JP2006048667A - Personal authentication device, robot controller using the same, authentication method and robot control method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a personal authentication device, authentication method by a vein pattern with high authentication precision and which makes an authentication system of information distributed type in consideration of protection of personal information possible, a robot controller and control method applying the authentication method. <P>SOLUTION: In the authentication device 1, a vein image of a wrist is picked up by an image input part 11 consisting of a light source 22 and a camera 21. Next, a vein pattern extracted from the vein image of the wrist in an image processing part 12 and a vein pattern preliminarily stored in an information registration storage part 14 are collated in an authentication processing part 13. Thus, personal authentication is performed. In addition, the robot controller has the authentication device 1 and a robot. The robot starts a substantial operation when a collation result transmitted from the authentication device 1 to the robot is affirmative. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a personal authentication device using a vein pattern of a wrist, a robot control device using the device, an authentication method, and a robot control method using the device.

  Part of the body and the characteristics of behavior vary depending on the individual human being. Therefore, there is a technique for authenticating the person using this. For example, authentication techniques based on fingerprints, irises, voices, backs of hands and finger veins have been proposed. In these authentication techniques, biometric information of individuals registered in advance is centrally managed, the biometric information of the person to be authenticated is compared with the registered biometric information, and whether or not authentication is possible is determined. In this specification, such an authentication technique is referred to as a device-type authentication technique.

  However, these device-type authentication technologies require that the authentication device itself be equipped with a database that stores personal biometric information acquired in advance, or that the database and the authentication device be connected via a communication network. In addition, the user of the device type authentication system needs to spend enormous costs and labor in managing personal information.

  On the other hand, in order to save such complexity of information management, there has been proposed one that enhances security by providing a fingerprint detection function in an interface of a wristwatch or the like. However, with regard to authentication using fingerprints, it is necessary to collect fingerprints in advance, and there is a problem that psychological resistance among users is strong against this.

  The present invention has been made in view of such a situation, and intends to provide a personal authentication device and an authentication method using a vein pattern that enable an information distribution type authentication system in consideration of protection of personal information. is there. Another object of the present invention is to provide a personal authentication device and an authentication method with high authentication accuracy.

  A personal authentication device according to the present invention extracts a light source and a camera for photographing a vein image of a wrist, a storage unit that stores a vein pattern of the wrist in advance, and a vein pattern included in the photographed vein image. And an authentication processing unit for performing personal authentication by comparing the extracted vein pattern with the stored vein pattern.

  The device may be like a watch worn on the operator's body. Also. The device may be provided in a mobile phone.

  The light source is, for example, near infrared rays. The camera is, for example, a CCD camera.

  It is preferable that the camera and the light source are close to each other and face the same direction. Further, the camera and the light source may be configured so as to be located in a recess formed in the apparatus and not to protrude outside the recess. In this case, the camera and the light source can be prevented from coming into direct contact with the human skin.

  With respect to the vein image of the wrist photographed by the device, the image processing unit can correct the positional deviation and rotation caused by the wearing of the device and extract the vein pattern.

  The vein image of the wrist may be an arbitrary position such as the back side of the wrist or the palm side of the wrist. However, it is desirable that the position is substantially the same as the position where the stored vein pattern is acquired.

  The vein pattern stored in advance in the storage unit may be rewritable. The vein pattern to be stored may be limited to one person.

  The authentication result by the authentication device according to the present invention can be used for an external device that requires authentication. In this case, the authentication device can transmit the verification result instead of the biometric information itself to the external device. The external device can control the operation according to the collation result. Here, the external device is a device to be controlled, such as a robot or a door.

The personal authentication method according to the present invention comprises the following steps:
(1) a step of taking a vein image of the wrist;
(2) storing a wrist vein pattern registered in advance in the storage unit;
(3) A step of extracting a vein pattern included in the photographed vein image and collating the extracted vein pattern with the registered wrist vein pattern to perform personal authentication.

