JP2019215218A - Detector - Google Patents

Abstract

To provide a detector and a detection program that can eliminate a burden on a user who sets a threshold according to a use state and detect the arrival of an object.SOLUTION: A detector 10 is a detector that detects the arrival of an object 100 in a detection range 10a on the basis of a signal value corresponding to a physical quantity the value of which changes according to whether the object arrives in the detection range, and comprises: a measuring unit 11 that sequentially converts the physical quantity into the signal values; a storage unit 12 that includes a storage area for ordering a predetermined number of signal values in order the signal values are acquired from the measuring unit and storing the signal values, and updates the stored predetermined number of signal values with a signal value newly acquired from the measuring unit at a first period; and a determination unit 13 that determines, at a frequency of once every time the update is performed once or a plurality of times, whether the object arrives in the detection range, on the basis of whether a plurality of signal values of predetermined order among the signal values stored in the storage unit satisfy a determination condition for determining whether the waveform of a signal value corresponds to a rising waveform or a falling waveform.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a detection device that detects arrival of an object.

  Conventionally, as a detection method for detecting the arrival of an object, the object is irradiated with light, to detect light transmitted through the object, to detect light shielding by the object, or to reflect light from the object. Or the method of detecting the As another detection method, a method of applying ultrasonic waves to an object and using reflection of ultrasonic waves is also known. In these existing detection methods, the magnitude of a signal value corresponding to a physical quantity such as the amount of received light or ultrasonic reception intensity is compared with a threshold value to obtain an output signal corresponding to the presence or absence of an object. Sometimes the arrival of an object is determined. Here, since the magnitude of the signal value corresponding to the physical quantity varies depending on the type of the object and the positional relationship between the object and the detection apparatus, the user may have to set a threshold after installing the detection apparatus. Many.

  Regarding the setting of the threshold value by the user, for example, in Japanese Patent Application Laid-Open No. H11-216, the SET key is pressed in a state where the work is arranged in the detection area, and the SET key is pressed again in a state where the work is removed from the detection area. It describes that a threshold value is set using two types of received light amounts measured by the above method.

  Further, in the photoelectric sensor described in Patent Literature 2, following the environmental factors and automatically adjusting a threshold value as a criterion for determining the amount of light, the received light amount current value data is constant after the photoelectric sensor makes a light incident determination. The light reception amount fluctuation profile during the period is measured. Then, it is determined whether or not there is a period in which the received light amount is constant at the maximum value, and the received light amount present value data measured when there is a constant period is made valid.

JP 2007-139494 A JP 2009-300111 A

  Conventionally, as described in Patent Literatures 1 and 2, on the assumption that a threshold value of a detection device is set in accordance with a use situation, a user can easily set a threshold value or readjust a threshold value initially set over time. Development has been conducted in the direction of reducing the burden.

  However, in the related art, the burden on the user to set the threshold value of the detection device according to the use situation cannot be removed.

  Therefore, the present invention provides a detection device that can detect the arrival of a target object without burdening the user for setting the threshold value according to the use situation.

  When detecting the arrival of an object, what is required in an actual use scene is a function of notifying that the object has arrived when the object arrives. On the other hand, it is rarely required to detect the presence / absence of the object at the present time. That is, even if the output value of the detection device corresponds to the presence / absence of the target object at the present time, the user must assume that the output value updated in a short cycle is obtained in time series, and the output value is no target. In many cases, the machine is caused to perform a predetermined operation triggered by an event that changes from a value corresponding to 1 to a value corresponding to the presence of an object or vice versa. Instead, for example, an output value corresponding to the presence or absence of an object at the present time is requested from a control system of the machine, and the machine is rarely operated according to a single output value obtained in response thereto. Therefore, if a sudden change in the signal value corresponding to the arrival of the object, that is, the rise or fall of the signal value waveform is detected, the practical requirement can be satisfied without using the threshold value.

  Therefore, the detection device according to an aspect of the present disclosure, based on a signal value corresponding to a physical quantity whose value changes depending on whether or not the object has arrived in the detection range, that the object has arrived in the detection range A measuring unit for sequentially converting a physical quantity into a signal value, and a storage area for storing a predetermined number of signal values in the order obtained from the measuring unit and storing the signal value in a first cycle. A storage unit that updates a predetermined number of signal values that have been updated with a signal value newly obtained from the measurement unit; and a frequency of the signal value stored in the storage unit once every time update is performed one or more times. Based on whether or not the signal values of a plurality of predetermined ranks satisfy a determination condition for determining whether or not a signal value corresponding to a rising waveform or a falling waveform satisfies, a target object is included in a detection range. A determining unit for determining whether or not the vehicle has arrived; Provided.

  According to this aspect, the presence or absence of the object in the detection range is detected by comparing the signal value at a certain point in time with the threshold, and it is determined whether or not the object has arrived based on a change in the detection result. It can be determined whether an object has arrived in the detection range based on whether or not a waveform composed of a predetermined number of signal values stored in the unit satisfies a predetermined condition. For this reason, the arrival of an object can be detected without the burden on the user who sets the threshold value according to the usage situation. Furthermore, since this determination condition is a condition for determining whether the waveform of the signal value corresponds to a rising waveform or a falling waveform, it is common even if the type of object and the installation state of the detection device are different. In many cases, the determination condition can be applied. In this respect as well, the burden on the user at the stage of preparation for detection execution is reduced.

  In the above aspect, the storage unit may delete the oldest signal value from the predetermined number of signal values and store the newly acquired signal value.

  According to this aspect, by using a FIFO memory as the storage unit, high-speed reading and writing can be performed while the hardware scale is reduced.

  In the above aspect, the first cycle may be changeable.

  According to this aspect, by appropriately setting the first cycle, it is possible to refer to a signal value over an appropriate time length when determining whether or not the target has arrived in the detection range.

  In the above aspect, the determination condition is that the signal value acquired at the first time point is substantially equal to the signal value acquired at the second time point after the first time point, and that the signal value acquired at the second time point is It may include that the absolute value of the difference between the signal value and the signal value acquired at the third time point after the second time point is larger than a predetermined value.

  According to this aspect, even when the signal value fluctuates according to the use situation, it is possible to stably detect the rise or fall of the signal value, and the user who sets the threshold value according to the use situation It is possible to detect the arrival of the object without burden.

  In the above aspect, the determination condition is that the signal value acquired at the first time point is substantially equal to the signal value acquired at the second time point after the first time point, and that the signal value acquired at the second time point after the first time point is The signal value obtained at the third time point is substantially equal to the signal value obtained at the fourth time point after the third time point, and the signal value obtained at the first time point and the signal value obtained at the second time point are obtained. The absolute value of the difference between one of the signal values obtained at the third time point and the signal value obtained at the fourth time point and the signal value obtained at the fourth time point may be greater than a predetermined value.

  According to this aspect, even when the signal value fluctuates according to the use situation, it is possible to stably detect the rise or fall of the signal value, and the user who sets the threshold value according to the use situation It is possible to detect the arrival of the object without burden.

  In the above aspect, the determination condition is a plurality of reference waveforms in which a waveform composed of a plurality of time-series signals is a machine learning data set by execution of a learned model specified by a parameter generated by machine learning. It may be that a positive result is obtained for having a feature in common with the feature of.

