Design and Experimental Evaluation of a Multi-Mode Mobile Robot Based on Eccentric Paddle Mechanism

In order to improve climbing performance of the robot in complex environments, the wheel-legged mechanism is gradually being widely used. In this letter, we simplify the previous eccentric paddle mechanism (ePaddle), and propose a 2-DOF ePaddle-based robot which integrates stability and maneuverability of wheeled robot and high step-climbing capability of legged robot. By means of 2-DOF ePaddle mechanism, this robot has three gaits of circular-wheeled (CW), passive-paddle-wheeled (PPW), and active-paddle-legged (APL). Based on the four-modules robot prototype, indoor and outdoor experiments are carried out. Results confirmed that three gaits are effective and feasible, and the robot has great step-climbing performance and environmental adaptability. According to the margin of slippage, step-climbing kinematics models under different gaits are proposed and the parametric analysis is carried out. Experimental results validate the accuracy of the obstacle-climbing model and the great ability of two-modules robot to climb steps. Performance criteria shows that the 2-DOF ePaddle-based robot has a significant improvement in step-climbing compared with 3-DOF ePaddle-based one.