The trajectory planning of redundant manipulator with gantry by using model predictive control

To solve the motion control problem of large-scale complex manipulators which are commonly used in industry recently, this paper focuses on manipulator system composed of a gantry and small-sized manipulators. Firstly the calculation formula for beam deflection under two independent concentrated loads is deduced by analyzing material mechanics. Then an accurate kinematics model of manipulator system is presented. On this basis, the model is simplified to be linear and low-order, for following algorithm design. For the multi-input multi-output (MIMO) high dimensional redundant model with joint constraints, an algorithm based on model predictive control (MPC) is proposed for trajectory planning. All of the joints are classified into different movement priorities according to their motion range and positioning accuracy. The redundancy problem can be solved by setting different weights for control variable of each joint in optimization problem. Meanwhile, rolling optimization style of MPC scheme makes it possible to online continuously make trajectory planning with updated information. The simulation results illustrate effectiveness of the algorithm proposed in this paper. In addition, for various setting points, different weighting selections are considered by analyzing joints' motion characteristics. © 2016, Editorial Department of Control Theory & Applications South China University of Technology. All right reserved.