
Driving offline 20 km.
The basis for the creation of LTS are mechatronic modules of the "motor-wheel" type based, as a rule, on high-torque electric motors.
Sea transport. MS are increasingly used to intensify the work of crews of sea and river vessels associated with the automation and mechanization of the main technical means, which include the main power plant with service systems and auxiliary mechanisms, the electric power system, general ship systems, steering gear and engines.
Integrated automatic systems for keeping a ship on a given trajectory (SUZT) or a ship intended for the study of the World Ocean on a given line of profile (SUZP) are systems that provide the third level of control automation. The use of such systems allows:
To increase the economic efficiency of maritime transportation by implementing the best trajectory, vessel movement, taking into account navigational and hydrometeorological conditions of navigation;
To increase the economic efficiency of oceanographic, hydrographic and marine geological exploration by increasing the accuracy of keeping the vessel on a given line of profile, expanding the range of wind wave disturbances that provide the required quality of control, and increasing the operating speed of the vessel;
Solve the problems of realizing the optimal trajectory of the vessel when it diverges from dangerous objects; improve safety of navigation near navigational hazards through more precise control of the vessel's movement.
Integrated automatic motion control systems according to a given geophysical research program (ASUD) are designed to automatically bring the vessel to a given profile line, automatically keep the geological and geophysical vessel on the profile line under investigation, and maneuver when changing from one profile line to another. The system under consideration makes it possible to increase the efficiency and quality of marine geophysical surveys.
In marine conditions, it is impossible to use conventional methods of preliminary exploration (search party or detailed aerial photography), therefore the seismic method of geophysical research has become the most widely used (Fig. 5.26). The geophysical vessel 1 tows a pneumatic gun 3, which is a source of seismic vibrations, a seismographic spit 4, on which receivers of reflected seismic vibrations are located, and an end buoy 5, on a cable-cable 2. The bottom profiles are determined by recording the intensity of seismic vibrations reflected from the boundary layers of 6 different breeds.
Fig.5.26. Scheme of geophysical surveys.
To obtain reliable geophysical information, the vessel must be kept at a given position relative to the bottom (profile line) with high accuracy, despite the low speed (3-5 knots) and the presence of towed devices of considerable length (up to 3 km) with limited mechanical strength.
The firm "Anjutz" has developed an integrated MS that ensures the vessel is kept on a given trajectory. On fig. 5.27 shows a block diagram of this system, which includes: gyrocompass 1; lag 2; instruments of navigation systems that determine the position of the vessel (two or more) 3; autopilot 4; mini-computer 5 (5a - interface, 5b - central storage device, 5c - central processing unit); punched tape reader 6; plotter 7; display 8; keyboard 9; steering machine 10.
With the help of the system under consideration, it is possible to automatically bring the vessel to a programmed trajectory, which is set by the operator using a keyboard that determines the geographical coordinates of the turning points. In this system, regardless of the information coming from any one group of instruments of a traditional radio navigation complex or satellite communication devices that determine the position of the vessel, the coordinates of the probable position of the vessel are calculated from the data provided by the gyrocompass and log.
Fig.5.27. Structural diagram of the integrated MS for keeping the ship on a given trajectory
The course control with the help of the system under consideration is carried out by an autopilot, the input of which receives information about the value of the given course ψset, formed by a mini-computer, taking into account the error in the position of the ship. The system is assembled in the control panel. In its upper part there is a display with controls for setting the optimal image. Below, on the inclined field of the console, there is an autopilot with control handles. On the horizontal field of the console there is a keyboard, with the help of which programs are entered into the mini-computer. There is also a switch with which the control mode is selected. In the base part of the control panel there are a mini-computer and an interface. All peripheral equipment is placed on special stands or other consoles. The system under consideration can operate in three modes: "Course", "Monitor" and "Program". In the "Course" mode, a given course is maintained with the help of an autopilot according to the readings of the gyrocompass. The "Monitor" mode is selected when the transition to the "Program" mode is being prepared, when this mode is interrupted, or when the transition through this mode is completed. The “Course” mode is switched over when malfunctions of the mini-computer, power sources or radio navigation complex are detected. In this mode, the autopilot operates independently of the mini-computer. In the "Program" mode, the course is controlled according to the data of radio navigation devices (position sensors) or a gyrocompass.
Maintenance of the ship's containment system on the ST is carried out by the operator from the control panel. The choice of a group of sensors to determine the position of the vessel is made by the operator according to the recommendations presented on the display screen. At the bottom of the screen is a list of all commands allowed for this mode, which can be entered using the keyboard. Accidental pressing of any prohibited key is blocked by the computer.
Aviation technology. The successes achieved in the development of aviation and space technology, on the one hand, and the need to reduce the cost of targeted operations, on the other hand, stimulated the development of a new type of technology - remotely piloted aircraft (RPV).
On fig. 5.28 shows a block diagram of the UAV remote flight control system - HIMAT. The main component of the HIMAT remote piloting system is the ground remote control station. The UAV flight parameters are received by the ground station via the radio link from the aircraft, are received and decoded by the telemetry processing station and transmitted to the ground part of the computer system, as well as to the information display devices in the ground control station. In addition, a picture of the external view displayed by a television camera is received from the RPV. The television image displayed on the screen of the ground workplace of the human operator is used to control the aircraft during air maneuvers, landing approach and during the landing itself. The cockpit of the ground remote control station (operator's workplace) is equipped with devices that provide indication of information about the flight and the state of the equipment of the RPV complex, as well as means for controlling the aircraft. In particular, at the disposal of the human operator there are handles and pedals for controlling the aircraft in roll and pitch, as well as an engine control handle. In the event of a failure of the main control system, the commands of the control system are given through a special remote control for discrete commands of the RPV operator.
