A pipe-belt machine fixed-point detection feedback system based on ultrasonic ranging

Abstract

The application provides a pipe belt machine fixed-point detection feedback system based on ultrasonic ranging, which comprises a plurality of ultrasonic ranging sensors and a processing device. The ultrasonic ranging sensors are installed on a mounting rack and connected to an edge computing terminal. The ultrasonic ranging sensors use the flight ranging principle to calculate the distance between the ultrasonic ranging sensors and the surface of the belt. The edge computing terminal is responsible for calculating the collected data, judging whether the belt has a fault and the fault type. The application can accurately measure the distance between the ultrasonic ranging sensors and the belt of the tubular belt conveyor without contact, can real-time feedback the fault type of the conveyor, including pipe twisting, reverse wrapping, pipe collapsing, pipe expanding, and can take timely countermeasures to avoid wasting time and causing more losses when discovering the fault and further judging the specific fault type. In addition, the application does not need a motor to drive the sensor to operate and manually set the initial position of the edge wrapping, and the detection capability is not limited by the twisting speed of the belt.

Description

Technical Field

[0001] This invention relates to the field of operation protection and detection technology for tubular belt conveyors in industries such as coal, power, and metallurgy, and specifically to a fixed-point detection feedback system for tubular belt conveyors based on ultrasonic ranging. Background Technology

[0002] Tubular belt conveyors, also known simply as tubular belt conveyors, are belt conveyors in which the conveyor belt, which serves as both the carrying and return branches, is coiled into a tubular shape. They are widely used in material transportation in industries such as metallurgy, power, and coal mining. However, during transport, they are prone to problems such as tube expansion, tube collapse, reverse wrapping, and tube twisting. Currently, there is a lack of timely, effective, highly accurate, and safe methods for detecting these faults. If abnormalities are not addressed promptly and repairs are not timely, significant losses can easily occur.

[0003] Existing fault detection technologies for tubular belt conveyors primarily use motor-driven ultrasonic ranging sensors to track the position of the belt overlap point through circular motion. The angle of misalignment and torsion at the overlap point is calculated using the motor's stepping displacement. However, this approach has limitations: it provides only a single fault type for tubular belt conveyors, identifying only misalignment and torsion faults. When the conveyor's edge torsion speed is too high or the motor is not activated to track the belt overlap point, the detection system loses its ability to track the overlap point and determine the fault. Furthermore, current fault type detection methods for tubular belt conveyors are not comprehensive, only detecting one or two fault types and failing to simultaneously and efficiently detect other fault types. Summary of the Invention

[0004] In view of one or more technical defects in the prior art, the present invention proposes the following technical solution.

[0005] A fixed-point detection feedback system for a tubular belt conveyor based on ultrasonic ranging includes multiple ultrasonic ranging sensors and a processing device: the ultrasonic ranging sensors are installed at equal intervals around the belt of the tubular belt conveyor in the circumferential direction, and the ultrasonic ranging sensors point to the center position of the belt of the tubular belt conveyor.

[0006] The ultrasonic ranging sensor acquires the ultrasonic ranging sequence during the actual operation of the tubular belt conveyor, and the processing device processes the ultrasonic ranging sequence and the pre-obtained theoretical ranging sequence to determine whether the tubular belt conveyor has a fault and the type of fault.

[0007] The ultrasonic ranging sequence is obtained by using the ultrasonic ranging sensor to obtain the actual distance between the ultrasonic ranging sensor and the belt surface of the tubular belt conveyor at a certain moment.

[0008] The theoretical ranging sequence is obtained by using the ultrasonic ranging sensor to measure the theoretical ranging sequence that corresponds to the ultrasonic ranging sequence during normal operation of the tubular belt conveyor.

[0009] Furthermore, the ultrasonic ranging sensor is installed as follows: a ring-shaped mounting platform is installed on the support of the tubular belt conveyor, such that the ring-shaped mounting platform is concentric with the hexagonal idler group of the tubular belt conveyor, the belt of the tubular belt conveyor passes through the center of the ring-shaped mounting platform, and the ultrasonic ranging sensor is pointed to the center of the belt of the tubular belt conveyor and installed evenly and equidistantly around the belt on the ring-shaped mounting platform.

[0010] The installation positions of the array of ultrasonic ranging sensors in the tubular belt conveyor and the installation positions between the ultrasonic ranging sensors are relatively fixed so that the spatial position of each ultrasonic ranging sensor is known. After measuring the ultrasonic ranging sequence, the ultrasonic ranging sensors superimpose the spatial positions to obtain the spatial position of the belt surface of the tubular belt conveyor, and perform positioning and tracking of the belt edge at any position when the belt torsional speed of the tubular belt conveyor is less than the speed of the ultrasonic ranging sensors.

[0011] Preferably, the edge computing terminal is installed at the bottom of the mounting frame, and there are 16 ultrasonic ranging sensors, which are installed on the mounting frame at an 18° interval between each pair of ultrasonic ranging sensors, arranged around both sides of the edge computing terminal.

