Method for positioning and identifying a steel coil

Abstract

The application discloses a steel coil and band positioning and identifying method, 1) after the tool head reaches the steel coil and band scanning position, the current ranging value is stored in the data buffer area; 2) the deviation of the current ranging value and the buffered ranging value is calculated; 3) if the absolute value of the ranging deviation calculated in step 2) is greater than the set threshold value and the ranging deviation value is less than 0, the first timer and the second timer are simultaneously triggered; 4) if the timing time of the first timer arrives and the timing time of the second timer does not arrive, the deviation of the current ranging value and the buffered ranging value is calculated again; 5) if the absolute value of the ranging deviation calculated in step 4) is greater than the set threshold value and the ranging deviation value is greater than 0, the "found band" signal is sent, the band counting value is added by 1, and the tool head coordinate position at this time is stored; 6) step 2) is returned to carry out the positioning and identifying of the next band of the current steel coil until the tool head leaves the steel coil and band scanning position. The method can improve the positioning and identifying accuracy of the steel coil and band, and reduce the missed report or false report.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of metallurgical industry, and particularly relates to a steel coil strapping positioning and identifying method. BACKGROUND

[0002] There are some industrial robot application scenarios in the metallurgical industry that need to identify and position the steel coil strapping; for example, the entry section of the cold rolling mill group needs to determine the number and position of the strapping on the incoming steel coil first, and then guide the unstrapping tool head installed on the sixth axis of the industrial robot to cut off and remove the strapping one by one and recycle it; for another example, the labeling robot at the exit section of the cold rolling mill group needs to determine the number and position of the strapping on the finished steel coil first, and then guide the labeling tool head installed on the sixth axis of the industrial robot to accurately paste the production label on the steel coil strapping. As can be seen, the identification and positioning of the number and position of the steel coil strapping are very important for the smooth implementation of the above industrial robot applications.

[0003] There are two kinds of existing mainstream steel coil strapping positioning and identifying technologies: one is to use image vision method to realize strapping identification and positioning by using the color difference between the steel coil and the strapping, but it needs to additionally configure cameras, light sources, image computers and other hardware, and the implementation process needs tedious position calibration and a large number of sample image training, which takes a long time to debug and is easily affected by the disturbance light such as rust on the surface of the steel coil, sunlight projection in the factory, lighting lamps, etc., and the cost performance is not high; the other is to use the ranging method based on ultrasonic wave, laser and other principles, but often ignores the influence of strapping width, thickness, material, manufacturing error and other factors on strapping positioning and identification, and the situation of strapping missed report or strapping false report occurs from time to time. SUMMARY

[0004] The purpose of the present application is to provide a steel coil strapping positioning and identifying method, which can accurately identify and position the total number and position of all strappings on the steel coil, improve the accuracy of steel coil strapping positioning and identification, and greatly reduce the probability of missed report or false report of steel coil strapping identification and positioning.

[0005] The technical solution adopted by the present application is:

[0006] A steel coil strip positioning and identifying method, comprising the steps of: 1) when the tool head reaches the steel coil strip scanning position, storing the current ranging value in the data buffer area; 2) calculating the deviation of the current ranging value and the buffered ranging value; 3) if the absolute value of the ranging deviation calculated in step 2) is greater than the set threshold value and the ranging deviation value is less than 0, simultaneously triggering the first timer and the second timer; 4) if the timing time of the first timer is up and the timing time of the second timer is not up, calculating again the deviation of the current ranging value and the buffered ranging value; 5) if the absolute value of the ranging deviation calculated in step 4) is greater than the set threshold value and the ranging deviation value is greater than 0, sending the "found strip" signal, adding 1 to the strip count value, and storing the tool head coordinate position at this time; 6) returning to step 2) to position and identify the next strip of the current steel coil until the tool head leaves the steel coil strip scanning position.

[0007] Preferably, the data buffer area is a first-in-first-out data queue.

[0008] Preferably, the buffered ranging value is the ranging value at the nth sampling time before the current sampling time in the data queue, wherein n is determined by the strip material characteristics and is an adjustable parameter.

[0009] Preferably, the set threshold value is an adjustable parameter determined by the strip thickness, and is greater than or equal to 0.5 times the strip thickness and less than or equal to 1.5 times the strip thickness.

