JP6800727B2 - Measurement system - Google Patents

Description

The present invention relates to a measurement system that transmits measurement data from a measuring instrument used in a machine tool such as a machining center to a personal computer (hereinafter referred to as a PC).

In recent years, a work (machined object, measured object) is measured with a machine tool or a measuring tool, and the measured value is equipped with an OS (operating system) such as WINDOWS (registered trademark) by USB (Universal Serial Bus) communication. It is being imported into a PC. PCs equipped with WINDOWS (registered trademark) can be used for real-time processing by apparently using the power of the CPU and bus for normal functions, but they are not suitable for real-time processing. Not in.

Real-time performance means that "processing can be reliably executed within a limited time", and WINDOWS (registered trademark) does not guarantee real-time performance even if a high-speed CPU is used. Therefore, a program (hereinafter referred to as a WINDOWS program) that operates on a PC equipped with WINDOWS (registered trademark) cannot perform precise time management.

Even if a WINDOWS program that requests data transmission at equal intervals is operated, in reality, a considerable time variation may occur, or an operation that greatly exceeds the scheduled time may occur. In particular, this becomes remarkable when another WINDOWS program such as statistical software or editing software is operated at the same time as the measurement value is taken in.

In a machining center or the like, the work may be measured during the machining of the work or at the end of the machining process, but if the amount of change in the measured value over time is large, accurate measurement becomes difficult. Therefore, in order to continue sending the measured values sampled at equal intervals by the measuring instrument to the PC equipped with WINDOWS (registered trademark), measures such as installing a memory on the measuring instrument side and temporarily storing the data there. Is required.

In addition, the data logger and the PC are connected with a USB cable to increase the communication speed between the data logger and the PC. Further, Patent Document 1 describes that the output signal of the sensor is stored in a memory and output to a PC by DMA (Direct Memory Access).

Japanese Unexamined Patent Publication No. 2006-105950

In the above-mentioned prior art, an expensive non-volatile memory is required, and the longer the measurement is continued, the larger the memory is required. Therefore, the size and cost of the measuring instrument increase, so that it is not suitable for transmitting measured values with high frequency. Also, in USB communication, active communication from the measuring instrument (device) side is not possible, so when sending data from the measuring instrument, fixed length data is sent only following the data transmission request from the PC (host) side. Will be sent.

Therefore, even if data transmission requests from the PC side to the measuring instrument side (and data transmission from the measuring instrument side) are made in quick succession, the interval limit of the transmission request (the limit of the interval at which the PC can constantly make continuous transmission requests). There is. Further, depending on the processing in the program and the state of other programs operating in parallel, the interval limit of the transmission request may be further extended.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to install WINDOWS (registered trademark) for precisely time-controlled data regardless of the interval of transmission request without installing a large memory or the like on the measuring instrument side. The purpose is to obtain a measurement system that can be easily captured by a PC.

In order to achieve the above object, the present invention is a measurement system for transmitting measurement data from a measuring instrument to a personal computer by USB communication, which is connected to the measuring instrument and manages the measured data for a specified time at specified intervals. The adapter includes an adapter that sequentially acquires and saves the data together with the number of acquisitions, and a means for connecting the adapter and the personal computer so that USB communication is possible, and the adapter is a data transmission area in the USB communication. A data transmission request comes from the personal computer, which has a data area capable of storing the measurement data for a plurality of times in a data memory having the capacity of the above and a number area for storing the number-of-times data indicating the number of acquisitions. In this case, the measurement data and the number of times data are set in the data transmission area and transmitted to the personal computer.

Further, in the above measurement system, the personal computer is further provided, the number of bytes of the measurement data is M bytes, the number of bytes of the number of times data is C bytes, and the personal computer is the number of times data transmitted from the adapter. When is (the number of bytes of the data transmission area −C) / M or less, it is desirable to judge that the measurement data is time-controlled at equal intervals.

