JPS61189462A - Detecting device for moving time - Google Patents

Abstract

PURPOSE:To measure the moving time or the moving group velocity of a material body changing the shape with the time by using a correlating device which performs turning arithmetic of two input pattern signals with the real time. CONSTITUTION:In case the moving material body 1 with an asymmetrical or indeterminate form is moved on a conveyor 2, an input device 3 obtains pattern information from two parts of the body 1 and supplies signals A4 and B5 to the real time operation type correlating device 6. The correlating device 6 performs the turning arithmetic of the signals A4 and B5 and the arithmetic result is given to a detector 7 and its peak value is detected and a degree of similarity between two signals is detected. Then, the arithmetic of the time difference elapsed from the input of the first pattern signal until its peak value is detected, is performed by using a synchronizing pulse from a generator 9. In this way, the moving time of the body 1 is measured and displayed as the time or the moving velocity by a display device 10.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for measuring the moving time or moving speed of an object, and in particular, it relates to a device for measuring the moving time or moving speed of an object, and in particular, it is capable of pattern matching by using a correlator that operates in real time. Since we decided to use the method to detect the position of the object to be measured, we can detect not only cases where the shape can be specified, but also cases where the shape changes, such as powder particles or smoke.
For this reason, it is characterized by providing a technique suitable for measuring the movement of objects whose shape is difficult to determine.

[Conventional technology]

This invention is a correlation device (patent application filed in 1973) filed by the same applicant.
No. 8-191691) (Inventor: Yuki Miyagi, some parts are common) f
It was completed based on the fact that was discovered during experiments using T.

[Problem that the invention seeks to solve]

This invention is useful when the shape of the object to be measured changes, such as when measuring the flow velocity of smoke or water vapor discharged from a chimney, or when measuring the velocity of flowing powder or granular material. This makes it possible to reasonably measure the travel time or speed even in the case of irregularly shaped objects or irregularly shaped objects that are not specified by the object.

This type of object, which does not have fixed feature points, has been considered difficult to detect because it is difficult to determine the reference point for measuring the travel time and speed of the signal. This invention solves this difficult problem.

In addition, as a variation of the application of this invention, the time required for the pattern of the measured object to change and reappear after the change is detected for a measured object whose pattern changes from time to time and a re-string pattern appears after a predetermined period of time has elapsed. It is also possible to

[Means for solving problems]

According to the apparatus of the present invention, the shape of the moving object to be measured is grasped as an overall pattern, and the movement of this pattern is detected to detect the moving group velocity of the object to be measured.

That is, the method detects how much the entire pattern has moved using a pattern matching method. Pattern matching of a moving object often requires high-speed correlation calculation processing, and this invention operates in real time. A correlator is used as a convolver.

Since this invention detects the movement of the pattern, there is no need to determine the reference point for measurement (for example, the green of an image, the apex of a pulse or the rising edge of an electrical signal, etc.), and It is only necessary to perform the measurement before the entire pattern disappears, and even if there is a partial fluctuation in velocity due to slight deformation within the pattern, the To detect the moving speed (group speed), an averaged speed (or moving time) can be obtained.

〔Example〕

The configuration of this invention will be explained with reference to the embodiment shown in FIG. FIG. 1 shows an apparatus for measuring the moving time (or moving speed) of a single moving object with an irregular shape. In this embodiment, a moving object 1 to be measured is input by a signal input device 3 as a patterned signal.

This signal input device 3 will be explained in detail later with reference to FIGS. 2 and 3, but it obtains pattern information from two locations on the moving object and inputs these two signals A and the double signal (4, 5) t I
It is sent to the correlator 6 which operates in J real time. A typical example of the correlator 6 that operates in real time is the above-mentioned patent application published in 1983.
The correlator according to No.-191691, in other words, is an acousto-optic correlator. By this correlator, the two signals A, B
The complication calculation is executed immediately, and the degree of similarity between the two signals is output. Normally, a cross-correlation operation is used to detect this degree of similarity, but since a convolution operation can be executed faster, the time axis of one of the input signals is reversed and a convergence operation is performed. The result is to obtain the same effect as if the cross-correlation calculation were executed in real time.

The situation during this time will be explained later with reference to FIG. The degree of similarity is detected by a peak value detector 7 that detects the peak value of the composure cyan calculation output. Then, the phase difference detector 8 calculates the elapsed time difference from the input of the first pattern signal until the peak value is detected. At this time, the synchronization pulse generated by the synchronization signal generator 9 can be used. The number of synchronization pulses measures the elapsed time until pattern matching is performed, that is, the moving time of the irregular or irregularly shaped moving object, and this is displayed on the display 10 as time or moving speed.

FIG. 2 is a diagram showing details of the method by which the pattern signal is input to the signal input device 3. A predetermined width d corresponding to the interval for defining the correlation calculation is determined in advance. In addition, a CCD is used as a first sensor that detects a linear pattern in the width direction by scanning the moving measured object 1 over the width d.
A photodetecting element array 31 such as a line sensor is placed. Further, a second sensor (photodetecting element array) 32 is placed parallel to the first sensor and spaced apart by a predetermined distance t in the moving direction of the object to be measured. This second sensor 32 is also of the same type as the first sensor 31, but is similar to the first sensor 32.
1 scanning direction 33 (33' at the image position) and a scanning direction 34 (34 at the image position) of the second sensor 32 (which is opposite to the scanning direction 34 at the image position). The signals obtained in step 32 are each signal A' (four).

