JPH04571Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a vehicle-mounted GPS receiving antenna.
Positioning System (hereinafter referred to as GPS) This makes it possible to receive as much GPS radio waves as possible from the horizontal direction without increasing the air resistance of the vehicle while the vehicle is in motion. relates to a vehicle-mounted GPS receiving antenna that allows the antenna itself to be stored inside the roof.

In recent years, the usefulness of GPS positioning devices has increased in order to transmit radio waves from multiple artificial satellites to confirm or determine the current location, traveling speed, etc. of users such as ships and aircraft that are constantly moving. It is attracting attention. 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, and there is no limit to the number of users. Objects that use 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, confirm one's current location in a short time, and find detours to a destination, it can have significant time and economic benefits. Good morning.

By the way, GPS positioning devices generally use three or more satellites. Each of these satellites is equipped with highly accurate atomic clocks, etc., but on the other hand,
No such expensive timing device is installed on the receiving side. Therefore, a clock offset appears in the time information on the receiving side. Therefore, in the current positioning method, radio waves from artificial satellites are simultaneously received, and the receiving point is determined based on pseudorange data including the receiver clock offset between each satellite and the receiving point, and the position data of each satellite. Calculate and display the position of.

As described above, in order to receive radio waves from GPS satellites, a receiving GPS antenna must be installed in a moving vehicle. In particular, the
Since it is preferable that the GPS antenna also receives radio waves from GPS satellites having a relatively low elevation angle, it is preferable to dispose the antenna so as to protrude upward from the roof of the automobile.

However, for example, when a rod-shaped antenna protrudes from the roof of an automobile, air resistance increases significantly during driving, resulting in an inconvenience that impairs the high-speed driving performance of the automobile. Furthermore, it is aesthetically undesirable for the antenna to protrude upward from the roof. On the other hand, the above problem can be solved by mounting a flat, low-height antenna such as a microstrip antenna on the roof of the automobile, or by embedding it in the roof so that there is no protrusion. It becomes difficult to receive radio waves from GPS satellites with low elevation angles.

The present invention has been made to overcome the above-mentioned disadvantages, and is to provide a flat plate on the roof of an automobile.
The GPS antenna is mounted so that it can protrude slightly, making it possible to receive radio waves from GPS satellites at low elevation angles without increasing air resistance while driving. In some cases, the GPS antenna is stored inside the roof,
The purpose of this is to provide an in-vehicle GPS antenna that can avoid damage to the antenna itself due to rotating brushes during automatic car washing, or protect the GPS antenna from unexpected accidents such as mischief. shall be.

In order to achieve the above object, the present invention forms a recess in the roof of an automobile, and arranges a GPS radio wave receiving antenna in the recess that protrudes when operated from inside the automobile, thereby detecting the current position of the automobile. The present invention is characterized in that the antenna is configured to protrude upward from the roof when positioning the vehicle, and is housed in the recess when other than positioning.

Next, preferred embodiments of the vehicle-mounted GPS antenna according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 and FIG. 2 are schematic diagrams of a car having a GPS antenna according to the present invention, and FIG.
In particular, this GPS receiving antenna is shown stored inside the roof of a car;
FIG. 2 is a schematic diagram showing a state in which a GPS antenna is exposed from the roof of a car to the outside for positioning.
That is, the automobile 10 consists of a body 12 and wheels 14 that support the body 12, and the antenna 16 is configured to be housed inside the roof portion 18 of the body 12. As shown in FIG. 2, the antenna 16 is configured to be exposed above the roof 18 and can be used for positioning.

Details of this antenna 16 are shown in FIGS. 3 and 4. In this case, a circular recess 30 is formed approximately in the center of the roof 18 of the automobile 10, and a circular hole 3 is further formed approximately in the center of the circular recess 30.
2 is formed. Rectangular holes 34a and 34b are formed in the peripheral wall 33 of the roof 18 that forms the circular recess 30, and a screw hole is formed in the peripheral wall 35 of the roof 18 that defines the hole 32. 3
6 is formed.

