Waterproof crawling robot

Abstract

This invention discloses a waterproof crawling robot. The robot includes a drive mechanism, a support and adjustment mechanism, a camera detection component, a striking communication mechanism, a coupling unit, and a control unit. The drive mechanism adopts four-wheel independent drive with differential steering; the support and adjustment mechanism is a cross-support rod structure. The striking communication mechanism consists of an eccentric cam + striker or an electromagnetic release + leaf spring striker, transmitting mechanical pulses to the pipe wall through the elastic pad or thin-film resonant cavity of the coupling unit. The control unit coordinates movement, detection, and communication, creating a silent time slot before and after striking to collect acoustic signals and achieve communication and echo ranging. This scheme utilizes strong rhythmic pulses as a synchronization reference for communication and positioning, effectively suppressing self-noise interference, achieving stable communication and centimeter-level positioning in metal, full water, and complex pipe networks, significantly improving task completion rate.

Description

Technical Field

[0001] This invention belongs to the field of pipeline inspection and maintenance technology, specifically a waterproof crawling robot. Background Technology

[0002] Pipeline crawling robots, as crucial equipment for pipeline internal inspection and maintenance, typically rely on motors, gears, tracks, or wheeled drive mechanisms to move forward in confined spaces. They are equipped with modules such as cameras and sensors to perform pipeline internal wall inspection, defect location, and operational monitoring. Existing communication and positioning methods mainly fall into two categories:

[0003] Cable communication and positioning: This method uses towed cables for data transmission and power supply, while relying on cable length or odometers to calculate location. However, this approach is prone to problems such as cable tangling and blockages in long-distance or winding pipes, limiting mechanical mobility and resulting in low task completion rates.

[0004] Wireless and acoustic communication: Radio communication is susceptible to shielding and attenuation in metal pipes or full water pipes, resulting in insufficient reliability; acoustic communication and echo-based ranging and positioning are gradually being regarded as alternatives. However, existing research is mostly based on static water tanks or short straight pipe sections for testing, and the algorithms are mostly designed for modeling external uniform background noise, without fully considering the dynamic noise interference during robot operation.

[0005] The applicant discovered in engineering applications that existing acoustic communication and ranging methods generally have the following technological gaps:

[0006] Pipeline robots inevitably generate broadband noise sources during operation:

[0007] High-frequency components: gear meshing, mechanical vibration;

[0008] Low-frequency components: the impact of tracks or wheels on pipe walls, and the pulsation of liquid pumps;

[0009] Broadband component: electromagnetic-acoustic coupled vibration generated by motor commutation and drive current fluctuations.

[0010] Because the pipe itself is a waveguide structure, structural noise easily couples into the sound field and attenuates very little in the low-frequency band. This noise highly overlaps with the frequency bands (hundreds of Hz to tens of kHz) on which acoustic communication and positioning depend, inevitably causing the communication signal to be masked or distorted, thereby increasing the bit error rate, increasing the ranging error, or even completely losing the effective signal.

[0011] Although self-noise interference is physically inevitable, it has not been systematically studied in existing technologies for several reasons, including:

[0012] Idealized experimental conditions: Most existing publicly available experiments are conducted in environments where the machine is stopped or at low speed and low noise, which makes it difficult to reflect real working conditions.

[0013] The research is fragmented: the mechanical team mainly focuses on propulsion torque and crawling stability, while the acoustics team mainly studies modulation methods and propagation characteristics, lacking interdisciplinary research on noise-communication coupling.

[0014] Difficult to model: The self-noise spectrum is affected by load, flow velocity, wear, etc., and exhibits a nonlinear and non-stationary process, which is far more complex than uniform background noise. Therefore, it has long been neglected in traditional acoustic communication research.

[0015] Therefore, the shortcomings of existing technologies are manifested in the publicly available pipeline robot communication and positioning technologies, mainly involving:

[0016] The attenuation characteristics of sound waves propagating in a pipe;

[0017] Various modulation and decoding methods;

[0018] Echo-based positioning algorithm.

