Design of digital controllers for MIMO nonlinear time-varying systems based on dynamic contraction method

The design of digital controllers based on the Dynamic Contraction Method for continuous-time multi-input multi-output nonlinear time-varying systems is presented. The control task is formulated as a tracing problem for output variables, where the desired decoupled output transients are accomplished under assumption of incomplete information about varying parameters of the system and external disturbances. The resulting continuous-time controller, which has a form of a low-order linear dynamical system followed by a matrix, is then digitally redesigned. The pseudo - continuous - time model of a control loop with a pure time delay is used to calculate the digital controller parameters.