| Research and design of unmanned intelligent cars is recognized by modern automobile industry as a key of development of the automobile industry in future. Stability control of unmanned intelligent vehicle is the basis of the research. In this paper, in the circumstances of obstacle avoidance, autonomous tracking and brake of the unmanned intelligent vehicle, appropriate control parameters and control algorithms were selected, which control unmanned vehicle that using the yaw moment. Some thoughts on stability control for unmanned vehicle motion were provided as well.The paper establishes eight-degree freedom model of the vehicle, the tire model, brake model, hydraulic model and the steering wheel model. The vehicle model is simulated by Simulink and necessity of the vehicle model research of unmaned vehicle motion and stability is verified.Later, based on the analysis of the state of motion and the unmanned vehicles model, the paper introduces how the instability state comes up, describes the stability control thought and control structure, chooses the yaw rate and sideslip angle as the main parameters of reseaching the unmaned vehicle stability. It depth study the relationship about the parameters and the state of unmaned vehicle, for estimating sideslip angle to use the extended Kalman filter algorithm and effectiveness of the algorithm is verified at same time.Based on the establishment of the vehicle dynamics model,we designed a fuzzy controller which is based on the yaw rate and a PID controller which is based on the sideslip angle. These controllers will an ideal yaw rate and an ideal sideslip angle as the control target, will the yaw moment that generated by the wheel brake force as output of the controller. we used the both coordination correlation control.At last, accounting an advantech IPC as control core, test hardware platform of the unmanned vehicle movement stability structured, the software monitor interface designed by the VB, the algorithm program writed, the control strategy through simulation and the the real unmaned vehicle testing that based on double lane change tested. It can be seen from the results of the experimental test that compare with the unmaned vehicle which no join any control systerm, when unmanned vehicle traveling in the automatic tracking process,the systerm has obvious advantages to maintain stable operation. |