[0019] However, none of these solutions address how to mitigate the interference of structural noise and residual vibration generated by the robot itself on signal acquisition and processing, nor do they address adaptive adjustment of silent time slots and residual vibration suppression. In other words, existing technologies generally assume that "noise is an external background," neglecting the fact that self-noise is the dominant interference source under real-world conditions.

[0020] Therefore, how to achieve reliable pipe wall acoustic communication and centimeter-level ranging in complex noise environments has become an unsolved technical problem in this field, and it is also the core problem that this invention aims to solve. Summary of the Invention

[0021] The purpose of this invention is to provide a waterproof crawling robot that can achieve stable communication and centimeter-level positioning in metal pipes, full water pipes, and multi-diameter environments. It creatively transforms unavoidable self-noise environments into beneficial reference conditions, achieving comprehensive performance improvements that have not been achieved by existing technologies.

[0022] The technical solution adopted in this invention is as follows:

[0023] A waterproof crawling robot, comprising:

[0024] A drive mechanism, including at least four drive wheels and a drive motor, is used to achieve propulsion and steering within the pipe;

[0025] The support adjustment mechanism, installed below the robot body, is a cross support rod structure used to adjust the robot height to accommodate pipes of different diameters.

[0026] The camera inspection component, installed at the front end of the robot, includes a camera and a retaining ring, and is used to acquire images of the pipeline;

[0027] A striking communication mechanism, including a mechanical striking component or an electronically controlled striking component, is used to generate mechanical pulses at a predetermined rhythm;

[0028] The coupling unit, connected to the striking communication mechanism, extends to the pipe wall and remains in contact with the pipe wall, and is used to transmit mechanical pulses to the pipe wall or the medium inside the pipe.

[0029] The control unit, including a microcontroller and a storage module, is used to coordinate the robot's movement, detection, and communication, and to perform acoustic signal processing and ranging calculations.

[0030] The drive mechanism is a four-wheel independent drive structure, and steering is achieved by differential control of the wheels on either side.

[0031] The tapping communication mechanism includes:

[0032] A mechanical striking assembly consisting of an eccentric cam and a striker, or

[0033] An electrically controlled striking assembly consisting of an electromagnetic release device and a leaf spring striker.

[0034] The impact pin is connected to the coupling unit via an elastic support to maintain stable contact and absorb impact during impact.

[0035] The coupling unit is provided with an elastic coupling pad or a thin film resonant cavity at its end to enhance acoustic energy transfer while avoiding damage to the tube wall.

[0036] The control unit controls the drive mechanism to enter zero torque mode or disengage the clutch before and after the tapping communication mechanism is activated, so as to form a silent time slot.

[0037] A communication and positioning method based on the aforementioned waterproof crawling robot includes:

[0038] S1: Drives the tapping communication mechanism to generate mechanical pulses at a predetermined rhythm;

[0039] S2: The mechanical pulse is transmitted to the pipe wall or the medium inside the pipe through the coupling unit;

[0040] S3: Control the drive mechanism to enter the silent time slot before and after the strike;

[0041] S4: Receive acoustic pulses using the control unit during the silence time slot;

[0042] S5: Decode communication data based on the acoustic pulse and / or measure distance based on the time difference between the pulse and the echo.

[0043] The data decoding process involves dividing the silence time slot into multiple time slots, with each slot corresponding to a bit or symbol. Acoustic pulses appear in different slots to represent different data.

[0044] Specifically, a reference pulse is emitted after a predetermined delay following the generation of the striking pulse, and the arrival time difference of the reference pulse is detected at transducers at different receiving points to estimate the effective sound velocity of the pipe section, and the ranging result is corrected based on the effective sound velocity.

[0045] In this system, multiple robots use different clock cycles or double-pulse intervals as communication identifiers to distinguish the communication signals of multiple robots in the same pipeline and avoid conflicts.

[0046] The duration of the silent time slot is dynamically adjusted by the control unit according to the motor noise attenuation curve to ensure that acoustic signals are collected within the time window with the least noise.

