Photoelectronic sensor, control program for photoelectronic sensor, and control method for photoelectronic sensor

Abstract

To provide a state discrimination device, etc., equipped with a user interface that allows easy configuration of a range for classifying a state of a detection object and the combination of on and off states for each output part that changes according to the classified range.SOLUTION: A state discrimination device comprises: a sensor that outputs a detection signal that changes continuously or in steps according to a state of a detection target; two or more output parts, each of which outputs either ON or OFF; a reception part that sequentially receives, from a user, two or more thresholds for setting ranges, without presenting distinctions between the output parts; a setting part that sets three or more ranges based on the thresholds received by the reception part, and sets for each output part whether to output ON or OFF when an output value of the detection signal falls within the respective ranges.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a photoelectric sensor, a control program for a photoelectric sensor, and a control method for a photoelectric sensor. [Background technology]

[0002] For example, photoelectric sensors are known that detect the presence or absence of an object to be inspected and the distance thereto. Patent Document 1 discloses a ToF (Time of Flight) sensor that detects the distance by measuring the time it takes for detection light projected onto the object to be inspected and then reflected back.

[0003] Some photoelectric sensors do not directly output the detected distance, but are equipped with multiple output units, and output whether or not a detection target is present within a set distance range based on the combination of on and off states of each output signal. For example, if the target to be detected appears in the range of 700 mm to 750 mm, set 700 mm and 750 mm as the thresholds of the output units. By acquiring the on and off states of each output signal of a photoelectric sensor with thresholds set in this way using an external analyzer, it is possible to determine whether or not a target is present within the range of 700 mm to 750 mm.

[0004] For example, if the first output unit is set to output ON and the second output unit is set to output OFF when the output value of the detection signal of the photoelectric sensor is included in the range of 700 mm to 750 mm, if the analyzer receives those output signals from the first output unit and the second output unit, it can determine that the detection target was present between 700 mm and 750 mm, and if it receives any other output signal, it can determine that the detection target was not present between 700 mm and 750 mm. The user sets a threshold value (700 mm, 750 mm, etc.) in advance in the photoelectric sensor depending on the range in which they want to check for the presence or absence of the detection target. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-53769 Summary of the Invention [Problem to be solved by the invention]

[0006] When setting a threshold value in such a conventional photoelectric sensor, the on / off state changes of each output unit and the relative relationships between the states of the output units were determined at the time of product shipment, so the user had to fully understand which threshold value should be set for which output unit and the relationships between them, and then input numerical values ​​by operating the operation buttons.

[0007] Such a threshold setting procedure requires the user to have prior knowledge for the setting, and the operation is also cumbersome. Furthermore, while a photoelectric sensor has been described in the above example, a condition determination device in which each of a plurality of output units switches between on and off depending on a range within which the output value of the detection signal output by the sensor falls is not limited to a photoelectric sensor. Any condition determination device combined with a sensor that outputs a detection signal that changes continuously or stepwise depending on the state of the detection target can cause each of the plurality of output units to output on or off depending on a range within which the output value of the detection signal output by such a sensor falls. However, such a condition determination device also has the same problems, requiring prior knowledge and cumbersome input operations for setting the threshold.

[0008] The present invention has been made to solve such problems, and provides a state determination device etc. that has a user interface that allows easy setting of ranges that divide the state of the object to be detected and combinations of on and off of each output section that change for each divided range. [Means for solving the problem]

[0009] A state determination device in a first aspect of the present invention includes a sensor that outputs a detection signal that changes continuously or stepwise depending on the state of an object to be detected, two or more output units that each output either on or off, a reception unit that sequentially receives two or more threshold values ​​for setting a range from a user without indicating the distinction between the output units, and a setting unit that sets three or more ranges based on the threshold values ​​received by the reception unit and sets for each output unit whether to output on or off when the output value of the detection signal falls within each range.

[0010] With a status determination device equipped with such a user interface, the user only needs to input a set number of numerical values ​​(which may be the output value of the detection signal itself or a status value such as a converted distance) that they wish to set as boundaries in order (which may be ascending, descending, or random).The user can easily set ranges that divide the status of the detection object and the on / off combinations of each output unit that change for each divided range, even if they do not understand the on / off state changes of each output unit or the relative relationships between the output units.

[0011] In the above-described state determination device, the setting unit may set all of the output units to output ON for a minimum range set by the smallest minimum threshold value among the threshold values ​​received by the receiving unit. This setting also accommodates the ON / OFF state changes in the previous example, making it easier for the analyzer to handle the output signal of the state determination device.

[0012] In the above-described state determination device, when the number of output units is N (N is an integer of 2 or more), the number of reception units is N+1 or more, N - One or less thresholds are accepted, and the setting unit accepts up to two thresholds according to the number of thresholds accepted by the accepting unit. N The ranges may be set for the output range of the detection signal. By receiving the threshold value in this way, consecutive ranges can be efficiently divided and set.

