Fast Location of Thermal Target with Low Offset and Spatial Filter of Winner-Take-All Circuit
A new modified infrared tracking sensor array with spatial filter is proposed, which identifies the locations and sizes of thermal object efficiently with the winner-take-all (WTA) circuit and a low offset correlated double sampling (CDS) circuit. The winner-take-all (WTA) circuit is used in combination with active readout circuit for thermopile array. In this circuit, thermal image intensity has been chosen for the input saliency map. The removal process is performed by zeroing the values of the thermal image background intensity levels, so only the potential thermal objects of interest are compared by the WTA. The offset reduction with CDS technique enhances the sensitivity of winner-take-all (WTA) circuit and shows a sharp selectivity which makes it possible to pick up only one winner pixel from each thermal object. In order to simulate and present the infrared thermal sensor array in this paper, the sensor array is integrated by using a 2P4M 0.35μm standard CMOS technology. This proposed architecture shows a high resolution with two orders higher than the circuits without CDS. The results have shown that integrated thermopile array with WTA and CDS can approach a high level of development, reliability and easy for high accuracy infrared tracking applications.
Zhengyi Jiang and Chunliang Zhang
J. Q. Wang et al., "Fast Location of Thermal Target with Low Offset and Spatial Filter of Winner-Take-All Circuit", Advanced Materials Research, Vols. 97-101, pp. 4371-4374, 2010