  A robot control apparatus according to the present invention includes the above-described personal authentication apparatus and a robot according to the present invention. The robot is configured to activate a substantial operation when a collation result transmitted from the personal authentication device to the robot is affirmative.

The robot control method using personal authentication according to the present invention includes the following steps:
(1) a step of taking a vein image of the wrist;
(2) storing a wrist vein pattern registered in advance in the storage unit;
(3) extracting a vein pattern included in the photographed vein image, collating the extracted vein pattern with the registered wrist vein pattern, performing personal authentication, and transmitting the collation result to the robot;
(4) A step of starting substantial operation of the robot when the collation result is affirmative.

  In the present invention, a personal vein pattern that can be personal information is stored in a storage unit of a portable personal authentication device. Therefore, it is not necessary to register the vein pattern in the server. If personal information is registered in the server, personal information may be leaked due to intrusion via the network or information theft. On the other hand, according to the present invention, it is possible to construct an information distribution type authentication system in consideration of protection of personal information.

  In the present invention, the image processing unit may correct the displacement and rotation of the captured vein image. In this way, it is possible to improve the accuracy of collation between the captured vein pattern and the registered vein pattern. Then, it becomes possible to improve the authentication accuracy in the authentication processing unit.

(Configuration of the first embodiment)
Hereinafter, the configuration of the authentication device 1 according to the first embodiment of the present invention will be described with reference to FIGS.

  The authentication device 1 of the present embodiment is portable. Specifically, the size is such that it can be attached to the arm 10 via the belt 3 (FIG. 2). That is, the authentication device 1 of the present embodiment has a substantially wristwatch-type appearance.

  The authentication device 1 includes an image input unit 11, an image processing unit 12, an authentication processing unit 13, an information registration storage unit (corresponding to a storage unit) 14, a wireless unit 15, and a crown switch 4.

  The image input unit 11 includes a camera 21 and a light source 22. The light source 22 is, for example, an LED (Light Emitting Device) that emits near infrared rays. The image input unit 11 is turned on by the crown switch 4, emits near-infrared light from the light source 22, and detects the reflected light with the camera 21, so that an image of the user's vein can be taken. Yes. Since the arterial and the veins have different oxygen contents and the infrared absorption rate is different, a vein image indicating the vein arrangement pattern can be detected separately from the artery. The image input unit 11 is located on a surface in contact with a person in the authentication device 1 (FIG. 3). Furthermore, the camera 21 and the light source 22 are located inside a recess 16 formed on one surface (side facing the human body) of the authentication device 1 (FIG. 4). Both the camera 21 and the light source 22 have a height that does not protrude outside the recess 16.

  The image processing unit 12 performs noise removal, gray scale conversion, image segmentation, median filtering, and histogram normalization on the wrist image captured by the image input unit 11 as preprocessing. This procedure is performed by reducing the resolution of the image within the frequency range necessary for analysis. Since such image processing is already known, detailed description thereof will be omitted.

  Further, the image processing unit 12 according to the present embodiment corrects deviation and rotation of the captured vein image.

  The authentication processing unit 13 extracts a vein pattern from the vein image generated by the image processing unit 12, compares the extracted vein pattern with the vein pattern stored in advance in the information registration storage unit 14, and performs authentication / non-authentication. To decide.

  For example, the image processing unit 12 and the authentication processing unit 13 of the present embodiment can be implemented by executing a computer program stored in a memory of a computer by a CPU. The information registration storage unit 14 can be configured by, for example, a computer internal memory or an external memory (including a case of a storage device such as a hard disk).

(Operation of the first embodiment)
Next, operation | movement of the authentication apparatus in this embodiment is demonstrated, referring FIG.

(Steps S201 to S203)
The information registration storage unit 14 stores vein pattern data for a predetermined person to be authenticated. In this storage, the person to be authenticated in advance picks up a vein image at an arbitrary position on the wrist by the image input unit 11 (S201), patterns the captured image (S202), and stores it in the information registration storage unit 14. (S203). Since this patterning operation can be performed using a known method, detailed description thereof is omitted. This operation is preferably performed in a state in which the wristwatch type authentication device 1 is attached to a normal mounting position as shown in FIG.

