Information processing apparatus and information processing method

Abstract

To provide an information processing apparatus and a method for processing information that can improve the accuracy of the calculation result of the movement distance of a workpiece as compared with existing ones.SOLUTION: An information processing apparatus (100) includes: an optical information acquisition unit (10) for acquiring one-dimensional optical information of a workpiece (W1); a distance estimation value acquisition unit (20) for acquiring an estimated value of a movement distance of the workpiece (W1); an optical information extraction unit (30) for extracting a part of information from the optical information acquired by the optical information acquisition unit (10) on the basis of the estimated value; a correlation value calculation unit (40) for calculating a correlation value indicating correlation of information extracted by the optical information extraction unit (30) from first optical information (A1) and second optical information (A2) acquired by the optical information acquisition unit (10); and a movement distance calculation unit (60) for calculating the movement distance of the workpiece (W1) on the basis of the correlation value calculated by the correlation value calculation unit (40).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an information processing device and an information processing method. [Background technology]

[0002] Conventionally, a displacement meter has been disclosed that measures the displacement (movement distance) of a measurement object (workpiece) transported by a transport device based on one-dimensional information from a line sensor that detects reflected light from the measurement object (workpiece) (see, for example, Patent Document 1). This displacement meter detects extreme values ​​(peaks) of the cross-correlation function of multiple images detected at different times by the line sensor, and calculates the amount of displacement of the measurement object based on the detection results. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-170550 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, in a displacement meter such as that described in Patent Document 1, the waveform of the cross-correlation function contains noise contained in the output from the line sensor, noise caused by conduction noise in the circuit, etc., and it may be difficult to detect a peak corresponding to the movement distance of the workpiece from the cross-correlation function, posing a problem that it is difficult to improve the accuracy of the movement distance calculation results.

[0005] The present disclosure was made in response to the recognition of the above-mentioned problems, and aims to provide an information processing device and an information processing method that can improve the accuracy of the calculation results of the workpiece movement distance compared to conventional methods. [Means for solving the problem]

[0006] The information processing device according to the present disclosure includes an optical information acquisition unit that acquires one-dimensional optical information of a workpiece based on light from the moving workpiece; a distance estimation value acquisition unit that acquires an estimate of the distance traveled by the workpiece from a first time to a second time; an optical information extraction unit that extracts a portion of information from the optical information acquired by the optical information acquisition unit based on the estimate; a correlation value calculation unit that calculates a correlation value indicating the correlation between the first extracted information extracted by the optical information extraction unit from the first optical information acquired by the optical information acquisition unit at the first time and the second extracted information extracted by the optical information extraction unit from the second optical information acquired by the optical information acquisition unit at the second time; and a movement distance calculation unit that calculates the movement distance of the workpiece based on the correlation value calculated by the correlation value calculation unit, wherein the optical information extraction unit extracts, from the first optical information, information of a portion that does not include information corresponding to the estimated distance from the front end of the workpiece in the movement direction as the first extracted information, and extracts, from the second optical information, information of a portion that does not include information corresponding to the estimated distance from the rear end of the workpiece in the movement direction as the second extracted information. [Effects of the Invention]

[0007] According to the present disclosure, the accuracy of the calculation results of the movement distance of the workpiece can be improved compared to the conventional art. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a schematic configuration of an information processing system according to a first embodiment. [Figure 2] 1 is a schematic diagram showing an optical system according to a first embodiment. [Figure 3] 2 is a schematic diagram showing optical information acquired by the optical sensor according to the first embodiment, viewed from a direction perpendicular to the surface of the workpiece. FIG. [Figure 4] 4 is a graph showing optical information acquired by the information processing device according to the first embodiment. [Figure 5] 1 is a diagram illustrating an example of a hardware configuration of an information processing device according to a first embodiment. [Figure 6]1 is a diagram illustrating an example of a hardware configuration of an information processing device according to a first embodiment. [Figure 7] 4 is a flowchart showing a travel distance calculation process performed by the information processing device according to the first embodiment. [Figure 8] 2 is a schematic diagram showing optical information acquired by the information processing device according to the first embodiment, viewed from a direction perpendicular to the surface of the workpiece. FIG. [Figure 9] 10 is a graph showing actual measurement values ​​of the relationship between the correlation value calculated by the information processing device according to the first embodiment and the amount of deviation of optical information. [Figure 10] 10 is a flowchart showing a travel distance calculation process performed by an information processing device according to the second embodiment. [Figure 11] 10 is a schematic diagram showing optical information acquired by an information processing device according to a second embodiment, viewed from a direction perpendicular to the surface of a workpiece. FIG. [Figure 12] 10 is a graph showing actual measurement values ​​of the relationship between the correlation value calculated by the information processing device according to the second embodiment and the amount of deviation of optical information. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Embodiment 1 First, the configuration of an information processing system according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram illustrating the information processing system according to the first embodiment. The information processing system according to the first embodiment is a system for measuring the movement distance of a workpiece W1 by calculating the movement distance of the workpiece W1 based on optical information from an optical sensor S1. For example, the workpiece W1, which is the object to be measured, is formed in a sheet shape and moves in one direction as the roll rotates while being unwound or wound into a roll. As shown in FIG. 1, the information processing system according to the first embodiment includes an optical system including a light source LT1 and an optical sensor S1, and an information processing device 100, which are electrically connected by wire or wirelessly so that information can be communicated from the optical sensor S1 to the information processing device 100.

