Unmanned flight device, system and method for gas detection in limited space

Abstract

The invention discloses an unmanned flight device, system and method for gas detection in a limited space, and relates to the technical field of unmanned aerial vehicles. The device comprises a main body frame, a shell, a flight assembly, a walking assembly and a rotor wing adjusting mechanism, the system comprises a multi-sensor module, a communication module, a power supply module and a control module, and the method completes detection operation by autonomously switching a walking / flight mode. Through cooperation of the walking assembly and the flying assembly and combination of the auxiliary propelling function of the rotor wing adjusting mechanism, the problem that an existing device is insufficient in environmental adaptability in a limited space is solved; through cooperative positioning of a multi-sensor module and a non-GPS, accurate detection and position matching of toxic gas are realized; through full-process autonomous control, dependence on manual operation and GPS signals is eliminated, the method has the advantages of being high in detection efficiency, high in safety and wide in adaptability, and the blank of the prior art in the field of limited space gas detection is effectively filled up.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle technology, specifically relating to an unmanned aerial vehicle device, system and method for gas detection in confined spaces, which is particularly suitable for detecting toxic and harmful gases in confined spaces such as underground pipelines, sealed storage tanks, and narrow alleys. Background Technology

[0002] With increasingly stringent safety regulations, the industry's demand for gas detection in confined spaces is becoming more urgent. The core requirement is to achieve accurate detection of the types and concentrations of gases in the space while avoiding direct exposure of personnel to hazardous environments. At the same time, it needs to be adaptable to special environments such as narrow confined spaces, numerous obstacles, and weak GNSS signals to ensure the safety and integrity of the detection process.

[0003] Two main types of detection solutions have emerged in the current technology: one is a purely walking detection robot, which is equipped with a tracked or wheeled structure on its bottom and can move along the ground in a limited space. It is equipped with gas sensors to complete close-range detection and is suitable for narrow passages. However, such devices cannot cross high obstacles, and the detection coverage is limited. The other type is an unmanned flying device, which uses multi-rotor lift to fly flexibly in space and cover a wider detection range. It is especially suitable for limited spaces with sufficient height. However, purely flying devices are prone to collisions in narrow passages, and their safety is insufficient.

[0004] Meanwhile, existing gas detection solutions also have the following drawbacks: First, they have limited detection capabilities, relying heavily on a single sensor, which is susceptible to environmental factors such as temperature and humidity, resulting in insufficient detection accuracy. Second, their positioning reliability is low, as they mostly rely on GNSS positioning, which significantly reduces positioning accuracy in GNSS-denied environments such as confined spaces, leading to inaccurate matching between detection data and location information. Third, they lack autonomous operation capabilities, relying heavily on external control terminals to send commands, which makes signal transmission susceptible to interference and requires manual judgment to switch operating modes, resulting in high operational complexity and significant response delays.

[0005] For example, prior art document CN106240807B discloses an unmanned aerial vehicle (UAV) integrating photoelectric detection, which adopts a multi-rotor flight structure and can only achieve photoelectric detection and 3D reconstruction. It lacks gas detection function and relies on GPS positioning and ground control, resulting in poor adaptability in confined spaces. Prior art document CN110481769B focuses on the structural simplification and flight stability of coaxial dual rotors, but does not involve walking function and gas detection module. Other prior art documents also fail to solve the comprehensive technical challenges of dual-mode movement, accurate gas detection, autonomous control, and non-GPS positioning in confined spaces.

[0006] Therefore, developing a confined space gas detection device, system, and method that combines walking and flying modes, multi-sensor collaborative detection, autonomous intelligent control, and non-GPS precise positioning has become an urgent technical problem to be solved. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide an unmanned aerial vehicle device, system and method for gas detection in a confined space, so as to solve the problems of insufficient motion adaptability, lack of autonomous operation capability and low detection and positioning reliability of gas detection devices in confined spaces in the prior art. To achieve the above objectives, the present invention provides the following technical solution: The primary objective of this invention is to provide an unmanned aerial vehicle (UAV) for gas detection in a confined space, comprising a main frame, an outer shell, four sets of flight components, and a locomotion component. The outer shell is wrapped around and connected to the outer surface of the main frame. The four sets of flight components are evenly distributed around the sidewalls of the outer shell, and the locomotion component is located at the bottom of the outer shell. Each flight assembly includes a second connecting arm, a bracket, a brushless DC motor, and propeller blades; two of the four flight assemblies are symmetrically fixed to the outer front sidewall of the outer shell via a first connecting arm; the other two of the four flight assemblies are symmetrically fixed to the outer rear sidewall of the outer shell via a rotor adjustment mechanism; one end of the first connecting arm is fixedly connected to the outer front sidewall of the outer shell, and the other end is fixedly connected to the corresponding second connecting arm; the fixed end of the rotor adjustment mechanism is fixedly connected to the outer rear sidewall of the outer shell, and the movable end of the rotor adjustment mechanism is fixedly connected to the second connecting arm; The bracket is fixedly connected to the end of the second connecting arm away from the housing; the housing of the brushless DC motor is fixedly connected to the upper surface of the bracket, and the output shaft of the brushless DC motor extends vertically upward; the spiral blades are symmetrically fixedly sleeved on the end of the output shaft of the brushless DC motor, and are used to rotate under the drive of the brushless DC motor to generate lift or thrust. The walking assembly includes a drive box fixedly connected to the lower surface of the housing, two sets of symmetrically arranged drive wheels, and tracks. The drive box integrates a drive motor and a reduction transmission mechanism. The two sets of drive wheels are rotatably connected to the two side walls of the drive box via a rotating shaft and are connected to the reduction transmission mechanism inside the drive box. The tracks are wrapped around the outer circumference of each set of drive wheels and are used to contact the ground to realize the walking movement of the device.

[0008] Furthermore, the rotor adjustment mechanism includes a connecting seat, an adjustment block, a first servo motor, and a second servo motor. One side of the connecting seat is fixedly connected to the outer casing, the adjustment block is disposed on the other side of the connecting seat, the first servo motor is fixedly connected to the top of the connecting seat, and the output end of the first servo motor is fixedly connected to the adjustment block. The second connecting arm is movably connected to the adjustment block, the second servo motor is fixedly connected to the surface of the adjustment block, and the output end of the second servo motor is fixedly connected to the second connecting arm.

[0009] Furthermore, side plates are fixedly connected to both sides of the outer shell in the width direction, and the side plates are located on the top outer side of the track; a protective cover is fixedly connected to the side of the second connecting arm away from the outer shell, and the protective cover covers the outside of the spiral blade.

[0010] Furthermore, the inner sidewall of the track is provided with toothed grooves evenly distributed along its length, and the toothed grooves mesh with the teeth on the outer circumferential surface of the drive wheel to prevent slippage between the track and the drive wheel; The walking assembly also includes two tensioning devices, which are rotatably connected to the two side walls of the drive box in the width direction via elastic brackets. Each tensioning device abuts against the inner side wall of the corresponding track to adjust the tension of the track. The inner cavity of the main frame is fixedly connected with multiple pairs of support columns extending in the vertical direction; the multiple pairs of support columns are respectively arranged at the four inner corners of the main frame, and the top of the support column is fixedly connected to the upper frame of the main frame and the bottom is fixedly connected to the lower frame of the main frame; the support columns and the frame of the main frame enclose an installation cavity for installing electronic modules.

