Investigation of Effects of Changing Length Scales of Uniformly Structured Rough Terrain on Hexapedal Locomotion using Simulation

Despite of having higher complexity, in both morphology and control strategies, bioinspired hexapod robots offer advantages such as higher mobility, omni-directional locomotion, ability to climb over obstacles, and greater adaptability to terrain and environment changes. While there have been numerous studies investigating the locomotion of hexapods over rough terrain utilizing exteroceptive sensing for terrain mapping and calculating optimum leg trajectories for unobstructed and fast locomotion, there have been none to study the locomotion over structured terrain, where structured terrain suggests terrain samples where surface features repeat in an alternating pattern in all directions giving rise to a checkerboard of surface structures. This study investigated the locomotion of a hexapod implementing an open-loop alternating tripod gait using a rigid body simulation package – V-REP. Different parameters of the robot locomotion were recorded while it navigated the generated terrain samples with grid sizes ranging from 0.16 times the stride length to 3.33 times the stride length. The results indicate that when the stride length was more than the substrate feature size, the nature of leg-surface interactions governed the speed, while the rate of the leg-surface interactions influenced the locomotion when the stride length was smaller than the surface feature size