JP4191428B2 - Camera type three-dimensional measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera-type three-dimensional measurement apparatus, and more particularly to a camera-type three-dimensional measurement apparatus capable of measuring the shape of a measurement object in a non-contact manner without attaching a reflective target to the measurement object.
[0002]
[Prior art]
Conventionally, in measurement using a CCD type three-dimensional measuring apparatus using a digital camera, a digital video camera, or the like, it is easy to measure an end of a measurement object.
However, when there is no feature point inside the measurement object, for example, when measuring a smooth material such as a plate material, a reflective target is generally attached to the measurement object as a substitute for the feature point before measurement. Thus, the work of attaching the target to the measurement object must be performed.
Then, after this mounting operation, the target is photographed and measured, and the operation of removing the target from the measurement object is performed again.
[0003]
[Problems to be solved by the invention]
However, the above-described three-dimensional measurement has a problem that it takes time and labor to attach and remove the target.
In addition, when the material of the measurement object is a glossy material such as aluminum, it is difficult to distinguish the target and the measurement object, and there is a problem that a characteristic point to be measured cannot be obtained even if the target is attached.
[0004]
Accordingly, the present invention has been made to solve the problems of the prior art, and the three-dimensional camera system in which the material of the measurement object is glossy such as aluminum and is difficult to measure with a normal reflective target. In measurement, a camera system that can form a target by irradiating a light beam of a specific wavelength, such as infrared rays, onto the measurement object, and measure the shape of the measurement object in a non-contact manner by measuring this target. The object is to provide a three-dimensional measuring apparatus.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a first invention of the present invention is a camera-based three-dimensional measurement apparatus that measures a measurement object in a non-contact manner, and irradiates a light beam in a predetermined wavelength range on the measurement object. A light source for forming the target, and an imaging means for imaging the measurement object irradiated with normal light and performing multiple exposure imaging of the target using a filter element that transmits only light having a wavelength in the predetermined wavelength range, It is characterized by having an image processing means for processing a multiple exposure image photographed using this photographing means into a stereoscopic image, and a measuring means for measuring a stereoscopic image obtained by this image processing means.
[0006]
In the first invention of the present invention configured as described above, the light source irradiates the measurement target with a light beam to form a target.
For this reason, a target can be easily made in a non-contact manner without attaching a reflective target on the measurement object, and the measurement setup work can be reduced. Further, even if the material of the measurement object is glossy such as aluminum and it is difficult to identify the feature points with a reflective target, it can be easily measured by irradiating the target.
In the present invention, the target is imaged by an imaging means using a filter element that transmits only a light beam having a specific wavelength. For this reason, the output of the light source can be suppressed, the target can be recognized more accurately, and the restrictions on the photographing conditions can be reduced.
[0007]
In the present invention, preferably, the filter element is arranged so that it can be selectively switched between the measurement object and the photographing means.
In the present invention, the light beam having a predetermined wavelength range is preferably infrared.
In the present invention, preferably, the imaging unit images the measurement object and the target irradiated on the measurement object from the light source at least at two different locations .
[0008]
A second invention of the present invention is a camera-based three-dimensional measurement method for measuring a measurement object in a non-contact manner, wherein a target is formed by irradiating a light beam in a predetermined wavelength range from a light source onto the measurement object. When a step of multiple exposure shooting targets with a filter element which transmits only light having a wavelength in a predetermined wavelength range with the normal light shooting illuminated measurement object, the multiple exposure images shooting A camera-based three-dimensional measurement method comprising: a step of performing image processing to form a stereoscopic image; and a step of measuring the obtained stereoscopic image.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5.
FIG. 1 is a schematic diagram showing a first embodiment of a camera-type three-dimensional measuring apparatus according to the present invention. As shown in FIG. 1, reference numeral 1 denotes the camera-type three-dimensional measuring apparatus according to the present embodiment, and this camera-type three-dimensional measuring apparatus 1 is a CCD camera such as a digital camera or a digital video camera for photographing a measurement object 2. 4 and an infrared slit light source device 8 that forms the target 6 by irradiating the measurement object 2 with infrared rays 20.
Further, the CCD camera 4 shown in FIG. 1 includes a CCD unit 10 which is a main part of the camera 4, a lens 12, a shutter 14 for adjusting the exposure of the lens 12, and a gap between the lens 12 and the shutter 14. And a band-pass filter 16 that can be appropriately inserted on the optical path.
[0010]
The bandpass filter 16 has a filter characteristic that transmits only infrared rays having a specific wavelength.
Here, FIG. 2 shows an example of filter characteristics of a band-pass filter that transmits only infrared rays having a specific wavelength. The vertical axis in FIG. 2 indicates the transmittance of the bandpass filter, and the horizontal axis in FIG. 2 indicates the wavelength of the light beam.
The filter characteristic of the bandpass filter 16 as shown in FIG. 2 preferably has a characteristic of transmitting only infrared rays having the same wavelength as the infrared rays 20 irradiated to the measurement object 2 from the infrared slit light source device 8. Good.
[0011]
Next, FIG. 3 is an enlarged perspective view showing the infrared slit light source device in the three-dimensional measuring apparatus of the present embodiment.
As shown in FIG. 3, the infrared slit light source device 8 includes an infrared light emitting diode 18 which is a main part of the device, a condensing reflection plate 22 that collects and reflects infrared light 20 generated from the infrared light emitting diode 18, and these A lens 24 that refracts and transmits the infrared ray 20 generated from the light emitting diode 18 and the infrared ray 20 reflected by the converging reflector 12 toward a predetermined position of the measurement object 2, and the infrared ray 20 transmitted through the lens 24 is slit. And a slit plate 28 including a slit 26 to be a light beam.
[0012]
Next, the operation (operation) of the first embodiment of the present invention will be described.
First, infrared rays 20 are output from the infrared light emitting diodes 18 of the infrared slit light source device 8. The output infrared ray 20 passes through the lens 24, passes through the slit 26, and is irradiated on the surface of the measurement object 2.
The irradiated infrared rays 20 form a plurality of dot sequences of infrared rays 20 on the measurement object 2. In addition, the dot sequence of the infrared rays 20 forms the spot-shaped target 6 or the mesh-shaped target 6 on the measurement object 2 according to the shape of the slit 26.
[0013]
Thus, after the infrared slit 20 is irradiated from the infrared slit light source device 8 to the measurement object 2 and the infrared target 6 is formed, the measurement object 2 is photographed by the CCD camera 4. Hereinafter, photographing of the measurement object 2 will be described with reference to FIG.
FIG. 4 is a schematic diagram showing an image obtained by photographing the measurement object.
In photographing the measurement object 2, first, photographing with normal light 30 such as sunlight (shown in FIG. 1) is performed without inserting the bandpass filter 16 between the lens 12 and the shutter 14 in the CCD camera 4. .
As shown in FIG. 4, the image 32 photographed with the normal light 30 (see FIG. 1) is an image that can recognize the entire shape including the end of the measurement target 2 and the like. The image 30 is an image in which some infrared rays of normal light are captured, but the infrared target is hardly recognized because of being influenced by disturbance light.
[0014]
Next, between the lens 12 and the shutter 14 in the CCD camera 4, a band-pass filter 16 that transmits only infrared rays having the same wavelength as the infrared rays 20 irradiated from the infrared slit light source device 8 to the measurement object 2 is inserted. Then, the measurement object 2 is imaged with infrared light.
As shown in FIG. 4, the image 34 obtained by infrared light is an image that can recognize only the infrared target 6 irradiated on the measurement object 2. The bandpass filter 16 has a filter characteristic as shown in FIG. 2 and transmits only the infrared ray having the same wavelength as the infrared ray 20 irradiated to the measurement object 2 from the infrared slit light source device 8. Only infrared rays having the same wavelength as that of the infrared rays 20 irradiated to the measurement object 2 are captured. For this reason, only the infrared target 6 can be clearly recognized without being affected by disturbance light.
Note that the insertion of the bandpass filter 16 on the optical path may be interlocked with the operation of the shutter 14 of the CCD camera 4 when the measurement object 2 is photographed.
[0015]
Here, the two images of the captured image 32 by the normal light and the captured image 34 by the infrared light captured as described above are actually combined into one image by multiple exposure. That is, finally, an image 36 by one multiple exposure in which the measurement object 2 and the target 6 overlap is obtained.
In order to make the image 36 a better image, it is preferable to correct the focus of the two images 32 and 34 as necessary.
[0016]
Next, imaging of the image 36 by such multiple exposure is performed at a plurality of imaging positions where the position of the CCD camera 4 is changed, and at least two images 36 with different angles are prepared for the same subject.
Furthermore, by performing a stereo viewing process (details will be described later) on the plurality of captured images 36, the image 36 is converted into a stereoscopic image, and three-dimensional measurement is performed on the stereoscopic image.
[0017]
Here, the principle of the above-described stereo vision processing of the captured image 36 will be described with reference to FIG.
FIG. 5 is a schematic diagram showing the principle of stereo vision processing, and shows a state where one camera 4 is photographing the measurement object 2 and the target 6 from two positions as an example.
Stereo vision processing is based on the principle of triangulation. In this principle of triangulation, first, as shown in FIG. 5, processing for obtaining the photographing position and photographing direction of the camera 4 from three-dimensional orthogonal coordinates is performed. . That is, by this process, three angles of the three coordinates of the position of the camera 4 and the shooting direction of the camera 4 are obtained for one image, and the shooting positions of the two cameras and the collimation angles of the cameras are determined.