Further, in the above measurement system, the number of bytes of the measurement data is M bytes, the number of bytes of the number of times data is C bytes, and the number of times data is (number of bytes of the data transmission area −C) / M in the adapter. When is reached, it is desirable to erase the oldest measurement data stored in the data area and store the latest measurement data in the data area.

Further, in the above measurement system, the number of bytes of the measurement data is 2 bytes, the number of bytes of the number of times data is 2 bytes, the number of bytes of the data transmission area is 64 bytes, and the adapter has 64 bytes of data memory. It is desirable to have the data area capable of storing the measurement data for 31 times and the number area for storing the number of times data.

Further, in the above measurement system, the personal computer is further provided, the number of bytes of the measurement data is 2 bytes, the number of bytes of the number of times data is 2 bytes, and the number of bytes of the data transmission area is 64 bytes. When the number of times data transmitted from the adapter is 31 or less, it is desirable to determine that the measurement data is time-controlled at equal intervals.

Further, in the above measurement system, the number of bytes of the measurement data is 2 bytes, the number of bytes of the number of times data is 2 bytes, the number of bytes of the data transmission area is 64 bytes, and the number of times data of the adapter is 31. When it reaches, it is desirable to erase the oldest measurement data stored in the data area and store the latest measurement data in the data area.

Further, in the above measurement system, the adapter sets the measurement data and the number of times data in the data transmission area, transmits the measurement data to the personal computer, and then transmits the measurement data and the number of times data. It is desirable to clear it.

Further, in the above measurement system, it is desirable that the adapter is connected to a plurality of the measuring instruments, and the measurement data of each is time-managed at specified intervals and sequentially acquired and stored.

According to the present invention, the adapter has a data area capable of storing a plurality of measurement data in a data memory having a capacity of a data transmission area in USB communication, and a number area for storing the number of times data, and measures the data. Data is sequentially acquired and saved at specified intervals, and when a data transmission request comes from the PC, the measurement data and the number of times data are set in the data transmission area and transmitted to the PC, so the minimum required. With the memory capacity, precisely time-controlled measurement data can be easily captured by a WINDOWS (registered trademark) -equipped PC regardless of the transmission request interval.

Block diagram of the measurement system according to the embodiment according to the present invention Block diagram of the measurement system according to another embodiment according to the present invention. Explanatory drawing which shows the data area of the data memory mounted on the adapter by one Embodiment of this invention. Flow chart on the measurement side in one embodiment Flow chart on the PC side in one embodiment

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of a measurement system according to an embodiment of the present invention. The measurement system includes a sensor 2, an adapter 1, and a PC 4 equipped with WINDOWS (registered trademark). The adapter 1 is a USB port of the PC 4 on the host side with a USB cable 3 which is a means for connecting the adapter 1 and the PC 4 so that USB communication is possible, or a USB hub (separately) capable of supplying power. (Not shown) is connected.

Of course, the adapter 1 may be provided with a USB connector as a means for connecting the adapter 1 and the PC 4 so that USB communication is possible, and may be directly connected to the USB port of the PC 4. The sensor 2 and the adapter 1 are connected by a connector 5, and power can be supplied and communication can be performed from the host side. High-speed communication is performed between the adapter 1 and the PC 4 by USB communication.

In a machining center or the like, a probe for measuring the dimensions of a work is mounted on a movable spindle as a sensor 2. The measurement data is wirelessly transmitted to the machine station, which is a fixed part of the machining center, by a spectral diffusion wireless link that sends a separate package of serial binary data. In this case, the machine station is connected to the adapter 1 and connected to the PC 4 with the USB cable 3.

