{"title":"Low-bandwidth Semi-active Damping for Suspension Control","authors":"R. Redfield","doi":"10.23919/ACC.1990.4790961","DOIUrl":"https://doi.org/10.23919/ACC.1990.4790961","url":null,"abstract":"Active damping has been shown to offer increased suspension performance in terms of vehicle isolaton, suspension packaging, and road-tire contact force. It can even approximate the performance of full state feedback control without requiring the difficult measurement of tire deflection. Many semi-active damping strategies have been introduced to approximate the response of active damping with the modulation of passive damping parameters. These strategies have typically required a relatevely high bandwidth for actuator response. This paper investigates the simulation performance and \"frequency response\" of two concepts in low-bandwidth semi-active suspension control. The first strategy controls the pressure drop in a hydraulic flow path, the second controls a hydraulic resistance. The bandwidth of these actuators is approximately an order of magnitude less than other semi-active devices. A quarter-car model is studied with the controlled damping replacing both passive and active damping of typical control schemes. Both low-bandwidth damping strategies perform remarkably well compared to both active and high-bandwidth, semi-active damping.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"161 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134083731","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}
{"title":"Measuring Rank Robustness of General Complex System Matrices with Respect to Real Matrix Perturbations","authors":"M. Wicks, R. Decarlo","doi":"10.23919/ACC.1990.4791186","DOIUrl":"https://doi.org/10.23919/ACC.1990.4791186","url":null,"abstract":"This paper examines the problem of computing the real matrix perturbation having smallest norm which causes a general complex (system) matrix to drop rank. Given the state model describing a linear time-invariant system, the norm of this matrix perturbation helps to determine the robustness of several system properties with respect to real parameter variations. The norm of this perturbation, or the real-restricted singular value of the complex matrix, is known to be a discontinuous function of the complex matrix. This paper presents some theoretical results characterizing the nature of this discontinuity and presents an experimental algorithm which may be used to compute the smallest real rank-reducing matrix perturbation and its norm. Some numerical examples are included.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134439963","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}
{"title":"Towards Less Conservative Stability Criterion for Discrete-Time Linear Uncertain Systems","authors":"K. Gu, W. Chai, N. Loh","doi":"10.23919/ACC.1990.4790922","DOIUrl":"https://doi.org/10.23919/ACC.1990.4790922","url":null,"abstract":"The stability problem of discrete-time linear uncertain systems is considered. The uncertainty is expressed in terms of uncertain system matrix, and is allowed to be arbitrary time varying. The criterion is based on quadratic stability. The necessary and sufficient condition of the quadratic stability is formulated in a two level optimization problem. The higher level of this optimization is proved to be convex. When the uncertainty bounding set is a hyperpolyhedron, the lower level can be reached by one of the finite number of vertices. An illustrative example is presented to show the advantage of the proposed criterion.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126590920","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}
{"title":"Decentralized Control of a Class of Large-Scale Systems by Uncertainty Estimator","authors":"Min-Shin Chen","doi":"10.23919/ACC.1990.4790776","DOIUrl":"https://doi.org/10.23919/ACC.1990.4790776","url":null,"abstract":"A new decentralized controller is proposed for a group of subsystems subject to unknown interconnections and external disturbances. Under the assumption that the interconnections and disturbances satisfy a structural condition, the new controller completely suppresses the effects of disturbances, and makes the overall system behave as an \"uncoupled\" system. In our control design, each local controller uses the uncertainty estimator proposed in [6] to obtain an estimate of the interconnections and disturbances, and then cancels these undesirable inputs directly. The major advantages of the proposed controller are that the interconnections need not satisfy the conical condition, and the strengths of interconnections and disturbances can be of any unknown size. The proposed decentralized controller is verified by a computer simulation study.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131051525","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}
{"title":"A Fast Parallel Dynamic Programming Algorithm for Optimal Control","authors":"J. Calvet, J. D. de Melo, J. M. Garcia","doi":"10.1109/ACC.1990.4174263","DOIUrl":"https://doi.org/10.1109/ACC.1990.4174263","url":null,"abstract":"A fast parallel dynamic programming algorithm which adresses to a broad class of discrete time optimal control problems is presented. Conditions for reducing the algorithm complexity are stressed. First experiments on a CRAY-2 vector quadriprocessor are given.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131153511","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}
