Vehicle, hill start control method and hill start control device for vehicle

Abstract

The invention discloses a vehicle and a hill start control method of the vehicle and a hill start control device. The method includes: obtaining vehicle speed, accelerator opening, engine speed, clutch shaft speed, road gradient and clutch output torque; Calculate vehicle acceleration torque and vehicle resistance torque based on torque, road gradient and clutch shaft speed; calculate target vehicle speed based on road gradient and accelerator opening, and then calculate based on the calculated difference between the target vehicle speed and vehicle speed, road gradient and accelerator opening Vehicle target acceleration torque, and calculate the engine demand torque and clutch target torque according to the vehicle target acceleration torque, vehicle resistance torque and engine speed; control the engine output torque to reach the engine demand torque, clutch output torque to reach the clutch target torque to make the vehicle speed reach the target speed, The acceleration torque of the vehicle reaches the target acceleration torque of the vehicle, so as to control the speed and acceleration of the vehicle and quickly realize the driver's intention.

Description

Technical field [0001] The present invention relates to the technical field of vehicles, and in particular to a method for controlling a vehicle's start on a slope, a vehicle control device for starting on a slope, and a vehicle. Background technique [0002] For vehicles equipped with automatic gearboxes in related technologies, the hill start control method is usually based on a flat start, using a constant speed strategy to control the engine, and adding a hill assist device, for example, ESP (Electronic Stability Program) ), EPB (Electrical Park Brake, electronic parking brake system) or hand brake signal, so as to achieve the purpose of preventing slipping. [0003] However, the disadvantage of the hill start control method that uses the constant engine speed as the control strategy in the related technology is that the output of the engine torque is only based on the accelerator pedal and does not take into account the influence of the slope resistance. It is difficult for t...

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Problems solved by technology

[0003] However, the disadvantage of the hill start control method based on the constant engine speed as the control strategy in the related art is that the output of the engine torque is only based on the accelerator pedal, and the influence of the hill resistance is not considered. In this situation, it is difficult for the driver to step on the accelerator pedal to a proper opening to generate a suitable torque, especially for novices. If the driver steps on the accelerator pedal to a small Step on the accelerator pedal to a larger opening, it is easy to accelerate too fast and knock down the vehicle in front

[0004] In addition, even if an additional ramp auxiliary device is added in the related art, it can only prevent the phenomenon of slipping, but cannot solve the phenomenon of excessive acceleration.

Especially in the case of a large slope, if the driver steps on the accelerator pedal to a small opening, the vehicle speed is likely to be zero, the vehicle neither moves forward nor reverses, and the clutch is in a state of wasted wear. The temperature will soon reach the protection threshold, and there will be no power output; if the driver steps on the accelerator pedal to a large opening, it is easy to cause excessive torque and excessive acceleration. At this time, in order to prevent excessive When approaching the vehicle in front, you have to step on the brake to stop, thus repeating the hill start action repeatedly, thereby reducing driver comfort and increasing unnecessary clutch wear

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