A method for accurately removing defective materials from a rubber ring sorting device

Abstract

The present invention provides a method for accurately rejecting defective materials in a rubber ring sorting device. The method comprises the following steps: Step S10, providing a circular turntable as a rotating platform. The turntable remains in a rotating state, and rubber rings sequentially fall onto the turntable via a preset slideway; Step S20, presetting an edge gap on the turntable, and using a slotted optical coupler installed thereon to determine the position as the zero point; Step S30, continuously capturing two images of the turntable with a camera, converting the two images into polar coordinates, and then performing a phase correlation operation; Step S40, determining the rotation angle value, and determining the turntable speed based on the time interval between camera captures; Step S50, determining the time to reject the material based on parameters such as the zero point, the turntable speed, and the time when the defective material was obtained; and Step S60, driving a lever device at the time of rejection to reject the material into a sorting bin. This method is intelligent, low-cost, and highly accurate.

Description

Technical Field

[0001] The present invention belongs to the field of sorting technology, and in particular relates to a method for accurately removing defective materials from a rubber ring sorting device. Background Art

[0002] Artificial intelligence (AI) is a hot technology in today's society. Intelligent rubber ring sorting, enabled by this technology, significantly improves sorting efficiency and accuracy compared to traditional manual sorting. The specific technology involves rubber rings falling onto a rotating table. A camera captures images of each ring, identifies them individually, and then uses a lever to push defective rubber rings into the appropriate bin. Precise rejection of defective materials on the sorting device's rotating table is a key technology. Computer vision identifies defective materials and calculates the rejection time, allowing the lever to accurately push them into the appropriate bin. Traditional methods of calculating the rejection time use encoders to determine the final rejection time based on the rotating table's speed and position. This method has the following drawbacks: 1. The encoder must be mounted on the rotating table motor and connected to the device processor via wiring, making installation and maintenance inconvenient. 2. The encoder hardware and wiring are subject to the risk of hardware failure and loose connections. If this occurs, the device will not function properly, reducing its stability.

[0003] In view of the above reasons, it is necessary to improve the many shortcomings of the existing technology of a method for accurately removing defective materials in a rubber ring sorting device. Summary of the Invention

[0004] The present invention provides a method for accurately rejecting defective materials in a rubber ring sorting device, aiming to provide an intelligent, low-cost, and high-precision method for rejecting defective materials in a rubber ring sorting device.

[0005] The present invention is implemented by providing a method for accurately removing defective materials from a rubber ring sorting device, the method comprising the following steps:

[0006] Step S10: a circular turntable is provided as a rotating platform, the rotating platform is kept in a rotating state, and the rubber rings fall onto the rotating platform in sequence through a preset slideway;

[0007] Step S20: a pre-set edge gap is set on the rotating platform, and the position of the edge gap is determined as the zero point by the slot-type optical coupler installed therein;

[0008] Step S30: The camera continuously captures two images of the turntable, converts the two images into polar coordinate images, and then performs phase correlation operation;

[0009] Step S40, obtaining the rotation angle value, and obtaining the rotation speed of the rotating stage according to the camera shooting time interval;

[0010] Step S50, according to the time of zero point, the rotation speed of the rotating table, the time of obtaining defective materials and other parameters, the time when the materials need to be rejected is obtained;

[0011] Step S60: At the time of rejecting the material, the lever device is driven to reject the material and put it into the sorting box.

[0012] Preferably, step S20 includes:

[0013] An edge gap is preset on the rotating table, and the slot-type optocoupler is stuck at the edge of the turntable. The slot-type optocoupler includes a light-emitting diode and a phototransistor. Among them, the slot-type optocoupler and the connector are soldered on the circuit board. After the connector obtains voltage from the outside, it provides power supply voltage to the slot-type optocoupler through the circuit board, and the light-emitting diode of the slot-type optocoupler remains in a light-emitting state. Due to the obstruction of the turntable, the light-emitting diode is not coupled to the base of the phototransistor, and the transistor is not turned on. When the preset edge gap of the rotating table in the rotating state turns to the slot-type optocoupler, the light of the light-emitting diode shines on the base of the slot-type optocoupler transistor through the gap, and the transistor is turned on instantly. In this way, a pulse signal can be sent to the processor through the connector, and the processor records this moment as the zero time. The edge gap and the lever device differ by 180 degrees.

