The Research Of Hardware-in-the-loop Simulation Test System For Vehicle Electronic Stability Control System

As the highest form in the field of active safety, Electronic Stability Control(ESC) system can maintain the vehicle stability by dominating the yaw moment effectively under extreme driving conditions. Now, commercialized ESC product has been developed in foreign countries. China is still weak in this area. Therefore, research on the key technologies in developing ESC is vital important for the research and development ability in Chinese auto industry.Based on certain industry project on ESC testing and control, research on ESC hardware in-loop simulating and testing system was conducted. ESC control system and control strategy were studied for providing theoretical and practical basis for ESC products.The main content of this paper were as follows:Firstly, on the basis of the study for ESC control system composition and the working principle and control strategy of the current mainstream, the overall structure of ESC strategy which includes state parameter estimation layer, control layer and the execution control layer had been accomplished by the application of modular design, which provides the basis for follow-up research work.Secondly, based on the needs of the ESC critical state parameters estimation and the target of accuracy and real time, 3-dof vehicle dynamic model was established and this paper proposed the longitudinal speed estimation method and nonlinear estimation of slip angle. Simulation experiment was carried out combine with the CarSim and the state parameter estimation model. The ESC simulation results showed that this method was not only suitable for practical application, but also had high accuracy.Thirdly, according to the nonlinear and time-varying system characteristics in the development process of ESC control strategy, the size of the yawing moment had been confirmed by fuzzy control model. The ideal yaw rate and ideal sideslip angle were confirmed by 2-dof vehicle dynamic model. In active braking control strategy, the unilateral brake scheme was selected, and the MATLAB/Stateflow was used to achieve the logic control. In terms of active control allocation strategy, four wheel brake cylinder pressure was obtained from the braking torque by the efficiency factor of CarSim software. Thus, the ESC motion control and the execution control layers were designed. The simulation tests were carried out combining with the state parameter estimation and CarSim vehicle model. The simulation results showed that the ESC hierarchical control strategy had better performance on control stability in the process of high speed in low adhesion road.Lastly, the system configuration of ESC HIL simulation test platform was proposed according to real company project requirement. The ESC HIL simulation test platform was established based on LabVIEW real-time simulation system of NI. And test verification was done. Simulation verifications were conducted on simulation system and signal system to ensure the validation of HIL test platform. The correctness of the HIL test platform was confirmed according to the results, which illustrated that the system can be used for ESC product test and simulation.