Modular three-degree-of-freedom self-adaptive pipeline inspection robot and control system

Abstract

The invention discloses a modularized three-degree-of-freedom self-adaptive pipeline inspection robot and a control system, and relates to the technical field of pipeline detection, in particular to the modularized three-degree-of-freedom self-adaptive pipeline inspection robot. The movement mechanism is composed of a head independent module, a middle independent module and a tail independent module, all the modules are connected through mechanical interfaces, independent disassembly, replacement and recombination of the modules are supported, the expandability and maintenance convenience of the robot are improved, each section is composed of a driving unit, a folding unit and a steering unit, and the folding units and the steering units are connected through the mechanical interfaces. The three-degree-of-freedom cooperative motion capability of axial driving, radial folding and yawing steering is provided for the robot, and the robot adapts to a complex pipeline topological structure through multi-mode motion; the controller feeds back information based on the sensor assembly, and closed-loop control over the robot system is achieved. The problems that an existing pipeline inspection robot is insufficient in adaptability, limited in motion freedom degree and insufficient in modular design in a complex pipeline environment are solved, and the internal problem of a pipeline can be effectively and autonomously detected.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline detection, and in particular to a modular three-degree-of-freedom adaptive pipeline inspection robot. Background Art

[0002] As the core carrier of modern urban lifeline projects, pipelines are widely used in water supply, gas supply, oil and gas transportation, chemical industry, medical treatment and other fields. With the refinement of industrial scenarios and the complexity of pipeline network topology, the application proportion of miniaturized, multi-branched, and unstructured pipelines has increased significantly. The leakage and structural defects of pipelines in long-term service due to corrosion, mechanical damage, geological subsidence and other factors are becoming increasingly prominent, seriously threatening public safety and the ecological environment.

[0003] However, current pipeline inspection technology has certain technical limitations. Manual inspections that rely on endoscopes or limited automated equipment are inefficient in narrow pipes and have high operating risks in high-risk environments. Mainstream pipeline inspection robots have a low pass rate in curved pipes due to their rigid structure and motion control algorithm, and have poor adaptability to slippery pipe walls with slopes. They may damage the pipeline during the inspection process and cannot accurately detect problems inside the pipeline. At the same time, these robots are difficult to meet complex and diverse inspection needs in terms of motion flexibility, structural maintainability, and multi-defect collaborative identification capabilities. Therefore, it is urgent to develop a pipeline inspection device with high mobility, modularity, and strong environmental adaptability to solve the technical difficulties of complex pipeline network inspections and support the safe operation and maintenance of urban infrastructure pipeline facilities. Summary of the invention

[0004] The present invention provides a modular three-degree-of-freedom adaptive pipeline inspection robot to solve the problems of insufficient adaptability, limited freedom of movement and insufficient modular design of existing pipeline inspection robots in complex pipeline environments, and can effectively and autonomously detect problems inside the pipeline.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A modular three-degree-of-freedom adaptive pipeline inspection robot includes a motion mechanism, a detection component, a sensor component and a controller; the motion mechanism is composed of three independent modules: the head, the middle and the tail, each of which integrates a drive unit, a folding unit and a steering unit. The modules are connected through a mechanical interface, which supports the separate disassembly and interchange of the modules, thereby improving the scalability and maintenance convenience of the robot.

[0007] Furthermore, the driving unit includes a driving shaft, a driving motor, an active driving bevel gear, a driven driving bevel gear, a transmission shaft, and a driving wheel; the driving shaft is installed on the driving motor, the active driving bevel gear is sleeved on the driving shaft and meshes with the driven driving bevel gear, the driven driving bevel gear is arranged on the transmission shaft, and the two driving wheels are fixedly connected to both ends of the transmission shaft.

[0008] Furthermore, the folding unit includes a folding motor, an active folding worm, a passive folding worm wheel, a folding shaft, a passive folding gear 1, a passive folding gear 2, a folding sleeve rod, a supporting pressure plate 2, and a supporting bearing 2; the active folding worm is sleeved on the rotating shaft of the folding motor and meshed with the passive folding worm wheel sleeved on the folding shaft, the two passive folding gears 1 are arranged on the folding shaft through the supporting bearing 2, the two supporting pressure plates 2 are sleeved on the supporting bearing and installed on both sides of the passive folding gear 1 to axially fix it, the passive folding gear 2 is meshed with the passive folding gear 2, and is fixedly connected to the folding sleeve rod.

