A system and method for measuring the ablation profile of a solid rocket motor nozzle after testing.

Abstract

This invention discloses a measurement system and method for measuring the ablation profile of a solid rocket motor nozzle after testing, relating to the fields of solid rocket motors and optical measurement. The measurement method employs a dual-path fusion scheme of vision and laser, integrating a laser sensor and an industrial camera into a single measurement unit, fixed to a six-axis industrial robot for motion tracking. First, dual laser sensors scan and measure the cross-sectional surface of the tested solid rocket motor nozzle to obtain corresponding three-dimensional height data, thereby acquiring information such as the flatness and contour range of the ablation profile to be measured. Then, the robot is controlled to automatically plan a path using this information, and the industrial camera acquires images of the entire ablation profile of the nozzle. Combined with the previously obtained three-dimensional height data, feature point data of the interface between the ablation profile and the carbonized layer are captured, and the corresponding curves and carbonized layer are calculated to achieve the measurement objective.

Description

Technical Field

[0001] This invention relates to a measurement system and method for measuring the ablation profile of a solid rocket motor nozzle after testing, belonging to the fields of solid rocket motors and optical measurement. Background Technology

[0002] Currently, the measurement of the ablation profile of the nozzle after solid rocket motor testing mainly relies on visual identification. Points at equal axial intervals are selected, and then the radial height is measured using instruments such as vernier calipers. The curve of the ablation profile and the carbonized layer interface is recorded and fitted to obtain data such as the carbonized layer thickness. However, this method has many problems. First, the flatness of the cross-section of the engine after testing cannot be guaranteed, so the measurement points may not be on the same plane, and the visually distinguishable feature points of the ablation profile and the carbonized layer interface also have certain errors. Second, the cross-sectional profile of the nozzle is a complex cubic curve, and its shape after ablation is even more irregular, making measurement extremely difficult. Furthermore, for large nozzles, the large number of data points collected to ensure the effectiveness of the fitted curve places a heavy workload on the measurement personnel. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a measurement system and method for measuring the ablation profile of the nozzle after a solid rocket motor test. This solves the measurement errors caused by uneven nozzle cross-section and unclear identification of the characteristic points of the ablation profile and carbonization layer interface, improves detection efficiency, and reduces the workload of measurement personnel.

[0004] The technical solution of this invention is: This invention discloses a nozzle ablation profile measurement system for a solid rocket motor after testing, comprising: a six-axis industrial robot, an adjustable LED light source, a laser sensor, an industrial camera, a measurement unit adapter bracket, a light source angle adjustment screw, a mobile computing workstation, and an electrical control cabinet. The system calculates the carbonization layer depth of the test component using a nozzle ablation profile measurement method. The laser sensor is positioned between the industrial camera and the measurement unit adapter bracket to acquire the three-dimensional height information of the test component. The laser sensor and industrial camera are connected to the mobile computing workstation and fixed to the six-axis industrial robot via the measurement unit adapter bracket. The adjustable LED light source is mounted on the measurement unit adapter bracket using the light source angle adjustment screw, and its brightness is controlled by the electrical control cabinet and the mobile computing workstation. The six-axis industrial robot's motion trajectory and speed are controlled by the electrical control cabinet and the mobile computing workstation.

[0005] In the above measurement system, the method for measuring the nozzle ablation profile is as follows: The test piece is placed on the nozzle support cone; the test piece includes an ablation profile and a carbonized layer interface; The electrical control cabinet and mobile computing workstation control the six-axis industrial robot to drive the laser sensor of the measurement unit to scan and measure the nozzle cross-section, obtain the three-dimensional height data of the part under test, and transmit it to the mobile computing workstation. Based on the three-dimensional height data, the mobile computing workstation calculates the contour range and flatness information of the ablation surface, plans the measurement motion trajectory of the industrial camera, and transmits the measurement motion trajectory and control commands to the electrical control cabinet. The electrical control cabinet controls the six-axis industrial robot to move to the origin of the measured motion trajectory based on the measured motion trajectory and control commands; The mobile computing workstation adjusts the angle and intensity of the adjustable LED light source based on the contour range and flatness information of the ablation surface. The electrical control cabinet controls a six-axis industrial robot carrying an industrial camera to acquire images along the measured motion trajectory, obtain image data, and transmit the image data to a mobile computing workstation. The mobile computing workstation performs image processing on the image data, combines the three-dimensional height data, captures feature point data of the ablation surface and the carbonization layer interface, fits the corresponding ablation surface and carbonization layer interface curves, and calculates the carbonization layer depth.

