JPS6288080A - Measuring instrument for approximate number of moving object - Google Patents

Abstract

PURPOSE:To attain a simplified measurement with a small-scaled and simple constitution by measuring the round number of an object to be measured calculating its own correlation function value based upon a signal from a photoelectric transducing device that is a special filter detector. CONSTITUTION:A photoelectric transducing device 8 is equipped with a photoelectric transducer 7 line-connected in a positive and a reversed directions electrically. The outputs of the photoelectric transducers 7 are inputted to a difference signal output circuit 4, then a signal that represents the difference of an absolute value of each level being outputted. The difference signal is inputted to an arithmetic part 16 through an A/D converter 15, and its own correlation function against the pattern of prescribed time length of the difference signal is calculated. A data processing part 20 calculates and outputs a data regarding the round number of an object 3 to be measured from its own correlation function value responding to the output from the arithmetic part 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an approximate measurement device for a moving object.

(Prior Art) For example, there are many cases where it is difficult to electrically measure the crowding of people in front of an elevator, the number of people gathered in a particular area, etc. As described above, in order to measure the approximate number of moving objects, a method is conventionally known in which the area to be measured is photographed with a television camera and the image is processed using a computer.

(Problem to be Solved by the Invention) However, in image processing apparatuses using computers, the algorithms used for analysis are extremely complex, and therefore the computers used for this purpose are large-sized combinations with high processing speeds. This poses a problem in that not only does the cost of the device become extremely high, but also the physical scale of the device becomes large, leading to various problems in handling.

SUMMARY OF THE INVENTION An object of the present invention is to provide an approximate number measuring device that can measure the approximate number of a moving object in a non-contact manner using a small-scale device without requiring a large-sized computer.

(Means for Solving the Problems) The content of the present invention for solving the above problems is that photoelectric conversion elements electrically connected in the forward and reverse directions are arranged in a required pattern on a plane. a photoelectric conversion device that outputs a first signal indicating the sum of outputs of the forward photoelectric conversion elements and a second signal indicating the sum of outputs of the reverse photoelectric conversion elements; and a photoelectric conversion device that outputs an image of a desired object to be measured on the photoelectric conversion device. a difference signal output circuit that responds to the first and second signals and outputs a difference signal according to the difference in absolute value of each level of the first and second signals; a calculation unit that calculates an autocorrelation function value for a pattern of a predetermined time length of the difference signal based on the calculation unit; and a calculation unit that responds to the output from the calculation unit and calculates data regarding the approximate number of the objects to be measured from the autocorrelation function value. The present invention also includes a data processing section for outputting data.

(Function) When the object to be measured is moving, the level of the difference signal fluctuates between positive and negative, and the autocorrelation function value of the level change pattern of the difference signal increases as the number of objects to be measured increases. Show trends. In the data processing section, an approximate number of the object to be measured is calculated based on the autocorrelation function value calculated by the calculation section, and the result of this calculation becomes the measured value.

(Embodiment) FIG. 1 shows a block diagram showing an embodiment of the approximate number measuring device according to the present invention. The approximate number measuring device 1 is a device for electrically measuring the approximate number of a plurality of moving objects 3 within a predetermined measurement area 2, and is configured as a housing 5 equipped with a lens 4. The photoelectric sensor 8 includes a photoelectric conversion device 7 disposed within an optical device 6.

The photoelectric conversion device 7 includes a photoelectric conversion plate 9, and its photoelectric conversion surface 9a is divided into a large number of vertical and horizontal sections as shown in FIG. 2, and each section has a photoelectric conversion element 10 consisting of a photodiode. The outputs of the photoelectric conversion elements 10 provided diagonally to each other are added together in opposite directions as shown in FIG.
a.

10b are differentially connected. The terminal 10c is a terminal connected to the common connection line 11 of each photoelectric conversion element 10, and load resistors 12 and 13 are connected between the terminals 10a and 100 and between the terminals 10b and 100, respectively. Therefore, each output current from the photoelectric conversion elements connected in the positive direction with respect to the common connection a10 flows into the load resistor 12, thereby causing the first level to rise according to the sum of the outputs of the positive direction photoelectric conversion elements. A signal v1 is developed across load resistor 12. On the other hand, each output current from the photoelectric conversion elements connected in the negative direction with respect to the common connection line 10 flows into the load resistor 13, which causes a level corresponding to the sum of the outputs of the negative direction photoelectric conversion elements. A second signal v2 of is generated across the load resistor 13.

