An integrated multispectral composite fire detector

Abstract

This utility model discloses an integrated multispectral composite fire detector, belonging to the field of fire protection facility technology. The detector includes a split-type snap-fit ​​housing, an integrated dual-spectral image acquisition unit, a power board, an image processing mainboard, and an interface board. The image acquisition unit includes two side-by-side special cameras, each capable of being equipped with lenses of different focal lengths, for simultaneously acquiring visible light and near-infrared images. The power board, image processing mainboard, and interface board are stacked on a main mounting bracket within the housing and connected via flexible wiring. The image processing mainboard runs a smoke and fire recognition algorithm, fusing and analyzing the dual-spectral images to achieve flame and smoke recognition and temperature trend discrimination based on near-infrared radiation. This utility model, through its integrated and modular design, solves the problems of complex structure and inconvenient maintenance of traditional multi-lens detectors, and has the advantages of compact structure, accurate detection, strong anti-interference capability, and convenient maintenance.

Description

Technical Field

[0001] This utility model relates to the field of fire protection facilities technology, specifically to a fire detection device based on image perception, and more particularly to an integrated multispectral composite fire detector. Background Technology

[0002] Fire detectors are the core sensing components of automatic fire alarm systems, and their reliability and early warning capabilities are directly related to the safety of life and property. Traditional fire detectors are mainly classified into single-function products based on their detection principles, such as smoke detectors, heat detectors, and flame (light radiation) detectors. However, actual fire scenarios are complex and varied, and the order and intensity of characteristic signals such as smoke, flame, and temperature are uncertain. Single-principle detectors are prone to missed or false alarms when dealing with complex interference environments (such as dust, water mist, non-fire heat sources, and ambient light), and they also have blind spots when facing certain special fire situations.

[0003] To improve detection reliability, composite fire detectors combining multiple sensing technologies have emerged on the market. Currently, a mainstream approach involves using multiple independent sensors or optical lenses to collect different physical signals. For example, simultaneously configuring independent color lenses, near-infrared lenses, and thermal imaging lenses to acquire visible light images, near-infrared images, and thermal imaging temperature field information, then performing data fusion for judgment. While this approach improves fire detection rates to some extent, its inherent drawbacks are also significant: First, the discrete structure of multiple lenses leads to complex internal optical paths and numerous components, resulting in a large detector size and high manufacturing costs. Second, the optical axis alignment requirements of multiple lenses are high, the assembly process is complex, and long-term use can lead to alignment deviations due to vibration or temperature changes, affecting detection accuracy. Finally, the internal structure of such devices is usually integrated or rigidly connected; if any component (such as a lens or interface circuit) fails, it often requires complete disassembly or return to the factory for repair, resulting in extremely poor on-site maintainability and modular replaceability, increasing the overall lifecycle cost.

[0004] Therefore, there is an urgent need in the existing technology for a new type of composite fire detector solution that can achieve multi-signal fusion detection, improve anti-interference capability, and fundamentally optimize structural design to achieve miniaturization, modularization and convenient maintenance. Utility Model Content

[0005] This invention addresses the shortcomings of existing composite fire detectors based on multiple discrete lenses, which suffer from complex structures and difficult maintenance. It proposes an integrated multispectral composite fire detector, which simplifies the system structure, facilitates maintenance, improves its multispectral composite detection performance and reliability in complex environments, and solves the problems of cost, accuracy and applicability.

[0006] To achieve the above objectives, this utility model provides an integrated multispectral composite fire detector, comprising: The integrated housing assembly consists of a removable bottom, front cover, top cover, and rear cover connected by a snap-fit ​​structure. An integrated dual-spectrum image acquisition unit is installed inside the front of the housing. It includes two special cameras, a first special camera and a second special camera, which are arranged side by side. Both are used to simultaneously acquire visible light and near-infrared spectral images and are equipped with lenses with different focal lengths. The power board supplies power to the various electrical components inside the detector. An image processing motherboard, connected to the image acquisition unit, is used to run a smoke and fire recognition algorithm to comprehensively analyze the spectral and dynamic features of the dual-spectrum image, thereby realizing flame and smoke recognition and temperature trend discrimination based on near-infrared radiation characteristics. Interface board, used to provide external communication interfaces; The power board, image processing motherboard, and interface board are stacked on the main mounting bracket inside the housing. The image processing motherboard is fixed above the power board, and the interface board is fixed above the image processing motherboard. The circuit boards are connected sequentially by flexible circuits. The image acquisition unit is fixed by an L-shaped mounting bracket, which is connected and fixed to the main mounting bracket.

