JP2013195083A - Position measuring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a system at low costs and to improve positioning accuracy.SOLUTION: A position measuring system includes a low bar 1 capable of obtaining a measuring value of a three-dimensional position by a GPS together with measuring time, a reference point position measuring device 2 for measuring a GPS position measuring value with three-dimensional positions set at a plurality of existing points, and a low bar position calculation device 3 capable of communicating with the low bar 1 and the reference point position measuring device 2. The low bar position calculation device 3 generates a difference triangle having three corresponding points selected from a plurality of existing position points within a difference space having a difference between the existing value of a measuring point at the existing position point and a measuring value set corresponding to a plane position, and corrects the measuring value of the low bar 1 with an interpolation or extrapolation value of the difference triangle at the plane position based on the measuring value of the low bar 1 to output the result to the low bar 1.

Description

  The present invention relates to a position measurement system.

  A so-called A-GPS (Assisted Global Positioning System) as described in Patent Document 1 has been proposed as a system for improving the accuracy of GPS position measurement used for portable information terminals such as cellular phones.

  In this system, accurate orbit data (ephemeris data) of a GPS satellite necessary for position measurement and a GPS signal from the GPS satellite are captured at a base station that relays communication such as a mobile phone as needed. When there is a GPS measurement request from the mobile phone, the nearest base station receives the GPS measurement request from the mobile phone, and in addition to the identification signal that identifies the GPS satellites that can be used by the mobile phone, and the ephemeris data, The GPS time correction information and the like are output to the mobile phone as assist data.

  The mobile phone that has received the assist data performs positioning calculation using the signal from the GPS satellite specified by the GPS satellite specifying information included in the assist data and the assist data. The assist data includes GPS time correction information. By using the correction information, positioning accuracy can be improved.

JP 2003-43127 A

  However, in the above-described conventional example, since the base station requires a high-precision measuring device, there is a disadvantage that the cost of system construction becomes high.

  The present invention has been made to solve the above-described drawbacks, and an object of the present invention is to provide a position measurement system capable of constructing a system at low cost and improving positioning accuracy.

According to the present invention, the object is
Rover 1 capable of acquiring a measurement value of a three-dimensional position by GPS together with a measurement time;
A reference point position measurement device 2 that is installed at a plurality of points where the three-dimensional position is known and measures the GPS position measurement value of the position known point;
The row bar position calculation device 3 is capable of communicating with the row bar 1 and the reference point position measurement device 2. The row bar position calculation device 3 includes a difference between a known value of a measurement element at the position known point and a measurement value ( a difference triangle 4 having vertices corresponding to three corresponding points selected from the plurality of position known points in the (P, δ) difference space in which δ) corresponds to the plane position (P);
Next, the position measurement system that corrects the measurement value of the rover 1 using the interpolation or extrapolation value of the difference triangle 4 at the plane position based on the measurement value of the rover 1 as an error value with respect to the measurement value and outputs the correction value to the rover 1. Is achieved by providing

  It is considered that the error element of the measurement value by GPS does not change rapidly in a narrow area where the same GPS satellite can be captured, but changes slowly, and the error value (δ) between the plane position (P) and the evaluation element The difference triangle 4 generated in the (P, δ) space that corresponds to () is considered to indicate the correspondence between the plane position and the error value.

  The plane position (P) can be defined by various coordinate systems. However, in order to facilitate understanding, hereinafter, (x, y, z) three-dimensional orthogonal coordinate system unless otherwise affected by this specification. The plane position (x, y) in FIG.

  Accordingly, when the error value at the plane position (P) = (x, y) based on the measurement value of the row bar 1 is obtained as an interpolation value or an extrapolation value of the difference triangle 4 using the position known point, the row bar 1 alone is obtained. It is possible to correct an error associated with the measurement at, thereby increasing the measurement accuracy.