[0013] In the above-described state determination device, when the number of output units is N (N is an integer of 2 or more), the number of reception units is N+1 or more, 2×(2 N The setting unit receives up to 2×(2 −1) thresholds according to the number of thresholds received by the receiving unit. N A range of (-1)+1 may be set for the output range of the detection signal. By receiving a threshold value in this way, it is possible to set multiple and discrete ranges of the width (distance range) to be detected.

[0014] A control program for a condition determination device in a second aspect of the present invention is a control program for a condition determination device that has a sensor that outputs a detection signal that changes continuously or stepwise depending on the condition of an object to be detected, and two or more output units that each output either on or off, and causes a computer to execute a reception step of receiving two or more threshold values ​​for setting a range from a user in order without indicating the distinction between the output units, and a setting step of setting three or more ranges based on the threshold values ​​received in the reception step, and setting for each output unit whether to output on or off when the output value of the detection signal falls within each range.

[0015] Furthermore, a control method for a state determination device in a third aspect of the present invention is a control method for a state determination device that includes a sensor that outputs a detection signal that changes continuously or stepwise depending on the state of an object to be detected, and two or more output units that each output either on or off, and includes a reception step of receiving two or more threshold values ​​for setting a range from a user in order without indicating the distinction between the output units, and a setting step of setting three or more ranges based on the threshold values ​​received in the reception step, and setting for each output unit whether to output on or off when the output value of the detection signal falls within each range.

[0016] In the second and third aspects, as in the first aspect, the user can easily set the ranges that divide the state of the object to be detected and the on / off combinations of each output unit that change for each divided range, without having to understand the on / off state changes of each output unit or the relative relationships between the output units. [Effects of the Invention]

[0017] The present invention can provide a state determination device or the like that has a user interface that allows easy setting of ranges that divide the state of an object to be detected and combinations of on and off of each output unit that change for each divided range. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating an example of a usage state of a photoelectric sensor that is an embodiment of a state determination device; [Figure 2] FIG. 1 is a system configuration diagram of a photoelectric sensor. [Figure 3] 10A and 10B are diagrams illustrating output signals of each output unit to which a threshold value is set. [Figure 4] FIG. 10 is a diagram showing how a threshold value is set by a user. [Figure 5] FIG. 10 is a diagram showing the relationship between on / off and range of each output unit. [Figure 6] FIG. 10 is a flowchart illustrating a processing procedure for setting a threshold value. [Figure 7] 10A and 10B are diagrams illustrating output signals from each output unit according to the first modified example. [Figure 8] 10A and 10B are diagrams illustrating output signals from each output unit according to a second modified example. [Figure 9] 10A and 10B are diagrams illustrating output signals from each output unit according to the third modified example. [Figure 10] FIG. 10 is a system configuration diagram of a pressure determination device which is another embodiment of the state determination device. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problems.

[0020] 1 is a diagram showing an example of a usage situation of a photoelectric sensor 100, which is an example of a state determination device in this embodiment. The photoelectric sensor 100 projects detection light L1 toward a workpiece and receives detection light L2 that is reflected back from the workpiece. The photoelectric sensor 100 described below is assumed to be equipped with a ToF distance measuring sensor that outputs a distance signal by measuring the round-trip time of the detection light, but the distance measuring sensor is not limited to this, and it may also be equipped with a distance measuring sensor of a triangulation type or the like.

[0021] The photoelectric sensor 100 includes an operation button 170 and a display panel 180. The operation button 170 accepts input operations related to the settings of the photoelectric sensor 100 from the user. The display panel 180 displays items related to the settings of the photoelectric sensor 100. As will be described in detail later, the user operates the operation button 170 while viewing the display panel 180 to set a plurality of threshold values ​​corresponding to the output values ​​of the detection signal of the ToF sensor.

[0022] For example, when three threshold values ​​of 600 mm, 700 mm, and 750 mm are set as shown in the figure, the photoelectric sensor 100 outputs a signal distinguishing whether the object to be detected is in a first range of 0 mm or more and less than 600 mm from the photoelectric sensor 100, a second range of 600 mm or more and less than 700 mm, a third range of 700 mm or more and less than 750 mm, or a fourth range of 750 mm or more (including the case where the object to be detected is not present). However, if there are multiple objects in the detection direction, the object closest to the photoelectric sensor 100 will be detected.

[0023] For example, as shown in the figure, assume that production line 900 is constructed so that if bolt 911 to be inspected is correctly attached to workpiece 910, its head passes through the second range, and other components do not pass through the second range. In this case, if photoelectric sensor 100 outputs an output signal indicating that an object (i.e., the head of bolt 911) is present in the second range, it is determined that bolt 911 is correctly attached to workpiece 910. On the other hand, if photoelectric sensor 100 does not output an output signal indicating that an object is present in the second range, but outputs an output signal indicating that an object is present in the third range through which the surface of workpiece 910 passes, it is determined that bolt 911 is not correctly attached to workpiece 910.

[0024] This determination is made by the analysis device 200 to which the cable 150 of the photoelectric sensor 100 is connected. The cable 150 transmits output signals from each of the multiple output units of the photoelectric sensor 100 to the analysis device 200. The cable 150 may also include a power supply line that supplies power from the analysis device 200 to the photoelectric sensor 100. The cable 150 may also include a grounding wire. The analysis device 200 is, for example, a PLC or a PC, and analyzes the output signal of the photoelectric sensor 100 using installed software, and displays the analysis results on, for example, a connected display monitor 210. In the illustrated example, the display monitor 210 displays that an object has been detected in the third range, which is equal to or greater than 700 mm and less than 750 mm.