[0011] The second objective of this invention is to provide an unmanned aerial vehicle (UAV) system for gas detection in a confined space, comprising the aforementioned UAV device, a multi-sensor module, a communication module, a power supply module, and a control module. The multi-sensor module is fixedly installed on the top wall of the outer shell and is used to collect environmental information and gas data. The multi-sensor module includes a lidar, an inertial measurement unit (IMU), an electrochemical sensor, an infrared sensor, and a temperature and humidity sensor. The lidar's detection end faces away from the outer casing and is used to scan the environment and generate a 3D map. The IMU is integrated inside the multi-sensor module and is used to detect the device's attitude, acceleration, and angular velocity. The electrochemical sensor's detection end is exposed to the external environment and is used to quantitatively detect low concentrations of toxic gases. The infrared sensor's detection end is exposed to the external environment and is used to qualitatively detect volatile organic compounds and obtain their concentrations. The temperature and humidity sensor's detection end is exposed to the external environment and is used to collect ambient temperature and humidity data. The communication module, the power module, and the control module are all fixedly installed in the mounting cavity of the main frame. The communication module is a wireless communication module, whose signal end establishes a wireless connection with an external terminal. The signal input / output end of the communication module is electrically connected to the signal input / output end of the control module to realize data transmission and command interaction.

[0012] Furthermore, the power module is a rechargeable lithium battery pack, and its power output terminal is electrically connected to the drive motor of the walking component, the brushless DC motor and servo motor of the flight component, the multi-sensor module, the communication module, and the control module, respectively, to provide working power.

[0013] Furthermore, the control module is a microprocessor-based control unit. Its control signal output terminal is electrically connected to the drive motor of the walking component, the brushless DC motor and servo motor of the flight component, and the control terminal of the communication module, respectively. Its signal input terminal is electrically connected to the signal output terminal of the multi-sensor module and the power detection terminal of the power supply module, respectively, for realizing the coordinated control of the system.

[0014] A third objective of this invention is to provide a method for using an unmanned aerial vehicle (UAV) device and system for gas detection in a confined space, applied to the aforementioned UAV system, comprising the following steps: S1: Equipment Deployment and Pre-preparation: The unmanned aerial vehicle (UAV) is placed on a flat surface at the entrance of the confined space, and the control module initiates a system self-test. The lidar scans the confined space entrance area, generates a preliminary 3D environmental map, and transmits it to the control module. The IMU (Inertial Measurement Unit) automatically calibrates the initial attitude of the device, records the initial position coordinates, and transmits them to the control module. The electrochemical and infrared sensors preheat for 30-60 seconds, detect the gas baseline value at the confined space entrance, and transmit it to the control module. The temperature and humidity sensors collect the ambient temperature and humidity at the entrance and transmit them to the control module. After the control module analyzes all data and confirms that each module is fault-free and the environmental parameters meet the operating conditions, it automatically generates a preliminary operating path covering the preset detection area, and the device enters an autonomous standby state. S2: Job Mode Judgment and Triggering: The control module determines the scene within a limited space based on the preliminary 3D environmental map generated by the LiDAR: If the width of the passage is less than the safe distance required for the device to fly, or if there are low obstacles with a height lower than the minimum flying height of the device, or if close-range detection along a fixed path is required, the walking mode is triggered. Flight mode is triggered if the detected space height is greater than the minimum flight height of the device, there are no complex low obstacles, or if it is necessary to quickly cross a wide obstacle that is wider than the track crossing capability. S3: Walking mode operation: The control module sends a standby command to the flight components, keeping all brushless DC motors off and the propeller blades stationary. Simultaneously, it sends a drive signal to the drive box, activating the drive motors within and driving the drive wheels on both sides to rotate synchronously via a reduction gear mechanism. This, in turn, drives the tracks, allowing the device to move along the initial operating path. During movement, the lidar scans the path ahead in real time. If the detected deviation of the movement speed from the preset speed exceeds 5%, the control module sends an adjustment signal to the elastic support of the tensioning device. The tensioning device moves outward, compressing the tracks until the movement speed returns to the preset range. If the lidar detects a small obstacle less than 10cm high ahead, or the IMU detects an increase in movement resistance exceeding a preset threshold, the control module triggers autonomous assisted propulsion: first, it sends a command to the first servo motor, which rotates the adjusting block around the connecting seat until it is parallel to the outer shell; then, it sends a command to the second servo motor, which rotates the second connecting arm, tilting the propeller blades 20-45° in the direction of movement. After the angle adjustment is complete, the control module activates the brushless DC motor on the second connecting arm. The rotating propeller blades generate forward thrust, assisting the tracks in crossing obstacles or reducing movement resistance. S4: Flight Mode Operation: The control module sends a stop command to the walking assembly, shutting down the drive motor and stopping the tracks. Simultaneously, it resets the first and second servo motors, returning the second connecting arm to its initial position. Then, the control module synchronously starts the brushless DC motors on the first and second connecting arms, causing the helical blades to rotate at high speed, generating vertical lift and propelling the device upwards. When the device flies over the preset detection area, the control module reduces the rotational speed of all helical blades, hovering the device directly above the detection area. The hovering height is set to 1-3 meters according to the detection requirements. Real-time attitude data is fed back via the IMU inertial measurement unit, and real-time environmental scanning by the lidar enables coordinated positioning, maintaining stable hovering. While hovering, the electrochemical and infrared sensors collect gas data from multiple angles within the area. After collection, the control module adjusts the helical blade rotational speed, propelling the device to the next detection area. S5: Data Processing and Early Warning Throughout the detection process, the IMU (Inertial Measurement Unit) records the device's trajectory and flight attitude in real time, while the temperature and humidity sensors record the ambient temperature and humidity. All data is transmitted to the control module in real time. The control module stores the data synchronously and performs environmental compensation on the gas concentration data in conjunction with the temperature and humidity data. If the concentration of toxic gas exceeds the preset threshold, the control module transmits the detection data and early warning information to the external terminal in real time through the communication module. S6: Autonomous return to base: After all preset detection areas have been inspected, the control module calls upon the walking and flight trajectory data recorded by the IMU inertial measurement unit and combines it with the return path scanned in real time by the lidar to autonomously plan the optimal return route: if the average width of the return path is greater than the safe distance required for the device to fly, the control device returns quickly in flight mode; if there is a narrow section in the return path, the control device returns smoothly in walking mode; after the device returns to the entrance of the confined space, the control module shuts down all working modules and completes the inspection operation.

[0015] Furthermore, in step S2, the safe distance required for the device to fly is 1.5 times the maximum lateral dimension of the device; the minimum flight altitude of the device is 1.2 times the maximum longitudinal dimension of the device. In step S3, the preset speed is set to 0.2-0.5 m / s based on the confined space environment; In step S4, during multi-angle acquisition, the control module adjusts the output angle of the second servo motor to drive the spiral blades on the second connecting arm to fine-tune the rotation speed, so that the device slowly rotates around the center of the detection area to achieve full-angle gas acquisition.

[0016] Furthermore, in step S4, the hovering height of the device is determined by the detection requirements. The IMU inertial measurement unit and the lidar work together to maintain stable hovering. In the hovering state, the electrochemical sensor and the infrared sensor collect gas samples from multiple angles in the area.

[0017] Compared with the prior art, the present invention has significant advantages and beneficial effects, specifically reflected in the following aspects: 1. By integrating walking and flying components, and combining the auxiliary propulsion function of the rotor adjustment mechanism, autonomous switching between "walking" and "flying" modes is achieved. The walking component is suitable for stable movement in narrow passages and low obstacle areas, avoiding the collision risk of pure flying devices; the flying component can cross wide obstacles or move quickly in areas with sufficient height, greatly expanding the detection coverage; the rotor adjustment mechanism provides auxiliary thrust during walking, enhancing obstacle-crossing ability and solving the environmental adaptability limitations of a single movement mode.