  Further, the reference point position measuring device 2 attached to the position known point is sufficient to be a GPS device that directly outputs GPS measurement values, and it is necessary to use a device capable of outputting assist data such as ephemeris data or GPS time correction data. Therefore, the system can be constructed at low cost.

  Furthermore, since the reference point position measuring device 2 is inexpensive, it is possible to easily increase the number of installation locations, and as a result, it becomes possible to select the difference triangle 4 that is relatively close to the row bar 1, The accuracy can be further improved.

  Further, the difference triangle 4 can be formed by three points whose error values are obtained as interpolated values, and by configuring in this way, the measurement accuracy can be increased.

Furthermore, the rover position calculation device 3
Statistical processing can be performed on a plurality of error values obtained by each of the plurality of generated difference triangles 4 and used as correction values for the measurement values of the rover 1.

  The error value can be obtained from one difference triangle 4, but can also be obtained by performing statistical processing on the value obtained from a plurality of difference triangles 4. When an error value is obtained from one difference triangle 4, for example, it is desirable to select the reference point position measuring device 2 having a measurement accuracy at least equivalent to the measurement accuracy of the row bar 1 to generate the difference triangle 4.

  Further, by configuring so that the error values of the plurality of difference triangles 4 are subjected to statistical processing, an error element unique to the difference triangle 4, for example, the influence of the error characteristics of the reference point position measuring device 2 that constitutes the difference triangle 4. Therefore, measurement accuracy can be further improved.

  Each reference point position measuring device 2 can use a GPS device with low accuracy. For example, a single positioning GPS device can be used.

  Furthermore, in the above, the case where the error value of the rover 1 is estimated based on one measurement value at the rover 1 has been shown, but correction is performed by performing statistical processing on a plurality of measurement values at the rover 1. When the value is obtained, it is possible to consider an error factor caused by the measurement timing.

The position measurement system includes
It is possible to communicate with the rover 1 capable of measuring its own position by GPS and the reference point position measuring device 2 installed at a plurality of known three-dimensional positions around the rover 1,
After arranging the corresponding point of each position known point in the (P, δ) difference space in which the difference (δ) between the known value and the measured value of the measurement element at the position known point is made to correspond to the plane position (P), Generate a difference triangle 4 with the three selected points from the corresponding points as vertices,
Next, the interpolation value of the difference triangle 4 at the plane position based on the measurement value of the rover 1 or the extrapolation value is used as an error value for the measurement value, the measurement value of the rover 1 is corrected, and the rover position calculation that is output to the rover 1 Device 3,
Or
The measured value of the three-dimensional position measured by the GPS measured in the rover 1 is estimated based on the difference between the measured value and the true value at a plurality of points where the three-dimensional positions arranged around the rover 1 are known. A rover position calculation device 3 that corrects a measurement value and outputs it to the rover 1,
After arranging the corresponding point of each position known point in the (P, δ) difference space in which the difference (δ) between the known value and the measured value of the measurement element at the position known point is made to correspond to the plane position (P), A difference triangle generation unit 5 for generating a difference triangle 4 having apexes at three points selected from the corresponding points;
An error calculation unit 6 for obtaining an interpolation value or an extrapolation value of the difference triangle 4 at a plane position based on the measurement value of the rover 1 as an error value with respect to the measurement value;
Can be used.

Furthermore, the measurement of the Rover 1 position is
The measured value of the three-dimensional position measured by the GPS measured in the rover 1 is estimated based on the difference between the measured value and the true value at a plurality of points where the three-dimensional positions arranged around the rover 1 are known. A rover 1 position measurement method for correcting a measurement value and outputting it to a rover 1,
Obtaining a three-dimensional position measurement value by GPS at the rover 1 together with a measurement time;
Obtaining a measurement value at the measurement time at the row bar 1 measured at four or more position known points whose three-dimensional positions are known;
After arranging the corresponding point of each position known point in the (P, δ) difference space in which the difference (δ) between the known value and the measured value of the measurement element at the position known point is made to correspond to the plane position (P), Generating a difference triangle 4 having apexes at three points selected from the corresponding points;
Correcting the measurement value of the rover 1 by using the interpolation or extrapolation value of the difference triangle 4 at the plane position based on the measurement value of the rover 1 as an error value with respect to the measurement value, and outputting to the rover 1;
It can be realized by a rover 1 position measuring method having

  According to the present invention, a measurement system with high positioning accuracy can be constructed at low cost.