[0018]
Next, collimation lines 38a, 38b, 38c and collimation lines 40a, 40b, 40c from two positions of the camera 4 toward the target 6 are determined, and these collimation lines 38a, 38b, 38c and collimation lines are determined. Intersection points with 40a, 40b and 40c are obtained. Here, since the intersection of these collimation lines is actually at the position of the target 6, if the coordinates of this intersection are determined, the coordinate value of the target is determined.
In this way, the three-dimensional measurement of the shape of the measurement object 6 can be performed by calculating the coordinate values of all the targets to be measured.
[0019]
According to the above-described camera-type three-dimensional measurement apparatus of the first embodiment of the present invention, a target can be easily created in a non-contact manner using infrared light without attaching a reflective target on the measurement object. Can do. For this reason, even if the material of the measurement object is glossy such as aluminum and it is difficult to identify the characteristic points with the reflective target, the measurement object can be easily measured by irradiating the measurement object.
In addition, since the camera-type three-dimensional measurement apparatus of the present embodiment uses a bandpass filter that transmits only light in the infrared wavelength range irradiated on the target, the influence of disturbance light during shooting is suppressed, and the light source The output can be suppressed. For this reason, it is possible to recognize the target more accurately even under normal light rays, and it is possible to reduce the restrictions on imaging conditions.
Furthermore, since the camera-type three-dimensional measuring apparatus of the present embodiment can suppress the output of the light source as described above, even if infrared laser light or the like is used as the light source, the output of the light source can be suppressed safely. Can be used.
In addition, since the camera-type three-dimensional measuring apparatus of the present embodiment uses a commercially available digital camera or digital video camera and a commercially available infrared light emitting diode, it is simple and low-cost.
[0020]
In the camera-type three-dimensional apparatus of this embodiment, an example using a bandpass filter has been described as an example. However, the present invention is not limited to a bandpass filter, and a sharp cut filter that attenuates light having a wavelength smaller than that of infrared rays. Other filters such as may be used. As a result, as in the case of the bandpass filter, normal light and infrared light image capturing can be performed while suppressing the influence of disturbance light by appropriately switching the filter during image capturing.
[0021]
In the present embodiment, an example using a CCD camera such as a digital camera or a digital video camera as a means for capturing a normal light image and an infrared light image is shown, but the present invention is not limited to these cameras. Stereo vision processing may be performed on an image obtained by photographing a measurement object using an infrared camera or a film-type photo camera.
When using an infrared camera, use an infrared filter that does not transmit infrared light instead of the bandpass filter described above, and when taking a normal light image, attach an infrared filter on the optical path of the camera, and When taking an image, the filter is switched so that the infrared filter is removed from the optical path of the camera.
Furthermore, in the present embodiment, it has been described that a single camera switches a filter while shooting at a plurality of different locations and obtains a stereoscopic image from these captured images. However, a single camera has a plurality of different locations. Instead of photographing from the above, a single camera may be installed and photographed for each of a plurality of different photographing locations, and a stereoscopic image may be obtained by performing stereo viewing processing on these photographed images.
[0022]
Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 6 is a schematic view showing a second embodiment of the camera type three-dimensional measuring apparatus according to the present invention.
Here, in FIG. 6, the same parts as those of the first embodiment shown in FIG.
As shown in FIG. 6, reference numeral 50 denotes the camera-type three-dimensional measurement apparatus according to the present embodiment. The camera-type three-dimensional measurement apparatus 50 is a digital camera or digital video camera that photographs the measurement object 2 with normal light. And a CCD camera for infrared light such as a digital camera or a digital video camera for photographing the infrared target 6 irradiated on the measurement object 2 with infrared light. .
[0023]
Next, the operation (operation) of the second embodiment of the present invention will be described.
First, one of the normal light CCD camera 52 and the infrared light CCD camera 54 is set to the photographing position.
For example, first, the normal light CCD camera 52 is set at the shooting position, and the normal light CCD camera 52 is used to shoot the whole image of the measurement object 2 with normal light.
After photographing with the normal light, an infrared light CCD camera 54 is installed at the same position as the photographing position of the normal light CCD camera 52, and the infrared light CCD camera 54 is used to infra-red the measurement object 2. The target 6 is imaged with infrared light.
[0024]
Next, image processing is performed so that the captured image 32 using normal light (see FIG. 4) and the captured image 34 using infrared light (see FIG. 4) obtained in this way are combined into a single image. An image 36 (see FIG. 4) in which the infrared target 6 overlaps the object 2 is obtained.