[0009] Further, the steering unit includes a steering motor, an active steering gear, a driven steering gear, a steering shaft 1, a steering worm, a steering worm wheel, a supporting tee, a steering shaft 2, a supporting pressure plate 1, a supporting bearing 1 and a body shell; the active steering gear is mounted on the rotating shaft of the steering motor and meshes with the driven steering gear sleeved on the steering shaft 1, the steering shaft 1 is mounted on the supporting pressure plate 1 through the supporting bearing 1, the supporting pressure plate 1 is fixedly connected to the steering motor housing, the steering worm is sleeved on the steering shaft 1 and meshes with the steering worm wheel, the supporting tee is fixedly connected to the through hole of the steering worm wheel, the steering shaft 2 is fixedly connected to the through hole of the supporting tee, and the body shell is mounted on the steering motor.

[0010] Furthermore, the detection component includes a ring-shaped lighting, a high-definition camera, and a steering gear pan-tilt platform; the ring-shaped lighting is installed around the high-definition camera, and the high-definition camera and the steering gear pan-tilt platform are fixed by bolts.

[0011] Furthermore, the servo gimbal includes a gimbal servo 1, a gimbal servo 2, a gimbal rudder arm, a gimbal connecting piece, a gimbal clamp arm, a gimbal clamp buckle, and a gimbal base; the gimbal clamp buckle fixes and tightens the high-definition camera through bolts, the gimbal clamp arm is fixedly connected to the gimbal clamp buckle, both ends of the gimbal connecting piece are respectively connected to the gimbal clamp arm and the gimbal rudder arm through movable shafts, the gimbal rudder arm is installed on the gimbal servo 1, the gimbal servo 2 is installed on the gimbal base, and the rudder arm of the gimbal servo 2 is fixedly connected to the gimbal servo 1.

[0012] Furthermore, the sensor assembly includes a photoelectric encoder, a nine-axis attitude sensor and a pressure sensor; the photoelectric encoder is used to obtain the speed signal of the motor, the nine-axis attitude sensor is used to collect the pitch angle θ, yaw angle ψ and roll angle φ of the motion mechanism, and the pressure sensor is used to receive the pressure signal applied by the folding unit to the tube wall.

[0013] Furthermore, the driving unit provides driving force to each section of the motion mechanism, and the driving shaft of the driving motor outputs power to the transmission shaft through a pair of orthogonally meshing bevel gear reducers, thereby realizing equal speed ratio torque transmission of the driving wheels.

[0014] Furthermore, the folding unit controls the size of the positive pressure applied by each driving mechanism to the tube wall, the folding motor output shaft drives the active folding worm to rotate, and through the meshing transmission of the worm and worm gear pair, a first-stage deceleration is achieved and the output torque is amplified, the passive folding worm gear is rigidly connected to the folding shaft, and the power is transmitted to the folding shaft; the passive folding gear 1 is symmetrically arranged at both ends of the folding shaft, and the gear forms an external meshing transmission with the passive folding gear 2 at the end of the folding sleeve rod, and the folding sleeve rod is fixedly connected to the lower section of the motion mechanism, and under the action of the meshing force of the passive folding gear, the axial displacement of the driving wheels of the two adjacent sections of the motion mechanism is converted into a radial expansion amount, so that it generates a contact positive pressure with the tube wall; in addition, the self-locking characteristics of the worm gear can effectively prevent the reverse transmission of motion, ensuring that the position of the folding unit is locked under pressure conditions.

[0015] Furthermore, the steering unit controls the rotation angle of the steering shaft 2 and the driving wheel thereon along the radial direction of the pipeline, so as to realize the steering of the pipeline inspection robot in the pipe; the power of the output shaft of the steering motor is transmitted to the steering shaft 1 through the gear reducer, and the end of the steering shaft 1 is fixedly connected to the steering worm, which forms an orthogonal meshing worm and worm gear pair with the steering worm wheel, and ensures the locking of the steering angle with its self-locking characteristics to prevent load back-drive; the steering worm wheel is fixedly connected to the support tee through the inner hole, and the steering shaft 2 passes through the through hole of the support tee and is rigidly connected thereto. When the steering worm wheel is driven to rotate by the worm, the support tee transmits the rotational motion to the steering shaft 2, driving its end driving wheel to deflect around the radial axis of the pipeline.

