JP2013181872A - Relative positioning device, relative positioning method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of being unable to acquire a relative position between terminals with high accuracy.SOLUTION: A relative position between terminals can be acquired with high accuracy by a relative positioning deice. The relative positioning device includes: an own terminal information group acquisition part for acquiring an own terminal information group including an own terminal measurement pseudo distance being pseudo distance between an own terminal and each satellite by using a satellite signal in each of received two or more satellites; an own terminal information group transmission part for transmitting the own terminal information group; a different terminal information group reception part for receiving a different terminal information group including a different terminal measurement pseudo distance being a pseudo distance between a different terminal and each satellite; a correlation determination part for determining whether a correlation is high about one common satellite between two common satellites by using the own terminal measurement pseudo distance and the different terminal measurement pseudo distance of the two common satellites, and an own terminal estimated distance and a different terminal estimated distance between the two common satellites and the own terminal; a relative position acquisition part for acquiring a relative position between the own terminal and the different terminal by using an own terminal satellite information group and a different terminal satellite information group of one or more satellites having a high correlation; and an output part for outputting the relative position.

Description

  The present invention obtains a relative position between terminals by using a signal from a satellite having a high spatial correlation (hereinafter also referred to as “correlation” as appropriate) of a pseudorange error between terminals, and outputs the relative position. It relates to devices and the like.

  Conventionally, there has been a technique for calculating the relative position between moving bodies from the absolute position of the moving bodies (see Non-Patent Document 1).

  In addition, there has been a technique for increasing the reception sensitivity when calculating the absolute position and increasing the number of satellites used so that positioning can be performed even in a poor reception environment (see Non-Patent Document 2).

  In addition, when calculating the absolute position, there has been a technique for reducing position errors by detecting and eliminating all reflected waves without using the reflected waves (see Non-Patent Documents 3 and 4).

  Furthermore, there has been a technique for exchanging pseudo distances between moving objects and calculating a relative position using a highly correlated satellite (see Non-Patent Document 5).

Ministry of Internal Affairs and Communications (ASV-4) Joint Experiment [Search February 14, 2012], Internet [URL: http://www.soumu.go.jp/main_sosiki/joho_tsusin/policyreports/chousa/its/pdf /081219_2_si2-4.pdf#search='Joint Experiment with Ministry of Internal Affairs and Communications (ASV4) '] Yasunori Aga, Koichi Shantou, Yoshiharu Ogasa, Masanobu Tokaibayashi, Kazutada Tanda, Nobuhiro Tsuda, High Sensitive GPS Receiver, JRC Japan Radio Technical Information No. 45, 2004 Kubo, Nobuaki, Yasuda, Akio: On the reduction of code multipath error in fixed-point positioning, Theory of Science (B), Vol. J86-B NO.1, pp.104-112, January 2003 Hiroshi Murata, Hidetoshi Nishimura, Junichi Meguro, Junichi Higuchi, Yoshiharu Amano, Takumi Hashizume: Improvement of positioning accuracy by multipath removal using an infrared all-around camera, 7th System Integration Division Lecture (SI2006) Yumotohana, Hideo Tsutsui, Taku Oyama, Ryu Miura, Sadao Obana: High-precision relative vehicle positioning in urban areas, IEICE Technical Report, SANE2010-159 (2011-2).

  However, in the prior art, the relative position between the terminals cannot be obtained with high accuracy.

  More specifically, in the technique of Non-Patent Document 1, since the relative position is calculated from the difference in absolute position, the accuracy of the relative position is deteriorated due to an uncorrelated error included in the absolute position.

  In the technique of Non-Patent Document 2, a reflected wave is received in addition to a direct wave by a high-sensitivity GPS receiver, and the reflected wave is used during positioning without being distinguished, resulting in a large error in the absolute position. sell.

  The techniques of Non-Patent Documents 3 and 4 aim to eliminate all reflected waves obtained by high-sensitivity GPS without using them. Therefore, the number of satellites that can be used during positioning decreases, and positioning may not be possible. In the technique of Non-Patent Document 3, a reflected wave cannot be determined without a reference station. Further, the technique of Non-Patent Document 4 requires complicated image processing.

  Furthermore, the technique of Non-Patent Document 5 mainly determines the spatial correlation of the pseudorange error of the common satellite indirectly using the SNR and the elevation angle, but the two receivers receive the same satellite. Even if the difference in SNR is small, the correlation of the pseudoranges is not always high. The accuracy of the function for determining the correlation of the common satellite may not be high.

  To summarize the above, the techniques of Non-Patent Document 1 to Non-Patent Document 5 have the problem shown in FIG. In FIG. 17, the effect of the present invention is also described.

  The relative positioning device according to the first aspect of the invention includes a satellite signal receiving unit that receives satellite signals of two or more satellites, and one of the satellite signals received by the satellite signal receiving unit or information acquired using the satellite signals. This is information related to the own terminal, and the own terminal information group related to the own terminal is acquired using the satellite signal for each of two or more satellites, including the own terminal measurement pseudorange that is the pseudorange between the own terminal and each satellite. The own terminal information group acquisition unit, the own terminal information group transmission unit that transmits part or all of the information of the own terminal information group, and the satellite signal received by the other terminal or the information acquired using the satellite signal Other terminal information including information on other terminal satellite information group for each of two or more satellites, which is information related to one or more other terminals, and including other terminal measurement pseudo distances that are pseudo distances between the other terminals and each satellite. Information on some or all of the group Other terminal information group reception unit for receiving, two or more common satellites of two or more common satellites where both the own terminal and the other terminal can receive satellite signals, and other two common satellites The terminal measurement pseudo distance, the own terminal estimated distance that is the distance between the two common satellites and the own terminal, and the other terminal estimated distance that is the distance between the two common satellites and the other terminal are acquired, and the own terminals of the two common satellites One common satellite of the two common satellites using the measurement pseudorange, the other terminal pseudo pseudorange of the two common satellites, the own terminal estimated distance of the two common satellites, and the other terminal estimated distance of the two common satellites A correlation determination unit that determines whether or not the own terminal satellite information group and the other terminal satellite information group are highly correlated, and the own terminal satellite information group of one or more satellites determined to be highly correlated, and Using other terminal satellite information group, A relative positioning device comprising a relative position acquisition unit that acquires a relative position between the terminal and an output unit for the relative position acquisition unit outputs a relative position acquisition.

  With this configuration, the relative position between terminals can be acquired with high accuracy.

  In the relative positioning device of the second aspect of the invention, the probability that the correlation determination unit receives the reflected wave is lower as the predetermined condition is satisfied among the common satellites. Reference satellite determining means for determining a satellite is provided, and the own terminal measurement pseudorange of the two satellites of the reference satellite and another common satellite, the other terminal measurement pseudorange of the two satellites, and the distance between the two satellites and the own terminal A certain self-terminal estimated distance and another terminal estimated distance which is a distance between two satellites and another terminal are acquired, and the self-terminal measurement pseudo-range of two satellites, two satellites other-terminal measurement pseudo-range, two satellites Relative positioning device that determines whether or not the own terminal satellite information group and the other terminal satellite information group are highly correlated with respect to other common satellites using the own terminal estimated distance and the other terminal estimated distance of the two satellites It is.

  With this configuration, the relative position between the terminals can be acquired with higher accuracy.

  Further, in the relative positioning device of the third aspect of the invention, in contrast to the second aspect of the invention, the correlation determining unit calculates the difference between the own terminal measurement pseudorange of two satellites and the other terminal measurement pseudorange of the two satellites. Calculate the double difference of the pseudo distance, which is the difference, and the double difference of the estimated distance, which is the difference between the estimated distance of the two satellites and the estimated distance of the other terminals of the two satellites. When the difference from the double difference is smaller than the threshold value, the relative positioning device determines that the self-terminal satellite information group and the other-terminal satellite information group are highly correlated with respect to other common satellites.

  With this configuration, the relative position between terminals can be acquired with high accuracy.

  The relative positioning device according to the fourth aspect of the invention is a relative positioning device in which the threshold is different for each satellite compared to the third aspect of the invention.

  With this configuration, the relative position between the terminals can be acquired with higher accuracy.

  In addition, the relative positioning device of the fifth aspect of the invention is a relative positioning device in which the threshold value is the same for all satellites as compared to the third aspect of the invention.

  With this configuration, the relative position between terminals can be acquired with high accuracy.

  Further, in the relative positioning device of the sixth aspect of the invention, in contrast to any of the first to fifth aspects of the invention, the own terminal information group acquisition unit is an SNR of the received satellite signal for every two or more satellites. A reception SNR acquisition unit is provided for acquiring a terminal reception SNR. The other terminal information group includes an other terminal reception SNR that is an SNR of a satellite signal received by the other terminal. One common of two common satellites using the terminal measurement pseudorange, the other terminal measurement pseudorange of two common satellites, the own terminal estimated distance of the two common satellites, and the other terminal estimated distance of the two common satellites For the satellite, it is determined whether or not the own terminal satellite information group and the other terminal satellite information group are highly correlated, and the own terminal received SNR and the other terminal received SNR are used to determine which of the two common satellites For one common satellite, It is determined whether or not the terminal satellite information group is highly correlated. If both the determinations indicate that the correlation is high, the own terminal satellite information group and the other terminal satellite information group are highly correlated. Relative positioning device.

  With this configuration, the relative position between the terminals can be acquired with higher accuracy.

  The relative position of the seventh aspect of the invention is that the self terminal information group acquisition unit uses the satellite signal received by the satellite signal reception unit for every two or more satellites, relative to any one of the first to sixth aspects of the invention. A measurement pseudo distance acquisition means for acquiring a self terminal measurement pseudo distance that is a pseudo distance between the own terminal and each satellite; and a reception SNR acquisition means for acquiring the self terminal reception SNR of the satellite signal for each of two or more satellites. Satellite position acquisition means for acquiring a satellite position indicating the position of the satellite for each of the two or more satellites, and an own terminal movement information that is information relating to the movement of the own terminal including the moving speed and moving direction of the own terminal. It is a relative position comprising terminal movement information acquisition means.

  With this configuration, the relative position between terminals can be acquired with high accuracy.