[0025] 2 is a system configuration diagram of the photoelectric sensor 100. The photoelectric sensor 100 is mainly composed of a control unit 110, a light emitting element 120, a light receiving element 130, an AD converter 140, a first output unit 151, a second output unit 152, a memory unit 160, an operation button 170, and a display panel 180. The control unit 110 is a processor (CPU: Central Processing Unit) that controls the photoelectric sensor 100 and executes programs. The control unit 110 may include an arithmetic processing chip such as an ASIC (Application Specific Integrated Circuit) and a processing circuit that processes various electrical signals. The control unit 110 executes a control program read from the memory unit 160 or provided from an external device via a cable 150, and performs various processes related to the detection of an object.

[0026] The light-projecting element 120 is a laser diode that emits laser light (e.g., red light of 635 nm to 680 nm), and emits detection light L1 modulated to a specific frequency (e.g., 330 MHz) under the control of the control unit 110. If the wavelength band of the detection light L1 is in the visible band, the spot irradiated on the workpiece can be seen, which is convenient for checking the inspection location where the inspection process is being performed. Note that the light-projecting element 120 is not limited to a laser diode that emits coherent light, and an element that emits incoherent light, such as an LED, may also be used.

[0027] The light receiving element 130 is, for example, an APD, SPAD, or PD, and converts the received detection light L2 into an electrical signal and transmits the converted detection signal to the AD converter 140. The AD converter 140 converts the analog detection signal received from the light receiving element 130 into a digital signal and outputs it to a setting unit 112 (described later) of the control unit 110. The light receiving timing of the light receiving element 130 and the conversion timing of the AD converter 140 are controlled by the control unit 110. Note that in the figure, the optical paths of the detection light L1 projected toward the workpiece and the detection light L2 received by the light receiving element 140 are shown as separate, but in reality, they are the same optical path as shown in FIG. 1, and the optical path of the detection light L2 heading toward the light receiving element 130 is separated from the optical path of the detection light L1 using, for example, a half mirror.

[0028] Each of the first output unit 151 and the second output unit 152 outputs an ON or OFF output signal assigned by the setting unit, as will be described in detail later. In this embodiment, the first output unit 151 outputs an ON or OFF output signal to a first signal line included in the cable 150, and the second output unit 152 outputs an ON or OFF output signal to a second signal line included in the cable 150. The cable 150 is connected to the analysis device 200. Note that the first output unit 151 and the second output unit 152 may employ an interface such as a wireless LAN or Bluetooth (registered trademark) and output their respective output signals to the analysis device 200 wirelessly.

[0029] The storage unit 160 is a non-volatile storage medium, and is configured, for example, by a flash memory. In addition to programs for controlling and processing the photoelectric sensor 100, the storage unit 160 can also store threshold values ​​input and set by the user, as well as various parameter values, functions, lookup tables, and the like used for other controls and calculations.

[0030] The operation button 170 is an operation member that accepts designation from the user. In this embodiment, three independent buttons are employed as described below, but the operation button 170 is not limited to this, and a cross button or the like may also be employed. Furthermore, the operation member is not limited to the operation button, and other devices such as a touch sensor may also be employed. The display panel 180 is, for example, a liquid crystal panel, and is used to display a setting screen required for setting items in the photoelectric sensor 100, and may also display distance information and the like as a detection result.

[0031] The control unit 110 also serves as a functional calculation unit that executes various calculations in response to processing instructed by a control program. The control unit 110 can function as a reception unit 111 and a setting unit 112. The reception unit 111 sequentially receives thresholds for setting ranges from the user via operations on the operation buttons 170. The reception unit 111 may also receive operations performed by the user on external devices such as the analyzer 200 via the cable 150. The setting unit 112 sets ranges based on the thresholds received by the reception unit 111, and sets the first output unit and the second output unit to output either "on" or "off" when an output value falls within each range. Specific processing by the reception unit 111 and the setting unit 112 will be described in detail later.

[0032] As described above, the photoelectric sensor 100 according to this embodiment includes two output units, the first output unit 151 and the second output unit 152. A user can set a threshold value that is a boundary of a range that changes the output signal of at least one of the first output unit 151 and the second output unit 152. Fig. 3 is a diagram illustrating the output signals of each output unit for which a threshold value has been set.

[0033] In this embodiment, the setting unit 112 sets four ranges, a first range, a second range, and a fourth range, using three thresholds, threshold A, threshold B, and threshold C, and sets, for each output unit, the first output unit 151 and the second output unit 152, whether to output ON or OFF when the output value of the detection signal falls within each range. Specifically, for the first output unit 151, ON and OFF state values ​​(hereinafter simply referred to as "state values") for each range are set so that the output signal switches from ON to OFF at threshold A, from OFF to ON at threshold B, and from ON to OFF at threshold C. That is, if the output value of the detection signal input from the AD converter 140 to the setting unit 112 is less than threshold A, the first output unit 151 outputs ON. Similarly, if the output value is equal to or greater than threshold A and less than threshold B, the first output unit 151 outputs OFF. If the output value is equal to or greater than threshold B and less than threshold C, the first output unit 151 outputs ON.

