Design and Control of a Piezo-Based Fast Tool Servo System for Precision Diamond Turning

2007 ◽  
Vol 339 ◽  
pp. 195-199 ◽  
Author(s):  
Y.H. Yang ◽  
Shi Jin Chen ◽  
K. Cheng
Keyword(s):  
Piezoelectric Actuator ◽  
Diamond Turning ◽  
Pi Control ◽  
Fast Tool Servo ◽  
Tracking Accuracy ◽  
Compact Structure ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Nonlinearity Effect ◽  
Loop Control System

A novel fast tool servo driven by piezoelectric actuator for precision diamond turning is designed in this paper. To overcome the inherent hysteresis and drift nonlinearity effect of the piezoelectric actuator, a closed-loop control system is established using strain gauge integrated in the actuator for position feedback, which has compact structure and can avoid interference in the machining. Furthermore, a fuzzy PI control algorithm is presented. It has not only the advantages of agility and adaptability of fuzzy control, but the characteristics of high accuracy of PI arithmetic. At last, experiments are carried out and the results show that the fuzzy PI control provides significantly better tracking accuracy and robustness against hysteresis and drift effects.

Turning of Micro-Structured Surfaces Based on a Fast Tool Servo System

2014 ◽  
Vol 684 ◽  
pp. 308-312 ◽  
Author(s):  
Xiao Hui Wang ◽  
Zhi Ding ◽  
Yu Zhen Ma
Keyword(s):  
Piezoelectric Actuator ◽  
Closed Loop ◽  
Tracking Error ◽  
Servo System ◽  
Diamond Turning ◽  
Fast Tool Servo ◽  
Precision Engineering ◽  
Loop Control ◽  
Structured Surfaces ◽  
Grid Surface

A fast tool servo system is developed for the fabrication of micro-structured surface on a diamond turning machine. The fast tool servo (FTS) system in this investigation employs a piezoelectric actuator to actuate the diamond tool and a capacitance probe as the feed back sensor. To compensate the inherent nonlinear hysteresis behavior of the piezoelectric actuator, Proportional Integral (PI) closed loop control with a feed-forward predictor is implemented. The result of closed loop experiment in FTS demonstrates that the tracking error has been reduced to a level of less than 150nm. Actual experiment of fabricating the sinusoidal grid surface was performed on an ultra-precision diamond turning machine designed by Center of Precision Engineering of HIT. The fabrication of a sinusoidal grid surface has indicated the effectiveness of the fabrication system.

An Expert Controller Based on Transient Response Patterns

2011 ◽  
Vol 219-220 ◽  
pp. 3-7
Author(s):  
Ning Zhang ◽  
Rong Hua Liu
Keyword(s):  
Control System ◽  
Transient Response ◽  
Closed Loop ◽  
Performance Criterion ◽  
Response Patterns ◽  
Loop Control ◽  
Expert Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Control Decision

An expert control system based on transient response patterns and expert system techniques is proposed in this paper. Depending on the features of the closed-loop control system determines the control decision and adjusts the parameters of the controller. The proposed method requires minimal proper information about the controlled plant and, with the linear re-excitation learning method, the system is kept satisfying the performance criterion.

scholarly journals Closed-loop control system for well-defined oxygen supply in micro-physiological systems

2017 ◽  
Vol 3 (2) ◽  
pp. 363-366
Author(s):  
Tobias Steege ◽  
Mathias Busek ◽  
Stefan Grünzner ◽  
Andrés Fabían Lasagni ◽  
Frank Sonntag
Keyword(s):  
Control System ◽  
Oxygen Supply ◽  
Closed Loop ◽  
Microfluidic System ◽  
Closed Loop Control ◽  
Loop Control ◽  
Cell Vitality ◽  
Closed Loop Control System ◽  
Loop Control System

AbstractTo improve cell vitality, sufficient oxygen supply is an important factor. A deficiency in oxygen is called Hypoxia and can influence for example tumor growth or inflammatory processes. Hypoxia assays are usually performed with the help of animal or static human cell culture models. The main disadvantage of these methods is that the results are hardly transferable to the human physiology. Microfluidic 3D cell cultivation systems for perfused hypoxia assays may overcome this issue since they can mimic the in-vivo situation in the human body much better. Such a Hypoxia-on-a-Chip system was recently developed. The chip system consists of several individually laser-structured layers which are bonded using a hot press or chemical treatment. Oxygen sensing spots are integrated into the system which can be monitored continuously with an optical sensor by means of fluorescence lifetime detection.Hereby presented is the developed hard- and software requiered to control the oxygen content within this microfluidic system. This system forms a closed-loop control system which is parameterized and evaluated.

