OPTICAL FLOW NAVIGATION SYSTEM

An optical navigation sensor includes four two-dimensional imagers, each aligned with an x or y axis of an orthogonal xyz coordinate system, and each defining mutually parallel vertical image directions and the same horizontal directions about a yaw axis. Translation or roll, pitch, and yaw cause image flow or movement, which can be determined by cross-correlation of successive images. Translation in the x or y direction is determined by differencing image motion in the horizontal direction, and translation in the z direction is determined by summing the image motion in the vertical direction. Pitch about x and roll about y are determined by differencing image motion in the vertical direction, and yaw about z is determined by summing the image flow in the horizontal direction.