Normal flow measurement visual motion sensor

This paper presents a two-dimensional programmable normal optical flow measurement chip implemented in 0.5mum CMOS process. The chip is composed of an array of 120times80 APS pixels. The processing circuitry at the periphery of this array computes partial derivatives with respect to space and time and uses them to calculate the normal flow. The spatial derivatives can be programmed to implement 5times5, 3times3 or 1times3 kernels to control the degree of smoothness of the derivatives. The chip occupies an area of 9 mm² and consumes 34.5 mW power (V_dd = 5V). The operation of the chip is demonstrated by first presenting results from individual blocks and then from system-level testing