拖拉机自动转向系统容错自适应滑模控制方法  

Fault-tolerant adaptive sliding mode control method of tractor automatic steering system

作　　者：贾全[1] 张小超[1] 苑严伟[1] 付拓 伟利国[1] 赵博[1] Jia Quan;Zhang Xiaochao;Yuan Yanwei;Fu Tuo;Wei Liguo;Zhao Bo(Chinese Academy of Agricultural Mechanization Sciences, Beijing 100083, China)

机构地区：[1]中国农业机械化科学研究院,北京100083

出　　处：《农业工程学报》2018年第10期76-84,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家重点研发计划项目(2017YFD0700400-2017YFD0700403);湖南省战略性新兴产业科技攻关类项目(S2016GXZLGG0101)

摘　　要：为提高拖拉机自动转向系统的可靠性,该文提出了一种具有前轮转角容错检测能力的径向基函数(radial basis function,RBF)网络自适应滑模控制方法。综合考虑拖拉机姿态信息和控制输出,基于卡尔曼滤波算法推导得出拖拉机前轮转角的两个估计值,并结合角度编码器实际测量值设计了前轮转角容错检测输出算法;以容错输出算法的输出值作为状态量,提出一种利用RBF网络进行干扰补偿的前轮角度自适应滑模控制方法,并通过仿真试验验证了算法的有效性。开展了拖拉机前轮转角容错检测和自动控制试验,结果显示:基于侧向加速度的转角预估值最大误差为2.94?,均方根误差为0.81?;基于横摆角速度的转角预估值的最大误差为1.73?,均方根误差为0.12?;当人为施加故障干扰时,算法可以提供容错的转角输出;拖拉机转向控制系统可以快速跟踪期望前轮角度且超调量较小,最大控制误差为0.21?,均方根误差为0.07?。试验结果表明,容错自适应滑模控制方法提高了自动转向控制系统的可靠性和准确性,有助于解决拖拉机前轮转角测量装置故障率高的问题。Unmanned tractors have become the focus of research in the field of intelligent agricultural machinery in recent years, which can effectively improve the agricultural productivity and the accuracy of operations. Automatic steering control system was a prerequisite for driverless tractors, and the key technologies included steering wheel angle detection method and angle tracking control algorithm. Steering wheel angle measurement results were the direct factors affecting the navigation effect. Encoder measurement and angular rate measurement were 2 commonly used front wheel angle measurement methods. Absolute angle measurement method had higher detection accuracy, but there were too many mechanical connectors using this method, and the calibration work was complex. The angular rate measurement method generally used inertial devices, which were easy to install and had a long working life. However, there was a random drift in the gyroscope and the accumulated error would affect the measurement accuracy. In practical applications, whatever the above-described measuring methods used, the angle measuring device was the most easily damaged component of the entire control system. For example, the angle measuring mechanism was easily damaged during operation by crops when it was installed in the position of the tractor front axle, it would cause signal output failure, and the reliability and safety of the unmanned system would be affected. In addition, the steering control system would be subject to a variety of non-linear factors such as mechanical clearance and hydraulic system lag during the working process, resulting in poor control effects. It was necessary to compensate for the uncertainties to further enhance the effect of angle tracking control. In order to solve the problems above, an RBF adaptive sliding mode control method with the ability of fault-tolerant detection of front wheel angle was proposed. First of all, a discrete state equation of the control system was deduced according to the structure of the tra

关 键 词：拖拉机 控制系统 转向 转角容错检测 RBF网络 滑模控制 

分 类 号：S24[农业科学—农业电气化与自动化]