JPH0580712B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention measures the number of moving objects passing through a monitoring surface, for example, the number of people entering and exiting a building, etc., using a storage type photodetector such as a CCD line sensor. The present invention relates to a moving body amount measuring device that displays a moving body amount.

(Prior Art) The inventors of the present application have developed a device for measuring the amount of moving objects by drawing a monitoring line consisting of two white lines on a monitoring surface such as an entrance or exit of a building, and monitoring by moving objects passing on this monitoring surface. We have proposed a device that detects the moving direction and number of moving objects by receiving changes in line brightness with a CCD line sensor, and measures and displays the number of people remaining in a building, for example.

(Problems to be Solved by the Invention) However, with such conventional moving body mass measuring devices, when multiple people line up side by side and pass through the monitoring surface at the same time, the monitoring line The number of people passing is determined by dividing the width of the brightness change caused by the specified width that serves as the discrimination standard. For example, when exiting a building, if the child who was carrying the child on the person's back was dropped off when entering the building and the child held hands as they left the building, the number of people identified at the time of entry and the number of people who left the building are different, so it may be mistaken. There was a risk that the measurement result would be incorrect.

(Means for Solving the Problems) The present invention was made in view of such conventional problems, and even if a plurality of moving objects overlap one another and pass through the monitoring surface, it is possible to accurately pass through the monitoring surface. An object of the present invention is to provide a moving body amount measuring device capable of detecting the number of moving objects.

In order to achieve this object, the present invention includes two
A storage type photodetector detects the change in brightness due to the passage of a moving object on a monitoring surface equipped with a book monitoring line, and the passing speed (V) of the moving object is determined from the light reception information of this storage type photodetector.
In addition to calculating the passing speed (V), the monitoring surface passing time per one reference moving object with a predetermined size is calculated.
(K), and the actual passing time of the moving object on the monitoring surface and the passing time per reference moving object obtained from the light reception information.
(K) is used to calculate the number of passing moving objects that overlap one another.

(Function) According to the configuration of the present invention, even if a plurality of moving objects pass through the monitoring surface at the same time while overlapping one another, the sizes predetermined based on the passing speed of the moving objects at that time The number of moving objects can be calculated by finding the passing time per standard moving object and dividing the actual passing time by the reference passing time per moving object. Even if a person passes by, the number of people passing by can be determined to be two, and accurate measurement results can be obtained.

(Embodiment) FIG. 2 is a block diagram schematically showing the configuration of an apparatus according to the present invention.

In Figure 2, 1 and 2 are charge-coupled devices (hereinafter referred to as ``CCD sensors'') as storage-type photodetectors.
As shown in Fig. 3, it has a structure in which a plurality of light-receiving pixels 3a to 3n are arranged linearly, and when light hits each light-receiving pixel, a certain accumulation time (exposure time) determined by the readout timing occurs. It is possible to obtain an accumulated charge proportional to the integral amount of incident light over .

Regarding the CCD sensors 1 and 2 having such a structure, in the present invention, all light reception data is not used as data used for calculation processing of traffic volume based on light reception data, and the shaded area in Fig. 3 is used. As shown, for example, every fourth light reception data A1, A5,
...A _o-1 , B2, B6, ...Bn are read out from the memory storing the light reception data by designation of the jumping address, and arithmetic processing is executed.

Furthermore, to explain one example in detail, for example,
As the CCD sensors 1 and 2, 2048 light-receiving pixels arranged in a straight line are used, and the light-receiving data of every 16 pixels is read out and data processing is performed. Here, depending on the configuration of the optical system that will be explained later,
For example, if the monitoring length of the monitoring surface per light-receiving pixel connected to the CCD sensor is 0.25cm,
Reading the received light data every 16 times means reading the received light data every 4 cm from the memory on the monitoring surface and perform data processing.

In this way, high-speed data processing is possible even when the number of pixels per line is large by data processing the light reception data read out at regular intervals among the light reception data obtained from the light reception pixels arranged in a straight line. becomes.