Fig.5.28. HIMAT RPV remote piloting system:
carrier B-52; 2 - backup control system on the TF-104G aircraft; 3 – line of telemetric communication with the ground; 4 - RPV HIMAT; 5 - lines of telemetric communication with RPV; 5 - ground station for remote piloting
As an autonomous navigation system that provides dead reckoning, Doppler ground speed and drift angle meters (DPSS) are used. Such a navigation system is used in conjunction with a heading system that measures the heading with a vertical sensor that generates roll and pitch signals, and an on-board computer that implements the dead reckoning algorithm. Together, these devices form a Doppler navigation system (see Figure 5.29). To improve the reliability and accuracy of measuring the current coordinates of the aircraft, DISS can be combined with speed meters
Fig.5.29. Diagram of a Doppler navigation system
The miniaturization of electronic elements, the creation and serial production of special types of sensors and indicator devices that work reliably under difficult conditions, as well as a sharp reduction in the cost of microprocessors (including those specially designed for cars) created the conditions for turning vehicles into MS of a fairly high level.
High-speed ground transport on a magnetic suspension is a clear example of a modern mechatronic system. So far, the world's only commercial transport system of this kind was put into operation in China in September 2002 and connects Pudong International Airport with downtown Shanghai. The system was developed, manufactured and tested in Germany, after which the train cars were transported to China. The guiding track, located on a high trestle, was manufactured locally in China. The train accelerates to a speed of 430 km/h and covers a distance of 34 km in 7 minutes (the maximum speed can reach 600 km/h). The train hovers over the guide track, there is no friction on the track, and air provides the main resistance to movement. Therefore, the train has been given an aerodynamic shape, the joints between the cars are closed (Fig. 5.30).
To ensure that the train does not fall onto the guide track in the event of an emergency power outage, it is equipped with powerful batteries, the energy of which is sufficient to bring the train to a smooth stop.
With the help of electromagnets, the distance between the train and the guide track (15 mm) during movement is maintained with an accuracy of 2 mm, which makes it possible to completely eliminate the vibration of the cars even at maximum speed. The number and parameters of the supporting magnets is a trade secret.
Rice. 5.30. Maglev train
The maglev transport system is fully controlled by a computer, since at such a high speed a person does not have time to respond to emerging situations. The computer also controls the acceleration and deceleration of the train, also taking into account the turns of the track, so passengers do not feel discomfort when accelerating.
The described transport system is characterized by high reliability and unprecedented accuracy in the implementation of the traffic schedule. During the first three years of operation, more than 8 million passengers were transported.
To date, the leaders in maglev technology (an abbreviation used in the West for the words "magnetic levitation") are Japan and Germany. In Japan, the maglev set a world record for the speed of rail transport - 581 km / h. But Japan has not yet progressed further than setting records, trains run only along experimental lines in Yamanashi Prefecture, with a total length of about 19 km. In Germany, maglev technology is being developed by Transrapid. Although the commercial version of the maglev did not take root in Germany itself, the trains are operated at the test site in Emsland by Transrapid, which has successfully implemented the commercial version of the maglev in China for the first time in the world.
As an example of already existing transport mechatronic systems (TMS) with autonomous control, we can cite the VisLab robot car and the laboratory of machine vision and intelligent systems of the University of Parma.
Four robotic cars have traveled an unprecedented 13,000 kilometers from Parma in Italy to Shanghai for autonomous vehicles. This experiment was intended to be a tough test for the TMC intelligent autonomous driving system. Her test took place in city traffic, for example, in Moscow.
Robot cars were built on the basis of minibuses (Figure 5.31). They differed from ordinary cars not only in autonomous control, but also in pure electric traction.
Rice. 5.31. VisLab self-driving car
Solar panels were located on the roof of the TMS to power critical equipment: a robotic system that rotates the steering wheel and presses the gas and brake pedals, as well as the computer components of the machine. The rest of the energy was supplied by electrical outlets during the journey.
Each robot car was equipped with four laser scanners in front, two pairs of stereo cameras looking forward and backward, three cameras covering a 180-degree field of view in the front "hemisphere" and a satellite navigation system, as well as a set of computers and programs that allow the car to make decisions. in certain situations.
Another example of an autonomously controlled mechatronic transport system is the RoboCar MEV-C robotic electric vehicle from the Japanese company ZMP (Fig. 5.32).
Fig.5.32. Robotic electric car RoboCar MEV-C
The manufacturer positions this TMS as a machine for further advanced development. The autonomous control device includes the following components: a stereo camera, a 9-axis wireless motion sensor, a GPS module, a temperature and humidity sensor, a laser rangefinder, Bluetooth, Wi-Fi and 3G chips, as well as a CAN protocol that coordinates the joint work of all components . RoboCar MEV-C measures 2.3 x 1.0 x 1.6 m and weighs 310 kg.
A modern representative of the transport mechatronic system is the transscooter, which belongs to the class of light vehicles with an electric drive.
Transscooters are a new type of transformable multifunctional ground vehicles for individual use with an electric drive, mainly intended for people with disabilities (Fig. 5.33). The main distinguishing feature of the transscooter from other land vehicles is the ability to cross flights of stairs and implement the principle of multifunctionality, and hence transformability in a wide range.
Rice. 5.33. The appearance of one of the samples of the transscooter family "Kangaroo"
The mover of the transscooter is made on the basis of a mechatronic module of the “motor-wheel” type. The functions and, accordingly, the configurations provided by the transscooters of the Kangaroo family are as follows (Fig. 5.34):
- "Scooter" - movement at high speed on a long base;
- "Armchair" - maneuvering on a short base;
- "Balance" - standing movement in the gyro stabilization mode on two wheels;
- "Compact-vertical" - movement while standing on three wheels in the gyro-stabilization mode;
- "Curb" - overcoming the curb immediately standing or sitting (some models have an additional function "Slanting curb" - overcoming the curb at an angle of up to 8 degrees);
- "Ladder up" - climbing the steps of the stairs in front, sitting or standing;
- "Ladder down" - descending the steps of the stairs in front, while sitting;
- "At the table" - low landing, feet on the floor.
Rice. 5.34. The main configurations of the transscooter on the example of one of its variants
The transscooter has an average of 10 compact high-torque electric drives with microprocessor control. All drives are of the same type - DC brushless motors controlled by signals from Hall sensors.
