Delta Mechanism Trajectory Tracking Control Based On Active Disturbance Rejection Control Technique

Delta robots have strong carrying capacity,simple drive installation,fast movement,and are widely used in food,pharmaceutical,electronics and other industries.The Delta mechanism is a highly coupled parallel mechanism.It is difficult to establish an accurate dynamic model,and the control effect is not ideal.For the trajectory tracking of Delta,combined with previous research results and active disturbance rejection control technique,it optimizes and enriches the control algorithm of Delta robot,which provides certain theoretical support for its industrial development.The geometric model of the Delta mechanism is constructed,and its degree of freedom is obtained by using the modified G-K formula.The structure is appropriately simplified,kinematics analysis is performed,and its kinematics solutions are obtained,and verified by MATLAB and ADAMS.Finally,the Delta's Jacobian matrix and workspace are obtained.The dynamics model of the Delta mechanism is established by using the principle of virtual work.Considering the complexity of the slave arm,a simplified dynamic model is obtained.Based on the simplified Delta mechanism dynamics model,the trajectory tracking control is performed by using the active disturbance rejection control technique.The stability analysis of the extended state observer and the closed-loop controller is carried out by using the self-stabilization domain method and the Lyapunov function,respectively.The Simulink and ADAMS are used to build a co-simulation platform and compared with PID control.The extended state observer is appropriately modified to a reduced-order extended state observer,which simplifies the process of parameter adjustment.Considering that the overshoot is still large,the linear controller is changed to a nonlinear controller.The convergences of the observer and controller are proved by using the Lyapunov function.By combining a co-simulation platform and comparing with the traditional active disturbance rejection control technique,the superiority and effectiveness of the control method are verified.