[0010] FIG. 2 is a schematic diagram showing an optical system according to the first embodiment. As shown in FIG. 2, the optical system according to the first embodiment includes, for example, a light source LT1, a condenser lens OP1, an imaging lens OP2, and an optical sensor S1. The light source LT1 is configured, for example, by an LED (Light-Emitting Diode) or a halogen lamp, and emits light when supplied with power. The condenser lens OP1 is configured by a simple lens or a compound lens, and condenses light from the light source LT1 onto the workpiece W1 to illuminate the surface W1a of the workpiece W1. The imaging lens OP2 is configured by a simple lens or a compound lens, and focuses light reflected from the surface W1a of the workpiece W1 onto the optical sensor S1. For example, the imaging lens OP2 is configured by a telecentric lens that focuses light reflected from the surface W1a of the workpiece W1 onto the optical sensor S1.

[0011] The optical sensor S1 is configured by a one-dimensional image sensor in which N imaging elements, numbered 1 to N (for example, N is a natural number equal to or greater than 2), are arranged. For example, the N imaging elements are arranged linearly along a specific direction. The optical sensor S1 acquires image data, which is one-dimensional optical information with a number of pixels corresponding to the number of imaging elements, based on, for example, reflected light from the surface W1a of the workpiece W1 moving in the movement direction D1. In other words, the optical sensor S1 acquires one-dimensional image data with a number of pixels corresponding to the number of imaging elements by capturing an image of the workpiece W1 moving in the movement direction D1. The optical sensor S1 acquires one-dimensional image data corresponding to the light receiving intensity of each imaging element at a specific time interval (imaging interval), and outputs the acquired image data to the information processing device 100.

[0012] Next, the configuration of the information processing device 100 will be described with reference to Figures 1 to 4. As shown in Figure 1, the information processing device 100 includes an optical information acquisition unit 10, a distance estimation value acquisition unit 20, an optical information extraction unit 30, a correlation value calculation unit 40, a peak position detection unit 50, a movement distance calculation unit 60, and a storage unit 70.

[0013] The optical information acquisition unit 10 acquires one-dimensional image data along the movement direction D1 of the workpiece W1 moving in the movement direction D1 based on information from the optical sensor S1. In other words, the optical information acquisition unit 10 acquires one-dimensional image data along the movement direction D1 of the workpiece W1 based on light from the workpiece W1 moving in the movement direction D1.

[0014] 3 is a schematic diagram showing image data A1 and A2 acquired by the optical sensor S1 according to embodiment 1, viewed from a direction perpendicular to the surface W1a of the workpiece W1. For example, when image data is acquired by the optical information acquisition unit 10 at time t1 (first time) and at time t2 (second time), which is a time after time t1, the condition under which the image data A1 acquired by the optical information acquisition unit 10 at time t1 and the image data A2 acquired at time t2 partially overlap each other (the hatched portion in FIG. 3) at a distance L2 is expressed by the following formula (1). In formula (1), v1 represents the moving speed of the workpiece W1, and L1 represents the distance on the surface W1a of the workpiece W1 at which the image data is acquired by the optical information acquisition unit 10. L1>v1×(t2-t1) (1)

[0015] Furthermore, since the movement distance Lm of the workpiece W1 in the movement direction D1 between time t1 and time t2 is equal to the difference between the distance L1 and the overlap distance L2 of the image data A1 and the image data A2, Lm is calculated using the following formula (2). Lm = L1 - L2 (2)

[0016] FIG. 4 is a graph showing image data A1 and A2 acquired by the information processing device 100 according to the first embodiment. In FIG. 4, the horizontal axis represents the numbers of the image sensors in the movement direction D1, from No. 1 at the rear end to No. N at the front end, and the vertical axis represents the light receiving intensity of each image sensor. For example, when the optical sensor S1 captures images of a workpiece W1 moving in the movement direction D1 at times t1 and t2, a specific position of the workpiece W1 captured by the Nth image sensor at time t1 is captured by the image sensor closer to No. 1 at time t2. As a result, as shown in FIG. 4, the waveform of the image data A2 acquired by the optical information acquisition unit 10 at time t2 is a waveform obtained by shifting the waveform of the image data A1 acquired by the optical information acquisition unit 10 at time t1 by an amount corresponding to the distance traveled in the movement direction D1 of the workpiece W1 between time t1 and time t2.

