Multi-sensor integrated detection device of tunnel track type inspection robot

Abstract

The utility model provides a multi-sensor integrated detection device of a tunnel track type inspection robot, which relates to the technical field of tunnel detection and comprises a forward sensing module, a motion sensing module, an environment monitoring module, a mechanical support structure and a protective shell. The forward sensing module and an infrared thermal imager are arranged in parallel through a monocular camera and a laser radar, and target depth and temperature detection is achieved based on baseline design and hardware linkage. The motion sensing module adopts double inertial measurement units which are symmetrically mounted, vibration interference is suppressed in combination with a silica gel shock pad, and pose data are output in a redundant manner; the environment monitoring module realizes smoke, temperature and humidity signal acquisition through a dustproof filter screen and a voltage division circuit; the mechanical supporting structure adapts to different tunnel sizes through the telescopic bracket and the magnetic suction quick release interface, and the maintenance is simplified; the protective shell adopts a diversion trench and an anti-static coating to enhance the waterproof and dustproof performance. According to the utility model, multi-sensor physical cooperation, redundant hardware design and modular construction are adopted.

Description

Technical Field

[0001] This utility model relates to the field of tunnel inspection technology, and in particular to a multi-sensor integrated inspection device for a tunnel track-type inspection robot. Background Technology

[0002] As a critical component of transportation and underground infrastructure, the real-time monitoring of tunnel structural safety and operational status is essential for ensuring traffic safety. However, the internal environment of tunnels is complex and harsh, characterized by enclosed spaces, insufficient light, extremely high humidity, and susceptibility to interference from smoke, water, and dust. Traditional manual inspection methods have significant shortcomings. Workers must venture deep into the tunnel, relying on handheld devices for visual inspections or simple measurements, which is inefficient and extremely risky, especially in emergencies such as fire hazards or hazardous gas leaks, where manual inspections struggle to respond quickly. Although automated inspection technologies have been gradually applied in recent years, existing solutions still have significant shortcomings in terms of environmental adaptability, detection accuracy, and long-term stability.

[0003] Existing automated detection devices mostly rely on a single sensor to achieve their functions, such as using only a visual camera or LiDAR for target recognition. Such designs are limited in complex scenarios: cameras produce blurry images in low light or smoky environments, making it difficult to extract effective features; LiDAR point cloud data noise surges when exposed to glare from water or dust, leading to target positioning errors. Furthermore, while some devices attempt to incorporate inertial measurement units (IMUs) to assist positioning, insufficient sensor redundancy and a lack of physical anti-interference design mean that mechanical vibrations and changes in temperature and humidity can easily cause data drift, resulting in significant error accumulation over long-term operation and failing to meet the requirements for high-precision pose estimation. Utility Model Content

[0004] To address the technical problems of insufficient sensor synergy, low hardware redundancy, weak anti-interference ability, and high equipment maintenance costs in existing technologies, this utility model provides a multi-sensor integrated detection device for a tunnel track-type inspection robot.

[0005] The technical solution provided by this utility model is as follows:

[0006] This utility model provides a multi-sensor integrated detection device for a tunnel track-type inspection robot, comprising: a forward sensing module, a motion sensing module, an environmental monitoring module, a mechanical support structure, and a protective shell;

[0007] The forward perception module consists of a monocular camera, an infrared thermal imager, and a lidar. The monocular camera and the lidar are installed parallel to each other at the front end of the robot, with the horizontal distance between them fixed at baseline B. The infrared thermal imager is located above the monocular camera, and the three are fixed by an integrated bracket.

[0008] The motion sensing module includes two inertial measurement units, which are symmetrically installed on both sides of the robot's center of gravity, and the mounting planes of the two inertial measurement units are perpendicular to the robot's direction of motion.

[0009] The environmental monitoring module includes a smoke sensor and a temperature and humidity sensor mounted on the top. The smoke sensor is fixed inside the robot's top protective cover via a threaded interface, while the temperature and humidity sensor is exposed on the surface of the protective cover.

[0010] The mechanical support structure consists of a retractable aluminum profile bracket and a quick-release interface. The bracket is height-adjustable by a stepper motor, and the quick-release interface adopts a magnetic snap-fit ​​composite structure.

[0011] Preferably, the protective shell is made of carbon fiber reinforced polycarbonate material, and the surface of the shell is provided with radial guide grooves with a groove depth of 3mm to 5mm and a groove spacing of 10mm to 15mm. The overall sealing rating of the shell is IP67.

