JP2013061170A - Positioning system, positioning terminal device and positioning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately measure a position of a positioning terminal device on the basis of positioning data transferred to a positioning server at predetermined timing without transferring positioning data to the positioning server every time the positioning terminal device acquires the positioning data.SOLUTION: A positioning system is provided with a positioning terminal device which comprises: a watch which has an accuracy of equal to or less than 1 second; a satellite receiver which receives signals from a plurality of satellites in response to an input of a trigger signal and measures synchronous timing of respective signals; a memory which stores data of the respective synchronous timing and measurement times of the respective synchronous timing obtained from the watch; and means which outputs the data in the memory at predetermined timing to an outside. The positioning system is also provided with a positioning server which: preliminarily acquires all satellite information from the satellites during a whole period of time that the positioning terminal device measures positions; and calculates positional information of the positioning terminal device on the basis of the data on the synchronous timing received from the memory of the positioning terminal device as well as the satellite information at the measurement time of the positioning terminal device.

Description

  The present invention receives a signal from a GPS (Global Positioning System) satellite by a positioning terminal device and a positioning server, transfers the positioning data acquired and stored by the positioning terminal device to the positioning server, and performs positioning terminal data processing to perform positioning terminal processing. The present invention relates to a positioning system for positioning a device, a positioning terminal device, and a positioning method.

  In the GPS positioning system, data such as GPS satellite ID information, time information, and navigation messages are transmitted by radio waves from a plurality of GPS satellites. The positioning terminal device receives each data of a plurality of receivable GPS satellites for a long time (about several minutes), calculates an accurate time and an accurate distance from the plurality of GPS satellites, and the result and GPS The positioning calculation of the positioning terminal device is performed from the satellite position information. A signal from a GPS satellite is a synchronization detection signal having a 1 ms cycle whose minimum unit is called a C / A (Coarse / Acquisition) code. Thereafter, a bit in 20 ms unit, a word in 600 ms unit, a subframe in 6 second unit, 30 The second frame is configured (Non-Patent Document 1). In order to perform positioning, it is necessary to acquire at least several frames, and therefore a reception time of at least several minutes is required.

FIG. 4 shows a configuration example of a conventional network-assisted GPS positioning system.
In FIG. 4, a positioning terminal device 40 includes a GPS receiver 41. The GPS receiver 41 starts a signal receiving operation from a GPS satellite in response to a positioning request, and wirelessly receives received positioning data via a wireless network. Transmit to the base station 60. The radio base station 60 is connected to the positioning server 50 via a wired network, and transmits the positioning data received from the positioning terminal device 40 to the positioning server 50. The positioning server 50 includes a GPS receiver 51 and constantly receives navigation messages.

  The positioning terminal device 40 transmits, as positioning data, a phase control amount of each GPS satellite and a bit pattern that can specify the position of the data of the navigation message that measures the time and the phase control amount of the clock at that time. The phase control amount focuses on the position where the data is well separated, such as the head C / A code of a specific bit, and the time difference of the correlation peak acquisition time of the C / A code corresponding to the same transmission time for each GPS satellite is determined as the positioning data. Used as

  The positioning server 50 performs pattern matching of the navigation message with respect to data before and after the time when the data is acquired from the bit pattern that is constantly received, specifies the position of the C / A code from which the phase control amount is acquired, and The transmission time of the C / A code is specified from the time information at the beginning of the frame. Thereby, the satellite position at the time of C / A code transmission is specified, and the positioning calculation of the positioning terminal device 40 is performed.

“Basic Principles of GPS and Future Usage Trends”, TESLA (Construction Electrical Engineering), Vol.131, pp.18-19, 2000.9 (http://www.kendenkyo.or.jp/pdf/technology/131 basic. pdf)

  In order for the positioning terminal device to perform positioning, it is necessary to receive GPS satellite radio waves for a long time, and power consumption is large. In addition, in the network assist type GPS positioning system, there is a method of saving the satellite reception time of the positioning terminal device, but it is necessary to communicate with the positioning server via the network every time the positioning data is transferred. Power consumption is required.

  The present invention does not transfer the positioning data acquired by the positioning terminal device to the positioning server each time, and the positioning server can accurately perform positioning of the positioning terminal device based on the positioning data transferred at a predetermined timing. It is an object to provide a system, a positioning terminal device, and a positioning method.

  A positioning system according to a first aspect of the present invention includes a timepiece having an accuracy of less than 1 second, a satellite receiver that receives signals from a plurality of satellites by inputting a trigger signal and measures the respective synchronization timings, A positioning terminal device having a memory for storing the measurement time of each synchronization timing obtained from the data and the clock, and means for outputting the information in the memory to the outside at a predetermined timing, and all the times of the positioning period in the positioning terminal device A positioning server that obtains all satellite information from the satellite and calculates position information of the positioning terminal device based on the synchronization timing data received from the memory of the positioning terminal device and the satellite information at the measurement time of the positioning terminal device With.

