an electronic control unit the ECU
The electronic control unit is referred to as an electronic control unit (ECU) is. Function of the electronic control unit is carried out in accordance with its program and data memory of the air flow meter and various information input sensors computing, processing, determination, and outputs a command signal to provide a certain width of the electrical pulse to the injector to control the injector the amount. The electronic control unit of a microcomputer, an input, an output and a control circuit.
DEFINITIONS
ECU (Electronic Control Unit) the electronic control unit, also known as ldquo; trip computer rdquo;, ldquo; onboard computer rdquo; like. From the use of perspective is a vehicle for computer controller, microcontroller, also known as a dedicated car. It ordinary microcontroller as large scale integration by the microprocessor (CPU), a memory (ROM ,, RAM), an input / output interface (I / O), analog to digital converter (A / D) and shaping, driving, etc. circuit.
ECU operating voltage range of the general (the internal key regulator device) in 6.5-16V, the operating current 0.015-0.1A, operating temperature minus 40-80 degrees. 1000Hz less able to withstand the vibration, thus the probability of damage is very small ECU, the ECU is a core part of the CPU, which has a function of computing and control, when the engine is running, it is collecting signals from the sensors, calculates, and operation result into a control signal to control the controlled object of work. It also exercise control memory (ROM ,, RAM), an input / output interface (I / O) and the other external circuit; stored in program memory ROM is precisely calculated and experimental data taken on the basis of a large number, the program inherent when the engine is operating, constantly calculating and comparing the signal acquisition to each sensor. The result of the comparison calculation and control of a number of parameters controlling ignition engine, air-fuel ratio, idle, exhaust gas recirculation and so on. It also has a faultProtection and self-diagnostic function, when the system failure, it can automatically record code and fault protection using an alternative procedure to read from said program to maintain the inherent operation of the engine in the RAM, able to open to the automobile repair shop.
ECU working conditions:
Vehicle ECU environment in which the complex is very bad, addition humidity, temperature, vibration, shock, dust, mud and sand, external environmental factors, water, oil, and other voltage fluctuations, electromagnetic environment is a problem can not be ignored. In order to make ECU to adapt to the harsh electromagnetic environment inside the car, consider the environment in which the ECU in the design of automotive electronic products as well as ECU testing and assessment is very important.
ECU’s self-diagnosis function:
ECU generally includes a self-diagnostic and protection function, when the system failure, it can in RAM automatically record the fault code and the use of protective measures alternative procedure read from said program to maintain the inherent operation of the engine. Meanwhile These error messages will be displayed on the dashboard and remain immortal, so that owners can discover problems and able to open the car repair shop.
Since the ECU for the function
Under normal circumstances, the RAM will keep your record data traveling, the ECU becomes learning process, to adapt to your driving habits to provide the best control state, the program is also called adaptive program. However, because it is stored in the RAM, the same code as an error, but to remove a battery loses power, all data will be lost.
ECU network
at present in a number of high-class cars, not only in the application engine ECU, ECU can find traces in many other places. For example, anti-lock braking system, four-wheel drive system, electronically controlled automatic transmission, active suspension systems, air bag system, the multi-adjustable electric seat so arranged the respective ECU. With the improvement of car electronic automation, ECU will be increasing, the line will become increasingly complex. To simplify the circuit and reduce the cost, the transfer of information between the plurality of cars on the ECU will use a technique called multiplexing communication network, the vehicle ECU to form a network system, andIt is the CAN data bus.