1,103 research outputs found
Full-Order Observer Design for a Class of Nonlinear Port-Hamiltonian Systems
In this paper, we present a simple method to design a full-order observer for a class of nonlinear port-Hamiltonian systems (PHSs). We provide a sufficient condition for the observer to be globally exponentially convergent. This condition exploits the natural damping of the system. The observer and its design are illustrated by means of an academic example system. Numerical simulations verify the convergence of the reconstructions towards the unknown system variables
Port-Hamiltonian modeling for soft-finger manipulation
In this paper, we present a port-Hamiltonian model of a multi-fingered robotic hand, with soft-pads, while grasping and manipulating an object. The algebraic constraints of the interconnected systems are represented by a geometric object, called Dirac structure. This provides a powerful way to describe the non-contact to contact transition and contact viscoelasticity, by using the concepts of energy flows and power preserving interconnections. Using the port based model, an Intrinsically Passive Controller (IPC) is used to control the internal forces. Simulation results validate the model and demonstrate the effectiveness of the port-based approach
Putting energy back in control
A control system design technique using the principle of energy balancing was analyzed. Passivity-based control (PBC) techniques were used to analyze complex systems by decomposing them into simpler sub systems, which upon interconnection and total energy addition were helpful in determining the overall system behavior. An attempt to identify physical obstacles that hampered the use of PBC in applications other than mechanical systems was carried out. The technique was applicable to systems which were stabilized with passive controllers
Permanent Magnet Synchronous Motors are Globally Asymptotically Stabilizable with PI Current Control
This note shows that the industry standard desired equilibrium for permanent
magnet synchronous motors (i.e., maximum torque per Ampere) can be globally
asymptotically stabilized with a PI control around the current errors, provided
some viscous friction (possibly small) is present in the rotor dynamics and the
proportional gain of the PI is suitably chosen. Instrumental to establish this
surprising result is the proof that the map from voltages to currents of the
incremental model of the motor satisfies some passivity properties. The
analysis relies on basic Lyapunov theory making the result available to a wide
audience
Full-Order Observer Design for a Class of Nonlinear Port-Hamiltonian Systems
In this paper, we present a simple method to design a full-order observer for a class of nonlinear port-Hamiltonian systems (PHSs). We provide a sufficient condition for the observer to be globally exponentially convergent. This condition exploits the natural damping of the system. The observer and its design are illustrated by means of an academic example system. Numerical simulations verify the convergence of the reconstructions towards the unknown system variables
Linear Matrix Inequality Design of Exponentially Stabilizing Observer-Based State Feedback Port-Hamiltonian Controllers
The design of an observer-based state feedback (OBSF) controller with
guaranteed passivity properties for port-Hamiltonian systems (PHS) is addressed
using linear matrix inequalities (LMIs). The observer gain is freely chosen and
the LMIs conditions such that the state feedback is equivalent to control by
interconnection with an input strictly passive (ISP) and/or an output strictly
passive (OSP) and zero state detectable (ZSD) port-Hamiltonian controller are
established. It is shown that the proposed controller exponentially stabilizes
a class of infinite-dimensional PHS and asymptotically stabilizes a class of
finite-dimensional non-linear PHS. A Timoshenko beam model and a
microelectromechanical system are used to illustrate the proposed approach
Twenty years of distributed port-Hamiltonian systems:A literature review
The port-Hamiltonian (pH) theory for distributed parameter systems has developed greatly in the past two decades. The theory has been successfully extended from finite-dimensional to infinite-dimensional systems through a lot of research efforts. This article collects the different research studies carried out for distributed pH systems. We classify over a hundred and fifty studies based on different research focuses ranging from modeling, discretization, control and theoretical foundations. This literature review highlights the wide applicability of the pH systems theory to complex systems with multi-physical domains using the same tools and language. We also supplement this article with a bibliographical database including all papers reviewed in this paper classified in their respective groups
Energy-based Modeling and Control of Interactive Aerial Robots:A Geometric Port-Hamiltonian Approach
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