To control such devices, a multifunctional microprocessor control system (CS) with an on-board computer is used. The architecture of the transscooter control system is two-level. The lower level is the maintenance of the drive itself, the upper level is the coordinated operation of the drives according to a given program (algorithm), testing and monitoring the operation of the system and sensors; external interface - remote access. The top-level controller (on-board computer) is Advantech PCM-3350, made in PC/104 format. As a lower-level controller, a specialized microcontroller TMS320F2406 from Texas Instruments for controlling electric motors. The total number of low-level controllers responsible for the operation of individual units is 13: ten drive control controllers; steering head controller, which is also responsible for displaying information displayed on the display; controller for determining the residual capacity of the battery; battery charge and discharge controller. Data exchange between the on-board computer of the transscooter and peripheral controllers is supported via a common bus with a CAN interface, which allows minimizing the number of conductors and achieving a real data transfer rate of 1 Mbps.
On-board computer tasks: control of electric drives, servicing commands from the steering head; calculation and display of the residual charge of the battery; solving a trajectory problem for moving up the stairs; possibility of remote access. The following individual programs are implemented via the on-board computer:
Acceleration and deceleration of the scooter with controlled acceleration / deceleration, which is personally adapted to the user;
A program that implements the algorithm for the operation of the rear wheels when cornering;
Longitudinal and transverse gyro stabilization;
Overcoming the curb up and down;
Movement up and down the stairs
Adaptation to the dimensions of the steps;
Identification of staircase parameters;
Wheelbase changes (from 450 to 850 mm);
Monitoring of scooter sensors, drive control units, battery;
Emulations based on the readings of the sensors of the parking radar;
Remote access to control programs, changing settings via the Internet.
The transscooter has 54 sensors that allow it to adapt to the environment. Among them: Hall sensors built into brushless motors; absolute angle sensors that determine the position of the components of the transscooter; resistive steering wheel sensor; infrared distance sensor for parking radar; an inclinometer that allows you to determine the slope of the scooter while driving; accelerometer and angular velocity sensor used to control gyro stabilization; radio frequency receiver for remote control; resistive linear displacement sensor to determine the position of the chair relative to the frame; shunts for measuring motor current and residual battery capacity; potentiometric speed controller; strain gauge weight sensor to control the weight distribution of the apparatus.
The general block diagram of the control system is shown in Figure 5.35.
Rice. 5.35. Block diagram of a control system for a transscooter of the Kangaroo family
Legend:
RMC - absolute angle sensors, DH - Hall sensors; BU - control unit; LCD - liquid crystal indicator; MKL - motor-wheel left; MCP - right wheel motor; BMS - power management system; LAN - port for external connection of the on-board computer for the purpose of programming, settings, etc.; T - electromagnetic brake.
The main advantages of mechatronic devices compared to traditional automation tools include:
Relatively low cost due to the high degree of integration, unification and standardization of all elements and interfaces;
High quality of the implementation of complex and precise movements due to the use of intelligent control methods;
High reliability, durability and noise immunity;
The structural compactness of the modules (up to miniaturization and micromachines),
Improved weight, size and dynamic characteristics of machines due to the simplification of kinematic chains;
The ability to integrate functional modules into complex mechatronic systems and complexes for specific customer tasks.
The volume of world production of mechatronic devices is increasing every year, covering all new areas. Today, mechatronic modules and systems are widely used in the following areas:
Machine tool building and equipment for automation of technological processes;
Robotics (industrial and special);
Aviation, space and military equipment;
Automotive (for example, anti-lock brake systems, vehicle stabilization and automatic parking systems);
Non-traditional vehicles (electric bicycles, cargo carts, electric scooters, wheelchairs);
Office equipment (for example, photocopiers and facsimile machines);
Elements of computer technology (for example, printers, plotters, disk drives);
Medical equipment (rehabilitation, clinical, service);
Household appliances (washing, sewing, dishwashers and other machines);
Micromachines (for medicine, biotechnology, communications and telecommunications);
Control and measuring devices and machines;
Photo and video equipment;
Simulators for training pilots and operators;
Show industry (sound and lighting systems).
Of course, this list can be expanded.
The rapid development of mechatronics in the 90s as a new scientific and technical direction is due to three main factors:
New trends in world industrial development;
Development of fundamental principles and methodology of mechatronics (basic scientific ideas, fundamentally new technical and technological solutions);
The activity of specialists in the research and educational fields.
The current stage of development of automated mechanical engineering in our country is taking place in the new economic realities, when there is a question about the technological viability of the country and the competitiveness of manufactured products.
The following trends of change in the key requirements of the world market in the area under consideration can be distinguished:
The need for the production and service of equipment in accordance with the international system of quality standards formulated in the standards ISO series 9000 ;
Internationalization of the market of scientific and technical products and, as a result, the need for active implementation of forms and methods into practice
international engineering and technology transfer;
Increasing the role of small and medium-sized manufacturing enterprises in the economy due to their ability to respond quickly and flexibly to changing market requirements;
The rapid development of computer systems and technologies, telecommunications facilities (in the EEC countries in 2000, 60% of the growth of the Total National Product occurred precisely due to these industries); a direct consequence of this general trend is the intellectualization of control systems for mechanical motion and technological functions of modern machines.
As the main classification feature in mechatronics, it seems appropriate to take the level of integration of the constituent elements. In accordance with this feature, mechatronic systems can be divided by levels or by generations, if we consider their appearance on the market of science-intensive products, historically mechatronic modules of the first level represent a combination of only two initial elements. A typical example of a first generation module is a "gear motor", where the mechanical gearbox and the controlled motor are produced as a single functional element. Mechatronic systems based on these modules have found wide application in the creation of various means of complex automation of production (conveyors, conveyors, rotary tables, auxiliary manipulators).
Second-level mechatronic modules appeared in the 80s in connection with the development of new electronic technologies, which made it possible to create miniature sensors and electronic units for processing their signals. The combination of drive modules with the above elements has led to the emergence of mechatronic motion modules, the composition of which fully corresponds to the definition introduced above, when the integration of three devices of different physical nature is achieved: 1) mechanical, 2) electrical and 3) electronic. On the basis of mechatronic modules of this class, 1) controlled power machines (turbines and generators), 2) machine tools and industrial robots with numerical control have been created.
