Bearing-Based Leader-Follower Formation Tracking Control Using Elevation Angle

This paper studies the elevation angle-based formation tracking control of multi-agent systems. Unlike bearing-based formation control, which uses bearing vectors, formation control using elevation angles eliminates the need for a global coordinate frame. This is beneficial because the coordinate frames of individual agents are often not aligned. Previous studies on elevation angle-based formation control have predominantly focused on leaderless formations. By incorporating a leader-follower structure, follower agents can effectively track and move with leaders, allowing the formation to move together and maneuver through obstacles. We consider three types of agents: single-integrator, double-integrator, and nonholonomic robots. For agents with a single integrator model, we first propose a control law for stationary leaders case and then modify the proposed control law to address moving leaders. Finite-time convergence to the desired formation is guaranteed. We then consider agents with double-integrator dynamics and nonholonomic robots, showing asymptotic convergence to the desired formation. Simulation results are provided to validate the proposed control laws.