[0018] 2. A multi-sensor collaborative detection scheme is adopted, with electrochemical sensors and infrared sensors complementing each other to achieve quantitative and qualitative detection of various toxic gases; temperature and humidity sensors provide environmental compensation, effectively reducing the impact of environmental factors on detection accuracy; lidar and IMU inertial measurement unit work together for positioning, eliminating dependence on GPS signals and enabling accurate positioning even in GNSS-denied environments such as confined spaces, ensuring accurate matching of detection data and location information.

[0019] 3. The entire process is autonomously controlled through the control module, from initial environmental scanning and path planning to mode switching, obstacle avoidance, parameter adjustment during operation, and return route planning. No manual intervention is required, avoiding the problems of external command transmission delay and interference, and greatly improving detection efficiency and safety.

[0020] 4. The side plates and protective covers effectively protect the tracks and propeller blades, reducing the risk of failure; the track tooth grooves and tension wheel design enhance walking stability; the support column structure of the main frame improves the overall strength and provides stable installation space for internal modules; the rechargeable lithium battery pack is equipped with a power detection chip, which facilitates real-time monitoring of power and ensures continuous operation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of one direction of the unmanned aerial vehicle device for gas detection in a confined space in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the unmanned aerial vehicle device for gas detection in a confined space in another direction according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the bottom structure of the unmanned aerial vehicle device for gas detection in a confined space in an embodiment of the present invention; Figure 4 This is a schematic diagram of the assembly structure of the flight component and the protective shield in an embodiment of the present invention; Figure 5 This is a three-dimensional structural schematic diagram of the flight component in an embodiment of the present invention; Figure 6 This is a schematic diagram of the assembly structure of the flight component and the rotor adjustment mechanism in an embodiment of the present invention; Figure 7 This is a schematic diagram of the main frame structure inside the outer shell in an embodiment of the present invention; Figure 8 This is a schematic diagram of the connection framework between the multi-sensor module and the control module in an embodiment of the present invention; Figure 9 This is a flowchart illustrating the usage method of the unmanned aerial vehicle device and system for gas detection in a confined space according to an embodiment of the present invention.

[0022] Figure label: 1-Main framework; 2-Outer shell; 3-Flight assembly; 31-First connecting arm; 32-Rotor adjustment mechanism; 321-Connecting seat; 322-Adjusting block; 323-First servo; 324-Second servo; 33-Second connecting arm; 34-Bracket; 35-Brushless DC motor; 36-Propeller blade; 4-Tramway assembly; 41-Drive box; 42-Drive wheel; 43-Track; 5-Side panels; 6-Protective cover; 7-Tensioning device; 8-Support column; 9-Multi-sensor module; 91-LiDAR; 92-IMU (Inertial Measurement Unit); 93-Electrochemical sensor; 94-Infrared sensor; 95-Temperature and humidity sensor; 10-Communication module; 11-Power supply module; 12-Control module. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Furthermore, the directional terms such as "front," "back," "up," and "down" used herein are defined based on the positions of the components in the accompanying drawings and their relative positions to each other, and are merely for the purpose of clarity and convenience in expressing the technical solution. It should be understood that the use of these directional terms should not limit the scope of protection claimed in this application.

[0026] Please see Figure 1-8 As shown, this embodiment of the invention provides an unmanned aerial vehicle (UAV) for gas detection in a confined space. The UAV includes a main frame 1, an outer shell 2, four sets of flight components 3, and a walking component 4. The outer shell 2 is wrapped around and connected to the outer surface of the main frame 1. The four sets of flight components 3 are evenly distributed around the side walls of the outer shell 2, and the walking component 4 is located at the bottom of the outer shell 2. Each flight assembly 3 includes a second connecting arm 33, a bracket 34, a brushless DC motor 35, and a propeller blade 36. Two of the four flight assemblies 3 are symmetrically fixed to the outer front wall of the outer shell 2 via the first connecting arm 31. The other two of the four flight assemblies 3 are symmetrically fixed to the outer rear wall of the outer shell 2 via the rotor adjustment mechanism 32. One end of the first connecting arm 31 is fixedly connected to the outer front wall of the outer shell 2, and the other end is fixedly connected to the corresponding second connecting arm 33. The fixed end of the rotor adjustment mechanism 32 is fixedly connected to the outer rear wall of the outer shell 2, and the movable end of the rotor adjustment mechanism 32 is fixedly connected to the second connecting arm 33.

[0027] The bracket 34 is fixedly connected to the end of the second connecting arm 33 away from the outer casing 2; the housing of the brushless DC motor 35 is fixedly connected to the upper surface of the bracket 34, and the output shaft of the brushless DC motor 35 extends vertically upward; the spiral blades 36 are symmetrically fixedly sleeved on the end of the output shaft of the brushless DC motor 35, and are used to rotate under the drive of the brushless DC motor 35 to generate lift or thrust.

[0028] The walking assembly 4 includes a drive box 41, drive wheels 42, and tracks 43. The drive box 41 is fixedly connected to the lower surface of the outer shell 2. The drive box 41 integrates a drive motor and a reduction transmission mechanism. Two sets of drive wheels 42 are symmetrically connected to the two side walls of the drive box 41 through a rotating shaft and are connected to the reduction transmission mechanism inside the drive box 41. The tracks 43 are wrapped around the outer circumference of each set of drive wheels 42 and are used to contact the ground to realize the walking movement of the device.

[0029] This technical solution is designed for gas detection scenarios in confined spaces. It features an amphibious unmanned aerial vehicle (UAV) that integrates air and land operations. The technical process revolves around the realization of two core actions: flight and walking. This not only solves the scenario limitations of a single flight or walking device, but also improves operational stability and adaptability.

[0030] In flight mode, after the device is activated, the brushless DC motors 35 in the four flight components 3 start synchronously. The motor output shaft drives the end-mounted helical blades 36 to rotate at high speed. According to aerodynamic principles, the rotating helical blades 36 cut through the air to generate upward lift. When the lift exceeds the overall weight of the device, the device leaves the ground and enters flight mode. The two front flight components 3 are connected to the outer shell 2 via a fixed first connecting arm 31, maintaining a stable flight attitude and providing basic lift support. The two rear flight components 3 are connected to the outer shell 2 via a rotor adjustment mechanism 32. By adjusting the angle of the movable end of the rotor adjustment mechanism 32, the tilt direction of the second connecting arm 33 can be changed, thereby adjusting the angle of the corresponding brushless DC motor 35 and helical blades 36. By adjusting the speed difference of the four motors and the angle of the rear rotor, various flight attitude adjustments such as ascent, descent, turning, and translation can be achieved to adapt to the complex path-swapping requirements within a limited space.

[0031] In walking mode, the device can switch to walking mode when it is in a low-ceilinged passageway, a confined space with a flat ground, or other scenarios unsuitable for flight. After the drive motor inside the drive box 41 starts, the power is transmitted to the drive wheels 42 on both sides after being reduced in speed and increased in torque by the reduction transmission mechanism. When the drive wheels 42 rotate, they drive the tracks 43 surrounding them to move synchronously. The tracks 43 generate friction when in contact with the ground, and the device moves smoothly on the ground with the help of this friction. At the same time, by adjusting the speed difference between the two drive wheels 42, the device can perform steering and other actions to complete ground movement and inspection operations.

[0032] Compared to drones that can only fly, this device's tracked walking component can handle scenarios with limited flight space. For example, in underground utility tunnels with extremely low elevations, the device can switch walking modes to move smoothly, avoiding collisions with the top or side walls during flight; when encountering ground obstacles, it can switch flight modes to cross the obstacles, achieving seamless switching between air and land, and solving the limitations of a single mode of movement in confined spaces.

[0033] Compared to ordinary wheels, tracked structures have a larger contact area with the ground. In complex ground environments such as dust and soft mud that may exist in a confined space, they can reduce the risk of the device sinking, while enhancing ground adhesion and ensuring stability during movement.

