Vibrational Control of a Laser Illuminated Thermochemical System

1988 ◽  
Vol 110 (2) ◽  
pp. 109-113 ◽  
Author(s):  
J. Bentsman ◽  
H. Hvostov
Keyword(s):  
Open Loop ◽  
Asymptotically Stable ◽  
Open Loop Control ◽  
Loop Control ◽  
Driven Systems ◽  
Vibrational Control ◽  
Stable Operating ◽  
Control Principle ◽  
Operating Regimes ◽  
Thermochemical Reaction

Vibrational control is a nonclassical open-loop control principle which proposes a utilization of zero mean parametric excitation of a dynamical system for achieving control objectives. In the present paper, excitations introduced into the incident power of a laser beam in a laser illuminated thermochemical reaction are shown to be capable of inducing asymptotically stable operating regimes with averages located at initially unstable steady states. This opens a possibility of alleviating measurement and actuator related difficulties associated with conventional methods in a stabilization of laser-driven systems.

Experiment With Vibrational Control of a Laser Illuminated Thermochemical System

1990 ◽  
Vol 112 (1) ◽  
pp. 42-47 ◽  
Author(s):  
J. Fakhfakh ◽  
J. Bentsman
Keyword(s):  
Open Loop ◽  
Control Technique ◽  
Loop Control ◽  
Vibrational Control ◽  
Incident Laser Power ◽  
Stable Operating ◽  
Vibrational Stabilization ◽  
Potential Applicability ◽  
On Line ◽  
Operating Regimes

Vibrational control is an open-loop control technique which utilizes zero mean parametric excitations to modify the behavior of dynamical systems in a desired manner. A potential applicability of vibrational control to laser illuminated thermochemical systems has been recently demonstrated analytically by Bentsman and Hvostov (1988). This paper presents experiments with vibrational stabilization of a laser illuminated thermochemical reaction that support the previous findings. A rectangular wave oscillating incident laser power is shown experimentally to induce asymptotically stable operating regimes with averages located at initially unstable steady states as predicted by vibrational control theory. Hence, vibrational control is demonstrated to be a feasible stabilizing strategy for laser induced reactions that needs no on-line measurements and complex actuators.

scholarly journals Interleaved DC-DC Converter with Discrete Duty Cycle and Open Loop Control

2016 ◽  
Vol 53 (4) ◽  
pp. 14-21
Author(s):  
K. Kroics ◽  
A. Sokolovs
Keyword(s):  
Duty Cycle ◽  
Control Algorithm ◽  
Open Loop ◽  
Current Loop ◽  
Open Loop Control ◽  
Output Current ◽  
Loop Control ◽  
Control Principle ◽  
Conduction Mode ◽  
Current Ripple

Abstract The authors present the control principle of the multiphase interleaved DC-DC converter that can be used to vastly reduce output current ripple of the converter. The control algorithm can be easily implemented by using microcontroller without current loop in each phase. The converter works in discontinuous conduction mode (DCM) but close to boundary conduction mode (BCM). The DC-DC converter with such a control algorithm is useful in applications that do not require precise current adjustment. The prototype of the converter has been built. The experimental results of the current ripple are presented in the paper.

Stabilization of the Side Pull-In Bifurcation of an Electrostatic Comb Drive Actuator Model Using Oscillatory Open-Loop Control

2011 ◽  
Author(s):  
I. P. M. Wickramasinghe ◽  
Jordan M. Berg
Keyword(s):  
Open Loop ◽  
Control Voltage ◽  
Stable Range ◽  
Open Loop Control ◽  
Comb Drive ◽  
Loop Control ◽  
Average Value ◽  
Electrostatic Mems ◽  
Operating Region ◽  
Stable Operating

The stable operating region of an electrostatic comb drive actuator in constant-gap mode is limited by a subcritical pitch-fork bifurcation known as side pull-in. We show that oscillatory open-loop control can forestall side pull-in and substantially extend the stable operating region. To our knowledge, this is the first demonstration of control of side pull-in without additional lateral actuators. To our knowledge it is also the first application of open-loop oscillatory control to an electrostatic MEMS model using a single control voltage. Simulations show the stable range of travel increased by over 60%, with an associated oscillation of less than 2%. Although feedback control has been used to stabilize a related bifurcation in electrostatic gap-closing actuators, we show that these approaches are unlikely to succeed for side pull-in. Finally, we present and validate formulas relating parameters of the oscillatory input to the average value and oscillations of the resulting displacement.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation

Precise open-loop control of MEMS deformable mirror shape

2008 ◽  
Author(s):  
Thomas Bifano ◽  
Jason Stewart ◽  
Alioune Diouf
Keyword(s):  
Open Loop ◽  
Deformable Mirror ◽  
Open Loop Control ◽  
Loop Control

Responses and Optimization of a PID-Based Speed Regulating System of the Planetary Mixer

2011 ◽  
Vol 418-420 ◽  
pp. 1865-1868
Author(s):  
Ming Jin Yang ◽  
Xi Wen Li ◽  
Zhi Gang Wang ◽  
Tie Lin Shi
Keyword(s):  
Control System ◽  
Open Loop ◽  
Open Loop Control ◽  
Efficient Operation ◽  
Loop Control ◽  
Loop Control System ◽  
Response Optimization ◽  
Close Loop Control ◽  
Close Loop Control System

The performance of speed regulating is very important to the mixing process with safe, efficient operation and high quality of production. Strategies and practices of responses and optimization of a PID-based speed regulating system of a planetary mixer were presented in this paper. Research results show that: by means of the signal constraint function presented by Simulink Response Optimization, optimization PID parameters of the 2-DOF-PID controller can be obtained, and the response of close-loop control system has quite good performance of overshoot, response time, and stability compared with an open-loop control system.

Experimental Verification of Open-loop Control for an Underwater Eel-like Robot

2002 ◽  
Vol 21 (10-11) ◽  
pp. 849-859 ◽  
Author(s):  
Kenneth A. Mcisaac ◽  
James P. Ostrowski
Keyword(s):  
Experimental Work ◽  
Experimental Verification ◽  
Vision System ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Position Sensing ◽  
Theoretical Predictions ◽  
Approximate Expressions ◽  
Good Agreement

In this paper, we describe experimental work using an underwater, biomimetic, eel-like robot to verify a simplified dynamic model and open-loop control routines. We compare experimental results to previous analytically derived, but approximate expressions for proposed gaits for forward/backward swimming, circular swimming, sideways swimming and turning in place. We have developed a five-link, underwater eel-like robot, focusing on modularity, reliability and rapid prototyping, to verify our theoretical predictions. Results from open-loop experiments performed with this robot in an aquatic environment using an off-line vision system for position sensing show good agreement with theory.

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