JP2007306540A - Position estimating method, position estimation system, and wireless communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position estimation system capable of reducing the problem that traffic increases as a range of position estimation and the number of reference terminals increase and also performing position estimation with high precision. <P>SOLUTION: In a position estimating method, information needed for position estimation is acquired from a radio signal, positions of a plurality of radio devices are estimated based upon the acquired information needed for position estimation, the position of a reference terminal 20, and distances among the plurality of radio devices, and the position of a target terminal 10 is estimated based upon the estimated positions of the respective radio devices. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a position estimation system that estimates the position of a wireless terminal based on a received wireless signal, and particularly relates to highly accurate position estimation.

  The conventional position estimation system, for example, “... the base station receives each radio signal transmitted from the radio communication terminal, measures the received signal strength of the received signal, and transmits to the information server, The information server receives the received signal strength from the base station, uses the received signal strength to determine a range where the wireless communication terminal corresponding to each received signal strength can exist, and from the overlap of each range Detecting the location of a wireless communication terminal ... "has been proposed (for example, see Patent Document 1).

  Also, for example, “a signal transmitted between a device whose position is known (112-118, 134-138, 224-228) and a device whose position is unknown (120-130, 222) and a set of positions are unknown. Between the first and second devices (120-130, 222) and the transmitted signal, and having a plurality of first sub-expressions and a plurality of signal measurement prediction sub-expressions having an extreme value when the predicted measurement signal is equal to the actual measurement signal A system for searching the position of a plurality of devices (112-130) by inputting a measurement signal to a graph function and optimizing the graph function has been proposed (see, for example, Patent Document 2).

  For example, when the target terminal transmits a signal and the reference terminal receives the signal from the target terminal, the received signal strength is transmitted to the position estimation server. The position estimation server estimates the most probable position of each target terminal using the received signal strength sent from each reference terminal. The radio propagation path environment fluctuates even when the target terminal does not move due to the influence of reflection and diffraction and the movement of a nearby person. A method has been proposed in which position estimation is performed in consideration of the above-described problems by modeling a radio propagation environment as a probability model (see, for example, Non-Patent Documents 1 to 4).

JP 2004-112482 A (Claim 1) JP 2005-507070 A (summary) Kentaro Yanagihara and 7 others, “Maximum Likelihood Positioning Method Using Received Signal Power in Sensor Networks”, Technical Report, IEICE, IN2004-327, pp.409-414 Kentaro Yanagihara and 6 others, "Indoor location estimation experiment using IEEE802.15.4", Technical Report, IEICE, SN2005-8, pp.33-38 Kentaro Yanagihara and 6 others, “Reduction Method of Location Estimation Data Traffic in Sensor Networks”, Proceedings of Society Conference, IEICE, A-21-20 Kentaro Yanagihara and 6 others, "Indoor location estimation experiment using IEEE802.15.4 -Effect of variation of pedestrians and reception sensitivity-", Proceedings of Society Conference, IEICE, A-21-22

  However, in the conventional position estimation system, it is necessary to increase the number of reference terminals as the area for position estimation increases. If a large number of reference terminals are installed, the system cost increases. In addition, depending on the installation environment, it may be impossible to physically install a large number of terminals. Further, in order to increase the position estimation accuracy, it is necessary to install reference terminals at a high density and collect a large amount of information in the position estimation device. However, if the number of reference terminals increases, the amount of communication for position estimation increases. An increase in the amount of communication for position estimation may degrade communication quality. Therefore, there has been a demand for a position estimation system that reduces the problem of increasing the amount of communication with an increase in the range for position estimation and the number of reference terminals, and at the same time enables highly accurate position estimation.

  The position estimation method according to the present invention includes a plurality of wireless devices, and a target terminal whose distance between the wireless devices is known and a plurality of reference terminals arranged at known positions transmit and receive wireless signals, and wireless A position estimation method for estimating a position of a target terminal based on a signal and a position of a reference terminal, acquiring information necessary for position estimation from a radio signal, at least information necessary for position estimation, and a reference terminal The estimated positions of the plurality of wireless devices are obtained based on the positions of the wireless devices and the distances between the plurality of wireless devices, and the position of the target terminal is estimated based on the estimated positions of the plurality of wireless devices.

  In addition, a target terminal having a plurality of radios, the distance between each radio is known, a plurality of reference terminals that are arranged at known positions and exchange radio signals with the target terminals, and a radio signal and a reference terminal A position estimation device that estimates the position of the target terminal based on the position and the distance between each wireless device, the position estimation device acquires information necessary for position estimation from a radio signal, and at least for the acquired position estimation The estimated position of each of the plurality of radios is obtained based on the necessary information, the position of the reference terminal, and the distance between the plurality of radios, and the position of the target terminal is estimated based on the estimated position of each of the plurality of radios Is.

  The present invention acquires information necessary for position estimation from a radio signal, and each of a plurality of radios based on at least the information necessary for position estimation, the position of a reference terminal, and the distance between the plurality of radios And estimating the position of the target terminal based on the estimated positions of each of the plurality of wireless devices, the accuracy of the estimated position of the target terminal can be improved without increasing the number of reference terminals.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a position estimation system according to Embodiment 1 of the present invention. In FIG. 1, the position estimation system includes a target terminal 10 and a plurality of reference terminals 20. The dotted line shown in FIG. 1 indicates transmission (broadcast) to all peripheral terminals without specifying a transmission partner. The reference terminal 20 is a terminal whose position is known in advance, and transmits a position estimation request signal. The target terminal 10 is a terminal whose position is to be estimated, measures the received power of the position estimation request signal transmitted from the reference terminal 20, and estimates the position of the target terminal 10.

  FIG. 2 is a diagram showing the configuration of the reference terminal according to Embodiment 1 of the present invention. 2, the reference terminal 20 includes an antenna 201, a transmission circuit 202, and a transmission data generation unit 203. The antenna 201 is an antenna for transmitting a radio signal. The transmission data generation unit 203 generates a position estimation request signal including an identification code unique to the reference terminal. The transmission circuit 202 converts the position estimation request signal generated by the transmission data generation unit 203 into a radio signal and outputs it to the antenna 201.

  FIG. 3 is a diagram showing the configuration of the target terminal according to Embodiment 1 of the present invention. In FIG. 3, the target terminal 10 includes a plurality of receivers 104 that are radio devices including an antenna 101, a reception circuit 102, and a reception data processing unit 103, a data aggregation unit 105, and a position estimation process that is a position estimation device. The unit 106 is configured. The antenna 101 is an antenna for receiving a radio signal. The reception circuit 102 receives a radio signal received by the antenna 101, processes the radio signal, converts it into digital information, and outputs the digital data to the reception data processing unit 103 as reception data. Further, the receiving circuit 102 measures the received power value S1 of the input radio signal, and outputs the information of the measured received power value S1 to the received data processing unit 103 as information necessary for position estimation. The reception data processing unit 103 processes the reception data input from the reception circuit 102. When the reception data is a position estimation request signal sent from the reference terminal 20, the information included in the position estimation request signal and the reception circuit The information including the received power value S 1 measured by 102 and the identification code unique to the receiver is output to the data aggregating unit 105. The data aggregation unit 105 collects information input from the plurality of receivers 104 and outputs the information to the position estimation processing unit 106. The position estimation processing unit 106 estimates the position of the target terminal 10 by an operation described later based on a plurality of information input from the data aggregation unit 105. The positional relationship between the antennas 101 of the receivers 104, which is the distance between the radio devices, is known. For example, the distance between the antennas 101 obtained when the target terminal 10 is manufactured is used. The operation of the first embodiment configured as described above will be described with reference to FIG.

  FIG. 4 is a flowchart showing the position estimation operation of the target terminal according to Embodiment 1 of the present invention. First, each reference terminal 20 transmits a position estimation request signal including an identification code unique to the reference terminal 20 (hereinafter referred to as a transmission terminal code). Each receiver 104 of the target terminal 10 receives the position estimation request signal transmitted from each reference terminal 20, measures the received power value S1 of the received position estimation request signal, information on the received power value S1, and transmission The terminal code information and the identification code information of the receiver are output to the data aggregating unit 105 (S1). The data aggregation unit 105 collects information input from the plurality of receivers 104 and outputs the collected information to the position estimation processing unit 106. Based on the information input from the data aggregation unit 105, the position estimation processing unit 106 executes a first estimation step for obtaining a first estimated position using the position of the antenna 101 of the receiver 104 as the estimated position of the receiver 104. (S2).

