JP2001311769A - Position measuring system and vehicle utilizing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire real-time and high-precision position information relatively rarely receiving the effect of a building or the like at any point on the ground and to achieve the high-level travel support and travel control of a vehicle based on the position information. SOLUTION: Radio waves of the position information and time information of ground stations are transmitted to flying bodies existing in the sky from four or more ground fixed stations having accurately known positions. Three or more flying bodies having clocks and existing in the sky measure their real- time positions by receiving signals from the ground fixed stations and transmit the results together with the time to the ground side. A position measuring device provided at a ground mobile station measures its real-time position based on the data of its clock by receiving signals from the flying bodies in the sky. The travel support and travel control of the vehicle are conducted based on the position measurement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of fixed ground stations whose positions are known in advance, a plurality of SPs that are suspended, fly, or float above the sky, and are arranged in the air, and a position measuring device. The present invention relates to a system for measuring a position with high accuracy and real time by a network system for information communication with a terrestrial mobile station, and a vehicle using the position measurement system.

[0002]

2. Description of the Related Art One of the conventional position measurement systems is a GP utilizing an artificial satellite at an altitude of about 20,000 km developed by the United States Department of Defense to measure the positions of stationary points and moving objects on the ground.
S (Global Positioning System)
em: Global Positioning System) is known. In the GPS, each satellite having an atomic clock transmits an orbit parameter and a highly accurate time signal based on the atomic clock to the ground side, and the GPS terminal on the receiving side has a stable clock such as a quartz clock. However, by comparing this with the time signal from the satellite, the propagation time between the satellite and the receiver, that is, the distance, is measured. (For example, Kunifumi Nosaka, Takuro Muratani, Ohmsha, new edition "Introduction to Satellite Communications", p. 222, 1994)

In the GPS, when the location is measured by signals from three satellites in the visible (reception) range, a two-dimensional position is measured, and the signals from four satellites in the visible (reception) range are measured. The three-dimensional position can be measured by measuring the location using the signal of (1).

[0004]

If the position accuracy by the GPS is left as it is, an error of several tens of meters or more will occur. In order to obtain a position with higher accuracy, a differential GPS that performs correction with a known ground station is required. Is used, but even in this case, an error of several meters is obtained. That is,
Even with the use of differential GPS, it is only possible to achieve a positional accuracy of a few meters. At such a level of positional accuracy, the application is at the navigation level, and more precise positional accuracy such as driving assistance and driving control of a vehicle is required. In such a region, there is a problem that the position accuracy is too coarse and cannot be used as it is.

[0005] In the RTK-GPS, which provides the highest accuracy currently considered by GPS, the delay time of positioning is the correction data processing time of the reference station, the time required for wireless data transmission, and the correction data processing time of the mobile station. Is the sum of
In modern technology, the sum of these times is about 1.2 seconds. If it is 1.2 seconds, a vehicle traveling at 100 km / h travels about 33 m per second.
The method of correcting the PS signal has a disadvantage that it takes too much time for calculation and transmission.

[0006] The frequencies of radio waves used for GPS are known to be L1 and L2, but the frequency of L1 is one.
575.42 MHz, L2 frequency is 1227.6 M
Hz, the wavelength of the frequency ranges from about 19 cm to about 2 cm.
4 cm. ("GPS Introduction Guide" supervised by Morizumi Mizumachi,
Satellite Positioning System Council, Nikkan Kogyo Shimbun 1993
Since the wavelength is long as described above, it is necessary to observe for a considerable period in order to calculate a position with high accuracy. Conversely, to shorten the observation period and measure the position with higher accuracy, it is necessary to use a higher frequency.
The S satellite is in the sky of about 20,000 km, and there is a problem that radio waves in a high frequency band cannot be used because the attenuation is remarkable at a high frequency band.

Further, even if an attempt is made to use a high frequency in order to improve the accuracy of the GPS, there is a problem that it is difficult to change the frequency and the like in accordance with the standard required by the user since the satellite is a US satellite.

[0008] In the position measurement by the GPS, since the satellite passes through the target area, there is a building.
It is uncertain whether more than one location information can be obtained, and there is a problem that the possibility of signal interruption is very high.

Further, in a position measurement by a GPS or a mere flying object such as a flying flight, the target passes through a target area. And its location is different, so it is extremely difficult to evaluate where on the ground the location information can be measured, and at which point the GPS satellites and flying objects cannot be seen due to the shadows of buildings, etc. There was a problem that it was difficult.

