A dual-field-of-view wideband multispectral acquisition system and method

Abstract

This invention discloses a dual-field-of-view wideband multispectral acquisition system and method. The system includes an image processor and a visible light visual sensor, an uncooled long-wave infrared detector, and a cooled mid-to-short-wave infrared detector, all connected to the image processor. The visible light visual sensor locates the device to be detected, converts the acquired visible light image into digital form, and sends it to the image processor. The image processor outputs an imaging control signal to the visible light visual sensor. The uncooled long-wave infrared detector has a first rotating filter wheel at its front end and detects ultra-wideband long-wavelength light (8-14 μm). The cooled mid-to-short-wave infrared detector has a second rotating filter wheel at its front end and detects ultra-wideband mid-to-short-wave light (1.5-6 μm). This invention combines thermal imaging with multispectral and visible light imaging multi-source fusion technology, solving the problem of efficient detection and accurate identification of multiple types of gases across a wide wavelength range.

Description

Technical Field

[0001] This invention belongs to the field of multispectral acquisition technology, and relates to a dual-field-of-view wideband multispectral acquisition system and method. Background Technology

[0002] Currently, most industrial sites use portable gas detection instruments based on chemical sensors or infrared imaging, with infrared imaging gas detection instruments being the main type, because infrared imaging has advantages such as long detection distance, high safety, high sensitivity, and dynamic intuitiveness.

[0003] Infrared imaging gas detection technology can be categorized based on whether its operating wavelength is defined, into traditional thermal radiation imaging technology and spectral thermal imaging technology. Based on its imaging principle, it can be divided into cooled infrared imaging technology and uncooled infrared imaging technology. Cooled infrared imaging technology uses the absorption of infrared radiation to generate electrical signals. Its detection element is a special semiconductor material, such as mercury oxide or indium antimonide. When infrared radiation shines on the detection element, it excites charge carriers within the element, thereby generating an electrical signal. However, due to the very short lifetime of charge carriers, the detection element needs to be cooled to a low temperature to ensure the detector's sensitivity and response speed. Uncooled infrared detectors use semiconductor materials, such as silicon and germanium. When infrared radiation shines on the detection element, it is converted into heat energy, causing a temperature change in the detection element, which in turn causes a change in the element's resistance. This change in resistance is converted into a current or voltage signal, which is then extracted, completing the infrared detection. However, existing rapid detection systems typically can only detect a single gas or a few types of gases within a narrow frequency band. Summary of the Invention

[0004] To solve the above problems, the technical solution of the present invention is: a dual-field-of-view wideband multispectral acquisition system, comprising an image processor and a visible light visual sensor, an uncooled long-wave infrared detector, and a cooled mid- and short-wave infrared detector, all connected to the image processor, wherein...

[0005] The visible light vision sensor locates the device to be detected, converts the acquired visible light image into digital form and sends it to the image processor, and the image processor outputs an imaging control signal to the visible light vision sensor.

[0006] The front end of the uncooled long-wave infrared detector is provided with a first rotating filter wheel, and the uncooled long-wave infrared detector detects ultra-wideband long waves of 8~14μm.

[0007] The cooled mid- and short-wave infrared detector is equipped with a second rotating filter wheel at its front end. The cooled mid- and short-wave infrared detector detects ultra-wideband mid- and short-wave wavelengths of 1.5 to 6 μm.

[0008] Preferably, the first rotating filter wheel includes a full-band opening and at least seven narrowband filters with different center wavelengths.

[0009] Preferably, the second rotating filter wheel includes at least eight narrowband filters with different center wavelengths.

[0010] Preferably, it also includes an intelligent gimbal for mounting a visible light vision sensor, an uncooled long-wave infrared detector, and a cooled mid- and short-wave infrared detector. The intelligent gimbal rotates 360° horizontally and -3° to +93° vertically.

[0011] Preferably, it also includes an electric optical zoom with a focusing distance greater than 3m.

[0012] To achieve the above objectives, the present invention also provides a dual-field-of-view wideband multispectral acquisition method, employing the aforementioned dual-field-of-view wideband multispectral acquisition system, comprising the following steps:

[0013] S10 uses a visible light vision sensor to provide visual assistance in locating the device to be inspected;

[0014] S20: The front end of the uncooled long-wave infrared detector is equipped with a first rotating filter wheel. By default, the entire wavelength aperture is open for light. When a leakage feature is detected, it switches to a cooled medium and short-wave infrared detector for spectral scanning.

[0015] After the S30 cooled mid-to-short wave infrared detector is started, the second rotating filter wheel at its front end rotates to perform narrow-band scanning in the range of 1.5 to 6 μm to identify gas types and determine concentrations.

[0016] Preferably, the first and second rotating filter wheels are driven independently, and filters with different bandwidths are selected.

[0017] Preferably, an intelligent gimbal and an electric optical zoom are provided to extend the detection distance and range.