[0034] Four sets of flight components 3 are evenly distributed around the outer shell 2. This symmetrical layout ensures a balanced distribution of lift, effectively preventing fuselage tilting due to uneven force during flight. The brushless DC motor 35 has a fast response speed and precise speed control. Combined with the symmetrical design of the propeller blades 36, it can quickly adjust the lift magnitude, adapting to the detection needs of frequent starts and stops and fine-tuning positions in confined spaces.

[0035] The rear rotor adjustment mechanism 32 can flexibly correct the flight attitude by adjusting the angle of the rear flight component 3. For example, when encountering airflow disturbances in a confined space, it can counteract the airflow influence by finely adjusting the rotor angle, ensuring the stable hovering of the device during gas detection and avoiding deviations in detection data due to fuselage shaking.

[0036] The combined structure of the main frame 1 and the outer shell 2 can not only protect the internal detection elements, circuits, etc., and prevent the core components from being damaged by collisions of debris in the limited space; it can also fix the connecting arms and components through the frame to ensure the structural stability during flight and walking.

[0037] Specifically, please refer to Figure 2 , 6 As shown, in one embodiment of the present invention, the rotor adjustment mechanism 32 includes a connecting seat 321, an adjustment block 322, a first servo motor 323, and a second servo motor 324. One side of the connecting seat 321 is fixedly connected to the outer shell 2, the adjustment block 322 is disposed on the other side of the connecting seat 321, the first servo motor 323 is fixedly connected to the top of the connecting seat 321, and the output end of the first servo motor 323 is fixedly connected to the adjustment block 322. The second connecting arm 33 is movably connected to the adjustment block 322, and the second servo motor 324 is fixedly connected to the surface of the adjustment block 322, and the output end of the second servo motor 324 is fixedly connected to the second connecting arm 33.

[0038] Specifically, in this embodiment, the rotor adjustment mechanism 32 is driven independently by two servo motors to drive the second connecting arm 33 to achieve angle adjustment in two vertical dimensions. The specific operation process is as follows: First-dimensional (lateral / left-right) angle adjustment: The first servo motor 323 is fixed to the top of the connecting base 321, and its output end is directly connected to the adjusting block 322. When the device needs to adjust the lateral angle of the flight component 3, the first servo motor 323 receives a control signal and starts, and the output shaft drives the adjusting block 322 to rotate around its own axis (lateral axis). The rotation of the adjusting block 322 will synchronously drive the connected second connecting arm 33, the second servo motor 324, and the subsequent motors and propeller blades to deflect as a whole, realizing the fine adjustment of the angle of the flight component 3 in the left-right direction, such as correcting the attitude of the fuselage tilting left and right.

[0039] Second-dimensional (longitudinal / forward / backward) angle adjustment: The second servo 324 is fixed to the surface of the adjustment block 322, and its output end is movably connected to the second connecting arm 33. When it is necessary to adjust the longitudinal angle of the flight component 3, the second servo 324 is activated independently, and the output shaft drives the second connecting arm 33 to rotate around the longitudinal axis. This action only changes the forward / backward tilt angle of the second connecting arm 33 and the end flight component, and does not affect the position of the adjustment block 322 and the first servo 323. For example, it can adjust the thrust direction of the propeller blades to achieve forward / backward translation or pitch attitude correction of the fuselage.

[0040] The dual servo motors can operate independently or be activated simultaneously. When complex attitude adjustments are required within a confined space (such as simultaneously correcting left and right tilt and forward and backward pitch), the control system sends coordinated signals to the two servos. The first servo adjusts the lateral angle, and the second servo adjusts the longitudinal angle. The combined action of these two motors enables the flight component 3 to achieve angular deflection in any direction, precisely matching the flight attitude control requirements.

[0041] Specifically, please refer to Figure 1 , 2 As shown in Figures 1 and 3, in one embodiment of the present invention, side plates 5 are fixedly connected to both sides of the outer shell 2 in the width direction, and the side plates 5 are disposed on the top outer side of the track 43; a protective cover 6 is fixedly connected to the side of the second connecting arm 33 away from the outer shell 2, and the protective cover 6 covers the outside of the spiral blade 36.

[0042] When the device moves within a confined space, obstacles on both sides (such as protruding pipe walls, gravel, pipelines, etc.) will first come into contact with the side plates 5, rather than directly colliding with the tracks 43 or the drive box 41. The side plates 5 withstand the impact force through their own rigidity, and their outer sides are usually designed to be smooth, which can reduce the frictional resistance with obstacles, allowing the device to maintain its walking posture when it comes into contact with obstacles, and preventing the tracks 43 from getting stuck or the side walls of the drive box 41 from being damaged.

[0043] The protective cover 6 is fixed to the end of the second connecting arm 33, completely covering the outside of the spiral blade 36 to form a full-circumference protective structure. When the device is in flight, the spiral blade 36 rotates at high speed. If it encounters foreign objects such as cables, pipes, or dust clumps in a confined space, the protective cover 6 will first prevent the foreign objects from contacting the blade. On the one hand, the hollow design of the protective cover 6 allows air to pass through without affecting the normal rotation of the spiral blade 36; on the other hand, solid foreign objects will be intercepted by the protective cover 6 to prevent them from becoming entangled or impacting the spiral blade 36, thus preventing blade deformation, breakage, or motor overload.

[0044] Specifically, please refer to Figure 3 As shown, in one embodiment of the present invention, the inner sidewall of the track 43 is provided with toothed grooves evenly distributed along its length direction. The toothed grooves mesh with the teeth on the outer peripheral surface of the drive wheel 42 to prevent slippage between the track 43 and the drive wheel 42.

[0045] In this embodiment, when the reduction transmission mechanism inside the drive box 41 drives the drive wheel 42 to rotate, the teeth on the outer circumference of the drive wheel 42 precisely engage with the grooves on the inner sidewall of the track 43, forming a meshing engagement. This meshing structure converts the rotational power of the drive wheel 42 into the linear motion of the track 43 through the physical engagement of the teeth and grooves. Compared to transmission methods that rely solely on friction, this meshing engagement directly restricts the relative sliding between the track 43 and the drive wheel 42, ensuring that the power transmission path remains uninterrupted even under varying forces or complex terrain conditions.

[0046] When the device turns, the two drive wheels 42 generate a speed difference. The wheel teeth drive the two tracks to form a speed difference through the tooth grooves. The meshing structure ensures that this speed difference can be accurately transmitted to the track 43, avoiding deviation of the steering angle due to slippage and ensuring the accurate execution of the steering action.

[0047] Specifically, please refer to Figure 3 As shown, in one embodiment of the present invention, the walking assembly 4 further includes two tensioning devices 7. The two tensioning devices 7 are rotatably connected to the two side walls of the drive box 41 in the width direction through elastic brackets, and each tensioning device 7 abuts against the inner side wall of the corresponding side track 43 for adjusting the tension of the track 43.

[0048] The tensioning device 7 dynamically adjusts the tension of the track 43 through the adaptive deformation of its elastic structure. In the initial tensioned state, the tensioning device 7 continuously abuts against the inner wall of the track 43 under the preload of the elastic bracket. At this time, the track 43 is at a suitable tension, ensuring stable meshing with the teeth of the drive wheel 42 and laying the foundation for power transmission. When the track 43 loosens due to long-term use, wear, or temperature changes, the pressure on the tensioning device 7 on the inner side of the track 43 decreases. The elastic potential energy of the elastic bracket is released, pushing the tensioning device 7 to move outward of the track 43, further tightening the track 43 to compensate for the looseness and restore the track 43 to a suitable tension.