[0014] Preferably, the step S30 includes:

[0015] The camera captures two consecutive images of the rotating stage, and the two-dimensional images obtained are: T(x,y) and R(x,y). Suppose an image W(x,y) is converted to an image in polar coordinates as W(ρ,θ), where ρ is the polar diameter and θ is the polar angle. The transformation relationship is as follows:

[0016]

[0017]

[0018] Where (x0, y0) is the center point of the transformation. The expression for transforming T(x, y) into polar coordinates is as follows:

[0019]

[0020] Since R(x,y) is the image of T(x,y) rotated by an angle of θ, the expression of R(x,y) is as follows:

[0021] R(x,y)=T(xcosθ+ysinθ,-xsinθ+ycosθ)

[0022] Obviously, by performing polar coordinate transformation on R(x,y), the expression can be obtained as follows:

[0023]

[0024] Formulas (1) and (2) above are expressions of T(x,y) and R(x,y) in polar coordinates. Let them be Q(u,v) and P(u,v), and we can conclude that Q(u,v) is P(u,v-θ).

[0025] Through polar coordinate transformation, the rotation angle value between the two images is converted into translation value.

[0026] Performing Fourier transform on Q(u,v) and P(u,v-θ) respectively, we can get:

[0027] F Q (u, v) = F P (u,v)e -j2πvθ (3)

[0028] F Q (u, v), F P (u, v) are the Fourier transform results of Q(u, v) and P(u, v) respectively.

[0029] Combine equation (3) to calculate the cross power spectrum of Q(u,v) and P(u,v):

[0030]

[0031] In formula (4), F Q The complex conjugate of (u, v), e -j2πvθ The inverse Fourier transform of a two-dimensional pulse function δ(x,y-θ) is the phase correlation algorithm. The peak value of θ is used to find the angle of rotation of the rotating stage. This is the angle of rotation of the rotating stage when the rotating stage is photographed twice in succession.

[0032] Preferably, the step S40 includes:

[0033] The obtained rotation angle value is set to w, and the camera shooting time interval is set by the software and is set to T. Then the obtained rotation speed V of the turntable is w / T (unit: r / s).

[0034] Preferably, the step S50 includes:

[0035] Let's assume the zero time obtained by the processor is t1. This time is obtained with each rotation of the rotary table. After the zero time is obtained, the camera begins identifying defective materials. The time at which defective materials are identified is t2. Because the zero time is 180 degrees different from the point where the material is rejected, the time required for the rotary table to move from the gap to the lever is 1 / (2V). The time required to reject the material is: 1 / (2V) - (t2 - t1).

[0036] Preferably, the step S60 includes:

[0037] The lever mechanism consists of a high-speed linear motor and a lever. The motor is connected to the lever, and a tapered hose is positioned at the front of the lever, with the lower end of the hose in contact with the rotating table. Once the processor calculates the material removal time, it sends a command to the high-speed linear motor at that time, causing it to reciprocate, generating thrust that drives the lever to quickly remove the material before quickly returning to its initial position.

[0038] Compared with the prior art, the present invention has the following advantages:

[0039] 1. Since image recognition through computer vision is an essential part of the detection device, the rotational speed of the rotary table can be calculated through image calculation through computer vision. This can be completed through the expansion of the software module without adding any hardware. This can eliminate the need for encoders and reduce hardware costs. At the same time, it avoids the inconvenience of encoder installation and maintenance and the risks of hardware failure and loose connections, thereby improving the stability of the device.

[0040] 2. Use slot-type optical couplers to identify the preset gap of the rotary table, thereby realizing the identification of the zero point. This method is very low-cost and has good stability.

