Low-cost depth camera design method for lunar surface application

Abstract

The invention relates to the technical field of deep space exploration, in particular to a lunar surface application-oriented low-cost depth camera design method. The embodiment of the invention provides a lunar surface application-oriented low-cost depth camera design method. The method comprises the following steps of: performing a high-temperature screening test and a temperature cycle test on a plurality of industrial-grade cameras; wherein the high-temperature screening test is to test the industrial-grade camera at a preset high temperature, and the temperature cycle test is to test the industrial-grade camera at a preset high temperature and a preset low temperature; selecting the industrial-grade camera passing the high-temperature screening test and the temperature cycle test as a camera to be designed; carrying out design transformation on the to-be-designed camera; wherein the design transformation comprises the design of an anti-mechanical structure. The embodiment of the invention provides a lunar surface application-oriented low-cost depth camera design method, and a low-cost depth camera can be obtained.

Description

Technical Field

[0001] The present invention relates to the field of deep space exploration technology, and in particular to a low-cost depth camera design method for lunar surface application. Background Art

[0002] Deep space exploration is an important direction for the future development of aerospace, and lunar exploration and manned lunar landing are major projects for my country in the next few years. Compared with industrial cameras and commercial cameras, the depth camera used for the tiny robots on the moon needs to experience the mechanical environment of random vibration and impact in the launch phase, and also needs to experience the thermal environment and complex lighting conditions of the moon during the working process. The temperature difference of the thermal environment on the moon is large, with higher maximum temperature and lower minimum temperature; the lighting background of the moon is relatively complex, and brighter scenes illuminated by the sun (such as lunar probes) and the black background of deep space appear in the camera market at the same time. Choosing a longer exposure time will make the image of the brighter scene saturated, while choosing a shorter exposure time will make the brighter scene dark and unrecognizable. Therefore, the depth camera needs to match the complex lighting environment of the moon.

[0003] At the same time, the lunar micro-robots have the characteristics of short development cycle and low cost, which also put forward low-cost development requirements for depth cameras. Summary of the invention

[0004] The embodiment of the present invention provides a low-cost depth camera design method for lunar surface application, which can obtain a low-cost depth camera.

[0005] The embodiment of the present invention provides a low-cost depth camera design method for lunar surface application, including:

[0006] Conducting high temperature screening tests and temperature cycle tests on multiple industrial cameras; wherein the high temperature screening test is to test the industrial cameras at a preset high temperature, and the temperature cycle test is to test the industrial cameras at a preset high temperature and a preset low temperature;

[0007] Selecting an industrial-grade camera that has passed the high-temperature screening test and the temperature cycle test as the camera to be designed;

[0008] The camera to be designed is subjected to a design modification; wherein the design modification includes a mechanical resistance structure design.

[0009] In a possible design, after selecting the industrial-grade camera that has passed the high-temperature screening test and the temperature cycle test as the camera to be designed, and before performing mechanical resistance structure design on the camera to be designed, the method further includes:

[0010] Performing a random vibration test on a plurality of the industrial-grade cameras; wherein the random vibration test is to apply vibrations of different frequencies to the industrial-grade cameras;

[0011] The design modification priority of the camera to be designed is determined according to whether it passes the random vibration test, and the cameras to be designed that pass the random vibration test are given priority. When the number of cameras to be designed with high priority is lower than the required number, the cameras to be designed with low priority are used.

[0012] In one possible design, the design modification also includes thermal design.

[0013] In one possible design, the camera after the design modification is also subjected to identification-level mechanical testing and identification-level thermal testing.

[0014] In a possible design, it also includes adjusting the exposure time of a camera that has passed the identification-level mechanical test and the identification-level thermal test.

[0015] In a possible design, the test parameters of the high temperature screening test are as follows:

[0016] The ambient pressure is normal pressure, the ambient humidity is 30-55%, the test temperature is 70℃, the temperature deviation is ±2℃, and the cumulative time is 180 hours;

[0017] The test parameters of the temperature cycle test are as follows:

[0018] The pressure environment is normal pressure, the temperature range is -40 ~ 75 ℃, the temperature change rate is not less than 5 ℃ / min, the cycle period is 4h, of which the high temperature stays for 1.5h and the low temperature stays for 2h. The number of cycles is less than 12.5 times, and the cumulative time is 180 hours.

[0019] In a possible design, the test parameters of the random vibration test are as follows:

[0020] Vibrate at least once in three mutually perpendicular directions: X, Y, and Z, for 1 minute each time, with a root mean square acceleration of 6.14g rms The frequency range of vibration includes 20~150Hz, 150~600Hz, 600~2000Hz, corresponding to 3dB / oct, 0.04g respectively 2 / Hz, power spectral density of -6dB / oct.

[0021] In one possible design, the anti-mechanical structure design includes replacing a high-rigidity outer shell, adding a mounting flange as a mounting interface for the camera to be designed, and determining the camera components that require vibration reduction design through mechanical simulation analysis, wherein the vibration reduction design includes setting vibration reduction pads.