This is signal B(5). In this embodiment, CC is used as a sensor.
Although a D-line sensor is mentioned, other sensors such as a television camera may also be used.

FIG. 3 shows the internal structure of one embodiment of the signal input device 3. The input pattern signal A' obtained by the photodetector array 31 is stored in a circular storage circuit 35. The circulation memory circuit 35 is
For example, in a device such as one horizontal scanning time delay element of a television, the content is erased by the clear reset signal 36, and the input pattern signal A of one scanning portion is erased by the synchronization signal 39.
' is read and stored in a circular manner, and a signal A(4) which is a repeating signal of the signal X is output. Photodetector array 32
The input pattern signal B obtained is output as 5.

[For production]

FIG. 4 is a waveform diagram schematically showing signals at each part. The horizontal axis is a time axis in which time progresses to the right.

I indicates the input pattern signal A' captured by the first sensor. The scale along the horizontal axis indicates divisions for one scan. Signals that are the same as the upper left pattern signal or that are inverted are distinguished by shading and shading on the diagram. ■ Signal A'
shows how the input pattern changes with each irregular or amorphous scan. 2 is a signal obtained by repeating one scan of the input pattern signal A'. (2) is input pattern signal B, and pattern signal A/ (2) is an input pattern signal obtained when the moving object to be measured that has generated (2) advances by distance t and reaches the second sensor position after time Td has elapsed. It is. in this case,
The signal A' of (2) is a pattern signal whose direction is reversed for each scan. (2) is the convolution calculation output when signal A and signal B (II and (2)) are added to the correlator. When the patterns of two input signals almost match, that is, when pattern matching is obtained, a waveform with a large peak in the center is obtained.9 This property is a feature of correlation calculation, and is a characteristic of the present invention. This is where it is used.

The peak value is detected by appropriately setting a threshold value.

This is shown in V. A time difference Td (phase difference) from the input pattern signal X to when the output signal of the peak value detector that detects this peak value is output is output from the phase difference detector. This is shown in ■.

[Other Examples]

In the embodiment shown in FIG. 1, the first sensor and the second sensor are separated by a predetermined distance t, and the appearance of identical patterns is detected by pattern matching using correlation calculation.

Alternatively, if the pattern of the object to be measured 1 changes from moment to moment and a re-string pattern appears after a predetermined period of time, the aim of the first sensor and the second sensor should be the same. It is preferable to set the conveyor to the position (1=0) (in this case, it is assumed that the conveyor is stopped). Then, the input pattern signals representing the pattern of the object to be changed are sequentially input to the input device after the change.

As described above, the present invention can be implemented by changing the configuration as appropriate depending on the purpose and use.

〔Effect of the invention〕

As explained above, in this invention, the scanning directions of the two input pattern signals are reversed and a correlator is used that can realize the convolution operation of the two input pattern signals in real time. It is possible to realize an unprecedented measurement technology that can measure the travel time or moving group velocity of not only moving objects that can be identified, but also irregular or irregularly shaped moving objects whose shapes change over time. Ta.

If equipped with an optical signal input device, remote sensing is possible, and projected images and reflected light patterns can also be measured.

The average group velocity can be measured even for objects whose shape changes slightly during movement, such as smoke or clouds.

As described above, it has various unique uses and has high industrial value.

[Brief explanation of the drawing]

FIG. 1 shows a block diagram of an embodiment of the apparatus of the present invention, that is, a moving time detection apparatus for an irregular or irregularly shaped object conveyed by a conveyor. 211i\,l are diagrams showing a pattern signal input method for explaining the operation of the signal input device used in the configuration of FIG. 1, and FIG. 3 is a diagram showing the configuration of a simple embodiment of the signal input device. It is. FIG. 4 is a schematic diagram showing the waveform of a signal which does not provide a detailed explanation of the present invention. In the figure, 3 is a signal input device, 6 is a correlator (an acousto-optic correlator in a preferred embodiment), 7 is a peak value detector, and 8 is a means for calculating a time difference (for example, a phase difference detector). Patent applicant: Anritsu Electric Co., Ltd. Agent: Patent attorney: Koike Ryutabe Kan/times

Claims (1)

[Claims] A first output pattern signal that sequentially receives input pattern signals representing a pattern of a measured object to be moved or changed after being moved or changed, and in which the input pattern signals are repeatedly arranged at a predetermined period; a signal input device (3) that generates a second output pattern signal that is delayed by a second period and is obtained by inversely arranging the input pattern signal within the predetermined period; a correlator (6) that performs a convolution operation on the output first output pattern signal and the second output pattern signal and outputs a convolution signal; a peak value detector (7) for detecting a peak value of a correlation signal output when the input pattern signal almost matches; an output signal of the peak value detector (7) is output from the time the input pattern signal is input; 1. A travel time detection device comprising: calculation means (8) for calculating a time difference between the two times.