JP2009222417A - Position detection system, sending device, position detection method, and position detection program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detection system capable of performing position detection of a receiving device surely. <P>SOLUTION: In the position detection system provided with a plurality of sending devices 1, a receiving devices 2, and a position information acquisition device 3 connected to the receiving device 2 with a network 4, the sending devices 1 are provided with light sending sections 7 for converting sending-device discriminative information into sending signals and performing transmission with predetermined directivities; the receiving device 2 is provided with a light receiving section 11 for receiving the sending signals, a storage section 14 for storing the received sending-device discriminative information and receiving-device discriminative information in association with each other as detection information, a control operation section 13 for controlling storage of the storage section 14, and a communication section 15 for transmitting the detection information; and the acquisition device 3 is provided with a communication section 16 for receiving the detection information, a storage section 18 for storing sending-device installation information of the sending devices 1 and the sending-device discriminative information in association with each other as sending-device information, and a control operation section 17 for acquiring receiving-device position information from the received detection information and the sending-device information. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a position detection system, a transmission apparatus, a position detection method, and a position detection program that specify the position of a receiving apparatus.

  In a position detection system that receives a directional signal transmitted from a fixed transmission device and identifies the current position of the reception device, there may be a region where signals transmitted from adjacent transmission devices overlap.

  In such a case, for example, in Patent Document 1, an overlapping area (A + B) of transmission data (beacon signals) from adjacent infrared light emitters 100 and 110 occurs as shown in FIG. Even if the codes assigned to each transmission data overlap, the overlap area is identified by setting the pulse signal of the transmission data in advance so that the logical sum of the codes becomes the data indicating the position of the overlap area. .

JP 2004-297466 A

  However, in Patent Document 1, when an overlapping area is generated by three or more infrared light emitters that are close to each other, it is necessary to consider the combination of codes for identifying a plurality of overlapping areas, so that the transmission device must be installed. There is a problem that the installation work becomes complicated. Furthermore, there is a problem that an accurate synchronization mechanism of transmission data is required to express an overlapping area by logical sum, and there is an upper limit on the number of beacons in the overlapping area depending on the configuration.

  The present invention has been made in view of the above, and an object of the present invention is to provide a position detection system, a transmission apparatus, a position detection method, and a position detection program that can reliably detect the position of a receiving apparatus.

  In order to solve the above-described problems and achieve the object, the present invention provides a plurality of transmitting devices, receiving devices, and receiving device location information that is connected to the receiving devices via a network and indicates the current location of the receiving devices. In the position detection system including the position information acquisition device to be acquired, the transmission device converts a transmission device identification information for identifying the transmission device into a transmission signal, and transmits a first transmission means for transmitting with a predetermined directivity. The receiving device includes: a first receiving unit configured to receive the transmitting device identification information that is the transmission signal; the received one or more transmitting device identification information; and a receiving device identification that identifies the receiving device. Detection information storage means for associating and storing information as detection information, control means for controlling storage of the detection information storage means, and second transmission means for transmitting the detection information, The position information acquisition device associates the second receiving means for receiving the detection information, the transmission device installation information indicating the installation position of the transmission device and the transmission device identification information, and stores the transmission device information as transmission device information. It is characterized by comprising an information storage means, an acquisition means for acquiring the receiving device position information from the received detection information and the transmitting device information.

  According to the present invention, in the transmitting device, a third receiving means for receiving another transmitting signal transmitted by another transmitting device, and when the other transmitting signal is received, the transmitting signal is transmitted first. The receiving device further comprises delay means for delaying by one predetermined time, and the control means stores the transmitting device identification information received within a second predetermined time longer than the first predetermined time as detection information. The detection information storage means is controlled as described above.

  Further, the present invention provides the transmitting apparatus, wherein a spreading code generating means for generating a plurality of spreading codes, a selecting means for selecting a desired spreading code, and the transmitting apparatus identification information are spread modulated by the desired spreading code. Signal transmitting means for generating a transmission signal, and in the receiving apparatus, spreading code generation means for generating the plurality of spreading codes, and despreading the transmission signal with the desired spreading code, and the transmitting apparatus Demodulating means for demodulating the identification information, and the control means controls the detection information storage means so as to store the transmission device identification information received within a third predetermined time as detection information; It is characterized by.

  Further, the present invention provides the transmitting device, wherein the signal combining unit further generates a transmission signal obtained by performing spread modulation on transmission cycle information indicating a transmission cycle of the transmission signal with the desired spreading code, and in the receiving device, The control means sets the third predetermined time to a time longer than the transmission cycle.

  According to the present invention, in the transmitting device, a first receiving means for receiving another transmitted signal transmitted by the other transmitting device, and a first code for determining a spread code obtained by spreading-modulating the other transmitted signal. Determining means, wherein the selecting means selects a spreading code other than the spreading code determined by the first determining means as the desired spreading code.

  Further, the present invention is characterized in that the receiving device further includes a second determination unit that determines the desired spread code obtained by performing spread modulation on the transmission signal.

  Moreover, the present invention is characterized in that, in the receiving device, the detection information storage means further stores time information indicating a time at which one or a plurality of the transmitting device identification information is received in association with each other.

  Further, the present invention provides the position information acquisition device, wherein the acquisition unit obtains the reception device position information from the received detection information, time information indicating a time when the detection information is received, and the transmission device information. It is characterized by acquiring.

  Further, the present invention is characterized in that the first transmission means transmits the transmission signal as an optical signal, and the first reception means receives the optical signal.

  According to the present invention, in a transmitting device that transmits uniquely determined transmitting device identification information, a transmitting unit that transmits the transmitting device identification information as an optical signal, and another light that is the optical signal transmitted by another transmitting device. It is characterized by comprising receiving means for receiving a signal and delay means for delaying transmission of the optical signal by a predetermined time when the other optical signal is received.

  In addition, the present invention provides a position detection device including a plurality of transmission devices, a reception device, and a location information acquisition device that is connected to the reception device via a network and acquires reception device location information indicating a current location of the reception device. A position detection method executed in a system, wherein the position information acquisition device associates transmission device installation information indicating an installation position of the transmission device with transmission device identification information for identifying the transmission device as transmission device information. A transmitting device information storing means for storing, wherein the transmitting device converts the transmitting device identification information into a transmitting signal and transmits the transmitting signal with a predetermined directivity; and the receiving device uses the transmitting signal. A first receiving step of receiving a certain transmitting device identification information; one or a plurality of the transmitting device identification information received by the receiving device in the first receiving step; A detection information storing step for associating and storing the reception device identification information for identifying the reception device as detection information; a second transmission step in which the reception device transmits the detection information; and the position information acquisition device, A second receiving step of receiving detection information; and an acquisition step of acquiring the receiving device position information from the detection information received by the second receiving step and the transmitting device information by the position information acquiring device. , Including.

  Further, the present invention is a position detection program for causing a computer to execute a position detection method.

  According to the present invention, the transmission device transmits the identification information of the transmission device with a transmission signal (beacon signal) having a predetermined directivity, and the reception device receives the received identification information of the transmission device and the identification information of the reception device. Is transmitted as detection information in association with each other, and the position information acquisition device obtains the current position information of the reception device from the received detection information and the transmission device information associated with the stored installation information and identification information of the transmission device. As a result, the position of the receiving apparatus can be reliably detected.

  Further, according to the present invention, the transmission device periodically transmits its own transmission signal (beacon signal) as it is depending on whether or not a transmission signal (beacon signal) is received from another transmission device, or is delayed by a certain amount of time. Since it transmits periodically after transmitting, even if the several transmission signal (beacon signal) transmitted from each transmission device is overlapped and irradiated, these transmission signals (beacon signal) are not overlapped, but the transmission device Can be accommodated within the period time (transmission period) of the receiver, and the receiving device can reliably receive these transmission signals (beacon signals), so even if the transmitting device is densely installed, There is an effect that the position can be reliably detected.

  In addition, according to the present invention, since the transmitting device transmits a transmission signal (beacon signal) obtained by spreading and modulating the identification information of its own transmitting device using a spreading code different from that of other transmitting devices, the transmitting device transmits the signal from each transmitting device. Even within a range where multiple outgoing signals (beacon signals) are overlapped, the receiving device despreads the received outgoing signals (beacon signals) with the same spreading code as the transmitting device, and the identification information of the transmitting device is accurately Since it can be obtained, the position of the receiving device can be reliably detected even if the transmitting devices are densely installed.

