JP7043660B1 - Information processing equipment and machine tools - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the measurement accuracy of a measurement object in a machine tool or the like. SOLUTION: The information processing apparatus acquires a coordinate value indicating a position of the measuring apparatus and a coordinate value from a first receiving unit for receiving a measured value indicating a distance from the measuring apparatus to a measurement object and a machining control unit. Measurement at the same time by correcting both or one of the measured value and the coordinate value based on the difference between the second receiver that receives the position time value indicating the timing and the measured time value and the position time value indicating the measurement timing. It is provided with an adjustment unit that specifies values and coordinate values. [Selection diagram] Fig. 2

Description

The present invention relates to a measuring technique in a machine tool or the like.

Machine tools include a device for cutting a work into a desired shape and a device for laminating metal powder or the like to make a work. Machine tools for cutting include a turning center that processes a workpiece by applying a cutting tool to a rotating work, and a machining center that processes a workpiece by applying a rotating tool to the workpiece. There is a multi-tasking machine equipped.

The tool is fixed to the tool holding part such as the spindle or the tool post. The machine tool processes the work while moving the tool holding portion while exchanging tools according to a machining program prepared in advance (see Patent Documents 1 and 2).

A measuring device (measuring head) can be attached to the spindle instead of a tool. The measuring device is equipped with a probe and measures the distance to the work as a measurement object directly under the measuring device. Not limited to the contact type, there are also measuring devices that measure the distance to the work in a non-contact manner using an optical sensor. The machine tool measures each part of the work while changing the relative positions of the measuring device and the work, and reproduces the three-dimensional shape of the work based on the set of measured values in each part of the work (see Patent Documents 3 and 4).

Japanese Unexamined Patent Publication No. 10-143216 Japanese Unexamined Patent Publication No. 2017-21472 Japanese Patent No. 5283563 International Publication No. 2005/065884

The relative positional relationship between the measuring device and the work changes at high speed. In order to reproduce the three-dimensional shape of the work, it is necessary to accurately associate the position information, which is the coordinate value of each point of the work, with the measured value. For that purpose, it is necessary to make the difference between the time when the position information of the work is acquired (hereinafter referred to as "position time") and the time when the measured value is acquired (hereinafter referred to as "measurement time") as small as possible. ..

For example, if the measured value V (t1) at the measurement time t1 and the position information P (t1 + Δt) at the position time t1 + Δt slightly later than the measurement time t1 are combined, the measured value V (t1) becomes the original measurement point. Will be considered as a measurement at a different point.

The information processing device according to an embodiment of the present invention includes a first receiving unit that receives a measured value indicating a distance from a measuring device of a machine to a measured object and a first time value indicating an acquisition timing of the measured value, and a machine. A measured value based on the difference between the second receiving unit that receives the coordinate value indicating the position of the measuring device and the second time value indicating the acquisition timing of the coordinate value from the numerical control unit, and the difference between the first time value and the second time value. And an adjustment unit for specifying the measured value and the coordinate value at the same time by correcting both or one of the coordinate values.

The machine tool in certain aspects of the invention is connected to a pulse generator.
This machine tool includes a measuring device, a tool holding unit for holding a tool or a measuring device, and a machining control unit for machining a work.
The pulse generator periodically transmits a pulse signal to the machining control unit. The measuring device transmits a measured value indicating the distance from the measuring device to the work and a timing signal indicating the measurement timing. The machining control unit transmits a coordinate value indicating the position of the tool holding unit and a count signal indicating the number of pulse signals received until the coordinate value is acquired.

According to the present invention, it becomes easy to improve the measurement accuracy of a measurement object in a machine tool or the like.

It is an external view of a machine tool. It is a conceptual diagram for demonstrating the acquisition method of the measured value and the position information in this embodiment. It is a figure which shows the more specific configuration about a pulse generator, a measuring apparatus, an information processing apparatus, and a processing control unit. It is a figure which shows an example of the structure of a pulse generator, a measuring device, an information processing device, and a processing control unit. It is a timing chart when the position information P is transmitted from a machining control unit. It is a time chart which shows the relationship between the measurement timing signal MS and the position acquisition signal GP. It is a hardware block diagram of a machine tool, a pulse generator, and an information processing apparatus. It is a functional block diagram of an information processing apparatus. It is a timing chart which shows the transmission timing of the measured value and the position information. It is a data structure diagram of the position information history in 1st Embodiment. It is a data structure diagram of the measurement history in 1st Embodiment. It is a schematic diagram for demonstrating the adjustment method of the measured value and the position information in 1st Embodiment. It is a data structure diagram of the position information history in 2nd Embodiment. It is a schematic diagram for demonstrating the adjustment method of the measured value and the position information in 2nd Embodiment.

The first embodiment and the second embodiment will be described separately based on the periodicity of the timing for acquiring the position information. When the first embodiment and the second embodiment are collectively referred to, or when there is no particular distinction, they are referred to as "the present embodiment".

[First Embodiment]
FIG. 1 is an external view of the machine tool 100.
The machine tool 100 in this embodiment is a vertical machining center. The machine tool 100 has a bed 102 and a column 104 installed on the bed 102. A spindle head 106 is attached to the column 104. The spindle head 106 is movable in the Z-axis direction (vertical direction). A spindle 108 is attached to the spindle head 106. The spindle 108 is rotatably attached to the spindle head 106 about the Z axis. A tool (not shown) is attached to the tip of the spindle 108. A measuring device 112 (measurement head) can also be attached to the spindle 108.

