Optimized Fuzzy Coordinated Control Strategy For Vehicle With Tire Blowout

Improving the safety of the vehicle after tire blowout is a focus problem in the field of tire blowout research in the whole world at present.Tire blowouts not only cause the vehicle to lose stability rapidly but also cause the vehicle to yaw to the side of the blown tire.At present,most scholars only focus on controlling the stability or trajectory of the vehicle after tire blowout,which results in a single control method that cannot achieve both stability and trajectory tracking.In order to further improve the safety of the vehicle after tire blowout,optimized fuzzy coordinated control strategy was proposed,which integrates the braking and steering of the front wheels.By coordinating the control of the two systems,the proposed system enables the vehicle to quickly regain stability and improve its ability to track the trajectory after the tire blowout.The main research contents of this paper are as follows:1.The high-precision vehicle dynamics simulation software Carsim was used to build a vehicle model and the overall operating conditions of the vehicle.Uni Tire model and ideal 2-dof model were built by Matlab/Simulink.By replacing the internal tire model of Carsim with the Uni Tire model,the effect of tire blowout can be better simulated.In order to simulate the situation of tire blowout more realistically,a second-order single-point preview driver model with a delay link was built to simulate the driver’s control situation by outputting the steering wheel angle.2.The fractional-order sliding mode control algorithm was used to build a differential braking controller,and the braking pressure of normal tires was controlled by using the yaw moment.The braking pressure was distributed to each wheel according to the braking force distribution strategy.The effectiveness of the differential braking stability control method was proved by the co-simulation of Matlab/Simulink and Carsim.3.The active steering controller was established by differential forward PID control algorithm,and a small steering angle was applied to the front wheels according to the deviation between the actual path and the target trajectory.The control quantity was transmitted to Carsim through Matlab/Simulink for simulation,which proved that the active steering control can reduce the lateral displacement of the vehicle.4.The fuzzy control algorithm was used to build the coordinated controller,which adjusts the control quantity of the two controllers according to the different speeds and stability,so that the coordinated control system can maintain the best control effect at all times.In order to obtain the best fuzzy control effect,the fuzzy rules of the fuzzy controller was optimized iteratively by using the whale optimization algorithm.The co-simulation results of Matlab/Simulink and Carsim show that the coordinated control combines the advantages of differential braking and active steering,which can not only quickly restore the stability of the vehicle with a blowout tire,but also reduce the lateral displacement of the vehicle.The innovations of this paper are as follows:1.The fractional-order sliding mode control algorithm was designed to enhance the robustness of the system based on the side yaw angle and yaw velocity of the centroid.PID controller was used to compensate the yaw moment and improve the stability of the vehicle.2.The differential forward PID control algorithm was designed to enhance the anti-interference performance of the system and the trajectory tracking ability of the vehicle based on the deviation of actual path and the target trajectory.3.The optimized fuzzy coordinated control strategy was designed based on the speed and stability of the vehicle,and the fuzzy rules are optimized by using the whale optimization algorithm.The weights of differential braking and active steering were distributed so that the coordinated control system can combine the advantages of both,and improved the stability and trajectory tracking ability of the vehicle with tire blowout.