Monocular vision measuring method of non-contact precision measuring corner

Abstract

The invention discloses a monocular vision measuring method of a non-contact precision measuring corner, belonging to the technical field of photoelectric detection and aiming at realizing wider measuring range, high measuring precision and more convenient operation. Based on a monocular vision principle, the method comprises the following steps of: fixing a test target with a double-circle sign on an object to be measured parallel to a rotating shaft; photographing a target surface by using a position-fixed digital camera; selecting a group of characteristic points and characteristic parameters of an image surface to establish a set of computing method and formula for solving the corner by taking an image of the double-circle sign as an oval; processing photos by using a sub-pixel processing method, solving an equation of an image surface oval and image surface coordinates of the characteristic points and solving a plane equation of the target surface and a corner of the object to bemeasured; accurately solving the position of an image point in the center of a circle without marking the position of the center of a circle of the target surface; and correcting a measuring error caused by unparallel relations of the target surface and the rotating shaft by using data obtained in the measuring process. The invention has the advantages of simple installation and adjustment of equipment, high measuring precision, high practicability and capability of being used for marking angular displacement transducers such as a rudder, a horizontal rudder of an aircraft and the like on site of an airport.

Description

Technical field [0001] The invention relates to a monocular vision measurement method for non-contact precise measurement of rotation angle, and belongs to the technical field of photoelectric detection. Background technique [0002] In the fields of aviation, aerospace and navigation, non-contact precision measurement methods and techniques with a large measurement range are often needed. For example, when developing a new type of aircraft or producing an aircraft, after the aircraft is completed, a test flight is required to test its flight performance. In order to obtain accurate performance test data, it is necessary to calibrate the aileron, flap, horizontal rudder and rudder angular displacement sensors on the aircraft at the airport before the flight test. Because it is not allowed to make any changes to the internal structure of the aircraft during this calibration process, a non-contact measurement method should be used. The document "High-precision in-plane rotation a...

AI Technical Summary

Problems solved by technology

However, the structure of the three-circle mark is relatively complicated and loose, and the intersection point of two intersecting straight line segments must be used to accurately mark the center position of each circle, which makes digital image processing difficult and takes a long time; due to the use of "three points to determine a plane" method Finding the plane equation of the target surface, this method is not strong in anti-interference ability, and the measurement accuracy is not high enough; especially, when the angle between the normal line of the target surface and the main optical axis of the camera is close to 0°, the measurement error will increase significantly; This method must also know the center distance of the camera pixels, so that the required results can be obtained during data processing

In the absence of a special digital camera for photogrammetry, it is generally difficult to accurately know the center distance of the camera pixels when measuring with an ordinary digital camera, and the internal parameters of the camera must be obtained through complex and precise calibration, which is not convenient enough to use

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