摘要:

Interpolation of a robot joint trajectory is realized using trigonometric splines. This method is based on the assumption that joint-space knots have been generated from cartesian knots by an inverse kinematics algorithm. The use of trigonometric splines results in smooth joint trajectories and is amenable to real-time obstacle avoidance. Some of the spline parameters can be chosen to minimize an objective function (e.g. jerk or energy). If the objective function is minimum jerk, a closed-form solution is obtained. This paper introduces a trajectory interpolation algorithm, discusses a method for trajectory optimization, and includes simulation examples.

ISSN:0020-7179    

DOI:10.1080/00207179308934404

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The early work of Liapunov produced some of the most powerful tools for stability analysis that remain to this day. To capture the class of all stabilizing controllers one would be well served by posing the problem in terms of the existence of a Liapunov function, since a Liapunov function is known to exist for stable systems. For linear systems, this paper derives the set of all quadratic Liapunov functions for output feedback control problems, and in this way parametrizes the set of all stabilizing controllers of fixed order. This is a unifying framework from which all other controllers can be produced by special choices of the free parameters in these controllers (we will show how to choose the free parameters to produce all covariance controllers and allH∞controllers of fixed order). These results also apply to robustness analysis, and provide a closed form expression for the set of all stabilizing real structured perturbations. Due to the assignment of a matrix property to the system (e.g. covariance matrix), this approach lends itself naturally to mixed problems with multiple objectives.

ISSN:0020-7179    

DOI:10.1080/00207179308934405

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A state observer is proposed for nonlinear continuous time systems which extends the well known Luenberger observer. In particular, on the basis of simple assumptions on the regularity of the system equations (observability and the global Holder condition for suitable functions), which are generally satisfied for physically meaningful dynamic systems, the global asymptotic convergence of the estimated state towards the true state is shown. Finally, some examples of applications are also reported showing the effectiveness of the proposed observer.

ISSN:0020-7179    

DOI:10.1080/00207179308934406

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The discretization of continuous time systems using shift operators often introduces non-minimum phase zeros. In this paper the conversion of continuous to delta operator systems and vice versa is considered and the relationship between the coefficients and poles of continuous time and delta operator systems is investigated for finite dimensional linear systems. The cases of both simple and multiple poles in the continuous time transfer functions are considered and it is shown that the poles, and coefficients of the delta operator transfer function converge to those of the associated continuous time system as the sampling time tends to zero.

ISSN:0020-7179    

DOI:10.1080/00207179308934407

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A simple and unified solution to the problem of estimating a signal corrupted by coloured as well as white measurement noise is presented. The approach requires the solution of a single diophantine equation. The unified formulation applies to the filtering, smoothing and prediction problems. A practical application of enhancing speech corrupted by noise is investigated.

ISSN:0020-7179    

DOI:10.1080/00207179308934408

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this article, adaptive discontinuous feedback regulators are proposed for the stabilization of switch mode controlled DC-to-DC power supplies of the buck, boost and buck-boost types. Adaptation is performed under the assumption of an unknown LC ‘input’ circuit natural oscillating frequency, unknown RC ‘output’ circuit time constant and unknown input source voltage. An average pulse-width-modulation (PWM) input-current regulation scheme, in continuous conduction mode, which accomplishes indirect stabilization of the average output load voltage, is used as the basis for the adaptive controller design. Adaptation is thus confined to the self-tuning of a (static) duty ratio synthesizer. The actual, discontinuous, adaptive PWM feedback strategy state responses exhibit remarkably good asymptotic convergence properties toward the adaptively controlled average designed responses, thus effectively compensating for the modelling error inherent in the average based feedback controller design. It is shown that only in the buck converter case, is a direct-output voltage-adaptive feedback control scheme feasible. In the boost, and the buck-boost, converter cases, the non-adaptive average output voltage regulation schemes lead to non-minimum phase closed loop situations. The performances of the proposed controllers are evaluated through computer simulations.

ISSN:0020-7179    

DOI:10.1080/00207179308934409

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The paper has as its theme a circle of problems related to LQG balancing, with a special emphasis on the related problems of model reduction and robust stabilization. The aim is to present a unified point of view to both previously described problems. The unification is achieved by focusing on the study of three functions and the relationships between them and the various operators that are associated with these functions. With an arbitrary transfer functionGone can associate, canonically, two objects—the conjugate inner function

ISSN:0020-7179    

DOI:10.1080/00207179308934410

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

We consider the class of interconnected non-linear dynamic systems suggested by the problem of longitudinal and lateral control of a platoon of vehicles on automated highways. After describing the physical setting from which the control problem arises, we propose a local indirect adaptive control scheme for this class of interconnected non-linear systems. Then, we establish that the proposed local adaptive control scheme is suitable for monotonically decreasing the magnitude of deviations of each dynamic system's state from its sink manifold provided that (a) the exogenous input is varying sufficiently slowly and (b) the parameter error is sufficiently small. As a consequence, these deviations are bounded with a bound independent of the number of subsystems in the interconnection.

ISSN:0020-7179    

DOI:10.1080/00207179308934411

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor