JPH09288162A - Receiving equipment for meeting whole attitude of flying body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To meet the whole attitude of a flying body by providing a plurality of global positioning system(GPS) antennas at opposite positions on the surface of the flying body and by subjecting a reception signal of each antenna to signal processing separately. SOLUTION: A plurality of GPS antennas 1 and 2 are provided at opposite positions on the surface of a flying body. Lead-in wires led out from the antennas 1 and 2 are not connected directly, but are separated, and GPS reception signals are subjected to signal processing separately. In more detail, each of GPS receivers 3A, 3B, 4A and 4B executes front-stage processing of signal waves transmitted from a GPS satellite and a ground reference station and outputs raw measuring data. A navigational computation processing part 5 executes generalized computation processing of these raw measuring data and determines pseudo-range(PR) measuring data, delta range measuring data and other computation data. Since the reception signals from the antenna 1 and 2 in a plurality are separated and subjected to the signal processing separately in this way, no phenomenon of multipass takes place.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver for all attitudes of an aircraft, and more particularly to a receiver for all attitudes of an aircraft installed on an aircraft such as an aircraft, a rocket, a missile, or an artificial satellite.

[0002]

2. Description of the Related Art A global positioning system (GPS) is used as a car navigation system and other positioning systems, and is also used as an ultra-precision positioning system for surveying land and measuring minute displacement of the ground due to an earthquake. However, it is originally a navigation device. That is, it is a navigation device that measures the timely position of an aircraft or other flight object to measure the flight route, or displays the timely position of the flight object in real time.

A differential global positioning device (DifferentialGPS = DGPS) wirelessly transmits measurement error information from the ground to a GPS receiver on the user side.
It is a positioning device that transmits to a PS receiver. The user receives the error information transmitted from the ground and corrects the measurement result by only the GPS based on this error information, thereby improving the measurement accuracy of the GPS. A transmitting station installed on the ground for calculating and transmitting the above error information is called a differential reference station, and a GPS device adopting this is called a differential GPS device. Just GPS
Positioning accuracy is about 80m, but DGPS is 5
High accuracy of about m can be obtained.

FIG. 6 (a) is a diagram showing navigation using general GPS in automobiles, ships, and aircraft. The antenna 1 is directed to a GPS satellite in the upper hemisphere on a horizontal plane. 3 is a GPS receiver and 6 is a control indicator. The antenna 1 is designed as described above so that the GPS is generally used by being installed in a moving body having a substantially horizontal posture. In this case, the vertical posture or the inverted posture cannot be dealt with. Therefore, a fighter, a rocket, which is a flying body that may take a vertical attitude or be in an inverted state.
A general GPS cannot be used as it is for a flying object such as a missile or an artificial satellite whose attitude changes drastically, and some kind of device must be used for mounting the antenna.

Here, referring to FIG. 5A, for example, in the case of a vertically launched aircraft such as a rocket, the GPS
If it is a normal GPS that uses only one antenna 1,
G in the hemispherical space above the horizontal plane including the GPS antenna 1
G existing in the half space on the side including the PS antenna 1
Since only PS satellites can be used, it is not possible to expect an appropriate geometric satellite arrangement, and the positioning accuracy is significantly reduced. Here, by mounting the GPS antenna 1 and the GPS antenna 2 at two opposite positions on the rocket body surface, all the spatial areas can be seen by combining the hemispherical spatial areas above the horizontal plane of the GPS antenna 1 and the GPS antenna 2. Since it can be put in, it is possible to eliminate the above defect. In this case, it is possible to receive all radio waves including the radio waves transmitted from the differential reference station installed on the ground below the flying body. The same applies to aircraft as shown in FIG. 5 (b).

