Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4789925
A. Krzyżak
We study the identification of single-input, single-output discrete Hammerstein system. We identify the parameters of the dynamic, linear subsystem by the correlation and Newton-Gauss method. The main results concern the identification of the nonlinear, memoryless subsystem. We impose no conditions on the functional form of the nonlinear subsystem, recovering the nonlinearity using the Fourier series regression estimate. We prove the density-free pointwise convergence of the estimate. The rates of pointwise convergence are obtained for smooth input densities and for nonlinearities of Lipschitz type.
{"title":"On Identification of Discrete Hammerstein Systems by the Fourier Series Regression Estimate","authors":"A. Krzyżak","doi":"10.23919/ACC.1988.4789925","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789925","url":null,"abstract":"We study the identification of single-input, single-output discrete Hammerstein system. We identify the parameters of the dynamic, linear subsystem by the correlation and Newton-Gauss method. The main results concern the identification of the nonlinear, memoryless subsystem. We impose no conditions on the functional form of the nonlinear subsystem, recovering the nonlinearity using the Fourier series regression estimate. We prove the density-free pointwise convergence of the estimate. The rates of pointwise convergence are obtained for smooth input densities and for nonlinearities of Lipschitz type.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"93 1","pages":"1321-1324"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75570723","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.1988.4789933
C. Wampler
An inverse kinematic function for a redundant manipulator is a generalization of the most common form of sensor-driven control for nonredundant manipulators. However, the nonuniqueness of the functions in the redundant case can be used to reduce joint speeds, avoid obstacles, and improve the usable workspace. This paper reviews our work of the last several years on the inverse function approach and discusses the practical considerations that recommend its use. Methods of representing the inverse functions are discussed and compared to the related extended Jacobian technique. Recent results on workspace limits are summarized, and the paper concludes with an indication of possible avenues for future research in the area.
{"title":"The Inverse Function Approach to Kinematic Control of Redundant Manipulators","authors":"C. Wampler","doi":"10.23919/ACC.1988.4789933","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789933","url":null,"abstract":"An inverse kinematic function for a redundant manipulator is a generalization of the most common form of sensor-driven control for nonredundant manipulators. However, the nonuniqueness of the functions in the redundant case can be used to reduce joint speeds, avoid obstacles, and improve the usable workspace. This paper reviews our work of the last several years on the inverse function approach and discusses the practical considerations that recommend its use. Methods of representing the inverse functions are discussed and compared to the related extended Jacobian technique. Recent results on workspace limits are summarized, and the paper concludes with an indication of possible avenues for future research in the area.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"75 1","pages":"1364-1369"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75700414","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.1988.4789838
C. Desoer, A. Gundes
A unified view of recent results in the algebraic theory of linear, time-invariant multiinput-multioutput control systems is presented, with emphasis on the unity-feedback system (one-degree-of-freedom design) and the more general two-input two-output plant and compensator configuration (four-degrees-of-freedom design). The issues of stability, parametrization of all stabilizing compensators, achievable input-output maps and decoupling are discussed.
{"title":"Issues in Algebraic Control Theory","authors":"C. Desoer, A. Gundes","doi":"10.23919/ACC.1988.4789838","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789838","url":null,"abstract":"A unified view of recent results in the algebraic theory of linear, time-invariant multiinput-multioutput control systems is presented, with emphasis on the unity-feedback system (one-degree-of-freedom design) and the more general two-input two-output plant and compensator configuration (four-degrees-of-freedom design). The issues of stability, parametrization of all stabilizing compensators, achievable input-output maps and decoupling are discussed.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"6 1","pages":"836-841"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75777923","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.1988.4173017
C. Chu
In this paper, reliable algorithms are developed to perform inner-outer, coprime, and spectral factorizations for discrete FDLTI systems. It is shown that the discrete algebraic Riccati equation plays an important role in obtaining state-space representations for all key factorizations. The implementation of algorithms can be carried out efficiently using real matrix operations.