The bed 102 is equipped with a saddle 110 that can be moved in the Y direction. A table 114 movable in the X direction is installed on the saddle 110. The work W to be machined and measured is placed on the table 114. The machine tool 100 changes the relative position of the work W and the measuring device 112, in other words, the measuring point of the work W, by moving the saddle 110 and the table 114 in the XY direction by the machining control unit (described later). Similarly, the machining control unit changes the distance between the work W and the spindle 108 by moving the spindle head 106 up and down.

The measuring device 112 periodically measures the distance from the measuring device 112 to the work W, and transmits a measured value V indicating the distance to the information processing device (described later). The information processing apparatus periodically accesses the machining control unit of the machine tool 100, and acquires the position information P commanded by the machining control unit to the saddle 110 or the like. The position information P referred to here is a set of X coordinate values, Y coordinate values, and Z coordinate values. The information processing apparatus recognizes the measurement point of the work W by the X coordinate value and the Y coordinate value. Further, the information processing apparatus recognizes the height of the work W from the Z coordinate value and the measured value V.

In the present embodiment, the measuring device 112 executes the distance measurement every 6 milliseconds, and continuously transmits the obtained measured value V to the measuring device. Further, the information processing apparatus accesses the machine tool 100 every 4 milliseconds and acquires the set position information P.

As described above, the acquisition of the measured value V by the measuring device 112 and the acquisition of the position information P by the information processing device are executed asynchronously. Therefore, the measurement time and the position time usually do not match. A method of executing the distance measurement in synchronization with the acquisition timing of the position information P is conceivable, but in order to realize the precise measurement, it is necessary to match the two timings with high accuracy, and the saddle 110 and the table 114 have Such control is very difficult due to the high speed movement.

FIG. 2 is a conceptual diagram for explaining a method of acquiring measured values and position information in the present embodiment.
The pulse generator 116 is a timing generator that periodically generates a pulse signal. The pulse generator 116 in the present embodiment simultaneously transmits a pulse signal to the measuring device 112 and the machining control unit 118 every 1 microsecond. The machining control unit 118 is a numerical control device that controls the saddle 110, the table 114, the spindle head 106, and the like in the machine tool 100.

The pulse signal transmitted from the pulse generator 116 is received by the measuring device 112 and the machining control unit 118. Since the pulse signal is transmitted via a dedicated line, the measuring device 112 and the machining control unit 118 ensure the same simultaneity at least in microsecond units at substantially the same timing, while ensuring the simultaneity of the pulse signal. To receive.

The measuring device 112 has a counter value CM as a first time value. The counter value CM is information indicating the measurement time (described later). The measuring device 112 counts up the counter value CM each time a pulse signal is received. The counter value CM indicates the number of times that the measuring device 112 has received the pulse signal.

The machining control unit 118 has a counter value CN as a second time value. The counter value CN is information indicating the position and time (described later). The machining control unit 118 counts up the counter value CN each time a pulse signal is received. The counter value CN indicates the number of times the machining control unit 118 has received the pulse signal.

The measuring device 112 and the machining control unit 118 count up the counter value CM and the counter value CN independently, but since the measuring device 112 and the machining control unit 118 receive the pulse signal at the same time, the counter value CM and the counter value CN are It will be counted up at the same timing.

The measuring device 112 measures the distance to the work W every 6 milliseconds. The measuring device 112 transmits the counter value CM at the time of measurement, that is, the counter value CM indicating the measurement time (hereinafter, referred to as “measurement time value CM”) to the information processing device 120 together with the measurement value V. The machining control unit 118 sets the Y coordinate of the saddle 110, the X coordinate of the table 114, and the Z coordinate of the spindle head 106. The information processing apparatus 120 acquires the position information P set by the machining control unit 118 every 4 milliseconds. At this time, in the information processing apparatus 120, the counter value CN at the time of acquisition of the position information P, that is, the counter value CN indicating the position time (hereinafter referred to as “position time value CN”) is also the position coordinate P (XYZ coordinate value). ) And get it.

As described above, the information processing apparatus 120 periodically acquires the measured value V and the measured time value CM. Further, the information processing apparatus 120 also periodically acquires the position information P and the position time value CN. The information processing apparatus 120 calculates the position information P at the measurement time by adjusting the measured value V and the position information P obtained asynchronously based on the measurement time value CM and the position time value CN (hereinafter, this). Such processing is called "time adjustment"). The details of the time adjustment will be described later in relation to FIGS. 9 and later.

FIG. 3 is a diagram showing a more specific configuration of the pulse generator 116, the measuring device 112, the information processing device 120, and the machining control unit 118.
As described above, the measuring device 112 periodically measures the distance to the work W. The measuring device 112 periodically asserts the "measurement timing signal MS". When the measurement timing signal MS is asserted, the distance measurement is executed and the measured value V is transmitted to the information processing apparatus 120 together with the measured time value CM. The measuring device 112 transmits the measured value V and the measured time value CM to the pulse generator 116 when the measurement timing signal MS is asserted, and the pulse generator 116 transmits the measured value V and the measured time value CM to the information processing device. It may be transmitted to 120. That is, the measuring device 112 may directly transmit the measured value V to the information processing device 120, or may transmit the measured value V to the information processing device 120 via the pulse generating device 116.

The machining control unit 118 is connected to the first axis linear scale 180, the second axis linear scale 182, and the third axis linear scale 184. The X coordinate value is measured by the first axis linear scale 180. The Y coordinate value is measured by the second axis linear scale 182. The Z coordinate value is measured by the third axis linear scale 184. The information processing apparatus 120 acquires the position measurement value CN together with the position coordinate P (X coordinate value, Y coordinate value and Z coordinate value) by accessing the latch program executed by the machining control unit 118.