As is already known, when the photoelectric conversion plate 9 is uniformly illuminated with light on its photoelectric conversion surface 9a or when a stationary pattern is projected onto the photoelectric conversion surface 9m, the photoelectric conversion plate 9 receives the first signal. The absolute values of each level of Vl and the second signal v2 are almost equal, and when the pattern projected on the photoelectric conversion surface 9 & changes, the first signal V is taken out as a positive level signal, and the negative The second signal is extracted as a level signal.
The sum with the signal V changes to positive or negative in relation to the change.

Returning to FIG. 1, in order to obtain a signal corresponding to the difference in the absolute value of each level between the first signal V violet and the second signal v2, the first signal v
1 and the second signal v2 are the ground terminal G and the input terminal 14 of the difference signal output circuit 14 configured as a differential amplifier circuit.
a and between the ground terminal G and the one input terminal 14b, and the difference signal output circuit 14 outputs the difference in the absolute value of each level between the first signal v1 and the second signal V. A difference signal v3 having a level corresponding to is output.

FIG. 3 shows an example of a level change in the difference signal v3 caused by the movement of the object 3 to be measured. The difference signal v3 is input to an analog-to-digital converter (IVD) 15, where the difference signal v3 is converted into the corresponding digital output data D.

The level of the difference signal V3 changes between positive and negative depending on the moving state of the objects 3 to be measured, and the value of the autocorrelation function that numerically indicates the state of the change pattern has a close correlation with the number of objects 3 to be measured. In order to measure the approximate number by paying attention to the point that the difference signal v3 is present, the digital output data D corresponding to the difference signal v3 is inputted to the calculation unit ]6, where the autocorrelation function value is calculated based on the digital output data D. . The autocorrelation function value calculation performed here is performed on the level pattern of the difference signal, and this calculation is repeatedly performed at predetermined time intervals.

The function value data FD indicating the calculation result in the calculation section 6 is input to the data processing section 20 which converts the function value data FD into approximate number data ND indicating the approximate value of the object to be measured. The data processing section 20 includes a data conversion section 21 into which the function value data FD is input, and standards necessary for the data conversion section 21 to convert the function value data FD into approximate number data indicating the approximate number of objects to be measured at that time. and a memory section 22 for supplying the data RD to the gator conversion section 21. When the photoelectric sensor 8 is installed in the measurement area 2 to be measured by the photoelectric sensor 8, a predetermined number of broken i4+1 bodies or similar objects are moved within this measurement area 2 to measure the object to be measured. Data indicating the relationship between the number and the contents of the function value data FD is obtained, and the data obtained by performing the K process is inputted from the input device 31 to the memory section 22 as the reference data RD and stored therein.

As can be seen from the above description, the required force reference data RD for the data conversion process executed in the data conversion unit 21
(a) varies greatly depending on the type of photoelectric sensor 8, the installation condition, the type of object to be measured, etc. Therefore, it is necessary to readjust the reference data RD to be stored in the memory section 22 every time the measurement conditions change. There is. Therefore, in this device, the display device 32 for displaying data is operated by the switch 33 to display the function value data FD or the outline from the data converter 21.

The configuration is such that either one of the numerical data ND can be selectively input. When obtaining the above-mentioned reference data RD, the switch 33 is switched as shown by the dotted line, and the function value data FD is obtained when a predetermined number of objects 3 to be measured are moving within the measurement region 2. The configuration is such that the value of can be easily read by the display device 32.

The function value data MF' is converted by the data converter 21 into approximate number data ND indicating the approximate number of the object to be measured 3 at the time, with reference to the reference data RD from the memory section 22.

Approximate number data ND is displayed on display @, 32 via switch 33.
is supplied to the display device 3, and the approximate number of the object to be measured 3 at each time is displayed on the display device 3.
Displayed by 2.

