Research On Active Braking Control Strategy Of Vehicle With Tire Blow-out

Vehicle tire blow-out is one of the main causes of traffic accidents. Tire blow-outcan change tire performance. Tire failure at high speeds can cause yaw, and theimproper operation will lead to traffic accidents. Therefore, with tire blow-out detectionand inhibition of yaw rate and COG slip angle changes as the goal, brake controlmethod for vehicle with tire blow-out and detection method for tire blow-out fault arestudied in this paper.Firstly, the vehicle dynamic characteristics on the blow-out conditions are analyzedin this paper. Cornering stiffness, vertical stiffness and rolling resistance coefficient ofvehicle will change after tire blow-out, and mutations of these parameters will affectvehicle dynamics. In this paper, selecting vehicle yaw rate and COG slip angle as statevariables, two degrees of freedom vehicle model is established, and yaw dynamiccharacteristic of vehicle with tire blow-out is analyzed. Then in order to test for thedynamic analysis results, simulation for tire blow-out conditions is made, utilizing theprofessional vehicle dynamics simulation software veDYNA in this paper. In addition,the results of emergency brake for the vehicle with tire blow-out show that the generalanti-lock brake system cannot meet the emergency braking control request for thevehicle with tire blow-out.Secondly, in order to study the impact of friction changes on the stability of thevehicle after tire blowout, the yaw rate and COG slip angle are selected as statevariables, and two degrees of freedom vehicle control model is established in this paper.A method of inhibition of yaw rate and COG slip angle changes, by regulating theexpected slip ratio of the none blow-out wheel, is proposed, and yaw stability controlleris designed. The controller designs additional yaw torque according to yaw rate andCOG slip angle, and calculates the expected slip ratio by combining the control model.And the expected slip ratio applies the braking torque to the wheel through the ABScontroller, thus achieving the additional yaw moment applied to the wheel. Therefore,through the planning of the slip ratio, the vehicle yaw stability control is achieved. Then,the controller is embedded in the simulation environment of veDYNA, and the resultsindicate that the method can effectively inhibit the vehicle with tire blow-out yaw,achieving yaw stability control to the vehicle while smooth braking.Finally, in order to solve the problem when the yaw stability controller should enable,fault diagnosis for the tire blow-out condition is studied in this paper. Fault model isestablished, based on the two degrees of freedom vehicle model and the mutant tireparameters when the tire blows out. And based on the research on the sliding modeobserver fault diagnosis theory, the tire blow-out failure item is reconstructed. When the fault item exceeds the setting threshold, set to identify the tire blowout failure, and theyaw stability controller acts. Then, the sliding mode observer is embedded in veDYNAenvironment, combined with the yaw stability controller. The simulation results showthat the designed sliding mode observer can effectively track the actual fault item, andtimely diagnosis tire blow-out failure, thus enabling the controller to achieve yawstability control.