Pub Date : 1988-06-15DOI: 10.1109/ACC.1988.4172753
C. R. Cutler, R. Hawkins
The installation of a large constrained multivariable controller on the second stage reactor of Suncor's hydrocracker unit has been completed. The control problem is complex and required an unusual controller structure to allow it to be solved with the computing resources available. The performance of the controller has been good, and has resulted in much more stable and consistent control of the whole hydrocracker complex. The controllers ability to operate the unit at its constraints provides significant economic benefits when the capacity of the unit is limiting.
{"title":"Application of a Large Predictive Multivariable Controller to a Hydrocracker Second Stage Reactor","authors":"C. R. Cutler, R. Hawkins","doi":"10.1109/ACC.1988.4172753","DOIUrl":"https://doi.org/10.1109/ACC.1988.4172753","url":null,"abstract":"The installation of a large constrained multivariable controller on the second stage reactor of Suncor's hydrocracker unit has been completed. The control problem is complex and required an unusual controller structure to allow it to be solved with the computing resources available. The performance of the controller has been good, and has resulted in much more stable and consistent control of the whole hydrocracker complex. The controllers ability to operate the unit at its constraints provides significant economic benefits when the capacity of the unit is limiting.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"74 1","pages":"284-291"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85804106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4789949
S. Greeley, D. Phillips, D. Hyland
Based on a recent survey of Large Space System concepts and the identified characteristics of ground-based experiments needed to demonstrate capability for future systems, a sequence of vibration control experiments have been designed and are being performed at Harris Corporation. The experiments involve a progression of structural configurations ranging from relatively simple one and two dimensional strctures to a large aperture, multi-segment optical structure. The experiments have been designed to evaluate a variety of control design methods including the Maximum Entropy/Optimal Projection method. This paper reviews the concepts and status of these experimental activities.
{"title":"Experimental Demonstration of the Maximum Entropy/Optimal Projection Design Theory for Active Vibration Control","authors":"S. Greeley, D. Phillips, D. Hyland","doi":"10.23919/ACC.1988.4789949","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789949","url":null,"abstract":"Based on a recent survey of Large Space System concepts and the identified characteristics of ground-based experiments needed to demonstrate capability for future systems, a sequence of vibration control experiments have been designed and are being performed at Harris Corporation. The experiments involve a progression of structural configurations ranging from relatively simple one and two dimensional strctures to a large aperture, multi-segment optical structure. The experiments have been designed to evaluate a variety of control design methods including the Maximum Entropy/Optimal Projection method. This paper reviews the concepts and status of these experimental activities.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"72 1","pages":"1462-1472"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77822781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4790052
Tong-heng Lee, K. Narendra
This paper considers the model reference adaptive control of a linear time-varying first-order discrete-time system. The principal result is a quantitative bound on the time-variations of the unknown parameter which ensures the boundedness of all the signals in the system. Since the quantitative bound provides a sufficient condition only, an example is also constructed to illustrate possible conditions for instability. A rigorous proof is provided for this instability result.
{"title":"Stable Direct Adaptive Control of Time-Varying Discrete-Time Systems: Detailed Analysis for a First-Order Plant","authors":"Tong-heng Lee, K. Narendra","doi":"10.23919/ACC.1988.4790052","DOIUrl":"https://doi.org/10.23919/ACC.1988.4790052","url":null,"abstract":"This paper considers the model reference adaptive control of a linear time-varying first-order discrete-time system. The principal result is a quantitative bound on the time-variations of the unknown parameter which ensures the boundedness of all the signals in the system. Since the quantitative bound provides a sufficient condition only, an example is also constructed to illustrate possible conditions for instability. A rigorous proof is provided for this instability result.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"74 1","pages":"1995-1999"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77911193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.1109/ACC.1988.4173164
P. Khargonekar, A. Pascoal, R. Ravi
In this paper we study some issues related to the stabilization of linear, time-varying (LTV) plants. We consider the class of finite-dimensional LTV plants and show that every plant that can be internally stabilized by output feedback can be stabilized by a stable LTV controller. We give a parametrization of all nonlinear time-varying controllers that stabilize a given LTV plant, and further, we show that every finite collection of LTV plants can be simultaneously stabilized by a stable LTV controller. Finally, we prove that every LTV plant can always be stabilized by a pair of simultaneously acting LTV controllers each reliable against a failure of the other.
