Compact rotating wheel near-infrared airborne multispectral system

Abstract

The utility model discloses a compact type rotation wheel near infrared airborne multispectral system has the following advantages: (1) near infrared lens and the filter wheel module accurate alignment, and the multiple wave band near infrared light after the filter wheel switching is transmitted to near infrared imaging sensor through the lens, need not for different wave band alone configuration camera, greatly reduces hardware investment, (2) visible light camera is responsible for high definition visible image acquisition, and near infrared module cooperates and completes airborne system data acquisition, and guarantees data integrity, (3) the brushless direct drive motor of drive module is connected directly with filter wheel, and effective control axial size provides stable power for filter wheel rotation, and the hall position sensing assembly of cooperation realization monitoring filter wheel actual position can realize the accurate switching of filter, and the light path of near infrared module is aligned, and the corresponding wave band light stable transmission is guaranteed, avoids data frame loss, (4) temperature and humidity sensor: real -time monitoring equipment whole working environment's temperature and humidity data.

Description

Technical Field

[0001] This utility model relates to the field of spectral imaging technology, and in particular to a compact rotary near-infrared airborne multispectral system. Background Technology

[0002] Airborne multispectral technology captures multi-band spectral information of ground features through airborne platforms, playing a crucial role in fields such as agricultural and forestry monitoring and emergency response. The near-infrared band, with its strong penetrating power and high sensitivity to vegetation and topographic changes, serves as the core support for accurate data acquisition. This technology demands extremely high equipment stability; defects in near-infrared components can easily lead to imaging anomalies or data failures, directly weakening the effectiveness of remote sensing applications. Therefore, ensuring high-quality equipment operation is paramount.

[0003] Existing near-infrared airborne multispectral equipment mostly adopts multi-camera combination or traditional rotary structure to achieve imaging. Although it can meet the basic detection requirements, it has the following problems: (1) Low structural integration and poor spatial adaptability: The multi-camera design results in a loose structure, large size, and high weight, which is difficult to adapt to the narrow installation space of small UAVs and significantly limits the flexibility of low-altitude operation; (2) Defects in filter switching mechanism: The switching mechanism occupies too much space and is prone to interference with other airborne equipment. The overall adaptability is insufficient and affects the system integration efficiency; (3) Insufficient transmission and positioning accuracy: The traditional rotary structure relies on gear transmission, which produces obvious eccentric vibration. When paired with photoelectric switches, the positioning error is large, resulting in poor consistency of imaging data, easy frame loss, and decreased data reliability; (4) Weak environmental adaptability: The stability is insufficient in high-altitude temperature change and vibration environment. The filter is prone to displacement and additional accessories are required to make up for the lack of protection and increase the maintenance burden; (5) Cost and flexibility bottleneck: The configuration cost of multi-camera is high and the flexibility of accessory customization is low. Small and medium-sized users cannot afford it, which restricts the popularization of technology and the expansion of applications.

[0004] These problems severely hinder the miniaturization of equipment and significantly reduce the quality of data acquisition, becoming major obstacles to current technological development and urgently needing to be addressed through innovative design. Utility Model Content

[0005] The purpose of this invention is to provide a compact rotary near-infrared airborne multispectral system, which solves the problems of existing near-infrared airborne multispectral equipment having a loose structure and large size, large space occupied by the filter switching mechanism, insufficient rotary switching accuracy, weak environmental adaptability, and an imbalance between cost and adaptability, which are out of touch with the actual installation and operation requirements of small airborne platforms, thus affecting the miniaturization of the equipment and the quality of data acquisition.

[0006] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a compact rotary near-infrared airborne multispectral system, including a protection module, a near-infrared module, a visible light camera, a temperature and humidity sensor, a rotary module, and a drive module;

[0007] The protective module includes an outer shell and a gimbal mounted on the outside of the outer shell;

[0008] The near-infrared module includes a near-infrared lens and a near-infrared imaging sensor;

[0009] The visible light camera is housed inside the housing and partially protrudes from the bottom of the housing. The optical axis of the visible light camera is parallel to the optical axis of the near-infrared module.