It is a block diagram which shows the structure of this invention. It is a figure which shows the operation | movement of this invention, (a) is a figure which shows the state which selected several position known points, (b) is a figure which shows the detail of one of them. It is explanatory drawing which shows the state which calculates | requires an error value from a difference triangle. It is a flowchart which shows the process of this invention.

  As shown in FIG. 1, the position measurement system includes a row bar 1 that is a mobile station, a reference point position measurement device 2 that is provided at a known point whose three-dimensional position is known, and a row bar position calculation device 3.

In the present embodiment, the rover 1 is a portable communication terminal device such as a smartphone, and includes a control unit 1a, a display unit 1b controlled by the control unit 1a, a GPS measurement unit 1c, and a communication unit 1d. The display unit 1b also serves as an operation unit. When a measurement operation is performed by the GPS measurement unit 1c, the measurement value (x _o , _yo , z _o ) (where x is longitude, y is latitude, z is altitude) And a position measurement request with a measurement time is output to the rover position calculation device 3.

  The GPS measurement unit 1c of the rover 1 is configured by a relatively inexpensive and low-accuracy GPS device such as a one-frequency type single-position GPS measurement device that performs positioning by receiving only the L1 band from a GPS satellite. be able to.

The reference point position measuring apparatus 2 includes a control unit 2a, a GPS measurement unit 2b controlled by the control unit 2a, and a communication unit 2c. The three-dimensional position (x _nf , y _nf , z _nf ) (where n is It is an integer and indicates an identification number assigned to the reference point position measuring apparatus 2.) is set to a known position such as a relay base station of a mobile phone, a city reference point, or the like. The control unit 2a of the reference point position measuring apparatus 2 performs position measurement at a predetermined timing after the operation starts, and stores the measurement results (x _no , y _no , z _no ) and the measurement time. As will be described later, since it is sufficient to output the measurement result in accordance with the measurement timing at the rover 1, the reference point position measuring device 2 holds the measurement result for about several seconds or several tens of seconds, and will be described later. Based on the measurement value inquiry request from the position calculation device 3, the measurement value at the inquiry time is returned.

  The GPS measuring unit 2b of the reference point position measuring device 2 is relatively similar to the rover 1 as in the case of the GPS measuring device of the single frequency type single positioning method that performs positioning by receiving only the L1 band from the GPS satellite. An inexpensive and low-accuracy GPS device can be used.

  The rover position calculation device 3 includes a control unit 3a, a communication unit 3b controlled by the control unit 3a, a difference triangle generation unit 5, an error calculation unit 6, a rover position calculation unit 3c, and a storage unit 7.

In the storage unit 7, the known point number of the position known point where the reference point position measuring device 2 is installed, the known value (x _nf , y _nf , z _nf ) of the three-dimensional position at each known point, and a predetermined value Measurement values (x _no , y _no , z _no ) of known points at the measurement time are stored.

The difference triangle generation unit 5 is activated when the control unit 3a receives the position measurement request from the row bar 1, and is measured by the row bar 1 on the plane coordinate (x, y) coordinates as shown in FIG. A known point located around the selected plane position (x _o , y _o ) is selected, a measurement value inquiry request is output to the reference point position measuring device 2 attached to the position known point of the selection destination, and the measured value Based on the response from the reference point position measuring apparatus 2 to the inquiry request, the difference triangle 4 is generated.