  Since wristwatches and mobile phones are not premised on lending / borrowing, this apparatus can store only one vein pattern. Furthermore, the information registration storage unit 14 stores a log of the number of authentications and authentication results.

  In addition, the image registered in the information registration storage unit 14 can be rewritten.

(Steps S101 and S102)
The person to be authenticated can perform authentication as necessary. When performing authentication, the authentication device 1 is set at the position of the wrist photographed at the time of registration or at a close position (S101). Usually, the place where the wristwatch is attached is determined, and in most cases, the authentication device 1 can be arranged at the same position as the position where the wristwatch is attached in step S201. After the position of the device 1 is determined, this is lightly fixed with the belt 3, and the crown switch 4 at the thumb position is pushed. Thereby, the near-infrared light source 22 emits light, and the reflected light can be detected by the camera 21 to perform imaging (S102).

  Since the camera 21 and the light source 22 are located in the depression of the authentication device 1, disturbance light is not easily incident and a stable vein image can be captured.

  Further, by arranging the camera 21 and the light source 22 in the recess 16 of the authentication device 1, the camera 21 and the light source 22 can be arranged at positions separated from the skin. Then, compared with the case where these are made to contact skin, there also exists an advantage that the reflected light from the light source 22 is easy to acquire with the camera 21. FIG.

(Steps S103 to S105)
Image processing has the most influence on the authentication accuracy. The image processing unit 12 performs noise removal, gray scale conversion, image segmentation, median filtering, and histogram normalization on the captured vein image as preprocessing (step S103). This procedure is performed by reducing the resolution of the image within the frequency range necessary for analysis. Further, the image processing unit 12 corrects the shift and rotation of the captured vein image (step S104). Thereafter, the vein pattern included in the vein image is extracted (patterned) (step S105).

(Steps S106 to S108)
The authentication processing unit 13 collates the vein pattern generated by the image processing unit 12 with the vein pattern stored in advance in the information registration storage unit 14 and determines authentication / non-authentication. Here, it is determined whether or not the vein pattern subjected to the image processing matches the vein pattern stored in the registration information storage unit 14. Specifically, for example, a registered vein pattern and a captured vein pattern are matched, and a correlation between the patterns is calculated as an evaluation value. Based on the magnitude of the evaluation value, it is determined that the person is the person or the other person (S107).

  Instead of communicating the biometric information itself to an external device that requires authentication, it is also possible to send a verification result. The external device (for example, a robot) can be configured to activate a substantial operation when the collation result transmitted from the authentication device 1 to the robot is affirmative. That is, the authentication device 1 of the present embodiment can be implemented as a part of the robot control device.

  Further, the authentication device 1 may be configured to transmit the authentication frequency log accumulated in the information registration storage unit 14 to the external device in addition to the verification result.

(Second Embodiment)
An authentication device according to a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the image input unit 11 is provided on the surface of the mobile phone 9. Specifically, a recess is formed on the surface of the mobile phone 9, and a camera 21 and a light source 22 constituting the image input unit 11 are arranged inside the recess. According to this configuration, it is possible to take a vein image of the wrist by holding the mobile phone 9 and bringing the image input unit 11 close to the wrist and pressing the switch. Here, the position where the image input unit 11 is arranged is preferably a position where the vein pattern stored in the information registration storage unit 14 is acquired. Other configurations and advantages of the second embodiment are the same as those of the first embodiment, and thus description thereof is omitted.

  Next, specific examples in the respective embodiments of the present invention will be described.

Example 1
In the first embodiment, a specific example of the preprocessing described in step S103 will be described. For example, the preprocessing is performed by performing the following steps (1) to (3).

(1) Contrast enhancement When the apparatus 1 is downsized, the vein image obtained by the image input unit 11 may have a low contrast ratio. Therefore, it is possible to adjust the contrast by creating a density histogram from the luminance information of the image and normalizing the histogram.

