What parts does the electronic control unit (ECU) consist of?

The ECU used in centralized engine system is mainly composed of input circuit, analog-to-digital converter (A/D converter), microcomputer and output circuit. When the engine is working in the input circuit, the signals of various sensors are input to ECU, and then enter the input circuit for processing. Different sensor input signals have different processing methods. Generally, the input signal is filtered out of impurities and converted into a rectangular wave before being converted into an input level. The signals transmitted by the A/D converter sensor to ECU include digital signals (such as Carmen vortex street air flowmeter signal, rotational speed signal, etc.). ).) and analog signals (such as vane air flowmeter signal, air temperature sensor signal, throttle position sensor signal, etc. )。 Digital signals can be directly input into the microcomputer, but the microcomputer cannot directly accept analog signals, and must be converted into digital signals through the A/D converter and then input into the microcomputer. Microcomputer is the nerve center of the control system, and its function is to calculate and process the signals sent by each sensor by using its stored programs and data, and send the processing results to the output circuit. Microcomputer is mainly composed of central processing unit (CPU), memory (RAM/ROM) and input/output (I/O) devices. The main function of the output loop is to amplify the processing results of the microcomputer and generate control signals that can control the work of the actuator. The output circuit is generally a power tube, which controls the grounding circuit of the actuator to be turned on or off according to the instruction of the microcomputer.