[0017] Therefore, by calculating a correlation value indicating the correlation between two waveforms of image data acquired at two different times and calculating the distance between the two waveforms where the correlation value is highest, the movement distance of the work W1 in the movement direction D1 from time t1 to time t2 can be calculated.

[0018] The distance estimate acquisition unit 20 acquires an estimate of the travel distance of the workpiece W1 during a specific period of time. In other words, the distance estimate acquisition unit 20 acquires an estimate of the travel distance of the workpiece W1 between a specific first time and a specific second time. For example, the distance estimate acquisition unit 20 acquires an estimate of the travel distance of the workpiece W1 by acquiring a set value of the transport speed of a transport device that moves the workpiece W1 from an external device (not shown) that is electrically connected to the information processing device 100. Specifically, the distance estimate acquisition unit 20 acquires an estimate of the travel distance of the workpiece W1 from the first time to the second time by multiplying the set value of the transport speed of the workpiece W1 acquired from the external device by the time from the first time to the second time. Furthermore, for example, the distance estimate acquisition unit 20 acquires an estimate of the travel distance of the workpiece W1 from the first time to the second time by acquiring information about the travel speed of the workpiece W1 at a time prior to the first time.

[0019] The optical information extraction unit 30 extracts a portion of information from the image data acquired by the optical information acquisition unit 10 based on the estimated value acquired by the distance estimation value acquisition unit 20. For example, based on the estimated value acquired by the distance estimation value acquisition unit 20, the optical information extraction unit 30 extracts first extracted information from image data A1 as first optical information acquired at a first time by the optical information acquisition unit 10, and extracts second extracted information from image data A2 as second optical information acquired at a second time by the optical information acquisition unit 10. Specifically, the optical information extraction unit 30 extracts, as the first extracted information, information from a portion of the image data A1 as the first optical information that does not include information about the leading end (e.g., information in the hatched portion in FIG. 3 ), and extracts, as the second extracted information, information from a portion of the image data A2 as the second optical information that does not include information about the trailing end (e.g., information in the hatched portion in FIG. 3 ). Here, the terms "leading end" and "rear end" refer to the leading end and rear end in the movement direction D1 of the workpiece W1. For example, the information on the leading end of image data A1 is information on a length corresponding to the distance from the leading end of image data A1 to the estimated value of the travel distance, and the information on the trailing end of image data A2 is information on a length corresponding to the distance from the trailing end of image data A2 to the estimated value of the travel distance. In other words, the information on the leading end of image data A1 and the trailing end of image data A2 is information on a range where the range imaged by optical sensor S1 at a first time and the range imaged at a second time do not overlap in the movement direction D1 of workpiece W1. Details of the information extracted by optical information extraction unit 30 from the image data acquired by optical information acquisition unit 10 will be described later.

[0020] The correlation value calculation unit 40 calculates a correlation value indicating the correlation between the two pieces of image data by comparing the image data acquired at two different times by the optical information acquisition unit 10. For example, when the image data A1 and image data A2 shown in FIG. 4 are acquired by the optical information acquisition unit 10, the correlation value calculation unit 40 calculates a correlation value indicating the correlation between the image data A1 and image data A2 by phase-only correlation.

[0021] For example, if the imaging element number is x, the waveform representing image data A1 is f1(x), and the waveform representing image data A2 is f2(x), the correlation value calculation unit 40 first calculates Fourier image data F1(u) and F2(u) by performing a discrete Fourier transform on f1(x) and f2(x), respectively. Note that in F1(u) and F2(u), u represents the spatial frequency. Furthermore, the correlation value calculation unit 40 calculates composite Fourier image data F3(u) by combining F1(u) and F2(u) using the following formula (2). Note that in formula (3), "*" represents the complex conjugate. F3(u)=F1*(u)·F2(u) ···(3)

[0022] Furthermore, the correlation value calculation unit 40 performs phase limitation processing on F3(u) to calculate Fourier image data F4(u) using the following formula (4): As a result, the amplitude of all frequencies of F3(u) is set to 1, and composite Fourier image data F4(u) containing only phase is obtained. F4(u)=F3(u) / |F3(u)| (4)

[0023] Furthermore, the correlation value calculation unit 40 performs an inverse Fourier transform on F4(u) to calculate the composite inverse Fourier image data f4(x). In the first embodiment, f4(x) constitutes a correlation value indicating the correlation between the image data acquired by the optical information acquisition unit 10 at two different times.

