JPH1096764A - Gps receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a GPS receiving device that can easily erase satellite information stored in a backup memory. SOLUTION: A GPS receiving device is provided with an arithmetic processing unit 1 for computing position information on the basis of a received GPS signal, and a memory 2 connected to the arithmetic processing unit 1 so as to backup-store GPS satellite information at the time of receiving the GPS signal. In this case, reset switches 3a, 3b are provided to erase satellite information backup-stored in the memory 2. Satellite information can thereby be erased only by the operation of the reset switches 3a, 3b without needing to input a command.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS receiver used for positioning a moving body such as an automobile or a ship.

[0002]

2. Description of the Related Art GPS (Global Position)
Nig System) is a system capable of detecting, based on a GPS signal transmitted from a GPS satellite orbiting the earth, latitude / longitude and altitude position information of a position where the GPS signal is received, time information, and the like.

There are more than twenty GPS satellites orbiting the earth. Of these GPS satellites, for example, four satellites that can be captured by a GPS receiver are selected, and transmitted from the four GPS satellites. Positioning can be performed using GPS signals. That is, the G transmitted from the GPS satellite
The PS signal includes almanac, which is general orbit information of all GPS satellites, and ephemeris, which is its own accurate orbit information, transmitted from each GPS satellite.
The GPS receiver that receives the S signal selects four orbiting GPS satellites that can be captured based on the almanac, and based on the ephemeris transmitted from the selected four GPS satellites, the GPS satellites are selected. It can calculate the exact position and determine the current position.

Here, for example, when positioning is performed by mounting a GPS receiver on an automobile, the GPS receiver is turned off when the operation of the automobile is stopped, and then the GPS receiver is restarted when the operation of the automobile is resumed. When the GPS receiver is turned on and restarted, the GPS receiver first searches for four GPS satellites that can be captured from more than twenty GPS satellites and starts positioning. GP
If the orbit information of the S satellite is stored, a GPS satellite that can be captured can be selected based on the orbit information, and the GPS satellite to be captured can be searched in a short time.

[0005] For this purpose, a backup memory is provided in the GPS receiver, and when the power of the GPS receiver is turned off, the orbit information, time information, and position information obtained by the positioning of the almanac or ephemeris at that time are transmitted to the satellite. The information is backed up in a backup memory. When the satellite information is backed up in this way, when the power is turned off, the power is turned on, and the GPS receiver is restarted, the position information, the orbit information, and the time information backed up in the backup memory are stored. GPS satellites in orbits that can be captured at the power-on and power-on points can be selected based on the information, and the GPS satellites to be captured can be searched for in a short time. It can be resumed in time.

[0006]

However, when the GPS receiver is moved over a long distance while the power of the GPS receiver is turned off, the following problem occurs. In other words, when the GPS receiver is moved for a long distance with the power turned off and then turned on again at a point far away from the power-off point, the GPS receiver is backed up in the backup memory. Orbital information of almanac and ephemeris at the point where the power is turned off is saved as satellite information as orbital information, so a GPS satellite that can be captured at a point different from the point where the GPS receiver is restarted is selected. Will be done. Since the GPS satellites selected in this way are often in orbits that cannot be captured at the point where the GPS receiver is restarted,
The S receiving apparatus continues to search for GPS satellites that cannot be acquired, and it takes a very long time to acquire four GPS satellites and resume positioning.

In such a case, the backup memory is initialized to delete the backed-up satellite information, a new almanac is received, all the GPS satellites are searched in order, and four GPS satellites are searched in order from the one with the strongest radio wave. When the GPS satellite of the aircraft is selected and activated in the initial state, the time for resuming the positioning by the GPS receiver becomes faster. Therefore, it has been studied to input a command for initializing the backup memory from a personal computer or the like to the GPS receiver via serial communication so that the satellite information backed up in the backup memory can be deleted. However, the method of initializing the backup memory by inputting commands in this way requires specialized knowledge for command input, and also allows command input when a personal computer is not at hand such as when going out to a distance. However, there is a problem that it is difficult to initialize the backup memory.

The present invention has been made in view of the above points, and has as its object to provide a GPS receiver capable of easily deleting satellite information backed up in a memory.

[0009]

A GPS receiving apparatus according to the present invention includes an arithmetic processing unit 1 for calculating position information based on a received GPS signal, and a GPS connected to the arithmetic processing unit 1.
In a GPS receiver comprising a memory 2 for backing up and saving satellite information of a GPS satellite at the time of receiving a PS signal, reset switches 3a and 3b for erasing satellite information backed up and stored in the memory 2 are provided. It is characterized by comprising.

[0010]

Embodiments of the present invention will be described below. FIG. 1 is a block diagram showing a circuit configuration of a GPS receiving device. The arithmetic processing device 1 is formed by a CPU or the like. When a GPS signal is received and input,
Latitude / longitude and altitude position information based on the PS signal,
It functions to detect time information and the like. The arithmetic processing unit 1 is connected to a ROM 5 storing a control program and a RAM 6 for temporarily storing data. The RAM 6 also serves as a backup memory 2 for backing up and saving satellite information when the GPS receiver is turned off, and is connected to a backup power supply via a backup power supply terminal 7a of the I / F connector 7. . A backup circuit 8 is provided on a backup power supply line between the backup power supply and the memory 2, and a reset switch 3 a is connected between the backup circuit 8 and the RAM 6 to the backup power supply line.
So that the power supply from the backup power supply to the RAM 6 serving as the memory 2 can be turned on / off. This reset switch 3a is normally on.

