Pub Date : 1988-06-15DOI: 10.23919/ACC.1988.4789984
Chia-Hsiang Liu, B. Womack
This paper presents a self-tuning technique designed to handle the periodical fast time-varying systems. The parameters of the system vary rapidly with unknown fequencies and amplitudes. We only know the form of variation is sinusoid. A frequency detector, which consists of a combined multistage estimator, a filter, a peak detector and a monitoring program, is used to estimate the frequencies of time-varying parameters. The estimated frequencies in turns are used in the estimator with time-varying model to obtain the fine estimates of the time-varying parameters which will be used to compute the parameters of adaptive controller. The result of this combination produces a satisfactory control performance unattainable otherwise. It also shows the feasibility of tailoring the existing adaptive control algorithm to fit the special type systems.
{"title":"Adaptive Control for Periodical Time-Varying Systems with Unknown Frequencies","authors":"Chia-Hsiang Liu, B. Womack","doi":"10.23919/ACC.1988.4789984","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789984","url":null,"abstract":"This paper presents a self-tuning technique designed to handle the periodical fast time-varying systems. The parameters of the system vary rapidly with unknown fequencies and amplitudes. We only know the form of variation is sinusoid. A frequency detector, which consists of a combined multistage estimator, a filter, a peak detector and a monitoring program, is used to estimate the frequencies of time-varying parameters. The estimated frequencies in turns are used in the estimator with time-varying model to obtain the fine estimates of the time-varying parameters which will be used to compute the parameters of adaptive controller. The result of this combination produces a satisfactory control performance unattainable otherwise. It also shows the feasibility of tailoring the existing adaptive control algorithm to fit the special type systems.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"3 1","pages":"1642-1647"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83362606","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.1988.4790117
E. Yi
The paper deal with the identification problem of the parameter of diffusion equation based on output measurment of distributed signals in the finite number of spatial points. The state of the diffusion equation is approximated by the distrbuted signais via the the spline approximation. The system governed by the diffusion eqution is trasformed to lumped parameter system and the parameter of the diffusion equation is identificated by the following least-squares algorithm.
{"title":"Parameter Identification of Diffusion Equation","authors":"E. Yi","doi":"10.23919/ACC.1988.4790117","DOIUrl":"https://doi.org/10.23919/ACC.1988.4790117","url":null,"abstract":"The paper deal with the identification problem of the parameter of diffusion equation based on output measurment of distributed signals in the finite number of spatial points. The state of the diffusion equation is approximated by the distrbuted signais via the the spline approximation. The system governed by the diffusion eqution is trasformed to lumped parameter system and the parameter of the diffusion equation is identificated by the following least-squares algorithm.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"3 1","pages":"2337-2339"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90234509","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.1988.4172735
H. Yoo, R. Ryan, R. Scott
The dynamic behavior of multibody systems containing structural elements undergoing large overall rotation and translation as well as small elastic deformations is considered. A systematic procedure, using assumed mode functions and von Kármán-type strain measures, is developed in order to properly account for motion-induced structural stiffness variations during arbitrary overall motion. The procedure is compared in terms of accuracy and efficiency with recently developed imbedded geometric constraint methods involving linear strain-displacement relationships and with more conventional multibody techniques. A numerical example involving a simply supported plate attached to a rigid body (floating frame) undergoing a prescribed large-displacement motion is presented. Extensions to complex multibody systems containing various element types will be discussed.
{"title":"Use of Assumed Modes in Equations Governing Large-Displacement Elastodynamic Plate Behavior","authors":"H. Yoo, R. Ryan, R. Scott","doi":"10.1109/ACC.1988.4172735","DOIUrl":"https://doi.org/10.1109/ACC.1988.4172735","url":null,"abstract":"The dynamic behavior of multibody systems containing structural elements undergoing large overall rotation and translation as well as small elastic deformations is considered. A systematic procedure, using assumed mode functions and von Kármán-type strain measures, is developed in order to properly account for motion-induced structural stiffness variations during arbitrary overall motion. The procedure is compared in terms of accuracy and efficiency with recently developed imbedded geometric constraint methods involving linear strain-displacement relationships and with more conventional multibody techniques. A numerical example involving a simply supported plate attached to a rigid body (floating frame) undergoing a prescribed large-displacement motion is presented. Extensions to complex multibody systems containing various element types will be discussed.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"29 1","pages":"170-177"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89621856","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.1988.4173147
C. Yue, T. Butsuen, J. Hedrick
A two degree of freedom (1/4 car model) is used to evaluate alternative linear control laws. Control laws considered are full state feedback, sprung mass absolute velocity feedback and an LQG regulator using suspension defelection as the measurement. It is shown that all three can yield improvements to the sprung mass ride quality but that overall the LQG regulator using suspension deflection provides the best trade-off between ride quality, suspension packaging and road holding constraints.
