Method for dynamically positioning and measuring head of tube push bench based on RGB (red, green and blue) image information processing

Abstract

The invention discloses a dynamic positioning and measuring method for a head of a tube push bench based on RGB image information processing, which combines laser guiding and image processing technologies and realizes high-precision attitude measurement of the head of the tube push bench. The system comprises a laser emitting device, a light target, an RGB camera, a signal processing unit and a display and control system. The laser emitting device emits red laser to the light target, a laser reference point on the light target serves as a known reference, and the RGB camera shoots an image in real time and transmits data to the signal processing unit; the signal processing unit extracts red and green light channel information in the image, calculates the relative position of a red laser point relative to a reference point, and calculates the dynamic position and change of the center of the machine head in real time based on geometric calculation and a Kalman filtering algorithm; and a calculation result is displayed in real time through the display and control system. The method has the characteristics of high precision and strong real-time performance, and can adapt to the dynamic measurement requirement of the head positioning of the pipe jacking machine in a complex construction environment.

Description

Technical Field

[0001] The present invention relates to the technical field of pipe jacking construction engineering, and in particular to a dynamic positioning and measuring method for a pipe jacking machine head based on RGB image information processing. Background Art

[0002] A pipe jacking machine is an advanced trenchless construction device for underground pipelines. Its primary task is to advance pipes along a predetermined path, precisely positioning and controlling the machine head's axis coordinates during the process. To ensure the stability and safety of the equipment during construction and to ensure that the quality and efficiency of the pipe jacking project meet project objectives, real-time monitoring of the machine head's axis positioning is crucial. Traditional monitoring methods utilize a laser beam to illuminate a target light target, using a laser positioning sensor or camera to monitor the image to obtain the target's position. This information is then calculated or visually observed to detect deviations in the machine's axis positioning. However, laser positioning sensors are expensive, bulky, and susceptible to temperature and humidity, presenting potential problems. Camera-based monitoring, while intuitive, is affected by the larger laser spot size and interference from stray light (such as reflected and scattered light from electronic equipment) within the pipe jacking machine, resulting in low positioning accuracy and inaccurate measurement results. Furthermore, data can only be recorded manually, not automatically, raising concerns about its authenticity.

[0003] In traditional laser measurement methods, the laser beam is often affected by ambient light during its propagation. This is especially true within the complex environment of a pipe jacking machine, where strong stray light can mix with the laser signal, causing attenuation, interference, or misjudgment. Therefore, effectively reducing the impact of stray light on laser measurement and improving measurement accuracy has become a pressing technical challenge for current laser attitude measurement systems. Summary of the Invention

[0004] The present invention aims to provide a method for measuring the dynamic positioning of a pipe jacking machine head based on RGB image information processing. By accurately extracting information from the red and green light channels, this method effectively filters out interference from other stray light and ensures the accuracy of measurement results. Compared with traditional technologies, this method has better anti-interference performance and can significantly improve measurement accuracy and stability in practical applications.

[0005] To achieve the above objectives, the present invention provides a method for dynamic positioning and measurement of a pipe jacking machine head based on RGB image information processing, comprising measuring the pipe jacking machine head using a measurement system. The measurement system comprises a laser emitting device, a light target, an RGB camera, a signal processing unit, and a display and control system. The laser emitting device is a red laser installed on the tunnel face opposite the pipe jacking machine construction position. The light target is located at the front of the pipe jacking machine head and is provided with multiple green laser reference points. The RGB camera is located above and behind the light target and is connected to a ground computer via a data cable. The signal processing unit is connected to the RGB camera. The display and control system displays the processing results of the signal processing unit on the computer operator interface and can manually or automatically adjust the head posture based on the calculation results. The dynamic positioning and measurement method includes the signal processing unit receiving image information from the RGB camera, converting the image into a matrix form, extracting corresponding information of the red and green light channels, locating the offset of the red laser point relative to the multiple laser reference points using an image analysis algorithm, and calculating the real-time position and change of the head center based on the offset.

[0006] Furthermore, the specific steps of using the image analysis algorithm to locate the offset of the red laser point relative to the laser reference point are as follows:

[0007] Step S1, color segmentation and red laser point extraction: convert the RGB image into the HSV color space, and extract the red area in the image by setting the hue (H value) range of the red light;

[0008] Step S2: Use the inRange function of OpenCV to extract the red part of the image and generate a binary mask of the red laser point;

[0009] Step S3: Use a contour detection method (such as findContours) to locate the position of the red laser point and calculate its centroid coordinates;

[0010] Step S4, target position extraction and geometric analysis: For the red laser point, extract its position coordinates (pixel coordinates) in the image; for the green reference point, use the same image processing method to extract its position coordinates (pixel coordinates) in the image, and perform position mapping based on the known actual position; based on the relative position of the red laser point and the green reference point, use a geometric algorithm to calculate the translation of the light target.

