An important direction of technological development. The development of the automobile industry has also driven the development of the electronics industry, especially in modern cars, electronics / electric appliances account for an increasing proportion of automobile manufacturing costs. According to the analysis and prediction of a foreign company (VDI), the cost of electronics / electric appliances in automobile manufacturing has increased year by year since the 1980s, and the cost share has reached about 15%. Mainly electronically controlled fuel injection, electronic engine control and electronic transmission control. After the 21st century, the growth rate will reach 25%, mainly including diesel injection, dirty guide devices and other electronic systems. Subsequently, the share of integrated automotive electronic equipment in the total cost of automobile manufacturing has maintained a steady growth trend, and it is expected to reach 30% by 2010. At present, the number of automotive electronic products is increasing. Many industrially developed countries have formed an independent Automotive electronics. The value of electronic products in the entire vehicle has also gradually increased. In 1991, the value of an electronic device on a car was US $ 825, which rose to US $ 1125 in 1995, and now it has reached US $ 2,000, which accounts for more than 30% of the total vehicle cost. In order to further improve the product level and competitiveness, major foreign automobile companies attach great importance to the research and development of automotive electronic products, and have invested a lot of funds, such as Toyota, which has invested up to 1.5 billion US dollars. With the continuous introduction of various electronic systems such as the engine electronic control system of the car, the air suspension control system of the transmission electronic control system, the anti-lock brake control system, the air control system, and the air conditioning control system, the intelligent and automatic control of the car has been realized. Into reality. The German MAN company is at the forefront of the world in the development of automotive control systems. It has taken the lead in using the self-developed electronic device -MAN-Tronic (MAN-Automotive Electronic Control System) on the recently launched TG-A car and has become a mature series of products. . 2 The development direction of automotive electronic technology and electronic control Automotive electronic technology is used to meet user expectations and requirements for automotive safety, reliability or practical functions. For car manufacturers, the key is to align their development goals with the high demands of users through technological innovation. For example, Division B has better combined its development goals with the needs of users. They continue to improve the driving power of cars, increase the power of engines, shape ergonomics, and pursue first-class quality. User requirements. Many automobile manufacturers have increased their investment in electronic technology and technological innovation through new technologies and new products, constantly changing and improving car functions. Today's electronic technology has fully achieved the goals and requirements that cannot be achieved by mechanical and hydraulic means, and is moving forward to achieve higher user expectations and requirements. The higher the degree of automation of the car, the more power electronic drive and conversion units in the car, and the more complex the control unit. The main functions of power electronic drive units in automobiles are motor drive, coil drive and electromagnetic clutch drive. The main control units in the car are ECUTCU and ABS. In addition, hybrid vehicles with broad development prospects are also closely related to power electronics. At present, there are two main trends in automotive electronic technology. One is that electronic control technology will gradually replace mechanical control technology, and the other is that active intelligent control based on energy conservation, environmental protection and safety will become increasingly popular. Automotive electronics technology will develop in four directions: functional diversification, technology integration, system integration, and communication networking. The focus of development includes powertrain control, chassis control, body control, active / passive security, automotive networks, communication systems, security and anti-theft technology, etc. Automotive electronic technology, including the adjustment of the engine, chassis running mechanism and auxiliary devices, has evolved from a single controller to a compound and integrated transmission control system. A single controller can be connected together to exchange data with each other through the CAN bus. The advantage of this interconnection is that the sensor signal can be used by many controllers at the same time, and all controllers share the same information. On the other hand, through this connection, newer functions can be developed within the entire system and the cost of the system can be reduced. Today, most functions of the engine can be controlled in real time, making the combustion process better, thereby increasing power and torque, and reducing emissions and fuel consumption. Of course, the development of a series of new functions has also increased the power consumption of automobiles, especially the use of electromagnetic clutches, electromagnetic brakes, etc. has brought certain difficulties to electrical energy regulation, which requires high efficiency generators and high efficiency power Electronic converter. Among the key technologies of automotive electronics, sensors, ECUs, actuators, control strategies, bus technologies, new 42V power supplies, and automotive safety technologies are the focus of future development. With more advanced smart sensors, fast-responsive actuators, high-performance ECUs, advanced control strategies, computer network technology, radar technology, and third-generation mobile communication technology widely used in automobiles, Hyundai Motor is moving towards more The development of intelligent, automated and informatized mechatronics products has reached the level of "Human-Automotive-Environment" coordination. Among them, sensors will develop toward multi-function, integration, intelligence and miniaturization; in terms of ECU, with the increasing concentration of automotive electronic control, the amount of information that needs to be processed continues to increase. Therefore, 16-bit and 32 Position will become the first choice for designers; electromagnetic and electric actuators