SMT circuit board assembly for automotive electronic PCB A32

Product Features: Automotive Electronics

Applications: Automotive electronic central control electronic equipment including air supply system, fuel supply system, electronic control system, ignition system, video, map navigation, Bluetooth equipment, as well as driving recorder, audio speaker, lighting system, wiper system, alternator, starters, automotive ignition systems, lighting and signals, automotive instrumentation and information display systems, automotive air conditioning systems, electronic control systems for engines, etc.

1. The system composition

The engine control system consists of three parts: sensor, controller and actuator. The sensor is a component that senses information and provides information such as automobile performance and engine operating conditions to the controller. The engine controller, is the engine control module (ECM), can receive information from the sensor and store relevant information, and after calculation and analysis, issue corresponding control commands to the actuator. An actuator is an actuator component that function is to execute the controller's instructions in order to achieve control objectives.

2. The control function

The automobile engine control system is an integrated control system with multiple control functions. Fuel injection control and ignition control are the main functions of the engine control system. The intake control, emission control, fault self-diagnosis and failure protection are all supplemented.

3. The control method

The control methods of the engine control system mainly include open loop control and closed loop control.

4. The principle of control

When the engine is started, the ECM enters the working state, and the corresponding program is read from the ROM to the CPU. These programs can be used to control ignition timing, fuel injection, idle speed, and so on. Through the control of the CPU, instruction is executed one by one. The engine information required to execute the program comes from each sensor. The signal from the sensor first enters the input circuit for processing. If it is a digital signal, it enters the microprocessor directly through the I/O interface; if it is an analog signal, it is converted into a digital signal by the A/D converter before entering the microprocessor via the I/O interface. Most of the information is temporarily stored in RAM and sent from the RAM to the CPU according to the instructions. Sometimes it is necessary to introduce reference data stored in the ROM into the CPU to compare the information of the input sensor with it. Each piece of information from the relevant sensor is sampled sequentially and compared to the reference data. After the CPU compares the data, it makes a decision and issues an output command signal. After the I/O interface, the necessary signal is also converted into an analog signal by the D/A converter, and finally through the output circuit to control the actuator action.