  In the first estimation stage, the estimated position of the antenna 101 of each receiver 104 is obtained based on the information of the received power value S1 of the position estimation request signal received by the receiver 104, the transmission terminal code, and the position of the reference terminal 20. . As the estimated position, for example, the existence probability at each point where the antenna 101 of the receiver 104 is considered to exist is calculated from the information exchanged between each reference terminal 20 and the receiver 104 and the position of the reference terminal 20. Next, using a method such as a maximum likelihood estimation method, a point having the highest existence probability of the antenna 101 is searched, and the corresponding point is set as an estimated position of the antenna 101. Further, for example, the estimated position is obtained by referring to a table indicating the relationship between the received power value S1 and the distance and obtaining the distances between the plurality of reference terminals 20 whose positions are known in advance and the antenna 101 of the receiver 104. In addition, the acquisition method of an estimated position is not restricted to this, You may obtain | require an estimated position using another method. The first estimation step (S2) is performed on the antennas 101 of all receivers 104 (S3).

  Next, the position of the antenna 101 of the receiver 104 is determined based on the first estimated position of each receiver 104 obtained in the first estimation step (S2) and the positional relationship between the antennas 101. A second estimation step for obtaining a second estimated position as an estimated position of the receiver 104 is executed. First, an arbitrary antenna 101 as a position estimation target is selected (S4). It is assumed that each antenna 101 other than the selected antenna 101 is present at the first estimated position described above. Next, a second estimation step (S5) is performed on the selected antenna 101.

  The second estimation stage includes information exchanged between each reference terminal 20 and the receiver 104, the position of the reference terminal 20, the first estimated position of the antenna 101 of the other receiver 104 of the target terminal 10, and each A point with the highest probability that the antenna 101 of the receiver 104 exists is searched from the distance information between the antennas 101, and the corresponding point is set as the estimated position of the receiver 104. As for the estimated position, for example, (1) center coordinates are set as estimated positions of other receivers 104 of the target terminal 10. (2) Draw a circle whose radius is the distance between the receiver 104 and another receiver 104 of the target terminal 10. (3) Next, the existence probability of the receiver 104 at each point on the circumference is obtained, and the point with the highest probability is set as the estimated position of the receiver 104. However, the estimated position of the other receiver 104 of the target terminal 10 includes an error, and the calculation may not converge. In this case, the range for obtaining the point with the highest probability may be the estimated position not on the circumference but on a donut-shaped region having a radius. In addition, the acquisition method of an estimated position is not restricted to this, You may obtain | require an estimated position using another method. Since the second estimated position obtained in this way uses information between the receivers 104 as compared with the first estimated position obtained in the first estimation stage, the estimation error is reduced. The above operation is repeatedly executed for all receivers 104 of all target terminals 10 (S6).

  By executing the second estimation stage, the estimated position of the receiver 104 is changed from the first estimated position to the second estimated position. Since the estimated position of the receiver 104 is used for position estimation of the other receivers 104, the change of the estimated position of the receiver 104 affects the position estimation of the other receivers 104. Therefore, when the estimated position of the receiver 104 is changed, the position estimation of the other receivers 104 is performed again. That is, with the second estimated position as the first estimated position, the second estimation step is repeatedly executed for all the receivers 104 other than the receiver 104 (S4 to S7). Whether or not to continue the second estimation step is determined for all the receivers 104 when the result of position estimation converges or due to constraints such as calculation time (S7).

  Note that, in the process of repeating the second estimation step (S4 to S7), depending on the positional relationship of the receiver 104, the update of the estimated position may affect each other, and the position estimation result may not converge. For example, if the second estimation stage is repeatedly performed, the two receivers may alternately estimate the two estimated positions, and the position estimation may not converge.

  Therefore, the position estimation processing unit 106 has a function of comparing the estimated position obtained when updating the estimated position and the past estimated position and correcting the estimated position according to the situation. For example, when the estimated position after the update and the estimated position before the update are greatly different, the position on the line segment connecting the estimated position before the update and the estimated position after the update is set as the estimated position after the update. Further, for example, the past estimated position is recorded by the position estimation processing unit 106, and the process is stopped when the updated estimated position is the same as the past estimated position.

  Note that the difference in information obtained by each receiver 104 may be used in the data aggregation unit 105 by using the property that a plurality of receivers 104 receive the same signal at the same time. For example, when the difference in the obtained information exceeds a predetermined specified value, it may be determined that the reliability of data having a small received power value S1 is low and the data may be discarded.

  In addition, when the position estimation processing unit 106 of the target terminal 10 performs position estimation, it is also possible to use information obtained in the past together. That is, by adding a function for measuring time to the received data processing unit 103 and the position estimation processing unit 106, a function for holding the data acquisition time is added. When using data, it is also possible to adopt a configuration in which the weight for past information is changed according to the elapsed time from the present. Since past data is considered to be less reliable than current data, a method of lowering the weight of older data can be considered. For example, a method of multiplying past data by using a reciprocal of a difference from the current time as a weight can be considered.

  In addition, by adding movement detection means having a function of detecting the movement of the terminal to the target terminal 10, when using past information, depending on the presence / absence and movement amount of the terminal, It is also possible to adopt a configuration in which the weight for information is changed. That is, a function for measuring time is added to the reception data processing unit 103 and the position estimation processing unit 106 of the target terminal 10, and a movement detection unit having a function of detecting the movement of the terminal is added to the position estimation processing unit 106. However, when using past information, it is also possible to adopt a configuration in which the weight for past information is changed according to the presence / absence and amount of movement of the terminal and the elapsed time from the present.

  Further, the received data processing unit 103 retains past information, etc., determines the reliability of the obtained information, and does not notify the data aggregation unit 105 of data with low reliability, thereby improving the accuracy of position estimation. It is also possible to take a configuration for performing the above.

  As described above, the information received by the plurality of receivers 104 included in the target terminal 10 is used by the position estimation processing unit 106 mutually using the position estimation results of the other receivers 104 and repeatedly estimated. Even in a situation where the number of reference terminals 20 is small, more accurate position estimation can be realized, and an increase in communication volume can be reduced.

  Moreover, if the relative positional relationship of each receiver 104 in the target terminal 10 is fixed, the direction and rotation of the target terminal 10 can be detected as a result of estimating the position of each receiver 104. Specifically, a method of installing receivers on the left and right sides of the moving body, a method of installing receivers on the left and right of glasses, helmets, clothes, etc. in order to detect the direction in which a person is facing can be considered.

  In the present embodiment, the target terminal 10 includes the position estimation processing unit 106. However, the present invention is not limited to this, and the position estimation processing unit 106 is separated from the target terminal 10 to obtain the position. It is also possible to adopt a configuration in which the estimation processing unit 106 is another position estimation device, and data is transmitted and received between the data aggregation unit 105 and the position estimation device by some communication means. With such a configuration, it is possible to perform position estimation of a plurality of target terminals 10 with a single position estimation apparatus.

  In this embodiment, the receiver 104 measures the received power value and outputs the receiver identification code. However, the present invention is not limited to this, and the receiver power value measurement and the receiver identification code are performed. These outputs may be performed by providing other components.

  In the present embodiment, a known distance is used as the distance between the plurality of antennas 101. However, the present invention is not limited to this, and the distance between the plurality of antennas 101 is set as an arbitrary distance, that is, actually. A distance different from the distance may be used. This is because when the position estimation is performed in two dimensions, it is necessary to use the distance between the antennas on the map on which the position estimation is performed. For example, when position estimation is performed in two dimensions, if a plurality of antennas 101 that are position estimation planes are installed on a straight line that is perpendicular to the plane on which position estimation is performed, the distance between antennas is 0 in the calculation. Become. Therefore, in this case, the position is estimated with the distance between the antennas set to zero. The distance between the antennas on the plane on which such position estimation is performed will be described with reference to FIG.

  FIG. 5 is a diagram showing the distance between the antennas on the position estimation plane according to Embodiment 1 of the present invention. FIG. 5 shows a state in which the target terminals 10-a and 10-b are each provided with two antennas 101 and are arranged on an estimation plane 500 that is a plane on which position estimation is performed. The distance between the antennas of the target terminals 10-a and 10-b is D as shown in FIG. However, when mapping to the estimated plane 500, the distance between the antennas is D in the case of the target terminal 10-a, but is 0 in the case of the target terminal 10-b.

  Further, in the case where position detection is performed by adding movement detection means to the target terminal 10 described above, if the antenna 101 is installed on a straight line that is perpendicular to the movement direction of the target terminal 10, the movement detection means Are detected to be the same for each antenna 101. Therefore, in this case as well, the position estimation may be performed with the distance between the antennas set to zero.

Embodiment 2. FIG.
In Embodiment 1 above, position estimation is performed for each antenna 101 of each receiver 104. However, in Embodiment 2, any one of a plurality of antennas 101 is used as a reference antenna, and the other antennas 101 are The position is estimated based on the relative position from the reference antenna. The configuration of the position estimation system and the configurations of the target terminal 10 and the reference terminal 20 are the same as those in the first embodiment.

  FIG. 6 is a flowchart showing the position estimation operation of the target terminal according to Embodiment 2 of the present invention. Each receiver 104 of the target terminal 10 receives the position estimation request signal transmitted from each reference terminal 20, measures the received power value S1 of the received position estimation request signal, information on the received power value S1, and transmission The terminal code information and the identification code information of the receiver are output to the data aggregating unit 105 (S11). The data aggregation unit 105 collects information input from the plurality of receivers 104 and outputs the collected information to the position estimation processing unit 106. The position estimation processing unit 106 performs an estimation operation for obtaining the estimated position of the receiver 104 based on the information input from the data aggregation unit 105 (S2). Here, the position estimation processing unit 106 uses any one of the plurality of antennas 101 of the target terminal 10 as a reference antenna, and the other antennas 101 have information on the distance from the reference antenna. When the target terminal 10 has three or more antennas 101, the target terminal 10 has information on the angle formed by the straight line connecting the first antenna and the second antenna and the straight line connecting the antenna and the first antenna. . With such information, the position of the antenna 101 other than the reference antenna indicates the angle between the position of the reference antenna, the straight line connecting the first antenna and the second antenna, and the reference coordinate axis, that is, the rotation of the terminal. It can be expressed as a parameter. By using this notation format, the position estimation processing unit 106 can perform position estimation without needing to perform repeated calculations when estimating the position from information obtained from the plurality of antennas 101. For example, when position estimation on a two-dimensional plane is taken as an example, the point where the position estimation function value is highest on the two-dimensional plane is set as the estimated position in normal estimation, but in this embodiment, the first antenna The point where the position estimation function value is highest in the three-dimensional space including the angle formed by the straight line connecting the second antenna and the reference line of the position estimation plane is obtained. The obtained results indicate the position where all the antennas are most likely to exist, based on the information and constraints obtained from all the antennas.

Next, position estimation using the relative position information from the reference antenna described above will be described. FIG. 7 is a diagram showing a relative position from the reference antenna according to Embodiment 2 of the present invention. The position estimation of each receiver 104 includes information on the received power value S1 of the position estimation request signal received by the receiver 104 and the transmission terminal code, the position of the reference terminal 20, the distance between the antennas 101, and the antenna 101 3 If there are more than one, the antenna of each receiver 104 is based on the angle formed by each antenna (the angle formed by the straight line connecting the first and second antennas and the straight line connecting the antenna and the first antenna for the third or more antennas). The estimated position 101 is obtained. An example of the estimation method is shown below. Hereinafter, the first antenna 101 is referred to as a reference antenna, and the second and subsequent antennas are referred to as additional antennas. The distance between the i-th antenna and the reference antenna is Di, and the angle formed by each antenna is θi (i> 2). Note that θ2 = 0.
In FIG. 7, for example, if the estimated position of the reference antenna is (x, y), the second and subsequent estimated positions are (x + Disin (α + θi), y + Dicos (α + θi)). α indicates the angle formed by the straight line connecting the first and second lines with the x axis in the position estimation coordinates, that is, the rotation of the entire target terminal 10. That is, when x, y, and α are determined, the positions of all the antennas 101 can be determined.
Assuming the estimated positions x and y of the reference antenna and the rotation angle α, the positions of all the antennas 101 can be assumed. At this time, the existence probability of the target terminal 10 at the assumed x, y, α can be calculated from the information exchanged between each reference terminal 20 and each receiver 104 and the position of the reference terminal 20.
Further, using a method such as the maximum likelihood estimation method, a point (x, y, α) having the highest existence probability of the target terminal 10 is searched, and the point is set as an estimated position of the target terminal 10.

  As described above, in the second embodiment, in addition to the effects of the first embodiment, the positions of all the antennas 101 can be estimated from the information regarding the positions between the antennas 101 of the receivers 104. The calculation time of position estimation can be shortened without the need for repeated calculations when estimating.

Embodiment 3 FIG.
FIG. 8 is a diagram showing the configuration of the position estimation system according to Embodiment 3 of the present invention. In FIG. 8, the position estimation system of the present embodiment includes a target terminal 10, a reference terminal 20, and a position estimation device 30. The target terminal 10 is a terminal that is a target of position estimation, and transmits a position estimation request signal. When the reference terminal 20 is a terminal whose position is known in advance and receives a position estimation request signal, the reference terminal 20 transmits information necessary for position estimation as a position estimation information signal. The position estimation device 30 estimates the position of each transmitter 114 from the collected position estimation information signals, and finally estimates the position of each target terminal 10. In addition, the dotted line in the figure indicates that transmission destinations are not specified and transmission to all peripheral terminals (broadcast) is performed, and the solid line indicates transmission toward a terminal indicated by an arrow (unicast).

  FIG. 9 is a diagram showing the configuration of the target terminal according to Embodiment 3 of the present invention. In FIG. 9, the target terminal 10 includes a plurality of transmitters 114 that are radio devices including an antenna 111, a transmission circuit 112, and a transmission data generation unit 113, and a transmission management unit 115. The transmission management unit 115 avoids interference between transmission signals transmitted from the respective transmitters 114, and considers processing delays at the respective reference terminals 20 and the like. The transmission command is output. Upon receiving an instruction from the transmission management unit 115, the transmission data generation unit 113 of each transmitter 114 generates a position estimation request signal including an identification code unique to the target terminal and an identification code unique to each transmitter 114, and transmits Output to the circuit 112. The transmission circuit 112 converts the position estimation request signal generated by the transmission data generation unit 113 into a radio signal and outputs it to the antenna 111. The antenna 111 transmits the input radio signal.

  FIG. 10 is a diagram showing a configuration of a reference terminal according to Embodiment 3 of the present invention. 10, the reference terminal 20 includes an antenna 211, a transmission circuit 212, a transmission data generation unit 213, a reception circuit 214, and a reception data processing unit 215. The antenna 211, the transmission circuit 212, and the reception circuit 214 have the same functions as the antenna 201, the transmission circuit 202, and the reception circuit 102 in Embodiment 1 described above. The transmission data generation unit 213 generates a position estimation information signal for transmitting the received power value S1 input by the reception data processing unit 215, which is information necessary for position estimation, to the position estimation device 30. The reception data processing unit 215 processes the reception data input from the reception circuit 214, and when the reception data is a position estimation request signal transmitted from the target terminal 10, the transmission data generation unit 213 It instructs the generation of transmission data including the identification code unique to the target terminal included in the information of the received power value S1 measured by the reception circuit 214 and the position estimation request signal and the identification code unique to each transmitter 114.

The operation of the thus configured third embodiment will be described. First, each transmitter 114 of the target terminal 10 sends a position estimation request signal including an identification code unique to the target terminal 10 and an identification code unique to each transmitter 114 to all peripheral terminals from the antenna 111 of each transmitter 114. Send. The reception circuit 214 of the reference terminal 20 that has received the position estimation request signal inputs the obtained information to the reception data processing unit 215, and it is appropriate that the reception data processing unit 215 uses the received signal for position estimation. Is determined, the transmission data generation unit 213 is instructed to generate a position estimation information signal. The position estimation information signal includes the identification code of the target terminal 10 included in the received position estimation request signal, the identification code of the transmitter 114, the received power value S1 of the received position estimation request signal, and the reference terminal 20 specific The identification code is included. The transmission circuit 212 transmits the position estimation information signal to the position estimation device 30.
The position estimation device 30 aggregates the data for each identification code of the target terminal 10 and the unique identification code of the transmitter 114 included in the position estimation information signal received from the reference terminal 20, and is the same as in the first embodiment described above. By operation, the position of each transmitter 114 of each target terminal 10 is estimated. In the present embodiment, since the estimation result of the target terminal 10 does not affect other target terminals 10, the processing in the position estimation device 30 is simple parallel processing.