  According to this aspect, the processing load of the detection device is reduced by determining whether the waveform configured by the current signal value has a feature common to the features of the plurality of reference waveforms by executing the learned model. It is possible to determine with high accuracy whether or not the target object has arrived in the detection range while reducing the amount.

  In the above aspect, an input unit that receives an input of a determination condition may be further provided.

  According to this aspect, it is possible to adjust the predetermined condition for determining that the object has arrived in the detection range, and it is possible to detect the arrival of the object based on a condition desired by the user.

  According to the present invention, there is provided a detection device capable of detecting the arrival of a target object without burdening a user who sets a threshold value according to a use situation.

It is a figure which shows the outline | summary of the detection system containing the detection apparatus which concerns on embodiment of this invention. It is a figure which shows the structure of the detection apparatus which concerns on this embodiment. It is a figure which shows an example of the signal value measured by the detection apparatus which concerns on this embodiment with a graph. It is a figure which shows an example of the predetermined number of signal values memorize | stored in the detection apparatus which concerns on this embodiment with a graph. In a 1st case, it is a figure which shows an example of the predetermined number of signal values memorize | stored in the detection apparatus which concerns on this embodiment with a graph. It is a figure which shows an example of the predetermined number of signal value memorize | stored in the detection apparatus which concerns on this embodiment in a 1st example. In a 2nd example, it is a figure which shows an example of the predetermined number of signal values memorize | stored in the detection apparatus which concerns on this embodiment with a graph. In a 2nd example, it is a figure which shows an example of the predetermined number of signal value memorize | stored in the detection apparatus which concerns on this embodiment. In a 3rd example, it is a figure which shows an example of the predetermined number of signal value memorize | stored in the detection apparatus which concerns on this embodiment with a graph. In a 3rd example, it is a figure which shows an example of the predetermined number of signal value memorize | stored in the detection apparatus which concerns on this embodiment. In a 4th example, it is a figure which shows an example of the predetermined number of signal values memorize | stored in the detection apparatus which concerns on this embodiment with a graph. In a 4th example, it is a figure which shows an example of the predetermined number of signal values memorize | stored in the detection apparatus which concerns on this embodiment. In a 5th example, it is a figure which shows an example of the predetermined number of signal value memorize | stored in the detection apparatus which concerns on this embodiment with a graph. In a 5th example, it is a figure which shows an example of the predetermined number of signal values memorize | stored in the detection apparatus which concerns on this embodiment. It is a figure which shows the example of the signal value assumed to be collected by the detection apparatus which concerns on this embodiment. It is a flowchart of the mounting method of the learned model performed by the detection apparatus which concerns on this embodiment. It is a flowchart of the setting method which sets the detection apparatus which concerns on this embodiment. It is a flowchart of the detection method performed by the detection apparatus which concerns on this embodiment.

  Hereinafter, an embodiment according to one aspect of the present invention (hereinafter, referred to as “the present embodiment”) will be described with reference to the drawings. In addition, in each figure, what attached | subjected the same code | symbol has the same or similar structure.

  First, a description will be given of a situation in which it is difficult for a conventional detection device to set a threshold value to be compared with a signal value for determining arrival of an object to a fixed value. When an object is detected by a sensor, the object depends on the individual circumstances such as what kind of facility where the sensor is installed, what kind of object the object is, and what physical quantity is measured by the sensor. The signal value measured in a state where there is no object is different from the signal value measured in the state where there is an object, and the speed at which the signal value changes is different. Here, the signal value measured when there is no object and the signal value measured when there is an object may be independent of each other or may be correlated to some extent.

  For example, if the sensor is a reflective sensor that irradiates the object with light and detects light reflected by the object, the factor that determines the amount of light received without the object is the arrangement of the sensor and the background reflector. Or the reflectance of a background reflector. In addition, factors that determine the amount of light received in the presence of an object include the arrangement of the sensor and the object and the reflectance of the object. For this reason, it is difficult to set a threshold value that is compared with a signal value to determine the arrival of an object as a fixed value, and it is necessary to set the threshold according to the use situation.

  If the sensor is a transmission type sensor that irradiates the target object with light and detects light transmitted through the target object, a factor that determines the amount of light received without the target object is the amount of projected light or Or a light receiving unit. In addition, the factor that determines the amount of light received when the object is present may be the transmittance of the object. For this reason, it is difficult to set a threshold value that is compared with a signal value to determine the arrival of an object as a fixed value, and it is necessary to set the threshold according to the use situation.

  Next, a situation in which the threshold value initially set in the conventional detection device must be readjusted with time will be described. When an object is detected by a sensor, the signal value may change over time due to contamination or deterioration of the sensor, or the signal value may change over time due to environmental changes.

  For example, when the sensor is a reflection type sensor or a transmission type sensor, dirt adheres to the optical window of the light emitting unit, so that the amount of emitted light decreases, and as a result, the amount of received light decreases. There is. On the other hand, the amount of received light may increase abruptly by removing dirt on the optical window of the light projecting unit. Further, when the light projecting element of the light projecting unit is deteriorated, the light projection amount may be decreased, and the light reception amount may be decreased. Furthermore, the amount of received light may vary due to variations in the brightness of the measurement environment due to the influence of sunlight or the like. Therefore, there is a case where the threshold value compared with the signal value has to be readjusted with time in order to determine the arrival of the object, and it is necessary to set the threshold value according to the use situation.

  As described below, the detection device 10 according to the present embodiment does not use a threshold value for a signal value in order to determine the presence or absence of a target object, and thus eliminates the burden on the user to set the threshold value in accordance with the usage status. be able to. However, setting items unique to the detection apparatus 10 according to the present embodiment may occur. However, in the detection apparatus 10 according to the present embodiment, the setting items can be reduced as much as possible, and can often be used without the setting items.

  As a setting item unique to the detection device 10 according to the present embodiment, there is a setting for determining a rising or falling of a signal value. In the detection apparatus 10 according to the present embodiment, the presence or absence of an object is determined by paying attention to the waveform (the rising or falling edge of the signal waveform) indicated by the signal value, resulting in a difference in the speed of movement of the object. It is desired that the user does not need to adjust for fluctuations in the rate of change in the amount of received light.

[Configuration example]
An example of the configuration of the detection apparatus 10 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a diagram showing an outline of a detection system 1 including a detection device 10 according to an embodiment of the present invention. The detection system 1 includes a detection device 10, a controller 20, a computer 30, a robot 40, and a transport device 50.

  The detection device 10 is a device that detects that the object 100 has arrived in the detection range 10a of the detection device 10 based on the measured signal value. The detection device 10 may be a reflective photoelectric sensor, for example. When the detection device 10 is configured by a reflective photoelectric sensor, the amount of reflected light to be detected increases when the object 100 arrives at the detection region of the detection device 10. In this embodiment, an example in which the detection device 10 is configured by a photoelectric sensor will be described in order to make the description more specific. By replacing the factor of variation and the like according to the detection principle of the sensor, it can be generalized when the detection device 10 is composed of an arbitrary sensor.

