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Articles 1 - 18 of 18
Full-Text Articles in Controls and Control Theory
Some Insights Into The Migration Of Double Imaginary Roots Under Small Deviation Of Two Parameters, Dina Alina Irofti, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu
Some Insights Into The Migration Of Double Imaginary Roots Under Small Deviation Of Two Parameters, Dina Alina Irofti, Keqin Gu, Islam Boussaada, Silviu-Iulian Niculescu
SIUE Faculty Research, Scholarship, and Creative Activity
This paper studies the migration of double imaginary roots of the systems’ characteristic equation when two parameters are subjected to small deviations. The proposed approach covers a wide range of models. Under the least degeneracy assumptions, we found that the local stability crossing curve has a cusp at the point that corresponds to the double root, and it divides the neighborhood of this point into an S-sector and a G-sector. When the parameters move into the G-sector, one of the roots moves to the right halfplane, and the other moves to the left half-plane. When the parameters move into the …
Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar
Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar
SIUE Faculty Research, Scholarship, and Creative Activity
This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters tau_i, i = 1, 2, . . . ,K. The characteristic quasipolynomial of such an equation is a multilinear function of exp(-tau_i s). It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delayper- scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence …
Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar
Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar
SIUE Faculty Research, Scholarship, and Creative Activity
This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters τi, i = 1, 2, . . . , K. The characteristic quasipolynomial of such an equation is a multilinear function of e−τis. It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delay-per-scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence between …
Safe Haptics-Enabled Patient-Robot Interaction For Robotic And Telerobotic Rehabilitation Of Neuromuscular Disorders: Control Design And Analysis, Seyed Farokh Atashzar
Safe Haptics-Enabled Patient-Robot Interaction For Robotic And Telerobotic Rehabilitation Of Neuromuscular Disorders: Control Design And Analysis, Seyed Farokh Atashzar
Electronic Thesis and Dissertation Repository
Motivation: Current statistics show that the population of seniors and the incidence rate of age-related neuromuscular disorders are rapidly increasing worldwide. Improving medical care is likely to increase the survival rate but will result in even more patients in need of Assistive, Rehabilitation and Assessment (ARA) services for extended periods which will place a significant burden on the world's healthcare systems. In many cases, the only alternative is limited and often delayed outpatient therapy. The situation will be worse for patients in remote areas. One potential solution is to develop technologies that provide efficient and safe means of in-hospital and …
A Reference Guide To Smith Predictor Based Methods For The Compensation Of Dead-Time Processes, Aidan O'Dwyer
A Reference Guide To Smith Predictor Based Methods For The Compensation Of Dead-Time Processes, Aidan O'Dwyer
Conference papers
An extensive literature exists on the compensation of time delayed processes. These compensation methods may be broadly divided into parameter optimised controllers, in which the controller parameters are adapted to the controller structure (the most common such controller is the proportional integral derivative, or PID, controller), and structurally optimised controllers, in which the controller structure and parameters are adapted optimally to the structure and parameters of the process model. Important structurally optimised compensator strategies are the Smith predictor and its variations. The purpose of this paper is to extract the essence of the developments in design, tuning and implementation of …
Towards An Expert System Approach For Pi Controller Design Of Delayed Processes, Michael Feeney, Aidan O'Dwyer
Towards An Expert System Approach For Pi Controller Design Of Delayed Processes, Michael Feeney, Aidan O'Dwyer
Conference papers
This paper will discuss the compensation of first order lag plus time delay (FOLPD) processes using PI controllers whose parameters are specified using appropriate tuning rules. The gain margin and phase margin of the compensated system, as the ratio of time delay to time constant of the process varies, are calculated for each tuning rule and an expert system is used to recommend a tuning rule for user defined requirements.
Time Delay Estimation In Signal Processing Applications: An Overview, Aidan O'Dwyer
Time Delay Estimation In Signal Processing Applications: An Overview, Aidan O'Dwyer
Conference papers
An extensive though scattered literature exists on the estimation of time delays in signal processing applications. However, it is possible to identify themes that are common to many of the available techniques. The intention of this paper is to provide a framework against which the literature may be viewed. In addition, original work on gradient based time delay estimation is described.
A Summary Of Pi And Pid Controller Tuning Rules For Processes With Time Delay. Part 1: Pi Controller Tuning Rules, Aidan O'Dwyer
A Summary Of Pi And Pid Controller Tuning Rules For Processes With Time Delay. Part 1: Pi Controller Tuning Rules, Aidan O'Dwyer
Conference papers
The ability of proportional integral (PI) and proportional integral derivative (PID) controllers to compensate many practical industrial processes has led to their wide acceptance in industrial applications. The requirement to choose either two or three controller parameters is perhaps most easily done using tuning rules. A summary of tuning rules for the PI control of single input, single output (SISO) processes with time delay is provided in this paper.
Pid Compensation Of Time Delayed Processes: A Survey, Aidan O'Dwyer
Pid Compensation Of Time Delayed Processes: A Survey, Aidan O'Dwyer
Conference papers
An extensive literature exists on the PID compensation of time delayed processes. It is possible to identify themes that are common to many of the available techniques. The intention of the paper is to provide a framework against which the literature may be viewed.
Convergence Of Parameter And Delay Estimates Using Open Loop Time Domain Gradient Methods, Aidan O'Dwyer, John Ringwood
Convergence Of Parameter And Delay Estimates Using Open Loop Time Domain Gradient Methods, Aidan O'Dwyer, John Ringwood
Conference papers
This paper discusses the estimation of the parameters of a single input, single output (SISO) process, modelled in first order lag plus delay (FOLPD) form, using gradient methods in the open loop time domain. The paper considers the convergence of the process parameters to the model parameters. The convergence of the model delay is discussed first, when the non-delay model and process parameters are identical. The convergence of all of the model parameters is then considered, when all of the process parameters are unknown.
A Summary Of Pi And Pid Controller Tuning Rules For Processes With Time Delay. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer
A Summary Of Pi And Pid Controller Tuning Rules For Processes With Time Delay. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer
Conference papers
The ability of proportional integral (PI) and proportional integral derivative (PID) controllers to compensate many practical industrial processes has led to their wide acceptance in industrial applications. The requirement to choose either two or three controller parameters is perhaps most easily done using tuning rules. A summary of tuning rules for the PID control of single input, single output (SISO) processes with time delay is provided in this paper.
A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 2: Structurally Optimised Controllers, Aidan O'Dwyer, John Ringwood
A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 2: Structurally Optimised Controllers, Aidan O'Dwyer, John Ringwood
Conference papers
Following on from Part 1, Part 2 of the paper considers the use of structurally optimised controllers to compensate time delayed processes.
Pi And Pid Controller Tuning Rules For Time Delay Processes: A Summary. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer
Pi And Pid Controller Tuning Rules For Time Delay Processes: A Summary. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer
Conference papers
A summary of tuning rules for the PID control of single input, single output (SISO) processes with time delay, modeled in stable first order lag plus time delay (FOLPD) form, is provided in this part of the paper.
Estimation Of The Parameters Of A Delayed Process Using Open Loop Time Domain Techniques, Morena Stolfa, Aidan O'Dwyer
Estimation Of The Parameters Of A Delayed Process Using Open Loop Time Domain Techniques, Morena Stolfa, Aidan O'Dwyer
Conference papers
In this paper, we present three different approaches to fit the experimental data of a process with time delay in the time domain. Two of the proposed methods are based on the step response, and the third is based on the pulse response. The effectiveness of these techniques is verified by simulation results and by real-time experimental data. Only first order lag plus time delay models are considered in this paper.
A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 1: Parameter Optimised Controllers, Aidan O'Dwyer, John Ringwood
A Classification Of Techniques For The Compensation Of Time Delayed Processes. Part 1: Parameter Optimised Controllers, Aidan O'Dwyer, John Ringwood
Conference papers
An extensive literature exists on the compensation of time delayed processes. It is possible to identify themes that are common to many of the available techniques. The intention of the two parts of this paper is to provide a framework against which the literature may be viewed; Part 1 of the paper considers the use of parameter optimised controllers for the compensation problem, with Part 2 of the paper considering the use of structurally optimised compensators. Conclusions are drawn at the end of Part 2.
Performance And Robustness Issues In The Compensation Of Folpd Processes With Pi And Pid Controllers, Aidan O'Dwyer
Performance And Robustness Issues In The Compensation Of Folpd Processes With Pi And Pid Controllers, Aidan O'Dwyer
Conference papers
This paper will discuss the compensation of first order lag plus time delay (FOLPD) processes using PI and PID controllers whose parameters are specified using appropriate tuning rules. The gain margin, phase margin and maximum sensitivity of the compensated system as the ratio of time delay to time constant of the process varies, are used as ways of judging the performance and robustness of the system.
Compensation Of Processes With Time Delays, Thomas Heeg, Aidan O'Dwyer
Compensation Of Processes With Time Delays, Thomas Heeg, Aidan O'Dwyer
Conference papers
Methods which allow comparisons in the use of PI and PID controller strategies for the control of first order lag plus time delay processes (FOLPD) are worthy of investigation because of the relative lack of work done in this area. In this paper, strategies for comparing performance and robustness for a PI or PID controlled FOLPD process are analysed and designed. The use of different PID controller structures for processes with time delay is also worth considering in detail. Various PID controller structures are compared by means of servo and regulator time responses, Bode plots and Nyquist plots.
Closed Loop Time Domain Gradient Methods For Parameter And Time Delay Estimation, M, Behan, M Cahill, M. Carry, G Clausen, V. Dooley, N. English, W. Grainger, D. O'Connor, Aidan O'Dwyer, John Ringwood
Closed Loop Time Domain Gradient Methods For Parameter And Time Delay Estimation, M, Behan, M Cahill, M. Carry, G Clausen, V. Dooley, N. English, W. Grainger, D. O'Connor, Aidan O'Dwyer, John Ringwood
Conference papers
This paper discusses the estimation of process parameters and time delay, in a Smith predictor structure, using gradient algorithms in the time domain. A number of estimation algorithms are outlined and applied in simulation to the estimation of the parameters of an appropriate process model. An analytical exploration of the technique is also provided.