[0010] The temperature and humidity sensor is located at the bottom of the housing;

[0011] The rotating wheel module is positioned between the near-infrared lens and the near-infrared imaging sensor, forming a complete optical path. The rotating wheel module includes a mounting base housed within the housing, a filter wheel rotatably connected to the mounting base, multiple filters of different specifications arranged in a circular array on the filter wheel, and a Hall position sensor component for monitoring the actual position of the filter wheel. The near-infrared lens is positioned below the mounting base and extends out of the housing, while the near-infrared imaging sensor is positioned above the mounting base and located within the housing. Any filter in the rotating wheel module aligns with the near-infrared lens during rotation.

[0012] The drive module is a brushless direct drive motor mounted on the mounting base and whose output shaft is connected to the filter wheel;

[0013] The near-infrared module, visible light camera, temperature and humidity sensor, rotary wheel module, and drive module are all connected to an external onboard computer via wiring to receive control signals and transmit collected data.

[0014] By adopting the above technical solution, the following advantages are achieved: (1) The near-infrared lens and the filter of the rotating wheel module are precisely aligned. After the filter wheel is switched, the near-infrared light of multiple bands is transmitted to the near-infrared imaging sensor through the lens to complete the near-infrared spectral data acquisition. There is no need to configure a separate camera for different bands, which greatly reduces the hardware investment; (2) The optical axis of the visible light camera is parallel to the optical axis of the near-infrared module. It is responsible for high-definition visible image acquisition and works with the near-infrared module to complete the airborne system data acquisition, ensuring data integrity; (3) The brushless direct drive motor of the drive module is directly connected to the filter wheel. The direct drive design eliminates the traditional transmission gear set, effectively controls the axial dimension, and provides stable power for the rotation of the filter wheel. With the Hall position sensor component that monitors the actual position of the filter wheel, the filter can be accurately switched, aligned with the optical path of the near-infrared module, and ensure the stable transmission of the corresponding band light, avoiding data frame loss; (4) Temperature and humidity sensor: Real-time monitoring of the temperature and humidity data of the overall working environment of the equipment, providing key environmental parameter references for the stable operation of the system.

[0015] A further feature of this invention is that the filter wheel is provided with a plurality of embedded mounting slots in a circumferential array, and a plurality of filters of different specifications are respectively embedded and installed in the plurality of embedded mounting slots.

[0016] By adopting the above technical solution, the "embedded" design of the embedded mounting slot allows the filter to fit tightly with the mounting slot, improving installation stability; the circular array distribution of multiple embedded mounting slots and multiple circular array distribution of filters ensures that the center of gravity of the filter wheel is evenly distributed, reducing vibration and shaking during high-speed rotation and ensuring the accuracy and reliability of the optical system in long-term operation.

[0017] A further feature of this invention is that the lower surface edge of the filter wheel is provided with multiple holes, two of which are symmetrically arranged on both sides of the rotation axis of the filter wheel, and the remaining multiple holes are distributed in a circular array and located between adjacent filters. The center of the two symmetrically arranged holes and the center of two of the multiple circularly arranged holes are on the same straight line. One of the two symmetrically arranged holes is defined as a mounting hole, and the remaining holes in the multiple circularly arranged holes, excluding the mounting hole closest to the two symmetrically arranged holes, are also defined as mounting holes. The remaining two holes are defined as counterweight holes.

[0018] The Hall position sensing component includes a Hall sensor mounted on a mounting base, multiple magnets mounted in mounting holes, and a counterweight block for balancing after the multiple magnets are installed in the counterweight holes.