[0010] Preferably, the first timer and the second timer are both pulse timers, and the timing set time calculation formula of the first timer and the second timer is:

[0011]

[0012]

[0013] In the formula, T sp1 is the timing set time of the first timer; T sp2 is the timing set time of the second timer; W strap is the strip width; V tool is the moving speed of the industrial robot tool head scanning the strip; ΔW n is the negative deviation of the strip width; ΔW p is the positive deviation of the strip width; W strap , V tool , ΔW n , ΔW p The four parameters are all adjustable parameters.

[0014] Preferably, the ranging value is collected by a high-precision laser ranging instrument, and the ranging value of the ranging instrument is transmitted to the control system through data communication.

[0015] Preferably, the tool head comprises a steel coil unbundling belt tool head, a steel coil labeling tool head.

[0016] Preferably, the bundled belt positioning and identifying method can be realized through software programming on a PLC, a DCS, a PC, an industrial computer, a single-chip microcomputer, and a DSP.

[0017] The present application has the following advantages:

[0018] The present method can accurately identify and locate the total number and position of all bundled belts on the steel coil, improves the accuracy of steel coil bundled belt positioning and identification, and greatly reduces the probability of missed or false reports of steel coil bundled belt identification and positioning, thereby laying a solid foundation for guiding the tool head installed on the industrial robot to perform subsequent actions.

[0019] The present method only needs to set a small number of experience parameters, and after several steel coil tests and parameter fine-tuning, the entire steel coil bundled belt identification process can be completed, avoiding the tedious calibration and sample training process required by image vision and color difference methods, greatly shortening the on-site debugging time and reducing the maintenance workload after production.

[0020] Compared with other bundled belt positioning and identifying methods using a ranging method, the present method fully considers the influence of factors such as bundled belt material, bundled belt width, bundled belt thickness, and bundled belt production size deviation on the bundled belt positioning and identifying process, and can accurately position and identify bundled belts of different widths, thicknesses, and materials (steel or plastic), thereby greatly avoiding missed or false reports of bundled belts.

[0021] The present method can be realized through software programming on various types of control system hardware platforms, and can be used not only for new cold rolling mill industrial robot systems, but also for the modification of existing cold rolling mill industrial robot systems, and can be used not only for mill inlet unbundling belt robot systems, but also for mill outlet labeling robots, thereby having strong realizability and wide applicability. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a flowchart of the steel coil bundled belt positioning and identifying method in the embodiment of the present application. DETAILED DESCRIPTION

[0023] The present application will be further described below in combination with the drawings and embodiments.

[0024] As shown in Figure 1 A steel coil bundled belt positioning and identifying method comprises the following steps:

[0025] 1) When the tool head reaches the steel coil bundled belt scanning position, the current ranging value is stored in the data buffer area.

[0026] The data buffer is a first-in first-out data queue: that is, the ranging values are stored in the data queue according to the sampling order, and 15-20 sampled ranging values are stored in the data queue, and the latest sampled ranging value is stored at the tail of the data queue while the earliest sampled ranging value is deleted from the head of the data queue, so that the 15-20 latest sampled ranging data values are always stored in the data buffer in the sampling order. The closer the tool head is to the surface of the measured object, the smaller the ranging value; the farther the tool head is from the surface of the measured object, the larger the ranging value.

[0027] 2) calculating the deviation of the current ranging value from the buffered ranging value;

[0028] The buffered ranging value is the ranging value at the nth sampling time before the current sampling time in the data queue, wherein n is determined by the material characteristics of the bale and is an adjustable parameter; the deviation ΔL1 of the current ranging value from the buffered ranging value is calculated according to the following formula: ΔL1 = L pv1 -L pv1-n ; wherein L pv1 is the current sampling ranging value, and L pv1-n is the sampling ranging value at the nth sampling time before the current sampling time stored in the data queue. When the bale is a steel bale, n is in the range of 5-7; when the bale is a plastic bale, n is in the range of 9-12. In this embodiment, the bale is a plastic bale, and n = 10.