The Design and Simulation of Three-Phase PWM Converter

2013 ◽  
Vol 321-324 ◽  
pp. 917-920
Author(s):  
Guang Ya Liu ◽  
Xiao Song Li
Keyword(s):  
High Frequency ◽  
Closed Loop ◽  
Voltage Source ◽  
Pwm Rectifier ◽  
Phase Voltage ◽  
Pwm Converter ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Three Phase ◽  
Loop Control System

Three-phase voltage source PWM rectifier generally adopts double closed loop control system. According to the high frequency characteristic of three-phase voltage source PWM rectifier, this paper put forward the setting method of current inner ring regulator and voltage outer ring regulator PI parameter. Finally, it is verified by simulation.

Controlled Freezing of Nonideal Solutions With Application to Cryosurgical Processes

1991 ◽  
Vol 113 (4) ◽  
pp. 430-437 ◽  
Author(s):  
H. M. Budman ◽  
J. Dayan ◽  
A. Shitzer
Keyword(s):  
Cooling Rate ◽  
Freezing Process ◽  
Data Sets ◽  
Tracking Accuracy ◽  
Loop Control ◽  
Set Point ◽  
New Device ◽  
Loop Control System ◽  
The Stability ◽  
Controlled Freezing

Success of a cryosurgical procedure, i.e., maximal cell destruction, requires that the cooling rate be controlled during the freezing process. Standard cryosurgical devices are not usually designed to perform the required controlled process. In this study, a new cryosurgical device was developed which facilitates the achievement of a specified cooling rate during freezing by accurately controlling the probe temperature variation with time. The new device has been experimentally tested by applying it to an aqueous solution of mashed potatoes. The temperature field in the freezing medium, whose thermal properties are similar to those of biological tissue, was measured. The cryoprobe temperature was controlled according to a desired time varying profile which was assumed to maximize necrosis. The tracking accuracy and the stability of the closed loop control system were investigated. It was found that for most of the time the tracking accuracy was excellent and the error between the measured probe temperature and the desired set point is within ±0.4°C. However, noticeable deviations from the set point occurred due to the supercooling phenomenon or due to the instability of the liquid nitrogen boiling regime in the cryoprobe. The experimental results were compared to those obtained by a finite elements program and very good agreement was obtained. The deviation between the two data sets seems to be mainly due to errors in positioning of the thermocouple junctions in the medium.

Closed Loop Identification by Optimization Method

2015 ◽  
Vol 1084 ◽  
pp. 636-641
Author(s):  
Valeriy F. Dyadik ◽  
Nikolay S. Krinitsyn ◽  
Vyacheslav A. Rudnev
Keyword(s):  
Closed Loop ◽  
Uranium Hexafluoride ◽  
Optimization Method ◽  
Model Parameters ◽  
Control Loop ◽  
Loop Control ◽  
Identification Method ◽  
Closed Loop Control System ◽  
Closed Loop Identification ◽  
Loop Control System

The article is devoted to the adaptation of the controller parameters during its operation as a part of a control loop. The possibility to identify the parameters of the controlled plant model in the closed control loop has been proved by a computer simulation. The described active identification method is based on the response processing of the closed loop control system to standard actions. The developed algorithm has been applied to determine the model parameters of the flaming fluorination reactor used for the production of uranium hexafluoride. Designed identification method improves the quality of the product and the efficiency of the entire production.

Adaptive synchronization of uncertain fractional-order chaotic systems using sliding mode control techniques

2019 ◽  
Vol 234 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Bahram Yaghooti ◽  
Ali Siahi Shadbad ◽  
Kaveh Safavi ◽  
Hassan Salarieh
Keyword(s):  
Control System ◽  
Sliding Mode Control ◽  
Fractional Order ◽  
Chaotic Systems ◽  
Closed Loop ◽  
Sliding Mode ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the effectiveness of this method.

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