Vehicle Acceleration Slip Regulation Control Based On Extremum Search Algorithm For Estimating Adhesion Coefficient

The anti-skid control of the vehicle is a form of active safety control.When the speed of the vehicle is greater than the speed of the vehicle during driving conditions,the vehicle will slip.The anti-skid system is a process in which the engine controls the driving torque to prevent wheel slip.Under the premise of ensuring that the vehicle is driving safely,the road adhesion is fully utilized.In order to solve the problems of slow response and poor robustness of the existing drive anti-skid control strategy,a drive anti-skid using a perturbation extreme value search algorithm to estimate the road adhesion coefficient is proposed Control Strategy.the main research work is as follows:(1)This paper first analyzes the driving equation of the vehicle.Through the driving equation of the vehicle,the relationship between the slip rate and the adhesion coefficient is analyzed.According to the relationship between the slip rate and the adhesion coefficient,the vehicle wheel tire-ground model and eight degrees of freedom required for the research of the driving anti-skid system are established.The overall vehicle dynamics mathematical model provides a basis for the study of disturbance extreme value search algorithms to estimate road surface adhesion coefficients and design-driven anti-skid control strategies.(2)In order to solve the problem of the accuracy and real-time of the existing road surface peak adhesion coefficient identification method,a method for estimating the road surface peak adhesion coefficient using a perturbation extreme value search algorithm is proposed.Regardless of the pavement conditions,the value of the adhesion coefficient in the adhesion coefficient-slip rate curve increases first and then decreases,that is,has an extreme value,so the disturbance extreme value search algorithm can be used to automatically search for the adhesion coefficient of the road surface-slip The maximum point of the adhesion coefficient in the curve is used to estimate the peak adhesion coefficient of the road surface,and then the adhesion coefficient estimation scheme using the extreme value search algorithm is designed.The method of simulation proves the recognition method of the road surface adhesion coefficient using the disturbance extreme value search algorithm.rationality.(3)Using the perturbation extremum to search the estimation result of the adhesion coefficient of the adhesion coefficient estimation scheme,the slip rate corresponding to the maximum value of the adhesion coefficient is used as the control target,and a dynamic of pedal signal feedforward control and negative feedback correction of the slip rate is designed.Drive anti-skid control strategy to control the wheel slip rate at the slip rate corresponding to the maximum value of the adhesion coefficient-slip rate curve adhesion coefficient;the design pre-sets a threshold upper limit and a threshold lower limit for the required slip rate As a control threshold,when the slip rate exceeds this threshold,the drive anti-skid control system will respond and control other relevant parameters of the vehicle until it returns to the set threshold upper limit and threshold The logical threshold value in the lower limit interval drives the anti-skid control strategy.(4)Under the three typical working conditions of icy road conditions,asphalt road conditions and docking road conditions,the simulation analysis of electric vehicle drive anti-skid control strategy was carried out to verify the drive anti-skid control strategy using extreme value search algorithm to estimate the road surface adhesion coefficient The effectiveness and advancedness of the research indicate that the driving anti-skid control scheme that uses the extreme value search algorithm to estimate the road surface adhesion coefficient can control the tire slip rate,adhesion coefficient and vehicle acceleration at the optimal slip rate,the most Optimal adhesion coefficient and optimal vehicle acceleration in the neighborhood of small,can quickly and effectively improve the stability and dynamics of the vehicle,which uses a pedal signal feedforward control and slip rate negative feedback correction drive anti-skid control scheme than using a logic gate The limit-driven anti-skid control scheme reacts more quickly and steadily.