Conveyor belt stream deviation material detection and deviation correction automation system

Abstract

The present application relates to a kind of conveyor material flow deviation detection and rectification automation system, comprising: laser line transmitter, for emitting laser line on material flow and conveyor, form material flow and the laser line of conveyor upper surface profile;Camera device, for real-time shooting laser line image;Control unit, for extracting material flow and conveyor profile data from laser line image, then extract material flow endpoint and barycenter and carry out material flow deviation detection;Also for when material flow occurs deviation, control corresponding motor of electric push rod work;Two by motor-driven electric push rod, electric push rod drive end is connected with corresponding baffle, to drive baffle movement;And two baffles, respectively set in the left and right sides of the lower end of drop port, to swing left and right under the drive of corresponding electric push rod, then adjust the drop position of material on conveyor, realize material flow deviation rectification.The system is highly automated, can automatically, efficiently and accurately detect material flow deviation and rectification.

Description

Technical Field

[0001] This invention relates to the field of material transportation technology, specifically to an automated system for detecting and correcting material deviation in conveyor belt flow. Background Technology

[0002] Conveyor belt material handling plays a vital role in industrial production, and is widely used in ports, mines, and power plants. During conveyor belt operations, belt misalignment is a common problem, potentially leading to belt tearing and material spillage. A significant contributing factor to this misalignment is that the material does not land in the exact center of the belt, resulting in uneven material distribution and ultimately belt deviation. Therefore, ensuring that material lands in the exact center of the belt is crucial for safe conveyor operation. However, in practice, this is very difficult. Due to variations in material flow rate, different flow rates will result in different material landing positions on the belt. Therefore, some conveyor belts use baffles at the material landing points, adjusting the baffles to regulate the landing point.

[0003] Existing methods of adjusting baffles primarily rely on manual adjustment, such as manually controlling a motor push rod to adjust the baffle position. This system has limitations in correcting material position; it cannot adjust the material flow position in real time and is restricted by the current material flow rate, making it unsuitable for all-time operation. Summary of the Invention

[0004] The purpose of this invention is to provide an automated system for detecting and correcting material deviation in conveyor belts. This system has a high degree of automation and can automatically, efficiently, and accurately detect and correct material deviation in the outflow.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: an automated system for detecting and correcting material deviation in conveyor belts, comprising:

[0006] A laser line emitter is installed above the conveyor belt downstream of the material inlet. It is used to emit laser lines and irradiate the material flow and the conveyor belt to form laser lines that conform to the material flow and the upper surface of the conveyor belt.

[0007] A camera device is installed above the conveyor belt downstream of the laser line emitter to capture real-time images of the laser line, including the material flow and the contour of the laser line on the upper surface of the conveyor belt.

[0008] The control unit is used to extract material flow and conveyor belt contour data from the laser line image, and then extract the material flow endpoints and center of gravity and perform material flow deviation detection; it is also used to control the motor of the corresponding electric push rod to work when material flow deviation occurs.

[0009] Two electrically driven push rods are respectively disposed on the outer sides of two baffles. The driving ends of the electric push rods are connected to the corresponding baffles to drive the baffles to move; and

[0010] Two baffles are respectively set on the left and right sides of the lower end of the material discharge port, so that they can swing left and right under the drive of the corresponding electric push rod, thereby adjusting the material discharge position on the conveyor belt and realizing material flow deviation correction.

[0011] Furthermore, a filter is provided at the front end of the camera device. The filter only allows the laser line frequency spectrum to pass through, filtering out other useless interference spectra, thereby obtaining a stable laser line image.

[0012] Furthermore, the specific method by which the control unit extracts material flow contour data from the laser line image is as follows:

[0013] Select the region of interest from the laser line image, and then extract the laser line region from the region of interest through image thresholding. Then, use the gray-scale centroid method to calculate the center point of each longitudinal section in the laser line region. Connect the center points of all longitudinal sections to obtain a contour laser line with only one pixel in each longitudinal section.