[0011] Furthermore, the image analysis algorithm further includes using a Kalman filter algorithm to smooth the position of the red laser point; reduce the impact of instantaneous offset, and ensure the real-time performance and accuracy of the system. The Kalman filter formula is as follows:

[0012]

[0013] in, is an estimated value, K k is the Kalman gain, z k is the observed value, H k is the measurement matrix.

[0014] Furthermore, the hue range of the red light is 0° to 15° and 170° to 180°.

[0015] Furthermore, the red laser is configured so that its laser emission direction is arranged along the designed axis of the pipe jacking construction, and initially the laser emitted by the red laser irradiates the center position of the light target and changes dynamically with the actual position of the pipe jacking machine.

[0016] Furthermore, the light target is a rectangular structure arranged at the front inner part of the pipe jacking machine head and corresponds to the red laser in a straight line; a laser reference point is set at each of the four corners of the light target; the four laser reference points correspond to the four corners of the rectangle, forming a reference coordinate system.

[0017] Furthermore, the display and control system displays the calculation results in real time, and manually or automatically adjusts the deviation correction of the machine head according to the calculation results to ensure that the head of the pipe jacking machine is accurately aligned along the design axis.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The present invention's dynamic positioning measurement method for the pipe jacking machine head can effectively filter out surrounding stray light interference and reduce the impact of ambient light on measurement results by selecting the red and green light channels of the RGB camera for information processing. Compared with existing methods, the technical solution of the present invention is more suitable for accurate measurement in complex environments.

[0020] (2) Compared with traditional laser measurement systems, the method of the present invention does not require complex hardware support, such as expensive filters or multi-wavelength laser devices, which greatly reduces costs. Through RGB cameras and simple algorithm processing, real-time and efficient dynamic measurement can be achieved.

[0021] (3) By utilizing the high resolution and fast image processing capabilities of the RGB camera, the method of the present invention can achieve high-precision positioning measurement of the head of the pipe jacking machine, and can adjust the correction control of the pipe jacking machine in real time during the construction process, ensuring the accuracy and safety of the construction, and ensuring that the construction quality and efficiency of the pipe jacking pipeline meet the project target requirements.

[0022] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0024] Figure 1 It is a structural diagram of the measurement system of the present invention;

[0025] Figure 2 This is a schematic diagram of the relative position structure of the green reference point and the red laser spot of the light target in the present invention;

[0026] Figure 3 This is a flow chart of the present invention for obtaining pixel coordinates of light spots using an image analysis algorithm;

[0027] Among them, 1-laser emitting device; 2-light target; 3-RGB camera; 4-computer; A-pipe jacking machine head; a-red laser point; b-laser reference point. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in this field based on these embodiments are all within the scope of protection of the present invention.

[0029] The present invention provides a method for dynamic positioning measurement of a pipe jacking machine head based on RGB image information processing, which uses a measurement system to measure the pipe jacking machine head. Specifically:

[0030] like Figure 1 As shown, the measurement system includes a laser emitting device 1, a light target 2, an RGB camera 3, a signal processing unit, and a display and control system. Laser emitting device 1 is a red laser installed on the tunnel face opposite the pipe jacking machine's construction location. The red laser is configured to emit a precise laser beam and is arranged along the designed axis of the pipe jacking construction. Initially, the laser light emitted by the red laser is irradiated at the center of the light target, and the laser light changes dynamically with the actual position of the pipe jacking machine. The laser light emitted by the red laser irradiates the light target as red laser point a. The red laser point a is initially irradiated at the center of the light target. During the pipe jacking construction, the red laser point a changes dynamically with the actual position of the pipe jacking machine.

[0031] The red laser uses a red laser with a wavelength of 650nm and is fixed in the starting shaft of the pipe jacking machine. The laser emits precise red laser light and illuminates the initial center position of the light target along the construction design axis. The light target 2 is located at the front of the head A of the pipe jacking machine and corresponds to the red laser line. There are four green laser reference points b on the light target 2. The positions of these green laser reference points correspond to the four corners of the rectangle, forming a fixed reference coordinate system, such as Figure 2 As shown in the figure, the dynamic displacement coordinate value of the pipe jacking machine head is calculated based on the relative position of the red laser point a and the laser reference point b.

[0032] An RGB camera 3 is mounted above and behind the light target and connected to a ground-based computer 4 via a data cable. It captures the light target image in real time and transmits it to the signal processing unit for subsequent analysis and processing. The RGB camera captures the light target image at a rate of 30 frames per second. The signal processing unit receives the image information from the RGB camera, converts the image into a matrix, extracts the corresponding information of the red and green light channels, and uses an image analysis algorithm to accurately locate the offset of the red laser point relative to the four green reference points. Based on this information, the real-time position and change of the aircraft head are calculated.