  Exemplary embodiments of a position detection system, a transmission device, a position detection method, and a position detection program according to the present invention will be explained below in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a schematic diagram showing the configuration of the position detection system according to the first embodiment, and FIG. 2 is a block diagram showing the configuration of the position detection system according to the first embodiment. The position detection system includes a plurality of transmission devices 1, a reception device 2, and a location information acquisition device 3, and the reception device 2 and the location information acquisition device 3 are connected to a wireless and wired network 4. Are connected to each other.

  The transmission device 1 transmits a beacon signal 5 including a beacon ID as an optical signal in a predetermined direction (lower side in FIG. 1) at a predetermined fixed period time (transmission cycle). The transmission cycle in which the transmission device 1 transmits the beacon signal 5 is the same for all transmission devices 1. A plurality of transmission devices 1 are installed at regular intervals in a facility such as a ceiling or a wall. The transmission device 1 includes a storage unit 6, a light transmission unit 7, a light reception unit 8, a delay unit 9, and a control calculation unit 10. Here, the beacon ID is a unique number assigned in advance to each of the plurality of transmission devices 1 and is identification information that can uniquely identify each of the plurality of transmission devices 1.

  FIG. 3 is a diagram illustrating an example of the configuration of the beacon signal 5. The beacon signal 5 includes a preamble signal 20 having a predetermined bit length for synchronization when received, a start signal 21 indicating a beacon ID start position, a beacon ID signal 22 indicating a beacon ID, and an end of the beacon ID signal 22 And a CRC signal 23 indicating data error correction information.

  The memory | storage part 6 memorize | stores beacon ID, for example, consists of ROM, RAM, etc. The light transmitting unit 7 modulates the beacon signal 5 including the beacon ID and transmits the modulated beacon signal 5 as an optical signal. The light transmitter 7 includes a modulation circuit that modulates the beacon signal 5 into an optical signal, and a light emitting element such as an LED or a laser that transmits the modulated optical signal. The signal modulation method may be a method generally used in optical communication or the like. For example, an optical modulation method such as an ASK (Amplitude Shift Keying) or PPM (Pulse Position Modulation) method is used in consideration of power consumption and usage environment. That's fine.

  The optical receiver 8 receives the optical signal and demodulates it into a beacon signal 5. Note that the optical signal received by the light receiving unit 8 may be the beacon signal 5 reflected by the floor or the like, or the beacon signal 5 of another transmitter 1 reflected by the floor or the like. The optical receiver 8 includes a photodetection element such as a photodiode or phototransistor that receives an optical signal, and a demodulation circuit that demodulates the received optical signal into a beacon signal 5.

  When the optical receiver 8 receives the beacon signal 5 of another transmitter 1, the delay unit 9 delays transmission of its own beacon signal 5 from the optical transmitter 8 for a predetermined time. The control calculation unit 10 performs control of various units constituting the transmission device 1 and various processes, and controls transmission of the beacon signal 5 as one of the processes. As the delay unit 9 and the control calculation unit 10, for example, a CPU or the like is used.

  The receiving device 2 receives the beacon signal 5 transmitted from the transmitting device 1 and transmits detection information in which a beacon ID obtained from the received beacon signal 5 is associated with a device ID described later. The receiving device 2 moves together with the person or the device when the person carrying the receiving device 2 or the device on which the receiving device 2 is installed moves in the room where the transmitting device 1 is installed. The receiving device 2 is arranged at a position where the beacon signal 5 from the transmitting device 1 can be received even during movement. The receiving device 2 includes an optical receiving unit 11, a determination unit 12, a control calculation unit 13, a storage unit 14, and a communication unit 15.

  The optical receiver 11 receives an optical signal and demodulates it into a beacon signal 5. The optical receiving unit 11 includes a photodetection element such as a photodiode or phototransistor that receives an optical signal, and a demodulation circuit that demodulates the received optical signal into a beacon signal 5. In the present embodiment, the optical receiver 11 receives one or a plurality of beacon signals 5 within the period time (transmission period) of the transmission device 1.

  The determination unit 12 determines whether or not the period time (transmission period) of the transmission device 1 has elapsed. The control calculation unit 13 performs control and various processes of each unit constituting the reception device 2, and one or a plurality of beacon signals 5 received within the period time (transmission cycle) of the transmission device 1 as one of the processes. Identifies the beacon ID included in the. For example, a CPU or the like is used for the determination unit 12 and the control calculation unit 13.

  The storage unit 14 stores in advance the device ID of the receiving device 2 and also stores detection information in which the beacon ID obtained from the received beacon signal 5 is associated with the device ID. Here, the device ID is a unique number assigned in advance to the receiving device 2, and is identification information that can uniquely identify the receiving device 2. FIG. 4 is a diagram illustrating an example of a configuration of detection information. The storage unit 14 includes, for example, a RAM.

  The communication unit 15 communicates with the position information acquisition device 3 via the network 4 using, for example, a wireless LAN. The communication unit 15 transmits the detection information stored in the storage unit 14 to the position information acquisition device 3 as one of the communication functions.

  The position information acquisition device 3 receives the detection information transmitted from the reception device 2, and also receives the detected detection information, the time information when the detection information is received, and the installation information and beacon indicating the installation position of the transmission device 1. The location information indicating the current location of the receiving device 2 is acquired from the transmitting device information associated with the ID, and the information is provided to various location information use services as necessary. The position information acquisition apparatus 3 includes a communication unit 16, a control calculation unit 17, and a storage unit 18.

  The communication unit 16 communicates with the receiving device 2 via the network 4 using, for example, a wireless LAN. The communication unit 16 receives detection information associating a beacon ID and a device ID from the receiving device 2 as one of communication functions.

  The control calculation unit 17 performs control of various units constituting the position information acquisition device 3 and various processes. The control calculation part 17 shows the detection information which linked | related beacon ID received from the receiver 2 and apparatus ID, the time information which received the said detection information, and the installation position of the transmitter 1 as one of the processes. The position information of the receiving device 2 is acquired from the transmitting device information that associates the installation information and the beacon ID. Here, the actual position information is information indicating where the receiving device 2 is located for each time. For example, a CPU or the like is used as the control calculation unit 17.

  The storage unit 18 stores the transmission device information of the transmission device 1 in advance and stores the acquired position information of the reception device 2. Note that the storage unit 18 may exist in the network 4 as a single storage device, for example, instead of in the position information acquisition device 3 as long as it can be referred to via the network 4. The storage unit 18 includes, for example, a RAM or an HDD.

(Position detection method)
A method for detecting the position of the receiving device 2 will be described. First, a mechanism in which the reception device 2 reliably receives the optical signal (beacon signal 5) from the transmission device 1 will be described. FIG. 5 is a diagram for explaining a region (irradiation range) in which the transmission device 1 transmits an optical signal (beacon signal 5). In the figure, two adjacent transmitting devices 1 (here, transmitting device 1A and transmitting device 1B) periodically transmit optical signals (here, beacon signal 5A and beacon signal 5B) to the lower side ( Usually, it is transmitted in the range of 1 to several seconds), and the transmission area (irradiation range) is almost fixed by the directivity.

  Here, the irradiation range A represents the range in which the beacon signal 5A of the transmission device 1A is irradiated, the irradiation range B represents the range in which the beacon signal 5B of the transmission device 1B is irradiated, and the irradiation range C represents the transmission device. A range in which the 1A beacon signal 5A and the beacon signal 5B of the transmitting device 1B are overlapped and irradiated is shown. The receiving device 2 is in one of the irradiation ranges A to C and receives the beacon signal 5, but here, the transmitting device 1 </ b> A and the transmitting device 1 </ b> B do not overlap with the transmission cycle of the partner beacon signal 5. Thus, its own beacon signal 5 is periodically transmitted.

  FIG. 6 is a diagram illustrating the beacon signal 5 received by the receiving device 2 when the receiving device 2 is in each irradiation range. In the irradiation range A, the receiving device 2 receives only the beacon signal 5A of the transmitting device 1A once every transmission cycle, and in the irradiation range B, receives only the beacon signal 5B of the transmitting device 1B once every transmission cycle. . Here, a time difference (corresponding to the waiting time portion in the figure) between the time when the transmitting device 1A transmits the beacon signal 5A to the irradiation range A and the time when the transmitting device 1B transmits the beacon signal 5B to the irradiation range B. There is. Accordingly, the receiving device 2 does not receive the beacon signal 5A and the beacon signal 5B in an overlapping manner in the irradiation range C where the beacon signal 5A and the beacon signal 5B are overlapped, and the beacon signal 5A and the beacon signal 5B are received. Can be received once every transmission period.