  Also in the present embodiment, as in the case of the first embodiment described above, in the process of iterative calculation, the update of the estimated position affects each other depending on the positional relationship of the transmitters, so that the position estimation result converges. There is a possibility that it will not. Therefore, the position estimation device 30 has a function of comparing the estimated position obtained when updating the estimated position and the past estimated position and correcting the estimated position according to the situation.

  As in the first embodiment, the target terminal 10 is equipped with a plurality of antennas 111, and by estimating the position of each transmitter 114, the direction and rotation of the terminal can be detected. In order to detect the direction and rotation, it is necessary to make a comparison with past estimation results.

  Further, in the present embodiment, a plurality of signals are transmitted from different transmitters 114 of the same target terminal 10, that is, from substantially the same position. The received data processing unit 215 of the reference terminal 20 may obtain and use the difference in information obtained from the plurality of signals. For example, when the difference in the obtained information exceeds a predetermined specified value, it may be determined that the reliability of data having a small received power value S1 is low and the data may be discarded.

  Note that the position estimation apparatus 30 may have a form in which information obtained in the past is used together when performing position estimation. That is, by adding the function of measuring the time to the received data processing unit 215 and the position estimation device 30, the function of holding the data acquisition time is added. When using, it is also possible to adopt a configuration in which the weight for past information is changed according to the elapsed time from the present.

  In addition, a movement detection unit having a function of detecting movement of the terminal is added to the transmission data generation unit 113 or the transmission management unit 115 of the target terminal 10, and the detected information is included in the position estimation request signal and transmitted. By including the movement information of the terminal also in the position estimation information signal, it is possible to adopt a configuration in which the weight for the past information is changed according to the presence / absence of the movement of the terminal and the movement amount when using the past information. It is. That is, a function for measuring time is added to the reception data processing unit 215 and the position estimation device 30, and a movement detection unit having a function of detecting movement of the terminal is added to the transmission data generation unit 113 or the transmission management unit 115. However, when using past information, it is also possible to adopt a configuration in which the weight for past information is changed according to the presence / absence and amount of movement of the terminal and the elapsed time from the present.

  In addition, the received data processing unit 215 holds past information, etc., determines the reliability of the obtained information, and does not notify the position estimation device 30 of information with low reliability, thereby improving the accuracy of position estimation. It is also possible to take a configuration for performing the above.

  In the present embodiment, since signals transmitted from the respective antennas 111 of the target terminal 10 are not transmitted at the same time, the reliability of the distance between the respective antennas is lowered. Therefore, when this embodiment is used, the estimated position may be calculated by giving a width to the distance between the antennas used for the calculation.

  The distance between the antennas used for the calculation may be determined regardless of the actual distance between the antennas. That is, an arbitrary distance may be used as the distance between the antennas. This is because when the position estimation is performed in two dimensions, it is necessary to use the distance between the antennas on the mapping to the plane used for the estimation. For example, when position estimation is performed in two dimensions, when a plurality of antennas are installed on a straight line that is perpendicular to the plane on which position estimation is performed, the distance between the antennas is 0 in the calculation. Therefore, in this case, the estimated position may be calculated by setting the distance between the antennas to zero.

  As described above, in the third embodiment, in addition to the effects of the first embodiment, the position estimation device 30 is provided, so that the estimated positions of the plurality of target terminals 10 are converted into a single position estimation device. 30. Moreover, it is not necessary to provide a position estimation device in the target terminal 10, and the circuit scale of the target terminal 10 can be reduced. Further, as in the first embodiment, the orientation and rotation of the target terminal 10 can be detected from the installation position of the transmitter 114 in the target terminal 10.

  In this embodiment, the transmitter 114 generates a position estimation request signal transmission command and a position estimation request signal. However, the present invention is not limited to this, and the position estimation request signal transmission command and position estimation are performed. The generation of the request signal may be performed by providing other components.

Embodiment 4 FIG.
In the third embodiment, the antenna 111 is provided for each transmitter 114 of the target terminal 10, but in the fourth embodiment, a plurality of antennas are provided in a single transmitter and an antenna for transmitting a transmission signal is provided. The position of the antenna 111 is estimated by switching. The configuration of the position estimation system and the configuration of the reference terminal 20 are the same as those in the third embodiment.

  FIG. 11 is a diagram showing the configuration of the target terminal according to Embodiment 4 of the present invention. In FIG. 11, the target terminal 10 includes a plurality of radio devices including a plurality of antennas 111, a transmission circuit 112 that constitutes a radio unit, a transmission data generation unit 113, a transmission management unit 115, and a changeover switch 116. The antenna 111 and the transmission circuit 112 have the same functions as the configuration of the target terminal 10 of the third embodiment described above. Upon receiving an instruction from the transmission management unit 115, the transmission data generation unit 113 generates a position estimation request signal including an identification code unique to the target terminal 10 and an identification code unique to each antenna 111, and outputs the position estimation request signal to the transmission circuit 112. To do. The selector switch 116 is operated so that a transmission signal is transmitted from the antenna 111 corresponding to the identification code of the antenna 111 included in the simultaneously generated signal. The changeover switch 116 switches the antenna 111 that transmits the transmission signal generated by the transmission circuit 112 in accordance with an instruction from the transmission data generation unit 113. The transmission management unit 115 determines the transmission of the position estimation request signal from each antenna 111 in consideration of the processing delay at each reference terminal 20 and outputs a transmission command to the transmission data generation unit 113. With such a configuration, the position of the antenna 111 of the target terminal 10 is estimated by the same operation as in the third embodiment.

  As described above, in the fourth embodiment, in addition to the effect of the third embodiment, the configuration of the target terminal 10 is greatly simplified by switching and using the plurality of antennas 111 in the target terminal 10. Therefore, the cost of the target terminal 10 can be reduced, and further, it can greatly contribute to the extension of the life due to the simplification of the circuit configuration.

Embodiment 5 FIG.
FIG. 12 is a diagram showing a configuration of a position estimation system according to Embodiment 5 of the present invention. In FIG. 12, the position estimation system of the present embodiment includes a target terminal 10, a reference terminal 20, and a position estimation device 30. The target terminal 10 is a terminal that is a target of position estimation, and transmits a position estimation request signal. Also, when a position estimation request signal from another target terminal 10 is received, information necessary for position estimation is transmitted as a position estimation information signal. When the reference terminal 20 is a terminal whose position is known in advance and receives a position estimation request signal, the reference terminal 20 transmits information necessary for position estimation as a position estimation information signal. The position estimation device 30 estimates the position of each transceiver 124 from the collected position estimation information signals, and finally estimates the position of each target terminal 10. The configuration of the reference terminal 20 and the configuration of the position estimation device 30 are the same as those in the third embodiment. Note that the dotted line in the figure indicates that transmission destinations are not specified and transmission to all peripheral terminals (broadcast) is performed, and the solid line indicates transmission toward a terminal indicated by an arrow (unicast).

  FIG. 13 is a diagram showing the configuration of the target terminal according to Embodiment 5 of the present invention. In FIG. 13, the target terminal 10 includes a plurality of transceivers 124 that are radio devices including an antenna 121, a reception circuit 122, and a reception data processing unit 123, a transmission management unit 125, a changeover switch 126, and a transmission The circuit 127 and the transmission data generation unit 128 are configured. The antenna 121 is an antenna for transmitting and receiving radio signals. The reception circuit 122 receives a radio signal received by the antenna 121, processes the radio signal, converts it into digital information, and outputs the digital data to the reception data processing unit 123 as reception data. In addition, the reception circuit 122 measures the received power value S1 of the input radio signal, and outputs information on the measured received power value S1 to the received data processing unit 123 as information necessary for position estimation. The reception data processing unit 123 processes the reception data, and transmits the measured reception power to the transmission management unit 125 when the reception data is a position estimation request signal transmitted from another target terminal 10. Instruct data creation. At this time, the identification codes of the target terminal 10 and the transceiver 124 that have transmitted the position estimation request signal are also notified. The transmission management unit 125 generates a position estimation information signal based on the data obtained from the position estimation request signal received from the other target terminal 10 input from each reception data processing unit 123, and sends it to the position estimation device 30. Send. In addition, the transmission signal from each transmitter / receiver 124 is prevented from interfering, and the processing delay in each target terminal 10 and reference terminal 20 is taken into consideration, and then the position estimation request signal of each transmitter / receiver 124 is transmitted. Issue a send command. The transmission data generation unit 128 generates a position estimation request signal and a position estimation information signal in accordance with an instruction from the transmission management unit 125 and outputs the position estimation request signal and the position estimation information signal to the transmission circuit 127. The selector switch 126 is operated so that a transmission signal is transmitted from the antenna 121 of the transceiver 124 corresponding to the identification code of the transceiver 124 included in the simultaneously generated signal. The changeover switch 126 switches the antenna 111 that transmits the transmission signal generated by the transmission circuit 127 in accordance with an instruction from the transmission data generation unit 128. In addition, the positional relationship between each transmitter / receiver 124 is known, for example, the distance between each transmitter / receiver 124 obtained at the time of manufacture of the target terminal 10 is used.

