A vehicle start control method, system and vehicle

Abstract

The present invention provides a vehicle start control method, system and vehicle. The method is that when a vehicle is detected to have a start demand, the vehicle power control unit PCU controls the power source torque and the clutch torque slope, and controls the power source torque and clutch reference. The torque and clutch offset torque work together to fine-tune the clutch target transmission torque in real time according to the actual speed of the power source. The invention controls the power source end and the clutch load end, and through the joint action of the clutch reference torque and the clutch offset torque, the speed fluctuation of the power source end is weakened, the stable torque output is ensured, and the vehicle has good starting smoothness and dynamic performance. Since there is no need to pass complex calculations to determine the torque output of the powertrain and the transmission torque of the clutch, the speed fluctuation caused by the PID closed-loop control is also weakened, and there is no need to refine the different stages of the speed ascent, so it is easier to control and calibrate.

Description

technical field [0001] The invention belongs to a control method in the field of vehicle power, and particularly relates to all vehicle start control methods for controlling power transmission through clutch disconnection, engagement and slipping. Background technique [0002] At present, the vehicles that control the power transmission through clutch disconnection, engagement and sliding friction start using the sliding friction method. The dry and wet clutches use different slip sizes to start, and most of the wet clutches use a larger slip and local constant speed control. Through the closed-loop speed, PID plays the main control role, and it is necessary to refine the speed-up stage. Most of the start-up processes have drivability problems such as sloshing and shock to varying degrees. The speed of clutch engagement and the smoothness of torque transmission directly determine the quality of the vehicle's starting drivability. And the PID value under a single working co...

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Problems solved by technology

And the PID value under a single working condition cannot adapt to complex and changeable environmental working conditions, such as normal temperature and low temperature working conditions, different control methods will be adopted

If the moment of inertia of the power source is calculated as feed-forward, it cannot directly reflect the starting drivability of the vehicle, especially for starting with a wet clutch, and it is necessary to increase the role of PID adjustment, which brings complicated calibration and faces the above-mentioned PID adjustment. bring about problems

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