JPH04164277A - Current position measurement device for mobile body - Google Patents

Abstract

PURPOSE:To enable the current position of a mobile body to be easily and accurately measured via a simple arithmetic process by measuring the current position via self-contained inertia navigation, when a current position measurement condition with GPS navigation is not satisfied. CONSTITUTION:When transmission data is not received from an earth satellite during the travel of a mobile body from an initial set position (reference position), the current position of the mobile body is obtained by a self-contained inertia navigation measurement section 5, and shown in a display section 12. In this case, when transmission data from three or more satellites satisfying a measurement condition with GPS navigation is received by a GPS receiving section 1, the current position of the mobile body is obtained by GPS navigation measurement section 2 and shown in the display section 12. Thereafter, the current position is continuously calculated by the self-contained inertia navigation measurement section 5, and shown in the display section 12, using the current position obtained with the GPS navigation as an initial set position. In this case, when transmission data from one or two earth satellites is received by the GSP receiving section 1, a complex arithmetic section 8 obtains the current position through arithmetic processing, combining the GPS and self-contained navigations. This current position is used as an initial set position for continuing to calculate the current position of the mobile body with the aforesaid section 5 and display the position in the display section 12 through the self-contained navigation.

Description

[Detailed description of the invention] Technical field The present invention relates to a device for measuring the current position of a moving object.

Conventionally, as a device for measuring the current position of a moving object, a transmitting device of each position station transmits the current position of the moving object on coordinates set by multiple position stations such as artificial satellites and ground base stations. Based on GPS (Global Positioning System) navigation, data regarding each position transmitted from the mobile body is received by a receiving device installed on the mobile body, and is determined by predetermined calculation processing according to the relative positional relationship between the mobile body and each position station. There is something.

However, with this GPS navigation, the absolute position on the GPS coordinates can be measured with high accuracy each time, but the ability to receive transmission data from multiple position stations at one location is important for measuring the current position of a mobile object. This is a condition in which it becomes impossible to measure the current position of a mobile object if it is unable to receive data transmitted from multiple position stations, which is the condition for measuring the current position, due to obstructions such as buildings in urban areas. There is a problem.

Therefore, conventionally, when measuring the current position of a mobile object using GPS navigation, when it becomes impossible to receive transmission data from multiple position stations that meet the measurement conditions, the distance sensor and direction sensor mounted on the mobile object are used. While detecting the traveling distance and traveling direction of the moving object, the system switches to independent inertial navigation in which the current position in J3 on the two-dimensional coordinates is determined by cumulative calculation processing.

However, with independent inertial navigation, position errors due to sensor accuracy cannot be denied, and as the moving object progresses, these errors accumulate, and if this independent inertial navigation continues for a long time, the position accuracy will decrease by α (lower). There is a problem with this.

Recently, in order to solve such problems, when measuring the current position of a mobile object using GPS navigation, even if it is not possible to receive position data from multiple position stations that meet the measurement conditions, at least A mobile object current position measuring device has been developed that can measure the current position of a mobile object using autonomous inertial navigation when it is possible to receive transmission data from one location station. ing.

If a moving object receives transmitted data from one artificial satellite at a certain point, and then travels and receives transmitted data from one artificial satellite at another point, self-contained inertial navigation can be used to A movement vector is determined, and the current position of the moving body is determined by arithmetic processing using the movement vector I.L and data received at each point (see Japanese Patent Laid-Open No. 137009/1983).

However, if such a measurement method is used, if data transmitted from one satellite cannot be received at different points, KIL + cannot be determined, and two observation points whose positions are uncertain. Since the current position is determined by calculation processing based on the relative positional relationship with the artificial satellite observed at each point,
The calculation process has become complicated.

