Study of a Precision Pneumatic Positioning Device Using PZT Dither

2011 ◽  
Vol 5 (6) ◽  
pp. 780-785 ◽  
Author(s):  
Yung-Tien Liu ◽  
◽  
Kuo-Ming Chang ◽  
Huang-Ren Lee ◽  
Keyword(s):  
High Frequency ◽  
Pid Controller ◽  
Position Control ◽  
Target Position ◽  
Positioning System ◽  
Optimal Parameters ◽  
High Frequency Response ◽  
Nonlinear Motion ◽  
Positioning Device ◽  
Motion Characteristic

A piezoelectric (PZT) actuator featuring a high frequency response is employed to serve as a highfrequency dither and to compensate for the nonlinear motion characteristic of a pneumatic positioning device. To examine the function of the PZT dither, system identification based on a linear model for describing the positioning device was performed. To obtain the most suitable actuating parameters of the PZT dither, the Taguchi method was employed. Using the optimal parameters, the positioning system implemented by the PID controller was configured. For a target position of 4 mm, position control with a positioning accuracy under 0.1 µm was demonstrated. Compared to the pneumatic positioning device using a traditional controller, the device presented in this study features better positioning ability.

Pneumatic Proportional Position Control System Based on BP Neural Networks

2004 ◽  
Vol 471-472 ◽  
pp. 528-531
Author(s):  
Y.J. Liu ◽  
X.Z. Kong ◽  
Z.W. Li
Keyword(s):  
Neural Networks ◽  
Working Conditions ◽  
Pid Controller ◽  
Position Control ◽  
Control Method ◽  
Back Propagation ◽  
Positioning System ◽  
Proportional Valve ◽  
Rod System ◽  
Position Control System

A PID controller based on Back-propagation neural networks is presented and used to the pneumatic proportional positioning system in this paper. A proportional valve-cylinder without rod system for buffering and positioning, which is controlled by microcomputer, is designed and completed in this paper. The experimental results show that the system gains self-adaptability because of the application of this control method. And the buffering and positioning of the cylinder can be implemented under different working conditions.

scholarly journals Position Control of Pneumatic Actuator Using Self-Regulation Nonlinear PID

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Syed Najib Syed Salim ◽  
Mohd Fua’ad Rahmat ◽  
Ahmad ’Athif Mohd Faudzi ◽  
Zool H. Ismail ◽  
Noorhazirah Sunar
Keyword(s):  
Pid Controller ◽  
Position Control ◽  
Self Regulation ◽  
Nonlinear Function ◽  
Experimental Tests ◽  
Pneumatic Actuator ◽  
Rate Variation ◽  
Positioning System ◽  
Error Signal ◽  
Nonlinear Gain

The enhancement of nonlinear PID (N-PID) controller for a pneumatic positioning system is proposed to improve the performance of this controller. This is executed by utilizing the characteristic of rate variation of the nonlinear gain that is readily available in N-PID controller. The proposed equation, namely, self-regulation nonlinear function (SNF), is used to reprocess the error signal with the purpose of generating the value of the rate variation, continuously. With the addition of this function, a new self-regulation nonlinear PID (SN-PID) controller is proposed. The proposed controller is then implemented to a variably loaded pneumatic actuator. Simulation and experimental tests are conducted with different inputs, namely, step, multistep, and random waveforms, to evaluate the performance of the proposed technique. The results obtained have been proven as a novel initiative at examining and identifying the characteristic based on a new proposal controller resulting from N-PID controller. The transient response is improved by a factor of 2.2 times greater than previous N-PID technique. Moreover, the performance of pneumatic positioning system is remarkably good under various loads.

An innovative prone positioning system for advanced deformity and frailty in complex spine surgery

2020 ◽  
Vol 32 (2) ◽  
pp. 229-234
Author(s):  
Benjamin Kolb ◽  
John Large ◽  
Stuart Watson ◽  
Glyn Smurthwaite
Keyword(s):  
Ankylosing Spondylitis ◽  
Three Dimensional ◽  
Technical Note ◽  
Positioning System ◽  
Prone Positioning ◽  
Economic Implications ◽  
Potential Safety ◽  
Chest Deformity ◽  
Positioning Device ◽  
Skin Quality

The authors present a technical note for a prone positioning system developed to facilitate cervical extension osteotomy for ankylosing spondylitis in the presence of severe deformity and frailty. Chin-on-chest deformity represents one of the most debilitating changes of ankylosing spondylitis. Where the chin-brow angle approaches or exceeds 90°, prone positioning becomes problematic due to the fixed position of the head. Furthermore, the challenge is compounded where physiological deconditioning leads to frailty, and the side effects of medical therapies decrease muscle mass and skin quality. Conventional prone positioning equipment is not able to cater to all patients. A versatile system was developed using a 3D reconstruction to enable a positioning simulation and verification tool. The tool was used to comprehensively plan the perioperative episode, including spatial orientation and associated equipment. Three-dimensional printing was used to manufacture a bespoke positioning device that precisely matched the contours of the patient, reducing contact pressure and risk of skin injury. The authors were able to safely facilitate surgery for a patient whose deformity and frailty may otherwise have precluded this possibility. The system has potential safety and economic implications that may be of significant utility to other institutions engaging in complex spinal surgery.

Study on Nonlinear Motion Behavior of Coupled Heave-Pitch for the Classic Spar Platform Based on AQWA

2012 ◽  
Vol 170-173 ◽  
pp. 2170-2174 ◽  
Author(s):  
Song Sang ◽  
Yuan Zhou ◽  
Xue Liang Jiang
Keyword(s):  
Incident Wave ◽  
Wave Amplitude ◽  
Wave Period ◽  
Critical Periods ◽  
Spar Platform ◽  
Natural Period ◽  
Nonlinear Motion ◽  
Motion Characteristic ◽  
Instability Parameter ◽  
Motion Behavior

This paper used AQWA software to research the nonlinear motion characteristic of heave-pitch coupling of classical Spar platform in regular waves. With classic Spar platform as an example, the wave amplitude and periodic changes’ effect to the nonlinear motion behavior of coupled heave-pitch is researched. After calculation, the critical periods corresponding to the different incident wave amplitude are obtained, based which, gets the instability parameter domain of coupling resonance of platform in the wave period-amplitude plane. The results in this paper show that the heave-pitch coupled resonance of platform depends on the wave amplitude and the ratio of the natural period of heave and pitch, and the incident wave period.

scholarly journals Optimized PID Position Control of a Nonlinear System Based on Correlating the Velocity with Position Error

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Nenad Muškinja ◽  
Matej Rižnar
Keyword(s):  
Pid Controller ◽  
Position Control ◽  
Design Approach ◽  
Control Loop ◽  
Real Time Control ◽  
Laboratory Setup ◽  
Time Control ◽  
Beam System ◽  
Ball Velocity ◽  
Ball And Beam System

We examined a design approach for a PID controller for a nonlinear ball and beam system. Main objective of our research was to establish a nonmodel based control system, which would also not be dependent on a specific ball and beam hardware setup. The proposed PID controller setup is based on a cascaded configuration of an inner PID ball velocity control loop and an outer proportional ball position control loop. The effectiveness of the proposed controller setup was first presented in simulation environment in comparison to a hardware dependent PD cascaded controller, along with a more comprehensive study on possible design approach for optimal PID controller parameters in relation to main functionality of the controller setup. Experimental real time control results were then obtained on a laboratory setup of the ball and beam system on which PD cascaded controller could not be applied without parallel system model processing.

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