Optimization-Based Flocking Control and MPC-Based Gait Synchronization Control for Multiple Quadruped Robots

In this letter, we focus on the flocking control and gait synchronization control of multiple quadruped robots to achieve the movement during patrol tasks. To achieve these goals, we propose an optimization-based distributed flocking controller and a model predictive control (MPC)-based gait synchronization controller. A constrained omnidirectional motion kinematic model is employed to simplify the model of a single quadruped robot. In the flocking controller, position and orientation consistency among the quadruped robots are considered. The constraint is designed to minimize the lateral movement velocity of the quadruped robots. As each robot approaches the destination, it maintains alignment of its orientation with the destination. Additionally, a control barrier function (CBF) is designed to maintain a safe distance between the quadruped robots. Moreover, the proposed MPC-based gait synchronization controller effectively achieves gait synchronization among multiple quadruped robots. Simulation and real world experiments demonstrate the effectiveness of the proposed algorithm.