In the process of ABS control, the Anti-lock braking system (ABS) of the vehicle adjusts the wheel cylinder brake pressure through the hydraulic actuator so as to control the movement of the wheel. The high-speed on-off valve (HSV) is the key components of the Anti-lock braking system. HSV affects the performance of the hydraulic actuator and the valve response characteristics affects the Anti-lock braking system pressure response as well as braking effect. In this paper, the electromagnetic field theory and flow field theory of HSV are analyzed, and simulation analysis of electromagnetic field characteristics of HSV is done by ANSYS. Combined with the ANSYS analysis results, a precise physical model of HSV is constructed in AMESim. Meanwhile, the valve response characteristics are analyzed. Moreover, the influence of different wheel cylinder diameter and PWM carrier frequency on hydraulic braking force characteristics are analyzed.
The open-loop control methods of hydraulic braking force based on Look-up tables and T-S fuzzy structure are comparatively analyzed. The results show that T-S fuzzy controller can be more direct and rapid training to obtain buck-boost surface without fitting and interpolation of data surface, it is more adaptable.
The single-wheel model and ABS sliding mode control module are established in Simulink. The inner ring of the module is hydraulic brake force controller, it is used to control hydraulic braking force precisely. The outer ring of the module is a sliding mode controller to control the wheel slip rate. Based on the above two open-loop control strategies, ABS control can be better achieved to realize anti-lock control of the vehicle in the emergency braking conditions.