Abstract: An apparatus for determining the location and state of an object in an environment is disclosed. Three or more light-emitting beacons are located in the environment, and each beacon transmits a light pattern that contains information needed to identify the beacon. An optical receiver is attached to the object whose location needs to be determined. The optical receiver comprising one or more cameras images the beacons, and identifies the apparent direction from which the beacon is coming based on the pixel or pixels illuminated by the beacon. The optical receiver also decodes the light pattern transmitted by each beacon to identify it. Finally, based on knowledge of the locations of the beacons in the environment and based on the apparent directions from which the beacons appear to be coming, the optical receiver determines its location, and thus the location of the object.

Abstract: An apparatus for determining the location and state of an object in an environment is disclosed. Three or more light-emitting beacons are located in the environment, and each beacon transmits a light pattern that contains information needed to identify the beacon. An optical receiver is attached to the object whose location needs to be determined. The optical receiver comprising one or more cameras images the beacons, and identifies the apparent direction from which the beacon is coming based on the pixel or pixels illuminated by the beacon. The optical receiver also decodes the light pattern transmitted by each beacon to identify it. Finally, based on knowledge of the locations of the beacons in the environment and based on the apparent directions from which the beacons appear to be coming, the optical receiver determines its location, and thus the location of the object.

Abstract: A method for providing vision based hover in place to an air vehicle is disclosed. Visual information is received using one or more image sensors on the air vehicle and based on the position of the air vehicle. A number of visual displacements is computed from the visual information. One or more motion values are computed based on the visual displacements. One or more control signals are generated based on the motion values.

Abstract: An optical flow sensor is presented that directly measures the translational component of the optical flow experienced by the sensor while it is on a moving platform. The translational optical flow is measured by using a gyro to measure the platform's angular rates and then incorporating these angular rates in the optical flow computations in a manner that bypasses lags in the optical flow sensor measurement. In one embodiment, individual “velocity report” optical flow measurements have their rotational component removed before these velocity reports are utilized in the remainder of the optical flow algorithm. In another embodiment, a movable window and shifting techniques are used to form a windowed image that has no rotational optical flow components. In another embodiment, an optical flow sensor is mounted on a gimbal and held to point in one direction even as the platform on which the optical flow sensor is mounted moves.

Abstract: An optical flow sensor is presented that directly measures the translational component of the optical flow experienced by the sensor while it is on a moving platform. A prior art method of measuring translational optical flow is to simply subtract angular rates as measured by a gyro form the optical flow measurements. However this method produces noisy translational optical flow measurements resulting from lags between the gyro measurement and the optical flow measurement. In the teachings herein, translational optical flow is measured by using a gyro to measure the platform's angular rates and then incorporating these angular rates in the optical flow computations in a manner that bypasses lags in the optical flow sensor measurement. In one embodiment, individual “velocity report” optical flow measurements have their rotational component removed before these velocity reports are utilized in the remainder of the optical flow algorithm.