  According to the relative positioning device of the present invention, the relative position between terminals can be obtained with high accuracy.

Conceptual diagram of relative positioning system including relative positioning device 1 in the first embodiment Block diagram of the relative positioning device 1 The block diagram of the relative position acquisition part 16 which comprises the relative positioning apparatus 1 A flowchart for explaining the operation of the relative positioning device 1 Flow chart explaining the correlation determination process A flowchart for explaining a process for calculating a value for determining the correlation Flow chart for explaining the relative position calculation process Conceptual diagram of the relative positioning device 1 The figure explaining the conversion from the same ECEF coordinate to ENU coordinate The figure which shows the data structure of the own terminal information group Flow chart explaining operation of own terminal Flow chart explaining operation of own terminal Block diagram of relative positioning apparatus 2 in the second embodiment Block diagram of relative positioning apparatus 3 in Embodiment 3 Overview of the computer system in the above embodiment Block diagram of the computer system The figure explaining the problem of the prior art

Hereinafter, embodiments of a relative positioning device and the like will be described with reference to the drawings. In addition, since the component which attached | subjected the same code | symbol in embodiment performs the same operation | movement, description may be abbreviate | omitted again.
(Embodiment 1)

  In this embodiment, by using the difference between the pseudorange difference between the common satellite and the mobile object and the estimated difference between the common satellite and the mobile object, the spatial correlation of the pseudorange error with respect to other satellites is increased or decreased. A relative positioning device that makes a determination, estimates the distance between the satellite and the relative positioning device using a highly correlated satellite, calculates the relative position between the host vehicle and the other vehicle, and outputs the relative position will be described. In addition, the own vehicle is a vehicle on which the own terminal, which is a relative positioning device that outputs a relative position, is mounted, and the other vehicle is a target vehicle whose relative position with respect to the own vehicle is calculated. The vehicle is equipped with a terminal.

  In this embodiment, after determining the reference satellite, the level of the spatial correlation of the pseudorange error with respect to the other satellite is determined using the difference in pseudorange with respect to the reference satellite and the difference in pseudorange with respect to the other satellite. A relative positioning device that estimates the distance between the host vehicle and the other vehicle using a highly correlated satellite, calculates the relative position between the host vehicle and the other vehicle, and outputs the relative position will be described.

  FIG. 1 is a conceptual diagram of a relative positioning system including a relative positioning device 1 according to the present embodiment. The relative positioning system includes two or more satellites (here, six satellites) and two relative positioning devices 1. Here, it is assumed that the relative positioning system outputs a relative position between the first relative positioning device 1 and the second relative positioning device 1. The first relative positioning device 1 is a local terminal, and the second relative positioning device 1 is another terminal that is not its own terminal, and is referred to as another terminal. In FIG. 1, there are six satellites, a1, a2, a3, a4, a5, and a6. Further, in FIG. 1, reference numeral 11 denotes a satellite signal receiver described later. The satellite signal receiving unit 11 has, for example, a GPS receiving antenna. Reference numerals 13 and 14 denote antennas that constitute a later-described own terminal information group transmitting unit and other terminal information group receiving unit, and are usually communication antennas. The satellite is usually a positioning satellite.

  FIG. 2 is a block diagram of the relative positioning device 1 in the present embodiment. FIG. 3 is a block diagram of the relative position acquisition unit 16 constituting the relative positioning device 1.

  The relative positioning device 1 includes a satellite signal reception unit 11, a local terminal information group acquisition unit 12, a local terminal information group transmission unit 13, another terminal information group reception unit 14, a correlation determination unit 15, a relative position acquisition unit 16, and an output. The unit 17 is provided.

  The own terminal information group acquisition unit 12 includes, for example, a measurement pseudo distance acquisition unit 121, a received SNR acquisition unit 122, a satellite position acquisition unit 123, and an own terminal movement information acquisition unit 124. In addition, the own terminal information group acquisition part 12 does not need to be provided with all said elements.

  In addition, the other terminal information group receiving unit 14 includes, for example, another terminal pseudo distance receiving unit 141, a received SNR receiving unit 142, and another terminal movement information receiving unit 143. The other terminal information group receiver 14 does not have to include all the above elements.

  The correlation determination unit 15 includes a reference satellite determination unit 151 and a correlation determination unit 152, for example.

  Further, the relative position acquisition unit 16 includes, for example, a position storage unit 161, a relative position storage unit 162, a predicted position acquisition unit 163, an estimated pseudo distance calculation unit 164, a position calculation unit 165, a relative position calculation unit 166, and a position accumulation unit 167. , And relative position storage means 168.

  A satellite signal receiving unit 11 constituting the relative positioning device 1 receives satellite signals of two or more satellites. The satellite signal is, for example, a GPS signal. The satellite signal receiving unit 11 is usually realized by a GPS receiver.

  The own terminal information group acquisition unit 12 acquires an own terminal information group that is a set of one or more own terminal information. The own terminal information is information related to the own terminal. The own terminal information group includes an own terminal satellite information group that is information for each satellite. The own terminal satellite information group includes the own terminal measurement pseudorange. The own terminal measurement pseudo distance is a pseudo distance between the own terminal and each satellite acquired by using the satellite signal received by the satellite signal receiving unit 11 for every two or more satellites. Also, the local terminal satellite information group may include, for example, the received SNR, the elevation angle of the satellite, the position (x, y, z) of the satellite, and the like. In addition to the local terminal satellite information group, the local terminal information group may include local terminal movement information that is information related to the movement of the local terminal, for example. Here, the own terminal movement information is information such as a movement speed and a movement direction, for example. The moving speed may be a three-dimensional speed or a two-dimensional speed. The pseudo distance is a distance index between the satellite and the terminal.

  The measurement pseudo distance acquisition means 121 constituting the own terminal information group acquisition unit 12 is the pseudo distance between the own terminal and each satellite using the satellite signal received by the satellite signal reception unit 11 for every two or more satellites. Get own terminal measurement pseudorange. Since the technique of the measurement pseudo distance acquisition unit 121 for acquiring the measurement pseudo distance is a known technique, a detailed description thereof will be omitted.

  The reception SNR acquisition means 122 acquires the local terminal reception SNR of the satellite signal for every two or more satellites. Since the technique for obtaining the signal-to-noise ratio (SNR) is a known technique, detailed description thereof is omitted.

  The satellite position acquisition unit 123 acquires a satellite position indicating the position of the satellite for every two or more satellites. Since the technique for acquiring the satellite position is a known technique, a detailed description thereof will be omitted.

  The own terminal movement information acquisition unit 124 acquires own terminal movement information which is information related to the movement of the own terminal including the moving speed and moving direction of the own terminal. The own terminal movement information acquisition means 124 calculates a moving speed by a vehicle speed pulse or an acceleration sensor, for example, and calculates a moving direction by a gyro or an electronic map. Since the technique for acquiring the own terminal movement information is also a known technique, detailed description thereof is omitted.

  The own terminal information group transmitting unit 13 transmits part or all of the information in the own terminal information group. The information transmitted by the own terminal information group transmission unit 13 is determined in advance. The own terminal information group transmitting unit 13 transmits, for example, a measurement pseudo distance and a received SNR. The transmission destination of the own terminal information group is another terminal referred to in this specification. However, the own terminal information group transmission unit 13 normally broadcasts information without designating the other party.

  The other terminal information group receiving unit 14 receives a part or all of the information of the other terminal information group transmitted by the other terminal (usually, the relative positioning device 1). The other terminal information group is information having the other terminal satellite information group. The other terminal satellite information is information relating to the other terminal, and usually has the same data structure as the own terminal satellite information. The other terminal satellite information includes another terminal measurement pseudo distance that is a pseudo distance between the other terminal and each satellite. Further, the other terminal satellite information may include, for example, a received SNR that is a signal-to-noise ratio of a satellite signal received by the other terminal, other terminal movement information, and the like. The other terminal movement information is information relating to the movement of the other terminal including the moving speed and the moving direction of the other terminal.

  The other terminal pseudo distance receiving means 141 constituting the other terminal information group receiving unit 14 receives the other terminal measured pseudo distance which is the pseudo distance between each satellite and the other terminal for every two or more satellites.

  The reception SNR reception unit 142 receives the other terminal reception SNR of the satellite signal of the other terminal for every two or more satellites.

  The other terminal movement information receiving unit 143 receives the other terminal movement information which is information related to the movement of the other terminal including the moving speed and the moving direction of the other terminal.

  For each common satellite, the correlation determination unit 15 uses the own terminal satellite information group acquired using the satellite signal transmitted from the common satellite and the other terminal acquired using the satellite signal transmitted from the common satellite. It is determined whether or not the correlation with the satellite information group is high. Note that the common satellite is a satellite in which both the terminal and the other terminal can receive satellite signals in common.

  Specifically, the correlation determination unit 15 includes two or more common satellites, their own terminal measurement pseudoranges, and the two common satellites other terminal measurement pseudoranges. The own terminal estimated distance, which is the distance to the terminal, and the other terminal estimated distance, which is the distance between the two common satellites and the other terminal, are acquired, and the own terminal measurement pseudo distance of the two common satellites, the other terminals of the two common satellites The own terminal satellite information group and the other terminal satellite for one common satellite of the two common satellites using the measurement pseudorange, the own terminal estimated distance of the two common satellites, and the other terminal estimated distance of the two common satellites It is determined whether or not the information group is highly correlated. One of the two common satellites here is usually a reference satellite described later. The reference satellite is preferably fixed, but may change dynamically.

  More specifically, the correlation determination unit 15 calculates the double difference of the pseudorange, which is the difference between the self-terminal measurement pseudorange of the two satellites and the other terminal measurement pseudorange of the two satellites, and the two satellites. When the double difference of the estimated distance, which is the difference between the own terminal estimated distance and the other terminal estimated distance of the two satellites, is calculated, and the difference between the pseudo-range double difference and the estimated distance double difference is smaller than the threshold value For other common satellites, it is determined that the self-terminal satellite information group and the other-terminal satellite information group are highly correlated. Here, the other common satellite is usually a common satellite that is not a reference satellite.