  The target object 100 is an object to be detected by the detection device 10, and may be, for example, a completed product to be produced or an unfinished product such as a part. Further, in this specification, the “object” may be a part of the object 100 (an end portion of the object 100, a pattern or a defect on the object 100, etc.) in addition to the entire object 100. When the object 100 is smaller than the detection region, as in the case where the object 100 is a particle or a pin, the entire object 100 may be a detection target.

  Note that the detection device 10 may be used for an application generally called a defect inspection, and in that case, the detection device 10 may detect that a defect portion of the object 100 has reached the detection range 10a. .

  The controller 20 controls the robot 40 and the transfer device 50. The controller 20 may be configured by, for example, a PLC (Programmable Logic Controller). The controller 20 detects that the object 100 has arrived based on the output from the detection device 10 and controls the robot 40.

  The computer 30 sets the detection device 10, the controller 20, and the robot 40. In addition, the computer 30 acquires the execution result of the control by the controller 20 from the controller 20. Furthermore, the computer 30 may include a learning device that generates, by machine learning, parameters used in an algorithm (learning model) for determining whether or not the object 100 has arrived at the detection range 10a by the detection device 10. Examples of the algorithm (learning model) include a neural network and a decision tree.

  The robot 40 operates and processes the target object 100 under the control of the controller 20. For example, the robot 40 may pick up the object 100 and move it to another location, or cut or assemble the object 100.

  The transfer device 50 is a device that transfers the target object 100 under the control of the controller 20. The transport device 50 may be, for example, a belt conveyor, and may transport the object 100 at a speed set by the controller 20.

  FIG. 2 is a diagram illustrating a configuration of the detection device 10 according to the present embodiment. The detection device 10 includes a measurement unit 11, a storage unit 12, a determination unit 13, a control unit 14, and an input / output unit 15.

<Measurement unit>
The measuring unit 11 sequentially converts a physical quantity whose value changes depending on whether or not the object 100 has arrived in the detection range 10a into a signal value. The measurement unit 11 may measure a physical quantity such as the amount of received light in the second period and output a signal value that is a digital value of three or more values. The signal value may be represented by 8 bits (256 values), for example. The second period may be 0.1 ms (milliseconds), for example.

  When the detection device 10 is a photoelectric sensor, the measurement unit 11 includes a lens for collecting incident light to a light receiving element, a light receiving element (for example, a photodiode) for converting light to a current signal, an amplifier for converting a current signal to a voltage signal, and a voltage. An A / D converter for converting a signal into a digital value may be included. Furthermore, the measurement unit 11 may include a low-pass filter, a high-pass filter, or the like by analog processing or digital processing, or may include a light projecting element (for example, an LED) that irradiates the object 100 with light.

<Storage unit>
The storage unit 12 stores a predetermined number of signal values in the order measured by the measurement unit 11. The memory | storage part 12 deletes the oldest signal value among predetermined number of signal values, and may memorize | store the newly measured signal value. In this way, by using a first-in first-out (FIFO) memory as the storage unit, it is possible to read and write at high speed while keeping the hardware scale small.

  In the detection device 10 according to the present embodiment, the storage unit 12 is configured by n-stage FIFO memories. The storage unit 12 has addresses of the first stage q0, the first stage q1, the second stage q2, the jth stage qj, the kth stage qk, and the nth stage qn. Here, j <k <n, and n may be about 100, for example. The storage unit 12 deletes the signal value sn stored in the n-th stage qn, which is the final stage, in the first cycle, and stores the signal values s0, s1, s2, sj, and sk stored in each stage. Shift to the next stage, and store the newly measured signal value in the first stage q0.

  Here, the first cycle may be the same as or different from the second cycle. For example, the second period may be fixed to a value (for example, 0.1 ms) unique to the sensor constituting the measurement unit 11. When the detection device 10 is a photoelectric sensor, the light projecting element may perform pulse projection with a second period, and the output of the light receiving element may be A / D converted with the second period in accordance with the timing of pulse projection. On the other hand, the first period may be settable by the computer 30 via the controller 20. The first period needs to be determined so that the range of the signal value waveform to be processed simultaneously is stored in the storage unit 12. The first period may be set longer than the second period, and the second period may be 1 ms, for example. When a plurality of signal values are generated within the first period, the average value of the signal values may be stored in the storage unit 12.

<Determining unit>
The determination unit 13 determines whether or not the object 100 has arrived in the detection range 10a based on whether or not a plurality of predetermined signal values among the signal values stored in the FIFO memory satisfy the determination condition. To do. The determination unit 13 may determine whether or not the object 100 has arrived in the detection range 10a in the first period. Here, the measurement part 11 may measure a signal value with the 2nd period below a 1st period. When the first period is equal to or longer than the second period, it is possible to refer to an appropriate number of signal values when determining whether or not an object has arrived in the detection range.

  The determination unit 13 may make a determination in the first cycle with reference to signal values stored in a plurality of stages of the storage unit 12 and output a determination result to the control unit 14. The determination unit 13 determines whether the object 100 has arrived in the detection range 10a based on whether the predetermined number of signal values stored in the storage unit 12 includes a rising waveform or a falling waveform. It's okay. That is, the determination condition may be a condition indicating that the predetermined number of signal values stored in the storage unit 12 includes a rising waveform or a falling waveform. Note that the determination unit 13 may determine one of the rising waveform and the falling waveform that is necessary for determining the arrival of the object 100.

  The determination condition such as which signal value stored in which address of the storage unit 12 is used for the determination by the determination unit 13 and what determination logic is used to make the determination may be set from the computer 30 via the controller 20. . Note that the determination condition may be set in the manufacturing stage of the detection apparatus 10.

  The determination result by the determination unit 13 may be a binary value corresponding to whether the target object 100 has arrived in the detection range 10a or whether the target object 100 has not arrived in the detection range 10a. May be represented by For example, when the determination result is ternary, in addition to the state in which the object 100 has arrived and the state in which the object 100 has not arrived, a state that has the possibility of arrival but has low accuracy may be added as the third state.

  According to the detection device 10 according to the present embodiment, the presence or absence of the target 100 in the detection range 10a is detected by comparing the signal value at a certain point in time with the threshold, and whether the target 100 has arrived is determined by a change in the detection result. Instead of determining whether or not the target 100 has arrived in the detection range 10a, based on whether or not a change in a predetermined number of signal values stored in the storage unit 12 satisfies the determination condition. Thus, the arrival of the target object 100 can be detected without the burden on the user who sets the threshold value in accordance with the use situation. More specifically, based on whether a change in a predetermined number of signal values stored in the storage unit 12 includes a rising waveform or a falling waveform, whether or not the object 100 has arrived in the detection range 10a is determined. Therefore, it is possible to detect the arrival of the object 100 without burdening the user who sets the threshold value according to the use situation.

<Control unit>
The control unit 14 controls the operation of the entire detection apparatus 10. The control unit 14 can be configured as, for example, a computer including a microprocessor, a memory, a detection device control program stored in the memory, and the like. The detection device control program may be provided by being stored in a computer-readable storage medium, or may be provided from the computer 30 of the detection system 1 via a communication path. The control unit 14 may make necessary settings for the first cycle, the second cycle, and the determination condition for the determination unit 13 to perform the determination according to the setting by the computer 30. Further, the microprocessor of the control unit 14 functions as the determination unit 13 by executing a detection device control program including a process for determining whether or not the object 100 has arrived in the detection range 10a by the detection device 10. Also good.

