Constant Time Delay Leader Following for Mobile Robots by using Model Predictive Control Tuned on Estimation Uncertainties
Robotics, Autonomous Systems
This work presents a constant time delay leader-follower system for wheeled mobile robots that can be used in a military vehicle convoy. It allows a follower vehicle to follow the same trajectory travelled by a leader with a speci ed time delay by estimating a sequence of waypoints travelled by the leader. This work focuses on the design of the two major components of the leader-follower system: the estimator and the controller. Di erent from previous works on constant time delay leaderfollower systems, where the two components are designed relatively independently, we propose a design that connects the two components by having a model predictive controller (MPC) whose tuning is based on the uncertainties of the estimated leader waypoints. By weighting the waypoint states in the MPC cost function as inversely proportional to their uncertainties, we achieve better tracking performance under the condition of noisy odometry sensor data compared to the traditional practice equallyweighted state errors. This approach reduces the dependence on empirical tuning and performance was studied both in simulation and on real robots in representative o - road environments. Currently, the system is designed to track the linear, longitudinal trajectories of the leader, as a starting point for tracking nonlinear trajectories in future work.