Publications de Alireza Karimi

Data-driven control in atomic force microscopy using a genetic algorithm

Increasing the scanning speed in Atomic Force Microscopy (AFM) relies on improving the tracking performance in the vertical direction of motion. The lightly damped resonances of piezo-actuators utilized in AFM nano-positioning stages hinder the maximum ach ...

2025

High-precision control of a robotic arm using frequency-based data-driven methods

Alireza Karimi, Philippe Louis Schuchert

Next-generation motion control systems require fast and precise control. However, advanced control strategies often rely on complex and costly system models. Data-driven methods have been proposed to design high-performance controllers without requiring a ...

2025

Data-Driven LPV Control for Harmonic Disturbance Rejection in a Hybrid Isolation Platform

Alireza Karimi

A novel approach for linear parameter-varying (LPV) controller synthesis for adaptive rejection of frequency-varying sinusoidal disturbances is proposed. Only the frequency response data of a linear time-invariant (LTI) multiple-input-multiple-output (MIMO ...

2025

Data-Driven Control Synthesis using Koopman Operator: A Robust Approach

Alireza Karimi, Mert Eyuboglu, Nathan Russell Powell

This paper proposes a data-driven control design method for nonlinear systems that builds upon the Koopman operator framework. In particular, the Koopman operator is used to lift the nonlinear dynamics to a higher-dimensional space where the so-called obse ...

2024

Data-driven fixed-structure frequency-based H2 and H∞ controller design

Alireza Karimi, Philippe Louis Schuchert, Vaibhav Gupta

The frequency response data of a generalized system is used to design fixed-structure controllers for the H2 and H∞ synthesis problem. The minimization of the two and infinity norm of the transfer function between the exogenous inputs and performance outpu ...

Elsevier BV2024

Data-Driven Output Feedback Control Based on Behavioral Approach

Alireza Karimi

In this work, we propose a novel data-driven representation for general linear time-invariant (LTI) systems based on behavioral system theory. This representation relies solely on input-output data, eliminating the need for exact knowledge of the system st ...

2024

Upgrading SPHERE with the second stage AO system SAXO+: frequency-based data-driven controller for adaptive optics

Alireza Karimi, Vaibhav Gupta

This study introduces a novel frequency-based data-driven controller for adaptive optics, using power spectral density for optimization while ensuring stability criteria. It addresses disturbance rejection, command amplitude constraints and system transfer ...

SPIE2024

Achieving robustness against uncertain time delays using non-parametric IQCs

Alireza Karimi, Vaibhav Gupta

With increasing control applications in large-scale distributed and networked systems, the impact of uncertain time delay is ever-increasing. This paper proposes the use of a novel non-parametric Integral Quadratic Constraint (IQC) to achieve robustness ag ...

Institute of Electrical and Electronics Engineers Inc.2024

Data-driven frequency-based feedforward control design for a robotic arm joint

Alireza Karimi, Philippe Louis Schuchert

Next-generation motion control systems require fast and precise control, but advanced control strategies often rely on complex and expensive models. This paper proposes a data-driven approach to tune controllers for a joint used in a robotic arm. This is a ...

IEEE2024

Koopman-based Data-driven Robust Control of Nonlinear Systems Using Integral Quadratic Constraints

Alireza Karimi, Mert Eyuboglu

This paper introduces a novel method for data-driven robust control of nonlinear systems based on the Koopman operator, utilizing Integral Quadratic Constraints (IQCs). The Koopman operator theory facilitates the linear representation of nonlinear system d ...

2024

Transient Stability Analysis of Power-Synchronized PLL-Less Grid-Following Inverters

Alireza Karimi

In the realm of modern power systems, grid-connected inverters are essential for integrating renewable energy resources. While grid-following inverters (GFLIs) currently dominate the market, grid-forming inverters (GFMIs) are pivotal for technology future ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2024

Data-driven IQC-Based Robust Control Design for Hybrid Micro-disturbance Isolation Platform

Alireza Karimi, Elias Sebastian Klauser, Vaibhav Gupta

A novel approach for robust controller synthesis, which models uncertainty as an elliptical set, is proposed in the paper. Given a set of frequency response functions of linear time-invariant (LTI) multiple-input multiple-output (MIMO) systems, the approac ...

IEEE2023

Frequency domain LPV controller synthesis for a positioning system with uncertain scheduling parameters

Alireza Karimi, Philippe Louis Schuchert

Ever-increasing demands from the industry require better performance out of the same system to achieve a competitive advantage. In systems functioning at different operating points, a fundamental trade-off between robustness and performance can limit the a ...

Elsevier2023

Achieving Optimal Performance With Data-Driven Frequency-Based Control Synthesis Methods

Alireza Karimi, Philippe Louis Schuchert

Frequency Response Function (FRF)-based control synthesis methods for Linear Time-Invariant (LTI) systems have been widely used in control theory and industry. Recently, there has been renewed interest in these methods, employing numerical optimization too ...

Ieee-Inst Electrical Electronics Engineers Inc2023

Frequency-domain data-driven position-dependent controller synthesis for Cartesian Robots

Alireza Karimi, Philippe Louis Schuchert

Cartesian robots have position-dependent dynamics that should be accounted for in high performance applications. Traditional methods design Linear Time Invariant (LTI) controllers which are robustly stable with respect to position variations, but require a ...

2023

Direct Data-Driven Vibration Control for Adaptive Optics

Alireza Karimi, Vaibhav Gupta

Adaptive optics (AO) systems are used in ground- based telescopes to improve image resolutions, especially for long-exposure photography, by compensating for the effects of atmospheric turbulence and internal vibrations. Most current AO systems are based o ...

2023

Data-Driven Robust Passivity-Based Controller Design for Grid-Connected Converters

Alireza Karimi, Seyed Sohail Madani

Due to the integration of renewable-based Distributed Generation Units (DGUs), Energy Storage Systems (ESSs) and electric car charging stations, more and more power electronic converters are connected to the grid. In grids with a high penetration rate of t ...

2023

Data-driven IQC-Based Uncertainty Modelling for Robust Control Design

Alireza Karimi, Elias Sebastian Klauser, Vaibhav Gupta

A new approach is presented in the paper for modelling uncertainty as an elliptical set for robust controller synthesis. The method involves finding the best linear nominal model and the corresponding elliptical uncertainty set that is consistent with a se ...

2023

Linear Parameter-Varying Control of A Power-Synchronized Grid-Following Inverter

Alireza Karimi, Behrooz Bahrani

This paper proposes a Linear Parameter-Varying loop-shaping controller for a power-synchronized grid-following inverter (PSGFLI). This control strategy regulates the inverter output active and reactive power at the terminal instead of the point of connecti ...

2022

Data-driven distributed online learning control for islanded microgrids

Alireza Karimi, Seyed Sohail Madani, Dongdong Zheng

In this paper, a new discrete-time data-driven distributed learning control strategy for frequency/voltage regulation and active/reactive power sharing of islanded microgrids is proposed. Instead of using the static droop relationship and the conventional ...

2022