Purpose The present invention has been made with the above points in mind.
I) When the conditions for measuring the current position using S navigation are no longer met, if the transmission data from one position station can be received, then when the current position can be measured using autonomous inertial navigation, one Current position of a mobile object 81 that allows the current position of a mobile object to be determined simply or through arithmetic processing by simply receiving transmission data from a location station.
The purpose of this invention is to provide a fixed device.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.In the following, an embodiment of the present invention will be described in detail. The principle of measuring the current position of a moving object according to the present invention when reception is not possible will be explained with reference to FIGS. 2 and 3.

First, a reference position A (Xo, Yo, Zo) on the GPS coordinates while the moving body is traveling is set.

Here, the GPS coordinates are three-dimensional coordinates whose origin is the center of the earth.

For example, this reference position A is the current position of the mobile body determined by conventional GPS navigation when transmission data from a plurality of position stations that satisfy measurement conditions by GPS navigation are received at one location.

Next, using the reference position A as the initial setting position, the position on the two-dimensional coordinates according to the travel of the moving body is successively determined by conventional independent inertial navigation.

Then, when one artificial satellite S installed at the position (Xs, Ys, Zs) on the GPS coordinates is observed at the current position B (X, Y, Z), the straight line distance I2 between A and -8 is
At the same time, the distance between the current position B and the artificial satellite S is measured according to the received data at that time.

The transmission data from the artificial satellite S includes satellite position information and transmission time information, and by receiving this data, the position of the satellite S (X, s.

YS, Zs), and the distance between the measurement position and the satellite S can be determined by measuring the propagation delay time until the radio waves transmitted at a predetermined timing are received using an atomic clock. Raoshiru.

Note that the discrepancy between the satellite's atomic clock and the clock on the receiving device mounted on the mobile object is based on the state when transmitting data from multiple position stations that meet the measurement conditions for GPS navigation at one location was previously received. It is possible to estimate from

Therefore, the current position B of the unknown moving object to be measured
(X, Y, Z) and the known position of the artificial satellite S (XS, Ys
, Zs), and the distance between them is 1, the following equation holds true.

D=J(X s'-"X)("i' s-Y)(Z
s -Z) - (1) Similarly, the current position B (X, Y, Z) of the moving object to be measured and the known reference position A (Xo, Y
o.

The following equation holds true between Zo) and the distance therebetween.

L = , f X o-X Y o -Y■7]=]
Go (2) Now, as shown in FIG. 3, the current position B (X).

Let Y, Z) be the position of the earth GLB-H at a distance r from the origin O on the GPS coordinates, and let the angle from the X axis of the line connecting the position B and the origin 0 be ψ, and the angle from the Z axis be O. Then, x, y, and z are given by the following equations.

X=r+5JnO view CO8ψ ・◆(3)Y
-r+5inOTs]nψ ・ (/I)Z
= r'cosO-(5) Here, the distance r from the origin O of the center of the earth can be measured using the altitude side, or can be obtained from the sea level data of the map where the current position B is located. It is. Alternatively, assuming that there is no unevenness on the earth's surface, the distance r
may be treated as a constant.

Therefore, by converting the polar coordinates to −8= using equations (3) to (5), the parameters of equations (]) and (2) become only 0゜ψ, and by solving the simultaneous equations, the unknown number O
1ψ can be obtained, and thereby the current position B (X, Y, Z) of the target moving body can be obtained.

At that time, since the simultaneous equations of equations (1) and (2) are square equations, two solutions to the equation are found, but there is a constant The position of the solution within the range of can be set as the current position.

Note that when setting the reference position A, it may be the position of the moving body determined by conventional self-contained inertial navigation and converted to a position on GPS coordinates.

In addition, the position of a moving object determined by autonomous inertial navigation is determined by continuously storing data on the position of the moving object that is sequentially determined as the moving object travels, taking into account the cumulative error when the position is determined. The pattern of the traveling trajectory of the moving object obtained through memory retention is matched with the road pattern on the map where the position of the moving object is displayed in an updated manner. This is the position of the moving object corrected so that it is on the road on the map.