[0012] Preferably, in the forward sensing module, the baseline B of the monocular camera and the LiDAR satisfies the following relationship:

[0013]

[0014] Where f is the focal length of the monocular camera, and D max d represents the maximum detection depth of the tunnel. min This is the minimum effective disparity threshold.

[0015] Preferably, in the motion sensing module, the two inertial measurement units are symmetrically distributed on both sides of the robot's center of gravity, and each inertial measurement unit has a shock-absorbing silicone pad with a thickness of 2mm to 4mm at the bottom of its housing.

[0016] Preferably, the magnetic snap-fit ​​composite structure of the quick-release interface includes a strong magnet embedded in the interface base for adsorbing the sensor base; and an elastic snap located on the side wall of the interface, with a snap-fit ​​depth of 3mm and a width of 5mm, for limiting the horizontal displacement of the sensor.

[0017] Preferably, the guide channels of the protective shell are radially distributed, and the bottom of the channels is provided with an antistatic coating with a thickness of 0.1mm to 0.3mm and a surface resistivity of less than 10. 6 Ω.

[0018] Preferably, in the environmental monitoring module, the air inlet of the smoke sensor is equipped with a detachable dust filter with a pore size of 0.1mm and made of stainless steel woven mesh.

[0019] Preferably, the telescopic aluminum profile bracket of the mechanical support structure includes an outer fixed sleeve with scale markings and an inner sliding rod, which are connected by ball bearings; the telescopic stroke is 200mm to 500mm, and the stepper motor drive accuracy is ±0.5mm.

[0020] The beneficial effects of the technical solution provided by this utility model include at least the following:

[0021] (1) In this utility model, the accuracy and reliability of tunnel environmental event detection are significantly improved by multi-sensor collaborative layout and redundant hardware design. The baseline optimization of monocular camera and lidar combined with infrared thermal imager realizes multi-dimensional perception of target depth and temperature, effectively overcoming the limitations of single sensor in complex environments such as low light and smoke. The dual IMU symmetrical installation and shock absorption structure design reduce vibration and drift interference, ensuring stable robot pose estimation. The modular quick-release interface and telescopic bracket design simplify the maintenance process. The guide channel and anti-static coating of the protective shell enhance the adaptability to harsh environments. The overall solution can achieve efficient and long-lasting tunnel inspection without relying on complex algorithms.

[0022] (2) In this utility model, physical structure innovation is the core. Through hardware signal linkage and mechanical structure optimization, rapid response and low-cost operation and maintenance are achieved. Multi-sensor signals are directly processed by dedicated circuits. Events such as fire and traffic violations are triggered by level comparators and relays to trigger local sound and light alarms. The response delay is low and the anti-interference ability is strong. The IP67 sealing and heat dissipation design of the protective shell ensures long-term stable operation of the equipment and reduces the failure rate. The mechanical quick-release structure and scale markings support manual quick replacement and calibration, which significantly reduces the maintenance difficulty and cost. The whole process is based on hardware collaboration and physical logic, without the need for computer program intervention. It has both high reliability and easy deployment and is suitable for various tunnel scenarios. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a multi-sensor integrated detection device for a tunnel track-type inspection robot, provided as an embodiment of the present invention. Detailed Implementation

[0025] The technical solution of this utility model will now be described with reference to the accompanying drawings.

[0026] In the embodiments of this utility model, words such as "exemplarily" and "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in this utility model should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in the embodiments of this utility model, the meaning expressed by "and / or" can be both, or it can be either one or the other.

[0027] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0028] Reference manual attached Figure 1 The diagram shows a structural schematic of a multi-sensor integrated detection device for a tunnel track-type inspection robot provided in an embodiment of the present invention.

[0029] This utility model embodiment provides a multi-sensor integrated detection device for a tunnel track-type inspection robot, including: a forward sensing module, a motion sensing module, an environmental monitoring module, a mechanical support structure, a protective shell, and an audible and visual alarm module, and their physical structure and connection methods.