FIG. 4 is a diagram showing an example of the configuration of the pulse generator 116, the measuring device 112, the information processing device 120, and the machining control unit 118.
The first axis motor 186 is a motor that moves the table 114 in the X-axis direction. The machining control unit 118 instructs the servo module 192 of the X-axis movement amount of the table 114. The servo module 192 rotates the first axis motor 186 according to the instructed movement amount. The amount of rotation of the first-axis motor 186 is measured by the encoder of the first-axis linear scale 180. The servo module 192 acquires a count value indicating the amount of movement on the X-axis from the encoder of the first-axis linear scale 180. The machining control unit 118 acquires the X coordinate value of the table 114 based on the count value acquired from the servo module 192.

The second axis motor 188 is a motor that moves the saddle 110 in the Y-axis direction. The machining control unit 118 instructs the servo module 194 of the Y-axis movement amount of the saddle 110. The servo module 194 rotates the second axis motor 188 according to the instructed movement amount. The amount of rotation of the second-axis motor 188 is measured by the encoder of the second-axis linear scale 182. The servo module 194 acquires a count value indicating the amount of Y-axis movement from the encoder of the second-axis linear scale 182. The machining control unit 118 acquires the Y coordinate value of the saddle 110 based on the count value acquired from the servo module 194.

The third shaft motor 190 is a motor that moves the spindle head 106 in the Z-axis direction. The machining control unit 118 instructs the servo module 196 of the Z-axis movement amount of the third-axis motor 190. The servo module 196 rotates the third axis motor 190 according to the instructed movement amount. The amount of rotation of the third axis motor 190 is measured by the encoder of the third axis linear scale 184. The servo module 196 acquires a count value indicating the Z-axis movement amount from the encoder of the third-axis motor 190. The machining control unit 118 acquires the Z coordinate value of the spindle head 106 based on the count value acquired from the servo module 196.

The processing control unit 118 acquires the position information P (X coordinate value, Y coordinate value and Z coordinate value) at the timing when the "position acquisition signal GP" is received from the information processing device 120, and processes the position information P. It is transmitted to the device 120. Further, the machining control unit 118 transmits the position measurement value CN from the dummy signal line to the information processing apparatus 120 when the position information P is acquired. The information processing apparatus 120 periodically transmits the position acquisition signal GP to the machining control unit 118, the machining control unit 118 acquires the position information P and transmits it to the information processing apparatus 120, and is a dummy of the dummy axis linear scale counter 198. The position / time value CN is transmitted to the information processing device 120 via the pulse generator 116 by the signal line.

The dummy axis linear scale counter 198 is a linear scale encoder that is not used when measuring the measured value V among the linear scales included in the machine tool 100. For example, if there is a surplus servo module, the linear scale encoder in the surplus servo module may be used. There is a removable substage, and when this substage is removed, the linear scale signal line corresponding to the substage may be used as a dummy signal line.

The measuring device 112 transmits the measured value V together with the measured time value CM to the information processing device 120. The measuring device 112 may transmit the measured value V to the pulse generating device 116, and the pulse generating device 116 may transmit the measured time value CM together with the measured value V to the information processing device 120.

FIG. 5 is a timing chart when the position information P is transmitted from the machining control unit 118.
The measuring device 112 periodically asserts the measurement timing signal MS. The measuring device 112 acquires the measured value V when the measurement timing signal MS is asserted. Apart from the distance measurement, the information processing apparatus 120 first transmits the reset signal Z to the dummy axis linear scale 198. The reset signal Z is an initialization signal for resetting the count of the position / time value CN in the machining control unit 118.

A pulse signal A and a pulse signal B deviated by a half cycle are transmitted from the pulse generator 116 to the machining control unit 118. Each time the rising edge and falling edge of the pulse signal A and the rising edge and falling edge of the pulse signal B are detected, the position-time value CN of the machining control unit 118 is counted up. The processing control unit 118 transmits the position / time value CN to the information processing apparatus 120 as the D signal of FIG.

FIG. 6 is a time chart showing the relationship between the measurement timing signal MS and the position acquisition signal GP.
When the movement command CMD is executed by the machining program or the like, the machining control unit 118 controls the first shaft motor 186 and the like to move the table 114, the saddle 110 and the spindle head 106 by a designated distance in a designated direction. Apart from moving the table 114 and the like, the information processing apparatus 120 periodically transmits the position acquisition signal GP. After the position acquisition signal GP is transmitted, the information processing apparatus 120 receives the position information P together with the position time value CN from the processing control unit 118. Similarly, the measuring device 112 periodically asserts the measurement timing signal MS. When the measurement timing signal MS is asserted, the measuring device 112 executes the distance measurement to acquire the measured value V, and transmits the measured value V together with the measured time value CM to the information processing device 120.

FIG. 7 is a hardware configuration diagram of the machine tool 100, the pulse generator 116, and the information processing device 120.
The machine tool 100 includes an operation control device 122, a machining control unit 118 (numerical control unit), a machining device 124, a tool changing unit 126, and a tool storage unit 128. The processing apparatus 124 corresponds to the machine configuration of the machine tool 100 including the bed 102, the column 104, the saddle 110, the table 114, the spindle head 106, and the like. The machining control unit 118, which functions as a numerical control device, transmits a control signal to the machining device 124 according to the machining program. The machining apparatus 124 moves the spindle head 106, the saddle 110, the table 114, and the spindle head 106 according to the instruction from the machining control unit 118 to machine the workpiece.