[0014] Furthermore, the specific method for the control unit to extract the material flow endpoint and center of gravity and perform material flow deviation detection is as follows:

[0015] Based on the obtained contour laser line, the centroid and coordinates of the two endpoints of the material flow are further extracted to establish a mathematical model of the material flow position;

[0016] Extract the material flow portion from the contour laser line based on the characteristics of the material flow protrusion: find the two peaks with the largest downward protrusion in the contour laser line, which are the left and right endpoints of the material flow, denoted as p. l p r The material flow section consists of the left and right endpoints p of the material flow. l p r The portion contained within; the centroid of the material flow is extracted using the first moment of the image, and the image spatial moment is defined as:

[0017] m ji =Σ x,y array(x,y)·x j ·y i (1)

[0018] Where, m ji Let (i,j) represent the (i+j)th order spatial moment of the image, (x,y) represent the coordinates of a point on the material flow, j represent the order of x, i represent the order of y, and Σ represent the spatial moments. x,y This represents the cumulative weighted pixel values ​​for all x and y values ​​within the image range; array(x,y) represents the image grayscale values; the centroid of the material flow p c =(xc y c ) Through moment calculation, Where m 10 ,m 01 Let m be the first moment of the image. 10 The first moment in the x-direction of the image region, i.e., the average position along the x-axis, is represented by m. 01 The first moment in the y-direction of the image region, i.e., the average position along the y-axis; m 00 The moment at the origin of the image is the sum of the pixel values;

[0019] If the x-coordinate of the center of gravity of the material flow is relative to the defined center point of the conveyor belt The deviation exceeds the set threshold t c If so, it is determined that the material flow is off-center, that is:

[0020]

[0021] If material flow deviation is detected, material flow deviation correction is required.

[0022] Furthermore, when a material deviation is detected, material deviation correction is performed; the control unit adjusts the position of the baffle by controlling the electric push rod, thereby adjusting the material drop position on the conveyor belt;

[0023] Considering the positions of the left and right endpoints of the material flow, and also taking into account the influence of the baffles on the material flow, the material flow deviation model is represented as the deviation between the x-coordinates of the left and right endpoints and the x-coordinates of the ideal position. The ideal position is defined as the x-coordinate position of the left and right endpoints of the material flow when the center of gravity of the material flow is moved to the defined center point of the conveyor belt. The calculation is as follows:

[0024]

[0025] Where, x l ,x r The x-coordinates of the left and right endpoints of the material flow; Let x be the x-coordinate of the left and right ideal positions; define the deviation as the left endpoint position of the material flow minus the left ideal position and the right endpoint position of the material flow minus the right ideal position:

[0026]

[0027] Where t is the time variable, i.e., e l (t), e r (t) represents the left and right deviations at time t, respectively.

[0028] Furthermore, the control unit is equipped with two PID controllers, which are used to control the motors on the left and right sides respectively. These motors control the electric push rods on the left and right sides, driving the corresponding baffles to extend or retract, so that the left and right ends of the material flow reach the ideal positions; the control signal u of the left motor...l (t) and the control signal u of the right motor r (t) is calculated using the following formula:

[0029]

[0030] Among them, e l (t),e r (t) represents the difference between the left and right endpoint positions of the material flow and the ideal left and right positions, respectively; K pl ,K il ,K dl It is the PID gain on the left, K pr ,K ir ,K dr This is the PID gain on the right; K cr ,K cl It is an intersecting term, representing the influence of the left electric actuator on the right end point and the influence of the right electric actuator on the left end point;

[0031] Motor control includes forward rotation, reverse rotation, and stop. Therefore, continuous motor control signals are converted into stepped signals (-1, 0, +1) to control the motor. l (t) and u r (t) is mapped to the discrete input signal of the motor, and the mapping is performed by setting a threshold:

[0032]

[0033]

[0034] Where T is the threshold of the mapping;

[0035] Based on the mapped motor input signal, the left and right motors are controlled to move the corresponding electric push rods to correct the material drop position. During system operation, the material position is monitored in real time, and the input of the left and right motors is adjusted by two PID controllers to keep the distance between the left and right ends of the material flow constant and keep the center of gravity of the material flow at the center of the conveyor belt.

