JP4450154B2 - Measurement processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a technique for sequentially guiding a plurality of objects to a measurement region of a sensor that measures a predetermined physical quantity and executing a predetermined measurement process on each object. In particular, this inventionA type that detects an object by changing the level of the output signal, such as a photoelectric sensor or a displacement sensor.While inputting the output from the sensor,Of the same type that is transported sequentially to the detection area of this sensorThe present invention relates to a measurement processing apparatus that sequentially executes measurement processing on an object and outputs the result to a host device.
[0002]
[Prior art]
For example, in a factory inspection line, a sensor for measurement is installed in the vicinity of a conveyor, and signals from sensors for workpieces that are sequentially conveyed are processed to determine whether the workpiece is good or bad. FIG. 17 shows an example of this type of inspection.
[0003]
In the illustrated example, a bottle 6 with a lid is used as an inspection object, and the lid 6a is inspected to be mounted or is not mounted in an inadequate state. Use two sets. The light projecting units 30A and 30B and the light receiving units 40A and 40B of each sensor are arranged to face each other via a conveyance conveyor (not shown). Further, the light projecting units 30A and 30B and the light receiving units 40A and 40B are arranged at intervals corresponding to the width of the bottle 6 to be inspected.
[0004]
Each of the light projecting units 30A and 30B is configured to emit band-like light 70A and 70B in the range from the shoulder portion of the bottle body 6b to the lid portion 6a. Although not shown in this figure, a timing sensor 203 (shown in FIG. 18) for measuring timing is provided in the vicinity of the position where the light projecting and receiving units are provided.
[0005]
FIG. 18 shows a schematic configuration of a system used for the inspection.
In the figure, the detection unit 200A is configured by the light projecting unit 30A and the light receiving unit 40A, and the detection unit 200B is configured by the light projecting unit 30B and the light receiving unit 40B. These detection units 200A and 200B are connected to signal processing units 201A and 201B, respectively. Each of the signal processing units 201A and 201B takes in output signals from the light receiving units 40A and 40B in response to a trigger signal from the timing sensor 203. Then, by applying amplification processing and A / D conversion processing to the received light signal, measurement data indicating the amount of received light is generated. Measurement data from each of the signal processing devices 201A and 202B is input to a host device 204 such as a PLC (programmable controller), and arithmetic processing and measurement processing for inspection are performed.
[0006]
The above inspection is performed by processing the received light amount acquired by each sensor at the timing when both side portions of the bottle 6 enter the irradiation areas of the respective band-like lights 70A and 70B. Here, as shown in FIG. 19, each of the light receiving portions 40A and 40B is set so as to individually measure the amount of light passing through the space between the bottle body 6b and the lid portion 6a at the front and rear positions. Here, when the lid portion is inclined, as shown in FIG. 19, the amount of the strip light 70A, 70B passing through the space between the bottle body 6b and the lid portion 6a is different between the front side and the rear side. It will be different. Based on the above principle, the host device 204 compares the received light amount of each of the light receiving units 30A and 30B with each other or compares each received light amount with a predetermined reference value, whereby the lid unit 6a is inclined or floated. Determine whether it has occurred.
[0007]
[Problems to be solved by the invention]
In the above inspection, since it is necessary to arrange the detection units 200A and 200B at intervals according to the width of the bottle 6, when a plurality of types of bottles having different widths are to be inspected, each time the inspection object is changed, the detection unit There arises a problem that the interval between 200A and 200B must be adjusted.
[0008]
Similar problems occur in addition to inspection using a transmission type length measuring sensor. For example, when inspecting the shape of a workpiece using a displacement sensor, the conventional inspection extracts the maximum or minimum value of the detection distance in a predetermined detection range on the workpiece. It is difficult to compare to the above, or to obtain the distance between the separated steps. Further, when a plurality of sensors are combined for such an inspection, as in the inspection of FIG. 17, it takes time to adjust the positioning of each sensor, and the adjustment must be performed every time the workpiece to be inspected is changed. .
[0009]
In general, the host device not only performs processing for inspection, but also controls various drive systems while inputting various signals and communicating with other devices. In such an apparatus, it is difficult to quickly respond to an input from a sensor while performing control other than inspection, and there are limitations in performing measurement processing while conveying a large number of workpieces at high speed.
[0010]
The present invention has been made paying attention to the above-described problems, and is interposed between the sensor and the host device so that it can respond to the output from the sensor at high speed and can execute measurement processing according to various purposes. It is an object to provide a simple device.
Another object of the present invention is to reduce the time and labor required for the positioning adjustment of the sensor even when the object to be measured is changed or to measure an object having a complicated shape, and to enable the measurement process to be resumed quickly. To do.
[0011]
[Means for Solving the Problems]
  The measurement processing apparatus according to the present invention is connected to a sensor of a type that detects an object by a change in the level of an output signal, and for the same type of object that is sequentially conveyed to the detection area of the sensor at a predetermined interval, It performs measurement processing using an output signal from the sensor, an input circuit for inputting the output signal from the sensor, a memory for storing measurement value data indicated by the signal input by the input circuit, An arithmetic circuit for measurement processing and an output circuit for outputting processing results of the arithmetic circuit to the outside are accommodated in a single housing and include a connector or an output signal line including an output terminal The cable is exposed to the outside of the housing. Further, the measurement processing apparatus includes a first registration unit that registers at least one set value of a trigger level for specifying a start point and an end point of a data accumulation period in the memory with respect to the measurement value data. The standard of the data accumulation period specified by the trigger levelThe length is registered by the number of data T stored when the measured value data generated during the data storage period is stored in the memory at regular intervals.The point in time corresponding to the measured value data in the data accumulation period orThe start point and end point of the period corresponding to the measurement value data to be measured depend on the number of data stored in the memory from the start point of the data storage period to the corresponding time point.Second registration means to be registered is further provided. The arithmetic circuit compares hourly measured value data with a trigger level registered in the first registration means.ByWhile determining the start point and end point of the data accumulation period,Between the start point and the end pointThe resulting measurement dataAt regular intervalsData storage means for storing in the memory, and the data storage meansNumber of data stored in memoryT1 andNumber of data indicating the standard time length of the data accumulation periodBased on the ratio with T,Measurement targetThe corresponding point in time or the corresponding periodThe number of data registered in the second registration means for the start point and end point ofAdjust and after that adjustmentThe number of dataCorresponding toOf time or periodAnd a calculation means for reading the measurement value data from the memory and executing a calculation process using the read data. Further, the output circuit is the same as the arithmetic circuit.Using the measured value data accumulated during the data accumulation period by determining the start and end points of the data accumulation periodEach time the arithmetic processing is finished, the arithmetic processing result is output to the output terminal or the output signal line.
