JPS63298065A - Speed measuring instrument for body - Google Patents

Abstract

PURPOSE:To find the moving distance and moving speed of a body and to measure the body which moves in three dimensional direction by irradiating the body which moves in space with flash light of different colors at specific time intervals, picking up images of the body by an image pickup device, and finding the moving direction from variation of colors in the images of the moving body. CONSTITUTION:When particles which flow in a duct 6 made of a transparent acryl or vinyl plate as shown by an arrow 7 are measured, slit light 5 from a light source 1 which is controlled by a power source 2 for the light source is projected on the particles in the duct 6. The movement of the particles in the duct 6 is picked up by a video camera 3 and the picked-up image is inputted to a computer 4. Light beams from lamps 10 and 11 of this light source 1 are passed through red and blue filters 14 and 15 for color separation and made into parallel light through cylindrical lenses 12 and 13, and the color is changed through a half-mirror 16. Then a computer 4 calculates the moving direction, distance, and speed from the movement of the particles which are displayed in red or black in the image.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a speed measuring device for an object moving in space.
In particular, the present invention relates to a velocity 11J device suitable for measuring multiple objects moving at high speed in space.

[Conventional technology]

In boiler equipment that uses pulverized coal as fuel, the coal pulverizer used in the boiler measures the concentration, particle size, speed, etc. of pulverized coal in the equipment in order to understand the performance of the pulverized coal burner. is essential.

For these measurements, there are two methods: one is to collect fine powder from a specific area within the target device and analyze it, and the other is to directly capture the powder with a measuring device.

The former method is often used to measure concentration and particle size, but the latter method is the only method available for speed measurement.

Laser Doppler velocimeters (hereinafter abbreviated as D and V) are well-known as devices for measuring the velocity of particles. L, D,
V is used to calculate the velocity using a Doppler signal emitted when a particle passes through the focal position of a laser beam. Since laser light has very high precision, this method allows speed measurements to be made with higher precision than other speedometers.

However, in L, D, and V, only the velocity of the focal point can be measured, so in order to obtain the velocity distribution of the entire target space, the entire space must be traced.

Therefore, a huge amount of time is spent on measurements. Also,
It cannot be applied when the speed distribution changes over time, such as when starting and stopping a boiler.

Therefore, measurement using images has recently become widespread as a method for determining the velocity distribution all at once. A specific example of this is shown in FIG. Figure 15 shows a buoy 53 floating on the surface of a water stream 52.
In this system, the movement of each buoy is photographed by a camera 50, and the speed of each buoy is calculated by dividing the distance traveled by the exposure time. In FIG. 15, the illumination is a continuous light lamp 51.
This is achieved by a lamp 10 that flashes at the same time the camera shutter opens, and a lamp 11 that flashes just before the camera shutter closes. At this time, a red filter 14 is placed in front of the lamp 10, and a blue filter 15 is placed in front of the lamp 11. An example photographed by this camera is shown in FIG. In FIG. 16, the oval image is the trail of the buoy that moved during the exposure time of the camera, the black circle mark is the starting point of the red color, and the white circle mark is the end point of the blue color. Divide the distance traveled from each starting point to the ending point by the exposure time to find the moving speed of the buoy.

In this example, a photo taken with a camera is developed, then imported into a computer and processed for image processing speed, which takes time.

The example shown in FIG. 17 solves this problem. In FIG. 17, a video camera 3 is used instead of the camera in FIG. 15, and the light is illuminated with only continuous light 51, and the image is directly captured into the computer 4. This image is shown in FIG. 18, which shows the images in the first and second frames of the video superimposed. Each buoy image appears as an oblong trail due to the video exposure time of 1/60 seconds. The velocity is calculated by determining the distance that the center of gravity of this trajectory has moved.

[Problem that the invention seeks to solve]

The two examples described above are the latest technologies, but both are applicable to very slow water flows of less than 1 m/s.