  In this way, the receiving device 2 can reliably receive all the beacon signals 5 that can be received within the range even in the range where the irradiation ranges of the beacon signals 5 overlap. And the position of the receiver 2 can be detected from the installation position of the transmitter 1 that has transmitted the beacon signal 5. In particular, when a plurality of beacon signals 5 are received, it can be determined that the receiving device 2 is within the overlapping range of beacon signals transmitted from the plurality of transmitting devices 1, so the installation interval between the plurality of transmitting devices 1 is reduced. By increasing the range in which the beacon signals overlap, it is possible to grasp the position of the receiving device 2 in detail.

  In this example, the case where the irradiation ranges of the beacon signals 5 of the two transmission devices 1 overlap has been described, but the reception device 2 even when the irradiation ranges of the beacon signals 5 of three or more transmission devices 1 overlap. Can be detected. In this case, it is necessary to set the transmission cycle in which the transmission device 1 transmits the beacon signal 5 so that all the beacon signals 5 of the transmission device 1 having overlapping irradiation ranges can be accommodated within the period time (transmission cycle).

(Operation of transmitter)
Next, the operation of each device will be described. First, the operation of the transmission device 1 will be described. FIG. 7 is a flowchart showing the operation of the transmission device 1. When the optical receiving unit 8 is activated (step S701), the control calculation unit 10 starts measuring the period time (transmission period) (step S702). And the control calculating part 10 judges whether the optical receiving part 8 received the beacon signal 5 of the other transmission apparatus 1 (step S703).

  Specifically, whether or not the optical receiver 8 receives an optical signal reflected from the floor, demodulates the optical signal into a beacon signal 5, and whether the control arithmetic unit 10 receives the demodulated beacon signal 5 or not. Judging. In the first step S703, it is only necessary to determine whether or not the beacon signal 5 has been received. However, in the second and subsequent steps S703, there is a possibility of receiving the own beacon signal 5. It is necessary to determine whether or not the beacon signal 5 of another transmitting device 1 has been received from the beacon ID included in the signal 5.

  When the control calculation unit 10 determines that the light reception unit 8 has not received the beacon signal 5 of the other transmission device 1 (step S703: No), the control calculation unit 10 acquires the beacon ID from the storage unit 6. (Step S704), the beacon signal 5 including the beacon ID is generated (Step S705). The optical transmission unit 7 modulates the generated beacon signal 5 (step S706) and transmits it as an optical signal (step S707).

  The control calculation unit 10 determines whether or not the cycle time (transmission cycle) of the beacon signal 5 has elapsed (step S708). While determining that the cycle time of the beacon signal 5 has not elapsed (step S708: No), the control calculation unit 10 waits without doing anything and determines that the cycle time of the beacon signal 5 has elapsed (step S708). : Yes), the process returns to step S703 and the following steps are repeated.

  In step S703, when the control calculation unit 10 determines that the light receiving unit 8 has received the beacon signal 5 of the other transmission device 1 (step S703: Yes), the delay unit 9 is within the cycle time (transmission cycle). A random waiting time is generated (step S709), and transmission of the beacon signal 5 is delayed. That is, the delay unit 9 prevents the transmission device 1 from performing operations from step S704 to step S708 during the waiting time. In addition, since the transmission apparatus 1 needs to transmit the beacon signal 5 within the period time (transmission period), that is, the beacon signal 5 needs to be stored within the period time (transmission period), the waiting time is maximum. It must be within the period time (transmission period).

  The control calculation unit 10 determines whether the waiting time has elapsed (step S710). The control calculation unit 10 waits without doing anything while determining that the waiting time has not elapsed (step S710: No), and returns to step S703 when determining that the waiting time has elapsed (step S710: Yes). Repeat the following steps. In addition, when the beacon signal 5 of the other transmission device 1 is received again in step S703 (step S703: Yes), the delay unit 9 further generates a random waiting time within the period time (transmission period) ( Step S709). Note that the waiting time at this time needs to be set so that the time obtained by adding the waiting time generated in the previous step S709 is at most a cycle time (transmission cycle).

  By executing the above steps, the transmission device 1 can periodically transmit its own beacon signal 5 so as not to overlap with the transmission cycle of the beacon signal 5 of another transmission device 1. That is, stable transmission of the beacon signal 5 becomes possible regardless of whether or not the irradiation ranges of the beacon signal 5 overlap.

  Moreover, in this example, before the transmission apparatus 1 transmits its own beacon signal 5, the presence / absence of reception of the beacon signal 5 of another transmission apparatus 1 is determined. However, the present invention is not limited to this. For example, after the transmitting device 1 transmits its own beacon signal 5, it is determined whether the beacon signal 5 received by the light receiving unit 8 is its own beacon signal 5 or the beacon signal 5 of another transmitting device 1. In the case of the beacon signal 5 of another transmitting device 1, the beacon signal 5 may be transmitted again after a predetermined time has elapsed.

  Further, a warning LED lamp is provided in the transmission device 1, and when the transmission device 1 repeats the retransmission process in steps S703-S709-S710 more than a specified number of times, the LED lamp is turned on. The user may be informed that all the beacon signals 5 of the transmitting device 1 whose irradiation ranges overlap within the cycle time (transmitting cycle) cannot be stored. In this case, by taking measures such as reducing the number of transmitters 1 installed or resetting the period, all the beacon signals 5 of the transmitters 1 whose irradiation ranges are overlapped are within the period time (transmission period). Can be stored.

  Furthermore, if the waiting time is set so as to be less than twice the transmission time of the beacon signal 5, the beacon signal in the overlapping irradiation region can be efficiently contained within the period time (transmission period).

(Receiver operation)
Next, the operation of the receiving device 2 will be described. FIG. 8 is a flowchart showing the operation of the receiving device 2. The optical receiving unit 11 is activated (step S801), and the determination unit 12 starts measuring the period time (transmission period) (step S802). When receiving the optical signal (step S803), the optical receiver 11 demodulates the signal into the beacon signal 5 (step S804). The control calculation unit 13 acquires a beacon ID from the demodulated beacon signal 5 (step S805).

  The determination unit 12 determines whether or not the period time (transmission period) has elapsed (step S806). When determining that the cycle time has not elapsed (step S806: No), the determining unit 12 returns to step S803 and performs the following steps. If the determination unit 12 determines that the cycle time has elapsed (step S806: Yes), the optical reception unit 11 receives the optical signal (step S807) and demodulates the signal into the beacon signal 5 (step S808). ). The control calculation unit 13 acquires a beacon ID from the demodulated beacon signal 5 (step S809).

  The control calculation unit 13 acquires the first beacon ID (beacon ID acquired in step S809) acquired after the period time (transmission period) has elapsed and the first after measurement of the period time (transmission period) starts. It is determined whether the beacon ID (here, the beacon ID acquired in the first step S805) is the same (step S810).

  FIG. 9 is a diagram illustrating the beacon signal 5 received by the receiving device 2. In the figure, the receiving device 2 is in a region where the optical signals transmitted by the two adjacent transmitting devices 1A and 1B overlap, and receives the respective optical signals. When the receiving device 2 receives the two beacon signals 5A and 5B in the same order within a period time (transmission period) as indicated by a solid line, that is, a beacon signal received for the first time after the start of the first period time (transmission period). And when the beacon signal received for the first time after the start of the next cycle time (transmission cycle) is the same beacon signal 5A, it can be seen that acquisition of the beacon ID is successful.

  On the other hand, when the receiving device 2 receives the next beacon signal 5A before the end of the first cycle time (transmission cycle) as indicated by a dotted line, that is, the reception device 2 receives the first time after the start of the next cycle time (transmission cycle). When the beacon signal is the beacon signal 5B, it can be seen that the acquisition of the beacon ID has failed because the optical signals transmitted by the two adjacent transmission devices 1 collide.

  When the control calculation unit 13 determines that the two beacon IDs are the same (step S810: Yes), the control calculation unit 13 determines that the acquisition of the beacon ID is successful, and all the beacon IDs acquired within the period time (transmission period) The device ID of the receiving device 2 is associated and stored as detection information in the storage unit 18 (step S811).

  Here, the beacon ID acquired first after the elapse of the cycle time (transmission cycle) (the beacon ID acquired in step S809) is acquired first after the start of the cycle time (transmission cycle) in the next cycle. Since it is a beacon ID, it is kept as it is. The communication unit 15 transmits the detection information stored in the storage unit 14 to the position information acquisition device 3 (Step S812). After step S812 is completed, the process returns to step S803 and the following steps are performed.