After forming the recess 30 in the roof portion 18 as described above, the antenna 1 according to the present invention is placed in the recess 30.
6 are fitted and engaged. That is, the antenna 16 includes a disc-shaped disc 38, a sealing ring 40 that fits into a circumferential groove formed on the outer peripheral wall of the disc 38, and a threaded groove extending downward from the center of the disc 38. A protrusion 42 is formed therein.
The GPS radio waves captured by the disk 38 are connected to the lower circumferential wall of the disk 38 via a connecting portion 43.
A conductive wire 45 for sending data to the GPS reception processing section is connected. In fact, the connecting portion 43 includes the hole 34a of the roof portion 18 for forming the circular recess 30;
34b, and is configured to introduce the conducting wire 45 into the interior of the automobile 10.

Next, a knob member 44 that is screwed into the threaded groove of the protrusion 42 is prepared. The knob member 44 has an annular protrusion 46 extending upward from its central portion, and an internal thread 48 is carved into the inner circumferential wall of the annular protrusion 46 to be threaded into the thread groove of the protrusion 42. There is. Note that an annular groove 50 is formed in the peripheral wall of the annular protrusion 46 .

Therefore, as described above, the disk 38 is inserted into the circular recess 3.
0, and the connecting portion 43 fits into, for example, a rectangular hole 34b. As mentioned above, the conductor 45 is then introduced into the interior of the motor vehicle 10 (see FIG. 4).

In this manner, when the disc 38 is fitted into the circular recess 30, the knob member 44 is then inserted into the automobile 10.
is connected to the disk 38 from inside the chamber. That is, when the annular protrusion 46 of the knob member 44 fits into the hole 32 and the knob member 44 is screwed, the protrusion 4
The second screw groove is screwed into the inner screw 48 to connect the disk 38.
and the knob member 44 are integrated. Therefore, if the bolt 52 is screwed into the screw hole 36, the bolt 52
The tip end faces the inside of the annular groove 50,
This knob member 44 is prevented from falling. At this time, the sealing ring 40 is in pressure contact with the peripheral wall 33 defining the circular recess 30.

The antenna constituting the in-vehicle GPS receiving device according to the present invention is basically configured as described above, and then receives radio waves from the GPS satellite, thereby detecting the current state of the vehicle 10 as it travels. The case of positioning will be explained below.

First, the overall configuration of the GPS receiver will be briefly explained. That is, in the receiving section 60, the frequency of the transmitted radio wave modulated by the PN code is converted by a frequency converter, and this is amplified and introduced into a correlator. PN demodulation is performed using the signal sent from the code generator. That is, as shown in FIG. 6, since the radio waves transmitted from the satellites S ₁ , S ₂ and S ₃ are spread spectrum by the PN code, the signal from the PN code generator is The signal is despread by , and then coherent detection is performed. This synchronous detection signal is reintroduced to the PN code generator to generate the PN code that is constantly being transmitted.
Despreading with radio waves containing code is now possible.
Controls the signal generation of the PN code generator. on the other hand,
The signals related to the received radio waves obtained in this way are counted based on the clock frequency sent from the reference oscillator to obtain pseudorange data.

That is, here, since there is a clock offset between the timing device mounted on the car 10 and the atomic clock mounted on the artificial satellite, pseudorange data is obtained here as distance data including this clock offset. . This pseudo distance data is sent to the arithmetic processing section 64 and obtained by arithmetic processing of the current position information of the vehicle.

Therefore, antenna 16 transmits the GPS radio waves from the satellite.
When the control unit 62 receives the information, the control unit 62 performs positioning of the traveling vehicle 10 with respect to the reception unit 60.
Commands the selection signal of the satellite that transmits the optimal radio waves.

As is well known, when using GPS satellites to measure the traveling speed, direction, and current location of a ship or aircraft, the optimal satellite with the best geometric positioning accuracy is selected, and these three satellites are S ₁ , S ₂ and
When the receiving unit 60 obtains the pseudorange to S ₃ through the process described above, the arithmetic processing unit 64 calculates the pseudorange data derived from this pseudorange data and the navigation message data previously received. By establishing a two-dimensional positioning and navigation equation based on the satellite positions of the three satellites S ₁ , S ₂ and S ₃ and solving the equation, the current position of the vehicle 10 can be determined. In this way, the current position, traveling direction, and speed of the vehicle 10 obtained by solving the navigation equation, the clock offset of the GPS navigation device, and the GPS
The rate of change of the clock offset of the navigation device is once sent to the memory 66 and stored there. On the other hand, these data are sent to the display section 68, making it possible to display at least the position, traveling direction, and speed of the vehicle 10 on the screen.

