Rapid Transportation of Flexible Assembly Cell Based on Non-singular Terminal Sliding Mode Control with Prescribed-Time Reaching Law

This paper focuses on the transportation of the assembly cell, and studies how to safely and quickly transport the assembly cell to the desired position. The vibration of the assembly cell has a non-ignorable impact on the movement of the transportation robot, so it is necessary to establish a rigid-flexible coupling dynamic model of the system. To improve the accuracy of the rigid-flexible coupling dynamic model, the geometric nonlinearity of structural deformation is considered in the process of dynamic model establishment and analysis. Based on this model, the fixed-time controller is designed using non-singular terminal sliding mode control method. In order to improve the control performance of the sliding mode controller, a general prescribed-time reaching law is proposed in this paper. Comparing with the traditional prescribed-time reaching law, the proposed prescribed-time reaching law can reduce the adverse effects caused by the switching the reaching law. At the same time, considering the uncertainty of the model and the external disturbance, a uniformly convergent observer is proposed to enhance the robustness of the control system, which can accurately estimate the disturbance in a fixed time. Due to more accurate model establishment and more general prescribed-time reaching law design, the proposed controller can complete the transportation task of the assembly cell more accurately, quickly and safely.