JP2015078870A - Data collection module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record measurement data at a regular angle even when a rotation direction changes in a data collection module which records information indicating an angle of a measuring object to rotate and the measurement data corresponding to the angle in association with each other.SOLUTION: A data collection module for recording information indicating an angle of a measuring object which rotates in positive and negative directions and the measurement data corresponding to the angle in association with each other comprises: a counter; an encoder input unit which inputs an angle detection signal indicating that a rotation angle of the measuring object changed at a prescribed angle and a signal for discriminating a rotation direction of the measuring object, and when the rotation direction is positive, increments a count value of a counter per angle detection signal and when the rotation direction is negative, decrements the count value of the counter per angle detection signal; and a trigger generation unit which outputs a trigger signal for recording a count value and measurement data in association with each other when the count value meets prescribed rules.

Description

  The present invention relates to a data collection module that records information indicating an angle or position of a measurement object that rotates or moves in the positive and negative directions and measurement data corresponding to the angle or position in association with each other.

  FIG. 4 is a block diagram showing an example of the configuration of a system for monitoring the shaft runout of a rotating machine such as a machine tool. In this figure, a machine tool 10 and a bearing 12 are fixed to a gantry 13, and the shaft of the machine tool 10 is supported by the bearing 12. A rotary encoder 14 is attached to the shaft 11, and the rotary encoder 14 detects the rotation of the shaft 11 and outputs a pulse signal every time it rotates a certain amount. A displacement sensor 15 is disposed in the vicinity of the shaft 11, and the displacement sensor 15 measures the shake of the shaft 11 and outputs an analog displacement signal.

  The pulse signal output by the rotary encoder 14 includes an A-phase signal and a B-phase signal output at a constant angular pitch, and an origin detection signal indicating that the origin of the shaft 11 has passed a predetermined position. The phases of the A-phase signal and the B-phase signal are slightly shifted, and the rotation direction can be determined depending on which is output first. Although both the A phase signal and the B phase signal can be used for angle detection, it is assumed here that the A phase signal is used for angle detection. For this reason, the A phase signal is also referred to as an angle detection signal.

  In this figure, the data collection module 300 includes an encoder input unit 310, a counter 320, an analog input unit 330, an AD converter 340, a data buffer 350, and a controller unit 360.

  The data collection module 300 is built in, for example, a PLC (not shown). The PLC controls the rotation of the shaft 11 of the machine tool 10 based on the data collected by the data collection module 300. Generally, a PLC is a control device that incorporates a microprocessor and uses a state machine based on a relay circuit as an operation model, and is mainly programmed with a ladder diagram.

  The encoder input unit 310 receives an origin detection signal, an A phase signal, and a B phase signal output from the rotary encoder 14. The A phase signal is also used as an angle detection signal. The encoder input unit 310 generates a signal for controlling the counter 320 from these pulse signals and outputs the signal to the counter 320. Specifically, if the rotation direction is the forward rotation direction, a signal for increasing the count value is output for each angle detection signal, and if the rotation direction is the reverse direction, a signal for decreasing the count value is output for each angle detection signal. To do. When the origin detection signal is detected, a signal for resetting the count value is output.

  The counter 320 counts based on the signal output from the encoder input unit 310 and outputs the count value to the data buffer 350. In addition, a counter pulse signal is output to the controller unit 360 every time an angle detection signal is input.

  The displacement signal output from the displacement sensor 15 is input to the analog input unit 330 via the amplifier 16. The analog input unit 330 outputs the input displacement signal to the AD converter 340.

  When the controller unit 360 receives the counter pulse signal from the counter 320, the controller unit 360 outputs a conversion start signal to the AD converter 340. When this conversion start signal is input, the AD converter 340 converts the analog displacement signal input from the analog input unit 330 into displacement data of a digital value and outputs it to the data buffer 350.

  When the conversion of the AD converter 340 is completed, the controller unit 360 outputs a save command signal to the data buffer 350. When this storage command signal is input, the data buffer 350 stores the count value of the counter 320 in association with the digital displacement data output from the AD converter 340. The controller unit 360 transmits the data stored in the data buffer 350 to other modules via the inter-module bus.

  FIG. 5 is a diagram illustrating an example of signals input to the data collection module 300. In this figure, an analog displacement signal indicating the shaft shake of the shaft 11 detected by the displacement sensor 15, an origin detection signal indicating that the origin of the shaft 11 has reached a specific position, an A phase signal (angle detection signal), B A phase signal is shown. As described above, both the A-phase signal and the B-phase signal are output as one pulse when the shaft 11 rotates by a predetermined angle (for example, 1 degree), but are out of phase. By detecting which phase of the A phase signal or the B phase signal is advanced, the rotation direction of the shaft 11 can be specified.

Japanese Patent Application No. 2012-60428

  The count value of the counter 320 is reset at the origin of the shaft 11 and increases for normal rotation and decreases for reverse for each angle detection signal output at every predetermined angle. For this reason, the count value of the counter 320 has a one-to-one correspondence with the rotation angle of the shaft 11.

  Therefore, measurement data for each angle can be obtained by recording measurement data such as displacement data in association with the count value for each counter pulse. However, if measurement data is recorded for each counter pulse, the processing load becomes excessive and a large amount of data area is required. For this reason, there are cases where it is desired to record the measurement data by dividing the counter pulse. For example, the counter pulse is divided by 4 and measurement data is recorded every 4 pulses.

  By the way, the shaft 11 can be rotated in the normal direction and reversed. However, when the measurement data is recorded in association with the count value for each counter pulse, even if the rotation direction changes in the middle, the axis 11 is changed to FIG. As shown, measurement data is recorded at each count value.

  On the other hand, when measuring data is recorded by dividing the counter pulse, if the rotation direction is constant, the measured data is regularly recorded at the count value corresponding to the divided value. When the rotation direction changes, the count value for recording the measurement data becomes irregular as shown in FIG.

  Since the count value corresponds to the rotation angle of the shaft 11, measurement data at an irregular rotation angle is recorded. However, depending on the measurement contents, there are cases where it is desired to record measurement data at regular and regular rotation angles.

  Such a problem also exists in the linear encoder that detects the movement amount. That is, when measuring data is recorded by dividing the counter pulse, if the moving direction changes, the count value for recording the measurement data becomes irregular, and the measurement data at irregular positions is recorded.

  Therefore, the present invention provides a data collection module that records information indicating the angle or position of a measurement object that rotates or moves in the positive and negative directions and measurement data corresponding to the angle or position, and the rotation direction or movement direction is It is intended to record measurement data at regular angles or positions even if it changes.

In order to solve the above-described problem, the data collection module according to the first aspect of the present invention records information that associates and records information indicating the angle of the measurement object that rotates in the positive and negative directions and measurement data corresponding to the angle. A collection module that inputs a counter, an angle detection signal indicating that the rotation angle of the measurement object has changed by a predetermined angle, and a signal for determining the rotation direction of the measurement object; An encoder input unit that increases the count value of the counter for each angle detection signal when positive, and decreases the count value of the counter for each angle detection signal when the rotation direction is negative; When a count value is input and the count value satisfies a predetermined rule, a trigger signal for recording the count value and the measurement data in association with each other is output. Characterized by comprising a trigger generating unit, a.
Here, according to the predetermined rule in the trigger generation unit, the count value may be a constant interval value corresponding to a predetermined frequency division value of the angle detection signal.
The trigger signal output from the trigger generator may be a trigger signal for digitally converting analog measurement data corresponding to the angle.
In order to solve the above-described problem, the data collection module according to the second aspect of the present invention records information that associates and records information indicating the position of the measurement object that moves in the positive and negative directions and measurement data corresponding to the position. A collection module that inputs a counter, a position detection signal indicating that the position of the measurement object has changed by a predetermined distance, and a signal for determining the movement direction of the measurement object; In this case, the encoder input unit increases the count value of the counter for each position detection signal, and decreases the count value of the counter for each position detection signal when the moving direction is negative, and the count value of the counter Trigger that outputs a trigger signal for recording the count value and the measurement data in association with each other when the count value satisfies a predetermined rule A generating unit, characterized by comprising a.

  According to the present invention, in the data collection module that records the information indicating the angle or position of the measurement object rotating or moving in the positive and negative directions and the measurement data corresponding to the angle or position, the rotation direction or movement direction is The measurement data can be recorded at regular angles or positions even if it changes.

It is a block diagram which shows the structure of the data collection module which concerns on this embodiment. It is a flowchart explaining the characteristic operation | movement of the data collection module which concerns on this embodiment. It is a figure explaining the count value which the data collection module which concerns on this embodiment records measurement data. It is a block diagram which shows the structural example of the system which monitors the axial shake of the rotating machines, such as a machine tool. It is a figure which shows the example of the signal input into a data acquisition module. It is a figure explaining the count value which the conventional data collection module records measurement data.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the data collection module 100 according to this embodiment. In this figure, the machine tool 10, the shaft 11, the bearing 12, the gantry 13, the rotary encoder 14, the displacement sensor 15, and the amplifier 16 are the same as those in the conventional example, and thus the description thereof is omitted. The data collection module 100 is built in, for example, a PLC (not shown). The PLC controls the rotation of the shaft 11 of the machine tool 10 based on the data collected by the data collection module 100.

  As shown in the figure, the data collection module 100 includes an encoder input unit 110, a counter 120, an analog input unit 130, an AD converter 140, a data buffer 150, and a controller unit 160.

  The encoder input unit 110 receives an origin detection signal, an A phase signal, and a B phase signal output from the rotary encoder 14. The A phase signal is also used as an angle detection signal. The encoder input unit 110 includes a direction determination unit 111 that determines the rotation direction of the shaft 11 based on the input order of the A-phase signal and the B-phase signal.

  The encoder input unit 110 generates a signal for controlling the counter 120 from the input pulse signal and outputs the signal to the counter 120. Specifically, if the rotation direction is the forward rotation direction, a signal for increasing the count value is output for each angle detection signal, and if the rotation direction is the reverse direction, a signal for decreasing the count value is output for each angle detection signal. To do. When the origin detection signal is detected, a signal for resetting the count value is output.

  The counter 120 counts based on the signal output from the encoder input unit 110 and outputs the count value to the data buffer 150 and the controller unit 160. That is, the count value itself is output to the controller unit 160, not the counter pulse signal indicating that the count value has changed.

  The displacement signal output from the displacement sensor 15 is input to the analog input unit 130 via the amplifier 16. The analog input unit 130 outputs the input displacement signal to the AD converter 140.

  The controller unit 160 is a block that controls the data collection module 100, and includes an AD conversion trigger generation unit 161 in the present embodiment. When the count value input from the counter 120 satisfies a predetermined condition, the AD conversion trigger generation unit 161 outputs a conversion start signal that functions as an AD conversion trigger signal to the AD converter 140.

  Here, the case where the count value satisfies the predetermined condition is a case where the count value matches a value at a constant interval according to the frequency division value of the angle detection signal. For example, when a displacement signal is recorded by dividing the angle detection signal by 4, the condition is satisfied when the count value is a multiple of 4, that is, when the lower 2 bits of the count value are “00”. When the displacement signal is recorded by dividing the angle detection signal by 2, the condition is satisfied when the count value is a multiple of 2, that is, the least significant bit of the count value is “0”.

  When the conversion start signal is input from the AD conversion trigger generation unit 161, the AD converter 140 converts the analog displacement signal input from the analog input unit 130 into digital value displacement data and outputs the digital displacement data to the data buffer 150. .

  When the conversion of the AD converter 140 is completed, the controller unit 160 outputs a save command signal to the data buffer 150. When this storage command signal is input, the data buffer 150 stores the count value of the counter 120 in association with the digital displacement data output from the AD converter 140. The controller unit 160 transmits the data stored in the data buffer 150 to other modules via the inter-module bus.

  Next, a characteristic operation of the data collection module 100 according to the present embodiment will be described with reference to the flowchart of FIG. The data collection module 100 receives in advance the setting of the frequency division value for the angle detection signal (S101). In setting the frequency division value, for example, values such as frequency division by 2, frequency division by 4, and frequency division by 8 are received from the user. However, the division value may be automatically determined based on other settings or the division value may be set to a predetermined fixed value.

  When measurement is started, the angle detection signal from the rotary encoder 14 is continuously input to the encoder input unit 110, and the encoder input unit 110 changes the count value of the counter 120 according to the rotation direction (S102).

