JPS61167886A - Navigation system for automobile - Google Patents

Abstract

PURPOSE:To display the accurate position of a vehicle by assuming artificially satellite when the arrival of a radio wave from one of three artificial satellites is stopped. CONSTITUTION:When there are three receivable satellites, a reception position computing element 22 calculates both data, i.e. tracks from signal lines 20a and 20b and pseudo distance and the reception position of the vehicle 10 is displayed 24. If one of the satellite is made unreceivable because of the presence of a shield, the position of the vehicle 10 at the position is regarded as a pseudo satellite and azimuth and distance data from a magnetic goniometer 14 and a distance meter 16 are inputted to a pseudo computing element 26. On the other hand, measured position data on the vehicle 10 at the time t1 is sent to the computing element 26 as position information on a pseudo satellite and the pseudo distance data on the pseudo satellite obtained by processing said azimuth and distance data is sent to the computing element 22. The computing element 22 computes the measured position of the vehicle 10 on the basis of received data from receivable satellites at the current time t2 from a receiver 18, i.e. pseudo distance and satellite position data, the pseudo distance of the pseudo satellite of the computing element 26, and the position of the pseudo satellite of the device 2, so that the measured position is displayed 24.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a navigation system for a vehicle, and more particularly to a navigation system for a vehicle.
When receiving radio waves from multiple artificial satellites belonging to the GPS system (hereinafter referred to as GPS), even if one of them is obstructed by a radio wave shielding object, the vehicle can still receive radio waves based on the information already obtained. The present invention relates to a navigation device for a vehicle that can confirm the driving position of a vehicle.

For users who move from time to time, such as ships and aircraft,
In recent years, the usefulness of GPS positioning devices has been attracting attention because they transmit radio waves from a plurality of artificial satellites to confirm or determine their current positions, traveling speeds, and the like. This GPS positioning device has the following characteristics: ■ It can be used continuously all over the world at any time. ■ It has extremely high accuracy in measuring position and speed. ■ There is no limit to the number of users.

From this point of view, objects using GPS positioning devices are not limited to ships and aircraft, but should also include automobiles. In particular, if it can be used to avoid traffic congestion in urban areas, quickly confirm one's current location, and find a detour to a destination, it will have a significant time and economical effect. You'll get it.

In general, GPS positioning devices typically utilize three or more satellites. Each of these artificial satellites is equipped with a high-precision atomic clock, etc., but on the other hand, such an expensive timekeeping device is not installed on the receiving side. Therefore, there is a time offset in the time information on the receiving side (therefore, on the receiving side, radio waves from artificial satellites are simultaneously received, and a pseudo The position of the receiving point is calculated and displayed based on the distance data and the position data of each receiving satellite.However, as is well known, in urban areas and mountainous areas, GPS
A predetermined number of radio waves from satellites belonging to the vehicle are blocked from reaching the vehicle, which has the disadvantage that it is difficult for the user to confirm his or her current location.

As a solution to this problem, a method of estimating and displaying the position using already obtained azimuth or distance data while positioning is not possible is considered, but since the position error of this estimated position accumulates over time, Although continuous position display is possible, the position measurement error increases. In particular, if the unreceivable state continues for a long time, the position measurement error will become extremely large.
This becomes an inconvenience that cannot be ignored.

The present invention has been made to solve the above-mentioned disadvantages, and by processing the direction data from the direction meter, the distance data from the distance meter, and the received data immediately before reception becomes impossible, sheet metal, three For automobiles using GPS, which can display the position continuously and without accumulating errors by utilizing pseudo-reception data, even when it is difficult to receive radio waves from multiple satellites at the same time. The purpose is to provide navigation equipment.

In order to achieve the above object, the present invention is mounted on a vehicle and receives radio waves transmitted from a plurality of satellites constituting a GPS, and collects position data of the satellites and information between the satellites and the vehicle. GPS that outputs pseudorange data of
The receiver, the direction meter and distance needle mounted on the vehicle, and the output side of the GPS receiver, direction meter, and distance meter are connected! It consists of a J reconnaissance distance calculator, a reception position calculator connected to the output sides of the GPS receiver and pseudorange calculator, and a position indicator connected to the reception position calculator. When all the radio waves from the plurality of satellites reach the GPS receiver, the pseudorange data from the GPS receiver and the position data of the satellite are processed and the measured position is output to the position indicator. At the same time, if there are radio waves from the satellite that cannot be obtained due to a radio wave blocker, the vehicle measurement position and the reception before the reception was interrupted by the radio wave blocker are stored in the storage device included in the reception position calculator. Read the time offset of the aircraft, obtain pseudo reception information using this information and the output information of the direction meter and distance meter, and measure the vehicle position using this pseudo reception information and the reception information obtained by receiving the actual satellite radio waves. It is characterized by being configured to perform the following.

