JP4511246B2 - Optical identification information acquisition device - Google Patents

Description

  The present invention relates to a configuration of an optical identification information acquisition device for identifying a tagged object by a tag that emits an optical signal.

  Optical tags for identifying a person or an object and specifying a position have been studied (for example, see Non-Patent Document 1 and Non-Patent Document 2).

  The purpose of such an optical tag is assumed to be applied to an augmented reality system, a context awareness service, or the like.

  Unlike wireless and ultrasonic tags, the optical tag captures the blinking signal of the light source using an image sensor. Therefore, from a relatively long distance (several meters), the optical tag has a small number of configurations (at least one transmitter and one transmitter). In the receiver, identification information acquisition (ID acquisition) for high-accuracy position specification and identification of the tagged object can be performed at the same time.

  On the other hand, the image sensor built in the identification information acquisition device (ID tracker) used on the receiving side is a high-density array of photodiodes and has a narrow dynamic range and low sensitivity, so that the receiving speed cannot be increased. There's a problem.

For this reason, in many optical tag researches, an ID of several bytes is transmitted by blinking, and data for various services is obtained from a database via a network such as a LAN based on the ID received by the tracker. (For example, see Non-Patent Document 3 and Non-Patent Document 4).
D. Moore, R. Want, B. Harrison, A. Gujar, and K. Fishkin: “Implementing Phicons: Combining Computer Vision with InfraRed Technology for Interactive Physical Icons”, Proceedings of UIST'99, pp. 67-68, 1999 . Nobuyuki Matsushita, Daisuke Hihara, Teruyuki Gomura, Shinichi Yoshimura, Junichi Kokimoto: “ID Cam: A Smart Camera that Can Get Scene and ID Simultaneously”, IPSJ Journal, Vol. 43, No. 12, pp. 3664 -3674, 2003. S. Feiner, B. MacIntyre, M. Haupt and E. Solomon: “Windows on the world: 2d windows for 3d augmented reality”, Proceedings of UIST'93, pp. 145-155, 1993. Jun Rekimoto, Katashi Nagao: “The World through the Computer: Augmented Interaction with Real World Environment”, Proceedings of UIST'95, pp. 29-36, 1995.

  FIG. 9 shows such a conventional ID tag 500.1-500. 2 is a diagram illustrating an example of a configuration of n and an ID tracker 600. FIG.

  In FIG. 9, ID tags 500.1 to 500.n attached to n observation objects, respectively. Of n, the configuration of the ID tag 500.1 is representatively shown.

  That is, the ID tag 500.1 is provided with an infrared LED (Light Emitting Diode) 502, and the microcontroller 504 controls the infrared LED 502 to emit light with a bit pattern corresponding to the ID.

  On the other hand, in the ID tracker 600, an image sensor, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor 602 detects an infrared LED 502 that emits light in a two-dimensional image, and a microcontroller 604 converts it into two-dimensional image data. Then, the data is transmitted to the mobile personal computer 700. From such two-dimensional image data, an identification information signal of a bit pattern corresponding to the light emission pattern of the infrared LED 502 can be detected. The mobile personal computer 700 accesses the identification information database server 800 via an external network, and obtains information such as the attribute of the object corresponding to the acquired identification information signal.

  In this case, for example, assuming a service that refers to the operating state of a machine based on the ID of a tag attached to a certain machine, a database that always reflects the state of the machine is required. Installation of such a database and an external network is not desirable from the viewpoint of equipment cost, communication efficiency, and security.

  An object of the present invention is to solve the problems of the conventional approaches as described above, and to provide an optical identification information acquisition apparatus capable of improving communication efficiency at low cost. .

  Another object of the present invention is to provide an optical identification information acquisition apparatus capable of ensuring security.

