无人驾驶喷雾机电控系统设计与试验

Design and Test of Electronic Control System for Unmanned Drive Sprayer

针对黄淮海地区实行秸秆全量还田模式下的麦玉轮作、麦豆轮作等,使得田间秸秆覆盖量较大,虽有效改善了土壤理化环境,却造成田间地表病虫害加重。为有效解决该问题,并提高作业效率,以自主设计的四轮驱动底盘为研究对象,设计了一种以电能为纯动力的无人驾驶喷雾机电控系统。该系统以STM32F103ZGT6微处理器为控制核心,基于模块化思想分别对喷雾机动力系统、网络通讯系统、转向系统和喷雾系统进行设计,实现远距离遥控精确行走和智能喷雾。性能试验结果表明:行驶速度为2～4 km/h时,低速转向的外轮转角小于等于23°,转弯半径大于等于1. 45 m,转弯路径无偏移现象,转向可靠;直线行驶50 m的平均偏移量为2. 42 m,单位距离平均偏移率4. 84 cm/m,偏移率较小;行驶速度为10 km/h整备状态下的喷雾爬坡度不大于25°;大田内试验时,在蓄电量充足情况下,行驶速度2～10 km/h时,最大续航时间不小于5. 50 h;在最大续航工作时间内,网络通信掉线次数小于等于1次,通信可靠性较好;遥控距离为0～500 m时,车速调节控制、转向调节控制以及药液电磁阀控制响应时间均小于0. 4 s。

An electric control system of sprayer was designed, which was driven by pure electric power and realized the unmanned self-propelled function. The STM32F103ZGT6 microprocessor was used as core and KeilμVision5 development platform was adopted in the system. Based on modular thinking, the development of sprayer power system, network communication system, steering system and spraying system was respectively carried out to realize remote control, precise walking and intelligent spraying. The field test results illustrated that when the sprayer was steered at speed of 2~4 km/h, the maximum rotation angle of the outer wheel was 23°, the minimum turning radius was 1.45 m, and the turning path had no deviation, the steering was reliable. The average offset was 2.42 m when the sprayer was straight running for 50 m, the average deviation was 4.84 cm/m, the offset was small, and the sprayer can be accurately controlled to drive by the route through the remote control. When the sprayer was spraying at top speed of 10 km/h, the effective climb gradient was less than 25°. The sprayer was tested in field, the maximum cruising time was greater than or equal to 5.50 h when the driving speed was 2~10 km/h with sufficient power storage. In the maximum battery life, the number of dropped calls of network communication was no more than 1, and the communication reliability was good. When the remote control distance of the sprayer was in the range of 0~500 m, the speed adjustment control, steering control and the response time of liquid medicine electromagnetic valve control were all less than 0.4 s. The general working condition of field operation was satisfied. This control system can effectively realize the separation of man and machine, ensure the safety of operators, suitable for most small farms, and effectively improve the operation efficiency of wheat plant protection.