Note that the density of the light reception data used for data processing corresponding to the light reception pixels is determined within the range where the passing of a person can be detected, for example, when the moving object is a person, and is variable within the range where the person can be detected. I can do it.

Next, the structure of the monitoring surface monitored by the two CCD sensors 1 and 2 and the detection optical system will be explained.

In this embodiment, taking as an example the passage of a person as a moving object to be detected, a light source installation groove 18 is formed in the floor surface 4 of an entrance of a building, etc.;
A plurality of fluorescent lamps 20 are arranged in a longitudinal direction facing upward, and a protective cover 22 made of a glass window is provided at the groove opening at the upper part of the fluorescent lamps 20.

As another example, as shown in the plan view of FIG. 4, this floor surface 4 is equipped with a transparent or milky-white transmission window that forms the monitoring lines A and B by the shaded area shown by the hatched area. This forms a line light source.

Referring again to FIG. 2, the images of the two monitoring lines A and B formed by the line light sources provided on the floor 4 are as follows:
The image of the monitoring line A is reflected from the condenser lens 6 by a half mirror 7 and is imaged on the CCD sensor 1. tie the
On the other hand, regarding the monitoring line B, the light passes from the condenser lens 6 through the half mirror 7 and is focused on the CCD sensor 2 as an image. With such an optical system, the monitoring lines A and B are connected to the light receiving pixels 1 in the CCD sensors 1 and 2.
per hit, for example 0.25cm each on the line
The image is reduced and formed.

On the other hand, regarding the monitoring lines A and B, in this embodiment, as an example, monitoring line A is installed outside the building, and monitoring line B is installed inside the building. Here, the interval l between the monitoring lines A and B formed in parallel is determined depending on the size of the moving object, and for example, when the moving object is a person, it is determined to be approximately 8.5 cm. Further, the widths of the monitoring lines A and B are determined by the size of the entrance/exit.

Referring to Figure 2 again, CCD sensors 1 and 2
receives a transfer clock from the CCD drive circuit 8 and outputs a light reception signal at fixed accumulation time intervals.

The outputs of the CCD sensors 1 and 2 are connected to the A/D converter 9a,
The signals 9b are converted into digital signals corresponding to the respective light reception levels, and are applied to the multiplexer 10.

Here, since the CCD sensors 1 and 2 are equipped with, for example, 2048 light-receiving pixels, if they are read out sequentially every second, the readout time will be long, so the A/D
Two systems of converters 9a and 9b are provided, and the received light signals are read out alternately in parallel to enable high-speed processing.

Following the multiplexer 10 are a background processing circuit 11 and a RAM for performing background processing on the received light data.
12a and 12b are provided.

The light reception data of the A line and the B line obtained in a steady state with no people passing on the monitoring lines A and B are written in the RAM 12a, and this written light reception data is converted into background processing for the background processing circuit 11. used as background reference data for

For example, the background processing circuit 11 inputs the background reference data stored in the RAM 12a to the multiplexer 10.
By subtracting the received light data obtained in real time via the , the received light data is created unaffected by the background.

On the other hand, for the other RAM 12b that is not used for storing background data, multiplexer 1
Writing of light reception data is performed in real time via RAM 12a, and background reference data can be refreshed by switching from RAM 12a to RAM 12b as needed.

The received light data subjected to background processing by the background processing circuit 11 is written to the buffer memory 14a or 14b via the gate circuit 13. The buffer memories 14a and 14b are an arithmetic processing unit 1 that executes arithmetic processing for measuring traffic volume via a gate circuit 15.
Connected to 6.

Here, the reason why two buffer memories 14a and 14b are provided is that when writing received light data to one buffer memory, for example, the buffer memory 14a, via the gate circuit 13, the other buffer memory 14b is written via the gate circuit 15. is connected to the arithmetic processing unit 16, and the buffer memory 1
The light reception data already stored in 4b is read into the arithmetic processing section 16 and data processing is performed.