[0030] In the forward sensing module, the monocular camera uses a Sony IMX477 sensor with a resolution of 12 megapixels and a focal length of 8mm. It is fixed to an integrated aluminum alloy bracket at the front of the robot via an M12 interface. The LiDAR is a Hesai PandarXT model with a maximum detection range of 100 meters and an accuracy of ±2 cm. It is installed parallel to the monocular camera, with a fixed horizontal distance of 20 cm between them. This distance is calculated based on a formula where the maximum tunnel detection depth is set to 50 meters and the minimum effective parallax threshold is 5 pixels. The infrared thermal imager is a FLIRA315 model with a thermal sensitivity not exceeding 50 milliklvin. It is mounted above the monocular camera and connected to the integrated bracket via bolts. The bracket is made of 6061-T6 aluminum alloy with an anodized surface. It has pre-drilled M6 threaded holes for fixing sensors, and the optical axis parallelism error is adjusted to within 0.1 degrees using a laser calibrator.

[0031] The motion sensing module comprises two ADIADIS16470 six-axis inertial measurement units (IMUs), with a measurement range of ±2000 degrees per second. They are symmetrically mounted on either side of the robot's center of gravity, spaced 15 cm apart, with the mounting plane perpendicular to the robot's direction of motion. Each IMU has a 3 mm thick silicone damping pad with a Shore A hardness of 40A attached to its bottom and is secured to the robot chassis with M3 screws. It connects to the central processing unit via an RS-422 interface, using shielded twisted-pair cables with a length limited to 30 cm to minimize signal interference.

[0032] The smoke sensor in the environmental monitoring module is the MQ-2 model. Its air inlet is fitted with a 0.1 mm pore size stainless steel dust filter (10 mm diameter), which is fixed inside the robot's top protective cover via a G1 / 4 threaded interface. The filter is designed to be removable and requires monthly cleaning to maintain detection sensitivity. The temperature and humidity sensor is the Sensirion SHT35 model, with an accuracy of ±1.5% relative humidity. It is exposed on the surface of the protective cover and sealed with a waterproof EPDM gasket. The cable passes through the inside of the protective cover and connects to the processing unit.

[0033] The retractable aluminum profile bracket with mechanical support structure consists of an outer fixed sleeve and an inner sliding rod. The outer sleeve has an outer diameter of 30 mm and is marked with graduations, while the inner sliding rod has an inner diameter of 28 mm. The two are connected by an LBR15 linear ball bearing. The telescopic stroke is 0 to 400 mm, controlled by a 57 stepper motor driving a synchronous belt with a driving accuracy of ±0.5 mm. The quick-release interface uses a magnetic snap-on composite structure. The base is embedded with a 10 mm diameter, 3 mm thick N52 neodymium iron boron magnet, and the side wall has elastic ABS snap-ons with a snap-on depth of 3 mm and a width of 5 mm. A 2 mm thick iron sheet is embedded at the bottom of the sensor base. After attraction, the snap-ons automatically lock; they can be released by pressing the snap-ons during disassembly.

[0034] The protective shell is made of carbon fiber reinforced polycarbonate, with a thickness of 3 mm, and is coated with a 0.2 mm thick antistatic coating with a resistivity of less than 10. 5 Ohms. The outer casing has radial drainage channels with a depth of 4 mm and a spacing of 12 mm. The bottom of the channels is inclined at 5 degrees to guide water flow. The seams are filled with silicone sealing strips with a width of 5 mm, and rubber washers are installed in the screw holes. The whole unit has passed the IP67 certification test and can be immersed in 1 meter of water for 30 minutes without leakage.

[0035] The audible and visual alarm module includes red, yellow, and blue LED lights with a brightness of 1000 candela per square meter, embedded in the top of the protective housing via an EPDM waterproof gasket. The directional speaker's sound outlets are arranged in a honeycomb pattern with a diameter of 2 mm, achieving a maximum sound pressure level of 110 dB. The alarm volume adaptively adjusts according to ambient noise. The LED lights and speaker are connected to the central processing unit via waterproof cables, and a 4G or 5G communication module simultaneously uploads the alarm signal to a remote monitoring platform.

[0036] In the forward sensing module, a monocular camera and a LiDAR are fixed parallel to each other via an integrated bracket, with a horizontal distance of 20 cm. Based on the baseline design, parallax data is directly generated, and target depth information is output by combining preset focal length parameters. An infrared thermal imager is mounted directly above the camera, and its signal output is linked to a smoke sensor via hardware circuitry. When the smoke concentration exceeds a threshold, the infrared module automatically switches to a high-sensitivity mode, controlling its power supply circuit via a relay to enhance temperature detection capabilities. The LiDAR synchronously scans the environment, and the generated 3D point cloud data is transmitted to the hardware logic module of the central processing unit via a dedicated interface. This data is then physically compared with the visual depth information to correct target position errors.

