Roland Longchamp

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Related publications (32)

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Data-Driven Controller Tuning Using Frequency Domain Specifications

Alireza Karimi, Roland Longchamp, Daniel Garcia

A model-free PID controller tuning approach is presented in this paper. The method can handle different stability and performance indicators in the frequency domain. The phase margin, gain margin, crossover frequency and more advanced indicators which are ...

2006

On the Consistency of Certain Identification Methods for Linear Parameter Varying Systems

Alireza Karimi, Roland Longchamp

The consistency of certain identification methods for Linear Parameter Varying systems is considered. More precisely, methods for the identification of SISO input-output models are analysed. In order to perform a consistency analysis the application of erg ...

2008

A Comparison of Iterative Learning Control Algorithms with application to a Linear Motor System

Alireza Karimi, Roland Longchamp

Iterative Learning Control (ILC) is a technique used to improve the tracking performance of systems carrying out repetitive tasks, which are affected by deterministic disturbances. The achievable performance is greatly degraded, however, when non-repeating ...

2006

Data-driven Precompensator Tuning for Linear Parameter Varying Systems

Alireza Karimi, Roland Longchamp

Methods for direct data-driven tuning of the parameters of precompensators for LPV systems are developed. Since the commutativity property is not always satisfied for LPV systems, previously proposed methods for LTI systems that use this property cannot be ...

IEEE2008

Fixed-Order Controller Design for Polytopic Systems Using Rank Deficiency in a Sylvester Matrix

Alireza Karimi, Roland Longchamp

Fixed-order controller design for LTI-SISO polytopic systems is investigated using rank deficiency constraint on the controller Sylvester resultant matrix. It is shown that the non-convexity of fixed-order controller design problem can be gathered in a ran ...

2008

Friction Modeling of a High-Precision Positioning System

Alireza Karimi, Roland Longchamp, Alain Curnier, Marc Kunze

Friction modeling of a high-precision positioning system using linear permanent magnet synchronous motors is investigated. The friction force is measured precisely by some specific experiments to eliminate the parasitic ripple force. The experimental data ...

2006

Modeling and Control of a Magnetically Levitated Planar Motor

Alireza Karimi, Roland Longchamp, Marc Kunze

This paper deals with the modeling and control of a magnetically levitated planar motor. The actuator considered has moving coils and stationary magnets. The principal objective is to develop a model which can be implemented in simulation. Therefore, the d ...

2009

Iterative Learning Control based on Stochastic Approximation

Alireza Karimi, Roland Longchamp

In this paper stochastic approximation theory is used to produce Iterative Learning Control algorithms which are less sensitive to stochastic disturbances, a typical problem for the learning process of standard ILC algorithms. Two algorithms are developed, ...

2008

Robust PID Controller Design by Linear Programming

Alireza Karimi, Roland Longchamp, Marc Kunze

A linear programming approach is proposed to tune fixed-order linearly parameterized controllers for stable LTI plants. The method is based on the shaping of the open-loop transfer function in the Nyquist diagram. A lower bound on the crossover frequency a ...

2006

RST Controller Design by Convex Optimization Using Frequency-Domain Data

Alireza Karimi, Roland Longchamp, Gorka Galdos Sanz de Galdeano

A new robust fixed-order RST controller design approach by convex optimization is proposed in this paper. Only frequency-domain data are considered in the approach for linear time-invariant single-input single-output systems. It is shown that performance s ...

2011

Interactive applications in a mandatory control course

Roland Longchamp, Yves Henri Philippe Piguet

This paper describes how a mandatory control course is enhanced with interactive applications. Basic concepts of automatic control, different ways to assess performance and robustness of a controlled system, and limits of closed- loop systems are illustrat ...

2006

Commande sous-optimale adaptative de systèmes non linéaires

Roland Longchamp

EPFL1978