  In the positioning system of the first invention, the positioning terminal device includes: a vibration sensor that detects vibration; an optical sensor that detects light quantity; and a determination circuit that outputs a trigger signal when the sensor output exceeds a predetermined value. Prepare.

  In the positioning system of the first invention, the positioning server is configured to correlate a plurality of time-series synchronization timings received from the positioning terminal device and correct an error in the position information calculation result.

  In the positioning method according to the second aspect of the invention, the positioning terminal device having a clock having an accuracy within 1 second is such that the satellite receiver receives signals from a plurality of satellites in response to the input of a trigger signal and measures the respective synchronization timings. The data of each synchronization timing and the measurement time of each synchronization timing obtained from the clock are stored in the memory, and the information in the memory is output to the outside at a predetermined timing. The positioning server All the satellite information is acquired from the satellite for the time of, the synchronization timing data is received from the memory of the positioning terminal device, and the position information of the positioning terminal device is obtained based on the data and the satellite information at the measurement time of the positioning terminal device. Calculate.

  In the positioning method of the second invention, the positioning server correlates a plurality of time-series synchronization timings received from the positioning terminal device, and corrects an error in the position information calculation result.

  According to a third aspect of the present invention, all satellite information is acquired from the satellite for all the positioning periods in the positioning terminal device, and the position information of the positioning terminal device is calculated based on the synchronization timing data received from the positioning terminal device. In a positioning terminal device of a positioning system provided with a positioning server, a clock having an accuracy of less than 1 second, a satellite receiver that receives signals from a plurality of satellites by inputting a trigger signal and measures respective synchronization timings, , A memory for storing the data of each synchronization timing and the measurement time of each synchronization timing obtained from the timepiece, and means for outputting the information in the memory to the outside at a predetermined timing.

  A positioning terminal device according to a third aspect of the present invention includes a vibration sensor that detects vibration, an optical sensor that detects light quantity, and a determination circuit that outputs a trigger signal when each sensor output exceeds a predetermined value.

  The present invention measures synchronization timing using a C / A code or the like in a positioning terminal device, and stores it in a memory inside the terminal together with a measurement timing of the synchronization timing obtained from a clock having an accuracy within 1 second. The positioning server always receives a signal from a satellite and stores all data of a positioning period in the positioning terminal device. Calculate the exact position of the positioning terminal device at the time of positioning by sending the data in the memory to the positioning server at a predetermined timing when the positioning terminal device connects to the positioning server and performing calculations within the positioning server. Can do. As a result, the positioning terminal device can minimize the reception time for positioning, and does not have to communicate every positioning, so that the power consumption can be kept extremely low.

It is a figure which shows the structural example of the positioning terminal device in Example 1 of the positioning system of this invention, and a positioning server. It is a figure which shows the structural example of the positioning terminal device in Example 2 of the positioning system of this invention. It is a figure which shows the process sequence example of the positioning method of this invention. It is a figure which shows the structural example of the conventional network assist type GPS positioning system.

FIG. 1 shows a configuration example of a positioning terminal device and a positioning server in Embodiment 1 of the positioning system of the present invention.
In FIG. 1, a positioning terminal device 10 constituting a positioning system includes a GPS receiver 11, a clock 12, and a memory 13, and a positioning server 20 includes a GPS receiver 21 inside or outside.

  When receiving a trigger signal for starting positioning, the GPS receiver 11 of the positioning terminal device 10 starts receiving signals from GPS satellites at the beginning of the second of the closest timing. For a plurality of GPS satellites, for example, C / When the A code is synchronized, the reception is stopped and the respective phase control amounts are calculated. At this time, it is unknown which frame signal or word signal the GPS satellite signal is, but the phase control amount is accurately calculated for digits of 1 ms or less, which is the time unit of the C / A code. . On the other hand, the positioning terminal device 10 has an accurate clock 12 (for example, a radio clock) in seconds, and the absolute accuracy thereof is 1 second or less.

  Here, if only the synchronization timing of the C / A code is acquired, the phase control amount in the positioning terminal apparatus 10 can be acquired with an accuracy of 1 ms or less. At this time, if the accuracy of the clock 12 is 1 ms or less, as shown in FIG. 1, the position of 1 ms or more is acquired from the clock 12, and the position of 1 ms or less is acquired based on the synchronization result of the C / A code. Thus, an accurate phase control amount can be acquired by combining them.

  If the accuracy of the clock 12 is 20 ms or less, the GPS satellite signal is received in bit units, the head C / A code of the bit is detected, and the phase control amount is calculated, similarly in bit time units. The phase control amount can be acquired with a certain accuracy of 20 ms or less. At this time, an accurate phase control amount can be acquired by acquiring a position of 20 ms or more from the clock 12 and acquiring a position of 20 ms or less based on the synchronization result of the bit and the C / A code and combining them. .