  The selected number of the reference point position measuring devices 2 is determined so that about 24 difference triangles 4 including the position of the row 1 can be formed so as to be close to the row 1 and perform statistical processing to be described later. The

As shown in FIG. 2B, the difference triangle 4 is a (x, y, δ) difference in which the difference (δ) between the true value and the measured value for the error evaluation element is associated with the (x, y) plane position. A triangle formed with the three points of known positions arranged in the space as vertices, and the error value δ of each known position point is an error evaluation element of x value,
δ _xn = x _nf -x _no ,
When the error evaluation element is a y value,
δ _yn = y _nf -y _no ,
When the error evaluation element is z value,
δ _zn = z _{nf -z no} ,
Given in.

The error calculation unit 6 interpolates an error value δ (δ _xn , δ _yn , δ _zn ) on the plane formed by the difference triangle 4 at the plane position (x _o , y _o ) measured by the row bar 1. It is calculated as a value and used as an error value for the error evaluation element.

The rover position calculation unit 3c performs statistical processing on a plurality of error values derived based on the plurality of difference triangles 4 to obtain an error estimated value, and then uses the error estimated value as a measurement value ( x _o , y _o , z _o ) in addition to the rover position, waiting for the output of the rover position, the control unit transmits the rover position information from the communication unit to the rover 1.

  For the statistical processing, for example, the least square method can be used.

  FIG. 4 shows the operation of this system. First, when the user of the rover 1 starts GPS position observation and acquires a measurement value (step R1), a position calculation request is output to the rover position calculation device 3 together with the measurement time and the measurement value, and a response is waited ( Step R2).

  In addition to outputting a single measurement value, the rover 1 outputs, for example, a predetermined number of measurement values executed at predetermined time intervals a plurality of times in accordance with the measurement value acquisition timing, or It can be set to output a representative value obtained by internally processing the result of continuous measurement for a certain period of time.

On the other hand, when the position calculation request from the row bar 1 is received (step C1), the row bar position calculation device 3 is positioned around the row bar 1 based on the planar position measurement values (x _o , _yo ) at the row bar 1. After selecting a plurality of position known points that can calculate the error value δ as an interpolation value, that is, the reference point position measuring device 2 (step C2), a measurement value inquiry request is output to the target reference point position measuring device 2 ( Step C3) and wait for a response (step C4).

  The measurement value inquiry request includes the measurement time information at the rover 1, and the reference point position measurement device 2 that has received the measurement value inquiry request (step S1) matches the measurement time at the rover 1 transmitted simultaneously. Alternatively, the measurement value of the reference point position measurement device 2 at the time of approach is output to the rover position calculation device 3 (step S2). If the measurement value query request is not received in step S1, the process waits until it is received.

  In this example, the measurement value in the reference point position measurement apparatus 2 is output in response to the measurement value inquiry request from the rover position calculation apparatus 3, but the reference point position measurement apparatus 2 performs measurement values. It is also possible to configure to output the measurement value to the rover position calculation device 3 at a predetermined timing without waiting for the inquiry request.

When the rover position calculation device 3 receives the measurement value from the reference point position measurement device 2 (step C4), it selects an x value, a y value, or a z value as an evaluation element (step C5), and the selected evaluation element The difference triangle 4 is generated in the difference space with the error value δ-axis as a step (step C6). Thereafter, an error value δ at (x _o , y _o ), which is a plane position measurement value at the row bar 1, is obtained by interpolation from the obtained difference triangle 4 (step C7). If the measurement value is not received in step C4, the process waits until it is received.

  The error value by the difference triangle 4 is performed for all the difference triangles 4 selected in step C2, and when the processing for all the difference triangles 4 is completed (step C8), the error value for the evaluation element is statistically calculated. Processing is performed to obtain an error estimated value (step C9).

When the calculation of the error estimated values for all the evaluation elements is completed as described above (step C10), the error estimated values are added to the measured values (x _o , _yo , z _o ) at the row bar 1 (step C11). The position information is output to the row bar 1 (step C12).

