基于不同电机的拖拉机自动导航转向控制系统性能对比

Performance Analysis and Comparison of Different Types of Steering Wheel Turning Control Motors in Automatic Navigation System

为了提高拖拉机在农田环境中自主导航作业的控制精度,设计开发了3种基于不同类型电机的方向盘转向控制系统,在分析步进电机、伺服电机和步进伺服电机3种电机的参数及其性能差异的基础上,设计了拖拉机自动转向执行机构,并配备了工控机PC、PLC控制器、前轮转角检测机构和GNSS定位系统等设备。设计了工控机车载终端软件,能够实现自动导航的嵌套双闭环控制及相应PID控制算法,设计了控制系统的电气原理图和PLC转向程序,在混凝土路面和田间播种作业两种工况下进行了拖拉机自动导航实验。实验结果表明,当拖拉机作业速度为0.8m/s时,两种实验条件下,步进电机导航系统的均方根误差分别为8.81cm和12.09cm,伺服电机导航系统的均方根误差分别为4.85cm和10.55cm,步进伺服电机导航系统的均方根误差分别为4.54cm和5.53cm,步进伺服电机在方向盘转向控制系统中自动导航效果较好。

In order to improve the control precision of the autonomous navigation operation of agricultural machinery in farmland environment,three steering wheel turning control systems based on different types of motors were designed and developed.Based on the analysis of the parameters of the three kinds of motors,such as stepper motor,servo motor and stepper servo motor,and their performance differences,the tractor automatic steering actuator was designed,and equipped with industrial computer PC,PLC controller,front wheel angle detection mechanism and GNSS positioning system.The design and development of the industrial vehicle terminal software can realize the automatic navigation nested double closed-loop control system and the corresponding PID control algorithm;the electrical schematic of the control system and the PLC steering program were designed.Finally,the tractor automatic navigation concrete pavement and field sowing test were carried out.When the tractor was linearly navigating at a speed of 0.8 m/s,under the two test conditions,the root mean square errors of the stepper motor navigation system were 8.81 cm and 12.09 cm,respectively,the root mean square errors of the servo motor navigation system were 4.85 cm and 10.55 cm,respectively,and the root mean square errors of the stepper servo motor navigation system were 4.54 cm and 5.53 cm,respectively.The test results showed that the stepper servo motor had the best performance for steering wheel turning control in the automatic navigation system.