Motion Planning and Control of Omni Directional Mobile Robot in Dynamic Environments - Matlab codes

Abstract

Motion control in dynamic environments is one of the most important problems in using the mobile robots in collaboration with human and other robots. In this paper, motion control of four Mecanum wheeled Omni-directional mobile robot (OMR) in dynamic environments is studied. The robot’s differential equations of motion are extracted using Kane’s method and converted to discrete state space form. Nonlinear Model predictive control (NMPC) strategy is designed based on the obtained mathematical model to stabilize the robot in desired position and orientation. As a main contribution of this work, velocity obstacles (VO) approach is reformulated to be introduced in NMPC system to avoid the robot from collision with moving and fixed obstacles online. Considering the robot physical restrictions, the parameters and functions used in the designed control system and collision avoidance strategy are determined through stability and performance analysis and some criteria are stablished for calculating the best values of these parameters. The effectiveness of the proposed controller and collision avoidance strategy is evaluated through computer simulations. The simulation results show that the proposed strategy is efficient in stabilizing the robot in desired configuration and avoiding collision with obstacles, even in narrow spaces and complicated arrangement of obstacles.