Design And Experiment Of Agricultural Robot Test Platform With Two Degrees Of Freedom

At present,the labor force engaged in agricultural production in China is generally older and the human resources are scarce.By using agricultural robots instead of farmers to complete some agricultural activities,production costs can be reduced to a large extent,labor intensity can be reduced,and agricultural production efficiency can be improved.At present,the domestic research on agricultural robots lacks relevant experimental platform,which will restrict scholars’ further research on agricultural robots.Therefore,it is of great significance to design and develop a matching test platform.The purpose of this project is to design a single leg test platform system for agricultural robots.The system has two degrees of freedom and can assist leg to move freely in horizontal and vertical directions.The virtual prototype of the test plat-form is created by ADAMS software to verify the correctness of motor selection,kinematics analysis and model establishment.Orthogonal test is carried out on the test platform to analyze the influence of period,step length,step height and angle of entry on leg walking,and to select the optimal gait parameters.The main contents of this paper are as follows:Firstly,according to the design requirements,the three-dimensional model of agricultural robot test platform is built by using CREO software,and the strength of key components is checked by ANSYS software.Based on the leg structure,the forward and inverse kinematics solutions are carried out,the motion space and joint angle of the foot end are obtained,and the foot end trajectory curve is finally determined.Secondly,the hardware selection of agricultural robot test platform is completed,including driving motor,driver,USB-CAN analyzer and power supply.The upper computer is made by C,and the motor is controlled by CAN communication,so that the legs can move according to the specified trajectory.Then,the virtual prototype test of the test platform is completed by ADAMS software,and the joint torque,angular velocity,foot force,foot trajectory curve are obtained by simulation calculation,which proves the correctness of motor selection and kinematics model.Finally,the influence of soil entry angle on robot walking is verified by mathematical model and simulation analysis.The orthogonal experiment of four factors and three levels are designed for the physical prototype experiment of robot walking in soil and grassland.The experimental data are processed by range analysis method,and the following conclusions are drawn:1.The factors affecting the motor torque when the robot moves are:penetration angle>step length>period>step height.2.When walking on the soil,the gait parameters of 2 seconds cycle,150 mm step length,25 mm step height and 90 degree entry angle are selected,and the average torque required for the movement of the mechanical leg is the lowest.3.When walking on grassland,the gait parameters of 1.5 seconds cycle,150 mm step length,25 mm step height and 90 angle of penetration are adopted,and the average torque required for the movement of mechanical legs is the lowest.