Energy based control strategies for mechanical systems

Currently, there is a need to develop new control strategies to face the challenges that arise from the growing robotic industry. Along with the increased complexity, these systems also contain non-linear characteristics. Thus, the use of linearization techniques are not enough for modelling and control. Furthermore, these systems typically contain components from different physical domains. To overcome these challenges, energy-based modelling techniques are used as  the energy is the common factor among all the different physical systems.

The Euler-Lagrange framework is used widely to develop control strategies from an energy setting-perspective for mechanical, electrical and electromechanical systems. However, this framework has a less clear physical structure than the port-Hamiltonian framework.

The port-Hamiltonian (PH) framework is used to developed energy-based control strategies as this provides a unified framework for modelling (non-linear) systems from different physical domains. Controls developed under PH framework show better and cleaner tuning properties, therefore, allowing better system performance.

Control designs for an underactuated mechanical system, i.e. systems with fewer inputs than degrees of freedom, are usually more complicated to develop than its counterpart, the fully actuated mechanical systems. Some approaches have been presented from a Euler-Lagrange framework but none of them from the port-Hamiltonian perspective.

This research will focus on developing energy-based control strategies for underactuated mechanical systems by using PH framework. Also, it will explore the performance of adaptive control developed under the PH framework.