Rifat Sipahi

ORCID: 0000-0001-9307-5324
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About
Contact & Profiles
Research Areas
  • Stability and Control of Uncertain Systems
  • Nonlinear Dynamics and Pattern Formation
  • Traffic control and management
  • Distributed Control Multi-Agent Systems
  • Neural Networks Stability and Synchronization
  • Transportation Planning and Optimization
  • Numerical methods for differential equations
  • Stability and Controllability of Differential Equations
  • Adaptive Control of Nonlinear Systems
  • Advanced Control Systems Design
  • Control and Stability of Dynamical Systems
  • Advanced Control Systems Optimization
  • Quantum chaos and dynamical systems
  • Control Systems and Identification
  • Advanced Differential Equations and Dynamical Systems
  • Human-Automation Interaction and Safety
  • Advanced Queuing Theory Analysis
  • Power System Optimization and Stability
  • Matrix Theory and Algorithms
  • Vehicle Dynamics and Control Systems
  • Traffic Prediction and Management Techniques
  • Supply Chain and Inventory Management
  • Autonomous Vehicle Technology and Safety
  • Petri Nets in System Modeling
  • Scheduling and Optimization Algorithms

Northeastern University
2015-2024

Universidad del Noreste
2017-2024

New York University
2020

Massachusetts General Hospital
2016

Boston University
2009-2014

Boston Medical Center
2014

University Medical Center
2014

Boston Engineering (United States)
2011

University of Connecticut
2002-2008

Université de Technologie de Compiègne
2006-2007

A general class of linear time invariant systems with delay is studied. Recently, they attracted considerable interest in the and control community. The complexity arises due to exponential type transcendental terms their characteristic equation. transcendentality brings infinitely many roots, which are cumbersome elaborate as evident from literature. number methodologies have been suggested limited ability assess stability parametric domain delay. This study offers an exact, structured...

10.1109/tac.2002.1000275 article EN IEEE Transactions on Automatic Control 2002-05-01

Time-delays are important components of many dynamical systems that describe coupling or interconnection between dynamics, propagation, transport phenomena in shared environments, heredity, and competition population dynamics. This monograph addresses the problem stability analysis stabilisation subjected to time-delays. It presents a wide self-contained panorama analytical methods computational algorithms using unified eigenvalue-based approach illustrated by examples applications...

10.1109/mcs.2010.939135 article EN IEEE Control Systems 2011-01-13

Stability analysis of a single-lane microscopic car-following model is studied analytically from the perspective delayed reactions human drivers. In literature, drivers are modeled with discrete delays, which assume that make their control decisions based on stimuli they receive point time in history. We improve this by introducing distribution assumes actions information distributed over an interval Such assumption more realistic, as it takes into consideration memory capabilities and...

10.1137/060673813 article EN SIAM Journal on Applied Mathematics 2007-12-20

An intriguing perspective is presented in studying the stability robustness of systems with multiple independent and uncertain delays. It based on a holographic mapping, which implemented over domain This mapping considerably alleviates problem, otherwise known to be notoriously complex. creates dramatic reduction dimension problem from infinity manageably small number. Ultimately process reduced within finite dimensional cube edges length 2pi new domain, what we call building block. In...

10.1109/tac.2007.898076 article EN IEEE Transactions on Automatic Control 2007-05-01

This note presents a design technique for the delay-based controller called proportional integral retarded (PIR), which solves regulation problem of general class stable second-order LTI systems. Using spectral analysis, yields tuning strategy PIR by placing triple real dominant root closed-loop system. result ultimately guarantees desired exponential decay rate σ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</sub> while achieving as an...

10.1109/tac.2015.2478130 article EN IEEE Transactions on Automatic Control 2015-09-14

Delay-independent stability (DIS) of a general class linear time-invariant (LTI) multiple time-delay system (MTDS) is investigated in the entire delay-parameter space. Stability such systems may be lost only if their spectrum lies on imaginary axis for some delays. We build an analytical approach that requires inspection roots finite number single-variable polynomials order to detect ever delays, excluding infinite The enables test necessary and sufficient conditions DIS LTI-MTDS,...