[0010] This means that it is difficult to know how much and at what point the influence of the shadow of the building will occur, especially in urban areas, so that the position can be measured using an object in the sky. There was a problem that it was extremely difficult to investigate the range in advance.

[0011] Therefore, even if the three-dimensional GIS on the ground side is completed, there is a problem that the GIS data cannot be effectively used in a GPS satellite or a flying object passing through the ground.

On the other hand, in order to mainly overcome the communication problems of satellites, research and development of aerial systems different from satellites are being conducted in Japan mainly by the Ministry of Posts and Telecommunications and the Science and Technology Agency. Especially through the troposphere affected by weather,
Airships in the stratosphere have been considered that can reach the stratosphere where there is no cloud and sunlight is always available during the day. However, when trying to raise an airship equipped with communication equipment to the stratosphere by the usual method, due to the problem of buoyancy, the size of the airship itself is about 250 m class, so it has to be huge, There was a problem that the cost per machine was enormous.

[0013] Attempting to reach the stratosphere by gas buoyancy alone results in a huge airship as described above, which is not only costly, but also has a problem that the number of airships is limited due to high cost. For example, the number of airships considered to be the stratospheric platform is about 15 in the Japanese archipelago. Therefore, arranging a large number of airships for position measurement on the national land has been a problem in terms of cost.

Further, as described above, if the airship that is suspended in the sky is huge, not only the manufacturing cost but also the launching cost and the storage space on the ground are huge, so the maintenance and management costs are enormous. There was a problem that it had to become something.

On the other hand, NASA and the like in the United States have developed high-altitude ultra-light aircraft that can reach the stratosphere, but because they are airplanes, they cannot float in the air and may crash if broken down. There was a problem.

[0016] Furthermore, high-altitude ultra-light aircraft have a wing length as long as 50 m to 100 m.
m), only wide runways can be used, and wide warehouses are required. In addition, there was a problem that the weight of the payload was limited due to the weight reduction of the agency.

The position measurement of a vehicle requires real-time performance and accuracy, and is an area where the most advanced position measurement is required. For this reason, magnetic nails, radio nails, ICs
Experiments have been conducted to embed nails etc. to grasp the running position of the vehicle, but with the method of installing nails on the road side, position measurement can be performed only on the embedded road, and users such as drivers From the point of view, there was a problem that only limited roads could be used.

[0018] This means that the position accuracy is understood with considerable accuracy at the place where the nail is installed, but the position measurement accuracy corresponding to the place where the nail is laid is not sufficient on the road where the nail is not installed. From the driver's point of view, there is a problem that confusion is likely to occur.

Further, if a large amount of equipment such as nails is installed on the road side, if it is to be changed to one having higher performance due to technological innovation, all the nails embedded in the road must be replaced. However, there was a problem with its exchangeability.

Further, regarding the measurement of the vehicle, even if the radio wave condition is good, the accuracy of control of the machine mounted on the vehicle is insufficient because the accuracy of the control of the machine mounted on the vehicle is insufficient because the limit is several meters until now. Therefore, there was a problem that advanced driving support was not possible. Further, when two-way communication of vehicle position information and the like is to be performed, there is a problem that only a limited road can be used if there is a receiving facility on the road side.

According to the present invention, the position can be measured in real time with high accuracy, and within the range of the measurement, it can be measured on all roads. Obtain a position measurement system that can be easily upgraded in accordance with innovations, etc., and especially with the highly accurate real-time position information obtained in this way, support and driving control of vehicles such as automobiles, connection with mobile phones and mobile computers. It aims to provide various advanced information services by cooperation.

[0022]

In order to achieve the above object, in the position measuring system of the present invention, four terrestrial fixed stations and four terrestrial fixed stations are used instead of a position measurement by a satellite or an air vehicle that traverses or passes an area to be measured. A network system having a total of at least 7 or 8 position points including at least three or more SPs constantly arriving in a certain space substantially above the area to be measured, together with ground fixed stations. , A system for performing position measurement.

That is, instead of satellites, four fixed ground stations whose positions are known are provided, and three or more SPs capable of flying, flying, and floating above the fixed stations are provided.
A system that measures the position of the terrestrial mobile station through a network by exchanging positional information and time information with each other by radio waves between the terrestrial fixed station and the terrestrial mobile station has been constructed.

