摘要:

A computationally powerful digital signal processor (DSP)-based implementation of adaptive speed control algorithms for a diesel-driven electric generating unit is described in this paper. The complexity of the algorithm and the short control interval required for this application necessitated the use of a DSP. Hardware and software have been designed such that the overall structure of the adaptive controller is similar to the corresponding components of a commercially available PI controller. Illustrative real-time tests with the proposed adaptive controller and the commercial controller illustrate the effectiveness of the adaptive controller.

ISSN:0020-7179    

DOI:10.1080/00207179408921476

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Simultaneous stabilization of a collection of linear time-invariant systems is considered. The aim is to develop a practical method for the design of a single feedback controller such that all the systems involved are stabilized with good transient responses. Hurwitz's necessary and sufficient conditions are used as the required set of constraints for simultaneous stability. For transient behaviour, we introduce the usual quadratic objective function as performance index for each system. Their sum is the objective function for the collection of systems and the problem is to minimize it by choosing a feedback gain vector subject to boundedness and the Hurwitz stability constraints. A computational technique is proposed for solving this problem. The results obtained give good transient behaviour. For illustration, two numerical examples are solved.

ISSN:0020-7179    

DOI:10.1080/00207179408921477

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A nonlinear multivariable bioreactor system has been the subject of two differential geometry feedback control design approaches. Exact linearization and input/output linearization are applied to the bioreactor model and verified by simulation experiments. Exact linearization via state feedback shows a high degree of coupling on the controlled variables and large changes on the manipulated variables. Input/output linearization, with the ability of implementing independent, decoupled control loops, gives more satisfactory results. The issues of invertabiity and parameter uncertainties are also discussed in this paper.

ISSN:0020-7179    

DOI:10.1080/00207179408921478

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An algorithm is developed for the computation of the transfer function matrix of a two-dimensional system, which is given in its generalized form. The algorithm is a recursion in terms of the original system matrix and does not require the inversion of a two-variable polynomial matrix. An algorithm for the evaluation of the Laurent expansion of the inverse of a two-variable polynomial matrix is also presented.

ISSN:0020-7179    

DOI:10.1080/00207179408921479

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Direct-drive connection of electric motors represents a suitable solution to friction and backlash problems introduced by mechanical reduction gears. Variable reluctance (VR) are a special type of switched reluctance motors whose construction is well suited for direct-drive connection. Although these motors are traditionally conceived as stepper motors, continuous motion can be obtained by implementing suitable closed-loop control in the drive. The authors' main aim is to design a high-performance robust controller for a VR motor intended for velocity trajectory tracking in robotics applications where continuous motion is required. A cascade controller structure (velocity-torque) is considered. In the design of the torque controller, both feedback linearizing and sliding mode techniques are considered. Feedback linearization performs slightly better in the ideal case, but under more realistic operating conditions the sliding mode controller demonstrates comparable or even better performance. A very simple but extremely robust velocity controller is designed using a dynamic sliding mode approach, ensuring robustness to large variations of load torque and inertia, typical of direct-drive robotics applications. A simulation experiment of the overall controller with the motor connected to a single link robotic arm shows very good tracking properties as well as insensitivity to large variations of load torque and inertia.

ISSN:0020-7179    

DOI:10.1080/00207179408921480

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The problem is addressed of deriving sampled-data control laws for a class of nonlinear continuous systems. The concept of approximate state-feedback linearizing control is defined for sampled-data models arising from the sampling of continuous-time systems. Such control laws are then designed for both non-adaptive and adaptive cases and a detailed performance analysis is performed.

ISSN:0020-7179    

DOI:10.1080/00207179408921481

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A new approach is presented to observing the state of a nonlinear control system. The class considered consists of nonlinear observable systems described by an ordinary differential equation in combination with a measurement equation. The system functions are required to be twice differentiable. Based on Newton's method, an iterative process of state approximation is derived. The algorithm computes a piecewise continuous function which is an ‘approximation’ of the true state. The convergence of the proposed algorithm is proved. Finally several examples show the performance characteristics of the method.

ISSN:0020-7179    

DOI:10.1080/00207179408921482

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Linear decoupling controllers of proportional derivative (PD) type are considered for natural and robotic systems operating under holonomic constraints. The dynamic system must be decomposed into orthogonal subspaces of motion and constraint. The incremental motion of the system along the two hyper-planes must be stable. Decoupling controllers, including both non-interacting and disturbance decoupling types, are parameterized using a single matrix parameter. The proof of stability is based on Lyapunov function approach.

ISSN:0020-7179    

DOI:10.1080/00207179408921483

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Concurrent discrete event systems are considered modelled by Petri nets with external input places (PNIPs), with a control specification assumed to be given in terms of a predicate. First, a necessary and sufficient condition is derived for the unique existence of maximally permissive feedback (MPF) in PNIPs controlled by either event assignment or resource allocation, which can be checked without constructing the set of all permissive feedbacks. Then it is shown that the unique existence of MPF in resource allocation control implies that it exists also in event assignment control.

ISSN:0020-7179    

DOI:10.1080/00207179408921484

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The automatic tuning of simple digital filters is discussed and an automatic tuning method is proposed for the phase-lead and phase-lag compensators in three steps. First, an appropriate test signal is automatically generated by introducing a nonlinear element into the system. Secondly, the new gain crossover frequency and corresponding gain are estimated. Thirdly, the compensator parameters are determined by corresponding formulae. The method can be easily implemented by microprocessors and will be found useful in a variety of applications..

ISSN:0020-7179    

DOI:10.1080/00207179408921485

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor