Monitoring module, x-ray diffraction device, and monitoring system

Abstract

To provide a monitoring module and a monitoring system that can guarantee that driving is performed at a constant speed and can make each measurement traceable.SOLUTION: A monitoring module for monitoring the operation of a stepping motor used in an X-ray diffraction device includes a detection unit 164 that detects a specific rotational position of a stepping motor and generates a detection signal, a measurement unit 165 for measuring the time spacing of the detection signals, a determination unit 166 that determines whether the measured value corresponding to the time spacing of the detection signals matches a reference value corresponding to the rotation time between specific rotation positions determined on the basis of an operation instruction to the stepping motor, and an information transmission unit 167 for transmitting abnormal operation information to the outside when the measured value does not match the reference value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a monitoring module, an X-ray diffraction apparatus and a monitoring system for monitoring the operation of a stepping motor. [Background technology]

[0002] X-ray diffraction instruments are equipped with various drive mechanisms that use stepping motors to move the goniometer and sample. Basically, stepping motors with a sufficient margin of torque for the torque required for driving are used, and the drive mechanisms are regularly maintained to prevent malfunctions, but it is also important to monitor the operation of the stepping motor. Stepping motors with encoders detect abnormal operation of the stepping motor from the difference between the command pulse to the stepping motor and the current position of the encoder.

[0003] However, when using a stepping motor with an encoder, (1) the motor is expensive, and (2) the motor size is large, making it prone to mechanical interference. If the stepping motor's operation is not monitored, loss of synchronism may occur due to deterioration of the grease in the drive mechanism, but this abnormality cannot be detected. In such cases, loss of synchronism is often inferred from abnormalities in the measurement profile. In this case, it is difficult to determine when the abnormality occurred, making it difficult to maintain traceability of each measurement profile.

[0004] In response to this, a technique is known for detecting step-out of a stepping motor using an origin sensor (see Patent Document 1). The device described in Patent Document 1 counts command pulses while the motor is rotating, and detects step-out of a motor without an encoder by determining that step-out has occurred if the counter value exceeds the number of pulses for one motor revolution before the output of the origin position sensor is output. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-93993 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the device described in Patent Document 1 can detect out-of-step, it cannot detect abnormalities such as when no pulse is output due to a malfunction of the pulse motor controller, or when a sensor output is generated even though the motor has made less than one rotation due to a malfunction of the origin sensor, etc.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a monitoring module and monitoring system that can ensure that a stepping motor is driven at a constant speed and maintain the traceability of each measurement. [Means for solving the problem]

[0008] (1) In order to achieve the above object, the monitoring module of the present invention is a monitoring module that monitors the operation of a stepping motor used in an X-ray diffraction apparatus, and is characterized by comprising: a detection unit that detects a specific rotational position of the stepping motor and generates a detection signal; a measurement unit that measures the time interval of the detection signal; a judgment unit that judges whether the measurement value corresponding to the time interval of the detection signal matches a reference value corresponding to the rotation time between the specific rotational positions determined based on an operation instruction to the stepping motor; and an information transmission unit that transmits abnormal operation information to the outside if the measurement value does not match the reference value.

[0009] (2) In the monitoring module described in (1) above, the detection unit is a rotation sensor that detects the detection signal every time the stepping motor rotates once.

[0010] (3) Furthermore, in the monitoring module described in (1) or (2) above, the determination unit is characterized in that it determines whether the measurement value matches the reference value by determining whether the difference between the measurement value and the reference value is within a predetermined range.

[0011] (4) In the monitoring module described in any one of (1) to (3) above, the stepping motor is used in a mechanism for adjusting the installation position of a goniometer, a sample stage, a variable slit, or a detector.

[0012] (5) Furthermore, the monitoring module according to any one of (1) to (4) above is characterized in that it further comprises a monitoring condition setting unit that sets the number of detection signals included in the time interval of the detection signals.

[0013] (6) Furthermore, the X-ray diffraction apparatus of the present invention is an X-ray diffraction apparatus in which the operation of the stepping motor is monitored, and is characterized in that it comprises a goniometer that controls the positions of an X-ray source, a sample, and a detector, an adjustment mechanism that adjusts the position of a sample stage that supports the sample, and the monitoring module described in (1) to (5) above, and the stepping motor drives at least one of the goniometer or the adjustment mechanism.

[0014] (7) Furthermore, the monitoring system of the present invention is a monitoring system for monitoring the operation of a stepping motor, and includes the X-ray diffraction apparatus described in (6) above and a processing device that controls the monitoring module, and is characterized in that the processing device displays operation assurance or operation abnormality based on the presence or absence of the transmitted operation abnormality information.

[0015] (8) In the monitoring system described in (7) above, the operational guarantee is numerical information indicating the reliability of a relationship between the rotation speed of the stepping motor and the reference value. [Brief description of the drawings]

[0016] [Figure 1]1 is a schematic diagram showing a configuration of a monitoring system according to the present invention; [Diagram 2] FIG. 2 is a block diagram showing a functional configuration of a monitoring module according to the present invention. [Diagram 3] FIG. 2 is a schematic diagram showing an example of the configuration of a monitoring module of the present invention; [Figure 4] 4 is a timing chart showing a pulse signal and a detection signal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Next, an embodiment of the present invention will be described with reference to the drawings. In order to facilitate understanding of the description, the same reference numerals are used to refer to the same components in each drawing, and duplicated description will be omitted.

[0018] [principle] In conventional position-based operation monitoring, the number of pulse signals between detection signals of a rotation sensor was checked for abnormalities. In this case, even if there is an abnormality in the rotation speed, if there is no abnormality in the position, it is determined that there is no abnormality. However, there is a unique circumstance in measurements using the X-ray diffraction device 100, in which reliability is guaranteed by driving the goniometer 130, the sample stage 140, etc. at a constant speed. Therefore, in this field, it would be very useful if a technology for monitoring the time it takes for the rotating shaft of a stepping motor to rotate a certain angle could be applied to continuous monitoring. The present invention is premised on such a circumstance, and is based on the unconventional idea of ​​monitoring time instead of position.

[0019] [Surveillance system] 1 is a schematic diagram showing the configuration of a monitoring system 10. The monitoring system 10 includes an X-ray diffraction apparatus 100 and a processing apparatus 200. The X-ray diffraction apparatus 100 irradiates a sample S0 with X-rays and detects the scattered X-rays, enabling X-ray diffraction measurement. The X-ray diffraction apparatus 100 drives each internal mechanism with a stepping motor M1, and a monitoring module 160 monitors that the stepping motor M1 is rotating the rotation shaft at a constant rotation speed.

[0020] [Processing device] The processing device 200 controls the operation of the X-ray diffraction device 100 and displays information transmitted from the monitoring module 160. For example, it displays operation guarantee or operation abnormality based on the presence or absence of transmitted operation abnormality information. The processing device 200 is configured by a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a memory connected to a bus. The processing device 200 may be a PC terminal or a server on the cloud. In addition to the entire device, some of the devices or some functions within the device may be provided on the cloud.

[0021] [X-ray diffraction equipment] The X-ray diffraction apparatus 100 includes an X-ray source 110, a variable slit 115, a detector 120, a goniometer 130, a sample stage 140, an adjustment mechanism 145, a stepping motor M1, and a monitoring module 160. The example shown in Fig. 1 is simplified, but in reality, the X-ray diffraction apparatus 100 may include a sample rotation and rocking mechanism, a mechanism for adjusting the installation position of the detector, and other driving mechanisms.

[0022] The X-ray source 110 generates X-rays and irradiates the X-rays toward the sample. The variable slit 115 is a slit with a variable opening width. The detector 120 detects the X-rays scattered by the sample S0. The goniometer 130 is controlled according to the measurement, and controls the positions of the X-ray source 110, the sample S0, and the detector 120. The goniometer 130 may be of any type, including a horizontal rotation type, a vertical type, or a horizontal sample type. The scanning axis of the goniometer 130 may include an in-plane (2θχ) axis in addition to the θ axis, 2θ axis, tilt axis, and in-plane rotation axis. The sample stage 140 supports the sample S0. The adjustment mechanism 145 adjusts the arrangement of the sample stage 140 supporting the sample S0. The arrangement includes not only the position but also the orientation and posture.

[0023] The stepping motor M1 transmits the rotational force of the rotation shaft to the variable slit 115, the goniometer 130, and the adjustment mechanism 145, and drives them. If there are other mechanisms for rotating and rocking the sample, they may also be driven. Although the same reference numerals are used for convenience, the stepping motors M1 that drive each mechanism are provided independently.