[0012]
The “sensor” in the present invention has a function of measuring various physical quantities such as light quantity, magnetic field change, radio wave intensity, vibration amount, etc., and is a single detection unit or the transmission type. Like the light projecting / receiving unit of the length measurement sensor, it includes a plurality of detection units. The detection unit can convert the measured physical quantity into an electrical signal and output it. In addition, the electrical signal can be digitally converted and output.
[0013]
Further, the sensor may be configured as a type in which the detection unit and the signal processing unit are separated. The signal processing unit preferably has a function of outputting a value (measurement value) indicating the physical quantity measured by the detection unit as digital data. Further, the signal processing unit can be configured to output a measurement value subjected to a predetermined correction process or output a measurement value averaged by a moving average process or the like. In addition, the measurement value can be converted into a form suitable for use in measurement processing. For example, in an optical displacement sensor, processing for converting a signal from a light receiving unit into distance data corresponds to this.
[0014]
In the above measurement processing apparatus, the input circuit can be configured to input an analog signal or a digital signal according to the output form on the sensor side. In addition, both analog and digital input circuits can be included so that any sensor can be used.
[0015]
The arithmetic circuit is preferably configured by a computer. The memory can be set in a built-in memory area of the computer. Alternatively, it can be set in an external memory device of the computer. The arithmetic processing executed by the arithmetic circuit can be variously set according to the purpose of the measurement processing. However, when used for the purpose of inspection, the arithmetic processing may include processing for determining whether the object is good or bad. it can.
[0016]
The output circuit desirably outputs to a host device such as a PLC or a personal computer. This is to make it possible to cope with a system in which the measurement result is used in a host device while performing measurement processing on a large number of objects in a factory production line, an inspection line, or the like.
[0017]
The connector or cable can be considered to connect the measurement processing apparatus to a host device. When a connector is used, it can be connected to the host device via an optional cable. When a cable is used, the cable can be connected to the host device directly or via an extension cable.
In addition to the output terminal, the connector may include an input terminal that receives a signal from a host device. Similarly, in addition to the output signal line, the cable can include an input signal line for transmitting a signal from a host device.
[0018]
  According to the measurement processing apparatus, the measurement value data indicated by the signal input from the sensor while the object passes through the detection region of the sensor while inputting the output from the sensor via the input circuit.In memory at regular intervalsAfter the accumulation of data related to one object is completed, the measurement value data of the measurement object can be read out from the accumulated measurement value data and a detailed measurement process can be performed. In addition, every time the measurement processing for one object is completed, the processing result is output to the host device, so that the inclination and floating of the lid as shown in FIG. 17 can be detected, or the shape of the object can be changed. Even in the case of detecting the measurement, the measurement process can be performed using the measurement result of the single sensor.
[0019]
  Furthermore, in the above measurement processing device, the time point corresponding to the measurement target data or the corresponding periodAre registered in the second registration means by the number of data accumulated in the memory from the start point of the data accumulation period to the corresponding time point, and the number of data isThe length of the actual data storage periodNumber of data representingStandard registered in T1 and the second registration meansNumber of data representing lengthAdjusted based on the ratio with T, and after adjustmentCorresponding to the number of dataSince the calculation using the measurement value data is executed, the calculation using the data suitable for the measurement process can be executed even when the conveyance speed of the object changes.
[0020]
  In a preferred aspect of the above-described measurement processing apparatus, the calculation means includes a time point corresponding to the measurement value data to be measured or a start point and an end point of the corresponding period.As a process for adjusting the data, the standard length of the data accumulation period is indicated by the number of data t registered in the second registration means at the corresponding time.Against TThe number of dataMultiplication by the ratio of T1 (T1 / T)Run.
[0021]
  For example, if the moving speed of the object changes, the length of the data accumulation periodNumber of data indicatingChanges from T to T1, and for this object, x from the start of the periodThe second data is measuredIn the target areaWith correspondingThen, the x can be calculated by the following equation (A).
  x = (T1 / T) × t (A)
[0022]
  Therefore, when the length of the data accumulation period changes, the calculation means calculates the value of x calculated using the above equation (A).Read measurement data of measurement target from memorybe able to. In addition, when the calculation using the measured value data within the predetermined period is executed, the corresponding point in the actual data accumulation period is determined by applying the above equation (A) for the start point and the end point of this period.The number of dataBy adjusting, the measured value data of the measurement targetRead from memorybe able to.
[0023]
  In another aspect of the measurement processing apparatus, an input unit for inputting a trigger level registered in the first registration unit and information registered in the second registration unit is further provided.
[0024]
  The trigger level input isNumeric inputCan be performed. OrFrom the sensor when measuring the model objectMeasured value data indicated by the signalAnd when the display reaches a predetermined value, the displayNumberAs trigger levelinputYou can also.The information registered in the second registration means can also be input while displaying the measured value data for the model workpiece.
