The Research Of Vehicle Stability Control Test And Control Algorithm In Adhered Limit State

With the development of the vehicle new technologies such as new energy vehicle and unpiloted vehicle, the new development of vehicle technology must have the new questions to propose and the new projects to solve. The automobile active safety technology becomes one focue in all researches. The vehicle stability control technologies is the most important part in the vehicle active safety technology. Now, the using vehicle stability control technologies is for adhere conditions, which means that the vehicle is controlled by utilizing the adhere condition in instability condition. The research of vehicle stability control beyond the adhere condition is rather few focued. Thus, it is necessary to research the vehicle stability control beyond the adhere condition. Based on the vehicle adhered limit state, the vehicle dynamice model, the test system, the vehicle estimation and the stability control are all needed to investigated.Based on the Lagrange dynamic equations set up a 10-free-degree vehicle dynamic model in adhered limit state, and the vehicle vertical load model, the tire model, the engine model and the transmission model in the paper. By utilizing these models, the vehicle motion characteristics are simulated to assist design, analysis and test in the theory. This would be helpful for next jobs.A test system of vehicle stability control in adhered limit state is developed for establishing the efficient and safe vehicle stability control test system. Based on the Matlab/Simulink, analyze and testify the ESP control performances of the independent vehicle system and the vehicle adhered limit state test system on three test condition including neutral steering, lacking steering, excessive steering. The conclusions tests that the vehicle adhered limit state test system affects little on the vehicle motion and vehicle stability performances, and is feasible in vehicle stability control test. In views of the stability control performances and engineering implementations, the horizontal pendulum restriction test system is chosed as implementation scheme through analyzing and comparing several test system cases. The vehicle test is completed by using of the horizontal pendulum restriction test system. The researches show that the test system is not only practicable in help of researching the vehicle stability control test and feasible but also advantaged in reliable, high efficiency and low cost compared with other vehicle stability control test.Estimate the pose of the center of vehicle mass not only in the linear state but also in the nonlinear state based on the Improved Particle Filter(IPF). Estimate the tire lateral stiffness in the linear state and the tire-road adhere coefficient in the nonlinear state based on the Extended Kalman filter (EKF). Based on the Matlab/Simulink, the filter simulation model fully verify that the filtering results are feasible and precise for estimateing the pose of the vehicle mass depending on the IPF and the EKF.The control boundary conditions are explored for distinguishing the adhere limit conditions and the adhere non-limit conditions. According to the control boundary, depending on braking and steering, the object tracking control is respectively realized by using the fuzzy controller, PID controller, sliding mode controller. Based on the Matlab/Simulink, set up the control simulation model, the results show that when the adhere performance is lose, the control in the adhered limit state would quickly make the vehicle motion trajectory approach to the objective trajectory.In summary, based on the 1 the vehicle adhered limit state test system, the vehicle stability control research beyond the adhere condition is valuable in theory and experiment for dynamic analysis, experiment system development, vehicle state estimate and control research.