The operation control device 122 includes an operation panel (not shown) that provides a user interface function to the operator. The operator controls the machining control unit 118 via the operation control device 122. The tool storage unit 128 stores the tool. The tool changing unit 126 corresponds to a so-called ATC (Automatic Tool Changer). The tool changing unit 126 takes out the tool from the tool storage unit 128 according to the changing instruction from the machining control unit 118, and exchanges the tool on the spindle 108 with the taken out tool. Further, the tool changing unit 126 can attach / detach the measuring device 112 to / from the spindle 108 instead of the tool.

The pulse generator 116 is connected to both the machining control unit 118 and the measuring device 112, and transmits a pulse signal at regular intervals. As described above, the pulse generator 116 in the present embodiment transmits a pulse signal at a high frequency of 1 microsecond.

The information processing device 120 periodically receives the measured value V and the measured time value CM from the measuring device 112. Further, the information processing apparatus 120 periodically receives the position coordinate P and the position time value CN from the machining control unit 118. The information processing device 120 may be configured as a part of the operation control device 122. The information processing apparatus 120 may be a general laptop PC (Personal Computer) or a tablet computer.
The machine tool 100 may include both or one of the pulse generator 116 and the information processing apparatus 120.

FIG. 8 is a functional block diagram of the information processing apparatus 120.
Each component of the information processing device 120 includes a CPU (Central Processing Unit), a computing unit such as various computer processors, a storage device such as a memory and a storage, hardware including a wired or wireless communication line connecting them, and a storage device. It is stored in the computer and realized by software that supplies processing instructions to the computer. The computer program may be composed of a device driver, an operating system, various application programs located on the upper layer thereof, and a library that provides common functions to these programs. Each block described below shows a block for each function, not a configuration for each hardware.

The operation control device 122 and the processing control unit 118 are also stored in a computer such as a processor, a storage device such as a memory and a storage device, hardware including a wired or wireless communication line connecting them, and a storage device. The software or program that supplies the processing instructions may be realized on an operating system separate from the information processing unit 120.

The information processing apparatus 120 includes a user interface processing unit 130, a data processing unit 132, a communication unit 134, and a data storage unit 136.
The user interface processing unit 130 accepts operations from the operator and is in charge of processing related to the user interface such as image display and audio output. The communication unit 134 is in charge of communication with external devices such as the processing control unit 118 and the processing device 124. The data processing unit 132 executes various processes based on the data acquired by the communication unit 134 and the user interface processing unit 130 and the data stored in the data storage unit 136. The data processing unit 132 also functions as an interface for the user interface processing unit 130, the communication unit 134, and the data storage unit 136. The data storage unit 136 stores various programs and setting data.

The user interface processing unit 130 includes an input unit 138 and an output unit 140.
The input unit 138 receives input from the user via a hard device such as a touch panel, a mouse, and a keyboard. The output unit 140 provides various information to the user via an image display or an audio output.

The communication unit 134 includes a reception unit 144 that receives data from an external device and a transmission unit 142 that transmits data to the external device.
The receiving unit 144 includes a first receiving unit 146 and a second receiving unit 148. The first receiving unit 146 periodically receives the measured value V together with the measured time value CM from the measuring device 112. The second receiving unit 148 periodically receives the position information P together with the position / time value CN from the machining control unit 118. In the present embodiment, the transmission unit 142 periodically transmits the position acquisition signal GP to the processing control unit 118, and the second receiving unit 148 returns the position information P from the processing control unit 118 in response to the position acquisition signal GP. And receive the location time value CN.

The data processing unit 132 includes an adjusting unit 150 and a shape reproducing unit 152. The adjusting unit 150 calculates the position information P at the measurement time based on the measurement time value CM and the position time value CN. The shape reproduction unit 152 generates three-dimensional data of the work W by reproducing the surface shape of the work W by a known method based on the position coordinates P and the measured value V after adjusting the time.

FIG. 9 is a timing chart showing the transmission timing of the measured value and the position information.
The pulse generator 116 transmits a pulse signal to the machining control unit 118 and the measuring device 112. In FIG. 9, the measured time value CM = 129, that is, when the measuring device 112 receives the 129th pulse signal, the measuring device 112 measures the distance to the work W directly underneath, and the measured value V is set as the data number M1. (Hereinafter referred to as "measured value (M1)") is transmitted to the information processing apparatus 120 together with the measured time value CM. The first receiving unit 146 of the information processing apparatus 120 receives the measured time value CM (hereinafter, referred to as “measured time value CM (M1)”) together with the measured value V (M1).

After about 6 milliseconds, the measuring device 112 measures the distance to the work W again. The data number at the time of measurement at this time is M2. The measured time value CM (M2) is "6200". The measuring device 112 measures the distance to the work W every 6 milliseconds, but the timing of the measurement may fluctuate by several microseconds due to fluctuations in the processing load of the measuring device 112 or the like. Logically, the next measurement time value CM (M2) of the measurement time value CM (M1) = 129 is 6129 (= 129 + 6000), but as shown in FIG. 9, the actual measurement time value CM (M2) = 6200. It has become slightly fluctuating. The measuring device 112 transmits the measured value V (M2) and the measured time value CM (M2) to the information processing device 120. Subsequently, the measuring device 112 transmits the measured value V (M3) and the measured time value CM (M2) = 12105 after about 6 milliseconds.

On the other hand, the information processing apparatus 120 periodically accesses the machining control unit 118 and acquires the position coordinates P from the machining control unit 118. In FIG. 9, as the data number N1, the measurement time value CN = 223, that is, the position coordinate P (N1) when the machining control unit 118 receives the 223rd pulse signal is the second reception unit of the information processing apparatus 120. 148 is received together with the position time value CN (N1).