By the way, in general, when the signals received by the two antennas are directly introduced into the receiver, a multipath phenomenon always occurs and the signals disappear, or the signal strength fluctuates drastically. Therefore, it is necessary to use a plurality of antennas and take measures against multipath cancellation. As will be described with reference to FIG. 6B, this is a pseudolite (Pseudolit).
It is a figure explaining control at the time of landing of the aircraft provided with DGPS which adopts the e) method. What is the pseudolite method?
The carrier frequency of the signal transmitted from the reference station installed on the ground, the modulation method and other transmission signal conditions are made equal to the transmission signal conditions of the signal transmitted from the GPS satellite, and the receiver of the transmission signal of the GPS satellite remains on the ground. It refers to a receiving method that can also receive a signal transmitted from a reference station. That is, this is a method in which the GPS receiver itself directly receives the radio wave transmitted from the ground reference station using the L-Band frequency. In this case, when the same signal is simultaneously input to both the GPS satellite receiving antenna 1 and the ground reference station receiving antenna 2, a multipath phenomenon occurs. That is,
Referring to FIG. 8, for example, a difference Δd in transmission path length from a radio wave source to a point P where two antennas are directly connected is Δd =
When (half wavelength) × (odd number), the incident signal may be canceled and disappear.

FIG. 6 (c) is a diagram showing a modification of the DGPS of FIG. 6 (b). Each of the GPS receiver 3 and the GPS receiver 4 is a bare receiver that constitutes a DGPS receiver. The GPS receiver 3 is a receiver that measures the pseudo range of GPS satellites and directly outputs the data group. The GPS receiver 4 is a receiver that receives and demodulates a signal transmitted from a reference station installed on the ground and outputs the signal as it is. In this case as well, the same signal may be simultaneously input to both the GPS satellite receiving antenna 1 and the ground station reference receiving antenna 2, but at this time a multipath phenomenon occurs.

FIG. 6 (d) shows the antenna direct connection portion of FIG. 6 (c) separated. In this case, since the antennas are separated, the multipath phenomenon does not occur, but in the case where the airframe is inverted, the GPS satellite reception antenna 1 and the ground station reference reception antenna 2 are inverted, so that they do not function properly. .

[0009]

SUMMARY OF THE INVENTION The present invention is to provide an all-attitude-compatible receiver for an aircraft which can solve all the above-mentioned problems and which can solve all the above-mentioned problems.

[0010]

In a receiver for all attitudes of an air vehicle equipped with a DGPS adopting a pseudolite system, a plurality of GPS antennas 1 and 2 are installed at positions facing each other on the surface of the air vehicle. The drop line derived from the GPS antenna is not directly connected but separated to form a receiver for all attitudes of the flying body, which separately processes the GPS received signals.

A GP having a high frequency section for pre-processing the GPS reception signal, an intermediate frequency section and a base band section.
Two S receivers 3 and 4 were provided for each GPS antenna to form a receiver for all attitudes of the flying body that outputs measured raw data. In addition, a navigation calculation processing unit 5 that comprehensively calculates and processes four or more measurement raw data.
A receiver for all attitudes of an aircraft is provided.

Here, the DG adopting the data link system
In a receiving device for all attitudes of an aircraft equipped with PS,
An antenna pair consisting of a GPS antenna and a data link dedicated antenna is installed at opposite positions on the surface of the aircraft, and the service lines derived from the antennas are not directly connected but separated to separate GPS reception signals and differential reference station reception signals. We constructed a receiver that can handle all attitudes of an aircraft that performs signal processing. A GPS having a high-frequency part, an intermediate-frequency part, and a baseband part for pre-processing a GPS reception signal
Each data link antenna is equipped with a receiver corresponding to each GPS antenna, outputs raw measurement data respectively, and has a high-frequency part, an intermediate-frequency part, and a baseband part for pre-processing a differential reference station reception signal. A receiver for all attitudes of the air vehicle, which is provided for each position and outputs measured raw data, is configured. In addition, a receiver corresponding to all attitudes of an air vehicle is provided with a navigation calculation processing unit that collectively calculates four or more measurement raw data.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. First, referring to FIG.
GPS antennas are located at two opposite locations on the rocket body surface.
By attaching the antenna 1 and the GPS antenna 2, the GPS antenna 1 is a hemispherical space on the radio wave capturing direction side.
And as a synthetic beam of the GPS antenna 2, the entire global space can be brought into view by both antennas. FIG. 5 (a) is based on the assumption of a rocket for launching a satellite, and is applicable to vertical launch. In particular, at the time of launch and landing recovery, it is possible to deal with the differential as it is, and highly precise flight control can be performed.