  If the accuracy of the clock 12 is 1 second or less, a GPS satellite signal is received in units of words, and if the phase control amount is calculated by detecting the leading C / A code of the leading bit of the word, the word The amount of phase control can be acquired with an accuracy of 600 ms or less, which is a time unit. At this time, the position of 1 second or more is acquired from the clock 12, and the position of 1 second or less is acquired based on the synchronization result of the word and the C / A code, and an accurate phase control amount is obtained by combining them. You can get it.

  As described above, if the accuracy of the timepiece 12 is 1 second or less, 20 ms or less, or 1 ms or less, the phase control amount can be acquired with accuracy according to any of the above methods.

  The phase control amount acquired in this way is input to and saved in the memory 13 of the positioning terminal device 10 together with the time information of the clock 12 and is not transferred to the positioning server 20. The positioning terminal device 10 enters a standby state after storing data, and minimizes power consumption of the battery-powered positioning terminal device 10. However, the clock 12 needs to operate continuously. Thereafter, the same operation is repeated each time a positioning trigger signal is input.

  Next, when the positioning terminal device 10 can be connected to the positioning server 20, for example, when the positioning terminal device 10 that has been moved returns to its permanent location and the external power source can be used, the positioning server 20 Data stored in the memory 13 is transferred to the positioning server 20 via a communication means (not shown). As a method of transferring the memory data, the positioning terminal device 10 may transfer the data to the positioning server 20 via a network, or the positioning terminal device 10 and the positioning server 20 may be directly connected by wireless or wired transfer. .

  The positioning server 20 acquires and stores all satellite information in a time zone in which the positioning terminal device 10 assumes positioning in advance using a GPS receiver 21 different from the positioning terminal device 10. When the positioning server 20 receives the phase control amount data of several satellites from the positioning terminal device 10, the data, the navigation data at the time when the positioning terminal device 10 performed positioning, and the positioning server 20 store in advance. Based on a part of the data, the accurate position of the positioning terminal device 10 is calculated and output by the same method as the normal GPS positioning. This completes the positioning of the positioning terminal device 10.

  The following is a simple estimate of the total amount of data acquired in this way and the amount of power consumption. In the case of the C / A code, the chip rate is about 1 MHz, and the accuracy of calculating the phase control amount in synchronization with this is approximately 1 μsec to 0.1 μsec. Therefore, it is only necessary to measure the phase control amount in units of 0.1 μsec and send only information on the timing within 1 ms, which is the unit of the C / A code, and satellites that have received information of almost 4 to 5 digits. What is necessary is just to acquire data every time. Therefore, the amount of data stored in the memory is 4 to 5 digits of phase control amount (in units of 0.01 to 0.1 μsec) per positioning point, and a maximum of 12 entertainment times (year / month / day / hour / minute / second). If six satellites are received, the total amount of information is 42 digits, that is, about 140 bits. Therefore, for example, even if positioning data is acquired every minute and continued for one week, it may be about 200 kbytes at most.

  At this time, assuming that the current consumption during operation of the GPS receiver is 10 mA and the operation time per positioning is 0.1 seconds, the total energy for satellite reception expected by the terminal in one month of measurement per minute is about 84 mAH. It can be seen that it can be operated with a small battery. On the other hand, if it is attempted to perform positioning every minute with the prior art, it is necessary to always energize, so it is necessary to mount a huge battery of 50000 mAH. Here, the operation time per positioning according to the present invention is set to 0.1 seconds. However, the operation time may be any time as long as it can measure the cross-correlation of the C / A code having a width of 1 ms, and a shorter operation time can be assumed. However, a larger value is used in consideration of the circuit startup time and the like.

FIG. 2 shows a configuration example of the positioning terminal device in the second embodiment of the positioning system of the present invention.
2, the basic configuration of the positioning terminal device 10 is the same as that of the first embodiment of FIG. 1, but includes a vibration sensor 14 and an optical sensor 15, and a determination circuit 16 that performs determination processing of each sensor data. In this configuration, the output of the determination circuit 16 is used as a trigger signal for starting positioning.

  The determination circuit 16 outputs a trigger signal when the amount of vibration detected by the vibration sensor 14 and the amount of light detected by the optical sensor 15 are each greater than a predetermined value. This condition is the moment when the positioning terminal apparatus 10 has moved in some way, and being brighter than a certain degree corresponds to the possibility of being outdoors. That is, it is necessary to perform positioning in order to capture movement, and it can be said that the condition is that a signal from a satellite can be reliably received if it is bright outdoors, so that effective data can be acquired. On the other hand, if there is no vibration, the positioning terminal device 10 is not moving, so that frequent positioning is meaningless.