  The operation of the fifth embodiment configured as described above will be described. First, the target terminal 10 transmits a position estimation request signal to all peripheral terminals. The position estimation request signal includes the identification code of the target terminal 10 and the identification code of the transceiver 124 used for transmission. Next, the reference terminal 20 or the target terminal 10 that has received the position estimation request signal measures the received power value S <b> 1 of the position estimation request signal and transmits a position estimation information signal to the position estimation device 30. For the position estimation information signal, the received power value S1 of the received position estimation request signal, the identification code of the target terminal 10 and the identification code of the transceiver 124 included in the received position estimation request signal, and the position estimation information signal are transmitted. The identification code of the reference terminal 20 or the target terminal 10 is included. When the position estimation apparatus 30 receives the position estimation information signal, the position estimation apparatus 30 stores information for each target terminal 10 that has transmitted the position estimation request signal, and for each transceiver 124 that is used for transmission, and uses it for position estimation of each target terminal 10. .

  FIG. 14 is a flowchart showing the position estimation operation of the position estimation apparatus according to Embodiment 5 of the present invention. In FIG. 14, the position estimation device 30 starts position estimation when receiving a position estimation information signal from each target terminal 10 or each reference terminal 20 (S21). An arbitrary target terminal 10 that is a target of position estimation is selected (S22), and a transceiver 124 that is a target of position estimation is selected from the selected target terminals 10 (S23). Next, based on the information of the position estimation information signal received and stored in the past, the first estimation step (S24) for obtaining the first estimated position of the transceiver 124 is executed.

  In the first estimation stage, the position estimation device 30 includes the received power value S1 of the position estimation request signal received by the reference terminal 20 included in the position estimation information signal received from each reference terminal 20, and the received position estimation request. Based on the identification code of the target terminal 10 and the identification code of the transceiver 124 included in the signal and the identification code of the reference terminal 20 that transmitted the position estimation information signal and the position of the reference terminal 20 The estimated position 124 is obtained. The method for obtaining the estimated position is the same as the operation in the first embodiment. In addition, the acquisition method of an estimated position is not restricted to this, You may obtain | require an estimated position using another method. The first estimation step (S24) is executed for all the transceivers 124 of all the target terminals 10 (S25, S26). In the procedure so far, position estimation is performed using only the position estimation information signal obtained from the reference terminal 20. This is because signals exchanged between the target terminals 10 cannot be used in a state where both positions are unknown.

  Next, the first estimated position of each transceiver 124 obtained in the first estimation step (S24), the positional relationship between each transceiver 124, and other targets other than the target terminal 10 to be estimated Based on the information of the position estimation request signal received from the terminal 10, a second estimation stage for obtaining the second estimated position of the transceiver 124 is executed. First, an arbitrary target terminal 10 that is a position estimation target is selected (S27), and a transceiver 124 that is a position estimation target is selected from the selected target terminals 10 (S28). Here, regarding the other transceivers 124 other than the selected transceiver 124, it is assumed that they exist at the above-described first estimated position, and the second estimation step (S29) is performed on the selected transceiver 124.

  In the second estimation stage, in addition to the information in the first estimation stage described above, the distance between each transmitter / receiver 124 obtained when the target terminal 10 is manufactured, and the target terminal 10 receives a position estimation request from another target terminal 10. The position is estimated using the information between the target terminals 10 obtained from the position estimation information signal received from the signal and transmitted to the position estimation device 30. The method for acquiring the estimated position is the same as the operation in the first estimation stage described above. In addition, the acquisition method of an estimated position is not restricted to this, You may obtain | require an estimated position using another method.

  By executing the second estimation stage, the estimated position of the transceiver 124 is changed from the first estimated position to the second estimated position. Since the estimated position of the transceiver 124 is used for the position estimation of the other transceivers 124, the change of the estimated position of the transceiver 124 affects the position estimation of the other transceivers 124. Therefore, when the estimated position of the transceiver 124 is changed, the position estimation of the other transceivers 124 is performed again. That is, with the second estimated position as the first estimated position, the second estimation stage is repeatedly executed for all the transceivers 124 other than the transceiver 124 (S27 to S31). Whether or not to continue the second estimation step is determined when the estimated positions of all the transmitters / receivers 124 included in the target terminal 10 are converged by the procedure S30, or by constraints such as calculation time, and the procedure S31. Whether or not to end the position estimation is determined when the estimated positions of all the target terminals 10 have converged, or by restrictions such as calculation time.

  In the position estimation in the position estimation device 30, it is possible to use a position estimation information signal obtained in the past. For example, a method of determining whether or not to use past information based on a difference between current information and past information, a method of taking an average of past and current information, and the like can be considered.

  In addition, by adding a function of measuring time to the received data processing unit 123 and the position estimation device 30, a function of holding the data acquisition time is added, and in the position estimation by the position estimation device 30, past data is stored. When using, it is also possible to adopt a configuration in which the weight for past information is changed according to the elapsed time from the present.

  In addition, a movement detection unit having a function of detecting movement of the terminal is added to the transmission data generation unit 128 or the transmission management unit 125, and is transmitted by being included in the position estimation request signal. By including the information, when using the past information, it is possible to adopt a configuration in which the weight for the past information is changed according to the presence / absence of the movement of the terminal and the movement amount.

  In addition, a function of measuring time is added to the reception data processing unit 123 and the position estimation device 30, and a movement detection unit having a function of detecting movement of the terminal is added to the transmission data generation unit 128 or the transmission management unit 125. When using past information, it is also possible to adopt a configuration in which the weight for past information is changed in accordance with the presence / absence and amount of movement of the terminal and the elapsed time from the present.

  In addition, the received data processing unit 123 holds past information and the like, judges reliability by comparing the obtained information and past information, and does not notify the position estimation device 30 of information with low reliability. Therefore, it is possible to adopt a configuration for improving the position estimation system.

  As described above, in the fifth embodiment, in addition to the effects of the first embodiment, by using the information between the target terminals 10, the position can be determined with higher accuracy even in a situation where the number of reference terminals 20 is small. An estimation can be made. In the first embodiment, the combination of transceivers used for position estimation is the number of reference terminals × the number of transceivers. However, in the fifth embodiment, the number of reference terminals × the number of transceivers + peripheral targets. The number of terminals × the number of transmitters / receivers × the number of transmitters / receivers is satisfied, and it is possible to efficiently estimate the position by exchanging one broadcast packet between many transmitters / receivers.

  In the present embodiment, the reception power value is measured and the position estimation information signal is generated by the transceiver 124. However, the present invention is not limited to this, and the reception power value measurement and the position estimation information signal are generated. For example, other components may be provided.

Embodiment 6 FIG.
In the sixth embodiment, the operation of the second embodiment is applied to the position estimation operation of the position estimation device of the fifth embodiment, and the positions of all the transceivers 124 are determined based on the information regarding the positions between the plurality of antennas 101. Is estimated. The configuration of the position estimation system and the configurations of the target terminal 10 and the reference terminal 20 are the same as those in the fifth embodiment.

  FIG. 15 is a flowchart showing the position estimation operation of the position estimation apparatus according to Embodiment 6 of the present invention. The position estimation apparatus 30 in the present embodiment uses an arbitrary one of the plurality of antennas 101 of each target terminal 10 as a reference antenna, and the other antennas 101 have information on the distance from the reference antenna. The positions of antennas other than the reference antenna are expressed by parameters indicating the coordinates and rotation of the reference antenna. In FIG. 15, the position estimation information signal is received by the same operation as in the fifth embodiment (S41), and the target terminal 10 that performs position estimation is selected (S42). Next, in the first estimation step (S43), only the information obtained from the reference terminal 20 is used, and the positions of all the transceivers 124 of the target target terminal 10 are determined by the same operation as in the second embodiment. presume. This first estimation step is performed for all target terminals 10 (S44). Next, the target terminal 10 that performs the second estimation stage is selected (S45), and in the second estimation stage (S46), in addition to the information obtained from the reference terminal 20, information obtained from the surrounding target terminals 10 is obtained. Then, using the estimated position of the peripheral target terminal 10 obtained in the first estimation stage, the positions of all the transceivers 124 of the target target terminal 10 are estimated by the same operation as in the second embodiment. This second estimation step is performed for all target terminals 10 (S47). Similar to the fifth embodiment, the second estimation step is repeatedly executed when the estimated positions of all the target terminals 10 have converged or until the number of times due to constraints such as calculation time is finished (S48).

