Research On State Parameters Estimation And Control Algorithm Of Electronic Stability Control System For Passenger Car

As a new active safety technology, Electronic Stability Control(ESC)system can maintain the vehicle stability by dominating the yaw moment effectively under extreme driving conditions. The technology has matured in foreign countries, but the research on which is still in the initial stage in China. Therefore, research on the theories and key technologies in developing ESC can have a great realistic significance in improving the ability of developing domestic automobile industry and related industries.Based on the technology needs of the BESTURN, this paper gives the research of estimation of vehicle State Parameters and the control algorithm of ESC in close cooperation with FAW Group Corporation R&D Center, which is associated with the 863 ministry of science and technology, international cooperation project and province and major projects technology support program. Meanwhile, the proposed algorithm is evaluated by hardware-in-the-loop test and the real test under various emergency maneuvers and road conditions. The test results show that the ESC algorithm developed is not only suitable for practical application, but also has high accuracy and robustness.1 Design of ESC software architectureBased on the technology needs of the BESTURN, the overall structure of ESC algorithms has been accomplished by the application of modular design, which provides the basis for follow-up research work.2 Estimation of key state parametersAccuracy and real time of vehicle state parameters are the prerequisite in the ESC control system. Based on the needs of the ESC critical state parameters estimation and the target of accuracy and real time, this paper proposes the on-line estimation method of tire force, vertical speed estimation method and nonlinear robust estimation of slip angle. The ESC simulation and test results show that this method isn't only suitable for practical application, but also has high accuracy and robustness.3 The research of control algorithmControl algorithm is the core of ESC control system. When the tire is in the nonlinear regions, the estimation accuracy of the traditional linear 2DOF single-track model has the serious shortage. For that an adaptive 2DOF single-track model is proposed by the application of self-tuning filtering theory in this paper. On this basis, the accuracy of 2DOF single-track model is improved. A 2DOF two-track model is established, based on which this paper gives the ESC algorithm using optimal control theory. Meanwhile, the coordinated control of ESC and ABS and practical method for the algorithm are proposed.4 The research of the hardware in the loopFor verifying the developed control algorithms, the hardware in the loop test is carried out using the ESC test bed in discussion group. The results show that the developed ESC control algorithm has a better performance and adaptability than normal PID control algorithm.5 The research of the road testThe real test is fulfilled using self-developed vehicle platform for verifying the actual control effects of the developed control algorithms. The test results show that the developed ESC algorithm in this paper has a good control effect and high robustness under different road conditions and various maneuvers.Through the research of the control algorithm of ESC, we can achieve the following conclusion:1) The overall structure of ESC algorithms accomplished in this paper can avoid cross-calls between layers, save the microprocessor memory, and be convenient for software maintenance and later extensions.2) The vertical speed observer and nonlinear robust estimation of slip angle proposed in this paper can satisfy the requirements of real time and accuracy. The ESC test results show that the observer isn't only suitable for practical application, but also has high accuracy and robustness.3) The adaptive 2DOF single-track model proposed by the application of self-tuning filtering theory significantly improves the accuracy of nonlinear zone. The ESC practical algorithm using optimal and fuzzy control theory improves the driving stability in different roads. The coordinated control of ESC and ABS is proposed, which solves the problem of coordinated control.4) The hardware in the loop and real test results show that the ESC control algorithm and estimation algorithm of state parameters in this paper can timely and accurately control the yaw rate and side-slip angle, and significantly improve the vehicle stability. Meanwhile the algorithm has a good control effect and high robustness under different road conditions.