  When the control calculation unit 13 determines that the two beacon IDs are not the same (step S810: No), the control calculation unit 13 determines that acquisition of the beacon ID has failed, and determines all beacon IDs acquired within the period time (transmission period). All are discarded (step S813).

  Here, the beacon ID acquired first after the elapse of the cycle time (transmission cycle) (the beacon ID acquired in step S809) is acquired first after the start of the cycle time (transmission cycle) in the next cycle. Since it is a beacon ID, it is kept as it is. After the end of step S813, the process returns to step S803 and the following steps are performed.

  In the next step S810, the control calculation unit 13 sets the beacon ID (beacon ID acquired in step S809) and the cycle time (transmission cycle) acquired first after the cycle time (transmission cycle) has elapsed. It is determined whether the beacon ID acquired first after the start of measurement (the beacon ID acquired in the previous step S809) is the same.

  By executing the above steps, the receiving device 2 can receive all the beacon signals 5 that can be received at the position and transmit the information to the position information acquiring device 3.

  Moreover, in this example, the receiving apparatus 2 has the same beacon signal received after the start of the first cycle time (transmission cycle) and the beacon signal received after the start of the next cycle time (transmission cycle). In this case, it is determined that the acquisition of the beacon ID has succeeded in only one cycle. However, if the beacon is careful, the beacon ID of the beacon ID is the same when the order of the beacon signals received for several cycles is the same. You may determine that the acquisition was successful.

(Operation of location information acquisition device)
Finally, the operation of the position information acquisition device 3 will be described. FIG. 10 is a flowchart showing the operation of the position information acquisition apparatus 3. The communication unit 16 receives the detection information in which the beacon ID and the device ID of the receiving device 2 are associated from the receiving device 2 (step S1001).

  The control calculation unit 17 detects the detection information in which the received beacon ID is associated with the device ID of the reception device 2, the time information when the detection information is received, and the installation position of the transmission device 1 stored in the storage unit 18. Based on the transmission device information in which the installation information to be shown and the beacon ID are associated with each other, the location information of the reception device 2 is acquired (step S1002).

  When the control calculation unit 13 stores the acquired position information in the storage unit 18 (step S1003), the control calculation unit 13 returns to step S1001 and performs the following steps. By executing the above steps, the position information acquisition device 3 can acquire the position information of the reception device 2.

(Method for associating transmission device installation information with beacon ID)
A method for associating the installation information and the beacon ID in the transmission device information will be described. FIG. 11 is a diagram illustrating the association between the installation information of the transmission device 1 and the beacon ID. In the figure, four transmitting devices 1A to 1D are installed in the living room A.

  When it is desired to install the transmitters 1A to 1D at random, after the transmitters 1A to 1D are installed on a structure such as a ceiling or a wall in the living room, all the transmitters 1A to 1D are operated, and a certain amount of time is required. After the elapse of the adjustment of the transmission period of the beacon signal between the transmitting devices 1A to 1D, the receiving device 1 is actually moved along the preset route 24, so that the transmitting devices 1A to 1D It is possible to associate the installation position with the beacon ID.

  For example, in the figure, when receiving device 1 receives beacon signals 5C and 5D when it is at point 25 on route 24, it can be seen that receiving device 1 is in a position where signals of transmitting devices 1C and 1D overlap. Then, if there is an object that exists at the position (or the closest position), for example, a printer, the position directly above the printer is determined as the installation position, and the position information of the printer is obtained from the building information such as the floor plan of the room. The installation position can be associated with the beacon signals 5C and 5D. If this method is used, the installation of the transmission device 1 can be simplified because the transmission device 1 can be installed randomly.

  Moreover, since the range which transmission apparatus 1A-1D irradiates beacon signals 5A-5D and the range which a mutual beacon signal overlaps can be calculated | required by calculation, when the installation position of transmission apparatus 1A-1D is known correctly From the calculation result, it is possible to associate the installation positions of the transmission devices 1A to 1D with the beacon ID. For example, in the figure, the center of gravity position 27 in the range 26 where the beacon signals 5A and 5C of the transmission devices 1A and 1C can be received is determined as the installation position, and the installation position and the beacon signals 5A and 5C can be associated. Furthermore, in order to raise the accuracy of the association between the installation information of the transmission devices 1A to 1D and the beacon ID, as described above, after the operation of the transmission devices 1A to 1D, 24 routes that have been set in advance for the reception device 1 are provided. It is also possible to adjust the calculation result based on the combination of the beacon signals 5A to 5D actually received by the receiving device 1.

(Modification)
As a modification of the first embodiment, an illuminating device such as LED lighting is used as a light emitting element used for the light transmitting unit 7 of the transmitting device 1, and the beacon signal 5 is superimposed on the illumination light (illumination signal). Thus, lighting of a room or the like and transmission of the beacon signal 5 can be performed simultaneously. FIG. 12 is a diagram for explaining a method of superimposing the illumination light and the beacon signal 5 when an LED is used as the light emitting element.

  As shown in the figure, the illumination signal 29 (for example, DC signal) generated by the illumination signal control unit 28 has a desired ratio, for example, 30% for the signal modulation signal 30 and 70% for the DC component signal 31. Is divided by the dividing unit 32. The signal modulation signal 30 is multiplied by the beacon signal 5 generated by the control calculation unit 10 of the transmission device 1 and modulated by the modulation unit of the light transmission unit 7. The modulated signal 33 is combined with the DC component signal 31 by the combining unit 34, and the LED (light emitting element) of the light transmitting unit 7 is caused to emit light as the illumination drive signal 35. Thus, 30% of the illumination signal 29 is for the signal modulation signal 30 and 70% is for the DC component signal 31, and the modulation degree of the LED illumination light is suppressed to 30%. The beacon signal 5 can be transmitted by visible light communication with reduced flickering.

  In the case of an illuminating device that emits light from an inverter, such as a fluorescent lamp, it is possible to perform transmission while suppressing flickering of illumination by modulating the cycle of the inverter signal with a beacon signal, and the frequency variation of the receiving device 1 The beacon signal can be received by demodulating by the optical receiver 11.

  As described above, according to the position detection system according to the first embodiment, the transmission device can directly transmit its own transmission signal (beacon signal) depending on whether or not the transmission signal (beacon signal) is received from another transmission device. Since it transmits periodically or periodically after a certain time delay, these transmission signals (beacon signals) transmitted from each transmission device overlap these irradiation signals ( All the beacon signals can be stored within the cycle time (transmission cycle) of the transmission device without overlapping, and the reception device can reliably receive these transmission signals (beacon signals). Even if they are densely installed, it is possible to reliably detect the position of the receiving device.

(Second Embodiment)
In the position detection system according to the first embodiment, each beacon signal in a range where the beacon signals are overlapped and irradiated by control by time division multiplexing is identified. However, the position detection system according to the second embodiment Then, each beacon signal in a range in which beacon signals are overlapped and irradiated by control by code division multiplexing is identified.

  A second embodiment will be described with reference to the accompanying drawings. With respect to the configuration example of the position detection system according to the present exemplary embodiment, a part different from the first exemplary embodiment will be described. The other parts are the same as those in the first embodiment, so the description is omitted with reference to the above description. FIG. 13 is a schematic diagram illustrating the configuration of the position detection system according to the second embodiment, and FIG. 14 is a block diagram illustrating the configuration of the position detection system according to the second embodiment.

  The position detection system includes a plurality of transmission devices 41, a reception device 42, and a position information acquisition device 43, and the reception device 42 and the position information acquisition device 43 are connected to the wireless and wired network 4. Are connected to each other.

  The transmission device 41 transmits a beacon signal 44 including a beacon ID as an optical signal in a predetermined direction (lower side in FIG. 11) at a predetermined fixed period time (transmission cycle). The transmission cycle in which the transmission device 41 transmits the beacon signal 44 is the same for all transmission devices 41. A plurality of transmission devices 41 are installed at fixed intervals in a facility such as a ceiling or a wall. The transmission device 41 includes a storage unit 6, a spread code generation unit 45, a selection unit 46, a signal synthesis unit 47, a light transmission unit 7, and a control calculation unit 10.