[0024] The correlation value calculation unit calculates the correlation value between the image data A1 and A2 within the range extracted from the image data A1 and A2 by the optical information extraction unit 30. In other words, the correlation value calculation unit calculates the correlation value between the image data A1 and A2 as a correlation value indicating the correlation between the first extracted information extracted from the image data A1 by the optical information acquisition unit 10 and the second extracted information extracted from the image data A2 by the optical information extraction unit 30. Details of the first extracted information and the second extracted information will be described later.

[0025] The peak position detection unit 50 detects the maximum peak position, which is the position of the maximum peak, from the waveform of f4(x) as the correlation value calculated by the correlation value calculation unit 40. In other words, the peak position detection unit 50 extracts x at which the waveform of f4(x) as the correlation value calculated by the correlation value calculation unit 40 shows the maximum peak. Note that x at which the waveform of f4(x) shows the maximum peak is a value expressed as a multiple of the distance (pixel pitch) between the imaging elements, which represents the amount of deviation between the image data A1 and the image data A2 caused by the movement of the workpiece W1 between time t1 and time t2.

[0026] The movement distance calculation unit 60 calculates the movement distance of the workpiece W1 in the movement direction D1 based on the correlation value calculated by the correlation value calculation unit 40. For example, the movement distance calculation unit 60 calculates the movement distance Lm of the workpiece W1 from time t1 to time t2 using the following formula (5) based on x indicating the maximum peak detected by the peak position detection unit 50. In formula (4), p indicates the distance between the imaging elements, and β indicates the magnification (lateral magnification) of the imaging lens OP2. Lm=x×p / β (5)

[0027] The storage unit 70 stores information used when the information processing device 100 performs each process and information indicating the results of each process. The storage unit 70 stores, for example, image data acquired by the optical information acquisition unit 10, an estimated value of the movement distance of the workpiece W1 acquired by the distance estimation value acquisition unit 20, information extracted by the optical information extraction unit 30, a function indicating each waveform calculated by the correlation value calculation unit 40, the result of processing by the movement distance calculation unit 60, various setting values ​​used when each component of the information processing device 100 performs processing, etc. When each component of the information processing device 100 performs each process, it references and reads the information stored in the storage unit 70 as necessary, and stores the result of each process in the storage unit 70.

[0028] Next, the hardware configuration of the information processing device 100 will be described with reference to FIGS. 5 and 6. FIG. 5 is a block diagram showing an example of the hardware configuration of the information processing device 100 according to the first embodiment, and FIG. 6 is a block diagram showing an example of a hardware configuration of the information processing device 100 according to the first embodiment, which is different from that shown in FIG. 5. For example, as shown in FIG. 5, the information processing device 100 includes a processor 100a, a memory 100b, and an I / O port 100c, and is configured so that the processor 100a reads and executes a program stored in the memory 100b. The memory 100b is configured, for example, by a non-volatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, or an EEPROM, or a combination thereof. The memory 100b may also be a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, a DVD, or the like. The memory 100b may also be an HDD or an SSD.

[0029] 6, the information processing device 100 includes a processing circuit 100d and an I / O port 100c, which are dedicated hardware. The processing circuit 100d is configured, for example, by a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a system LSI (Large-Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. Each function of the information processing device 100 is realized by the processor 100a or the processing circuit 100d, which is dedicated hardware, executing a program that is software, firmware, or a combination of software and firmware. The information processing device 100 may also include hardware other than those described above, such as a hardware timer.

[0030] Next, the movement distance calculation process performed by the information processing device 100 will be described with reference to Fig. 1 and Fig. 7 to Fig. 9. Fig. 7 is a flowchart showing the movement distance calculation process performed by the information processing device 100 according to embodiment 1. The movement distance calculation process performed by the information processing device 100 shown in Fig. 7 is a process for calculating the movement distance of the workpiece W1 based on image data acquired by the optical information acquisition unit 10.

[0031] 7, when the information processing device 100 starts the movement distance calculation process, it first acquires reference optical information (step ST01). In this process, the information processing device 100 acquires, by the optical information acquisition unit 10, image data as reference optical information, which is optical information that serves as a reference when the correlation value calculation unit 40 calculates a correlation value.

[0032] After performing the process of step ST01, the information processing device 100 acquires measured optical information (step ST02). In this process, when the correlation value calculation unit 40 calculates the correlation value, the information processing device 100 acquires, by the optical information acquisition unit 10, image data as measured optical information, which is optical information to be compared with the reference optical information acquired in the process of step ST01. Note that in this process, the information processing device 100 acquires new image data as measured optical information acquired by the optical sensor S1 at a predetermined specific time interval after the image data as the reference optical information acquired in the process of step ST01 is acquired by the optical sensor S1.

[0033] After performing the process of step ST02, the information processing device 100 acquires an estimated value of the movement distance (step ST03). In this process, the information processing device 100 acquires, by the distance estimated value acquisition unit 20, an estimated value of the movement distance of the workpiece W1 during the period from when the image data as the reference optical information is acquired to when the image data as the measurement optical information is acquired.