[0016] Furthermore, the servo gimbal can control the pitch and yaw angles of the camera. The gimbal servo drives the gimbal rudder arm, drives the gimbal clamp arm to swing through the gimbal connector, and then controls the up and down pitch movement of the high-definition camera fixed in the gimbal clamp, and its pitch angle α satisfies:

[0017]

[0018] Among them, θ1 is the rotation angle of the rudder arm, L1 is the length of the rudder arm, and L2 is the length of the connecting piece.

[0019] The second pan-tilt servo is fixedly connected to the pan-tilt base, and the rudder arm of the second pan-tilt servo is rigidly connected to the housing of the first pan-tilt servo. The horizontal deflection of the camera is achieved by swinging the rudder arm of the second pan-tilt servo.

[0020] Furthermore, the annular lighting of the detection module can provide a stable light source, and clear and properly exposed image information inside the pipe can be obtained through the high-definition camera, so that cracks, structural defects, corrosion and other problems inside the pipe can be checked and analyzed.

[0021] Furthermore, the controller receives the signal from the sensor assembly and can collect the speed pulse value, posture angle and support positive pressure data of the pipeline inspection robot. Based on the feedback information of the sensor, the motion mechanism motor can be closed-loop controlled to realize the vector torque distribution of the drive motor, the radial position servo control of the folding motor and the angle closed-loop adjustment of the steering motor; at the same time, the controller can process and analyze the image information collected by the camera of the detection assembly, and control the brightness of the ring lighting and the rotation angle of the servo gimbal.

[0022] In this technical solution, it should be noted that the electronic devices of the robot are powered and transmit data through external cables.

[0023] Beneficial effects of the present invention:

[0024] (1) The present invention proposes a modular three-degree-of-freedom adaptive pipeline inspection robot, which adopts a three-section modular motion mechanism. Each section can move independently and can adapt to complex pipeline structures. At the same time, its structural design is compact and can operate efficiently in a pipeline environment with limited space. Each module can be disassembled and replaced separately, which is convenient for maintenance and repair.

[0025] (2) The present invention proposes a modular three-degree-of-freedom adaptive pipeline inspection robot, in which the driving unit adopts an orthogonal bevel gear transmission structure to realize the vertical steering of the power shaft and the transmission shaft, ensuring the equal speed ratio output of the two driving wheels and avoiding the pipe wall slippage caused by differential speed; at the same time, the three-section driving unit is independently controlled, and when a single section fails, the basic movement ability can be maintained by reorganizing the power of the remaining two sections, thereby improving the system reliability.

[0026] (3) The present invention proposes a modular three-degree-of-freedom adaptive pipeline inspection robot, in which the folding unit converts axial displacement into radial expansion through a worm gear and double gear meshing transmission. The folding angle and the positive pressure applied to the pipe wall can be controlled by adjusting the output torque of the folding motor, thereby ensuring the stability of traction under slippery pipe walls and slope environments. At the same time, the self-locking characteristics of the worm gear reducer are utilized, and the motor can lock the driving wheel position without outputting torque, thereby reducing system energy consumption and preventing the mechanism from retreating due to pipe wall impact.

[0027] (4) The present invention proposes a modular three-degree-of-freedom adaptive pipeline inspection robot, in which the motor output torque of the steering unit of the robot is transmitted through the master-slave gear reducer and the worm gear reducer to achieve high-precision control of the deflection angle of the driving wheel; at the same time, the worm gear self-locking mechanism can prevent the steering angle from shifting due to external disturbances.

[0028] (5) The present invention proposes a modular three-degree-of-freedom adaptive pipeline inspection robot. The detection component of the robot adopts a dual-axis servo gimbal equipped with a camera with a circular array lighting lamp, which can realize multi-angle visual detection under different lighting conditions, thereby improving the pipeline detection efficiency.