  In addition, since vibration and light can be generated by these, for example, by connecting a small vibration generator or a small solar cell as a power source, this low power consumption positioning terminal device even in an environment without an external power source or a battery Can be operated. Conversely, in an environment where those generators cannot generate electricity, it can be considered that the terminal does not move, or because it is in a position where satellites such as indoors are not visible, it is not necessary to perform positioning, A positioning terminal device that can automatically perform positioning according to the necessity of positioning is realized. The level triggered by the sensor output can also be set in advance according to the scene where positioning is desired.

FIG. 3 shows an example of the processing procedure of the positioning method of the present invention.
There is a possibility that the data acquired by the positioning terminal device includes an error, for example, because the positioning terminal device has shortened the time for receiving the satellite radio waves to the minimum.

  The positioning terminal device inputs a plurality of time-series data to the positioning server. The positioning server performs positioning calculation based on a plurality of time-series data by the method described in the first embodiment, and outputs a plurality of positioning results corresponding to each point. Next, it is determined whether or not the positioning result at each point is valid. If it is valid, the positioning result is output.

  Here, since a plurality of time-series data correspond to the history of movement of the positioning terminal device, it is possible to correct the positioning data using this. For example, an estimated moving speed is estimated from past data, and if there is a movement that greatly exceeds the speed, it is corrected as a measurement error. Also, as is done in the prior art, correction is also made when the positioning position is not three-dimensionally on the earth due to various errors during satellite reception.

  For example, when the accuracy of the clock is unexpectedly 1 ms or more (that is, when the accuracy is in the second unit, but the accuracy is not up to 1 ms), the measurement is immediately started from the trigger. There is a possibility that the result of the C / A code detected in (1) is deviated from the C / A code to be originally measured. However, since the measurement is performed at a plurality of locations in time series, if the C / A code shift is constant in all data, the time error (in which the most likely positioning result is derived in the positioning server) C / A code shift amount) can be determined, and positioning can be performed based on this.

DESCRIPTION OF SYMBOLS 10 Positioning terminal apparatus 11 GPS receiver 12 Clock 13 Memory 14 Vibration sensor 15 Optical sensor 16 Judgment circuit 20 Positioning server 21 GPS receiver

Claims (7)

A clock having an accuracy of less than 1 second, a satellite receiver that receives signals from a plurality of satellites by inputting a trigger signal and measures each synchronization timing, data of each synchronization timing, and each synchronization obtained from the clock A positioning terminal device having a memory for storing timing measurement time, and means for outputting information in the memory to the outside at a predetermined timing;
All the satellite information is acquired from the satellite for all the time of the positioning period in the positioning terminal device, the synchronization timing data received from the memory of the positioning terminal device, and the satellite at the measurement time of the positioning terminal device And a positioning server that calculates position information of the positioning terminal device based on the information. The positioning system according to claim 1,
The positioning terminal device includes a vibration sensor that detects vibration, an optical sensor that detects light quantity, and a determination circuit that outputs the trigger signal when the sensor output exceeds a predetermined value. Positioning system. The positioning system according to claim 1,
The positioning system is configured to correlate a plurality of time-series synchronization timings received from the positioning terminal device, and to correct an error in a calculation result of position information. A positioning terminal device having a clock having an accuracy of less than 1 second is such that a satellite receiver receives signals from a plurality of satellites by inputting a trigger signal, measures each synchronization timing, Store the measurement time of each synchronization timing obtained from the clock in the memory, output the information in the memory to the outside at a predetermined timing,
The positioning server acquires all satellite information from the satellite for all the time of the positioning period in the positioning terminal device, receives the data of the synchronization timing from the memory of the positioning terminal device, and the data and the positioning terminal A positioning method, comprising: calculating position information of the positioning terminal device based on satellite information at a measurement time of the device. The positioning method according to claim 4, wherein
The positioning method, wherein the positioning server correlates a plurality of time-series synchronization timings received from the positioning terminal device, and corrects an error in a position information calculation result. A positioning server that obtains all satellite information from the satellites for all the times of the positioning period in the positioning terminal device and calculates position information of the positioning terminal device based on synchronization timing data received from the positioning terminal device is provided. In the positioning terminal device of the positioning system,
A clock with an accuracy of less than 1 second;
A satellite receiver that receives signals from a plurality of satellites by inputting a trigger signal and measures each synchronization timing;
A memory that stores data of each synchronization timing and a measurement time of each synchronization timing obtained from the clock;
A positioning terminal device comprising: means for outputting the information in the memory to the outside at a predetermined timing. The positioning terminal device according to claim 6,
A vibration sensor for detecting vibration;
An optical sensor for detecting the amount of light;
A positioning terminal device comprising: a determination circuit that outputs the trigger signal when each sensor output exceeds a predetermined value.

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