[0019] By adopting the above technical solution, during the rotation of the filter wheel, the magnet approaches the Hall sensor. The Hall sensor senses the change in magnetic field and outputs a pulse signal. Each pulse signal corresponds to "a position interval" of the filter wheel's rotation. By counting the number of pulses, the real-time position of the filter wheel can be calculated. Furthermore, in order to distinguish the starting position of the filter wheel, the positions of the magnets installed in the defined mounting holes of the two symmetrically arranged holes are deviated, so that the Hall sensor senses that the magnetic field of the magnet at the position of the magnet is different from that of the other magnets, which is used to identify the starting position. A counterweight is added in the counterweight hole on the filter wheel to achieve weight balance after multiple magnets are installed, which can reduce the rotational eccentricity of the filter wheel and reduce the amplification effect of airborne vibration.

[0020] A further feature of this invention is that: heat dissipation vents are provided on both sides of the outer casing, and rain covers located at the heat dissipation vents are provided on both sides of the outer casing.

[0021] By adopting the above technical solution, a rain cover is installed at the heat dissipation vent, which provides rain protection without affecting heat dissipation.

[0022] A further feature of this invention is that the wiring of the near-infrared module, visible light camera, temperature and humidity sensor, rotary wheel module, and drive module all passes through the connection between the outer shell and the gimbal and enters the gimbal, and then exits after being routed inside the gimbal. The connection between the outer shell and the gimbal, as well as the location on the gimbal where the wiring can exit, are provided with inner wiring protection rings.

[0023] By adopting the above technical solution, the wiring of the near-infrared module, visible light camera, temperature and humidity sensor, rotary wheel module, and drive module all passes through the connection between the outer shell and the gimbal and enters the gimbal. After being routed inside the gimbal, the wiring exits. In addition, internal wiring protection rings are installed at the connection between the outer shell and the gimbal, as well as at the locations on the gimbal where the wiring can exit. This can prevent the wiring from being exposed, tangled, or damaged by external forces, and prevent moisture and dust from the airborne environment from entering the equipment.

[0024] In summary, the beneficial effects of this utility model are:

[0025] (1) Compact integrated design suitable for airborne scenarios: The brushless direct drive motor and filter wheel are directly connected, eliminating the need for a transmission gear set to control the axial dimension, greatly reducing the size of the equipment and perfectly adapting to the limited installation space of small airborne platforms. The rain cover provides rain protection without affecting heat dissipation, solving the pain points of traditional equipment being large in size and requiring additional accessories for heat dissipation protection;

[0026] (2) High-precision switching ensures imaging quality: The traditional photoelectric switch is replaced by a combination of Hall sensor and magnet. The position of the filter wheel is monitored in real time through pulse signal. The starting position is accurately located by the magnet gap design at a specific position to avoid switching errors. At the same time, the filter wheel has a reserved counterweight hole to adjust the dynamic balance, reduce the eccentricity problem caused by airborne vibration, realize the rapid switching of multiple bands, eliminate poor data consistency and frame loss, and improve the accuracy of multispectral imaging.

[0027] (3) High cost performance and high reliability are combined: a single device integrates multiple band filters, eliminating the need for redundant configuration of multiple cameras and significantly reducing hardware investment costs; the filters adopt an embedded mounting slot design to prevent displacement during airborne vibration, and the rain cover blocks rainwater intrusion, improving long-term operational stability in complex environments. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of this utility model;

[0029] Figure 2 This is a schematic diagram of the near-infrared module and the rotating wheel module in this utility model;

[0030] Figure 3 This is a schematic diagram of the rotating wheel module in this utility model;

[0031] Figure 4 This is an exploded view of the rotating wheel module in this utility model;

[0032] Figure 5 This is a schematic diagram of the structure of the filter wheel in this utility model;

[0033] Figure 6 This is a schematic diagram of the internal cable protection ring in this utility model.