In this case, as described above, in the present invention, the antenna 16 for receiving GPS radio waves is arranged approximately at the center of the roof section 18. So the operator does this
When attempting to measure the current position of the traveling automobile 10 using the GPS receiving device, first, the knob member 44 is rotated in a predetermined direction in a room such as a driver's seat. At this time, the tip of the bolt 52 serves as a guide within the annular groove 50. In the disk 38, the ring 40 is in pressure contact with the peripheral wall 33, and therefore does not rotate due to its frictional resistance. Therefore, the rotational movement of the knob member 44 pushes the disk upward. Note that the connecting portion 43 is located in the hole 34b and is displaced upward. In this way, as shown in FIG. 4, the antenna 16 rises to the position indicated by the two-dot chain line. The antenna 16 is in a state of slightly protruding above the roof portion 18.

Therefore, it is easy to receive radio waves obtained from the artificial satellites S ₁ , S ₂ and S ₃ , and this antenna 1
Since 6 is disc-shaped, air resistance does not particularly increase during running. Furthermore, the current situation is that positioning is virtually impossible when the angle of elevation of the artificial satellite is less than 5 degrees, but as in the present invention, the antenna 16 is exposed at a part that protrudes slightly from the roof 18. It is also possible to avoid positioning being impossible due to constraints on the elevation angle of the artificial satellite.

On the other hand, such an antenna 16 is preferably stored within the roof portion 18, for example, when washing a car. Therefore, in such a case, the operator should rotate the knob member 44 indoors in the opposite direction, and the disk 38 of the antenna 16 will be lowered to the solid line position shown in FIG. leading to. At this time, for example, even if the car wash liquid attempts to enter the interior of the vehicle from the roof portion 18, this can be easily avoided due to the presence of the sealing ring 40.

As described above, according to the present invention, when a car equipped with a GPS navigation device is driving, it is possible to receive radio waves from artificial satellites without increasing air resistance even slightly and without impairing the aesthetic appearance. It is possible to perform vehicle positioning using Furthermore, since it can be added to existing automobiles, it has the advantage of being inexpensive and easy to install.

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 are possible without departing from the gist of the present invention. Of course.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a car equipped with a GPS receiver according to the present invention, particularly with the antenna housed in the roof, and Figure 2 is a diagram of the antenna shown in Figure 1 exposed to the outside from the roof. Schematic diagram, 3rd
The figure is an exploded perspective view of the antenna of the GPS receiver according to the present invention, Figure 4 is a partially omitted longitudinal cross-sectional view of the antenna shown in Figure 3, and Figure 5 is the GPS reception shown in Figures 1 to 4. Block circuit explanatory diagram of equipment, etc.
FIG. 6 is a schematic explanatory diagram showing the correlation between a car equipped with a GPS receiver and an artificial satellite. 10...Car, 12...Body, 14...Wheels, 16...Antenna, 18...Roof, 38...
...Disc, 40... Seal ring, 44...
Knob member, 46... annular protrusion, 50... annular groove.

Claims (1)

[Claims for Utility Model Registration] (1) A GPS that has a recess formed in the roof of an automobile and that projects into the recess when operated from inside the automobile.
A radio wave receiving antenna is disposed, and the antenna is configured to protrude upward from the roof when positioning the current position of the vehicle, and to be housed in the recess when other than positioning. An in-vehicle GPS receiving antenna that is characterized by: (2) Utility Model Registration In the antenna described in claim 1, the antenna includes a substantially flat main body, a sealing ring member that fits into a circumferential groove formed in the flat main body, and the main body. A vehicle-mounted GPS receiving antenna comprising a first threaded part protruding from the interior of the vehicle, a knob member that rotates in the interior of the vehicle, and a second threaded part formed on the knob member and screwed into the first threaded part. .