The development of the third generation of mechatronic systems is due to the appearance on the market of relatively inexpensive microprocessors and controllers based on them and is aimed at the intellectualization of all processes occurring in a mechatronic system, primarily the process of controlling the functional movements of machines and assemblies. At the same time, new principles and technologies for manufacturing high-precision and compact mechanical units are being developed, as well as new types of electric motors (primarily high-torque brushless and linear), feedback and information sensors. Synthesis of new 1) precision, 2) information and 3) measuring science-intensive technologies provides the basis for the design and production of intelligent mechatronic modules and systems.
In the future, mechatronic machines and systems will be combined into mechatronic complexes based on common integration platforms. The purpose of creating such complexes is to achieve a combination of high productivity and at the same time the flexibility of the technical and technological environment due to the possibility of its reconfiguration, which will ensure competitiveness and high quality of products.
Modern enterprises embarking on the development and production of mechatronic products must solve the following main tasks in this regard:
Structural integration of subdivisions of mechanical, electronic and informational profiles (which, as a rule, functioned autonomously and separately) into single design and production teams;
Training of "mechatronic-oriented" engineers and managers capable of system integration and management of the work of highly specialized specialists of various qualifications;
Integration of information technologies from various scientific and technical fields (mechanics, electronics, computer control) into a single toolkit for computer support of mechatronic tasks;
Standardization and unification of all used elements and processes in the design and manufacture of MS.
The solution of these problems often requires overcoming the management traditions that have developed at the enterprise and the ambitions of middle managers who are accustomed to solving only their narrow-profile tasks. That is why medium and small enterprises that can easily and flexibly vary their structure are more prepared for the transition to the production of mechatronic products.
Similar information.
Road transport plays an important role in the country's transport system and economy. The car is widely used for the transportation of goods to railways, river and sea berths, maintenance of industrial trade enterprises, agricultural workers, and provides transportation of passengers. Road transport accounts for about half of passenger and freight traffic (Fig. 12.1)
Figure 12.1– Transport distribution
Literally a hundred years have passed since the appearance of the first car, and there is practically no field of activity in which it would not be used. Therefore, the automotive industry in the economies of developed countries is now the leading branch of engineering. There are reasons for this:
Firstly, every day people need more and more cars to solve various economic problems;
Secondly, this industry is knowledge-intensive and high-tech. It "pulls" many other industries with it, the enterprises of which carry out its numerous orders. Innovations introduced in the automotive industry inevitably force these industries to improve their production as well. Due to the fact that there are a lot of such industries, as a result, there is a rise in the entire industry, and, consequently, the economy as a whole;
Thirdly, the automotive industry in all developed countries is one of the most profitable sectors of the national economy, since it contributes to an increase in trade and brings considerable income to the state treasury through sales on the domestic and world markets;
Fourth, the automotive industry is a strategically important industry. The development of this industry makes the country economically strong and therefore more independent. The widespread use of the best examples of automotive technology in the army, no doubt, increases the country's defense power.
Now in the automotive industry, there are a number of trends that testify to its importance and importance, as well as related industries in the economies of industrialized countries. There is a completely new approach to the technical development of the car, the organization and technology of its production. The scientific and technological trends are to reduce fuel consumption and reduce harmful emissions, develop an ultralight car, improve safety, quality, reliability and durability, as well as the development of intelligent road and road systems.
The development of mechatronics in cars (Fig. 12.2) and on production machines has its own characteristics. In automobiles, the expansion of automation, and therefore mechatronics, began mainly in the field of comfort devices. The first of the mechatronic units, as is historically customary, there was an engine with a fuel supply system and automatic control of it. The second is the attachment power control system (EHR), the world leader in the production of which is Bosch. The third is transmission. Here the process began with the advent of mechanical transmissions with switching stages under load. They appeared hydraulic, then electro-hydraulic switching devices, and then electronic automatic switching control. Western firms (German ZF and others) began to supply automobile plants and produce for sale transmissions in such a complete set
The strength and benefit of the mechatronic design of the units is especially clearly seen in the example of transmissions, which, in the presence and absence of automatic control with the same other components of the complex, show a striking contrast in the characteristics of both themselves and the vehicles equipped with them. In mechatronic form, they provide an order of magnitude more favorable characteristics in almost all indicators of machine operation: technical, economic and ergonomic.
Comparing mechatronic complexes with their non-mechatronic prototypes in terms of technical perfection, it is easy to see that the former are significantly superior to the latter, not only in terms of general indicators, but also in terms of the level and quality of design. This is not surprising: the synergistic effect is manifested not only in the final product, but also in the design process due to a new approach to design.
Figure 12.2– Classification of mechatronic vehicle systems
When controlling the operation of a car engine, various systems are used:
- AVCS (Active Valve Control System)- the variable valve timing system on Subaru vehicles changes the valve lift height depending on the instantaneous engine load. common rail(Nissan) - an injection system that supplies fuel to the cylinders through a common line under high pressure. It has a number of advantages that make driving more enjoyable for the driver: common rail diesel engines are characterized by both excellent throttle response and low fuel consumption, eliminating the need to stop frequently at gas stations.
- GDI- Gasoline Direct Injection, which can be translated as "engine with direct fuel injection", that is, the fuel on such an engine is not injected into the intake manifold, but directly into the engine cylinders. M-Fire- combustion process control system - significantly reduces the opacity of exhaust gases and the content of nitrogen oxides in them with a simultaneous increase in power and a decrease in noise level.
- MIVEC(Mitsubishi) - optimally controls the opening of the intake valves in accordance with the operating conditions of the engine, which improves the stability of the engine at idle, power and torque characteristics for the entire operating range.
- VTEC(Honda) - Variable valve timing system. They are used to improve torque characteristics in a wide range of revolutions, as well as to improve the economy and environmental performance of the engine. Also used on Mazda vehicles.
