JPH1047984A - Car navigator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance accuracy of a route guidance in response to the type of roads and a jam condition of roads at an intersecting point to turn. SOLUTION: A route guide timing controller 20 comprises: a register Ts(20-a) for setting reference time Ts; a register Tw(20-b) for setting time interval Tw to calculate arrival time Tr to an intersecting point in which own car is turned; and a register Ti(20-c) for setting minimum time unit Ti when calculating this time interval Tw. In the route guidance of a car navigating device having this route guide timing controller 20, operations are performed by using own car's travelling condition information, own car's position information and position information of intersecting points to be guided as judgement elements, to calculate time to reach the intersecting point in which own car should be guided, and to change a timing to output a route guidance, whereby the route guidance is transferred to a driver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a car navigation system that outputs travel route guidance information according to a course set before a start of travel and during travel.

[0002]

2. Description of the Related Art As disclosed in Japanese Patent Application Laid-Open No. Sho 62-151713, a conventional car navigation system displays the position of a vehicle on a map displayed on a display in the vehicle. In addition, by providing information such as a destination to the car navigation device, a route to the destination can be searched, and the vehicle can smoothly reach the destination while receiving a route display on a display or voice guidance. The route guidance method of the car navigation device is disclosed in Japanese Patent Application No. Hei.
As disclosed in Japanese Unexamined Patent Publication No. 916, as the vehicle approaches an intersection to be turned, the route guidance mode is changed according to the remaining distance to improve the reliability of route guidance to the driver. There is also.

[0003]

However, according to the system in which the route guidance mode is changed according to the remaining distance to the intersection to be turned to improve the reliability of route guidance to the driver, the type of road (general road, Expressway), the congestion of the road, the speed of the vehicle, etc.
It is not an appropriate method. For example, if the intersection to be turned is congested and the voice guidance is set to be output at the remaining 200 m, it takes five minutes or more for the vehicle to reach the intersection to be turned. The effect of voice guidance is expected to be considerably reduced.

In view of the above, the present invention sets the timing for changing the display mode of the car navigation device and the timing for outputting route guidance with reference to the time when the vehicle is expected to reach an intersection to be turned. In this way, it is an object to improve the effect of route guidance. In addition, the route guidance of the car navigation system should take into account factors such as the type of road (general road and expressway), the state of congestion on the road, and the traveling speed of the vehicle. The purpose is to improve.

[0005]

According to the present invention, in order to achieve the above object, a calculation is performed by using the traveling state information of the own vehicle, the position information of the own vehicle, and the position information of the intersection to be guided as judgment factors. Calculate the time when the vehicle arrives at the intersection,
The route guidance is output at an optimal timing according to the traffic condition around the own vehicle.

According to the present invention, the route guidance of the car navigation apparatus is calculated using the traveling state information of the own vehicle, the position information of the own vehicle, and the position information of the intersection to be guided as the judgment factors, and the own vehicle guides. By calculating the time to reach the power intersection and changing the timing to output route guidance,
This has an effect that the reliability of transmitting the route guidance to the driver is improved as compared with the conventional method of controlling the timing of outputting the route guidance only by the distance to the intersection where the vehicle and the vehicle should turn.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 is a diagram showing a relationship between a host vehicle and an intersection. In FIG. 1, reference numeral 10 denotes a host vehicle, 11 denotes a host vehicle speed V, 12 denotes an intersection to be turned, and 13 denotes a host vehicle. 10 and intersection 12
Is shown.

Now, it is assumed that the host vehicle 10 is running at the host vehicle speed V11. The intersection at which the car navigation device on which the traveling route is set in advance provides route guidance is the intersection 12 to be turned. The distance 13 between the vehicle 10 and the intersection 12 at which the vehicle 10 should turn is defined as a distance L.

When the vehicle 10 is traveling at the speed V, the time required to reach the intersection to be turned is calculated by (Equation 1).