[0012] Using ultrasonic ranging sensors in tubular belt conveyors can reduce the impact of light, dust, dirt, and high humidity on measurement results. Ultrasonic ranging sensors have high sensitivity, high penetration capability, and high resistance to the environment, and their measurement accuracy is higher compared to other measuring devices.

[0013] Furthermore, the processing device includes an edge computing terminal and an industrial control computer. The edge computing terminal is mounted on a ring-shaped mounting platform to calculate the ultrasonic ranging sequence and theoretical ranging sequence acquired by the ultrasonic ranging sensor, and to send fault information back to the background system of the industrial control computer.

[0014] The edge computing terminal can provide the nearest service, resulting in faster network service. The ultrasonic ranging sequence and theoretical ranging sequence are processed on the edge computing terminal, and the fault judgment result is sent to the industrial control computer backend. This can reduce network bandwidth, reduce network latency, and increase privacy protection.

[0015] Measuring the distance between the ultrasonic ranging sensor and the side belt of the tubular belt conveyor using the ultrasonic ranging sensor will not damage the target being measured, and it has the characteristics of fast response speed, wide measurement range and high measurement accuracy.

[0016] Furthermore, the fault types include pipe twisting fault, pipe collapse fault, pipe expansion fault, and reverse wrapping fault;

[0017] The tube twisting fault and tube collapse fault are determined by calculating the correlation coefficient between the ultrasonic ranging sequence and the theoretical ranging sequence and comparing it with a pre-obtained threshold to determine whether the fault has occurred.

[0018] The tube expansion fault is determined by calculating the number of items smaller than the minimum distance threshold between the tubular belt conveyor and the ultrasonic ranging sensor, and judging whether the number of items smaller than the minimum distance threshold is greater than the number of items smaller than the minimum distance threshold that the ultrasonic ranging sensor can tolerate when it is working normally.

[0019] The reverse fault is determined by subtracting the preceding term from the subsequent term in the ultrasonic ranging sequence to obtain the corresponding adjacent difference sequence, and the sign of the term with the largest absolute value in the adjacent difference sequence is used to determine whether the fault has occurred.

[0020] Furthermore, the fault type includes a torsion tube fault, the method for determining which is as follows:

[0021] The torsion correlation coefficient ρ1 between the theoretical ranging sequence and the ultrasonic ranging sequence corresponding to the tubular belt conveyor under normal operating conditions is calculated one by one, and it is determined whether the torsion correlation coefficient ρ1 is greater than the torsion correlation coefficient threshold k1. If all the torsion correlation coefficients ρ1 are less than the torsion correlation coefficient threshold k1, then the tubular belt conveyor has a torsion fault; otherwise, the tubular belt conveyor is in normal condition.

[0022] The formula for calculating the correlation coefficient ρ1 of the torsion tube is:

[0023]

[0024] Wherein, X is the ultrasonic ranging sequence, Y is the theoretical ranging sequence, Cov(X,Y) is the covariance of the ultrasonic ranging sequence X and the theoretical ranging sequence Y, D(X) is the variance of the ultrasonic ranging sequence X, and D(Y) is the variance of the theoretical ranging sequence Y.

[0025] Preferably, the threshold value of the torsion tube correlation coefficient k1 is 0.85.

[0026] Furthermore, the fault types include pipe collapse faults, and the method for determining them is as follows:

[0027] The correlation coefficient ρ2 between the theoretical ranging sequence and the ultrasonic ranging sequence corresponding to the pipe collapse fault is calculated one by one, and it is determined whether the correlation coefficient ρ2 is greater than the correlation coefficient threshold k2. If all the calculated correlation coefficients ρ2 are greater than the correlation coefficient threshold k2, then the tubular belt conveyor has experienced a pipe collapse fault; otherwise, the tubular belt conveyor is in normal condition.

[0028] The formula for calculating the correlation coefficient ρ2 is:

[0029]

[0030] Wherein, X is the ultrasonic ranging sequence, M is the collapse theoretical ranging sequence, Cov(X,M) is the covariance of the ultrasonic ranging sequence X and the collapse theoretical ranging sequence M, D(X) is the variance of the ultrasonic ranging sequence X, and D(M) is the variance of the collapse theoretical ranging sequence M.

[0031] Preferably, the threshold value of the pipe collapse correlation coefficient k2 is 0.85.

[0032] The correlation coefficients ρ1 and ρ2 of pipe twisting can better describe the relationship between theoretical ranging sequence variables and ultrasonic ranging sequence variables, as well as the strength and direction of this relationship. This enables inspection personnel to make better predictions and decisions, and to make timely judgments and take appropriate measures regarding the type of fault.

[0033] Furthermore, the fault type includes tube expansion fault, and the method for determining it is as follows:

[0034] Calculate the total number of times in the ultrasonic ranging sequence that the distance between the belt of the tubular belt conveyor and the ultrasonic ranging sensor is less than the minimum distance threshold k3 under normal operation, and determine whether the total number is greater than another threshold k4. If the total number is greater than the other threshold k4, the tubular belt conveyor has experienced a tube expansion fault; otherwise, the tubular belt conveyor is in normal condition.