  As described above, in the sixth embodiment, in addition to the effects of the fifth embodiment, the positions of all the transmitters / receivers 124 can be estimated based on the information regarding the positions between the transmitter / receivers 124, and the positions are estimated. In this case, the calculation time for position estimation can be shortened without the need for repeated calculations.

  In the first to sixth embodiments described above, the system that performs position estimation using the received power value of the radio signal as information necessary for position estimation has been described. However, the present invention wirelessly transmits information necessary for position estimation. The information is not limited to the received power value of the signal, and can be information that can be measured by the target terminal 10 or the reference terminal 20, regardless of the type of information, for example, information that can estimate the distance between terminals such as a delay time, a plurality of terminals It may be an angle formed by or other information.

Embodiment 7 FIG.
In the first embodiment, the position estimation is performed using the distance between the antennas 101 of the target terminal 10. However, in the seventh embodiment, it is assumed that the plurality of antennas 101 exist at the same point. Perform the calculation. That is, the position estimation calculation is performed with the distance between the antennas 101 set to zero. The configuration of the position estimation system and the configurations of the target terminal 10 and the reference terminal 20 are the same as those in the first embodiment.

  The received data processing unit 103 of the target terminal 10 according to the seventh embodiment processes the received data input from the receiving circuit 102. If the received data is a position estimation request signal sent from the reference terminal 20, the position estimation is performed. Information including information included in the request signal and information of the received power value S 1 measured by the receiving circuit 102 is output to the data aggregation unit 105. That is, in Embodiment 1 described above, information on the identification code unique to the receiver 104 is output to the data aggregating unit 105, but this embodiment is not necessary. The operation of position estimation in the present embodiment having such a configuration will be described next.

  FIG. 16 is a flowchart showing the position estimation operation of the target terminal in the seventh embodiment of the present invention. First, each reference terminal 20 transmits a position estimation request signal including the transmission terminal code of the reference terminal 20. Each receiver 104 of the target terminal 10 receives the position estimation request signal transmitted from each reference terminal 20, measures the received power value S1 of the received position estimation request signal, information on the received power value S1, and the transmission terminal code Is output to the data aggregating unit 105 (S51). Next, the data aggregating unit 105 collects information input from the plurality of receivers 104 without distinguishing the input receivers 104 and outputs the collected information to the position estimation processing unit 106. The position estimation processing unit 106 obtains the estimated position of the target terminal 10 according to the following procedure based on the information input from the data aggregation unit 105 (S52).

  Specifically, the estimated position of the target terminal 10 is obtained based on the information of the received power value S1 of the position estimation request signal received by each receiver 104, the transmission terminal code, and the position of the reference terminal 20. As the estimated position, for example, the existence probability at each point where the target terminal 10 is considered to be present is calculated from the information exchanged between each reference terminal 20 and an arbitrary receiver 104 and the position of the reference terminal 20. Next, using a method such as a maximum likelihood estimation method, a point having the highest existence probability of the target terminal 10 is searched, and the corresponding point is set as the estimated position of the target terminal 10. Further, for example, the estimated position is obtained by referring to a table indicating the relationship between the received power value S1 and the distance and obtaining the distances between the plurality of reference terminals 20 whose positions are known in advance and the target terminal 10. In addition, the acquisition method of an estimated position is not restricted to this, You may obtain | require an estimated position using another method.

  As described above, in the seventh embodiment, in addition to the effects of the first embodiment, since the positions of the plurality of antennas 101 are regarded as the same, the calculation processing of the estimated position of the position estimation processing unit 106 is simplified, and estimation is performed. The time required for calculation can be shortened.

Embodiment 8 FIG.
In Embodiments 3 and 4 described above, position estimation is performed using the distances between the antennas 101 of the target terminal 10, but in Embodiment 8, a plurality of antennas 111 of the target terminal 10 are present at the same point. Then, the position estimation is calculated. That is, the position estimation calculation is performed with the distance between the antennas 101 set to zero. The configuration of the position estimation system and the configurations of the target terminal 10, the reference terminal 20, and the position estimation device 30 are the same as those in the third embodiment.

  Upon receiving an instruction from transmission management section 115, transmission data generation section 113 of each transmitter 114 in Embodiment 8 generates a position estimation request signal including an identification code unique to the target terminal and outputs it to transmission circuit 112. To do. That is, in the above-described third embodiment, the position estimation request signal including the identification code of each transmitter 114 is generated. However, in this embodiment, only the identification code unique to the target terminal 10 is used. The information included in the estimated information signal is different. The operation of position estimation in the present embodiment having such a configuration will be described next.

  First, each transmitter 114 of the target terminal 10 transmits a position estimation request signal including an identification code of an identification code unique to the target terminal 10 to all peripheral terminals from the antenna 111 of each transmitter 114. The reception circuit 214 of the reference terminal 20 that has received the position estimation request signal inputs the obtained information to the reception data processing unit 215, and it is appropriate that the reception data processing unit 215 uses the received signal for position estimation. If it is determined, the transmission data generation unit 213 is instructed to generate a position estimation information signal. The position estimation information signal includes the identification code of the target terminal 10 included in the received position estimation request signal, the received power value S1 of the received position estimation request signal, and the identification code unique to the reference terminal 20. The transmission circuit 212 transmits the position estimation information signal to the position estimation device 30. The position estimation device 30 aggregates data for each identification code of the target terminal 10 included in the position estimation information signal received from the reference terminal 20, and performs the same operation as in the above-described seventh embodiment to determine the position of each target terminal 10. Is estimated. In the present embodiment, since the estimation result of the target terminal 10 does not affect the estimation of the other target terminals 10, the estimation calculation of each terminal in the position estimation device 30 is a simple parallel process.

  In the configuration of the fourth embodiment, the operation of the target terminal 10 of the eighth embodiment described above may be applied. In this case, by not including an identification code unique to the antenna 111 in the position estimation request signal transmitted from each antenna 111 of the target terminal 10, position estimation can be performed by the same operation as in the present embodiment.

  As described above, in the eighth embodiment, in addition to the effects of the third embodiment, the calculation amount in the position estimation device 30 can be reduced. Accordingly, it is possible to perform position estimation of more target terminals 10 with the single position estimation device 30. Furthermore, the information amount of the position estimation request signal transmitted from the target terminal 10 can be reduced.

  Further, when the eighth embodiment is applied to the fourth embodiment, in addition to the effects of the fourth embodiment, the same signal is transmitted from the plurality of antennas 111 by the changeover switch 116, and the target The configuration of the terminal 10 can be simplified.

Embodiment 9 FIG.
In the fifth embodiment, the position estimation is performed using the distance between the antennas 101 of the target terminal 10. However, in the ninth embodiment, the plurality of antennas 121 of the target terminal 10 are considered to exist at the same point. Position estimation. That is, the position estimation calculation is performed with the distance between the antennas 101 set to zero. The configuration of the position estimation system and the configurations of the target terminal 10, the reference terminal 20, and the position estimation device 30 are the same as those in the fifth embodiment.

  In the ninth embodiment, the reception data processing unit 123 of each transmitter 124 performs measurement for the transmission management unit 125 when the received data is a position estimation request signal transmitted from another target terminal 10. Instructs the generation of transmission data of the received power. At this time, the identification code of the target terminal 10 that has transmitted the position estimation request signal is also notified. That is, in the fifth embodiment described above, the position estimation request signal including the identification code of each transmitter 124 is notified. However, in this embodiment, only the identification code of the target terminal 10 is used, so the position estimation request signal and the position estimation are transmitted. The information contained in the information signal is different. The operation of position estimation in the present embodiment having such a configuration will be described next.

  The target terminal 10 transmits a position estimation request signal to all peripheral terminals. The position estimation request signal includes the identification code of the target terminal 10. Next, the target terminal 10 and the reference terminal 20 that have received the position estimation request signal measure the received power value S <b> 1 of the position estimation request signal, and transmit the position estimation information signal to the position estimation device 30. The position estimation information signal includes the received power value S1 of the received position estimation request signal, the identification code of the target terminal 10 included in the received position estimation request signal, and the target terminal 10 or the reference that transmits the position estimation information signal. The identification code of the terminal 20 is included. When receiving the position estimation information signal, the position estimation device 30 stores information for each target terminal 10 that has transmitted the position estimation request signal, and uses it for position estimation of each target terminal 10.