- DPS- Dual Pump System - two oil pumps connected in series (i.e. one after the other). If the speed of both oil pumps is equal, "even" oil circulation takes place, i.e. there are no areas with high and low pressure (Fig. 12.3).
Figure 12.3– Dual Pump System
- common rail(English) common highway) is a modern technology of fuel supply systems in diesel engines with direct injection. In the common rail system, the pump pumps fuel at high pressure (250 - 1800 bar, depending on the engine operating mode) into the common fuel line. Electronically controlled injectors with solenoid or piezoelectric valves inject fuel into the cylinders. Depending on the design, the nozzles produce from 2 to 5 injections per 1 cycle. Accurate calculation of the injection start angle and the amount of injected fuel allow diesel engines to meet the increased environmental and economic requirements. In addition, diesel engines with the common rail system have closely approached, and in some cases surpassed gasoline engines in their power and dynamic characteristics.
There are different types of mechatronic transmission devices:
- CVT- Automatic transmission with CVT. It is a mechanism with a gear ratio change range greater than that of a 5-speed manual gearbox.
- DAC- Downhill Assist Control - the system controls the behavior of the machine on steep slopes. The wheels are equipped with sensors that measure the speed of rotation of the wheels and constantly compare it with the speed of the car. Analyzing the received data, the electronics brakes the front wheels in time to a speed of about 5 km / h.
- DDS- Downhill Drive Support - a system for controlling movement in Nissan cars on steep descents. DDS automatically maintains a speed of 7 km/h when descending, preventing the wheels from locking up.
-Drive Select 4x4- All-wheel drive can be switched on and off on the move at speeds up to 100 km/h.
-TSA(Trailer Stability Assist) - a vehicle stabilization system while driving with a trailer. When losing stability, the car, as a rule, begins to chat on the road. In this case, TSA brakes the wheels "diagonally" (left front - right rear or right front - left rear) out of phase with the oscillation, while reducing vehicle speed by reducing the fuel supply to the engine. Used on Honda vehicles.
- Easy Select 4WD- the all-wheel drive system, widely used in Mitsubishi cars, allows you to change 2WD to 4WD, and vice versa, while the car is moving.
- Grade Logic Control- the system of "smart" gear selection provides uniform traction, which is especially important when climbing uphill.
- Hypertronic CVT-M6(Nissan) - provide smooth, stepless acceleration without jerks, characteristic of traditional automatic machines. In addition, they are more economical than traditional automatic transmissions. The CVT-M6 is designed for drivers who want to combine the benefits of automatic and manual water transmissions. By moving the gearshift lever to the slot farthest from the driver, you get the opportunity to switch six gears with fixed gear ratios.
- INVECS II- adaptive automatic (Mitsubishi) - automatic transmission with a sport mode and the possibility of mechanical control.
- EBA- an electronic pressure control system in the hydraulic brake system, which, in case of emergency braking and insufficient effort on the brake pedal, independently increases the pressure in the brake line, making it many times faster than a person. And the EBD system evenly distributes braking forces and works in conjunction with ABS - anti-lock braking system.
-ESP+- anti-skid stabilization system ESP - the most complex system using the capabilities of anti-lock, anti-slip with traction control and electronic throttle control systems. The control unit receives information from the sensors of the angular acceleration of the car, the angle of rotation of the steering wheel, information about the speed of the car and the rotation of each of the wheels. The system analyzes this data and calculates the trajectory of movement, and if in turns or maneuvers the real speed does not coincide with the calculated one and the car “takes out” outside or inside the turn, it corrects the trajectory of movement by braking the wheels and reducing engine thrust.
- HAC- Hill-start Assist Control - the system controls the behavior of the car on steep slopes. HAC not only prevents wheel spin when starting up a slippery slope, but also can prevent rolling back if the vehicle speed is too low and it slides down under the weight of the body.
- Hill Holder- with this device, the car is held on the brakes even after the brake pedal is released, the Hill Holder is turned off only after the clutch pedal is released. Designed to start moving uphill.
- AIRMATIC Dual Control- Active air suspension with electronic adjustment and adaptive damping system ADS II operates in fully automatic mode (Fig. 12.4). Compared with the traditional steel suspension, it greatly improves driving comfort and safety. AIRMATIC DC works with air cushions, which are electronically made stiffer or softer depending on the driving situation. If the sensors detect a sporty driving style, for example, the normally comfortable air suspension is automatically stiffened. Suspension and damping can also be set to sporty or comfortable mode manually via a switch.
Electronics works with four different damping modes (ADS II), which adapt automatically on each wheel to the road conditions. Thus, the car rolls smoothly even on a bad road without sacrificing stability.
Figure 12.4– AIRMATIC Dual Control
The system is also equipped with a vehicle leveling function. It provides, even with a loaded vehicle, an almost constant ground clearance, which gives the vehicle stability. When driving at high speed, the vehicle may automatically lower to reduce body tilt. At speeds above 140 km/h, the vehicle automatically lowers by 15 mm, and at speeds below 70 km/h, the normal level is restored again. In addition, for bad roads, it is possible to manually raise the car by 25 mm. When driving for a long time at a speed of about 80 km/h or when the speed is exceeded 120 km/h, the normal level is automatically restored again.
Also in cars, various braking systems are used to significantly reduce the braking distance, competent interpretation of the driver's behavior during braking, activation of the maximum braking force in case of recognition of emergency braking.
- Brake Assistant (BAS), which is fitted as standard on all Mercedes-Benz passenger cars, interprets the driver's braking behavior and, in the event of emergency braking detection, generates the maximum braking force if the driver himself does not apply enough pressure on the brake pedal. The development of the brake assistant is based on data received by the Mercedes-Benz Accident Research Department: in a critical situation, drivers press the brake pedal quickly, but not hard enough. In this case, the brake assistant can effectively support the driver.