  When the count value of the counter 120 changes, the count value is input to the AD conversion trigger generation unit 161 of the controller unit 160 (S103).

The AD conversion trigger generation unit 161 determines whether the input count value satisfies the activation condition (S104). That is, it is determined whether or not the count value is a constant interval value according to the frequency division value. When the input count value satisfies the activation condition (S104: Yes), the AD conversion trigger generation unit 161 A conversion start signal serving as a trigger for AD conversion is output to the AD converter 140 (S105). On the other hand, when the input count value does not satisfy the activation condition (S104: No), the conversion start signal is not output to the AD converter 140.

  The data collection module 100 repeats the above operation every time an angle detection signal is input (S102-).

  By performing such an operation, the data collection module 100 according to the present embodiment performs measurement data with a regular count value that is a multiple of 4, for example, even if the rotation direction changes, as shown in FIG. Is recorded. Since the count value corresponds to the rotation angle of the shaft 11, measurement data at regular rotation angles at regular intervals is recorded.

  In this embodiment, one type of analog measurement data is used, but two or more types may be used. In this case, an analog input unit 130 and an AD converter 140 are provided for each measurement data, and the AD conversion trigger generation unit 161 outputs a conversion start signal to each AD converter 140 at the same time.

  The data collection module 100 can also be applied when a linear encoder that detects the position of the measurement object is used instead of the rotary encoder 14 that detects the rotation angle of the shaft 11. In this case, from the linear encoder, a position detection signal indicating that the position of the measurement object has changed by a predetermined distance, a signal for the direction determination unit 111 to determine the moving direction of the measurement object, and the measurement object are predetermined. An origin detection signal indicating that the position has been passed is input.

  The encoder input unit 110 outputs a signal for increasing the count value for each position detection signal if the movement direction is positive, and outputs a signal for decreasing the count value for each position detection signal if the movement direction is negative. To do. When the origin detection signal is detected, a signal for resetting the count value is output.

  Further, the analog input unit 130 receives a measurement analog signal corresponding to the position of the measurement object, for example, a vertical displacement amount. Other blocks can be the same as in the above-described embodiment.

DESCRIPTION OF SYMBOLS 10 ... Machine tool, 11 ... Axis, 12 ... Bearing, 13 ... Mount, 14 ... Rotary encoder, 15 ... Displacement sensor, 16 ... Amplifier, 100 ... Data collection module, 110 ... Encoder input part, 111 ... Direction determination part, 120 ... Counter 130 ... Analog input unit 140 ... AD converter 150 ... Data buffer 160 ... Controller unit 161 ... Conversion trigger generation unit

Claims (4)

A data collection module that records information indicating an angle of a measurement object rotating in a positive and negative direction and measurement data corresponding to the angle,
A counter,
An angle detection signal indicating that the rotation angle of the measurement object has changed by a predetermined angle and a signal for determining the rotation direction of the measurement object are input, and when the rotation direction is positive, the angle detection signal An encoder input unit that increases the count value of the counter every time and decreases the count value of the counter for each angle detection signal when the rotation direction is negative;
A trigger generation unit that inputs a count value of the counter and outputs a trigger signal for recording the count value and the measurement data in association with each other when the count value satisfies a predetermined rule; Data collection module characterized by   2. The data collection module according to claim 1, wherein the predetermined rule in the trigger generation unit is that the count value is a constant interval value corresponding to a predetermined frequency division value of the angle detection signal. .   The data collection module according to claim 1 or 2, wherein the trigger signal output from the trigger generation unit is a trigger signal for digitally converting analog measurement data corresponding to the angle. A data collection module that records information indicating the position of the measurement object moving in the positive and negative directions and measurement data corresponding to the position in association with each other,
A counter,
A position detection signal indicating that the position of the measurement object has changed by a predetermined distance and a signal for determining the movement direction of the measurement object are input, and when the movement direction is positive, for each position detection signal An encoder input unit for increasing the count value of the counter and decreasing the count value of the counter for each position detection signal when the moving direction is negative;
A trigger generation unit that inputs a count value of the counter and outputs a trigger signal for recording the count value and the measurement data in association with each other when the count value satisfies a predetermined rule; Data collection module characterized by