Fuzzy-logic Applied To Yaw Moment Control For Vehicle Stability

Steering at high speed or low frictional coefficient road, due to interference factors of the shift or the outside accident etc., vehicle's lateral adhesion force tend to limit of adhesion easily to have vehicle stability loss, thus the traffic accidents happened. According to control methods of the national and international vehicle handling and stability, aimed at the highly complex nonlinear characteristics of vehicle dynamics system, yaw moment control system based on fuzzy logic is proposed; the vehicle handling and stability control are modeled as follows:Firstly, combining 8DOF (Degree of Freedom) model of vehicle, 2DOF of vehicle with nonlinear tire model, system dynamic model is gotten for the study of vehicle stability.Secondly, vehicle stability control system consist of fuzzy-logic controller with inputs as deviations of yaw rate and sideslip angle, output as yaw moment, and system dynamic model, is proposed, achieving both good responses of yaw rate and sideslip angle.Finally, taking specific vehicle for simulation example, applying the above control strategy, simulated under different conditions of velocity, steering angle and road, both the response lines of yaw rate and sideslip angle are gotten. Comparing simulation results with non-controlled system, and test results separately, as result, fuzzy controller analysis of vehicle stability is effective.