For a better understanding, let's briefly review the technology of modern brake systems: the brake booster, which amplifies the pressure created by the driver's foot, consists of two chambers, which are separated from each other by a movable membrane. If braking is not performed, then there is a vacuum in both chambers. Depressing the brake pedal in the brake booster opens a mechanical control valve that allows air into the rear chamber and changes the pressure ratio in the two chambers. The maximum effort is created when atmospheric pressure reigns in the second chamber. In the brake assistant (BAS), a so-called diaphragm movement sensor determines whether the braking is extreme. It detects the movement of the membrane between the chambers and transmits the value to the BAS control unit. Constantly comparing the values, the microcomputer recognizes the moment when the speed of pressing the brake pedal (equal to the speed of movement of the membrane in the brake booster) exceeds the standard value - this is emergency braking. In this case, the system activates a magnetic valve through which the rear chamber is instantly filled with air and maximum braking force is generated. Despite this automatic full braking, the wheels do not lock up, because the well-known anti-lock braking system ABS doses the braking force, optimally keeping it on the verge of blocking, thereby maintaining vehicle controllability. If the driver takes his foot off the brake pedal, a special actuation sensor closes the solenoid valve and the automatic brake boost is deactivated.
Figure 12.6– Brake Assistant (BAS) Mercedes
- Anti-lock braking system (ABS)(German antiblockiersystem English Anti-lock Brake System (ABS)) - a system that prevents the vehicle's wheels from blocking during braking. The main purpose of the system is to reduce the braking distance and ensure the controllability of the vehicle during hard braking, and eliminate the possibility of its uncontrolled slip.
ABS consists of the following main components:
Speed or acceleration (deceleration) sensors mounted on the wheel hubs of the vehicle.
Control valves, which are elements of the pressure modulator, installed in the line of the main brake system.
A control unit that receives signals from sensors and controls the operation of the valves.
After the start of braking, the ABS begins a constant and fairly accurate determination of the speed of rotation of each wheel. In the event that one wheel begins to rotate significantly slower than the others (which means that the wheel is close to blocking), a valve in the brake line limits the braking force on that wheel. As soon as the wheel begins to rotate faster than the rest, the braking force is restored.
This process is repeated several times (or several tens of times) per second, and usually results in a noticeable pulsation of the brake pedal. The braking force can be limited both in the entire braking system at the same time (single-channel ABS), and in the braking system of the side (two-channel ABS) or even a single wheel (multi-channel ABS). Single-channel systems provide fairly effective deceleration, but only if the traction conditions of all wheels are more or less the same. Multi-channel systems are more expensive and more complicated than single-channel systems, but they are more effective when braking on uneven surfaces, if, for example, when braking, one or more wheels hit ice, a wet section of the road, or a shoulder.
Control and navigation systems are widely used in modern cars. .
- DISTRONIC system– implements electronic control of the distance to the vehicle in front using radar, simple operation with the TEMPOMAT lever, provides additional comfort on autobahns and similar roads, maintains the working condition of the driver.
The distance controller DISTRONIC maintains the required distance from the vehicle in front. If the distance decreases, the braking system is activated. If no vehicle is driving ahead, DISTRONIC maintains the speed set by the driver. DISTRONIC provides additional comfort for driving on the Autobahn and similar roads. The microcomputer processes radar signals at a speed of 30 to 180 km / h, which is installed behind the grille. Radar pulses are reflected from the vehicle in front, processed, and based on this information, the distance to the front vehicle and its speed are calculated. If a Mercedes-Benz vehicle with DISTRONIC approaches the vehicle in front too closely, DISTRONIC automatically reduces the throttle and applies the brakes to maintain the set distance. If it is necessary to brake strongly, the driver is informed about this by means of an acoustic signal and a warning light - this means that the driver must press the brake pedal himself. If the distance increases, then DISTRONIC again provides the necessary distance and accelerates the car to the set speed. DISTRONIC is a further development of the standard TEMPOMAT function with variable speed limit SPEEDTRONIC
Figure 12.7– Control and navigation system
Mercedes-Benz has introduced the first AIR-matic mechatronic air suspension with ADS shock absorber control as standard on S-Class sedans.
In the AIR-matic system, the pillar of the S-class sedan contains a pneumatic elastic element: the role of springs familiar to us is performed by compressed air enclosed under a rubber-cord shell. Even in the rack there is a shock absorber with an unusual "extension" on the side. Naturally, the car has a full-fledged pneumatic system (compressor, receiver, lines, valve devices). And also - a network of sensors and, of course, a processor. How the system works. At the command of the processor, the valves open the access of air from the pneumatic system to the elastic elements (or bleed air from there). Thus, the level of the floor of the body changes: its dependence on the speed of the car is incorporated into the system. The driver can also "show the will" - raise the car, say, to move significant bumps.
ADS performs more “fine” work - controls shock absorbers. When the shock absorber rod moves, part of the fluid flows not only through the valves in the piston, but also through the very “extension” inside which the actuator is a valve system that provides four possible shock absorber operation modes. Based on the information coming from the sensors and in accordance with the algorithm selected by the driver (“sporty” or “comfortable”), the processor selects for each shock absorber the mode that is most appropriate to the “current moment” and sends commands to the actuators.
Modern cars are equipped climate control system. This system is designed to create and automatically maintain a microclimate in the car. The system ensures the joint operation of heating, ventilation and air conditioning systems through electronic control.
The use of electronics made it possible to achieve zonal climate control in the car. Depending on the number of temperature zones, the following climate control systems are distinguished:
single-zone climate control;
Dual zone climate control
three-zone climate control;
Four-zone climate control.
The climate control system has the following general device:
air conditioning system;
· control system.
Climate control includes structural elements of heating, ventilation and air conditioning systems, including:
heater radiator;
Supply air fan
air conditioner, consisting of an evaporator, compressor, condenser and receiver.
Main elements climate control systems are:
input sensors;
· Control block;
executive devices.
Input sensors measure the corresponding physical parameters and convert them into electrical signals. Control system input sensors include:
outside air temperature sensor;
solar radiation level sensor (photodiode);
output temperature sensors;
damper potentiometers;
evaporator temperature sensor;
pressure sensor in the air conditioning system.