[0006] In the above measurement system, there are two adjustable LED light sources, symmetrically distributed on both sides of the industrial camera; there are also two laser sensors.

[0007] In the above measurement system, the measurement unit adapter bracket is connected to the six-axis industrial robot by strong magnetic force.

[0008] In the above measurement system, the power of the laser sensor is 1~2mW and the emitted laser wavelength is 600~900nm.

[0009] In the above measurement system, the adjustable LED light source adopts a blue cold light source, supports PWM light source intensity control, and the maximum adjustable light source intensity is greater than 4000 Lux.

[0010] In the above measurement system, the illumination angle of the LED adjustable light source is adjustable, and the adjustment angle is 0~360°; the LED adjustable light source and the measurement unit adapter bracket are detachably connected by the light source angle adjustment screw.

[0011] In the above measurement system, scanning measurement is performed at a speed of 10 mm / s to 50 mm / s.

[0012] In the above measurement system, the image acquisition speed is greater than or equal to 20 FPS and the resolution is greater than or equal to 2452×2056.

[0013] In the above measurement system, the effective number of feature point data collection points is 5~20 per mm.

[0014] This invention discloses a method for measuring the ablation profile of a solid rocket motor nozzle after testing, employing a measurement system comprising: The test piece is placed on the nozzle support cone; the test piece includes an ablation profile and a carbonized layer interface; The electrical control cabinet and mobile computing workstation control the six-axis industrial robot to drive the laser sensor of the measurement unit to scan and measure the nozzle cross-section, obtain the three-dimensional height data of the part under test, and transmit it to the mobile computing workstation. Based on the three-dimensional height data, the mobile computing workstation calculates the contour range and flatness information of the ablation surface, plans the measurement motion trajectory of the industrial camera, and transmits the measurement motion trajectory and control commands to the electrical control cabinet. The electrical control cabinet controls the six-axis industrial robot to move to the origin of the measured motion trajectory based on the measured motion trajectory and control commands; The mobile computing workstation adjusts the angle and intensity of the adjustable LED light source based on the contour range and flatness information of the ablation surface. The electrical control cabinet controls a six-axis industrial robot carrying an industrial camera to acquire images along the measured motion trajectory, obtain image data, and transmit the image data to a mobile computing workstation. The mobile computing workstation performs image processing on the image data, combines the three-dimensional height data, captures feature point data of the ablation surface and the carbonization layer interface, fits the corresponding ablation surface and carbonization layer interface curves, and calculates the carbonization layer depth.

[0015] The advantages of this invention over the prior art are as follows: (1) The present invention uses a laser sensor to acquire three-dimensional data of the profile and compensates and corrects the camera motion trajectory adjustment, thereby eliminating the measurement error caused by the unevenness of the nozzle cutting profile to the greatest extent. (2) The present invention adopts a dual-path fusion scheme of industrial camera and laser sensor to capture the feature points of the ablation surface and the carbonization layer interface, so as to maximize the accuracy of the curve measurement points; (3) The present invention adopts a fully automated six-axis industrial robot solution throughout the process. The measurement accuracy is no longer limited by the nozzle size, which not only greatly improves the measurement efficiency, but also reduces the labor intensity of the measurement personnel. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing the measurement status of the nozzle ablation profile after the solid rocket motor test of the present invention.

[0017] Figure 2 This is a schematic diagram of the solid rocket motor nozzle ablation profile measurement unit structure according to the present invention. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific examples.