[0035] Furthermore, the threshold k4 is the maximum number of ultrasonic ranging sequences smaller than the minimum distance threshold k3 that the belt of the tubular belt conveyor can tolerate during normal operation.

[0036] Preferably, the minimum distance threshold k3 is 185.

[0037] Preferably, the maximum number of ultrasonic ranging sequences less than the minimum distance threshold k3 that the belt of the tubular belt conveyor can tolerate during normal operation is 6.

[0038] Furthermore, the fault type includes reverse packet fault, and its determination method is as follows:

[0039] The ultrasonic ranging sequence is subtracted from each subsequent term to obtain the corresponding adjacent difference sequence. The sign of the term with the largest absolute value in the adjacent difference sequence is then determined to be consistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor. If the sign of the term with the largest absolute value is inconsistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor, the tubular belt conveyor has experienced a reverse wrapping fault. If the sign of the term with the largest absolute value is consistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor, the tubular belt conveyor is in a normal state.

[0040] Furthermore, the theoretical positive or negative sign of the normal wrapping direction of the tubular belt conveyor is determined by the fact that the left side wrapping the right side of the belt is positive, and the right side wrapping the left side is negative.

[0041] The present invention also proposes a readable computer storage medium storing computer program instructions thereon, characterized in that the computer program instructions, when executed by a processor, implement the system as described in any of the preceding claims.

[0042] The technical advantages of this invention are as follows: It uses an ultrasonic ranging sensor to perform real-time, non-contact detection of the tubular belt conveyor belt, exhibiting strong environmental resistance. Equipped with an edge computing terminal, it utilizes the ultrasonic ranging sensor combined with an edge computing module to determine the operating status of the tubular belt conveyor in real-time and with high precision. This includes methods for identifying different types of faults in the tubular belt conveyor, providing real-time feedback on various fault types when a fault occurs, promptly detecting specific fault types and issuing alarms. This allows inspection personnel to respond more quickly to specific fault types, avoiding unnecessary losses caused by the time wasted on further fault type analysis after detection. Furthermore, the fault tracking capability of this invention is unaffected by the edge twisting speed and does not require manual setting of the initial position to drive the motor, significantly improving both the speed of fault detection and the time required to respond to faults. Attached Figure Description

[0043] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0044] Figure 1 This is a front view of the installation of a pipe conveyor fixed-point detection feedback system based on ultrasonic ranging, according to an embodiment of the present invention.

[0045] Figure 2This is a side view of the installation of a pipe conveyor fixed-point detection feedback system based on ultrasonic ranging, according to an embodiment of the present invention.

[0046] Figure 3 This is a schematic diagram of the physical installation of a pipe conveyor fixed-point detection feedback system based on ultrasonic ranging, according to an embodiment of the present invention.

[0047] Figure 4 This is a schematic diagram of device fault types for a pipe conveyor fixed-point detection feedback system based on ultrasonic ranging, according to an embodiment of the present invention. Detailed Implementation

[0048] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] Figure 1 This is a front view of the installation of a pipe conveyor fixed-point detection feedback system based on ultrasonic ranging, according to an embodiment of the present invention. It includes multiple ultrasonic ranging sensors 1-1 and a processing device.

[0051] By mounting a ring-shaped mounting frame 1-2 on the support of the tubular belt conveyor 1-4, the ring-shaped mounting frame 1-2 is concentric with the hexagonal idler roller group 1-3 of the tubular belt conveyor 1-4. The belt of the tubular belt conveyor 1-4 passes through the center of the ring-shaped mounting frame 1-2. The ultrasonic ranging sensor 1-1 is installed evenly and equidistantly around the belt of the tubular belt conveyor 1-4 in the circumferential direction, and the ultrasonic ranging sensor 1-1 points to the center position of the belt of the tubular belt conveyor 1-4.

[0052] It should be noted that the processing device includes edge computing terminals 1-5 and industrial control computers, and the installation of industrial control computers 2-3 is as follows: Figure 2 As shown, the edge computing terminal 1-5 is installed on the mounting frame 1-2 to calculate the ultrasonic ranging sequence and theoretical ranging sequence acquired by the ultrasonic ranging sensor 1-1, and to send the fault information back to the industrial control computer 2-3 background system.

[0053] It should be noted that in the actual field environment, the industrial control computers 2-3 are installed as close as possible to the site environment.

[0054] In one specific embodiment, the industrial computer 2-3 is welded to the mounting frame 1-2 ( Figure 2 2-2) Side view of the device, the specific installation diagram of the side is as follows: Figure 2 As shown.

[0055] It should be noted that the ultrasonic ranging sensor 1-1 is mounted on the mounting frame 1-2. Figure 2 On 2-2), not with the tubular belt conveyor 1-4 ( Figure 2 The belt contact in 2-1) of the figure, the thin red column in the figure represents the measuring distance range of the ultrasonic ranging sensor 1-1, so as to adjust the mounting frame 1-2 ( Figure 2 The size of 2-2 in the middle.