{"title":"Alternative Control Laws for Automotive Active Suspensions","authors":"C. Yue, T. Butsuen, J. Hedrick","doi":"10.1109/ACC.1988.4173147","DOIUrl":"https://doi.org/10.1109/ACC.1988.4173147","url":null,"abstract":"A two degree of freedom (1/4 car model) is used to evaluate alternative linear control laws. Control laws considered are full state feedback, sprung mass absolute velocity feedback and an LQG regulator using suspension defelection as the measurement. It is shown that all three can yield improvements to the sprung mass ride quality but that overall the LQG regulator using suspension deflection provides the best trade-off between ride quality, suspension packaging and road holding constraints.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"41 1","pages":"2373-2378"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87969743","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.1988.4789982
M. Workman, G. Franklin
Following a brief review of the Proximate Time-Optimal Servomechanism (PTOS) and the Adaptive version of PTOS (APTOS), implementation technique will be described which make both algorithms practical for discrete time control of second order plants with real roots. The double integrator plant and the real pole plus an integrator plant are both used as examples. The effects of unmodeled dynamics on the algorithms are discussed and illustrated by simulation and experiment.
{"title":"Implementation of Adaptive Proximate Time-Optimal Controllers","authors":"M. Workman, G. Franklin","doi":"10.23919/ACC.1988.4789982","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789982","url":null,"abstract":"Following a brief review of the Proximate Time-Optimal Servomechanism (PTOS) and the Adaptive version of PTOS (APTOS), implementation technique will be described which make both algorithms practical for discrete time control of second order plants with real roots. The double integrator plant and the real pole plus an integrator plant are both used as examples. The effects of unmodeled dynamics on the algorithms are discussed and illustrated by simulation and experiment.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"47 1","pages":"1629-1635"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87981159","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.1988.4172714
E. Rogers, D. Owens
A state feedback control law for a class of linear dynamic systems termed differential unit memory linear multipass processes is defined. Further, the design of this law for closed-loop stability is considered. In particular, a recently developed computationally feasible stability test is used to present some preliminary work on this problem.
{"title":"Stability and State Feedback Control of Differential Unit Memory Linear Multipass Processes","authors":"E. Rogers, D. Owens","doi":"10.1109/ACC.1988.4172714","DOIUrl":"https://doi.org/10.1109/ACC.1988.4172714","url":null,"abstract":"A state feedback control law for a class of linear dynamic systems termed differential unit memory linear multipass processes is defined. Further, the design of this law for closed-loop stability is considered. In particular, a recently developed computationally feasible stability test is used to present some preliminary work on this problem.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"74 1","pages":"51-52"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86312234","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.1988.4790092
J. Weiss
This paper considers the problem of detecting failures in single input single output (SISO) systems using analytic redundancy concepts. Since the models used in such concepts are subject to eror, a method of determining detection thresholds that account for these errors is sought. In many applications, error can be characterized by a bound on the magnitude of the "error transfer function" as a function of frequency. Such a characterization has been used to determine fixed thresholds that account for modeling errors when input signals to the plant are bounded and have known temporal characteristics [1]. Frequently, however, the input signals are not known a-priori and any reasonable bound on their size results in overly conservative (i.e., too large) thresholds. The methodology presented here utilizes a straightforward application of Parseval's relation to develop a threshold computation that is performed on-line as a function of the input signal. The threshold is set at a quiescent value to account for sensor noise, and is adjusted (upward) according to the activity of the input signal. An application to detection of actuator failures is presented.