[0025]
  In another aspect of the measurement processing apparatus, the measurement unit that measures an elapsed time after the end point of the data storage period is determined by the data storage unit, and the time measured by the measurement unit exceeds a predetermined reference time. And error output means for outputting error information when the error occurs.
[0026]
  According to the measurement means and the error output means, the abnormality is overlooked even when the starting point of the data accumulation period cannot be determined because abnormality has occurred in the object and the measured value data has not reached the trigger level. Can be prevented.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of an inspection system to which the present invention is applied.
In this inspection, the bottles 61, 62,... With lids are inspected, and the lid portion 6a is mounted with an inclination (inclination) or the lid portion 6a is mounted with an insufficient state (inclination). This is for detecting floating. In the figure, reference numeral 5 denotes a conveyor that conveys the bottles 61, 62... (Hereinafter also referred to as “workpieces”) to be inspected. At a predetermined position of the conveyor 5, a light projecting unit 3 and a light receiving unit 4 that constitute a detection unit of a transmission type length measuring sensor are arranged to face each other along the width direction. The light projecting unit 3 and the light receiving unit 4 are electrically connected to a signal processing unit 2 described later.
[0038]
The light projecting unit 3 emits a band-like light 7 having a predetermined width toward the light receiving unit 4, and the light receiving unit 4 receives the amount of light received at predetermined time intervals under the control of the signal processing unit 2. get. The emission position and the emission range of the belt-like light 7 are adjusted so as to be applied from the shoulder portion of the bottle body 6b to be measured to the entire lid portion 6a.
[0039]
The signal processing unit 2 receives the analog signal indicating the amount of received light from the light receiving unit 4 and performs amplification processing or digital conversion processing on the signal to generate digital data indicating the amount of received light. Hereinafter, the digital data is referred to as “light reception data”, and the value indicated by the light reception data is referred to as “measurement value”. The hourly light reception data is input to the measurement processing apparatus 1 according to the present invention. The measurement processing device 1 executes a measurement process necessary for determining whether the lid 6a is tilted or floating, for each work, and determines whether each work is good or bad. The determination result and the measurement processing result are output to a host device (not shown) such as a PLC or a personal computer. Upon receiving this output, the host device performs processing such as notifying the defective work to be collected on the subsequent correction line and outputting information indicating the content of the failure.
[0040]
FIG. 2 shows the appearance of the measurement processing device 1 and the signal processing unit 2 used in the inspection system. The signal processing unit 2 is generally called an “amplifier unit”.
The body of the measurement processing device 1 and the signal processing unit 2 is composed of a casing 10 of the same standard. A substrate on which an input / output circuit for a microcomputer or an external device is mounted is incorporated in each housing 10, and a display unit 102 and an input unit 103 to be described later are provided on the upper surface. This upper surface is protected by a cover body 11 that can be opened.
[0041]
Openings 12 are formed on both side surfaces of the housing 10. Each of these openings 12 is provided with a slide-type lid 13, and a female connector 14 is provided therein.
[0042]
The measurement processing device 1 and the signal processing unit 2 are connected in a state in which a relay board (not shown) is interposed between the respective side surfaces. For this connection, male connectors that engage with the connectors 14 and 14 in each housing 10 are provided on both sides of the relay board. Note that the lid portion 13 is usually covered on the opening portion 12 of each housing 10 on the side not connected to the relay board.
[0043]
Connection cables 15, 16 a and 16 b are drawn out from the respective end faces of the housing 10. The cable 15 common to the measurement processing device 1 and the signal processing unit 2 includes a power supply line, an external input line for timing signals described later, an output line for outputting a processing result, and the like. Further, a connector 19 shown in FIGS.
[0044]
The cable from the other end surface differs depending on the device. The cable 16b on the signal processing unit 2 side is used to connect to the detection unit of the sensor, and a sensor connector 17 is provided at the tip. The light projecting unit 3 and the light receiving unit 4 in FIG. 1 are connected to the connector 17 via a cable (not shown) having a branch connector.
On the other hand, the cable 16a on the measurement processing device 1 side is for connecting to the above-mentioned host device, and a connection connector 18 of the RS-232C standard is provided at the tip.
[0045]
FIG. 3 shows an electrical configuration of the measurement processing apparatus 1.
The measurement processing apparatus 1 includes an EEPROM 101, a display unit 102, an input unit 103, two communication processing circuits 104 and 104, a detection unit processing circuit 105, an external input circuit 106, and an analog output circuit 107, which are connected to a CPU 100 that is a control subject. A digital output circuit 108, an RS-232C standard interface circuit 109 (hereinafter simply referred to as “interface circuit 109”), a reset circuit 110, and the like.
[0046]
The CPU 100 includes a ROM in which programs and the like are stored, and a RAM for temporarily storing work data generated during measurement processing. The EEPROM 101 is for storing set values such as a trigger level described later. The built-in RAM of the CPU 100 is provided with a memory area (hereinafter referred to as “buffer” for convenience) for storing received light data.
The input unit 103 is used for inputting the set value. Further, the display unit 102 can display information for supporting the input of the setting value and information for confirming the setting content, and can also display a processing result for each work during the measurement processing.
[0047]
The communication processing circuit 104 is interposed between the CPU 100 and the connector 14 and is used to execute communication for inputting the received light data with the signal processing unit 2. The communication processing circuit 104 includes a circuit that prevents inflow of current when the power is not turned on. The interface circuit 109 is for communicating with the host device and is connected to the connector 18 via the cable 16a.
[0048]
The detection unit processing circuit 105 is used when the measurement processing device 1 is directly connected to the light projecting / receiving units 3 and 4 of the photoelectric sensor. The driving circuit for the light projecting unit 3 and the signal from the light receiving unit 4 are used. And an A / D conversion circuit for digitally converting the amplified received light signal.
