JP2017139155A - Control device, control method, measuring device, and article manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device advantageous for identifying an abnormal load among a plurality of loads.SOLUTION: The control device that controls a plurality of loads 200 supplies electric current to a plurality of loads 200 so that a plurality of electric powers having different sizes from each other are consumed by the plurality of loads 200. On the basis of the total sum of the electric power consumed by the plurality of loads 200, abnormal loads among the plurality of loads 200 are identified.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device, a control method, a measurement device, and an article manufacturing method.

  In recent years, LEDs (Light Emitting Diodes) have been applied as light sources for illumination devices used in industrial devices (such as measuring devices). As this light source, an LED array in which a plurality of LEDs are connected in series is connected in parallel. In order to control the light source, it is necessary to detect a failure of the LED array (LED). Patent document 1 is disclosing the apparatus provided with the detection circuit which detects the failure of several LED separately. Patent document 2 is disclosing the apparatus which detects the disconnection (open) of the circuit which comprises an LED array for every LED array.

Patent No. 4963471 Japanese Patent No. 5576892

  In Patent Document 1, for example, the same number of detection circuit elements (for example, switches) as LEDs are required, which may be disadvantageous in terms of circuit scale. Patent Document 2 may be disadvantageous in terms of circuit scale depending on the number of LED arrays.

  For example, an object of the present invention is to provide a control device that is advantageous for specifying an abnormal load among a plurality of loads.

In order to solve the above problems, the present invention is a control device for controlling a plurality of loads,
An abnormal load among the plurality of loads based on the sum of the power consumed by the plurality of loads by supplying current to the plurality of loads so that the plurality of loads consume different amounts of power. It is characterized by specifying.

  According to the present invention, for example, it is possible to provide a control device that is advantageous for specifying an abnormal load among a plurality of loads.

It is a figure which shows the structure of the power supply circuit which concerns on 1st Embodiment. It is a figure which shows the structure of the power supply circuit contained in the control apparatus which concerns on 1st Embodiment. 3 is a flowchart showing an operation flow of the power supply circuit of FIG. 2. It is a figure explaining the setting method of an output current (drive current). It is a figure which shows the structure of the power supply circuit using a PWM control circuit. It is a figure which shows the structure of the power supply circuit contained in the control apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the flow of operation | movement of the power supply circuit of FIG. It is a figure which shows the structure of the power supply circuit contained in the control apparatus which concerns on 3rd Embodiment. It is a flowchart which shows the flow of operation | movement of the power supply circuit of FIG. It is a figure which shows the structural example of a measuring device.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a power supply circuit according to the present embodiment. The power supply circuit 300 allows a constant current to flow through the load 200. The load 200 is, for example, a blue LED having a main wavelength of 460 nm or a plurality of LEDs connected in series (LED array). Of course, other elements may be used. The power supply circuit 300 includes a DC / DC converter (drive circuit) 10, a DC power supply 20, and a drive command unit 30. The direct current power supply 20 supplies electric power to the DC / DC converter 10 and includes, for example, an AC power supply and a switching power supply that converts AC100V to DC24V. The DC / DC converter 10 is controlled by an enable signal and a current command value (instruction value) output from the drive command unit 30. The drive command unit 30 is configured by, for example, an FPGA (Field Programmable Gate Array). Drive command unit 30 outputs to DC / DC converter 10 an instruction value that indicates the magnitude of the current flowing through load 200.

  The DC / DC converter 10 includes an input capacitor 11, a switch 12 and a switch 13, an inductor 14, an output capacitor 15, a current detection resistor 16, a differential amplifier 17, a comparison circuit 18, and a control circuit 19. Composed. The input capacitor 11 is for smoothing ripples generated by the switching operation of the DC / DC converter 10, and is, for example, an aluminum electrolytic capacitor of several tens to several hundreds μF. The switch 12 and the switch 13 are for converting the electric power supplied from the DC power supply 20 together with the inductor 14 into electric power necessary for driving the load 200. This is realized by, for example, an n-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The opening / closing of the switch is controlled by the control circuit 19.