{"title":"On Discrete Inner-Outer and Spectral Factorizations","authors":"C. Chu","doi":"10.1109/ACC.1988.4173017","DOIUrl":"https://doi.org/10.1109/ACC.1988.4173017","url":null,"abstract":"In this paper, reliable algorithms are developed to perform inner-outer, coprime, and spectral factorizations for discrete FDLTI systems. It is shown that the discrete algebraic Riccati equation plays an important role in obtaining state-space representations for all key factorizations. The implementation of algorithms can be carried out efficiently using real matrix operations.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"13 1","pages":"1699-1700"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74415578","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.1988.4172864
K. Dean Minto
Despite the impact that the Stable Factorization (SF) approach has had on the academic community, its widespread acceptance and application by industry has been hampered by the natural lag in the development of design algorithms and their associated numerically reliable CAD implementations. Indeed, it is safe to say that computer-aided design support for the Stable Factorization methodology (and in fact, many of the principle design algorithms) have not as yet matured to the point where they may be readily applied by practising engineers. In this paper we describe on-going research aimed at refining one such design algorithm, namely simultaneous stabilization. Through application of the simultaneous stabilization design technique to a realistic aerospace control problem we seek to demonstrate the practical utility of the method, and identify the technical issues that remain to be resolved. The focus of this study is the GE T700 turboshaft engine, when coupled to the Apache and Blackhawk helicopter airframes. We describe our experiences with an indirect design technique to obtain an LTI compensator that simultaneously satisfies two loop-shaping type performance criteria, one for each engine-airframe combination.
{"title":"Towards Simultaneous Performance: Application of Simultaneous Stabilization Techniques to Helicopter Engine Control","authors":"K. Dean Minto","doi":"10.1109/ACC.1988.4172864","DOIUrl":"https://doi.org/10.1109/ACC.1988.4172864","url":null,"abstract":"Despite the impact that the Stable Factorization (SF) approach has had on the academic community, its widespread acceptance and application by industry has been hampered by the natural lag in the development of design algorithms and their associated numerically reliable CAD implementations. Indeed, it is safe to say that computer-aided design support for the Stable Factorization methodology (and in fact, many of the principle design algorithms) have not as yet matured to the point where they may be readily applied by practising engineers. In this paper we describe on-going research aimed at refining one such design algorithm, namely simultaneous stabilization. Through application of the simultaneous stabilization design technique to a realistic aerospace control problem we seek to demonstrate the practical utility of the method, and identify the technical issues that remain to be resolved. The focus of this study is the GE T700 turboshaft engine, when coupled to the Apache and Blackhawk helicopter airframes. We describe our experiences with an indirect design technique to obtain an LTI compensator that simultaneously satisfies two loop-shaping type performance criteria, one for each engine-airframe combination.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"10 1","pages":"852-859"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73356700","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.1988.4790075
M. Raghuveer
A new approach for estimating phase coupling due to quadratic nonlinearity is developed. The method is different from the periodogram approaches to bicoherence estimation and can be used in situations where high resolution frequency and bifrequency estimation are required. Least squares fitting is done between expressions for the autocorrelation and third moment sequences of sinusoidal signals and corresponding estimates of autocorrelation and third moments from samples of the process under consideration. The fraction of the power contributed by quadratic nonlinearity to bifrequencies is then estimated from the result of the least squares fit. Simulation examples illustrating the approach are also presented.
{"title":"High Resolution Estimation of Quadratic Phase Coupling in Nonlinear Systems","authors":"M. Raghuveer","doi":"10.23919/ACC.1988.4790075","DOIUrl":"https://doi.org/10.23919/ACC.1988.4790075","url":null,"abstract":"A new approach for estimating phase coupling due to quadratic nonlinearity is developed. The method is different from the periodogram approaches to bicoherence estimation and can be used in situations where high resolution frequency and bifrequency estimation are required. Least squares fitting is done between expressions for the autocorrelation and third moment sequences of sinusoidal signals and corresponding estimates of autocorrelation and third moments from samples of the process under consideration. The fraction of the power contributed by quadratic nonlinearity to bifrequencies is then estimated from the result of the least squares fit. Simulation examples illustrating the approach are also presented.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"29 1","pages":"2124-2128"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73981290","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.1988.4789683
D. Williamson, R. Skelton
The existing q-Markov COVER realization theory does not take into account the problems of arithmetic errors due to both the quantization of states and coefficients of the reduced order model. All q-Markov COVERs allow some freedom in the choice of parameters. In this paper we exploit this freedom in the existing theory to optimize the models with respect to these finite wordlength effects.
{"title":"Optimal q-Markov Cover for Finite Precision Implementation","authors":"D. Williamson, R. Skelton","doi":"10.23919/ACC.1988.4789683","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789683","url":null,"abstract":"The existing q-Markov COVER realization theory does not take into account the problems of arithmetic errors due to both the quantization of states and coefficients of the reduced order model. All q-Markov COVERs allow some freedom in the choice of parameters. In this paper we exploit this freedom in the existing theory to optimize the models with respect to these finite wordlength effects.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"44 1","pages":"16-21"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79086041","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.1988.4789721
J. Alvarez, E. Hernández, R. Suárez
A differential geometric methodology is used to establish, at the structural level (regardless of specific controllers), the existence of a global solution of the nonlinear control problem associated to a free-radical, polymerization reactor. The structural characterization turns out to depend exclusively on stoichiometric constraints and on parameters associated to the reaction kinetic scheme. At the design stage, a controller is built by means of feedback design for a linear equivalent of the process. Numerical simulations corroborate the globality of the controller.
