Objective To solve the problem of endpoint trajectory tracking control in the application of mechanical arms in the agricultural field, and ensure the high-precision trajectory tracking and stable operation of the agricultural picking robot picking end.

Method It is suggested to use a hyperbolic tangent function-based sliding mode tracking control approach for a picking robot arm. A model of the manipulator dynamics based on the workspace was built using inverse kinematics, and a sliding mode tracking controller for the hyperbolic tangent function was created. The asymptotic stability of the control system was guaranteed by the Lyapunov function. The simulation control system of the manipulator was built in the MATLAB/Simulink environment to verify the control algorithm, and the tracking effect of the sliding mode controller on the end trajectory of the manipulator was analyzed.

Result The simulation test results showed that the sliding mode controller based on the hyperbolic tangent function achieved high-precision trajectory tracking and stable control, improved the convergence speed of the terminal trajectory tracking, reduced the robot end trajectory tracking control error, and reduced the convergence time of the terminal trajectory tracking curve by 50%, effectively improved the real-time performance and tracked accuracy of the robot picking system compared with the switching function sliding mode controller.

Conclusion The research can provide an effective control method for the practical application of robotic arm picking.