To achieve the above object, the optical identification information acquisition device of the present invention, by taking a plurality of objects optically, there in the optical identification information acquisition device for identifying a plurality of objects, respectively Each of the plurality of objects is provided with an identification tag device for identifying the corresponding object, and the identification tag device identifies the corresponding object in the first communication period according to the control signal. The light is transmitted in the first light emission pattern corresponding to the information, and the identification information and the attribute information of the corresponding object are expressed in the second communication period different from the first communication period according to the control signal . and a first light emitting means for transmitting light at the second light emission pattern, a first light receiving means for receiving a control signal for controlling the first light emitting means, a first for storing attribute information of Storage means, Receiving light from another tag device, based on the identification information to identify the position of the identification tag device, as well as acquiring attribute information further includes an identification information tracking apparatus for delivering a control signal to the identification tag device The identification information tracking device includes a photographing unit for photographing light from the identification tag device as a two-dimensional image, a second light receiving unit for receiving attribute information, and a second unit for sending a control signal. An identification tag whose position is detected by the identification information based on the first emission pattern in the two-dimensional image, including a light emitting means, and a control means for controlling the photographing means and the second light emitting means. the device sequentially selects, Ru is sent a control signal for causing the transmission of the attribute information in the second illumination pattern for each selected identification tag device from the second light emitting means.

Preferably, the first light emission pattern is a pattern that changes at a lower speed than the second light emission pattern.

  Preferably, the first storage means stores a first secret key unique to the corresponding identification tag device, and the identification information tracking device uses second storage means for storing a unique second secret key. The communication between the identification tag device and the identification information tracking device is encrypted with a public key corresponding to the other party's secret key.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the present invention, as will be described in detail below, the data recording by the optical tag itself and the high-speed communication between the optical tag and the tracker enable the tag and the tracker to directly transmit and receive data, and the system configuration that does not use the external network. Take. As a result, the ID tracker can directly acquire the status information of the object, and the cost of the system and the efficiency of communication can be expected.

[Embodiment 1]
[Configuration of the present invention]
FIG. 1 shows an optical tag 10.1-10. 2 is a block diagram for explaining a configuration of n and an ID tracker 20. FIG.

  In FIG. 1, ID tags 10.1 to 10. attached to n observation objects, respectively. Of n, the configuration of the ID tag 10.1 is representatively shown.

  That is, the infrared tag 12 is provided in the ID tag 10.1. As will be described in detail later, the microcontroller 16 controls the infrared LED 12 to emit light at a low speed with a bit pattern corresponding to the ID information in a predetermined period of communication, and in the other predetermined period, the infrared LED The LED 12 is controlled to emit light at a high speed with a bit pattern corresponding to data (attribute information) indicating ID information and attributes of the object. Such attribute information of the object is stored in the memory 18.

  Further, the ID tag 10.1 is provided with a photodiode 14 and receives a control signal from the ID tracker 20. The microcontroller 16 operates based on this control signal.

  On the other hand, in the ID tracker 20, an image sensor, for example, a CMOS image sensor 24 detects the infrared LED 12 that emits light in a two-dimensional image, and the microcontroller 28 converts the infrared LED 12 into two-dimensional moving image data. Send to computer 100. From such two-dimensional image data, an identification information signal of a bit pattern corresponding to the low-speed light emission pattern of the infrared LED 12 can be detected. Further, the ID tracker 20 is also provided with a photodiode 22, and the photodiode 22 is a data obtained by converting the light emission pattern corresponding to the ID information from the infrared LED 12 and the attribute information of the object into a bit pattern when emitting light at high speed. Is output to the microcontroller 28. The microcontroller 28 transmits the output from the CMOS image sensor 24 and the output from the photodiode 22 to the mobile personal computer 100. Based on the signal from the microcontroller 28, the mobile personal computer 100 identifies the infrared LED 12 in the two-dimensional image, specifies its position, and acquires the ID information of the object.

  That is, there are two types of transmission from the infrared LED 12 of the ID tag 10.1: low-speed transmission for the image sensor 24 for acquiring the position of the ID tag 10.1 and high-speed transmission for the photodiode 22 that performs data communication. It is said that.

  On the other hand, the ID tracker 20 is further provided with an infrared LED 26, and the infrared LED 26 emits light with a high-speed light emission pattern corresponding to a control signal given from the microcontroller 28 under the control of the mobile personal computer 100.