  The control unit 14 may realize a FIFO memory by controlling the memory of the control unit 14 according to the detection device control program, and may replace the storage unit 12 with the memory of the control unit 14. In this case, the shift of the signal value to the subsequent stage of the FIFO memory can be performed by updating the access location on the memory, not the physical shift of the stored data. The storage unit 12 may be realized by dedicated hardware.

  When the determination unit 13 determines that the target object 100 has arrived, the control unit 14 holds the output state to the outside indicating that the target object 100 has arrived for a predetermined period of time or until reset from outside. You may do so.

<Input / output unit>
The input / output unit 15 outputs at least a signal corresponding to the arrival of the object 100 to the outside. The input / output unit 15 may output a binary voltage signal or current signal corresponding to the arrival and non-arrival of the object 100 through a single signal line. Note that when the detection apparatus 10 does not accept setting by communication from the outside, the input / output unit 15 may have only the output unit regardless of the name of the input / output unit 15.

  The input / output unit 15 may include a network interface, receive setting information, and output a determination result by the determination unit 13.

  The input / output unit 15 may receive an input of a determination condition used for determination by the determination unit 13. Thereby, the determination conditions for determining that the target object 100 has arrived in the detection range 10a can be adjusted, and the arrival of the target object 100 can be detected based on the user's desired conditions. The detection device 10 may further include an operation key and an indicator lamp not shown.

  FIG. 3A is a graph illustrating an example of a signal value measured by the detection device 10 according to the present embodiment. In the figure, time is shown on the horizontal axis, signal values are shown on the vertical axis, and changes in signal values over time are shown by graphs.

  The intervals of t0, t1, t2... T6 shown on the horizontal axis are the first period, and may be, for example, 1 ms intervals. The signal value may be any electrical signal, but may be a voltage signal, for example, in which case the unit is volts.

  In this example, for the sake of simplicity, the signal values are shown as waveforms that do not include broken-line noise, but the waveform actually obtained may be a waveform on which noise is superimposed, or The rising portion and the falling portion may be curved.

  FIG. 3B is a graph illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment. In the figure, the horizontal axis indicates the FIFO stage, the vertical axis indicates the signal value, and the signal value stored in the storage unit 12 is indicated by a graph.

  Q0, q1, q2... Q6 shown on the horizontal axis indicate the number of stages in the storage unit 12 (FIFO memory). In the present example and the first to fifth examples described below, the number of stages of the FIFO memory is set to a total of seven in order to simplify the description, but the number of stages may be larger, for example, 100 It may be about a step.

  In this example, the storage unit 12 stores the seven signal values in the order measured by the measurement unit 11. That is, the signal value “8” measured at time t6 is stored in the first stage q0, and the signal value “8” measured at time t5 is stored in the first stage q1. The same applies to the second stage q2 to the fifth stage q5, and the signal value “4” measured at time t0 is stored in the sixth stage q6.

  FIG. 4A is a graph illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the first case. In the figure, the horizontal axis indicates the FIFO stage, the vertical axis indicates the signal value, and the signal value stored in the storage unit 12 is indicated by a graph.

  FIG. 4B is a diagram illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the first case. In the same figure, the signal values shown in FIG. Hereinafter, the notation “c (n)” (where n is an integer) indicates the nth cycle of FIFO memory update. Which cycle is selected as the 0th cycle is arbitrary. In addition, the signal values stored in the FIFO memory in the nth period are collectively referred to as “signal value c (n)”.

  In the first case, the signal value c (-5) measured and stored by the time when the object 100 has not arrived in the detection range 10a is shown by a solid line, the oldest signal value is deleted thereafter, and a new signal value is newly added. The signal value c (−4) storing the measured signal value is indicated by a broken line. The signal value c (−5) is “4” for the first stage q0 to the sixth stage q6, indicating that the target object 100 has not arrived in the detection range 10a. Thereafter, the detection apparatus 10 deletes the oldest signal value stored in the sixth stage q6, shifts the signal value stored in the first stage q0 to the fifth stage q5 by one stage, and newly measures the signal value “ 5 ”is stored in the first stage q0. The signal value c (−4) is “5” for the first stage q0 and “4” for the first stage q1 to the sixth stage q6, indicating that the object 100 has entered the detection range 10a.

  Similarly, after storing the signal value c (−4), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “6” is stored in the first stage q0. The signal value c (−3) is shown by a dashed line. After storing the signal value c (−3), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “7” is stored in the first stage q0. The value c (-2) is indicated by a two-dot chain line. After storing the signal value c (−2), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. The value c (-1) is shown by a dotted line. After storing the signal value c (−1), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. The value c (0) is shown by a solid line. Further, after storing the signal value c (0), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. c (1) is indicated by a broken line. Further, after storing the signal value c (1), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. c (2) is indicated by a one-dot chain line. Further, after storing the signal value c (2), the oldest signal value “5” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. c (3) is indicated by a two-dot chain line. In addition, after storing the signal value c (3), the oldest signal value “6” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. c (4) is indicated by a dotted line. Finally, after storing the signal value c (4), the oldest signal value “7” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. The value c (5) is indicated by a solid line.

  As described above, in a situation where the signal values stored in the storage unit 12 change every moment, the determination unit 13 determines whether a predetermined number of signal values satisfy the determination condition while measuring the signal values by the measurement unit 11. Then, it is determined whether or not the target object 100 has arrived in the detection range 10a. Here, the determination condition is that the signal value acquired at the first time point is substantially equal to the signal value acquired at the second time point after the first time point, and the signal acquired at the second time point. The signal value acquired at the third time point after the second time point is larger than the value, and the absolute value of the difference may be larger than the predetermined value. Hereinafter, this condition is referred to as a first determination condition. The first determination condition is an example of a condition indicating that a predetermined number of signal values include a rising waveform. In this example, when the signal value pattern sequentially stored in the FIFO memory has a predetermined rising waveform, it is determined that the object 100 has arrived in the detection range 10a.

  In the case of the present example, the signal value acquired at the first time point in the first determination condition may be the signal value stored in the sixth stage q6, and the signal value acquired at the second time point may be the fifth stage. The signal value stored in q5 may be the signal value stored in the fourth stage q4, and the signal value acquired at the third time point may be the signal value stored in the fourth stage q4. That is, the first determination condition is that the signal value stored in the sixth stage q6 is substantially equal to the signal value stored in the fifth stage q5, and that the signal value stored in the fifth stage q5 is May include that the signal value stored in the fourth stage q4 is larger and the absolute value of the difference is larger than a predetermined value.

  Here, the expression that two signal values are substantially equal means not only that the two signal values are completely equal, but also that the two signal values are not completely equal, but the difference between the signal values is within the range of influence of noise. It is determined that there is. For example, the signal value stored in the sixth stage q6 when the difference between the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 is within a range of ± 0.2. And the signal value stored in the fifth stage q5 may be determined to be substantially equal.

  In addition, that the difference between two signal values is larger than a predetermined value means that the difference between the two signal values is different beyond the range of influence of noise. For example, when the value obtained by subtracting the signal value stored in the fifth stage q5 from the signal value stored in the fourth stage q4 is greater than 0.2, the signal value stored in the fifth stage q5 is It may be determined that the signal value stored in the fourth stage q4 is larger and the absolute value of the difference is larger than a predetermined value.

