Method and device for controlling vehicle power source torque during engine start

Abstract

The invention discloses a control method and device of vehicle power source torque in the process of starting an engine. A vehicle power source includes the engine and a motor, and a clutch is arranged between the engine and an input shaft of a transmission. The method includes the steps of obtaining torque demanded by a driver, torque of an engine shaft end and a modification value of motor torque, wherein the modification value of the motor torque is correlative with expected motor rotation speed and actual motor rotation speed; according to the torque demanded by the driver, the torque of the engine shaft end and the modification value of the motor torque, carrying out calculation to obtain target torque of the motor; controlling the motor to output torque according to the target torqueof the motor. By adopting the scheme above, the smoothness of a hybrid power vehicle with one motor and one clutch can be improved in the process of starting the engine, the response time length in the process of starting the engine is shortened, and the cost for controlling the vehicle power source torque and the axial size of the vehicle are reduced.

Description

technical field [0001] The invention relates to the field of vehicle control, in particular to a method and device for controlling the torque of a vehicle power source during engine startup. Background technique [0002] Since hybrid electric vehicles have multiple power sources including motors and engines, if the driver’s torque demand increases significantly during pure motor driving, it is the focus and difficulty of hybrid electric vehicles to quickly and smoothly connect to the engine to achieve high torque demand. Starting time, vehicle smoothness, and driving experience are all important evaluation indicators for hybrid electric vehicles. For hybrid vehicles with a single motor and single clutch configuration, when starting the engine while driving, the motor and clutch are needed to increase the engine speed to reach the speed required for engine fuel injection and ignition. However, due to unstable and biased torque changes on the engine side , resulting in unexpe...

AI Technical Summary

Problems solved by technology

For hybrid vehicles with a single motor and single clutch configuration, when starting the engine while driving, the motor and clutch are needed to increase the engine speed to reach the speed required for engine fuel injection and ignition. However, due to unstable and biased torque changes on the engine side , resulting in unexpected vibration or unexpected acceleration and deceleration of the vehicle, so if the motor side only simply compensates the torque on the engine side and the driver's demand torque, it cannot eliminate unexpected vibration and acceleration and deceleration, and a single-motor single-clutch configuration will occur. The problem of low ride comfort and long response time during engine start of hybrid vehicles

[0003] In order to solve the problems of low smoothness and long response time in the process of starting the engine of a hybrid vehicle with a single-motor and single-clutch configuration, an existing solution is to set a clutch between the motor of the hybrid vehicle and the input shaft of the transmission.

[0004] However, if the above-mentioned method is used to control the torque of the vehicle power source, or the required vehicle axial size is large, the cost is high, or the ride comfort during the start-up process of the hybrid vehicle with a single-motor and single-clutch configuration is low and Problem with long response times

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