Control of a flexible spacecraft using discrete IDA-PBC design

This paper has two objectives, first synthesize a discrete-time IDA-PBC for an underactuated port-Hamiltonian system, and second stabilize the angular position of an experimental testbed used in aerospace engineering. Based on the energetic integrator, the discrete-time methodology that exactly preserves the passivity property is presented for a linear Hamiltonian system with physical damping. A stability condition is given when taking the desired Hamiltonian as Lyapunov candidate function. The model of the spacecraft is composed of a rigid central body actuated by a torque motor around the vertical axis with two flexible appendages and a local mass at the tip of each appendage. Experiments are carried out to assess the validity of the more theoretical design methodology. The results show that the performances of our design results are better compared to an emulation controller obtained by sample and hold or Tustin transformation of the continuous-time controller

Total Energy Shaping with Neural Interconnection and Damping Assignment - Passivity Based Control

In this work we exploit the universal approximation property of Neural Networks (NNs) to design interconnection and damping assignment (IDA) passivity-based control (PBC) schemes for fully-actuated mechanical systems in the port-Hamiltonian (pH) framework. To that end, we transform the IDA-PBC method into a supervised learning problem that solves the partial differential matching equations, and fulfills equilibrium assignment and Lyapunov stability conditions. A main consequence of this, is that the output of the learning algorithm has a clear control-theoretic interpretation in terms of passivity and Lyapunov stability. The proposed control design methodology is validated for mechanical systems of one and two degrees-of-freedom via numerical simulations.Comment: Accepted in 4th Annual Learning for Dynamics and Control (L4DC) Conferenc

Contributions to ida-pbc with adaptive control for underactuated mechanical systems

This master thesis is devoted to developing an adaptive control scheme for the well- known Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC) technique. The main objective of this adaptive scheme is to asymptotically stabilize a class of Underactuated Mechanical Systems (UMSs) in the presence of uncertainties (not necessarily matched). This class of UMSs is characterized by the solvability of the Partial Differential Equation (PDE) resulting from the IDA-PBC technique. Two propositions are stated in this work to design the adaptive IDA-PBC. One of the main properties of these propositions is that even though the parameter estimation conver- gence is not guaranteed, the adaptive IDA-PBC achieves asymptotic stabilization. To illustrate the effectiveness of these propositions, this work performs simulations of the Inertia Wheel Inverted Pendulum (IWIP) system, considering a time-dependent input disturbance, a type of physical damping, i.e., friction (not considered in the standard IDA-PBC methodology), and parameter uncertainties in the system (e.g., inertia).Tesi