In this way, data in one buffer memory can be processed while writing data in the other buffer memory, so that the CCD sensor side and the processing unit 1
There is no need for timing alignment with the CCD sensor 6 side, and the transfer of light reception data from the CCD sensors 1 and 2 and the data processing by the arithmetic processing unit 16 can be made independent.

The arithmetic processing unit 16 is executed under program control by, for example, a CPU, and is executed by either one of the buffer memories 14a or 1 selected by the gate circuit 15.
The light reception data stored in 4b is read at a predetermined data sampling period T, for example, every T=1 ms, and arithmetic processing for measuring the amount of traffic is performed.

The calculation process for measuring the traffic volume in the calculation processing unit 16 has already been proposed by the inventors of the present application in Japanese Patent Application No. 1987-190297 (see Japanese Patent Application Laid-Open No. 62-49598).
Perform the same process as disclosed in et al.

Furthermore, in addition to the above-mentioned traffic volume measurement process, the arithmetic processing unit 16 performs a process of determining the number of people passing through when a plurality of moving objects overlap one another and pass through the monitoring line, which will be explained later.

FIG. 1 is a block diagram showing an embodiment for determining the number of people when a plurality of moving objects overlap one another and pass through a monitoring line, which is provided in the arithmetic processing section 16 of FIG. 2.

First, the basic principle of determining the number of people in the embodiment of FIG. 1 will be explained with reference to the state of people passing through the monitoring line in FIG. 5 as follows.

Figure 5 shows monitoring line A for monitoring lines A and B.
FIG. 2 is an explanatory diagram showing a state in which two people M1 and M2 are passing through one behind the other, one behind the other. Specifically, a person M1 passes by carrying a child M2 on his back.

For such people M1 and M2 to pass, the fifth
As shown in Figure a, when the width W of the brightness change due to the moving object M1 on the monitoring line A reaches a predetermined width, for example, W = 20 cm, the data on the monitoring lines A and B that are carried out at a predetermined period T is shown. A counter starts counting the number of samplings.

Subsequently, after a certain period of time has passed from the state shown in FIG. 5a, as shown in FIG. 5b, the moving object M1 reaches the monitoring line B, and the width of the brightness change due to the moving object M1 on the monitoring line B becomes W=20 cm. When this is reached, the counter sets the number of times of data sampling starting from the time of passing the A line, for example, the value of N, as k=N1. That is, this k is the number of times of sampling from when the moving object M1 reaches the monitoring line A until it reaches the monitoring line B.

Therefore, the number of sampling times from when the moving object M1 reaches the monitoring line A until it reaches the monitoring line B.
Based on (k), calculate the passing speed (V) of the moving object using the following formula.

V=l/(k×T) [m/s] ...(1) where l is the line width Once the passing speed (V) of the moving object is determined in this way, the moving object to be measured In other words, if the size that serves as the criterion for determining a person is determined in advance, and for example, the chest width L of the person serving as the criterion is set to 19 cm, then the passing speed (V) obtained by the above equation (1) is Based on the predetermined chest width L = 19 cm for the person who is the reference moving object, the A-line passage time for each reference moving object.
(K) is found as K=L/V[sec]...(2).

Furthermore, since the mobile object M1 was just on the monitoring line A in FIG. 5a, that is, the monitoring line A is W=20.
cm or more until the next overlapping moving object M2 leaves the monitoring line A as shown in Fig. 5c, that is, when the monitoring line A becomes W = 20 cm or less. The number of samplings obtained is set as m=N2, and the number of people passing through (M) is determined based on this number of samplings (m) as M=(m×T)/K[people]...(3). That is, equation (3) shows that when the leading moving object M1 crosses the monitoring line A as shown in FIG. The number of people passing M is calculated by dividing the passing time (m x T) by the A line passing time (K) per unit moving object calculated using the above formula (2).
seek.

