JPH06221861A - On-vehicle navigation device - Google Patents

Abstract

PURPOSE:To save power consumption of on-vehicle battery, etc., by providing an intermittent power supply control means that cuts off supplying of power to a car position detecting means anywhere except reception points of electric wave required for position detection. CONSTITUTION:A car position detecting means 2 comprises a global position measuring system (GPS) receiver 2a and a signpost receiver 2b. The receiver 2a receives navigation wave from a GPS satellite, for detecting car position. The receiver 2b receives navigation wave from a signpost transmitter assigned at a roadside, etc., and then supplies the position data to a controller 6, for detecting car position. An estimation travel detecting unit 3, in case it can not receive the navigation wave by using the receivers 2a and 2b, calculates car position using assumed values. A power supply control means 6a controls supply of power to the receivers 2a and 2b. In short, when a car reaches the point where navigation wave is received, the car position detecting means 2 is supplied with power, however, supply of power is cut off anywhere other than the point for reception, thus power is saved during that period.

Description

Detailed Description of the Invention

[0001]

The present invention relates to GPS (Global Positio).
nig System (Global Positioning System) satellites and navigation signals for position detection from the sign post transmitter,
The present invention relates to a vehicle-mounted navigation device having a vehicle position detection unit that obtains the current position of the vehicle by an absolute value, and particularly to a vehicle navigation device that saves power consumption of the vehicle position detection unit.

[0002]

2. Description of the Related Art Conventionally, an on-vehicle navigation device of this type is mounted on a vehicle such as an automobile. As an example thereof, navigation radio waves from a plurality of GPS satellites are received to detect the current position of the own vehicle ( In the following, a GPS receiver that detects an absolute value of the vehicle position) and this GPS receiver,
When a vehicle enters a tunnel, etc., it may not be possible to receive navigation radio waves from GPS satellites. In that case, the navigation radio waves from the sign post transmitter are received to detect the vehicle position as an absolute value. Some include both a sign post receiver and an absolute position detecting means.

[0003]

However, in such a conventional vehicle-mounted navigation device, even in an area where navigation radio waves from GPS satellites, sign post transmitters, etc. cannot be received, or in points that are not important on the vehicle travel route,
Electric power is constantly supplied from the vehicle battery or the like to the vehicle position detecting means and is always operated. For this reason, the power consumed by the vehicle position detection means is not necessarily small.

Moreover, since it is expected that devices such as communication devices and audio equipment will be mounted on vehicles in the future, it is expected that the power demand of the vehicle-mounted battery will increase more and more. For this reason, power saving of the vehicle-mounted battery is required.

Therefore, the present invention has been made in consideration of such circumstances, and an object thereof is to provide an in-vehicle navigation device capable of saving power consumption without deteriorating the position detection accuracy of the vehicle. And

[0006]

The present invention is configured as follows in order to solve the above-mentioned problems.

The invention according to claim 1 of the present application (hereinafter, referred to as the first
The invention of claim 1) is a vehicle-mounted navigation device that is mounted on a vehicle and has a vehicle position detection unit that receives a radio wave on which a signal necessary for position detection is superimposed and detects the current position of the vehicle. When the vehicle arrives at a point to receive the electric power, the electric power is supplied to the vehicle position detecting means, and at other points, the electric power is intermittently supplied by stopping the electric power supply. To do.

Further, in the invention according to claim 2 of the present application (hereinafter referred to as the second invention), the intermittent power feeding means is manually selected to stop the intermittent power feeding to the vehicle position detecting means and continuously. It is characterized by having an intermittent power supply stopping means for supplying power.

[0009]

[Action]

<First Invention> When the vehicle reaches the receiving point of the navigation radio wave necessary for detecting the own vehicle position, the power feeding control means
Electric power is supplied to the own vehicle position detecting means to start the own vehicle position detecting operation, but when the vehicle is at a place other than the point to be received, the electric power supply to the own vehicle position detecting means is stopped,
During that time, power is saved.

Therefore, according to the present invention, the vehicle position detecting means is not continuously supplied with electric power but is supplied with electric power intermittently, so that power consumption can be saved accordingly.

<Second Invention> However, if necessary, the power supply control means can be continuously supplied with power by stopping the intermittent power supply operation by means of manual selection.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of an embodiment of an on-vehicle navigation device according to the first invention of the present application. In the figure, the on-vehicle navigation device 1 is mounted on a moving body such as an automobile. Yes, a GPS receiver 2a and a sign post receiver 2b that are vehicle position detecting means
A vehicle position detection unit 2 having both a vehicle speed sensor, a vehicle speed sensor and a gyro, a speculative travel detection unit 3, a CD-ROM (read-only compact disk memory) storing a map and information related thereto, and A CD that drives this to read out map information and related information
A CD-ROM unit 4 having a ROM driver,
For example, a display operation unit 5a for selecting a display mode or the like, a display device 5 having a display screen 5c such as a CRD (cathode ray tube) or LCD (liquid crystal display device) for displaying a vehicle position mark 5b indicating the vehicle position, It has a speaker (not shown) which is a voice output means for outputting voice information, and a controller 6 including a CPU and a ROM, a RAM and the like as a storage and a working area thereof and including a microprocessor for controlling the entire system. .

The speculative traveling detection unit 3 calculates the position of the own vehicle with the estimated value when the GPS receiver 2a and the sign post receiver 2b cannot receive the navigation radio wave and cannot detect the position of the own vehicle with the absolute value. And has a vehicle speed sensor and a gyro. The vehicle speed sensor outputs a pulse train having a number of pulses proportional to the number of rotations of the axle of the vehicle, for example, to detect the traveling distance of the vehicle by counting the number of pulses, and the gyro is a traveling direction of the vehicle. Is to detect.

On the other hand, the GPS receiver 2a has, for example, four Gs.
The navigation radio wave transmitted from the PS satellite to the ground is received to detect the position of the own vehicle as an absolute value.

Further, the sign post receiver 2b receives a navigation radio wave superposed with position data indicating its installation point from a sign post transmitter (not shown) installed on the roadside or the like, and outputs this position data. This is given to the controller 6 so that the own vehicle position is detected by an absolute value. The sign post transmitter is installed, for example, on a shoulder of a guide route of a vehicle, on stanchions or the like that are erected at required intervals in the longitudinal direction, and position data indicating the installation point is superimposed on radio waves and transmitted wirelessly. It is a thing.

The controller 6 controls the entire system in accordance with the processing programs and data stored in the ROM and RAM, and controls the power supply to the guide route setting means (not shown) and the vehicle position detection unit 2. And a control means 6a.

The guide route setting means, when inputting, for example, a departure point and a destination of a vehicle by operating an input unit or a display operation unit 5a (not shown), obtains a guide route connecting these two points by an optimum route, and, for example, The display device 5 as shown in FIG.
The guide route a, the guide points b, and the sign post installation positions c are displayed on the display screen 5c of FIG.

Each guidance point b is set at an intersection of roads intersecting with the guidance route a and indicates a point where position data should be collected. The sign post installation position c is a sign post along the guidance route a. It shows the location where the transmitter is installed.

The power supply control means 6a controls the power supply to the GPS receiver 2a and the sign post receiver 2b in order to save the power of the power source such as an on-vehicle battery.

That is, when the distance between the respective sign post transmitters is sufficiently shorter than the predetermined value, the power feeding control means 6a receives the next navigation wave immediately after receiving the navigation wave from the sign post transmitter. Therefore, the power supply to the sign post receiver 2b is not stopped (turned off), but in the area where the sign post transmitter is not installed, since the navigation radio wave cannot be received, the sign post receiver 2b cannot be received.
Does not need to be operated, and power supply to this is turned off to save power consumption of a power source such as an on-vehicle battery. The program is shown in FIG. In addition, in FIG. 3, P1 to P1
1 shows each step of a flowchart.

That is, as shown in FIG. 3, the power supply control means 6
When the sign post receiver 2b receives power and is turned on at P1, the data receiving program starts at the same time as it is turned on, and when the vehicle enters the sign post data receiving area, at P2, the position data (Xi, Yi) is calculated.