FIG. 2 is a block diagram of a measurement system according to another embodiment, in which a plurality of sensors 2 are used to transmit and receive wireless communication to and from the adapter 1. Since the adapter 1 has a small capacity, for example, a memory equivalent to 64 bytes, it may be small, lightweight, and excellent in portability. Therefore, it is also possible to incorporate a wireless communication reception function in the adapter 1, and by receiving the transmission data from the sensor 2, the communication cable does not interfere with the measurement data from various measuring instruments. Can be easily imported into. Further, it becomes easy to simultaneously capture a plurality of measurement data into the PC 4 by using a plurality of sensors 2.
In this case, the adapter 1 may be connected to a plurality of measuring instruments such as sensors by wireless communication, and each measurement data may be time-managed at specified intervals to be sequentially acquired and stored. At this time, the adapter 1 and the measuring instrument such as a sensor may be connected by wire instead of wirelessly. Further, in FIGS. 1 and 2, the sensor 2 and the adapter 1 have different configurations, but since the adapter 1 can be miniaturized, the function of the adapter 1 is incorporated in the housing of the sensor 2, and the sensor 2 and the adapter 1 are incorporated. May be integrated.

In the WINDOWS program, for example, it is not possible to guarantee the accuracy of the time from when a human presses a button on a keyboard or the like until the button is reflected in the application and the timer starts and stops. The OS does not guarantee this operation timing at all, and it is not abnormal even if an event arrives at the program 0.5 seconds later. If polling is performed earnestly and the button state of the keyboard is grasped, the loop will rotate in about 1 msec or less on average and the average speed will be high, but since the loop speed is not guaranteed, it will sometimes become extremely slow.

It also puts you in an almost infinite loop, causing other programs and services running with you to stop working properly. In other words, due to the mechanism of the multitasking OS, running processes and threads are switched at regular intervals, and even if the cycle is about 10 to 15 ms, the time to return to the transmission request in the next own process, for example, the measurement state, is Not guaranteed.

Therefore, normally, even if data transmission requests (and data transmission from the measuring instrument side) are continuously made from the PC4 side to the adapter 1 side, the interval cannot be constantly set to 10 ms or less. It becomes even more unstable depending on the processing in the program and the state of other programs running in parallel.

USB communication is a serial bus in which the host PC4 transfers data bit by bit in order, and a plurality of peripheral devices can be connected. Therefore, the host initiates all transitions. The first packet in this processing unit is called a token (token), and the device address and endpoint are indicated. Then, it is described whether the process is read or write, and what continues, and it is generated by the host PC4. The next packet is a data (Data) packet that carries the actual data unit and serves as a data transmission area. Next, it is a handshake packet that reports whether instructions and data have been received correctly.

In USB communication, interrupt transfer is performed in measurement and data transfer of man-machine equipment, and the adapter 1 on the USB device side generates an interrupt, but before that, you have to wait until the patrol inquiry (polling) by PC4 on the host side. Must be. The maximum capacity of the in-packet data unit in interrupt transfer is 64 bytes at full speed (USB1.1). That is, in USB communication, a 64-byte data transmission area is always prepared when one transmission is performed (whether or not it is necessary).

Next, the configuration on the measurement side will be described. The measurement data of the sensor 2 which is a measuring instrument is transmitted to the PC 4 via the adapter 1 by utilizing the data transmission area of 64 bytes in the USB communication, and the data length is composed of 2 bytes. As a result, the data memory mounted on the adapter 1 has a small capacity of about 64 bytes. Further, the adapter 1 is equipped with a real-time clock (RTC) and can acquire measurement data by sampling at specified intervals (below the transmission request interval limit of PC4) and time-controlled, that is, sampling at precise equal time intervals. It shall be.

FIG. 3 is an explanatory diagram showing a data area of the data memory mounted on the adapter 1. The data memory has a data area that can store 31 measurement data 11 according to the 2-byte measurement data length (when the length of one measurement data is set to 2 bytes), and the 2-byte number data 10 [ It has a number-of-times area for storing [data indicating the number of acquired data (in other words, the number of acquired data)]. A memory of this level is sufficiently possible even with a low-performance microcomputer, and can be incorporated in a small adapter 1.

FIG. 4 shows a flowchart on the measurement side. The adapter 1 sequentially stores the measured values in the data area of the data memory according to the sampling as the measured values sampled by the sensor 2 at equal intervals by the mounted real-time clock (RTC). Also, the number of times saved is counted and saved in the number of times area. When 31 measurements are performed and the measurement data is saved in the data memory, the oldest measurement data is erased and the latest measurement data is stored in the data area. This history is saved and recognized by the microcomputer of the adapter 1. In the actual measurement, the measurement is executed after the designated time has elapsed from the previous measurement. In addition, the number of times data is incremented by 1 as the measurement is executed.