[0049]
The external input circuit 106 is used when a trigger signal is input from an external timing sensor. The analog output circuit 107 is for converting the light reception data received from the signal processing unit 2 and the result of measurement processing by the CPU 100 into analog signals and outputting them. The digital output circuit 108 is for outputting digital data indicating the discrimination processing result of the CPU 100 and the like. Signal lines from the external input circuit 106, the analog output circuit 107, and the digital output circuit 108 are included in the cable 15.
[0050]
FIG. 4 shows an electrical configuration of the signal processing unit 2.
The signal processing unit 2 is not provided with the interface circuit 109 to the host device, but has the same configuration as that of the measurement processing device 1 except for the above. Therefore, in FIG. 4, each structure is shown with the code | symbol which attached | subjected A to the same number as the corresponding structure of FIG.
[0051]
In the inspection system of FIG. 1, the light projecting / receiving units 3 and 4 are connected to the detection unit processing circuit 105 </ b> A on the signal processing unit 2 side. The measurement processing apparatus 1 inputs light reception data from the signal processing unit 2 via the connector 14 and the communication processing circuit 104, and executes arithmetic processing and determination processing for inspection. In the following, the calculation process and the determination process are collectively referred to as “measurement process”.
[0052]
The result of the measurement process is output to the host device via the interface circuit 109. Note that the measurement processing result can be output to a second host device or a device other than the host device via the analog output circuit 107 and the digital output circuit 108. Similarly, the signal processing unit 2 can output measurement data or the like to a device other than the measurement processing device 1 using the analog output circuit 107A and the digital output circuit 108A.
[0053]
In addition, the measurement processing apparatus 1 can connect the two signal processing units 2 and 2 using the connectors 14 and 14 on both sides, and individually execute the measurement processing for the signal processing units 2 and 2. Further, although not necessary when performing the inspection as shown in FIG. 1, the signal processing unit 2 is connected to the other signal processing unit 2 via the connector 14 on the side opposite to that connected to the measurement processing device 1. Can be connected. In this case, the signal processing unit 2 inputs measurement data from another signal processing unit 2 connected thereto, and performs arithmetic processing (for example, difference calculation or average value) using the input value and the measurement value in its own device. The calculation result can be transmitted to the measurement processing apparatus 1.
[0054]
In addition, the light projecting unit 3 and the light receiving unit 4 can be directly connected without connecting the signal processing unit 2 to the measurement processing device 1. In this case, since the measurement processing apparatus 1 is connected with the cable 16b instead of the cable 16a, the output to the host device is performed using the analog output circuit 107 and the digital output circuit 108.
[0055]
FIG. 5 shows an example of changes in measured values in the inspection of FIG. 1 together with the measurement processing method.
According to the setting of the optical system as shown in FIG. 1, the measured value is kept constant until the work enters the band-like light 7. The measured value is decreased by the amount 7 is shielded from light. In this embodiment, a portion in which a space is interposed between the bottle body 6b and the lid portion 6a from among the change curves of the measured values from when the workpiece enters the band light 7 until it finishes passing through the band light 7; A feature point corresponding to the boundary with the portion where the space disappears is extracted. In the figure, A is a feature point corresponding to the front boundary, and B is a feature point corresponding to the rear boundary.
[0056]
In the measurement processing apparatus 1, a level L1 corresponding to the measurement value immediately after the work enters the strip light 7 is set in advance as a trigger level. The CPU 100 of the measurement processing apparatus 1 inputs the hourly received light data, and the period during which the measured value is equal to or lower than the trigger level L1 is the period from when the workpiece enters the band light 7 until it finishes passing the band light 7 To do. Then, while determining the start point and end point of this period based on the trigger level L1, the received light data within the period is stored in the built-in RAM (hereinafter, the period for storing the received light data is referred to as “data storage”). Term "). Further, when the accumulation of the received light data for one work is completed, the feature points A and B in the figure are extracted by performing a differentiation process on the waveform indicated by the accumulated measurement value.
[0057]
Further, the CPU 100 executes a calculation for subtracting a predetermined reference value from the measurement values corresponding to the feature points A and B and a calculation for obtaining a difference between the measurement values. Here, if the lid 6a is not tilted or floated, it is considered that any calculation result is a value that approximates zero.
[0058]
The built-in RAM is provided with two buffers for storing the received light data. As shown in FIG. 6, the CPU 100 performs measurement processing using the received light data that has been accumulated in the other buffer while accumulating the received light data in one buffer by sequentially performing the data accumulation processing for each buffer. I am trying to do it. In this way, by executing the data accumulation process and the measurement process in parallel, even if the interval between each work is set short or the work is transported at high speed, the measurement process for each work is a problem. It can be made to progress without.
[0059]
FIG. 7 shows another setting example of the data accumulation period for the received light data. In these examples, a period from when the workpiece enters the band light 7 until it finishes passing through the band light 7, in other words, a part of the period during which the received light data can be accumulated is defined as a data accumulation period. It is a thing.
[0060]
In FIG. 7 (1), two trigger levels L1 and L2 are set in the range of change in the measured value obtained while the work passes through the strip light 7, and the measured value is between these trigger levels L1 and L2. Two periods T_A, T_BIs the data accumulation period. As in the example of FIG. 5, the first trigger level L <b> 1 is set according to the measurement value immediately after the workpiece enters the band-shaped light 7 or immediately before passing the band-shaped light 7. The second trigger level L2 is set in the vicinity of an intermediate position between the minimum value that can be taken by the feature points A and B and the minimum received light amount L0 that can be obtained while the workpiece passes through the belt-like light 7. Therefore, period T_AIncludes the feature point A in the period T_BIncludes the feature points B, respectively.