{"title":"Optimal Eigenstructure Achievement with Robustness Guarantees","authors":"Robert F. Wilson, J. Cloutier","doi":"10.23919/ACC.1990.4790874","DOIUrl":"https://doi.org/10.23919/ACC.1990.4790874","url":null,"abstract":"A new aigenstructure. assignment procedure is presented. In this new method, the best eigenstructure achievable is attained by minimizing with respect to the eigenvalues and the inconsequential components of the desired eigenvectors. This is in contrast to existing techniques which fix the eigenvalues a priori, thereby freezing the subspaces within which the eigenvectors must reside. An added benefit of the technique is that the minimization can be performed subject to an algebraic Riccati constraint, thus providing the closed-loop system with the same gain and phase margins inherent in the linear quadratic regulator. With an estimator in the loop, the procedure can be modified to design a target feedback loop for loop transfer recovery, breaking the loop at either the plant's input or output. An example is given to illustrate the technique.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"137 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133041221","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}
{"title":"Simultaneous Model Identification and Control of a Semi-batch Chemical Reactor","authors":"E. S. Meadows, J. Rawlings","doi":"10.23919/ACC.1990.4791014","DOIUrl":"https://doi.org/10.23919/ACC.1990.4791014","url":null,"abstract":"A commercially useful dehydrohalogenation reaction is controlled by manual addition of a strong base to a semibatch chemical reactor. Because overaddition of base incurs a severe economic penalty, accurate knowledge of process parameters is essential for any automatic control scheme. This investigation uses a sequential parameter estimation/optimal control algorithm to minimize the time to reach the desired composition while providing the desired assurance that excess base was not added.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133483355","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}
{"title":"On Decentralized Observers","authors":"V. Leite","doi":"10.23919/ACC.1990.4790770","DOIUrl":"https://doi.org/10.23919/ACC.1990.4790770","url":null,"abstract":"This note studies the observer problem in decentralized linear systems using the geometric approach. The decentralized observer problem is formulated in a very general form, and the relation between decentralized observers and its centralized constitutive parts is investigated. The decentralized separation principle is also considered.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"241 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133573505","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}
J. Yuan, K. Bellgardt, C. Posten, W. Jiang, W. Deckwer
{"title":"A Combined Cell-Cycle and Metabolic Model of Baker's Yeast and its Application in Process Optimization","authors":"J. Yuan, K. Bellgardt, C. Posten, W. Jiang, W. Deckwer","doi":"10.23919/ACC.1990.4791207","DOIUrl":"https://doi.org/10.23919/ACC.1990.4791207","url":null,"abstract":"A cell cycling model for unequal budding yeast Saccharomyces cerevisiae is proposed and verified in the sense of steady state with experimental data available in the literature. As the quality of yeast is strongly influenced by the cycling process, the model can be used to optimize and control the quality of the harvested yeast cells. The input variable of the cell cycling model is the specific growth rate ¿, which is obtained from a metabolic model for S. cerevisiae proposed earlier. With this extended model system, simulations were done to optimize the profit of a commercial scale fed-batch baker's yeast production process by dynamically manipulating the substrate feeding rate. Also substrate concentration in the feed, aeration rate, fermentation interval and other operating conditions are subject to optimization. The result of the optimization deviates significantly from usual feeding policies.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133408152","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}
{"title":"Experiments with End-Point Control of a Flexible Link using the Inverse Dynamics Approach and Passive Damping","authors":"T. Alberts, L. Love, E. Bayo, H. Moulin","doi":"10.23919/ACC.1990.4790758","DOIUrl":"https://doi.org/10.23919/ACC.1990.4790758","url":null,"abstract":"Achieving accuracy in end-point positioning while avoiding end-point oscillations is one of the major open problems in the control of light and high precision manipulators. The authors of this paper have independently proposed passive damping and active control methods for positioning the end-point of flexible manipulators. In this paper experimental results obtained using a combination of the two approaches are presented. The active control method considered involves computing the inverse dynamics of the arm to determine a torque command trajectory that will permit the realization of a prescribed endpoint trajectory. The passive control serves to reduce unwanted oscillations resulting from unavoidable system non-idealities.","PeriodicalId":307181,"journal":{"name":"1990 American Control Conference","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1990-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131439889","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}