As a means for matching the pattern of the traveling trajectory of a moving object and the road on the map and correcting the position of the moving object that has deviated from the road on the map due to the cumulative error, for example, Japanese Patent Application Laid-Open No. 2006-4181.7 Means known from the gazette are applied.

Furthermore, the reference position A may be a position obtained by receiving a position signal on the GPS coordinates emitted from a position mark such as a sign post installed on the ground when the moving object passes the position mark. good.

Further, the reference position A may be manually set as a known position on the GPS coordinates.

FIG. 1 shows an embodiment of the current position measuring device for a moving object according to the present invention, in which the basic components are an antenna AN
Based on the GPS receiving unit 1 that receives transmitted data from multiple artificial satellites installed on GPS coordinates via T, and the transmitted data from multiple artificial satellites that meet measurement conditions by GPS navigation received at one location a GPS navigation measurement unit 2 that determines the position of the moving body through predetermined calculation processing; and the position of the moving body determined by the GPS navigation measurement unit 2 is set as the reference position (A), and the data of that position is stored in the memory 4. The distance sensor 6 detects the travel distance of the moving object, and the direction sensor 7 detects the moving direction of the moving object, and the position data read from the memory 4 and given through the memory control section 3 is used. Using the reference position (A) as the initial setting position, the position of the moving body on the two-dimensional coordinates is successively determined by cumulative calculation processing, and the determined position is set as the current position (B) and the reference position (A, ), the received data on one artificial satellite given from the GPS receiving section 1, and the data of the reference position (A) given from the memory control section 3. , according to the distance (L) data given from the independent inertial navigation measurement section 5 and the altitude data given from the altitude measurement section 9 mounted on the mobile object, the current position is determined as described above! Distance (D) between (B) and one artificial satellite (S) being observed at that time and distance r from the center of the earth to the current position
and a complex arithmetic processing section 8 that calculates the current position (B) by performing predetermined arithmetic processing to solve the simultaneous equations based on equations (1) and (2).

Further, a reference position setting section 10 is provided, and as described above, G is emitted from a position sign such as a sign post.
By receiving the position signal of "PS coordinate", the reference position (A) can be set by manual operation or by the above-mentioned map matching means.

Then, under the control of the memory control section 3, each time the reference position is determined by the GPS navigation measurement section 2 and the reference position is set by the reference position setting section 10, the position data is updatedly stored in the memory 4. Ru.

In addition, in this embodiment, the current position data PDI obtained from the composite arithmetic processing unit 8, the current position data PDI provided from the GPS navigation measurement unit 2, or the current position data PDI obtained from the independent inertial navigation measurement unit 5. A display control unit 11 is provided that displays the current position of the mobile object on the road map displayed on the screen of the display unit 12 according to data PD3 of the current position (converted to a position on GPS coordinates). .

The display control unit 11 controls the storage medium playback unit 1 according to the selection designation of the map and its display scale input from the operation unit 13.
4, a map information storage medium 15 such as a CD-ROM
selectively reads out map information from the display unit 12 to project a predetermined map surface image on the screen of the display unit 12, and updates the current position of the moving body on the map projected on the screen according to its scale. To go.

Note that the operation of each component and the exchange of various data between them are performed centrally under program control using a CPU (microcomputer), not shown.

Furthermore, it goes without saying that the arithmetic processing of each component may be executed by a microcomputer.

The operation of the device for measuring the current position of a moving object configured as described above will be described below with reference to flowcharts 1 to 1 in FIG. 4.

When the mobile body travels from the initial setting position, the independent inertial navigation measurement unit 5 calculates the current position according to the travel of the mobile body (step 1).

At that time, if the satellite cannot be observed at all and no data transmitted from the satellite is received by the GPS receiver I, the data of the current position determined by the independent inertial navigation measurement unit 5 will be transferred to the display control unit 1. .1, display section 12
The current position of the moving object is displayed using autonomous inertial navigation (step 2).