[0024] The monitoring module 160 monitors the operation of the stepping motor M1 used in the X-ray diffraction apparatus 100. For example, the stepping motor M1 used in the goniometer 130, the sample stage 140 or the slit variable mechanism, and the detector installation position adjustment mechanism can be monitored. This makes it possible to ensure that the rotation speed of the rotation axis caused by the stepping motor M1 is constant for driving such as measurement scanning by the gonio arm, rotation and oscillation by the sample stage 140, adjustment of the aperture width by the variable slit 115, and adjustment of the camera length by the detector installation position adjustment mechanism.

[0025] [Monitoring module configuration] 2 is a block diagram showing the functional configuration of the monitoring module 160. The monitoring module 160 includes a monitoring condition setting unit 161, an operation instruction unit 162, a pulse signal output unit 163, a detection unit 164, a measurement unit 165, a judgment unit 166, and an information transmission unit 167. Of these, the monitoring condition setting unit 161, the operation instruction unit 162, the pulse signal output unit 163, the measurement unit 165, the judgment unit 166, and the information transmission unit 167 are configured by integrated circuits on a motor driver board D1 in a pulse motor controller. The integrated circuit is preferably an FPGA (Field Programmable Gate Array). Instead of a board, it may be configured by a control device such as a PLC (Programmable Logic Controller).

[0026] The monitoring condition setting unit 161 sets monitoring conditions such as the time interval of the detection signal before operation. The time interval of the detection signal is the time interval for every predetermined number of detection signals. It may be every one or every two. For example, the number of rotations of the motor is set as the monitoring condition, and monitoring can be performed based on the time between the detection signals for each number of rotations of the motor. It is also possible to set a threshold value for the difference between the time interval of the measured detection signal and a reference value. The set threshold value determines whether the difference is within a predetermined range, and whether an operation abnormality occurs. Since the predetermined range changes depending on the measurement, it is preferable to set it by an instruction from the processing device 200.

[0027] The operation instruction unit 162 calculates the number of pulse signals and the pulse signal speed required for the stepping motor M1 to move by the operation, and outputs an operation start command. The pulse signal output unit 163 outputs a pulse signal to the driver of the stepping motor M1 in accordance with the operation start command.

[0028] The detector 164 detects that the rotation shaft of the stepping motor M1 is at a specific rotation position and generates a detection signal. The specific rotation position refers to a position at every fixed angle, and may be, for example, 60°, 120°, 180°, etc. at every 60°, or 360°, 720°, etc. at every 360°.

[0029] The detection unit 164 is a rotation sensor that outputs a detection signal each time the rotation shaft of the stepping motor M1 rotates a certain angle. It is particularly preferable to use a rotation sensor that can detect one rotation (a so-called index sensor). This allows a monitoring system to be constructed at lower cost than when an encoder is used. In addition, the size of the motor unit is reduced, allowing the attachment to be made more compact. Note that when using a rotation sensor, it is assumed that a motor driver board equipped with a function for detecting abnormalities in the motor's operation is used.

[0030] The rotation sensor can be composed of, for example, a disk with a notch attached to the rotating shaft of the stepping motor M1 and a photosensor that emits a signal at the notch position. By aligning the central axis of the disk with the central axis of the rotating shaft and forming a notch in one place on the disk, a detection signal can be obtained from the rotation sensor once per rotation. Alternatively, a disk with markers, a magnetic sensor, etc. may be used to detect rotation.

[0031] The rotation sensor does not necessarily have to be one that can detect a signal once per rotation, as long as it outputs a detection signal each time the rotating shaft rotates a certain angle. It may also be one that detects a signal once per 1 / 2 rotation, or one that detects a signal once per 1 / 3 rotation.

[0032] An encoder can also be used as a type of rotation sensor. An encoder has detection points at multiple locations on a disk, and outputs a detection signal when the sensor detects a detection point. Conventional rotation sensors are used to confirm a position. In the present invention, the rotation speed of the stepping motor M1 can be guaranteed by measuring the time interval of the detection signal.

[0033] The measuring unit 165 measures the time interval of the detection signal obtained from the detecting unit 164. The judging unit 166 judges whether or not the measurement value corresponding to the time interval of the detection signal is a reference value corresponding to the rotation time between specific rotation positions determined based on the operation instruction to the stepping motor M1. The "measurement value" includes not only the measurement value but also an equivalent numerical value calculated from the measurement value. It is preferable to judge whether or not the measurement value matches the reference value depending on whether or not the difference between the measurement value and the reference value is within a predetermined range. This makes it possible to judge that an abnormality exists when the time it takes for the rotating shaft of the stepping motor M1 to move between specific rotation positions is not constant. The reference value and the measurement value may be the time itself for the rotating shaft to rotate between specific rotation positions, or may be a numerical value equivalent thereto, such as the rotation speed or the time per rotation.

