High-precision hyperspectral imager
Through the mobile platform driven by linear motors and linear encoder, combined with the splicing technology of visible light cameras and multiple hyperspectral imagers, the problems of uneven movement speed and insufficient band coverage of hyperspectral imagers are solved, achieving higher accuracy and better Wide band imaging reduces manufacturing costs.
Patent Information
- Application Number
- CN202420406855.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-01
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-03-01
AI Technical Summary
The existing hyperspectral imager has uneven movement speed due to screw curvature and thread transmission errors, which affects imaging accuracy, and it is difficult for a single camera to cover a wide band, resulting in high manufacturing costs.
The mobile platform is driven by a linear motor and a linear encoder, and the focus is adjusted by the visible camera, combined with the first and second hyperspectral imagers to collect signals from different bands, and data processing and image stitching are carried out through the imaging system to achieve a wider Operating band and higher imaging accuracy.
Eliminates the uneven movement speed problem caused by screw curvature and thread gap, improves imaging accuracy, reduces manufacturing costs, and expands the scanning range of the hyperspectral imager.
Smart Images
Figure CN222211968U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of hyperspectral imagers, and in particular to a high-precision hyperspectral imager. Background Art
[0002] Hyperspectral imaging technology is based on a large number of narrow-band image data technology. It combines imaging technology with spectral technology to detect the two-dimensional geometric space and one-dimensional spectral information of the target and obtain continuous, narrow-band image data with high spectral resolution.
[0003] Before the hyperspectral image is taken with the corresponding spectroscopic imaging, the lens module is required to converge the image of the object to the focal plane where the slit is located. The image is cut and selected through a micron-sized slit for line imaging. This line image is dispersed into multiple single-band line images within the working band of the hyperspectral imager through the subsequent hyperspectral optical system. In other words, the hyperspectral imager needs to be moved, and the slit selects images of different parts, and then performs spectroscopic processing. By selecting line images of different parts of a specific band for splicing, the hyperspectral image information within the working band of the hyperspectral imager is obtained.
[0004] In the related technology, a motor lead screw transmission is usually used to drive the hyperspectral imager to move for imaging. However, due to manufacturing errors, the lead screw itself has a certain curvature problem, and there is also a matching gap between the threaded transmission of the lead screw and the slider. This will cause the translation speed of the slider to fluctuate during the constant speed rotation of the motor, which will ultimately be reflected in the uneven movement speed of the slit, affecting the imaging accuracy.
[0005] In addition, due to the material of the sensor, the band of a single hyperspectral imager is relatively narrow, usually divided into 400nm~1000nm, 900nm~1700nm, 900nm~2500nm, etc., but some requirements require a band of 400~2500nm. If a single camera is used to achieve such a wide band, it is very difficult and the manufacturing cost is very expensive. Utility Model Content
[0006] The utility model aims to provide a high-precision hyperspectral imager to improve imaging accuracy and scanning range, while reducing the manufacturing cost of the hyperspectral imager.
[0007] In order to solve the above technical problems, the utility model adopts the following technical solutions.
[0008] The utility model provides a high-precision hyperspectral imager, which comprises a mobile platform and an adjustable focal length lens arranged on one side of the mobile platform, wherein a visible light camera, a first hyperspectral imager and a second hyperspectral imager are also arranged on the mobile platform, and the lens of the visible light camera, the slit of the first hyperspectral imager and the slit of the second hyperspectral imager are located on the same plane;
[0009] The high-precision hyperspectral imager also includes a linear motor and a linear encoder, the linear motor includes a motor stator and a motor mover, the motor stator extends along a straight line direction, and the straight line direction is parallel to the plane, the motor mover is movably connected to the motor stator, and the motor mover is fixedly connected to the mobile platform, and the motor stator drives the visible light camera, the first hyperspectral imager, and the second hyperspectral imager to align the adjustable focal length lens respectively through the motor mover;
[0010] The linear encoder comprises an encoder stator and an encoder mover, the encoder stator extends in a direction parallel to the motor stator, the encoder mover is movably connected to the encoder stator, and the encoder stator is fixedly connected to the mobile platform;
[0011] The working band of the first hyperspectral imager is different from the working band of the second hyperspectral imager, and the high-precision hyperspectral imager also includes an imaging system, which processes data and stitches images of the spectral signals collected by the first hyperspectral imager and the second hyperspectral imager respectively on the object to be measured.