  The inductor 14 is for power conversion, and is an inductor of several to several tens of μH, for example. The output capacitor 15 is for smoothing ripples appearing at the output section, and is an aluminum electrolytic capacitor of several tens to several hundreds μF, for example. The current detection resistor 16 is for detecting the current flowing to the load 200, and is a high-precision resistor of several to several tens of mΩ, for example. Since the current value detected by the current detection resistor 16 is a weak signal, it is amplified by the differential amplifier 17 and input to the comparison circuit 18. The comparison circuit 18 compares the current command value output from the drive command unit 30 with the current value amplified by the differential amplifier 17 and outputs the result to the control circuit 19.

  The control circuit 19 opens and closes the switches 12 and 13 based on the comparison result. For example, when the detected current value is smaller than the current command value output from the drive command unit 30, the switch 12 is closed and the switch 13 is opened. Conversely, when the detected current value is larger than the current command value, the switch 12 is opened and the switch 13 is closed. In this way, the opening and closing of the switches 12 and 13 are controlled to supply a current as the current command value to the load 200. Note that the differential amplifier 17, the comparison circuit 18, and the control circuit 19 may be configured using an IC for a power supply circuit. Further, some ICs include the switches 12 and 13 and the inductor 14, and the DC / DC converter 10 may be configured using the switches.

  In the power supply circuit 300 configured as described above, when detecting a failure of the load 200 to be driven, it is common to monitor the voltage at both ends (point A and point B) of the load 200. For example, consider a case where one blue LED is connected as the load 200. The output voltage of the DC power supply is 24V. At this time, if the load 200 is short-circuited, the voltage at both ends becomes 0 V, so that the failure can be detected. On the other hand, when the load 200 is in an open failure, the DC / DC converter 10 operates to supply the load 200 with the current according to the current command value from the drive command unit 30, so that the switch 12 remains open. Therefore, the voltage at both ends of the load 200 is 24 V, and a failure can be detected.

  FIG. 2 is a diagram illustrating a configuration of a power supply circuit included in the control device according to the present embodiment. The power supply circuit 100 is a circuit that drives four loads 200, and includes a power detection unit 40, a faulty system identification unit 50, and a storage unit 60 in addition to the configuration of FIG. The power detection unit 40 includes, for example, a current detection resistor of several to several tens of mΩ, an operational amplifier for amplifying a detected signal, and an A / D converter that converts an analog signal into a digital signal. The power detection unit 40 detects the total power (supply power value) consumed by at least a part of the plurality of loads 200. Moreover, the failure system identification part 50 and the memory | storage part 60 are comprised by FPGA, for example. Note that the DC / DC converter 10 shown in the figure may be configured, for example, like the DC / DC converter 10 shown in FIG. 1 or may be replaced with another drive circuit.

  FIG. 3 is a flowchart showing an operation flow of the power supply circuit 100 of FIG. The flowchart of this embodiment has two modes. A normal drive mode for driving the load 200 and a fault system identification mode for identifying a faulty abnormal load 200 (fault system, fault array). In S <b> 101, the drive command unit 30 sends a current command value to the DC / DC converter 10 and sets the output current value of the DC / DC converter 10. For example, when the load connected to the DC / DC converter is an LED, this current value is set according to the light emission amount necessary for the LED. This current command value may be an analog signal, or serial communication such as SPI (Serial Peripheral Interface).