[0034] Similarly, the setting unit 112 sets the state value for the second output unit 152 so that the output signal thereof switches from ON to OFF at threshold B. That is, if the output value of the detection signal input from the AD converter 140 to the setting unit 112 is less than threshold B, the second output unit 152 outputs ON, and if the output value is equal to or greater than threshold B, the second output unit 152 outputs OFF. Note that the light receiving element 130 is adjusted so as to output, for example, the maximum value when it does not receive detection light L2, and in this case the detection signal has an output value equal to or greater than threshold C. Therefore, even if no target is detected, both the first output unit 151 and the second output unit 152 output OFF.

[0035] When setting the state values ​​as described above, the setting unit 112 adjusts the on / off combinations of the two output units in each range so that they do not overlap with combinations in other ranges. By making such adjustments, it becomes possible to determine which of the multiple ranges the detection target object falls within. The setting unit 112 may adjust the on / off combinations by, for example, referring to a pattern map prepared in advance, or may perform a process of searching for a combination each time.

[0036] As described above, the threshold value is a value set corresponding to the output value of the detection signal output by the AD converter 140. The output value of the detection signal is a distance measurement result of the ToF sensor, and therefore corresponds to the distance to the target. Therefore, in this embodiment, the threshold values ​​are accepted as the distance to the target so that the user can more intuitively recognize the threshold values. For example, as shown in the figure, threshold value A is set to a value corresponding to a distance of 600 mm from the photoelectric sensor 100. Similarly, threshold value B is set to a value corresponding to 700 mm, and threshold value C is set to a value corresponding to 750 mm. In this embodiment, as also described in FIG. 1 , a range of less than 600 mm from the photoelectric sensor 100 is defined as a first range, a range of 600 mm or more but less than 700 mm is defined as a second range, a range of 700 mm or more but less than 750 mm is defined as a third range, and a range of 750 mm or more is defined as a fourth range. Note that the ToF sensor in this embodiment employs a method in which the amount of charge photoelectrically converted by the light-receiving element is converted by the AD converter 140 to calculate the phase difference between the emitted and received light and convert the result into the distance to the target; however, the type of ToF sensor is not limited to this. For example, a ToF sensor may be of a type that does not use an AD converter, but instead photoelectrically converts the light received by a light receiving element, digitizes the electrical signal, and detects the rising edge of the digitized signal using a counter circuit to calculate the time difference between the emitted and received light and convert it into the distance to the target.

[0037] 4 is a diagram showing how a user sets threshold values. A setting screen for setting threshold values ​​is displayed on display panel 180. While viewing display panel 180, the user operates operation buttons 170 to input the numerical values ​​of each threshold value.

[0038] The setting screen includes displays of a title 181, an input threshold 182, an up indicator 183, a down indicator 184, a decision indicator 185, and a number indicator 186. The title 181 prompts the user to input a threshold, for example, by saying "Please input the threshold." The input threshold 182 indicates the distance (mm) as the threshold to be set. When the user presses the left button 171, the up indicator 183 is inverted and the value of the input threshold 182 increases by a predetermined amount (e.g., 10 mm), and when the user presses the right button 173, the down indicator 184 is inverted and the value of the input threshold 182 decreases by a predetermined amount (e.g., 10 mm). The figure shows the right button 173 being pressed.

[0039] When the center button 172 is pressed after the value of the input threshold 182 has been adjusted in this way, the decision indicator 185 is inverted and the value is set as one threshold.

[0040] The number indicator 186 indicates the number of thresholds to be set and the number of the currently displayed threshold setting. In the example shown, it is displayed as 1 / 3, indicating that there are three thresholds to be set and that the currently displayed threshold setting is the first of these. The number of thresholds to be set is determined in advance based on the number of output units and the number of detection ranges that can confirm the presence of a detection target.

[0041] The user does not need to know which output unit and which threshold the threshold to be input on the setting screen will be set as. That is, the user only needs to input a predetermined number of numerical values ​​in order, without being aware of the distinction between the output units, such as the first output unit 151 and the second output unit 152, or how the thresholds to be input for those output units will be set. Therefore, the distinction between the output units for which thresholds are to be set is not presented on the setting screen. Furthermore, the order in which the user inputs numerical values ​​may be ascending, descending, or random. If the receiving unit 111 specifies ascending order, it may be limited to accepting numbers in ascending order. Alternatively, if a function for sorting input numerical values ​​is provided, the input numerical values ​​may be accepted randomly and then sorted in ascending or descending order.

[0042] For example, if the receiving unit 111 receives three thresholds of "700 mm," "600 mm," and "750 mm," the setting unit 112 assigns the smallest value, "600 mm," to threshold A, the intermediate value, "700 mm," to threshold B, and the largest value, "750 mm," to threshold C. Then, for each range divided by thresholds A, B, and C, the setting unit 112 sets whether to output on or off from the first output unit 151 and the second output unit 152.

