Study of Hopping Mechanics for Different Terrain Conditions for Hopping on a Low-Gravity Surface

To enhance mobility on a low-gravity surface, we are exploring a concept of a Bio-Inspired Hopping Robot (BIHR), which is a robot that utilizes the hopping motion of animals, particularly kangaroos and grasshoppers, as the primary mode of locomotion. Taking advantage of the low-gravity environment, the BIHR robot can travel for a much larger distance in a much shorter time than a conventional wheeled rover on an unstructured, uneven and steep terrain. This paper presents a study to reveal how the terrain’s mechanics properties affect the outcome of the hopping effort of a leg design. This knowledge is necessary for prediction of hopping mobility in different terrain conditions, and thus contributes to the design of the robot and its intended missions. We started the research with an experimental approach by designing and testing a single leg mechanism. The prototype leg consists of three leg segments (thigh, shin and foot) and three connecting joints. The leg is attached to a fixed test stand and has the capability to perform a single hop in the vertical direction. The base of the test stand can be covered with a variety of terrain materials ranging from a solid rocky surface to a thick layer of fine powder in order to evaluate how the leg/foot will perform on different types of terrain conditions.