Guaranteed collision-free trajectory tracking of multiple nonholonomic WMRs subject to multiple constraints

The ability to avoid the possible impending collision should be essential for a team of wheeled mobile robots (WMRs) while they execute the trajectory tracking task. Conflict and congestion induced by the same path competition are major challenges in collision avoidance. To cope with these challenges, this paper proposes a time-varying position-based simultaneous obstacle avoidance and trajectory tracking (TV-SOATT) method that coordinates WMRs’ velocities. The proposed TV-SOATT method provides the motion-liveness and safety by introducing the radial bounds for reaching the desired trajectory and forecasting a collision. The pause or wander problem of the WMRs resulting from the path conflict is solved. Multiple illustration examples verify that all WMRs can adaptively adjust their respective positions to satisfy various constraints, achieving collision-free trajectory tracking. Extensive comparison illustrates effectiveness and superiority of our method.