Step-climbing maneuver for transleg in the wheeled mode

Transleg is a transformable leg-wheel robot conceived to work in the unstructured environment. The steps exist all over this environment, so it is essential that Transleg has the ability to negotiate the steps. The step-climbing performance of Transleg in the wheeled mode is studied in this paper. Transleg owns four leg-wheel and one spine mechanisms, and only the leg-wheel mechanisms are used in the study of this paper. Each leg-wheel is actuated by two actuators. One is for driving the thigh in the legged locomotion and wheel in the wheeled locomotion. The other is for driving the shank in the legged locomotion. For the low steps, Transleg can climb easily, only driving the wheels. To find the height of step Transleg can climb in this way, it is driven to climb the steps with different heights. The results show that Transleg can cross steps whose heights are a little lower than the radius of its wheels 55mm in the wheeled mode. To climb the higher steps, a step-climbing maneuver is designed. In this maneuver, the shanks play an important role. Some simulations are done to verify this maneuver, and the results show that Transleg can negotiate the steps with the height of 94mm which are much higher than the radius of its wheels using this step-climbing maneuver.