Cai Ligang

Enhanced fuzzy sliding mode controller for a 3-DOF Parallel link manipulator

This paper presents an enhanced fuzzy sliding mode controller (EFSMC) for improving the tracking-performance of 3-DOF Parallel link manipulator, in which the fuzzy logic system is adopted as the adaptation mechanism to tune the gain of the sliding mode controller. The EFSMC can drive the state variables of 3-DOF Parallel link manipulator to hit a user-defined sliding surface quickly and slide along it. The sliding and global stability conditions are formulated and analyzed in terms of Lyapunov full quadratic form. To meet the real-time requirement of the parallel link manipulator, the region-wise linear technology is introduced to reduce the fuzzy rules of the EFSMC. The simulation results have shown that the proposed controller can achieve a higher performance with minimum reaching time and smooth control actions. In addition, it shows that the controller is effective and robust to the parametric variation and external disturbance.

Dynamic Response Analysis Based on Pile-Soil-Heavy Duty Machine Tool

Characteristics of the large self-weight and large load of heavy machine tool, lead to the change of ground motion character, its dynamic response is directly affected by pile-soil structure. This paper, through the introduction of large guide joint, the pile soil contact surface, boundary conditions of artificial interception area and the equivalent stiffness and damping, builds an easily achieved soil-pile-heavy machine tool dynamic model, studies the system step response law in the different soil layer, provides the theory basis for the foundation soil design of heavy machine tool.