Conference Paper: Piezoelectric sensors for taxiway airport traffic control system[Show abstract] [Hide abstract] ABSTRACT: This paper reviews the operation principles of piezoelectric sensors for airport surface movement control. Using an array of sensors, it enables the detection of moving objects as well as their classification according to their tire configurations, velocity, and direction of movement. Preliminary experimental results using thin film piezoelectric sensors confirm the predicted operation characteristics and show the applicability of piezoelectric sensors for monitoring airport surface movement. A preliminary version using piezoresistive thin film sensors has been presented and published . This paper also provides an approach to eliminate the insensitive zone and reveals more insights on feasible design.
- [Show abstract] [Hide abstract] ABSTRACT: In this correspondence, reconstruction of a uniformly sampled sequence from a nonuniformly sampled transient sequence using symmetric extension is described. First, a relationship between the discrete Fourier transform (DFT) of a uniformly sampled sequence and the DFT of a nonuniformly sampled sequence is obtained. From the relationship, the formula to reconstruct the DFT of a uniformly sampled sequence from the DFT of a nonuniformly sampled sequence is derived when the nonuniform sampling ratios are known. Second, a symmetric extension of the nonuniformly sampled sequence is described to avoid discontinuity that adds high-frequency content in the DFT. Finally, experimental results are presented.
- [Show abstract] [Hide abstract] ABSTRACT: This paper outlines the operation principles with the piezo electric sensors for airport surface movement control. This type of sensor enables one not only to essentially reduce power consumption to a level acceptable by sustainable sensor network, but also to perform moving object detection on voltage impulse created by pressure from moving objects, as well as to perform automatic classification of objects according to their weights, speed and direction of movement. The preliminary result of experimental tests on piezo thin film sensor, which is light weight and bears similar physical properties as piezo electric sensor, confirms the predicted operation characteristics, and shows the applicability of piezo electric sensors for monitoring airport surface movement.
- [Show abstract] [Hide abstract] ABSTRACT: This is a paper describing theories and applications of digital spectrum analysis technique for nonuniformly sampled very fast burst like signals. The difficulty in sampling this kind of signals lies in the fact that the length of the signal is shorter than the affordable sampling time of current measuring instrumentation. The majority of the digital signal processing theories for nonuniformly sampled signals developed so far has always assumed random equivalent time sampling (or periodic nonuniform sampling) on signals with length much longer than the affordable sampling time. However, in practice, very fast burst-like signals occur in much scientific instrumentation and new digital spectrum analysis technique for nonuniformly sampled signals of this class is in demand. In this paper, we first derive a digital spectral representation of a nonuniformly sampled very fast burst-like signal, and then present a detailed spectrum analysis of a nonuniformly sampled sinusoid cycle. It is found that DFT of a nonuniformly sampled very fast burst-like signal can be represented in terms of the DFT of sampled data sequence obtained by sampling the signal at uniform rate. The signal-to-noise ratio of the sampling results is discussed. We then introduced a practical high-speed waveform digitizer for very fast burst-like signal, and indicated the theory developed in this paper can be applied to analyze the errors caused by timing jitter. Specifically, we analyze waveform digitizers which utilize delay line techniques to extend their capabilities with the current monolithic A/D converter technology. Theoretical results are confirmed by the simulation results with a very fast burst-like signal.