Motion Analysis with Experimental Verification of the Hybrid Robot PEOPLER-II for Reversible Switch between Walk and Roll on Demand

Abstract

We propose a newly renovated mobile robot PEOPLER-II (Perpendicularly Oriented Planetary Legged Robot), and addresses its motion analysis for switching its locomotion from leg-type to wheel-type and vice versa. For the leg-type locomotion, particularly in a transitional state of sitting or standing, we propose a control method based on minimization of the total energy cost using the distribution of the motor power payload in the hip and knee joints, in addition to the method of keeping the same payload factor. Also, we discuss robot configurations for switching between the two locomotion types by considering environmental factors such as walking gaits, ground inclination angle and robot’s traveling direction. Knee joint position of a pivotal foot determines knee ahead and knee behind gaits. In each switch, we check such characteristics as the hip joint rotation direction, robot center trajectory, and necessary total power in a practical point of use. Then we build three beneficial switching cycles aiming for moderate use of a motor, rider’s comfort, and power saving. Finally, we demonstrate the switching by considering the aim and verify that the results of the analysis become useful for enabling switching on demand.