Next, the operation of the apparatus shown in FIG. 1 will be explained. First, once the installation of the photoelectric sensor 8 is completed, switch 3
3 as shown by the dotted line, move a predetermined number of objects 3 to be measured or something similar within the measurement area 2, and display the contents of the resulting function value data FD on the display device 32. #) Read. This operation is performed several times by changing the number of objects to be measured, and the data indicating the relationship between the number of objects to be measured and the function value data FD obtained as a result is stored in the memory section 23 as reference data RD. It is input in advance from the input device 31.

After completing the measurement preparation in this way, switch 3
3 as shown by the solid line, and the contents of the approximate number data ND are displayed on the display device 32. In this state, when the object to be measured 3 moves within the measurement area 2, the function value data FD having a value corresponding to the number of objects to be measured 3 is inputted to the data conversion section 21, where the reference data RD obtained in advance is used. It is converted into approximate number data ND indicating the approximate number of the object to be measured at any given time. Approximate number data ND is switch 3
3 to the display device 32, and can directly display a plurality of objects to be measured 3 at any given time.

In the above embodiment, as shown in FIG. 2, the photoelectric conversion plate 9 includes photoelectric conversion elements connected in the positive direction (indicated by +) and photoelectric conversion elements connected in the negative direction (indicated by -). Although a photoelectric conversion plate 9 having a configuration in which the photoelectric conversion elements are arranged alternately in the vertical and horizontal directions was used, the photoelectric conversion elements were arranged at +1.0. It is easily understood from the above description that a two-dimensional M-sequence type in which a load of −1 is applied and randomly arranged may be used.

According to this configuration, the calculations for processing the output signal from the sensor are as simple as calculating the autocorrelation function value and data conversion, so even if a computer is used, it can be done on a very small scale. , the device can also be made smaller.

Furthermore, since the photoelectric sensor used in this device does not extract the image data of the measurement area 2, there is no risk of infringing on the privacy of a person, especially when the object to be detected is a person. This is significantly superior to conventional methods that process images using images from television cameras.

(Effects) According to the present invention, as described above, the approximate number of objects to be measured is measured by calculating the autocorrelation function value based on the signal from the photoelectric conversion device, which is a spatial filter detector. Therefore, the hardware configuration can be small and simple, and the approximate number of objects to be measured can be easily measured without requiring complicated algorithms. Furthermore, since the output from the sensor is not a video signal, it has the excellent effect of being able to be used without any problems even in places where people's privacy must be protected.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the approximate number measuring device according to the present invention, FIG. 2 is an explanatory diagram of the photoelectric conversion surface of the photoelectric conversion plate shown in FIG. 1, and FIG. 3 is the photoelectric conversion shown in FIG. 1. The circuit diagram of the device, FIG. 4, is a waveform diagram showing an example of the waveform of the difference signal. DESCRIPTION OF SYMBOLS 1... Approximate number measuring device, 2... Measurement area, 3... Measured object, 6... Optical device, 7... Photoelectric conversion device, 9
...Photoelectric conversion plate, 10...Photoelectric conversion element, 14...
- Difference signal output circuit, 16... calculation section, 20... data processing section, vl... first signal, ■ goose... second signal,
v3...Difference signal.

Claims (1)

[Claims] 1. Photoelectric conversion elements electrically connected in the forward direction and reverse direction are arranged in a required pattern on a plane, and a first signal indicating the sum of outputs of the forward direction photoelectric conversion elements and the output of the reverse direction photoelectric conversion elements a photoelectric conversion device that outputs a second signal indicating the sum; an optical device that forms an image of a desired object on the photoelectric conversion device;
and a difference signal output circuit that outputs a difference signal according to the difference in the absolute value of each level of the second signal, and calculates an autocorrelation function value for a pattern of a predetermined time length of the difference signal based on the difference signal. Approximate measurement of a moving object, comprising: a calculation section; and a data processing section that responds to the output from the calculation section and calculates and outputs data regarding the approximate number of the object to be measured from the autocorrelation function value. Device.