On the decoupling of linear time-varying control systems

Some recent results concerning the input-output decoupling problem of time-invariaut systems, for which the decoupling matrix B* is not invertible, are extended to time-varying systems. It is shown that the maximum number of input-output pairs which can be decoupled by linear state feedback is equal to rank B*(t) = r , where r is assumed to be constant over the entire time interval of interest. An illustrative example is provided.