Pixel-level APS Sensor Integration and Sensitivity Scaling for Vision Based Speed Measurement

A dual-pixel APS sensor architecture is proposed in this paper, for vision based speed measurement applications, based on a novel double exposure method. The sensor integrates two type of imaging elements on pixel level, and is designed to generate two spatially and temporally coherent images. The primary sensor generates a good quality image for vehicle identification, while the output of the secondary sensor is used to calculate speed estimates, based on the intra-frame displacement of the vehicle's headlight. A scaling process has also been developed for the sensitivity of the secondary sensor, based on photodiode parasitic capacitor discharge time.