  FIG. 17 is a flowchart showing a position estimation operation of the position estimation apparatus according to the ninth embodiment of the present invention. Similar to the above-described fifth embodiment, the position estimation device 30 starts position estimation when receiving a position estimation information signal from each target terminal 10 or each reference terminal 20 (S61), and performs arbitrary estimation as a position estimation target. The target terminal 10 is selected (S62). Next, based on the received and stored information of the position estimation information signal, an estimation calculation for obtaining the estimated position of the target terminal 10 is executed (S63).

  The estimation calculation is performed on the received power value S1 of the position estimation request signal received by the reference terminal 20 and the received position estimation request signal included in the position estimation information signal received by the position estimation device 30 from each reference terminal 20. Based on the identification code of the target terminal 10 included, the identification code of the reference terminal 20 that transmitted the position estimation information signal, and the position of the reference terminal 20, the estimated position of the target terminal 10 that is the target of position estimation is obtained. The method for obtaining the estimated position is the same as the operation in the first embodiment. The estimation calculation (S63) is executed for all target terminals 10 (S64). The steps S62 to S64 are repeated until the estimated positions of all target terminals converge or the preset number of repetitions is reached (S65). This is because if the estimated position of the target terminal 10 changes, it affects the position estimation result of the terminal that exchanged the position estimation request signal with the terminal.

  As described above, in the ninth embodiment, in addition to the effects of the fifth embodiment, the calculation amount in the position estimation device 30 can be reduced. Accordingly, it is possible to perform position estimation of more target terminals 10 with the single position estimation device 30. Further, by removing the identification code of the transmitter / receiver 124 from the position estimation request signal and the position estimation information signal, the amount of communication is reduced, and more communications other than position estimation can be performed.

It is a figure which shows the structure of the position estimation system in Embodiment 1 of this invention. It is a figure which shows the structure of the reference terminal in Embodiment 1 of this invention. It is a figure which shows the structure of the target terminal in Embodiment 1 of this invention. It is a flowchart which shows the position estimation operation | movement of the target terminal in Embodiment 1 of this invention. It is a figure which shows the distance between antennas on the position estimation plane in Embodiment 1 of this invention. It is a flowchart which shows the position estimation operation | movement of the target terminal in Embodiment 2 of this invention. It is a figure which shows the relative position from the reference | standard antenna in Embodiment 2 of this invention. It is a figure which shows the structure of the position estimation system in Embodiment 3 of this invention. It is a figure which shows the structure of the target terminal in Embodiment 3 of this invention. It is a figure which shows the structure of the reference terminal in Embodiment 3 of this invention. It is a figure which shows the structure of the target terminal in Embodiment 4 of this invention. It is a figure which shows the structure of the position estimation system in Embodiment 5 of this invention. It is a figure which shows the structure of the target terminal in Embodiment 5 of this invention. It is a flowchart which shows the position estimation operation | movement of the position estimation apparatus in Embodiment 5 of this invention. It is a flowchart which shows the position estimation operation | movement of the position estimation apparatus in Embodiment 6 of this invention. It is a flowchart which shows the position estimation operation | movement of the target terminal in Embodiment 7 of this invention. It is a flowchart which shows the position estimation operation | movement of the position estimation apparatus in Embodiment 9 of this invention.

Explanation of symbols

  10 target terminal, 20 reference terminal, 30 position estimation device, 101 antenna, 102 reception circuit, 103 reception data processing unit, 104 receiver, 105 data aggregation unit, 106 position estimation processing unit, 111 antenna, 112 transmission circuit, 113 transmission Data generation unit, 114 transmitter, 115 transmission management unit, 116 changeover switch, 121 antenna, 122 reception circuit, 123 reception data processing unit, 124 transceiver, 125 transmission management unit, 126 changeover switch, 127 transmission circuit, 128 transmission data Generation unit, 201 antenna, 202 transmission circuit, 203 transmission data generation unit, 211 antenna, 212 transmission circuit, 213 transmission data generation unit, 214 reception circuit, 215 reception data processing unit, 500 estimation plane, S1 reception power value.

Claims (25)