Next, a preferred embodiment of an automobile navigation system using GPS will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the basic configuration of an automobile navigation system according to the present invention, in which reference numeral 10 indicates a vehicle. The vehicle 10 is equipped with a GPS receiving antenna 12 and a compass, such as a magnetic compass 14 and a distance meter 16. The output side of the GPS receiving antenna 12 is connected to a GPS receiver 18,
Furthermore, this GPS receiver 18 transmits two signals [20a
, 20b. Each of the signal lines 20a and 20b is connected to a reception position calculator 22, and the output side of the reception position calculator 22 is connected to a position indicator 24. On the other hand, the output sides of the magnetic compass 14 and the distance meter 16 are respectively connected to a pseudorange calculator 26, and the other input terminal of the pseudorange calculator 2G is connected to the receiving position calculator 26.
The output side of the storage device 25 included in 2 is connected.

The output side of the pseudorange calculator 26 is connected to the reception position calculator 22 including the storage device 25.

In this case, the reception position calculator 22 and the pseudo distance calculator 2
6 consists of a microprocessor.

In some cases, it is also possible to replace the reception position calculator 22 and pseudorange calculator 26 with one microprocessor.

Next, the operation and effects of the automobile navigation system configured as described above will be explained.

As shown in FIGS. 3 and 4, a GPS positioning device generally captures radio waves from three artificial satellites 100, 200 and 300 using a GPS receiving antenna 12. In this case, each radio wave includes satellite position information (orbit information) and time information. Although not shown, each satellite is equipped with an extremely accurate clock such as an atomic clock, and the timing signal output from this clock measures the time, and the orbit information provides position information for that time. . On the other hand, vehicle 1
From an economical point of view, the 0 is equipped with a clock configured to utilize a crystal oscillator rather than a highly accurate clock such as the atomic clock. Therefore, the vehicle clock includes a time offset, and even if the time offset is unknown, the third artificial technique is needed to determine the reception position! 300 is required.

Therefore, under the above premise, the device of the present invention has 3
Radio waves from each of the artificial satellites 100, 200, and 300 are captured by the GPS receiving antenna 12. That is, at time t1, the GPS receiving antenna 12 mounted on the vehicle IO receives GPS signals sent from the respective artificial satellites 100 to 300, and this GPS signal is introduced into the GPS receiver 18 and amplified. The signal is then demodulated and then sent to the receiving position calculator 22. In this case, the signal line 20a is for deriving pseudorange data, while the signal line 20b is used for sending trajectory data. Here, the pseudorange data is calculated by taking into account the deviation between the timing signal synchronized with the time output of the atomic clock mounted on the artificial satellites 100 to 300 and the time output output from the clock mounted on the vehicle 10. The so-called
This is distance information that includes a time offset.

Therefore, as shown in FIG. 2A, when the artificial satellite 100, the artificial satellite 200, and the artificial satellite 300 are each at the position of the time t1, the traveling vehicle IO is at the position of the time t1. Assuming that the vehicle 10 is traveling on a road where there are no radio wave obstacles, the radio waves are sent to the vehicle 10 from the satellite 1OO1 satellite 200 and the satellite 300, respectively.

If there are three or more receivable satellites, the reception position calculator 22 receives orbit data and pseudo image distance data from the signal lines 20a and 20b, processes them, and calculates the distance to the vehicle 1.
0's reception position and sends the result to the position indicator 24. The position display device 24 can display the result numerically or as a travel trace on, for example, a CRT or the like.

However, time changes from time t1 to time t2, and therefore the artificial satellite 100 moves to the position of time t2, the artificial satellite 200 similarly moves to the position of time t2, and furthermore, the artificial satellite 300 moves to the position of time t2. Move to the location at time t2.

Of course, during this time, the vehicle 10 is also displaced to the position at time t2.

Therefore, in the above-mentioned displacement state, the vehicle 10 cannot receive the radio waves from the artificial satellite 300 because the radio waves are blocked by a radio wave shielding object, for example, the high-rise building 400. Therefore, in this case, 300 satellites
The position of the vehicle 10 at time t1 is used as the pseudo satellite 500 instead of the position of the vehicle 10 at time t1. That is, the magnetic compass 14
The direction data sent from the distance meter 16 and the distance data sent from the distance meter 16 are introduced into the pseudo distance calculator 26,
On the other hand, the reception position calculator 22 stores the measured position and time offset of the vehicle 10 at the time t1 in the storage device 25.
I remember it. Therefore, from this storage device 25, the time t
The measured position data of the vehicle 10 at
It is sent to the computing unit 26 as position information. The pseudorange calculator 26 calculates the azimuth data, the distance data, and the pseudosatellite 500.
The pseudorange data regarding the pseudosatellite 500 obtained by processing the position data and the time offset of the receiver is sent to the receiving position calculator 22. The reception position calculator 22 is
As shown in FIG. 2B, from the GPS receiver 18 at time t
2, the received data of the satellite 100 and the satellite 200, that is, the pseudorange data and satellite position data, the pseudorange data about the pseudosatellite 500 sent from the pseudorange calculator 26, and the pseudorange data supplied from the storage device 25. The measured position of the vehicle 10 is calculated using the position data of the satellite 500, and is displayed as a numerical value on the position display 24 or as a travel trace on a map. That is, pseudosatellite 500
As shown by the broken line, even if the estimated position A becomes the estimated position A, the estimated position A and the actual reception position B at this time t2
Utilizing the pseudorange data calculated by adding the time offset of the GPS receiver 18 to the distance between the By using this, it becomes possible to obtain position information in place of the actual measured position of the satellite 300. For example, as shown in FIG. 3, an artificial satellite 100 and an artificial satellite 200.