To judge the number of people passing through M given by this equation (3), for example, if the number of people passing through M satisfies the condition of 0≦M<1.5, it is determined that the number of people passing through M = 1 person, and the number of passing people M is , When the condition of 1.5≦M<2.5 is satisfied, it is determined that the number of people passing through is M=2.

Next, the configuration of the apparatus shown in FIG. 1 for realizing the discrimination and separation of the number of passing moving objects that overlap each other before and after the moving objects described based on FIG. 5 will be described.

First, 24 is a digital comparator, to which A line data is input at every predetermined sampling period T, and is compared with the minimum line width W for mobile body discrimination set by the reference voltage source 25. Therefore, the digital comparator 24 generates an H level output when the A line data changes in brightness by the minimum line width W set by the reference voltage source 25. The output of the digital comparator 24 is given to a counter 26 that counts sampling pulses.
is reset, and counting of sampling pulses starts from this reset. That is, as shown in FIG. 5a, the counter 26 starts counting sampling pulses from when the moving body M1 has just arrived at the monitoring line A and the minimum line width W of luminance change reaches, for example, W=20 cm.

On the other hand, B line data is given to the digital comparator 27, and like the digital comparator 24, the minimum line width W for determining whether a person passes through the line is set to the digital comparator 27 by the reference voltage source 25. Figure 5b
As shown in FIG. 3, when the width of the brightness change of the B line data exceeds the minimum line width W, an H level output is generated. Furthermore, the A line data is given to the digital comparator 28, and the minimum line width W for determining whether a person is passing is set in the digital comparator 28 by the reference voltage source 25. When the width of the luminance change due to the moving object becomes less than the minimum line width W as shown in FIG. 5c, an H level output is generated.

That is, the digital comparator 24 detects the state in which the moving object M1 approaches the A line as shown in FIG.
The digital comparator 28 detects that the moving object M1 is approaching the monitoring line B as shown in FIG. Detects the state that has occurred.

The count output of the counter 26 is the latch circuit 29, 3
In the above example, the latch circuit 29 latches the count output N1 of the counter 26 with the H level output of the digital comparator 27 as N1=k, while the latch circuit 30 latches the H level output of the digital comparator 28. The count output N2 of the counter 26 is latched as N2=m using the level output. That is,
As shown in FIGS. 5a and 5b, the latch circuit 29 latches the number of sampling times (k) from the moment when the moving object is on the monitoring line A until it reaches the monitoring line B. The number of sampling times (m) from when the moving object arrives until it leaves the monitoring line A is latched.

The output of the latch circuit 29 is given to a speed calculating section 31, and the speed calculating section 31 calculates the passing speed (V) according to the above-mentioned (1). For this speed calculation, the line width (l) and sampling period (T) are set as constants. The output of the speed calculating section 31 is given to the passing time calculating section 32, and the passing time calculating section 32 calculates the A line passing time (K) per person of the reference moving body using the above-mentioned equation (2). Body chest width (L)
is set as a constant.

The output of the transit time calculation unit 32 is given to the number of people calculation unit 33, and the number of people calculation unit 33 calculates the number of sampling times (m) latched in the latch circuit 30, the passage time (K) from the passage time calculation unit 32, and the sampling period ( The number of people M passing through is calculated by executing the calculation of the above equation (3) based on T) and the constant. The output of the number of people calculation unit 33 is given to the number of people determination unit 34, and the number of people determined by the number of people determination unit 34 is as follows: When 0≦M<1.5, M=1 [person] When 1.5≦M<2.5, M=2 [Person] When 2.5≦M<3.5, M=3 [Person] and finally determine the number of people passing through.

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to the flowchart shown in FIG. Now, as shown in FIG.
A line data and B line data are read in with a predetermined sampling period T, and in the next judgment block 42 it is checked whether the A line data is equal to or larger than the minimum line width W for identifying a moving object. .

