JPS61182506A - Measuring instrument of displacement variable - Google Patents

Abstract

PURPOSE:To measure a displacement variable for a time change precisely with a small memory capacity by deciding the size of the displacement variable from a measuring part, and on the basis of the measured result, controlling recording state in the memory. CONSTITUTION:An allowable range deciding circuit 4 compares current scanning data with the preceding scanning data only by one scanning and decides whether the displacement variable is included within a set allowable range or not. If the displacement variable is included within the allowable range, writing in a displacement data memory 7a is interrupted by a memory writing controller 5 and the contents of a counter memory 7b in the memory 7 which correspond to the preceding displacement data only by one scanning by an address setting circuit 6 are increased by +1. If the variable is not included within the allowable value, the circuit 6 increases the address of the memory 7 and optoelectric signal data are written in the memory 7a through the controller 5. The writing control or the like of picture data is executed in accordance with the displacement variable. Since the memory capacity can be reduced, the displacement of an object which may be suddenly changed can be precisely measured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device that uses light to non-contactly measure the displacement of a rapidly changing object on a time axis.

2. Description of the Related Art In recent years, the amount of displacement of an object has been increasingly measured in a non-contact manner using light. Furthermore, there are cases where the amount of displacement to be measured changes rapidly after a certain elapsed time, such as the snap action movement of a bimetal.

Such a measuring device needs to accurately measure the amount of displacement with respect to time. FIG. 6 shows the configuration of a conventional displacement measuring device using optical means, where 1 is a measuring section equipped with an integral type sensor such as a COD camera or ITV camera, and 2 is a measuring section equipped with an integral type sensor such as a COD camera or an ITV camera. Photoelectric signal (video signal)
3 is a memory for recording the digitized photoelectric signal.

In this device, a measurement unit 1 outputs a photoelectric signal and a synchronization signal obtained every time scanning is repeated. this house,
The photoelectric signal is converted into a digital signal by a digitizing circuit 2, and sequentially recorded based on a synchronizing signal. For example, if the measurement unit 1 operates at a scanning repetition time of Δt (reciprocal of the scanning repetition frequency) and the object exhibits displacement as shown in FIG. The signal is stored.

Problems to be Solved by the Invention Conventional displacement measuring devices have had the following problems.

Measurement unit 1 [Equipped with an integral type sensor such as a COD camera or an ITV camera, and the sensitivity of the integral type sensor is given as the product of the amount of incident light and the scanning repetition time, that is, the amount of exposure. Here, if the scanning repetition time is changed, the sensitivity of the sensor changes, making it impossible to accurately measure the level of the amount of incident light. Furthermore, it is not possible to measure the amount of displacement when there is a sudden change. Therefore, in order to use such an integral type sensor as a measuring section of a displacement measuring device, it is necessary to keep the scanning repetition time constant and to perform measurements while keeping the sensitivity of the integral type sensor constant.

However, if the scanning repetition time is fixed with an integral type sensor,
Photoelectric signals are output at fixed time intervals regardless of the amount of displacement of the object, and a large memory capacity is required to record these photoelectric signals. For example, assume that the object exhibits a change as shown in FIG.

The measurement unit 1 outputs a photoelectric signal and a synchronization signal at a scanning repetition time of Δt. As a result, the displacement is divided and measured at time intervals of Δt. Therefore, in the part shown by the person in Figure 7, the displacement of the object is small and sufficient resolution can be obtained on the time axis, but for the part shown in B where the object changes rapidly, , resolution on the time axis decreases, making it impossible to accurately measure temporal changes in displacement. In order to accurately measure the temporal change in the portion indicated by B, it is necessary to reduce the scanning repetition time Δt to, for example, Δ′tAO and increase the resolution for the eight portions. However, when these two methods are used, the resolution of the part shown to humans is also high, and A
In some parts, more data than necessary for the time axis is stored in memory, and a large amount of memory capacity is required.

The present invention aims to solve the above problems,
Displacement that determines the magnitude of the displacement from the measurement unit, controls the recording state to the memory based on the result, and accurately measures the displacement over time with a small memory capacity. The purpose is to provide a measuring device.

Means for Solving the Problems As shown in FIG. 1, the displacement measuring device of the present invention includes a buffer memory 3 for storing photoelectric signals from a measuring section 1 using an integral type sensor for one scan, and a buffer memory 3 for storing photoelectric signals for one scan. A permissible value determination circuit 4 that compares the data with the data before one scan and determines whether the change range is within the permissible value, and a displacement data memory 7a and a counter that stores the number of occurrences of the same image data corresponding to the displacement data memory. The image forming apparatus includes a memory 7 consisting of a memory 7b, a memory write controller 6 that controls data written to the memory, and a memory address setting circuit 6 that controls the write address of the same image data.