[0007] The following is a detailed introduction to each part: The integrated housing assembly constitutes the external protective body of the detector. It consists of four independent sheet metal parts: a bottom, a front cover, a top cover, and a rear cover. The edges of each part are precisely interlocked through sheet metal bending, enabling tool-free rapid assembly and disassembly. The inner side of the front cover has a slot for mounting a filter plate. The rear cover has enhanced rigidity, and its outer side has mounting screws, serving as stress points for fixing the entire detector to the mounting surface. This design allows for independent operation of specific functional modules during maintenance.

[0008] The integrated dual-spectrum image acquisition unit is the core sensing component of the detector. It includes two special cameras, a first special camera and a second special camera, which are fixed side-by-side on the same image acquisition board. Both cameras are capable of simultaneously acquiring visible light and near-infrared images, but they are equipped with lenses of different focal lengths to achieve monitoring coverage of different distances and ranges. The corresponding image sensor chip is directly integrated into the image acquisition board, which is fixed by an L-shaped mounting bracket.

[0009] The detector's core circuitry employs an integrated, stacked circuit module, mounted on the main mounting bracket. The power board, as the bottom layer, is directly fixed to the main mounting bracket using power board mounting screws. The image processing motherboard, serving as the core computing layer, is elevated and fixed to the power board using motherboard stacking studs and screws, housing a high-performance processor and memory. The interface board, serving as the external interaction layer, is further elevated and fixed to the image processing motherboard using interface board stacking studs and screws. The circuit boards are connected by flexible wiring (such as flexible circuit boards), forming a clearly defined electrical system that is easy to disassemble and maintain individually.

[0010] The L-shaped mounting bracket is connected to the main mounting bracket via self-tapping screws, ensuring the stability and positional adjustability of the optical unit. The motherboard stacking studs and screws and the interface board stacking studs and screws provide lifting space to facilitate heat dissipation and wiring.

[0011] The algorithm running on the image processing motherboard is the foundation for the implementation of composite detection. By analyzing bispectral images and comprehensively applying spectral feature analysis, it distinguishes the scattering differences of smoke in the visible and near-infrared bands, uses dynamic feature analysis to determine smoke diffusion using the frame difference method, and uses radiation feature analysis to determine temperature trends based on near-infrared intensity, thus achieving highly interference-resistant identification of flames, smoke, and high temperatures.

[0012] Further technical solutions: The two special cameras can be configured with lenses of different focal lengths according to the actual monitoring scenario requirements. Optionally, the lenses can be selected and combined from lenses with different focal lengths such as 4mm, 6mm, 8mm, and 12mm. By configuring different focal lengths, the two cameras can respectively achieve wide-angle monitoring and detailed monitoring of key areas, thereby expanding the monitoring range and improving the ability to identify distant fires without increasing the number of detectors.

[0013] The interface board is designed to be compatible with multiple industrial standard communication interfaces. Specifically, the interface board integrates at least two of the following: RJ45 Ethernet interface, CAN bus interface, and RS485 interface. This allows the detector to be flexibly connected to fire alarm systems or intelligent building management systems based on different communication protocols (such as TCP / IP, CAN bus, Modbus, etc.), significantly enhancing the system integration adaptability and versatility of the equipment.

[0014] Inside the housing, a three-color indicator light is located on the upper part of the L-shaped mounting bracket. This indicator light is electrically connected to the image processing motherboard and is used to visually display the detector's operating status, fire alarm, and fault information.

[0015] Compared with existing technologies, the integrated multispectral composite fire detector of this invention, through the systematic design of integrated construction, module stacking, and modular snap-fit ​​connection, brings the following significant advantages: 1. Significantly simplified structure and reduced overall cost. The adoption of a single image acquisition unit integrating dual-spectral sensing fundamentally replaces the complex optical system with multiple independent lenses in traditional solutions. This greatly reduces the number of components, assembly processes, and optical axis calibration difficulty, enabling miniaturization and weight reduction of the detector, and effectively lowering material and production costs.

[0016] 2. Improved Detection Performance and Reliability. Dual-spectral images are acquired synchronously from the source, providing a spatiotemporally consistent foundation for fusion analysis of the algorithm. By integrating multi-dimensional features such as visible light color texture, near-infrared spectral radiation, and dynamic trends, the algorithm can accurately distinguish between real fires and complex interferences such as sunlight, lamplight, water mist, and dust. This enables early and accurate composite detection of flames, smoke, and high-temperature trends, significantly improving alarm accuracy and anti-interference capabilities.

