JP2008241079A - Navigation system - Google Patents

Abstract

[PROBLEMS] To make it possible to use a CPDGPS calculation result with very good position accuracy even for a flying object with low calculation capability, and to accurately grasp the trajectory and arrival point of the flying object in real time on the command station side. Get a possible navigation system.
The observation data of the GPS receiver by the navigation device 1 mounted on the flying object is transmitted to a command station 8 that monitors and controls the flying object, and the data of the GPS reference station 11 is transmitted on the command station 8 side. Perform CPDGPS calculations in combination. The calculation result is retransmitted to the flying object through telemetry, and is used for correcting the self-position calculation of the combined GPS / INS navigation calculation by the navigation computer. Further, in this process, the command station 8 can accurately grasp the trajectory of the flying object, so it is possible to grasp whether or not it has been accurately guided to the target coordinates.
[Selection] Figure 1

Description

  The present invention relates to a navigation system, and more particularly to a self-positioning technique necessary for guiding a flying object in a navigation system.

  In the localization of the self-position coordinates necessary for the guidance of the flying object, the self-position calculation by the inertial device has been the mainstream. In the self-position calculation by the inertial device, there is a problem that there is no means for correcting the deviation of the initial value of the self-position and that errors accumulate as the flight time becomes longer. In view of this, a method of correcting the self-position using GPS (Global Positioning System) has been devised, and a flying object that has already been used for navigation calculation using GPS has been put into practical use. For example, the US precision guided bomb JDAM (official name GBU-29 / -30 / -31 / -32) uses GPS and INS (Inertial Navigation System) for guidance, and seekers for terminal guidance Some have been devised to improve accuracy. Several other methods have been proposed as a flying object guidance method combining GPS and INS (see, for example, Patent Document 1).

  As is generally known, GPS receives a radio signal including a satellite orbit from a plurality of launched GPS satellites and time data from an atomic clock mounted on the GPS satellite by a GPS antenna, The GPS receiver calculates the relative distance difference with each satellite based on the time difference of the received radio waves, and obtains the current location information by obtaining the intersection of the hyperboloid which is the locus. By capturing the radio waves of three satellites, the position on the plane on the earth can be determined (two-dimensional positioning), and by capturing the radio waves of four or more satellites, more advanced information can be obtained (three-dimensional positioning).

  INS is a gyroscope, a direction is obtained with an accelerometer, a speed is obtained by integrating these, and a distance traveled is obtained by integrating the speed. It is a guidance device. In the INS, if the position where the user was first entered is input, the position and speed of the user can always be calculated and grasped based on the principle. However, when moving over a long distance, errors are accumulated and the accuracy is lowered. Therefore, correction is often made using GPS guidance or a Doppler radar navigation system.

  Since these conventional technologies perform self-localization using only observation values of a GPS receiver mounted on a moving object such as a flying object, an error is inevitably generated, and the self-localization accuracy is It is about a few meters to a few dozen meters.

  On the other hand, if a relative positioning method such as CPDGPS (Carrier Phase Differential GPS), which is generally known as a high-accuracy GPS positioning method, is used, positioning calculation can be performed with an accuracy of several centimeters to several tens of centimeters. . In this method, a GPS reference station (fixed station) whose position is known in addition to the mobile body receives GPS radio waves and eliminates the error. Therefore, in order to calculate CPDGPS with a flying object, not only GPS observation data obtained by the flying object itself, but also GPS observation data received by a GPS reference station whose coordinates are accurately known is necessary. There is a problem in that it is necessary to transmit data from the GPS reference station to the flying object and the calculation load thereof.

JP-T-2006-514258

  As described above, it is desirable to use the CPDGPS calculation in order to accurately calculate the self-position of the flying object, but the CPDGPS calculation also requires GPS observation data of a GPS reference station whose coordinates are accurately known. Therefore, the method of transmitting the observation data to the flying object and performing the CPDGPS calculation on the flying object side is generally low because the capacity of the computer mounted on the flying object is low. The problem and its computational load are major problems.

  Another problem is that with conventional flying objects, there is no way to determine the trajectory of the flying object on the command station side, and how much accuracy will fly to the coordinates (target coordinates) set as the target. Since there is no way to know with high accuracy whether the body has arrived, there was a problem that it was impossible to accurately grasp whether the mission by the flying object was successful.

  The present invention has been made to solve such a problem, and makes it possible to use a CPDGPS calculation result having a very good position accuracy even in a flying object having a low calculation ability, and in real time. The object is to obtain a navigation system that can accurately grasp the trajectory and the arrival point on the command station side.