[0056] It should be noted that the mounting frames 1-2 ( Figure 2 (2-2) Adjust the size according to the measurement distance range of the ultrasonic ranging sensor 1-1 by combining visual inspection and tape measure measurement.

[0057] In one specific embodiment, the edge computing terminal 1-5 performs calculations and judgments 30 times per second, and the industrial control computer 2-3 reads data at a frequency of no less than 20Hz to ensure measurement and calculation accuracy.

[0058] In one specific embodiment, the edge computing terminal 1-5 is mounted on the mounting bracket 1-2 ( Figure 2 At the bottom position of 2-2), 16 ultrasonic ranging sensors 1-1 are used on site to surround the tubular belt conveyor 1-4. Figure 2 The belt in 2-1) is mounted on the mounting stand 1-2. Figure 2 The components 2-2) are installed at equal intervals of 18° around the edge computing terminals 1-5 in the circumferential direction.

[0059] It should be noted that the industrial control computer 2-3 is based on the on-site tubular belt conveyor 1-4 ( Figure 2 Set the packing parameters according to the actual packing direction in section 2-1).

[0060] It should be noted that the edge computing terminal can provide the nearest end service, resulting in a faster network service effect. The data processing of the ultrasonic ranging sequence and the theoretical ranging sequence is performed on the edge computing terminal, and the result of the fault judgment is sent to the industrial control computer backend. This can reduce network bandwidth, reduce network latency, and increase privacy protection.

[0061] It should be noted that using ultrasonic ranging sensors in tubular belt conveyors can reduce the impact of light, dust, dirt, and high humidity on the measurement results. Ultrasonic ranging sensors have high sensitivity, high penetration capability, and high resistance to the environment, and their measurement accuracy is higher compared to other measuring devices.

[0062] Figure 3 This is a schematic diagram of the physical installation of a pipe conveyor fixed-point detection feedback system based on ultrasonic ranging, according to an embodiment of the present invention. It includes multiple ultrasonic ranging sensors 3-1 and a processing device.

[0063] The annular mounting frame 3-2 is mounted on the support of the tubular belt conveyor 3-4, such that the annular mounting frame 3-2 is concentric with the hexagonal idler roller group 3-3 of the tubular belt conveyor 3-4. The belt of the tubular belt conveyor 3-4 passes through the center of the annular mounting frame 3-2. The ultrasonic ranging sensor 3-1 is installed evenly and equidistantly around the belt of the tubular belt conveyor 3-4 in the circumferential direction, and the ultrasonic ranging sensor 3-1 points to the center position of the belt of the tubular belt conveyor 3-4.

[0064] It should be noted that the processing device includes an edge computing terminal 1-5 and an industrial control computer 2-3. The edge computing terminal 1-5 is installed on the ring-shaped mounting frame 3-2 to calculate the ultrasonic ranging sequence and theoretical ranging sequence acquired by the ultrasonic ranging sensor 3-1, and to send the fault information back to the background system of the industrial control computer 2-3.

[0065] It should be noted that in actual field environments, the industrial control computers 2-3 are installed nearby according to the field environment to adapt to the needs of different application scenarios, realize the safety guarantee of the tubular belt conveyor, and perform remote management and monitoring in the background to reduce the pressure of manual inspection.

[0066] In one specific embodiment, the industrial control computer 2-3 is welded to the side of the annular mounting frame 3-2, and the side mounting diagram of the device is shown in the figure below. Figure 2 As shown.

[0067] It should be noted that the ultrasonic ranging sensor 3-1 is installed on the ring-shaped mounting frame 3-2 and does not contact the belt of the tubular belt conveyor 3-4. The number of ultrasonic ranging sensors 3-1 installed can be determined according to the site conditions.

[0068] It should be noted that the ultrasonic ranging sensor 3-1 is installed at equal intervals pointing towards the center of the tubular belt conveyor 3-4, which can detect belt faults of the tubular belt conveyor 3-4 from all directions and multiple angles, making fault detection more timely.

[0069] It should be noted that the size of the ring-shaped mounting frame 3-2 is adjusted by a combination of visual inspection and tape measure measurement according to the measurement distance range of the ultrasonic ranging sensor 3-1.

[0070] It should be noted that using ultrasonic ranging sensors in tubular belt conveyors can reduce the impact of light, dust, dirt, and high humidity on the measurement results. Ultrasonic ranging sensors have high sensitivity, high penetration capability, and high resistance to the environment, and their measurement accuracy is higher compared to other measuring devices.

