Showing papers by "Olav Egeland published in 2005"
TL;DR: In this paper, a method for generating a new and efficient time-domain formulation of the equations of motion for a vessel with frequency-dependent hydrodynamic coefficients is presented. But this method relies on the use of convolution terms, whereas in this work state-space models are used.
117 citations
08 Jun 2005
TL;DR: In this paper, the observer design for a flexible robot arm with a tip load is considered, where the robot arm is modeled as an Euler-Bernoulli beam and clamped to a motor at one end and attached to a force actuator at the other.
Abstract: In this paper, we consider the observer design for a flexible robot arm with a tip load. The robot arm is modeled as an Euler-Bernoulli beam. The beam is clamped to a motor at one end and attached to a force actuator at the other. Based on measurements at the boundaries, an exponentially stable observer is proposed. The existence, uniqueness and stability of solutions of the proposed observer are based on semigroup theory. Numerical simulation results are included to illustrate the performance of the proposed observer.
18 citations
12 Dec 2005
TL;DR: In this paper, the problem of output feedback tracking control of an Euler-Bernoulli beam is addressed, and a tracking controller which allows the robot arm to follow time-varying references and damp out the elastic vibrations is designed.
Abstract: In this paper, we address the problem of output feedback tracking control of a. The robot arm is modeled as an Euler-Bernoulli beam. The beam is clamped to amotor at one end and attached to a force actuator at the other. Based on measurements at the boundaries, a uniformly exponentially stable observer is proposed. Using the information from the observer, a tracking controller which allows the robot arm to follow time-varying references and damp out the elastic vibrations is designed. The existence, uniqueness and stability of solutions of the closed loop system and the observer are based on semi group theory. Numericals imulation results are included to illustrate the performance of the proposed control laws and the proposed observer. The simulation results are in agreement with the theoretical results.
12 citations
10 Jan 2005
11 citations
18 Sep 2005
TL;DR: In this paper, an efficient state-space formulation is presented to represent frequency-dependent added mass and potential damping in the equations of motion for a surface ship, which is of interest in design of marine control systems and in real-time simulators of marine systems.
Abstract: In this paper, efficient state-space formulations are presented to represent frequency-dependent added mass and potential damping in the equations of motion for a surface ship. This is of interest in design of marine control systems, and in real-time simulators of marine systems. We investigate the structural properties, e.g. passivity, of the radiation forces. Subsequently we look at the state-space realizations of the radiation forces, and how the structural properties are contained in these models. The state-space models are of high order and it is necessary to use model reduction techniques to make them efficient for computer simulation and control synthesis. Finally, we investigate different model reduction procedures applied on the state-space models of the radiation forces, and compare them in terms of accuracy, complexity and algorithm cost.
4 citations