Experimental Verification of Wide-Field-Integration of Optic Flow for State Estimation

Abstract

This paper discusses the performance of Wide-Field-Integration (WFI) of optic flow when it is applied to a guidance and navigation system for space probes near asteroid surface. WFI of optic flow is a state estimation method inspired by the visual processing system of compound eyes of flying insects. This method has attractive features: low computational cost, applicableness to a lowresolution image sensor, and robustness for unknown environments. Unlike the theory of WFI of optic flow, the region of an image sensor is limited in a real system. In this paper, the effects of the directions of optical axes on estimation accuracy are investigated in numerical simulations and experiments. The evaluation results in simulations indicate the proper directions of optic flow sensors. The results also indicate that under a limited field of view, one optic flow sensor has frequently difficulty to distinguish motion variables from WFI of optic flow. Finally, the results obtained in numerical simulations are examined in experiments by using two image sensors.