[0017] 3. Improved ease of maintenance and usability. Through the integrated design of the stacked circuit modules and the integrated housing assembly, field personnel can quickly replace the power board, image processing motherboard, or interface board by removing the back cover without the need for specialized tools or complete disassembly; and can independently clean or replace optical components by removing the front cover.

[0018] 4. Enhanced Installation Adaptability and System Compatibility. The standardized square housing and rear cover mounting screw design allow for easy adaptation to various on-site installation conditions, including wall mounting and ceiling mounting. Meanwhile, the interface board provides multiple industry-standard communication interfaces (such as RJ45, CAN, RS485), ensuring seamless integration of the detector with various existing fire alarm systems or intelligent management platforms, resulting in flexible deployment and significantly enhanced applicability. Attached Figure Description

[0019] Figure 1 This is a front cross-sectional view of Embodiment 1 of the present invention; Figure 2 This is a top cross-sectional view of Embodiment 1 of the present invention; Figure 3 This is a front cross-sectional view of Embodiment 2 of this utility model; Figure 4 This is a top cross-sectional view of Embodiment 2 of the present invention.

[0020] In the diagram: 1-Integrated housing assembly; 2-Filter plate; 3-Special camera one; 4-Special camera two; 5-Image acquisition board; 6-Power board; 7-Image processing motherboard; 8-Interface board; 9-Tri-color indicator light; 10-Box bottom; 11-Front cover; 12-Top cover; 13-Rear cover; 14-Mounting screws; 15-L-shaped mounting bracket; 16-Main mounting bracket; 17-Motherboard stacking studs and screws; 18-Interface board stacking studs and screws; 19-Power board fixing screws; 20-Self-tapping screws. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. Example

[0022] Please see Figure 1 and Figure 2 This embodiment provides a basic structure for an integrated multispectral composite fire detector.

[0023] The detector is externally a single-piece housing assembly 1, with a filter plate 2 mounted on its front end. Inside the housing, located at the front, is the core sensing component: a single-piece dual-spectrum image acquisition unit. This unit includes two special cameras, a first special camera 3 and a second special camera 4, arranged side-by-side, both fixed to the same image acquisition plate 5. Preferably, the first special camera 3 can be configured with a lens with a focal length of 4mm or 6mm to achieve wide-angle monitoring (field of view approximately 70° to 50°); the second special camera 4 can be configured with a lens with a focal length of 8mm or 12mm to achieve detailed monitoring of key areas at a distance (field of view approximately 30° to 20°). The image sensor chips (visible light and near-infrared) of both cameras are directly mounted on the image acquisition plate 5, ensuring that the dual-channel image data maintains spatiotemporal synchronization and pixel-level registration from the source of acquisition.

[0024] Inside the rear of the casing, the core electronic system employs an integrated, stacked circuit module. The bottom layer is the power board 6, responsible for connecting to and converting external power to supply power to the entire device. The middle layer is the image processing motherboard 7, acting as the "brain," which is fixed above the power board 6 in a stacked manner. This motherboard preferably features a dual-core ARM Cortex-A7 processor, running an embedded intelligent image analysis program. The top layer is the interface board 8, which is also fixed above the image processing motherboard 7 in a stacked manner. This interface board integrates at least two of the following: an RJ45 Ethernet interface, a CAN bus interface, and an RS485 interface, to ensure compatibility with different systems. The circuit boards are connected via flexible wiring.

[0025] The image acquisition board 5 is secured by a mounting bracket, which ensures the stability of the optical module. At the top of the mounting bracket is a three-color indicator light 9, connected to the image processing motherboard 7, used to indicate power, fire alarm, fault, and other statuses.

[0026] The working principle and beneficial effects of this embodiment are as follows: Two specialized cameras simultaneously acquire visible and near-infrared dual-spectral images of the monitored area and transmit them to the image processing motherboard 7. The motherboard's smoke and fire recognition algorithm performs comprehensive analysis of the images: flame identification is achieved by analyzing the radiation characteristics of flames in a specific color space and near-infrared band; accurate smoke identification is achieved by comparing the differences in scattering characteristics of smoke in the visible and near-infrared bands (e.g., 550nm vs. 850nm), combined with frame difference analysis to analyze dynamic diffusion trends and edge detection to identify irregular contours; furthermore, the algorithm establishes a correlation model between near-infrared image radiation intensity and temperature to identify abnormal high-temperature trends. This multi-dimensional feature fusion analysis based on a single hardware platform greatly improves detection accuracy and false alarm resistance in complex environments. Simultaneously, the integrated dual-camera design replaces the traditional multi-lens discrete system, significantly simplifying the structure and reducing costs. Example

[0027] Please see Figure 3 and Figure 4 Based on the basic structure and principle shown in Example 1, this embodiment further demonstrates its specific mechanical structure, connection relationship and modular maintenance design in detail.

