Many control problems are naturally expressed in continuous time. Yet, in Iterative Learning Control of linear systems, sampling the output signal has proven to be a convenient strategy to simplify the learning process while sacrificing only marginally the overall performance. In this context, the control action is similarly discretized through zero-order hold - thus leading to a discrete-time system. With this paper, we want to investigate an alternative strategy, which is to track sampled outputs without masking the continuous nature of the input. Instead, we look at the whole input evolution as an element of a functional subspace. We show how standard results in linear Iterative Learning Control naturally extend to this context. As a result, we can leverage the infinite-dimensional nature of functional spaces to achieve exact tracking of strongly non-square systems (number of inputs less than outputs). We also show that constraints - like those imposed by intermittent control - can be naturally integrated within this framework.

JF - 2021 60th IEEE Conference on Decision and Control (CDC) PB - IEEE UR - https://ieeexplore.ieee.org/document/9683673 ER - TY - JOUR T1 - Control architecture for human-like motion with applications to articulated soft robots JF - Frontiers in Robotics and AI Y1 - 2020 A1 - Angelini, Franco A1 - Della Santina, Cosimo A1 - Garabini, Manolo A1 - Bianchi, Matteo A1 - Bicchi, Antonio VL - 7 ER - TY - CONF T1 - Iterative learning control as a framework for human-inspired control with bio-mimetic actuators T2 - Conference on Biomimetic and Biohybrid Systems Y1 - 2020 A1 - Angelini, Franco A1 - Bianchi, Matteo A1 - Garabini, Manolo A1 - Bicchi, Antonio A1 - Della Santina, Cosimo JF - Conference on Biomimetic and Biohybrid Systems PB - Springer ER - TY - JOUR T1 - Time generalization of trajectories learned on articulated soft robots JF - IEEE Robotics and Automation Letters Y1 - 2020 A1 - Angelini, Franco A1 - Mengacci, Riccardo A1 - Della Santina, Cosimo A1 - Catalano, Manuel G A1 - Garabini, Manolo A1 - Bicchi, Antonio A1 - Grioli, Giorgio VL - 5 ER -