[0029] (6) The present invention proposes a modular three-degree-of-freedom adaptive pipeline inspection robot. The control system of the robot is based on the data fusion of a nine-axis attitude sensor, a photoelectric encoder and a pressure sensor to achieve three-degree-of-freedom closed-loop control of the driving, folding and steering of the motion mechanism chain links, thereby improving the motion accuracy and adaptability in complex and narrow pipeline spaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is an axonometric view of the robot of the present invention;

[0031] Figure 2 is a top view of the robot of the present invention;

[0032] Figure 3 It is a schematic diagram of the structure of the detection component of the robot of the present invention;

[0033] Figure 4 It is a control system block diagram of the robot of the present invention;

[0034] Figure 5 Schematic diagram of the motion state of the robot of the present invention.

[0035] In the figure: 1. driving shaft; 2. driving motor; 3. active driving bevel gear; 4. driven driving bevel gear; 5. transmission shaft; 6. driving wheel; 7. folding motor; 8. active folding worm; 9. passive folding worm gear; 10. folding shaft; 11. passive folding gear 1; 12. passive folding gear 2; 13. folding sleeve rod; 14. supporting pressing plate 2; 15. supporting bearing 2; 16. steering motor; 17. active steering gear; 18. driven steering gear; 19. , steering shaft one; 20, steering worm; 21, steering worm wheel; 22, supporting tee; 23, steering shaft two; 24, supporting clamping plate one; 25, supporting bearing one; 26, body shell; 27, detection component; 28, ring lighting; 29, high-definition camera; 30, gimbal servo one; 31, gimbal servo two; 32, gimbal rudder arm; 33, gimbal connecting part; 34, gimbal clamp arm; 35, gimbal clamp; 36, gimbal base; 37, sensor component. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] like Figure 1-3 As shown, a modular three-degree-of-freedom adaptive pipeline inspection robot includes four parts, namely, a motion mechanism, a detection component, a sensor component and a controller; wherein the motion mechanism is composed of three independent modules, namely, a head, a middle and a tail, and the modules are connected through a mechanical interface to support the separate disassembly, replacement and reorganization of the modules, thereby improving the scalability and maintenance convenience of the robot; each section is composed of a driving unit, a folding unit and a steering unit, which provide the robot with three-degree-of-freedom collaborative motion capabilities of axial drive, radial folding and yaw steering, and adapt to complex pipeline topological structures through multimodal motion; the detection component includes a ring lighting, a high-definition camera and a servo gimbal, which are used to obtain high-definition images inside the pipe and can dynamically adjust the lighting brightness and observation angle; the sensor component includes a photoelectric encoder, a nine-axis attitude sensor and a pressure sensor, which are used to monitor the robot's motion state in real time; the controller realizes closed-loop control of the robot system based on the feedback information of the sensor component, and simultaneously processes and analyzes the image information of the detection component.

[0038] like Figure 1-2As shown, the driving unit includes a driving shaft 1, a driving motor 2, an active driving bevel gear 3, a driven driving bevel gear 4, a transmission shaft 5, and a driving wheel 6; the output shaft of the driving motor 2 is fixedly connected to the driving shaft 1, and the active driving bevel gear 3 is sleeved on the driving shaft 1 and orthogonally meshed with the driven driving bevel gear 4. The driven driving bevel gear 4 is fixed to the middle of the transmission shaft 5 by interference fit, and the driving wheels 6 are installed at both ends of the transmission shaft 5 through bearing seats. After the driving motor 2 is powered on, the power is transferred to the transmission shaft 5 after being turned by the bevel gear pair, driving the driving wheels 6 on both sides to rotate synchronously, ensuring that the two wheels have equal speed ratio output, and avoiding the pipe wall slippage caused by differential speed. The three-section driving unit is independently controlled, and the driving torque of each section is coordinated by the controller to realize complex movements of the robot such as climbing slopes and crossing obstacles in the pipe.