[0037] The motion sensing module employs dual inertial measurement units (IMUs) symmetrically mounted on either side of the robot's center of gravity. The output signals from both IMUs are averaged in real-time using a redundant circuit design to eliminate drift from a single sensor. Silicone shock-absorbing pads are installed at the bottom of the IMUs to mechanically isolate vibration interference. The acceleration and angular velocity data are used by a hardware integration circuit to calculate the robot's pose change, and the result is directly input to the pose correction module. This module consists of an analog comparator and an operational amplifier. Based on a preset threshold, it determines the pose deviation and outputs a correction signal to the mechanical drive unit to adjust the robot's trajectory.

[0038] The smoke sensor in the environmental monitoring module has a built-in stainless steel filter to reduce false alarms due to dust through physical filtration. Its analog signal is digitized by an analog-to-digital converter and then fed into the event judgment logic board along with the voltage signal from the infrared thermal imager. This logic board uses a multi-comparator circuit to trigger a fire alarm relay when both the smoke concentration and temperature signals simultaneously exceed preset levels. The output of the temperature and humidity sensor is connected to the environmental status monitoring module via a voltage divider circuit to control the start and stop of the cooling fan in the protective housing in real time, ensuring stable temperature of internal components.

[0039] The mechanical support structure achieves height adjustment via a retractable aluminum profile bracket. The bracket houses a stepper motor driving a gear set, which receives pulse signals from the posture correction module to control the extension stroke. The quick-release interface employs a composite structure of magnetic attraction and elastic clips. The sensor base is embedded with an iron plate and attracted by a strong magnet, with a clip depth of 3 mm. Mechanical locking ensures stability during rapid replacement. The protective shell surface features radial flow channels, 4 mm deep, tilted at 5 degrees to guide water flow. Carbon fiber reinforcement and an anti-static coating reduce environmental interference through physical properties. The IP67 sealing structure achieves waterproofing and dustproofing through silicone strips and rubber gaskets.

[0040] The audible and visual alarm module consists of multi-color LED lights and a directional speaker. Its control circuit directly receives the level signal from the event judgment logic board. A fire alarm triggers a high-frequency flashing of the red LEDs, simultaneously closing a relay to activate the speaker circuit. The volume is adjusted via an analog signal from an environmental noise sensor—when noise increases, the feedback circuit automatically raises the speaker drive voltage to a maximum of 110 dB. Events involving vehicles crossing lanes or driving in the wrong direction are detected by a position comparator, triggering a combination of a yellow LED and a specific frequency of audible and visual signals. All alarm signals are converted into radio frequency signals via the hardware encoding circuit of the 4G / 5G communication module and transmitted to the remote monitoring terminal via an antenna.

[0041] System maintenance is achieved through a hardware self-test circuit, which periodically sends pulse signals to each sensor to check if its response current is within the rated range. In case of abnormality, a relay cuts off the power to the faulty module and illuminates the status indicator light. Operations such as filter disassembly and cleaning of the smoke sensor, and calibration of the bracket scale, rely entirely on the physical structure design and require no software intervention. The entire process is achieved through sensor hardware collaboration, circuit signal processing, and mechanical structure linkage; all functions are implemented by the physical structure, without any control components dependent on computer programs.

[0042] The beneficial effects of the technical solution provided by this utility model embodiment include at least the following:

[0043] (1) In this utility model, the accuracy and reliability of tunnel environmental event detection are significantly improved by multi-sensor collaborative layout and redundant hardware design. The baseline optimization of monocular camera and lidar combined with infrared thermal imager realizes multi-dimensional perception of target depth and temperature, effectively overcoming the limitations of single sensor in complex environments such as low light and smoke. The dual IMU symmetrical installation and shock absorption structure design reduce vibration and drift interference, ensuring stable robot pose estimation. The modular quick-release interface and telescopic bracket design simplify the maintenance process. The guide channel and anti-static coating of the protective shell enhance the adaptability to harsh environments. The overall solution can achieve efficient and long-lasting tunnel inspection without relying on complex algorithms.