  The correlation determination unit 15 calculates a difference in pseudorange between two or more common satellites, determines whether the difference in pseudorange is smaller than a threshold, and determines that a common satellite that is equal to or greater than the threshold has low correlation. It is preferable to do. Here, the threshold value is preferably different for each satellite.

  The reference satellite determination unit 151 constituting the correlation determination unit 15 determines a satellite having a lower probability of receiving a reflected wave as a predetermined condition is satisfied among the common satellites. Here, the predetermined condition is preferably, for example, a satellite having the highest elevation angle. Further, for example, the predetermined condition may be a satellite having the highest received SNR. The satellite determined here is a reference satellite.

  Correlation determining means 152 is a self-terminal measurement pseudorange of two satellites of the reference satellite and each common satellite determined by reference satellite determination means 151, another terminal measurement pseudorange of the two satellites, and the two satellites and self-estimation. The self-terminal estimated distance that is the distance to the terminal and the other-terminal estimated distance that is the distance between the two satellites and the other terminal are acquired, and the self-terminal measurement pseudo distance of the two satellites, the other terminal of the two satellites The self-terminal satellite information group and the other-terminal satellite information group are highly correlated with respect to each common satellite using the measurement pseudorange, the self-terminal estimated distance of the two satellites, and the other-terminal estimated distance of the two satellites. Determine whether or not.

  The relative position acquisition unit 16 uses the self-terminal satellite information group and the other-terminal satellite information group of one or more satellites determined to have high correlation by the correlation determination unit 15 to use the relative position between the own terminal and the other terminal. To get.

  The position storage means 161 constituting the relative position acquisition unit 16 stores the time point position before the own terminal, which is the position at the time point before the own terminal, and the time point position before the other terminal, which is the position before the other terminal. obtain. The previous time point is a time point n (for example, 1) seconds before the current time point. Note that “n” is the time of the cycle for calculating the relative position. Moreover, the initial value of the time position before the own terminal and the time position before the other terminal are position information calculated by a known single positioning technique.

  The relative position storage unit 162 can store at least temporarily the relative position between the own terminal and the other terminal.

  The predicted position acquisition unit 163 acquires the current terminal current predicted position, which is the position after n seconds from the own terminal, using the previous terminal time point position and the own terminal movement information, and the other terminal previous time point position and the other terminal Using the terminal movement information, the other terminal current predicted position, which is the position after n seconds of the other terminal, is acquired. In addition, the own terminal movement information and the other terminal movement information here are the movement speed and the movement direction of the own terminal and the other terminal. Further, the position after n seconds may be considered as the current position. Also, a method for calculating a position after n seconds from the previous time point when the previous time point position, the moving speed, and the moving direction are given is known.

  The estimated pseudo distance calculating means 164 uses one's own terminal current predicted position and the satellite position of one or more satellites to calculate one or more own terminal estimated pseudo distances that are pseudo distances between the own terminal and one or more satellites. Is calculated. Further, the estimated pseudo distance calculating means 164 uses one of the other terminal current predicted positions and the satellite positions of one or more satellites to estimate one or more other terminals that are pseudo distances between the other terminals and the one or more satellites. Calculate the pseudorange. Further, the estimated pseudo distance calculating means 164 uses the current predicted position of the terminal itself and the satellite positions of one or more satellites determined to be highly correlated, and the pseudo distance between the terminal and the one or more satellites. One or more own terminal estimated pseudo distances are calculated. In addition, the estimated pseudo-range calculation means 164 uses the predicted current position of the other terminal and the satellite position of one or more satellites determined to have high correlation as the pseudo distance between the other terminal and the one or more satellites. It is preferable to calculate one or more other terminal estimated pseudoranges.

  The position calculation means 165 includes the own terminal current predicted position, the own terminal measurement pseudorange of one or more satellites determined to have high correlation, and the own terminal of one or more satellites determined to have high correlation. Using the estimated pseudo distance, the own terminal position that is the position of the own terminal is calculated. In addition, the position calculation means 165 includes the predicted current position of other terminals, one or more other terminal measurement pseudoranges determined to be highly correlated, and one or more satellites determined to be highly correlated. The other terminal position, which is the position of the other terminal, is calculated using the other terminal estimated pseudo distance.

  The relative position calculation means 166 calculates the relative position between the own terminal and the other terminal from the own terminal position and the other terminal position. The process of calculating the relative position of the two terminals when the positions of the two terminals are given is a known technique.

  The position accumulating unit 167 accumulates the position of the own terminal and the position of the other terminal in the position storing unit 161 as the time point position before the own terminal and the time point before the other terminal that is the position of the time point before the other terminal. The own terminal position and the other terminal position are the positions of the respective terminals at the present time, and are information calculated by the position calculating means 165.

  The relative position storage unit 168 stores the relative position calculated by the relative position calculation unit 166 in the relative position storage unit 162. The relative position storage unit 168 temporarily stores the relative position being calculated by the relative position calculation unit 166 in the relative position storage unit 162. That is, the relative position accumulation unit 168 temporarily accumulates the relative position every time the own terminal position and the other terminal position are updated while the own terminal position and the other terminal position are updated using the pseudo distance. .

  The output unit 17 outputs the relative position acquired by the relative position acquisition unit 16. The relative position is, for example, the relative position of the relative position storage unit 162. Moreover, the timing which the output part 17 outputs a relative position is not ask | required. Each time the relative position acquisition unit 16 acquires the relative position, the relative position may be output, or when a reception unit (not shown) receives an output instruction from the user, the relative position may be output. Moreover, the aspect in which the output part 17 outputs a relative position is not ask | required. For example, the output unit 17 may determine that the distance between the two terminals indicated by the relative position is within a threshold, and output a warning sound or the like indicating that the two vehicles are too close. Here, output refers to display on a display, projection using a projector, printing with a printer, sound output, transmission to an external device, storage in a recording medium, and output to other processing devices or other programs. It is a concept that includes delivery of processing results. The output unit 17 may or may not include an output device such as a display or a speaker. The output unit 17 can be realized by output device driver software, or output device driver software and an output device.

  Note that the above-mentioned own terminal information group acquisition unit 12, measurement pseudo distance acquisition unit 121, reception SNR acquisition unit 122, satellite position acquisition unit 123, correlation determination unit 15, reference satellite determination unit 151, correlation determination unit 152, relative The position acquisition unit 16, the predicted position acquisition unit 163, the estimated pseudo distance calculation unit 164, the position calculation unit 165, the relative position calculation unit 166, the position storage unit 167, and the relative position storage unit 168 are usually realized by an MPU, a memory, or the like. Can be done. The processing procedure of the own terminal information group acquisition unit 12 or the like is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  In addition, the own terminal information group transmitting unit 13 is usually realized by a wireless or wired communication unit, but may be realized by a broadcasting unit.

  Further, the other terminal information group receiving unit 14 is usually realized by a wireless or wired communication means, but may be realized by a means for receiving a broadcast.

  Further, the position storage means 161 and the relative position storage means 162 are preferably non-volatile recording media, but can also be realized by volatile recording media.

  Next, operation | movement of the relative positioning apparatus 1 is demonstrated using the flowchart of FIG.

  (Step S401) The satellite signal receiving unit 11 determines whether or not a satellite signal has been received. If a satellite signal is received, the process goes to step S402, and if not, the process returns to step S401. Here, it is assumed that the satellite signal receiving unit 11 receives satellite signals from one or more satellites.

  (Step S402) The own terminal information group acquisition part 12 substitutes 1 to the counter i.

  (Step S403) The own terminal information group acquisition unit 12 determines whether or not the i-th satellite signal is present in the satellite signals received in step S401. If the i-th satellite signal exists, the process goes to step S404, and if not, the process goes to step S406.

  (Step S404) The own terminal information group acquisition unit 12 acquires one or more own terminal satellite information from the i-th satellite signal and adds it to the own terminal satellite information group.

  (Step S405) The own terminal information group acquisition unit 12 increments the counter i by one. The process returns to step S403.

  (Step S406) The own terminal movement information acquisition unit 124 of the own terminal information group acquisition unit 12 acquires the own terminal movement information.

  (Step S407) The own terminal information group transmitting unit 13 transmits to one or more other information from the own terminal satellite information group acquired in Step S404 and the own terminal movement information acquired in Step S406. Configure own terminal information group.

  (Step S408) The own terminal information group transmitting unit 13 transmits the own terminal information group configured in step S407.

  (Step S409) The other terminal information group receiving unit 14 determines whether or not another terminal information group has been received. If other terminal information group is received, it will go to step S410, and if not received, it will return to step S409.

  (Step S410) Correlation determining unit 15 determines, for one or more satellites corresponding to one or more satellite signals received by satellite signal receiving unit 11, its own terminal (own terminal satellite information group) and another terminal (other terminal satellite). It is determined whether or not the information group is highly correlated. Such processing is called correlation determination processing. The correlation determination process will be described with reference to the flowchart of FIG.

  (Step S411) The relative position acquisition unit 16 acquires the relative position between the own terminal and the other terminal using the own terminal satellite information group and the other terminal satellite information group of one or more satellites determined to have high correlation. To do. Such a process is called a relative position calculation process. The relative position calculation process will be described with reference to the flowchart of FIG.

  (Step S412) The output unit 17 outputs the relative position acquired in step S411. The process returns to step S401.

  In the flowchart of FIG. 4, the process ends when the power is turned off or the process ends.

  Next, the correlation determination process in step S410 will be described using the flowchart of FIG.

  (Step S501) The reference satellite determination unit 151 of the correlation determination unit 15 uses the identifier of one or more satellites included in the own terminal information group and the identifier of one or more satellites included in the other terminal information group to determine the common satellite information. Get an identifier. The satellite identified by such an identifier is a common satellite.

  (Step S502) The reference satellite determination unit 151 acquires the elevation angle corresponding to the identifier of the common satellite acquired in step S501, which is the elevation angle of the own terminal information group. Then, the reference satellite determining unit 151 acquires the satellite identifier of the satellite having the highest elevation angle. A satellite identified by such a satellite identifier is a reference satellite.

  (Step S503) The correlation determination unit 152 acquires the measurement pseudorange of the reference satellite.

