Design Of Digital Control System Research Articles

Optimal design of digital control systems with large plant uncertainty

In this paper, we extend a practical optimal-design procedure that has been presented in our previous work for single-loop digital control systems. The plant transfer function is given with prescribed bounds on its parameters, and a digital controller is to be designed so that the system response to a deterministic input is optimal and lies within permissible bounds. The w-plane method for the discrete design is used so that the design procedure to be presented is still based on frequency-domain concepts.

Critical control weighting for non‐minimum‐phase stochastic control systems

AbstractBecause of its capability of handling non‐minimum‐phase zeros and its simplicity in digital implementation, the generalized minimum‐variance control strategy has been used extensively in the design of stochastic digital control systems. However, the choice of a suitable control weighting factor within the performance index is not always straightforward and very often designers have to rely on a trial‐and‐error approach. This paper establishes conditions on the limits of the weighting factor for closed‐loop stability. Expressions for computing exactly the minimum stability value of control weighting for processes modelled by a dead time plus a rational transfer function of up to fourth order are derived.

New algebraic method for the design of digital control systems

A new simple method is proposed for designing a single-loop digital controller using a computer-oriented algebraic method. The aim of this paper is to determine the parameters of the controller of a linear digital control system, provided the configuration of the controller has been specified. The proposed controller can achieve an arbitrarily specified closed-loop response and is determined by solving a set of linear algebraic equations. An example is given to show the characteristic features of the method.

駆動電圧および電流に振幅制限がある場合の直流サーボモータの最短時間ディジタル制御システムの構成

駆動電圧および電流に振幅制限がある場合の直流サーボモータの最短時間ディジタル制御システムの構成

操作量に振幅制限がある場合の最短時間ディジタル制御システムの構成法

操作量に振幅制限がある場合の最短時間ディジタル制御システムの構成法

Design of a microcomputer based servomechanism controller

A systematic procedure for the design of a robust digital control system using a microcomputer based controller, is described such that the process output asymptotically tracks a reference signal in the presence of disturbances. The procedure incorporates analog to digital conversion (ADC) and digital to analog conversion (DAC), times and microcomputer computation delay into the design. Guidelines for the choice of the sample period, computation delay, and quantization due to the ADC's and DAC's are developed with reference to a specific example.

Digital control systems design based on the least squares approximation of open-loop transfer characteristics. 1st report Case of single-input single-output system.

A new method of designing a digital controller is proposed in this paper. We consider the design problem that the closed-loop system with a cascade compensator approximates the reference model endowed with desirable characteristics. A integrated square error criterion is introduced as a measure of the approximation. Minimizing the criterion, a linear equation is obtained for unknown parameters of the reduced-order controller. The method is not based on the approximation of the high-order controller which realizes exactly the specified reference model, but on the approximation of the open-loop transfer function. Strong points of the method are that the order of the controller can be arbitrarily specified and that the order of the plant model is not required as a priori knowledge. A example is given to illustrate the effectiveness of this design method.

Digital control system analysis and design

Digital control system analysis and design

Book reviews - Digital control system analysis and design

Book reviews - Digital control system analysis and design

Design of digital flight-mode control systems for helicopters with non-linear actuators

SummaryThe synthesis of discrete-time tracking systems incorporating Lur’e plants with multiple non-linearities is illustrated by the design of a fast-sampling digital controller and associated transducers for the automatic control of the longitudinal motions of the CH-47 helicopter with both gang-collective and differential-collective non-linearities. In particular, it is demonstrated that non-interacting control of the vertical velocity and pitch attitude of the helicopter is readily achievable for large classes of non-linear actuator characteristics such as ‘deadzone’ provided that the controller and transducer parameters are chosen so as to ensure that state-bounded absolutely stable tracking occurs.

Computer - Aided Design of Industrial Automation

In recent years, computers with their great computational power have assumed very important role in the logic design of industrial digital control systems. The implementation of large-scale digital systems is an example of one design problem which can be impractical to solve by hand. How to enable production engineer to improve the existing control network, or to design the absolutely new one, presuming, as it is very olten, that he is not a control design specialist. On the basis of new technological demands, an engineer should form a desired control specification which represent the input format to available computer. Computer should produce desired logic equations as a basis for the immediate realization, since the system is reliable and minimal in sense of number of required components. Software for complete design of digital control networks will be presented in the paper. It is applicable for treating deterministic as well as stochastic systems, both combinational and sequential etc. The concept of use of interactive computer graphics and other available computer aids in synthesis process is given. A relevant example is included in order to illustrate the program package.