A target terminal having a plurality of wireless devices, the distance between each wireless device being known, and a plurality of reference terminals arranged at known positions transmit and receive wireless signals, and the wireless signal and the position of the reference terminal A position estimation method for estimating the position of the target terminal based on:
The information necessary for position estimation is acquired from the radio signal, and at least the information necessary for position estimation, the position of the reference terminal, and the relative position between the radios including the distance between the radios From the information indicating the relationship, the estimated position of each of the plurality of radios is obtained,
A position estimation method, wherein the position of the target terminal is estimated based on estimated positions of the plurality of radio devices. A target terminal having a plurality of wireless devices, the distance between each wireless device being known, and a plurality of reference terminals arranged at known positions transmit and receive wireless signals, and the wireless signal and the position of the reference terminal A position estimation method for estimating the position of the target terminal based on:
The information necessary for position estimation is acquired from the radio signal, and at least the information necessary for the position estimation, the position of the reference terminal, and the distance between the radios, respectively. Create an evaluation function in a multidimensional space that identifies the location of
By obtaining a point at which the value of the evaluation function takes an extreme value, an estimated position of each of the plurality of wireless devices is obtained,
A position estimation method, wherein the position of the target terminal is estimated based on estimated positions of the plurality of radio devices. A target terminal having a plurality of wireless devices, the distance between each wireless device being known, and a plurality of reference terminals arranged at known positions transmit and receive wireless signals, and the wireless signal and the position of the reference terminal A position estimation method for estimating the position of the target terminal based on:
Information necessary for position estimation is acquired from the radio signal, at least the information necessary for position estimation, the position of the reference terminal, the distance between the radios, and the reference plane set in the estimation area And an evaluation function having a variable of an angle formed by the target terminal and a position of a reference antenna included in an arbitrary radio among the plurality of radios,
By obtaining a point at which the value of the evaluation function takes an extreme value, an estimated position of each of the plurality of wireless devices is obtained,
A position estimation method, wherein the position of the target terminal is estimated based on estimated positions of the plurality of radio devices. A target terminal having a plurality of wireless devices, the distance between each wireless device being known, and a plurality of reference terminals arranged at known positions transmit and receive wireless signals, and the wireless signal and the position of the reference terminal A position estimation method for estimating the position of the target terminal based on:
Obtaining information necessary for position estimation from the radio signal, and at least obtaining the first estimated position of each of the plurality of radios based on the acquired information necessary for position estimation and the position of the reference terminal,
Based on at least a first estimated position of each of the plurality of radios, a distance between the radios, information necessary for position estimation obtained from the radio signal, and a position of the reference terminal Determining a second estimated position of the radio;
A position estimation method, wherein the position of the target terminal is estimated based on second estimated positions of the plurality of wireless devices. A target terminal having a plurality of radios and a known distance between each radio;
A plurality of reference terminals that are arranged at known positions and exchange radio signals with the target terminal,
A position estimation device that estimates the position of the target terminal based on the wireless signal, the position of the reference terminal, and the distance between the wireless devices;
The position estimation device acquires information necessary for position estimation from the radio signal,
From at least the information necessary for the position estimation, the position of the reference terminal, and information indicating the relative positional relationship between the radios including the distance between the radios, each of the plurality of radios Find the estimated position,
A position estimation system for estimating a position of the target terminal based on an estimated position of each of the plurality of wireless devices. A plurality of the target terminals;
The plurality of radios of the target terminal respectively transmit information on identification codes unique to the target terminal and a position estimation request signal including information on identification codes unique to the radio,
Receiving each of the position estimation request signals transmitted from the target terminal other than the target terminal,
The target terminal measures information necessary for position estimation from the position estimation request signals received by the plurality of wireless devices, and is included in the measured position estimation request signal and the information necessary for the position estimation. Transmitting a position estimation information signal including information on an identification code unique to the target terminal and information on the identification code unique to the radio and information on the identification code unique to the target terminal that has received the position estimation request signal;
The reference terminal receives the position estimation request signal transmitted from the plurality of radios of the target terminal,
The information necessary for position estimation is measured from the received position estimation request signal, the information necessary for the position estimation, the identification code unique to the target terminal included in the position estimation request signal, and the radio specific Transmitting a position estimation information signal including information on an identification code and information on an identification code unique to the reference terminal that has received the position estimation request signal;
The position estimation device receives the position estimation information signal transmitted from the target terminal and the reference terminal,
Information necessary for position estimation included in the position estimation information signal received from the reference terminal;
Information of an identification code unique to the target terminal and an identification code unique to the radio;
Information of an identification code unique to the reference terminal;
The location of the reference terminal;
Obtaining the estimated position of each of the plurality of radios based on the distance between each radio and the angle formed by each radio,
The position estimation system according to claim 5, wherein the position of the target terminal is estimated based on the estimated positions of the plurality of wireless devices. A target terminal having a plurality of radios and a known distance between each radio;
A plurality of reference terminals that are arranged at known positions and exchange radio signals with the target terminal,
A position estimation device that estimates the position of the target terminal based on the wireless signal, the position of the reference terminal, and the distance between the wireless devices;
The position estimation device acquires information necessary for position estimation from the radio signal,
Obtaining at least a first estimated position of each of the plurality of radios based on the acquired information necessary for the position estimation and the position of the reference terminal;
Based on at least a first estimated position of each of the plurality of radios, a distance between the radios, information necessary for position estimation obtained from the radio signal, and a position of the reference terminal Determining a second estimated position of the radio;
A position estimation system, wherein the position of the target terminal is estimated based on second estimated positions of the plurality of wireless devices. The reference terminal transmits a position estimation request signal including information on an identification code unique to the reference terminal,
The plurality of radios of the target terminal each receive the position estimation request signal transmitted from the reference terminal,
The target terminal incorporates the position estimation device, measures information necessary for position estimation from the position estimation request signals received by the plurality of radios, and measures the information necessary for the position estimation, Information on the identification code specific to the reference terminal included in the position estimation request signal and information on the identification code specific to the radio that has received the position estimation request signal are input to the position estimation device, respectively.
The position estimation device includes information necessary for the position estimation;
Information of an identification code unique to the reference terminal;
Information on the identification code unique to the radio;
Obtaining a first estimated position of each of the plurality of radios based on the position of the reference terminal;
A first estimated position of each of the plurality of radios;
A distance between each of the radios;
Information necessary for the position estimation;
Information of an identification code unique to the reference terminal;
Information on the identification code unique to the radio;
Obtaining a second estimated position of each of the plurality of radios based on the position of the reference terminal;
The position estimation system according to claim 7, wherein the position of the target terminal is estimated based on second estimated positions of the plurality of wireless devices. The plurality of radios of the target terminal each transmit a position estimation request signal including information of an identification code unique to the radio,
The reference terminal receives the position estimation request signal transmitted from the plurality of radios, measures information necessary for position estimation from the received position estimation request signal,
A position estimation information signal including the measured information necessary for the position estimation, information on the identification code unique to the radio included in the position estimation request signal, and information on the identification code unique to the reference terminal is transmitted. ,
The position estimation device receives the position estimation information signal transmitted from the reference terminal, and includes information necessary for the position estimation included in the received position estimation information signal;
Information on the identification code unique to the radio;
Information of an identification code unique to the reference terminal;
Obtaining a first estimated position of each of the plurality of radios based on the position of the reference terminal;
A first estimated position of each of the plurality of radios;
A distance between each of the radios;
Information necessary for the position estimation;
Information on the identification code unique to the radio;
Information of an identification code unique to the reference terminal;
Obtaining a second estimated position of each of the plurality of radios based on the position of the reference terminal;
The position estimation system according to claim 7, wherein the position of the target terminal is estimated based on second estimated positions of the plurality of wireless devices. A plurality of the target terminals;
The plurality of radios of the target terminal respectively transmit information on identification codes unique to the target terminal and a position estimation request signal including information on identification codes unique to the radio,
Receiving each of the position estimation request signals transmitted from the target terminal other than the target terminal,
The target terminal measures information necessary for position estimation from the position estimation request signals received by the plurality of wireless devices, and is included in the measured position estimation request signal and the information necessary for the position estimation. Transmitting a position estimation information signal including information on an identification code unique to the target terminal and information on the identification code unique to the radio and information on the identification code unique to the target terminal that has received the position estimation request signal;
The reference terminal receives the position estimation request signal transmitted from the plurality of radios of the target terminal,
The information necessary for position estimation is measured from the received position estimation request signal, the information necessary for the position estimation, the identification code unique to the target terminal included in the position estimation request signal, and the radio specific Transmitting a position estimation information signal including information on an identification code and information on an identification code unique to the reference terminal that has received the position estimation request signal;
The position estimation device receives the position estimation information signal transmitted from the target terminal and the reference terminal,
Information necessary for position estimation included in the position estimation information signal received from the reference terminal;
Information of an identification code unique to the target terminal and an identification code unique to the radio;
Information of an identification code unique to the reference terminal;
The location of the reference terminal;
Determining a first estimated position of each of the plurality of radios based on
Information necessary for position estimation included in the position estimation information signal received from the target terminal and the reference terminal;
Information on an identification code unique to the target terminal that has transmitted the position estimation request signal and an identification code unique to the radio, and
Information of an identification code unique to the reference terminal;
An identification code unique to the target terminal;
A first estimated position of each of the plurality of radios;
A distance between each of the radios;
Obtaining a second estimated position of each of the plurality of radios based on the position of the reference terminal;
The position estimation system according to claim 7, wherein the position of the target terminal is estimated based on second estimated positions of the plurality of wireless devices.   When the second estimated position of the wireless device is obtained, the position estimating device uses the second estimated position of the wireless device as a first estimated position, and the second estimated position of a wireless device other than the wireless device The position estimation system according to claim 7, wherein the position estimation system is obtained again.   The plurality of radios of the target terminal include a plurality of antennas for transmitting and receiving radio signals, a changeover switch connected to the plurality of antennas, and any one of the plurality of antennas by the changeover switch. The position estimation system according to claim 5, further comprising a wireless unit connected thereto.   The target terminal or the reference terminal measures a received power value of the radio signal, and uses the measured information of the received power value as information necessary for the position estimation. Crab position estimation system.   The position estimation system according to claim 13, wherein the position estimation device uses the information of the received power value as information necessary for the position estimation when the received power value of the radio signal is larger than a predetermined value. . The target terminal includes movement detection means for detecting movement of the target terminal,
Including information on the movement of the target terminal in the position estimation information signal;
Each time the position estimation device receives the position estimation information signal, the position estimation apparatus accumulates information included in the position estimation information signal, selects the accumulated information based on information on the movement of the target terminal, and The position estimation system according to claim 7, wherein second estimated positions of the plurality of wireless devices are obtained using the selected information.   Each time the position estimation apparatus receives the position estimation information signal, the position estimation apparatus accumulates information included in the position estimation information signal, and the accumulated information is determined according to an elapsed time since the reception of the position estimation information signal. The position estimation system according to claim 7, wherein a second estimated position of the plurality of wireless devices is obtained using the selected information.   The position estimation device has information on a relative position of the target terminal with respect to the target terminal with respect to the plurality of wireless devices, and is based on the information on the relative position and second estimated positions of the plurality of wireless devices. The position estimation system according to claim 7, wherein the direction of the target terminal is estimated.   The position estimation device accumulates information included in the position estimation information signal every time the position estimation information signal is received, information on the relative position, and second estimated positions of the plurality of radios, The position estimation system according to claim 17, wherein the rotation of the target terminal is estimated based on the accumulated information.   A radio communication terminal comprising the target terminal of the position estimation system according to claim 11 or claim 11 dependent on claim 8.   The position estimation method according to any one of claims 1 to 4, wherein the position of the target terminal is estimated with the distance between the wireless devices as an arbitrary distance.   The position estimation method according to any one of claims 1 to 4, wherein the position of the target terminal is estimated by setting the distance between the wireless devices to be 0. The position estimation device includes:
The position estimation system according to any one of claims 5 to 18, wherein the position of the target terminal is estimated by using a distance between the radio devices as an arbitrary distance. The position estimation device includes:
19. The position estimation system according to claim 5, wherein the position of the target terminal is estimated by setting the distance between the wireless devices to 0. The plurality of wireless devices are:
The wireless communication terminal according to claim 19, wherein the wireless communication terminal is arranged on a straight line perpendicular to the moving direction or position estimation plane of the target terminal. The plurality of radios of the target terminal each include an antenna for transmitting and receiving radio signals,
The antenna is
The wireless communication terminal according to claim 19, wherein the wireless communication terminal is arranged on a straight line perpendicular to the moving direction or position estimation plane of the target terminal.

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