[0034] After performing the processing of step ST03, the information processing device 100 extracts information of a portion that overlaps with the measured optical information from the reference optical information (step ST04), and extracts information of a portion that overlaps with the reference optical information from the measured optical information (step ST05). In the processing of steps ST04 and ST05, the information processing device 100 extracts information of a mutually overlapping range from the image data A1 as the reference optical information and the image data A2 as the measured optical information, respectively, by the optical information extraction unit 30, based on the estimated value of the movement distance of the workpiece W1 acquired in the processing of step ST03.

[0035] 8 is a schematic diagram showing image data as optical information acquired by the information processing device 100 according to embodiment 1, viewed from a direction perpendicular to the surface W1a of the workpiece W1. Specifically, FIG. 8 is a schematic diagram showing image data A1 as reference optical information acquired by the information processing device 100 according to embodiment 1 and image data A2 as measurement optical information, viewed from a direction perpendicular to the surface W1a of the workpiece W1. In FIG. 8, the image data A1 is composed of a plurality of pixel data from pixel data F1 at the front end to pixel data R1 at the rear end in the movement direction D1 of the workpiece W1, and the image data A2 is composed of a plurality of pixel data from pixel data F2 at the front end to pixel data R2 at the rear end in the movement direction D1 of the workpiece W1, and the image data A1 and the image data A2 are acquired as image data of the same length.

[0036] 8, when image data A1 and image data A2 are acquired by imaging a workpiece W1 moving in a movement direction D1, information P1 in the image data A1, which is information about a length corresponding to the distance traveled by the workpiece W1 from the front end of the workpiece W1 in the movement direction D1, corresponds to a range that was not imaged when image data A2 was acquired by imaging the workpiece W1, and information P2 in the image data A2, which is information about a length corresponding to the distance traveled by the workpiece W1 from the rear end of the workpiece W1 in the movement direction D1, corresponds to a range that was not imaged when image data A2 was acquired by imaging the workpiece W1. In other words, information P1 in the image data A1, which is information about a length corresponding to the distance traveled by the workpiece W1 from the front end of the workpiece W1 in the movement direction D1, does not overlap with image data A2, and information P2 in the image data A2, which is information about a length corresponding to the distance traveled by the workpiece W1 from the rear end of the workpiece W1 in the movement direction D1, does not overlap with image data A1.

[0037] For this reason, when the correlation value between image data A1 and image data A2 is calculated while each of information P1 and information P2 is included, a peak (false peak) that does not correspond to the actual amount of deviation between image data A1 and image data A2 may appear in the waveform of the correlation value at a position other than the peak (true peak) that corresponds to the actual amount of deviation between image data A1 and image data A2. In such a case, if various noises are superimposed on the peak that does not correspond to the actual amount of deviation between image data A1 and image data A2, it may be difficult to detect the peak position that corresponds to the actual amount of deviation between image data A1 and image data A2.

[0038] In contrast, the information processing device 100 according to the first embodiment is configured to extract information of a portion not including information P1 from image data A1, extract information of a portion not including information P2 from image data A2 using an optical information extraction unit, and calculate a correlation value between image data A1 and image data A2 within the range of the extracted information. In other words, the information processing device 100 according to the first embodiment is configured to extract, from image data A1, information of a portion not including information corresponding to the distance of the estimated value of the travel distance from the front end in movement direction D1 of the workpiece W1 as first extracted information, and extract, from image data A2 using the optical information extraction unit, information of a portion not including information corresponding to the distance of the estimated value of the travel distance from the rear end in movement direction D1 of the workpiece W1 as second extracted information, and calculate a correlation value between the first extracted information and the second extracted information, which have the same number of pixels. In other words, the information processing device 100 according to the first embodiment is configured to extract, from the image data A1, information in a range that overlaps with the image data A2 as first extracted information, extract, from the image data A2, information in a range that overlaps with the image data A1 as second extracted information by an optical information extraction unit, and calculate a correlation value between the first extracted information and the second extracted information, which have the same number of pixels. This allows the information processing device 100 to improve the accuracy of detecting a peak corresponding to the actual amount of deviation between the image data A1 and the image data A2, compared to when calculating a correlation value between the entire image data A1 and the entire image data A2.

[0039] After performing the processes of steps ST04 and ST05, the information processing device 100 calculates a correlation value between the reference optical information and the immediately preceding measured optical information (step ST06). In this process, the information processing device 100 uses the correlation value calculation unit 40 to calculate a correlation value between the information extracted from the image data A1 as the reference optical information in the process of step ST04 and the information extracted from the image data A2 as the measured optical information in the process of the immediately preceding step ST05.

