A Technical Note on a Semigraphical Synthesis Procedure

1967 ◽  
Vol 89 (2) ◽  
pp. 263-266
Author(s):  
M. J. Rabins ◽  
C. A. Wasynczuk
Keyword(s):  
Time Constant ◽  
Controller Design ◽  
Technical Note ◽  
Multiple Time ◽  
Linear Elements ◽  
Graphical Technique ◽  
Synthesis Procedure ◽  
The Relationship ◽  
Logical Criterion ◽  
System Phase

The problem of synthesizing a controller to yield a specified overall system phase margin requires specification of both the time constant (or constants) and the gain of the controller, but the choice of the two is not independent. A graphical technique is developed for plotting the relationship between the gain and the time constant in a straightforward manner. A logical criterion results upon which to base the controller design. The method is presented for a first order controller, but the approach may be extended to multiple time constant controllers. The method is applied in the frequency domain to linear elements. Phase shifting nonlinearities can be accommodated by judicious use of describing function results.

Respiratory mechanics in mechanically ventilated patients with respiratory failure

1985 ◽  
Vol 58 (6) ◽  
pp. 1849-1858 ◽  
Author(s):  
A. Rossi ◽  
S. B. Gottfried ◽  
B. D. Higgs ◽  
L. Zocchi ◽  
A. Grassino ◽  
...  
Keyword(s):  
Time Constant ◽  
Inflation Rate ◽  
Respiratory Mechanics ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Airway Occlusion ◽  
The Relationship ◽  
Resistance Value ◽  
Ventilated Patients

In 11 mechanically ventilated patients, respiratory mechanics were measured 1) during constant flow inflation and 2) following end-inflation airway occlusion, as proposed in model analysis (J. Appl. Physiol. 58: 1840–1848, 1985. During the latter part of inflation, the relationship between driving pressure and lung volume change was linear, allowing determination of static respiratory elastance (Ers) and resistance (RT). The latter represents in each patient the maximum resistance value that can obtain with the prevailing time constant inhomogeneity. Following occlusion, Ers and RT were also obtained along with RT (min) which represents a minimum, i.e., resistance value that would obtain in the absence of time constant inhomogeneity. A discrepancy between inflation and occlusion Ers and RT was found only in the three patients without positive end-expiratory pressure, and could be attributed to recruitment of lung units during inflation. In all instances Ers and RT were higher than normal. RT(min) was lower in all patients than the corresponding values of RT, indicating that resistance was frequency dependent due to time constant inequalities. Changes in inflation rate did not affect Ers, while RT increased with increasing flow.

Simulation Research on Hydraulic Stewart Force Feedback Master-Slave System

2013 ◽  
Vol 347-350 ◽  
pp. 3954-3959
Author(s):  
Jing Wei Hou ◽  
Ding Xuan Zhao ◽  
Ying Zhao ◽  
Yu Xin Cui
Keyword(s):  
Force Feedback ◽  
Controller Design ◽  
Load Force ◽  
Force Model ◽  
Slave System ◽  
Simulation Research ◽  
Control Framework ◽  
Hydraulic Servo ◽  
The Relationship ◽  
Master Slave System

a virtual prototype program of hydraulic Stewart force feedback master-slave system is developed to solve the modeling problems when plant developing and controller design. The following work is done based on the Stewart manipulator simulation program built in Matlab/SimMechanics platform: 1. Master/slave force feedback control framework is built based on the relationship between force on cylinders and upper platform.; 2. A new Stewart platform with load force model on the upper platform hydraulic servo system is built as the slave hand. The validity of the functions is verified by simulation experiment.

Effect of a spider toxin (JSTX) on excitatory postsynaptic current at neuromuscular synapse of spiny lobster

1987 ◽  
Vol 58 (2) ◽  
pp. 319-326 ◽  
Author(s):  
A. Miwa ◽  
N. Kawai ◽  
M. Saito ◽  
H. Pan-Hou ◽  
M. Yoshioka
Keyword(s):  
Membrane Potential ◽  
Neuromuscular Junction ◽  
Time Constant ◽  
Spiny Lobster ◽  
Neuromuscular Synapse ◽  
Ionic Channel ◽  
Excitatory Postsynaptic Potential ◽  
Excitatory Postsynaptic Current ◽  
Steady Level ◽  
The Relationship

1. We studied the blocking properties of a spider (Nephila clavata) toxin (JSTX) purified from venom on the spiny lobster neuromuscular junction. 2. When a small amount of JSTX was applied to the neuromuscular junction, the excitatory postsynaptic potential (EPSP) was partially suppressed. The amplitude of EPSPs remained at a steady level for several hours during the washing of the preparation, showing that the action of JSTX is irreversible. 3. We recorded the excitatory postsynaptic current (EPSC) from synaptic site using a macro-patch electrode. The amplitude of EPSC increased linearly with hyperpolarization of the membrane potential in the presence and absence of JSTX. 4. The decay phase time constant of EPSC and spontaneous EPSC was decreased by hyperpolarizing the membrane potential both in the absence and in the presence of JSTX. The relationship between the decay time constant and the membrane potential was not modified by JSTX. 5. It is suggested that JSTX irreversibly blocks EPSC by acting on the site that is apart from the ionic channel of the glutamate receptor molecule.

