- Sort by:
- Newest first
- Titles A to Z
Filter by subject:
- Computer and control engineering [11]
- Systems and control theory [11]
- Mathematical techniques [11]
- Control theory [11]
- Specific control systems [11]
- Discrete control systems [11]
- Algebra [8]
- Control system analysis and synthesis methods [8]
- Multivariable control systems [3]
- Optimisation techniques [2]
- [2]
- http://iet.metastore.ingenta.com/content/subject/c1330,http://iet.metastore.ingenta.com/content/subject/c1340j,http://iet.metastore.ingenta.com/content/subject/c1120,http://iet.metastore.ingenta.com/content/subject/c1200,http://iet.metastore.ingenta.com/content/subject/c1220,http://iet.metastore.ingenta.com/content/subject/c3000,http://iet.metastore.ingenta.com/content/subject/c3100,http://iet.metastore.ingenta.com/content/subject/c3120,http://iet.metastore.ingenta.com/content/subject/c3120c
- c1330,c1340j,c1120,c1200,c1220,c3000,c3100,c3120,c3120c
- [2],[2],[1],[1],[1],[1],[1],[1],[1]
- /search/morefacet;jsessionid=3ngwtht496esr.x-iet-live-01
- /content/searchconcept;jsessionid=3ngwtht496esr.x-iet-live-01?operator4=AND&operator5=AND&operator6=AND&pageSize=20&sortDescending=true&value5=c1000&value6=c1100&facetNames=pub_concept_facet+pub_year_facet+pub_concept_facet+pub_concept_facet+pub_concept_facet+pub_concept_facet&value3=1990&value4=c1340&option6=pub_concept_facet&value1=c1340d&option5=pub_concept_facet&value2=c&option1=pub_concept&facetOptions=2+3+4+5+6+7&option2=pub_concept_facet&option3=pub_year_facet&option4=pub_concept_facet&sortField=prism_publicationDate&operator3=AND&operator2=AND&operator7=AND&option7=pub_concept_facet&value7=
- See more See less
Filter by content type:
Filter by publication date:
- 1990 [11]
Filter by author:
- K.I. Diamantaras [2]
- P.N. Paraskevopoulos [2]
- A. Gupta [1]
- B.B. Das [1]
- C. Mohtadi [1]
- D. Jordan [1]
- D.L. Cooper [1]
- G. Tao [1]
- I.S. Apostolakis [1]
- J.C. Geromel [1]
- J.J. da Cruz [1]
- L. Jetto [1]
- L.F. Godbout [1]
- M.C.F. de Oliveira [1]
- P.A. Ioannou [1]
- P.J. Fleming [1]
- R. Unnikrishnan [1]
- S. Bingulac [1]
- S.K. Zachariah [1]
- See more See less
In this paper we present some useful properties of strictly positive real transfer matrices for both continuous and discrete-time linear time-invariant systems in the frequency and state space domains. Some of these properties follow from known results and are presented for the sake of completeness. The new results obtained are mainly for discrete-time systems and include the discretetime version of the Lefschetz-Kalman-Yakubovich lemma for transfer matrices.
The paper considers the optimisation of pulse-position pulsewidth-modulated (PPPWM) control of a position servosystem. The optimisation is carried out via an equivalent PPPWM transformation of the linear optimal control law. The technique developed here is applicable to both tracking and regulator problems, and the equivalence assumes the existence of at least one pole at the origin for the plant transfer function, which is normally true for any position servosystems. The control signal is optimised with respect to the discrete quadratic performance index and a closed-loop analytical solution can be obtained. The solution for a second-order system is simple, as shown, and readily applicable to real-time sampled-data position servosystems.
The paper develops a model for a closed-loop digital control system that incorporates multirate sampling with dynamic compensation. The model completely represents system behaviour at a base sampling rate and at the integral multiple sampling rates in the system. A key feature of the model is that sampling rates can be modified conveniently, without significantly changing the structure of the model. Based on the multirate closed-loop system model, frequency-domain transfer characteristics of the system are developed. These functions are presented in such a way that the performance of different sampling regimes can be compared directly. The eigenvalues of the closed-loop system are also defined so that effects of sampling rate variation may be investigated. An example is included to illustrate use of the model
The simultaneous ripple-free tracking problem of a prespecified class of inputs is considered. The purpose is that of providing a general and complete characterisation of all ripple-free controllers for SISO discrete systems. In the control problem treated in the paper, references are assumed to be generated by an ensemble of linear time-variant systems. Both the plant and the inputs may be unstable. By adoptintg a polynomial algebra approach, a necessary and sufficient condition is established for the existence of a causal stabilising deadbeat controller, so that the ripple free performance is attained, independent of the initial state of the plant, and for each admissible input. The proposed design procedure proves to be very simple and efficient. A detailed analysis of the least degree solution of the control problem is also presented.
A computational improvement on an algorithm previously derived for the calculation of the natural log of a square matrix is presented, allowing a more general use of the algorithm. This algorithm is useful in estimating the state-space model of a continuous-time multivariable system from data obtained with a discrete-time model.
An orthogonal series approach is presented for state-space analysis of 1-D and 2-D linear time-invariant discrete systems. This approach makes use of the backward shift operation matrix derived in the paper, and yields explicit expressions for the state and output orthogonal coefficient matrixes. These expressions involve only multiplication of small dimension matrixes thus simplifying the computational effort as compared to known orthogonal function techniques, where the inversion of large matrixes is required.
A multi-objective optimisation approach is proposed to facilitate the mapping of continuous-time controllers into the discrete domain. This technique enables the control engineer to meet a set of different objectives in a balanced way and exploits the availability of suitable software.
An algorithm is proposed for characteristic polynomial assignment via state feedback for a wide class of two-dimensional discrete systems. For this class of systems, the required feedback vector is given analytically.
A modified approach for reducing the order of discrete time systems is presented. The objective of the reduction process is to preserve specific design parameters of the transfer function such as phase margin, gain margin, and bandwidth. This approach is attractive because it can be easily implemented and does not involve any complex algebra.
A frequency-domain approach to the absolute stability analysis of multivariable time-invariant discrete-time linear quadratic regulators is developed in the paper. An imbedding form of a fundamental equality relating the return-difference and the open-loop transfer matrices is the key for the application of the Popov criterion in the analysis. This imbedding form also establishes a necessary condition for a closed-loop matrixtransfer function to have been obtained through an LQ design.
A paper by Bode has shown the limitations of using a feedback structure in terms of an integral constraint on the sensitivity function for open-loop stable continuous-time systems. The paper by Mohtadi examines and derives equivalent results for discrete-time feedback systems. These integral constraints also provide some guidelines regarding the philosophy of feedback design specifically for sampled-data systems. For example, it is shown that, for all sampled-data control systems, there is a maximum sampling frequency, beyond which little improvement in performance is gained.