Radio waves from four or more fixed stations on the ground are used for measuring the position of the SP. The radio wave from the ground fixed station preferably has an extremely high frequency of several tens of GHz or more. Upon receiving radio waves from the ground fixed station, the position measuring device mounted on the SP calculates the real-time accurate position information of the SP. Based on the calculation result, the current position information of the SP is transmitted to the terrestrial mobile station side. This transmission radio wave also preferably has an extremely high frequency of several tens of GHz or more. In this case, it is desirable to transmit highly accurate time information from a radio clock or an atomic clock.

In the terrestrial mobile station, a device for receiving the position information of the SP is provided, and the obtained position / time information and
The information is processed and the position is calculated.

[0026] The SP may be in a certain space by turning or circling.

On the ground side, locations where SP signals can be received are evaluated by GIS, and based on the evaluation results, each SP can be deployed in a certain space above the sky.

By the way, the altitude of the SP exceeds the stratosphere beyond the troposphere, considering that the weather is likely to change, clouds are formed, and dates and times when sunlight cannot be used come out. Area is desirable. In the stratosphere, sunlight is at least always available during the day, which is desirable from the viewpoint of securing energy for control.

However, if an airship capable of reaching the stratosphere is to be manufactured, the airship must be huge due to the buoyancy of the gas. In order to solve this, it is preferable that the airship is provided with all wings such as an airplane.

The ground mobile station of the position measurement system is mounted on a car, a railroad, or a vehicle of a new traffic. Also, two ground mobile stations were provided before and after the vehicle as needed. 2
The location of one ground mobile station is preferably, for example, a license plate.

The vehicle may include a traffic information providing device, a driving support device, a travel control device, and the like based on real-time position information measured by the ground mobile station.

When the vehicle travels on a road on the ground, information may be exchanged with the geographic information system so that matching can be performed.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings based on embodiments. In FIG. 1, four or more ground fixed stations 1 each having a clock at a position of a base are arranged. From the ground fixed stations 1 (GP1 to GP4), the ground fixed station transmission radio waves 3 (GW1 to GW4) are transmitted to the sky platform 2 existing in the sky. In the figure, the data is transmitted only to SP1 for easy viewing.
For P, at least four fixed ground stations 1 transmit position information and time information. In each SP, after calculating the position, the calculated position information and time signal are transmitted to the ground mobile station 4 by the SP transmission radio wave 5 (SW1 to SW4 in FIG. 1). The terrestrial mobile station 4 receives radio signals from three or more SPs to measure only planar position information, and four or more S signals to measure three-dimensional position information.
Receiving the radio signal from P, the own clock determines the distance from each SP according to the time difference of the radio wave, and obtains real-time and accurate position information of the self. The terrestrial mobile station exchanges information with the three-dimensional GIS6,
Understand which point is moving in the whole.

In the embodiment shown in FIG. 2, from the start of position measurement (step A) to the end of position measurement (step K).
Up to this point, each stage has been described. When the measurement is started (step A), first, from four or more ground fixed stations,
The position information and the time are transmitted to the SP in the sky (steps BC). Next, the radio wave from the fixed station
Then, the SP receives radio waves and measures the distance to each fixed station. (Steps D to F) Thus, in the SPs in the sky, the distance to the ground fixed station whose position is known is known, so that highly accurate real-time position measurement of each SP can be performed. (Step G) Then,
From each SP, the position information and time information of each SP are transmitted by radio waves toward the ground side (step H), and the terrestrial mobile station receives the radio waves of these SPs (step I), and receives each SP. Is measured from the difference from the time that the user has. As a result, the position of the terrestrial mobile station is measured.
(Steps J-K).

The embodiment shown in FIG. 3 is a view in which the operation trajectory of each SP is viewed from above. The SPs are arranged in a grid, but the SPs are efficiently arranged by turning the SPs in a certain space. Also,
By turning, the lift receives the lift force, and the SP can have a smaller gas volume and the size is reduced accordingly.

In the embodiment shown in FIG. 4, the operation trajectory of each SP is viewed from above. Each SP is arranged in a cellular shape, and the SP is efficiently arranged by turning the SP in a certain fixed space as described above. Also,
By turning, the lift receives the lift force, and the SP can have a smaller gas volume and the size is reduced accordingly.

In the embodiment shown in FIG. 5, the flying platform 2 has a lift. This platform is
It is an airship type, which is much less likely to fall than an airplane type, and is always propelled by a propeller. A solar cell is stuck on the upper side, and can be propelled at all times. The airship has a lifting body, and gains lift by propulsion. In the fuselage, three gas bags are provided.