  The spreading code generation unit 45 generates a spreading code such as an M-sequence code or a Gold code string. The selection unit 46 selects an appropriate spreading code from the spreading code group generated by the spreading code generation unit 45 based on the setting information. The setting information is information set by the position of a mechanical switch (not shown) provided in the transmission device 41. The signal synthesis unit 47 generates an information signal (baseband signal) configured in a predetermined format including a beacon ID necessary for generating the beacon signal 44, and further, the spreading code and the baseband signal selected by the selection unit 46 And the beacon signal 44 is generated. For example, a CPU or the like is used for the spread code generation unit 45, the selection unit 46, and the signal synthesis unit 47.

  FIG. 15 is a diagram illustrating an example of the configuration of the beacon signal 44 and a method for generating the beacon signal 44 in the signal synthesis unit 47. The beacon signal 44 has a start information block 48 having a predetermined bit length and pattern for synchronization upon reception, a beacon ID block 49 indicating a beacon ID, and a predetermined bit length and pattern indicating the end of the beacon signal. It consists of a stop information block 50.

  The baseband signal 51 is a binary data signal before the beacon signal 44 is generated by the spreading process, and is configured in the same format as the beacon signal 44. In this example, the spread code 52 is an M-sequence code having 7 chips equal to the bit width of the baseband signal. Then, the signal synthesizer 47 performs a spreading process that takes a logical product of the baseband signal 51 and the spreading code 52 synchronized with the baseband signal 51 to generate a beacon signal 44 that is a modulated signal by direct spreading. .

  The receiving device 42 receives the beacon signal 44 transmitted from the transmitting device 41, and associates the beacon ID obtained from the received beacon signal 44, time information indicating the time when the beacon ID is acquired, and the device ID. Send detection information. The receiving device 42 moves together with a person or a device when a person carrying the receiving device 42 or a device in which the receiving device 42 is installed moves in a room where the transmitting device 41 is installed. The receiving device 42 is arranged at a position where the beacon signal 44 from the transmitting device 41 can be received even during movement. The receiving device 42 includes an optical receiving unit 11, a spread code generation unit 53, a demodulation unit 54, a control calculation unit 55, a storage unit 56, and a communication unit 15.

  The spreading code generation unit 53 generates the same spreading code group as the spreading code group generated by the spreading code generation unit 45 of the transmission device 41. The demodulator 54 demodulates the baseband signal 51 from the beacon signal 44 by despreading processing using the spreading code generated by the spreading code generator 53. For the spread code generation unit 53 and the demodulation unit 54, for example, a CPU or the like is used.

  The control calculation unit 55 performs control of various units constituting the reception device 42 and various processes. As one of the processes, the control calculation unit 55 determines whether or not a predetermined observation time has elapsed, and is included in one or a plurality of beacon signals 44 received within a period time (transmission period). The beacon ID being identified. As the control calculation unit 55, for example, a CPU or the like is used.

  The storage unit 56 stores the device ID of the receiving device 42 in advance, and also stores the beacon ID obtained from the received beacon signal 44, time information indicating the time when the beacon ID is acquired, and detection information associated with the device ID. Remember. FIG. 16 is a diagram illustrating an example of a configuration of detection information.

The position information acquisition device 43 receives the detection information transmitted from the reception device 42, and
Position information indicating the current position of the reception device 42 is acquired from the received detection information and transmission device information in which the installation information indicating the installation position of the transmission device 41 and the beacon ID are associated with each other. Is provided to various location information use services. The position information acquisition device 43 includes a communication unit 16, a control calculation unit 57, and a storage unit 18.

  The control calculation unit 57 controls each part of the position information acquisition device 43 and performs various processes. As one of the processes, the control calculation unit 57 detects the beacon ID received from the receiving device 2, the time information, the detection information associated with the device ID, the installation information indicating the installation position of the transmission device 41, and the beacon ID. The position information of the receiving device 42 is acquired from the transmitting device information associated with the. As the control calculation unit 57, for example, a CPU or the like is used.

(Position detection method)
A method for detecting the position of the receiving device 42 will be described. First, a mechanism in which the receiving device 42 reliably receives the optical signal (beacon signal 44) from the transmitting device 41 will be described. FIG. 17 is a diagram illustrating an area (irradiation range) where the transmission device 41 transmits an optical signal (beacon signal 44). In the figure, two adjacent transmission devices 41 (here, transmission device 41A and transmission device 41B) periodically transmit optical signals (here, beacon signal 44A and beacon signal 44B) to the lower side ( Usually, it is transmitted in the range of 1 to several seconds), and the transmission area (irradiation range) is almost fixed by the directivity. Note that the transmission device 41A and the transmission device 41B are set in advance such that the setting information of the selection unit 46 is different, and therefore the spreading codes selected by the selection unit 46 are also different.

  Here, the irradiation range A represents the range in which the beacon signal 44A of the transmission device 41A is irradiated, the irradiation range B represents the range in which the beacon signal 44B of the transmission device 41B is irradiated, and the irradiation range C represents the transmission device. The beacon signal 44 </ b> A of 41 </ b> A and the beacon signal 44 </ b> B of the transmission device 41 </ b> B are overlapped and represent a range to be irradiated. The receiving device 42 is in any one of the irradiation ranges A to C, and receives the beacon signal 44. However, unlike the position detection system according to the first embodiment, the transmitting device 41A and the transmitting device 41B are mutually opposed. Without considering the transmission of the beacon signal 44, the own beacon signal 44 is periodically transmitted.

  FIG. 18 is a diagram illustrating a beacon signal 44 received by the receiving device 42 when the receiving device 42 is in each irradiation range. In the irradiation range A, the receiving device 42 receives only the beacon signal 44A of the transmitting device 41A once every transmission cycle, and in the irradiation range B, receives only the beacon signal 44B of the transmitting device 41B once every transmission cycle. .

  Furthermore, in the irradiation range C where the beacon signal 44A and the beacon signal 44B are overlapped and received, the receiving device 42 receives a signal in which the beacon signal 44A and the beacon signal 44B overlap each other once every transmission period. However, since the beacon signal 44A and the beacon signal 44B are spread with different spreading codes, the receiving device 42 separates the beacon signal 44A and the beacon signal 44B from the duplicate signals by despreading processing using each spreading code. Is possible. Therefore, it is possible to accurately receive the beacon signal 44 from the duplicate signal received within a predetermined time (observation cycle) set longer than the cycle time (transmission cycle) in consideration of signal duplication.

  Thus, the receiving device 42 can reliably receive all the beacon signals 44 that can be received within the range even in the overlapping range of the irradiation ranges of the beacon signals 44. Then, the position of the receiving device 42 can be detected from the installation position of the transmitting device 41 that has transmitted the beacon signal 44. In particular, when a plurality of beacon signals 44 are received, since it can be determined that the receiving device 42 is in a range where beacon signals transmitted from the plurality of transmitting devices 41 overlap, the installation interval between the plurality of transmitting devices 41 is reduced. By increasing the range where the beacon signals overlap, it is possible to grasp the position of the receiving device 42 in detail.

  In this example, the case where the irradiation ranges of the beacon signals 44 of the two transmission devices 41 overlap has been described, but the reception device 42 even when the irradiation ranges of the beacon signals 44 of the three or more transmission devices 41 overlap. Can be detected. In this case, it is necessary to set the setting information so that each transmitting device 41 selects a different spreading code.

(Operation of transmitter)
Next, the operation of each device will be described. First, the operation of the transmission device 41 will be described. FIG. 19 is a flowchart showing the operation of the transmission device 41. When the transmitter 41 is activated, the spreading code generation unit 45 generates a spreading code group (step S1901), and the selection unit 46 selects one appropriate spreading code from the generated spreading code group (step S1902). ). The signal synthesis unit 47 acquires the beacon ID from the storage unit 6 (step S1903), and generates the baseband signal 51 (step S1904). Further, the signal synthesis unit 47 generates a beacon signal 44 by spreading the spreading code selected by the selection unit 46 and the baseband signal 51 (step S1905).

  The optical transmission unit 7 modulates the generated beacon signal 44 (step S1906) and transmits it as an optical signal (step S1907). The control calculation unit 10 determines whether or not the cycle time (transmission cycle) of the beacon signal 44 has elapsed (step S1908). While determining that the cycle time of the beacon signal 44 has not elapsed (step S1908: No), the control calculation unit 10 waits without doing anything and determines that the cycle time of the beacon signal 44 has elapsed (step S1908). : Yes), the process returns to step S1901, and the following steps are repeated. Instead of returning to step S1901, it may return to step S1906 and repeat the following steps.