After about 4 milliseconds, the information processing apparatus 120 accesses the machining control unit 118 again and acquires the position coordinate P (N2) and the position time value CN (N2) = 4229. After that, the information processing apparatus 120 acquires the position coordinate P (N3) and the position time value CN (N3) = 8501, and the position coordinate P (N4) and the position time value CN (N4) = 12387.

FIG. 10 is a data structure diagram of the position information history 160 in the first embodiment.
The position information history 160 is stored in the data storage unit 136 of the information processing apparatus 120. The position information history 160 indicates the position information P and the position time value CN periodically acquired by the second receiving unit 148 from the machining control unit 118. The position information P includes an X coordinate value, a Y coordinate value, and a Z coordinate value.

For example, in the position information P (N2), the X coordinate value is "475.534", the Y coordinate value is "937.986", the Z coordinate value is "-480.210", and the position time value CN (N2). = 4229. That is, the position information P (N2) indicates the position of the work W when the machining control unit 118 receives the 4229th pulse signal from the pulse generator 116. More specifically, the position information P (N2) indicates the X coordinate value, the Y coordinate value, and the Z coordinate value of the spindle head 106 at the measurement point (below the spindle head 106) at the position time value CN (N2).

FIG. 11 is a data structure diagram of the measurement history 170 according to the first embodiment.
The measurement history 170 is stored in the data storage unit 136 of the information processing apparatus 120. The measurement history 170 shows the measured value V and the measured time value CM periodically received by the first receiving unit 146 from the measuring device 112. As described above, the measured value V indicates the distance from the tip position of the measuring device 112 to the surface of the work W.

For example, the measured value (M2) is "207.244", and the measured time value CM (M2) = 6200. This indicates the distance from the measuring device 112 to the work W when the measuring device 112 receives the 6200th pulse signal from the pulse generating device 116.

FIG. 12 is a schematic diagram for explaining a method of adjusting the measured value and the position information in the first embodiment.
The horizontal axis represents time, and the vertical axis represents the X coordinate value as a representative of the position information P. As mentioned above, the measurement time and the position time usually do not match. In the present embodiment, the position coordinate P (assumed value) at the measurement time is calculated by a linear interpolation formula to adjust the position coordinate P in time.

First, the X coordinate value (assumed value) in the measurement time value CM (M1) is calculated. The adjusting unit 150 is the difference between the position time value CN (N1) = 223 and the position time value CN (N2) = 4229 obtained after the measurement time value CM (M1) = 129, that is, {CN (N2)-. Based on CN (N1)} = 4006, the time change rate d1 of the X coordinate value is calculated. The X coordinate value corresponding to the position time value CN (N1) = 223 is X (N1) = 453.444, and the X coordinate value corresponding to the position time value CN (N2) = 4229 is X (N2) = 475.534. Then,
d1 = {X (N2) -X (N1)} / {CN (N2) -CN (N1)}
= (475.534-453.444) / 4006
= 0.00551
Will be. Based on the difference d1 between the position time value CN (N1) = 223 and the measured time value CM (M1) = 129, that is, {CN (N1) -CM (M1)} = 94, based on the slope d1 obtained by the above equation. , When X (M1) as an assumed value in the measured time value CM (M1) is calculated,
X (M1) = X (N1) -d1 x {CN (N1) -CM (M1)}
= 453.444-0.00551 × 94
= 452.926
Will be.

Therefore, the X coordinate value (assumed value) in the measured time value CM (M1) is extrapolated based on X (N1) = 453.444 and X (N2) = 475.534 in the other position time value CN. You can ask.

Next, the X coordinate value (assumed value) in the measurement time value CM (M2) is calculated. The adjusting unit 150 is the difference between the position time value CN (N2) = 4228 and the position time value CN (N3) = 8501 before and after the measurement time value CM (M2) = 6200, that is, {CN (N3) -CN (N2). )} = 4273, the time change rate d2 of the X coordinate value is calculated.
d2 = {X (N3) -X (N2)} / {CN (N3) -CN (N2)}
= (498.214-475.534) / 4273
= 0.0053
Will be. Based on the difference d2 between the measured time value CM (M2) = 6200 and the position time value CN (N2) = 4229, that is, {CM (M2) -CN (N2)} = 1971 by the slope d2 obtained from the above equation. , X (M2) is calculated
X (M2) = X (N2) + d2 × {CM (M2) -CN (N2)}
= 475.534 + 0.0053 × 1971
= 485.980
Will be.

Therefore, the X coordinate value in the measured time value CM (M2) can be obtained by a linear interpolation formula based on X (N2) and X (N3) in the other position time value CN.

The Y coordinate value and the Z coordinate value can be calculated by the same method. According to such a control method, the position coordinate P in the measured time value CM when the measured value V is obtained can be reasonably obtained from the neighboring data, so that the measurement time and the position time are asynchronous. Also, the position coordinate P (measurement point) of the work W and the measured value V can be matched.

The count value is based on X (N1) = 453.444 at the position time value CN (N1) = 223 and X (M1) = 452.926 (assumed value) at the measurement time value CM (M1) = 129. It is also possible to obtain X (200) at CN, CM = 200.

First, the adjusting unit 150 has X coordinates based on the difference between the position time value CN (N1) = 223 and the measured time value CM (M1) = 129, that is, {CN (N1) -CM (M1)} = 94. Calculate the time change rate du of the value.
du = {X (N1) -X (M1)} / {CN (N1) -CM (M1)}
= 453.444-452.926 / 94
= 0.518 / 94
= 0.00551
Will be. With the slope du obtained from the above equation, X (200) is based on the difference between the time value CN, CM (200) and the measured time value CM (M1) = 129, that is, {200-CM (M1)} = 71. ),
X (200) = X (M1) + du × {200-CM (M1)}
= 452.926 + 0.00551 × 71
= 453.317
Will be.