will gradually replace pneumatic / hydraulic actuators; in terms of control strategy, PID control theory is currently used, and optimal control, adaptive control and fuzzy will be used more in the future control. The electronic control unit ECU on the car is composed of a microcomputer and peripheral circuits. The microcomputer is a unit that integrates a microprocessor (CPU), memory, and input / output interfaces on a chip. The main part of the ECU is a microcomputer, and the heartware is the CPUECU that converts the input signal into a digital form, performs comparison processing based on the stored data, calculates the output value, and then the output signal is controlled by the power drive circuit to control several adjustments I! Service components, such as ignition coils and electronic switches. Therefore, the ECU is actually an electronic control unit, which is composed of three parts: input circuit, microcomputer and power drive circuit. The input circuit accepts signals input by sensors and other devices, filters and amplifies the signals, and then converts them to a certain volt input level. The signal sent from the sensor to the ECU input circuit has both analog and digital signals. The analog-to-digital converter in the input circuit can convert the analog signal into a digital signal and then pass it to the microcomputer. The microcomputer performs arithmetic processing on the above-mentioned pre-processed signal, and sends the processed data to the output circuit. The output circuit amplifies the power of digital information, and some of them also need to be restored to analog signals to drive the controlled regulator I! Clothing components work. In the next 5 to 10 years, the next-generation high-speed fault-tolerant bus represented by TTP / C and FlexRay will replace high-speed CAN, thus changing the current pattern of LIN, low-speed CAN, and high-speed CAN. In addition, the existing 12V power supply system's power supply capacity has been unable to meet the needs of new electronic equipment in the design of next-generation vehicles, and the use of the new 42V power supply has become inevitable. In terms of car safety that is generally concerned, automatic collision avoidance systems, safety systems that monitor driver behavior, tire comprehensive detection systems, adaptive automatic driving systems, driver identification systems, and body dynamic control systems will become the development of a new generation of vehicle safety technology direction. 3. The electronic technology of the engine and electronic control The electronic ignition timing is to use a special microcomputer or large-scale integrated circuit to control the ignition timing in real time. Its key component is a high-precision knock sensor. Electronically controlled fuel supply system is currently the most commonly used gasoline injection system, followed by electronic control of electronic carburetor and diesel engine. Their key components include the air intake sensor and nozzle. The application of electronic technology to the engine is comprehensive, so that it is easy to reduce costs and improve performance. For example, the ECC system produced by Nissan has various control functions such as ignition timing, gasoline injection, exhaust gas recirculation, idle speed adjustment and fault self-diagnosis. Electronic control of the gasoline engine. The use of electronic fuel injection technology (EFI) for gasoline engines is one of the effective measures for modern vehicles to increase power, reduce fuel consumption and reduce pollution. The engine electronic control unit ECU or electronic control unit is an integrated control device for the engine. The function of the ECU is to calculate, process, judge and determine the fuel injection amount of the engine according to the signals input by various sensors, and control the fuel injection pulse of the fuel injector according to the fuel injection amount. First, it calculates the basic fuel injection amount based on the amount of air sucked by the engine and the engine speed, and then makes corrections based on the signals input by various sensors, and finally determines the total fuel injection time and fuel injection pulse. The ECU controls not only fuel injection but also ignition timing, idle speed and exhaust emissions. EFI technology is an advanced engine electronic management system. Its basic working principle is that sensors send the data of the gasoline engine's working conditions, such as load size, speed, speed, and intake air temperature, to the computer for processing. Determine the fuel supply to ensure the normal operation of the engine under various operating conditions. Today's EFI has evolved from a single control to multiple centralized controls, based on parameters such as vehicle speed, ambient temperature and engine speed, automatically perform fuel injection, air-fuel ratio, ignition time, idle speed and exhaust gas recirculation (ECR) of the engine Comprehensive control. The effect is as follows: output power is increased by 10%, fuel consumption is reduced by 10%, exhaust emissions are reduced by 90%, startup time is shortened by 50%, acceleration time is shortened by 50% (0 ~ 100kn / h). In vehicles equipped with automatic transmission, the automatic transmission is controlled by the engine The control is combined with an electronic control device for comprehensive management. The basic electronic control items of the gasoline engine are as follows: First, fuel ration. This is the most important electronic control project for gasoline engines. The control object is the mass ratio of air and fuel entering the engine, which is determined by the ECU according to the parameters such as engine load, speed and coolant temperature. The load is the driver's torque requirement for the engine, which is transmitted to the ECU through the intake air volume or the oil pedal position. The actuator is an electric fuel pump and electromagnetic injector. The fuel quantity quantitatively affects the power, fuel economy, comfort, emissions and the safety of parts and components of the car; the second is the ignition timing. Ignition timing is usually expressed in terms of how many degrees of crank angle the piston is before the top dead center of the compression stroke when ignition occurs, that is, the ignition advance angle. The actuator is an ignition coil. Ignition timing also affects the car's power, fuel economy, comfort, emissions and component safety; third is knock control. Gasoline engine knocking can damage the engine and worsen emissions and fuel economy. The main way to avoid knocking through electronic control is to reduce the ignition advance