丘陵果园除草机器人底盘系统设计与试验

Design and Experiment of Chassis Control System for Weeding Robot in Hilly Orchard

针对丘陵果园环境非结构化且复杂多变,常规的除草方式效率低等问题,设计了一种果园除草机器人底盘系统。根据果园丘陵地形地貌环境,确定车体控制方式和除草机器人底盘的总体结构方案,主要包括液压传动系统、电气控制系统等。设计配套的除草车电气控制系统和遥控接收、车载主控和导航功能的CAN通信协议。以运动控制为核心,采用角度传感器、电机驱动、车载主控、导航模块,构成闭环控制。使用自抗扰控制算法,以油阀控制电机为对象应用Simulink仿真,仿真结果显示自抗扰控制相比PID控制调节时间减少0.42 s,超调幅度减小11.5%,稳定时间缩短0.14 s。田间试验表明,运用自抗扰控制、结合导航功能的除草机器人行走速度均值为6.2 km/h,均方差0.037 km/h,作业效率0.51 hm~2/h,有效除草率均值97.46%,可在25°斜面上正常行走,对导航路径的跟踪误差标准差为4.732 cm,运动控制响应及时,能够提高除草作业安全性和准确性。

Aiming at the problems of unstructured and complex hilly orchard environment and low efficiency of conventional weeding methods,an orchard weeding robot chassis system was proposed.According to the hilly terrain and landform environment of the orchard,the vehicle body control mode and the overall structure scheme of the weeding robot chassis were determined,mainly including the hydraulic transmission system,and electrical control system,etc.With motion control as the core,in order to improve the control accuracy of the hydraulic system,the supporting electrical control system,remote control receiver and CAN communication protocol of the weeding vehicle were designed,which were composed of the main controller,remote control receiver,motor drive module and navigation module,and the software flow was determined.The motion controller was designed based on the active disturbance rejection control algorithm.The robot track speed was determined by the valve angle of the hydraulic system,it can be seen that the dynamic performance of the motor directly connected to the control valve was the motion control target.The Simulink simulation model was established by taking the motor angle of the hydraulic valve as the object and the speed,disturbance and output as the state variables.The simulation results showed that the ADRC reduced the adjustment time by 0.42 s,the overshoot by 11.5%and the stability time by 0.14 s compared with the PID control.Ground experiments were arranged to verify the effectiveness of the robot system.The experiments showed that the average walking speed of the weeding robot using active disturbance rejection control combined with navigation function was 6.2 km/h,the mean square deviation was 0.037 km/h,the operation efficiency was 0.51 hm~2/h,and the average effective weeding rate was 97.46%.It can walk normally on a 25°slope,and the standard deviation of tracking error for the navigation path was 4.732 cm.The motion control response was timely,which can improve the safety and accuracy of weeding operation.