Relative Displacement Measurement Based Affine Formation Tracking Control for Nonholonomic Kinematic Agents

This paper investigates the affine formation tracking control problem based on the relative displacement measurements for multiple nonholonomic unicycle-type agents. We assume a subset of the agents, the leaders, are completely controlled in the desired affine formation. The control scheme designed for the followers is based on relative measurements, which assists to improve the practicability of the affine formation control approach with various sensing conditions. The proposed control scheme consists of an estimator for the reference position and a displacement-based controller. The reference control law provides a baseline for the time-varying formation tracking control. Then, a distributed controller is designed combined with the relative displacement measurements. Our stability analyses confirm the convergence of the control scheme to the target affine formation while tracking the leaders. Finally, simulations are carried out and the effectiveness of our control approach is verified.