[0039] like Figure 1-2 As shown, the folding unit includes a folding motor 7, an active folding worm 8, a passive folding worm wheel 9, a folding shaft 10, a passive folding gear 11, a passive folding gear 2 12, a folding sleeve rod 13, a supporting pressing plate 2 14, and a supporting bearing 2 15; the output shaft of the folding motor 7 is fixedly connected to the active folding worm 8, and meshes with the passive folding worm wheel 9 to form a first-stage reduction. The passive folding worm wheel 9 is rigidly connected to the folding shaft 10 through a flat key, and the passive folding gear 11 is installed at both ends of the folding shaft 10 through the supporting bearing 2 15. The passive folding gear 11 is externally meshed with the passive folding gear 2 12 at the end of the folding sleeve rod 13, and the supporting pressing plate 2 14 axially limits the passive folding gear 11 through bolts. When the folding motor 7 is started, the worm and worm wheel pair transmits power to the folding shaft 10, drives the passive folding gear 11 to rotate, and drives the passive folding gear 2 12 to drive the folding sleeve rod 13 to radially expand and contract. This movement converts the axial displacement into the radial expansion of the driving wheel 6, so that it generates a positive contact pressure with the pipe wall. The self-locking property of the worm gear can prevent the reaction force of the pipe wall from causing the mechanism to retreat, ensuring the stable adhesion of the driving wheel 6 in the slippery pipe wall.

[0040] like Figure 1-2As shown, the steering unit includes a steering motor 16, an active steering gear 17, a driven steering gear 18, a steering shaft 19, a steering worm 20, a steering worm wheel 21, a support tee 22, a steering shaft 23, a support pressing plate 24, a support bearing 25 and a housing 26; the output shaft of the steering motor 16 is mounted with the active steering gear 17, and meshes with the driven steering gear 18 sleeved on the steering shaft 19. The steering shaft 19 is mounted on the support pressing plate 24 through the support bearing 25, and the steering worm 20 is connected to the steering shaft 19 through a flat key, and meshes orthogonally with the steering worm wheel 21. The inner hole of the steering worm wheel 21 is interference fit with the support tee 22, and the steering shaft 23 passes through the through hole of the support tee 22 and is fixedly connected. When the steering motor 16 is started, the gear pair drives the steering worm 20 to rotate, driving the steering worm wheel 21 and the supporting tee 22 to rotate, thereby causing the steering shaft 23 to deflect around the pipeline radial direction to adjust the steering angle of the driving wheel 6. The steering angle can be locked by the worm wheel self-locking mechanism to prevent the angle from being offset due to external disturbance.

[0041] like Figure 3 As shown, the detection component 27 is installed at the front end of the head movement mechanism, including a ring lighting lamp 28, a high-definition camera 29, and a servo platform. The servo platform includes a platform servo 1 30, a platform servo 2 31, a platform rudder arm 32, a platform connecting piece 33, a platform clamp arm 34, a platform clamp buckle 35, and a platform base 36; the ring lighting lamp 28 is arranged around the high-definition camera 29, the platform clamp buckle 35 clamps the high-definition camera 29 by bolts, the platform clamp arm 34 is hinged with the platform connecting piece 33, and the platform rudder arm 32 is driven by the platform servo 1 30. When the platform servo 1 30 rotates by an angle θ1, the platform clamp arm 34 drives the pitch angle α of the camera 29 to satisfy:

[0042]

[0043] Among them, L1 is the length of the rudder arm and L2 is the length of the connecting piece.

[0044] The rudder servo 2 31 drives the rudder base 36 to rotate horizontally through the rudder arm to achieve panoramic scanning of the camera. The ring lighting 28 automatically adjusts the brightness according to the light intensity in the tube to ensure uniform image exposure.

[0045] Figure 4The control system block diagram of the pipeline inspection robot mainly includes a controller, a detection component 27, a sensor component 37 and a motion mechanism; wherein the sensor component 37 includes a photoelectric encoder, a nine-axis attitude sensor and a pressure sensor; the photoelectric encoder collects the speed signals of the drive motor 2, the folding motor 7 and the steering motor 16 in real time; the nine-axis attitude sensor is installed inside each section of the body, and outputs the pitch angle θ, the yaw angle ψ and the roll angle φ by fusing the accelerometer, gyroscope and magnetometer data through Kalman filtering; the pressure sensor is embedded in the folding sleeve rod 13 to monitor the positive pressure applied to the pipe wall; the controller receives the sensor data and the detection component image data After that, the following closed-loop control is performed: ① According to the attitude angle and pressure feedback, the PWM duty cycle of the folding motor 7 is adjusted to control the radial expansion of the driving wheel 6; ② Based on the encoder pulse difference, the output torque of the three driving motors 2 is distributed through the vector control algorithm; ③ According to the deviation between the target steering angle and the current angle, the PID algorithm is used to adjust the speed of the steering motor 16, thereby controlling the radial rotation angle of the driving wheel 6; ④ The brightness of the annular lighting 28 is adjusted and the rotation angle of the servo gimbal is adjusted to obtain a normal and clear panoramic image of the tube, and then the image recognition algorithm is used to analyze the tube image captured by the high-definition camera 29, and mark defective areas such as cracks and corrosion.