A reset switch 3b is connected to the I / O port of the arithmetic processing unit 1. Reference numeral 13 denotes a pull-up resistor, 14 denotes a ground, and when the reset switch 3b is off, a Hi signal is input to the arithmetic processing unit 1, and when the reset switch 3b is turned on, the signal is Lo.
become. This reset switch 3b is normally off.

In FIG. 1, reference numeral 9 denotes an R / F connector to which a GPS antenna (not shown) is connected. An analog processing unit 10 is provided between the R / F connector 9 and the arithmetic processing unit 1, and the signal is received by the GPS antenna. The GPS signal is amplified by the analog processing unit 10 and input to the arithmetic processing unit 1. The power supply terminal 7b of the I / F connector 7
Is connected to the main power supply of the GPS receiver. Further, a personal computer or the like can be connected to the serial input / output terminal 7c of the I / F connector 7, so that serial communication can be performed between the personal computer and the arithmetic processing unit 1. In FIG. 1, 7d is I /
This is a ground terminal of the F connector 7.

In the GPS receiver formed as described above, when performing GPS positioning, the orbit information, time information, and position of almanac and ephemeris based on GPS signals received from GPS satellites and the position obtained by positioning are used. Although the information is temporarily stored in the RAM 6 as satellite information, when the main power is turned off and the operation of the GPS receiver is stopped, the power is supplied from the backup power supply to the RAM 6 at the same time by the operation of the backup circuit 8. The satellite information temporarily stored in the RAM 6 is backed up. That is, the RAM 6 acts as the backup memory 2, and the satellite information at the time when the power is turned off is backed up.

Therefore, when the main power is turned on next and the GPS receiver is restarted, the power is turned on based on the position information, the orbit information and the time information stored in the backup memory 2. The arithmetic processing unit 1 can calculate and select a GPS satellite in an orbit that can be captured at that point in time, and can search for the GPS satellite to be captured in a short time. By receiving GPS signals transmitted from a number of GPS satellites, positioning can be resumed in a short time.

On the other hand, after moving a long distance from the point where the main power supply of the GPS receiver is turned off and then turning on the main power supply of the GPS receiver to resume positioning, the reset switch 3a is operated and turned off. By shutting off the power supply to the backup memory 2 from the backup power supply, the memory 2 is initialized and the satellite information stored in the memory 2 is erased. When the memory 2 is initialized and the satellite information is erased, it can be performed only by pressing the reset switch 3a or the like, and a command for initializing the backup memory 2 is transmitted by serial communication. There is no need for input, and it is not necessary to require specialized knowledge for command input or a personal computer for command input, and the memory 2 can be initialized very easily. Is what you can do. When the memory 2 is thus initialized and the satellite information is erased, the operation is started from an initial state in which an almanac is newly received and all the GPS satellites are searched in order.

In erasing the satellite information stored in the memory 2 as backup, it is also possible to operate the reset switch 3b connected to the arithmetic processing unit 1 in addition to the reset switch 3a for shutting off the backup power supply. it can. That is, the reset switch 3
When b is off, the Hi signal is input to the processing unit 1, but the program of the processing unit 1 is set so that the memory 2 is initialized when the processing unit 1 detects the Lo signal. I have. Therefore, the reset switch 3b
Is turned on, the signal becomes Lo, so that the memory 2 can be initialized and the satellite information can be erased. Here, a plurality of reset switches 3b having the circuit configuration of FIG. 1 are connected to a plurality of I / O ports of the arithmetic processing device 1, respectively, to determine which of the information stored in the memory 2 is to be deleted. If a program of the arithmetic processing unit 1 is set so as to be assigned to an I / O port, it is possible to select information that can be deleted.
For example, time information, position information, almanac orbit information, ephemeris orbit information, etc. are selected from the satellite information stored in the memory 2 according to the reset switch 3b to be operated, and only some of the information is selected. It becomes possible to erase.

[0017]

As described above, according to the present invention, the received GP
An arithmetic processing device that calculates position information based on the S signal;
A memory connected to the arithmetic processing unit and having a memory for backing up and saving the satellite information of the GPS satellite at the time of receiving the GPS signal, a reset switch for erasing the satellite information backed up and stored in the memory. Since the satellite information is provided, it is possible to erase the satellite information backed up in the memory by operating the reset switch, and it is very easy to erase the satellite information without inputting a command. Is what you can do.

[Brief description of the drawings]

FIG. 1 is a block diagram of a circuit configuration according to an example of an embodiment of the present invention.

[Explanation of symbols]

 1 arithmetic processing unit 2 memory 3a, 3b reset switch

Claims (1)

[Claims] 1. An arithmetic processing device for calculating position information based on a received GPS signal, and a memory connected to the arithmetic processing device for backing up and saving satellite information of a GPS satellite at the time of receiving the GPS signal. A GPS receiver comprising a reset switch for erasing satellite information backed up in a memory in the GPS receiver formed.