Abstract:At present, most apple-picking robots use industrial mechanical arms. Motor and reduction gears are generally used in the joint control for apple-picking robots to improve the control accuracy and increase the driving torque. It will undoubtedly increase the complexity and reduce the control performance to the system. In order to improve this situation, a joint control scheme of apple-picking robot based on DC torque motor and harmonic reducer is proposed . The system can greatly reduce the volume of driving mechanism, improve the system rigidity, achieve precise control of low speed and stability. The MATLAB simulation results show that the system overshoot and steady state error were all zero under the step inputs of 0.5°and 60°, the system output could completely follow the input by taking sinusoidal signal with 5°amplitude and 3.14rad/s frequency as system input. The control precision of the system reached the requirement of apple picking. It’s able to provides a strong theoretical support for simplifying the mechanical arm structure and even realizing direct drive for apple-picking robot.