[0061]
In FIG. 7B, as in the example of FIG. 5, only a single trigger level L1 is set based on the measurement level immediately after the work enters the strip light 7. However, in this example, two periods T separated by a predetermined time interval within a period in which the measured value is equal to or lower than the trigger level L1._A, T_BIs a data accumulation period. Period T_AIs a period T including a period including the feature point A._BCorresponds to a period including the feature point B, respectively. These periods are set by, for example, measuring a model workpiece, extracting a time point at which measurement data corresponding to each feature point A and B is obtained, and inputting data indicating the time point from the input unit 103. The The light reception data from the signal processing unit 2 is input at regular time intervals, so that the period T_A, T_BCan be converted into the number of input data. Therefore, the CPU 100 counts the input data every hour starting from the time when the measured value reaches the trigger level L1, and the counted value is the period T_AAnd period T_BThe input data accumulation process is performed when the input data is in the numerical range corresponding to.
[0062]
7 (1) and 2 (2) above, the light reception data obtained by narrowing down the periods including the feature points A and B individually from the light reception data obtained while the workpiece passes through the strip light 7 is used. Can be accumulated. Therefore, the number of accumulated data can be reduced and the buffer capacity can be saved. In particular, when the bottle with a narrow mouth width is replaced with a bottle with a wide mouth width, the number of data to be accumulated increases in the setting shown in FIG. 5, but most of the increase is extracted from the feature points A and B. Is not included in the range (the range indicated by the symbol S in FIG. 7). On the other hand, according to the settings as shown in FIGS. 7 (1) and (2), by providing appropriate setting values, it is possible to narrow down the period in which changes necessary for measurement appear and accumulate received light data. Even if the length of the range S changes, efficient data processing can be performed without greatly changing the number of accumulated data.
[0063]
Next, FIGS. 8, 9, and 10 show the processing procedure of the measurement processing apparatus 1 when the methods of FIGS. 5 and 7 (1) and (2) are used. Note that the measurement processing apparatus 1 selectively executes any one of the procedures in FIGS. 8 to 10. Here, in order to avoid confusion between steps, the procedure in FIG. The procedure of 9 is started from step 21 and the procedure of FIG. 10 is started from step 41, respectively. In the following description and drawings, the step is indicated as “ST”.
[0064]
First, when the procedure of FIG. 8 corresponding to the method of FIG. 5 is performed, an array D (i) for accumulating received light data and a variable M for temporarily storing a measurement value indicated by the received light data every hour. And prepare. When the processing of FIG. 6 is executed, the array D (i) is composed of two arrays, and the array to be used is switched every time processing for one work is completed. The same applies to the arrays D1 (i) and D2 (j) in FIGS.
[0065]
8 are executed for each workpiece. First, after i is set to the initial value “1” in ST1, the measured value is acquired in the next ST2 and stored in the variable M. To do. Hereinafter, this M is referred to as “measured value M”.
[0066]
In ST3, the measured value M is compared with the trigger level L1. Here, if the measured value M is larger than L1, ST3 becomes “NO”, the process returns to ST2, and the next measured value is acquired. In the same manner, the measurement value for every hour is continuously acquired until the measurement value M becomes L1 or less.
[0067]
When the measured value M is equal to or less than L1, the process proceeds to ST4, where M is stored as the first accumulated data (D (1)). Next, in ST5, the measurement value is acquired again. Thereafter, the process advances from ST6 to ST7 and ST8 in order and returns to ST5, thereby accumulating the measured values every hour.
[0068]
When the measured value M acquired at a predetermined time becomes larger than L1, the process proceeds from ST6 to ST9, and using the accumulated received light data, a differential operation for extracting the feature points A and B, and each feature point A , B and the like using the measured values corresponding to B. In the next ST10, the quality of the work is determined based on the result of the difference calculation, and the determination result is output in ST11. If it is determined as “bad” in ST10, the calculation result can also be output together in ST11 (the same applies to the output processing of FIGS. 8, 9, and 10).
[0069]
When executing the procedure of FIG. 9 corresponding to FIG._AAn array D1 (i) for accumulating the received light data for the period T, and the period T_BAnd an array D2 (j) for accumulating the received light data. In the first ST21, after setting i and j to the initial value “1”, the measurement value is acquired in the next ST22, and the measurement value M is compared with the trigger levels L1 and L2 in the next ST23. Then, the time point when the measured value M satisfies the condition of L2 ≦ M ≦ L1 is defined as the period T_AThe accumulation of received light data is started (ST24). Thereafter, in ST25-28, by executing the processing according to ST5-8 of FIG._AThe received light data for is stored.
[0070]
Period T_AWhen the data storage process is completed, ST29 and ST30 are repeatedly executed until the measured value M again satisfies the condition of L2 ≦ M ≦ L1. When the measured value M satisfies the above condition, the period T_BIs received (ST31-35).
[0071]
In this way, the period T_A, T_BAfter the accumulation of the received light data is finished, the calculation process (ST36) using the accumulated received light data, the discrimination process based on the calculation result (ST37), and the output of the discrimination result (ST38) are executed in order. The processing related to the workpiece is terminated.
[0072]
Next, when the procedure of FIG. 10 corresponding to FIG. 7 (2) is executed, as in the case of FIG._AArray D1 (i) for accumulating the received light data according to the period T_BAnd an array D2 (j) for accumulating the received light data.
[0073]
In this embodiment, after the initial values of i and j are set to “0” in ST41, ST42 for acquiring the measured value and ST43 for comparing the acquired measured value M with the trigger level L1 are repeatedly executed. . Here, when the measured value M becomes equal to or lower than the trigger level L1, the process proceeds from ST43 to ST44, where_ACheck if it is the starting point of.