[0029] 3) if the absolute value of the ranging deviation calculated in step 2) is greater than the set threshold value and the ranging deviation value is less than 0, then the first timer and the second timer are simultaneously started;

[0030] The set threshold value is an adjustable parameter and is greater than or equal to 0.5 times the thickness of the bale and less than or equal to 1.5 times the thickness of the bale; that is, when ΔL1 calculated in step 2) satisfies the following conditions, the first timer and the second timer are simultaneously started:

[0031] ABS(ΔL1) > ΔL sp and ΔL1 < 0

[0032] wherein ABS(ΔL1) is an absolute value function, and the set threshold value ΔL sp is an adjustable parameter and satisfies 0.5 × D strap ≤ ΔL sp ≤ 1.5 × D strap , D strap is the thickness of the bale. In this embodiment, the thickness of the bale D strap = 0.9 mm, and the set threshold value ΔL sp = 0.54 mm.

[0033] 4) if the timing time of the first timer is up and the timing time of the second timer is not up, then the deviation of the current ranging value from the buffered ranging value is calculated again;

[0034] The deviation ΔL2 of the current ranging value and the buffered ranging value is calculated again according to the following formula: ΔL2 = L pv2 -L pv2-n ; wherein L pv2 is the sampling ranging value at the current time, L pv2-n is the ranging value at the n-th sampling time before the current sampling time saved in the data queue; when the bale belt is a steel bale belt, n ranges from 5 to 7; when the bale belt is a plastic bale belt, n ranges from 9 to 12. In the embodiment, the bale belt is plastic, and n = 10.

[0035] The first timer and the second timer are both pulse timers, and the timing setting time of the first timer and the second timer is calculated according to the following formula:

[0036]

[0037]

[0038] In the formula, T sp1 is the timing setting time of the first timer, for controlling the running of the first timer;

[0039] In the formula, T sp2 is the timing setting time of the second timer, for controlling the running of the second timer;

[0040] In the formula, W strap is the width of the bale belt, which is set according to the actual width of the bale belt, and in the embodiment, W strap = 32 mm;

[0041] V tool is the moving speed of the industrial robot carrying the tool head to scan the bale belt, and in the embodiment, V tool = 50 mm / s;

[0042] ΔW n is the negative deviation of the width of the bale belt, which is an empirical parameter provided by the bale belt manufacturer, and in the embodiment, ΔW n = 5 mm;

[0043] ΔW p is the positive deviation of the width of the bale belt, which is an empirical parameter provided by the bale belt manufacturer, and in the embodiment, ΔW p = 5 mm;

[0044] According to the above formula, T sp1 = 540 ms, and T sp2 = 740 ms

[0045] The above W strap , V tool , Δw n, AW p All the four parameters are adjustable parameters, which can be flexibly adjusted according to actual conditions.

[0046] 5) If the absolute value of the ranging deviation calculated in step 4) is greater than the set threshold value and the ranging deviation value is greater than 0, a "find the band" signal is sent, the band count value is added by 1, and the tool head coordinate position at this time is stored;

[0047] That is, when the calculated AL2 in step 4) satisfies the following formula at the same time, a "find the band" signal is sent, the band count value of the current steel coil is added by 1, and the band position coordinates determined by the tool coordinate system of the industrial robot at this time are stored.

[0048] ABS(AL2) > AL sp and AL2 > 0

[0049] Where ABS(AL2) is an absolute value function, the set threshold value AL sp is an adjustable parameter, and satisfies 0.5xD strap ≤ AL sp ≤ 1.5xD strap , D strap is the band thickness. In the embodiment, the band thickness D strap = 0.9mm, and the set threshold value AL sp = 0.54mm.

[0050] 6) Return to step 2) to continue positioning and identifying the next band of the current steel coil, until the tool head leaves the steel coil band scanning position; when the tool head leaves the steel coil band scanning position, the band count value of the current steel coil is the total number of bands existing on the steel coil, and the stored tool head coordinate position after position offset is the relative position of each band on the steel coil.

[0051] The ranging value is collected by a high-precision laser range finder, and the ranging value of the range finder is transmitted to the control system through data communication. In the embodiment, a high-precision laser range finder with a repeated measurement accuracy of 30μm is selected, and the ranging value of the laser range finder is transmitted to the control system through Profinet field bus communication, avoiding the interference of traditional analog hard-wired mode on measurement data transmission.

[0052] The tool head includes a steel coil unbundling tool head and a steel coil labeling tool head. In the embodiment, the tool head is a steel coil labeling tool head, and through identifying the position of the band on the steel coil, the industrial robot can be guided to accurately paste the production label on the steel coil band.