[0047] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0048] This invention incorporates a striking communication mechanism into a waterproof crawling robot. Instead of relying on complex filtering and vibration isolation methods to passively suppress self-noise, the robot actively designs a striking structure similar to a "mechanical metronome" to strike the pipe wall or resonant cavity at a fixed frequency, generating high-amplitude, concentrated, and sparsely distributed low-frequency pulses. These pulses are easily identifiable and simultaneously serve as the modulation reference for the communication signal and the time synchronization anchor for ranging / positioning. This transforms the originally random, complex, and difficult-to-model robot self-noise into an irrelevant background, no longer obscuring the clearly rhythmic striking signal. Unlike existing technologies that generally rely on "noise suppression," this invention proposes for the first time a strategy of "using rhythm to replace noise," giving the communication and positioning system natural anti-interference capabilities in waveguide environments like pipes. Since the striking pulse simultaneously serves as the clock for both communication and ranging, it avoids the problems of multiple clock drifts and synchronization errors in traditional systems, achieving an integrated design for communication and positioning. The test results show that, under conditions of high-noise pumping stations, multiple bends in the pipe section, and full water conditions, the link signal-to-noise ratio of the present invention remains in the range of 17–22 dB, the bit error rate is stable at the order of 10⁻³, and the root mean square error of ranging can be controlled at 1.2–3.5 cm. Compared with existing wireless and wired comparison systems, it shows higher communication availability and lower positioning error.

[0049] Meanwhile, employing differentiated cycle periods or double-pulse intervals enables multi-robot identification, ensuring conflict-free collaborative operation. By utilizing elastic coupling pads or thin-film resonant cavities, this invention improves acoustic coupling efficiency while avoiding pipe wall damage, balancing energy utilization and engineering safety. Therefore, this invention achieves stable communication and centimeter-level positioning in metal pipes, full-water pipes, and multi-diameter environments, creatively transforming unavoidable self-noise environments into beneficial reference conditions, achieving comprehensive performance improvements unattainable by existing technologies. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the robot of the present invention;

[0051] Figure 2 This is a schematic diagram of the mechanical striking assembly of the present invention;

[0052] Figure 3 This is a schematic diagram of the structure of the electronically controlled striking assembly of the present invention;

[0053] Figure 4 This is a schematic diagram of the coupling unit using an elastic coupling pad in this invention;

[0054] Figure 5 This is a schematic diagram of the coupling unit using a thin-film resonant cavity in this invention;

[0055] Figure 6 This is a schematic diagram of the control unit of the present invention;

[0056] Figure 7 This is a flowchart illustrating the communication and positioning method of the present invention.

[0057] In the diagram, 100 is the drive mechanism; 101 is the drive wheel; 102 is the drive motor; 200 is the support adjustment mechanism; 201 is the cross support rod structure; 300 is the striking communication mechanism; 310 is the coupling unit; 320 is the mechanical striking assembly; 321 is the eccentric cam; 322 is the striking pin; 330 is the electrically controlled striking assembly; 331 is the electromagnetic release device; 332 is the leaf spring striking pin; 340 is the elastic coupling pad; 350 is the thin film resonant cavity; 400 is the camera detection assembly; 401 is the camera; 402 is the fixing ring; 500 is the control unit; 501 is the microcontroller; and 502 is the storage module. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0059] See Figures 1 to 6This invention relates to a waterproof crawling robot, including a drive mechanism 100, a support adjustment mechanism 200, a camera detection component 400, a tapping communication mechanism 300, a coupling unit 310, and a control unit 500.

[0060] The robot body is elongated, approximately 400–800 mm long, 120–250 mm wide, and 100–200 mm high. The outer shell is made of aluminum alloy or stainless steel and treated with an anti-corrosion coating to ensure long-term operation in pipeline environments containing water and chemical media.

[0061] The drive mechanism 100, used for propulsion and steering within the pipe, includes four drive wheels 101, 50–120 mm in diameter, with 3–5 mm deep tread patterns on their outer surfaces to enhance friction. Each drive wheel is controlled by an independent drive motor 102, which is a brushless DC motor with a rated power of 20–50 W. The motors are connected to the wheels via reduction gearboxes (transmission ratio 1:20–1:40) to ensure low-speed, high-torque operation of the robot within the pipe. Steering can be achieved via differential speed control between the drive wheels on either side.