  In S <b> 102, the drive command unit 30 sends an enable signal to the DC / DC converter 10 to start driving the load 200. For example, the enable signal may be a digital signal having a binary signal level of Low and High, and the driving of the load 200 may be started when the signal level is switched from Low to High. Here, when the load connected to the DC / DC converter is an LED, the light emission amount of the LED can be adjusted by changing the current command value, but the color of light changes according to the output current value. A phenomenon called shift occurs. In order to avoid this color shift, when adjusting the light emission amount of the LED, the signal level of the enable signal can be switched at high speed and the light emission amount can be adjusted by the duty ratio instead of making the current command value constant. That is, in the power supply circuit of FIG. 2, the light emission amount can be adjusted by the current command value, and the light emission amount can be adjusted by the duty ratio of the enable signal. In the light emission amount adjustment method using the enable signal, the output current value is constant, and therefore the forward voltage of the LED is also constant. In S103, the drive command unit 30 monitors the supplied power based on the output value of the power detection unit 40. Monitoring is continued if the supplied power is within a predetermined range. Further, the period of monitoring may be determined according to the application of the power supply circuit. The predetermined range can be determined based on, for example, the amount of power supplied when the load is normal.

  If it is determined in S103 that the power supply amount is outside the allowable range (NO), the process shifts to the fault system identification mode, and in S104, the drive command unit 30 stops driving the load. For example, the load is stopped by switching the signal level of the enable signal from High to Low. In S105, the drive command unit 30 sets the output current of the DC / DC converter 10 anew.

  4A and 4B are diagrams illustrating a method for setting an output current (drive current). In this figure, consider a case where there are three drive systems (LED arrays) and one LED is included in each array. In order to simplify the description, a method for adjusting the light emission amount using an enable signal in which the forward voltage does not change is considered. In this light emission amount adjusting method, the drive current flows intermittently. Hereinafter, the average of the intermittent drive currents is referred to as an average drive current. Here, since the power consumption in each LED is the product of each average driving current and the forward voltage, the power consumption is 0 in a short failure where the forward voltage is 0 or an open failure where no current flows. That is, when the power consumption of any LED becomes 0, the corresponding power is not supplied from the DC power supply 20, and thus the output value of the power detection unit 40 changes. A faulty system is identified from the amount of change.

In FIG. 4A, average drive currents flowing through the drive systems 1 to 3 are i _{1 to} i ₃ , respectively, and V _LED is a forward voltage of the LED. 0 in the table indicates that the drive system is normal, and 1 indicates that a failure has occurred. The three drive systems and the two states can be classified into eight cases of states 0 to 7. For example, state 1 is a case where only drive system 1 has failed. The eight states of states 0 to 7 can be considered as binary numbers representing decimal numbers from 0 to 7 if the drive system 1 is LSB and the drive system 3 is MSB. For example, the binary display of 3 is “011”, which is the same value as in state 3.

  The failure system is identified based on the power value detected by the power detection unit 40. Therefore, the power consumption generated in each drive system is made unique by weighting the power consumption of each drive system. This corresponds to, for example, an operation of adding and weighting each bit to a power of 2 when converting a binary number to a decimal number.

FIG. 4B shows the amount of power consumed in each system when i ₁ is 1 A (= 2 ⁰ ), i ₂ is 2 A (= 2 ¹ ), and i ₃ is 4 A (= 2 ² ). The correspondence between the total and the failure state is shown. In this embodiment, each drive system includes one LED, and the number of LED failures is either 0 or 1, so that power of 2 is weighted. When two LEDs are connected, the number of LED failures is 0, 1 or 2, and therefore, for example, a power of 3 should be weighted. In other words, the weighting performed when the number of LEDs included in the drive system (the number in series) is n is a power of n + 1 ((n + 1) ⁰ , (n + 1) ^1, etc.). The weighting may be a weighting of a constant multiple of power (0.1A, 0.2A, 0.4A, etc.).

  Here, if there is an open-failed LED, no current flows through the column, so the power consumption is zero. That is, since all of the LEDs in the row have the same power consumption change as when a short circuit failure has occurred, the failure system can be identified even in the case of an open failure. In the above example, the forward voltage of all LEDs is common because of the light emission amount adjustment method using the enable signal. On the other hand, when the light emission amount is adjusted by the current command value, the forward voltage of each LED varies depending on the current value. However, even in this case, since the power consumption of each LED may be weighted by a power of 2, it is sufficient to set a current value such that the power consumption is a power of 2 based on the characteristics of the LED.

