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Your search keyword '"Riewruja, Vanchai"' showing total 102 results
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102 results on '"Riewruja, Vanchai"'

2. Linear Variable Differential Transformer Signal Conditioning Circuit Based on Phase-Locked Loop.

Author

Songsuwankit, Kanoknuch, Petchmaneelumka, Wandee, Riewruja, Vanchai, and Rerkratn, Apinai

Subjects
DIFFERENTIAL transformers, PHASE-locked loops, MICROROBOTS, NONLINEAR oscillators, ELECTRIC inductance, OPERATIONAL amplifiers, SQUARE waves
Abstract

The purpose of this paper is to propose a novel technique for extracting the position signal from an inductive displacement transducer named a linear variable differential transformer (LVDT). In general, the movement of the LVDT core causes its primary inductance change in linear form. The primary winding of the LVDT is used as a time-dependent element for the triangular and square wave generator, which can be called self-oscillation, to generate frequency. The advantage of the proposed technique is that it can measure the displacement using the LVDT without an external oscillator. The change in primary inductance causes the frequency deviation generated by the oscillator. The deviated frequency is captured and converted into a voltage signal using the principle of the phase-locked loop. All the components used in this study are commercially available. The merits of this proposed technique are simple configuration, small size, and low cost. Moreover, the operating range of the LVDT can be extended without the limitation of the nonlinear transfer characteristic. The performance of the proposed technique is discussed in detail and confirmed by experimental implementation. Experimental results show that the maximum error from the proposed technique is about 0.42% and the operating range of the LVDT can be extended to more than 200%. It can be seen that the proposed technique is suitable for embedded measurement in small or micro robots. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Simple LVDT Demodulator

Author

Rerkratn, Apinai, primary, Luangpol, Amata, additional, Riewruja, Vanchai, additional, and Petchmaneelumka, Wandee, additional

Published
2020
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25. Nonlinear backstepping control design applied to magnetic ball control

Author

P. Pranayanuntana and Riewruja Vanchai

Subjects
Nonlinear system, Exponential stability, Control theory, Backstepping, Control system, Ball (bearing), Piecewise, Nonlinear control, Robust control, Mathematics
Abstract

The backstepping nonlinear control design scheme has been used for many years. The paper presents the use of backstepping nonlinear control design to asymptotically track the position of a magnetic ball-levitated ball. The model of the magnetic ball used is nonlinear. The design uses the backstepping nonlinear control to make the ball able to track an output signal x, a vertical position from some reference point, to a continuous twice-differentiable positive reference signal x/sub r/, asymptotically. This design suggests the use of 2 inputs u/sub 1/ and u/sub 2/ working mutually exclusively together to generate a piecewise continuous control law u.

Published
2002

50. Simple resistance-to-period converter for resistive sensors.

Author

Tongpakpanang, Jaturon, Rerkratn, Apinai, Kaewpoonsuk, Anucha, Riewruja, Vanchai, and Petchmaneelumka, Wandee

Abstract

A method for realization of resistance-to-period converter is introduced in this article. The principle of converter utilizes the behavior of designed astable multivibrator, which is implemented using commercial available and low cost devices. The operation of proposed converter circuit is in current mode. Therefore, the resistance is linearly converted to period and also converted to frequency with invert proportional relationship. The conversion gain of the proposed converter can be adjusted by electronic means. The configuration of the proposed converter is simple and small in size. Experimental results verifying the proposed converter performance are included in detail. The relative error of about 0.8 % is observed. [ABSTRACT FROM PUBLISHER]

Published
2012

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