State Estimation Of Tractor Semi-trailer Based On Kalman Filtering

As the size of our country’s economy grows, our highway network will continue to extend. Furthermore, the method of ’Drop-and-pull Transport’ is in the promotion vigorously in China and the tractor semi-trailer will highlight its role in the country’s economic development, quantity of which will reach a new peak. Due to high centroid position, large load and complex structure, the loss of accident with it is huge. The application of active safety control system used in tractor semi-trailer is a good way to reduce traffic accident. Foreign manufactures have developed some that systems and have made them commercialized. However, it stays on the theoretical research in China. And there is a major problem has not been resolved about active safety control system on tractor semi-trailer, it is state estimation of tractor semi-trailer. The technology is confidential, but we know that much state information is by estimation. It is of great research value to study state estimation on tractor semi-trailer. It can provide some reference value for self-development of active safety control system on tractor semi-trailer in China.First of all, referring to the domestic and foreign literature on the state estimation of vehicle, State estimation of tractor semi-trailer based on Kalman Filtering is presented, such as yaw rate of tractor, slip angle of tractor, hitch articulation rate and hitch articulation.Secondly, State estimation theory and Kalman Filtering theory are studied deeply. At the same time, it is clear how to apply Kalman Filtering algorithm successfully. In order to illustrate the feasibility of state estimation of tractor semi-trailer based on Kalman Filtering, some successful application examples based on Kalman Filtering about state estimation are introduced in this paper, especially the application of state estimation in the automobile.Thirdly, state estimation based on Kalman Filtering is based on the mathematical model before, so we must know the mathematical model of tractor semi-trailer. On the basis of studying the structure of tractor semi-trailer in detail, three degree-of-freedom mathematical model of tractor semi-trailer is established. A virtual model of tractor semi-trailer for virtual test is also established to verify that that mathematical model is correct.At last, two state estimators are designed, and their effect of state estimation are made comparison. By the co-simulation test on TruckSim and Matlab/Simulink, the effect of state estimation is very good. At the same time, the factors affecting the accuracy of state estimation based on the Kalman Filtering are analyzed.Some state information of the tractor semi-trailer which is running is estimated based on Kalman Filtering, such as the tractor yaw rate, the tractor slip angle, hitch articulation rate and hitch articulation. At last, state estimation based on Kalman Filtering is verified to work well by the co-simulation test. All do in this paper can provide some reference value for self-development of active safety control system on tractor semi-trailer in China.