[0011]

## EQU1 ## However, the arrival time Td = L / V However, the arrival time Td differs depending on the situation around the host vehicle 10, and is determined by the traffic situation up to the distance L to the intersection 12 to be turned. In addition, since the traffic condition up to the intersection 12 to be turned changes with time, the arrival time Td
Cannot be uniquely determined.

Therefore, by calculating the average speed of the traveling speed of the vehicle 10 at regular intervals, it is possible to determine the arrival time based on the traffic conditions around the vehicle. Here, assuming that the arrival time based on the surrounding traffic conditions is Tr and the average speed of the own vehicle speed is Va, it can be obtained by (Equation 2).

[0013]

## EQU2 ## If the output timing of the route guidance of the car navigation device is controlled by using the arrival time Td = L / Va (expression 2), the car navigation device can reach the intersection 12 to be turned a certain time before the arrival time. Route guidance can be output.

FIG. 2 is a block diagram showing a configuration of the car navigation device according to the first embodiment of the present invention, in which voice guidance is performed as a route guidance output device. In FIG. 2, reference numeral 20 denotes a route guidance timing control device that controls the output timing of the route guidance of the car navigation device. Here, 20-a is a register for setting a reference time Ts for how long before the vehicle 10 arrives at the intersection 12 to be turned, the route guidance should be output. The setting of this time can be changed depending on the element of the road segment (such as an expressway) on which the vehicle is traveling. 20-b
Is a register for setting a time interval Tw for calculating a predicted arrival time Tr of the vehicle 10 reaching the intersection 12 to be turned. 20-c
Is a register for setting the minimum time unit Ti for calculating the time interval Tw.

Reference numeral 21 denotes a voice data buffer for storing voice data for route guidance output by the car navigation device. Reference numeral 22 indicates to the route guidance timing control device 20 that voice data has been stored in the voice data buffer 21. This is an audio data standby signal to be notified. Reference numeral 23 denotes a voice guidance start signal for notifying the voice data buffer 21 that voice guidance is to be started. Reference numeral 24 denotes an interval timer for operating the entire process at a certain fixed time interval, 25 denotes a voice generator, 26 denotes a voice data generator, and 27 denotes a CPU for controlling a car navigation device.

Next, the external operation of the route guidance timing control device 20 will be described. Basic processing is performed by the CPU 27 that controls the car navigation device. First, Ts setting register 20-a, Tw setting register 20-b, Ti setting register
Set the numerical value to 20-c. Next, the interval timer
24 is activated, and the route guidance timing control device 20 is activated. Then, when the audio data is stored in the audio data buffer 21 from the audio data generating unit 26, the audio data standby signal 22 is transmitted to the route guidance timing control device 20. Thereafter, when the route guidance timing control device 20 recognizes the timing of outputting the route guidance, it transmits a voice guidance start signal 23 to the voice data buffer 21 and outputs the voice data to the voice generation device 25.

FIG. 3 is a flowchart showing the flow of the internal operation (processing) of the present invention, and the flow of the entire processing will be briefly described.

First, it is determined whether audio data has been prepared (S1), and if not, the process is terminated. If they have been prepared, the times Ts and Tw are set (S
2). When the time Tw has elapsed (S3), (S4). The distance L to the intersection to be turned and the average speed Va of the vehicle are obtained (S5), (S6),
Calculate the predicted arrival time Tr to the intersection to be turned (S
7). When Tr becomes Ts or less, route guidance is output.
(S8), (S9). If Tr is larger than Ts, the process returns to the process of calculating Tr again. The time interval for calculating Tr is controlled by an externally provided variable Ti.

Next, the processing of the present invention will be described step by step.

(Step S1) It is determined whether or not voice data for route guidance to be performed by the car navigation device at the intersection 12 to be turned is ready. When the preparation is completed, the process proceeds in the direction indicated by "Yes", and when the preparation is not completed, the process proceeds in the direction indicated by "No".

(Step S2) The car navigation device sets a time Ts from when the voice guidance is output to when the car navigation device reaches the intersection 12 to be turned. Further, a time interval Tw for calculating a predicted time until the vehicle 10 reaches the intersection 12 to be turned is set.

(Step S3) The time T is cleared.