[0071] Figure 4 This is a schematic diagram of device fault types for a tubular belt conveyor fixed-point detection feedback system based on ultrasonic ranging, according to an embodiment of the present invention. The normal operating state of the tubular belt conveyor is shown in Figure 4-1. The fault types include belt twisting fault 4-2, belt collapse fault 4-3, belt expansion fault 4-4, and reverse wrapping fault 4-5. Specifically, belt twisting fault 4-2 refers to belt twisting during operation; belt collapse fault 4-3 refers to belt collapse during operation, resulting in a flattened and elliptical shape; belt expansion fault 4-4 refers to belt expansion during operation, meaning the belt diameter is larger than the normal operating diameter (small circles in the figure represent materials being transported); and reverse wrapping fault 4-5 refers to an incorrect belt wrapping direction during operation, i.e., opposite to the pre-set belt wrapping direction during normal operation.

[0072] It should be noted that the ultrasonic ranging sequence during the actual operation of the belt is obtained by the ultrasonic ranging sensor, and the ultrasonic ranging sequence is processed by the processing device to determine whether the tubular belt conveyor has a fault and the type of fault.

[0073] It should be noted that the ultrasonic ranging sequence is obtained by using the ultrasonic ranging sensor to obtain the actual distance between the ultrasonic ranging sensor and the belt surface of the tubular belt conveyor at a certain moment.

[0074] It should be noted that, during normal operation, the tubular belt conveyor uses the ultrasonic ranging sensor to measure the theoretical ranging sequence that corresponds to the ultrasonic ranging sequence.

[0075] It should be noted that during normal operation of the tubular belt conveyor, any of the ultrasonic ranging sensors can detect the belt wrap edge of the tubular belt conveyor.

[0076] It should be noted that the method for judging the aforementioned torsion tube fault 4-2 is as follows:

[0077] The torsion correlation coefficient ρ1 between the theoretical ranging sequence and the ultrasonic ranging sequence under normal operating conditions of the tubular belt conveyor is calculated one by one, and it is determined whether the torsion correlation coefficient ρ1 is greater than the torsion correlation coefficient threshold k1. If all the torsion correlation coefficients ρ1 are less than the torsion correlation coefficient threshold k1, the tubular belt conveyor has a torsion fault; otherwise, the tubular belt conveyor is in normal condition.

[0078] The formula for calculating the correlation coefficient ρ1 of the torsion tube is:

[0079]

[0080] Wherein, X is the ultrasonic ranging sequence, Y is the theoretical ranging sequence, Cov(X,Y) is the covariance of the ultrasonic ranging sequence X and the theoretical ranging sequence Y, D(X) is the variance of the ultrasonic ranging sequence X, and D(Y) is the variance of the theoretical ranging sequence Y.

[0081] It should be noted that the theoretical ranging sequence Y was obtained by the inventor through multiple experiments.

[0082] It should be noted that the correlation coefficient ρ1 is less than the threshold k1 of the torsion tube correlation coefficient. That is, the actual ultrasonic ranging result is not similar to the theoretical ranging result obtained when the belt edge of the tubular belt conveyor is within the detection range of any ultrasonic ranging sensor. In other words, the belt edge of the tubular belt conveyor is outside the detection range of the ultrasonic ranging sensor, and at this time, the tubular belt conveyor has experienced a torsion tube fault.

[0083] It should be noted that the threshold k1 of the torsion tube correlation coefficient was obtained in advance through multiple experiments.

[0084] In a specific exemplary embodiment, at a certain moment, all ultrasonic ranging sensors (16 in this example) obtain an ultrasonic ranging sequence X = [215, 175, 193, 201, 201, 199, 198, 204, 196, 200, 209, 210, 207, 206, 199, 196] using the method described above. An experimentally obtained theoretical ranging sequence Y = [220, 170, 190, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200, 200]. The pre-obtained threshold k1 for the torsion tube correlation coefficient is 0.85. According to the formula for calculating the torsion tube correlation coefficient ρ1:

[0085]

[0086] The calculated correlation coefficient ρ1 = 0.8749 is greater than the correlation coefficient threshold k1. Therefore, the belt edge of the tubular belt conveyor is within the detection range of the ultrasonic ranging sensor, and the tubular belt conveyor is in normal condition.

[0087] In a specific exemplary embodiment, at a certain moment, all ultrasonic ranging sensors (16 in this example) obtain an ultrasonic ranging sequence X = [201,199,198,204,215,175,193,201,204,206,209,201,202,197,194,198] according to the method described above. An experimentally obtained theoretical ranging sequence Y = [220,170,190,200,200,200,200,200,200,200,200,200,200,200,200,200,200,200,200,200]. The threshold k1 for the torsion tube correlation coefficient, obtained beforehand through experiments, is 0.85. According to the formula for calculating the torsion tube correlation coefficient ρ1:

[0088]

[0089] The calculated torsion correlation coefficient ρ1 = 0.0537 is less than the torsion correlation coefficient threshold k1. Therefore, the belt edge of the tubular belt conveyor is outside the detection range of the ultrasonic ranging sensor. Similarly, the calculated torsion correlation coefficients for all other torsion theoretical ranging sequences are all less than the torsion correlation coefficient threshold k1. Therefore, the belt edge of the tubular belt conveyor is outside the detection range of all ultrasonic ranging sensors, and the tubular belt conveyor has experienced a torsion failure.