[0062] The support adjustment mechanism 200, installed below the robot body, is used to adjust the robot's height to accommodate pipes of different diameters. It is a cross-support rod structure 201, shaped like an "X". Its two ends are connected to the robot body and wheel brackets via pivots. This mechanism can be driven by a small motor or pneumatic cylinder to extend and retract the cross rods. The support range is adjustable, accommodating pipes with inner diameters of 150–600 mm.

[0063] The camera inspection component 400, mounted on the front end of the robot, is used to acquire images of the pipeline. A camera 401 with a resolution of 1080p and a lens field of view of 120° is mounted on the front end. A retaining ring 402 with a diameter of 60–100 mm is provided on the outer side of the camera. The retaining ring 402 has 6–12 threaded holes evenly distributed, which can be used to install LED lights with a light intensity of 200–400 lm for imaging in low-light environments.

[0064] The striking communication mechanism 300 includes a mechanical striking assembly 320 or an electrically controlled striking assembly 330, used to generate mechanical pulses at a predetermined rhythm. The mechanical striking assembly 320 consists of an eccentric cam 321 and a striking pin 322. The eccentric cam 321 is driven by a miniature DC motor with a speed of 60–300 rpm. The cam profile is elliptical or eccentrically circular, with an eccentricity of 3–6 mm. The striking pin 322 has a diameter of 8–12 mm and a length of 30–50 mm, and is made of high-strength steel. The striking pin is held in its initial position by a return spring and is pushed forward as the cam rotates, completing one impact. The electrically controlled striking assembly 330 includes an electromagnetic release 331 and a leaf spring striking pin 332. The electromagnetic release is a coil + moving iron core structure with a rated voltage of 12V. The leaf spring striking pin 332 is made of elastic steel sheet with a thickness of 1–2 mm and a length of 30–60 mm, and has an impact head at the end. When energized, the electromagnet pulls the leaf spring, causing the striking pin to spring out rapidly and strike the coupling unit 310.

[0065] The coupling unit 310, connected to the impact communication mechanism 300, extends to the pipe wall and maintains contact with it, transmitting mechanical pulses to the pipe wall or the medium inside the pipe. The elastic coupling pad 340 is made of polyurethane or nitrile rubber with a Shore A hardness of 60–80. It has a thickness of 5–15 mm and a diameter of 20–50 mm. It buffers the impact and ensures stable energy transmission to the pipe wall. The thin-film resonant cavity 350 is formed by enclosing the front cavity with a metal or polymer thin film (thickness 0.1–0.3 mm). The cavity depth is 10–30 mm and the diameter is 20–40 mm. The thin film vibrates under impact, converting mechanical energy into broadband sound waves that are transmitted to the pipe wall or the liquid inside the pipe.

[0066] The control unit 500, including a microcontroller 501 and a storage module 502, coordinates the robot's movement, detection, and communication, and performs acoustic signal processing and ranging calculations. The microcontroller 501 has a main frequency of 72–168MHz. The storage module 502 includes a Flash memory for storing algorithm code and measurement data. The control unit 500 is connected to the drive mechanism 100, the camera detection component 400, and the tapping communication mechanism 300 via I / O interfaces. Before and after a tapping action, the control unit temporarily disconnects the motor drive or controls the motor to enter a zero-torque mode, thus creating a silent time slot.

[0067] See Figure 7 This embodiment also provides a communication and positioning method based on a waterproof crawling robot. This method achieves data communication and pipe wall distance measurement through mechanical pulse signals when the robot is operating inside a pipe. The specific steps are as follows:

[0068] S1: Mechanical pulse generation

[0069] The striking communication mechanism 300, under the control of the control unit 500, generates mechanical pulses at a frequency of 1–10 Hz. When the mechanical striking component 320 is used: a micro DC motor drives the eccentric cam 321 to rotate, periodically pushing the striker 322 forward to strike the coupling unit 310, thereby generating pulses. The motor speed is controlled by a PWM signal output from the MCU (microcontroller 501), and the frequency can be precisely adjusted. When the electrically controlled striking component 330 is used: the electromagnetic release 331 is periodically energized and released under the control of the MCU, causing the leaf spring striker 332 to pop out and strike the coupling unit 310. The striking frequency is precisely set by a timer interrupt.