[0033] like Figure 3 As shown, the signal processing unit in the computer runs on the algorithm module of the computer, receives the image and performs red and green light channel segmentation, target extraction, Kalman filter smoothing and geometric analysis, which specifically includes the following steps:

[0034] 1. After the RGB camera captures the target image, the signal processing unit converts the RGB image into the HSV color space and sets thresholds for the hue ranges of red and green light respectively. The red light range: H value is 0° to 15° and 170° to 180°; the green light range: H value is 35° to 85°.

[0035] 2. Use OpenCV's inRange function to generate the corresponding binary mask to separate the red laser point and the green reference point.

[0036] 3. Use the contour detection method findContours to extract the contours of the red laser point and the green reference point, and calculate their centroid coordinates (pixel coordinates).

[0037] 4. Perform Kalman filtering on the position of the light spot in each frame of the image to eliminate the random offset caused by stray light. The Kalman filter formula is:

[0038]

[0039] in, is an estimated value, K k is the Kalman gain, z kis the observed value, H k is the measurement matrix.

[0040] 5. Through actual calibration, the pixel coordinates of the laser reference point are mapped to the real space position; based on the relative position of the red laser point and the green laser reference point, the translation of the light target is calculated.

[0041] 6. Display the calculation results in real time on the operation interface.

[0042] In a specific embodiment, if the deviation exceeds the allowable range, the display and control system sends an adjustment signal to the machine head controller, and corrects the machine head posture through a correction operation to ensure that the pipe jacking machine advances along the designed axis.

[0043] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for dynamic positioning measurement of a pipe jacking machine head based on RGB image information processing, characterized in that: The invention comprises using a measuring system to measure a pipe jacking machine head (A), wherein the measuring system comprises a laser emitting device (1), a light target (2), an RGB camera (3), a signal processing unit and a display and control system, wherein the laser emitting device (1) is a red laser arranged on the tunnel face opposite to the construction position of the pipe jacking machine, the light target (2) is arranged at the front of the pipe jacking machine head (A), and a plurality of green laser reference points (b) are arranged on the light target (2), and the RGB camera (3) is arranged above and behind the light target (2) and is connected to the ground through a data line. The computer (4) is connected to the signal processing unit; the signal processing unit is connected to the RGB camera (2); the display and control system displays the processing results of the signal processing unit on the operator interface of the computer (4); the dynamic positioning measurement method includes the signal processing unit receiving image information from the RGB camera (2), converting the image into a matrix form, extracting corresponding information of the red light and green light channels, locating the offset of the red laser point relative to the multiple laser reference points (b) through an image analysis algorithm, and calculating the real-time position and change of the center of the machine head according to the offset.

2. The dynamic positioning measurement method according to claim 1, characterized in that: The specific steps for using image analysis algorithms to locate the offset of the red laser dot relative to the laser reference point are: Step S1, color segmentation and red laser point extraction: convert the RGB image into the HSV color space, and extract the red area in the image by setting the hue range of the red light; Step S2: Use the inRange function of OpenCV to extract the red part of the image and generate a binary mask of the red laser point; Step S3: using the contour detection method to locate the position of the red laser point and calculate its centroid coordinates; Step S4, target position extraction and geometric analysis: For the red laser point, extract its position coordinates in the image; for the green reference point, use the same image processing method to extract its position coordinates in the image, and perform position mapping based on the known actual position; based on the relative position of the red laser point and the green reference point, use a geometric algorithm to calculate the translation of the light target.

3. The positioning measurement method according to claim 2, characterized in that: The image analysis algorithm further includes using a Kalman filter algorithm to smooth the position of the red laser point; the Kalman filter formula is as follows: in, is an estimated value, K k is the Kalman gain, z k is the observed value, H k is the measurement matrix.

4. The positioning measurement method according to claim 2, characterized in that: The hue range of the red light is 0° to 15° and 170° to 180°.

5. The positioning measurement method according to claim 1, characterized in that: The red laser is configured such that its laser emission direction is arranged along the design axis of the pipe jacking construction, and initially the laser emitted by the red laser irradiates the center position of the light target (2) and changes dynamically with the actual position of the pipe jacking machine.

6. The positioning measurement method according to claim 5, characterized in that: The light target (2) is a rectangular structure arranged at the front of the head (A) of the pipe jacking machine and corresponds to the red laser line; a laser reference point (b) is arranged at each of the four corners of the light target (2); the four laser reference points (b) correspond to the four corners of the rectangle, forming a reference coordinate system.

7. The positioning measurement method according to claim 1, characterized in that: The display and control system displays the calculation results in real time and manually or automatically adjusts the deviation correction of the machine head according to the calculation results to ensure that the pipe jacking machine head (A) is accurately aligned along the design axis.

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