Mobility enhancement design and control for a Dual-Wheel Dual-Armed Mobile Manipulator

Recently domestic Wheeled Mobile Robot(WMR) such as "iRobot Roomba Vacuum Cleaning Robot" is becoming popular. However, such WMR has poor mobility to surmount the obstacles like the door sill, which greatly limits its functionality. Instead of using complex wheel mechanisms, another possible solution is to use external manipulator. Mobile Manipulator(MM) is a robotic system combing the mobile robot and manipulator, hence inherits their natural advantages. Most researches payed attention to enhancing manipulability instead of enhancing the mobility of the hybrid mobile manipulator. In this paper we propose to use two manipulators to enhance the mobility of a WMR-Roomba to surmount the obstacle. The mobile manipulators can work in two different modes. When the mobile manipulator moves on flat ground, wheels are the main driving unit and can achieve high motion efficiency; When the WMR encounters the obstacle, manipulators are the main driving unit and can achieve high mobility. The design and control procedure of the Dual-Wheel Dual-Armed Mobile Manipulator(DWDAMM) is presented. By analyzing the kinematics of the Mobile Manipulators and using cubic polynomial interpolation method, the parameter design and trajectory planning problem are turned into an optimization problem. Simulation experiments were performed using MATLAB and SimMechanics. Results show that the proposed design and control method are effective and can enhance mobility of the original wheeled mobile robot.