[0012] In some embodiments of the present application, two linear motors are provided, and are respectively disposed on both sides of the mobile platform;
[0013] The linear encoder is arranged between the two linear motors.
[0014] In some embodiments of the present application, the motor mover is provided with limiting structures on both sides of the linear direction;
[0015] Limit switches are provided at both ends of the motor stator;
[0016] When the limit switch senses the limit structure, the motor mover stops moving and moves in the opposite direction during the next operation.
[0017] In some embodiments of the present application, the linear motor is a flat linear motor.
[0018] In some embodiments of the present application, the working band of the first hyperspectral imager and the working band of the second hyperspectral imager are continuous; or, the working band of the first hyperspectral imager and the working band of the second hyperspectral imager have an intersecting portion.
[0019] In some embodiments of the present application, the high-precision hyperspectral imager further includes a housing;
[0020] The mobile platform, the visible light camera, the first hyperspectral imager, the second hyperspectral imager and the driving assembly are all arranged in the housing;
[0021] The adjustable focal length lens is arranged outside the shell.
[0022] In some embodiments of the present application, the installation positions of the visible light camera, the first hyperspectral imager, and the second hyperspectral imager relative to the mobile platform in a direction perpendicular to the plane are adjustable.
[0023] It can be seen from the above technical solutions that the embodiments of the utility model have at least the following advantages and positive effects:
[0024] In the high-precision hyperspectral imager of the embodiment of the utility model, the visible light camera is first used to focus on the object to be measured, the linear motor makes the visible light camera align with the adjustable focus lens, and then the focus adjustment of the adjustable focus lens is completed through the image displayed on the device by the visible light camera. Since the lens of the visible light camera, the slit of the first hyperspectral imager and the slit of the second hyperspectral imager are located on the same plane, after the focusing is completed by the visible light camera, the focusing of the first hyperspectral imager and the second hyperspectral imager is also completed at the same time.
[0025] Then the linear motor makes the first hyperspectral imager align with the adjustable focal length lens, and the first hyperspectral imager completes the spectral signal collection of the first working band. Finally, the linear motor makes the second hyperspectral imager align with the adjustable focal length lens, and the second hyperspectral imager completes the spectral signal collection of the second working band.
[0026] The imaging system processes the spectral signals collected by the first hyperspectral imager and the second hyperspectral imager respectively and performs image stitching to complete the spectral image with both the first working band and the second working band, which has a wider working band than the hyperspectral imager with only a single working band. A larger scanning range can be obtained by simply superimposing the spectral signals of the first hyperspectral imager and the second hyperspectral imager, which reduces the manufacturing cost of high-precision hyperspectral imagers.
[0027] It should be noted that when the first hyperspectral imager and the second hyperspectral imager are aligned with the adjustable focal length lens, since it is a line image collected by a slit, the mobile platform needs to keep moving, and the first working band is divided into multiple bands within its range for imaging, and the second working band is divided into multiple bands within its range for imaging. By adopting a linear motor, compared with the form of motor screw transmission, the problem of uneven moving speed of the mobile platform caused by the screw curvature and thread gap is eliminated, and the imaging accuracy is improved. The linear encoder can be used to accurately collect the position of the mobile platform, so as to accurately control the linear motor and further ensure the imaging accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The various objects, features and advantages of the present invention will become more apparent by considering the following detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings are only exemplary illustrations of the present invention and are not necessarily drawn to scale. In the accompanying drawings, the same reference numerals always represent the same or similar parts. Among them:
[0029] Figure 1 FIG. 1 is a schematic diagram of the overall structure of a high-precision hyperspectral imager according to an exemplary embodiment.
[0030] Figure 2 is a schematic structural diagram of a visible light camera, a first hyperspectral imager, and a second hyperspectral imager according to an exemplary embodiment.
[0031] Figure 3 is a schematic structural diagram of a moving platform, a linear motor, a linear encoder, a limit structure and a limit switch according to an exemplary embodiment.