[0046] Figure 5 They are three typical working states of the robot in the pipeline, namely horizontal linear motion, climbing and obstacle crossing motion, and curved pipe turning motion; under the horizontal linear motion condition, the output torque of the three drive motors 2 is distributed through closed-loop control based on the encoder feedback pulse value, so as to drive the robot to walk horizontally and straightly in the pipeline; under the climbing and obstacle crossing conditions, the output torque of the folding motor 7 is adjusted according to the attitude angle and pressure feedback to control the radial expansion of the drive wheel 6, increase the friction of the robot when climbing and achieve obstacle crossing by pitching the fuselage at a certain angle; under the curved pipe turning condition, the rotation speed of the steering motor 16 is closed-loop controlled according to the deviation value between the target turning angle and the current attitude angle, and the radial rotation angle of the driving wheel 6 of the head movement mechanism is adjusted to achieve active steering movement of the robot in the curved pipe.

[0047] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A modular three-degree-of-freedom adaptive pipeline inspection robot, characterized by: The robot consists of four parts: a motion mechanism, a detection component, a sensor component and a controller. The motion mechanism consists of three independent modules: the head, the middle and the tail. The modules are connected through mechanical interfaces to support the separate disassembly, replacement and reorganization of the modules, thus improving the scalability and maintenance convenience of the robot. Each section consists of a drive unit, a folding unit and a steering unit, which provide the robot with three-degree-of-freedom collaborative motion capabilities of axial drive, radial folding and yaw steering, and adapt to complex pipeline topology through multimodal motion. The detection component includes a ring lighting, a high-definition camera and a servo gimbal, which are used to obtain high-definition images inside the pipe and dynamically adjust the lighting brightness and observation angle. The sensor component includes a photoelectric encoder, a nine-axis attitude sensor and a pressure sensor, which are used to monitor the robot's motion status in real time. The controller realizes closed-loop control of the robot system based on the feedback information of the sensor component, and processes and analyzes the image information of the detection component at the same time.

2. A modular three-degree-of-freedom adaptive pipeline inspection robot according to claim 1, characterized in that: The drive unit comprises a drive shaft (1), a drive motor (2), an active drive bevel gear (3), a driven drive bevel gear (4), a transmission shaft (5), and a drive wheel (6); the output shaft of the drive motor (2) is fixedly connected to the drive shaft (1); the active drive bevel gear (3) is sleeved on the drive shaft (1) and is orthogonally meshed with the driven drive bevel gear (4); the driven drive bevel gear (4) is fixed to the middle of the transmission shaft (5) by interference fit, and the drive wheels (6) are mounted at both ends of the transmission shaft (5) via bearing seats.

3. The modular three-degree-of-freedom adaptive pipeline inspection robot according to claim 1, characterized in that: The folding unit comprises a folding motor (7), an active folding worm (8), a passive folding worm wheel (9), a folding shaft (10), a passive folding gear 1 (11), a passive folding gear 2 (12), a folding sleeve rod (13), a supporting pressing plate 2 (14), and a supporting bearing 2 (15); the output shaft of the folding motor (7) is fixedly connected to the active folding worm (8) and meshes with the passive folding worm wheel (9) to form a first-stage reduction; the passive folding worm wheel (9) is rigidly connected to the folding shaft (10) via a flat key, and both ends of the folding shaft (10) are connected via the supporting The passive folding gear one (11) is mounted on the supporting bearing two (15); the passive folding gear one (11) is externally meshed with the passive folding gear two (12) at the end of the folding sleeve rod (13); the supporting clamping plate two (14) axially limits the passive folding gear one (11) through bolts; when the folding motor (7) is started, the worm gear pair transmits power to the folding shaft (10), driving the passive folding gear one (11) to rotate, driving the passive folding gear two (12) to drive the folding sleeve rod (13) to radially extend and retract.