[0043] 5 is a diagram showing the relationship between the on / off states of each output unit and the range of detection. When thresholds A to C are set as described above, the relationship between the on / off combinations of the output signals of first output unit 151 and second output unit 152 and the range of the object to be detected is determined.

[0044] As shown in the figure, when the output signal of first output unit 151 is on and the output signal of second output unit 152 is on, the detected object is present in the first range, which is a range of 0 mm or more and less than 600 mm. Similarly, when the output signal of first output unit 151 is off and the output signal of second output unit 152 is on, the detected object is present in the second range, which is a range of 600 mm or more and less than 700 mm. Furthermore, when the output signal of first output unit 151 is on and the output signal of second output unit 152 is off, the detected object is present in the third range, which is a range of 700 mm or more and less than 750 mm. Furthermore, when the output signal of first output unit 151 is off and the output signal of second output unit 152 is off, the detected object is present in the fourth range, which is a range of 750 mm or more (or no object is detected).

[0045] 6 is a flow diagram illustrating the processing procedure for setting the threshold value by the control unit 110. The flow starts when the user operates the operation button 170 to call up a setting screen for setting the threshold value.

[0046] In step S101, the accepting unit 111 displays a setting screen for accepting the first threshold on the display panel 180. That is, in the example of Fig. 3, the number indicator 186 is displayed as "1 / 3." In the following step S102, the accepting unit 111 detects an operation of the operation button 170, and accepts the input numerical value as the first threshold.

[0047] In step S103, the reception unit 111 determines whether the received thresholds have reached a specified number. In this embodiment, three thresholds, thresholds A to C, need to be set, so the specified number is 3. If it is determined that the specified number has not been reached, the process returns to step S101. Note that on the screen for receiving the second threshold, the number indicator 186 is displayed as "2 / 3," and on the screen for receiving the third threshold, the number indicator 186 is displayed as "3 / 3." If it is determined that the specified number has been reached, the process proceeds to step S104.

[0048] The setting unit 112 sets three or more ranges from the respective threshold values ​​received in step S102, and sets a state value indicating whether to output ON or OFF for each range in each of the first output unit 151 and the second output unit 152. When the setting is complete, the series of processes ends.

[0049] Through this series of processes, the output signal of the first output unit 151 is determined to have an ON → OFF → ON → OFF state change and the threshold values ​​A to C that define the transition between these states. The output signal of the second output unit 152 is determined to have an ON → OFF waveform change and the threshold value B that defines the transition between these states. That is, when the setting unit 112 receives a detection signal, the combination of ON and OFF states to be output by the first output unit 151 and the second output unit 152 is determined so that it can be determined which of the multiple ranges defined by the threshold values ​​the signal falls within. Note that, in this example, the first range, which is the minimum range defined by the minimum threshold value A, is set to output ON from both the first output unit 151 and the second output unit 152. That is, the waveforms of the output signals of the first output unit 151 and the second output unit 152 are set to start with ON. This follows the previous example of setting the closest range to "ON." By following the previous example in this way, the output signals of the photoelectric sensor are easier for the analyzer to handle.

[0050] Although one embodiment has been specifically described above, this embodiment can be modified in various ways, and some modifications will be introduced below.

[0051] 7 is a diagram illustrating the output signals of each output unit according to the first modified example. In the above-described main embodiment, the setting unit 112 set state values ​​that change from ON to OFF to ON to each of successive thresholds A to C as the output signal to be output by the first output unit 151. In contrast, in the first modified example, the setting unit 112 sets state values ​​that change from OFF to ON at threshold A and from ON to OFF at threshold C as the output signal to be output by the first output unit 151. The waveform of the output signal from the second output unit 152 is the same as in the above-described main embodiment.

[0052] When the waveforms of the output signals and the respective threshold values ​​are set in this way, and the output signal of the first output unit 151 is off and the output signal of the second output unit 152 is on, the detected object is within the first range of 0 mm or more, X aSimilarly, when the output signal of the first output section 151 is on and the output signal of the second output section 152 is on, the detected object is within the second range of X a mm or more b When the output signal of the first output section 151 is ON and the output signal of the second output section 152 is OFF, the detected object is within the third range, X b mm or more c When the output signal of the first output section 151 is off and the output signal of the second output section 152 is off, the detected object is in the fourth range, X c mm or more (or the object is not detected).

[0053] 8 is a diagram illustrating output signals of each output unit according to the second modified example. In the above-described main embodiment, the photoelectric sensor 100 is configured to include two output units, the first output unit 151 and the second output unit 152. However, the number of output units included in a photoelectric sensor is not limited to two. Increasing the number of output units allows for an increase in the number of ranges. The photoelectric sensor according to the second modified example includes three output units (a first output unit, a second output unit, and a third output unit).

