Basic components of automotive electronic control systems
Automotive electronic control systems mainly include electronic control units (including software), sensors and actuators.
- Electronic control unit
The electronic control unit (ECU) is the "brain" of the automotive electronic control system. It comprehensively analyzes and processes the electrical signals input by each sensor and the feedback electrical signals of some actuators, provides reference voltage to the sensor, and then outputs control signals to the actuator to make the actuator work according to the requirements of the control target.
The software is integrated and stored in the electronic control unit. The core is a microprocessor. This type of microprocessor usually uses a single-chip microcomputer, which has easy function expansion and higher control accuracy. It is used in electronic control systems to complete data acquisition, calculation processing, output control, system monitoring and self-diagnosis, etc. Most electronic control units have similar circuit structures. The changes in their control functions mainly depend on the changes in the developed software and input and output modules, and should be determined according to the functions of the electronic control system.
- Sensors
Sensors are the "clairvoyant eyes" and "clairaudient ears" of the automotive electronic control system. They convert various physical parameters of the vehicle's operating conditions and status, and the vehicle's driving conditions and status into electrical signals and transmit them to the electronic control unit.
- Actuator
The actuator is the "hand" and "foot" of the automotive electronic control system. The electronic control unit controls the controlled object through the actuator. The actuator responds quickly to the control signal output by the electronic control unit, so that the controlled object works in the set optimal state.
For example, the fuel injector. The amount of fuel injected by the injector is determined by the ECU. The ECU controls the needle valve of the injector and determines the length of time the needle valve is open (injection pulse time). The amount of fuel injected is a set value in the ECU memory. This set value is pre-set according to the engine conditions, which are determined by the engine speed and intake volume.
Basic principles of automotive electronic control systems
The automotive electronic control system stores a series of instruction programs in the ECU program memory in advance. These instruction programs have been set during design and manufacturing. The electronic control unit input signals come from various sensors of the control system.
When the ECU is working, it receives signals from sensors distributed in various parts of the car. It compares these input information with the "standard parameters" in the memory and controls the actuator to take corresponding actions based on the results.