(Receiver operation)
Next, the operation of the receiving device 42 will be described. FIG. 20 is a flowchart showing the operation of the receiving device 42. When the optical receiving unit 11 is activated (step S2001), the control calculation unit 55 starts measuring the observation cycle time (step S2002). Note that the observation cycle is set in advance to a time longer than the cycle time (for example, twice the cycle period). The demodulator 54 selects one spread code generated by the spread code generator 53 (step S2003). When receiving the optical signal (step S2004), the optical receiver 11 demodulates the signal into the beacon signal 44 (step S2005).

  The demodulator 54 performs detection synchronization processing (step S2006), and demodulates the signal (baseband signal 51) from the beacon signal 44 by despreading processing using the selected spreading code (step S2007). The control calculation unit 55 determines whether or not the demodulated signal is the baseband signal 51 (step S2008). If the control calculation unit 55 determines that the demodulated signal is the baseband signal 51 (step S2008: Yes), it acquires a beacon ID from the baseband signal 51 (step S2009), and proceeds to step S2010. If the control calculation unit 55 determines that the demodulated signal is not the baseband signal 51 (step S2008: No), the process proceeds directly to step S2010.

  In step S2010, the control calculation unit 55 determines whether the observation cycle time has elapsed. When determining that the observation cycle time has not elapsed (step S2010: No), the control calculation unit 55 returns to step S2004 and performs the following steps. When determining that the observation cycle time has elapsed (step S2010: Yes), the control calculation unit 55 stores the acquired beacon ID in the storage unit 56 (step S2011).

  The demodulator 54 determines whether there are any other spreading codes generated by the spreading code generator 53 (step S2012). When the demodulation unit 54 determines that there are other spreading codes generated by the spreading code generation unit 53 (step S2012: Yes), it selects another spreading code (step S2013), returns to step S2004, and performs the following steps: repeat. When the demodulation unit 54 determines that there is no other spreading code generated by the spreading code generation unit 53 (step S2012: No), the control calculation unit 55 obtains all the acquired beacon IDs and times when the beacon IDs are acquired. The time information shown and the device ID of the receiving device 42 are associated with each other and stored in the storage unit 56 as detection information (step S2014). Here, the times of the time information are all the same time, for example, the time when the optical signal is received for the first time after selecting the first spreading code.

  The communication unit 15 transmits the detection information stored in the storage unit 56 to the position information acquisition device 43 (step S2015). After step 2015 ends, the process returns to step S2003, and the following steps are performed. By executing the above steps, the receiving device 42 can receive all the beacon signals 44 that can be received at the position and transmit the information to the position information acquiring device 43.

(Operation of location information acquisition device)
Finally, the operation of the position information acquisition device 43 will be described. FIG. 21 is a flowchart showing the operation of the position information acquisition device 43. The communication unit 16 receives detection information that associates the beacon ID, the time information, and the device ID of the receiving device 42 from the receiving device 42 (step S2101).

  The control calculation unit 57 includes the received beacon ID, time information, and detection information associated with the device ID of the reception device 2, installation information indicating the installation position of the transmission device 41 stored in the storage unit 18, and the beacon ID. Is acquired based on the transmission device information associated with (step S2102).

  When the control calculation unit 57 stores the acquired position information in the storage unit 18 (step S2103), the control calculation unit 57 returns to step S2101 and performs the following steps. By repeating the operations from step S2101 to step S2103, the position information acquisition device 43 can acquire the position information of the reception device. By executing the above steps, the position information acquisition device 43 can acquire the position information of the reception device 42.

  Note that the method for associating the installation information and the beacon ID in the transmission device information is the same as in the first embodiment, and thus the description thereof is omitted.

  As described above, according to the position detection system according to the second embodiment, a transmission signal (beacon signal) in which the transmission device spreads and modulates the identification information of its own transmission device using a spreading code different from other transmission devices. Therefore, even in a range where a plurality of transmission signals (beacon signals) transmitted from each transmission device are overlapped and irradiated, the reception device reverses the received transmission signal (beacon signal) with the same spreading code as the transmission device. Since it is spread and the identification information of the transmitting device can be accurately acquired, the position of the receiving device can be reliably detected even if the transmitting devices are densely installed.

(Third embodiment)
In the position detection system according to the third embodiment, the spreading code that spreads the baseband signal of its own sending device from the result of the receiving device receiving and despreading the beacon signal sent from the other sending device. In addition, the reception device receives the beacon signal received from the transmission device and performs a despreading process to determine whether or not the spreading code is used for the spreading process of the baseband signal in the beacon signal.

  A third embodiment will be described with reference to the accompanying drawings. With respect to the configuration example of the position detection system according to the present exemplary embodiment, a part different from the second exemplary embodiment will be described. The other parts are the same as those in the second embodiment, so the description is omitted with reference to the above description. FIG. 22 is a schematic diagram illustrating the configuration of the position detection system according to the third embodiment, and FIG. 23 is a block diagram illustrating the configuration of the position detection system according to the third embodiment.

  The position detection system includes a plurality of transmission devices 61, a reception device 62, and a position information acquisition device 43, and the reception device 62 and the position information acquisition device 43 are connected to the wireless and wired network 4. Are connected to each other.

  The transmission device 61 transmits a beacon signal 44 including a beacon ID as an optical signal in a predetermined direction (lower side in FIG. 22) at a predetermined fixed period time (transmission cycle). Note that the transmission cycle in which the transmission device 61 transmits the beacon signal 44 is the same for all transmission devices 61. A plurality of transmission devices 61 are installed at fixed intervals in a facility such as a ceiling or a wall. The transmission device 61 includes a storage unit 63, a spread code generation unit 45, a selection unit 64, a signal synthesis unit 47, a light transmission unit 7, a control calculation unit 10, an optical reception unit 65, a despreading unit 66, and a determination unit 67. It is prepared for.

  The memory | storage part 63 memorize | stores beacon ID and a spreading code, for example, consists of ROM, RAM, etc. The selection unit 64 selects the same spreading code as the spreading code stored in the storage unit 63 from the spreading code group generated by the spreading code generation unit 45. The optical receiver 65 receives the optical signal and demodulates it into a beacon signal 44. Note that the optical signal received by the optical receiver 65 may be the beacon signal 44 reflected by the floor or the like, or the beacon signal 44 of another transmitter 61 reflected by the floor or the like. The optical receiver 65 includes a photodetection element such as a photodiode or phototransistor that receives an optical signal, and a demodulation circuit that demodulates the received optical signal into a beacon signal 44.

  The despreading unit 66 despreads the received beacon signal 44 of the other transmission device 61 with the spreading code stored in the storage unit 63. The determination unit 67 determines whether or not to change the spreading code stored in the storage unit 63 from the correlation output value that is the result of the despreading process performed by the despreading unit 66. For the selection unit 64, the despreading unit 66, and the determination unit 67, for example, a CPU or the like is used.

  The receiving device 62 received the beacon signal 44 transmitted from the transmitting device 61, and associated the beacon ID obtained from the received beacon signal 44, time information indicating the time when the beacon ID was acquired, and the device ID. Send detection information. The receiving device 62 moves together with the person or the device when the person carrying the receiving device 62 or the device on which the receiving device 62 is installed moves in the room where the transmitting device 61 is installed. The receiving device 62 is disposed at a position where the beacon signal 44 from the transmitting device 61 can be received even during movement. The receiving device 62 includes an optical receiving unit 11, a spread code generation unit 53, a demodulation unit 54, a control calculation unit 55, a communication unit 15, a determination unit 68, and a storage unit 69.

  The determination unit 68 determines whether or not there is a beacon signal 44 that has been spread-processed with the spread code, from the correlation output value that is the result of despreading the beacon signal 44 with the spread code by the demodulation unit 54. For the determination unit 68, for example, a CPU or the like is used.

  The storage unit 69 stores the device ID of the receiving device 42 in advance, and also stores the beacon ID obtained from the received beacon signal 5, time information indicating the time when the beacon ID is acquired, and detection information associated with the device ID. Remember. Further, the storage unit 69 stores the spreading code determined by the determining unit 68 as being used for the spreading process.

(Operation of transmitter)
Next, the operation of the transmission device 61 will be described. FIG. 24 is a flowchart showing the operation of the transmission device 61. When the optical receiver 65 of the transmitter 61 is activated (step S2401), the control calculation unit 10 determines whether or not the optical receiver 65 has received the beacon signal 44 of another transmitter 61 (step S2402). . Specifically, when the light receiving unit 65 receives an optical signal reflected from a floor surface or the like, it is determined that the beacon signal 44 of another transmitting device 1 has been received. If it is determined that the light receiving unit 65 has not received the beacon signal 44 of another transmitting device 1 (step S2402: No), the process proceeds to step S2406.

