Showing papers on "PID controller published in 1976"

Regulated mains power pack with phase:shift correction - has multi-loop control system with proportional differential action

Abstract: The regulated mains power supply with phase-shift correction comprises a rectifier (1) with mains input (2) whose output is connected to a controlled switch (4). The switch is followed by an L-C low-pass filter (6, 7) bridged by a diode (8). The load (10) is connected across the filter output. The output is taken to an adder (13) having a reference input (15) and whose output is taken to a PI controller (12). The controller output is taken to an adder (16) which has an input taken from the filter input (18) via a smoothing circuit or integrator (17) having a first-order phase-shift. The adder output is taken to a proportional controller (19). The controller output drives the switch (4). The multi-loop control system provides an optimum phase margin of +90 deg. with which to compensate the phase-shift due to the low-pass filter.

Simple Tuning of Discrete PI and PID Controllers

Abstract: The paper investigates the effectiveness of a simple procedure for tuning discrete PI and PID controllers applied to processes subject to set point changes and load disturbances Previous work is extended to obtain closed-loop stability properties and a complete set of graphical tuning relationships to minimise the ITAE performance index when the process under control can be represented adequately by a single time constant and time delay In addition, the simple tuning procedure is shown to exhibit satisfactory performance when applied to the control of a process represented by an eighth order transfer function

Extremum controller design

Abstract: An extremum "on-off" controller whose detailed description is given here is designed to continuously operate an industrial process at the extreme value of the process output. The process investigated consists of the following in cascade: a pure time delay, a parabolic function, and a first-order lag. A simple method is presented for selection of the three controller parameters, a gain, a velocity constant, and a dead time. The gain and the velocity constant are chosen so as to obtain a desired average output for the oscillation cycle. The main advantages of the controller designed are speed in reaching the extremum and low sensitivity to disturbances (because of low value of gain). A step-by-step procedure for the control system design is given.

A Torque Magnetometer with Proportional-Integrating-Differentiating (PID) Compensation

Abstract: A magnetometer for measuring torques in the range 10-10 Nm -5·10-4 Nm (10-3 dyncm -5·103 dyncm) is described. Torque compensation is achieved by feedback from a photodetector into a PID regulator system which generates a current through a compensation coil located in the field of permanent magnets. Stability criteria for the regulator system are discussed. The apparatus permits continuous measurement of the torque as a function of angle with simultanuous registration of the data on x-y-recorder and on paper tape for computer analysis. Measurements can be made in the temperature range 4.2 K to 400 K.

Integrated circuit proportional integral differential controller - has multiple channels and gives wide range of gain settings

Abstract: The PID controller, for application in process control and mechanical control systems, gives good noise suppression and failsafe characteristics The controller consists of an input summing amplifier to which the input set point and a measure of the system output controlled variable are fed This is followed by three parallel connected amplifiers, one with a proportional, one with an integral and one with a differential gain characteristic These are followed by another summing amplifier These linear amplifiers incorporate gain varying features In the integration channel, the integration time is determined by an input resistance, and the range is determined by a switchable feedback capacitance

Bleibende Regeldifferenz bei Zweipunktreglern mit PID-Verhalten / Permanent control difference for two-point controllers with PID-behaviour

Abstract: [1] Galiana, F.D.: On the approximation of multiple input mul t ip le-output constant linear systems. Int. J. Control 17(1973) 6, pp. 1313-1324. [2] Wilson, D.A.: Model reduction for multivariable systems. Int. J. Control 20 (1974) 1, pp. 57-64. [3] Riggs, J.B.; Edgar, T. F.: Least squares reduction of linear systems using impulse response. Int. J. Control 20 (1974) 2, pp. 213-223. [4] Dourdoumas, Ν.: Approximation linearer zeitinvarianter Systeme durch Systeme niedriger Ordnung. Regelungstechnik und Prozeß Datenverarbeitung 22 (1974) Teil 1: 6, S. 178-1 SO; Teil 2: 7, S. 217-221. [5] Rao, S.V.; Lamba, S.S.: A new frequency domain technique for the simplification of linear dynamic systems. Int. J. Control 20 (1974) 1, pp. 71-79. [6] Schwarz, H R.: Ein Verfahren zur Stabilitätsfrage bei MatrizenEigenwertproblemen. ZAMP 7 (1956) pp. 473-500. [7] Chidambara, M. R.: Two simple techniques for the simplification of large dynamic systems. Proc. 1969 J.A.C.C.. Boulder, Colorado (1969) pp. 669-674. [8] Levine, W.S , Äthans, Μ.: On the determination of the optimal constant output feedback gains for linear multivariable systems. IEEE Trans, on Auto. Control AC-15 (1970) 1, pp. 44-48. [9] Kleinman, D.L.: On the linear regulator problem and the matrix Riccati equation. M.I.T. Electronic Systems Lab., Cambridge, Mass., Techn. Rept. ESL-R-271 (1966).

A satellite digital controller or 'play that PID tune again, Sam'

Abstract: The problem discussed is to design a digital controller for a typical satellite. The controlled plant is considered to be a rigid body acting in a plane. The controller is assumed to be a digital computer which, when combined with the proposed control algorithm, can be represented as a sampled-data system. The objective is to present a design strategy and technique for selecting numerical values for the control gains (assuming position, integral, and derivative feedback) and the sample rate. The technique is based on the parameter plane method and requires that the system be amenable to z-transform analysis.

An electronic control meter

Abstract: PURPOSE:The providing of an electronic control meter capable of correct PID calculation or PD calculation for any input without being effected by noise, power failure and producing drift.

Performance Measures of Human Tracking Utilizing PID Modeling and a Closed Loop Error Metric

Abstract: : Data from an antiaircraft artillery simulator is used to validate the dependence of tracking performance measured by the closed loop error and parameters obtained from a Proportional Integral Derivative (PID) model of the man A comparison of three tracking teams is used as the data base with an azimuth and elevation operator composing each team Although this problem is nonstationary, precognitive (a learned tracking task), two axis, and very difficult to model by conventional means, the PID model provides a simple approach to relate the error in the closed loop to the model parameters from each team In order to provide adequate statistical estimates of these model parameters, identification techniques are applied to the same team (replications) tracking a similar arc tangent flyby trajectory Statistical analysis was applied to the identified parameters between trackers to evaluate the credibility of this approach

Discussion of: Parameter Estimation With Closed-Loop Operating Data

Abstract: control methods are to be applied successfully. However, major improvements in the performance of standard PID (proportional-integral-derivative) controllers can be obtained by the use of closed-loop (or open-loop) identification and parameter estimation for tuning the controller. Closed-loop rather than open-loop identification and parameter estimation discussed by Box and M\acGregor and others appears to be the most fruitful approach to practical on-line implementation for use in adaptive control. 2. CONTRIBUTIONS OF BOX-MACGREGOR PAPER The most important contribution of this paper is the development of a necessary and sufficient condition for obtaining unique estimates for the parameters of a general dynamic-stochastic model using data taken from a process that was operating under MMSE (minimum mean square error) control. They illustrate by way of examples the effect of a dither signal on the process input, and process time delay on parameter estimation under MMSE optimal and suboptimal feedback control. This is compared with parameter estimation under pure feedback control.