(2) Noise removal The device 1 is a contact type that comes into contact with the user's skin. For this reason, it is expected that the obtained vein image includes not only luminance unevenness but also a lot of noise. Since noise in the image greatly affects the authentication accuracy, it is important how noise can be removed. Therefore, for example, noise removal can be performed using a moving average filter and a median filter. Although general noise can be sufficiently removed by this, it is preferable to perform processing such as expansion / contraction processing or opening / closing processing for large-sized noise because these filters are not sufficient. Since these processes are well known, description thereof will be omitted.

(3) Binarization by dynamic threshold processing In general binarization (conversion from a grayscale image to a monochrome image), the threshold is fixed to one value and the entire image is binarized. When the authentication device 1 in the above embodiment is ultra-compact, considerable luminance unevenness is expected in the obtained vein image corresponding to the photographing part. For this reason, there are many cases where vein shape does not appear well in binarization with a fixed threshold. Therefore, dynamic threshold processing is used. In this method, the entire image is divided into local small portions, a threshold value is obtained for each small portion, and binarization is performed in accordance with the luminance unevenness of each portion. As for the dynamic threshold processing, a method using a Laplacian histogram, a method using discriminant analysis, and the like can be performed. Since these methods are also well known, description thereof will be omitted.

(Example 2)
In the second embodiment, a specific example of image correction described in step S104 will be described with reference to FIGS.

  First, an example of a vein image obtained by the image input unit 11 is schematically shown in FIG. On the other hand, as described in the first embodiment, the vein pattern for authentication is stored in the information registration storage unit 14 (steps S201 to S203 in FIG. 5).

(Step Sa-1 in FIG. 8)
The image processing unit 12 extracts feature points from the vein image after the preprocessing. In this embodiment, three points are extracted for each input image. In FIG. 7, three feature points 6 to 8 are shown. The feature point is a region centering on any one of the branch, intersection, and bend in the vein 5. Among these three points, the feature point located at the center is set as the maximum feature point. In this embodiment, the feature point 7 is the maximum feature point.

(Step Sa-2)
Next, primary discrimination is performed. In the primary determination, it is determined whether or not the combination of the three feature points described above has been obtained after the process of step Sa-1. If there is, proceed to the next step. If not, the process ends and the process is repeated from step S102.

(Step Sa-3)
Next, secondary discrimination is performed. In the secondary discrimination, only the maximum feature point is matched with the template. Specifically, for example, the following is performed.

In the image data conversion in step S202, a plurality of images that are rotated little by little only about the maximum feature point among the registered vein patterns are stored in the information registration storage unit 14 as templates (that is, partial templates). deep. As a partial template, for example, the following is preferably registered. However, when the authentication device is a wristwatch type, when the device is worn on the arm, rotation in the palm direction (rotation around the direction orthogonal to the length direction of the arm) usually does not occur. . In such a case, it is considered unnecessary to prepare a partial template corresponding to the following rotation (1).
(1) Rotated in the palm direction up to + 30 ° to -30 °, and (2) Rotated in the lateral direction up to + 30 ° to -30 °.

  The number of partial templates of this embodiment is about 4 to 8 per one maximum feature point.

Next, the correlation between the partial template and the maximum feature point of the input image (vein image) is obtained. The correlation is performed using, for example, the following three elements.
1. Branch pattern 2. Branch length 3. Branch point and branch point angle In this way, the matching of the maximum feature point and the partial template is confirmed, and the most matching partial template is selected.

(Step Sa-4)
Next, the image deformation angle of the input image (vein image) is calculated using the rotation angle information of the selected partial template. As a method for calculating such a deformation angle, since a known method can be used, detailed description thereof is omitted.

(Step Sa-5)
Next, using the obtained image deformation angle, the entire input image (vein image) is corrected to obtain an image without inclination. In this example, this data is the pattern data (extracted vein pattern) in step S105. That is, in this embodiment, step Sa-5 and step S105 are substantially the same.

(Example 3)
In the third embodiment, a specific example of matching described in step S106 will be described. This collation can be performed, for example, by a phase only correlation method between the extracted vein pattern and the stored vein pattern.