[0054] In a case where three output units are provided, the receiving unit 111 may receive four to seven thresholds inclusive, depending on the state values ​​set for each output unit. As shown in the example, in this modified example, seven thresholds, from threshold A to threshold G, are received and eight ranges, from first to eighth, are set. The setting unit 112 sets state values ​​that change from OFF to ON to OFF to ON to OFF to ON to OFF to ON to OFF to ON for each of the consecutive thresholds A to G as the output signal to be output from the first output unit. The setting unit 112 also sets state values ​​that change from ON to OFF at threshold B, from OFF to ON at threshold D, and from ON to OFF at threshold F as the output signal to be output from the third output unit. When the state values ​​are set in this manner, it is possible to determine which range the output value of the detection signal falls within based on the combination of ON and OFF of the output signals output by the first output unit, second output unit, and third output unit, respectively. In other words, the correspondence between the combination of on and off output signals from the first output section, the second output section, and the third output section and the range of the object to be detected is determined.

[0055] Specifically, as shown in the figure, when the output signals of the first output unit, the second output unit, and the third output unit are (off, on, on), the detected object is within the first range of 0 mm or more. a Similarly, when the value is (on, on, on), the second range is X a mm or more b If it is in the range of less than mm and is (off, off, on), it is in the third range, X b mm or more c If it is in the range of less than mm and is (on, off, on), it is in the fourth range, X c mm or more d If it is in the range of less than mm and is (off, on, off), it is in the 5th range, X d mm or more e If it is in the range of less than mm and is (on, on, off), it is in the 6th range, X e mm or more fIf it is in the range of less than mm and is (off, off, off), it is in the 7th range, X f mm or more g If it is in the range of less than mm and is (on, off, off), it is in the 8th range, X g mm or more (or the object is not detected).

[0056] In the example of Fig. 8, seven threshold values ​​are accepted to realize the maximum number of ranges (=8) that can be divided by three output units, but if the number of ranges is reduced, the number of accepted threshold values ​​can also be reduced accordingly. When the number of output units provided in the photoelectric sensor is N (N is an integer of 2 or more), the setting unit 112 can set a maximum of 2 threshold values ​​for the output range of the detection signal. N In other words, the reception unit 111 can set N+1 or more consecutive ranges depending on the number of ranges to be set. N The setting unit 112 receives one or less thresholds, and sets the output range of the detection signal to two or more in accordance with the number of thresholds received by the receiving unit 111. N By accepting threshold values ​​and setting each range in this way, it is possible to efficiently divide and set the consecutive ranges.

[0057] FIG. 9 is a diagram illustrating output signals of each output unit according to the third modified example. In the above-described main embodiment, the first modified example, and the second modified example, examples have been described in which the output values ​​of the detection signal are divided into continuous ranges. That is, in any divided range, the presence or absence of an object can be indicated, distinguished from other ranges, by a combination of on and off output signals output from each of the multiple output units. However, depending on the usage of the photoelectric sensor, it may be better to output an output signal indicating the presence or absence of an object in a discretely divided range, rather than dividing into continuous ranges. The third modified example is an example that meets such a requirement.

[0058] The photoelectric sensor according to the third modification includes two output units (a first output unit and a second output unit). As shown in the example, in this modification, it is assumed that the receiving unit 111 receives six thresholds, from threshold A to threshold F, and sets seven ranges, from a first range to a seventh range. The setting unit 112 sets, as an output signal to be output from the first output unit, a state value that changes from OFF to ON at threshold A, from ON to OFF at threshold B, from OFF to ON at threshold E, and from ON to OFF at threshold F. The setting unit 112 also sets, as an output signal to be output from the second output unit, a state value that changes from OFF to ON at threshold C, from ON to OFF at threshold D, from OFF to ON at threshold E, and from ON to OFF at threshold F.

[0059] When six thresholds and state values ​​of each output unit are set in this way, the first range (0 to threshold A), the third range (threshold B to C), the fifth range (threshold D to E), and the seventh range (threshold F and above), in which the output signal of the first output unit 151 and the output signal of the second output unit are both off, cannot be distinguished from each other and are therefore treated as non-detection ranges. In other words, it is not possible to determine in which of these ranges the target object is present.

[0060] On the other hand, when the output signal of the first output section is on and the output signal of the second output section 152 is off, the detected object is in the second range, X a mm (corresponding to threshold A) or more X b Similarly, when the output signal of the first output unit is off and the output signal of the second output unit is on, the detected object is in the fourth range, X c mm (corresponding to threshold C) or more X d It can be determined that the detected object is in the range of less than 1 / 3 mm (corresponding to threshold D). Also, when the output signal of the first output unit is on and the output signal of the second output unit is on, the detected object is in the sixth range, X e mm (corresponding to threshold E) or more X fIt can be determined that the object is present in a range of less than mm (corresponding to threshold F). That is, the second range, fourth range, and sixth range can be detection ranges in which the presence of the object to be detected can be determined. After inputting a threshold, for example, the user can select three detection ranges in which the presence of the object to be detected can be determined, and the receiving unit 111 transfers these three selected detection ranges to the setting unit 112. The setting unit 112 sets the first output unit and the second output unit to output either on or off so that these are detection ranges in which the presence of the object to be detected can be determined.