Referring to FIG. 5 (b), it is the same even if a total of two GPS antennas 1 and 2 are installed at the upper and lower positions facing each other on the surface of the body of the aircraft. Can be covered. Depending on the shape of the airframe, a blind spot (Blind Spot), which is an area that is not covered in the rear part, may occur, but there is no particular problem unless it occurs in the front. FIG. 5 (b) is assumed when the aircraft is landing. The upper GPS antenna 1 captures the signal transmitted from the GPS satellite, and the lower GPS antenna 2 captures the signal transmitted from the ground reference station. To do. By installing two antennas, regardless of the attitude of the aircraft at the time of landing, seamless coverage (Seamless Coverage) can always be performed and signal reception can be continued without interruption.

If the received signals from the two antennas are directly introduced into the receiver, the multipath phenomenon always occurs as described above and the signals disappear, or the signal strength fluctuates drastically. Since it is necessary to avoid the multipath phenomenon when the antenna of 1 is used, this will be described with reference to FIG. FIG. 1 is a DGPS that is equipped with two GPS antennas and four receivers and supports all attitudes of a flying vehicle.
It is a figure explaining a receiver. Where multiple G
Since the service line derived from the PS antenna is not directly connected but separated and the GPS antenna reception signals are processed separately, the multipath phenomenon caused by the GPS antenna itself does not occur.

3A, 3B, 4A and 4B are all
It constitutes a GPS receiver of the receiving device for all postures of the aircraft. These GPS receivers pre-process signal radio waves transmitted from GPS satellites and ground reference stations and output raw measurement data. The navigation calculation processing unit 5 uses these GPs.
In cooperation with the S receiver, the raw measurement data is comprehensively calculated to obtain pseudo range (PR) measurement data, delta range measurement data and other calculation data, or correction data is read and other calculations are performed. . In this GPS receiver, the pre-processing unit for signal radio waves comprises a high frequency unit (RF), an intermediate frequency unit (IF) and a base band unit (BB), and pre-processes the GPS reception signal by these. Reference numeral 6 indicates a control indicator.

GPS receiver 3A and GPS receiver 3B
In the state shown in the figure, the signal received from the GPS satellite is received and captured through the upper antenna 1, and the pseudo range measurement, the delta range measurement and other measurements are performed in cooperation with the navigation calculation processing unit 5. To do. The GPS receiver 4A and the GPS receiver 4B receive the signal transmitted from the ground reference station via the lower antenna 2 in the illustrated state, and cooperate with the navigation calculation processing unit 5 to demodulate the received data. Then, the correction data is obtained.

Next, the signal reception condition of the embodiment of the receiver for all postures shown in FIG. 1 will be described with reference to FIG. FIG. 2 is a flow chart for explaining the reception processing of the receiver for all attitudes of the flying object of FIG. The flight vehicle captures and receives signals transmitted from GPS satellites and ground reference stations, but the required signal radio wave reception conditions vary depending on the attitude of the traveling flight vehicle. Step S1
At, the antenna 1 and the antenna 2 capture and receive signals transmitted from GPS satellites to recognize the arrangement of GPS satellites and the number of captured satellites, and also recognize the reception status of signals transmitted from the ground reference station. In step S2, it is determined whether the arrangement of GPS satellites and the number of captured satellites are appropriate, and whether or not there is a signal transmitted from the ground reference station. As a result, the reception status is diverged in various ways as follows.

The branch is a case where the antenna 1 captures sufficient and sufficient GPS satellites to execute GPS independent positioning (Stand Alone Navigation). The branch is
Antenna 1 is required and sufficient to execute GPS independent positioning 4
This is a case where three or more GPS satellites cannot be captured and only three or less GPS satellites are captured.

