Pneumatic control method based on PWM valves and used for gear shifting of synchronizer

Abstract

The invention relates to the technical field of automobile control, and especially relates to a pneumatic control method based on PWM valves and used for gear shifting of a synchronizer. The pneumaticcontrol method based on the PWM valves and used for gear shifting of the synchronizer comprises the following steps: when a gear shifting process is started, a forward PWM valve is fully-open, and areverse PWM valve is closed; when a movement speed of the synchronizer is greater than the maximum permissible value of the movement speed of the synchronizer in a gear disengagement process, the dutycycle of the forward PWM valve and the duty cycle of the reverse PWM valve are adjusted, and gear disengagement speed control is carried out; the process enters a synchronization phase, the duty cycle of the forward PWM valve is increased step by step, and the reverse PWM valve is closed; the process enters a ring pulling phase, the duty cycle of the forward PWM valve is adjusted to be a set dutycycle command value of ring pulling action; the process enters a gear engagement phase, the duty cycle of the forward PWM valve and the duty cycle of the reverse PWM valve are adjusted, and gear engagement speed control is carried out; and after a gear is engaged in place, the forward PWM valve is fully opened for a set time and then closed, and the reverse PWM valve is closed. According to the pneumatic control method based on the PWM valves and used for gear shifting of the synchronizer, the gear shifting quality can be improved, and the service life of the synchronizer can be prolonged.

Description

technical field [0001] The invention relates to the technical field of automobile control, in particular to a pneumatic control method for synchronizer shifting based on a PWM valve. Background technique [0002] Cars play an important role in the transportation of modern society. During the movement of the car, the speed of the car needs to be adjusted by shifting gears. Synchronizer shifting, as a typical shifting method, is widely used in automatic transmissions. Synchronizer shift actuators include electric shift actuators, hydraulic shift actuators and pneumatic shift actuators. The pneumatic shift actuator has the advantages of low cost, quick shifting action, and simple structure. Therefore, the pneumatic shift actuator is widely used in automatic transmissions equipped with synchronizers. [0003] However, pneumatic control has the disadvantages of high compressibility of compressed air, strong time delay and strong nonlinearity. During the gear shifting process o...

AI Technical Summary

Problems solved by technology

[0003] However, pneumatic control has the disadvantages of high compressibility of compressed air, strong time delay and strong nonlinearity.

During the shifting process of the synchronizer, the shifting impact and shifting noise caused by the pneumatic shift actuator are relatively large, which reduces the shifting quality and the service life of the synchronizer, and even causes the synchronization function of the synchronizer to fail, resulting in "tooth-beating abnormality". "ringing" phenomenon; at the end of the synchronizer shifting, the synchronizer moves at a higher speed, resulting in a greater end-face impact noise

Images