Operation The above-mentioned tolerance value determination circuit 4 compares the current scan data and the data from one scan ago, and determines whether the difference between them, that is, the amount of displacement, is within the set tolerance value. If it is within the set tolerance, the memory write controller 5 prevents writing of the photoelectric signal data (digital signal) to the displacement data memory 7a, and the address setting circuit 6 responds to the displacement data of the previous scan. The counter memory 7b in the memory 7 is incremented (+1). On the other hand, if it is outside the set allowable value, the memory setting circuit 6 increments the address in the memory 7 and writes the photoelectric signal data to the displacement data memory through the memory write controller 5.

In this way, image data writing control, writing control to the counter memory, and memory address setting control are performed depending on the magnitude of the displacement amount. Therefore, the memory capacity can be reduced. It is possible to accurately record the temporal displacement of an object that changes rapidly.

Embodiment FIG. 2 shows the configuration of a displacement measuring device according to an embodiment of the present invention. In this example, an m-pixel-dimensional CCD camera 1a is used as the measurement unit 1, but a two-dimensional camera or an ITV camera can be similarly considered.

In Fig. 2, 8 is a binarization circuit, 8a- is a voltage comparator, 8 b id is a binarization reference voltage, 3a is an m-bit shift register, 4 & is a digital comparator, 4b is a tolerance detection circuit, and 6d is an address. It is a counter. Furthermore, the displacement data memory 7a and the counter memory 7b correspond to addresses from the address counter 6d, as shown in FIG.

The operation of the displacement measuring device configured as described above will be explained below with reference to the timing chart of FIG. 4.

From the m-pixel-dimensional can camera 1a, a time-series photoelectric signal (video signal, waveform (b) shown in Figs. 2 and 4) is generated.
- synchronization signal for each scan (shown in Figures 2 and 4 (a)
waveform) and a clock signal corresponding to each pixel of the COD camera 1B- is output. Of these, the photoelectric signal is sent to the voltage comparator Sa in the binarization circuit 8, where it is binarized using the binarization reference voltage 8b, and the waveform shown in Fig. 4 (*) is obtained. →, at the time of (t-1) scanning, one from n pixels of the photoelectric signal from the CCD camera 1a.
It is assumed that an object exists between pixels, and that an object exists between pixels n and 1 when scanning. Then (t
+1) During scanning, the object moves and the CCD camera 1a
Of the photoelectric signals from (n-1-p) pixels to (1+
p) An object exists at the pixel, and (t+ (2
) During scanning, similarly from (n+p) pixels to (1
-)-p) It is assumed that an object exists at the pixel.

The output of the binarization circuit 8, that is, the binarized light? The lf signal is sent to the m-bit shift register 3a of the buffer memory 3, and image data for one scan is stored in synchronization with the clock of the CCD camera 1a.

That is, at the start of t scanning, the photoelectric signal (image data) during (t-1) scanning is transferred to the m-bit shift register 3.
It is stored in a. When scanning starts, CC
In synchronization with the clock signal from the D camera 1a, the image data for t scanning is sequentially written into the m-bit shift register 3B, and at the same time, the image data for (-1) scanning is read from the m-bit shift register. The output signal is output and supplied to the permissible value determination circuit 4. The digital comparator 4a in the allowable value determination circuit 4 performs the scanning operation of the CCD camera 1a (1-
1) Compare the data during scanning and the image data during t-scanning. In FIG. 6, since the object has not changed between the (t-1) scan and the t scan, the permissible value detection circuit 4b determines that it is within the permissible value. Tolerance value detection circuit 4b When the Fit scan is completed, the output is sent based on the comparison result.

Since the comparison result between the (t-1) scan and the t-scan is within the allowable value, the output (E) of the allowable value detection circuit 4a is reset. The output of the allowable value determination circuit 4 is sent to the memory write controller 5 and the memory address setting circuit e. The memory write controller 6 outputs the signal ((E) and the buffer memory 3
The image data is stored in memory 7 at the next scan (for example, the comparison result at t scan is at (t+1) scan).
It is determined whether to write to the displacement amount data memo IJ7a within. In FIG. 4, the comparison result at the time of t scanning shows that the amount of displacement is within the allowable value, so the gate 5b is closed (t
-4-1) Prevent writing of image data during scanning. On the other hand, the memory address setting circuit receives the signal (e) and the synchronization signal (scanning repetition signal) from the CCD camera 1a, and when the output of the tolerance value judgment circuit 4 is sent, that is, the amount of displacement is within the tolerance value. At this time, the gate 6 & closes to prevent the address counter 6 d from counting up, and the counter memory 7 in the memory 7 passes through the gate 6 c.
A pulse is supplied to b, and the counter memory 7b is incremented to count the number of times the same displacement data appears.

On the other hand, when the output of the permissible value determination circuit 4 is set, that is, when the displacement amount exceeds the permissible value, the address counter 4d is incremented through the gate 6a, and new displacement data is stored in the displacement data memory 7a in the next scan. written to. At this time, since the counter memory 7b and the displacement data memory 7a have an address-corresponding configuration as shown in FIG. 3, the address of the counter memory 7b is also incremented.

