Robust and ultrafast decentralized control

Decentralized control is linked to sensitivity reduction in unity feedback systems [1, 2]. It is proposed in this paper to extend this result to unstable invertible plants in order to also achieve ultrafast and robust control through a new control method. The present result is a multivariable extension of the single-input single-output case [3] which has been recently tested successfully at McGill University [4, 5]. It was shown that it is possible to get a time response with minimal overshoot and with settling time equal to rise time while keeping good stability margins. This design can be extended to a family of multivariable unstable invertible systems that are ultimately (i.e. at high frequency) diagonally dominant, ensuring decentralized control while using local (i.e. diagonal) controllers. Simulation results confirm the ultrafast, robust and decentralized control property.