  In Fast Fourier Transform (FFT), both an amplitude component and a phase component are extracted from an image. On the other hand, the phase-only correlation method is a method for obtaining a correlation using only phase information among them, as already known. Unlike general pattern matching, the correlation value appears as a sharp peak. Since such a method is already known, further detailed explanation is omitted.

  Note that the authentication device 1 according to the present invention is not limited to the implementation of the above-described authentication method, and communicates with an external device through the wireless unit 15 to acquire and distribute information and execute an external device control program. Etc. can also be performed.

  Various modifications are made without departing from the spirit of the present invention.

  In addition, hardware, software, a network, a combination thereof, and other arbitrary means can be used as specific means of each unit (including functional blocks) for realizing the embodiment.

It is a block diagram which shows schematic structure of the personal authentication apparatus by the vein pattern of the wrist in 1st Embodiment of this invention. It is explanatory drawing for demonstrating mounting | wearing of the authentication apparatus of FIG. It is explanatory drawing in the state which looked at the authentication apparatus of FIG. 1 from the back side. FIG. 1A is a rear view of the authentication device. FIG. (B) is a schematic cross-sectional view along the line AA in FIG. 3 is a flowchart for explaining the operation of the authentication device of FIG. 1. It is explanatory drawing for demonstrating the authentication apparatus in 2nd Embodiment of this invention. It is a figure which shows an example of a vein image typically. 6 is a flowchart for explaining a second embodiment;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Authentication apparatus 11 Image input part 21 Camera 22 Light source 12 Image processing part 13 Authentication processing part 14 Information registration storage part (memory | storage part)
DESCRIPTION OF SYMBOLS 15 Radio | wireless part 3 Belt 4 Crown switch 5 Vein 6-8 Feature point 9 Cellular phone 10 User's arm

Claims (10)

  A light source and camera for photographing a vein image of the wrist, a storage unit for storing the vein pattern of the wrist in advance, and extracting the vein pattern included in the photographed vein image, and storing the extracted vein pattern A personal authentication apparatus comprising: an authentication processing unit that performs personal authentication by collating with a wrist vein pattern that has been made, and is portable.   The personal authentication apparatus according to claim 1, wherein the apparatus is attached to an operator's body.   The personal authentication device according to claim 1, wherein the device is provided in a mobile phone.   The said light source and a camera are arrange | positioned inside the hollow formed in the said apparatus, and become a structure which does not protrude outside the hollow, The Claim 1 characterized by the above-mentioned. Personal authentication device.   The image processing unit further corrects misalignment and rotation of the photographed wrist vein image, and the authentication processing unit applies the corrected wrist vein image to the corrected wrist vein image. The personal authentication device according to claim 1, wherein the personal authentication is performed by extracting a vein pattern included.   6. The personal authentication apparatus according to claim 1, wherein the vein pattern stored in advance is rewritable and only for one person.   The personal authentication device according to claim 1, wherein the personal authentication verification result is transmitted to an external device that requires authentication instead of the biometric information itself. A personal authentication method characterized by comprising the following steps:
(1) a step of taking a vein image of the wrist;
(2) A step of previously storing a wrist vein pattern in the storage unit;
(3) A step of extracting a vein pattern included in the photographed vein image and comparing the extracted vein pattern with the stored wrist vein pattern to perform personal authentication.   The personal authentication device according to claim 1 and a robot, wherein the robot substantially operates when a collation result transmitted from the personal authentication device to the robot is affirmative. A robot control device characterized by being configured to start up. A robot control method using personal authentication, characterized by comprising the following steps:
(1) a step of taking a vein image of the wrist;
(2) A step of previously storing a wrist vein pattern in the storage unit;
(3) extracting a vein pattern included in the captured vein image, collating the extracted vein pattern with the stored wrist vein pattern, and performing personal authentication, and transmitting the collation result to the robot;
(4) A step of starting substantial operation of the robot when the collation result is affirmative.

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