摘要:

Using the widely accepted philosophy that simple control design procedures are of great value in producing acceptable controllers for plant with a degree of dynamic and/or structural simplicity, particularly in the situation where closed-loop performance requirements are modest, recent work on the use of approximate models and plant step data in multivariable design is applied to produce simple, robust design algorithms for process plant which, in the presence of suitable precompensation, has ‘small’ interaction effects and/or simple loop dynamics that can be approximated by delay-lag models. In one form, the results have a structure and generate a procedure identical to the inverse Nyquist array design technique, with Gershgorin circles replaced by ‘confidence circles’ deduced from simple graphical operations on plant step data. Other interpretations of the work lead to estimates of the maximum gain required to retain stability in Davison's robust feedback regulator. An optimisation procedure for choice of precompensator using step data is also outlined with strong connections with the method of pseudodiagonalisation.

DOI:10.1049/ip-d.1986.0001

出版商:IEE    

年代:1986

数据来源: IET

摘要:

The optimal fixed-lag deconvolution smoothing problem is solved in the frequency domain. It is shown how the smoother may be implemented online by using an innovations moving average description, thus avoiding a two-pass algorithm, involving causal and anticausal filtering. The optimal smoother is given in polynomial matrix form, which makes the solution relatively simple to implement.

DOI:10.1049/ip-d.1986.0002

出版商:IEE    

年代:1986

数据来源: IET

摘要:

The usual plant structure assumed in self-tuning problems is not sufficiently general to cover some industrial control problems, such as autopilot design. An LQG-based control law is developed for this type of industrial situation. The cost function includes dynamic weighting elements, which allows integral action to be introduced and robustness characteristics to be modified. The system model involves a reference signal, disturbances which affect the output to be controlled and coloured measurement noise. The way in which the optimal control law is incorporated in a self-tuning control system is also described, using the ship steering problem to illustrate its utility in applications.

DOI:10.1049/ip-d.1986.0003

出版商:IEE    

年代:1986

数据来源: IET

摘要:

A mixed method of discrete system model reduction retaining the advantages of the power decomposition method and the system identification method is proposed. From the viewpoint of energy contributions to the system output, the dynamic modes with dominant energy contributions, instead of those with dominant eigenvalues, will be preserved by power decomposition method. Having determined the denominator of the reduced model, the parameters of the numerator are found by system identification technique. The reduction procedure is fully computer-oriented. The reduced model is always stable if the original one is stable. Moreover, the reduced model gives good approximation in both the transient and the steady-state responses of the original system.

DOI:10.1049/ip-d.1986.0004

出版商:IEE    

年代:1986

数据来源: IET

摘要:

The dynamic behaviour of the range space of a linear operatormtused to form a switching function in a scalar-variable-structure control system is described. It is shown that as the operatormtis defined for less than the full-state vector complement, the dynamic order of the range space increases. It is also shown that the range space can be stabilised by compensation techniques, without affecting the null space behaviour of the control system.

DOI:10.1049/ip-d.1986.0005

出版商:IEE    

年代:1986

数据来源: IET