电液耦合转向系统应急转向控制方法研究

针对重载商用车应急转向难题，提出一种采用新型电动化的商用车电液耦合转向系统(Integratedelectric-hydraulic steeringsystem,IEHS)实现应急转向的新方法，针对电液耦合转向系统应急转向切换控制平顺性和时效性关键问题，研究一种基于混杂理论的电液耦合转向系统应急转向控制方法，以满足最新应急转向法规对重载商用车转向系统的新强制要求。其中，上层根据混杂切换逻辑进行正常转向与应急转向模式的切换控制，下层采用模糊PID控制对目标电流的精准跟随。在MATLAB/Simulink环境下进行正常转向和应急转向之间切换控制的仿真验证，同时在硬件在环试验台架上进行对应急转向功能的试验验证。仿真和试验结果表明，所提出的应急转向控制方法能够在电液耦合转向系统液压部分失效的情况下较好地实现应急转向功能，并保证混杂切换的时效性和平顺性，满足应急转向法规的要求。

Research on Emergency Steering Control Method of Integrated Electric-hydraulic Steering System for Commercial Vehicle

Aiming at the problem of emergency steering of heavy commercial vehicles, a new method to realize emergency steering by using a new integrated electric-hydraulic steering system(IEHS) for commercial vehicle is proposed. Aiming at the key problems of smoothness and effectiveness of emergency steering switching control of IEHS system, an emergency steering control method of IEHS system based on hybrid theory is studied, to meet the new mandatory requirements of the latest emergency steering regulations on the steering system of heavy commercial vehicles. Among them, the upper layer performs the hybrid switching control of normal steering and emergency steering mode according to the switching logic, and the lower layer uses fuzzy PID control to accurately follow the target current. The simulation verification of switching control between normal steering and emergency steering is carried out under the environment of MATLAB / Simulink, and the test verification of emergency steering function is carried out on the hardware in the loop test bench. The simulation and test results show that the proposed emergency steering control method can better realize the emergency steering function when the hydraulic part of IEHS system fails, ensure the timeliness and smoothness of hybrid switching, and meet the requirements of emergency steering regulations.