{"title":"Stabilization of Linear Time-Varying Systems Strong, Simultaneous and Reliable Stabilization","authors":"P. Khargonekar, A. Pascoal, R. Ravi","doi":"10.1109/ACC.1988.4173164","DOIUrl":"https://doi.org/10.1109/ACC.1988.4173164","url":null,"abstract":"In this paper we study some issues related to the stabilization of linear, time-varying (LTV) plants. We consider the class of finite-dimensional LTV plants and show that every plant that can be internally stabilized by output feedback can be stabilized by a stable LTV controller. We give a parametrization of all nonlinear time-varying controllers that stabilize a given LTV plant, and further, we show that every finite collection of LTV plants can be simultaneously stabilized by a stable LTV controller. Finally, we prove that every LTV plant can always be stabilized by a pair of simultaneously acting LTV controllers each reliable against a failure of the other.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"27 1","pages":"2477-2482"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72887423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4789897
G. R. Arulalan, P. Ralston, T. L. Ward
Lathe turning is a single point cutting process, thus the cutting edge of the tool is not accessible for direct tool wear measurement. A variety of indirect in-process measurements have been proposed and/or tested in laboratories, but none have found practical application. A new approach to in-process tool wear sensing is described in this paper. It employs an observable, control-oriented state space model having a six-variable state vector. Four state variables are measureable by practical means, but the other two are tool wear characteristics that cannot be directly measured. In past work, the operation of a linear observer for tool wear was verified by simulation. This paper describes an adaptive observer that reduces the dependence on knowledge of plant parameters. Its operation is being verified by simulation. The results of the simulation will permit the development of requirements for practical application in the adaptive control of lathes.
{"title":"Adaptive Observer for Optimal Control of Lathe Tool Wear","authors":"G. R. Arulalan, P. Ralston, T. L. Ward","doi":"10.23919/ACC.1988.4789897","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789897","url":null,"abstract":"Lathe turning is a single point cutting process, thus the cutting edge of the tool is not accessible for direct tool wear measurement. A variety of indirect in-process measurements have been proposed and/or tested in laboratories, but none have found practical application. A new approach to in-process tool wear sensing is described in this paper. It employs an observable, control-oriented state space model having a six-variable state vector. Four state variables are measureable by practical means, but the other two are tool wear characteristics that cannot be directly measured. In past work, the operation of a linear observer for tool wear was verified by simulation. This paper describes an adaptive observer that reduces the dependence on knowledge of plant parameters. Its operation is being verified by simulation. The results of the simulation will permit the development of requirements for practical application in the adaptive control of lathes.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"1 1","pages":"1168-1171"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82202380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4790125
P. Leucht
The design of a control system to coordinate the steering of the four wheels of an advanced vehicle is described. The Linear Quadratic Gaussian, design process is applied to a directional dynamics model that includes yaw, lateral, and roll degrees-of-freedom for the vehicle and steering rotation degrees-of-freedom for the front and rear wheels. Vehicle oscillations, overshoot, sideslip, and response times to steering inputs are minimized at all forward speeds. Left-to-right steering corrections augment the control design to eliminate tire scrub and squeal in low speed and parking maneuvers. Simulation results illustrate the advantages of active four-wheel-steering over two-wheel-steering and proportional four-wheel-steering and the insensivity of the design to changes in vehicle speed, trim, loading, and tire characteristics.
{"title":"Active Four-Wheel-Steering Design for an Advanced Vehicle","authors":"P. Leucht","doi":"10.23919/ACC.1988.4790125","DOIUrl":"https://doi.org/10.23919/ACC.1988.4790125","url":null,"abstract":"The design of a control system to coordinate the steering of the four wheels of an advanced vehicle is described. The Linear Quadratic Gaussian, design process is applied to a directional dynamics model that includes yaw, lateral, and roll degrees-of-freedom for the vehicle and steering rotation degrees-of-freedom for the front and rear wheels. Vehicle oscillations, overshoot, sideslip, and response times to steering inputs are minimized at all forward speeds. Left-to-right steering corrections augment the control design to eliminate tire scrub and squeal in low speed and parking maneuvers. Simulation results illustrate the advantages of active four-wheel-steering over two-wheel-steering and proportional four-wheel-steering and the insensivity of the design to changes in vehicle speed, trim, loading, and tire characteristics.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"49 1","pages":"2379-2384"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81403519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4790059
I. Horowitz
In QFT, the feedback design problem has always been that of achieving defined performance over specified range of plant uncertainty, with minimum "cost of feedback". Eigenvalue realization was always considered an incidental problem. Two benchmark problems are presented. The first is a 2×2 highly uncertain nonlinear plant. The second is a 3×7 digital (60 Hz) flight control problem with uncertainty consisting of 36 possible effector failure cases with no failure detection and identification, i.e. a fixed compensation design. Both problems were solved by QFT with satisfactory results.