  When it is determined that the light receiving unit 65 has received the beacon signal 44 of another transmitting device 61 (step S2402: Yes), the despreading unit 66 stores the received beacon signal 44 of the other transmitting device 61 in the storage unit 63. A despreading process is performed using the spread code (step S2403). The determination unit 67 determines whether or not the correlation output value that is the result of the despreading process performed by the despreading unit 66 is higher than a predetermined threshold value (step S2404).

  If the determination unit 67 determines that the correlation output value is higher than a predetermined threshold value, that is, the spread code of the storage unit 63 is the same as the spread code of the other transmitter 61 (step S2404: Yes), the spread code The generation unit 45 generates a new spreading code and replaces it with the spreading code in the storage unit 63 (step 2405). Then, the process returns to step S2402, and the following steps are repeated. If the determination unit 67 determines that the correlation output value is not higher than the predetermined threshold value, that is, the spread code of the storage unit 63 is not the same as the spread code of the other transmitting device 61 (step S2404: No), it remains as it is. Proceed to the next Step 2406.

  In step S2406, the signal synthesis unit 47 acquires the beacon ID from the storage unit 63, and in the next step S2407, the signal synthesis unit 47 generates the baseband signal 51. Further, the signal synthesis unit 47 generates a beacon signal 44 by spreading the spread code stored in the storage unit 63 selected by the selection unit 64 and the baseband signal 51 (step 2408).

  The optical transmission unit 7 modulates the generated beacon signal 44 (step S2409) and transmits it as an optical signal (step S2410). The control calculation unit 10 determines whether or not the cycle time (transmission cycle) of the beacon signal 44 has elapsed (step S2411). While determining that the cycle time of the beacon signal 44 has not elapsed (step S2411: No), the control calculation unit 10 waits without doing anything and determines that the cycle time of the beacon signal 44 has elapsed (step S2411). : Yes), the process returns to step S2406 and the following steps are repeated. Instead of returning to step S2406, the process may return to step S2409 and repeat the following steps. By executing the above steps, it is possible to automatically set the spreading code when setting the transmission device 61.

(Receiver operation)
Next, the operation of the receiving device 62 will be described. FIG. 25 is a flowchart showing the operation of the receiving device 62. When the optical receiver 11 is activated (step S2501), the demodulator 54 selects one spread code generated by the spread code generator 53 (step S2502). When receiving the optical signal (step S2503), the optical receiver 11 demodulates the signal into the beacon signal 44 (step S2504).

  The demodulator 54 performs detection synchronization processing (step S2505), and despreads the beacon signal 44 with the selected spreading code (step S2506). The determination unit 68 determines whether or not the correlation output value that is the result of the despreading processing performed by the demodulation unit 54 is higher than a predetermined threshold value (step S2507). If the determination unit 68 determines that the correlation output value is higher than the predetermined threshold, that is, there is a beacon signal 44 that has been spread with the selected spread code (step S2507: Yes), the spread code is stored in the storage unit 69. (Step S2508), and the process proceeds to step S2509. If the determination unit 68 determines that the correlation output value is not higher than the predetermined threshold value, that is, there is no beacon signal 44 that has been spread with the selected spread code (step S2507: No), the process proceeds to step S2509.

  In step S2509, the demodulation unit 54 determines whether there are other spreading codes generated by the spreading code generation unit 53. When the demodulation unit 54 determines that there are other spreading codes generated by the spreading code generation unit 53 (step S2509: Yes), it selects another spreading code (step S2510), returns to step S2503, and performs the following steps: repeat. When the demodulation unit 54 determines that there is no other spreading code generated by the spreading code generation unit 53 (step S2509: No), the demodulation unit 54 selects one spreading code stored in the storage unit 69 ( Step S2511).

  When receiving the optical signal (step S2512), the optical receiver 11 demodulates the signal into the beacon signal 44 (step S2513). The demodulator 54 performs detection synchronization processing (step S2514), and demodulates the baseband signal 51 from the beacon signal 44 by despreading processing using the selected spreading code (step S2515). The control calculation unit 55 acquires the beacon ID from the baseband signal 51 and stores it in the storage unit 69 (step S2516).

  The demodulator 54 determines whether there are other spreading codes stored in the storage unit 69 (step S2517). When the demodulation unit 54 determines that there are other spreading codes stored in the storage unit 69 (step S2517: Yes), it selects another spreading code (step S2518), returns to step S2512, and performs the following steps. repeat. When the demodulation unit 54 determines that there is no other spreading code stored in the storage unit 69 (step S2517: No), the control calculation unit 55 indicates all acquired beacon IDs and times when the beacon IDs are acquired. The time information and the device ID of the receiving device 62 are associated with each other and stored in the storage unit 69 as detection information (step S2519). Here, the times of the time information are all the same time, for example, the time when the optical signal is received for the first time after selecting the first stored spread code.

  The communication unit 15 transmits the detection information stored in the storage unit 69 to the position information acquisition device 43 (step S2520). After the end of step 2520, it returns to step S2502 and performs the following steps.

  By executing the above steps, it is possible to greatly reduce the receiving operation processing with the spreading code that has not been transmitted by the receiving device 62, and it is possible to speed up the receiving process and to save energy in the receiving device 62. Become.

  Note that the operation of the position information acquisition device 43 and the method of associating the installation information and the beacon ID in the transmission device information are the same as in the second embodiment, and a description thereof will be omitted.

  As described above, according to the position detection system according to the third embodiment, the transmitting device receives the optical signal transmitted from the other transmitting device, and despreads the beacon signal demodulated from the optical signal with the spreading code. By determining whether or not the correlation output value obtained is higher than a predetermined threshold, it is possible to select a spreading code for spreading the baseband signal of its own transmitter, so use it in the transmitter It is possible to automatically set the spreading code to be performed.

  Furthermore, according to the position detection system according to the third embodiment, whether or not the correlation output value obtained by despreading the beacon signal received by the receiving device with the spreading code is higher than a predetermined threshold value. Since it is possible to determine the spreading code used for the baseband signal spreading process in the beacon signal, it is possible to greatly shorten the reception operation processing with the spreading code that is not used, It is possible to increase the speed of the reception process and save energy in the reception device.

(Modification)
Note that the position detection system according to the first to third embodiments can be variously modified. For example, the beacon signal transmitted by the transmitting device is made different from the transmission cycle of the transmitting device for each installed room. The transmission period information may be inserted into. In this case, it is possible to change the transmission period for each room in which the reception apparatus moves by appropriately acquiring the transmission period information and changing the cycle time (transmission period) and the observation period. Therefore, in a room such as a conference room where there is little movement, the power consumption of the transmission device can be suppressed by increasing the period interval.

  In the position detection systems according to the first to third embodiments, the position information acquisition device acquires the position information of the reception device from the detection information received from the reception device. Alternatively, information relating the installation information of the transmitting device and the beacon ID may be stored in advance to acquire the position information of itself.

  In the case of a system in which a receiving device is mounted on an information portable device such as a PDA or a mobile phone, a part of the function of the control calculation unit of the position information acquisition device may be performed in the receiving device. For example, the transmission device installation information is stored in an external database, and the receiving device acquires the information from the database via the network after acquiring the beacon ID, and acquires the location information of the information portable device itself. Good.

  In the position detection systems according to the first to third embodiments, a beacon signal is converted into an optical signal, that is, transmission and reception are performed using light as a medium. For example, it is possible to use ultrasonic waves or high-frequency radio waves.

(Hardware configuration)
The position information acquisition device according to the first to third embodiments includes a control device such as a CPU, a storage device such as a ROM (Read Only Memory) and a RAM, an external storage device such as an HDD and a CD drive device, and a display. It has a display device such as a device and an input device such as a keyboard and a mouse, and has a hardware configuration using a normal computer.

  The position detection program executed by the transmission device, the reception device, and the position information acquisition device according to the first to third embodiments is a file in an installable format or an executable format, and is a CD-ROM, a flexible disk ( (FD), CD-R, DVD (Digital Versatile Disk), and the like may be recorded and provided on a computer-readable recording medium.

