Study of the Influence of the Mecanum-Wheel Design and Contact Forces on the Control Accuracy of Mobile Robot-Manipulator KUKA YouBot

Abstract

The dynamics and control of the KUKA youBot robot, which consists of a mecanum-platform and a five-axis manipulator fixed on it, is considered. A mathematical model of the dynamics of a mobile robot-manipulator has been developed taking into account the design of the mecanum-wheels, multicomponent contact friction, dynamics of robot drives and the mutual influence of the platform and the manipulator. A robot motion control law is proposed that ensures precise movement of the robot to the required position. According to the results of numerical simulation, the operability of the proposed control is confirmed. At the same time, at the end of the transient process, there are high frequency oscillations in the coordinate of the platform geometric platform, the platform heading angle and the angles of the manipulator links. To reduce amplitude of these high frequency oscillations, it is necessary more accurately compensate for the action of gravitational forces. It is shown that due to the mutual influence of the dynamics of the manipulator on the platform, platform displacements occur relative to the initial position. Based on the simulation results, the influence of the design of the mecanum-wheels, multicomponent contact friction and dynamics robot drives, as well as the mutual influence of the platform and the manipulator on the dynamics of the KUKA youBot robot, is shown. Further research involves a more detailed analysis and synthesis of control algorithms within the framework of theories of optimal or adaptive control.