The number of outlet temperature sensors is determined by the design of the climate control system. An outlet temperature sensor for the footwell can be added to the outlet temperature sensor. In a two-zone climate control system, the number of outlet temperature sensors is doubled (sensors on the left and right), and in a three-zone climate control system it is tripled (left, right and rear).
The damper potentiometers record the current position of the dampers. Evaporator temperature and pressure sensors ensure the operation of the air conditioning system. The electronic control unit receives signals from the sensors and, in accordance with the programmed program, generates control actions on the actuators.
The actuating devices include damper drives and an electric motor of the supply air fan, with the help of which the set temperature regime is created and maintained. The shutters can be mechanically or electrically driven. The following dampers can be used in the air conditioner design:
supply air damper
central damper;
temperature control dampers (in systems with 2 or more control zones);
Recirculation damper
· dampers for defrosting glasses.
The climate control system provides automatic temperature control in the car interior within the range of 16-30 °C.
The desired temperature value is set using the controls on the dashboard of the car. The signal from the regulator goes to the electronic control unit, where the corresponding program is activated. In accordance with the established algorithm, the control unit processes the signals from the input sensors and activates the necessary actuators. If necessary, the air conditioner is turned on.
A modern car is a source of increased danger. The steady increase in the power and speed of the car, the traffic density of traffic flows significantly increase the likelihood of an emergency.
To protect passengers in an accident, technical safety devices are being actively developed and implemented. In the late 1950s, there were seat belts designed to hold passengers in their seats in a collision. In the early 1980s, there were airbags.
The totality of structural elements used to protect passengers from injury in an accident constitutes the vehicle's passive safety system. The system should provide protection not only for passengers and a particular vehicle, but also for other road users.
The most important components of the car's passive safety system are:
· seat belts;
Seat belt tensioners
active head restraints
airbags;
· car body, resistant to deformation;
emergency disconnect battery;
a number of other devices (rollover protection system on a convertible; child safety systems - mounts, seats, seat belts).
The modern passive safety system of the car has an electronic control that ensures the effective interaction of most components.
Control system includes:
input sensors;
· Control block;
Actuating devices of system components.
The input sensors fix the parameters at which an emergency occurs and convert them into electrical signals. Input sensors include:
shock sensor;
The switch of the lock of a seat belt;
Front passenger seat occupancy sensor
· Seat position sensor for driver and front passenger.
As a rule, two are installed on each side of the car. shock sensor. They provide the appropriate airbags. In the rear, shock sensors are used when the vehicle is equipped with electrically operated active head restraints. The seat belt buckle switch detects the use of the seat belt.
The front passenger seat occupied sensor allows you to save the corresponding airbag in the event of an emergency and the absence of a passenger in the front seat.
Depending on the seating position of the driver and front passenger, which is fixed by the corresponding sensors, the order and intensity of the application of the system components changes.
Based on the comparison of the sensor signals with the control parameters, the control unit recognizes the onset of an emergency and activates the necessary actuators of the system elements.
The actuators of the elements of the passive safety system are:
airbag igniter;
· Seat belt tensioner igniter;
· Igniter (relay) of the battery emergency disconnector;
· Igniter of the drive mechanism of active head restraints (when using head restraints with electric drive);
· the control lamp signaling about not fastened seat belts.
Actuators are activated in a certain combination in accordance with the installed software.
ISOFIX- Isofix child seat mounting system. Externally, child seats with this system are distinguished by two compact locks located on the back of the sled. The locks capture a six-millimeter bar hidden behind plugs at the base of the seatback.
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Ministry of Higher and Secondary Special Education of the Republic of Uzbekistan
Bukhara Engineering and Technology Institute
Independent work
Mechatronic systems for road transport
Plan
Introduction
1. Purpose and problem statement
2. Control laws (programs) of gear shifting
3. Modern car
4. Advantages of the novelty
Bibliography
Introduction
Mechatronics arose as a complex science from the merging of separate parts of mechanics and microelectronics. It can be defined as a science that deals with the analysis and synthesis of complex systems that use mechanical and electronic control devices to the same extent.
All mechatronic systems of cars according to their functional purpose are divided into three main groups:
Engine control systems;
Transmission and running gear control systems;
Salon equipment control systems.
The engine management system is divided into gasoline and diesel engine management systems. By appointment, they are monofunctional and complex.
In monofunctional systems, the ECU only sends signals to the injection system. The injection can be carried out continuously and in pulses. With a constant supply of fuel, its amount changes due to a change in pressure in the fuel line, and with a pulse, due to the duration of the pulse and its frequency. Today, one of the most promising areas for the application of mechatronics systems are cars. If we consider the automotive industry, then the introduction of such systems will make it possible to achieve sufficient production flexibility, to better capture fashion trends, to quickly introduce advanced developments of scientists and designers, and thereby obtain a new quality for car buyers. The car itself, especially a modern car, is the object of close consideration from a design point of view. The modern use of the car requires increased requirements for driving safety, due to the ever-increasing motorization of countries and the tightening of environmental standards. This is especially true for metropolitan areas. The answer to today's challenges of urbanism is the design of mobile tracking systems that control and correct the characteristics of the operation of components and assemblies, achieving optimal indicators for environmental friendliness, safety, and operational comfort of the car. The urgent need to complete car engines with more complex and expensive fuel systems is largely due to the introduction of increasingly stringent requirements for the content of harmful substances in exhaust gases, which, unfortunately, is only just beginning to be worked out.
In complex systems, one electronic unit controls several subsystems: fuel injection, ignition, valve timing, self-diagnosis, etc. The diesel engine electronic control system controls the amount of fuel injected, the injection start time, the current of the torch plug, etc. In the electronic transmission control system, the object of regulation is mainly the automatic transmission. Based on signals from throttle angle sensors and vehicle speed, the ECU selects the optimal transmission ratio, which improves fuel efficiency and drivability. Chassis control includes control of the processes of movement, changes in the trajectory and braking of the car. They affect the suspension, steering and braking system, ensure that the set speed is maintained. Interior equipment management is designed to increase the comfort and consumer value of the car. For this purpose, air conditioning, an electronic instrument panel, a multifunctional information system, a compass, headlights, an intermittent wiper, a burnt-out lamp indicator, an obstacle detection device when reversing, anti-theft devices, communication equipment, central locking of door locks, power windows, reclining seats, safety mode, etc.