  The present invention is a navigation system comprising a navigation device mounted on a flying object and a command station that communicates with the navigation device, wherein the navigation device is a GPS object side GPS for receiving GPS observation data. Receiving means, flying object side transmitting means for transmitting the GPS observation data observed by the flying object side GPS receiving means to the command station, and the position of the flying object transmitted from the command station Using the flying object side receiving means for receiving position coordinate data, inertial guidance means for acquiring INS data, the INS data, and the position coordinate data received by the flying object side receiving means, Navigation calculation means for performing compound navigation calculation by INS, and guidance control means for performing guidance control of the flying object based on the calculation result by the compound navigation calculation; The command station comprises command station side receiving means for receiving the GPS observation data transmitted from the flying object side transmitting means, GPS reference station data receiving means for receiving GPS observation data from a GPS reference station, and CPDGPS calculation is performed using the GPS observation data received by the flying object navigation device received by the command station side receiving means and the GPS observation data from the GPS reference station, and the flight from the GPS reference station is performed. Relative position vector calculating means for calculating a relative position vector to the body, absolute position coordinate calculating means for converting the calculated relative position vector into absolute position coordinates using the coordinates of the GPS reference station, and The absolute position coordinates are transmitted as the position coordinate data to the flying object side receiving means of the navigation device. A navigation system comprising a command station side transmission means.

  The present invention is a navigation system comprising a navigation device mounted on a flying object and a command station that communicates with the navigation device, wherein the navigation device is a GPS object side GPS for receiving GPS observation data. Receiving means, flying object side transmitting means for transmitting the GPS observation data observed by the flying object side GPS receiving means to the command station, and the position of the flying object transmitted from the command station Using the flying object side receiving means for receiving position coordinate data, inertial guidance means for acquiring INS data, the INS data, and the position coordinate data received by the flying object side receiving means, Navigation calculation means for performing compound navigation calculation by INS, and guidance control means for performing guidance control of the flying object based on the calculation result by the compound navigation calculation; The command station comprises command station side receiving means for receiving the GPS observation data transmitted from the flying object side transmitting means, GPS reference station data receiving means for receiving GPS observation data from a GPS reference station, and CPDGPS calculation is performed using the GPS observation data received by the flying object navigation device received by the command station side receiving means and the GPS observation data from the GPS reference station, and the flight from the GPS reference station is performed. Relative position vector calculating means for calculating a relative position vector to the body, absolute position coordinate calculating means for converting the calculated relative position vector into absolute position coordinates using the coordinates of the GPS reference station, and The absolute position coordinates are transmitted as the position coordinate data to the flying object side receiving means of the navigation device. Because it is a navigation system equipped with command station side transmission means, it is possible to use the CPDGPS calculation result with very good position accuracy even for a flying object with low calculation capability, and also the trajectory and arrival of the flying object in real time The point can be accurately grasped on the command station side.

Embodiment 1 FIG.
Hereinafter, the navigation system according to the first embodiment of the present invention will be described with reference to the drawings. In the first embodiment, the flying object is assumed to be launched with a fixed coordinate value (target coordinates) set in advance as a target, and the GPS observation data on the flying object side is transmitted to the command station by telemetry. A navigation system that executes processing with a high calculation load on the command station side will be described.

  FIG. 1 shows the configuration of a navigation system that enables highly accurate self-position evaluation according to the first embodiment. In FIG. 1, 1 is a navigation device (mobile station) mounted on a flying body (mobile body), and 8 is a command station (fixed station or mobile station) that communicates with the navigation apparatus 1.

  As shown in FIG. 1, the navigation device 1 includes a navigation computer 2 for performing GPS and INS combined navigation calculations, and GPS observation data (orbits of GPS satellites and atoms mounted on the GPS satellites). GPS antenna 3 for receiving at least two or more GPS satellites (including time data from a clock), and GPS reception data obtained by receiving GPS observation data received by the GPS antenna 3 and acquiring its own position coordinates 4 and an inertial sensor (INS: Inertial Navigation System) 5 for obtaining INS data used in the navigation calculation by the navigation computer 2 are provided, and it is possible to configure a navigation system combining GPS and INS. It has become. Although combined navigation with GPS and INS can be performed only with the above configuration, a telemetry transceiver 7 is added to the navigation device 1 to perform CPDGPS calculation to further increase accuracy, and the command station 8 Transmit GPS observation data observed with a flying object.

  The command station 8 acquires the GPS observation data from the telemetry transmission / reception 9 for receiving the GPS observation data from the flying object navigation device 1 and the GPS reference station 11 (fixed station) whose coordinates are accurately known. A computer 10 that performs CPDGPS calculation using both the GPS observation data and the GPS observation data from the flying object is provided. In this configuration, the command station 8 receives GPS observation data obtained by the flying object by the telemetry transceiver 9 and receives GPS observation data acquired by the GPS reference station 11 whose position is known. CPDGPS calculation is performed using Specifically, the computer 10 calculates a relative position vector from the GPS reference station 11 to the flying object based on the GPS observation data obtained by the flying object and the GPS observation data acquired by the GPS reference station 11. . Note that the command station 8 may be installed not only in a facility on the ground but also in a moving body such as an aircraft or a ship. The calculation accuracy depends on the number of GPS signal frequencies used in the calculation, the magnitude of the observed error, and the observation time. If a sufficient number of GPS satellites can be secured, an accuracy of several centimeters to several tens of centimeters can be obtained. It is possible to calculate the relative position vector.

