JPS61260121A - Device for inspecting indication of measuring instrument - Google Patents

Abstract

PURPOSE:To make inspected quality uniform by measuring the central position of the scale pattern of a measuring instrument main body and the rotational center of a pointer from a scale position and deciding whether or not said measured values lie within the prescribed standard range. CONSTITUTION:An inspecting device is constituted of the measuring instrument main body 1 placed on an X/Y moving mechanism 2, a television camera 3 disposed at the upper position from the measuring instrument main body 1, an image processor 4, a test position setting means 5, a positioning servo device 7 controlling the moving mechanism 2, a test signal generator 6 giving a test signal to the pointer of the measuring instrument, a CPU 8 deciding whether an object to be inspected is good or not and a timer 9. Then the moving mechanism 2 is controlled to measure the central position of each scale pattern of the measuring instrument main body 1, and the rotational center of the pointer is calculated from said scale position. The test signal from the test signal generator 6 is impressed on the measuring instrument main body 1, and such decision is made whether or not the scale position of the measuring instrument main body 1 and the indication position of the pointer lie within the prescribed standard range.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application This invention relates to a measuring instrument indicator inspection device that automates the inspection of the indicating accuracy of a scale and pointer in an analog measuring instrument.

B6 Summary of the Invention This invention is a measuring instrument indicating and inspecting device that automatically tests the accuracy of indication between a scale and a pointer in an analog measuring instrument such as an ammeter or a voltmeter. While observing the movement of the pointer on the main body, the xY moving device W is controlled (by the output of the CPU) when the main body of the measuring instrument is placed, and the center position of each scale pattern on the main body of the measuring instrument is measured, and from these scale positions By calculating the center of rotation of the pointer and determining from O:PUIC whether the scale position and the position of the 1iUN hand are within a predetermined range.

The purpose of the present invention is to automatically and quickly test the accuracy of indications between the pointer and the scale in analog measuring instruments, and to ensure uniformity of test quality.

C0 Conventional Technology IE Inspection of analog indication rotation measuring instruments (hereinafter referred to as meters) such as current meters and voltmeters has traditionally been carried out by inspectors who visually check whether the scale on the meter panel and the indications on the pointer are in accordance with a predetermined standard. There is a means to check whether it is within the range, and a means to use an automatic test device as shown in FIG. FIG. 7 is a schematic configuration diagram of the latter device.
/ is the meter panel. On the surface of the meter panel 7/, scale patterns 7a to 71 are formed by means of printing or the like in areas where the symbols "/" to "rJVc" overlap.

Scale patterns 7a to 71 are formed by means such as printing at positions corresponding to the center positions of these scale patterns 7a to 71. Optical fibers 7J a~
One end of 731 is drilled, and the other end leads to the proximity sensor unit 7≠. These optical fibers 73a to 73
1 and a proximity sensor unit 7 constitute a proximity switch. That is, the pointer 76 inspects the accuracy of the scale and the pointer by operating a proximity switch.O7j is a test signal generator, which supplies the test pattern from this device 7j to the meter to check the accuracy of the pointer 7t and the scale. 7 patterns! This is to test whether the indication accuracy of L to 7/1 is within the range of a predetermined standard.

D0 Problems to be Solved by the Invention Among the above two testing means, the visual inspection means has the problem that the indication accuracy test is subject to inspector fatigue and individual differences, and it is not possible to carry out continuous inspection work over a long period of time.

Nineteenth, with the latter automatic inspection device, it is difficult to maintain the accuracy of the meter mounting position, and if the printing accuracy of the scale cannot be ensured sufficiently, there is a problem that the inspection content itself becomes unreliable.

In addition to the above testing methods, it is also possible to use a single TV camera to photograph the entire meter and perform automatic inspection.
The resolution of the TV camera is 256X258 or 512
Means for solving the O E0 problem in which there is a problem in which the position of the meter pointer cannot be accurately measured with an accuracy of ±02 degrees because there are only around 512 pixels This invention is constructed as follows. . Namely.

The present invention includes: a television camera disposed in the upper part of the measuring instrument body to observe the movement of the pointer; a moving mechanism disposed in the lower part of the measuring instrument body for expanding the observation field of the camera; A positioning servo device that controls this mobile device W, an image processing device that receives the video signal output of the camera and processes the input nine signals for binary image processing, dimension measurement processing, and angle measurement processing, and this image processing device. between an inspection point setting means for setting an inspection point, a test signal generating device supplied to the measuring instrument body and giving a test signal to the pointer of the measuring instrument, and the test signal generating device, the image processing device, and the positioning servo device; It consists of a PU that sends and receives signals, controls these devices, and determines whether the test passes or fails.

