Development of a Running Hexapod Robot with Differentiated Front and Hind Leg Morphology and Functionality

Abstract

This article introduces an innovative model-based strategy for designing a legged robot to generate animal-like running dynamics with differentiated leg braking and thrusting force patterns. Linear springs were utilized as legs, but instead of having one end of each spring connected directly to the hip joint, one extra bar was added to offset the spring's direction. The robot's front and hind legs were offset with the same magnitudes but in different directions. Therefore, the legs produced different ground braking and thrusting force patterns. The robot's running motion was planned based on its reduced-order model. The model's fixed-point and passive-dynamics motion served as the robot's reference motion. The proposed strategy was experimentally validated, and the results confirmed that the robot could successfully perform stable running in a differentiated leg force pattern.