[0022] In one possible design, the thermal design includes measuring the temperature of the components of the camera to be designed, and adopting boss heat dissipation, heat dissipation by heat dissipation cable and spraying thermal control black paint on the inner wall of the shell of the camera to be designed for radiant heat dissipation for components with temperatures higher than preset values.

[0023] In one possible design, the exposure time control includes:

[0024] Test the dynamic range of the camera's exposure time for clear imaging under simulated strong light from the moon;

[0025] Test the imaging effect of the camera facing the detector under the conditions of simulated black background and strong light from the moon;

[0026] According to the dynamic range of exposure time and the imaging effect, precise control of camera exposure time is achieved.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] The present invention starts from low cost and develops a depth camera based on an industrial camera (for example, a COTS industrial camera, a single camera costs less than ten thousand), which has obvious cost advantages compared with conventional aerospace product manufacturing methods (a single camera costs about one million).

[0029] The present invention aims at the high reliability of depth cameras and provides a high-reliability component screening method based on COTS cameras, which can eliminate products with the risk of early failure to maintain the performance robustness of camera components. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a flowchart of a method for designing a low-cost depth camera for lunar surface applications provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected" and "fixed" should be understood in a broad sense, for example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the description of this specification, it should be understood that the directional words such as "upper" and "lower" described in the embodiments of the present invention are described at the angles shown in the drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0035] Please refer to Figure 1 The embodiment of the present invention provides a low-cost depth camera design method for lunar surface application, including:

[0036] Conduct high temperature screening tests and temperature cycle tests on multiple industrial cameras; the high temperature screening test is to test the industrial cameras at a preset high temperature, and the temperature cycle test is to test the industrial cameras at a preset high temperature and a preset low temperature;

[0037] Industrial-grade cameras that have passed the high-temperature screening test and the temperature cycle test are selected as the cameras to be designed;

[0038] The camera to be designed is redesigned, wherein the design modification includes the design of anti-mechanical structure.

[0039] In this embodiment, a plurality of industrial-grade cameras are first selected, for example, COTS industrial cameras, by conducting high-temperature screening tests and temperature cycle tests, testing industrial cameras at high temperatures and high temperature differences, and marking the cameras that pass the tests as cameras to be designed. The cameras to be designed that pass the tests are subjected to mechanical resistance structural design to enhance their mechanical resistance performance so that they can better adapt to the lunar environment.

[0040] In some embodiments of the present invention, after selecting an industrial-grade camera that has passed a high-temperature screening test and a temperature cycle test as the camera to be designed, and before performing mechanical resistance structure design on the camera to be designed, the method further includes:

[0041] Conduct random vibration tests on multiple industrial cameras; the random vibration test involves applying vibrations of different frequencies to the industrial cameras;

[0042] The design modification priority of the camera to be designed is determined according to whether it passes the random vibration test. The cameras to be designed that pass the random vibration test are given priority. When the number of cameras to be designed with high priority is lower than the required number, the cameras to be designed with low priority are used.

[0043] In this embodiment, in order to further screen the industrial cameras, the cameras to be designed are prioritized through random vibration tests, and the cameras that pass the random vibration test are designed and modified first. If the number of cameras to be designed with high priority is lower than the required number, the cameras with low priority are designed and modified.

[0044] It should be noted that if the number is still lower than the required number after adding the cameras to be designed with low priority, high temperature screening tests and temperature cycle tests can be conducted on multiple industrial-grade cameras again to screen out more cameras to be designed.

[0045] In some embodiments of the present invention, the design modification also includes thermal design.

[0046] In this embodiment, in order to further increase the adaptability of the camera to the temperature environment of the lunar surface, thermal design may also be performed on the camera to be designed.

[0047] In some embodiments of the present invention, it also includes conducting identification-level mechanical tests and identification-level thermal tests on the camera after the design modification.

[0048] After completing the design modification of the camera to be designed, before it is put into use, the camera needs to undergo identification-level mechanical tests and identification-level thermal tests. Identification-level mechanical tests and identification-level thermal tests are tests to determine whether the test target is suitable for aerospace-level environments. Specifically, the conditions of the two identification-level tests are as follows:

[0049] The identification grade mechanical test conditions are as follows:

[0050]

[0051] The identification grade thermal vacuum test conditions are as follows:

[0052]

[0053]

[0054] In some embodiments of the present invention, the method further includes adjusting the exposure time of a camera that has passed the identification-level mechanical test and the identification-level thermal test.

[0055] The present invention proposes precise control of camera exposure time, which is to adaptively control the camera exposure time according to the complex lighting conditions on the lunar surface, and can meet the requirements of simultaneous imaging of brighter scenery and deep space black background.