[0090] It should be noted that the method for judging the pipe collapse fault 4-3 is as follows:

[0091] The correlation coefficient ρ2 between the theoretical ranging sequence and the ultrasonic ranging sequence corresponding to the pipe collapse fault is calculated one by one, and it is determined whether the correlation coefficient ρ2 is greater than the threshold k2. If all the calculated correlation coefficients ρ2 are greater than the threshold k2, then the tubular belt conveyor has experienced a pipe collapse fault; otherwise, the tubular belt conveyor is in normal condition.

[0092] The formula for calculating the correlation coefficient ρ2 of the collapsed pipe is:

[0093]

[0094] Wherein, X is the ultrasonic ranging sequence, M is the collapse theoretical ranging sequence, Cov(X,M) is the covariance of the ultrasonic ranging sequence X and the collapse theoretical ranging sequence M, D(X) is the variance of the ultrasonic ranging sequence X, and D(M) is the variance of the collapse theoretical ranging sequence M.

[0095] It should be noted that the collapse management theoretical ranging sequence M was obtained by the inventor through multiple experiments.

[0096] It should be noted that the threshold value of the pipe collapse correlation coefficient k2 was obtained in advance through multiple experiments.

[0097] In a specific exemplary embodiment, at a certain moment, all ultrasonic ranging sensors (16 in this example) obtain the actual ultrasonic ranging sequence according to the method described above.

[0098] X=[199,198,204,201,203,205,218,237,239,223,215,206,207,209,206,202],

[0099] The obtained collapse management theoretical ranging sequence

[0100] M=[200,200,200,200,200,210,220,240,240,220,210,200,200,200,200,200],

[0101] The threshold value of the pipe collapse correlation coefficient k2, obtained through prior experiments, is 0.85. Based on the calculation formula for the pipe collapse correlation coefficient ρ2:

[0102]

[0103] The calculated correlation coefficient ρ2 of the ultrasonic ranging sensor is 0.96, which is greater than the threshold k2 of the correlation coefficient of tube collapse. Therefore, the tubular belt conveyor has experienced a tube collapse failure.

[0104] It should be noted that the method for judging the tube expansion fault 4-4 is as follows:

[0105] Calculate the total number of times in the ultrasonic ranging sequence that the distance between the belt of the tubular belt conveyor and the ultrasonic ranging sensor is less than the minimum distance threshold k3 during normal operation, and determine whether the total number is greater than another threshold k4. If the total number is greater than the other threshold k4, then the tubular belt conveyor has experienced a tube expansion fault; otherwise, the tubular belt conveyor is in normal condition.

[0106] It should be noted that the threshold k4 is the maximum number of ultrasonic ranging sequences smaller than the minimum distance threshold k3 that the belt of the tubular belt conveyor can tolerate during normal operation.

[0107] It should be noted that the minimum distance threshold k3 was obtained in advance through multiple experiments.

[0108] It should be noted that the threshold k4 for the number of ranging measurements that can be tolerated beyond the range is the result obtained in advance through multiple experiments.

[0109] In a specific exemplary embodiment, the minimum distance threshold k3 = 185 is obtained in advance through experiments. The maximum number of ultrasonic ranging sequences smaller than the minimum distance threshold k3 that the tubular belt conveyor can tolerate during normal operation is threshold k4, which is 6. At a certain moment, all ultrasonic ranging sensors (16 in this example) obtain the actual ultrasonic ranging sequence [183, 176, 190, 201, 166, 177, 188, 196, 187, 182, 195, 193, 187, 184, 182, 187] according to the above method. Among them, the number of sequences smaller than the minimum distance threshold k3 is 7, and the number of sequences larger than the threshold k4 is 7. Therefore, the tubular belt conveyor has experienced a tube expansion failure.

[0110] It should be noted that the method for determining the reverse packet faults 4-5 is as follows:

[0111] The ultrasonic ranging sequence is subtracted from each subsequent term to obtain the corresponding adjacent difference sequence. The sign of the term with the largest absolute value in the adjacent difference sequence is then determined to be consistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor. If the sign of the term with the largest absolute value is inconsistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor, then the tubular belt conveyor has experienced a reverse wrapping fault. If the sign of the term with the largest absolute value is consistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor, then the tubular belt conveyor is in a normal state.

[0112] It should be noted that the theoretical positive and negative values ​​of the normal belt wrapping direction are determined based on the fact that the left side of the belt wrapping direction of the tubular belt conveyor wrapping the right side is positive, and the right side of the belt wrapping direction of the tubular belt conveyor wrapping the left side is negative.

