Dynamic event-triggered linear formation stabilization for nonholonomic mobile robots

Formation control is critical for nonholonomic mobile robot systems. Existing approaches commonly rely on persistent motion excitation, such as nonzero linear velocity or self-rotation, to cope with nonholonomic constraints. This paper addresses the more challenging problem of formation stabilization, which precludes undesired persistent motions in a steady state. The objective is to drive a group of nonholonomic robots to a desired stationary formation while simultaneously achieving orientation consensus. Based on the leader follower linear formation framework, a distributed control strategy is developed for nonholonomic mobile robots. The nonholonomic constraints are addressed by incorporating position errors into the orientation controller, thereby avoiding undesired equilibria induced by the nonholonomic kinematics. Furthermore, a dual-condition dynamic event-triggered mechanism is developed to reduce communication load while guaranteeing global exponential stability and rigorously excluding Zeno behavior. Without relying on additional motion excitation, the proposed method enables nonholonomic mobile robots to achieve the desired formation. Numerical simulations are presented to validate the effectiveness of the proposed control strategy.