[0041] 3. Accurate elimination is achieved by calculating the rotation angle of the turntable based on a phase correlation algorithm. This image calculation method is a frequency domain calculation method, which does not rely on light intensity and does not require additional image preprocessing algorithms, providing a reliable guarantee for achieving final accurate elimination.

[0042] 4. The high-speed linear motor is used as the lever drive device to remove defective materials. It has good reliability, no need for additional auxiliary equipment, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a flow chart of an embodiment of a method for accurately removing defective materials from a rubber ring sorting device according to the present invention;

[0044] Figure 2 Shown is a schematic diagram of a sorting device according to an embodiment of the present invention;

[0045] Figure 3 FIG2 is a schematic diagram of the installation of a slot-type optical coupler according to an embodiment of the present invention;

[0046] Figure 4 Shown is a schematic diagram of material removal time calculation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The embodiment of the present invention discloses a method for accurately removing defective materials from a rubber ring sorting device, aiming to provide an intelligent, low-cost, and high-precision method for removing defective materials.

[0048] Please refer to Figure 1 In one embodiment of the present invention, the method for accurately removing defective materials from the rubber ring sorting device includes the following steps:

[0049] Step S10: a circular turntable is provided as a rotating platform, the rotating platform is kept in a rotating state, and the rubber rings fall onto the rotating platform in sequence through a preset slideway;

[0050] Step S20: a pre-set edge gap is set on the rotating platform, and the position of the edge gap is determined as the zero point by the slot-type optical coupler installed therein;

[0051] Step S30: The camera continuously captures two images of the turntable, converts the two images into polar coordinate images, and then performs phase correlation operation;

[0052] Step S40, obtaining the rotation angle value, and obtaining the rotation speed of the rotating stage according to the camera shooting time interval;

[0053] Step S50, according to the time of zero point, the rotation speed of the rotating table, the time of obtaining defective materials and other parameters, the time when the materials need to be rejected is obtained;

[0054] Step S60: At the time of rejecting the material, the lever device is driven to reject the material and put it into the sorting box.

[0055] Further, refer to Figure 2 , the sorting device comprises:

[0056] The rotating table 201 is generally a circular turntable; the rotating table is preset with an edge gap 202; a rubber ring 203 falls onto the rotating table; a lever device 204; a camera 206, which is located directly above the material falling area of ​​the rotating table; a processor 205; after the camera 206 captures the image, the image data is transmitted to the processor via a communication cable; a fixing frame 207 is used to fix the camera and processor.

[0057] Further, refer to Figure 3 , the step S20 includes:

[0058] A pre-set edge gap 302 is provided on the rotating table 301, and a slot-type optocoupler 303 is positioned at the edge of the turntable. The slot-type optocoupler 303 includes a light-emitting diode 306 and a phototransistor 307. The slot-type optocoupler 303 and connector 305 are soldered to a circuit board 304. The connector 305 receives voltage from an external source and supplies it to the slot-type optocoupler 303 via the circuit board 304. This causes the LED 304 in the slot-type optocoupler 303 to remain illuminated. However, due to the obstruction caused by the turntable, the illuminated diode is not coupled to the base of the phototransistor 307, rendering the transistor non-conductive. When the rotating table's pre-set edge gap 302 reaches the slot-type optocoupler, light from the LED passes through the gap and strikes the base of the phototransistor, instantly turning on the transistor. This allows a pulse signal to be transmitted via the connector to the processor, which records this moment as zero. The edge gap and the lever mechanism are 180 degrees apart.

