Authors

Abstract

To solve the problem of poor steering performance of existing self-driving tractors based on electro-hydraulic coupled steering systems (E-HCSS) under multiple influencing factors, the research on electro-hydraulic coupled steering characteristics of self-driving tractors was carried out in this paper. Taking the electro-hydraulic coupled steering system as the research object, the E-HCSS test bench of the tractor was built, and the influencing factors affecting the responsiveness of the steering process were obtained through theoretical analysis: hydraulic fluid temperature, oil supply pressure and driving speed. The hydraulic fluid temperature, oil supply pressure and driving speed were taken as the test factors, and the steering system response time and response error were taken as the performance indexes for the single-factor steering test and orthogonal test. By establishing the regression mathematical model between the influencing factors and the indexes, the interactive influence of the factors on the indexes was analyzed, the optimal parameter combination was obtained, and the optimization results were verified. The test results indicated that the tractor electro-hydraulic coupling steering system could achieve good steering performance under the optimal parameter combination, and the optimal parameter combination was: hydraulic oil temperature 60°C, hydraulic oil pressure 15 MPa and driving speed 8 km/h. The study's results were as follows: hydraulic oil temperature 60°C, hydraulic oil pressure 15 MPa and driving speed 8 km/h. The study's results could provide a reference for the steering control of the self-driving tractor, the design of the self-driving steering system and the optimization of the parameters.

Abstract in Chinese

针对自动驾驶拖拉机电液耦合转向系统转向过程中受液压系统液压油温度、供油压力以及转向频率等的影响，本文通过搭建拖拉机电液耦合转向试验台，以电液耦合转向系统为研究对象，建立转向过程中的功率模型及响应模型，通过理论分析得到影响转向过程总功率及响应能力的影响因素：液压供油压力、液压供油温度及转向频率。以液压供油压力、液压供油温度及转向频率为试验因素，以转向系统总功耗、响应能力为性能指标进行转向特性分析试验，试验内容为自动驾驶拖拉机正弦路径跟踪试验。通过建立各影响因素与指标之间的回归数学模型，分析各因素对指标的交互影响，获得最优参数组合：对优化结果进行验证试验，试验结果表明在最优参数组合下：液压供油压力、液压供油温度及转向频率。研究结果可为自动驾驶拖拉机转向控制、自动驾驶转向系统设计及参数优化提供参考。