[0061] In the example of FIG. 9, six threshold values ​​are accepted to realize the maximum number of ranges (=7) that can be distinguished by two output units, but if the number of ranges is reduced, the number of accepted threshold values ​​can also be reduced accordingly. Also, if the number of output units is increased, the detection range in which the presence of a detection target can be determined can be increased. When the number of output units provided in the photoelectric sensor is N (N is an integer of 2 or more), the setting unit 112 sets the output value of the detection signal to a maximum of 2×(2 N The detection ranges can be divided into (2N-1) ranges that are 2×(2N-1) or more, depending on the number of ranges to be set. N The setting unit 112 receives up to 2×(2 −1) threshold values, and sets the output value of the detection signal according to the number of threshold values ​​received by the receiving unit 111. N The range can be divided into (-1) + 1 or less consecutive ranges, of which a maximum of (2N-1) can be used as detection ranges. By accepting thresholds and setting each range in this way, multiple and discrete detection ranges can be set. Of course, two or more consecutive detection ranges can also be set.

[0062] In this embodiment including the modified examples described above, the setting unit 112 sets at least one of the multiple thresholds received by the receiving unit 111 as a boundary, and each output unit included in the photoelectric sensor outputs either on or off in accordance with the setting. However, rather than each output unit included in the photoelectric sensor outputting on or off in accordance with only one threshold set by the setting unit 112, it is desirable that, as in this embodiment including the modified examples described above, at least one of the multiple output units outputting on or off in accordance with at least two or more thresholds set by the setting unit 112. Setting thresholds in this manner increases the number of combinations of on and off states of the output signal, which increases the number of set ranges and enables more advanced object detection.

[0063] Furthermore, the number of threshold values ​​input by the user is determined according to the number of output units and the number of detection ranges in which the presence of a detection target can be determined, as explained using Figures 3, 8, and 9. In other words, the number of threshold values ​​to be set is determined according to the hardware specifications of the output units provided in the photoelectric sensor and the software specifications relating to the allocation of detection ranges in which the presence of a detection target can be determined.

[0064] Furthermore, the example of the setting screen for threshold setting described with reference to FIG. 4 may be modified in various ways. In the example of FIG. 4, the setting of a distance as the threshold is described, but the digital value of the detection signal or another converted value may be set as the threshold. Furthermore, the threshold setting is not limited to being set via the setting screen, and a user interface using voice recognition, for example, may be adopted. Furthermore, a configuration may be adopted in which a value input by a user to an external device is accepted via a communication means. Furthermore, a teaching method may be adopted in which a threshold is set based on the measured distance by actually placing an object to be detected and pressing a button.

[0065] In the present embodiment including the modified examples described above, a photoelectric sensor has been described as an example of a state determination device, but the state determination device may be combined with a sensor that outputs a detection signal that changes continuously or stepwise depending on the state of the detection object. Suitable sensors that can be combined include, for example, an ultrasonic sensor that measures the distance to the detection object in the same way as a photoelectric sensor, a temperature sensor that measures the temperature of the detection object, a pressure sensor that measures pressure, and a flow sensor that measures the flow rate of the detection object passing through an observation point.

[0066] As another embodiment of the state determination device, an example of a pressure determination device that is a state determination device incorporating a pressure sensor will be described. Fig. 10 is a system configuration diagram of pressure determination device 300. Pressure determination device 300 is composed of sensor unit 310 that is brought into contact with an object to be detected, control unit 320 that supervises processing, and cable 350 that connects these. Elements that are functionally similar to those of photoelectric sensor 100 described in Fig. 2 are assigned the same reference numerals as those used in Fig. 2, and descriptions thereof will be omitted unless otherwise noted.

[0067] The sensor unit 310 is mainly composed of a strain gauge 311 and an AD converter 140. The strain gauge 311 is an element whose resistance changes in response to, for example, a pressing force F, and generates a detection signal in response to the detected pressure and transmits it to the AD converter 140. The AD converter 140 converts the analog detection signal received from the strain gauge 311 into a digital signal and outputs it to the setting unit 112 of the control unit 110 via a cable 350. The pressure detection timing of the strain gauge 311, the conversion timing of the AD converter 140, etc. are controlled by the control unit 110.

[0068] Because the detection signal transmitted from the AD converter 140 to the setting unit 112 continuously changes depending on the pressure applied to the detection target, the processing of the control unit 110 in the control unit 320 is substantially the same as the processing of the photoelectric sensor 100 described above. That is, the user only needs to sequentially input thresholds according to the range of pressure to be detected, and can determine whether the pressure applied to the detection target falls within that range from the combination of on and off states of the output signals output from the first output unit 151 and the second output unit 152. The output value of the detection signal output from the strain gauge 311 or other sensor may be corrected before being input to the setting unit 112 or before the setting unit 112 determines which range the output value falls within. For example, temperature correction based on the ambient temperature may be performed. In this case, the setting unit 112 determines which range the corrected output value falls within.

[0069] Here, the main configurations of the above-described state determination device, control program for the state determination device, and control method for the state determination device will be summarized.