In this manner, normal light and infrared light are photographed at the same photographing positions of the normal light CCD camera 52 and the infrared light CCD camera 54 at a plurality of photographing positions, and the angles of the same subject are changed. At least two images 36 are prepared.
Further, similarly to the stereo vision processing in the first embodiment, a stereo image is created by stereo vision from the obtained images 36, and the shape of the measurement object of this stereo image is measured three-dimensionally.
[0025]
In the second embodiment of the present invention, the positions of the two cameras are set to the same position and the same subject is photographed. However, as a modification of the present embodiment, the normal light CCD camera 52 and the infrared light are used. The measurement object 2 may be photographed by shifting the positions of the two cameras of the CCD camera 54 for use.
In this case, the characteristics relating to the difference in camera position and the difference between the two images when a certain common reference point is photographed from different positions by the two cameras are examined in advance. When the normal light photographed image 32 and the infrared light photographed image 34 are actually synthesized, the positional information of the normal light CCD camera 52 and the infrared light CCD camera 54 and the above-described characteristics relating to the image shift. Then, correction such as coordinate conversion is performed on at least one of the normal light image 32 and the infrared light image 34 to synthesize the images 32 and 34.
[0026]
According to the camera-type three-dimensional measurement apparatus of the second embodiment of the present invention described above, unlike the three-dimensional measurement apparatus of the first embodiment of the present invention, normal light imaging of a measurement object without switching the camera filter. Infrared light photography can be performed simultaneously with two cameras, so that work efficiency can be improved.
In the three-dimensional measuring apparatus of the present embodiment, an example in which one CCD camera for normal light and one CCD camera for infrared light are used is described as an example. However, the number of these cameras is limited. Alternatively, the measurement object may be photographed simultaneously by two or more units.
[0027]
【The invention's effect】
As described above, according to the camera-type three-dimensional measurement apparatus of the present invention, it is possible to irradiate the measurement target with the infrared target while suppressing the output of the light source and suppressing the influence of disturbance light. Three-dimensional shape measurement can be easily performed without mounting.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a first embodiment of a camera-type three-dimensional measuring apparatus according to the present invention.
FIG. 2 shows an example of filter characteristics of a bandpass filter.
FIG. 3 is an enlarged perspective view showing an infrared slit light source device in the camera-type three-dimensional measuring apparatus according to the first embodiment of the present invention.
FIG. 4 is a schematic diagram showing an image obtained by photographing a measurement object.
FIG. 5 is a schematic diagram illustrating the principle of stereo vision processing.
FIG. 6 is a schematic view showing a second embodiment of the camera-type three-dimensional measuring apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,50 Camera type three-dimensional measuring device 2 Measurement object 4 CCD camera 6 Target 8 Infrared slit light source device 10 CCD part 12, 24 Lens 14 Shutter 16 Band pass filter 18 Infrared light emitting diode 20 Infrared 22 Condensing reflector 26 Slit 28 Slit plate 30 Normal light 32 Normal light captured image 34 Infrared light captured image 36 Multiple exposure captured images 38a, 38b, 38c, 40a, 40b, 40c Line of sight 52 CCD camera for normal light 54 CCD camera for infrared light

Claims (4)

A camera-type three-dimensional measuring device that measures a measurement object in a non-contact manner,
A light source that irradiates a measurement object with a light beam in a predetermined wavelength range and forms a discrete point sequence on the surface of the measurement object ;
Imaging means for imaging the measurement object irradiated with normal light and performing multiple exposure imaging of the target using a filter element that transmits only light having a wavelength in the predetermined wavelength range;
Using this photographing means, a plurality of multiple exposure images obtained by photographing the measurement object and the target irradiated on the measurement object from the light source at at least two different positions are subjected to image processing by a stereo image method. Image processing means for converting the image into a stereoscopic image;
Measuring means for measuring a stereoscopic image obtained by the image processing means;
A camera-type three-dimensional measuring apparatus characterized by comprising:   The camera-type three-dimensional measurement apparatus according to claim 1, wherein the filter element is arranged so as to be selectively switched between the measurement object and the photographing means.   The camera-type three-dimensional measuring apparatus according to claim 1, wherein the light beam in the predetermined wavelength range is an infrared ray. A camera-based three-dimensional measurement method for measuring a measurement object in a non-contact manner,
Irradiating a measurement object with a light beam in a predetermined wavelength range from a light source to form a target that forms a discrete point sequence on the surface of the measurement object ;
Photographing the measurement object irradiated with normal light in at least two different locations and performing multiple exposure photographing of the target using a filter element that transmits only light having a wavelength in the predetermined wavelength range; and
A process of processing a plurality of photographed multiple exposure images by a stereo image method to form a stereoscopic image;
A step of measuring the obtained stereoscopic image;
A camera-type three-dimensional measurement method characterized by comprising:

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