[0040] After performing the process of step ST06, the information processing device 100 calculates the movement distance of the workpiece W1 (step ST07). In this process, for example, the information processing device 100 first detects the maximum peak position from the waveform of the correlation value calculated in the process of step ST06 using the peak position detection unit 50. For example, if the estimated value of the movement distance acquired in the process of step ST03 matches the movement distance of the workpiece W1 from time t1 when image data A1 is acquired to time t2 when image data A2 is acquired, the maximum peak position of the waveform of the correlation value will be a position indicating that the amount of deviation between image data A1 and image data A2 is zero. Therefore, the maximum peak of the waveform of the correlation value will be located at a position indicating the difference between the estimated value of the amount of deviation between image data A1 and image data A2 based on the estimated value of the movement distance and the true value of the amount of deviation between image data A1 and image data A2 based on the actual movement distance.

[0041] 9 is a graph showing actual measured values ​​of the relationship between the correlation value calculated by the information processing device 100 according to Embodiment 1 and the amount of deviation of image data as optical information. As shown in Fig. 9, by calculating the correlation value between the first extracted information and the second extracted information extracted by the optical information extraction unit 30, peak PK1, which is the maximum peak of the waveform, clearly appears at a position based on the movement distance.

[0042] Furthermore, in the processing of step ST07, the information processing device 100 calculates the movement distance of the workpiece W1 using the above-mentioned formula (5) based on the amount of deviation between the image data as reference optical information obtained from the detected maximum peak position and the image data as measured optical information, the distance between the imaging elements, and the magnification of the imaging lens.

[0043] After performing the processing of step ST07, the information processing device 100 determines whether or not a termination condition has been met (step ST08). In this processing, the information processing device 100 determines whether or not a condition for terminating the calculation of the movement distance of the workpiece W1 has been met. For example, the conditions for terminating the calculation of the movement distance of the workpiece W1 include the fact that the integrated value of the movement distance of the workpiece W1 has reached a preset value, or the fact that a signal for terminating the calculation of the movement distance has been input to the information processing device 100 from an input device (not shown) by an operator operating the input device.

[0044] If the termination condition is not met in the processing of step ST08 (NO in step ST08), the information processing device 100 sets the measured optical information as reference optical information (step ST09) and deletes the previously acquired estimated value of the travel distance (step ST10). In this processing, the information processing device 100 calculates a new travel distance of the workpiece W1 based on the newly acquired optical information and the newly acquired estimated value of the travel distance, so sets the previously acquired measured optical information as reference optical information and deletes the previously acquired estimated value of the travel distance. After performing the processing of step ST10, the information processing device 100 returns the processing to step ST02. Note that the information processing device 100 may be configured to acquire the travel distance calculated in the immediately preceding processing of step ST07 as the estimated value of the travel distance of the workpiece W1 in the processing of step ST03 performed for the second or subsequent times.

[0045] In the process of step ST08, if the termination condition is met (YES in step ST08), the information processing device 100 terminates the travel distance calculation process.

[0046] As described above, the information processing device 100 according to the first embodiment includes an optical information acquisition unit 10 that acquires one-dimensional optical information of the workpiece W1 based on light from the moving workpiece W1, a distance estimation value acquisition unit 20 that acquires an estimated value of the movement distance of the workpiece W1 between a first time t1 and a second time t2, an optical information extraction unit 30 that extracts some information from the optical information acquired by the optical information acquisition unit 10 based on the estimated value, and first extracted information extracted by the optical information extraction unit 30 from image data A1 as first optical information acquired by the optical information acquisition unit 10 at the first time t1 and second optical information acquired by the optical information acquisition unit 10 at the second time t2. and a movement distance calculation unit 60 that calculates the movement distance of the workpiece based on the correlation value calculated by the correlation value calculation unit 40. The optical information extraction unit 30 is configured to extract, from the image data A1, information of a portion that does not include information P1 corresponding to an estimated distance from the front end of the workpiece W1 in the movement direction D1, as the first extracted information, and to extract, from the image data A2, information of a portion that does not include information P2 corresponding to an estimated distance from the rear end of the workpiece W1 in the movement direction D1, as the second extracted information.

[0047] With this configuration, the information processing device 100 can suppress the influence of noise when calculating the movement distance of the workpiece W1 based on the correlation value, and can improve the accuracy of the calculation results of the movement distance of the workpiece W1 compared to conventional methods.