[0070] [Appendix 1] a sensor (130, 311) that outputs a detection signal that changes continuously or stepwise depending on the state of an object to be detected; Two or more output units (151, 152) each outputting on or off; a receiving unit (111) that sequentially receives two or more thresholds for setting a range from a user without indicating the distinction between the output units; a setting unit (112) that sets three or more ranges based on the threshold value received by the receiving unit, and sets for each output unit whether to output ON or OFF when the output value of the detection signal falls within each of the ranges; A state determination device comprising: [Appendix 2] 2. The state determination device according to claim 1, wherein the setting unit sets all of the output units to output on for a minimum range set by a smallest minimum threshold value among the threshold values ​​received by the receiving unit. [Appendix 3] When the number of the output units is N (N is an integer of 2 or more), The reception unit is N+1 or more N - accept one or less of said thresholds; The setting unit sets a maximum of two thresholds according to the number of thresholds received by the receiving unit. N 3. The state determination device according to claim 1, wherein the ranges are set for an output range of the detection signal. [Appendix 4] When the number of the output units is N (N is an integer of 2 or more), The reception unit is N+1 or more 2×(2 N -1) or less of said threshold values; The setting unit sets a maximum of 2×(2 N 3. The state determination device according to claim 1, wherein −1)+1 ranges are set for an output range of the detection signal. [Appendix 5] A control program for a state determination device including a sensor (130, 311) that outputs a detection signal that changes continuously or stepwise depending on the state of an object to be detected, and two or more output units (151, 152) that each output an on or off signal, a receiving step of sequentially receiving two or more thresholds for setting a range from a user without indicating the distinction between the output units; a setting step of setting three or more ranges based on the threshold value received in the receiving step, and setting for each output unit whether to output ON or OFF when the output value of the detection signal falls within each of the ranges; A control program for the state determination device that causes a computer to execute the above. [Appendix 6] A control method for a state determination device including a sensor (130, 311) that outputs a detection signal that changes continuously or stepwise depending on the state of an object to be detected, and two or more output units (151, 152) that each output an on or off signal, a receiving step of sequentially receiving two or more thresholds for setting a range from a user without indicating the distinction between the output units; a setting step of setting three or more ranges based on the threshold value received in the receiving step, and setting for each of the output units whether to output ON or OFF when the output value of the detection signal falls within each of the ranges; A control method for a state determination device having the above-mentioned features. [Explanation of symbols]

[0071] 100...photoelectric sensor, 110...control unit, 111...reception unit, 112...setting unit, 120...light-emitting element, 130...light-receiving element, 140...AD converter, 150...communication cable, 151...first output unit, 152...second output unit, 160...storage unit, 170...operation button, 171...left button, 172...center button, 173...right button, 180...display panel, 181...title, 182...input threshold, 183...up indicator, 184...down indicator, 185...determination indicator, 186...number indicator, 200...analysis device, 210...display monitor, 300...pressure determination device, 310...sensor unit, 311...strain gauge, 320...control unit, 350...cable, 900...production line, 910...work, 911...bolt

Claims

1. a sensor that outputs a detection signal that changes continuously or stepwise depending on the state of an object to be detected; two or more output sections, each of which outputs either on or off; a receiving unit that sequentially receives two or more thresholds for setting a range from a user without indicating the distinction between the output units; a setting unit that sets three or more ranges based on the threshold value received by the receiving unit, and sets, for each of the output units, whether to output ON or OFF when the output value of the detection signal falls within each of the ranges; A state determination device comprising:

2. The state determination device according to claim 1 , wherein the setting unit sets all of the output units to output ON for a minimum range set by a smallest minimum threshold value among the threshold values ​​received by the receiving unit.

3. When the number of the output units is N (N is an integer of 2 or more), The reception unit is N+1 or more N Accepting a threshold value less than or equal to −1; The setting unit sets a maximum of two thresholds according to the number of thresholds received by the receiving unit. N 3. The state determination device according to claim 1, wherein the ranges are set for an output range of the detection signal.

4. When the number of the output units is N (N is an integer of 2 or more), The reception unit is N+1 or more 2×(2 N -1) or less of the threshold values; The setting unit sets a maximum of 2×(2 N 3. The state determination device according to claim 1, wherein the ranges -1) +1 are set for the output range of the detection signal.

5. A control program for a state determination device having a sensor that outputs a detection signal that changes continuously or stepwise depending on the state of an object to be detected, and two or more output units that each output either on or off, a receiving step of sequentially receiving two or more thresholds for setting a range from a user without indicating the distinction between the output units; a setting step of setting three or more ranges based on the threshold value received in the receiving step, and setting for each output unit whether to output ON or OFF when the output value of the detection signal falls within each of the ranges; A control program for the state determination device that causes a computer to execute the above.

6. A control method for a state determination device having a sensor that outputs a detection signal that changes continuously or stepwise depending on the state of an object to be detected, and two or more output units that each output either on or off, comprising: a receiving step of sequentially receiving two or more thresholds for setting a range from a user without indicating the distinction between the output units; a setting step of setting three or more ranges based on the threshold value received in the receiving step, and setting for each of the output units whether to output ON or OFF when the output value of the detection signal falls within each of the ranges; A control method for a state determination device having the above-mentioned features.

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