Automatic detection and correction method for coating thickness of straight cylinder section of solid rocket motor

Abstract

The invention belongs to the technical field of industrial detection, and particularly relates to an automatic detection and correction method for coating thickness of a straight cylinder section of asolid rocket motor. The method comprises the following steps: 1) installing a linear laser displacement sensor I and a linear laser displacement sensor II; 2) modeling the interior of the rocket engine twice; 3) acquiring data vectors of the line laser displacement sensor I and the line laser displacement sensor II for a certain detection position respectively; 4) calculating slope of the cylindrical surface axis of a right-angle structure during two-time modeling on the basis of a data vector;5) calculating the number of offset points measured twice by the line laser displacement sensor I; 6) calculating the distance between the measuring point corresponding to the i-th dataof the vector and the measuring surface of the line laser displacement sensor II in the axial direction; 7) obtaining a corrected detection result.The data measured by the line laser displacement sensor II is used for correcting the data measured by the line laser displacement sensor I, error influencing factors in the detection process are fully considered, and measurement errors are reduced.

Description

technical field [0001] The invention belongs to the technical field of industrial detection, and in particular relates to an automatic detection and correction method for the coating thickness of the straight barrel section of a solid rocket motor. Background technique [0002] A solid rocket motor generally consists of a metal shell, a coating (insulation layer, lining or cladding) and a propellant. The coating is generally made of a gel-like composite material that is cured onto the metal shell through a specific process. The thickness of the coating has strict requirements, so in the production process, it is necessary to detect the thickness of the coating before filling the propellant, and the internal state and surface structure of the coating cannot be changed during the detection. [0003] The existing detection methods include ultrasonic detection method, eddy current detection method and laser detection method. "Plate Wave Induced Longitudinal Wave Ultrasonic Test...

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Problems solved by technology

"Plate Wave Induced Longitudinal Wave Ultrasonic Testing Technology" can detect the thickness of the coating inside the steel shell (see Chinese Patent No. 93118358.8), but this method needs to contact the steel shell, and its applicability is related to the sound attenuation coefficient and thickness of the coating; eddy current The detection method is to directly touch the eddy current probe to the coating to measure the coating thickness in the steel shell, but this method is easily affected by the soft and hard strength of the coating, and it belongs to contact measurement, which will cause pollution on the coating surface; the laser thickness measurement method The laser displacement sensor is used to measure the displacement of the sensor to the surface before and after the coating is sprayed, and the coating thickness value can be obtained by subtracting the two measured values ​​(see Chinese Patent No. CN201310137425.2), but in the actual detection Due to the two subtraction measurements, the rocket engine's irregular jumping up and down, forward and backward movement, and inclination during the detection process will all have an impact, resulting in a large error in the measured data

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