独立轮电液伺服转向系统数学建模与验证

Modeling and experiment validation of electro-hydraulic servo steering system with independent wheels

针对独立轮电液助力转向系统结构简单、控制灵活,可满足传统单自由度梯形转向机构实现多轴车辆蟹行、原地转向、横移等特殊工况要求的情形,建立阀控单缸独立轮电液助力转向系统拉格朗日动力学模型.根据实际重型车辆转向系统搭建了1∶1实验台架,并基于dSPACE和硬件在环设计动力学模型实验验证方案.通过给定包括手动随机信号在内的多种输入信号,对比动力学模型和实验台架,得到反馈转角、压力和跟踪误差曲线.实验结果表明,转向角度、转向缸两腔压力等曲线匹配良好,验证所建动力学模型的正确性.该模型可为今后独立轮电液伺服转向系统的非线性控制与分析提供参考.

Aiming at the requirements of simple structure,flexible control and special working conditions of single-degree-of-freedom trapezoidal steering mechanism for multi-axis vehicles,such as crab-walking,in-situ steering and transverse movement,a Lagrange dynamics model of valve-controlled single-cylinder independent wheel electro-hydraulic servo steering system(EHSSS)was established.An 1∶1 experimental bench was built according to the actual heavy vehicle steering system,and a dynamic model experimental verification scheme was designed based on dSPACE and hardware in the loop.By giving a variety of input signals including manual random signals and comparing the dynamic model with the experimental bench,the curve of feedback angle,pressure and tracking error is obtained.The experimental results show that the curves of the angle and the pressure of the steering cylinders are matched,and the correctness of the dynamic model is verified.This model can provide reference for the nonlinear control,and analysis of the independent wheels EHSSS.