[0070] S2: Energy Coupling

[0071] The pulse is transmitted to the pipe wall or fluid through the coupling unit 310, forming an acoustic signal. If the end of the coupling unit is an elastic coupling pad 340, made of polyurethane or nitrile rubber with a Shore A hardness of 60–80 and a thickness of 5–15 mm, it can ensure energy transmission and protect the pipe wall. If it is a thin-film resonant cavity 350, it consists of a metal or polymer thin film enclosed in a cavity, with a film thickness of 0.1–0.3 mm and a cavity depth of 10–30 mm. Upon impact, the thin film resonates, effectively coupling acoustic energy to the pipe wall or fluid. The end face of the coupling unit maintains a pressure of 5–15 N against the pipe wall to ensure stable energy transmission.

[0072] S3: Silent Slot

[0073] To avoid motor noise interference, the drive motor stops or enters zero-torque mode within 10–50 ms before and after the impact. Before the impact is triggered, the MCU shuts down the motor via a PWM control signal or puts the motor into zero-current control mode, allowing the drive wheel to rotate freely. After the impact, the machine remains stationary for 20–40 ms to allow motor and mechanism noise to decay. To optimize control, the control unit can use an accelerometer or built-in acoustic sensor to monitor the noise RMS value. When the noise drops below 20% of the initial value, the signal acquisition window is automatically opened, rather than for a fixed duration.

[0074] S4: Signal Acquisition

[0075] During the silent time slot, the control unit 500's built-in piezoelectric transducer or an external acoustic sensor acquires acoustic signals. The transducer uses a piezoelectric ceramic sheet, operates at a frequency of 5–20 kHz, and is attached to the robot's shell and in contact with the tube wall. The signal is amplified by a low-noise amplifier with a gain of 40–60 dB and then sampled by the MCU's ADC at a sampling rate of at least 100 kHz. The MCU performs bandpass filtering on the acquired signal, for example, at 4–25 kHz, to suppress low-frequency motor noise.

[0076] S5: Decoding and Ranging

[0077] Perform the following operations according to different work modes:

[0078] In the communication mode, the silence time slot is divided into multiple time slots, such as 4 slots, each 20ms. Pulses appearing in different slots correspond to different data symbols, for example: slot 1=00, slot 2=01, slot 3=10, slot 4=11. The control unit performs CRC verification on the decoded data to ensure reliability.

[0079] In ranging mode, the control unit records the pulse transmission time and the echo reception time, and calculates the time difference Δt.

[0080] Distance formula: Where, d: ranging result, in meters; c: speed of sound, in meters per second, obtained from the speed of sound correction step; Δt: time difference between transmission and echo, in seconds;

[0081] Furthermore, a reference pulse is transmitted with a predetermined delay after the striking pulse is generated, and the arrival time difference of the reference pulse is detected at transducers at different receiving points to estimate the effective sound velocity of the pipe section. The ranging result is then corrected based on the effective sound velocity. In this embodiment, the reference pulse is transmitted with a delay of 20–50 ms after the striking pulse and is received by multiple transducers. Actual sound velocity formula: Where c: speed of sound, in meters per second; Δd: known distance between sensors, in meters; Δt: time difference between different sensors receiving the reference pulse, in seconds. This correction formula takes into account the influence of temperature and pressure changes in the pipeline medium on the speed of sound.

[0082] Furthermore, multiple robots employ different beat cycles or double-pulse intervals as communication identifiers to distinguish their communication signals within the same conduit and avoid conflicts. In this embodiment, different robots use different frequencies f, for example, f1=2Hz, f2=3Hz, f3=5Hz; and different intervals ΔT, for example, ΔT1=20ms, ΔT2=40ms, ΔT3=60ms. f is the beat frequency in Hertz; ΔT is the double-pulse interval in milliseconds, serving as the ID identifier.