[0036] Compared with existing technologies, this invention has the following advantages: This invention provides an automated system for detecting and correcting material deviation in conveyor belts. This system acquires material flow and conveyor belt contour data through laser line projection and image acquisition technology, then extracts the material flow endpoints and center of gravity to detect material deviation. When the material flow center is detected to be outside the center of the conveyor belt, it is determined that material deviation has occurred. Then, based on the degree of deviation as a feedback signal, a motor drives an electric push rod to adjust the position of the material discharge port baffle, thereby adjusting the material's discharge position on the conveyor belt and achieving the material deviation correction effect. This invention achieves full automation of the entire material deviation detection and correction process. The detection and correction process is efficient and accurate, possessing strong practicality and broad application prospects. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the automatic conveyor belt material flow deviation detection and correction system according to an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the contour laser line in an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of extracting the centroid and endpoint of the material flow from the contour laser line in an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram illustrating the principle of material flow deviation correction in an embodiment of the present invention. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0043] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] like Figure 1 As shown, this embodiment provides an automated system for detecting and correcting material deviation in conveyor belts, including: a laser line emitter, a camera device, a control unit, two motor-driven electric push rods, and two baffles.

[0045] The laser line emitter is positioned above the conveyor belt downstream of the material inlet and is used to emit laser lines and irradiate the material flow and the conveyor belt, forming laser lines that conform to the material flow and the upper surface contour of the conveyor belt as the material flow changes.

[0046] The camera device is positioned above the conveyor belt downstream of the laser line emitter to capture real-time images of the laser line, including the material flow and the contour of the laser line on the upper surface of the conveyor belt. To address the interference problem of structured light (laser line) under strong light, in this embodiment, a filter is installed at the front end of the camera device, allowing only the frequency spectrum of the structured light (laser line) to pass through while filtering out other useless interference spectra, thereby obtaining a stable laser line image.

[0047] The control unit is used to extract material flow and conveyor belt contour data from the laser line image, and then extract the material flow endpoints and center of gravity and perform material flow deviation detection; it is also used to control the motor of the corresponding electric push rod to work when material flow deviation occurs.

[0048] The two electric push rods driven by the motor are respectively set on the outside of the two baffles. The driving end of the electric push rod is connected to the corresponding baffle to drive the baffle to move.

[0049] The two baffles are respectively set on the left and right sides of the lower end of the material discharge port, so that they can swing left and right under the drive of the corresponding electric push rod, thereby adjusting the material discharge position on the conveyor belt and realizing material flow deviation correction.

[0050] In this embodiment, the specific method by which the control unit extracts material flow contour data from the laser line image, and then extracts the material flow endpoints and center of gravity to perform material flow deviation detection is as follows:

[0051] After receiving the laser line image, the control unit selects the region of interest (ROI) from the image and then extracts the laser line region from the ROI using image thresholding. Next, it calculates the center point of each longitudinal section within the laser line region using the grayscale centroid method. Connecting the center points of all longitudinal sections yields a contour laser line where each longitudinal section contains only one pixel. Figure 2 As shown.

[0052] Based on the obtained contour laser line, the centroid and coordinates of the two endpoints of the material flow are further extracted to establish a mathematical model of the material flow position, such as... Figure 3 As shown.

[0053] Extract the material flow portion from the contour laser line based on the characteristics of the material flow protrusion: find the two peaks with the largest downward protrusion in the contour laser line, which are the left and right endpoints of the material flow, denoted as p. l p r The left and right endpoints are as follows Figure 3 The blue dot indicates the material flow section, which consists of the left and right endpoints p. l pr The portion contained within. The center of gravity of the material flow, such as... Figure 3 The green dot is shown in the image. The centroid of the material flow is extracted using the first moment of the image. The image spatial moment is defined as:

[0054] m ji =∑ x,y array(x,y)·x j ·y i (1)

[0055] Where, m ji Let (i,j) represent the (i+j)th order spatial moment of the image, (x,y) represent the coordinates of a point on the material flow, j represent the order of x, and i represent the order of y. ∑ x,y This represents the cumulative weighted pixel values ​​for all x and y values ​​within the image range; array(x,y) represents the image grayscale values; the centroid of the material flow p c =(x c y c ) Through moment calculation, Where m 10 ,m 01 Let m be the first moment of the image. 10 The first moment in the x-direction of the image region, i.e., the average position along the x-axis, is represented by m. 01 The first moment in the y-direction of the image region, i.e., the average position along the y-axis; m 00 The moment at the origin of the image is the sum of the pixel values.

[0056] If the x-coordinate of the center of gravity of the material flow is relative to the defined center point of the conveyor belt The deviation exceeds the set threshold t c If so, it is determined that the material flow is off-center, that is:

[0057]

[0058] If material flow deviation is detected, material flow deviation correction is required.

