Sliding Mode Formation Control of Mobile Robots with Input Delays

Group of robots have become important platforms in applications such as search and rescue, active mapping, and load transportation. Maintaining the group formation while tracking prescribed trajectories is critical in these applications. The performance of the formation can be compromised due to time-delays present in the natural response of the internal actuators. Furthermore, the stability of the system can be compromised. In this work, we proposed a cascade control scheme to tackle an input delay in the kinematics of the mobile robots. An inner velocity control loop is designed based on an approximation for the input delay, while an outer loop takes care of maintaining the shape and posture of the formation. We validate our approach by comparing the performance of our control methodology in simulation with a standard PI and a sliding controller under the assumption of different values input delays.