Adaptive feature extraction to detect letters and edges on vehicle landing surfaces

Abstract

A vison-based landing system comprises a processor onboard an aerial vehicle, an onboard vision sensor, onboard aiding sensors, and a data storage unit. The processor hosts an adaptive feature extraction module operative to perform a method that comprises capturing an image of a landing area having a plurality of edge features; calculating an estimated slope of an expected edge feature; calculating an expected gradient direction of the expected edge feature; selecting a horizontal basis kernel for the expected edge feature along an expected horizontal gradient; selecting a vertical basis kernel for the expected edge feature along an expected vertical gradient; calculating a combined convolution kernel for the expected edge feature based on the horizontal and vertical basis kernels, the estimated slope, and the expected gradient direction; and performing a convolution operation on the image using the combined convolution kernel to obtain an edge feature image of the landing area.