[0113] In one specific embodiment, the normal wrapping direction of the tubular belt conveyor belt is set to left wrapping right. Using the obtained ultrasonic ranging sequence [201,199,198,204,215,175,193,201,204,206,209,201,202,197,194,198], the adjacent difference sequence Ser = [-2,-1,6,11,-40,18,8,3,2,3,-8,1,-5,-3,4] is obtained by subtracting the preceding term from the following term. The term with the largest absolute value, -40, is then found from the adjacent difference sequence Ser. The sign of the term with the largest absolute value, -40, is negative. The wrapping direction of the tubular belt conveyor belt is then right wrapping left, which is opposite to the set normal wrapping direction. Therefore, the tubular belt conveyor experiences a reverse wrapping fault.

[0114] It should be noted that the thresholds k1, k2, k3, and k4 mentioned above are obtained in advance by collecting normal ranging sequences of the belt edge of the tubular belt conveyor under the coverage of various ultrasonic ranging sensors over a period of time as theoretical ranging sequences, and are calculated based on the actual size of the tubular belt conveyor on site, the belt diameter and operating conditions of the tubular belt conveyor, and the actual design size and installation position of the ultrasonic ranging sensor bracket.

[0115] It should be noted that the threshold value k1 of the torsion tube correlation coefficient is set according to the stability of the operation of the tubular belt conveyor at the project site. If the operation of the tubular belt conveyor at the site is relatively stable, the value of the threshold value k1 of the torsion tube correlation coefficient is set closer to 1. If the operation of the tubular belt conveyor is relatively unstable and the size changes significantly, the threshold value is appropriately lowered to reduce misjudgment.

[0116] It should be noted that the thresholds k2, k3, and k4 were obtained by collecting the average distance values ​​of normal points of each ultrasonic ranging sensor and combining them with the project user's judgment criteria for pipe collapse and pipe expansion.

[0117] It should be noted that when calculating the threshold, attention should be paid to balancing the sensitivity of the alarm when the tubular belt conveyor malfunctions with the accuracy of the data acquired by the ultrasonic ranging sensor.

[0118] Finally, it should be noted that the above embodiments are for illustration only and not for limiting the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.

[0119] The specific embodiments of this application have been described above, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0120] In the description of this application, it should be understood that the terms "upper," "lower," "inner," "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and for simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The simple fact that certain measures are recited in mutually different dependent claims does not indicate that combinations of these measures cannot be used for improvement. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A fixed-point detection feedback system for a tubular belt conveyor based on ultrasonic ranging, comprising multiple ultrasonic ranging sensors and a processing device: the ultrasonic ranging sensors are uniformly and equidistantly installed around the belt of the tubular belt conveyor in the circumferential direction, and the ultrasonic ranging sensors point to the center position of the belt of the tubular belt conveyor. The ultrasonic ranging sensor acquires the ultrasonic ranging sequence during the actual operation of the tubular belt conveyor, and the processing device processes the ultrasonic ranging sequence and the pre-obtained theoretical ranging sequence to determine whether the tubular belt conveyor has a fault and the type of fault. The fault types include pipe twisting fault, pipe collapse fault, pipe expansion fault, and reverse wrapping fault; The tube twisting fault and tube collapse fault are determined by calculating the correlation coefficient between the ultrasonic ranging sequence and the theoretical ranging sequence and comparing it with a pre-obtained threshold to determine whether the fault has occurred. The tube expansion fault is determined by calculating the number of items smaller than the minimum distance threshold between the tubular belt conveyor and the ultrasonic ranging sensor, and then judging whether the number of items smaller than the minimum distance threshold between the tubular belt conveyor and the ultrasonic ranging sensor is greater than the threshold number of items smaller than the minimum distance threshold between the tubular belt conveyor and the ultrasonic ranging sensor that the ultrasonic ranging sensor can tolerate when it is working normally. The reverse fault is determined by subtracting the preceding term from the subsequent term in the ultrasonic ranging sequence to obtain the corresponding adjacent difference sequence, and the sign of the term with the largest absolute value in the adjacent difference sequence is used to determine whether the fault has occurred. The method for determining tube expansion failure is as follows: Calculate the total number of times in the ultrasonic ranging sequence that the distance between the belt of the tubular belt conveyor and the ultrasonic ranging sensor is less than the minimum distance threshold k3 when the machine is operating normally, and determine whether the total number is greater than another threshold k4. If the total number is greater than the other threshold k4, the tubular belt conveyor has experienced a tube expansion failure; otherwise, the tubular belt conveyor is in normal condition. The threshold k4 is the maximum number of ultrasonic ranging sequences that the tubular belt conveyor belt can tolerate during normal operation, which is less than the minimum distance threshold k3 between the tubular belt conveyor and the ultrasonic ranging sensor. The ultrasonic ranging sequence is obtained by using the ultrasonic ranging sensor to obtain the actual distance between the ultrasonic ranging sensor and the belt surface of the tubular belt conveyor at a certain moment. The theoretical ranging sequence is obtained by using the ultrasonic ranging sensor to measure the theoretical ranging sequence that corresponds to the ultrasonic ranging sequence during normal operation of the tubular belt conveyor.

