Abstract
EHB (electro-hydraulic brake system) can provide active and decoupled brake for electric intelligent vehicles. However, modelling and control of automotive electro-hydraulic brake systems are always challenging due to the complex and highly nonlinear dynamic characteristics of the braking process. In this paper, a nonlinear backstepping control algorithm for EHB based on the bond graph model is introduced. A nonlinear, single-wheel brake system model is constructed using the bond graph method, in which the capacitive effect of the hydraulic fluid and the damping and inertia effects of calipers are considered. Based on this nonlinear model, a backstepping controller with good robustness is designed, and the control signals of the inlet and outlet valves are described by a unified expression. Moreover, the effects of the controller parameters on brake-pressure control are discussed in details, and suitable design parameters are chosen. Finally, the proposed algorithm is verified by the simulation and hardware-in-the-loop tests. The results show that valves are properly regulated by the backstepping controller, and the brake pressure follows the desired value rapidly and accurately.
Highlights
Faster and more accurate response are always required for the brake pressure control
Based on the state-equation-presented reference model, nonlinear states such as brake pressure and the compressibility of brake fluid can be considered during controller design, and better control performance can be achieved, but an applicable control method must be applicable for the nonlinear characteristics
This paper introduces a novel nonlinear backstepping control algorithm for an electro-hydraulic brake system (EHB) based on the bond graph model
Summary
Faster and more accurate response are always required for the brake pressure control. The nonlinear characteristics of control valves, compressibility of brake fluid, and resistance and stiffness of the brake system should be considered, and the nonlinearity of the wheel-pressure gradient should be described. The compressibility of the hydraulic fluid and the compliance of the circuits were considered in their study It contained state variables, such as the volume changes in the accumulator, front and rear line, and four calipers, which are not necessary for brake pressure control, it has been proved to be applicable for modelling EHB system based on bond graph method. Based on the state-equation-presented reference model, nonlinear states such as brake pressure and the compressibility of brake fluid can be considered during controller design, and better control performance can be achieved, but an applicable control method must be applicable for the nonlinear characteristics.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.