As shown in FIG. 5a, when the leading moving object M1 is on the A line and the width of the brightness change of the A line data exceeds the minimum line width W, the process proceeds to block 44 where the count number of the counter representing the number of samplings is counted. Increment N. Next, block
At step 46, data sampling is performed in the next sampling period, and at decision block 48, it is checked whether the B line data exceeds the minimum line width W.

After repeating the predetermined data sampling, as shown in FIG.
If the count value of the counter at this time is, for example, the value of N1, then proceed to block 50, and if the count number of the counter at this time is the value of N1, k
= set to N1. Next, in block 52, the passing speed (V) is calculated based on the above equation (1), and the process further proceeds to block 54, where the A line passing time (K) for each reference moving body is calculated based on the above equation (2). Find it using the formula.

Next, in block 56, the counter is incremented as the number of samplings progresses, and then in block 58, the A and B line data are sampled in the next sampling period, and in judgment block 60, the A line data becomes less than or equal to the minimum line width W. Check whether or not. When the A-line data becomes less than the minimum line width W after a predetermined sampling number has elapsed, that is, when the moving object M2 passes through the A-line as shown in FIG. m as shown
=N2, and in block 64, the number of people passing through M is calculated based on the above equation (3).

Once the number of people passing through (M) is calculated in block 64,
In the next judgment block 66, it is checked whether the number of passing persons (M) is greater than or equal to 0 and less than 1.5. If this condition is satisfied, the process proceeds to block 62, where the number of passing persons is set as M=1, and in block 70. The count number N is reset to N=0 and the process returns to block 40 again.

On the other hand, if the number of people passing (M) calculated in block 64 does not satisfy the condition of decision block 66, the process proceeds to decision block 72, where it is checked whether the number of people passing (M) is 1.5 or more and less than 2.5, and the condition is checked. If this is satisfied, the number of people passing through is determined to be M=2 in block 74, and the process returns to block 40 via block 70.
If the condition of the determination block 66 is not satisfied, for example, it is checked whether the number of people passing through M is 2.5 or more and less than 3.5, and if this condition is satisfied, it is determined that M=3 people. Therefore, sufficient discrimination processing can be performed even if there are two or more people in front and behind each other.

FIG. 7 is a flowchart showing another embodiment of the determination process performed by the arithmetic processing unit 16 of FIG. 2 when a plurality of moving objects pass one behind the other. The principle of the discrimination process shown in the flowchart of FIG. 7 will be explained with reference to FIG. 8 as follows.

FIG. 8a shows a state in which moving bodies M1 and M2, which are overlapped one behind the other, are approaching the monitoring line A.
When the minimum line width of the brightness change in the monitoring line A of the moving body M1 reaches W, counting of the number of samplings of the A and B line data is started. Subsequently, after a predetermined number of samplings, as shown in FIG. 8b, the first moving object M1 approaches the monitoring line B, that is, the width of the brightness change of the monitoring line B by the moving object M1 is the minimum line width. If it is detected that W has been exceeded and the number of samplings from Figure 8a to Figure 8b is (k), then V=l/(k×T)[m/s]...(4) The velocity (V) of the body can be determined.

If the passing speed (V) of the moving object is determined in this way, since the chest width (L) of the person serving as the reference moving object is predetermined, for example, L = 20 cm, the chest width (L)
The passage time (K) required for a person (reference moving object) to pass through the monitoring line A is calculated as K=L/V [sec] (5).

If we can obtain the transit time (K) between monitoring lines A for one mobile object with chest width (L) in this way, then
The number of sampling times (m) from when the moving object M1 reaches line A shown in Figure 8 until the moving object M2, which is overlapped behind it, passes through the monitoring line B as shown in Fig. 8c.
From, M=(m-k)T/K[person]...(6) Find the number of people passing through (M).

Of course, since the number of people (M) calculated by the above formula (6) includes numbers below the decimal point, it depends on whether the following conditions are satisfied: 0≦M<1.5 1.5≦M<2.5 2.5≦M<3.5 1 person passed by,
It is determined that there are two people, three people, etc.

