Techniques for dynamic maneuvering of hexapedal legged robots

Legged locomotion is a very important mode of transportation which can reach a larger percentage of the terrestrial world than wheeled and tracked vehicles, though they may be quicker and more efficient in some situations. Biomimetics is the application of principles learned in biological systems to manmade systems. The Sprawl family of robots are inspired by research on cockroaches and other agile runners. Studies on these robots have led to design improvements and robot parameter tuning that achieves the best performance from the various members. However, the area of maneuverability had been overlooked. Without maneuverability, these robots are limited to straight running and stability investigations. The experiments are far from trivial, but with maneuverability these studies gain additional real-world applicability. Biologists investigations have given insight into the ways that cockroaches run and turn. Cockroaches maintain an alternating tripod gait, but shift the foot placement and sweep angle of the legs in order to change the turning moment about their center of mass. Because of their performance and versatility, the Sprawlettes and iSprawl, two members of the Sprawl family, serve as a good platforms to study biomimetic inspired maneuvers.; In this thesis, the dynamic maneuverability of the Sprawlettes is thoroughly investigated. First, parameter reduction using Design of Experiment techniques identified the effectiveness of ipsilateral leg angles. The workspace and use of these parameters was examined to enable these 3 parameters to be reduced to a single turnfactor variable which moves smoothly through the workspace and provides a full range of turning behavior. This analysis involved experiments on the robots and in simulation to help expedite the process. As iSprawl came to fruition, it was included in these analyses for comparison and greater insight on legged maneuverability. System identification techniques have been applied to identify bandwidth limitations (∼1-3Hz for both systems) and characterize the turning dynamics. The similarities and differences in the Sprawlettes and iSprawl have contributed to the understanding and explanation of turning behavior for dynamic legged robots. Using the information gained in the process, dynamic maneuverability concepts were developed and tested to aid future investigations in this relatively new field.