[0032] The description of the accompanying drawings is as follows: 1. Mobile platform; 2. Adjustable focal length lens; 3. Visible light camera; 4. First hyperspectral imager; 41. Slit; 5. Second hyperspectral imager; 51. Slit; 6. Linear motor; 61. Motor stator; 62. Motor mover; 7. Linear encoder; 71. Encoder stator; 72. Encoder mover; 8. Housing; 81. Limit structure; 82. Limit switch. DETAILED DESCRIPTION
[0033] Although the present invention can be easily embodied as embodiments of different forms, only some of the specific embodiments are shown in the drawings and described in detail in this specification. It should be understood that this description should be regarded as an exemplary description of the principles of the present invention and is not intended to limit the present invention to that described herein.
[0034] Thus, a feature indicated in this specification will be used to illustrate one of the features of an embodiment of the utility model, rather than implying that each embodiment of the utility model must have the described feature. In addition, it should be noted that this specification describes many features. Although some features can be combined together to illustrate possible system designs, these features can also be used in other combinations that are not explicitly described. Thus, unless otherwise stated, the described combinations are not intended to be limiting.
[0035] In the embodiments shown in the drawings, the indications of directions (such as up, down, left, right, front and back) used to explain the structure and movement of various elements of the utility model are not absolute but relative. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the descriptions of the positions of these elements change, the indications of these directions also change accordingly.
[0036] See also Figures 1 to 3 A high-precision hyperspectral imager provided by an embodiment of the utility model includes a mobile platform 1 and an adjustable focal length lens 2 arranged on one side of the mobile platform 1, and a visible light camera 3, a first hyperspectral imager 4 and a second hyperspectral imager 5 are also arranged on the mobile platform 1, and the lens of the visible light camera 3, the slit 41 of the first hyperspectral imager 4 and the slit 51 of the second hyperspectral imager 5 are located on the same plane.
[0037] The high-precision hyperspectral imager also includes a linear motor 6 and a linear encoder 7. The linear motor 6 includes a motor stator 61 and a motor mover 62. The motor stator 61 extends in a straight line direction, and the straight line direction is parallel to the plane. The motor mover 62 is movably connected to the motor stator 61, and the motor mover 62 is fixedly connected to the mobile platform 1. The motor stator 61 drives the visible light camera 3, the first hyperspectral imager 4, and the second hyperspectral imager 5 to respectively align the adjustable focal length lens 2 through the motor mover 62.
[0038] The linear encoder 7 includes an encoder stator 71 and an encoder mover 72, the encoder stator 71 extends in a direction parallel to the motor stator 61, the encoder mover 72 is movably connected to the encoder stator 71, and the encoder stator 71 is fixedly connected to the mobile platform 1. It can be understood that the moving direction of the motor mover 62, the encoder mover 72 and the mobile platform 1 is a linear direction parallel to the plane where the lens of the visible light camera 3 is located.
[0039] Among them, the working band of the first hyperspectral imager 4 is different from the working band of the second hyperspectral imager 5. The high-precision hyperspectral imager also includes an imaging system, which processes data and stitches images of the spectral signals collected by the first hyperspectral imager 4 and the second hyperspectral imager 5 respectively.
[0040] Through the above structural design, the visible light camera 3 is first used to focus on the object to be measured, and the linear motor 6 makes the visible light camera 3 align with the adjustable focal length lens 2, and then the focus adjustment of the adjustable focal length lens 2 is completed through the image displayed on the device by the visible light camera 3. Since the lens of the visible light camera 3, the slit 41 of the first hyperspectral imager 4 and the slit 51 of the second hyperspectral imager 5 are located on the same plane, after the focus is completed by the visible light camera 3, the focus of the first hyperspectral imager 4 and the second hyperspectral imager 5 is also completed at the same time.
[0041] Then the linear motor 6 makes the first hyperspectral imager 4 align with the adjustable focal length lens 2, and the first hyperspectral imager 4 completes the spectral signal acquisition of the first working band. Finally, the linear motor 6 makes the second hyperspectral imager 5 align with the adjustable focal length lens 2, and the second hyperspectral imager 5 completes the spectral signal acquisition of the second working band.