[0034] Reference numerals: 1. Protective module; 11. Housing; 111. Rain cover; 12. Gimbal; 121. Internal cable routing ring; 2. Near-infrared module; 21. Near-infrared lens; 22. Near-infrared imaging sensor; 3. Visible light camera; 4. Temperature and humidity sensor; 5. Rotary wheel module; 51. Mounting base; 52. Filter wheel; 521. Embedded mounting slot; 522. Mounting hole; 523. Counterweight hole; 524. Counterweight block; 53. Filter; 54. Hall position sensing component; 541. Hall sensor; 542. Magnet; 6. Drive module. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings.

[0036] Example: A compact rotary near-infrared airborne multispectral system, such as Figure 1 and Figure 2As shown, it includes a protection module 1, a near-infrared module 2, a visible light camera 3, a temperature and humidity sensor 4, a rotating wheel module 5, and a drive module 6.

[0037] like Figure 1 As shown, the protection module 1 includes a housing 11 and a gimbal 12 disposed on the outside of the housing 11.

[0038] like Figure 1 and Figure 2 As shown, the near-infrared module 2 includes a near-infrared lens 21 and a near-infrared imaging sensor 22.

[0039] like Figures 2 to 4 As shown, the rotating module 5 is positioned between the near-infrared lens 21 and the near-infrared imaging sensor 22, forming a complete optical path. The rotating module 5 includes a mounting base 51 housed within the housing 11, a filter wheel 52 rotatably connected to the mounting base 51, six filters 53 of different specifications arranged in a circumferential array on the filter wheel 52, and a Hall effect position sensor component 54 for monitoring the actual position of the filter wheel 52. The near-infrared lens 21 is positioned below the mounting base 51 and extends through the housing 11, while the near-infrared imaging sensor 22 is positioned above the mounting base and within the housing 11. During rotation, any filter 53 of the rotating module 5 aligns with the near-infrared lens 21.

[0040] like Figure 3 and Figure 4 As shown, the filter wheel 52 has six embedded mounting slots 521 arranged in a circular array, and six filters 53 of different specifications are respectively embedded and installed in the multiple embedded mounting slots 521.

[0041] like Figures 3 to 5As shown, the lower surface edge of the filter wheel 52 has eight holes. Two holes are symmetrically arranged on both sides of the rotation axis of the filter wheel 52, and the remaining six holes are arranged in a circular array between adjacent filters 53. The center of the two symmetrically arranged holes and the center of the six circularly arranged holes are on the same straight line. One of the two symmetrically arranged holes is defined as the mounting hole 522, and the other five holes in the six circularly arranged holes, excluding the mounting hole 522 closest to the two symmetrically arranged holes, are defined as mounting holes 522. The remaining two holes are defined as counterweight holes 523. The Hall position sensing assembly 54 includes a Hall sensor 541 mounted on the mounting base 51 and six magnets 542 disposed in the mounting holes 522. A counterweight block 524 is disposed in the counterweight hole 523 to balance the system after the six magnets 542 are installed. At this time, five of the six magnets 542 are arranged in an arc array (the magnetic field sensed by the Hall sensor 541 is the same), and the other magnet 542 is retracted inward toward the rotation axis of the filter wheel 52 (the magnetic field sensed by the Hall sensor 541 is different from that at other positions of the magnet 542).

[0042] like Figure 1 As shown, the visible light camera 3 is housed within the housing 11 and partially protrudes from the bottom of the housing 11. The optical axis of the visible light camera 3 is parallel to the optical axis of the near-infrared module 2. The visible light camera 3 is responsible for acquiring high-definition visible images and works in conjunction with the near-infrared module 2 to complete the acquisition of airborne system data, ensuring data integrity.

[0043] like Figure 1 As shown, the temperature and humidity sensor 4 is located at the bottom of the housing 11. The temperature and humidity sensor 4 monitors the temperature and humidity data of the overall working environment of the equipment in real time, providing key environmental parameter references for the stable operation of the system.

