Dynamics and distributed control of Tetrobot modular robots

This paper proposes a distributed control scheme for a highly redundant parallel Tetrobot mechanism. The architecture of the proposed distributed control is composed of processors dedicated to each module and a network used to communicate the information between the modules. Each processor computes the kinematics, dynamics and control input for the dedicated module using the subsystem dynamic model and the information communicated only from adjacent modules. The simulation results of set-point and tracking control are provided to demonstrate the feasibility of the proposed scheme and compared to centralized control. The results show that the controlled node reaches the desired position without a steady state error even though the convergence rate is slower than for the centralized scheme. To improve the problem caused by a local optimization technique, an iteration scheme of local optimization was also applied to obtain a global solution to generate the paths of uncontrolled nodes