Therefore, the process of determining the number of people will be specifically explained based on the flowchart of FIG. 7 as follows.

First, the calculation of the passing speed (V) from block 40 to block 58 is the same as in the flowchart of FIG. In other words, as shown in FIG. 8c, the moving body M2 overlapped behind
is checking whether or not it passes through the B line.
When the line is passed, the value of the count number N at that time is set as m=N3 in block 68, and the block
At 80, the number of people (M) is calculated from the above equation (6). Determination block 66 after calculating the number of people (M) in block 80
The subsequent processing is also the same as the flowchart in FIG.

Further, as a block configuration for implementing the flowchart in FIG. 7, the digital comparator 28 in FIG. 1 is configured to generate an H level output when the B line data becomes less than the minimum line width, and The output k of the latch circuit 29 may be input as an input to the number of people calculating section 33.

In addition, although the above-mentioned embodiment took as an example the passing of a person as a moving body, the present invention is not limited to this, and can also detect the amount of passing vehicles and luggage.
In this case, the distance between the two monitoring lines A and B may be set to an appropriate value based on the size and moving speed of the moving object.

Furthermore, in the above embodiment, the moving object is configured to be monitored from above in the moving direction.
A line light source may be installed on the ceiling and monitored from below.

(Effects of the Invention) As described above, according to the present invention, a change in brightness due to the passage of a moving object on a monitoring surface equipped with two monitoring lines is detected by a storage type photodetector, and the storage type photodetector Calculate the passing speed (V) of the moving object from the light reception information of the device, and calculate the monitoring surface passing time (K) for each reference moving object with a predetermined size from the passing speed (V).
The moving object's passing time on the monitoring surface actually obtained from the light reception information and the passing time per reference moving object (K)
Since the number of moving objects passing is calculated based on the , it is possible to accurately determine the number of passes.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a schematic block diagram showing the overall configuration of the present invention, and FIG. 3 is an explanatory diagram showing the structure of a CCD line sensor used in the present invention. , FIG. 4 is a plan view of the monitoring surface, FIG. 5 is an explanatory diagram showing a state in which two moving objects overlap one another and pass through the monitoring surface, and FIG. 6 shows the number of people according to the embodiment of FIG. 1. FIG. 7 is a flowchart showing the discrimination process; FIG. 7 is a flowchart showing another number of people discrimination process according to the present invention; FIG. be. 1, 2: CCD sensor, 3a to 3n: light receiving pixel,
4: Monitoring surface, 5: Reflecting mirror, 6: Condensing lens,
7: Half mirror, 8: CCD drive circuit, 9a,
9b: A/D converter, 10: Multiplexer, 1
1: Background processing circuit, 12a, 12b: RAM, 1
3, 15: Gate circuit, 14a, 14b: Buffer memory, 16: Arithmetic circuit, 17: Display, 1
8: Light source installation groove, 20: Fluorescent lamp, 22: Transparent window,
24, 27, 28: Digital comparator, 2
5: constant voltage source, 26: counter, 29, 30: latch circuit, 31: speed calculation section, 32: passing time calculation section, 33: number of people calculation section, 34: number of people determination section.

Claims (1)

[Scope of Claims] 1. A storage type photodetector comprising a plurality of light-receiving pixels arranged in series to detect changes in the brightness of the monitoring lines caused by a moving body passing over a monitoring surface in which two monitoring lines are arranged in parallel at a predetermined interval. A moving object amount measuring device that receives light from the storage type photodetector and measures the number of moving objects based on the received light information, comprising: a speed calculation means that calculates a passing speed of the moving object based on the light reception information of the storage type photodetector; a transit time calculation means for calculating the passage time per reference moving object having a predetermined size based on the passing speed determined by the speed calculation means; and a moving object obtained from the light reception information of the storage type photodetector. and a passage number calculation means for calculating the number of passages of moving bodies that have passed at one time based on the actual passage time of the vehicle and the reference passage time per one moving body determined by the passage time calculation means. A mobile body mass measuring device.