[0048] In addition, in embodiment 1, the information processing device 100 is configured to extract, from the image data A1, information of a portion that does not include information P1 corresponding to the estimated distance from the front end of the workpiece W1 in the movement direction D1 as first extracted information, and to extract, from the image data A2, information of a portion that does not include information P2 corresponding to the estimated distance from the rear end of the workpiece W1 in the movement direction D1 as second extracted information, but this is not limited to this. The information processing device may be configured to extract first extracted information from the first optical information so as not to include information corresponding to the estimated distance from the leading end in the direction of movement of the workpiece, and to extract second extracted information from the second optical information so as not to include information corresponding to the estimated distance from the trailing end in the direction of movement of the workpiece. For example, the information processing device may be configured to extract, as first extracted information, information from the first optical information that includes a portion of the information corresponding to the estimated distance from the leading end in the direction of movement of the workpiece at the boundary between the information corresponding to the estimated distance from the leading end in the direction of movement of the workpiece and the information of other parts, or to extract, as second extracted information from the second optical information, information that includes a portion of the information corresponding to the estimated distance from the trailing end in the direction of movement of the workpiece at the boundary between the information corresponding to the estimated distance from the trailing end in the direction of movement of the workpiece and the information of other parts.

[0049] Furthermore, the information processing device is not limited to the configuration in which it extracts, from the image data A1, all information of a portion that does not include information P1 corresponding to the estimated distance from the leading end in the movement direction D1 of the workpiece W1 as the first extracted information, and extracts, from the image data A2, all information of a portion that does not include information P2 corresponding to the estimated distance from the trailing end in the movement direction D1 of the workpiece W1 as the second extracted information. The information processing device may be configured to extract, from the first optical information, first extracted information that does not include information corresponding to the estimated distance from the leading end in the movement direction of the workpiece, and to extract, from the second optical information, second extracted information that does not include information corresponding to the estimated distance from the trailing end in the movement direction of the workpiece. For example, the information processing device may be configured to extract, from the first optical information, information of a portion that does not include information corresponding to the estimated distance from the leading end in the movement direction of the workpiece as the first extracted information, and to extract, from the second optical information, information of a portion that does not include information corresponding to the estimated distance from the trailing end in the movement direction of the workpiece as the second extracted information.

[0050] Embodiment 2 Next, an information processing device according to embodiment 2 will be described with reference to Fig. 1 and Fig. 10 to Fig. 12. The information processing device according to embodiment 2 differs from information processing device 100 according to embodiment 1 in the range of information extracted from optical information acquired in the movement distance calculation process, but other details are the same, and the same components as those in embodiment 1 are denoted by the same reference numerals and names, and description thereof will be omitted.

[0051] 10 is a flowchart showing processing performed by the information processing device according to Embodiment 2. Note that part of the processing performed by the information processing device according to Embodiment 2 is similar to the processing performed by the information processing device 100 according to Embodiment 1, and therefore, description of processing similar to the processing performed by the information processing device 100 according to Embodiment 1 will be omitted.

[0052] When the information processing device according to the second embodiment performs the process of step ST03, it extracts two pieces of information from the reference optical information that overlap with the measured optical information. nThe information of the measured optical information is extracted (step ST14), and the two overlapping optical information with the reference optical information are extracted. n In the processes of steps ST04 and ST05, the information processing device according to the second embodiment extracts information of overlapping ranges from the image data as the reference optical information and the image data as the measurement optical information based on the estimated value of the moving distance of the workpiece W1 acquired in the process of step ST03. n In other words, the information processing device according to the second embodiment extracts, by the optical information extraction unit 30, information of a mutually overlapping range from the image data as the reference optical information and the image data as the measurement optical information, based on the estimated value of the movement distance of the workpiece W1 acquired in the processing of step ST03, information corresponding to a power of 2 number of pixels, as the first extracted information and the second extracted information.

[0053] By extracting some information from image data A1 and image data A2 in this manner, the information processing device of embodiment 2 can use a fast Fourier transform (FFT) when performing a Fourier transform on the acquired optical information, thereby speeding up processing.

[0054] Furthermore, in the processing of steps ST04 and ST05, when the information processing device of embodiment 2 extracts some information from image data A1 and image data A2, it extracts some information from image data A1 that does not include information corresponding to the estimated distance from the front end of the workpiece W1 in the movement direction D1 as first extracted information, and extracts some information from image data A2 that does not include information corresponding to the estimated distance from the rear end of the workpiece W1 in the movement direction D1 as second extracted information.

[0055] 11 is a schematic diagram showing optical information acquired by an information processing device according to embodiment 2, viewed from a direction perpendicular to the surface of the workpiece. For example, as shown in FIG. 11, the information processing device extracts from image data A1 two pieces of information that do not include information P1 and that include information C1 at the center of the image data A1. n The information E1 of the length of the workpiece W1 is extracted as the first extracted information, and the information E1 of the length of the workpiece W1 is extracted from the image data A2, and the information E1 of the length of the workpiece W1 is extracted as the first extracted information. The ... n The information E2 about the length of the minute is extracted as the second extracted information.

[0056] By extracting some information from image data A1 and image data A2 in this manner, the information processing device of embodiment 2 can improve the accuracy of extracting the maximum peak corresponding to the actual amount of deviation between image data A1 and image data A2, and can also shorten the time required for processing.

