Distributed Kinematic Motion Control of Multi-Robot Coordination Subject to Physical Constraints

This paper presents a kinematic motion control strategy for an n-axle Compliant Framed Modular wheeled Mobile Robot (CFMMR). This robot is essentially a passive-joint active-wheel snake robot where coordinated motion of the robot modules is critical for maximizing mobility and minimizing traction forces. A distributed master—slave kinematic motion control structure is proposed where the front axle module of the robot is the master and subsequent axle modules are slaves. An existing path manifold based controller is used to guide the motion of the master. Two steering algorithms with different specializations are then proposed for the slave modules. Performance of the steering algorithms is characterized based upon their capability to reduce traction forces, control final robot posture, and maneuver in a limited space. It is shown that these algorithms satisfy the physical constraints of the robot, which are characterized by path curvature and velocity limitations. Simulation and experimental results validate and characterize the performance of the algorithms.