[0059] The step S30 includes:

[0060] The camera captures two consecutive images of the rotating stage, and the two-dimensional images obtained are: T(x,y) and R(x,y). Suppose an image W(x,y) is converted to an image in polar coordinates as W(ρ,θ), where ρ is the polar diameter and θ is the polar angle. The transformation relationship is as follows:

[0061]

[0062]

[0063] Where (x0, y0) is the center point of the transformation. The expression for transforming T(x, y) into polar coordinates is as follows:

[0064]

[0065] Since R(x,y) is the image of T(x,y) rotated by an angle of θ, the expression of R(x,y) is as follows:

[0066] R(x,y)=T(xcosθ+ysinθ,-xsinθ+ycosθ)

[0067] Obviously, by performing polar coordinate transformation on R(x,y), the expression can be obtained as follows:

[0068]

[0069] Formulas (1) and (2) above are expressions of T(x,y) and R(x,y) in polar coordinates. Let them be Q(u,v) and P(u,v), and we can conclude that Q(u,v) is P(u,v-θ).

[0070] Through polar coordinate transformation, the rotation angle value between the two images is converted into translation value.

[0071] Performing Fourier transform on Q(u,v) and P(u,v-θ) respectively, we can get:

[0072] F Q (u, v) = F P (u,v)e -j2πvθ (3)

[0073] F Q (u, v), F P (u, v) are the Fourier transform results of Q(u, v) and P(u, v) respectively.

[0074] Combine equation (3) to calculate the cross power spectrum of Q(u,v) and P(u,v):

[0075]

[0076] In formula (4), F Q The complex conjugate of (u, v), e -j2πvθ The inverse Fourier transform of a two-dimensional pulse function δ(x,y-θ) is the phase correlation algorithm. The peak value of θ is used to find the angle of rotation of the rotating stage. This is the angle of rotation of the rotating stage when the rotating stage is photographed twice in succession.

[0077] The step S40 includes:

[0078] The obtained rotation angle value is set to w, and the camera shooting time interval is set by the software and is set to T. Then the obtained rotation speed V of the turntable is w / T (unit: r / s).

[0079] Further, refer to Figure 4 , the step S50 includes:

[0080] Let's assume the zero time obtained by the processor is t1. This time is obtained with each rotation of the rotary table. After the zero time is obtained, the camera begins identifying defective materials. The time at which defective materials are identified is t2. Because the zero time is 180 degrees different from the point where the material is rejected, the time required for the rotary table to move from the gap to the lever is 1 / (2V). The time required to reject the material is: 1 / (2V) - (t2 - t1).

[0081] The step S60 includes:

[0082] The lever mechanism consists of a high-speed linear motor and a lever. The motor is connected to the lever, and a tapered hose is positioned at the front of the lever, with the lower end of the hose in contact with the rotating table. Once the processor calculates the material removal time, it sends a command to the high-speed linear motor at that time, causing it to reciprocate, generating thrust that drives the lever to quickly remove the material before quickly returning to its initial position.

[0083] In the present invention, the processor can be an industrial computer, which is connected to the camera and controls the camera to capture images to collect material images, thereby realizing image recognition of defective materials and calculation of the rotation speed of the rotary table. After the slot-type optical coupler detects the zero point, it sends a TTL signal to the adapter board, which converts the TTL signal into serial port data and sends it to the industrial computer through the serial port. The adapter board provides power supply voltage to the slot-type optical coupler through the connector. The adapter board receives the control signal from the industrial computer through the serial port, and then sends it to the high-speed linear motor through the network port, controlling it to perform reciprocating motion, thereby removing the material.

[0084] The above description is merely a preferred embodiment of the present invention, which is provided to help understand the core concept of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions, and other improvements made within the method and concept of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for accurately removing defective materials from a rubber ring sorting device, characterized in that: The method comprises the following steps: Step S10: a circular turntable is provided as a rotating platform, the rotating platform is kept in a rotating state, and the rubber rings fall onto the rotating platform in sequence through a preset slideway; Step S20: A margin gap is preset on the rotating platform, and the position is determined as the zero point by a slot-type optical coupler installed thereon. The margin gap and the lever device are at an angle of 180 degrees. Step S30: The camera continuously captures two images of the turntable, converts the two images into polar coordinate images, and then performs phase correlation calculation to obtain the rotation angle of the turntable; Step S40, obtaining the rotation angle value, and obtaining the rotation speed of the rotating stage according to the camera shooting time interval; Step S50, according to the zero time, the rotation speed of the rotating table, and the time when the defective material is obtained, the time when the material needs to be rejected is obtained; Step S60: At the time of rejecting the material, the lever device is driven to reject the material and put it into the sorting box.

