scholarly journals Modal Engineering of Inductive Circuits to Achieve Rapid Settling Times

2021 ◽  
Author(s):  
Josh Javor ◽  
Lawrence Barrett ◽  
Matthias Imboden ◽  
Russ Giannetta ◽  
David K. Campbell ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Open Loop ◽  
Hall Sensor ◽  
Control Algorithms ◽  
Rf Coils ◽  
Design Element ◽  
Open Loop Control ◽  
Modeling Tools ◽  
Loop Control ◽  
Important Design

Inductive circuits and devices are a ubiquitous and important design element in many applications such as magnetic drives, galvanometers, magnetic scanners, applying DC magnetic fields to systems, RF coils in NMR systems and vast array of other applications. They are widely used to generate both DC and AC magnetic fields. Many of these applications require a rapid step and settling time, turning the DC or AC magnetic field on and off quickly. The inductive response normally makes this a challenging thing to do. In this article we discuss open loop control algorithms for achieving rapid step and settling times in four general categories of applications: DC and AC systems where the system is either under or over damped. Each of these four categories requires a different algorithm which we describe here. We show the operation of these drive methods using Simulink and Simscape modeling tools, analytical solutions to the underlying differential equations and in experimental results using an inductive magnetic coil and a Hall sensor. Finally, we demonstrate application of these techniques to significantly reduce ringing in a standard NMR circuit. We intend this article to be practical with useful, easy to apply algorithms and helpful tuning tricks.

Yield Improvement via minimization of step height non-uniformity in Chemical Mechanical Planarization (CMP)

2005 ◽  
Vol 867 ◽  
Author(s):  
Muthukkumar Kadavasal ◽  
Sutee Eamkajornsiri ◽  
Abhijit Chandra ◽  
Ashraf F. Bastawros
Keyword(s):  
Chemical Mechanical Planarization ◽  
Open Loop ◽  
Step Height ◽  
Control Algorithms ◽  
Open Loop Control ◽  
Time Step ◽  
Surface Evolution ◽  
Loop Control ◽  
Final Surface ◽  
Pattern Density

AbstractObtaining local and global planarity is one of the prime criteria in dielectric and metal planarizations. Although Chemical Mechanical Planarization (CMP) helps us achieve this criterion in constant pattern density surfaces, the same is not true for variable pattern density surfaces this results in formation of global step heights across the die. This paper provides a pressure open loop control algorithms for obtaining planarity across a die containing variations in pattern densities. Based on the variation of pattern density and surface heights across the die, the surfaces are separated into zones and the pressure is varied spatially and/or temporally to obtain uniform surface heights, with enhanced step height uniformity. One of the algorithms looks ahead and recalculates/modifies the pressure values by identifying the step heights that could be formed after a specified time step. The final surface predictions have improved uniformity on the upper surface as well as on the step heights across the entire die. The simulation would help us track the polishing process for each time step and guide us with the optimized pressure values that can be applied in order to an uniform final surface evolution.

scholarly journals Modal Engineering for MEMS Devices: Application to Galvos and Scanners

2020 ◽  
Author(s):  
Lawrence Barrett ◽  
Matthias Imboden ◽  
Josh Javor ◽  
David K. Campbell ◽  
David J. Bishop
Keyword(s):  
High Speed ◽  
Open Loop ◽  
Optical Systems ◽  
Control Algorithms ◽  
Mems Devices ◽  
Open Loop Control ◽  
Optical Elements ◽  
Loop Control ◽  
High Q ◽  
Change Position

Optical systems typically use galvanometers (aka galvos) and scanners. Galvos move optical elements such as mirrors, quasi-statically, from one static position to another, and an important figure of merit is their step-settle relaxation time. Scanners move in an oscillatory fashion, typically at the device resonant frequency. MEMS devices, which have many advantages and are often used in such optical systems, are typically high Q devices. Moving from one position to another for a galvo or one frequency/amplitude to another for scanners, can take many periods to settle following the ring down. During these transitions, the optical system is inactive and the time is not being efficiently used. In this article we show how a novel class of open loop control algorithms can be used to rapidly change position, frequency and amplitude, typically in well under the period of the device. We show how the MEMS designer can excite, with complete, high-speed control, a vibrational mode of the system. We call this modal engineering, the ability to control the modes of the system in a practical, fast way. This control of the modes is accomplished with open loop control algorithms.

Optimal Control of Nonlinear Structures

1988 ◽  
Vol 55 (4) ◽  
pp. 931-938 ◽  
Author(s):  
J. N. Yang ◽  
F. X. Long ◽  
D. Wong
Keyword(s):  
Optimal Control ◽  
Control Systems ◽  
Active Control ◽  
Control Algorithm ◽  
Open Loop ◽  
Control Algorithms ◽  
Nonlinear Structures ◽  
Open Loop Control ◽  
Loop Control ◽  
Optimal Control Algorithms

Three optimal control algorithms are proposed for reducing oscillations of flexible nonlinear structures subjected to general stochastic dynamic loads, such as earthquakes, waves, winds, etc. The optimal control forces are determined analytically by minimizing a time-dependent quadratic performance index, and nonlinear equations of motion are solved using the Wilson-θ numerical procedures. The optimal control algorithms developed for applications to nonlinear structures are referred to as the instantaneous optimal control algorithms, including the instantaneous optimal open-loop control algorithm, instantaneous optimal closed-loop control algorithm, and instantaneous optimal closed-open-loop control algorithm. These optimal algorithms are computationally efficient and suitable for on-line implementation of active control systems to realistic nonlinear structures. Numerical examples are worked out to demonstrate the applications of these optimal control algorithms to nonlinear structures. In particular, control of structures undergoing inelastic deformations under strong earthquake excitations are illustrated. The advantage of using combined passive/active control systems is also demonstrated.

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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