{"title":"Nonlinear Control of a Two-Input, Trhee-State Polymerization Reactor","authors":"J. Alvarez, E. Hernández, R. Suárez","doi":"10.23919/ACC.1988.4789721","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789721","url":null,"abstract":"A differential geometric methodology is used to establish, at the structural level (regardless of specific controllers), the existence of a global solution of the nonlinear control problem associated to a free-radical, polymerization reactor. The structural characterization turns out to depend exclusively on stoichiometric constraints and on parameters associated to the reaction kinetic scheme. At the design stage, a controller is built by means of feedback design for a linear equivalent of the process. Numerical simulations corroborate the globality of the controller.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"7 1","pages":"233-239"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79673352","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.1988.4789981
W. Blokland, J. Sztipanovits
Unstable, dynamically changing environments represent a major challenge for the design of adaptive control systems. Significant changes in the process model, various hardware failures may require the modification of the basic control law in order to maintain the control of the plant. To support the design and implementation of structurally adaptive systems, we have developed a new architecture and programming tools. The architecture enables on-line and automatic reconfiguration of the control structure. The most important features of our approach are: (1) knowledge-based techniques are used to represent the model of the process and the possible control schemes including alternatives and selection rules, (2) a graph-oriented computational model has been defined which allows the efficient implementation of reconfigurable signal processing systems and (3) a special interpretation technique has been developed which can build and dynamically change the signal-flow of signal processing and control systems. The operation of the system can be conceptualized in the following way. The actual state of the process is continuously monitored. If a significant change is detected, the process model will be updated which will start a reasoning process on the effects of the change. The result may be a partial or full reconfiguration of the cotroller without interrupting the system operation. The method has been implemented and tested in different applications. The paper will present the structure of a fault tolerant controller built for the control of a chemical process with unreliable sensors.
{"title":"Knowledge-Based Approach to Reconfigurable Control Systems","authors":"W. Blokland, J. Sztipanovits","doi":"10.23919/ACC.1988.4789981","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789981","url":null,"abstract":"Unstable, dynamically changing environments represent a major challenge for the design of adaptive control systems. Significant changes in the process model, various hardware failures may require the modification of the basic control law in order to maintain the control of the plant. To support the design and implementation of structurally adaptive systems, we have developed a new architecture and programming tools. The architecture enables on-line and automatic reconfiguration of the control structure. The most important features of our approach are: (1) knowledge-based techniques are used to represent the model of the process and the possible control schemes including alternatives and selection rules, (2) a graph-oriented computational model has been defined which allows the efficient implementation of reconfigurable signal processing systems and (3) a special interpretation technique has been developed which can build and dynamically change the signal-flow of signal processing and control systems. The operation of the system can be conceptualized in the following way. The actual state of the process is continuously monitored. If a significant change is detected, the process model will be updated which will start a reasoning process on the effects of the change. The result may be a partial or full reconfiguration of the cotroller without interrupting the system operation. The method has been implemented and tested in different applications. The paper will present the structure of a fault tolerant controller built for the control of a chemical process with unreliable sensors.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"24 1","pages":"1623-1628"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84364328","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.1988.4172781
A. Mahalanabis, Bin Zhou
This paper is concerned with the development of a joint probabilistic data association based fixed-lag smoothing algorithm for the recursive tracking of multiple targets in cluttered environment. The improvement in accuracy of track estimation achieved by introducing a time lag of one or two sampling periods for a radar tracking problem are also demonstrated by using simulation experiment.
{"title":"A Joint Probabilistic Data Association Smoothing Algorithm for Multitarget Tracking","authors":"A. Mahalanabis, Bin Zhou","doi":"10.1109/ACC.1988.4172781","DOIUrl":"https://doi.org/10.1109/ACC.1988.4172781","url":null,"abstract":"This paper is concerned with the development of a joint probabilistic data association based fixed-lag smoothing algorithm for the recursive tracking of multiple targets in cluttered environment. The improvement in accuracy of track estimation achieved by introducing a time lag of one or two sampling periods for a radar tracking problem are also demonstrated by using simulation experiment.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"47 1","pages":"430-435"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84542609","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}