[0019] like Figure 1 , Figure 2 As shown, this invention discloses a nozzle ablation profile measurement system after solid rocket motor testing, comprising: a six-axis industrial robot 1, an adjustable LED light source 2, a laser sensor 3, an industrial camera 4, a measurement unit adapter bracket 5, a light source angle adjustment screw 6, a mobile computing workstation 9, and an electrical control cabinet 10. The system calculates the carbonization layer depth of the test part using a nozzle ablation profile measurement method. The laser sensor 3 is placed between the industrial camera 4 and the measurement unit adapter bracket 5 to acquire the three-dimensional height information of the test part. The laser sensor 3 and the industrial camera 4 are connected to the mobile computing workstation 9 and fixed to the six-axis industrial robot 1 via the measurement unit adapter bracket 5. The adjustable LED light source 2 is mounted on the measurement unit adapter bracket 5 using the light source angle adjustment screw 6, and its brightness is controlled by the electrical control cabinet 10 and the mobile computing workstation 9. The six-axis industrial robot 1's motion trajectory and speed are controlled by the electrical control cabinet 10 and the mobile computing workstation 9. Two adjustable LED light sources 2 are symmetrically distributed on both sides of the industrial camera 4; two laser sensors 3 are also present. The LED adjustable light source 2 has an adjustable illumination angle of 0~360°. The LED adjustable light source 2 and the measurement unit adapter bracket 5 are detachably connected via a light source angle adjustment screw 6. The LED adjustable light source 2 uses a blue cold light source, supports PWM light source intensity control, and has a maximum adjustable light source intensity greater than 4000 Lux. The laser sensor 3 has a power of 1~2mW and emits a laser wavelength of 600~900nm. In this embodiment, the test piece is the cut solid rocket motor nozzle 7 after testing. The measurement unit adapter bracket is connected to the six-axis industrial robot using a strong magnetic force.

[0020] The nozzle ablation profile measurement method employs a dual-path fusion scheme of vision and laser, utilizing a powerful mobile computing workstation to calculate and process the acquired 3D height and image data to achieve the measurement objective. Specifically: Step 1: Place the test piece on the nozzle support cone 8; the test piece includes the ablation surface and the carbonized layer interface; Step 2: The electrical control cabinet 10 and the mobile computing workstation 9 control the six-axis industrial robot 1 to drive the laser sensor 3 of the measurement unit to scan and measure the nozzle cross-section, obtain the three-dimensional height data of the part to be measured, and transmit it to the mobile computing workstation 9; the scanning speed of the scanning measurement is 10mm / s~50mm / s.

[0021] Step 3: The mobile computing workstation 9 calculates the contour range and flatness information of the ablation surface based on the three-dimensional height data, plans the measurement motion trajectory of the industrial camera 4, and transmits the measurement motion trajectory and control commands to the electrical control cabinet 10. Step 4: The electrical control cabinet 10 controls the six-axis industrial robot 1 to move to the origin of the measured motion trajectory according to the measured motion trajectory and control instructions; Step 5: The mobile computing workstation 9 adjusts the angle and intensity of the adjustable LED light source 2 according to the contour range and flatness information of the ablation surface; Step 6: The electrical control cabinet 10 controls the six-axis industrial robot 1, which carries the industrial camera 4, to perform image acquisition along the measurement motion trajectory, obtain image data, and transmit the image data to the mobile computing workstation 9; the image acquisition speed is greater than or equal to 20 FPS, and the resolution is greater than or equal to 2452×2056.

[0022] Step 7: The mobile computing workstation 9 performs image processing on the image data, combining it with 3D height data to capture feature point data of the ablation surface and the carbonization layer interface, fitting the corresponding ablation surface and carbonization layer interface curves, and calculating the carbonization layer depth. The effective number of feature point data acquisition points is 5~20 / mm.

[0023] This invention discloses a method for measuring the ablation profile of a solid rocket motor nozzle after testing, comprising the following steps: The test piece is placed on the nozzle support cone 8; the test piece includes the ablation profile and the carbonized layer interface; The electrical control cabinet 10 and the mobile computing workstation 9 control the six-axis industrial robot 1 to drive the laser sensor 3 of the measurement unit to scan and measure the nozzle cross-section, obtain the three-dimensional height data of the part to be measured, and transmit it to the mobile computing workstation 9. Based on the three-dimensional height data, the mobile computing workstation 9 calculates the contour range and flatness information of the ablation surface, plans the measurement motion trajectory of the industrial camera 4, and transmits the measurement motion trajectory and control commands to the electrical control cabinet 10. The electrical control cabinet 10 controls the six-axis industrial robot 1 to move to the origin of the measured motion trajectory according to the measured motion trajectory and control instructions; The mobile computing workstation 9 adjusts the angle and intensity of the adjustable LED light source 2 based on the contour range and flatness information of the ablation surface; The electrical control cabinet 10 controls the six-axis industrial robot 1, which carries the industrial camera 4, to collect images along the measurement motion trajectory, obtain image data, and transmit the image data to the mobile computing workstation 9. The mobile computing workstation 9 performs image processing on the image data, combines it with three-dimensional height data, captures feature point data of the ablation surface and the carbonization layer interface, fits the corresponding ablation surface and carbonization layer interface curves, and calculates the carbonization layer depth.

