Vehicle driving speed control method and system

Abstract

The invention provides a vehicle driving speed control method and system. The method comprises the steps that the driving speed of a vehicle and the opening degree of an accelerator pedal are monitored in real time, the current driving speed of the vehicle, a first opening degree value of the accelerator pedal after the opening degree of the accelerator pedal is changed and an accelerator pedal opening degree reduction amplitude value are obtained, and a corresponding target vehicle speed is obtained according to the first opening degree value of the accelerator pedal; whether a driver intendsto decelerate or not is determined according to the current driving speed of the vehicle, the target vehicle speed and the accelerator pedal opening reduction amplitude value; and if the driver intends to decelerate, expected braking strength of the driver is obtained through the current driving speed of the vehicle and the target vehicle speed, the power generation torque of a vehicle motor is controlled and adjusted according to the expected braking strength, and the vehicle is controlled to decelerate and run. The contradiction between the electric braking strength and the comfort of a driver is balanced, and the energy consumption level of a vehicle is improved.

Description

technical field [0001] The present invention relates to the technical field of vehicle control, in particular to a vehicle speed control method and system. Background technique [0002] As energy consumption and emission standards become more and more stringent, various configurations of new energy vehicles have become the research and development focus of various automobile manufacturers, and the energy recovery rate directly affects energy consumption and emission levels. The greater the energy recovery rate, the stronger the electric braking intensity. When the electric braking intensity cannot match the driver's expected vehicle braking intensity, there will be an irreconcilable contradiction between the energy recovery rate and driving comfort. [0003] There are currently three high-intensity electric braking technical solutions, (1) The braking system is upgraded to a serial braking system. This type of system can be freely switched between electric braking and hydrau...

AI Technical Summary

Problems solved by technology

The greater the energy recovery rate, the stronger the electric braking intensity. When the electric braking intensity cannot match the driver's expected vehicle braking intensity, there will be an irreconcilable contradiction between the energy recovery rate and driving comfort.

[0003] There are currently three high-intensity electric braking technical solutions, (1) The braking system is upgraded to a serial braking system. This type of system can be freely switched between electric braking and hydraulic braking. When the driver brakes When the demand is less than the set threshold, full electric braking can be realized, and the intensity of electric braking can be changed according to the opening of the brake pedal. The hardware cost of this solution is high. After the hardware specification is set, the maximum set threshold of electric braking cannot Continue to increase through the software; (2) Set different levels of electric braking strength, the driver can adjust the electric braking strength in real time according to needs, the electric braking strength cannot be adjusted linearly in this scheme, when the electric braking strength level changes There is a sudden change in the deceleration of the vehicle; (3) Taking the change of vehicle speed as the control target, when the vehicle speed exceeds the speed set by the accelerator pedal opening, it will actively trigger the electric brake to reduce the vehicle speed, and the electric brake can be controlled by the change of the accelerator pedal opening. Braking intensity, this scheme does not consider the driver's deceleration intention, even if the driver has no deceleration intention, when the vehicle speed increases due to downhill or other reasons, the on-board computer will actively trigger the electric brake to reduce the vehicle speed

[0004] It can be seen that in the prior art, the driver's deceleration intention is not fully considered, and the vehicle speed change is the control target.

Images