Transient switching control strategy from regenerative braking to anti-lock braking with a semi-brake-by-wire system

Abstract

Regenerative braking is an important technology in improving fuel economy of an electric vehicle (EV). However, additional motor braking will change the dynamic characteristics of the vehicle, leading to braking instability, especially when the anti-lock braking system (ABS) is triggered. In this paper, a novel semi-brake-by-wire system, without the use of a pedal simulator and fail-safe device, is proposed. In order to compensate for the hysteretic characteristics of the designed brake system while ensure braking reliability and fuel economy when the ABS is triggered, a novel switching compensation control strategy using sliding mode control is brought forward. The proposed strategy converts the complex coupling braking process into independent control of hydraulic braking and regenerative braking, through which a balance between braking performance, braking reliability, braking safety and fuel economy is achieved. Simulation results show that the proposed strategy is effective and adaptable in different road conditions while the large wheel slip rate is triggered during a regenerative braking course. The research provides a new possibility of low-cost equipment and better control performance for the regenerative braking in the EV and the hybrid EV.

Keywords:

• Regenerative braking
• semi-brake-by-wire system
• anti-lock braking system
• cooperative control
• sliding mode control
• switching compensation strategy

Acknowledgements

The authors thank the Brilliance-Auto Company for providing the passenger cars and the tyre parameters for the experiments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors greatly appreciate the support from the National Science Fund for Excellent Young Scholars of the People's Republic of China [grant number 51422505] and the National Key Science and Technology Projects (2013ZX04002-071).