(Step S4) The time T and the time Tw are compared.

(Step S5) The distance L between the vehicle 10 and the intersection 12 to be turned is calculated from the vehicle position data recognized by the car navigation device, and the previously calculated old distance data L is updated.

(Step S6) The current vehicle speed is recognized from the data of the angular velocity sensor of the car navigation device, and the average speed Va of the vehicle is calculated. Then, the previously calculated old average speed data Va is updated.

(Step S7) From the distance L calculated in step S5 and the average speed Va calculated in step S6, a predicted arrival time Tr until the vehicle 10 reaches the intersection 12 to be turned is calculated. Then, the previously calculated predicted arrival time Tr is updated.

(Step S8) It is determined whether the time Tr calculated in step S7 is equal to or smaller than the time Ts set in step S2. If they are equal or smaller, the process proceeds in the direction indicated by "Yes". If they are larger, the process proceeds in the direction indicated by "No".

(Step S9) The car navigation device outputs the prepared route guidance voice data.

(Step S10) The result of addition of the time T and the time Ti is substituted into the time T again.

(Embodiment 2) Referring to FIG. 2 showing the configuration of a car navigation system according to Embodiment 1, an audio data buffer connected to a route guidance timing control device 20
21, the display state can be changed by using a device for display display instead of the sound generation device 25 and the sound data generation unit 26. In this case, the data is used as display display data instead of the voice guidance data shown in FIG.

(Embodiment 3) As Embodiment 3,
By using Embodiments 1 and 2 together, route guidance to the driver can be further improved.

[0032]

As described above, the car navigation system of the present invention controls the timing at which route guidance is output by predicting the time at which the vehicle will reach an intersection to be turned. Therefore, the route guidance can be output at the optimal timing according to the traffic condition around the own vehicle, and the driver can be surely recognized the route guidance. In particular, when performing route guidance in a congested portion of a road, if control is performed based on the distance from the vehicle to an intersection where the vehicle should turn, as in the related art, the route guidance is output and then the intersection where the vehicle should actually turn is reached. There is a large time difference before the driver may forget the route guidance. Employing the present invention improves the driver's recognition of route guidance. In addition, when an automobile runs at a high speed, such as on an expressway, by changing the time setting according to the traveling speed of the own vehicle, fine route guidance can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between an own vehicle and an intersection.

FIG. 2 is a block diagram illustrating a configuration of a car navigation device according to Embodiment 1 of the present invention.

FIG. 3 is a flowchart showing a flow of processing in the internal operation of FIG. 2;

[Explanation of symbols]

10 ... own vehicle, 11 ... own vehicle speed V, 12 ... intersection to be turned, 13 ... distance L, 20 ... route guidance timing control device, 20-a ... Ts setting register, 20-b ... Tw setting register, 20-c ... Ti setting register, 21 ... Audio data buffer, 22 ... Audio data standby signal, 23 ... Audio guidance start signal, 24 ... Interval timer,
25… Sound generator, 26… Sound data generator, 27
... CPU.

Claims (5)

[Claims] An operation is performed using the traveling state information of the own vehicle, the position information of the own vehicle, and the position information of an intersection to be guided as judgment factors, and a time required for the own vehicle to reach the intersection is calculated.
A car navigation device that outputs route guidance at an optimal timing according to a traffic condition around a host vehicle. 2. A CP for controlling a car navigation device.
U, an interval timer for operating the whole process at a certain time interval, and a route guidance output device, which indicates how long before the vehicle reaches the intersection to be turned, the route guidance should be output. From a register for setting a reference time Ts, a register for setting a time interval Tw for calculating an estimated arrival time Tr of an intersection at which the vehicle should turn, and a register for setting a minimum unit time Ti for calculating the time interval Tw. And a route guidance timing control device. 3. The car navigation device according to claim 1, wherein said route guidance output device uses voice guidance. 4. The route guidance output device uses a change in a display state of a display.
Or the car navigation device according to 2. 5. The car navigation device according to claim 1, wherein said route guidance output device uses both voice guidance and a change in a display state of a display.