Implementation of a leader-follower controller for a skid-steering wheel-legged robot

In this paper, we present a leader-follower controller for the Micro-Hydraulic Toolkit (MHT), a skid-steering wheel-legged robot designed by Defence Research and Development Canada - Suffield Research Centre. The objective of the controller is to maneuver the MHT towards a desired position with respect to a designated leader. Using the range and bearing of the leader from the robot, the leader-follower controller computes the desired wheel velocities of the MHT to achieve leader-follower formation control. In addition to performing wheeled locomotion to follow the leader, the MHT is capable of using its legs to reconfigure its posture. Thus, moving beyond standard implementations, the leader-follower control strategy presented in this paper is combined with a velocity-based inverse kinematics controller developed in previous work to control the posture of the MHT during leader-follower maneuvers. The results of the leader-follower scenarios implemented in simulation and on the physical MHT demonstrate the robot's ability to execute leader-follower formation control and posture control simultaneously, adding to the versatility of the vehicle to negotiate uneven terrains.