  (Step S504) The correlation determining means 152 estimates the distance of the reference satellite. An example of the distance estimation method will be described later.

  (Step S505) The correlation determining means 152 substitutes 1 for the counter i.

  (Step S506) The correlation determining unit 152 determines whether or not the i-th common satellite exists. If the i-th common satellite exists, the process proceeds to step S507, and if not, the process returns to the upper process. The common satellite here excludes the reference satellite.

  (Step S507) The correlation determination unit 152 acquires the measurement pseudorange of the i-th common satellite.

  (Step S508) The correlation determining means 152 estimates the distance of the i-th common satellite.

  (Step S509) The correlation determining unit 152 calculates a value for determining the correlation. Such processing will be described with reference to the flowchart of FIG.

  (Step S510) The correlation determination means 152 acquires the threshold value of the i-th common satellite. A specific example of the threshold acquisition method will be described later.

  (Step S511) The correlation determining unit 152 determines whether or not the value acquired in step S509 is within a threshold value. If it is within the threshold value, the process goes to step S512, and if not, the process goes to step S513.

  (Step S512) The correlation determining means 152 temporarily stores the identifier of the i-th common satellite in a buffer (not shown).

  (Step S513) The correlation determination means 152 increments the counter i by 1. The process returns to step S506.

  Next, the value calculation processing for correlation determination in step S509 will be described with reference to the flowchart of FIG.

  (Step S601) Correlation determining means 152 acquires the own terminal measurement pseudorange of the i-th common satellite.

  (Step S602) Correlation determining means 152 acquires the own terminal measurement pseudorange of the reference satellite.

  (Step S <b> 603) The correlation determination unit 152 acquires the other terminal measurement pseudorange of the i-th common satellite.

  (Step S604) The correlation determination means 152 acquires the other terminal measurement pseudorange of the reference satellite.

  (Step S605) Correlation determining means 152 acquires the self-terminal estimated distance of the i-th common satellite.

  (Step S606) Correlation determining means 152 acquires the estimated terminal distance of the reference satellite.

  (Step S607) The correlation determining means 152 acquires the other terminal estimated distance of the i-th common satellite.

  (Step S608) Correlation determining means 152 acquires the other terminal estimated distance of the reference satellite.

(Step S609) The correlation determining unit 152 calculates a value for determining the correlation using the values acquired from step S601 to step S608. Return to upper process. Note that the value for determining the correlation is, for example, a difference | (P _ab ^(kl) between a double difference (P _ab ^(kl) ) of a pseudo distance described later and a double difference (ρ _ab ^(kl) ) of an estimated distance. −ρ _ab ^(kl) ) |.

  In the flowchart of FIG. 6, the information acquisition order, acquisition method, and the like from steps S601 to S608 are not limited.

  Next, the relative position calculation process in step S411 will be described with reference to the flowchart of FIG.

  (Step S701) The relative position acquisition unit 16 acquires the self-terminal measurement pseudorange of one or more common satellites having high correlation. Further, the relative position acquisition unit 16 acquires the other terminal measurement pseudorange of one or more common satellites having high correlation. Also, the position of one or more common satellites with high correlation is acquired.

  (Step S702) The relative position acquisition unit 16 acquires the position of the own terminal previous time and the speed of the own terminal. Further, the relative position acquisition unit 16 acquires the position of the time before the other terminal and the speed of the other terminal. The speed here is preferably a three-dimensional speed, but may be a two-dimensional speed.

  (Step S703) The relative position acquisition unit 16 acquires the position of one or more common satellites with high correlation acquired in Step S701, the own terminal measurement pseudorange, the position of the previous time acquired in Step S702, and the own terminal. The position of the terminal is calculated using the speed.

  (Step S704) The relative position acquisition unit 16 acquires the position of one or more common satellites with high correlation acquired in Step S701, the other terminal measurement pseudorange, the position of the previous time acquired in Step S702, and the position of the other terminal. The position of the other terminal is calculated using the speed.

  (Step S705) The relative position acquisition unit 16 acquires the relative positions of the own terminal and the other terminal using the position of the own terminal and the position of the other terminal. Return to upper process.

  Hereinafter, a specific operation of the relative positioning device 1 in the present embodiment will be described. The conceptual diagram of the relative positioning apparatus 1 is FIG.

  Here, the satellite signal receiving unit 11 of the relative positioning device 1 (own terminal) receives positioning signals from, for example, the satellites l and k in FIG. Similarly, the satellite signal receiving unit 11 of the relative positioning device 1 (another terminal) also receives positioning signals from, for example, the satellites 1 and k in FIG.

Next, the own terminal information group acquisition unit 12 of the own terminal measures the pseudo distance p between the satellite l and the satellite k and the own terminal using the positioning signals from the satellite l and the satellite k. As shown in Equation 1 below, the measured pseudorange p is not only the estimated distance ρ, but also the receiver time error Δt, satellite time error ΔT (c: light velocity), ionosphere error d _ion , troposphere _Can be calculated using the error d.sub.trop due to, and the error .epsilon.

  The own terminal information group acquisition unit 12 of the own terminal acquires own terminal satellite information other than the pseudo distance p. Note that the local terminal satellite information other than the pseudo distance p is, for example, the received SNR, the elevation angle of the satellite, the position (x, y, z) of the satellite, and the like.

  In addition, the own terminal information group acquisition unit 12 of the own terminal acquires the own terminal movement information including the three-dimensional speed.

  Next, the own terminal information group transmitting unit 13 configures an own terminal information group to be transmitted to another terminal from one or more pieces of information of the acquired own terminal satellite information group and own terminal movement information. And the own terminal information group transmission part 13 transmits the comprised own terminal information group.

  Similarly, the own terminal information group acquisition unit 12 of the other terminal acquires the own terminal movement information of the other terminal (for the own terminal, the other terminal movement information). Then, the own terminal information group transmitting unit 13 of the other terminal transmits to one's own terminal (or another terminal for other terminals) from one or more pieces of information of the acquired own terminal satellite information group and own terminal movement information. The local terminal information group (other terminal information group for the local terminal) is configured and transmitted.

  Next, the other terminal information group receiving unit 14 of the own terminal receives the other terminal information group.

  Next, the correlation determination unit 15 of the own terminal determines the correlation between the satellite l and the satellite k as follows. First, the reference satellite determining unit 151 of the correlation determination unit 15 uses the identifier of the common satellite (here, the identifier of one or more satellites included in the own terminal information group and the identifier of one or more satellites included in the other terminal information group) Then, satellite l and satellite k) are acquired.

  Next, the reference satellite determining unit 151 of the correlation determining unit 15 acquires the elevation angle corresponding to the identifiers of the common satellites l and k. Then, the reference satellite determination unit 151 acquires the satellite identifier l of the satellite with the highest elevation angle. That is, the reference satellite determining unit 151 determines the satellite l as a reference satellite.

Next, the correlation determination unit 152 acquires the measurement pseudorange (p _a ^(l) ) of the reference satellite l. Note that the measurement pseudorange is the own terminal measurement pseudorange of the reference satellite. Correlation determining means 152 estimates the estimated distance (ρ _a ^(l) ) of reference satellite l. The estimated distance is the estimated distance of the reference satellite's own terminal.

Next, the correlation determination means 152 acquires the measurement pseudorange (p _a ^(k) ) of the common satellite k. The measurement pseudorange is the own terminal measurement pseudorange of the common satellite k. Further, the correlation determining means 152 estimates the estimated distance (ρ _a ^(k) ) of the common satellite k. Note that the estimated distance is the own terminal estimated distance of the common satellite k.

Next, the correlation determination means 152 acquires the other terminal measurement pseudorange (p _b ^(k) ) of the common satellite k. In addition, the correlation determination unit 152 acquires the other terminal measurement pseudorange (p _b ^(l) ) of the reference satellite l.

Further, the correlation determination unit 152 acquires the other terminal estimated distance (ρ _b ^(k) ) of the common satellite k. In addition, the correlation determination unit 152 acquires the other terminal estimated distance (ρ _b ^(l) ) of the reference satellite l.

Next, the correlation determination unit 152 substitutes the information acquired above into the following formula 2 to estimate the double difference (P _ab ^(kl) ) of the pseudorange measured for each of the satellites k and l. the difference between the distance double difference of ^(ρ _ab ^(kl)) and ^{_{(P ab (kl) -ρ ab}} (kl)) is calculated.

In Equation 2, P _ab ^(k1) −ρ _ab ⁽ _k1 ) remains without an error component (d _ion , d _trop ) and a common component (Δt, ΔT) having high spatial correlation at a short distance. The part is mostly the effect of reflected waves and thermal noise.

In Equation 2, P _a ^(k) is a pseudo distance between the moving object a (which may be referred to as the terminal a) and the satellite k. P _ab ^(kl) is a double difference of pseudoranges measured by the mobile bodies a and b with respect to the satellites k and l, respectively. Furthermore, ρ _ab ^(kl) is a double difference of the estimated distance.

In Equation 2, if the elevation angle of the satellite l is high (for example, if the satellite l is a quasi-zenith satellite), the error component is not affected by the reflected wave, and most of the error component is thermal noise. Is small. Then, (ε _a ^(k) −ε _b ^(k) ) is approximately P _ab ^(kl) −ρ _ab ^(kl) .

Here, if the value of | P _ab ^(kl) −ρ _ab ^(kl) | is large, | ε _a ^(k) −ε _b ^(k) | is large, and one mobile unit (own terminal or others) The terminal) is receiving the direct wave, and the other mobile body (the other terminal or the own terminal) is highly likely to receive the reflected wave. Thus, the correlation determination unit ^{_{152, | P ab (kl)}} -ρ ab (kl) | when the value of is greater than the threshold value, the correlation of the pseudo distance measured respectively at the two terminals is determined to be low. Note that being larger than the threshold is a concept including the threshold or more. Further, the threshold value in this case may be held by the correlation determination unit 152.