[0049] When the device encounters protrusions or obstacles while moving within a confined space, or when the force on the track 43 increases instantaneously, the pressure on the tensioning device 7 on the inner side of the track 43 increases. The elastic support is compressed and deformed, causing the tensioning device 7 to retract inward towards the track 43, providing a buffer space for the track 43 and preventing it from being torn or damaged due to excessive instantaneous force. During movement, the tensioning device 7 continuously makes minute adjustments according to the changes in force on the track 43. Through the expansion and contraction deformation of the elastic support, the tension of the track 43 is balanced in real time, ensuring that the track 43 always maintains stable engagement with the drive wheel 42 without slippage or jamming.

[0050] Specifically, please refer to Figure 7 As shown, in one embodiment of the present invention, the inner cavity of the main frame 1 is fixedly connected with multiple pairs of support columns 8 extending in the vertical direction; the multiple pairs of support columns 8 are respectively disposed at the inner corners of the main frame 1, and the top end of the support column 8 is fixedly connected to the upper frame of the main frame 1 and the bottom end is fixedly connected to the lower frame of the main frame 1; the support column 8 and the frame of the main frame 1 enclose and form an installation cavity for installing electronic modules.

[0051] In this embodiment, multiple pairs of support columns 8 are fixed at the four inner corners of the main frame 1, with the top end directly connected to the upper frame and the bottom end directly connected to the lower frame, forming a three-dimensional reinforced structure. The support columns 8 bear the longitudinal force of the upper and lower frames of the main frame 1, and at the same time, through the layout of the inner corner positions, they disperse the lateral impact force (such as collision and vibration) generated when the device flies or moves, preventing the frame from deforming or breaking due to concentrated force.

[0052] The support columns 8 and the frame of the main body 1 enclose an independent mounting cavity, in which electronic modules (such as gas detection sensors, control systems, batteries, communication modules, etc.) can be precisely embedded. The spacing of the support columns 8 is adapted to the mounting dimensions of the electronic modules, providing circumferential restraint for the modules and forming a physical protective space for the electronic modules through the enclosure of the frame and support columns 8.

[0053] Please see Figure 7 , 8As shown, another embodiment of the present invention also provides an unmanned aerial vehicle system for gas detection in a confined space. The unmanned aerial vehicle system includes the unmanned aerial vehicle device described above, a multi-sensor module 9, a communication module 10, a power supply module 11, and a control module 12. The multi-sensor module 9 is fixedly installed on the top wall of the outer shell 2 and is used to collect environmental information and gas data. The multi-sensor module 9 includes a lidar 91, an inertial measurement unit (IMU) 92, an electrochemical sensor 93, an infrared sensor 94, and a temperature and humidity sensor 95. The lidar 91 has its detection end facing away from the outer casing 2 and is used to scan the environment and generate a 3D map. The IMU 92 is integrated inside the multi-sensor module 9 and is used to detect the attitude, acceleration, and angular velocity of the device. The detection end of the electrochemical sensor 93 is exposed to the external environment and is used to quantitatively detect low concentrations of toxic gases. The detection end of the infrared sensor 94 is exposed to the external environment and is used to qualitatively detect volatile organic compounds and obtain their concentrations. The detection end of the temperature and humidity sensor 95 is exposed to the external environment and is used to collect ambient temperature and humidity data. The communication module 10, power module 11, and control module 12 are all fixedly installed in the mounting cavity of the main frame 1. The communication module 10 is a wireless communication module, whose signal end establishes a wireless connection with an external terminal. The signal input / output end of the communication module 10 is electrically connected to the signal input / output end of the control module 12 to realize data transmission and command interaction.

[0054] In this embodiment, the lidar 91 scans in a direction away from the outer shell 2, and generates a three-dimensional map of a limited space by emitting laser and receiving reflected signals, thus clarifying the distribution of environmental obstacles; the IMU inertial measurement unit 92 detects the flight / walking attitude, acceleration and angular velocity of the device in real time, providing data support for attitude control.

[0055] Electrochemical sensor 93 is exposed to the outside environment and quantitatively detects low concentrations of toxic gases (such as carbon monoxide and hydrogen sulfide) through chemical reactions. Infrared sensor 94 utilizes the characteristic of molecular absorption of infrared spectra to qualitatively identify volatile organic compounds (VOCs) and obtain their concentrations. Temperature and humidity sensor 95 directly collects ambient temperature and humidity data, providing environmental parameters for the calibration of gas detection results. The collected data is transmitted to control module 12 via a line. Control module 12 integrates and processes the multidimensional data (such as combining a 3D map to plan a path, adjusting rotor / track movements based on attitude data, and analyzing whether gas concentrations exceed limits).

[0056] The communication module 10 establishes a link with an external terminal via wireless connection. On the one hand, it transmits the integrated detection data (gas concentration, temperature and humidity, environmental map) to the external terminal in real time. On the other hand, it receives control commands (such as starting / stopping detection, adjusting the operation path, and switching flight / walking modes) sent by the external terminal and transmits them to the control module 12. The power module provides stable power to the multi-sensor module, communication module, control module, and the power components (motors, servos, etc.) of the unmanned aerial vehicle, ensuring the continuous operation of each module. The control module 12 sends control signals to the flight component 3 and the walking component 4 based on the received sensor data and external commands, such as avoiding obstacles according to the 3D map, correcting attitude according to IMU data, and adjusting the detection point position according to gas concentration data to achieve precise operation.

[0057] Specifically, please refer to Figure 7 As shown, in one embodiment of the present invention, the power module 11 is a rechargeable lithium battery pack, and its power output terminal is electrically connected to the drive motor of the walking component 4, the brushless DC motor 35 and servo motor of the flight component 3, the multi-sensor module 9, the communication module 10, and the control module 12, respectively, to provide working power.

[0058] Once the rechargeable lithium battery pack is fully charged, it is distributed to various electrical components of the system via the power output terminal. Power is delivered to the drive motor of the walking component 4, the brushless DC motor 35 and servo motors of the flight component 3, the multi-sensor module 9, the communication module 10, and the control module 12, ensuring that all core components receive power synchronously. The output voltage and current of the lithium battery pack are internally regulated to match the power parameters of different components. For example, it provides high-power electricity to the brushless DC motor 35 and the drive motor, and low-power stable electricity to the sensors, communication module 10, and control module 12. Simultaneously, it maintains stable output voltage when components switch operating states (such as from flight to walking, or sensor start / stop), preventing voltage fluctuations from affecting component operation.

[0059] Specifically, please refer to Figure 7 As shown, in one embodiment of the present invention, the control module 12 is a microprocessor-based control unit. Its control signal output terminal is electrically connected to the drive motor of the walking component 4, the brushless DC motor 35 and servo motor of the flight component 3, and the control terminal of the communication module 10, respectively. Its signal input terminal is electrically connected to the signal output terminal of the multi-sensor module 9 and the power detection terminal of the power module 11, respectively, for realizing the coordinated control of the system.

[0060] In this embodiment, the signal input terminal of the control module 12 synchronously receives two types of key signals. One type is the detection signal from the multi-sensor module, including the environmental 3D map data of the lidar 91, the device attitude data of the IMU inertial measurement unit 92, the detection data of various gas sensors, and temperature and humidity data; the other type is the power detection signal from the power module 11, which acquires information such as the remaining battery power and voltage status in real time.