In the embodiment shown in FIG. 6, the structure of the levitation force of the lifting body type airship shown in FIG. 5 is shown. Since turning (propulsion) provides lift, the amount of light gas can be reduced by that much, the body can be made smaller, and the cost can be greatly reduced, and a large number of SPs can be deployed. Become.

In the embodiment shown in FIG. 7, the flow of the SP deployment plan is shown. First, 3D GIS of the target area
To build. Next, determine the location of the SP, and in the virtual space,
Evaluate which point becomes a shadow and cannot exchange signals with the SP. In this way, the optimal SP
Develop a deployment plan for This kind of flow can be done,
This is because the SP can exist in a certain space.

In the embodiment shown in FIG. 8, the vehicle 6 (automobile)
Ground mobile station 4 (A, B) at front and rear of
Is provided. Since the position measuring system of the present invention can provide a position with extremely high accuracy in three dimensions, if two positions are provided, all the behaviors of the vehicle can be accurately calculated in real time. It is also possible to directly measure the amount of pitching, rolling and yawing.

In the embodiment shown in FIG.
This is a step for realizing automatic driving. First, the position of the vehicle is measured, and the position information of the own vehicle is transmitted to the SP in the sky (steps AB). At this time, if the vehicle is provided with two ground mobile stations, the behavior of the vehicle can all be grasped on the SP side. SP
As described above, not only information on each vehicle but also various information devices can be used to grasp traffic information on the suburbs, which is distributed from the SP to the vehicles. (Step C). Also, the vehicle can collect and collate data with the three-dimensional GIS (step D), and can evaluate traffic near the vehicle. (Step E), thus,
When the position, behavior, and surrounding environment of a vehicle can be grasped digitally, it can be evaluated in a virtual space by a vehicle-mounted computer, and when driving, warning and safety support, and in turn, automatic driving Command can be issued. (Step F) Based on a control command signal from the computer, actuators provided in the vehicle, such as an engine slot, handling, and a brake, are activated (Step G), and advanced driving support and automatic driving can be performed. . (Step H)

[0042]

Since the present invention is configured as described above, it has the following effects.

Since the SP for transmitting position information from the sky stays in a certain space, the area where radio waves of four or more SPs can be received at all times is conversely determined. Can be evaluated in advance whether or not the position can be measured with high accuracy using SP.

In the above SP, the aerial space is appropriate in the stratosphere, but since it is only about 20 km above the ground, high frequencies that cannot be used by satellites can be used. became. That is, the conventional GP
If the S satellite is a radio wave of 1 to 2 GHZ, it is possible to use a high frequency of several tens of GHZ or more in SP, so that high accuracy and more real-time measurement can be performed for the high frequency. .

At the time of measuring the position of the SP, the position is measured by radio waves of four or more known ground stations, so that the position of the SP can be measured with extremely high accuracy. In addition, since the position measurement is performed by utilizing the radio waves from the SPs in the sky after the high-precision position is identified as described above, the position measurement can be performed with much higher accuracy than the satellite based on the orbit information.

Since the lift was generated,
It was possible to ascend to the sky by that lift, making it easier to reach the stratosphere. In other words, by constantly making a round flight or turning flight in a certain space, it is possible to stay in the specified airspace.

As a result, the airship can obtain the rising force by the buoyancy caused by the gas and the lift caused by the hull shape, and the size of the hull can be reduced by the amount of the lift generated.

As described above, since the SP body can be made smaller, the number can be increased, and a position information system using only the SP can be constructed.

[0049] Since the SP can exist in a certain space, according to the position measurement request on the ground,
It is possible to do that arrangement. Therefore, it is possible to freely dispose as required in both a grid shape and a cellular shape. An optimal SP in the sky can be arranged according to the demands of the equipment on the ground, the position measurement, and the evaluation by the geographic information system.

As described above, since the SP body can be made smaller, the number of SPs can be increased, and a position information system using only SPs can be constructed.

[0051] Since the SP can exist in a certain space, according to a position measurement request on the ground,
It is possible to do that arrangement. Therefore, an SP in the sky can be arranged according to the equipment on the ground side and the demand for position measurement.

Since the measurement system using the SP covers a wide range, it is not limited to a specific type of road, such as a magnetic nail system, but can be an unspecified and wide range. Real-time and highly accurate position measurement can be performed on any road within the cover.

As described above, since position measurement with extremely high accuracy can be performed in real time, the on-board computer can control driving assistance of the vehicle based on accurate real-time position information.

