摘要
矿用电动轮自卸车采用全液压转向系统,该系统由转向液压蓄能器与转向液压泵提供转向动力,实际转向速度受路面、转向油液压力与流量影响,是典型的大惯性且响应时变的执行系统。其转向速度时变特性对车辆横向运动与纵向运动提出了具有时变性的协同控制要求,间接制约了无人驾驶电动轮自卸车的横向运动能力。若不考虑转向速度约束和时变特性的速度规划与控制,将会造成横纵向运动协同性效果不佳,进而导致车辆无法有效循迹。文章首先根据全液压转向系统原理分析了影响转向速度的关键因素;然后基于车辆运动学模型进行变形推导,确定了转向响应速度对车辆横纵向运动协同的约束;最后结合转向蓄能器压力信息,建立了转向响应速度评估模型及符合横纵向运动协同约束的速度调整方法,从而实现了考虑转向速度时变特性的速度调控方法。实际测试结果表明,所设计的速度调控方法实现了电动轮自卸车对连续极限弯道路径良好跟踪行驶,平均横向误差0.2 m,保证了电动轮自卸车对曲率复杂变化路径的持续循迹能力。
Full hydraulic steering system adopted by mine electric-wheel dump truck is powered by steering hydraulic accumulator and steering hydraulic pump. Its actual steering response ability affected by road surface condition, steering oil pressure and flow, thus, it is a typical large inertia and time-varying execution system. Time-varying characteristics of the steering speed put forward time-varying coordination requirements for the lateral and longitudinal motion which indirectly restricted lateral motion ability of the unmanned mine truck. Speed planning and control without considering steering speed characteristics will result in poor coordination of lateral and longitudinal motion, which will lead to ineffective vehicle tracking. Firstly, this paper analyzes the key factors of time-varying response characteristics of the full hydraulic steering system based on its system principle. Secondly, the constraint of steering speed on the coordination of lateral and longitudinal motion is determined based on the deformation derivation of the truck kinematics model. Finally, combined with the pressure information of the steering accumulator, evaluation model of steering response capability and speed adjustment method in accordance with lateral and longitudinal cooperative constraints are established. Actual test results show that the designed speed adjustment method can achieve good tracking of the mine truck on the continuous limit curve path, with an average lateral error of 0.2 m, and ensure the continuous tracking ability of the mine electric-wheel dump truck on the complex curvature path.
作者
康远荣
刘勇
蓝德劭
袁希文
郜永涛
KANG Yuanrong;LIU Yong;LAN Deshao;YUAN Xiwen;GAO Yongtao(CRRC Zhuzhou Institute Co.,Ltd.,Zhuzhou,Hunan 412001,China)
出处
《控制与信息技术》
2022年第5期86-93,共8页
CONTROL AND INFORMATION TECHNOLOGY
基金
国家重点研发计划(2021YFB2501802)。
关键词
矿用电动轮自卸车
转向速度
时变特性
无人驾驶
协同约束
速度调控
electric-wheel mine dump truck
steering speed
time-varying characteristics
unmanned driving
cooperative constraint
speed adjustment