[0061] The microprocessor integrates and analyzes the collected multi-source data. It plans the optimal detection path using a 3D map, calculates attitude corrections based on IMU attitude data, determines whether to adjust detection points or evacuate based on gas detection data, and balances power consumption across components by referencing battery data (e.g., prioritizing core detection and communication functions when battery is low). Simultaneously, it receives external control commands from the communication module 10 and integrates data feedback to form targeted control decisions. Based on the decision results, the control module 12 sends precise control signals to each actuator. It outputs speed adjustment and angle correction commands to the brushless DC motor 35 and servo motors of the flight component 3, start / stop and speed difference commands to the drive motor of the walking component 4, and data transmission trigger and command feedback commands to the communication module 10, achieving coordinated action and function of each component.

[0062] Please see Figure 9 As shown, another embodiment of the present invention also provides a method for using an unmanned aerial vehicle (UAV) device and system for gas detection in a confined space, applied to the aforementioned UAV system. The method includes the following steps: S1: Equipment Deployment and Pre-preparation: The unmanned aerial vehicle (UAV) is placed on a flat surface at the entrance of the confined space, and the control module 12 initiates a system self-test. The lidar 91 scans the confined space entrance area, generates a preliminary 3D environmental map, and transmits it to the control module 12. The inertial measurement unit (IMU) 92 automatically calibrates the initial attitude of the device, records the initial position coordinates, and transmits them to the control module 12. The electrochemical sensor 93 and infrared sensor 94 preheat for 30-60 seconds, detect the gas baseline value at the confined space entrance, and transmit it to the control module 12. The temperature and humidity sensor 95 collects the ambient temperature and humidity at the entrance and transmits it to the control module 12. After the control module 12 analyzes all the data and confirms that each module is fault-free and the environmental parameters meet the operating conditions, it automatically generates a preliminary operating path covering the preset detection area, and the device enters an autonomous standby state. S2: Job Mode Judgment and Triggering: Control module 12 determines the scene within the confined space based on the preliminary 3D environmental map generated by lidar 91: If the width of the passage is less than the safe distance required for the device to fly, or if there are low obstacles with a height lower than the minimum flying height of the device, or if close-range detection along a fixed path is required, the walking mode is triggered. If the detected space height is greater than the minimum flight height of the device, there are no complex low obstacles, or it is necessary to quickly cross a wide obstacle that is wider than the crossing capacity of the track 43, the flight mode is triggered. S3: Walking mode operation: Control module 12 sends a standby command to flight component 3, keeping all brushless DC motors 35 off and the propeller blades 36 stationary; simultaneously, it sends a drive signal to drive box 41, starting the drive motor inside drive box 41, which drives the drive wheels 42 on both sides to rotate synchronously through the reduction transmission mechanism, thereby driving the track 43 to rotate, and the device moves along the initial working path; during the movement, lidar 91 scans the path ahead in real time. If it detects that the movement speed deviates from the preset speed by more than 5%, control module 12 sends an adjustment signal to the elastic bracket of tensioning device 7, and tensioning device 7 moves outward to compress track 43 until the movement speed returns to the preset range; if lidar 91 detects an object with a height less than 10cm ahead... If a small obstacle is encountered, or if the IMU (Inertial Measurement Unit) 92 detects that the walking resistance has increased beyond a preset threshold, the control module 12 triggers autonomous assisted propulsion: First, a command is sent to the first servo motor 323, which drives the adjusting block 322 to rotate around the connecting seat 321 until it is parallel to the outer shell 2; then a command is sent to the second servo motor 324, which drives the second connecting arm 33 to rotate, causing the spiral blade 36 to tilt 20-45° in the walking direction; after the angle adjustment is completed, the control module 12 starts the brushless DC motor 35 on the second connecting arm 33, and the spiral blade 36 rotates to generate forward thrust, assisting the track 43 in crossing obstacles or reducing walking resistance; S4: Flight Mode Operation: The control module 12 sends a stop command to the walking assembly 4, shutting down the drive motor and stopping the track 43. Simultaneously, it controls the first servo motor 323 and the second servo motor 324 to reset, restoring the second connecting arm 33 to its initial position. Then, the control module 12 synchronously starts the brushless DC motors 35 on the first connecting arm 31 and the second connecting arm 33, causing the helical blades 36 to rotate at high speed, generating vertical lift and lifting the device. When the device flies to the preset detection area, the control module 12 reduces the rotation speed of all the helical blades 36, hovering the device directly above the detection area. The hovering height is set to 1-3m according to the detection requirements. The device uses the IMU inertial measurement unit 92 to provide real-time attitude data and the lidar 91 to scan the environment in real-time for coordinated positioning, maintaining stable hovering. While hovering, the electrochemical sensor 93 and the infrared sensor 94 collect gas samples from multiple angles within the area. After collection, the control module 12 adjusts the rotation speed of the helical blades 36, propelling the device to the next detection area. S5: Data Processing and Early Warning Throughout the detection process, the IMU inertial measurement unit 92 records the device's trajectory and flight attitude in real time, and the temperature and humidity sensor 95 records the ambient temperature and humidity in real time. All data is transmitted to the control module 12 in real time. The control module 12 stores the data synchronously and performs environmental compensation on the gas concentration data in conjunction with the temperature and humidity data. If the concentration of toxic gas exceeds the preset threshold, the control module 12 transmits the detection data and early warning information to the external terminal in real time through the communication module 10. S6: Autonomous return to base: After all preset detection areas have been inspected, the control module 12 calls the walking and flight trajectory data recorded by the IMU inertial measurement unit 92, and combines it with the return path scanned in real time by the lidar 91 to autonomously plan the optimal return route: if the average width of the return path is greater than the safe distance required for the device to fly, the control device returns quickly in flight mode; if there is a narrow section in the return path, the control device returns smoothly in walking mode; after the device returns to the entrance of the confined space, the control module 12 shuts down all working modules and completes the inspection operation.

[0063] This method of use requires no manual intervention throughout the entire process, from pre-preparation and mode judgment to operation execution and return. Operators only need to monitor from an external terminal, avoiding entry into high-risk environments in confined spaces and completely eliminating safety risks such as poisoning and hypoxia. The self-checking, calibration, and baseline acquisition processes in the pre-preparation phase reduce manual debugging time and improve operation startup efficiency. The autonomous return function prevents the device from getting lost or stranded in complex environments, ensuring safe recovery of the equipment. Mode judgment based on quantitative standards allows the device to flexibly switch between walking / flying modes according to spatial height, obstacle type, and passage width, adapting to diverse scenarios in confined spaces such as "narrow passages, low obstacles, and wide obstacle crossings," avoiding the limitations of a single mode.

[0064] The walking mode features a tensioning device with dynamic speed adjustment and a flight-assisted obstacle crossing mechanism, while the flight mode features collaborative positioning and hovering. These features address issues such as walking stability, obstacle crossing difficulty, and flight detection accuracy, ensuring continuous detection in different scenarios.

[0065] Specifically, in one embodiment of the present invention, in step S2, the safe distance required for the device to fly is 1.5 times the maximum lateral dimension of the device; the minimum flight altitude of the device is 1.2 times the maximum longitudinal dimension of the device.

[0066] In step S3, the preset speed is set to 0.2-0.5 m / s according to the limited space environment; in step S4, during multi-angle acquisition, the control module 12 adjusts the output angle of the second servo motor 324 to drive the spiral blade 36 on the second connecting arm 33 to fine-tune the rotation speed, so that the device slowly rotates around the center of the detection area to achieve full-angle gas acquisition.

[0067] In the specific technical solution of this embodiment, the control module 12 retrieves the maximum lateral dimension and maximum longitudinal dimension preset by the device, and calculates 1.5 times the safe flight distance and 1.2 times the minimum flight altitude, respectively. Combining the three-dimensional map data scanned by the lidar, it compares the channel width with the safe flight distance and the spatial height with the minimum flight altitude. If the channel width is less than the safe distance or the spatial height is less than the minimum flight altitude, the walking mode is directly triggered; otherwise, the flight mode is triggered, avoiding erroneous mode switching caused by fuzzy judgment.