Design of Digital Control Systems with Finite Setting Time Via Nonlinear Programming Approach

In this paper, a deadbeat-model performance index is obtained by using the deadbeat model which plays the role of the ideal specification of the desired system performance. Another two performance indices are also defined such that a final performance index PI is formulated. The parameter optimization technique utilizing this performance index PI for the design of digital control systems with finite settling time is developed. The Quasi-Newton unconstrained nonlinear programming algorithm is applied to evaluate the gradient of the performance index PI. Practical constraints can be placed upon the allowable regions of the design parameters in a straight forward manner. The optimized design parameters are determined when the performance index PI is minimized A computer program has been implemented in FORTRAN. Examples demonstrate applications of this systematic design technique to small as well as large digital control systems are presented.

Digital control system analysis and design

During the 1960's, with the introduction of digital computers, we have witnessed an intensive activity in discrete-data control systems [1]-[9]. With the recent invention of the “ubiquitous” microprocessors, there is a renewed interest in digital control systems [10]-[15]. The present book by Phillips and Nagle is one of such recent books.

Model simplification and digital design of multivariable sampled-data control systems via a dominant-data matching method

A dominant-data matching method is developed for model simplification and design of digital multivariable sampled-data control systems. A mixed method combining dominant-data matching and the dominant-pole technique is also derived for determining a stable reduced-degree multivariable digital controller. A real semiactive terminal homing missile system is used as an illustrative example.

Shiryayev sequential probability ratio test for redundancy management

An essential aspect in the design of fault-tolerant digital flight control systems is the design of failure detection and redundancy management systems. A decision rule, the Shiryayev sequential probability ratio test (SPRT), is derived from a dynamic programming approach and is used to detect failures between similar instruments, as well as between dissimilar instruments through analytic redundancy. Unlike the Wald SPRT, which tests for the presence of failure or no failure in all of the data sequence, the Shiryayev SPRT detects the occurrence of a fault in the data sequence in minimum time if certain conditions are met. The performance of the Shiryayev SPRT in detecting a failure between two rate gyros as compared to standard fixed interval schemes is presented, as well as the performance of a single accelerometer failure using translational kinematic equations to form a parity relation for analytic redundancy.

Design of tunable digital set-point tracking and disturbance-rejection controllers for Lur'e plants with multiple non-linearities

Abstract The class of Lur'e plants with multiple non-linearities which are amenable to tunable error-actuated digital control ia characterized in terms of the properties of the transfer function matrices of the linear components of such plants. It is shown that this characterization greatly facilitates the design of closed-loop digital control systems incorporating such Lur'e plants which exhibit state-bounded absolutely stable tracking. These general results are illustrated by designing a tunable error-actuated digital set-point tracking and disturbance-rejection controller for a Lur'e plant in corporating a boiler furnace with four non-linear actuators.

Disturbance-utilizing controllers for noisy measurements and disturbances II. The discrete-time case

Abstract This paper considers the discrete-time counterpart, of the ‘ noisy ’ disturbance-utilizing control problem treated in the preceding paper. The results are applicable to the design of high-performance digital control systems for plants with both waveform-type and noise-type disturbances.

Roundoff noise and scaling in the digital implementation of control compensators

Researchers in digital signal processing have examined at length the effects of finite wordlength in the design of digital filters. The issues that have been considered apply to any digital system. In particular, the design of digital control systems must consider these issues. In this paper we will use, adapt, and extend the ideas developed in digital signal processing to the issue of roundoff noise in digital linear-quadratic-Gaussian (LQG) compensators. We will then examine the roundoff noise effects for a particular LQG example and several different implementation structures.

Steady-state error conditions for use in the design of look-ahead digital control systems

Steady-state error conditions relating to step and ramp inputs often are used in designing control systems. The purpose of this correspondence is to develop such steady-state error conditions as they apply to the design of a class of look-ahead or preview control systems in which future knowledge of system inputs is utilized.

Development of Adaptation and Identification Algorithms in Adaptive Digital Aircraft Control Systems

Design of adaptive digital control systems (ADCS) for maneuverable aircraft which embody combined adaptive control results in systems employing logical adaptation. The structure and parameters of digital control algorithms in the main loop are readjusted periodically during the flight by a two-level scheme. The block of identification algorithms incorporates algorithms for estimating the dynamic responses of the aircraft and functional monitoring of confident identification. The effectiveness of this approach to design of aircraft ADCS is illustrated by simulation of the manual control of longitudinal flight.