[0044] like Figure 1 and Figure 2 As shown, the drive module 6 is a brushless direct drive motor mounted on the mounting base 51 and whose output shaft is connected to the filter wheel 52.

[0045] like Figure 1 As shown, heat dissipation vents (not shown) are provided on both sides of the outer casing 11. Rain covers 111 located at the heat dissipation vents are provided on both sides of the outer casing 11. A cooling fan is also added at one of the heat dissipation vents inside the outer casing 11, so that air enters the outer casing 11 from one heat dissipation vent and is exhausted from the other heat dissipation vent, thereby improving heat dissipation efficiency.

[0046] like Figures 1 to 6As shown, the near-infrared module 2 (mainly the near-infrared lens 21 and near-infrared imaging sensor 22), visible light camera 3, temperature and humidity sensor 4, rotary wheel module 5 (mainly the Hall sensor 541), and drive module 6 are all connected to an external onboard computer via wiring to receive control signals and transmit collected data. The wiring of the near-infrared module 2, visible light camera 3, temperature and humidity sensor 4, rotary wheel module 5, and drive module 6 passes through the connection between the outer casing 11 and the gimbal 12, enters the gimbal 12, and exits after routing within the gimbal 12. Each exit point on the gimbal 12 is equipped with an inner wiring guard ring 121. The inner wiring guard ring 121 has a snap-fit ​​groove on its circumference, ensuring installation and fixation during elastic deformation. Additionally, an inner wiring guard ring 121 (not shown in the figure) can be added at the connection between the gimbal 12 and the outer casing 11 to prevent moisture and dust from entering the interior of the outer casing 11.

[0047] Implementation results: (1) The near-infrared lens 21 and the filter 53 of the rotating wheel module 5 are precisely aligned. The six bands of near-infrared light after the filter wheel 52 is switched are transmitted to the near-infrared imaging sensor 22 through the lens to complete the near-infrared spectral data acquisition. There is no need to configure a separate camera for different bands, which greatly reduces the hardware investment; (2) The optical axis of the visible light camera 3 is parallel to the optical axis of the near-infrared module 2. It is responsible for high-definition visible image acquisition and works with the near-infrared module 2 to complete the airborne system data acquisition and ensure data integrity; (3) The brushless direct drive motor of the drive module 6 is directly connected to the filter wheel 52. The direct drive design eliminates the traditional transmission gear set, effectively controls the axial dimension, and provides stable power for the rotation of the filter wheel 52. With the Hall position sensor component 54 that monitors the actual position of the filter wheel 52, the filter 53 can be accurately switched and aligned with the optical path of the near-infrared module 2 to ensure stable transmission of the corresponding band of light and avoid data frame loss; (4) Temperature and humidity sensor 4: Real-time monitoring of the temperature and humidity data of the overall working environment of the equipment, providing key environmental parameter references for the stable operation of the system.

[0048] The "embedded" design of the recessed mounting slot 521 allows the filter 53 to fit tightly with the mounting slot, improving installation stability. The circular array distribution of multiple recessed mounting slots 521 and the circular array distribution of the six filters 53 ensures that the center of gravity of the filter wheel 52 is evenly distributed, reducing vibration and shaking during high-speed rotation and ensuring the accuracy and reliability of the optical system during long-term operation.

[0049] During the rotation of the filter wheel 52, the magnet 542 approaches the Hall sensor 541. The Hall sensor 541 senses the change in magnetic field and outputs a pulse signal. Each pulse signal corresponds to a "position interval" of the filter wheel's rotation. By counting the number of pulses, the real-time position of the filter wheel 52 can be calculated. Furthermore, to distinguish the starting position of the filter wheel 52, the position of the magnet 542 installed in the defined mounting holes 522 of the two symmetrically arranged holes is deviated, so that the Hall sensor 541 senses that the magnetic field of the position of the magnet 542 is different from that of the other magnets 542, which is used to identify the starting position. A counterweight 524 is added in the counterweight hole 523 on the filter wheel 52 to achieve weight balance after the installation of multiple magnets 542, which can reduce the rotational eccentricity of the filter wheel 52 and reduce the amplification effect of airborne vibration.

