Electronic Throttle Control System (ETC) was born with Drive-by-Wire. It replaces the traditional mechanical connection between the accelerator pedal and the throttle body, and establishes a connection between the accelerator pedal and the throttle valve through a wire, which can improve engine control and avoid adverse consequences caused by improper operation of the accelerator pedal by the driver. By adding corresponding sensors and electronic control units, it accurately controls the throttle opening in real time. It can realize engine torque control and precise air-fuel ratio control, which helps to improve the driving dynamics, smoothness and economy of the car, and can effectively reduce emissions pollution. At present, ETC is widely used in automotive power control systems such as ASR, CCS and VSC, and has gradually become the standard configuration of high-end cars.
In the traditional engine design scheme, the position of the throttle is mainly controlled by a mechanical linkage (Bowdon cable), which also includes springs, pulleys and other parts. Bowden cable has played his role well for a long time, but there are also many shortcomings:
1) it is noisy;
2) it contains multiple wires, and the two ends of the wires are connected to the accelerator pedal and the throttle valve disc, respectively Are connected, so many parts must be arranged in a very small space;
3) Since the entire operation process is completed by a mechanical linkage mechanism, from the driver to issue an operation instruction to the execution by pressing the accelerator pedal There will be a time lag when the mechanism responds, which will cause the best fuel economy performance and emission performance expected by the driver to be different from what the engine actually achieves.
ETC basic composition and working principle
The electronic throttle control system consists of a throttle, a throttle position sensor, a throttle control unit ECU, a throttle actuator (DC motor), a throttle indicator, and a throttle pedal position sensor.All are used to determine, adjust and The components that monitor the position of the throttle are all electronic throttle systems.
The working principle of the electronic throttle control system: The accelerator pedal position sensor transmits the information that the driver needs to accelerate or decelerate to the throttle electronic control unit ECU. The ECU calculates the corresponding optimal throttle position based on the obtained information and sends a control signal to the throttle. Valve actuator. The throttle actuator opens the throttle valve to the calculated optimal throttle opening position, and then the ECU communicates with other electronic control units (such as the automatic transmission electronic control unit ECU, cruise control unit CCS, etc.) through the CAN bus. ) To communicate and obtain other operating conditions information. And various sensors will transmit some information to the throttle electronic control unit ECU (such as engine speed gear position, throttle position, air-conditioning energy consumption, etc.), the ECU will continuously modify the optimal position of the throttle according to these information, so that the throttle The opening of the valve reaches the ideal position required by the driver. The entire system control process is a typical closed-loop position feedback control. The accelerator pedal position sensor and the throttle position sensor are equipped with a main and auxiliary system. Therefore, when the system fails, the continuous monitoring function can be maintained to ensure the safety of operation.