1. Purpose and problem statement
The decisive importance that belongs to the electronic system in the car makes us pay increased attention to the problems associated with their maintenance. The solution to these problems is to include self-diagnosis functions in the electronic system. The implementation of these functions is based on the capabilities of the electronic systems already used on the vehicle for continuous monitoring and fault detection for the storage of this information and diagnostics. Self-diagnostics of mechatronic systems of cars. The development of electronic engine and transmission control systems has led to an improvement in the performance of the car.
Based on the signals from the sensors, the ECU generates commands to engage and disengage the clutch. These commands are given to a solenoid valve that engages and disengages the clutch actuator. Two solenoid valves are used for shifting gears. By combining the open-close states of these two valves, the hydraulic system sets four gear positions (1, 2, 3 and overdrive). When shifting gears, the clutch disengages, thereby eliminating the effects of changing torque associated with gear shifting.
2.
Control laws (programs) of gear shifting in automatic transmission provide optimal transmission of engine energy to the wheels of the car, taking into account the required traction and speed properties and fuel economy. At the same time, programs for achieving optimal traction-speed properties and minimum fuel consumption differ from each other, since the simultaneous achievement of these goals is not always possible. Therefore, depending on the driving conditions and the desire of the driver, you can select the "economy" program to reduce fuel consumption, the "power" program using a special switch. What were the parameters of your desktop computer five or seven years ago? Today, the system blocks of the late 20th century seem to be atavism and only pretend to be a typewriter. A similar situation with automotive electronics.
3. modern car
It is now impossible to imagine a modern car without compact control units and actuators - actuators. Despite some skepticism, their implementation is progressing by leaps and bounds: you will no longer surprise us with electronic fuel injection, servo mirrors, sunroofs and windows, electric power steering and multimedia entertainment systems. And how not to remember that the introduction of electronics into a car, in essence, was started from the most responsible body - the brakes. Now back in 1970, the joint development of Bosch and Mercedes-Benz, under the modest abbreviation ABS, revolutionized active safety. The anti-lock braking system not only ensured the controllability of the car with the pedal pressed "to the floor", but also prompted the creation of several related devices - for example, a traction control system (TCS). This idea was first implemented back in 1987 by one of the leading developers of on-board electronics - the Bosch company. In essence, traction control is the opposite of ABS: the latter keeps the wheels from slipping when braking, and TCS when accelerating. The electronics unit monitors traction on the wheels through several speed sensors. Should the driver "stomp" on the accelerator pedal harder than usual, creating a threat of wheel slippage, the device will simply "strangle" the engine. Design "appetite" grew from year to year. Just a few years later, ESP, the Electronic Stability Program, was created. Having equipped the car with sensors for the angle of rotation, wheel speed and lateral acceleration, the brakes began to help the driver in the most difficult situations that arise. By slowing down one or another wheel, the electronics minimizes the risk of car drift during high-speed passage of difficult turns. The next stage: the on-board computer was taught to slow down ... simultaneously 3 wheels. Under certain circumstances on the road, this is the only way to stabilize the car, which the centrifugal forces of the movement will try to take away from a safe trajectory. But so far, electronics has been trusted only with a "supervisory" function. The driver still created pressure in the hydraulic drive with the pedal. The tradition was broken by the electro-hydraulic SBC (Sensotronic Brake Control), which has been standard on some Mercedes-Benz models since 2006. The hydraulic part of the system is represented by a pressure accumulator, the main brake cylinder and lines. Electric - pump pump, creating a pressure of 140-160 atm. , pressure sensors, wheel speed and brake pedal travel. By pressing the latter, the driver does not move the usual rod of the vacuum booster, but presses the “button” with his foot, giving a signal to the computer, as if he were controlling some kind of household appliance. The same computer calculates the optimal pressure for each circuit, and the pump, through control valves, supplies fluid to the working cylinders.
4. Advantages of the novelty
Advantages of the novelty- speed, combination of ABS and stabilization system functions in one device. There are other benefits as well. For example, if you suddenly take your foot off the gas pedal, the brake cylinders will bring the pads to the disc, preparing for emergency braking. The system is even linked to... windshield wipers. According to the intensity of the work of the "wipers", the computer draws a conclusion about the movement in the rain. The reaction is short and imperceptible for the driver to touch the pads on the discs for drying. Well, if you are "lucky" to get into a traffic jam on the rise, do not worry: the car will not roll back until the driver moves his foot from the brake to the gas. Finally, at speeds below 15 km/h, the so-called soft deceleration function can be activated: when the gas is released, the car will stop so gently that the driver does not even feel the final “dive”. mechatronics microelectronics engine transmission
What if the electronics fail? It's okay: the special valves will open completely, and the system will work like a traditional one, however, without a vacuum booster. So far, designers do not dare to completely abandon the hydraulic brake devices, although eminent companies are already developing "liquid-free" systems with might and main. For example, Delphi announced the solution of most of the technical problems that until recently seemed dead ends: powerful electric motors - substitutes for brake cylinders have been developed, and electric actuators have been made even more compact than hydraulic ones.
List l iterations
1. Butylin V.G., Ivanov V.G., Lepeshko I.I. et al. Analysis and prospects for the development of mechatronic control systems for wheel braking // Mechatronika. Mechanics. Automation. Electronics. Computer science. - 2000. - No. 2. - S. 33 - 38.
2. Danov B.A., Titov E.I. Electronic equipment of foreign cars: Transmission, suspension and brake control systems. - M.: Transport, 1998. - 78 p.
3. Danov B. A. Electronic control systems for foreign cars. - M.: Hot line - Telecom, 2002. - 224 p.
4. Shiga H., Mizutani S. Introduction to automotive electronics: TRANS. from Japanese - M.: Mir, 1989. - 232 p.
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