Further, the data memory of the adapter 1 may have at least the capacity of the data transmission area in USB communication, and may have a larger capacity so that more measurement data 11 can be stored. In this case, when the measurement data 11 is to be saved in the data memory more than the number of times that can be saved, the oldest measurement data may be erased and the latest measurement data may be stored in the data area.

When the data memory of the adapter 1 is the capacity of the data transmission area in USB communication, when a data transmission request comes from the PC 4 to the adapter 1, all the measurement data 11 and the number of times data 10 stored in the data memory are stored. It is set in the 64-byte data transmission area in USB communication and transmitted to the PC4. After that, all the measurement data 11 and the number of times data 10 in the data memory are cleared.

When the data memory of the adapter 1 is larger than the capacity of the data transmission area in USB communication, when a transmission request comes from the PC 4 to the adapter 1, the number of times that the data can be transmitted (data transmission area) is stored in the data memory. When the number of bytes in the above is 64 bytes, the measurement data 11 and the number of times data 10 (31) are set in the 64-byte data transmission area in USB communication and transmitted to the PC 4. After that, all the measurement data 11 and the number of times data 10 transmitted to the PC 4 are cleared.

FIG. 5 shows a flowchart on the PC side. The structure of the WINDOWS program will be described. The PC 4 notifies the adapter 1 of the transmission request frequently and at the shortest possible time interval within a range that does not significantly affect other programs and services. The short time interval is longer than the sampling time interval of the measurement data 11 and shorter than the sampling time interval of 31 measurements. During the measurement, it is desirable to preferentially assign processing to other programs and services. When it is necessary to capture the measurement data at intervals of 10 ms, an interval of 10 ms × 31 may be used, but a time interval of 100 ms, which is 1/2 to 1/4 of that, preferably 1/3, is preferable.

Since the adapter 1 has a data area capable of storing the measurement data 11 for a plurality of times in a data memory having a capacity of a data transmission area in USB communication and a number area for storing the number of times data, the adapter 1 has a number of times data from the PC4. It is desirable that the interval of the transmission request to the adapter 1 is within the time of the number of measurement data that can be stored in the adapter 1 × the sampling time interval. In other words, within this range, time management is performed even if the transmission request is not constant due to processing by the WINDOWS program or the state of other programs operating in parallel, that is, sampling is performed at precise equal time intervals. Measurement data can be acquired.

If the number of times data 10 transmitted from the adapter 1 is 31 or less, the PC 4 can recognize that the measurement data transmitted from the adapter 1 is time-managed measurement data at regular intervals. When the number of times data 10 exceeds 31, it can be identified by the WINDOWS program as the time management could not be performed for the time of (number of times −31) × the specified interval.

In the above description, the data transmission area in USB communication is 64 bytes, the measurement data 11 for one time is 2 bytes, and the number data 10 is 31 as the limit, but these values are the data transmission area, the measurement data 11, and the number of times. It may be determined according to the number of bytes of data 10.

Here, the number of bytes of the measurement data 11 is the number of bytes (data capacity) reserved for one measurement data 11, and any data value is always represented by this number of bytes. Will be done. Similarly, the number of bytes of the number-of-times data 10 is also the number of bytes (data capacity) secured regardless of the value of the data, and the value of the data is always represented by the data capacity of the number of bytes.

For example, when the number of bytes of the measurement data 11 and the number of times data 10 is other than 2 bytes, if the number of bytes is expressed as M bytes and C bytes, respectively, one transmission [(number of bytes in the data transmission area-C). It is possible to send [(64-C) / M] data when the data transmission area is 64 bytes.

Therefore, if the number of measurement data transmitted from the adapter 1 is [(64-C) / M] or less, it can be determined and recognized as time-controlled measurement data at equal intervals. Otherwise, time management can be performed for the time of [(number of times- (64-C) / M) x specified interval] (when the data transmission area is 64 bytes, the time of [(number of times-31) x specified interval]. It can be identified by the WINDOWS program as not.