2. The method for accurately removing defective materials from a rubber ring sorting device according to claim 1, characterized in that: The step S20 includes: An edge gap is preset on the rotating table, and a slot-type optocoupler is stuck at the edge of the turntable. The slot-type optocoupler includes a light-emitting diode and a photosensitive transistor, wherein the slot-type optocoupler and the connector are welded on the circuit board. After the connector obtains voltage from the outside, it provides power supply voltage to the slot-type optocoupler through the circuit board, and the light-emitting diode of the slot-type optocoupler remains in a light-emitting state. Due to the obstruction of the turntable, the light-emitting diode is not coupled to the base of the photosensitive transistor, and the transistor is not turned on. When the preset edge gap of the rotating table in the rotating state moves to the slot-type optocoupler, the light of the light-emitting diode shines on the base of the slot-type optocoupler transistor through the gap, and the transistor is instantly turned on, so that a pulse signal can be sent to the processor through the connector, and the processor records this moment as the zero time.

3. The method for accurately removing defective materials from a rubber ring sorting device according to claim 1 is characterized in that: The step S30 includes: The camera captures two consecutive images of the rotating stage, and the two-dimensional images obtained are: T(x, y) and R(x, y). Suppose an image W(x, y) is converted to an image in polar coordinates as W(ρ, θ), where ρ is the polar diameter and θ is the polar angle. The transformation relationship is as follows: Where (x0, y0) is the center point of the transformation. The expression for transforming T(x, y) into an image in polar coordinates is as follows: (1) Since R(x,y) is the image of T(x,y) rotated by an angle of θ, the expression of R(x,y) is as follows: R(x,y)=T(xcosθ+ysinθ,-xsinθ+ycosθ) Obviously, by performing polar coordinate transformation on R(x,y), we can get the following expression: (2) Formula (1) and formula (2) above are the expressions of T(x,y) and R(x,y) in polar coordinates. Let them be Q(u,v) and P(u,v), and we can get: Q(u,v) is P(u,v-θ), Through polar coordinate transformation, the rotation angle between the two images is converted into translation. Perform Fourier transform on Q(u,v) and P(u,v-θ) respectively, and we can get: (3) 、 They are the results of Fourier transform of Q(u,v) and P(u,v), Combined with formula (3), the cross power spectrum of Q(u,v) and P(u,v) is calculated as follows: (4) In formula (4), for The complex conjugate of The inverse Fourier transform of a two-dimensional pulse function δ(x, y-θ) is the phase correlation algorithm. The peak value of θ is used to find the angle of rotation of the rotating stage. This is the angle of rotation of the rotating stage when the rotating stage is photographed twice in succession.

4. The method for accurately removing defective materials from a rubber ring sorting device according to claim 1, characterized in that: The step S40 includes: The obtained rotation angle value is set to w, and the camera shooting time interval is set by the software and is set to T. Then the obtained rotation speed V of the turntable is w / T (unit: r / s).

5. The method for accurately removing defective materials from a rubber ring sorting device according to claim 1, characterized in that: The step S50 includes: Assume that the zero time obtained by the processor is t1. This time can be obtained every time the turntable rotates one circle. After the zero time is obtained, the camera starts to identify defective materials. The time when the defective materials are identified is t2.

6. The method for accurately removing defective materials from a rubber ring sorting device according to claim 1, characterized in that: The step S60 includes: The lever device consists of a high-speed linear motor and a lever. The high-speed linear motor is connected to the lever. A conical hose is placed at the front end of the lever, and the lower end of the hose is in contact with the rotating table. When the processor calculates the time to remove the material, it sends an instruction to the high-speed linear motor at that moment. The high-speed linear motor then performs reciprocating motion, first generating thrust to drive the lever to quickly remove the material, and then quickly returning to its initial state.

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