Therefore, the assumed value of the X coordinate value in the time value CN and CM (200) can be obtained by a linear interpolation formula based on the X coordinate value in the other position time value CN or the measured time value CM. By adjusting both the position time value and the measurement time value in this way, the X coordinate value at an arbitrary time value (example: 200) can be calculated.

[Second Embodiment]
The information processing apparatus 120 of the first embodiment has been described as acquiring the position information P from the machining control unit 118 about every 4 milliseconds. Actually, it is conceivable that the timing at which the information processing apparatus 120 acquires the position coordinates P from the machining control unit 118 becomes unstable. For example, when a part of the function of the communication unit 134 is configured as software for transmitting a position acquisition request every 4 milliseconds, an overhead is generated due to periodical release (starting) of the software. In addition, the time until the position acquisition request reaches the machining control unit 118 via a wired cable such as Ethernet (registered trademark) and the machining control unit 118 completes reading the position information P from the built-in memory is also in microseconds. When you look at it, there are variations. In the second embodiment, the time adjustment when the position time value CN does not have the periodicity as in the first embodiment will be described.

FIG. 13 is a data structure diagram of the position information history 160 in the second embodiment.
In the position information history 160 shown in FIG. 13, the position / time value CN (N1) = 1705, the position / time value (N2) = 2505, and the position / time value (N3) = 5505. That is, the position information P (N2) is acquired 800 microseconds (= 2505-1705) after the acquisition of the position information P (N1), and the position information P (N3) is acquired 300 microseconds after the acquisition of the position information P (N2). ) Has been acquired. The measurement history 170 is the same as that of the first embodiment.

FIG. 14 is a schematic diagram for explaining a method of adjusting the measured value and the position information in the second embodiment.
Even when the acquisition timing of the position information P has almost no periodicity, the time adjustment method of the position information P is the same.

First, the X coordinate value in the measured time value CM (M1) when the measured value V (M1) is acquired is calculated. The adjusting unit 150 sets the difference between the position time value CN (N1) and the position time value CN (N2) obtained after the measurement time value CM (M1), that is, {CM (N2) -CM (N1)}. Based on this, when the time change rate d3 of the X coordinate value is calculated,
d3 = {X (N2) -X (N1)} / {CM (N2) -CM (N1)}
Will be. Based on the slope d3 obtained by the above equation, the difference between the position time value CN (N1) and the measurement time value CM (M1), that is, based on {CN (N1) -CM (M1)}, the measurement time value CM ( When X (M1) in M1) is calculated,
X (M1) = X (N1) -d3 x {CN (N1) -CM (M1)}
Will be.
When the actual numerical value is applied, d3 = 0.0015 and X (M1) = −1.21.

Next, the X coordinate value in the measurement time value CM (M2) is calculated. The adjusting unit 150 is based on the difference between the position time value CN (N3) and the position time value CN (N4) before and after the measurement time value CM (M2), that is, {CN (N4) -CN (N3)}. The time change rate d4 of the X coordinate value is calculated.
d4 = {X (N4) -X (N3)} / {CN (N4) -CN (N3)}
Will be. With the slope d4 obtained from the above equation, X (M2) is calculated based on the difference between the measured time value CM (M2) and the position time value CN (N3), that is, {CM (M2) -CN (N3)}. When calculated,
X (M2) = X (N3) + d4 × {CM (M2) -CN (N3)}
Will be.
When the actual numerical value is applied, d4 = 0.0015 and X (M2) = 7.89.

[Summary]
The machine tools 100 and 120 have been described above based on the embodiments.
In the present embodiment, the pulse generator 116 transmits a pulse signal to the machining control unit 118 and the measuring device 112 synchronously and at a constant cycle. The measuring device 112 acquires the measured value V at its own pace and transmits the measured value V together with the measured time value CM to the information processing device 120. The measured time value CM becomes a so-called time stamp, and the information processing apparatus 120 can accurately recognize the timing at which the measured value V is actually acquired. Similarly, the information processing apparatus 120 also receives the position information P from the machining control unit 118 together with the position time value CN at its own pace. Also in this case, the position / time value CN becomes a time stamp, and the information processing apparatus 120 can accurately recognize the timing at which the position information P is actually set. Since the information processing apparatus 120 can interpolate and calculate the position information P (coordinate value) at the measurement time based on the measurement time value CM and the position time value CN, the measurement value V and the position information P can be calculated with an accuracy of microseconds. Can be aligned.

According to this embodiment, since it is not necessary to synchronize the measuring device 112 and the machining control unit 118, it is not necessary to introduce a control mechanism for synchronizing the measuring device 112 and the machining control unit 118.

The present invention is not limited to the above-described embodiment or modification, and the components can be modified and embodied within a range that does not deviate from the gist. Various inventions may be formed by appropriately combining a plurality of components disclosed in the above-described embodiments and modifications. In addition, some components may be deleted from all the components shown in the above embodiments and modifications.

[Modification example]
The machine tool 100 in the present embodiment has been described as being a machining center. The machine tool 100 is not limited to a machining center, but can be applied to a turning center or a multi-tasking machine.