[0059] When a material flow deviation is detected, material flow correction is performed. The control unit adjusts the position of the baffle by controlling the electric push rod, thereby adjusting the material's drop position on the conveyor belt. The principle behind this is as follows: Figure 4 As shown.

[0060] Considering the positions of the left and right endpoints of the material flow, and also taking into account the influence of the baffles on the material flow, the material flow deviation model is represented as the deviation between the x-coordinates of the left and right endpoints and the x-coordinates of the ideal position. The ideal position is defined as the x-coordinate position of the left and right endpoints of the material flow when the center of gravity of the material flow is moved to the defined center point of the conveyor belt. The calculation is as follows:

[0061]

[0062] Where, x l ,x r The x-coordinates of the left and right endpoints of the material flow; Let x be the x-coordinate of the left and right ideal positions. Define the deviation as the left endpoint position of the material flow minus the left ideal position and the right endpoint position of the material flow minus the right ideal position:

[0063]

[0064] Where t is the time variable, i.e., e l (t), e r (t) represents the left and right deviations at time t, respectively.

[0065] In this embodiment, the control unit is equipped with two PID controllers, which control the motors on the left and right sides respectively. These motors control the electric push rods on the left and right sides, driving the corresponding baffles to extend or retract, so that the left and right ends of the material flow reach the ideal positions. The control signal u for the left motor... l (t) and the control signal u of the right motor r (t) is calculated using the following formula:

[0066]

[0067] Among them, u l (t), u r (t) represents the control input for the left and right motors, e l (t),e r (t) represents the difference between the left and right endpoint positions of the material flow and the ideal left and right positions, respectively; K pl ,K il ,K dl It is the PID gain on the left, K pr ,K ir ,K dr This is the PID gain on the right; K cr ,K cl It is an intersecting term, representing the influence of the left electric actuator on the right endpoint and the influence of the right electric actuator on the left endpoint.

[0068] Motor control includes forward rotation, reverse rotation, and stop. Therefore, continuous motor control signals are converted into stepped signals -1, 0, +1 to control the motor. l (t) and u r (t) is mapped to the discrete input signal of the motor, and the mapping is performed by setting a threshold:

[0069]

[0070]

[0071] Where T is the threshold for mapping.

[0072] Based on the mapped motor input signal, the left and right motors are controlled to move the corresponding electric push rods to correct the material drop position. During system operation, the material position is monitored in real time, and the input of the left and right motors is adjusted by two PID controllers to keep the distance between the left and right ends of the material flow constant and keep the center of gravity of the material flow at the center of the conveyor belt.