When two ground mobile stations are mounted on a vehicle, the movement of the vehicle can be accurately grasped at a spatial level, so that extremely high traveling control can be performed.

If the ground mobile station provided in the vehicle can perform two-way communication, it becomes possible to grasp the real-time position of each vehicle with extremely high accuracy, thereby preventing collisions and accidents. Control can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of a position measuring system according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating operation steps of an embodiment of the position measurement system of the present invention.

FIG. 3 is a diagram illustrating an arrangement of SPs in the position measurement system of the present invention.

FIG. 4 is a diagram illustrating an SP arrangement of the position measurement system of the present invention.

FIG. 5 is a perspective view illustrating an SP of the position measurement system of the present invention.

FIG. 6 is a block diagram illustrating a levitation force of an SP of the position measurement system of the present invention.

FIG. 7 is a flowchart illustrating steps of an SP deployment plan of the position measurement system of the present invention.

FIG. 8 is a side view illustrating a vehicle using the position measurement system of the present invention.

FIG. 9 is a flowchart illustrating steps of driving assistance / running control of a vehicle utilizing the position measurement system of the present invention.

[Explanation of symbols]

 1 GP1 to GP4: ground fixed station 2 SP1 to SP4: sky platform 3 GW1 to GW4 ground fixed station transmission radio wave 4 ground mobile station 5 SW1 to SW4 SP transmission radio wave 6 vehicle (automobile)

Claims (12)

[Claims] The present invention is characterized in that a position is known, a clock is provided, and self-position information is transmitted together with time information by radio waves. , Sky Platform
m: described as SP. ) Side, a plurality of four or more ground fixed stations arranged on the ground equipped with a transmitting device for transmitting, and a clock which exists in a certain space in the sky, and has a clock.
A receiving device for receiving the radio waves from one or more ground fixed stations; and a position calculating device for calculating the position of the SP based on the time of a clock having the time information. A receiving device including a transmitting device that transmits to the ground side by radio waves, a plurality of SPs, a clock, and a position information and a time information transmitted from the SPs. And a terrestrial mobile station characterized in that it performs its own position measurement based on the position information and the time information. 2. The position measuring system according to claim 1, wherein the clock used is a radio clock or an atomic clock, and a high-precision time signal is used. 3. The position measurement according to claim 1, wherein the method existing in a certain space above the SP is performed by means of a turning flight or a round flight of the SP. system. 4. In the SP, the configuration of the entire arrangement of each of the SPs in the air is such that the individual S
The arrangement of P falls within a specific range, and when the specific range is set as a core, the cores are arranged so as to be in a grid shape or a cellular shape when viewed from the whole arrangement. 3. The position measuring system according to 3. 5. A two-dimensional or three-dimensional geographic information system GIS (GIS: Geographical In
Based on the analysis of the formation system and the relation with the arrangement of ground facilities such as roads and building structures, the optimal arrangement plan of each SP in the sky is established. When the core falls within a specific range and the specific range is set as a core, the cores are grid-shaped, cellular-shaped,
The position measurement system according to claim 1, wherein the position measurement system is arranged in a line shape. 6. Signals from a plurality of said SPs or GPS (G
local Positioning System:
Receiving the signal of the Global Positioning System), calculating its own position, correcting the SP signal by comparing the calculated position data with its own known position data, and correcting the SP. A fixed ground station that can transmit a signal and has at least one SP that retransmits a correction signal from the fixed ground station to the measurement target area as pseudo-range correction data is installed. The position measuring system according to claim 1, wherein: 7. The SP for redistribution according to claim 5,
At least one SP equipped with a multi-beam transmitter capable of retransmitting a correction signal of a target ground fixed station as pseudo distance correction data to a target area under the control of the ground station is incorporated. The position measuring system according to claim 1, wherein: 8. A terrestrial mobile station of the position measuring system according to claim 1 is mounted, and a traffic information providing device, a driving assistance device, a travel control device, etc. A vehicle comprising: a vehicle; 9. The vehicle according to claim 8, further comprising a correction device that performs matching with a geographic information system. 10. The vehicle according to claim 1, wherein two or more ground mobile stations are provided in the vehicle.
The vehicle according to claim 8. 11. The vehicle according to claim 8, wherein a result of position measurement or the like is transmitted to said SP. 12. The system according to claim 8, wherein the SP side collects position information of two or more vehicles provided with ground mobile stations and receives the information or information based on the information.
12. The vehicle according to 11.