[0034] When the measured value is not the reference value, the information transmission unit 167 transmits the operation abnormality information to the outside. This makes it possible to guarantee that the components of the X-ray diffraction apparatus 100 are driven at a constant speed, and to maintain the traceability of each measurement profile. Note that the operation abnormality information may be transmitted by not periodically transmitting and receiving normality information.

[0035] [Configuration example] Fig. 3 is a schematic diagram showing an example of the configuration of the monitoring module 160. In the configuration example shown in Fig. 3, first, based on a command from a HOST PC (processing device), the main controller (1) calculates the number of pulse signals and the pulse signal speed required for driving each mechanism and moving by the measurement operation, and sets the monitoring conditions such as the reaction time of the rotation sensor S1 during constant speed operation (excluding acceleration and deceleration time) in the FPGA (5) before the operation. With this setting, it is possible to measure the time between detection signals for every 100 rotations of the motor, for example. Also, for example, when measuring 20 deg / min, it is possible to guarantee that the operation was performed within a speed range of 20 deg / min ±0.05%.

[0036] The main controller (1) sets the number of pulse signals, pulse signal speed settings, and operation start commands in the PMC (2). The PMC (2) then outputs pulse signals to the stepping motor driver (3). Note that PMC is an abbreviation for Pulse Motor Controller. Note that the main controller and FPGA can be considered as one unit in terms of configuration.

[0037] The FPGA (5) of the motor driver board D1 counts the input pulse signals and measures the time interval of the detection signal. For each rotation of the stepping motor M1 (e.g., 500 pulses depending on the resolution), a detection signal is output from the rotation sensor. The measurement result of the time interval of the detection signal is sent to the main controller (1).

[0038] With this configuration, if there is an abnormality in the PMC peripheral circuitry and no pulse signal is being output, it is possible to detect the abnormality that no pulse signal is being output even though operation has started.If a pulse signal is being output but the detection signal is not detected for more than one motor rotation, it is possible to recognize that the motor has lost synchronism or the rotation sensor (no output) has failed, and the abnormality can be detected.

[0039] The rotation sensor outputs a detection signal once every time the stepping motor M1 rotates once. The time interval at which the rotation sensor responds during constant speed operation of the stepping motor M1 (excluding acceleration and deceleration times) is constant.

[0040] Conventionally, during measurement at a speed of, for example, 20 deg / min (or 20 mm / min), it was not possible to guarantee the reliability of the measurement because it was not possible to know whether the drive mechanism was actually moving in that direction. By measuring the interval between detection signals using the FPGA (5), it is possible to measure the variation in the motor operation speed during measurement. This makes it possible to guarantee the operation of the stepping motor M1 when the measurement was performed. It is also possible to guarantee the operation of the drive mechanism for each angle and position within the measurement range.

[0041] For example, when measuring a diffraction angle range of 10 to 15 deg at 20 deg / min, the following numerical ranges indicating reliability can be obtained. [Table 1]

[0042] The stepping motor M1 is used not only to drive the goniometer during measurement, but also for various drive mechanisms such as the slit adjustment axis of the incident and receiving optical systems, the rotation and oscillation axis of the sample stage. In X-ray diffraction measurements, the slit width on the incident side may be automatically changed while changing the diffraction angle so that the irradiation width on the sample surface is constant, or the sample may be rotated or oscillated at a constant speed to reduce the influence of orientation or coarse particles. With the above configuration, the operation of the stepping motor can be guaranteed for the drive mechanism of each axis during measurement. In addition, since the motor speed during movement is grasped by the main controller (1), it is possible to guarantee the operation not only during measurement but also during movement by a simple drive mechanism. For example, when moving an axis before starting measurement, it is monitored whether the motor moved at the speed of the axis movement, so it is possible to guarantee that the slit width of the variable slit, the XY coordinate position of the sample stage, and the camera length of the detector moved correctly to the set position.

[0043] [Monitoring module operation] An operation example of the monitoring module 160 configured as above will be described. Fig. 4 is a timing chart showing a pulse signal and a detection signal. The pulse signal is a signal for operating the stepping motor M1, and the detection signal is represented by "INDEX" and indicates a signal detected by the detection unit 164.