At the next P3, the preset guide route a
The position data (Xs, Ys) of the sign post transmitter at the next point after the received sign post transmitter is retrieved from the database of the installation points of the sign post transmitter on the path of. These two position data (Xi, Yi) and (Xs,
Ys) and the linear distance Lis to the sign post (transmitter) at the next point are calculated by the following equation (1).

[0024]

[Equation 1]

Next, at P5, the moving speed Vi of the vehicle is obtained by the vehicle speed sensor, and the estimated arrival time Tis to the next sign post is obtained by the following equation (2).

[0026]

[Equation 2] Tis = Lis / Vi (2)

After this, at P6, the estimated arrival time Tis to the next sign post and the detection time Ts immediately below the sign post receiver 2b, that is, the in-vehicle sign post receiver 2b comes closest to the sign post transmitter. , The reception level of the sign post receiver 2b reaches a peak, and the time required to obtain the point directly below the sign post transmitter is compared, and T
If is> Ts is not satisfied, the position data will not be received unless the position data is immediately received from the next sign post transmitter. Therefore, the power supply to the sign post receiver 2b is not turned off, and the next sign post transmitter is continuously turned off. The process returns to P2 to perform the position data reception process, and the following steps are repeated.

On the other hand, in P6, when the estimated arrival time Tis to the next sign post is longer than the direct point detection time Ts of the sign post receiver 2b, that is, Tis> Ts.
If the above condition is satisfied, there is sufficient time until the next sign post data is received, so the power supply to the sign post receiver 2b is turned off at P7.

At P8 thereafter, the sign post receiver 2
At the same time when the power supply to b is turned off, the estimated travel detection unit 3 starts to measure the travel distance ΔLM, the remaining distance ΔLis to the next sign post is calculated at P9, and the estimated arrival time Tis is calculated at P10, and P11 is calculated. When the estimated arrival time Tis becomes shorter than the time point Ts immediately below,
That is, when the vehicle enters the next sign post receiving area, the process returns to P1, the power supply of the sign post receiver 2b is turned on again, the next sign post position data is received, and so on.

On the other hand, when the GPS receiver 2b is operated, for example, when the sign post transmitter is not installed on the guidance route a, the power feeding control means 6a provides guidance on the guidance route a shown in FIG. Since it is sufficient to receive the position data near the point b, the power supply to the GPS receiver 2a is turned off between the adjacent guidance points b and b.

That is, in this case, the program shown in FIG. 4 is started. That is, the power feeding control means 6a uses P10
When the power supply to the GPS receiver 2a is turned on at 0, the next P
At 110, positioning of the current position (Xi, Yi) and moving speed Vi
Is measured, and the position (Xp, Yp) of the nearest guidance point a is searched at P120.

Next, at P130, the two distance data (Xi, Yi) and (Xp, Yp) are calculated as the linear distance Lip to the nearest guidance point a by the following equation (3).

[0033]

[Equation 3]

Further, using the moving speed Vi and the distance Lip calculated in the next P140, the estimated arrival time Tip to the nearest guidance point a is calculated by the following equation (4).

[0035]

[Equation 4] Tip = Lip / Vi (4)

Thereafter, the estimated arrival time Tip to the nearest guidance point a at P150 is compared with the time Tg required for positioning after the on-control of the GPS receiver 2b, and Tip> Tg.
Is not established, that is, when the positioning required time Tg is shorter than the estimated arrival time Tip, the next position data must be received immediately after receiving the position data. Therefore, the GPS receiver 2a is supplied with power. Instead of turning it off, in order to immediately measure the next current position and measure the moving speed Vi, the process returns to P110 and repeats the following steps.

On the other hand, at P150, the nearest guidance point b
If the estimated arrival time Tip until is longer than the time Tg required for positioning after the on-control of the GPS receiver 2a, that is, if YES, there is sufficient time until the nearest guidance point b is received. At P160, the power supply to the GPS receiver 2a is turned off.

