Generating Optimized Trajectories of Industrial Robots in CP Motion without Kinetic Models

Abstract

This study proposes a method of generating the optimized trajectory, which determines change of the displacement of a robot with respect to time, to reduce electrical energy or the peak current value occurred in motors. Previously, a lot of studies tried to optimize the trajectory of a robot, needing its kinetic model to obtain the input torque or energy as the evaluation value. However, the construction of the kinetic model is considerably difficult, because it needs to identify or to measure a lot of specifications of a robot. Thus, the present study proposes the method that obtains the evaluation value by measuring the currents, powers and so on of an actual robot in operation. Therefore, it does not need the analysis of the motion of a robot with the kinetic model. The proposed method optimizes the trajectories with a heuristic procedure by evaluating the measured values. In this study, we addressed the optimization method for continuous path controlled robots and applied it to a commercially available industrial manipulator, confirming that the generated trajectory can reduce electrical energy and the peak current value in a short time.