_Conversely, ^| if the value is ^{small, | | P ab (kl)} -ρ ab (kl)) ε a (k) -ε b (k) | values is small. In such a case, the two mobile units (own terminal and other terminal) both receive the direct wave, or both receive the reflected wave, but there is a spatial correlation of the reflected wave, and the error component cancels out. Has been. Therefore, the correlation determining means 152 can compare | P _ab ^(kl) −ρ _ab ^(kl) | with a threshold value, and the own terminal and the other terminals can determine the spatial correlation of the pseudorange measured with respect to the satellite k. . Here, the value | P _ab ^(kl) −ρ _ab ^(k1) | to be compared with the threshold value is a difference between the double difference of the pseudo distance and the double difference of the estimated distance. A threshold different from the threshold may be compared. Here, the information having the same meaning is information regarding a difference between the double difference of the pseudo distance and the double difference of the estimated distance. For example, the value to be compared with the threshold value is multiplied by x, a normalized value, or the like. is there.

Here, the double difference (ρ _ab ^(kl) ) of the estimated distance ρ is used, but in reality, the correlation determination means 152 does not know ρ _ab ^(kl) at the current time and uses conventional information. Predict. That is, if the correlation determination unit 152 calculates a position with high accuracy without using a received wave with low correlation when positioning at the previous time using the Kalman filter, the position of the calculated previous time is determined. The position information at the current time can be predicted using the information and the measured speed information. In addition, the correlation determination unit 152 estimates the distance between the predicted position of the mobile body (terminal) and the position of the satellite, compares the measured pseudo distance with the estimated distance, and if both distances greatly deviate ( If the threshold value is greater than or equal to the threshold), it is determined that the measured pseudo-range includes a reflected wave with low correlation.

  More specifically, the correlation determination unit 152 uses the distance calculated from the position of the satellite and the predicted position of the moving body as described above as the estimated value of the estimated distance.

  In the following description, it is preferable that the threshold value for determining a highly correlated satellite is different for each satellite. The threshold value in such a case will be described below. Here, attention is paid to the horizontal relative position between the moving bodies (terminals). The effect of the pseudorange error on the error of the horizontal relative position differs depending on the elevation angle of the satellite used during positioning. When the accuracy of the horizontal relative position is determined in advance, the allowable error in the pseudorange of each satellite is different. Therefore, it is preferable to determine a threshold value for determining the correlation of the pseudoranges for each satellite.

  Specifically, the threshold value is determined for each satellite as follows.

First, as shown in FIG. 8, the correlation determination unit 152, the position of the movable body a and b _r a, and _{r b,} the relative position of the moving body a and b _"r ab ₌ r a -r _b" And In FIG. 8, r ₀ is a reference position in the vicinity of the moving bodies a and b, its longitude and latitude are λ and φ, respectively, and the positions of the satellites that a and b can receive in common are r ^{(1) , r} (2), ···, a ^{r (K),} a and b are pseudorange vectors measured respectively common satellites is _{P a} and _{P b,} to.

Further, as shown in Formula 3, the pseudo-range difference (P _a −P _b ) can be calculated using the relative position (r _ab ) as a parameter (Δl _ab is a component corresponding to a time error). However, H is a matrix of K rows and 4 columns indicating the arrangement of K satellites, and “− (r ⁽¹⁾ −r ₀ ) ^T / | (r ⁽¹⁾ −r ₀ ) |” is the first. Is a normalized three-dimensional vector indicating the direction from the satellite to the reference position r ₀ , and “− (r ^(K) −r ₀ ) ^T / | (r ^(K) −r ₀ ) |” is the Kth satellite. the normalized three-dimensional vector indicating a direction to a reference position r ₀ from. Therefore, the correlation determining unit 152 can calculate the relative position _rab from the pseudorange difference (P _a −P _b ) and H.

The above satellite position ^r in Equation ^{3 (1), r (2} ), ···, r (K) and the vehicle position _r a, _{r b} is the ECEF (Earth-Centered Earth-Fixed ) coordinate. The horizontal relative position between vehicles should be calculated in an ENU (East-North-Up) coordinate system near the vehicle.

Therefore, the correlation determination unit 152 converts the ECEF coordinates (x, y, z) shown in FIG. 9 into ENU coordinates (e, n, u) using Expression 4. Incidentally, ECEF coordinates are coordinates with the origin of the center of the earth mass system (geocentric earth fixed coordinate system), ENU coordinates of the vehicle position r _a, the point is a reference position in the vicinity of r _b (r ₀ = Taking (x ₀ , y ₀ , z ₀ )) as the origin, the Z-axis is positive in the zenith direction (upward on the vertical line), the X-axis is taken east at a right angle, and the Y-axis is taken in the north direction Coordinate system, also called horizon orthogonal coordinates.

That is, the correlation determining unit 152 calculates the horizontal relative position r _ab ^nu between the terminal a (which may be referred to as the moving object a) and b using the following Equation 5.

For terminals a and b, if the correlation of the pseudorange measured with respect to the common satellite k is high, most of the errors are canceled out, so the difference in pseudorange with the kth satellite is small. If there is an error that cannot be offset in the pseudo-range of the k-th satellite, the influence of the error on the horizontal position is calculated by Equation 6. If the error of the horizontal relative position of the terminals a and b is required to be d or less, the error of the pseudorange of the kth satellite should be d _k or less shown in Equation 7. That is, the correlation determining unit 152 calculates d _k in Expression 7 as a threshold value for each satellite. Here, the correlation determination means 152 acquires the threshold value (d _k ) of the satellite k.

Next, the correlation determining unit 152 determines whether or not | (P _ab ^(kl) −ρ _ab ⁽ _k1 )) | is equal to or less than a threshold value (d _k ). Then, it is assumed that the correlation determination unit 152 determines that | (P _ab ^(kl) −ρ _ab ⁽ _k1 )) | is equal to or less than a threshold value (d _k ). Next, the correlation determining means 152 temporarily stores the identifier of the common satellite k in a buffer (not shown). That is, the common satellite k is selected as a highly correlated satellite.

  The correlation determination unit 152 performs the above processing on all the common satellites, and determines one or more satellites with high correlation.

Next, the relative position at the current time is calculated by the process described with reference to the flowchart of FIG. 7 using the pseudorange of the satellites in a set of one or more common satellites having a high pseudorange correlation.
(Concrete example)

  Hereinafter, a more specific operation for calculating the relative positions of the two terminals (the own terminal “a” and the other terminal “b”) will be described.

  Now, as shown in FIG. 1, two terminals (for example, relative positioning devices mounted on two vehicles in inter-vehicle communication) receive signals from GPS satellites a1, a2, a3, a4, a5, and a6. The relative position is calculated by exchanging the measured pseudo distance and speed information.

  The own terminal a receives the positioning signals from the GPS satellites a 1, a 2, a 3, a 4, a 5 via the GPS reception antenna 11, and the measurement pseudo distance acquisition means 121 constituting the own terminal information group acquisition unit 12 Measure pseudorange. Also, the received SNR acquisition unit 122 measures the received SNR. In addition, the own terminal movement information acquisition unit 124 calculates a speed using a vehicle speed pulse or an acceleration sensor. In addition, the own terminal movement information acquisition unit 124 calculates a moving direction using an electronic map or a gyro, and further calculates a three-dimensional speed. Then, the own terminal information group transmitting unit 13 transmits the measured three-dimensional speed and pseudorange / SNR via the communication antennas 13 and 14 in the format shown in FIG.

  Further, the other terminal b operates in the same manner as the own terminal a. However, the other terminal b receives positioning signals from the GPS satellites a2, a3, a4, a5, and a6.

  Note that the message 201 in FIG. 10 is the own terminal information group, and the message 202 is the other terminal information group. It can be said that 201 and 202 are location exchange messages between terminals. Here, the headers 201 and 202 are composed of a message source address (SRC) and a destination address (broadcast address). The payloads 201 and 202 are composed of the three-dimensional speed of the transmission source, the satellite number (PRN) of the satellite that can be received by the transmission source, the pseudorange p, and the SNR.

In addition, the position information vector X of the terminal is “X = (x, y, z, δ, v _x , v _y , v _z )”. Here, (x, y, z) is an ECEF coordinate, δ is a pseudo-range error portion corresponding to a receiver time error, and (v _x , v _y , v _z ) is 3 in the ECEF coordinate system. Dimensional velocity. That is, “x = X _{1 ← → 3} ” indicates a position, and “v = X _{5 ← → 7} ” indicates a speed. “X _{1 ← → 3} ” indicates the first to third elements of the position information vector X. The measurement information vector Y of the terminal is assumed to be “Y = (p ⁽¹⁾ , p ⁽²⁾ ,..., P ⁽ⁿ⁾ , v _x , v _y , v _z ) ^T ”. The measurement information vector Y includes the measured pseudoranges of n satellites and the three-dimensional velocity of the terminal.

  The operation of the own terminal “a” in such a case will be described using the flowcharts of FIGS. 11 and 12.

  (Step S1101) The own terminal information group acquisition unit 12 of the own terminal a measures the three-dimensional speed of the own terminal. In addition, the own terminal information group acquisition unit 12 measures the pseudorange and SNR based on the received signals from the satellites a1, a2, a3, a4, and a5, decodes the satellite calendar by a known method, and calculates the satellite position and elevation angle. To do. Terminal b operates in the same manner as terminal a. However, the terminal b receives positioning signals from the satellites a2, a3, a4, a5, and a6.

  (Step S1102) The own terminal information group transmitting unit 13 of the own terminal “a” transmits the pseudo distance, SNR, and three-dimensional velocity for each satellite in the message 201 and transmits them. The other terminal b operates in the same manner.

  (Step S1103) The other terminal information group reception unit 14 of the own terminal a receives the message 202 including the three-dimensional speed of the other terminal b, the satellite number of the satellite that can be received, the pseudorange, and the SNR. Similarly, the other terminal b receives the message 201 from the own terminal a.

(Step S1104) The correlation determination unit 15 of the own terminal a receives the set of satellites (a1, a2, a3, a4, a5) that the own terminal a can receive and the set of satellites (a2, a3, The common part (a2, a3, a4, a5) of a4, a5, a6) is calculated, and this common satellite set is set to CS _All = {a2, a3, a4, a5}. CS _All is a buffer for storing the identifier of the common satellite.