[0044] (2) In this utility model, physical structure innovation is the core. Through hardware signal linkage and mechanical structure optimization, rapid response and low-cost operation and maintenance are achieved. Multi-sensor signals are directly processed by dedicated circuits. Events such as fire and traffic violations are triggered by level comparators and relays to trigger local sound and light alarms. The response delay is low and the anti-interference ability is strong. The IP67 sealing and heat dissipation design of the protective shell ensures long-term stable operation of the equipment and reduces the failure rate. The mechanical quick-release structure and scale markings support manual quick replacement and calibration, which significantly reduces the maintenance difficulty and cost. The whole process is based on hardware collaboration and physical logic, without the need for computer program intervention. It has both high reliability and easy deployment and is suitable for various tunnel scenarios.

[0045] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

[0046] The following points need to be explained:

[0047] (1) The accompanying drawings of this utility model embodiment only involve the structure involved in this utility model embodiment. Other structures can refer to the general design.

[0048] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the present invention, i.e., these drawings are not drawn to actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "below" another element, the element may be "directly" located "on" or "below" the other element or there may be intermediate elements.

[0049] (3) Where there is no conflict, the embodiments of this utility model and the features in the embodiments can be combined with each other to obtain new embodiments.

[0050] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. The protection scope of this utility model shall be determined by the protection scope of the claims.

Claims

1. A multi-sensor integrated detection device for a tunnel track-type inspection robot, characterized in that, include: Forward sensing module, motion sensing module, environmental monitoring module, mechanical support structure, and protective shell; The forward perception module consists of a monocular camera, an infrared thermal imager, and a lidar. The monocular camera and the lidar are installed parallel to each other at the front end of the robot, with the horizontal distance between them fixed at baseline B. The infrared thermal imager is located above the monocular camera, and the three are fixed by an integrated bracket. The motion sensing module includes two inertial measurement units, which are symmetrically installed on both sides of the robot's center of gravity, and the mounting planes of the two inertial measurement units are perpendicular to the robot's direction of motion. The environmental monitoring module includes a smoke sensor and a temperature and humidity sensor mounted on the top. The smoke sensor is fixed inside the robot's top protective cover via a threaded interface, while the temperature and humidity sensor is exposed on the surface of the protective cover. The mechanical support structure consists of a retractable aluminum profile bracket and a quick-release interface. The bracket is height-adjustable by a stepper motor, and the quick-release interface adopts a magnetic snap-fit ​​composite structure.

2. The multi-sensor integrated detection device for a tunnel track-type inspection robot according to claim 1, characterized in that: The protective shell is made of carbon fiber reinforced polycarbonate material. The surface of the shell is provided with radial drainage grooves with a groove depth of 3mm to 5mm and a groove spacing of 10mm to 15mm. The overall sealing rating of the shell is IP67.

3. The multi-sensor integrated detection device for a tunnel track-type inspection robot according to claim 1, characterized in that: In the forward sensing module, the baseline B between the monocular camera and the LiDAR satisfies the following relationship: Where f is the focal length of the monocular camera, and D max d represents the maximum detection depth of the tunnel. min This is the minimum effective disparity threshold.

4. The multi-sensor integrated detection device for a tunnel track-type inspection robot according to claim 1, characterized in that: In the motion sensing module, the two inertial measurement units are symmetrically distributed on both sides of the robot's center of gravity, and each inertial measurement unit has a shock-absorbing silicone pad with a thickness of 2mm to 4mm at the bottom of its housing.

5. The multi-sensor integrated detection device for a tunnel track-type inspection robot according to claim 1, characterized in that: The magnetic snap-fit ​​composite structure of the quick-release interface includes a strong magnet embedded in the interface base for adsorbing the sensor base; and an elastic snap located on the side wall of the interface, with a snap-fit ​​depth of 3mm and a width of 5mm, for limiting the horizontal displacement of the sensor.

6. The multi-sensor integrated detection device for a tunnel track-type inspection robot according to claim 2, characterized in that: The protective shell has radially distributed flow channels, and the bottom of the channels is coated with an antistatic coating with a thickness of 0.1mm to 0.3mm and a surface resistivity of less than 10. 6 Ω.

7. The multi-sensor integrated detection device for a tunnel track-type inspection robot according to claim 1, characterized in that: In the environmental monitoring module, the air inlet of the smoke sensor is equipped with a detachable dust filter with a pore size of 0.1mm and made of stainless steel woven mesh.

8. The multi-sensor integrated detection device for a tunnel track-type inspection robot according to claim 1, characterized in that: The retractable aluminum profile bracket of the mechanical support structure includes an outer fixed sleeve with scale markings and an inner sliding rod, which are connected by ball bearings; the telescopic stroke is 200mm to 500mm, and the stepper motor drive accuracy is ±0.5mm.

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