Dynamic Analysis of a Rimless Wheel on Randomly Generated Rough Terrain

Some modern walking robots are capable of walking over very rough terrain. However, these robots often require significantly more energy to do so than a human. Passive-dynamic walking robots are often quite energy-efficient, but are usually only able to walk over smooth surfaces. In this work, we examine the dynamics of a 2D rimless wheel, an often studied simple model for walking. This paper analyzes the motion of a rimless wheel on slanted ground with a roughness level that is significantly smaller than the dimensions of the rimless wheel itself. The roughness of the ground is randomly generated but bounded in magnitude. The minimum angle of inclination required for a rimless wheel to walk down both smooth and rough ramps is determined. The rimless wheel is capable of walking down a rough surface but requires higher angles of inclination than when it is walking on a smooth surface. For the rimless wheel we examined with 5 legs, the minimum slope required for a rough surface is 12.4% higher than that required for a smooth surface, and for 10 legs, the minimum slope for a rough surface is 40.83% higher than the smooth surface.