[0056] In some embodiments of the present invention, the test parameters of the high temperature screening test are as follows:

[0057] Test parameter name Test parameter values Environmental pressure Normal pressure Ambient humidity 30％-55％ Test temperature +70℃ Temperature deviation ±2℃ time 180 hours in total

[0058] The test parameters of the temperature cycle test are as follows:

[0059]

[0060] In some embodiments of the present invention, the test parameters of the random vibration test are as follows:

[0061]

[0062]

[0063] In some embodiments of the present invention, the anti-mechanical structure design includes replacing a high-rigidity outer shell, adding a mounting flange as a mounting interface for the camera to be designed, and determining the camera components that require vibration reduction design through mechanical simulation analysis, wherein the vibration reduction design includes setting vibration reduction pads.

[0064] In some embodiments of the present invention, the thermal design includes measuring the temperature of the components of the camera to be designed, and adopting boss heat dissipation, heat dissipation by heat dissipation cable and spraying thermal control black paint on the inner wall of the shell of the camera to be designed for radiant heat dissipation for components with temperatures higher than preset values.

[0065] In some embodiments of the present invention, exposure time regulation includes:

[0066] Test the dynamic range of the camera's exposure time for clear imaging under simulated strong light from the moon;

[0067] Test the imaging effect of the camera facing the detector under the conditions of simulated black background and strong light from the moon;

[0068] According to the dynamic range of exposure time and imaging effect, the camera exposure time can be precisely controlled.

[0069] In this embodiment, the exposure time of the depth camera that has successfully passed the appraisal-level mechanical and thermal test is precisely controlled, the detector simulation structure is designed and put into production, and a complex lighting test simulating sunlight is carried out in a stray light darkroom.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-cost depth camera design method for lunar surface applications, characterized in that: include: Conducting high temperature screening tests and temperature cycle tests on multiple industrial cameras; wherein the high temperature screening test is to test the industrial cameras at a preset high temperature, and the temperature cycle test is to test the industrial cameras at a preset high temperature and a preset low temperature; Selecting an industrial-grade camera that has passed the high-temperature screening test and the temperature cycle test as the camera to be designed; The camera to be designed is subjected to a design modification; wherein the design modification includes a mechanical resistance structure design.

2. The method according to claim 1, characterized in that: After selecting the industrial-grade camera that has passed the high-temperature screening test and the temperature cycle test as the camera to be designed, and before designing the mechanical resistance structure of the camera to be designed, the method further includes: Performing a random vibration test on a plurality of the industrial-grade cameras; wherein the random vibration test is to apply vibrations of different frequencies to the industrial-grade cameras; The design modification priority of the camera to be designed is determined according to whether it passes the random vibration test, and the cameras to be designed that pass the random vibration test are given priority. When the number of cameras to be designed with high priority is lower than the required number, the cameras to be designed with low priority are used.

3. The method according to claim 1, characterized in that The design transformation also includes thermal design.

4. The method according to claim 1, characterized in that It also includes identification-level mechanical testing and identification-level thermal testing on cameras that have completed design modifications.

5. The method according to claim 4, characterized in that It also includes exposure time control for cameras that have passed identification-level mechanical tests and identification-level thermal tests.

6. The method according to claim 1, characterized in that The test parameters of the high temperature screening test are as follows: The ambient pressure is normal pressure, the ambient humidity is 30-55%, the test temperature is 70℃, the temperature deviation is ±2℃, and the cumulative time is 180 hours; The test parameters of the temperature cycle test are as follows: The pressure environment is normal pressure, the temperature range is -40 ~ 75 ℃, the temperature change rate is not less than 5 ℃ / min, the cycle period is 4h, of which the high temperature stays for 1.5h and the low temperature stays for 2h. The number of cycles is less than 12.5 times, and the cumulative time is 180 hours.

7. The method according to claim 2, characterized in that The test parameters of the random vibration test are as follows: Vibrate at least once in three mutually perpendicular directions: X, Y, and Z, for 1 minute each time, with a root mean square acceleration of 6.14g rms The frequency range of vibration includes 20~150Hz, 150~600Hz, 600~2000Hz, corresponding to 3dB / oct, 0.04g respectively 2 / Hz, power spectral density of -6dB / oct.

8. The method according to claim 1, characterized in that: The anti-mechanical structure design includes replacing a high-rigidity outer shell, adding a mounting flange as a mounting interface for the camera to be designed, and determining the camera components that require vibration reduction design through mechanical simulation analysis, wherein the vibration reduction design includes setting vibration reduction pads.

9. The method according to claim 3, characterized in that: The thermal design includes measuring the temperature of the components of the camera to be designed, and adopting boss heat dissipation, heat dissipation by heat dissipation cable and spraying thermal control black paint on the inner wall of the shell of the camera to be designed for radiation heat dissipation for the components whose temperature is higher than the preset value.

10. The method according to claim 5, characterized in that The exposure time control includes: Test the dynamic range of the camera's exposure time for clear imaging under simulated strong light from the moon; Test the imaging effect of the camera facing the detector under the conditions of simulated black background and strong light from the moon; According to the dynamic range of exposure time and the imaging effect, precise control of camera exposure time is achieved.

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