In FIG. 4, the operation during (t+1) scanning is as follows: As a result of comparing the (t-1) scanning and t scanning, the amount of displacement is within the allowable value, so the counter memory 7b is incremented to change the displacement of the image data. Writing to the quantity data memory 7a is not performed.

In this way, when scanning, (t-1) scan image data and t-scan rain image data are compared, and (t-4-1) whether to write the image data to memory or increment the counter memory during scan. Judge and based on the result (1-)-
1) Execute write control to memory during scanning.

Next, during the (t+2) scan, write control is performed based on the comparison result of the image data during the t scan and the (t-1-1) scan, which were similarly compared during the (t+1) scan. In FIG. 4, if the comparison result exceeds the allowable value, the memory write controller 5 supplies data from the (t+1) scan to the displacement data memo IJ 7a, and new data is recorded. On the other hand, the memory address setting circuit 6 prevents the increment of the counter memory and increments the address counter 6d'iz before writing the image data (the waveform is shown in FIG.
g) All references) 0 Next, the recording state in the memory 7 will be explained.

As shown in FIG. 3, the image data is stored in the memory 7 when the amount of displacement is within the allowable value, the counter memory at the same address, for example address 1, is incremented without rewriting the amount of displacement data memory 7a, and the amount of displacement is When the allowable value is exceeded, new image data is stored in the displacement data memory at the next address.

As a result, the contents of the displacement amount data memory and counter memory corresponding to each address are in the form of storing image data and the number of times it appears.

A recording state when the displacement of an object that changes rapidly after a certain period of time is measured using this method as shown in FIG. 5 will be described. With respect to the scanning repetition frequency of the COD camera, almost no new image data is recorded in the memory in areas A, M, and C, where there is little change, and new image data is recorded in area B, where the displacement is large. . For the displacement shown in Fig. 5, tl, tn, t? l
Image data is recorded in the order of +t...tm, and from t2 to tn- and after tm+1, the number of appearances is only counted in the counter memory, and no new image data is stored in memory.

Generally, the number m of pixels per one scan of image data, that is, the number of focuses per address in the memory, is several tens to tens of thousands of times larger than the number m of bits in the counter memory. Therefore, by reducing the amount of image data recorded, it is possible to measure the temporal displacement of an object that changes rapidly with a small memory capacity.

In addition, to reproduce recorded data, if you arrange the same image data on the time axis by the number of counts in the counter memory,
Displacement with respect to the time axis can be reproduced.

As described above, according to this embodiment, the current scan data and the previous scan data are compared, it is determined whether the result is within the allowable value, and data written into the memory is controlled based on this. By doing so, it is possible to accurately measure the amount of sudden and rapid displacement with a small memory capacity without changing the scanning repetition time of the integral type optical sensor.

In this embodiment, the memory is composed of a displacement amount data memory and a counter memory arranged to correspond to the same address. A similar effect can be obtained by using a configuration in which quantity data is stored. Furthermore, an integral type two-dimensional sensor can be used in the measurement section.

Effects of the Invention According to the present invention, it is possible to accurately measure the amount of temporal displacement of an object that changes suddenly and rapidly with a small memory capacity without changing the scanning repetition frequency of an integral optical sensor.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the displacement measuring device of the present invention, FIG. 2 is a block diagram showing the configuration of the displacement measuring device of the embodiment, and FIG. 3 is a diagram showing the internal configuration of the memory. FIG. 4 is a diagram showing a timing chart, FIG. 5 is a diagram showing a measurement example, FIG. 6 is a block diagram showing the configuration of a conventional displacement measuring device, and FIG. 7 is a diagram showing a measurement example in the conventional example. It is. 1... Measuring section, 2... Digitization circuit, 3... Buffer memory, 4... Tolerance value judgment circuit, 5... Memory writing controller,
6...Memory address setting circuit, 7...
・Memory, 7a...Displacement amount data memory, 7b
...Counter memory, 8...Binarization circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person
1f! ! ! l Figure 3
A Y collection
Otsu - Shi Figure 5 Masu is the cry Figure 6 Figure 7 Sho Kan - Gin threshold

Claims (1)

[Claims] A measurement section equipped with an integral sensor that periodically obtains photoelectric signals, a digitization circuit that converts the photoelectric signals from the measurement section into digital signals, and a buffer memory that stores the digitized photoelectric signals for only one scan. and a tolerance determination circuit that receives signals from the digitization circuit and the buffer memory and compares the data from one scan before with the current scan data to determine whether the data is within tolerance, and a synchronization signal from the measurement section. A memory address setting unit that receives a comparison signal from the tolerance determination circuit and generates a signal to increment a counter memory if the change in the current scan data is within the tolerance, and increments the address counter if it exceeds the tolerance. , a memory write controller that receives output signals from the buffer memory and the allowable value determination circuit and stops writing data into the memory only when the current data exceeds the allowable value; and a memory write controller and the memory address setting circuit. A displacement measurement device that receives an output signal from a photoelectric signal and a memory that records the number of appearances corresponding to the photoelectric signal.