[0050] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

Claims

1. A compact rotary near-infrared airborne multispectral system, characterized in that: It includes a protection module (1), a near-infrared module (2), a visible light camera (3), a temperature and humidity sensor (4), a rotating wheel module (5), and a drive module (6); The protective module (1) includes a housing (11) and a gimbal (12) disposed on the outside of the housing (11); The near-infrared module (2) includes a near-infrared lens (21) and a near-infrared imaging sensor (22); The visible light camera (3) is installed inside the housing (11) and partially protrudes from the bottom of the housing (11). The optical axis of the visible light camera (3) is parallel to the optical axis of the near-infrared module (2). The temperature and humidity sensor (4) is located at the bottom of the housing (11); The rotating wheel module (5) is positioned between the near-infrared lens (21) and the near-infrared imaging sensor (22) and forms a complete optical path. The rotating wheel module (5) includes a mounting base (51) located inside the housing (11), a filter wheel (52) rotatably connected to the mounting base (51), multiple filters (53) of different specifications distributed in a circular array on the filter wheel (52), and a Hall position sensing component (54) for monitoring the actual position of the filter wheel (52). The near-infrared lens (21) is positioned below the mounting base (51) and extends out of the housing (11). The near-infrared imaging sensor (22) is positioned above the mounting base and located inside the housing (11). Any filter (53) of the rotating wheel module (5) aligns with the near-infrared lens (21) during rotation. The drive module (6) is a brushless direct drive motor mounted on the mounting base (51) and whose output shaft is connected to the filter wheel (52); The near-infrared module (2), visible light camera (3), temperature and humidity sensor (4), rotating wheel module (5), and drive module (6) are all connected to an external onboard computer via lines to receive control signals and transmit collected data.

2. The compact rotary near-infrared airborne multispectral system according to claim 1, characterized in that: The filter wheel (52) has a circumferential array of multiple embedded mounting slots (521), and multiple filters (53) of different specifications are respectively embedded in the multiple embedded mounting slots (521).

3. A compact rotary near-infrared airborne multispectral system according to claim 1, characterized in that: The lower surface edge of the filter wheel (52) is provided with a plurality of holes, two of which are symmetrically arranged on both sides of the rotation axis of the filter wheel (52), and the remaining plurality of holes are arranged in a circular array and located between adjacent filters (53). The center of the two symmetrically arranged holes and the center of two of the plurality of circularly arranged holes are on the same straight line. One of the two symmetrically arranged holes is defined as a mounting hole (522), and the remaining holes in the plurality of circularly arranged holes, excluding the mounting hole (522) close to the two symmetrically arranged holes, are also defined as mounting holes (522). The remaining two holes are defined as counterweight holes (523). The Hall position sensing component (54) includes a Hall sensor (541) disposed on a mounting base (51), a plurality of magnets (542) disposed in mounting holes (522), and a counterweight (524) disposed in a counterweight hole (523) for balancing after the plurality of magnets (542) are installed.

4. A compact rotary near-infrared airborne multispectral system according to claim 1, characterized in that: The outer casing (11) has heat dissipation vents on both sides, and rain shields (111) located at the heat dissipation vents are provided on both sides of the outer casing (11).

5. A compact rotary near-infrared airborne multispectral system according to claim 1, characterized in that: The wiring of the near-infrared module (2), visible light camera (3), temperature and humidity sensor (4), rotary wheel module (5), and drive module (6) all passes through the connection between the outer shell (11) and the gimbal (12) and enters the gimbal (12). After the wiring is routed inside the gimbal (12), it exits. The gimbal (12) is provided with an inner wiring guard ring (121) at each position where the wiring can pass through.

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