20 Operation The mobile unit W is controlled to measure the center position of each scale pattern on the main body of the measuring instrument, and the rotation center of the pointer is calculated from these scale position forces. Thereafter, a test signal is applied from a test signal generator to the measuring instrument body to determine whether the scale position of the measuring instrument body and the indicated position of the pointer are within a predetermined standard range.

G. Embodiment Figure 1 is a block diagram showing an embodiment of the present invention. In this fa1 diagram, / is the main body of a measuring instrument such as an ammeter or voltmeter, and / is the main body of the measuring instrument such as an XY moving machine. Reference numeral 03 is a video camera placed above the measuring instrument main body l, and the video camera 3 is moved in the horizontal (horizontal) and vertical (Y) directions. processing bag f
The video output signal is inputted to Rp, and the video output signal is subjected to processing such as binarization, one-dimensional inspection, and measurement of the center position of the scale by the image processing device μ, and then displayed on a diskless device (not shown). ! is an inspection point setting means, and this setting means specifies an inspection point roughly →λ with respect to the image processing bag Rμ. t is a test signal generator that drives the pointer (not shown) of the measuring instrument main body l, and 7 is! An XYY positioning servo device that controls the YY movement mechanism 2, and these devices 4 and 7 and the image processing device Hiroshi are connected to the opryr and oP'arrt.
Sequence control of the entire inspection and pass/fail determination of the inspection are performed.

is a timer.

Next, the operation of inspecting the pointing accuracy of the pointer and scale will be described using the above embodiment.

[1] First, K for measuring the center position of each scale is determined as follows.

Measuring instrument body / t-XY transfer machine set here, its
The YY movement mechanism 21: Rough positioning is performed by controlling the XY positioning servo device 7. For example, assume that the XY table is ±10μ and the camera is 21 pixels.

Once the positioning has been performed, as shown in Figure 2, the 7 patterns of scale "1" provided on the panel surface of the measuring instrument body are photographed by the video camera 3, and the video signals are sent to the image processing device. Have Hiro input.

In the image processing device Hiro, a test pattern L! is applied to the video signal.
and 1m are processed so that they are arranged as shown in FIG. 2, and are displayed on a display device and stored in a memory in 0PUr or the like. After that, along the inspection pattern 21 and i snow, the memory (not shown) t-OPt
Scan by rr.

Intersection point of scale “1” with pattern 7 u b P t + P
* and PsePnt-determine.

Next, the center of the intersection P1ePl? , and find the midpoint Aro of the intersection P3+P4, and find the midpoint P10t of the midpoint P8ePg? scale"
1” as the center coordinates. Also, the intersection P 1 m P m
Alternatively, find the slope θ with respect to the X axis from PleP4, and check the inspection pattern J! from the midpoint PLO! Scan 3 and mark “1”
Find the outer peripheral point P I A'i.

The midpoint PIO and the outer circumferential point obtained in this manner are stored in one memory.

Similarly, each scale rOJ ~ "8" scale pattern 7 pieces a
~ Find the center coordinates A00 to A80 of 7co1, and
Determine the outer circumferential point POm~P8At-.

[2] Next, the center of rotation of the pointer is calculated from the outer peripheral points A1am to P8m of the scale pattern.

8(a) and 8(b) show an application example in which a circular scale pattern is printed, and FIG. 8(B) is an application example in which a rectangular scale pattern is printed. First, FIG. 8(b) will be described. In Fig. 8, for example, the outer peripheral point PIA, :P4.

The center of rotation I'IO is calculated from the XY coordinates of the eight points on the P8 frame using an algorithm that finds the center of a circle. In the case of Fig. 8B, the X coordinate of the center of rotation of the pointer moves from the midpoint of the I coordinate of the outer peripheral point PI and l'gA.

By internally dividing the Y coordinates of the outer peripheral points F4A and P8A by an appropriate ratio, the Y coordinate of the center of one rotation is determined, and the center of rotation of the pointer is calculated. The thus calculated value is stored in the memory in 0PUr and the next processing is performed.

[3] The test signal is supplied from the test signal generator 1j to the measuring instrument main body 1, and the indicated position of the pointer with respect to the scale "0" to "8" is measured.