(Step S1105) The correlation determining unit 15 of the own terminal a has the elevation angle of each satellite calculated by the own terminal a = {23, 55, 36, in the common satellite set CS _All = {a2, a3, a4, a5}. 18}, the satellite a3 having the highest elevation angle is selected from the satellites whose SNR exceeds the threshold value (or may be equal to or higher than the threshold value), is designated as the reference satellite, and its number is l. That is, here, the correlation determination unit 15 determines a common satellite having the highest elevation angle as a reference satellite among the satellites having an SNR larger than the threshold value. Needless to say, the elevation angle of each satellite = {23, 55, 36, 18} is an example. Here, the reference satellite is selected from the satellites whose SNR exceeds the threshold, but such processing is not essential.

  (Step S1106) Correlation determining unit 15 of own terminal a initializes a Kalman filter for position prediction. That is, the correlation determination unit 15 checks a flag indicating whether or not the initial value of the Kalman filter is determined in the two terminals. If the flag is not attached (if the initial value is not decided), the process goes to step S1107. If the flag is attached (if the initial value is decided), the process goes to step S1110.

(Step S1107) correlation determination unit _15, to the common satellites in _{CS All,} difference SNR measured at two terminals will determine the following: constant threshold, such common satellites and _{CS WeakCorr.} Note that CS _{Week Corr} is a buffer that stores identifiers of common satellites having an SNR difference equal to or less than a certain threshold.

(Step S1108) The correlation determining unit 15 determines whether the number of satellites in the CS _{Week Corr} is 4 or more. If the number of satellites is 4 or more, independent positioning can be performed, and the process goes to step S1109. Further, if the number of satellites in CS _{Week Corr} is 3 or less, independent positioning is not possible, so correlation determination unit 15 waits until independent positioning is possible and ends.

(Step S1109) The correlation determination unit 15 uses the pseudo-range and position of the common satellite in the CS _{Week Corr} for the terminals a and b, and the ECEF position x ⁺ _{a, 0} of the mobile bodies a and b by a known method. And x ⁺ _{b, 0} are calculated. The correlation determination unit 15 then sets the initial value of the Kalman filter of the terminal a “X ⁺ _{a, 0} = [x ⁺ _{a, 0} , δa _{, 0} , va _{, 0} ] ^T , P ⁺ _{a, 0} = I ₇ · σ (σ is a parameter) ”. “X ⁺ _{a, 0} ” is an initial value of the position of the terminal a, “δ _{a, 0} ” is an initial value of the time error, and “va _{, 0} ” is an initial value of the three-dimensional velocity of the terminal a. Value. “P ⁺ _{a, 0} ” is a covariance matrix of X ⁺ _{a, 0} , and “I ₇ ” is a 7 × 7 unit matrix. The initial value of the Kalman filter of the terminal b, the ^{_{"X + b, 0 = [x}} + b, 0, δ b, 0, v b, 0] T, P + b, 0 = I 7 · σ 0 " And Then, a flag with an initial value of the Kalman filter is added and the process ends.

(Step S1110) When the flag for which the initial value of the Kalman filter is determined is added, the correlation determination unit 15 of the terminal a determines a threshold for determining the correlation of the pseudoranges measured at the terminals a and b. Is calculated. Here, m is the current time. That is, the correlation determination unit 15 determines the states X ⁺ _{a, m−1} , P ⁺ _{a, m−1} and X ⁺ _{b, m−1} of the Kalman filters of the two terminals a and b at time _m−1 . P ⁺ _{b, m−1} are read.

(Step S1111) The correlation determination unit 15 predicts the states of the two terminals at time m. Specifically, the correlation determination unit 15 acquires the state of the terminal “a” using Equation 8 below.

  In Equation 8, Φ is a state transition matrix, and Q is a state randomness matrix. The state transition matrix is a matrix representing the relationship of predicting the position of the current time using the position information and speed information of the previous time, and τ is the difference between the previous time and the current time. The state randomness matrix is a matrix representing the degree to which the state cannot be predicted by random elements.

(Step S1112) correlation determination unit 15, the predicted position ^x of the own terminal a obtained in Step S1111 _{- a,} a _m and _{r 0.}

(Step S1113) The correlation determination unit 15 calculates H indicating the azimuth between the common satellite positions r ^(k) and r ₀ in CS _All . In addition, the above-mentioned numerical formula 3 is used for calculation of H.

(Step S1114) correlation determining section 15 calculates the _{R L} with _{r 0.} Note that _RL is calculated using Equation 5.

(Step S1115) The correlation determination unit 15 calculates G using _RL and H. G is calculated using Equation 5.

(Step S1116) The correlation determination unit 15 calculates the allowable value d _k of the pseudorange difference for each common satellite (k) in CS _All . The allowable value d _k is calculated using Equation 7.

(Step S1117) The correlation determining unit 15 uses the double difference “ρ _ab ^(kl) = ( ⁾ for the common satellite k other than the reference satellite 1 using the predicted positions and the satellite positions of the terminals a and b in CS _All . [rho] _a ^(k) - _[ rho] _b ^(k) )-([rho] _a ^(l) -[rho] _b ^(l) ) ". However, ^{_{"ρ a (k) = | x}} - a, m -r (k) |, ρ b (k) = | x - b, m -r (k) |, ρ a (l) = | x - _{a, m} −r ^(l) |, ρ _b ^(l) = | x ⁻ _{b, m} −r ^(l) | ”.

(Step S1118) correlation determination unit _15, the _{CS All,} to the common satellites k other than l, double difference pseudorange ^{_{"p ab (kl) = (p}} a (k) -p b (k)) - calculating the ^{_{(p a (l) -p b}} (l)) . "

(Step S1119) The correlation determining unit 15 determines whether or not “| p _ab ⁽ k1 ⁾ −ρ _ab ⁽ _k1 ⁾ | <d _k ” holds for the common satellite k other than 1 in CS _All . to decide. If established, the terminals a and b are assumed to have a high pseudorange correlation with the common satellite k, and the correlation determination unit 15 puts the identifier (for example, k) of the satellite k in CS _StrongCorr . The CS _{Strong Corr} is a buffer that stores an identifier of a satellite having a high pseudorange correlation.

(Step S1120) The relative position acquisition unit 16 calculates the relative position between the terminal a and the terminal b at the current time using the pseudorange of the satellites in the common satellite set CS _StrongCorr having a high pseudorange correlation.

Specifically, the relative position acquisition unit 16, the measurement information _{^{"Y a, m = (p a}} (1), p a (2), ···, p a (n), v ax, v ay, v _az) ^T "and" _{^{Y b, m = (p b}} (1), p b (2), ···, p b (n), v bx, v by, because the _v ^{bz) T} ", the terminal a , B to extract the pseudo-range of the satellite and the three-dimensional velocity in the CS _StrongCorr . Information including the pseudorange and the three-dimensional velocity is assumed to be “Y ′ _{a, m} ” and “Y ′ _{b, m} ”. Then, the relative position acquisition unit 16 calculates the Kalman gains “K _{a, m} ” and “K _{b, m} ” of the moving bodies a and b using the following formula 9. Further, the relative position acquisition unit 16 uses the Kalman gains “K _{a, m} ” and “K _{b, m} ” and uses Equation 9 to calculate a new state “X ⁺ _{a, m} "and" X ⁺ _{b, m} "are calculated, and error matrices" P ⁺ _{a, m} "and" P ⁺ _{b, m} "are also calculated.

In Equation 9, ρ _{a, m} is a vector of the distance between the satellite position in CS _StrongCorr and the predicted position x ⁻ _{a, m of} terminal a, and ρ _{b, m} is the satellite position in CS _{Strong Corr} . This is a vector of the distance between the predicted position x ⁻ _{b, m} of the moving object b.

Then, the relative position acquisition unit ^16, _{X + a,} then ^x _{+ a,} a _m and _{r a} in _{^m, X + b,} ^x in the _{m + b,} a _m and ^{_{r b, r a, b enu}} = R L ( From “r _a −r _b ”, “r _{a, b} ^enu = (Δe _{a, b} , Δn _{a, b} , Δu _{a, b} )” is calculated, and the horizontal relative position “(Δe) between the terminal a and the terminal b is calculated. _{a, b} , Δn _{a, b} ) ”.
However, Δe _{a, b} is the east direction and Δn _{a, b} is the north direction.

  As mentioned above, according to this Embodiment, the relative position between terminals can be acquired with high precision. More specifically, in this embodiment, when the correlation of measured pseudoranges is determined for satellites that can be received in common between moving objects, the signals that can be received in common by both receivers. Among them, a received wave having a high pseudo-correlation including a reflected wave is used, and a reflected wave having a low correlation is excluded. Therefore, the number of satellites used for positioning can be increased while avoiding the bad influence of reflected waves, and the relative position can be obtained with high accuracy.

  Further, according to the present embodiment, the relative positioning device 1 has a shortage of satellites and can acquire the relative position even in a place where the radio wave environment is bad. In the relative positioning device 1, a reflected wave having a correlation can be used, and the reflected wave error can be reduced, so that the relative position can be acquired with high accuracy.

  In the present embodiment, a three-dimensional speed is used as the speed of the terminal device (moving body). However, a two-dimensional speed may be used.

  Furthermore, the processing in the present embodiment may be realized by software. Then, this software may be distributed by software download or the like. Further, this software may be recorded and distributed on a recording medium such as a CD-ROM. This also applies to other embodiments in this specification. In addition, the software which implement | achieves the relative positioning apparatus 1 in this Embodiment is the following programs. In other words, this program causes a computer to receive a satellite signal reception unit that receives satellite signals of two or more satellites, and one of the satellite signal received by the satellite signal reception unit or information acquired using the satellite signal. This is information related to the own terminal, and the own terminal information group related to the own terminal is acquired using the satellite signal for each of two or more satellites, including the own terminal measurement pseudorange that is the pseudorange between the own terminal and each satellite. A local terminal information group acquisition unit, a local terminal information group transmission unit that transmits part or all of the information of the local terminal information group, and a satellite signal received by another terminal or the satellite signal. Information including one or more other terminal satellite information groups for each of two or more satellites, which is information relating to one or more of the other terminals, and includes other terminal measurement pseudo distances that are pseudo distances between the other terminals and each satellite. , The other end The other terminal information group receiving unit that receives part or all of the information group, and two or more common satellites that can receive satellite signals by both the own terminal and the other terminal. The terminal measurement pseudo distance, the other terminal measurement pseudo distance of the two common satellites, the own terminal estimated distance that is the distance between the two common satellites and the own terminal, and the distance between the two common satellites and the other terminal The other terminal estimated distance is acquired, the own terminal measured pseudo distance of the two common satellites, the other terminal measured pseudo distance of the two common satellites, the own terminal estimated distance of the two common satellites, and the two common satellites Correlation determination for determining whether or not the self-terminal satellite information group and the other-terminal satellite information group are highly correlated with respect to one common satellite of the two common satellites using the other-terminal estimated distance And the correlation is high The relative position acquisition unit that acquires the relative position between the own terminal and the other terminal using the own terminal satellite information group and the other terminal satellite information group of one or more disconnected satellites, and the relative position acquisition unit acquires The program for functioning as an output unit that outputs the relative position.