{"title":"Quantitative Feedback Theory (QFT)","authors":"I. Horowitz","doi":"10.23919/ACC.1988.4790059","DOIUrl":"https://doi.org/10.23919/ACC.1988.4790059","url":null,"abstract":"In QFT, the feedback design problem has always been that of achieving defined performance over specified range of plant uncertainty, with minimum \"cost of feedback\". Eigenvalue realization was always considered an incidental problem. Two benchmark problems are presented. The first is a 2×2 highly uncertain nonlinear plant. The second is a 3×7 digital (60 Hz) flight control problem with uncertainty consisting of 36 possible effector failure cases with no failure detection and identification, i.e. a fixed compensation design. Both problems were solved by QFT with satisfactory results.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"2 1","pages":"2032-2037"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82097703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.1109/ACC.1988.4172933
M. Sain, B. Wyman, J. Peczkowski
This paper presents and characterizes a new module Z' of zeros in solutions P(z) to the linear transfer function equation T(z) = P(z) M(z). Unlike the module Z of [1], Z' is finitely generated and torsion, and is thus of classical, finite-dimensional, state-space type. It is, however, a more elaborate module than Z in terms of its submodules and factors. In addition, Z of [1] is established as an essential submodule of the extended, ¿-zeros of P(z).
{"title":"Zeros in Plant Specification: Constraints and Solutions","authors":"M. Sain, B. Wyman, J. Peczkowski","doi":"10.1109/ACC.1988.4172933","DOIUrl":"https://doi.org/10.1109/ACC.1988.4172933","url":null,"abstract":"This paper presents and characterizes a new module Z' of zeros in solutions P(z) to the linear transfer function equation T(z) = P(z) M(z). Unlike the module Z of [1], Z' is finitely generated and torsion, and is thus of classical, finite-dimensional, state-space type. It is, however, a more elaborate module than Z in terms of its submodules and factors. In addition, Z of [1] is established as an essential submodule of the extended, ¿-zeros of P(z).","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"15 1","pages":"1243-1248"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78792590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4790081
S. D. Katebi, M. Katebi
A combined frequency and time domain design technique is described for a class of multivariable feedback systems containing a set of coupled nonlinear elements of any general multivalued form. The parameter of the compensator is initially derived from the frequency domain analysis and automatically adjusted by the numerical synthesis routine in order to meet specified time domain performance. The method employs a combined analytical and synthesis procedures and provides a powerful tool in the design of a wide class of nonlinear multivariable feedback systems. Example is presented to demonstrate the efficiency of the proposed design technique.
{"title":"Combined Frequency and Time Domain Techniques for the Design of Compensator for Multivariable Nonlinear Control Systems","authors":"S. D. Katebi, M. Katebi","doi":"10.23919/ACC.1988.4790081","DOIUrl":"https://doi.org/10.23919/ACC.1988.4790081","url":null,"abstract":"A combined frequency and time domain design technique is described for a class of multivariable feedback systems containing a set of coupled nonlinear elements of any general multivalued form. The parameter of the compensator is initially derived from the frequency domain analysis and automatically adjusted by the numerical synthesis routine in order to meet specified time domain performance. The method employs a combined analytical and synthesis procedures and provides a powerful tool in the design of a wide class of nonlinear multivariable feedback systems. Example is presented to demonstrate the efficiency of the proposed design technique.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"24 1","pages":"2162-2167"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78982967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4789867
C. M. Oakley, R. Cannon
Understanding how to control the flexibility in mechanical manipulator allows us to increase their performance and to reliably design and control larger, lighter, and more power-efficient manipulators. To date, a number of papers and some experiments have addressed the control of single-link flexible manipulators. In order to understand fully and to control a larger, more useful class of manipulators, we need to extend our knowledge further to the two-link configuration. To this end, this paper addresses the dynamics and control of a two-link manipulator with a very flexible forearm. Further, to verify the theoretical developments, an experimental planar two-link flexible manipulator system has been constructed. A nonlinear model of the experimental manipulator is developed using an assumed-modes description for the deflections in the forearm link. The design of an initial collocated proportional-plus-derivative controller is presented and implemented on the experimental manipulator. For a step command of 10° in each joint, the simulation and experimental responses are found to be in excellent agreement.
{"title":"Initial Experiments on the Control of a Two-Link Manipulator with a Very Flexible Forearm","authors":"C. M. Oakley, R. Cannon","doi":"10.23919/ACC.1988.4789867","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789867","url":null,"abstract":"Understanding how to control the flexibility in mechanical manipulator allows us to increase their performance and to reliably design and control larger, lighter, and more power-efficient manipulators. To date, a number of papers and some experiments have addressed the control of single-link flexible manipulators. In order to understand fully and to control a larger, more useful class of manipulators, we need to extend our knowledge further to the two-link configuration. To this end, this paper addresses the dynamics and control of a two-link manipulator with a very flexible forearm. Further, to verify the theoretical developments, an experimental planar two-link flexible manipulator system has been constructed. A nonlinear model of the experimental manipulator is developed using an assumed-modes description for the deflections in the forearm link. The design of an initial collocated proportional-plus-derivative controller is presented and implemented on the experimental manipulator. For a step command of 10° in each joint, the simulation and experimental responses are found to be in excellent agreement.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"15 1","pages":"996-1003"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86853139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}