单HST履带式拖拉机差速转向控制系统研究  

Differential Steering Control System for Single HST Tracked Tractors

作　　者：秦维贤 张光强 胡书鹏 周豫鸽 温昌凯 付卫强[2,5] 孟志军 QIN Weixian;ZHANG Guangqiang;HU Shupeng;ZHOU Yuge;WEN Changkai;FU Weiqiang;MENG Zhijun(School of Agricultural Engineering,Jiangsu University,Zhenjiang 212013,China;Intelligent Equipment Research Center,Beijing Academy of Agriculture and Forestry Science,Beijing 100097,China;State Key Laboratory of Intelligent Agricultural Power Equipment,Luoyang 471039,China;College of Engineering,China Agricultural University,Beijing 100083,China;National-Local Engineering Laboratory for Beidou Navigation,Intelligent Control and Telematics of Agricultural Machinery,Beijing 100097,China)

机构地区：[1]江苏大学农业工程学院,镇江212013 [2]北京市农林科学院智能装备技术研究中心,北京100097 [3]智能农业动力装备全国重点实验室,洛阳471039 [4]中国农业大学工学院,北京100083 [5]农机北斗导航与智能测控国家地方联合工程实验室,北京100097

出　　处：《农业机械学报》2024年第S1期405-411,426,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2022YFD200150302);中国烟草总公司重点研发项目(110202301013-3);智能农业动力装备全国重点实验室建设项目(PT2024-49)

摘　　要：针对单路静液压传动(Hydro static transmission,HST)履带式拖拉机自动转向控制时存在平稳性差、转向控制分辨率低和单边制动转向对土壤破坏严重的问题,提出了一种基于状态反馈的差速转向控制系统。首先分析了单HST实现差速转向的机构原理;其次,根据履带式拖拉机运动学模型,设计了基于脉宽调制原理(Pulse width modulation,PWM)的差速转向控制方法,通过精确调节转向液压缸行程实现更高的转向控制分辨率和稳定性;接着应用STM32F4单片机为核心的控制器同时进行直线路径规划和转向控制,完成车载控制器设计;最后分别开展在水泥路面和田间3种速度条件下的实车试验。试验结果表明,在速度2、3、5 km/h条件下,水泥路面直线跟踪距离绝对偏差平均值分别为1.6、2.2、3.1 cm,标准差分别为2.7、2.9、3.6 cm;田间地面直线跟踪距离绝对偏差平均值为1.7、1.9、2.9 cm,标准差为2.2、2.1、3.4 cm。结果表明,该系统在不同环境下均表现出优于传统单边制动转向控制效果,显著提升了转向精度和平稳性。To address the issues of poor stability,low steering control resolution,and severe soil damage caused by unilateral braking steering in the automatic steering control of a single hydro static transmission(HST)tracked tractor,a differential steering control system based on state feedback was proposed.Firstly,the mechanism of differential steering using a single HST was analyzed.Then,based on the kinematic model of the tracked tractor,a differential steering control method using pulse width modulation(PWM)was designed.This method improved steering control resolution and stability by precisely adjusting the stroke of the steering hydraulic cylinder.Next,a control system was developed with an STM32F4 microcontroller as the core,which integrated both linear path planning and steering control,completing the design of the onboard controller.Finally,field tests were conducted under three speed conditions on both cement and field surfaces.The test results showed that at speed of 2 km/h,3 km/h and 5 km/h,the mean absolute errors of straight-line tracking on the cement surface were 1.6 cm,2.2 cm and 3.1 cm,respectively,with standard deviations of 2.7 cm,2.9 cm and 3.6 cm.On the field surface,the mean absolute errors were 1.7 cm,1.9 cm and 2.9 cm,with standard deviations of 2.2 cm,2.1 cm and 3.4 cm,respectively.These results demonstrated that the system outperformed traditional unilateral braking steering in various environments,significantly improving steering accuracy and stability.

关 键 词：履带式拖拉机 静液压传动 差速转向 控制方法 

分 类 号：S219.2[农业科学—农业机械化工程]