In order to handle objects with higher speeds than this, in the example shown in FIG.
,000 or so. Further, in the example shown in FIG. 17, there are problems such as the need to increase the intensity of the continuous light lamp 51 in the same way and the number of video frames to be taken to about 1/1o, ooo.

Increasing the intensity of the lamp is not impossible, but requires larger equipment, and combustible materials such as coal particles moving through the air pose a fire hazard.

On the other hand, it is currently almost impossible to increase the shutter speed of a camera or the number of frames of a video.

As mentioned above, it is impossible to measure the speed of multiple high-speed objects using the current speed needle.

[Problem that the invention seeks to solve]

As described above, speed measuring devices that measure the speed of objects using images are limited by the illuminance of the lighting device and the exposure time and number of frames of the image input device. There was a problem that measurements could not be taken quickly.

An object of the present invention is to provide a speed measuring device that eliminates the above-mentioned drawbacks and can measure speed simply and quickly.

[Means for solving problems]

The present invention has been made to solve the above problems, and is a device for measuring the speed of an object moving in space, which illuminates the object by emitting flashes of different colors at predetermined time intervals. , a device for photographing an illuminated object, a device that captures an image of the object photographed by the device, determines the direction of movement of the object from changes in color as it moves within the image, and determines the distance of movement from changes in the position of the object; The present invention further provides an object speed measuring device, further comprising an image processing device that calculates the moving speed of the object based on the flash time interval of the illumination device and the moving distance.

〔Example〕

FIG. 1 shows the overall configuration of an embodiment in which particles flowing in a duct 6 in a direction 7 are measured. 1 is a light source, 2 is a power source for the light source, 3 is a video camera, and 4 is a computer.

The duct 6 is made of transparent acrylic or vinyl board. Particles in the duct are irradiated with slit light 5 from a light source 1 to provide tomographic illumination. This is video camera 3
The image is photographed using a computer 4 and analyzed using a computer 4.

FIG. 2 shows the internal structure of the light source 1. The light emitted from the rod-shaped lamps 10 and 11 passes through a red filter 14 and a blue filter 15, respectively, and is color-coded. Thereafter, the light passes through cylindrical lenses 12 and 13, respectively, and becomes parallel light. These parallel lights each pass through a half mirror 16 and illuminate the same cross section.

FIG. 3 shows an embodiment of the electrical system of the present invention. A video signal from the video camera 3 enters the computer 4 and the synchronization signal generator 20. The synchronization signal generator extracts only synchronization signals corresponding to the number of frames from a video signal of 60 frames per second. This enters the light source power supply 2 and causes the lamp 10 to emit light. Therefore, first, red slit light is irradiated. Next, the synchronization signal enters the delay circuit 21, is delayed by a minute time, and then enters the light source power supply 2, causing the lamp 11 to emit light.

In other words, blue slit light is irradiated.

This light emission is repeated for each frame of the video.

Figure 4 shows an image of particles reflected in one frame. Black circle marks are red, and white circle marks are blue. First, the red slit light shines, and then the blue light shines, so the black circle mark is the starting point and the white circle mark is the ending point. Therefore, by finding the moving distance of each particle and dividing it by the delay time of the light source, the velocity vector of each particle can be calculated. This calculation can be performed manually when the number of particles is small, but when the number of particles is large, it is performed by a computer.

In addition, in this example, since the number of particles is small and the distance traveled is small, the correspondence between the starting point and the ending point of each particle is performed based on the logic that ``those that are the shortest distance from each other are the starting point and ending point of the same particle.'' ing.

Another embodiment is shown in FIG. In FIG. 5, a rotating mirror 30 is provided in place of the half mirror 16 in FIG. 2. A disk 31 shown in FIG. 6 is attached to the same axis as the rotating mirror 30, and the rotating mirror is connected to the slit light at an angle of Oo, 45°.
When the position is reached, the reflecting plates 32 and 33 reflect the light from the lamp 34 onto the photodiode 36. The light reception signal of the photodiode is input to the power supply 2 through a cable 37, and each lamp is caused to emit light. In this example, since no half mirror is used, there is little reduction in the amount of light and the efficiency is high.