[0024] In summary, this invention can efficiently and accurately obtain the ablation profile data of the nozzle under test and fit the corresponding curve model.

[0025] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0026] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for measuring the ablation profile of a solid rocket motor nozzle after testing, characterized in that, The measurement system includes: a six-axis industrial robot (1), an adjustable LED light source (2), a laser sensor (3), an industrial camera (4), a measurement unit adapter bracket (5), a light source angle adjustment screw (6), a mobile computing workstation (9), and an electrical control cabinet (10); wherein, the laser sensor (3) is placed between the industrial camera (4) and the measurement unit adapter bracket (5) to acquire the three-dimensional height information of the workpiece to be measured; the laser sensor (3) and the industrial camera (4) are connected to the mobile computing workstation (9) and fixed to the six-axis industrial robot (1) through the measurement unit adapter bracket (5); the adjustable LED light source (2) is installed on the measurement unit adapter bracket (5) with the light source angle adjustment screw (6), and its brightness is controlled by the electrical control cabinet (10) and the mobile computing workstation (9); the six-axis industrial robot (1) has its motion trajectory and speed controlled by the electrical control cabinet (10) and the mobile computing workstation (9); The method for measuring the ablation profile of the nozzle is as follows: The test piece is placed on the nozzle support cone (8); the test piece includes an ablation profile and a carbonized layer interface; The electrical control cabinet (10) and the mobile computing workstation (9) control the six-axis industrial robot (1) to drive the laser sensor (3) of the measuring unit to scan and measure the nozzle cross-section, obtain the three-dimensional height data of the part to be measured, and transmit it to the mobile computing workstation (9). The mobile computing workstation (9) calculates the contour range and flatness information of the ablation surface based on the three-dimensional height data, plans the measurement motion trajectory of the industrial camera (4), and transmits the measurement motion trajectory and control commands to the electrical control cabinet (10). The electrical control cabinet (10) controls the six-axis industrial robot (1) to move to the origin of the measured motion trajectory according to the measured motion trajectory and control instructions; The mobile computing workstation (9) adjusts the angle and intensity of the adjustable LED light source (2) according to the contour range and flatness information of the ablation surface; The electrical control cabinet (10) controls the six-axis industrial robot (1) to carry an industrial camera (4) to collect images along the measured motion trajectory, obtain image data, and transmit the image data to the mobile computing workstation (9). The mobile computing workstation (9) performs image processing on the image data, combines the three-dimensional height data, captures the feature point data of the ablation surface and the carbonization layer interface, fits the corresponding ablation surface and carbonization layer interface curve, and calculates the carbonization layer depth.

2. The method for measuring the ablation profile of a solid rocket motor nozzle after testing, as described in claim 1, is characterized in that: There are two adjustable LED light sources (2), which are symmetrically distributed on both sides of the industrial camera (4); there are two laser sensors (3).

3. The method for measuring the ablation profile of a solid rocket motor nozzle after testing, as described in claim 1, is characterized in that: The measuring unit adapter bracket (5) is connected to the six-axis industrial robot (1) by strong magnetic force.

4. The method for measuring the ablation profile of a solid rocket motor nozzle after testing, as described in claim 1, is characterized in that: The power of the laser sensor (3) is 1~2mW and the emitted laser wavelength is 600~900nm.

5. The method for measuring the ablation profile of a solid rocket motor nozzle after testing, as described in claim 1, is characterized in that: The LED adjustable light source (2) adopts a blue cold light source, supports PWM light source intensity control, and the maximum adjustable light source intensity is greater than 4000 Lux.

6. The method for measuring the ablation profile of a solid rocket motor nozzle after testing, as described in claim 1, is characterized in that: The illumination angle of the LED adjustable light source (2) is adjustable, and the adjustment angle is 0~360°; the LED adjustable light source (2) and the measuring unit adapter bracket (5) are detachably connected through the light source angle adjustment screw (6).

7. The method for measuring the ablation profile of a solid rocket motor nozzle after testing, as described in claim 1, is characterized in that: The scanning measurement is performed at a speed of 10 mm / s to 50 mm / s.

8. The method for measuring the ablation profile of a solid rocket motor nozzle after testing, as described in claim 1, is characterized in that: The image acquisition has an acquisition speed of ≥20 FPS and a resolution of ≥2452×2056.

9. The method for measuring the ablation profile of a solid rocket motor nozzle after testing, as described in claim 2, is characterized in that: The effective number of feature point data points is 5~20 per mm.

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