The branch is a case where the radio wave transmitted from the ground reference station can be normally received. In this case, there are two cases where the received data is obtained from only one antenna and the received data is obtained from both antennas.
There is a street. The branch is a case where the radio wave transmitted from the ground reference station cannot be normally received by any antenna.

The branch is a case where the antenna 2 captures GPS satellites necessary and sufficient for executing GPS independent positioning (Stand Alone Navigation). This is equivalent to the case where the flying body is reversed. The branch is
Antenna 2 is necessary and sufficient to execute GPS independent positioning 4
This is a case in which more than three GPS satellites cannot be captured, and only three or less GPS satellites are captured, which is the same case as. This corresponds to the case where the flying body is in the state of being directly beside the roll angle of 90 °, for example. in this case,
Both antenna 1 and antenna 2 are normally 3 or less G
This is the case when only the PS satellites can be captured, or four or more satellites are captured, but the GPS satellite arrangement is not appropriate and good navigation data cannot be obtained.

Here, how to deal with each case will be described. First, a case in which the radio wave transmitted from the ground reference station cannot be normally received by any antenna will be described with reference to FIG. FIG.
Is the GPS, DG of the receiver for all attitudes of the flying object of FIG.
It is a flowchart explaining the operation process of PS independent positioning.

(Step S3) When it is determined in step S2 of FIG. 2 that the radio wave transmitted from the ground reference station cannot be normally received by any antenna, the process proceeds to step S3 of FIG. . Step S3
In, the situation of GPS satellite acquisition and reception is
And which of the two is

(1) When it is judged to be a branch in step S3. (Step S4) GP captured and received via the antenna 1
The signals transmitted from the S satellites are calculated in the GPS receiver to obtain the pseudo range measurement data sequence and the delta range measurement data sequence.

(Step S5) Navigation calculation is executed based on the measurement data obtained in step S4. (Step S6) Lever arm correction is applied to the navigation calculation result in step S5 based on the measurement data obtained through the antenna 1.

(Step S7) The correction result in step S6 is subjected to coordinate conversion processing, interface matching processing and other processing to obtain and output navigation data. (2) When it is determined to be a branch in step S3. (Step S4) GP captured and received via the antenna 1
The signals transmitted from the S satellites are calculated in the GPS receiver to obtain the pseudo range measurement data sequence and the delta range measurement data sequence.

(Step S5) Navigation calculation is executed based on the measurement data obtained in step S4. (Step S6) Lever arm correction is performed on the navigation calculation result in step S5 based on the measurement data obtained via the antenna 2.

(Step S7) The correction result in step S6 is subjected to coordinate conversion processing, interface matching processing and other processing to obtain and output navigation data. (3) When it is determined in step S3 that the branch is a branch or a branch.

(Step S4) In the GPS receiver, the signals transmitted from the GPS satellites captured and received via the antenna 1 and the antenna 2 are subjected to calculation processing to obtain a pseudo range measurement data sequence and a delta range measurement data sequence. (Step S5) Navigation calculation is executed based on the measurement data obtained in step S4.

(Step S6) The navigation calculation result in step S5 is subjected to coordinate conversion processing, interface matching processing and other processing to obtain and output navigation data. Next, a case where the radio wave transmitted from the ground reference station can be normally received will be described with reference to FIG. FIG. 4 is a flow chart for explaining an operation process of differential positioning of the receiving device for all attitudes of the flying object of FIG.

(Step S3 ') If it is determined in step S2 of FIG. 2 that the radio wave transmitted from the ground reference station has been normally received, step S3 of FIG.
Move to 3 '. In step S3 ', it is determined whether the status of the GPS satellite acquisition and reception is or.

(1 ') When it is judged to be a branch in step S3'. (Step S4 ′) The signals transmitted from the GPS satellites captured and received via the upper antenna 1 are calculated in the GPS receiver to obtain the pseudo range measurement data sequence and the delta range measurement data sequence.