  When the rover 1 receives a response signal from the rover position calculation device 3 in response to the above request signal (step R3), the received position information is displayed on the display unit (step R4) and waits for the next measurement.

1 Rover 2 Reference Point Position Measurement Device 3 Rover Position Calculation Device 4 Difference Triangle 5 Difference Triangle Generation Unit 6 Error Calculation Unit

Claims (8)

A rover capable of acquiring a measurement value of a three-dimensional position by GPS together with a measurement time;
A reference point position measurement device that is installed at a plurality of points where a three-dimensional position is known and measures a GPS position measurement value of the position known point;
The rover, and a rover position calculation device capable of communicating with the reference point position measurement device,
The rover position calculation device includes the plurality of known positions in a (P, δ) difference space in which a difference (δ) between a measured value and a known value of a measurement element at the position known point is associated with a planar position (P). Generate a difference triangle whose apex is the corresponding point selected from the three points,
Next, a position measurement system that corrects the measurement value of the rover using the difference triangle interpolation or extrapolation value at the plane position based on the measurement value of the rover as an error value with respect to the measurement value, and outputs the corrected value to the rover.   The position measurement system according to claim 1, wherein the difference triangle is formed by three points whose error values are obtained as interpolation values.   3. The position measurement according to claim 1, wherein the rover position calculation device performs statistical processing on a plurality of error values obtained by each of the difference triangles generated by a plurality of difference triangles, and uses the result as a correction value for the measurement value of the rover. system.   4. The position measurement system according to claim 1, wherein the reference point position measurement device is formed by a single positioning GPS.   The position measurement system according to claim 1, wherein measurement at the row bar and the position-known point is executed at a plurality of measurement timings. It is possible to communicate with a rover capable of measuring its own position by GPS and a reference point position measuring device installed at a plurality of known three-dimensional positions around the rover.
After arranging the corresponding point of each position known point in the (P, δ) difference space in which the difference (δ) between the known value and the measured value of the measurement element at the position known point is made to correspond to the plane position (P), Generate a difference triangle with the 3 points selected from the corresponding points as vertices,
Next, a position measurement device that corrects the measurement value of the rover using the difference triangle interpolation or extrapolation value at the plane position based on the measurement value of the rover as an error value with respect to the measurement value, and outputs the correction value to the rover. The measured value of the three-dimensional position measured by the GPS at the rover is estimated based on the difference between the measured value and the true value at a plurality of known points, and the measured value of the rover is calculated. A position measuring device that corrects and outputs to the rover,
After arranging the corresponding point of each position known point in the (P, δ) difference space in which the difference (δ) between the known value and the measured value of the measurement element at the position known point is made to correspond to the plane position (P), A difference triangle generation unit that generates a difference triangle having apexes at three points selected from the corresponding points;
An error calculation unit for obtaining a difference triangle interpolation or extrapolation value as an error value for the measurement value at a plane position based on the measurement value of the rover;
A position measuring device having The measured value of the three-dimensional position measured by the GPS at the rover is estimated based on the difference between the measured value and the true value at a plurality of known points, and the measured value of the rover is calculated. A position measurement method for correcting and outputting to the rover,
Obtaining a three-dimensional position measurement value by GPS at the rover together with a measurement time;
Obtaining a measurement value at a measurement time at the rover measured at four or more known position points at a known three-dimensional position;
After arranging the corresponding point of each position known point in the (P, δ) difference space in which the difference (δ) between the known value and the measured value of the measurement element at the position known point is made to correspond to the plane position (P), Generating a difference triangle having three points selected from the corresponding points as vertices;
A step of correcting the measurement value of the rover using the difference triangle interpolation or extrapolation value at the plane position based on the measurement value of the rover as an error value with respect to the measurement value, and outputting to the rover;
A position measurement method.

Images