[0083] Furthermore, the duration of the silence slot is dynamically adjusted by the control unit 500 according to the motor noise attenuation curve to ensure that acoustic signals are acquired within the time window of minimum noise. The signal acquisition window is activated when the root mean square (RMS) noise value drops below 20% of the initial value. The initial value is the reference noise level during normal motor operation. This method achieves dynamic adjustment: extending the silence slot (e.g., 60–80 ms) when noise is high and shortening the slot when noise is low, thereby improving communication efficiency.

[0084] Furthermore, in the waterproof crawling robot of this invention, the striking communication mechanism 300 applies a mechanical impact to the coupling unit 310 via an eccentric cam 321 + striker 322 or an electromagnetic release device 331 + leaf spring striker 332 to generate an acoustic pulse signal. However, the applicant's research has revealed that this impact not only generates propagating sound waves in the pipe wall or the medium inside the pipe, but also inevitably excites residual vibrations in the robot body, coupling unit, and elastic coupling pad 340 or thin-film resonant cavity 350. These residual vibrations have a certain natural frequency and decay time constant. If the silent time gap, i.e., the time window for signal reception when the drive mechanism stops, is set too short, the residual vibration signal will still exist, leading to an increase in noise level and interfering with the acquisition and interpretation of acoustic signals.

[0085] Aftershock is a free vibration caused by the residual elastic deformation after the impact of the firing pin. Its characteristic frequency is related to the equivalent contact stiffness of the coupling element material. and effective quality Relevant. The natural frequency can be expressed as:

[0086] ;in: The inherent frequency of the coupling unit, in Hz; Equivalent contact stiffness, N / m; Effective vibration mass, kg. The damping characteristics of residual vibration are determined by the quality factor. Characterized by its time constant Approximately:

[0087] ;in: : Residual vibration decay time constant, s; Quality factor, dimensionless, determined by material damping. When the silent time gap is less than... At that time, the residual amplitude is usually still 5-10% greater than the initial value, which will seriously affect the received signal.

[0088] In practical implementation, the control unit 500 can call the acoustic sensor to collect the original waveform after each impact, and identify the main frequency through Fast Fourier Transform (FFT) or autoregressive modeling. The decay rate is used to obtain the real-time quality factor Q. For example, in a certain experiment, the elastic pad 340 was 10mm thick and 30mm in diameter, and the material was Shore A70 polyurethane. The test results showed that its dominant and residual frequencies were 8kHz, the Q value was approximately 10, and the corresponding τ=0.4ms. The waveform decayed to less than 5% of its initial amplitude within 1ms.

[0089] Based on the above parameters, the silent time slot adaptive adjustment of the control unit 500 no longer uses a fixed value for setting the silent time slot, but rather adaptively adjusts it according to the residual vibration attenuation law. Specifically, it includes the following steps:

[0090] Parameter estimation: Measuring the residual frequency during the first hit or periodic training hits. And quality factor Q;

[0091] Time slot calculation: According to the formula

[0092] ;

[0093] Determine the length of the silence time slot, where α ≥ 3;

[0094] Dynamic update: Repeatedly estimate the residual vibration characteristics under different temperature and pressure conditions, and update them in real time. .

[0095] When the robot using this implementation method was tested inside a DN300 steel pipe, the silent time slot was adjusted from a fixed 20ms to a dynamic 12–18ms, while still ensuring complete attenuation of residual vibrations. Simultaneously, the average waiting time was shortened, and the communication rate was increased by approximately 20%. In a water-containing environment, the signal-to-noise ratio increased from 14dB in the original scheme to 20dB, effectively reducing the bit error rate.

[0096] To verify the communication stability and ranging accuracy of the waterproof crawling robot of this invention in complex pipeline environments, the applicant designed and implemented a series of comparative experiments. The experiments mainly focused on the following aspects:

[0097] Signal transmission performance: Comparing the signal transmission method of the tapping communication mechanism and coupling unit used in this invention with the signal transmission capability of ordinary crawling robots without tapping mechanisms in metal pipes and full water pipe sections.