[0068] The control module 12 sets the preset speed to 0.2-0.5 m / s (which can be adjusted according to the environment) and compares the actual speed with the preset speed in real time during the movement. When the deviation exceeds 5%, an adjustment signal is immediately sent to the tensioning device 7, which adjusts the tension by squeezing the track through the elastic bracket until the speed returns to the preset range, thus realizing quantitative closed-loop control of the speed.

[0069] After the device hovers directly above the detection area, the control module 12 sends an angle adjustment signal to the second servo motor 324, while simultaneously fine-tuning the rotational speed of the helical blades on the second connecting arm 33. Through the synergistic effect of the servo motor driving the deflection of the connecting arm and the difference in blade rotational speed, the device slowly rotates around the center of the detection area, ensuring that the electrochemical sensor 93 and the infrared sensor 94 can cover a 360° range of the detection area, completing the full-angle gas data acquisition.

[0070] In another embodiment of the present invention, in step S4, the hovering height of the device is determined by the detection requirements. The IMU inertial measurement unit 92 and the lidar 91 work together to maintain stable hovering. In the hovering state, the electrochemical sensor 93 and the infrared sensor 94 collect gas in the area from multiple angles.

[0071] Once the device flies to the preset detection area, the control module 12 sets the hovering height according to the detection requirements (such as target gas density and detection point characteristics). The IMU inertial measurement unit 92 collects the device's attitude angle, acceleration, and angular velocity data in real time, capturing minor body movements (such as tilting or offset caused by airflow disturbances); the lidar 91 simultaneously scans the surrounding environment of the detection area to obtain the relative distance data between the device and the ground and obstacles. Both data are transmitted to the control module 12 in real time. The control module 12 performs algorithmic fusion analysis and dynamically adjusts the speed of the brushless DC motor 35 and the servo angle of the flight component 3 to counteract body movements, maintain hovering height and horizontal attitude stability, and ensure that the device is always directly above the detection area.

[0072] After hovering and stabilizing, the electrochemical sensor 93 and infrared sensor 94 begin data acquisition. The control module 12, by adjusting the servo motors of the flight component 3 (such as the second servo motor 324) or fine-tuning the motor speed, drives the fuselage to slowly rotate around the hovering point, or adjusts the angle of the sensor mounting carrier, ensuring that the detection ends of the two sensors cover a 360° range of the detection area. During data acquisition, the sensors continuously capture gas molecules from different directions, simultaneously recording gas concentration data from various angles, achieving multi-angle, blind-spot-free data acquisition.

[0073] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the scope of protection of this invention.

Claims

1. An unmanned aerial vehicle for gas detection in a confined space, characterized in that, It includes a main frame (1), an outer shell (2), four sets of flight components (3) and a walking component (4). The outer shell (2) is wrapped and connected to the outer surface of the main frame (1). The four sets of flight components (3) are evenly distributed around the side wall of the outer shell (2), and the walking component (4) is located at the bottom of the outer shell (2). Each flight assembly (3) includes a second connecting arm (33), a bracket (34), a brushless DC motor (35), and a propeller blade (36); two of the four flight assemblies (3) are symmetrically fixed to the outer front wall of the outer shell (2) via a first connecting arm (31); the other two of the four flight assemblies (3) are symmetrically fixed to the outer rear wall of the outer shell (2) via a rotor adjustment mechanism (32); one end of the first connecting arm (31) is fixedly connected to the outer front wall of the outer shell (2), and the other end is fixedly connected to the corresponding second connecting arm (33); the fixed end of the rotor adjustment mechanism (32) is fixedly connected to the outer rear wall of the outer shell (2), and the movable end of the rotor adjustment mechanism (32) is fixedly connected to the second connecting arm (33); The bracket (34) is fixedly connected to the end of the second connecting arm (33) away from the outer shell (2); the housing of the brushless DC motor (35) is fixedly connected to the upper surface of the bracket (34), and the output shaft of the brushless DC motor (35) extends vertically upward; the spiral blades (36) are symmetrically fixedly sleeved on the end of the output shaft of the brushless DC motor (35) for rotating under the drive of the brushless DC motor (35) to generate lift or thrust; The walking assembly (4) includes a drive box (41) fixedly connected to the lower surface of the outer shell (2), two sets of symmetrically arranged drive wheels (42) and tracks (43); the drive box (41) integrates a drive motor and a reduction transmission mechanism; the two sets of drive wheels (42) are rotatably connected to the two side walls of the drive box (41) through a rotating shaft, and are connected to the reduction transmission mechanism inside the drive box (41); the tracks (43) are wrapped around the outer circumference of each set of drive wheels (42) for contacting the ground to realize the walking movement of the device.

2. The unmanned aerial vehicle for gas detection in a confined space according to claim 1, characterized in that, The rotor adjustment mechanism (32) includes a connecting seat (321), an adjustment block (322), a first servo motor (323), and a second servo motor (324). One side of the connecting seat (321) is fixedly connected to the outer shell (2). The adjustment block (322) is disposed on the other side of the connecting seat (321). The first servo motor (323) is fixedly connected to the top of the connecting seat (321), and the output end of the first servo motor (323) is fixedly connected to the adjustment block (322). The second connecting arm (33) is movably connected to the adjustment block (322). The second servo motor (324) is fixedly connected to the surface of the adjustment block (322), and the output end of the second servo motor (324) is fixedly connected to the second connecting arm (33).

3. The unmanned aerial vehicle for gas detection in a confined space according to claim 1, characterized in that, Side plates (5) are fixedly connected to both sides of the outer shell (2) in the width direction, and the side plates (5) are located on the top outer side of the track (43); the second connecting arm (33) is fixedly connected to a protective cover (6) on the side away from the outer shell (2), and the protective cover (6) covers the outside of the spiral blade (36).

4. The unmanned aerial vehicle for gas detection in a confined space according to claim 1, characterized in that, The inner sidewall of the track (43) is provided with toothed grooves evenly distributed along its length direction. The toothed grooves mesh with the teeth on the outer circumferential surface of the drive wheel (42) to prevent slippage between the track (43) and the drive wheel (42). The walking assembly (4) also includes two tensioning devices (7). The two tensioning devices (7) are rotatably connected to the two side walls of the drive box (41) in the width direction through elastic brackets, and each tensioning device (7) abuts against the inner side wall of the corresponding track (43) to adjust the tension of the track (43). The inner cavity of the main frame (1) is fixedly connected with multiple pairs of support columns (8) extending in the vertical direction; the multiple pairs of support columns (8) are respectively located at the four inner corners of the main frame (1), and the top of the support column (8) is fixedly connected to the upper frame of the main frame (1), and the bottom is fixedly connected to the lower frame of the main frame (1); the support column (8) and the frame of the main frame (1) enclose to form an installation cavity for installing electronic modules.

5. An unmanned aerial vehicle system for gas detection in a confined space, characterized in that, The device includes any one of claims 1-4, a multi-sensor module (9), a communication module (10), a power module (11), and a control module (12). The multi-sensor module (9) is fixedly installed on the top wall of the outer shell (2) and is used to collect environmental information and gas data. The multi-sensor module (9) includes a lidar (91), an inertial measurement unit (IMU) (92), an electrochemical sensor (93), an infrared sensor (94), and a temperature and humidity sensor (95). The lidar (91) has its detection end facing away from the outer shell (2) and is used to scan the environment and generate a three-dimensional map. The IMU (92) is integrated inside the multi-sensor module (9) and is used to detect the attitude, acceleration, and angular velocity of the device. The detection end of the electrochemical sensor (93) is exposed to the external environment and is used to quantitatively detect low concentrations of toxic gases. The detection end of the infrared sensor (94) is exposed to the external environment and is used to qualitatively detect volatile organic compounds and obtain their concentrations. The detection end of the temperature and humidity sensor (95) is exposed to the external environment and is used to collect ambient temperature and humidity. The communication module (10), the power module (11) and the control module (12) are all fixedly installed in the mounting cavity of the main frame (1). The communication module (10) is a wireless communication module, whose signal end establishes a wireless connection with an external terminal. The signal input / output end of the communication module (10) is electrically connected to the signal input / output end of the control module (12) to realize data transmission and command interaction.