  In the case of this example, a condition that the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 among the signal values c (-5) to c (5) are substantially equal. Are signal values c (−5) to c (0). In addition, the signal value that satisfies the condition that the signal value stored in the fourth stage q4 is larger than the signal value stored in the fifth stage q5 and the absolute value of the difference is larger than a predetermined value, The signal values are c (0) to c (3). Therefore, in this example, the signal value that satisfies the first determination condition is only the signal value c (0). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (0) is stored.

  In this example, the case where the rising portion of the waveform is detected has been described. However, when the falling portion of the waveform is detected, the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 are used. The difference from the signal value is within the range of ± 0.2, and the signal value stored in the fourth stage q4 is smaller than the signal value stored in the fifth stage q5, and the absolute value of the difference Is larger than 0.2 as the determination condition. This is the same for the second to fifth cases described below.

  Note that the first determination condition further includes that the signal value acquired at the third time point is substantially equal to the signal value acquired at the fourth time point after the third time point, and that the signal value acquired at the third time point is obtained. The signal value acquired at the fourth time point may be larger than the signal value obtained at the fourth point in time, and the condition that at least one of the absolute value of the difference is larger than a predetermined value may be included. Here, the signal value acquired at the fourth time point may be the signal value stored in the third stage q3, and the first determination condition is that the signal value stored in the fourth stage q4 and the third stage The signal value stored in q3 is substantially equal, and the signal value stored in the third stage q3 is larger than the signal value stored in the fourth stage q4, and the absolute value of the difference is predetermined. It may include a condition that it is at least either greater than the value of. Alternatively, the condition for detecting the rising portion of the waveform may include a condition that three or more signal values are monotonically increasing (monotonically decreasing when the falling portion of the waveform is detected). This is the same for the second to fifth cases described below.

  The determination condition is that the signal value acquired at the first time point is substantially equal to the signal value acquired at the second time point after the first time point, and that the signal value acquired at the third time point after the second time point is obtained. The signal value obtained at the fourth time point after the third time point is substantially equal to the signal value obtained at the first time point and the signal value obtained at the second time point. Either of the signal value acquired at the third time point and the signal value acquired at the fourth time point are larger than any of them, and the absolute value of the difference is larger than a predetermined value. Good. Hereinafter, this condition is referred to as a second determination condition. The second determination condition is an example of a condition indicating that a predetermined number of signal values include a rising waveform. In this example, when the signal value pattern sequentially stored in the FIFO memory has a predetermined rising waveform, it is determined that the object 100 has arrived in the detection range 10a.

  In the case of the present example, the signal value acquired at the first time point in the second determination condition may be the signal value stored in the sixth stage q6, and the signal value acquired at the second time point may be the fifth stage. q5, the signal value obtained at the third time point may be the signal value stored at the first stage q1, and the signal value obtained at the fourth time point may be the first stage. It may be the signal value stored in q0. That is, the second determination condition is that the signal value stored in the sixth stage q6 is substantially equal to the signal value stored in the fifth stage q5, and the signal value stored in the first stage q1 is In the first stage q1, the signal value stored in the first stage q0 is substantially equal to the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5. One of the stored signal value and the signal value stored in the first stage q0 may be larger, and the absolute value of the difference may be greater than a predetermined value.

  In the case of this example, a condition that the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 among the signal values c (-5) to c (5) are substantially equal. Are signal values c (−5) to c (0). The signal values satisfying the condition that the signal value stored in the first stage q1 and the signal value stored in the first stage q0 are substantially equal are signal values c (0) to c (5). Further, any one of the signal value stored in the first stage q1 and the signal value stored in the first stage q0 is higher than any one of the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5. The signal values satisfying the condition that the difference is larger and the absolute value of the difference is larger than a predetermined value are signal values c (−4) to c (4). Therefore, in this example, the signal value that satisfies the second determination condition is only the signal value c (0). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (0) is stored.

  In this example, the case where the rising portion of the waveform is detected has been described. However, when the falling portion of the waveform is detected, the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 are used. The difference from the signal value falls within a range of ± 0.2, and the difference between the signal value stored in the first stage q1 and the signal value stored in the first stage q0 falls within a range of ± 0.2. And any one of the signal value stored in the first stage q1 and the signal value stored in the first stage q0 than one of the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5. That is, the absolute value of the difference is larger than 0.2, which may be used as the determination condition. This is the same for the second to fifth cases described below.

  In the first determination condition and the second determination condition, the signal values acquired at three or more times are used to determine whether or not the signal values are substantially equal, and the signal values are substantially spontaneously substantially different from other signal values. If unequal signal values occur, such signal values may be excluded. For example, it may be determined whether or not the signal value is an outlier, and the outlier may be excluded. Thereby, malfunction due to noise can be reduced.

  The detection device 10 may receive an input of the first determination condition or the second determination condition via the input / output unit 15. In addition, before determining the determination condition, the data of the signal value actually measured is sent from the detection apparatus 10 to the computer 30, and it is used to confirm whether the determination condition prototyped using the data works well on the actually measured waveform. The simulation may be performed by the computer 30. Alternatively, the determination condition creation procedure performed by the user may be programmed and the determination condition creation using the computer 30 semi-automated. The determination condition thus created may be set in the detection device 10 from the computer 30 via the controller 20 or at the manufacturing stage of the detection device 10.

  FIG. 5A is a graph showing an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the second case. In the figure, the horizontal axis indicates the FIFO stage, the vertical axis indicates the signal value, and the signal value stored in the storage unit 12 is indicated by a graph.

  FIG. 5B is a diagram illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the second case. In the same figure, the signal values shown in FIG.

  In the second case, the reflectance of the object 100 is larger than that in the first case, and the signal value measured by the measuring unit 11 when the object 100 arrives in the detection range 10a is larger than that in the first case. This shows a large example. Specifically, the signal value measured by the measurement unit 11 when the object 100 arrives in the detection range 10a in the second case is 1.25 times that in the first case. In FIG. 5a, after storing the signal value c (−2), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “10” is stored in the first stage q0. The resulting signal value c (-1) is shown by a broken line. After storing the signal value c (−1), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “10” is stored in the first stage q0. The value c (0) is shown by a solid line.

  As described above, even when the reflectance of the object 100 is large and the signal value stored in the storage unit 12 is relatively large, the determination unit 13 measures the signal value by the measurement unit 11 It can be determined whether or not the target object 100 has arrived in the detection range 10a based on whether or not the signal value of satisfies the determination condition. Here, the determination condition may be at least one of the first determination condition and the second determination condition.

  In the case of this example, a condition that the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 among the signal values c (-5) to c (5) are substantially equal. Are signal values c (−5) to c (0). In addition, the signal value that satisfies the condition that the signal value stored in the fourth stage q4 is larger than the signal value stored in the fifth stage q5 and the absolute value of the difference is larger than a predetermined value, The signal values are c (0) to c (3). Therefore, in this example, the signal value that satisfies the first determination condition is only the signal value c (0). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (0) is stored.