The artificial satellites 300 can substantially transmit radio waves to the vehicle 10 during the times indicated by solid lines. However, when the shielding object 400 exists, the vehicle 10 is substantially unable to receive radio waves from the satellite during the time interval shown by the broken line. 200 and satellite 300, the satellite position error increases all at once, as indicated by diagonal lines in the graph. Of course, if the position returns to the solid line position, accurate position information is obtained and the error is corrected. However, as shown in FIG. 4, when trying to estimate the position of the vehicle 10 using azimuth data and distance data without particularly utilizing the pseudosatellite 500, the estimated position error is shown by a broken line. increases significantly. However, if the measured position at time t1 is assumed to be the pseudosatellite 500 as described above, and the reception position of the vehicle 10 at time t2 is determined based on the information obtained, the position error will be as shown by the solid line in FIG. In this way, it is possible to confirm the position at the current point almost accurately without any slight accumulation.

As is clear from the above explanation, when trying to obtain position information from three artificial satellites using a GPS positioning device, one of the satellites may be blocked by a radio wave blocker, causing the radio waves to reach the target. Even if a satellite is intercepted, by assuming a pseudo-satellite, the vehicle's current position can be determined based on the reception information obtained from the satellite and the reception information of the satellite that effectively transmits radio waves. measurement becomes possible. For this reason, it is not necessary to simply estimate the position of the vehicle using a compass pointer and a distance pointer as in the prior art, and therefore, the position can be accurately measured without accumulating errors through the estimation. For this reason, there is an advantage that even when attempting to change the running direction from that point to a new point, it can be done extremely effectively and accurately.

Although the present invention has been described above with reference to preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design can be made without departing from the gist of the present invention. Of course.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of an automobile navigation device according to the present invention, FIGS. 2A and B are explanatory diagrams showing the positional relationship between an artificial satellite, a pseudosatellite, and a vehicle when there is a radio wave shielding object, and FIG. The figure is a waveform diagram showing the reception status of radio waves from an artificial satellite, and FIG. 4 is a diagram comparing measurement errors between the conventional device and the device of the present invention. 10... Vehicle 12... Antenna 14... Direction meter 16... Distance needle 18... GPS receiver 2
0a, 20b...Signal line 22...Receiving position calculator 24...Position indicator 25...Storage device 26...Pseudo range calculator 100.200.300...Artificial satellite 400...
Obstruction SOO...Wi value satellite Fig, 1 Procedural amendment (Own ship 25/13/1985 1, Incident indication 1985 Patent application No. 007218 2, Title of invention Automobile diversion device 3, Amendment Patent applicant address: 5-1-1 Shimotatsujaku, Mitaka-shi, Tokyo Name: Japan Radio Co., Ltd. 4, Agent Spontaneous Patent Application No. 60-007218 Amendment 1, Specification The "Detailed Description of the Invention" has been amended as follows: 1)) "Pseudo Hygiene 50" on page 12, lines 2 and 3.
0" is corrected to "estimated position of vehicle IO at time t8". (2) Change the “distance to the actual reception position B” on page 12, line 5 to “Pseudo sanitary 50
The straight line distance between G and G is corrected. (3) On page 12, line 7, amend "using," to "and."

Claims (1)

[Claims] (1) GPS reception that receives radio waves transmitted from a plurality of artificial satellites that are mounted on a vehicle and make up the GPS, and outputs position data of the artificial satellites and pseudo distance data between the artificial satellites and the vehicle. a direction meter and a distance meter mounted on the vehicle; a pseudo-range calculator connected to output sides of the GPS receiver, direction meter, and distance meter;
It consists of a receiving position calculator connected to the receiver and the output side of the pseudorange calculating unit, and a position indicator connected to this receiving position calculating unit. When the radio waves reach the GPS receiver, the pseudorange data from the GPS receiver and the position data of the artificial satellite are processed and the measured position is output to the position display, and at the same time, the measured position is outputted to the position display device. If there is a radio wave from an artificial satellite that is not present, read the vehicle measurement position and the time offset of the receiver before the reception was interrupted by the radio wave shield from a storage device included in the reception position calculator;
This information and the output information of the direction meter and distance meter are used to obtain pseudo reception information, and the vehicle position is measured using this pseudo reception information and the reception information obtained by receiving actual satellite radio waves. Features of automotive navigation equipment.