{"title":"Threshold Computations for Detection of Failures in SISO Systems with Transfer Function Errors","authors":"J. Weiss","doi":"10.23919/ACC.1988.4790092","DOIUrl":"https://doi.org/10.23919/ACC.1988.4790092","url":null,"abstract":"This paper considers the problem of detecting failures in single input single output (SISO) systems using analytic redundancy concepts. Since the models used in such concepts are subject to eror, a method of determining detection thresholds that account for these errors is sought. In many applications, error can be characterized by a bound on the magnitude of the \"error transfer function\" as a function of frequency. Such a characterization has been used to determine fixed thresholds that account for modeling errors when input signals to the plant are bounded and have known temporal characteristics [1]. Frequently, however, the input signals are not known a-priori and any reasonable bound on their size results in overly conservative (i.e., too large) thresholds. The methodology presented here utilizes a straightforward application of Parseval's relation to develop a threshold computation that is performed on-line as a function of the input signal. The threshold is set at a quiescent value to account for sensor noise, and is adjusted (upward) according to the activity of the input signal. An application to detection of actuator failures is presented.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"1 1","pages":"2213-2218"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88719998","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.1988.4789751
Stephen P. Boyd, V. Balakrishnan, P. Kabamba
We present a simple bisection algorithm to compute the H∞ norm of a transfer matrix. The bisection method is far more efficient than algorithms which involve a search over frequencies, and moreover can compute the H∞ norm with guaranteed accuracy.
{"title":"On computing the H∞ norm of a transfer matrix","authors":"Stephen P. Boyd, V. Balakrishnan, P. Kabamba","doi":"10.23919/ACC.1988.4789751","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789751","url":null,"abstract":"We present a simple bisection algorithm to compute the H<sub>∞</sub> norm of a transfer matrix. The bisection method is far more efficient than algorithms which involve a search over frequencies, and moreover can compute the H<sub>∞</sub> norm with guaranteed accuracy.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"9 1","pages":"396-397"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83516211","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}
This paper presents a new method which significantly improves the computational efficiency of time-optimal path-following planning algorithms for robot manipulators with limited actuator torques. The approach exploits the fact that the characteristic switching points of earlier techniques can be found directly in a straightforward fashion. Numerical examples, while showing the consistency of the algorithm with the existing techniques, demonstrate its potential for increasing computational efficiency by several orders of magnitude.
{"title":"Improving the Efficiency of Time-Optimal Path-Following Algorithms","authors":"J. Slotine, Hyun S. Yang","doi":"10.1109/70.88024","DOIUrl":"https://doi.org/10.1109/70.88024","url":null,"abstract":"This paper presents a new method which significantly improves the computational efficiency of time-optimal path-following planning algorithms for robot manipulators with limited actuator torques. The approach exploits the fact that the characteristic switching points of earlier techniques can be found directly in a straightforward fashion. Numerical examples, while showing the consistency of the algorithm with the existing techniques, demonstrate its potential for increasing computational efficiency by several orders of magnitude.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"21 1","pages":"2129-2134"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78672691","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.1988.4789985
Y. Strassberg, J. Dayan
A new adaptive-control scheme based on the coefficient plane theory is presented. The MRAC scheme has a small number of parameters to be estimated. Updating the controller, after the estimation stage, is based on the sensitivity function of the whole system. The scheme is especially easy to realize for systems controlled by a sequence of steps (point to point) similar to the common policy in many robot servo systems. A simulation example of a simple third order SISO system controlled by the proposed adaptive scheme is presented. The estimation is based on the analysis of the output signal and on the identification of the coefficient plane parameters b and c of the entire system The adaptive-control law is then uniquely computed.
{"title":"Model-Reference Adaptive-Control Scheme for Servo Systems based on the Coefficient-Plane Method","authors":"Y. Strassberg, J. Dayan","doi":"10.23919/ACC.1988.4789985","DOIUrl":"https://doi.org/10.23919/ACC.1988.4789985","url":null,"abstract":"A new adaptive-control scheme based on the coefficient plane theory is presented. The MRAC scheme has a small number of parameters to be estimated. Updating the controller, after the estimation stage, is based on the sensitivity function of the whole system. The scheme is especially easy to realize for systems controlled by a sequence of steps (point to point) similar to the common policy in many robot servo systems. A simulation example of a simple third order SISO system controlled by the proposed adaptive scheme is presented. The estimation is based on the analysis of the output signal and on the identification of the coefficient plane parameters b and c of the entire system The adaptive-control law is then uniquely computed.","PeriodicalId":6395,"journal":{"name":"1988 American Control Conference","volume":"3 1","pages":"1648-1652"},"PeriodicalIF":0.0,"publicationDate":"1988-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83526794","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}