Hub-motor-driven automobile electromechanical fluid redundant braking system and control method

Abstract

The invention discloses a hub-motor-driven automobile electromechanical fluid redundant braking system and a control method. The control method of the braking system comprises the steps that is a hubmotor is utilized preferentially to conduct regenerative braking, an electro-mechanical-type braking system is used for traveling braking compensation and parking braking, a hydraulic braking system is used for failure compensation, and the three sets of braking systems are synergetic; and current automobile condition information and driver operation are obtained through an automobile controller,the driving intention is recognized, the automobile stability state is monitored, the road surface condition and the power battery state are synthesized, the braking mode is judged, the total brakingtorque demand is solved, braking torques of four wheels are reasonably distributed, and a hub motor controller, an electro-mechanical-type braking system controller and an electric mechanical brakingbooster are synergetic to conduct braking control to reach the braking target jointly and guarantee traveling stability. The hub-motor-driven automobile electromechanical fluid redundant braking system and the control method can achieve efficient braking energy recovery and four-wheel active-distribution-type braking, and have the advantages of being high in braking capacity, high in sensitivity,quick in response, high in safety, high in reliability and the like.

Description

technical field [0001] The invention relates to the technical field of automobile braking safety, in particular to a braking system of an automobile driven by a hub motor and a control method thereof. Background technique [0002] The ability to stop a car in a short distance while maintaining the stability of the direction of travel and maintain a certain speed when driving downhill is called the braking performance of the car. Braking performance is one of the important performance indicators of automobiles, which is directly related to traffic safety. In order to realize automobile braking, a special braking system must be installed on the automobile. Generally speaking, the braking system is classified by function, including the service brake system, parking brake system, second brake system and auxiliary brake system, among which the service brake system and the parking brake system are essential for passenger cars. system. [0003] For conventional passenger cars, t...

AI Technical Summary

Problems solved by technology

When braking, the in-wheel motor can provide part or all of the braking torque of the vehicle, and the motor itself is in the state of generating power to charge the power battery; however, the braking torque provided by the motor is limited, and the state of the power battery also affects the regenerative braking capability of the motor Forming constraints, under the requirements of ensuring system safety, the motor braking mode is not enough to meet the braking requirements under all working conditions. Therefore, the in-wheel motor drive vehicle retains the hydraulic braking system, and at the same time, retains the parking braking system

[0005] The traditional hydraulic braking system uses a dual-circuit braking system as the second braking system, that is, when one circuit braking system fails, the other circuit braking system can still provide a minimum braking capacity. The main disadvantages of using the second braking system in action are insufficient braking strength and reduced braking stability

In addition, the working environment of hub motors is harsher than that of ordinary motors, and they are subjected to uneven ground impacts and strong current impacts, resulting in a high probability of failure of mechanical and electrical components; at the same time, conventional hydraulic systems also have a certain probability of failure

If there is leakage of the brake oil circuit, the failure occurs in emergency braking conditions. Considering that the hydraulic brake system has a long response time when the brake pressure of each wheel cylinder is greatly adjusted and the braking torque provided by the motor is limited, the car will face serious problems. Risk of loss of stability or even a traffic accident

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