Cooperative transportation of an object with a nonholonomic constraint by a swarm of nonholonomic robots

Abstract

In this paper, we propose a novel distributed method for cooperative transportation of an object with passive fixed wheels using a swarm of nonholonomic differential-drive wheeled robots. Because each robot and the transported object have wheels fixed to them and do not slide along the axle direction, their velocity constraints are nonholonomic. Therefore, when the robots transport the object, all velocity constraints of the robots and the object must be satisfied simultaneously. Then, we propose a method that enables transporting the object while satisfying the constraints. Each robot finds the object’s instant center of rotation from the object’s desired velocity and angular velocity, and each robot finds its velocity input and angular velocity input to move while attaching to the object and directing each robot’s axle to the instant center of rotation. Each robot moves with its velocity input and angular velocity input, and robots transport the object. We verified the effectiveness of the proposed method in dynamic simulations.