At the same time as the power supply is turned off, the estimated travel detection unit 3 starts measuring the moving distance ΔLm at P170.
The remaining distance Δ to the nearest guidance point a on P180
Lis and the estimated arrival time Tis are further calculated in P190, and the estimated arrival time Tip and the positioning required time Tg are compared in P200. When Tip> Tg is not established, that is, the nearest guidance point b is approached. Sometimes P10
Returning to 0, the power supply to the GPS receiver 2a is turned on again, and the positioning of the vehicle and the moving speed Vi are measured.

Therefore, according to the present embodiment, the time until the vehicle arrives at the next sign post transmitter or the nearest guidance point a receives the navigation radio wave and is directly below the sign post transmitter 2b. When it is sufficiently longer than the time Ts required to detect the position and the time Tg required for positioning after the ON control of the GPS receiver 2a, the power supply to the GPS receiver 2a and the sign post receiver 2b is stopped. It is possible to save power consumption of a power source such as a vehicle-mounted battery without lowering the vehicle position detection accuracy.

In the above embodiment, the case where the power feeding control means 6a intermittently feeds power to the vehicle position detecting means 2 has been described, but the present invention is not limited to this, and for example, the power feeding control means 6a can be used. The operation may be stopped as necessary, and the vehicle position detection means 2 may be continuously supplied with power.

The estimated traveling detection unit 3 may be omitted. In this case, for example, after the GPS receiver 2a is powered off, the estimated traveling detection unit 3 moves the moving speed V of the vehicle.
Since i cannot be detected, the estimated arrival time Tip to the nearest guidance point a cannot be obtained. For this purpose, the flowcharts of FIGS.
It may be changed to FIG.

That is, by replacing P170 to P200 of FIG. 4 with P210 and P220 of FIG. 5, respectively, from the arrival time Tis to the nearest guidance point b,
Power is supplied to the vehicle position detection unit 2 for a half time [1/2 (Tip-Tg)], for example, with a margin from the time obtained by subtracting the time Tg required for positioning after the on-control of the GPS receiver 2a. May be stopped (turned off) to save power consumption.

Further, by replacing P6 and P11 shown in FIG. 3 with P300 and P310 of FIG. 6 respectively and deleting P10 of FIG. 3, the sign post receiver 2b is obtained.
Even after the power supply to the sign post is stopped, the remaining distance to the next sign post is monitored, and when the vehicle travels the remaining distance, it returns to P1 again to supply power to the sign post receiver 2b. Good.

According to these embodiments, by omitting the speculative traveling detection unit 3, the control method is simplified and
The hardware configuration can be simplified and the number of parts can be reduced, and the cost can be reduced.

[0045]

As described above, the first invention of the present application is
Since the power supply control means intermittently supplies power to the vehicle position detection means, power consumption can be saved as compared with the case of continuous power supply.

In the second invention of the present application, the operation of the power supply control means can be continuously stopped by manual selection as needed, and power can be continuously supplied to the vehicle position detection means.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of a vehicle-mounted navigation device according to the first invention of the present application.

FIG. 2 is a diagram showing an example of a display by the display device shown in FIG.

FIG. 3 is a flowchart of a processing program of a charging control unit shown in FIG.

FIG. 4 is a flowchart of a processing program of the charging control unit shown in FIG.

FIG. 5 is a flowchart of a processing program of another embodiment.

FIG. 6 is a flowchart of a processing program according to still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 In-vehicle navigation device 2 Vehicle position detection means 2a GPS receiver 2b Sign post receiver 3 Guessing running detection unit 4 CD-ROM unit 5 Display device 5a Display operation part 5b Vehicle position mark 5c Display screen 6 Controller 6a Power supply control means

Claims (2)

[Claims] 1. An in-vehicle navigation device, which is mounted on a vehicle and has a vehicle position detecting means for detecting a current position of the vehicle by receiving an electric wave on which a signal required for position detection is superimposed, the vehicle transmitting the electromagnetic wave. When the vehicle arrives at a point to be received, the vehicle position detecting means is supplied with electric power, while at other points, the vehicle is provided with an intermittent electric power supplying means for intermittently supplying electric power. In-vehicle navigation device. 2. The vehicle-mounted navigation according to claim 1, wherein the intermittent power supply means has an intermittent power supply stopping means for stopping the intermittent power supply to the vehicle position detecting means by manual selection and continuously supplying the power. apparatus.