Method and device for measuring geometrical characteristics of inner cavity of solid rocket engine

Abstract

A method and a device for measuring geometrical characteristics of an inner cavity of a solid rocket engine belong to the field of non-contact measurement, and the device is characterized by comprising an LED lighting source, a structured light optical module, a signal acquisition module and an upper computer, the structured light optical module and the signal acquisition module are both arranged in an inner cavity of the solid rocket engine; the LED illumination light source is connected with the structured light optical module through the light guide pipe; and the signal acquisition module is connected with the upper computer. White light excited by an LED is used as a light source, a structured light optical system is used for directly projecting specific structured light for illumination, the technical difficulty and complexity of traditional structured light monocular distance measurement are reduced, submillimeter-level deformation measurement precision is obtained, meanwhile, the size of an endoscopic link is greatly reduced through optical fiber integration, and the measurement precision is improved. Therefore, the solid rocket engine ignition hole and other existing windows are fully utilized, quantitative testing is achieved, safety and reliability are achieved, integration and applicability are achieved, the complexity is controllable, the measuring environment is moderate, and the method is suitable for application and popularization.

Description

technical field [0001] The invention pertains, in particular, to a method and a device for measuring the geometric characteristics of the inner cavity of a solid rocket motor. Background technique [0002] The solid rocket motor is an important power device of the aerospace delivery system. It is generally composed of an ignition device, a combustion chamber, a nozzle, etc. The inner cavity of the solid rocket motor does not undergo unexpected deformation or rupture during storage and transportation. The basic premise of its normal startup and smooth work. Measuring the changes of geometric features such as the deformation of the inner cavity and then evaluating the state of the solid rocket motor has been highly concerned by the aerospace industry for a long time. [0003] The solid rocket motor has a closed structure and limited measurement window, and a large number of energetic materials such as gunpowder and explosives are used, which greatly restricts the development ...

AI Technical Summary

Problems solved by technology

Among the above technologies: (1) The endoscopic image is intuitive and easy to use, but only supports rough detection of surface cracks and foreign objects in the inner hole of the drug column, and cannot quantify geometric information such as deformation; (2) X-ray projection imaging method There is no need to set or open the physical window on the solid rocket motor, and the geometric information of mm-level resolution on the imaging section can be obtained under protective conditions such as a shielded lead room. Combined with prior work such as contour recognition and feature positioning, the inner surface of the grain , the deformation of the inner cavity such as the inner side of the insulation structure is measured

(3) The ultrasonic reflection test technology needs to embed a certain number of ultrasonic sensors in the structure of the solid rocket motor in advance, and form an array layout to form an ultrasonic propagation and reflection characteristic control mode, which is generally used for the combustion of grains under conditions such as start-up and work. It is difficult to implement position measurement and sensor embedding, and the hidden danger of electric excitation source caused by sensor signal extraction is extremely great

However, the laser point cloud method has a continuous interaction between the laser beam and the measured structure, and the existence of energetic materials such as gunpowder and explosives in solid rocket motors limits its technical applicability; structured light ranging depends on complex precision such as grating diffraction and coding calibration. The optical path system has high requirements for measures such as vibration control of the measurement environment, and the cost-benefit ratio of high-precision measurement capability, economic cost, and use cost is too low

Images