Further, if the data transmission area is 64 bytes or more, for example, S bytes, the number obtained by subtracting the number of bytes of the number of times data 10 from the number of bytes of the data transmission area is divided by the number of bytes of the measurement data 11 for one transmission. , [(SC) / M] data can be sent (when the data transmission area is S bytes). Therefore, if the number of measurement data transmitted from the adapter 1 is [(SC) / M] or less, it can be recognized that the measurement data is time-controlled at equal intervals. Otherwise, the WINDOWS program can identify that time management was not possible.

In the above description, as the sensor 2, a probe for measuring the dimensions of a workpiece used in a machining center or the like has been illustrated as an example, but the sensor 2 is a length measuring device (electric micrometer and optical scale) and position detection. A probe, a temperature sensor, a vibration sensor, a barometric pressure sensor, a pressure sensor, a humidity sensor, and the like can also be applied in the same manner as in one embodiment.

1 Adapter 2 Sensor (Measuring instrument)
3 USB cable 4 PC
5 Connector 10 times data 11 Measurement data

Claims (8)

In a measurement system for transmitting measurement data from a measuring instrument to a personal computer via USB communication,
An adapter that is connected to the measuring instrument, manages the measurement data at specified intervals, sequentially acquires it, and saves it together with the number of acquisitions.
A means for connecting the adapter and the personal computer so as to enable USB communication is provided.
The adapter
It has a data area capable of storing a plurality of times of the measurement data in a data memory having a capacity of a data transmission area in the USB communication, and a number area for storing the number of times data indicating the number of acquisitions.
A measurement system characterized in that when a data transmission request comes from the personal computer, the measurement data and the number of times data are set in the data transmission area and transmitted to the personal computer. Further equipped with the personal computer
Assuming that the number of bytes of the measurement data is M bytes and the number of bytes of the number of times data is C bytes, the personal computer uses [(number of bytes of the data transmission area −C) / M for the number of times data transmitted from the adapter. ] The measurement system according to claim 1, wherein in the following cases, it is determined that the measurement data is time-controlled at equal intervals. Let the number of bytes of the measurement data be M bytes and the number of bytes of the number of times data be C bytes.
When the number of times data reaches [(number of bytes of the data transmission area-C) / M], the adapter erases the oldest measurement data stored in the data area and updates the data area. The measurement system according to claim 1 or 2, wherein the measurement data of the above is stored. Assuming that the number of bytes of the measurement data is 2 bytes, the number of bytes of the number of times data is 2 bytes, and the number of bytes of the data transmission area is 64 bytes, the adapter stores the measurement data for 31 times in a 64 byte data memory. The measurement system according to any one of claims 1 to 3, further comprising the data area that can be stored and the number of times area that stores the number of times data. Further equipped with the personal computer
Assuming that the number of bytes of the measurement data is 2 bytes, the number of bytes of the number of times data is 2 bytes, and the number of bytes of the data transmission area is 64 bytes, the personal computer has 31 or less number of times data transmitted from the adapter. The measurement system according to any one of claims 1 to 4, wherein the measurement data is determined to be time-controlled measurement data at equal intervals. Assuming that the number of bytes of the measurement data is 2 bytes, the number of bytes of the number of times data is 2 bytes, and the number of bytes of the data transmission area is 64 bytes, the adapter enters the data area when the number of times data reaches 31. The measurement system according to any one of claims 1 to 5, wherein the oldest stored measurement data is erased and the latest measurement data is stored in the data area. The adapter is characterized in that the measurement data and the number of times data are set in the data transmission area, transmitted to the personal computer, and then the transmitted measurement data and the number of times data are cleared. Item 6. The measuring system according to any one of Items 1 to 6. The measurement system according to claim 1, wherein the adapter is connected to a plurality of the measuring instruments, and each of the measurement data is time-managed at a designated interval to be sequentially acquired and stored.