  In the above program, the correlation determination unit includes a reference satellite determination unit that determines a satellite that has a lower probability of receiving a reflected wave as a predetermined condition is satisfied among the common satellites. The own terminal measurement pseudorange of two satellites, that is, the satellite and another common satellite, the other terminal measurement pseudorange of the two satellites, the own terminal estimated distance that is the distance between the two satellites and the own terminal, and the two satellites And the other terminal estimated distance, which is the distance between the two satellites, the own terminal measured pseudo distance of the two satellites, the other terminal measured pseudo distance of the two satellites, the own terminal estimated distance of the two satellites, and the Using the other terminal estimated distance of two satellites, the computer functions as the one for determining whether or not the own terminal satellite information group and the other terminal satellite information group are highly correlated with respect to the other common satellite Let It is preferred.

  Further, in the above program, the correlation determination unit includes a double difference of a pseudorange, which is a difference between a difference in own terminal measurement pseudorange of the two satellites and another terminal measurement pseudorange of the two satellites, and the 2 Calculate the double difference of the estimated distance that is the difference between the estimated distance of the two satellites and the estimated distance of the other terminals of the two satellites, and the difference between the double difference of the pseudo distance and the double difference of the estimated distance is When it is small, it is preferable to make the computer function as one that determines that the other terminal satellite information group and the other terminal satellite information group are highly correlated with respect to the other common satellite.

  In the above program, the correlation determining unit calculates a pseudo-range difference between two or more common satellites, determines whether the pseudo-range difference is smaller than a threshold, and a common satellite that is equal to or greater than the threshold is correlated. It is preferable to make a computer function as what is judged to be low.

  In the above program, it is preferable that the threshold value is different for each satellite and the computer is caused to function.

  In the above program, the own terminal information group acquisition unit uses the satellite signal received by the satellite signal reception unit for each of two or more satellites, and the own terminal measurement pseudo-range is a pseudo distance between the own terminal and each satellite. Measurement pseudo-range acquisition means for acquiring a distance, reception SNR acquisition means for acquiring the reception terminal SNR of the satellite signal for each of two or more satellites, and a satellite position indicating the position of the satellite for each of the two or more satellites A computer functioning as comprising: a satellite position acquisition means for performing acquisition, and own terminal movement information acquisition means for acquiring own terminal movement information that is information relating to movement of the own terminal including the movement speed and movement direction of the own terminal. Is preferred.

(Embodiment 2)
In the present embodiment, a case will be described in which the relative positioning device uses the threshold value d _k for determining the correlation of the pseudo distance as a fixed value.

  FIG. 13 is a block diagram of the relative positioning device 2 in the present embodiment. The relative positioning device 2 includes a satellite signal reception unit 11, a local terminal information group acquisition unit 12, a local terminal information group transmission unit 13, an other terminal information group reception unit 14, a correlation determination unit 25, a relative position acquisition unit 16, and an output. The unit 17 is provided.

  The correlation determination unit 25 includes a reference satellite determination unit 151 and a correlation determination unit 252.

  Correlation determining unit 25 includes two or more common satellites whose own terminal measurement pseudorange and two other satellites another terminal measurement pseudorange among two or more common satellites in which both the own terminal and the other terminal can receive satellite signals. Get the own terminal estimated distance that is the distance between the two common satellites and the own terminal, and the other terminal estimated distance that is the distance between the two common satellites and the other terminal, and measure the own terminal measured pseudo distance of the two common satellites The other terminal measurement pseudorange of two common satellites, the own terminal estimated distance of the two common satellites, and the other terminal estimated distance of the two common satellites are used for one common satellite of the two common satellites. It is determined whether or not the terminal satellite information group and the other terminal satellite information group are highly correlated.

  The correlation determination unit 25 is configured to calculate a double difference of a pseudorange, which is a difference between a difference between two satellites' own-terminal measurement pseudoranges and another satellite's other-terminal measurement pseudoranges, two-satellite's own-terminal estimated distances, and 2 Calculate the double difference of the estimated distance, which is the difference from the other terminal estimated distance of one satellite, and if the difference between the double difference of the pseudo distance and the double difference of the estimated distance is smaller than the threshold, It is determined that the own terminal satellite information group and the other terminal satellite information group are highly correlated.

  The correlation determination unit 25 calculates a pseudorange difference between two or more common satellites, determines whether the pseudorange difference is smaller than a threshold, and determines that a common satellite that is equal to or greater than the threshold has low correlation. The threshold value here is the same value for all satellites. The correlation determination unit 25 may store a threshold value in advance, or may select one satellite, calculate a threshold value corresponding to the selected satellite, and use the calculated threshold value for other satellites. It may be applied. The threshold value calculation method may be the method described in the first embodiment. One satellite may be selected in any way. For example, the satellite with the highest SNR may be selected, or the satellite with the second highest elevation angle may be selected. Since the operation of the correlation determining unit 252 is the same as the operation of the correlation determining unit 25 described above after the reference satellite is determined, the description thereof is omitted.

  The correlation determination unit 25 and the correlation determination unit 252 can usually be realized by an MPU, a memory, or the like. The processing procedure of the correlation determining unit 25 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  As mentioned above, according to this Embodiment, the calculation for acquiring a relative position can be simplified. Therefore, the relative position can be calculated at a higher speed.

(Embodiment 3)
In the present embodiment, when the correlation of pseudo distances is determined, the difference between the pseudo distance difference and the estimated distance difference described in the first embodiment “| (P _ab ^(kl) −ρ _ab ^(kl) ) |” Is compared with the first threshold (d _k ), and the SNR difference “(SNR _a ^(k) −SNR _b ^(k) )” is compared with the second threshold to The relative positioning device 3 to be determined will be described.

  FIG. 14 is a block diagram of the relative positioning device 3 in the present embodiment. The relative positioning device 3 includes a satellite signal reception unit 11, a local terminal information group acquisition unit 12, a local terminal information group transmission unit 13, another terminal information group reception unit 14, a correlation determination unit 35, a relative position acquisition unit 16, and an output. The unit 17 is provided.

  The correlation determination unit 35 includes a reference satellite determination unit 151 and a correlation determination unit 352.

  The correlation determination unit 35 calculates the self-terminal measurement pseudo distance of the two common satellites, the other terminal measurement pseudo distance of the two common satellites, the self-terminal estimation distance of the two common satellites, and the other terminal estimation distance of the two common satellites. And determining whether or not the own terminal satellite information group and the other terminal satellite information group are highly correlated with respect to one common satellite of the two common satellites, and the own terminal reception SNR and the other terminal reception Using SNR, it is determined whether one terminal satellite information group and another terminal satellite information group have a high correlation for one of the two common satellites. In the case where it is determined that the local terminal satellite information group and the other terminal satellite information group are highly correlated.

More specifically, the correlation determination unit 35 compares the difference “| (P _ab ^(kl) −ρ _ab ⁽ _k1 )) |” between the pseudo-range difference and the estimated distance difference with the first threshold value (d _k ). To do. Further, the correlation determination unit 35 compares the SNR difference “(SNR _a ^(k) −SNR _b ^(k) )” with the second threshold value. Then, if both are equal to or less than the threshold value, the correlation determining unit 35 determines that the correlation of the pseudo distance to the satellite k is high, and uses the satellite k for acquisition of the relative position. Since the operation of the correlation determination unit 352 is the same as the operation of the correlation determination unit 35 described above after the reference satellite is determined, description thereof is omitted.

  The correlation determination unit 35 and the correlation determination unit 352 can be usually realized by an MPU, a memory, or the like. The processing procedure of the correlation determining unit 35 is usually realized by software, and the software is recorded on a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

  As described above, according to the present embodiment, the determination of correlation can be made more strict and the reliability of determination of correlation can be improved.

  FIG. 15 shows the appearance of a computer that executes the program described in this specification to realize the relative positioning devices of the various embodiments described above. The above-described embodiments can be realized by computer hardware and a computer program executed thereon. FIG. 15 is an overview of the computer system 300, and FIG. 16 is a block diagram of the system 300.

  In FIG. 15, a computer system 300 includes a computer 301 including a CD-ROM drive, a keyboard 302, a mouse 303, and a monitor 304.

  16, in addition to the CD-ROM drive 3012, the computer 301 includes an MPU 3013, a bus 3014 connected to the MPU 3013 and the CD-ROM drive 3012, a ROM 3015 for storing a program such as a bootup program, and an MPU 3013. And a RAM 3016 for temporarily storing instructions of the application program and providing a temporary storage space, and a hard disk 3017 for storing the application program, the system program, and data. Although not shown here, the computer 301 may further include a network card that provides connection to a LAN.

  A program that causes the computer system 300 to execute the functions of the relative positioning device of the above-described embodiment is stored in the CD-ROM 3101 or the FD 3102, inserted into the CD-ROM drive 3012 or the FD drive 3011, and further stored in the hard disk 3017. May be forwarded. Alternatively, the program may be transmitted to the computer 301 via a network (not shown) and stored in the hard disk 3017. The program is loaded into the RAM 3016 at the time of execution. The program may be loaded directly from the CD-ROM 3101, the FD 3102 or the network.