In the present embodiment, it has been described that the assumed value of the position information P at the measurement time is obtained by a linear interpolation formula based on the position information P of each of the position time closest to the measurement time and the position time closest to the measurement time. As a correction method in time adjustment, a method other than the linear interpolation method can be considered. For example, the adjusting unit 150 may calculate a linear regression equation from a plurality of positional information by the least squares method, and calculate the positional information P at the measurement time based on the linear regression equation.

When adjusting the time, it is desirable to calculate the position information P at the same time as the measurement time, but the "same time" here can be regarded as the same within a predetermined allowable range of, for example, about 1 to 100 microseconds. It suffices if there is a degree of identity.

The adjusting unit 150 may calculate the measured value V at the position time instead of calculating the position information P at the measurement time. For example, in the case of FIG. 12, based on the measured value V (M1) and the measured value V (M2), the measured value V (N1) in the middle may be calculated by a linear interpolation formula.

The adjusting unit 150 may also calculate the measured value V and the position information P at any time point such as the count value CN, CM = 1000, 2000 by a linear interpolation formula or the like. For example, the adjusting unit 150 calculates the position information P at the count value CN = 1000 in FIG. 8 based on the position information P (N1) and the position information P (N2), and measures the measured value V at the same time as the measured value V ( It may be calculated based on M1) and the measured value V (M2).

More specifically, for example, it is assumed that the position time value CN (N2) = 4229 and the measurement time value CM (M2) = 6200 (see FIG. 12). Here, it is also possible to calculate the position information P (5000) and the measured value V (5000) at the time value CN and CM = 5000. The X coordinate value in the position time value CN (N2) is P (N2), the measured value is V (N2), the X coordinate value in the measured time value CM (M2) is P (M2), and the measured value is V (M2). do. The measured values V (N2) and the X coordinate value P (M2) are estimated values calculated by the above algorithm.

The X coordinate value (5000) can be calculated based on X (N2) = 475.534 and X (M2) = 485.980. Based on the difference between the position time value CN (N2) = 4229 and the measured time value CM (M2) = 6200, that is, {CM (M2) -CN (N2)} = 1971, the time change rate d5 of the X coordinate value is calculated. When calculated,
d5 = {X (M2) -X (N2)} / {CM (M2) -CN (N1)}
= (485.98-475.534) / 1971
= 0.0053
Will be. Based on the difference d5 between the position time value CN = 5000 and the measured time value CM (M2) = 6200, that is, {CM (5000) -CN (N2)} = 771, X ( If you calculate 5000),
X (5000) = X (N2) + d5 × {CM (M2) -CN (N2)}
= 475.534 + 0.0053 × 771
= 479.62
Will be. The same applies to the Y coordinate value and the Z coordinate value.

Similarly, the measured value V (5000) can be calculated based on the measured value V (N2) and the measured value V (M2). When the time change rate d6 of the measured value V is calculated based on the difference between the position time value CN (N2) and the measured time value CM (M2), that is, {CM (M2) -CN (N2)},
d6 = {V (M2) -V (N2)} / {CM (M2) -CN (N1)}
Will be. With the slope d6 obtained from the above equation, V (5000) is calculated based on the difference between the position time value CN (N2) and the measured time value CM (M2), that is, {CM (M2) -CN (N2)}. When calculated,
V (5000) = V (N2) + d6 × {CM (M2) -CN (N2)}
Will be. As described above, the position coordinate P (5000) and the measured value V (5000) can be estimated by correcting both the position coordinate P and the measured value V even at the time point = 5000 when the position and the measurement are not performed.

The information processing apparatus 120 acquires the position time value CN in addition to the three types of position information P (X, Y, Z) from the processing control unit 118. The position-time value CN may be received from an unused signal line among a plurality of signal lines included in the machining control unit 118. For example, the angle of rotation of the spindle 108 may not be needed when using the measuring device 112. Therefore, when the work W is measured by the measuring device 112, if it is not necessary to send and receive the rotation angle, the information processing device 120 sets the position and time via the signal line for transmitting and receiving the rotation angle of the machining control unit 118. You may get the value CN. By acquiring the position-time value CN via an existing and unused signal line, the present invention can be easily applied to the existing machine tool 100.

In the present embodiment, it has been described that the information processing apparatus 120 periodically accesses the machining control unit 118, and the machining control unit 118 acquires the position information P designated by the machining apparatus 124 by a so-called polling method. As a modification, the machining control unit 118 may periodically transmit the position information P to the information processing device 120 in the same manner as the measuring device 112. Similarly, the information processing device 120 may periodically access the measuring device 112 and acquire the measured value V detected by the measuring device 112 by a polling method.

The measurement method by the pulse generator 116 and the information processing apparatus 120 can be applied to other than machine tools. For example, the robot may be equipped with a measuring device 112, and the information processing device 120 may recognize the shape of an obstacle by acquiring both the position information of the robot and the measured value indicating the distance from the robot to the obstacle. ..

The object formed by the work W is arbitrary. For example, when a gear is formed from the work W, each part of the work W is measured by the measuring device 112, and the shape reproducing unit 152 reproduces a three-dimensional image of the teeth of the gear by computer graphics. Precise time adjustment is especially important when forming objects with complex shapes such as gears.

In this embodiment, a pulse signal is transmitted from the pulse generator 116 to both the measuring device 112 and the machining control unit 118. Each time the measuring device 112 receives a pulse signal, the measured time value CM (count value) stored inside the measuring device 112 is counted up. Further, it has been described that each time the machining control unit 118 receives a pulse signal, the position / time value CN (count value) stored inside the machining control unit 118 is counted up.