[0018] Compared with existing technologies, the beneficial effects of this invention are as follows: Addressing the need for high sensitivity and wide-band detection, this invention proposes an infrared imaging system with dual fields of view (visible and infrared), a wide band (covering the 1.5~14μm infrared frequency band), and multispectral capabilities (divided into 8 spectral segments within the 1.5-14μm band). The multi-source fusion technology of thermal imaging, multispectral imaging, and visible light imaging solves the problem of efficient detection and accurate identification of multiple types of gases within a wide band.

[0019] To address the short lifespan of cooled mid-to-short-wave infrared detectors used for infrared spectral imaging, an online intelligent detection technology is proposed that utilizes a combination of an uncooled long-wave infrared detector and a cooled mid-to-short-wave infrared detector. First, a visible light visual sensor is used to locate key equipment for detection. Then, the long-wave uncooled infrared detector performs infrared thermal radiation imaging to detect gas leaks in real time. Finally, upon detection of a gas leak, the mid-to-short-wave cooled infrared detector is activated for multispectral detection to determine the gas type and leakage rate. The visible light sensor and the long-wave uncooled infrared detector operate continuously, while the cooled mid-to-short-wave infrared detector only activates from standby mode after an incident. This collaborative operation significantly reduces the operating time of the cooled mid-to-short-wave infrared detector, extending its service life. Attached Figure Description

[0020] Figure 1 This is a structural block diagram of a dual-field-of-view broadband multispectral acquisition system according to a specific embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of an uncooled long-wave infrared imaging detector in a dual-field-of-view wideband multispectral acquisition system according to a specific embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the structure of a cooled mid-to-shortwave infrared imaging detector in a dual-field-of-view wideband multispectral acquisition system according to a specific embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the intelligent gimbal structure of a dual-field-of-view wideband multispectral acquisition system according to a specific embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0026] To address the complex and diverse application environments, this invention designs three imaging systems, constructing a dual-field-of-view, wide-band, multispectral optical system. (See [link to relevant documentation]). Figure 1The system includes a visible light visual sensor 10, an uncooled long-wave infrared detector 20, and a cooled mid-to-short-wave infrared detector 30. First, the visible light visual sensor 10 is used to locate the key equipment to be detected. Then, the uncooled long-wave infrared detector performs infrared thermal radiation imaging, detecting leaks by utilizing the temperature difference between the leaking gas and the container. Next, the cooled mid-to-short-wave infrared detector performs multispectral detection to determine the gas type and leak rate. Finally, a highly intelligent pan-tilt unit and automatic zoom control extend the detection range and distance. The visible light visual sensor 10, the uncooled long-wave infrared detector 20, and the cooled mid-to-short-wave infrared detector 30 are all connected to an image processor 40. The image processor 40 performs image preprocessing, target recognition, and image fusion, then outputs the fused image to the FPGA processing platform and the GPU processing platform.

[0027] The visible light vision sensor 10 converts the acquired visible light image into digital form and sends it to the image processor 40. The image processor 40 outputs an imaging control signal to the visible light vision sensor 10. The visible light vision sensor 10 is used to locate the position of key detection equipment and to achieve 24-hour real-time monitoring. It features an image resolution of 1920*1080, a 1 / 2.8″ Progressive Scan CMOS sensor, a 25x optical zoom lens (f=4.8mm~120mm), an aperture of F1.6-F3.5, a minimum illumination of 0.01Lux, and an ICR filter-based day / night switching mode. It supports real-time video transmission, backend storage and playback, JPG image capture, video recording, and remote monitoring from the client.

[0028] The uncooled long-wave infrared detector 20 has a first rotating filter wheel 21 at its front end. The uncooled long-wave infrared detector 20 detects ultra-wideband long waves in the 8~14μm range. The uncooled long-wave infrared detector 20 has the advantages of low cost, easy integration, and long operating life, and is designed as a module for 24-hour operation. The uncooled long-wave infrared detector 20 operates in the 8~14μm infrared long-wave band. See [link to relevant documentation]. Figure 2 In addition to seven narrowband infrared filters, the first rotating filter wheel 21 has a reserved full-band circular aperture. By default, the uncooled long-wave infrared detector 20 images through the full-band circular aperture and uses a temperature difference mode for gas leak detection. When a gas leak is detected, the uncooled long-wave infrared detector 20 controls the circular filter wheel to rotate, performing a narrowband scan in the long-wave infrared range to determine the gas type and leak amount. For the mid- and short-wave infrared range, the cooled mid- and short-wave infrared detector 30 will be activated for spectral scanning.