  In the case of this example, among the signal values c (−5) to c (5), the signal value stored in the sixth stage q6 is substantially equal to the signal value stored in the fifth stage q5. Are signal values c (−5) to c (0). The signal values satisfying the condition that the signal value stored in the first stage q1 and the signal value stored in the first stage q0 are substantially equal are signal values c (0) to c (5). Further, any one of the signal value stored in the first stage q1 and the signal value stored in the first stage q0 is higher than any one of the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5. The signal values satisfying the condition that the difference is larger and the absolute value of the difference is larger than a predetermined value are signal values c (−4) to c (4). Therefore, in this example, the signal value that satisfies the second determination condition is only the signal value c (0). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (0) is stored.

  FIG. 6A is a graph illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the third case. In the figure, the horizontal axis indicates the FIFO stage, the vertical axis indicates the signal value, and the signal value stored in the storage unit 12 is indicated by a graph.

  FIG. 6B is a diagram illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the third case. In the same figure, the signal values shown in FIG.

  In the third case, the background reflectance is smaller than in the first case, and the signal value measured by the measurement unit 11 when the target 100 does not arrive in the detection range 10a is smaller than that in the first case. An example is shown. Specifically, the signal value measured by the measurement unit 11 when the object 100 does not arrive in the detection range 10a in the third case is 0.5 times that in the first case. In FIG. 6a, after storing the signal value c (−2), the oldest signal value “2” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. The resulting signal value c (-1) is shown by a broken line. After storing the signal value c (−1), the oldest signal value “2” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. The value c (0) is shown by a solid line.

  As described above, even when the background reflectance is small and the signal value stored in the storage unit 12 is relatively small, the determination unit 13 measures the signal value by the Can be determined whether or not the object 100 has arrived in the detection range 10a based on whether or not satisfies the determination condition. Here, the determination condition may be at least one of the first determination condition and the second determination condition.

  In the case of this example, a condition that the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 among the signal values c (-5) to c (5) are substantially equal. Are signal values c (−5) to c (0). In addition, the signal value that satisfies the condition that the signal value stored in the fourth stage q4 is larger than the signal value stored in the fifth stage q5 and the absolute value of the difference is larger than a predetermined value, The signal values are c (0) to c (3). Therefore, in this example, the signal value that satisfies the first determination condition is only the signal value c (0). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (0) is stored.

  In the case of this example, among the signal values c (−5) to c (5), the signal value stored in the sixth stage q6 is substantially equal to the signal value stored in the fifth stage q5. Are signal values c (−5) to c (0). The signal values satisfying the condition that the signal value stored in the first stage q1 and the signal value stored in the first stage q0 are substantially equal are signal values c (0) to c (5). Further, any one of the signal value stored in the first stage q1 and the signal value stored in the first stage q0 is higher than any one of the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5. The signal values satisfying the condition that the difference is larger and the absolute value of the difference is larger than a predetermined value are signal values c (−4) to c (4). Therefore, in this example, the signal value that satisfies the second determination condition is only the signal value c (0). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (0) is stored.

  FIG. 7A is a diagram illustrating, in a fourth case, an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in a graph. In the figure, the horizontal axis indicates the FIFO stage, the vertical axis indicates the signal value, and the signal value stored in the storage unit 12 is indicated by a graph.

  FIG. 7B is a diagram illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the fourth case. In the same figure, the signal values shown in FIG.

  The fourth case shows an example in which the light emission amount of the measuring unit 11 is smaller than that of the first case, and the signal value measured by the measuring unit 11 is smaller than that in the first case. Specifically, the signal value measured by the measurement unit 11 when the object 100 arrives in the detection range 10a in the fourth case is 0.5 times that in the first case, and the target value is in the detection range 10a. The signal value measured by the measurement unit 11 when the object 100 has not arrived is also 0.5 times that in the first case. In FIG. 7A, after storing the signal value c (−2), the oldest signal value “2” stored in the sixth stage q6 is deleted, and the newly measured signal value “4” is stored in the first stage q0. The resulting signal value c (-1) is shown by a broken line. After storing the signal value c (−1), the oldest signal value “2” stored in the sixth stage q6 is deleted, and the newly measured signal value “4” is stored in the first stage q0. The value c (0) is shown by a solid line.

  As described above, even when the amount of light emitted from the measurement unit 11 is small and the signal value stored in the storage unit 12 is relatively small, the determination unit 13 measures the signal value by It can be determined whether or not the target object 100 has arrived in the detection range 10a based on whether or not the signal value of satisfies the determination condition. Here, the determination condition may be at least one of the first determination condition and the second determination condition.

  In the case of this example, a condition that the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 among the signal values c (-5) to c (5) are substantially equal. Are signal values c (−5) to c (0). In addition, the signal value that satisfies the condition that the signal value stored in the fourth stage q4 is larger than the signal value stored in the fifth stage q5 and the absolute value of the difference is larger than a predetermined value, The signal values are c (0) to c (3). Therefore, in this example, the signal value that satisfies the first determination condition is only the signal value c (0). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (0) is stored.

  In the case of this example, among the signal values c (−5) to c (5), the signal value stored in the sixth stage q6 is substantially equal to the signal value stored in the fifth stage q5. Are signal values c (−5) to c (0). The signal values satisfying the condition that the signal value stored in the first stage q1 and the signal value stored in the first stage q0 are substantially equal are signal values c (0) to c (5). Further, any one of the signal value stored in the first stage q1 and the signal value stored in the first stage q0 is higher than any one of the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5. The signal values satisfying the condition that the difference is larger and the absolute value of the difference is larger than a predetermined value are signal values c (−4) to c (4). Therefore, in this example, the signal value that satisfies the second determination condition is only the signal value c (0). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (0) is stored.

  FIG. 8A is a graph illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the fifth case. In the figure, the horizontal axis indicates the FIFO stage, the vertical axis indicates the signal value, and the signal value stored in the storage unit 12 is indicated by a graph.

  FIG. 8B is a diagram illustrating an example of a predetermined number of signal values stored in the detection device 10 according to the present embodiment in the fifth case. In the same figure, the signal values shown in FIG.

  The fifth case shows an example in which the movement of the object 100 is faster than in the first case. Specifically, the signal value measured by the measurement unit 11 when the object 100 arrives in the detection range 10a in the fifth case is the same size as in the first case, but the signal value changes. fast. In FIG. 5a, after storing the signal value c (−2), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. The resulting signal value c (-1) is shown by a broken line. After storing the signal value c (−1), the oldest signal value “4” stored in the sixth stage q6 is deleted, and the newly measured signal value “8” is stored in the first stage q0. The value c (0) is shown by a solid line.

  Thus, even when the movement of the target object 100 is fast and the signal value stored in the storage unit 12 changes relatively sharply, the determination unit 13 measures the signal value by the measurement unit 11, It can be determined whether or not the target object 100 has arrived in the detection range 10a based on whether or not a predetermined number of signal values satisfy the determination condition. Here, the determination condition may be at least one of the first determination condition and the second determination condition.

  In the case of this example, a condition that the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5 among the signal values c (-5) to c (5) are substantially equal. Are signal values c (−5) to c (1). In addition, the signal value that satisfies the condition that the signal value stored in the fourth stage q4 is larger than the signal value stored in the fifth stage q5 and the absolute value of the difference is larger than a predetermined value, Signal values c (1) and c (2). Therefore, in this example, the signal value that satisfies the first determination condition is only the signal value c (1). Therefore, the determination unit 13 determines that the object 100 has arrived in the detection range 10a in the cycle in which the signal value c (1) is stored.

