Braking control device and control method used for electric automobile

Abstract

The invention relates to a braking control device and control method used for an electric automobile. According to the braking control device disclosed by the invention, the regenerative braking force of a motor and hydraulic braking force of a hydraulic control system are adjusted to perform compensation on characteristics of a transmission system. The braking control device is characterized by comprising a motor torque sensor, a motor rotating speed sensor, a wheel rotating speed sensor and a vehicle-mounted braking control system, wherein the vehicle-mounted braking control system comprises a half shaft torque determining module, a tooth space condition determining module, a tooth space compensation control module, an elasticity compensation control module and a control time detecting module; the tooth space condition is determined through the tooth space condition determining module, and according to the tooth space condition at a position where gears in the transmission system are meshed, tooth space compensation control or elasticity compensation control is performed on the transmission system through the tooth space compensation control module or the elasticity compensation control module, so that risk that regenerative braking torque impacts and vibrations at corresponding wheels caused by the tooth space and the elasticity of the transmission system can be reduced. The braking control device can be widely applied in the technical field of electric vehicles.

Description

technical field [0001] The invention relates to a braking control device and a control method for an electric vehicle, belonging to the technical field of electric vehicles. Background technique [0002] In electric vehicles such as pure electric vehicles, hybrid electric vehicles and fuel cell electric vehicles, part of the kinetic energy of the vehicle can be converted into electric energy through the motor feedback braking function to improve the energy economy of the vehicle, and the motor torque control can also be used to quickly Accurate characteristics dynamically adjust electric vehicles at a higher frequency to achieve improved vehicle anti-lock braking effects. In the prior art, when the regenerative braking is performed by the motor, the default transmission system is rigid, and the control of the regenerative braking torque of the motor is open-loop. , to achieve the target slip ratio at the corresponding wheel by controlling the regenerative braking torque of ...

AI Technical Summary

Problems solved by technology

And when the vehicle changes from driving to braking, the contact surface of the gears in the drive train is reversed, and the drive train passing through the backlash will cause an impact when the gears re-contact, resulting in the oscillation of the torque at the wheel

When the motor feedback braking torque is dynamically adjusted at a higher frequency, especially in the anti-lock braking process using the motor, the negative influence of the elasticity and backlash of the drive train is intensified, resulting in slip ratio control effect and driving Ride comfort further deteriorates

[0004] In the prior art, a powertrain characteristic compensation method is proposed for the driving process of internal combustion engine vehicles. However, this compensation method only involves compensating the powertrain characteristics during the driving process of traditional internal combustion engine vehicles, and does not target electric vehicles, especially electric vehicles. Compensation of drive train characteristics during braking

Due to the faster motor torque response of electric vehicles, and there may be coupling between regenerative braking force and hydraulic braking force during braking, the compensation control of the drive train characteristics during motor regenerative braking is more complicated

Images