[0029] The cooled mid-to-shortwave infrared detector 30 has a second rotating filter wheel 31 at its front end. The cooled mid-to-shortwave infrared detector 30 detects ultra-wideband mid-to-shortwave wavelengths of 1.5–6 μm. The cooled mid-to-shortwave infrared detector 30 has the advantage of high detection sensitivity, but also the disadvantages of complex structure and short operating life; therefore, it is designed for servo standby operation. See also... Figure 3 After the uncooled long-wave infrared detector 20 detects a gas leak, the cooled mid-to-short-wave infrared detector 30 activates and enters its working mode, controlling the rotation of the second rotating filter wheel 31 to perform a narrow-band scan within the mid-to-short-wave infrared range to determine the gas type and leakage amount. This servo standby working mode can greatly extend the service life and enable the gas leak detector to identify most industrial gases in the short-wave to long-wave spectral range.

[0030] See the intelligent gimbal structure. Figure 4 Measuring 210mm in width and 310mm in height, this unit houses a visible light vision sensor 10, an uncooled long-wave infrared detector 20, and a cooled mid-to-short-wave infrared detector 30. The intelligent pan-tilt unit expands the detection field of the infrared imaging gas leak detector to a 360° field of view across the entire installation location. It allows control of motion parameters such as direction, angle, speed, preset position, and cruise scanning via commands. Selectable parameters are as follows: vertical angle -3° to +93°; horizontal angle 360° continuous rotation with no blind spots; preset points can be set with 8 scan lines, each with up to 32 preset points; vertical rotation speed is 200° / s via key control and 0.05°–100° / s via manual control; horizontal rotation speed is 200° / s via key control and 0.05°–150° / s via manual control; automatic flip function allows for 180° automatic flipping for continuous monitoring in the vertical direction.

[0031] It also includes an electric optical zoom with a focusing distance greater than 3 meters. To achieve imaging of distant objects, an optical electric zoom system was designed. Driven by dual motors, the lens moves back and forth, thereby changing the focal length. Ultimately, this enables clear imaging of objects from near to far, increasing the monitoring distance of the infrared imaging gas leak detector.

[0032] The present invention provides a dual-field-of-view broadband multispectral acquisition method, comprising the following steps:

[0033] S10, with visual assistance provided by the visible light vision sensor 10, locates the device to be inspected;

[0034] S20, the front end of the uncooled long-wave infrared detector 20 is arranged with a first rotating filter wheel 21, which is open to light in the full band by default. When a leakage feature is detected, it is switched to the cooled medium and short-wave infrared detector 30 for spectral scanning.

[0035] S30 After the cooled medium-short wave infrared detector 30 is started, the second rotating filter wheel 31 set at its front end rotates to perform narrow-band scanning in the range of 1.5 to 6 μm to identify gas types and determine concentrations.

[0036] For specific implementation details, please refer to the system implementation examples, which will not be repeated here.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-field-of-view wideband multispectral acquisition method, characterized in that, The dual-field-of-view wideband multispectral acquisition system includes an image processor and a visible light visual sensor, an uncooled long-wave infrared detector, and a cooled mid- and short-wave infrared detector, all connected to the image processor. The visible light vision sensor locates the device to be detected, converts the acquired visible light image into digital form and sends it to the image processor, and the image processor outputs an imaging control signal to the visible light vision sensor. The front end of the uncooled long-wave infrared detector is provided with a first rotating filter wheel, and the uncooled long-wave infrared detector detects ultra-wideband long waves of 8~14μm. The front end of the cooled mid-shortwave infrared detector is provided with a second rotating filter wheel, and the cooled mid-shortwave infrared detector detects ultra-wideband mid-shortwave wavelengths of 1.5 to 6 μm. The first rotating filter wheel includes a full-band opening and at least seven narrowband filters with different center wavelengths; The second rotating filter wheel includes at least eight narrowband filters with different center wavelengths; It also includes a smart gimbal, which is used to carry a visible light vision sensor, an uncooled long-wave infrared detector and a cooled mid- and short-wave infrared detector. The smart gimbal rotates 360° horizontally and -3° to +93° vertically. It also includes an electric optical zoom with a focusing distance greater than 3m; The data collection method includes the following steps: S10 uses a visible light vision sensor to provide visual assistance in locating the device to be inspected; S20: The front end of the uncooled long-wave infrared detector is equipped with a first rotating filter wheel. By default, the entire wavelength aperture is open for light. When a leakage feature is detected, it switches to a cooled medium and short-wave infrared detector for spectral scanning. After the S30 cooled mid-to-short wave infrared detector is started, the second rotating filter wheel at its front end rotates to perform narrow-band scanning in the range of 1.5 to 6 μm to identify gas types and determine concentrations.

2. The dual-field-of-view wideband multispectral acquisition method according to claim 1, characterized in that, The first and second rotating filter wheels are driven independently, and filters with different bandwidths can be selected.

3. The dual-field-of-view wideband multispectral acquisition method according to claim 1, characterized in that, It is equipped with an intelligent gimbal and an electric optical zoom to extend the detection distance and range.

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