饲草推送机器人磁条导航自动充电研究

Automatic Charging of Forage Pushing Robot by Magnetic Stripe Navigation

为了实现牛场勤密饲喂,饲草推送机器人自动充电系统采用上置对接式,由充电桩、机器人充电控制部分组成。充电桩包含蓄电池充电器、充电电路和充电电极等;机器人充电控制部分包含控制器、行走驱动模块、电源监控模块、传感数据采集模块、继电器和充电电极等。在充电对接部位建立坐标系XYZ,根据电极长度、电极压缩行程、电极宽度,确定X、Y、Z轴的对接容错范围。根据半开放式牛场工作环境,在自动充电区域设置充电桩、磁条导航路径。饲草推送机器人在磁条导航过程中,通过磁导航传感器实时检测磁信号,获得磁导航偏差,采用模糊PID控制算法,得到左右轮速度控制量后,转换成对应电动机角速度值,控制器输出对应占空比的PWM信号控制电动机转速。结合磁导航传感器特性和试验,获得模糊控制器的输出参数调整规则。自动充电磁条导航试验结果表明:当磁导航偏差绝对值|e|为最大值时,比例系数调整值ΔKp最大值为1. 28,最小值为1. 03;积分系数调整值ΔKi最大值为0. 13,最小值为0. 06;微分系数调整值ΔKd最大值为-1. 18,最小值为-1. 5;通过模糊PID控制,PID控制器系数可进行自适应修正; X轴、Y轴和Z轴最大对接偏差绝对值分别是4. 1、1. 9、0. 7 cm,对接偏差均在容错范围之内。

In order to realize frequent feeding in cattle farm,automatic charging system of forage push robot adopted upper docking type,and it included charging pile and charging control part of the robot.The charging pile included battery charger,charging circuit and charging electrode. The charging control part of robot included controller, walking driving module, power monitoring module, sensor data acquisition module,relay and charging electrode. A coordinate system XYZ was set up at the charging junction. According to electrode length,electrode compression stroke and electrode width,the fault tolerance range of X,Y and Z axes was determined. According to the working environment of semi-open cattle farm,charging piles and magnetic stripe navigation charging path were set up in automatic charging area. During the navigation of forage pushing robot,magnetic navigation sensor detected magnetic signal,and magnetic navigation deviation was obtained by data processing. A fuzzy PID control was adopted.When the control speeds of the left and right wheels of the forage pushing robot was obtained,the speed value of each wheel was converted to angular velocity value of according motor. The controller outputed PWM signal of corresponding duty ratio to control the rotation speed of motor. Combining with the characteristic and experiment of magnetic navigation sensor,the adjustment rules of output parameters of fuzzy controller was obtained. The results of charging and docking tests by magnetic strip navigation were as follow. When the absolute value | e | of magnetic navigation deviation was the maximum,the maximum value of proportional coefficient adjustment value ΔKpwas 1. 28,and the minimum value was 1. 03. The maximum value of the integral coefficient adjustment value ΔKiwas 0. 13,and the minimum value was0. 06. The maximum value of differential coefficient adjustment value ΔKdwas-1. 18,and the minimum value was-1. 5. PID controller coefficient can be adaptively corrected by the fuzzy PID control. The maximum docking deviations of magnetic navigation on X axis,Y axis and Z axis were 4. 1 cm,1. 9 cm and 0. 7 cm,respectively,and the docking deviations were within the fault tolerance range.