  Next, the computer 10 converts the calculated relative position vector into absolute position coordinates using the coordinates of the GPS reference station 11, and the flying object position coordinate data is transmitted through the telemetry transceiver 9 as the flying object position coordinate data. Transmit to the telemetry transceiver 7 of the navigation device 1. When taking such a form, the time delay until the calculated absolute position coordinate data is transmitted to the flying object becomes a problem, but the flying object side stores the coordinates of the past self-localization results. (Not shown), and the difference between the coordinate value and the coordinate value transmitted from the command station 8 is calculated by the navigation computer 2 to calculate and correct the self-position error. Normally, when a GPS / INS combined navigation system is configured, the position error does not change randomly, but changes slowly with a certain time constant. Even if there is a delay, the error correction of the self-position coordinates can be performed effectively. The storage device and the navigation computer 2 constitute error correction means for correcting an error for a time delay due to transmission of absolute position coordinate data received by the telemetry transceiver 7. The position coordinate data thus corrected for errors is used as GPS observation data, and is used together with the INS data of the inertial sensor 5, and the navigation computer 2 performs navigation calculation using GPS and INS. obtain. The navigation computer 2 inputs the calculated self-positioning result to the guidance device 6 provided in the navigation device 1, and the guidance device 6 performs guidance control of the flying object based on the result.

  As described above, in the present embodiment, the GPS observation data of the flying object GPS receiver 4 is transmitted to the command station 8 that monitors and controls the flying object, and the GPS reference station 11 on the command station 8 side. The CPDGPS calculation is executed in combination with GPS observation data from the satellite, and the calculation result is retransmitted to the flying object through telemetry and used for correction of the self-position calculation. The CPDGPS calculation result with very good position accuracy can be used, and the flying object guidance control based on the accurate self-positioning result of the flying object can be performed.

  In addition, since the GPS observation data of the flying object GPS receiver 4 is transmitted to the command station 8, the command station 8 can accurately grasp the trajectory of the flying object in the process. It becomes possible to grasp whether or not the target is accurately guided to the target coordinates. Therefore, the command station 8 can know not only whether the flying object has reached the target coordinates, but also the accuracy of the arrival.

  In the above description, an example in which CPDGPS calculation is executed by the command station 8 and the calculation result is retransmitted to the flying object through telemetry and used for correction of self-position calculation has been described. For example, when communication with the command station 8 cannot be performed due to a communication abnormality or the like, the navigation computer 2 uses the GPS observation data acquired by the GPS receiver 4 and the INS data acquired by the inertial sensor 5. May be used to perform combined navigation by GPS and INS, obtain a self-positioning result, and the guidance device 6 may perform guidance control of the flying object based on the result.

It is a block diagram which shows the structure of the navigation system which concerns on Embodiment 1 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Flight object navigation device, 2 Navigation computer, 3 GPS antenna, 4 GPS receiver, 5 Inertial sensor, 6 Guidance device, 7 Telemetry transceiver, 8 Command station, 9 Telemetry transceiver, 10 Calculator, 11 GPS reference station.

Claims (2)

A navigation system comprising a navigation device mounted on a flying object and a command station that communicates with the navigation device,
The navigation device is
A flying object side GPS receiving means for receiving GPS observation data;
A flying object side transmitting means for transmitting the GPS observation data observed by the flying object side GPS receiving means to the command station;
A flying object side receiving means for receiving position coordinate data indicating the position of the flying object transmitted from the command station;
Inertial guidance means for acquiring INS data;
Using the INS data and the position coordinate data received by the flying object side receiving means, navigation calculating means for performing a combined navigation calculation by GPS and INS, and a flying object based on the calculation result by the combined navigation calculation And guidance control means for performing guidance control of
The command station is
Command station side receiving means for receiving the GPS observation data transmitted from the flying object side transmitting means,
GPS reference station data receiving means for receiving GPS observation data from the GPS reference station;
CPDGPS calculation is performed using the GPS observation data received by the flying object navigation device received by the command station side receiving means and the GPS observation data from the GPS reference station, and the flight from the GPS reference station is performed. A relative position vector computing means for calculating a relative position vector to the gland;
Absolute position coordinate calculation means for converting the calculated relative position vector into absolute position coordinates using the coordinates of the GPS reference station;
A navigation system comprising: command station side transmission means for transmitting the obtained absolute position coordinates as the position coordinate data to the flying object side reception means of the navigation device. The navigation device is
The navigation system according to claim 1, further comprising error correction means for correcting an error corresponding to a time delay due to transmission of the position coordinate data received by the flying object side reception means.

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