Simulation Of Active Steering Intelligent Control Strategy And Hardware-in-loop Experiment Of Heavy Vehicle

With the increasing of heavy-duty vehicles accident rate on the road,improving the driving stability and safety of heavy-duty vehicles has become a widespread concern.According to the wheel angle input by the driver,the active front wheel steering system can calculate a modified angle and apply it to the steering wheel,so as to optimize the steering process of the vehicle and ensure the driving track and stability of the vehicle.It is a research hotspot in the field of automotive intelligence.The intelligent control algorithms,such as sliding mode control and model predictive control,are more and more concerned because they are suitable for nonlinear systems and have strong adaptability to the changes of parameters.Therefore,the research of the active steering intelligent control strategy for heavy-duty vehicles has important theoretical and practical significance.In this dissertation,based on a three-axis commercial vehicle,the whole vehicle dynamics model is established in Trucksim,and the accuracy of the model is verified by using the real vehicle experimental data.At the same time,the simulation condition of double lane shifting on B-level road is established.Then the variable transmission ratio curve of vehicle steering system is designed,the sliding mode variable structure control strategy with improved exponential approach rate is proposed,and the active steering control system based on sliding mode variable structure control is established,the control effect under various vehicle speeds and road surfaces is simulated and analyzed.In addition,the linear time-varying model predictive control strategy is proposed,and a vehicle active steering control system based on model prediction is established.Through the joint simulation of Trucksim and Simulink,the control effect of active steering system under various vehicle speeds and road surfaces is analyzed.Finally,a hardware-in-loop experiment of the sliding mode variable structure active steering control system is carried out by using the three-axis vehicle chassis electric control comprehensive test platform,and the sensitivity analysis of vehicle speed and road adhesion coefficient that affect the control effect is carried out.Research shows that(1)the active steering intelligent control strategy designed in this dissertation can effectively improve the stability and safety of heavy-duty vehicles during steering,and the peak values of vehicle's lateral acceleration,sideslip angle,sprung mass roll angle,and yaw rate are significantly reduced in steering,which can be reduced by 10% to 20% under sliding mode variable structure control and 25% to 40% under linear time-varying model predictive control.(2)The effectiveness of the sliding mode variable structure active steering system is verified by hardware-in-loop experiment and the adaptability of the control strategy to vehicle speed and road adhesion coefficient is good.Therefore,the active steering controller based on heavy-duty commercial vehicles can ensure the stability of the vehicle when steering and has good working condition adaptability.The research results of this dissertation can provide new ideas and directions for the research of heavy-duty vehicle handling stability control.