  In the case of this example, among the signal values c (−5) to c (5), the signal value stored in the sixth stage q6 is substantially equal to the signal value stored in the fifth stage q5. Are signal values c (-5) to c (1). The signal values satisfying the condition that the signal value stored in the first stage q1 is substantially equal to the signal value stored in the first stage q0 are signal values c (−1) to c (5). . Further, any one of the signal value stored in the first stage q1 and the signal value stored in the first stage q0 is higher than any one of the signal value stored in the sixth stage q6 and the signal value stored in the fifth stage q5. The signal values satisfying the condition that the difference is larger and the absolute value of the difference is larger than a predetermined value are signal values c (−3) to c (3). Therefore, in the case of this example, the signal values satisfying the second determination condition are the signal values c (−1), c (0), and c (1). Therefore, the determination unit 13 determines that the target object 100 has arrived at the detection range 10a during the period in which the signal values c (-1), c (0), and c (1) are stored.

  As shown in each of the above cases, it is assumed that the signal value fluctuates according to the use situation. Nevertheless, the rising or falling of the signal value can be stably detected, and the threshold value is set. The arrival of the object can be detected without the burden on the user that is set according to the usage situation.

  In the first to fifth cases described above, for ease of understanding, it is assumed that the middle point of the rising portion of the waveform of the signal value c (0) is stored in the third stage q3 of the FIFO stage, and the first determination condition In both the first and second determination conditions, the determination condition is satisfied near the signal value c (0). Of course, the signal value satisfying the determination condition may not be stored in the middle stage of the FIFO stage at the midpoint of the rising edge of the waveform.

  In the first determination condition, the signal values stored in the fourth stage q4 to the sixth stage q6 or the third stage q3 to the sixth stage q6 of the FIFO stage are used for the determination, and the signal values stored in the first stage q0 to the second stage q2 are used. The signal value is not used for judgment. Here, the first determination condition is corrected to a determination condition using the first stage q0 to the third stage q3 so that the determination condition is satisfied when the middle point of the rising portion of the waveform is stored in the first stage q1. Then, the rise can be detected three cycles earlier in the first cycle. More specifically, the first determination condition is that the signal value stored in the third stage q3 is substantially equal to the signal value stored in the second stage q2, and is stored in the second stage q2. The condition may be that the signal value stored in the first stage q1 is larger than the signal value and the absolute value of the difference is larger than a predetermined value. Further, the signal value stored in the first stage q1 is substantially equal to the signal value stored in the first stage q0 and the signal value stored in the first stage q0 is greater than the signal value stored in the first stage q1. A condition that the value is larger and at least one of the absolute value of the difference is larger than a predetermined value may be added. For example, in the case of the first case, a signal value that satisfies this determination condition is a signal value c (−3). In this way, not only the first determination condition, but by setting the determination condition using the previous stage of the FIFO memory as much as possible, the rising of the signal waveform can be detected earlier, and the object 100 can be detected in the detection range 10a. It becomes possible to detect the arrival earlier.

  Whether or not the object 100 has arrived in the detection range 10a is determined by executing a learned model specified by parameters generated by machine learning, so that a waveform composed of a plurality of signal values in a time series It can also be determined as a determination condition that a positive result is obtained for having a feature common to the features of the plurality of set reference waveforms.

  FIG. 9 is a diagram illustrating an example of a signal value constituting a rising waveform that may be measured in various states of the detection device 10 and the transport device 50 by the detection device 10 according to the present embodiment. In the figure, the same signal value as the signal value c (0) stored in each case from the first case to the fifth case is shown as a signal value constituting a rising waveform that may be measured. . The waveform composed of the signal values shown in the figure is an example of a reference waveform prepared as a machine learning data set. When the arrival of the object 100 is detected from the falling waveform, the falling waveform is set as a reference waveform. A rising waveform or a falling waveform that may be measured for various types of objects 100 by the detection apparatus 10 may be used as the reference waveform.

  The determining unit 13 measures the signal value by the measuring unit 11 and, based on whether or not the predetermined number of signal values stored in the storage unit 12 satisfies the determining condition, the object 100 arrives in the detection range 10a. It is determined whether or not. As a result, even if the signal value fluctuates according to the use situation, the rising waveform that may be measured when the object 100 arrives in the detection range 10a, that is, a machine learning data set is obtained. It is possible to determine whether or not the detection object 100 has arrived based on whether or not the characteristics common to the characteristics of the plurality of reference waveforms are included, and eliminate the burden on the user of setting the threshold according to the usage situation. Thus, the arrival of the object 100 can be detected.

  In the case of this example, the plurality of signal values constituting the reference waveform are the same signal values as the signal values c (0) stored in the first to fifth cases. However, the signal values constituting the reference waveform do not have to be actually measured signal values, but may be signal values generated by a person or by some algorithm.

  FIG. 10 is a flowchart of a method of setting a learned model executed by the detection device 10 according to the present embodiment. The learned model setting method is a method in which a learned model is generated by a learning device, and the learned model is set (implemented) in the detection device 10.

  First, for a plurality of reference waveforms used as a machine learning data set, a plurality of signal values constituting each reference waveform are prepared (S30). For example, signal values as shown in FIG. 9 are prepared.

  Next, the learning device, which is a computer, determines whether or not the waveform composed of the predetermined number of signal values stored in the storage unit 12 has a feature common to the features of the plurality of reference waveforms. A learned model is generated by machine learning (S31). Here, the learned model may be an arbitrary model, but may be a neural network or a decision tree, for example. The algorithm for generating the parameters of the learned model by machine learning may be any algorithm. For example, in the case of a neural network, the parameters are generated by an error back propagation method using a momentum method, Adam, or the like. For example, a decision tree may be a CART (Classification and Regression Trees) or an ID3 (Iterative Dichotomiser 3).

  Finally, the generated learned model is set (implemented) in the detection device 10 (S32). This completes the setting method.

FIG. 11 is a flowchart showing the setting method for setting the detection apparatus 10 according to the present embodiment more comprehensively including the setting method of FIG.
First, the 1st period which determines whether the target object 100 arrived at the detection range 10a is determined (S10). The first period is based on the time required for the rise or fall of the signal value waveform so that the signal value necessary for determining whether or not the object 100 has arrived in the detection range 10a is stored in the storage unit 12. May be determined.

  Next, a determination condition for determining whether the waveform of the signal value corresponds to a rising waveform or a falling waveform is determined (S11). The determination condition may be, for example, the first determination condition described above, the second determination condition, or a predetermined result obtained by executing the learned model. The determination condition may include designation of a plurality of time points used for determination among the acquisition time points of the predetermined number of signal values stored in the storage unit 12. For example, three or more FIFO stages storing signal values used for determination among a predetermined number of signal values stored in the storage unit 12 may be designated as time points used for determination.

  Then, the first cycle and the determination condition are set in the detection device 10 (S12). This completes the setting method.

  The setting of the first cycle may be performed based on an input by a user in the computer 30 or an input by a user using an operation switch (not shown) provided in the detection device 10.