The example shown in FIG. 7 uses one lamp 10 and a rotating double-sided reflecting mirror 40. The double-sided reflector 40 connects the slit light to 45° and 45°+180”
The lamp will light up when this happens. Note that red and blue filters 14 and 15 are attached to the surface of the double-sided reflective mirror. In this case, it can be made extremely inexpensively. However, since the light is emitted at minute intervals, the amount of charge to the capacitor in the power supply cannot keep up, and the amount of light decreases.

The example in Figure 8 uses three lamps 10, 11, 110,
The light is fired three times in one frame. Red 14, blue 15, and yellow 114 are used as filters. 12.
13 and 112 are cylindrical lenses, and 30 is a rotating mirror. An example photographed with this device is shown in Fig. 1O. In FIG. 10, black circles represent red, white circles with dots represent blue, and white circles represent yellow. In other words, they are the starting point, intermediate point, and ending point, respectively. In this case, the emission interval between the red and blue colors is so small that they almost overlap, and this is used to find the end point corresponding to each particle. Although the intermediate points are omitted in FIG. 9, it is difficult to correlate the starting point and the ending point when the movement of the particles becomes complicated. Therefore, by utilizing the fact that the end point is on the extension line of the starting point and the intermediate point as shown in FIG. 10, the correspondence can be easily established.

FIG. 11 shows a system in which two mirrors are stacked on top of each other without using a half mirror, and although the field of view is limited, it is characterized by its ease of construction.

FIG. 12 shows a case in which color is not used and monochrome is used. In this case, the emission intensity is gradually lowered as shown in FIG. The starting point, intermediate point, and ending point can be determined from the brightness of the image.

In FIG. 13, the horizontal axis shows the time at which light was emitted within one frame, and the light emission intensity obtained by dividing by the light emission intensity of one frame for gentle and long sleeves is made dimensionless.

In FIG. 14, color filters 41, 42, and 43 of different colors are inserted at the exit portion of the slit light to form three layers of the slit light. When using slit light, only velocity components parallel to the slit light can be detected, but by using three layers, components perpendicular to the slit light can also be detected.

〔Effect of the invention〕

According to the present invention, it is possible to quickly and easily measure the moving direction and moving speed of an object that moves three-dimensionally at high speed.

[Brief explanation of drawings]

1 is an overall configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the internal structure of the light source in FIG. 1, FIG. 3 is a diagram showing the electric circuit in FIG. 1, and FIG. 5 is a plan view of a light source in another embodiment of the present invention, FIG. 6 is a supplementary explanatory diagram of FIG. 5, and FIGS. 7 and 8 are , FIGS. 9 and 10 are images taken with the apparatus of FIG. 8, and FIGS. 11 and 12 are diagrams showing other embodiments of the present invention.
The figure is a plan view showing another embodiment of the present invention, and FIG.
12 is a supplementary explanatory diagram, FIG. 14 is a plan view showing another embodiment of the present invention, FIGS. 15 and 17 are views showing a conventional example, and FIGS. 18 is a diagram showing an image taken with the camera of FIG. 17. FIG. 1... Light source, 2... Power source for light source, 3... Video camera, 4... Computer, 5... Slit light, 6
···duct. Agent Patent Attorney Takeshi Kawakita Cho 5 Nisritsuto Hikari 6: Duct Figure 5 Figure 6 Figure 8 Figure 9 Figure 10 Period (exit) '3

Claims (1)

[Claims] A device for measuring the speed of an object moving in space, which includes a device that illuminates the object by emitting flashes of different colors at predetermined time intervals, a device that photographs the illuminated object, and a device that photographs the illuminated object. An image of an object is captured, the direction of movement of the object is determined from changes in the color of the object moving within the image, the distance of movement is determined from changes in the position of the object, and the distance of movement of the object is determined based on the flash time interval of the illumination device and the distance of movement. 1. A speed measuring device for an object, comprising: an image processing device for determining a moving speed.