[0074]
In ST44, the number of executions of ST46 is equal to the period T._AWhether or not it corresponds to the start time of_AUntil the value corresponding to the starting point of ST46 is reached, ST46 and ST44 for obtaining the measurement value are repeated. Then, when ST44 becomes “YES”, in the following ST45 to 49, the period T_AThe process of accumulating each received light data in sequence is executed. In ST49, similar to ST44, based on the number of executions of ST48, the period T_ADetermine the end point of.
[0075]
Period T_AWhen the data storage process related to is completed, the period T_BThe data accumulation process is executed (ST50 to 55). Thereafter, in ST56 to 58, the calculation process, the discrimination process, and the output process are sequentially executed, and the process for one work is ended.
[0076]
In the procedures of FIGS. 9 and 10, each period T_A, T_BAlthough the arrays D1 (i) and D2 (j) are set for each, the present invention is not limited to this._A, T_BThe received light data may be stored in series.
Next, the procedure shown in FIGS. 8 to 10 is based on the premise that the workpiece is conveyed smoothly. If there is a possibility that the workpiece stops during the conveyance, the procedure shown in FIG. 11 is performed. It is desirable to perform appropriate processing.
[0077]
In FIG. 11, as in FIG. 8, the data accumulation process is performed within a period in which the measured value falls below the trigger level L1, but the accumulation process is interrupted when the work stops during the data accumulation period. I am doing so. In FIG. 11, in order to simplify the comparison with FIG. 8 and simplify the description, the steps corresponding to ST1 to ST11 are shown as ST1 to ST11.
[0078]
In this embodiment, ST3-1 is added between ST3 and ST4, and ST6-1 and ST6-2 are added between ST6 and ST7, respectively.
Mb in each step added here is a variable for storing the measurement value acquired immediately before. In ST 3-1, when the previous determination of ST 3 is “YES”, that is, the measurement value M acquired in ST 2 becomes equal to or lower than the trigger level L 1, the measurement value M is stored in Mb. This measured value M is processed as the first accumulated data in the next ST4.
[0079]
In ST6-1, the difference between the measurement value M acquired in ST5 and the previous measurement value Mb is obtained, and this difference is compared with a predetermined threshold Th. Here, Th corresponds to the amount of change in the measured value when the workpiece is moving, and is set prior to the measurement process, similarly to the trigger level L1. In this embodiment, the measurement data is accumulated only when the difference between the measurement values M and Mb is larger than the threshold value Th, and when the difference is less than the threshold value Th, the measurement data is accumulated. I am trying not to. When measurement data is accumulated, in ST6-2, the value of Mb is updated with the measurement value M related to the accumulation data.
[0080]
According to the procedure as shown in FIG. 11, when the work is stopped during the data accumulation period, the data accumulation process is stopped. Therefore, unnecessary data can be prevented from increasing, and efficient data can be obtained after the accumulation process. Processing can be performed. Similarly, the procedure shown in FIGS. 9 and 10 can be handled in the middle of stopping the work by making a change according to FIG.
If a state in which the workpiece does not move (for example, a state in which ST6-1 is “NO” in FIG. 11) continues for a predetermined time, the processing may be stopped and warning information may be output. .
[0081]
Next, in the procedure of FIG. 8 or FIG. 11, the time point when the measured value has changed from a state greater than the trigger level L1 to a value less than or equal to L1 is set as the starting point of the data accumulation period, but instead of this trigger level L1, The starting point of the data accumulation period may be determined based on a trigger signal from the timing sensor. In this case, if the work is transported at a constant speed, the end point of the data accumulation period can be determined based on the passage of time after the trigger signal is input. The determination may be made based on the trigger level.
In addition, although there is a possibility that the number of accumulated data increases, a period from when a trigger signal is input to when the next trigger signal is input may be set as a data accumulation period.
[0082]
Next, the measurement processing apparatus 1 can be set so that a certain number of received light data is always accumulated, or the accumulated data has a certain level of resolution or more.
[0083]
First, when the number of accumulated data is maintained at a fixed number (hereinafter referred to as “N”), an input of the length T of the data accumulation period is received from the input unit 103 prior to the measurement process. The CPU 100 sets the sampling interval t (t = T / N) of the received light data based on the input time length T and the data number N. Then, in the measurement process, as shown in FIG. 12, after the start of the data accumulation period, the received light data is captured and accumulated at each sampling interval t. In the above setting process, the set value is displayed by displaying the set t value or the number of samples (number of data / msec) per predetermined time unit (for example, 1 millisecond) on the display unit 102. It is desirable to be able to confirm.
[0084]
When the resolution is made constant, input of data indicating the resolution (the number of samplings per predetermined time unit or the sampling interval t) is accepted prior to the measurement process. Thus, the CPU 100 can capture and store received light data at regular intervals t after the start of the data storage period. In addition, in the data input before the measurement processing, the input of the length T of the data accumulation period is received together with the data indicating the resolution, and the number n (n = T / t) of data sampled within this time T is displayed on the display unit. It is desirable to display it on 102 and to let the user confirm the setting contents. In addition, when the number of data n is less than the minimum number of data required for the measurement process, the setting by the input data is canceled and predetermined warning information is displayed, so that the user can be satisfied with the input data deficiency. It is desirable to notify.
[0085]
Next, when the conveyance speed of the workpiece fluctuates, measurement processing using a certain number of received light data can be performed by performing thinning processing on the stored received light data after data storage.
[0086]
In this adjustment, it is necessary to obtain a standard time length of the data accumulation period by using a model work in advance and set the time length and the number of data necessary for the measurement process. These set values can be input using the input unit 103 while displaying the measurement result for the model workpiece on the display unit 102, for example.
[0087]
Based on the set value, the CPU 100 samples the received light data accumulated for each workpiece at a predetermined thinning interval, and then executes a measurement process using the sampled received light data.