As a modification, the pulse generator 116 may transmit a pulse signal only to the machining control unit 118. The measuring device 112 periodically and self-excitably asserts the measurement timing signal MS as in the present embodiment. The measuring device 112 executes the measurement when the measurement timing signal MS is asserted, and transmits the measured value V to the information processing device 120. On the other hand, the measuring device 112 also transmits the measurement timing signal MS to the pulse generating device 116 at the time of assertion.

In the modified example, the pulse generator 116 manages the measurement time value CM (count value) instead of the measurement device 112. The counter built in the pulse generator 116 counts up the measured time value CM each time a pulse signal is transmitted, and when the measurement timing signal MS is received from the measuring device 112, the measured time value CM at that time is information processing device. Send to 120. Since the measurement timing signal MS is asserted every 6 milliseconds, the pulse generator 116 transmits the measurement time value CM to the information processing device 120 about every 6 milliseconds. The adjusting unit 150 of the information processing device 120 receives the measured value V from the measuring device 112, and receives the measured time value CM from the pulse generating device 116. Further, the information processing apparatus 120 receives the position information P and the position time value CN from the processing control unit 118. After that, in the same manner as in the present embodiment, the adjusting unit 150 may perform time adjustment based on the measured time value CM and the position time value CN.

100 machine tools, 102 beds, 104 columns, 106 spindle heads, 108 spindles, 110 saddles, 112 measuring devices, 114 tables, 116 pulse generators, 118 machining controls, 120 information processing devices, 122 operation control devices, 124 machining devices. , 126 Tool change unit, 128 Tool storage unit, 130 User interface processing unit, 132 Data processing unit, 134 Communication unit, 136 Data storage unit, 138 Input unit, 140 Output unit, 142 Transmitter unit, 144 Receiver unit, 146th Receiver 148 2nd receiver, 150 adjustment unit, 152 shape reproduction unit, 160 position information history, 170 measurement history, 180 1st axis linear scale, 182 2nd axis linear scale, 184 3rd axis linear scale, 186th 1-axis motor, 188 2-axis motor, 190 3-axis motor, 192 servo module, 194 servo module, 196 servo module, 198 dummy axis linear scale

Claims (9)

A first receiving unit that acquires a measured value indicating a distance from a measuring device mounted on a machine tool to an object to be measured and a first time value indicating an acquisition timing of the measured value.
Of the plurality of scale counters built in the machining control unit of the machine tool, the coordinate values indicating the positions of the measuring devices are acquired from the first to third scale counters, and the coordinate values of the coordinate values are obtained from the fourth scale counter. The second receiver that acquires the second time value indicating the acquisition timing, and
An information processing device including an adjusting unit for calculating the coordinate value at the acquisition timing of the measured value by correcting the coordinate value based on the difference between the first time value and the second time value. The second receiver is
The three-dimensional position coordinate values of the measuring device are acquired from each of the first to third scale counters, and the three-dimensional position coordinate values are acquired.
The information processing apparatus according to claim 1, wherein the second time value written in the fourth scale counter by the machine tool is acquired via a signal line connected to the fourth scale counter. The second receiving unit acquires the coordinate value and the second time value at a timing asynchronous with the timing at which the first receiving unit receives the measured value and the first time value from the measuring device. , The information processing apparatus according to claim 1 or 2. The information processing device according to any one of claims 1 to 3, wherein the second time value is a numerical value indicating the count number of pulse signals received from the pulse generator by the numerical control unit . The measuring device is fixed to the tool holding portion of the machine tool.
The information processing device according to any one of claims 1 to 4, wherein the measured value indicates a distance from the measuring device to a work which is a measurement target. Connected to the pulse generator,
With a measuring device
A tool holder that holds the tool or the measuring device,
Equipped with a machining control unit for machining workpieces
The machining control unit has a built-in multiple scale counters.
The pulse generator periodically transmits a pulse signal to the machining control unit.
The measuring device transmits a measured value indicating the distance from the measuring device to the work and a measurement timing signal indicating the measurement timing.
The machining control unit sets coordinate values indicating the positions of the tool holding units in the first to third scale counters, and indicates the number of pulse signals received until the acquisition of the coordinate values in the fourth scale counter. A machine tool that sets a second time value and transmits the coordinate value and the second time value by the first to fourth signal lines corresponding to the first to fourth scale counters, respectively. It is connected to an information processing device that receives the measured value, the first time value indicated by the measurement timing signal, the coordinate value, and the second time value.
The information processing apparatus corrects both or one of the measured value and the coordinate value based on the difference between the first time value and the second time value to obtain the measured value and the coordinate value at the same time. The machine tool according to claim 6, which is calculated. The information processing device receives the measured value at the measurement timing from the measuring device, and receives the measured value from the measuring device.
The measuring device transmits the measurement timing signal to the pulse generator, and the measuring device transmits the measurement timing signal to the pulse generating device.
The pulse generator updates the count value indicating the number of times the pulse signal is transmitted each time the pulse signal is transmitted, and the count value when the measurement timing signal is received from the measurement device is used as the first time value. Send to the information processing device,
The information processing device periodically sends a position acquisition request to the processing control unit, and the information processing device periodically sends a position acquisition request.
The machine tool according to claim 7, wherein the machining control unit transmits the coordinate value and the second time value to the information processing apparatus when the position acquisition request is received. The information processing apparatus sets the coordinate values at the measurement timing to be the target of the correction calculation as the pre-coordinate values which are the coordinate values acquired before the measurement timing and the second time value at the time of acquiring the pre-coordinate values. The operation according to claim 8, wherein the post-coordinate value, which is a coordinate value acquired after the measurement timing, and the second time value at the time of acquisition of the post-coordinate value are used as variables for calculation by a linear interpolation formula. machine.

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