[0053] The bundle positioning and identifying method can be realized by software programming on a plurality of hardware platforms such as PLC, DCS, PC, industrial computer, single-chip microcomputer and DSP. In the embodiment, the bundle positioning and identifying method is realized by LAD language software programming in Step7 programming software of Siemens S7-1200 PLC.

[0054] The method can accurately identify and locate the total number and positions of all the bundles on the steel coil, improves the accuracy of bundle positioning and identification of the steel coil, greatly reduces the probability of missed or false reporting of the bundle positioning and identification of the steel coil, and lays a solid foundation for guiding the tool head installed on the industrial robot to perform subsequent actions. The method only needs to set a small number of experience parameters, and after several steel coil tests and parameter fine-tuning, the bundle identification process of the entire steel coil can be completed, avoiding the tedious calibration and sample training process required by image vision and color difference methods, greatly shortening the on-site debugging time and reducing the maintenance workload after production. Compared with other bundle positioning and identifying methods using the distance measuring method, the influence of factors such as bundle material, bundle width, bundle thickness, bundle production size deviation on the bundle positioning and identifying process is fully considered in the method, and the bundle of different width, thickness and material (steel or plastic) can be accurately positioned and identified, which greatly avoids the situation of missed or false reporting of the bundle. The method can be realized by software programming on a plurality of types of control system hardware platforms, and can be used for new cold rolling mill industrial robot system, and can be used for modification of existing cold rolling mill industrial robot system, and can be used for bundle dismounting robot system at the entrance of the mill, and can be used for label sticking robot at the exit of the mill, and has strong realizability and wide applicability.

[0055] It should be understood that the above description can be improved or changed by those skilled in the art, and all these improvements and changes shall fall within the protection scope of the appended claims of the present application.

Claims

1. A steel coil strap positioning and identification method, characterized in that: The method comprises the steps of: 1) storing the current ranging value in a data buffer area when the tool head reaches the steel coil bundle scanning position; 2) calculating the deviation of the current ranging value and the buffered ranging value; 3) if the absolute value of the ranging deviation calculated in step 2) is greater than a set threshold value and the ranging deviation value is less than 0, simultaneously triggering the start of a first timer and a second timer; 4) if the timing time of the first timer is up and the timing time of the second timer is not up, calculating again the deviation of the current ranging value and the buffered ranging value; 5) if the absolute value of the ranging deviation calculated in step 4) is greater than the set threshold value and the ranging deviation value is greater than 0, issuing a "bundle found" signal, increasing the bundle count value by 1, and storing the coordinate position of the tool head at this time; 6) returning to step 2) to position and identify the next bundle of the steel coil, until the tool head leaves the steel coil bundle scanning position. The buffered ranging value is the ranging value at the nth sampling time before the current sampling time in the data queue, wherein n is determined by the material characteristics of the bundle and is an adjustable parameter. The first timer and the second timer are both pulse timers, and the timing setting time of the first timer and the second timer is calculated as follows: wherein set a time for the timing of the first timer; set a time for the timing of the second timer; is the width of the bundle; is the speed of the movement of the bundle by the industrial robot with the tool head scanning the bundle; is the negative deviation of the width of the bundle; is the positive deviation of the width of the bundle; All four parameters are adjustable parameters.

2. The steel coil strap positioning and identification method of claim 1, wherein: The data buffer area is a first-in first-out data queue.

3. The steel coil strap positioning and identification method of claim 1, wherein: The set threshold value is an adjustable parameter determined by the bundle thickness, and is greater than or equal to 0.5 times the bundle thickness and less than or equal to 1.5 times the bundle thickness.

4. The steel coil strap positioning and identification method of claim 1, wherein: The ranging value is collected by a high-precision laser range finder, and the ranging value of the range finder is transmitted to the control system through data communication.

5. The steel coil strap positioning and identification method of claim 1, wherein: The tool head comprises a steel coil bundle dismounting tool head and a steel coil labeling tool head.

6. The steel coil strap positioning and identification method of claim 1, wherein: The bundle positioning and identifying method can be realized through software programming on various hardware platforms such as PLC, DCS, PC, industrial computer, single-chip microcomputer and DSP.

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