(Step S5 ') GPS-only positioning navigation calculation is executed based on the measurement data obtained in step S4'. (Step S6 ′) The signal transmitted from the ground reference station received via the lower antenna 2 is subjected to calculation processing in the GPS receiver to obtain a differential correction data string.

(Step S7 ') The GPS single positioning navigation calculation result obtained in step S5' is corrected based on the differential correction data obtained in step S6 '. (Step S8 ') Coordinate conversion processing to the GPS independent positioning navigation calculation result corrected in Step S7',
Performs interface matching processing and other processing to obtain and output differential navigation data.

(2 ') When it is judged to be a branch in step S3'. (Step S4 ′) The signals transmitted from the GPS satellites captured and received via the upper antenna 2 are calculated in the GPS receiver to obtain the pseudo range measurement data sequence and the delta range measurement data sequence.

(Step S5 ') A GPS-only positioning navigation calculation is executed based on the measurement data obtained in step S4'. (Step S6 ′) The signal transmitted from the ground reference station received via the lower antenna 1 is subjected to calculation processing in the GPS receiver to obtain a differential correction data string.

(Step S7 ') The GPS single positioning navigation calculation result obtained in step S5' is subjected to correction processing based on the differential correction data obtained in step S6 '. (Step S8 ') Coordinate conversion processing to the GPS independent positioning navigation calculation result corrected in Step S7',
Performs interface matching processing and other processing to obtain and output differential navigation data.

(3 ') When it is judged in step S3' that it is a branch or a branch. (Step S4 ′) The signal transmitted from the GPS satellite captured and received via the antenna 1 and the antenna 2 is sent to the GPS.
In the receiver, the pseudo range measurement data sequence and the delta range measurement data sequence are obtained by performing calculation processing.

(Step S5 ') GPS-only positioning navigation calculation is executed based on the measurement data obtained in step S4'. (Step S6 ′) The signal transmitted from the ground reference station received via the antenna 1 and the antenna 2 is subjected to calculation processing in the GPS receiver to obtain each differential correction data string.

(Step S7 ') The GPS independent positioning navigation calculation result obtained in step S5' is subjected to correction processing based on the differential correction data obtained in step S6 '. (Step S8 ') Coordinate conversion processing to the GPS independent positioning navigation calculation result corrected in Step S7',
Performs interface matching processing and other processing to obtain and output differential navigation data.

Although the above embodiments have been described with respect to the receiving device for all attitudes of the flying body, which has the DGPS adopting the pseudolite system, the present invention is also applied to the aircraft having the DGPS adopting the data link system. can do. Referring to FIG. 7, this is a diagram for explaining control at the time of landing of an air vehicle equipped with a DGPS adopting a data link system. The data link system is the most general form of construction of the current differential system, and the transmission signal transmitted from the differential reference station uses transmission radio waves of frequencies in the FM band and the VHF band. Therefore, unlike the pseudolite method described above,
The data link dedicated antenna 2 ′ and the data link dedicated receiver 4 ′ are provided separately from the GPS receiver 4. This will be described with reference to FIG. 1. Instead of the GPS receivers 3B and 4B, the data link dedicated receiver 3'B is provided.
And 4'B, and antennas 1'and 2'dedicated to the data link.

[0042]

As described above, the receiver for all postures of the present invention is a DGP adopting a pseudolite system.
S is equipped on the flying body, and a plurality of GPS antennas 1 and 2 are provided.
Are installed at opposing positions on the surface of the air vehicle, and the service lines derived from the multiple GPS antennas are separated without being directly connected.
By separately processing the PS received signals, it is possible to deal with all attitudes of the flying object, including vertical, inverted, and sideways directions, and also to perform differential operations for all attitudes. Furthermore, even if a plurality of antennas are adopted, the multipath phenomenon associated therewith does not occur.