[0042] The imaging system processes data and stitches the spectral signals collected by the first hyperspectral imager 4 and the second hyperspectral imager 5 respectively, and completes a spectral image with both the first working band and the second working band, which has a wider working band than a hyperspectral imager with only a single working band. A larger scanning range can be obtained by simply superimposing the spectral signals of the first hyperspectral imager 4 and the second hyperspectral imager 5, thereby reducing the manufacturing cost of a high-precision hyperspectral imager.
[0043] It should be noted that when the first hyperspectral imager 4 and the second hyperspectral imager 5 are aligned with the adjustable focal length lens 2, since it is a line image collected by a slit, the mobile platform 1 needs to keep moving, and the first working band is divided into multiple bands within its range for imaging, and the second working band is divided into multiple bands within its range for imaging. In other words, the imaging system first needs to splice the images of the multiple bands divided by the first working band, and splice the images of the multiple bands divided by the second working band, and then the imaging system splices the images of the first working band and the second working band.
[0044] It is understandable that when the first hyperspectral imager 4 and the second hyperspectral imager 5 are aligned with the adjustable focal length lens 2, the moving speed of the mobile platform 1 needs to correspond to the acquisition frame rate of the hyperspectral camera to ensure the imaging quality.
[0045] By adopting the linear motor 6, the problem of uneven moving speed of the mobile platform 1 caused by the curvature of the screw and the thread gap is eliminated compared to the form of motor screw transmission, and the imaging accuracy is improved. The linear encoder 7 can be used to accurately capture the position of the mobile platform 1, so as to accurately control the linear motor 6 and further ensure the imaging accuracy. It is ensured that the collected images are not distorted after splicing, and the relationship between the moving distance and the acquisition frame of the hyperspectral imager is improved. At the moment of acquisition, the camera is in a stationary state, and the stability of the collected spectral image is improved. It can be understood that due to the existence of thread matching clearance in the form of motor screw transmission, the mobile platform 1 is easy to shake at the moment of acquisition, which affects the imaging stability.
[0046] The moving speed of the linear motor 6 can be set as follows: the moving speed of switching the first hyperspectral imager 4 and the second hyperspectral imager 5 to align the adjustable focal lens 2 is greater than the moving speed when the first hyperspectral imager 4 and the second hyperspectral imager 5 are aligned with the adjustable focal lens 2 for collecting, thereby improving the measurement efficiency.
[0047] The working band of the first hyperspectral imager 4 and the working band of the second hyperspectral imager 5 are continuous. For example, the working band of the first hyperspectral imager 4 is 400nm~1000nm, and the working band of the second hyperspectral imager 5 is 1000nm~2500nm. Finally, after superposition, the working band range of the high-precision hyperspectral imager that can be measured is 400nm~2500nm, thereby improving the scanning range of the hyperspectral imager.
[0048] Alternatively, the working band of the first hyperspectral imager 4 and the working band of the second hyperspectral imager 5 have an intersecting part. For example, the working band of the first hyperspectral imager 4 is 400nm to 1000nm, and the working band of the second hyperspectral imager 5 is 900nm to 2500nm. Finally, after superposition, the working band range that can be measured by the high-precision hyperspectral imager is 400nm to 2500nm, thereby increasing the scanning range of the hyperspectral imager.
[0049] The high-precision hyperspectral imager also includes a housing 8. The mobile platform 1, the visible light camera 3, the first hyperspectral imager 4, the second hyperspectral imager 5 and the driving assembly are all arranged in the housing 8, and the housing 8 plays a protective role. The adjustable focal length lens 2 is arranged outside the housing 8 to facilitate focal length adjustment.
[0050] There are two linear motors 6, which are respectively arranged on both sides of the mobile platform 1, and the linear encoder 7 is arranged between the two linear motors 6. The two linear motors 6 on both sides of the mobile platform 1 can improve the moving stability of the mobile platform 1, avoid shaking of the mobile platform 1, and thus improve the imaging accuracy. The structural layout of the linear encoder 7 arranged between the two linear motors 6 is more reasonable.
[0051] Limit structures 81 are provided on both sides of the motor mover 62 in the linear direction. Limit switches 82 are provided at both ends of the motor stator 61. When the limit switch 82 senses the limit structure 81, the motor mover 62 stops moving and moves in the opposite direction when it works next time. The limit switch 82 and the limit structure 81 are used to detect the extreme position of the motor mover 62 to stop the motor mover 62 and avoid excessive movement of the mobile platform 1 to cause structural collision. The limit switch 82 can be a slot-type photoelectric sensor.