scholarly journals Nonlinear Compound Control for Nonsinusoidal Vibration of the Mold Driven by Servo Motor with Variable Speed

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Li ◽  
Yi-ming Fang ◽  
Jian-xiong Li ◽  
Zhuang Ma
Keyword(s):  
Control Method ◽  
Controller Design ◽  
Rotation Speed ◽  
Pi Control ◽  
Variable Speed ◽  
Servo Motor ◽  
Motor Speed ◽  
Vector Method ◽  
Compound Control ◽  
The Relationship

In this paper, a fuzzy PI control method based on nonlinear feedforward compensation is proposed for the nonsinusoidal vibration system of mold driven by servo motor, rotated in single direction with variable speed. During controller design, there are mainly two issues to consider: (i) nonlinear relationship (approximate periodic function) between mold displacement and servo motor speed and (ii) uncertainties caused by backlash due to motor variable speed. So, firstly, the relationship between mold displacement and motor rotation speed is built directly based on the rotation vector method. Then, an observer is designed to estimate the uncertainties and feedforward compensation. Secondly, as the motor rotates in single direction with variable speed, a fuzzy control with bidirectional parameter adjustment is adopted to improve rapidity and stability based on the traditional PI method. Finally, some simulation results show the effectiveness of the proposed control method.

Servocontrol of the GS16 Turbine Gas Metering Valve by Physics-Based Robust Controller Synthesis

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Kamran E. Shahroudi ◽  
Peter M. Young
Keyword(s):  
Physical Meaning ◽  
State Feedback ◽  
Controller Design ◽  
Controller Synthesis ◽  
Design Approach ◽  
Balanced Truncation ◽  
Feedback Form ◽  
Robust Controller ◽  
Synthesis Procedure ◽  
Detailed Outline

We present a design approach for robust controller synthesis using a μ-synthesis procedure, which returns a controller in an observor/state-feedback form with physically meaningful states. We are also able to (approximately) retain this physical meaning when using balanced truncation to (significantly) reduce the controller order, as is often necessary in practice. The advantages of this physics-based approach are illustrated by a detailed outline of the controller design for Woodward Governor’s GS16 Turbine Gas Metering Valve.

Transient Response Control of Two-Mass System via Polynomial Approach

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Yue Qiao ◽  
Junyi Cao ◽  
Chengbin Ma
Keyword(s):  
Time Constant ◽  
Transient Response ◽  
Controller Design ◽  
Polynomial Method ◽  
Transient Responses ◽  
Mass System ◽  
Response Control ◽  
Characteristic Ratio ◽  
Starting Point ◽  
Generalized Time

This paper discusses the application of polynomial method in the transient response control of a benchmark two-mass system. It is shown that transient responses can be directly addressed by specifying the so-called characteristic ratios and the generalized time constant. The nominal characteristic ratio assignment (CRA) is a good starting point for controller design. And the characteristic ratios with lower indices have a more dominant influence. Two practical low-order control configurations, the integral-proportional (IP) and modified-integral-proportional-derivative (m-IPD) controllers are designed. The primary design strategy of the controllers is to guarantee the lower-index characteristic ratios to be equal to their nominal values, while the higher-index characteristic ratios are determined by the interaction with the generalized time constant and the limits imposed by zeros, a specific control configuration, etc. The demonstrated relationship between the transient responses and the assignments of characteristic ratios and generalized time constant in simulation and experiments explains the effectiveness of the polynomial-method-based controller design.

An examination of the relationship between time‐domain integral chargeability and the Cole‐Cole impedance model

Geophysics ◽  
1995 ◽  
Vol 60 (4) ◽  
pp. 1249-1252 ◽  
Author(s):  
Kenneth Duckworth ◽  
H. Thomas Calvert
Keyword(s):  
Electrical Properties ◽  
Frequency Dependence ◽  
Time Constant ◽  
Time Domain ◽  
Induced Polarization ◽  
Dc Resistivity ◽  
Impedance Model ◽  
Domain Integral ◽  
The Relationship

The Cole‐Cole impedance model developed in Pelton et al. (1978) for describing the induced polarization (IP) phenomenon has proven to be useful for characterizing the electrical properties of rocks. The model characterizes the impedance Z(ω) of a rock using only four parameters as follows [Formula: see text] where [Formula: see text] is the DC resistivity, m is the dimensionless chargeability, τ is the time constant, c is the frequency dependence, and [Formula: see text] [Formula: see text]

Sign in / Sign up

Export Citation Format

Share Document