Here, the all-attitude-compatible receiver of the present invention is further equipped with two GPS receivers each having a high-frequency unit for preprocessing the GPS reception signal, an intermediate-frequency unit, and a baseband unit for each GPS antenna. To obtain accurate navigation data for all attitudes of the flying body, including vertical, inverted, and sideways, by providing the navigation calculation processing unit 5 that outputs the measured raw data respectively and collectively processes the measured raw data. You can

That is, when the antenna captures a sufficient number of GPS satellites necessary for executing GPS-only positioning, and its position is also suitable, the navigation data is obtained based on the data transmitted from these GPS satellites. By this, accurate positioning can be performed. Here, if the radio wave transmitted from the ground reference station can be normally received, the differential correction data is obtained, and the GPS is calculated based on the differential correction data.
By performing correction processing on the individual positioning data, more accurate positioning can be performed.

When all of the plurality of antennas cannot capture 4 or more GPS satellites necessary and sufficient for executing GPS independent positioning, and only 3 or less GPS satellites are captured, or GPS has been acquired more than 4
Even if the satellite arrangement is not proper, accurate positioning can be performed by obtaining the navigation data based on the signal data transmitted from the GPS satellites captured and received via the plurality of antennas. Here, when the radio wave transmitted from the ground reference station can be normally received, differential correction data is obtained, and G is calculated based on the differential correction data.
By performing the correction process on the PS independent positioning data, more accurate positioning can be performed.

Further, the present invention can be similarly applied to an air vehicle equipped with a DGPS adopting the data link system to exert its effect.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an example.

FIG. 2 is a flowchart illustrating a receiving process according to the embodiment.

FIG. 3 is a flowchart illustrating an operation process of independent positioning according to the embodiment.

FIG. 4 is a flowchart illustrating an operation process of differential positioning according to the embodiment.

FIG. 5 is a diagram showing an installation position of an antenna.

FIG. 6 is a view for explaining a conventional example of a navigation body equipped with GPS or DGPS.

FIG. 7 is a diagram illustrating another embodiment.

FIG. 8 is a diagram illustrating multipath.

[Explanation of symbols]

 1 antenna 2 antenna 3 GPS receiver 4 GPS receiver 5 Navigation calculation processing unit 6 Control indicator

Claims (6)

[Claims] 1. A DGPS adopting a pseudolite system
In a receiver for all postures of a flying vehicle, the GPS receiving signals are installed by installing a plurality of GPS antennas at positions facing each other on the surface of the flying vehicle and separating lead-in wires derived from the plurality of GPS antennas without directly connecting them. A receiver for all attitudes of an aircraft, characterized by performing signal processing separately for each. 2. The receiver for all attitudes of an aircraft according to claim 1, wherein a GPS receiver having a high-frequency unit, an intermediate-frequency unit, and a baseband unit for pre-processing a GPS reception signal corresponds to each GPS antenna. A receiving device corresponding to all attitudes of a flying object, characterized in that it is equipped with two of each and outputs measured raw data respectively. 3. The receiver for all attitudes of an air vehicle according to claim 2, further comprising a navigation calculation processing unit for comprehensively calculating and processing four or more measurement raw data. Receiving device for all attitudes of flying aircraft. 4. An all-attitude attitude receiving device for a flying body equipped with a DGPS that employs a data link system, wherein an antenna pair consisting of a GPS antenna and a data link dedicated antenna is installed at positions facing each other on the surface of the flying body. 1. The receiving device corresponding to all attitudes of an aircraft, characterized in that the drop line derived from is separated without being directly connected and the GPS reception signal and the differential reference station reception signal are separately processed. 5. The receiving device for all attitudes of an aircraft according to claim 4, wherein a GPS receiver having a high frequency part, an intermediate frequency part and a base band part for pre-processing a GPS reception signal corresponds to each GPS antenna. Equipped with a data link receiver having a high frequency section, an intermediate frequency section and a base band section for preprocessing the differential reference station reception signal, which outputs the measured raw data, respectively, corresponding to each data link antenna, respectively. A receiver for all attitudes of a flying vehicle, which outputs measured raw data. 6. The receiving device for all attitudes of an aircraft according to claim 5, further comprising a navigation calculation processing unit that collectively calculates four or more measurement raw data. Receiving device for all attitudes of flying aircraft.