  Further, the position detection program executed by the transmission device, the reception device, and the position information acquisition device according to the first to third embodiments is stored on a computer connected to a network such as the Internet, and is transmitted via the network. You may comprise so that it may provide by downloading. The position detection program executed by the transmission device, the reception device, and the position information acquisition device according to the first to third embodiments may be provided or distributed via a network such as the Internet.

  Further, the position detection program executed by the transmission device, the reception device, and the position information acquisition device according to the first to third embodiments may be provided by being incorporated in advance in a ROM or the like.

  The position detection program executed by the transmission device, the reception device, and the position information acquisition device according to the first to third embodiments includes the above-described units (control calculation unit, determination unit, spreading code generation unit, signal synthesis unit). , A demodulator, a selector, and a despreader). As actual hardware, the CPU (processor) reads out the position detection program from the ROM and executes the position detection program. A control calculation unit, a determination unit, a spread code generation unit, a signal synthesis unit, a demodulation unit, a selection unit, and a despreading unit are generated on the main storage device.

It is the schematic which shows the structure of the position detection system concerning 1st Embodiment. It is a block diagram which shows the structure of the position detection system concerning 1st Embodiment. It is a figure which shows an example of a structure of a beacon signal. It is a figure which shows an example of a structure of detection information. It is a figure explaining the area | region (irradiation range) which a transmission apparatus transmits an optical signal (beacon signal). It is a figure showing the beacon signal which a receiving device receives, when a receiving device exists in each irradiation range. It is a flowchart which shows operation | movement of a transmission device. It is a flowchart which shows operation | movement of a receiver. It is a figure which shows the beacon signal which a receiver receives. It is a flowchart which shows operation | movement of a positional information acquisition apparatus. It is a figure explaining the correlation with the installation information of a transmission device, and beacon ID. It is a block diagram which shows the structure of the position detection system concerning embodiment. It is the schematic which shows the structure of the position detection system concerning 2nd Embodiment. It is a block diagram which shows the structure of the position detection system concerning 2nd Embodiment. It is a figure which shows an example of a structure of a beacon signal, and the production | generation method of the beacon signal in a signal synthetic | combination part. It is a figure which shows an example of a structure of detection information. It is a figure explaining the area | region (irradiation range) which a transmission apparatus transmits an optical signal (beacon signal). It is a figure showing the beacon signal which a receiving device receives, when a receiving device exists in each irradiation range. It is a flowchart which shows operation | movement of a transmission device. It is a flowchart which shows operation | movement of a receiver. It is a flowchart which shows operation | movement of a positional information acquisition apparatus. It is the schematic which shows the structure of the position detection system concerning 3rd Embodiment. It is a block diagram which shows the structure of the position detection system concerning 3rd Embodiment. It is a flowchart which shows operation | movement of a transmission device. It is a flowchart which shows operation | movement of a receiver. It is a figure explaining a prior art.

Explanation of symbols

1, 1A, 1B, 41, 41A, 41B, 61 Transmitting device 2, 42, 62 Receiving device 3, 43 Location information acquisition device 4 Network 5, 5A, 5B, 44, 44A, 44B Beacon signal 6, 14, 18, 56, 63, 69 Storage unit 7 Optical transmission unit 8, 11, 65 Optical reception unit 9 Delay unit 10, 13, 17, 55, 57 Control operation unit 12, 67, 68 Determination unit 15, 16 Communication unit 20 Preamble signal 21 Start signal 22 Beacon ID signal 23 CRC signal 24 Directions 25 Point 26 Range 27 Center of gravity position 28 Illumination signal control unit 29 Illumination signal 30 Signal modulation signal 31 DC component signal 32 Dividing unit 33 Signal 34 Combining unit 35 Illumination drive signal 45, 53 Spread Code Generator 46, 64 Selector 47 Signal Synthesizer 48 Start Information Block 49 Beacon ID Lock 50 stop information block 51 the baseband signal 52 spread code 54 demodulator 66 despreader 100, 110, 120 IR emitter

Claims (12)

In a position detection system comprising a plurality of transmission devices, a reception device, and a position information acquisition device that is connected to the reception device via a network and acquires reception device position information indicating a current position of the reception device,
The transmitting device is
First transmission means for converting the transmission device identification information for identifying the transmission device into a transmission signal and transmitting it with a predetermined directivity;
The receiving device is:
First receiving means for receiving the transmitting device identification information which is the transmission signal;
A detection information storage means for associating and storing the received one or a plurality of the transmission device identification information and the reception device identification information for identifying the reception device as detection information;
Control means for controlling storage of the detection information storage means;
Second transmission means for transmitting the detection information,
The position information acquisition device includes:
Second receiving means for receiving the detection information;
Transmitting device information storage means for storing the transmitting device installation information indicating the installation position of the transmitting device and the transmitting device identification information in association with each other, and storing the information as transmitting device information;
An acquisition means for acquiring the reception device position information from the received detection information and the transmission device information;
A position detection system characterized by In the transmitting device,
Third receiving means for receiving another outgoing signal transmitted by the other transmitting device;
A delay means for delaying transmission of the transmission signal by a first predetermined time when the other transmission signal is received;
In the receiving device,
The control means controls the detection information storage means so as to store, as detection information, the transmitting device identification information received within a second predetermined time longer than the first predetermined time;
The position detection system according to claim 1. In the transmitting device,
Spreading code generating means for generating a plurality of spreading codes;
Selecting means for selecting a desired spreading code;
A signal synthesis means for generating a transmission signal obtained by spreading and modulating the transmission device identification information by the desired spreading code;
In the receiving device,
Spreading code generating means for generating the plurality of spreading codes;
Demodulating means for despreading the transmission signal with the desired spreading code and demodulating it into the transmission device identification information;
The control means controls the detection information storage means to store the transmission device identification information received within a third predetermined time as detection information;
The position detection system according to claim 1. In the transmitting device,
The signal synthesis means further generates a transmission signal obtained by spreading and modulating transmission cycle information indicating a transmission cycle of the transmission signal with the desired spreading code,
In the receiving device,
The control means sets the third predetermined time to a time longer than the transmission cycle;
The position detection system according to claim 3. In the transmitting device,
A fourth receiving means for receiving another outgoing signal transmitted by the other transmitting device;
First determining means for determining a spreading code obtained by spreading-modulating the other outgoing signal,
The selecting means selects a spreading code other than the spreading code determined by the first determining means as the desired spreading code;
The position detection system according to claim 3 or 4, wherein The receiving device is:
Further comprising second determination means for determining the desired spreading code obtained by spreading-modulating the transmission signal;
The position detection system according to any one of claims 3 to 5. In the receiving device,
The detection information storage means includes
Furthermore, associating and storing time information indicating the time when the one or a plurality of the transmitting device identification information is received,
The position detection system according to any one of claims 1 to 6. In the position information acquisition device,
The acquisition means includes
Obtaining the reception device position information from the received detection information, time information indicating a time when the detection information is received, and the transmission device information;
The position detection system according to any one of claims 1 to 6. The first transmission means transmits the transmission signal as an optical signal,
The first receiving means receives the optical signal;
The position detection system according to claim 1, wherein: In a transmitting device that transmits uniquely determined transmitting device identification information,
Transmitting means for transmitting the transmitter identification information as an optical signal;
Receiving means for receiving another optical signal which is the optical signal transmitted by another transmitting device;
Delay means for delaying transmission of the optical signal by a predetermined time when the other optical signal is received;
A transmitter characterized by. A position executed by a position detection system including a plurality of transmitting apparatuses, a receiving apparatus, and a position information acquisition apparatus that is connected to the receiving apparatus via a network and acquires receiving apparatus position information indicating a current position of the receiving apparatus A detection method,
The position information acquisition device includes a transmission device information storage unit that associates transmission device installation information indicating an installation position of the transmission device with transmission device identification information that identifies the transmission device, and stores the information as transmission device information.
A first transmission step in which the transmission device converts the transmission device identification information into a transmission signal and transmits the signal with a predetermined directivity;
A first receiving step in which the receiving device receives the transmitting device identification information which is the outgoing signal;
A detection information storage step in which the reception device associates and stores one or more of the transmission device identification information received in the first reception step and reception device identification information for identifying the reception device as detection information; ,
A second transmission step in which the receiving device transmits the detection information;
A second receiving step in which the position information acquisition device receives the detection information;
The location information acquisition device includes the acquisition step of acquiring the reception device location information from the detection information received in the second reception step and the transmission device information;
A position detection method characterized by the above.   A position detection program for causing a computer to execute the position detection method according to claim 11.

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