  Returning to the flowchart of FIG. In S <b> 106, the drive command unit 30 starts driving the load 200. In S107, the fault system identification unit 50 identifies the fault system by referring to the table stored in the storage unit 60 using the output value (supply power value) of the power detection unit 40. This table is a table representing the relationship between the power consumption and the failure state as shown in FIG. The memory capacity necessary for the storage unit 60 is, for example, 16 bits × 256 = 4096 bits when the supply power value is a digital signal of 8 bits (= 256) and the failure data indicating the failure state has a data length of 16 bits. This memory capacity can be easily realized by using, for example, a memory built in the FPGA. The fault system identification unit 50 decodes the fault data and identifies the fault system.

  In S <b> 108, the drive command unit 30 stops driving the load 200. Note that the drive time of the load 200 in the fault system identification mode may be determined based on the time during which the output of the power detector 40 is stabilized as long as the fault system can be correctly identified. That is, S107 and S108 may be interchanged.

  Note that the DC / DC converter 10 may be replaced with a PWM control circuit. FIG. 5 is a diagram illustrating a configuration of a power supply circuit using the PWM control circuit. The power supply circuit 400 includes a PWM control circuit 70, a DC power supply 20, and a drive command unit 30, and drives the load 200 by PWM control. The operation of the PWM control circuit 70 is controlled by an enable signal from the drive command unit 30 and a duty command value. The drive command unit 30 is composed of, for example, an FPGA. The PWM control circuit 70 includes an input capacitor 71, a switch 72, a control circuit 73, and a current limiting resistor 74. The input capacitor 71 is for smoothing ripples generated by the switching operation of the PWM control circuit 70, and is, for example, an aluminum electrolytic capacitor of several tens to several hundreds μF. The switch 72 is turned on / off by the opening / closing operation. This is realized by, for example, an n-channel MOSFET. The opening / closing of the switch is controlled by the control circuit 73. The current limiting resistor 74 is a resistor for limiting the current flowing to the load. This resistance value is determined from the voltage value of the DC power supply 20 and the current value flowing to the load 200.

  When the PWM control circuit 70 configured in this way is replaced with the DC / DC converter 10 in the power supply circuit 100 of FIG. 2, only the current command value is changed to the Duty command value, and the algorithm of the present invention described above is used. There is no difference. When the PWM control circuit 70 is used, the power source may be an alternating current.

  The power supply circuit included in the control device according to the present embodiment increases the scale of the failure detection circuit by setting the current value that flows to the load so that the power value consumed by each system (LED array) is unique. It is possible to identify the fault system.

  As described above, according to the present embodiment, it is possible to provide a control device that detects an LED array failure, which is advantageous in terms of circuit scale.

(Second Embodiment)
Next, a power circuit included in the control device according to the second embodiment of the present invention will be described. The present embodiment is characterized in that the current value setting step in the first embodiment is repeated a plurality of times. FIG. 6 is a diagram illustrating a configuration of a power supply circuit 100a included in the control device according to the present embodiment. The configuration is the same as that of the power supply circuit of the first embodiment shown in FIG. 2 except that the fault system identification unit 50 outputs data to the drive command unit 30. When an LED array with low power consumption is included, depending on the resolution of the A / D converter that constitutes the power detection unit 40, detection of power (= detection of failure) can be difficult. The present embodiment corresponds to such a case.

FIG. 7 is a flowchart showing an operation flow of the power supply circuit 100a of FIG. Description of the steps already described in FIG. 3 is omitted. In the present embodiment, the failure system identification mode includes a step of determining whether or not the failure system has been identified (S209). Since this determination is a determination of the presence or absence of a faulty system, if there are one or more faulty systems, it is determined that the faulty system has been identified, and the faulty system identification mode ends. When the failed system could not be identified (NO), in S210, the failed system identifying unit 50 outputs current value resetting data to the drive command unit 30. In S211, the drive command unit 30 resets the current command value based on the current value reset data. This resetting is performed so that the current value of each system is different from the previous value. For example, the setting is performed such that the largest current flows through the LED array with low power consumption. The current command value to be sent to each system is a power of the number of LEDs + 1, and an exponent that should be a power is, for example, any of non-negative integers equal to or less than the number of systems-1 (the number of loads-1). ((Number of LEDs + 1) ⁰ to (number of LEDs + 1) ^{number of systems-1} ). That is, the setting of the current command value is performed at the maximum of the number of systems including resetting.

