摘要:

A practical, non-linear controller design methodology is presented for robot manipulators guaranteeing that the robot end-point follows an input command vector ‘closelj’ when the robot is not constrained by the environment, and that the contact force is a function of the same input command vector (used in the unconstrained environment) when the robot is constrained by the environment. The controller is capable of ‘handling’ both types of constrained and uncon5trained manoeuvres, and is robust to bounded uncertainties in the robot dynamics. The controller does not need any hardware or software switch for the transition between unconstrained and constrained manoeuvring. Stability of the environment and the manipulator taken as a whole has been investigated, and a bound for stable manipulation has been derived. For stability, there must be some initial compliancy either in the robot or in the environment. A unified approach to modelling robot dynamics is expressed in terms of sensirivity functions, as opposed to the lagrangian approach. allowing the incorporation of the dynamic behaviour of all the robot manipulator elements.

ISSN:0020-7179    

DOI:10.1080/00207178908559664

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The state-observability problem for bearings-only tracking of a constant velocity target by a moving observer in two spatial dimensions is analysed. Specifically, we establish general necessary and sufficient conditions for observability and characterize the class of observer motions for which the state remains unobservable. In the course of the analysis, previously developed observability criteria are identified as special cases of our results.

ISSN:0020-7179    

DOI:10.1080/00207178908559665

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The existence of optimal control for non-linear multiple-delay systems having an implicit derivative with quadratic performance is proved. The results are established by an iterative technique and by using the Darbo fixed point theorem.

ISSN:0020-7179    

DOI:10.1080/00207178908559666

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The robustness properties of tunable digital set-point tracking PID controllers are assessed. This assessment is effected by characterizing, in terms of the steady-state transfer function matrices of nominal and actual plants, the admissible plant perturbations that can be tolerated by such tunable digital PID controllers. The resulting robustness theorem is illustrated by designing an autopilot for a missile in the form of a tunable digital set-point tracking PID controller.

ISSN:0020-7179    

DOI:10.1080/00207178908559667

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The following problem is considercd: ‘Given a multivariable system withminputs androutputs and anr×mmatrix whose non-negative (i,j)th element represents the cost of setting up a feedback link from thejth output to theith input, sind a set of feedback links with minimum total cost, which does not give rise to sixed modes’. Utilizing the graph-theoretic characterization of structurally sixed modes, the problem is decomposed into two subproblems, which are then solved by using concepts and results from network theory. A combination of the optimum solutions of the subproblems provides a suboptimal solution to the original problem.

ISSN:0020-7179    

DOI:10.1080/00207178908559668

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The problem of obtaining a minimal-order realization of a trajectory sensitivity model is investigated for a linear multi-input multi-output system. The dimension of the minimal realization is a function of some structural parameters of the system model and can be computed in a closed form. Several examples are given to illustrate the results.

ISSN:0020-7179    

DOI:10.1080/00207178908559669

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The problem of controlling a single-link flexible arm is investigated. With reference to an approximate finite-dimensional model of the robot, a non-linear controller and observer are derived. A method to derive approximate asymptotic observers is proposed. Simulation tests to validate the effectiveness of the control/observation laws are included.

ISSN:0020-7179    

DOI:10.1080/00207178908559670

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The quantum-mechanical formulation of a class of stochastic optimal control problems is investigated and two versions of non-linear Schrödinger equation are derived. First, a wave-function is introduced which connects the probability density function of a diffusion process with the minimum cost functional of the stochastic optimal control problem associated with the diffusion process. It is then demonstrated that this wave-function satisfies a kind of Schrödinger-Langevin equation in quantum physics. Finally, the probabilistic interpretation of the wave-function is discussed.

ISSN:0020-7179    

DOI:10.1080/00207178908559671

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A study of the robust performance problem when the plant transfer function is ill-conditioned is made. This is achieved by studying the equivalent problem of robust stability against simultaneous perturbations at plant input and output; the appropriate robustness test for this problem is Doyle's structured singular value. Bounds upon the structured singular value that display the interrelation between plant directionality properties, design specifications, and the compensator are derived. The procedure reveals that certain parameters, which we term'coupling coefficients', play a critical role in determining whether a feedback system with an ill-conditioned plant can be destabilized by small simultaneous perturbations. Perturbations that potentially cause instability are also identified. A simple special case is studied for which the coupling coefficients and problematic perturbations have straightforward and intuitively plausible interpretations.

ISSN:0020-7179    

DOI:10.1080/00207178908559672

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A study is made of a special case of the robust performance problem given by Freudenberg (1989). When the weightings used to describe the uncertainty and performance specifications vary only with frequency, then it is possible to strengthen the results in the above-mentioned work by deriving both upper and lower bounds upon the structured singular value. Both sets of bounds are stated in terms of the coupling coefficients introduced by Freudenberg (1989), and essentially yield necessary and sufficient conditions for the structured singular value to be small. This information is used to suggest a strategy for compensator design to achieve robust performance despite plant ill-conditioning. Applying this strategy to an example, it can be seen how the design trade-offs quantified by the Bode gain-phase relation manifest themselves in the robust performance problem. Finally, the design is compared with one obtained using the'µ-synthesis' approach.

ISSN:0020-7179    

DOI:10.1080/00207178908559673

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor