Parallel analog VLSI architectures for computation of heading direction and time-to-contact
Giacomo Indiveri, Jörg Krämer, Christof Koch · CaltechAUTHORS (California Institute of Technology) · 1995
We describe two parallel analog VLSI architectures that integrate optical flow data obtained from arrays of elementary velocity sensors to estimate heading direction and time-to-contact. For heading direction computation, we performed simulations to evaluate the most important qualitative properties of the optical flow field and determine the best functional operators for the implementation of the architecture. For time-to-contact we exploited the divergence theorem to integrate data from all velocity sensors present in the architecture and average out possible errors. 1 Introduction We have designed analog VLSI velocity sensors invariant to absolute illuminance and stimulus contrast over large ranges that are able to achieve satisfactory performance in a wide variety of cases; yet such sensors, due to the intrinsic nature of analog processing, lack a high degree of precision in their output values. To exploit their properties at a system level, we developed parallel image pr...