A 128×128 Electronically Multi-Foveated Dynamic Vision Sensor With Real-Time Resolution Reconfiguration

• Published in: IEEE access 2024, Vol.12, p.192656-192671
• Main Authors: Faramarzi, Farnaz, Linares-Barranco, Bernabe, Serrano-Gotarredona, Teresa
• Format: Article
• Language: English
• Subjects: Automation; Circuits; Data processing; Dynamic range; Fovea; Foveated dynamic vision sensor; foveated vision; High resolution; macro-pixel; Moving object recognition; multi-fovea; Noise sensitivity; Photoelectric effect; Photoreceptors; pixel grouping; Pixels; Real time; Real-time systems; Reconfiguration; Robot sensing systems; Robotics; Sensitivity; Sensors; Spatial data; Spatial resolution; Switches; Transient analysis; Vision sensors; Voltage; Voltage control
• ISSN: 2169-3536; 2169-3536
• DOI: 10.1109/ACCESS.2024.3519035

This paper presents the design and implementation of a 128\times 128 electronically foveated dynamic vision sensor (EF-DVS) fabricated using 350 nm CMOS technology. The EF-DVS integrates a novel pixel grouping approach that permits real-time dynamic resolution adjustments via external digital signals. Previous approaches rely on physically crafting high- and low-resolution regions, which require a mechanical setup for tracking moving objects within the fovea. Here, our innovation supports flexible and fast operation modes, acting on amplified photocurrents, allowing the sensor to operate in both high-resolution and low-resolution settings, and to configure multiple high-resolution regions of interest (ROIs) with arbitrary shapes and sizes within the pixel array in real-time. Although the pixel circuitry is more complex than its un-foveated predecessor, we have kept the same pixel area, sacrificing slightly fixed pattern noise (FPN). The sensor achieves a latency of 3.66~{\mu \text {s}} and demonstrates a contrast sensitivity down to 1.03%. It maintains a dynamic range exceeding 120 dB and an intra-scene dynamic range above 60 dB. Notably, the power consumption is reduced with respect to its predecessor, down to 0.7 mW at 100 Keps when configured in low-resolution mode with a 2\times 2 pixel grouping. The ability to dynamically adjust spatial resolution reduces noise event rates, enhances sensitivity, and lowers both data bandwidth and processing requirements. These features make the EF-DVS a suitable candidate for applications in robotics, surveillance, and real-time monitoring systems where efficient data processing and low latency are critical.