  The determination of the determination condition and the setting to the detection device 10 are preferably performed by a supplier of the detection device 10. Here, the supplier of the detection device 10 refers to a person other than the final user of the detection device 10 such as a manufacturer, a seller, or a service provider related to the introduction of the detection device 10. Since the determination condition is a condition for determining whether the waveform of the signal value corresponds to the signal value constituting the rising waveform or the falling waveform, the type of the object 100 in the final user of the detection apparatus 10 Even a supplier who does not know the installation state of the detection device 10 can determine the determination condition. Furthermore, even if the final user of the detection device 10 has various situations such as the type of the object 100 and the installation state of the detection device 10, the user can detect the situation without performing machine learning or teaching each time in those situations. The device 10 can be used. A plurality of time points used for determination may not be included in settable determination conditions and may not be changed in the detection apparatus 10. When the updated version (improved version) of the determination condition is prepared by the supplier of the detection device 10 by re-executing S30 and S31 or S11, the last setting step (S32, Only S12) may be performed by the final user of the detection apparatus 10 that has received the updated determination condition.

  According to the setting method according to the present embodiment, instead of determining whether an object has arrived in the detection range based on a change in the presence / absence determination of the object by comparing the signal value and the threshold, storage is performed. A user who sets a threshold value according to a use condition by determining whether an object has arrived in a detection range based on whether a predetermined number of signal values stored in the unit satisfies a determination condition. It is possible to detect the arrival of the target object without burden.

  FIG. 12 is a flowchart of a detection method executed by the detection device 10 according to the present embodiment. The detection method is a method for determining whether or not the object 100 has arrived at the detection range 10 a by the determination unit 13.

  First, the detecting device 10 causes the measuring unit 11 to sequentially convert physical quantities into signal values in the second cycle, and waits for an update timing of the storage unit 12 in the first cycle (S20). Then, the oldest signal value is deleted and the signal value newly acquired by the measurement unit 11 is added to the storage unit 12 that stores the predetermined number of signal values in order of acquisition (S21). .

  Thereafter, the detection device 10 determines whether or not the period is a period for determining whether the signal value satisfies the determination condition (S22). Here, when it is a period to determine (S22: YES), the determination unit 13 determines whether or not the signal values of a plurality of predetermined ranks among the signal values stored in the storage unit 12 satisfy the determination condition. Determine (S23). The determination condition may be, for example, the first determination condition described above, the second determination condition, or a predetermined result obtained by executing the learned model. If the predetermined signal values stored in the storage unit 12 satisfy the determination condition (S23: YES), the detection device 10 determines that the object 100 has arrived in the detection range 10a, and the determination The result is output by the input / output unit 15 (S24). When the output of the determination result is finished, when it is not a cycle for determining whether or not the signal value satisfies the determination condition (S22: NO), and when the predetermined signal values do not satisfy the determination condition (S23: NO), The detection apparatus 10 returns to the process of waiting for the update timing of the storage unit 12 in the first period (S20). The above processing may be repeated continuously.

  According to the detection method according to the present embodiment, the presence or absence of the target in the detection range is detected by comparing the signal value at a certain point in time with the threshold, and it is determined whether the target has arrived based on a change in the detection result. Instead of determining whether an object has arrived in the detection range based on whether a waveform composed of a predetermined number of signal values stored in the storage unit satisfies the determination condition, the threshold value is determined. It is possible to detect the arrival of the target object without the burden on the user who sets according to the use situation. Furthermore, since this determination condition is a condition for determining whether the waveform of the signal value corresponds to a rising waveform or a falling waveform, it is common even if the type of object and the installation state of the detection device are different. In many cases, the determination condition can be applied. In this respect as well, the burden on the user at the stage of preparation for detection execution is reduced.

  The embodiments described above are for facilitating the understanding of the present invention, and are not intended to limit the present invention. Each element included in the embodiment and its arrangement, material, condition, shape, size, and the like are not limited to those illustrated, and can be changed as appropriate. In addition, the structures shown in different embodiments can be partially replaced or combined.

[Appendix 1]
The object (100) arrives at the detection range (10a) based on a signal value corresponding to a physical quantity whose value changes depending on whether the object (100) arrives at the detection range (10a). A detecting device (10) for detecting that
A measurement unit (11) for sequentially converting the physical quantity into the signal value;
A storage area for storing a predetermined number of the signal values in the order obtained from the measurement unit (11) is provided, and the predetermined number of the stored signal values is stored in the measurement unit (11) in a first period. A storage unit (12) for updating with the signal value newly acquired from
The signal values of a plurality of predetermined ranks among the signal values stored in the storage unit (12) have a rising waveform or a falling waveform at a frequency of once every time the update is performed once or a plurality of times. A determination unit that determines whether or not the object (100) has arrived in the detection range (10a) based on whether or not a determination condition for determining whether or not the signal value is included is satisfied. (13)
A detection device (10) comprising:

  DESCRIPTION OF SYMBOLS 1 ... Detection system, 10 ... Detection device, 10a ... Detection range, 11 ... Measurement part, 12 ... Storage part, 13 ... Judgment part, 14 ... Control part, 15 ... Input / output part, 20 ... Controller, 30 ... Computer, 40 ... Robot, 50 ... Conveying device, 100 ... Object

Claims (7)

A detection device that detects that the object has arrived in the detection range based on a signal value corresponding to a physical quantity whose value changes depending on whether the object has arrived in the detection range,
A measurement unit that sequentially converts the physical quantity into the signal value;
A storage area for storing a predetermined number of the signal values in the order obtained from the measurement unit is provided, and the predetermined number of the stored signal values are newly acquired from the measurement unit in a first period. A storage unit to be updated with a signal value;
A signal in which the signal values of a plurality of predetermined ranks among the signal values stored in the storage unit constitute a rising waveform or a falling waveform at a frequency of once every time the update is performed once or a plurality of times. A determination unit that determines whether or not the object has arrived in the detection range, based on whether or not the determination condition for determining whether or not the value falls within the detection range;
A detection device comprising: The storage unit deletes the oldest signal value from the predetermined number of signal values and stores the newly acquired signal value.
The detection device according to claim 1. The first period can be changed.
The detection device according to claim 1 or 2. The determination condition is as follows:
The signal value acquired at the first time point is substantially equal to the signal value acquired at the second time point after the first time point;
An absolute value of a difference between the signal value acquired at the second time point and the signal value acquired at a third time point after the second time point is larger than a predetermined value,
The detection device according to claim 1. The determination condition is as follows:
The signal value acquired at the first time point is substantially equal to the signal value acquired at the second time point after the first time point;
The signal value acquired at a third time point after the second time point is substantially equal to the signal value acquired at a fourth time point after the third time point;
One of the signal value acquired at the first time point and the signal value acquired at the second time point, the signal value acquired at the third time point, and the signal value acquired at the fourth time point The absolute value of the difference from any one of is greater than a predetermined value,
The detection device according to claim 1. The determination condition includes a plurality of reference waveforms in which a waveform composed of a plurality of time-series signal values is set as a machine learning data set by executing a learned model specified by a parameter generated by machine learning. A positive result for having a feature in common with a feature,
The detection device according to claim 1. An input unit that receives an input of the determination condition;
The detection device according to any one of claims 1 to 6.

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