Design and Implementation of a Two-Wheel and Hopping Robot with a Linkage Mechanism

Wheeled robots exhibit fast and stable motion on a flat road but lack the ability to overcome the obstacles and rough terrains. To address this shortage, a two-wheel hopping robot is proposed by combining the wheel locomotion and bounce movement. A gear train and a four-bar linkage are employed for jumping. In particular, the take-off angle is dependent on the link length of the four-bar linkage, thus providing versatile flight trajectories. Therefore, the dependency of the hopping performance on the four-bar linkage can be maximized. A four-bar linkage with the same length is used for the specific trajectory and balance control of the inverted pendulum model of the prototype. Dynamics analyses and simulations have been conducted to verify the robot design and its parameters. By jumping tests, the hopping performance is compared with other robots in a quantitative manner. The experimental results show that the wheeled hopping robot has the advantages of light mass and jumping height efficiency.