[0098] Ranging and positioning accuracy: This study examines whether the ranging method implemented by the present invention using acoustic pulse and silent time slot decoding can significantly reduce cumulative error compared with the traditional positioning method that relies on odometers.

[0099] Interference resistance: The communication stability of this invention under high background noise conditions through adaptive silent time slots and residual vibration suppression strategies is evaluated to verify whether it is superior to the ordinary crawling robot in the control group.

[0100] Multi-machine collaborative capability: Test whether the clock cycle and double pulse interval identification mechanism adopted in this invention can avoid conflicts and improve system scalability when multiple robots are running simultaneously.

[0101] Energy utilization and pipe wall protection: Verify whether the coupling unit (elastic coupling pad or thin film resonant cavity) of the present invention can effectively buffer impacts and avoid damage to the pipe wall while ensuring efficient transmission of acoustic energy.

[0102] The experiment selected six robot prototypes with different parameter configurations according to the present invention, and set up two groups of existing mainstream pipeline crawling robots on the market as control groups (both of which do not have a tapping communication mechanism and rely only on wireless radio frequency or visual odometry for communication and positioning). Under the same pipeline environment and operating conditions, the communication success rate, bit error rate, ranging error, signal-to-noise ratio and operating efficiency of each group of robots were recorded and compared.

[0103] The pipeline conditions are as follows: DN250–DN300, length 20–80m, straight pipe / elbow / tee combination; medium is air or full water; flow velocity 0–1.0m / s; temperature 20℃ / 55℃.

[0104] Test subject:

[0105] This invention includes a tapping communication mechanism 300, a coupling unit 310, a silence time slot, sound speed correction, and time slot decoding.

[0106] Comparison A: Ordinary crawling robot (cable communication / power supply; no tapping / coupling / silent window; no acoustic ranging).

[0107] Comparison B: Ordinary crawling robot (wireless data transmission; no tapping / coupling / silent window; wireless / airborne acoustic communication within the pipe, but lacks pipe wall acoustic communication and the ranging algorithm of this invention).

[0108] I. Test Conditions

[0109]

[0110] II. System Configuration Comparison

[0111]

[0112] III. Test Results

[0113]

[0114] Among them, communication availability is the percentage of communication links that are available; RbR_b (bit / s) is the effective communication rate, in bits per second; BER (×10⁻³) is the bit error rate, expressed as BitErrorRate multiplied by 10⁻³; RMSE (cm) is the root mean square error of ranging, in centimeters; SNR (dB) is the received signal-to-noise ratio, in decibels; and task completion rate (%) is the success rate of completing the entire pipeline detection task.

[0115] Analysis of experimental results:

[0116] Communication availability: This invention relies on the pipe wall / medium acoustic link, which remains stable under conditions of metal / full water / long distance / multiple bends; Control B (wireless) is unusable over large areas of metal / full water pipe sections; Control A (wired) is limited by mechanical accessibility, and the task completion rate is significantly lower in T3 / T6.

[0117] Ranging and positioning capabilities: This invention features impact TOF ranging and online sound velocity correction, with an RMSE of 1.2–3.5 cm; the two ordinary control models do not have equivalent ranging capabilities (requiring external positioning or cable rulers) and cannot provide data in the same dimension.

[0118] Noise immunity / multipath capability: In high-noise (T4) pump station and three-way multipath (T6) scenarios, this invention maintains an SNR of 17–18 dB using silent time slot adaptive + dual-frequency short pulse + guard interval adaptive; ordinary wireless basically loses connection in these scenarios; although wired communication is possible, "noise immunity" and "multipath" are meaningless (its link is not acoustic) and it does not have acoustic ranging capability.

[0119] Energy efficiency and performance: This invention achieves R under comparable task layer throughput. b 70–120 bit / s, BER≤2×10⁻³, and due to the shortened mute window / noise avoidance, there are fewer retransmissions and lower power consumption per bit; compared with wired A, the "speed" depends more on the cable bandwidth, but mechanical throughput leads to a decrease in overall efficiency (pause, reversing, cable unwinding).

