Feedback Control of a Thermomechanical Inplane Microactuator Using Piezoresistive Displacement Sensing

2004 ◽  
Author(s):  
Robert K. Messenger ◽  
Timothy W. McLain ◽  
Larry L. Howell
Keyword(s):  
Thin Film ◽  
Feedback Control ◽  
Signal Strength ◽  
Mems Devices ◽  
Integral Control ◽  
Output Displacement ◽  
Limited Success ◽  
And Performance ◽  
Proportional Integral Control ◽  
Analog Circuitry

Feedback control has proven useful in improving reliability and performance for a variety of systems. However there has been limited success implementing feedback control on surface micromachined MEMS devices. The inherent difficulties in sensing microscale phenomena complicate the development of an economical transducer that can accurately monitor the states of a surface micromachined system. We have demonstrated a simple and effective sensing strategy that uses the piezoresistive property of the polysilicon thin film of which surface micromachined MEMS devices are fabricated. The states of the device are monitored by measuring the change in resistance of flexible members which deflect as the device moves. Measurement of the output displacement of an in-plane thermal actuator is presented as a candidate application. While there still is a noise issue to be dealt with, this approach provides adequate signal strength to implement feedback control using off-chip analog circuitry. Implementation of proportional/integral control on the system is successfully demonstrated.

Radial-basis-function-based feedforward—feedback control for air—fuel ratio of spark ignition engines

2008 ◽  
Vol 222 (3) ◽  
pp. 415-428 ◽  
Author(s):  
Y J Zhai ◽  
D L Yu
Keyword(s):  
Neural Network ◽  
Feedback Control ◽  
Fuel Injection ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Integral Control ◽  
Engine Simulation ◽  
Fuel Ratio ◽  
Angle Change ◽  
Proportional Integral Control

In this paper, a feedforward—feedback control is developed for the air—fuel ratio (AFR) of spark ignition engines using neural network estimators. To maintain the AFR at stoichiometric value, the throttle angle change is seen as a disturbance, from which the air flowrate is predicted. The injected fuel is also predicted using the inverse of the fuel injection dynamics. The proposed method is evaluated on an engine simulation benchmark and the performance is shown much improved over proportional—integral control. The new method needs moderate computation and therefore has strong potential to be used in production engines.

FEEDBACK CONTROL AND STATISTICAL PROCESS MONITORING

1996 ◽  
Vol 03 (03) ◽  
pp. 231-241 ◽  
Author(s):  
J. BERT KEATS ◽  
DOUGLAS C. MONTGOMERY ◽  
GEORGE C. RUNGER ◽  
WILLIAM S. MESSINA
Keyword(s):  
Feedback Control ◽  
Process Control ◽  
Statistical Process ◽  
Integral Control ◽  
Engineering Process Control ◽  
Proportional Integral ◽  
The Mean ◽  
Proportional Integral Control ◽  
Differential Control ◽  
Statistical Process Monitoring

In the industrial world, different methodologies have been applied to reduce variability. Engineers whose training is in the quality assurance sciences have frequently used statistical process control (SPC) whereas engineers whose background includes control theory have employed engineering process control (EPC), often in the form of feedback control. SPC is usually applied to processes that vary about a fixed mean, with successive observations viewed as statistically independent. EPC is usually applied to processes in which successive observations are related over time, and where the mean drifts dynamically. The objective of SPC is to reduce variability by the elimination of assignable causes that shift the mean off-target, while EPC continuously adjusts manipulatable variables in the process to keep the mean on target. This study demonstrates the effectiveness of integrating SPC with feedback control for three commonly encountered schemes: Integral Control, Proportional-Integral Control, and Proportional-Integral-Differential Control. A simulation study demonstrates that the combined EPC/SPC scheme significantly reduces overall variability in comparison to feedback control alone when assignable causes are present.

Fabrication and Performance Investigation of Karma Alloy Thin Film Strain Gauge

2021 ◽  
Author(s):  
Peng Lei ◽  
Congchun Zhang ◽  
Yawen Pang ◽  
Shenyong Yang ◽  
Meiju Zhang
Keyword(s):  
Thin Film ◽  
Strain Gauge ◽  
Alloy Thin Film ◽  
And Performance

Measurement of d15 Shear-Mode Piezoelectric Response in PZT Thin Film

2009 ◽  
Vol 421-422 ◽  
pp. 95-98
Author(s):  
Tsuyoshi Aoki ◽  
Shigeyoshi Umemiya ◽  
Masaharu Hida ◽  
Kazuaki Kurihara
Keyword(s):  
Thin Film ◽  
Fem Analysis ◽  
Active Part ◽  
Piezoelectric Response ◽  
Small Displacement ◽  
Shear Mode ◽  
Mems Devices ◽  
Pzt Film ◽  
Pzt Thin Film ◽  
Piezoelectric Constants

Piezoelectric films using d15 shear-mode can be applied to many useful MEMS devices. The small displacement derived from the d15 shear-mode was directly observed by a SPM measurement. An isolated PZT(52/48) active part having a pair of driving Cu electrodes was processed in a 5 m-thick sputtering film. The displacement measurement of the active part and its FEM analysis suggested that the estimated d15 piezoelectric constant of the film was 590 pm/V. And, the d31 value of the film was -120 pm/V measured by a conventional cantilever method. The obtained piezoelectric constants of the PZT film are near those of bulk.

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