  In the configuration as described above, the fixed-length ID information from the infrared LED 12 of the ID tag 10.1 is Manchester encoded and modulated into a 200 Hz infrared signal and transmitted. The data is similarly Manchester encoded and modulated into a 10 kHz infrared signal and transmitted. The image sensor 24 captures ID information and position information by photographing at a frame rate of 400 Hz, and the photodiode 22 receives data. The position information, ID information, and data acquired by the ID tracker 20 are sent to the mobile personal computer 100 via a communication path such as RS-232C, for example.

  The mobile personal computer 100 may use a wearable device such as a PDA (Personal Digital Assistance).

  When the above configuration is implemented on a trial basis, a communication speed of 4.8 kbps is confirmed. Furthermore, an improvement in communication speed can be expected by changing the circuit.

  As for dynamic data transmission from the IR tag 10.1 side and reception processing function on the ID tracker 20 side, an 8-bit data string that changes dynamically is sent from the IR tag 10.1 side to 200 Hz as needed. As an infrared signal, data acquisition by the image sensor 24 was confirmed.

  That is, in the configuration shown in FIG. 1, the communication speed can be increased by adding the infrared communication function of the infrared LED 12 and the photodiode 22 and the infrared LED 26 and the photodiode 14. In addition, the status information of the target object (change in the status of the target object, shape of the target object, annotation, etc.) is recorded in a memory connected to the microcontroller 16 that controls the ID tag 10.1, and dynamic data transmission is performed. By providing a reception processing function, it is possible to construct a system that does not require an external network.

  That is, the feature of this system is that it is possible to construct a system having a similar function with a small-scale system without using a large-scale system that centrally manages IDs like the ubiquitous ID center.

(protocol)
If the photodiode 22 of the ID tracker 20 receives signals from a plurality of tags at the same time, the infrared signal pattern may be erroneously recognized.

  Therefore, it is necessary to control the tags so that signals are not transmitted from a plurality of tags at the same time.

  FIG. 2 is a communication sequence diagram for explaining such a communication protocol.

  As a method for transmitting data to a specific tag, first, the ID tracker 20 detects the ID information of the ID tag being transmitted by the image sensor 24 (S01, S02). Next, the ID tracker 20 transmits a start signal for permitting data transmission to one of the ID tags having the detected ID information (tag 1 in the figure) from the infrared LED 26 together with the ID information of the ID tag. (S03) This causes the tag 1 to start transmitting data (S04).

  At this time, the other ID tag (tag 2 in the figure) recognizes that data transmission is not permitted because a start signal is issued to an ID tag having ID information other than itself. (S03 ').

  The ID tracker 20 that has completed the reception of data from the tag 1 transmits a stop signal to the tag 1 together with the ID information of the tag 1 to stop the tag 1 from transmitting data (S05). By repeating these processes for another tag in the image sensor 24, data is acquired from all tags (S06 to S08).

(Application example)
As an application of the present invention, a system that combines individual information of individual objects and provides a user with more information is assumed.

  First, IR tags 10.1-10. The configurations of the ID tracker 20 and the mobile personal computer 100 for acquiring information from n will be further described.

  In the following description, it is assumed that the mobile personal computer 100 is a PDA.

[Configuration of PDA 100]
FIG. 3 is a block diagram showing the configuration of the PDA 100.

  Referring to FIG. 3, the PDA 100 includes an external medium drive 116 for reading information on an external medium 150 such as a memory card, a CPU (Central Processing Unit) 110 connected to the bus BS1, and a ROM (Read Only Memory). ) And RAM (Random Access Memory), and a timer 122 for providing time used by the system. Preferably, the PDA 100 may include a communication interface 118 for exchanging data with the LAN using a wireless connection or the like.

  The PDA 100 further includes an external device interface 120 for receiving data from the input device 160 that is connected to the PDA 100 as needed and used for data input by a user. The external device interface 120 receives data from the ID tracker 20 attached to the headset 140 worn by the observer 2 on the head. If necessary, the ID tracker 20 itself also has an IR tag 10. i may be attached | subjected.