[0073] In operation, this system first emits a laser line (controllable by the control unit) and illuminates the material flow and conveyor belt, creating a laser line that reflects the changing contours of the material flow and conveyor belt surfaces. Simultaneously, the control unit controls a camera to capture real-time images of the laser line, including the contours of the material flow and conveyor belt surfaces. The camera transmits these images to the control unit, which extracts the contour data of the material flow and conveyor belt from the images, further identifying the material flow endpoints and center of gravity for material deviation detection. When the control unit determines that material flow deviation has occurred, it calculates the deviation data and uses this as a feedback signal to control the motors via two PID controllers. The motors control the corresponding electric push rods, driving the corresponding baffles to extend or retract. Throughout this process, the system continuously performs image acquisition, data extraction, material flow deviation detection, and PID control, ensuring that the left and right endpoints of the material flow continuously approach the ideal position, ultimately achieving the goal of correcting material flow deviation.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An automated system for detecting and correcting material deviation in conveyor belts, characterized in that, include: A laser line emitter is installed above the conveyor belt downstream of the material inlet. It is used to emit laser lines and irradiate the material flow and the conveyor belt to form laser lines that conform to the material flow and the upper surface of the conveyor belt. A camera device is installed above the conveyor belt downstream of the laser line emitter to capture real-time images of the laser line, including the material flow and the contour of the laser line on the upper surface of the conveyor belt. The control unit is used to extract material flow and conveyor belt contour data from the laser line image, and then extract the material flow endpoints and center of gravity and perform material flow deviation detection; it is also used to control the motor of the corresponding electric push rod to work when material flow deviation occurs. Two electric push rods driven by motors are respectively set on the outside of two baffles. The driving end of the electric push rod is connected to the corresponding baffle to drive the baffle to move. as well as Two baffles are respectively set on the left and right sides of the lower end of the material discharge port, so that they can swing left and right under the drive of the corresponding electric push rod, thereby adjusting the material discharge position on the conveyor belt and realizing material flow deviation correction. The specific method by which the control unit extracts material flow contour data from the laser line image is as follows: Select the region of interest from the laser line image, and then extract the laser line region from the region of interest through image thresholding; then calculate the center point of each longitudinal section in the laser line region using the gray-scale centroid method, and connect the center points of all longitudinal sections to obtain a contour laser line with only one pixel in each longitudinal section; The specific method for the control unit to extract the material flow endpoint and center of gravity and perform material flow deviation detection is as follows: Based on the obtained contour laser line, the centroid and coordinates of the two endpoints of the material flow are further extracted to establish a mathematical model of the material flow position; Extract the material flow portion from the contour laser line based on the characteristics of the material flow protrusion: Identify the two peaks with the largest downward protrusion in the contour laser line as the left and right endpoints of the material flow, denoted as... , The material flow section consists of the left and right ends of the material flow. , The portion contained within; the centroid of the material flow is extracted using the first moment of the image, and the image spatial moment is defined as: （1） in, Represents the (i+j)th order spatial moment of the image. Represents the coordinates of a point on the material flow. express The order of express The order of This represents the cumulative weighted pixel values ​​for all x and y values ​​within the image range. Represents image grayscale value; material flow center of gravity Through moment calculation , ,in For the first moment of the image, The first moment in the x-direction of the image region, i.e., the average position along the x-axis. The first moment in the y-direction of the image region, i.e., the average position along the y-axis; The moment at the origin of the image is the sum of the pixel values; If the x-coordinate of the center of gravity of the material flow is relative to the defined center point of the conveyor belt The deviation exceeds the set threshold If so, it is determined that the material flow is off-center, that is: （2） If material flow deviation is detected, material flow deviation correction is required; The control unit is equipped with two PID controllers, one for controlling the left motor and the other for controlling the right motor. These motors control the electric push rods on the left and right sides, driving the corresponding baffles to extend or retract, ensuring the left and right ends of the material flow reach the desired positions. The control signal for the left motor... and the control signal of the right motor Calculated using the following formula: （5） in, These are the differences between the left and right endpoint positions of the material flow and the ideal left and right positions; It's the PID gain on the left. It is the PID gain on the right; It is an intersecting term, representing the influence of the left electric actuator on the right end point and the influence of the right electric actuator on the left end point; Motor control includes forward rotation, reverse rotation, and stop. Therefore, continuous motor control signals are converted into stepped signals -1, 0, +1 to control the motor. and The discrete input signals mapped to the motor are mapped by setting a threshold: in, The threshold for mapping; Based on the mapped motor input signal, the left and right motors are controlled to move the corresponding electric push rods to correct the material drop position. During system operation, the material position is monitored in real time, and the input of the left and right motors is adjusted by two PID controllers to keep the distance between the left and right ends of the material flow constant and keep the center of gravity of the material flow at the center of the conveyor belt.

2. The automated system for detecting and correcting material deviation in conveyor belts according to claim 1, characterized in that, The camera device has a filter at the front end that allows only the laser line frequency spectrum to pass through, filtering out other useless interference spectra, thereby obtaining a stable laser line image.

3. The automated system for detecting and correcting material deviation in conveyor belts according to claim 1, characterized in that, When a material flow deviation is detected, the deviation is corrected; the control unit adjusts the position of the baffle by controlling the electric push rod, thereby adjusting the material drop position on the conveyor belt. Considering the positions of the left and right endpoints of the material flow, and also taking into account the influence of the baffles on the material flow, the material flow deviation model is represented as the deviation between the x-coordinates of the left and right endpoints and the x-coordinates of the ideal position. The ideal position is defined as the x-coordinate position of the left and right endpoints of the material flow when the center of gravity of the material flow is moved to the defined center point of the conveyor belt. The calculation is as follows: （3） in, The x-coordinates of the left and right endpoints of the material flow; Let x be the x-coordinate of the left and right ideal positions; define the deviation as the left endpoint position of the material flow minus the left ideal position and the right endpoint position of the material flow minus the right ideal position: （4） Where t is the time variable, i.e. , These represent the left and right deviations at time t, respectively.

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