10.1109/tac.2011.2168992 article EN IEEE Transactions on Automatic Control 2011-09-28

The occurrence of the regenerative chatter phenomenon in milling process is studied for cutters with non-uniform distribution (called variable-pitch cutters). dynamic model developed and evaluated from stability point view. mathematical characterization problem falls within a general class delay differential equations (DDE) multiple rationally independent delays. contribution this paper adoption mathematically novel very recent paradigm to determine analytically bounds stable versus unstable...

10.1177/1077546307078754 article EN Journal of Vibration and Control 2007-07-01

A consensus-control protocol is designed and implemented here on a three-robot system arranged horizontal platform, in which camera used to track robot positions, personal computer broadcasts commands the robots based this via Bluetooth connection, where such are affected by time delays. The design involves some salient features of graph-based approach, an input-output linearization scheme, addressing uncertainties control problem. By implementing experiments, we show that consensus can be...

10.1109/tcst.2015.2458776 article EN publisher-specific-oa IEEE Transactions on Control Systems Technology 2015-08-14

This paper explores the deliberate introduction of delays in feedback loops and their positive impact on linear time-invariant, single-input, single-output (LTI-SISO) systems. The delay, considered as a design parameter, is intentionally induced using class delay-based controllers, aiming at improving closed-loop system performance by deploying pole-placement technique to attain fastest velocity response control commands. technique, based an algebraic geometric analysis, able extract exact...

10.1137/15m1050999 article EN SIAM Journal on Control and Optimization 2017-01-01

This article considers the containment of heterogeneous linear time-invariant multi-human multi-agent systems with a distributed dynamic state feedback control law. The unique aspect this problem lies in presence multiple human operators. Each operator commands subset agents while observing same or different subset. Commanding based on their observation approach operators makes them integral components network rather than simple providers reference signals. setup requires new set conditions...

10.1109/tsmc.2024.3358232 article EN IEEE Transactions on Systems Man and Cybernetics Systems 2024-02-16

A new methodology, advanced clustering with frequency sweeping (ACFS), is introduced for the stability analysis of most general class linear time-invariant time-delay systems multiple delays. ACFS a cross fertilization algebraic geometry, technique and root paradigm, it can directly extract 2-D sections views in any two-delay domain. In this domain, also test delay-independent based on necessary sufficient conditions, compute, delay-dependent case, precise lower upper bounds only parameter,...

10.1109/tac.2010.2090734 article EN IEEE Transactions on Automatic Control 2010-11-10

We investigate the use of a derivative-free control scheme called multiple-delay proportional-retarded (PR) protocol to achieve fast consensus in large-scale multiagent system. The delays are intentionally introduced PR with purpose creating derivative-like controllers that rely only on position measurements, thus mitigating undesirable noise effects. main result places spectral abscissa dynamics at desired locus and also achieves user-defined "separation," both which directly influence...

10.1109/tcyb.2018.2798163 article EN publisher-specific-oa IEEE Transactions on Cybernetics 2018-02-21

A novel analytical tool is presented to assess the stability of simultaneous machining (SM) dynamics, which also known as parallel machining. In SM, multiple cutting tools, are driven by spindles at different speeds, operate on same workpiece. Its superior efficiency main reason for using SM compared with traditional single (STM). When optimized in sense maximizing rate metal removal constrained machined surface quality, typical “chatter instability” phenomenon appears. Chatter instability...

10.1115/1.2037086 article EN Journal of Manufacturing Science and Engineering 2005-02-15

A trajectory-tracking problem is considered for a linear time invariant (LTI) dynamics with fixed control law. However, the feedback line affected by multiple delays. The stability of becomes complex problem. It well known that time-delayed LTI systems may exhibit stable operating zones (which we call pockets) in space Our aim this paper to locate and experimentally validate these pockets. For analytical determination pockets utilize new methodology, cluster treatment characteristic roots...

10.1177/1077546305055777 article EN Journal of Vibration and Control 2005-08-18

10.1016/j.ijpe.2009.07.013 article EN International Journal of Production Economics 2009-08-13

This study investigates the stability of a class single-delay interconnected dynamics where share only delayed information with each other while seeking consensus in large scale network fixed topology. The coupled dynamics, which are infinite dimensional because presence delays, can remain stable for at most certain amount delays called delay margin. margin is intricately determined by nature connectivity and coupling strengths among dynamics. Here we present systematic approach to correlate...

10.1049/iet-cta.2010.0202 article EN IET Control Theory and Applications 2011-03-03
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