静液压—机械驱动桥式履带底盘分段跟随转向控制研究

为提高静液压-机械驱动桥式履带底盘转向的可操作性及安全性,设计了一种分段跟随控制策略及利用转向盘输入的转向电控系统。根据打滑条件下履带底盘转向分析结果,求解出理论转向轨迹,并根据机械驱动桥响应复位时间进行分段处理。实际履带底盘转向轨迹根据控制策略中所划分的行驶方向角度与位置偏离限控制每一分段时间内驱动桥的离合制动器作用状态,实时跟随理论轨迹。建立了控制策略的评价方法,并进行了算法仿真和电控系统设计及实车试验。仿真结果表明控制算法履带底盘转向相对误差为5.9%~10%,执行器作用平均频率为2.5~6.6 Hz。实车试验表明,利用转向盘输入的电控转向系统可满足静液压-机械驱动式履带底盘的转向需求,能够实现驾驶人员转向意图,转向过程平稳。同时,电控系统能够有效减少履带底盘转向过程中的原地滑转,从而减小对地面和农作物的损伤。

Subsection Following Steering Control Strategy and Test of Hydrostatic-mechanical Driving Crawler Chassis

A kind of subsection following steering control strategy and steering wheel input-based electronic control system were proposed to improve the steering maneuverability and security of the hydrostatic-mechanical driving crawler chassis. According to the steering analysis results of the crawler chassis under skid condition, the theoretical steering track was obtained, and it was segmented by mechanical drive axle responding time. Actual steering track followed theoretical steering track by controlling barking-clutch performance in every subsection period according to vehicle direction angle and position tolerances defined in control strategy. The evaluation system of the strategy was established, and the steering relative errors, relative steering radius ratio, executing frequency were selected as evaluation indexes. Algorithm stimulation and real vehicle test with steering electronic controller by adopting this strategy were also carried out. The stimulation results obtained by Matlab showed that the relative error of steering radius was between 5.9% and 10%, and the average frequency of actuator working was from 2.5Hz to 6.6Hz. The real vehicle test results showed that the electronic steering control system and control strategy had well steering performance, and it could meet various steering needs with stable process, and eliminate the destruction to soil and crops via decreasing the pivot steering slipping.