At that time, if the GPS receiving unit I receives transmission data from three or more artificial satellites that meet the measurement conditions for GPS navigation, the GPS navigation measurement unit 2 determines the current position of the mobile object, and The data of the current position is given to the display control unit 11, and the current position of the moving body is displayed on the display unit I2 by GPS navigation (steps 3 and 4).
).

Thereafter, the current position of the moving object determined by the GPS navigation is used as the initial setting position, and the calculation and display of the current position of the moving object by the independent inertial navigation is continuously performed.

In addition, at that time, in the GPS receiving section 1, one or two
When transmission data from one artificial satellite is received, the current position of the moving body is determined in the complex arithmetic processing unit 8, and the data of the current position is given to the display control unit 11, and the display unit 12 is displayed according to the present invention. The current position of the moving body is displayed using a complex calculation process that combines GPS navigation and independent inertial navigation (steps 5 and 6).

Thereafter, the current position of the moving object determined by the complex arithmetic processing is used as the initial setting position, and the calculation and display of the current position of the moving object by autonomous inertial navigation is continued.

1-1 Current position measuring device L of a moving object according to the present invention:
+j, cJ)S such as multiple artificial #f stars in one place
Transmitted data from the position station installed at coordinate 2 = 15
- Even when reception is no longer possible and the conditions for measuring the current position using GPS navigation are no longer met, a reference position can be set on the GPS coordinates and the distance in direct meters from that reference position to the current position can be calculated using independent inertia. By determining it by navigation, if transmission data from one position station can be received at one point, the current position can be measured, and G
PSPI5. The current position can be easily and precisely determined by simple calculation processing based on the relative positional relationship between the known reference point W and the position station and the unknown current position. It has advantages.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of the current position measuring device for a moving body according to the present invention, FIG. 2 is a diagram showing the positional relationship between a reference position, an artificial satellite, and the current position on GPS coordinates, and FIG. 3 is a diagram showing the current position on the GPS coordinates with the center of the earth as the origin, and FIG. 4 is a flowchart 1 of the processing in the same embodiment. 1.Gl'S receiving section 2..GPS navigation measurement section:
3 Memory control unit 4 Memory 5 Independent inertial navigation measurement unit 6 Distance sensor 7 Direction sensor 8
Composite calculation processing unit 9...Altitude side measurement unit 10...Reference position setting unit 11...Display control unit 12...Display unit 1
3-・Operation ff1ll/l...Storage medium playback section 15
Map information storage medium A... Reference position B Current position S... Artificial satellite

Claims (1)

[Claims] 1. means for setting a reference position on GPS coordinates, means for determining the straight-line distance from which a moving body passes the reference position to the current position by autonomous inertial navigation, and an artificial satellite; or means for receiving data transmitted from one location station installed on the coordinates, such as a base station on the ground, and determining the location of that station and the distance between the location station and the current location; and means for calculating the current position on the coordinates according to a reference position, the position of the station, a straight line distance between the reference position and the current position, and a distance between the position station and the current position. A device for measuring the current position of a moving object. 2. The current position of the mobile object according to the above item 1, wherein the reference position is the position of the mobile object determined by GPS navigation when data transmitted from a plurality of location stations is received at one location. Position measuring device. 3. The device for measuring the current position of a moving body according to item 1 above, wherein the reference position is the position of the moving body determined by independent inertial navigation and converted to a position on GPS coordinates. 4. The reference position is a position obtained by receiving a position signal emitted from a position mark such as a sign post installed on the ground when the moving object passes the position mark. A device for measuring the current position of a moving body according to the description in item 1. 5. The current position measuring device of a moving body according to item 1 above, wherein the reference position is manually set as a known position on GPS coordinates. 6. The calculation process for determining the current position on the GPS coordinates is satisfied by the first equation, which is established by the position of one position station, the current position, and the distance between them, and the reference position, the current position, and the straight line distance between them. 1. The current position measuring device of a moving body according to the above item 1, characterized in that the device calculates a solution of simultaneous equations according to the second equation.