A CMOS Ultra-Low Power Vision Sensor With Image Compression and Embedded Event-Driven Energy-Management

This paper presents an energy-aware CMOS vision sensor, targeted to surveillance and monitoring applications. The 64 × 64 pixels sensor directly estimates and binarizes the spatio-temporal contrast with a power consumption of 30 μW, at 30 fps and 3.3 V supply voltage. The sensor embeds event detection and energy management capabilities, which meet the requirements of an energy autonomous system. Data compression and fast readout delivering turn into a chip low power performance and duty-cycle optimization of the external processor, devoted to visual processing and communication. A preliminary prototype of vision system has been developed, estimating motion and looking for events occurring in the scene. It consists of the vision sensor interfaced with a small-density CPLD and a tiny micro-controller for data readout and communication. Here, the vision system performs ultra-low power consumption of about 1 mW. The presented system exhibits an operating life of more than four months, powered with 950 mA·h battery and a duty-cycle of 5%.