Open AccessContactless high frequency inductive position sensor with DSP read out electronics utilizing band-pass sampling
Author(s) -
Bernhard Aschenbrenner,
Bernhard Zagar
Publication year - 2014
Publication title -
acta imeko
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.178
H-Index - 12
eISSN - 2221-870X
pISSN - 0237-028X
DOI - 10.21014/acta_imeko.v3i3.76
Subject(s) - inductive sensor , position sensor , signal (programming language) , sampling (signal processing) , lookup table , electrical engineering , digital signal processing , demodulation , position (finance) , electronic engineering , electronics , transmitter , antenna (radio) , acoustics , transducer , computer science , engineering , physics , filter (signal processing) , rotor (electric) , channel (broadcasting) , finance , economics , programming language
This paper presents a precise, reliable, low cost and contactless inductive absolute position measurement system for rough industrial environments. It offers a high inherent resolution (0.04 % of antenna length), and measures absolute position over a relative wide measurement range. The main property for this kind of sensor is its good immunity to external noise and target misalignment off the measurement axis. The measurement range and the precision are extended by adding additional and finer pitched receive coils. This sensor works on similar principles as resolvers but consists of a rectangular antenna PCB, a small moveable passive LC resonant circuit and a signal processing unit. Furthermore, the used read out electronics utilizes under-sampling to demodulate the sensor output signals and the corresponding position is estimated from a lookup table (LUT) implemented on a digital signal processor (DSP) to avoid singularities in the inverse tangent and cotangent calculation. Moreover, the mechanical transducer arrangement, the signal condition electronics design and measurement results of the transmitter to receiver signal coupling and relative position error will be presented.