6. The unmanned aerial vehicle system for gas detection in a confined space according to claim 5, characterized in that, The power module (11) is a rechargeable lithium battery pack, and its power output terminal is electrically connected to the drive motor of the walking component (4), the brushless DC motor (35) and servo motor of the flight component (3), the multi-sensor module (9), the communication module (10), and the control module (12) respectively, to provide working power.

7. The unmanned aerial vehicle system for gas detection in a confined space according to claim 5, characterized in that, The control module (12) is a microprocessor-based control unit. Its control signal output terminal is electrically connected to the drive motor of the walking component (4), the brushless DC motor (35) and servo motor of the flight component (3), and the control terminal of the communication module (10). Its signal input terminal is electrically connected to the signal output terminal of the multi-sensor module (9) and the power detection terminal of the power module (11) to realize the coordinated control of the system.

8. A method for using an unmanned aerial vehicle (UAV) device and system for gas detection in a confined space, characterized in that, The unmanned aerial system applied to any one of claims 5-7 includes the following steps: S1: Equipment Deployment and Pre-preparation: The unmanned aerial vehicle is placed on a flat surface at the entrance of a confined space. The control module (12) initiates a system self-test. The lidar (91) scans the confined space entrance area, generates a preliminary three-dimensional environmental map, and transmits it to the control module (12). The IMU inertial measurement unit (92) automatically calibrates the initial attitude of the device, records the initial position coordinates, and transmits them to the control module (12). The electrochemical sensor (93) and infrared sensor (94) preheat for 30-60 seconds, detect the gas baseline value at the entrance of the confined space, and transmit it to the control module (12). The temperature and humidity sensor (95) collects the ambient temperature and humidity at the entrance and transmits it to the control module (12). The control module (12) analyzes all the data, confirms that each module is fault-free and that the environmental parameters meet the operating conditions, and automatically generates a preliminary operating path covering the preset detection area. The device then enters an autonomous standby state. S2: Job Mode Judgment and Triggering: The control module (12) determines the scene within the limited space based on the preliminary 3D environmental map generated by the lidar (91): If the width of the passage is less than the safe distance required for the device to fly, or if there are low obstacles with a height lower than the minimum flying height of the device, or if close-range detection along a fixed path is required, the walking mode is triggered. If the detected space height is greater than the minimum flight height of the device, there are no complex low obstacles, or it is necessary to quickly cross a wide obstacle that is wider than the crossing capability of the track (43), the flight mode is triggered. S3: Walking mode operation: The control module (12) sends a standby command to the flight component (3), keeping all brushless DC motors (35) off and the propeller blades (36) stationary; at the same time, it sends a drive signal to the drive box (41), the drive motor in the drive box (41) starts, and drives the drive wheels (42) on both sides to rotate synchronously through the reduction transmission mechanism, thereby driving the track (43) to rotate, and the device moves along the initial working path; during the movement, the laser radar (91) scans the path ahead in real time. If it detects that the deviation between the walking speed and the preset speed exceeds 5%, the control module (12) sends an adjustment signal to the elastic bracket of the tensioning device (7), and the tensioning device (7) moves outward to squeeze the track (43) until the walking speed returns to the preset range; if the laser radar (91) detects that there is a deviation ahead, the control module (12) sends an adjustment signal to the elastic bracket of the tensioning device (7), .... If a small obstacle less than 10cm high is encountered, or if the IMU (Inertial Measurement Unit) (92) detects that the walking resistance has increased beyond a preset threshold, the control module (12) triggers autonomous assisted propulsion: First, a command is sent to the first servo motor (323), which drives the adjusting block (322) to rotate around the connecting seat (321) until it is parallel to the outer shell (2); then a command is sent to the second servo motor (324), which drives the second connecting arm (33) to rotate, causing the helical blade (36) to tilt 20-45° in the direction of travel; after the angle adjustment is completed, the control module (12) starts the brushless DC motor (35) on the second connecting arm (33), and the helical blade (36) rotates to generate forward thrust, which assists the track (43) in crossing obstacles or reducing walking resistance; S4: Flight Mode Operation: The control module (12) sends a stop command to the walking assembly (4), causing the drive motor to shut down and the track (43) to stop; at the same time, it controls the first servo motor (323) and the second servo motor (324) to reset, so that the second connecting arm (33) returns to its initial position; then the control module (12) synchronously starts the brushless DC motor (35) on the first connecting arm (31) and the second connecting arm (33), and the spiral blades (36) rotate at high speed to generate vertical lift, driving the device to rise; when the device flies to the airspace above the preset detection area, the control module (12) Reduce the rotation speed of all helical blades (36) to hover the device directly above the detection area. The hovering height is set to 1-3m according to the detection requirements. The attitude data is fed back in real time by the IMU inertial measurement unit (92) and the environment is scanned in real time by the lidar (91) to achieve coordinated positioning and maintain hovering stability. In the hovering state, the electrochemical sensor (93) and the infrared sensor (94) collect gas in the area from multiple angles. After the collection is completed, the control module (12) adjusts the rotation speed of the helical blades (36) to drive the device to fly to the next detection area. S5: Data Processing and Early Warning Throughout the detection process, the IMU inertial measurement unit (92) records the device's walking trajectory and flight attitude in real time, and the temperature and humidity sensor (95) records the ambient temperature and humidity in real time. All data are transmitted to the control module (12) in real time. The control module (12) stores the data synchronously and performs environmental compensation on the gas concentration data in combination with the temperature and humidity data. If the concentration of toxic gas exceeds the preset threshold, the control module (12) transmits the detection data and early warning information to the external terminal in real time through the communication module (10). S6: Autonomous return to base: After all preset detection areas have been detected, the control module (12) calls the walking trajectory and flight trajectory data recorded by the IMU inertial measurement unit (92), and combines the return path scanned in real time by the lidar (91) to autonomously plan the optimal return route: if the average width of the return path is greater than the safe distance required for the device to fly, the control device will return quickly in flight mode; if there is a narrow section in the return path, the control device will return smoothly in walking mode; after the device returns to the entrance of the confined space, the control module (12) shuts down all working modules and completes the detection operation.

9. The method of using the unmanned aerial vehicle device and system for gas detection in a confined space according to claim 8, characterized in that, In step S2, the safe distance required for the device to fly is 1.5 times the maximum lateral dimension of the device; the minimum flight altitude of the device is 1.2 times the maximum longitudinal dimension of the device. In step S3, the preset speed is set to 0.2-0.5 m / s based on the confined space environment; In step S4, during multi-angle acquisition, the control module (12) adjusts the output angle of the second servo motor (324) to drive the spiral blade (36) on the second connecting arm (33) to fine-tune the rotation speed, so that the device slowly rotates around the center of the detection area to achieve full-angle gas acquisition.

10. The method of using the unmanned aerial vehicle device and system for gas detection in a confined space according to claim 8, characterized in that, In step S4, the hovering height of the device is determined by the detection requirements. The IMU inertial measurement unit (92) and the lidar (91) work together to maintain stable hovering. In the hovering state, the electrochemical sensor (93) and the infrared sensor (94) collect gas in the area from multiple angles.

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