angle. Therefore, knock control is implemented by ignition timing control. But too small ignition advance angle will affect fuel economy. The purpose of knock control is to keep the ignition advance angle at a critical point where knocking does not occur; Fourth, the control of evaporative emissions from the fuel tank. The evaporative emissions from the fuel tank are all carbon and ammonia compounds, which are harmful substances. They must be adsorbed by an activated carbon tank, and the activated carbon tank should be cleaned with fresh air when appropriate. The cleaning air flow is sent to the cylinder for combustion through the intake pipe. The cleaning can not be carried out under any working conditions, so the electronic control of the diesel engine is controlled by using the canister control valve to control the cleaning air flow. Exhaust gas purification and energy saving are two major problems that automobile products need to solve urgently. Modern vehicle diesel engines have high working pressure, full combustion, and fuel consumption about 20% lower than gasoline engines. Traditional diesel engines have the problem of inaccurate fuel supply. The solution is to use electronically controlled fuel injection technology. Diesel electronic control technology is currently mainly used in diesel injection, exhaust gas recirculation, exhaust gas catalytic conversion and other aspects. The current advanced diesel engine electronic technology is a common rail electronically controlled fuel injection system. It consists of solenoid valve, sensor and central processing unit. Unlike traditional injection systems, pressure generation and injection are not related to each other in the common rail system. Within certain limits, the choice of injection pressure is not affected by engine speed and fuel injection. Compared with the gasoline engine, the electronically controlled fuel injection system of the diesel engine has many similarities and is basically the same in terms of computer management of the whole machine. However, due to the variety of diesel engine injection systems, the hardware of the electronic control system is also diverse. , Timing, fuel injection pressure, fuel injection path and other parameters for comprehensive control, the software is also more difficult than the gasoline engine. The first-generation diesel electronically controlled fuel injection system is also called a position control system. It replaces the governor with an electronic servo mechanism to control the position of the fuel supply sleeve to achieve the adjustment of the fuel supply. This type of technology has been developed to control both timing and pre-control. Jet TICS system. The second-generation system is also called a time control system. Its characteristic is that the oil supply still maintains the traditional pulsating plunger pump oil method, but the oil quantity and timing adjustment are determined by the powerful and fast response of the computer-controlled solenoid valve to determine the opening and closing time . The third generation is also called a direct numerical control system. It completely decouples the traditional fuel supply method of the sub-cylinder of the oil pump, and realizes various complex fuel supply regulations and characteristics through the integrated control of common rail pressure and injection pressure / time. . Powerful and fast linear response solenoid valve is a technical difficulty common to various systems. Due to the variety of diesel engine injection systems, there are inline pumps and distribution pumps with variable pre-stroke TICS systems, time-based pump nozzle systems, pressure-storage common rail systems and high-pressure common rail systems. Various technical solutions are developed on the original basis, but the high-pressure common rail system is the general development direction. 4 The electronic control of the transmission system The application of the electronically controlled automatic transmission of the car meets the requirements of people pursuing easy operation and fuel economy. The electronically controlled automatic transmission realizes automatic shifting, automatic control of clutch and oil opening through electronic technology, and can automatically select the best gear and the best shift time. There are 3 kinds of control methods: electronic control pneumatic control, electronic control hydraulic control and electronic control motor control. The electronic transmission can bring the theoretically optimal operating specifications into the transmission system to obtain maximum power transmission and minimum fuel consumption. There are four types of known electronic transmissions: the traditional hydraulic transmission is electronically controlled to improve its flap; the electronically controlled planetary transmission automatic transmission; the automatic transmission using electromagnetic clutch coupling; the belt transmission stepless speed change Automatic Transmission. The automatic transmission is mainly controlled by the continuously variable transmission and the gearbox controller TCU according to the sensor input signal and the switch signal to control the solenoid valve clutch and the motor that controls the variable ratio to achieve the purpose of automatic transmission. The electronic control device of the automatic transmission is composed of the signal input system computing system and the control signal output system. The signal input system includes: transmission input speed sensor, transmission output speed sensor, engine cooling temperature sensor, throttle position sensor, engine crankshaft speed sensor, lubricating oil temperature sensor, brake switch and other signals. After these signals are input to the TCU, after calculation or table look-up, and then output control signals to control the current of the electromagnetic clutch, the current of the magnetic clutch depends on the running state of the car. The TCU controls the size of the electromagnetic clutch energizing current or turns it off according to the driving status of the car. When the vehicle speed is slow or stopped, the TCU does not start the electromagnetic clutch. When the vehicle speed reaches a certain value, the TCU starts the electromagnetic clutch. The control of the transmission ratio of the automobile gearbox is also made by TCU. The TCU controls the transmission ratio of the gearbox according to the input signal parameters of the vehicle speed, engine speed and throttle â–¡ opening degree to adjust the motor forward or reverse and accelerate or decelerate to achieve the car The best running state. (To be continued)
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