[0120] Therefore, compared with a "common crawling robot (without a slapping structure)," this invention has significant technical advantages in terms of usability, robustness, ranging, and positioning capabilities.

[0121] Inside a metal and water-filled pipe, a conventional wireless system fails.

[0122] While wired connections can transmit data, they are limited by the mechanical accessibility and operational efficiency of elbows / tees, and lack acoustic ranging capabilities, thus they cannot replace this invention.

[0123] This invention achieves stable communication and centimeter-level ranging under various harsh working conditions through a combination of striking, coupling, silent window adaptive, sound velocity correction, and multipath protection. This comprehensive capability is unattainable in ordinary solutions without striking structures.

[0124] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A waterproof crawling robot, characterized in that, include: The drive mechanism (100) includes at least four drive wheels (101) and a drive motor (102) for propulsion and steering within the pipe; The support adjustment mechanism (200), installed below the robot body, is a cross support rod structure (201) used to adjust the robot height to adapt to pipes of different diameters; A camera detection component (400), installed at the front end of the robot, includes a camera (401) and a retaining ring (402) for acquiring images of the pipeline; A striking communication mechanism (300), including a mechanical striking component (320) or an electrically controlled striking component (330), is used to generate mechanical pulses at a predetermined rhythm; The coupling unit (310) is connected to the tapping communication mechanism (300), with its end extending to the pipe wall position and maintaining contact with the pipe wall, for transmitting mechanical pulses to the pipe wall or the medium inside the pipe; The control unit (500), including a microcontroller (501) and a storage module (502), is used to coordinate robot movement, detection and communication, and to perform acoustic signal processing and ranging calculations; The tapping communication mechanism (300) includes: A mechanical striking assembly (320) consisting of an eccentric cam (321) and a striking pin (322), or The electromagnetic release device (331) and the leaf spring striker (332) constitute an electrically controlled striking assembly (330). The impact pin is connected to the coupling unit (310) via an elastic support to maintain stable contact and absorb impact during impact. The coupling unit (310) is provided with an elastic coupling pad (340) or a thin film resonant cavity (350) at its end to enhance acoustic energy transfer while avoiding damage to the tube wall.

2. The waterproof crawling robot according to claim 1, characterized in that, The drive mechanism (100) is a four-wheel independent drive structure, and the wheels on either side can be steered through differential control.

3. The waterproof crawling robot according to claim 1, characterized in that, Before and after the tapping communication mechanism (300) is activated, the control unit (500) controls the drive mechanism (100) to enter zero torque mode or disengage the clutch to form a silent time slot.

4. A communication and positioning method for a waterproof crawling robot based on any one of claims 1 to 3, characterized in that, include: S1: Drive the tapping communication mechanism (300) to generate mechanical pulses at a predetermined rhythm; S2: The mechanical pulse is transmitted to the pipe wall or the medium inside the pipe through the coupling unit (310); S3: Control the drive mechanism (100) to enter the silent time slot before and after the strike; S4: Receive acoustic pulses using the control unit (500) during the silence time slot; S5: Decode communication data based on the acoustic pulse and / or measure distance based on the time difference between the pulse and the echo.

5. The method according to claim 4, characterized in that, The data decoding divides the silence time slot into multiple time slots, each slot corresponding to a bit or symbol, and acoustic pulses appear in different slots to represent different data.

6. The method according to claim 4, characterized in that, After the striking pulse is generated, a reference pulse is emitted with a predetermined delay, and the arrival time difference of the reference pulse is detected at transducers at different receiving points to estimate the effective sound velocity of the pipe section, and the ranging result is corrected based on the effective sound velocity.

7. The method according to claim 4, characterized in that, Multiple robots use different clock cycles or double-pulse intervals as communication identifiers to distinguish the communication signals of multiple robots in the same pipeline and avoid conflicts.

8. The method according to claim 4, characterized in that, The duration of the silent time slot is dynamically adjusted by the control unit (500) according to the motor noise attenuation curve to ensure that acoustic signals are collected within the time window with the least noise.

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