2. The system according to claim 1, characterized in that, The ultrasonic ranging sensor is installed as follows: a ring-shaped mounting frame is installed on the support of the tubular belt conveyor, such that the ring-shaped mounting frame is concentric with the hexagonal idler group of the tubular belt conveyor, the belt of the tubular belt conveyor passes through the center of the ring-shaped mounting frame, and the ultrasonic ranging sensor is pointed to the center of the belt of the tubular belt conveyor and installed evenly and equidistantly around the belt on the ring-shaped mounting frame. The installation positions of the array of ultrasonic ranging sensors in the tubular belt conveyor and the installation positions between the ultrasonic ranging sensors are relatively fixed so that the spatial position of each ultrasonic ranging sensor is known. After measuring the ultrasonic ranging sequence, the ultrasonic ranging sensors superimpose the spatial positions to obtain the spatial position of the belt surface of the tubular belt conveyor, and perform positioning and tracking of the belt edge at any position when the belt torsional speed of the tubular belt conveyor is less than the speed of the ultrasonic ranging sensors.

3. The system according to claim 1, characterized in that, The processing device includes an edge computing terminal and an industrial control computer. The edge computing terminal is installed on a ring-shaped mounting frame to calculate the ultrasonic ranging sequence and theoretical ranging sequence acquired by the ultrasonic ranging sensor, and to send fault information back to the background system of the industrial control computer.

4. The system according to claim 1, characterized in that, The method for determining the torsion tube fault is as follows: The torsional tube correlation coefficients of the theoretical ranging sequence and the ultrasonic ranging sequence corresponding to the normal operation of the tubular belt conveyor are calculated one by one, and it is determined whether the torsional tube correlation coefficient is greater than the torsional tube correlation coefficient threshold k1. If all the torsional tube correlation coefficients are less than the torsional tube correlation coefficient threshold k1, then the tubular belt conveyor has a torsional tube fault; otherwise, the tubular belt conveyor is in normal condition. The formula for calculating the correlation coefficient of the torsion tube is: ， Wherein, X is the ultrasonic ranging sequence, Y is the theoretical ranging sequence, Cov(X,Y) is the covariance of the ultrasonic ranging sequence X and the theoretical ranging sequence Y, D(X) is the variance of the ultrasonic ranging sequence X, and D(Y) is the variance of the theoretical ranging sequence Y.

5. The system according to claim 1, characterized in that, The method for determining the pipe collapse fault is as follows: The correlation coefficient between the theoretical ranging sequence and the ultrasonic ranging sequence corresponding to the pipe collapse fault is calculated one by one, and it is determined whether the correlation coefficient is greater than the threshold k2. If all the calculated correlation coefficients are greater than the threshold k2, then the tubular belt conveyor has experienced a pipe collapse fault; otherwise, the tubular belt conveyor is in normal condition. The formula for calculating the correlation coefficient of the collapsed pipe is: ， Wherein, X is the ultrasonic ranging sequence, M is the collapse theoretical ranging sequence, Cov(X,M) is the covariance of the ultrasonic ranging sequence X and the collapse theoretical ranging sequence M, D(X) is the variance of the ultrasonic ranging sequence X, and D(M) is the variance of the collapse theoretical ranging sequence M.

6. The system according to claim 1, characterized in that, The method for determining the reverse packet fault is as follows: The ultrasonic ranging sequence is subtracted from each subsequent term to obtain the corresponding adjacent difference sequence. The sign of the term with the largest absolute value in the adjacent difference sequence is then determined to be consistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor. If the sign of the term with the largest absolute value is inconsistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor, the tubular belt conveyor has experienced a reverse wrapping fault. If the sign of the term with the largest absolute value is consistent with the theoretical sign of the normal belt wrapping direction of the tubular belt conveyor, the tubular belt conveyor is in a normal state.

7. The system according to claim 3, characterized in that, The edge computing terminal is installed at the bottom of the mounting frame. There are 16 ultrasonic ranging sensors, which are installed on the mounting frame at an 18° interval between each pair of ultrasonic ranging sensors, and arranged around both sides of the edge computing terminal.

8. The system according to claim 4, characterized in that, The threshold value of the correlation coefficient k1 of the torsion tube is 0.

85.

9. The system according to claim 5, characterized in that, The threshold value of the correlation coefficient k2 for the collapsed pipe is 0.

85.

10. The system according to claim 1, characterized in that, The minimum distance threshold k3 between the tubular belt conveyor and the ultrasonic ranging sensor is 185 mm. The maximum number of ultrasonic ranging sequences that the tubular belt conveyor can tolerate during normal operation, which is less than the minimum distance threshold k3 between the tubular belt conveyor and the ultrasonic ranging sensor, is threshold k4, which is 6.

11. The system according to claim 6, characterized in that, Theoretically, the positive or negative sign of the normal belt wrapping direction of the tubular belt conveyor is determined by the following: the left side wrapping the right side of the belt wrapping direction is positive, and the right side wrapping the left side is negative.

12. A readable computer storage medium storing computer program instructions thereon, characterized in that, The computer program instructions, when executed by a processor, implement the system as described in any one of claims 1-11.

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