[0052] In this embodiment, the linear motor 6 is a flat-plate linear motor 6 , which occupies less space and is conducive to product miniaturization. In other embodiments, the linear motor 6 can also be a U-shaped slot linear motor 6 or a tubular linear motor 6 .
[0053] The installation positions of the visible light camera 3, the first hyperspectral imager 4 and the second hyperspectral imager 5 relative to the mobile platform 1 in a direction perpendicular to the plane are adjustable to ensure that the lens of the visible light camera 3, the slit 41 of the first hyperspectral imager 4 and the slit 51 of the second hyperspectral imager 5 are located on the same plane.
[0054] In this embodiment, a plurality of strip holes extending in a direction perpendicular to the plane are provided on the mobile platform 1, and the visible light camera 3, the first hyperspectral imager 4, and the second hyperspectral imager 5 are locked in the strip holes by fasteners. Since the locking position of the fasteners in the strip holes is adjustable, the installation positions of the visible light camera 3, the first hyperspectral imager 4, and the second hyperspectral imager 5 are adjusted.
[0055] Although the utility model has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the utility model can be implemented in a variety of forms without departing from the spirit or essence of the utility model, it should be understood that the above-mentioned embodiments are not limited to any of the aforementioned details, but should be widely interpreted within the spirit and scope defined by the attached claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the attached claims.
Claims
1. A high-precision hyperspectral imager, characterized in that: It comprises a mobile platform and an adjustable focal length lens arranged on one side of the mobile platform, wherein the mobile platform is also provided with a visible light camera, a first hyperspectral imager and a second hyperspectral imager, and the lens of the visible light camera, the slit of the first hyperspectral imager and the slit of the second hyperspectral imager are located on the same plane; The high-precision hyperspectral imager also includes a linear motor and a linear encoder, the linear motor includes a motor stator and a motor mover, the motor stator extends along a straight line direction, and the straight line direction is parallel to the plane, the motor mover is movably connected to the motor stator, and the motor mover is fixedly connected to the mobile platform, and the motor stator drives the visible light camera, the first hyperspectral imager, and the second hyperspectral imager to align the adjustable focal length lens respectively through the motor mover; The linear encoder comprises an encoder stator and an encoder mover, the encoder stator extends in a direction parallel to the motor stator, the encoder mover is movably connected to the encoder stator, and the encoder stator is fixedly connected to the mobile platform; The working band of the first hyperspectral imager is different from the working band of the second hyperspectral imager, and the high-precision hyperspectral imager also includes an imaging system, which processes data and stitches images of the spectral signals collected by the first hyperspectral imager and the second hyperspectral imager respectively on the object to be measured.
2. The high-precision hyperspectral imager according to claim 1, characterized in that: The linear motors are provided with two and are respectively arranged on both sides of the moving platform; The linear encoder is arranged between the two linear motors.
3. The high-precision hyperspectral imager according to claim 1, characterized in that: The motor mover is provided with limiting structures on both sides of the linear direction; Limit switches are provided at both ends of the motor stator; When the limit switch senses the limit structure, the motor mover stops moving and moves in the opposite direction during the next operation.
4. The high-precision hyperspectral imager according to claim 1, characterized in that: The linear motor is a flat-plate linear motor.
5. The high-precision hyperspectral imager according to claim 1, characterized in that: The working band of the first hyperspectral imager and the working band of the second hyperspectral imager are continuous; or, the working band of the first hyperspectral imager and the working band of the second hyperspectral imager have an intersecting part.
6. The high-precision hyperspectral imager according to claim 1, characterized in that: The high-precision hyperspectral imager also includes a housing; The mobile platform, the visible light camera, the first hyperspectral imager, the second hyperspectral imager and the driving assembly are all arranged in the housing; The adjustable focal length lens is arranged outside the shell.
7. The high-precision hyperspectral imager according to claim 1, characterized in that: The installation positions of the visible light camera, the first hyperspectral imager and the second hyperspectral imager relative to the mobile platform in a direction perpendicular to the plane are adjustable.