  Here, for example, the drive command unit 30 refers to the current command value stored in the internal memory in advance based on the current value resetting data to set each system (the set of the DC / DC converter 10 and the load 200). ) Reset the current command value output to. The current value resetting data may be a process execution flag for executing a process of switching the address of the internal memory to be referred between the systems.

  The power supply circuit included in the control device according to the present embodiment can identify a fault system without increasing the scale of the fault detection circuit even when controlling an LED array that consumes less power and is difficult to detect a fault. The same effects as those of the first embodiment are obtained.

(Third embodiment)
Next, a power circuit included in the control device according to the third embodiment of the present invention will be described. This embodiment corresponds to a case where the number of drive systems (LED arrays) is larger than a settable current value. FIG. 8 is a diagram illustrating a configuration of a power supply circuit 100b included in the control device according to the present embodiment. Unlike the above embodiment, a large number of DC / DC converters 10 and loads 200 are included. In addition, about the structure similar to the said embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  Since there is a limit to the total amount of current that can be supplied from the DC power supply 20 to each system and the current that can be supplied to each load 200, the current value that can be set is also limited. Therefore, the load 200 to which the power supply circuit 100b of this embodiment is connected is divided into blocks each having a predetermined number of loads 200 as one set. The fault system is identified for each block.

  FIG. 9 is a flowchart showing an operation flow of the power supply circuit 100b of FIG. Description of the steps already described in the above embodiment is omitted. It is assumed that the block division method and the block to be driven first in the fault system identification mode are determined in advance. In S105, the drive command unit 30 performs current value setting for all the drive systems. In the present embodiment, it is sufficient that the fault system can be identified in the same block, and therefore, the current value setting may be the same setting for different blocks. Here, for example, the drive command unit 30 stores the drive system driven in the failure system identification mode in the internal memory as drive system data, and outputs an enable signal to each drive system with reference to the drive system data. It is configured as follows. This drive system data is updated based on the drive block data output from the fault system identification unit 50. In S106, the drive command unit 30 starts driving the block to be driven first.

  In S107, the fault system identification unit 50 decodes the fault data using the drive block data and the supplied power value, and identifies the fault system. This decoding process includes a process of converting relative address information for specifying each system in the drive block having the failure data into absolute address information for specifying each system in all the drive systems. . In S309, the failure system identification unit 50 determines whether all the blocks have been driven based on the value of the drive block data. If it is determined that all the blocks are not driven (No), the fault system identification unit 50 updates the drive block data and drives the updated drive block data to drive the non-driven block. The data is output to the unit 30 (S310). The drive command unit 30 switches drive blocks by updating drive system data based on the drive block data (S311). On the other hand, when it is determined that all the blocks have been driven (Yes), the fault system identification mode ends.

    The power supply circuit included in the control device according to the present embodiment identifies a failure system without enlarging the failure detection circuit even when controlling more LED arrays than the number of current values that can be set. The same effect as the first and second embodiments can be obtained.

  The setting of the current value is not limited to the weighting by the power of the number of LEDs + 1, but may be a current value that can uniquely identify each system.