[0057] Fig. 12 is a graph showing actual measurement values ​​of the relationship between the correlation value calculated by the information processing device according to embodiment 2 and the amount of deviation of image data as optical information. As shown in Fig. 12, by calculating the correlation value between the first extracted information and the second extracted information extracted by the optical information extraction unit according to embodiment 2, the position of the maximum peak PK2 of the waveform becomes clear, similar to the peak PK1 of the waveform according to embodiment 1 shown in Fig. 9.

[0058] The information E1 as the first extracted information may be extracted so that the length from the information C1 to the leading end is the same as the length from the information C1 to the trailing end, or may be extracted so that the lengths are different. The length of the information E1 and the lengths from the information C1 to the leading end and the trailing end are appropriately set based on the moving speed of the workpiece W1, the imaging interval, the noise situation, etc., so that the maximum peak tends to appear at a position corresponding to the actual amount of deviation between the image data A1 and the image data A2.

[0059] In any of the above-described embodiments, the information processing device is configured to calculate a correlation value indicating the correlation between image data as reference optical information and image data as measurement optical information by phase-only correlation, but is not limited to this. The information processing device may be configured to calculate a correlation value indicating the correlation between optical information acquired by the optical information acquisition unit at two different times, and may be configured to calculate the correlation value using other pattern matching methods such as normalized cross-correlation (NCC), sum of absolute difference (SAD), or sum of squared difference (SSD), or may be configured to use a known method for estimating a correlation value at a pixel unit or less when using these methods.

[0060] In addition, the present disclosure allows for free combination of the respective embodiments, modification of any of the components of the respective embodiments, or omission of any of the components of the respective embodiments. [Explanation of symbols]

[0061] 10: Optical information acquisition section 20: Distance estimation value acquisition unit 30: Optical information extraction section 40: Correlation value calculation unit 50: Peak position detector 60: Travel distance calculation unit 70: Storage section 100: Information processing device A1, A2: Image data C1: Information D1: Movement direction E1, E2: Information F1: Pixel data F2: Pixel data L1, L2: distance LT1:Light source Lm: Travel distance OP1: Condenser lens OP2: Imaging lens P1, P2: Information PK1, PK2: Peak R1, R2: pixel data S1: Optical sensor W1: Work W1a: Surface t1: 1st time t2: 2nd time

Claims

1. an optical information acquisition unit that acquires one-dimensional optical information of a moving workpiece based on light from the workpiece; a distance estimation value acquisition unit that acquires an estimate of a movement distance of the workpiece between a first time and a second time; an optical information extraction unit that extracts a portion of information from the optical information acquired by the optical information acquisition unit based on the estimated value; a correlation value calculation unit that calculates a correlation value indicating a correlation between first extracted information extracted by the optical information extraction unit from the first optical information acquired at the first time by the optical information acquisition unit and second extracted information extracted by the optical information extraction unit from the second optical information acquired at the second time by the optical information acquisition unit; a movement distance calculation unit that calculates a movement distance of the workpiece based on the correlation value calculated by the correlation value calculation unit, The optical information extraction unit extracts the first extracted information from the first optical information so as not to include information corresponding to the estimated value of the distance from the front end of the workpiece in the movement direction, and extracts the second extracted information from the second optical information so as not to include information corresponding to the estimated value of the distance from the rear end of the workpiece in the movement direction.

1. An information processing device comprising:

2. The optical information extraction unit extracts, from the first optical information and the second optical information, information corresponding to a power of 2 number of pixels as the first extracted information and the second extracted information.

3. The information processing apparatus according to claim 1, wherein the information processing apparatus is a computer.

3. An information processing method performed by an apparatus including an optical information acquisition unit, a distance estimation value acquisition unit, an optical information extraction unit, a correlation value calculation unit, and a movement distance calculation unit, The optical information acquisition unit acquires one-dimensional optical information of the workpiece based on light from the moving workpiece; a step in which the distance estimated value acquisition unit acquires an estimated value of a movement distance of the workpiece from a first time to a second time; a step in which the optical information extraction unit extracts some information from the optical information acquired by the optical information acquisition unit based on the estimated value; a step in which the correlation value calculation unit calculates a correlation value indicating a correlation between first extracted information extracted by the optical information extraction unit from first optical information acquired at the first time by the optical information acquisition unit and second extracted information extracted by the optical information extraction unit from second optical information acquired at the second time by the optical information acquisition unit; The movement distance calculation unit calculates a movement distance of the workpiece based on the correlation value calculated by the correlation value calculation unit, The optical information extraction unit extracts the first extracted information from the first optical information so as not to include information corresponding to the estimated value of the distance from the front end of the workpiece in the movement direction, and extracts the second extracted information from the second optical information so as not to include information corresponding to the estimated value of the distance from the rear end of the workpiece in the movement direction.

1. An information processing method comprising:

Images