Same-axis-center-distance equal-optical-flow catadioptric camera distance measurement system and distance measurement method thereof

Abstract

The invention discloses a same-axis-center-distance equal-optical-flow catadioptric camera distance measurement system and a distance measurement method thereof. A center symmetry axis of a rotating body mirror plane and the optical axis of a perspective camera are collinear and have a fixed distance; a measured object is placed below the rotating body mirror plane, incident light of a measured object space point is reflected through the mirror plane and then imaged to the perspective camera, and the rotating body mirror plane has a mirror plane contour with an equal-optical-flow characteristic. The method comprises the steps: firstly building a simulation environment, and setting system parameters to obtained a relational expression between the axis center distance and the optical flow value; then actually measuring the distance, and after the camera acquires an image, calculating the optical flow value of the measured object space point at an imaged position on a camera imaging plane; and calculating the axis center distance from the measured object space point to the camera optical axis by using the relational expression, and thus achieving the distance measurement. With utilization of the equal-optical-flow characteristic of the rotating body mirror plane, the corresponding relationship is formed among the measured object space point, the camera optical axis and the optical flow, and thus the distance of a scene can be directly measured; and the system and the method can be used for unmanned aerial vehicle navigation and collision avoidance, and detect the height to the ground and the distance to obstacles.

Description

Technical field [0001] The invention relates to a distance measuring system and a distance measuring method in the computer vision field. Specifically, it relates to a distance measuring system and a distance measuring method for an optical flow catadioptric camera with coaxial center distance. Background technique [0002] Compared with other sensors (ultrasonic distance sensors, lidar, etc.), image sensors have a large amount of information, are inexpensive, and have mature technology. However, due to the large amount of information carried by the image sensor and the ambiguity of its information, it becomes extremely difficult to extract effective information from the image. Optical flow is the change of an object in an image, so it contains a lot of information about the movement of the object. A large amount of evidence, such as Literature 1 (Srinivasan, Mandyam V., and Shaowu Zhang. "Visual motor computations in insects." Annu. Rev. Neurosci. 27(2004): 679-696.), shows th...

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Problems solved by technology

[0004] Combining the characteristics of optical flow and catadioptric cameras, aiming at the shortcomings of existing catadioptric cameras, the purpose of the present invention is to provide a distance measuring system and a distance measuring method for optical flow catadioptric cameras with equal coaxial center distances

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