Research And Simulation Of Vehicle Sideslip Motion Control At J-turn

Under rapidly steering or lane change maneuver at high speed, the vehicle tend to produce great yaw moment and result into sideslip motion, moreover, in case of starting to slip, it will be rapidly lose controls. In this paper, based on the abroad achievements in this field, sideslip motion of the vehicle rapidly steering is analyzed, in order to control it, the control logic is designed and several methods are implied.The actual model and the desired model of the vehicle rapidly steering is built, the variation law of vehicle motion state is researched, then research on relation between vehicle sideslip motion and motion state, and the case of vehicle sideslip is also decision. By analyzing the instability, the yaw moment used for restoration stability can be calculated, and then the best braking wheel can be selected. That is, the vehicle stability is improved through the yaw moment generated from braking force. In this paper, three control logics and algorithms are built, they are fuzzy control method for vehicle yaw stability, a fuzzy control method to improve vehicle yaw stability based on integrated yaw moment control and active front steering, vehicle brake stability on turning lane based on ABS and generalized predictive control for vehicle yaw rate. The validity of the control strategies are proved through the simulate results; the conclusions were drawn initially as followings:(1)The validity of the control strategies are proved through the simulate results, comparing and analyzing the experiment results, it is shown that: Based on fuzzy control for vehicle yaw stability, amplitude value of the yaw rate and the side slip angle are reduced, but the decrease of overshoot of the yaw rate is little. A fuzzy control method to improve vehicle yaw stability based on integrated control of yaw moment control and active front steering can effectively control the yaw rate and side slip angle synchronously, and enable the vehicle have good tracking property. A generalized predictive control method for vehicle yaw stability can enable the controller acts on before vehicle instability; therefore, it can keep timely and effective stable operation state of vehicle, due to reducing the centrifugal force based on decreased speed using vehicle braking, so it can improve vehicle stability. Based on vehicle ABS, by controlling yaw moment of vehicle and regulating slip rate of wheels, the dynamic regulation of yaw moment in vehicle braking is realized, therefore, vehicle stability on turning lane is improved.(2)By comparison, the control effect based on combined control method is better than that of DYC only.(3)Road adhesion coefficient, vehicle speed and steering characteristic had definite influence on control effect (This paper only consider the difference of road adhesion coefficient). The vehicle instability is easy to happen along with the lower of road adhesion coefficient and increasing of vehicle speed, by this, it can be seen that the vehicle based on stability control has many advantages over the vehicle of no control, in the contrary; the control effect is not evident.