(Embodiment related to measuring device / article manufacturing method)
The control device including the power supply circuit described above can be applied to the measurement device 1000 described later. The load connected to the power supply circuit is, for example, a light source (for example, an LED light source) in a projection unit (described later). FIG. 10 is a diagram illustrating a configuration example of the measurement apparatus 1000 according to the present embodiment. In the figure, a measurement apparatus 1000 includes a projection unit (first projection unit 1100, second projection unit 1200), an imaging unit 1300, a storage unit 1400, and a processing unit 1500. In the figure, OBJ indicates an object (object). The first projection unit 1100 projects pattern light 1110 onto the object 1. The second projection unit 1200 projects illumination light 1210 (non-pattern light) onto the object 1. The pattern light 1110 is patterned light (pattern light or light having the first pattern). Illumination light 1210 is non-patterned light (non-patterned light, light not having the first pattern, light having a second pattern different from the first pattern, or (substantially) uniform illumination light) It is. The imaging unit 1300 captures the object OBJ on which the pattern light 1110 is projected to obtain a pattern image (first image), and captures the object OBJ on which the illumination light 1210 is projected to capture a grayscale image (first image and the first image). Obtain a different second image). The storage unit 1400 stores various data necessary for measurement.

  The processing unit 1500 performs processing for recognizing the area of the object OBJ based on the pattern image and the grayscale image. The object OBJ may be a part for manufacturing (processing) an article. Here, the part is processed or assembled by a processing unit (for example, a robot (hand)) 2100 or held or moved for the purpose (generally referred to as processing). The processing unit is controlled by the control unit 2200. The control unit 2200 receives information on the region (position and orientation) of the object 1 obtained by the processing unit 1500 and controls the operation of the processing unit 2100 based on the information. The processing unit 2100 and the control unit 2200 constitute a processing apparatus 2000 that performs processing on the object OBJ. Further, the measuring device 1000 and the processing device 2000 constitute a processing system. Note that the measuring device is not limited to recognizing (measuring) the region of the object OBJ, and may be, for example, a device that recognizes (measures or inspects) a defect of the object. When recognizing the defect, at least one of the above-described pattern image and grayscale image can be used. In addition, illumination suitable for the type of defect can be selectively used from among various known illuminations. Then, an image (third image) obtained by imaging the illuminated object OBJ can be used.

  The measuring device described above can be used in an article manufacturing method. The article manufacturing method can include a step of measuring an object using the measuring device and a step of processing the object measured in the step. The process can include, for example, at least one of processing, cutting, conveyance, assembly (assembly), inspection, and selection. The article manufacturing method of the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

(Other embodiments)
As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 100 Power supply device 10 DC / DC converter 20 DC power supply 30 Drive command part 40 Power detection part 50 Fault system identification part 60 Storage part 200 Load

Claims (10)

A control device for controlling a plurality of loads,
Based on the sum of the power consumed by the plurality of loads by supplying current to the plurality of loads so that the plurality of loads consume a plurality of different amounts of power, respectively. A control device characterized by identifying an abnormal load. A detection unit that detects a sum of power consumed by at least a part of the plurality of loads;
2. The control device according to claim 1, wherein the identification is performed by supplying the current when the total detected by the detection unit is out of an allowable range.   The control device according to claim 1, wherein the plurality of electric powers have a plurality of values that can perform the specification based on the sum.   Each value of the plurality of electric powers is a constant of a power of a value obtained by adding 1 to the number of elements included in a row of at least one element connected in series as a load among the plurality of loads corresponding thereto. The control device according to claim 1, wherein the control device is doubled.   5. The control device according to claim 4, wherein the exponent that is a power is one of a non-negative integer equal to or less than a number obtained by subtracting 1 from the number of the plurality of loads.   Re-setting related to the plurality of powers such that power consumed by the least consumed power among the plurality of loads is larger than power consumed by at least one other load among the plurality of loads. The control device according to claim 1, wherein:   The control apparatus according to claim 1, wherein a plurality of sets in which the plurality of loads are set as one set are controlled. A method for identifying an abnormal load among a plurality of loads,
Identifying the abnormal load based on the sum of the power consumed by the plurality of loads by supplying current to the plurality of loads such that the plurality of loads consumes a plurality of different amounts of power, respectively. The method characterized by performing. A measuring device having a plurality of light sources,
A measuring device comprising the control device according to claim 1, wherein the plurality of light sources are controlled as a plurality of loads. A step of measuring an object using the measuring device according to claim 9;
Processing the object subjected to the measurement in the step;
A method for producing an article comprising:

Images