Research on optimal tracking control for ABS slip ratio of high speed vehicle in complex road conditions

For the purpose of investigating control strategy of making high speed vehicle brake steadily in complex road conditions,an affine nonlinear dynamic model of anti-lock braking system (ABS) slip ratio is built.Then,comprehensive optimization of slip ratio error with its changing rate is taken as control objective,and analytical solutions of optimal slip ratio and control torque are derived through minimum principle.And then,real time cooperative computation of brake torque without any adhension coefficient information of complex road conditions can be accomplished by utilizing analytical solution of optimal slip ratio with feedback signals such as brake deceleration,brake speed of vehicle and angular velocity of tire.Therefore,an optimal tracking control method for ABS slip ratio of high speed vehicle in complex road conditions and disturbances is established.Through Matlab/Simulink numerical evaluation of effect of proposed optimal control for tracing different objective slip ratio in different complex road conditions,it can be observed that the target slip ratio can be synchronized with actual slip ratio at any specified time,and also slip ratio error is determined by its initial value and ratio between weight of slip ratio error and that of its change rate in control objective functional.Consequently,it can be concluded that steady accomplishment of such rapid and precise brake action in complex road conditions at any time is feasible