[0028] In this embodiment, the integrated housing assembly 1 is composed of four independently detachable components connected by a snap-fit ​​structure: a base 10 as the main body, a front cover 11 on which the filter plate 2 is mounted, an upper cover 12, and a rear cover 13. The edges of each component are interlocked by sheet metal bending. The rear cover 13 has enhanced rigidity and is provided with mounting screws 14 on its outer side, serving as the main load-bearing support point when the entire detector is wall-mounted or suspended.

[0029] All internal modules are supported by the main mounting bracket 16. The power board 6 is directly secured to the bottom of the main mounting bracket 16 using power board fixing screws 19. The image acquisition board 5 of the image acquisition unit is fixed by an L-shaped mounting bracket 15, which is connected to the front of the main mounting bracket 16 by self-tapping screws 20. The image processing motherboard 7 is raised and fixed above the power board 6 using motherboard stacking studs and screws 17. The interface board 8 is further raised and fixed above the image processing motherboard 7 using interface board stacking studs and screws 18. A three-color indicator light 9 is installed in a prominent position on the L-shaped mounting bracket 15.

[0030] The beneficial effects of this embodiment in terms of installation and maintenance are as follows: Easy installation: Installers only need to use mounting screws 14 to fix the entire detector to the wall.

[0031] Modular maintenance: This design creates a clear maintenance path. If a circuit component needs replacement (such as the power board 6, image processing motherboard 7, or interface board 8), maintenance personnel only need to open the rear cover 13 to directly access all the stacked circuit boards, unscrew the corresponding screws, and replace any board individually without disassembling the front optical components. If cleaning the filter 2 or maintaining the camera is required, only the front cover 11 needs to be opened. The L-shaped mounting bracket 15 is connected to the main mounting bracket 16 via self-tapping screws 20, allowing the entire optical module to be removed as an independent module.

[0032] Sturdy Structure: The stacked stud system 17 and 18 not only provides raised space between circuit boards to facilitate heat dissipation and wiring, but also forms a robust framework together with the main mounting bracket 16. The rear cover 13, as the main mounting surface, effectively distributes the stress to the entire housing through the snap-fit ​​structure.

[0033] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated multi-spectral composite fire detector, characterized by, include: An integrated housing assembly, which consists of a detachable bottom, front cover, top cover, and rear cover connected by a snap-fit ​​structure; An integrated dual-spectrum image acquisition unit is fixedly installed inside the front side of the housing assembly. It includes two special cameras, a first special camera and a second special camera, which are arranged side by side with different focal lengths. The two cameras are used to simultaneously acquire visible light and near-infrared spectral images. An integrated, stacked circuit module is located inside the rear of the housing assembly and includes a power board, an image processing motherboard, and an interface board. The power board, image processing motherboard, and interface board are stacked and fixedly mounted on a main mounting bracket and connected sequentially via flexible wiring to form an integrated circuit module. The image processing motherboard is electrically connected to the image acquisition unit and is used to analyze the acquired bispectral images to achieve flame and smoke identification and temperature trend determination.

2. The integrated multi-spectral composite fire detector of claim 1, wherein: In the integrated dual-spectrum image acquisition unit, special camera one and special camera two are fixed on the same image acquisition board, which is mounted on an L-shaped mounting bracket, together forming an integrated optical module that can be detached and assembled as a whole; the L-shaped mounting bracket is detachably connected to the main mounting bracket.

3. The integrated multi-spectral composite fire detector of claim 2, wherein: The L-shaped mounting bracket is equipped with a three-color indicator light.

4. The integrated multi-spectral composite fire detector of claim 1, wherein: In the integrated stacked circuit module, the image processing motherboard is fixed above the power board by motherboard stacking studs and screws; the interface board is fixed above the image processing motherboard by interface board stacking studs and screws; the stacking studs and screws constitute the rigid support frame of the integrated stacked circuit module.

5. The integrated multi-spectral composite fire detector of claim 1, wherein: The snap-fit ​​structure of the integrated housing assembly ensures the integrity of the overall structure while allowing the front or rear cover to be independently disassembled for maintenance.

6. The integrated multi-spectral composite fire detector of claim 1, wherein: The interface board is equipped with at least two of the following: an RJ45 interface, a CAN bus interface, and an RS485 interface.

7. The integrated multi-spectral composite fire detector of claim 1, wherein: The image processing motherboard uses a dual-core ARM Cortex-A7 processor.

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