Development of an adaptive hexapod robot based on Follow-the-contact-point gait control and Timekeeper control

In this paper, a new control method for a hexapod robot walking on irregular terrain based on a human operator's foot-placement navigation is proposed and evaluated. The control method is based on the Follow-the-contact-point (FCP) gait control that operates on the principle that each leg follows the contact point of its foreleg. Hence, planning the contact points for all the legs are summarized to one of the front legs. To dedicate the FCP gait control to a hexapod robot, three control architectures are added. First, new constraints in the transition from a stance phase to a swing phase are added to maintain static stability when a leg leaves the ground. Second, a real-time posture control system for contacting legs is added. The third is an adaptive control to adjust the time elapsed in each control mode, by which specifications of deadlock-free and static stability are satisfied. The proposed control architecture is installed to a small hexapod robot, and its performance is evaluated through experiments wherein the robot walks on uneven terrain.