  The program does not necessarily include an operating system (OS), a third party program, or the like that causes the computer 301 to execute the functions of the relative positioning device of the above-described embodiment. The program only needs to include an instruction portion that calls an appropriate function (module) in a controlled manner and obtains a desired result. How the computer system 300 operates is well known and will not be described in detail.

  In the above program, in the step of transmitting information, the step of receiving information, etc., processing performed by hardware, for example, processing performed by a modem or an interface card in the transmission step (only performed by hardware) Processing) is not included.

  Further, the computer that executes the program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

  Further, in each of the above embodiments, it goes without saying that two or more communication units existing in one apparatus may be physically realized by one medium.

  In each of the above embodiments, each process (each function) may be realized by centralized processing by a single device (system), or by distributed processing by a plurality of devices. May be.

  The present invention is not limited to the above-described embodiments, and various modifications are possible, and it goes without saying that these are also included in the scope of the present invention.

  As described above, the relative positioning device according to the present invention has an effect that the relative position between the terminals can be obtained with high accuracy, and is useful as an inter-vehicle communication system or the like.

1, 2, 3 Relative positioning device 11 Satellite signal receiving unit 12 Own terminal information group acquiring unit 13 Own terminal information group transmitting unit 14 Other terminal information group receiving unit 15, 25, 35 Correlation determining unit 16 Relative position acquiring unit 17 Output Unit 121 measurement pseudo distance acquisition means 122 received SNR acquisition means 123 satellite position acquisition means 124 own terminal movement information acquisition means 141 other terminal pseudo distance reception means 142 reception SNR reception means 143 other terminal movement information reception means 151 reference satellite determination means 152, 252 and 352 Correlation determination means 161 Position storage means 162 Relative position storage means 163 Predicted position acquisition means 164 Estimated pseudo distance calculation means 165 Position calculation means 166 Relative position calculation means 167 Position storage means 168 Relative position storage means

Claims (9)

A satellite signal receiver for receiving satellite signals of two or more satellites;
The satellite signal received by the satellite signal receiver or information relating to one or more own terminals of information acquired using the satellite signals, and using the satellite signals for each of two or more satellites, The own terminal information group acquisition unit that acquires the own terminal information group related to the own terminal, including the own terminal measurement pseudo distance that is a pseudo distance with each satellite;
A self-terminal information group transmitter that transmits part or all of the self-terminal information group;
Information having another terminal satellite information group for each of two or more satellites, which is information on one or more of the satellite signals received by the other terminals or information acquired using the satellite signals. And other terminal information group receiving unit for receiving information on a part or all of the other terminal information group, including other terminal measurement pseudo distance that is a pseudo distance between each satellite and
Of two or more common satellites where both the own terminal and other terminals can receive satellite signals, the own terminal measurement pseudorange of two common satellites, and the other terminal measurement pseudorange of the two common satellites, the two common A self-terminal estimated distance that is a distance between the satellite and the self-terminal, and a different terminal-estimated distance that is a distance between the two common satellites and the other terminal; For one common satellite of the two common satellites using the other terminal measurement pseudorange of the two common satellites, the own terminal estimated distance of the two common satellites, and the other terminal estimated distance of the two common satellites, A correlation determination unit that determines whether or not the self-terminal satellite information group and the other-terminal satellite information group are highly correlated;
A relative position acquisition unit that acquires a relative position between the own terminal and the other terminal using the own terminal satellite information group and the other terminal satellite information group of one or more satellites determined to have high correlation;
A relative positioning device comprising: an output unit that outputs the relative position acquired by the relative position acquisition unit. The correlation determination unit
A reference satellite determining means for determining a satellite having a lower probability of receiving a reflected wave as a predetermined condition is satisfied among the common satellites;
The self-terminal measurement pseudorange of two satellites of the reference satellite and another common satellite, the other-terminal measurement pseudorange of the two satellites, the self-terminal estimation distance that is the distance between the two satellites and the self-terminal, and the 2 The other terminal estimated distance, which is the distance between one satellite and another terminal, is acquired, the two terminal's own terminal measured pseudo distance, the two satellites' other terminal measured pseudo distance, the two satellite's own terminal estimated distance, And determining whether or not the self-terminal satellite information group and the other-terminal satellite information group are highly correlated with respect to the other common satellite using the other-terminal estimated distance of the two satellites. Relative positioning device. The correlation determination unit
The double difference of the pseudorange which is the difference between the difference between the two satellites 'own terminal measurement pseudoranges and the other satellite's other terminal measurement pseudoranges, the two satellites' own terminal estimated distances and the two satellites When the difference between the estimated distance double difference, which is the difference from the estimated distance of other terminals, is smaller than the threshold, the difference between the pseudo distance double difference and the estimated distance double difference is less than the threshold value. The relative positioning device according to claim 2, wherein the terminal satellite information group and the other terminal satellite information group are determined to have high correlation. The relative positioning device according to claim 3, wherein the threshold value is different for each satellite. The relative positioning device according to claim 3, wherein the threshold value is the same for all satellites. The own terminal information group acquisition unit
A reception SNR acquisition means for acquiring a local terminal reception SNR that is an SNR of a satellite signal to be received for each of two or more satellites;
The other terminal information group is:
The other terminal receiving SNR which is the SNR of the satellite signal received by the other terminal,
The correlation determination unit
Using the own terminal measurement pseudorange of the two common satellites, the other terminal measurement pseudorange of the two common satellites, the own terminal estimated distance of the two common satellites, and the other terminal estimated distance of the two common satellites, For one common satellite of the two common satellites, it is determined whether or not the own terminal satellite information group and the other terminal satellite information group are highly correlated; and
Whether the own terminal satellite information group and the other terminal satellite information group are highly correlated with respect to one common satellite of the two common satellites using the own terminal received SNR and the other terminal received SNR. 6. If it is determined that both of the determinations indicate that the correlation is high, the self-terminal satellite information group and the other-terminal satellite information group are highly correlated. Any of the relative positioning devices described. The own terminal information group acquisition unit
Measurement pseudo-range acquisition means for acquiring a self-terminal measurement pseudo distance that is a pseudo distance between the own terminal and each satellite using the satellite signal received by the satellite signal receiving unit for every two or more satellites;
Reception SNR acquisition means for acquiring the own terminal reception SNR of the satellite signal for each of two or more satellites;
Satellite position acquisition means for acquiring a satellite position indicating the position of the satellite for every two or more satellites;
The relative position according to any one of claims 1 to 6, further comprising own terminal movement information acquisition means for acquiring own terminal movement information which is information relating to movement of the own terminal including a moving speed and a moving direction of the own terminal. A relative positioning method realized by a satellite signal reception unit, a local terminal information group acquisition unit, a local terminal information group transmission unit, another terminal information group reception unit, a correlation determination unit, a relative position acquisition unit, and an output unit,
A satellite signal receiving step in which the satellite signal receiving unit receives satellite signals of two or more satellites;
The own terminal information group acquisition unit is information on one or more own terminals among the satellite signals received in the satellite signal receiving step or information acquired using the satellite signals, and for each of two or more satellites Using the satellite signal, the own terminal information group acquisition step for acquiring the own terminal information group related to the own terminal, including the own terminal measurement pseudo distance that is a pseudo distance between the own terminal and each satellite;
The own terminal information group transmitting unit transmits part or all of the information of the own terminal information group,
Other terminal satellite information for each of two or more satellites, which is information related to one or more of the other terminals among the satellite signals received by the other terminals or the information acquired using the satellite signals. Other terminal information group receiving step for receiving information on a part or all of the other terminal information group, including other terminal measurement pseudoranges that are pseudoranges between other terminals and each satellite.
The correlation determination unit is configured to measure the own terminal measurement pseudorange of two common satellites and the other terminal measurement of the two common satellites among two or more common satellites in which both the own terminal and the other terminals can receive satellite signals. The pseudo-range, the own terminal estimated distance that is the distance between the two common satellites and the own terminal, and the other terminal estimated distance that is the distance between the two common satellites and the other terminal are acquired. Of the two common satellites, using the terminal measurement pseudorange, the other terminal measurement pseudorange of the two common satellites, the own terminal estimated distance of the two common satellites, and the other terminal estimated distance of the two common satellites A correlation determination step of determining whether or not the self-terminal satellite information group and the other-terminal satellite information group have a high correlation for one common satellite;
The relative position acquisition unit acquires a relative position between the own terminal and the other terminal using the own terminal satellite information group and the other terminal satellite information group of one or more satellites determined to have high correlation. A relative position acquisition step;
A relative positioning method, wherein the output unit includes an output step of outputting the relative position acquired by the relative position acquisition unit. Computer
A satellite signal receiver for receiving satellite signals of two or more satellites;
The satellite signal received by the satellite signal receiver or information relating to one or more own terminals of information acquired using the satellite signals, and using the satellite signals for each of two or more satellites, The own terminal information group acquisition unit that acquires the own terminal information group related to the own terminal, including the own terminal measurement pseudo distance that is a pseudo distance with each satellite;
A self-terminal information group transmitter that transmits part or all of the self-terminal information group;
Information having another terminal satellite information group for each of two or more satellites, which is information on one or more of the satellite signals received by the other terminals or information acquired using the satellite signals. And other terminal information group receiving unit for receiving information on a part or all of the other terminal information group, including other terminal measurement pseudo distance that is a pseudo distance between each satellite and
Of two or more common satellites where both the own terminal and other terminals can receive satellite signals, the own terminal measurement pseudorange of two common satellites, and the other terminal measurement pseudorange of the two common satellites, the two common A self-terminal estimated distance that is a distance between the satellite and the self-terminal, and a different terminal-estimated distance that is a distance between the two common satellites and the other terminal; For one common satellite of the two common satellites using the other terminal measurement pseudorange of the two common satellites, the own terminal estimated distance of the two common satellites, and the other terminal estimated distance of the two common satellites, A correlation determination unit that determines whether or not the self-terminal satellite information group and the other-terminal satellite information group are highly correlated;
A relative position acquisition unit that acquires a relative position between the own terminal and the other terminal using the own terminal satellite information group and the other terminal satellite information group of one or more satellites determined to have high correlation;
A program for functioning as an output unit that outputs the relative position acquired by the relative position acquisition unit.