The indicated position is measured using the following means, using the center of the pointer elevation as shown in FIG. To carry out this procedure, place the inspection pattern in advance near the scale for the guideline "1"
1 e ' 1 set, raise the needle and test pattern 11
Intersection with 1°21 1 * Pl and Pll * PI
4. Ask for money.

First, the center of the guideline is determined from the intersection points PI and -P.

(Support) Intersection P1 Midpoint P1g of Toaro and Intersection P13゜P 14 Midpoint P!・After finding the midpoint P11 e
Find the midpoint I' 041 t- of PI, and find this midpoint PO
41 pointer slope --- Center.

(b) Next, set the center of the guideline IAI to the intersection 1'tt・Pts
The first line connecting Ye and the second line connecting the intersection pHs PI4
Obtained as the intersection point P 04m (intersection of two straight lines) on the extension of the straight line.

The indicated position of the pointer nail is measured from the middle point A041 of the nine pointers IA/ obtained in the above 0), and this measured value '10PUr is stored in the memory. After that, the following process is performed to end the instruction inspection◇ [4] It is determined by @0Ptrr whether the center of the pointer and scale is within the standard range.

As shown in the table below, the center of rotation of the pointer (X1o * yt・
).

Once the center coordinates of each scale and the center coordinates of the pointers are determined, it is determined whether the instructions of each pointer are correct as follows.

Table (a) In the case of measurement with a finger index of 0: Check whether the angle formed by the 8 points is within the judgment value range. The 8 points are the center coordinates of the scale (xpoo, 7? (10), the rotation center coordinates (X
IOe 716) and the central locus of the guideline Ill (xpoo
oe ypoess).

(b) In case of measurement of finger index "1" to "7", it is carried out as shown in FIG.

First, point B is measured based on point A. Next, measure the point mouth based on the point. Measured value 2 at that time is obtained from the following equation.

For example, when the scale is "1", 1000X5°'50' +1000=gl11000
= becomes.

This value is compared with the judgment value 0 Judgment value 1000±1 帥≧1100 rpm, so the judgment result is normal (ok).

(c) In the case of finger index "8", 0 people 0 m in the above formula (
Angle) t can be determined in advance by setting it in advance and performing the same process as the finger index "1" to "7".

If the accuracy of indication of the pointer of the measuring instrument body is inspected as described above, the inspection can be done quickly and accurately.The operation of the above-described embodiment is shown in a flowchart as shown in FIG. Each step “1” in Figure 6
The explanation for "4" is the same as above. .

H0 Effects of the invention As described above, according to the invention, the center position of the scale pattern on the measuring instrument body is measured, the rotation center of the pointer is measured from the scale position, and the range of the predetermined standard is determined from these measured values. Since it is automatically determined whether or not it is within the specified range, the quality of the inspection indicated by the measuring instrument's pointer is stable, and one continuous inspection can be performed for a long time, and the inspection time for one device is extremely short. There are advantages to making time. t7'h
This method has advantages such as being able to perform inspection without being affected by scale printing errors, and being able to perform angle measurement and finger index inspection with high accuracy (within ±α2dog or ±α1deg).

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIGS. 2 to 6 are for explaining the operation of the embodiment of FIG. 1, and FIG. 2 shows the center coordinates and peripheral points of the scale. Figure 8 is an explanatory diagram for determining the center of rotation of the pointer, and Figure 4 is an explanatory diagram for determining the center of the pointer.
FIG. 5 is a diagram for explaining whether the center of the pointer and scale is within the standard range, and FIG. 6 is a 70-chart for inspection. @Figure 7 is a schematic configuration diagram showing a conventional example. L...Measuring instrument body, K...XY movement mechanism, 3...
Video camera, Hiro... Image processing device! ...Inspection point setting means, B...Test signal generator, 7...XY
Positioning servo device, t...c+pT10 Figure 1 Figure 2 Figure 5 Figure 6

Claims (1)

[Claims] (1) A television camera disposed above the measuring instrument body to observe the movement of the pointer of the measuring instrument; and a moving mechanism disposed below the measuring instrument body for expanding the observation field of the camera. a positioning servo device that controls this moving mechanism; an image processing device that receives an output signal from the video camera and performs binary image processing, dimension measurement processing, and angle measurement processing on the input signal; an inspection point setting means for setting an inspection point signal in a processing device; a test signal generating device supplied to the measuring instrument body and giving a test signal to a pointer of the measuring instrument; the test signal generating device, an image processing device, and a positioning device. C that sends and receives signals between servo devices, controls these devices, and determines whether the inspection passes or fails.
A measuring device indicating and inspecting device consisting of a PU.