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Distribution of precise time reference in an Ethernet network allows the implementation of distributed measurement systems, overcoming the limitations of a complex architecture. This paper deals with a displacement sensor network that is built over Ethernet and synchronized according to IEEE 1588. Measurement devices share the same time reference, enabling accurate calculation of cross-derived quantities (multidimensional speed and acceleration). In this paper, a description of the sensor architecture is given, and attention is focused on the IEEE 1588 implementation. In particular, the proposed low-cost system does not use any dedicated synchronization hardware, but it can reduce the deviation from time reference down to 20 μs. [ABSTRACT FROM AUTHOR]

This paper describes an innovative approach for position estimation using traditional displacement inductive sensors such as linear variable transducers. In addition, the same algorithm offers an evaluation of velocity and acceleration. However, the same approach can be applied to any other kind of alternating-current-excited sensor. The proposed method overcomes the typical limit of traditional processing techniques as coherent demodulation or spectral analysis by implementing a least mean squares estimation of the variables of interest. A working prototype has been designed around a low-cost digital signal processor from Texas Instruments Inc., and an estimation time on the order of 1 ms has been obtained. In static conditions, the resolution is about 0.01% of the full scale of the considered sensor, which is on the same order as the one obtained with spectral estimation. In dynamic conditions, simulations show a performance improvement in position and velocity estimation with a sensible root mean square error (RMSE) reduction. The experimental results in dynamic conditions are difficult to quantify, owing to noise, even if the performances are better than with traditional methods. [ABSTRACT FROM AUTHOR]

This paper presents a novel instrument for the analysis of signals coming from a matrix of differential variable reluctance transducers (DVRTs). The signal processing technique is based on a fast Fourier transform (FFT) evaluation. The main objectives are compactness and a short elaboration time. In particular, information from up to 11 different sensors can be simultaneously processed with an overall measuring time of about 300 µs. Experimental results show a standard deviation in the ±0.3 µm order. [ABSTRACT FROM AUTHOR]