[0044] When an instruction is given from the control device to the stepping motor M1 during measurement using the X-ray diffraction device 100, the monitoring conditions are set according to the instruction, and an operation instruction is given. Then, the pulse signal output unit 163 outputs a pulse signal at regular intervals so that the stepping motor M1 is driven at a rotation speed according to the operation instruction. The stepping motor M1 rotates its rotation shaft according to this pulse signal.

[0045] Meanwhile, the detector 164 outputs a detection signal each time the stepping motor M1 rotates a certain angle. The measuring unit 165 measures the time interval between a predetermined number of detection signals as a measurement value of the time taken to rotate the certain angle.

[0046] The determination unit 166 determines whether the measured value matches the reference value when the rotation time between specific rotation positions determined based on the operation instruction is set as the reference value. For example, by verifying the number of pulse signals per detection signal, it is possible to confirm whether the stepping motor M1 is out of step, but it is not possible to confirm that the rotation speed is constant. However, it is possible to guarantee the rotation speed by comparing the time required between specific rotation positions calculated according to the operation instruction with the time interval of the detection signal measured by the sensor. The information transmission unit 167 transmits operation abnormality information to the processing device 200 when the calculated rotation speed does not match the reference value. The processing device 200 can immediately detect device malfunctions by notifying the occurrence of motor operation abnormality on the application. In this way, the operation of the stepping motor M1 can be monitored.

[0047] [Show reliability] The performance guarantee displayed by the processing device 200 is preferably numerical information indicating the reliability of the relationship between the stepping motor rotation speed and the reference value. The numerical value indicating the reliability is, for example, a numerical range of ±x% in which the detected stepping motor rotation speed falls with respect to the reference value. This allows the user to objectively check the reliability of the measurement on the spot when using the X-ray diffraction device. [Explanation of symbols]

[0048] 10. Surveillance System 100 X-ray Diffraction Instrument 110 X-ray source 115 Variable Slit 120 Detector 130 Goniometer 140 Sample stage 145 Adjustment mechanism 160 Monitoring Module 161 Monitoring condition setting section 162 Operation instruction section 163 Pulse signal output section 164 Detector 165 Measurement Division 166 Judgment section 167 Information Transmission Department 200 Processing equipment D1 Motor driver board M1 Stepping Motor S0 sample S1 Rotation Sensor

Claims

1. A monitoring module for monitoring operation of a stepping motor used in an X-ray diffraction apparatus, comprising: A detection unit that detects a specific rotational position of the stepping motor and generates a detection signal; A measurement unit that measures a time interval of the detection signal; a determination unit that determines whether a measurement value corresponding to a time interval of the detection signal matches a reference value corresponding to a rotation time between the specific rotation positions that is determined based on an operation command to the stepping motor; a information transmission unit that transmits abnormal operation information to an outside source when the measured value does not match the reference value.

2. 2. The monitoring module according to claim 1, wherein the detection unit is a rotation sensor that detects the detection signal every time the stepping motor makes one rotation.

3. 3. The monitoring module according to claim 1, wherein the determination unit determines whether the measurement value matches the reference value by determining whether a difference between the measurement value and the reference value is within a predetermined range.

4. 3. The monitoring module according to claim 1, wherein the stepping motor is used in a mechanism for adjusting the installation position of a goniometer, a sample stage, a variable slit, or a detector.

5. 3. The monitoring module according to claim 1, further comprising a monitoring condition setting unit that sets the number of detection signals included in the time interval of the detection signals.

6. An X-ray diffraction apparatus in which the operation of the stepping motor is monitored, a goniometer for controlling the positions of the X-ray source, the sample and the detector; an adjustment mechanism for adjusting the position of a sample stage supporting the sample; A monitoring module according to claim 1 or 2, The X-ray diffraction apparatus according to claim 1, wherein the stepping motor drives at least one of a goniometer and the adjustment mechanism.

7. A monitoring system for monitoring operation of the stepping motor, comprising: The X-ray diffraction apparatus according to claim 6, a processing device for controlling the monitoring module; The monitoring system is characterized in that the processing device displays an operation guarantee or an operation abnormality based on the presence or absence of the transmitted operation abnormality information.

8. 8. The monitoring system according to claim 7, wherein the operation guarantee is numerical information indicating reliability of a relationship between the rotation speed of the stepping motor and the reference value.

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