Unidrive modular robot: Dynamics, control, and experiments

In this paper, a control design methodology for the new class of modular robots so-called "unidrive modular robots" is introduced. Unidrive modular robots because of employing only a single drive for operating all the joints have a substantial advantage over regular modular robots in terms of the mass of each module. The drive is mounted at the robot base and all joints tap power from the single drive using clutches. By controlling the engagement time of the clutches, the position and velocity of the joints are regulated. In this work, a general state space model of the robot is first developed and then based on the theory of variable structure systems and sliding mode control a design methodology for local controllers is introduced. The control design technique is validated by experimental results.