[0088]
Since the hourly received light data from the signal processing unit 2 is input with a constant time interval, the CPU 100 can convert the length of the standard data accumulation period and the thinning interval into the number of data. Similarly, after the accumulation process is completed, the number of accumulated received light data can be regarded as the length of the data accumulation time. Here, when the number of data corresponding to the standard length of the data accumulation period is D, the number of actually accumulated data is D1, and the standard thinning interval is Δd, the following equation (1) is used to decimate the accumulated data. The interval Δd1 can be obtained.
Δd1 = (D1 / D) × Δd (1)
[0089]
FIG. 13 shows an example of thinning-out processing when the length of the data accumulation period changes to half of the standard length D. In this case, since the thinning interval Δd1 for the stored light reception data is half of the standard thinning interval Δd, the same number of light reception data as when the data is stored with the standard length is extracted.
[0090]
FIG. 14A shows another processing method when the workpiece conveyance speed fluctuates. In this embodiment, a workpiece having a step is an inspection target, but a predetermined trigger level L1 is set while a plurality of workpieces 61, 62, 63... The point of accumulating the received light data within the period below is the same as in the embodiment shown in FIGS.
[0091]
In this embodiment, for each workpiece, light reception data corresponding to a specific part is extracted from changes indicated by accumulated light reception data. If the shape of each workpiece is appropriate, the measured value indicated by the received light data corresponding to the specific part should be the same value. However, when the moving speed of each workpiece changes and the respective data accumulation periods differ as in the illustrated example, the time point at which the received light data corresponding to a specific part is obtained naturally also changes. .
[0092]
In FIG. 14 (2), when the three works 61, 62, and 63 are sequentially conveyed in FIG. 14 (1), the data accumulation periods T1, T2, and T3 for the works 61, 62, and 63 are gradually shortened. Here is an example. In the figure, p1, p2, and p3 are points corresponding to the received light data corresponding to the specific part for the workpieces 61, 62, and 63, respectively. T1, t2, and t3 indicate time lengths from the time when the data accumulation period is started until the points p1, p2, and p3 are reached.
[0093]
Assuming that the length T1 of the data accumulation period and the time length t1 until reaching the point p1 are registered as standard data for the first work 61, the points for the other works 62 and 63 are described above. The time lengths t2 and 53 until reaching p2 and p3 can be obtained by the following equations (2) and (3), respectively. In actual calculations, T1, T2, T3, and t1 can all be converted into the number of data.
t2 = (T2 / T1) × t1 (2)
t3 = (T3 / T1) × t1 (3)
[0094]
14 (2) shows an example in which the received light data for one point on the workpieces 61, 62, and 63 is extracted. Similarly, when extracting received light data for a predetermined range on the workpiece, The data extraction range can be adjusted based on the ratio between the standard length of the data accumulation period and the actual length of the data accumulation period.
In addition, the formulas (2) and (3) are based on the assumption that each workpiece moves at a constant speed. It is desirable to extract the received light data over a predetermined range centered at.
[0095]
By the way, when the start point of the data accumulation period is determined based on the trigger level, when an abnormality occurs in the measurement target portion of the workpiece and the strip light 7 is not shielded, the processing for the next workpiece is performed without detecting the abnormality. There is a problem that it will shift to.
[0096]
FIG. 15 shows a specific example in which the above problem occurs.
In this embodiment, the inspection similar to that shown in FIG. 1 is performed, but the work 63 from which the lid portion 6a is missing is transported third in the drawing. For the workpiece 63, the measured value while passing through the belt-like light 7 does not become the trigger level L1 or less, so that the accumulation process for the next workpiece 64 is started without the received light data being accumulated. Therefore, the lack of the lid portion 6a of the work 63 is overlooked.
[0097]
In order to deal with such a problem, the measurement processing device 1 measures an elapsed time from the end point every time the data accumulation period ends, and an error occurs when this time exceeds a predetermined reference time. Information can be output. The reference time is set based on the time corresponding to the normal conveyance interval of the workpiece, but if the workpiece conveyance speed may vary, the reference time is adjusted according to the variation range. Is desirable.
[0098]
FIG. 16 shows an example in which the measurement processing apparatus 1 is applied to a measurement system using a displacement sensor. FIG. 16A shows a specific example of the measurement process, and the detection unit 8 of the displacement sensor is provided above the workpiece 60 provided with a step. Although not shown in this figure, the position of the detection unit 8 is fixed, and a plurality of workpieces 60 are set to be sequentially guided to the detection area.
[0099]
FIG. 16 (2) shows a change in measurement data obtained in the above measurement system together with a specific example of measurement processing.
The measurement processing apparatus 1 according to this embodiment inputs measurement data indicating the detection distance from the signal processing unit 2 connected to the detection unit 8 and uses the same method as in FIG. Two periods T separated by a predetermined time within a period below a predetermined trigger level L3_A, T_BIs set as the data accumulation period. The trigger level L3 of this embodiment is set based on the measured value corresponding to the highest surface in the workpiece 60.
[0100]
In this embodiment, each data storage period T_A, T_BEvery time, the maximum value and the minimum value are obtained from the data accumulated in the period. In the figure, P1 and B1 are respectively periods T_ACorresponds to the maximum and minimum values. In addition, P2 and B2 are respectively periods T_BCorresponds to the maximum and minimum values.
[0101]
The measurement processing device 1 is used for each period T_A, T_BEvery time, the difference between the maximum value and the minimum value within the period can be obtained. In addition, as shown in FIG._AMaximum value P1 and period T_BFor example, the difference T from the minimum value B2 in the_A, Period T_BIt is possible to execute arithmetic processing using both of these data.
