A Hybrid Multirobot Control Architecture for Object Transport

A hybrid force/position control architecture for object transportation by a mobile robot formation is introduced. The architecture consists of an object level controller that computes actuation forces/torques to push an object along a desired path. These desired forces/torques are provided to a multirobot actuation subsystem that uses a closed-loop hybrid force/position controller to generate commands for individual robots within the subsystem. Accordingly, these robots apply the required net force and torque to the object while also maintaining relative positions with respect to themselves and to the object, thereby ensuring stable motion and efficient torque generation. This novel use of a hybrid controller for the mobile multirobot cluster prevents large environmental forces on the object. Furthermore, abstraction of the cluster as an actuator enhances flexibility, making design of the object controller independent of the number, location, and maneuverability of individual robots. The architecture is validated experimentally.