  The external medium 150 is a medium capable of recording information such as programs installed in the computer main body.

  As an example of an application of a system including the PDA 100 and the ID tracker 20 having the above-described configuration, a user who has the ID tracker 20 from a whiteboard that displays the presence / absence of members at a company or school will be described below. Describe a system that allows you to obtain member status and history immediately.

  FIG. 4 is a diagram showing an example of the configuration of a whiteboard that displays the presence / absence of such members.

  Referring to FIG. 4, the present system includes a presence management whiteboard 300, name tags 10.11 to 10.14, and magnets 10.21 to 10.24 as objects in the real world.

  FIG. 5 is a diagram illustrating an example of information acquired by the ID tracker 20 that is attribute information of each object.

  As shown in FIG. 4, ID tags 10.01 to 10.03 are also attached to the whiteboard 300 itself. As shown in FIG. 5, the whiteboard 300 has a name, shape, and presence as unique attribute information. It has information about the range where the magnet is pasted, such as leaving and leaving.

  That is, the shape data includes the coordinates (0, 0) and (120, 90) of the lower left corner a and the upper right corner b of the whiteboard.

  Similarly, the seating range on the whiteboard 300 is given by the coordinates of its four vertices c, d, g, and h, and the leaving range is given by the coordinates of its four vertices d, e, h, and i. The range of rest is given by the coordinates of its four vertices e, f, i, b.

  In addition, the name tags 10.11 to 10.14 and the magnets 10.21 to 10.24 each have a built-in optical tag. As unique attribute information, the name tags 10.11 to 10.14 are the name, shape, and owner name. The magnets 10.21 to 10.24 have information on names, owner names, shapes, and operation times. The shape information is expressed by (vertical dimension) × (horizontal dimension).

  FIG. 6 shows, based on the information acquired by the ID tracker 20, the PDA 100 on the whiteboard of the object with the IR tag 10.11 and the object with the IR tag 10.21. It is a figure which shows the result of having recognized the position.

  That is, information for the user is generated in the PDA 100 by combining the position information acquired from the ID tracker 20 and the unique information transmitted by each IR tag.

  In the example shown in FIG. 6, the object to which the IR tag 10.11 is attached is the name tag of the owner “Taro”, the coordinates thereof are (25, 65), and the IR tag 10.21 is attached. It is recognized that the target object is the magnet of the owner “Taro” and its coordinates are (60, 65). As a result, Taro's magnet is in the “attended” range, so it can be determined that Taro is currently present.

  As described above, the feature of this system is that it enables data communication of an object whose shape is small and cannot be connected to a network, and can be used with a system connected to an external network to reduce equipment costs. .

[Modification of Embodiment 1]
In the first embodiment, neither the signal emitted from the infrared LED 12 nor the signal emitted from the infrared LED 26 is particularly encrypted. Although it can be said that the security has been improved by not using the external network, in such a configuration, it cannot be said that the security for the attribute information of the object included in the signal emitted from the tag is sufficient.

  Therefore, as a modification of the first embodiment, a configuration in which the signal emitted from the infrared LED 12 and the signal emitted from the infrared LED 26 are encrypted with a public key will be described.

  FIG. 7 shows optical tags 10.1 to 10 of the modification of the first embodiment. 2 is a block diagram for explaining a configuration of n and an ID tracker 20. FIG.

  A difference from the configuration of FIG. 1 is that the memory 30 is also provided in the ID tracker 30, and at least the secret key 1 unique to the ID tracker 30 is stored in the memory 30. Furthermore, in FIG. 7, the memory 18 in the IR tag 10.1 stores at least the secret key 2 unique to the IR tag 10.1. A unique secret key is also stored for each of the other IR tags.

  At this time, among the signals emitted from the infrared LED 12, data such as attribute information is encrypted by the microcontroller 16 with the public key 1 of the ID tracker 20 and transmitted. However, ID information is transmitted in plain text.