[0102]
Although the conventional displacement sensor has a function to hold the maximum value and the minimum value of the measurement values obtained during a predetermined measurement period, it does not have a function to hold a plurality of measurement values. It was only possible to measure the distance to the lower surface. For this reason, in order to measure each level | step difference in detail about the workpiece | work 60 like FIG. 16 (1), it was necessary to use a some sensor. On the other hand, according to the above embodiment, by setting a period according to the measurement purpose from the measurement data obtained during the period when the workpiece 60 passes through the detection area of the detection unit 8, Measurement processing can be executed. Therefore, it is possible to perform more detailed measurement processing than before using the single detection unit 8.
[0103]
【The invention's effect】
  According to the measurement processing device according to the present invention, it is possible to respond at high speed to the output from the sensor,Even if the conveyance speed of the object changes, the measured value data of the measurement object is used.Measurement processing according to the purpose can be executed, and the processing result can be output to the host device. In addition, according to the measurement processing apparatus according to the present invention, even when there are a plurality of measurement target parts in the object, measurement processing using a single sensor is possible. It can be shortened. Even when the type of the object is changed, it is not necessary to adjust the positioning of the sensor in the same manner, so that it is possible to easily cope with a production line and an inspection line for high-mix low-volume production.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of an inspection system using a measurement processing apparatus according to the present invention.
FIG. 2 is a perspective view showing an external appearance of a measurement processing device and a signal processing unit.
FIG. 3 is a block diagram of a measurement processing apparatus.
FIG. 4 is a block diagram of a signal processing unit.
FIG. 5 is a diagram showing a change in measurement data and a measurement processing method according to the inspection of FIG. 1;
FIG. 6 is a diagram illustrating timings of data accumulation processing and measurement processing.
FIG. 7 is a diagram illustrating another setting example of the data accumulation period.
FIG. 8 is a flowchart showing a processing procedure based on the method of FIG. 5;
FIG. 9 is a flowchart showing a processing procedure based on the method of FIG.
FIG. 10 is a flowchart showing a processing procedure based on the method of FIG.
FIG. 11 is a flowchart in the case where a response when a workpiece is stopped is incorporated in the procedure of FIG.
FIG. 12 is a diagram illustrating a method for maintaining a constant number of received light data.
FIG. 13 is a diagram illustrating an example of adjusting the thinning interval of data after accumulation processing;
FIG. 14 is a diagram illustrating an example of adjustment of data extraction when the moving speed of the workpiece changes.
FIG. 15 is a diagram showing a problem when the belt-like light is not shielded by the work.
FIG. 16 is a diagram showing an outline of a measurement system to which the measurement processing apparatus according to the present invention is applied, a change in measurement data, and a specific example of the measurement process.
FIG. 17 is a diagram showing an example of a conventional inspection system.
FIG. 18 is a block diagram showing a configuration of a conventional inspection system.
FIG. 19 is a diagram showing the principle of inspection according to the system of FIGS.
[Explanation of symbols]
1 Measurement processing equipment
2 Signal processor
3 floodlight
4 Light receiver
7 Band light
8 detector
10 housing
14 Connector
100 CPU
101 EEPROM
104 Communication processing circuit
105 Processing Circuit for Detection Unit
106 External input circuit
107 Analog output circuit
103 Digital output circuit
109 Interface circuit

Claims (4)

Measurement using the output signal from the sensor for the same type of object that is connected to a sensor of the type that detects the object by changing the level of the output signal and is sequentially conveyed to the detection area of the sensor at a predetermined interval. A device for executing processing,
An input circuit for inputting an output signal from the sensor, a memory for storing measured value data indicated by a signal input by the input circuit, an arithmetic circuit for measurement processing, and a processing result of the arithmetic circuit An output circuit for outputting to the outside is housed in a single casing, and a connector including an output terminal or a cable including an output signal line is exposed to the outside of the casing.
A first registration means for registering at least one set value of a trigger level for specifying a start point and an end point of a data accumulation period in the memory with respect to the measurement value data, and the trigger level. The standard length of the data storage period is registered by the number T of data stored when the measured value data generated during the data storage period is stored in the memory at regular intervals, and the standard length In the data accumulation period, the time point corresponding to the measurement value data to be measured or the start point and end point of the period corresponding to the measurement value data to be measured are from the start point of the data accumulation period to the corresponding time point. A second registration means registered according to the number of data stored in the memory ,
The arithmetic circuit compares the measured value data of each hour with the trigger level registered in the first registration means to determine the start point and end point of the data accumulation period, and from the start point to the end point. Data storage means for storing the measured value data generated between them in the memory at regular intervals; data indicating the number of data T1 stored in the memory by the data storage means and the standard length of the data storage period based on the ratio between the number T, the adjusting the number of data registered in the second registration means per start point and end point of the period in which the time or corresponding corresponding to the measured value data of the measurement object, after the adjustment Computation means for reading out the measured value data at the time or period corresponding to the number of data from the memory, and performing arithmetic processing using the read data,
The output circuit determines the start point and end point of the data accumulation period and ends the calculation process result using the measurement value data accumulated in the data accumulation period. Measurement processing device that outputs to terminals or output signal lines. The calculation means adjusts the time point corresponding to the measurement value data to be measured or the start point and end point of the corresponding period to the number of data t registered in the second registration means at the corresponding time point. The measurement processing apparatus according to claim 1, wherein a calculation for multiplying a ratio (T1 / T) of the number of data T1 to T indicating a standard length of the data accumulation period is performed . The measurement processing apparatus according to claim 1, further comprising an input unit configured to input a trigger level registered in the first registration unit and information registered in the second registration unit . Measuring means for measuring the elapsed time from the end point of the data storage period determined by the data storage means, and error output means for outputting error information when the time measured by the measuring means exceeds a predetermined reference time The measurement processing apparatus according to claim 1, further comprising:

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