4. The modular three-degree-of-freedom adaptive pipeline inspection robot according to claim 1, characterized in that: The steering unit comprises a steering motor (16), an active steering gear (17), a driven steering gear (18), a steering shaft (19), a steering worm (20), a steering worm wheel (21), a supporting tee (22), a steering shaft (23), a supporting pressing plate (24), a supporting bearing (25) and a housing (26); the output shaft of the steering motor (16) is mounted with the active steering gear (17) and meshes with the driven steering gear (18) sleeved on the steering shaft (19); the steering shaft (19) is mounted on the supporting pressing plate (24) through the supporting bearing (25). (24), the steering worm (20) is connected to the steering shaft one (19) through a flat key, and is orthogonally meshed with the steering worm wheel (21); the inner hole of the steering worm wheel (21) is interference fit with the support tee (22), and the steering shaft two (23) passes through the through hole of the support tee (22) and is fixedly connected; when the steering motor (16) is started, the gear pair drives the steering worm (20) to rotate, driving the steering worm wheel (21) and the support tee (22) to rotate, thereby causing the steering shaft two (23) to deflect around the pipeline radial direction, thereby adjusting the steering angle of the driving wheel (6).

5. The modular three-degree-of-freedom adaptive pipeline inspection robot according to claim 1, characterized in that: The detection assembly (27) is installed at the front end of the head movement mechanism, and includes a ring-shaped lighting lamp (28), a high-definition camera (29), and a steering gear pan-tilt, wherein the steering gear pan-tilt includes a pan-tilt servo (30), a pan-tilt servo (31), a pan-tilt rudder arm (32), a pan-tilt connecting piece (33), a pan-tilt clamp arm (34), a pan-tilt clamp buckle (35), and a pan-tilt base (36); the ring-shaped lighting lamp (28) is arranged around the high-definition camera (29), the pan-tilt clamp buckle (35) clamps the high-definition camera (29) by bolts, the pan-tilt clamp arm (34) is hinged to the pan-tilt connecting piece (33), and the pan-tilt rudder arm (32) is driven by the pan-tilt servo (30); when the pan-tilt servo (30) rotates by an angle θ1, the pan-tilt clamp arm (34) drives the camera (29) to a pitch angle α that satisfies: Its pitch angle α satisfies: Among them, θ1 is the rotation angle of the rudder arm, L1 is the length of the rudder arm, and L2 is the length of the connecting piece; The second pan-tilt servo (31) drives the pan-tilt base (36) to rotate horizontally via the rudder arm, thereby realizing panoramic scanning of the camera; the annular lighting lamp (28) automatically adjusts the brightness according to the light intensity in the tube, thereby ensuring uniform image exposure.

6. A modular three-degree-of-freedom adaptive pipeline inspection robot control system, characterized in that It comprises a controller, a detection component (27), a sensor component (37) and a motion mechanism; the sensor component (37) comprises a photoelectric encoder, a nine-axis attitude sensor and a pressure sensor; the photoelectric encoder collects the speed signals of the drive motor (2), the folding motor (7) and the steering motor (16) in real time; the nine-axis attitude sensor is installed inside each section of the machine body, and outputs a pitch angle θ, a yaw angle ψ and a roll angle φ by fusing the data of the accelerometer, the gyroscope and the magnetometer through Kalman filtering; the pressure sensor is embedded inside the folding sleeve (13) to monitor the positive pressure applied to the pipe wall; after receiving the sensor data and the image data of the detection component, the controller performs the following closed-loop control: ① According to the attitude angle and pressure feedback, the PWM duty cycle of the folding motor (7) is adjusted to control the radial expansion amount of the driving wheel (6); ② based on the encoder pulse difference, the output torque of the three driving motors (2) is distributed through a vector control algorithm; ③ according to the deviation between the target steering angle and the current angle, the rotation speed of the steering motor (16) is adjusted by a PID algorithm, thereby controlling the radial rotation angle of the driving wheel (6); ④ the brightness of the annular lighting lamp (28) is adjusted and the rotation angle of the servo gimbal is adjusted to obtain a normal and clear panoramic image of the tube, and then the image of the tube captured by the high-definition camera (29) is analyzed by an image recognition algorithm, and defective areas such as cracks and corrosion are marked.

Images