  On the other hand, among the signals emitted from the infrared LED 26, the control signal is the selected IR tag 10. It is encrypted and transmitted by the microcontroller 28 with the public key 2 of i (i: a natural number equal to or less than n). However, ID information is transmitted in plain text.

  Note that the public key of the transmission partner may be stored in the memory 18 or the memory 30 in advance. Alternatively, after performing mutual authentication by a known method, IR tags 10.1-10. Public keys may be exchanged between n and the ID tracker 20.

  FIG. 8 is a diagram illustrating an example of a configuration of a signal emitted from the infrared LED 12.

  The header includes ID information in plain text, and the body includes data encrypted with the public key 1 of the transmission destination ID tracker 20.

  With the above configuration, IR tags 10.1-10. n, the ID tracker 20 can obtain the information transmitted from the other party by decrypting it with its own secret key, but a device that does not know the secret key cannot know the contents of the information.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Optical tag 10.1-10. Which is the optical identification information acquisition apparatus of this invention. 2 is a block diagram for explaining a configuration of n and an ID tracker 20. FIG. It is a communication sequence diagram for demonstrating the protocol of communication. 1 is a block diagram showing the configuration of a PDA 100. FIG. It is a figure which shows an example of a structure of the white board which displays the presence / absence of a member. It is a figure which shows the example of the information which is attribute information which each target object has, and the ID tracker 20 acquires. Based on the information acquired by the ID tracker 20, the PDA 100 recognizes the position on the whiteboard of the object to which the IR tag 10.11 is attached and the object to which the IR tag 10.21 is attached. It is a figure which shows a result. Optical tags 10.1-10 of the modification of Embodiment 1. 2 is a block diagram for explaining a configuration of n and an ID tracker 20. FIG. It is a figure which shows the example of a structure of the signal which infrared LED12 emits. Conventional ID tags 500.1 to 500. 2 is a diagram illustrating an example of a configuration of n and an ID tracker 600. FIG.

Explanation of symbols

  10.1-10. n IR tag, 12 infrared LED, 14 photodiode, 16 microcontroller, 18 memory, 20 ID tracker, 22 photodiode, 24 infrared image sensor, 26 infrared LED, 28 microcontroller, 30 memory.

Claims (3)

By capturing a plurality of objects optically, an optical identification information acquisition device for identifying the plurality of objects, respectively,
Each of the plurality of objects is provided with an identification tag device for identifying the corresponding object,
The identification tag device
Light is transmitted in the first light emission pattern corresponding to the identification information for identifying the corresponding object in the first communication period according to the control signal, and is different from the first communication period in accordance with the control signal. First light emitting means for transmitting light in a second light emission pattern for expressing the identification information and attribute information of the corresponding object in a second communication period ;
A first light receiving means for receiving said control signal for controlling the first light emitting means,
First storage means for storing the attribute information;
Identification that receives light from the identification tag device, identifies a position of the identification tag device based on the identification information, acquires the attribute information, and sends the control signal to the identification tag device Further comprising an information tracking device ,
The identification information tracking device includes:
Photographing means for photographing light from the identification tag device as a two-dimensional image;
A second light receiving means for receiving the attribute information;
A second light emitting means for sending the control signal;
Control means for controlling the photographing means and the second light emitting means,
The control means sequentially selects the identification tag device whose position is detected by the identification information based on the first light emission pattern in the two-dimensional image, and selects the identification tag device for each selected identification tag device. It said control signal for causing the transmission of the attribute information in the second light emission pattern Ru is transmitted from said second light emitting means, the optical identification information acquisition device. The optical identification information acquisition apparatus according to claim 1, wherein the first light emission pattern is a pattern that changes at a lower speed than the second light emission pattern . The first storage means stores a first secret key unique to the corresponding identification tag device,
The identification information tracking device further includes second storage means for storing a unique second secret key,
The communication between the identification tag device before Ki識 specific information tracking device is encrypted by the public key corresponding to the private key of the other party, the optical identification information acquisition apparatus according to claim 1.

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