JP2913857B2 - Destination guidance device used for vehicle navigation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a vehicle navigation system having a position detecting function for detecting the current position of a vehicle using a distance sensor and a direction sensor, and provides a driver with accurate destination guidance. The present invention relates to a destination guide device that can be used.

[0002]

2. Description of the Related Art Conventionally, a traveling distance sensor and a direction sensor (one of a geomagnetic sensor and a turning angular velocity sensor) have been used as a method for detecting the position of a vehicle traveling on an arbitrary part of a road traffic network. And a processing device for performing necessary processing on output signals from both sensors, and a distance change amount Δd and azimuth θ (in the case of a geomagnetic sensor) or azimuth change amount Δθ (turning angular velocity sensor) Dead reckoning navigation that obtains the estimated position data of the vehicle using the above method is proposed. This method uses, for example, an east-west component Δx of Δd (= Δd × cos θ) based on Δd and θ.
And the north-south direction component Δy (= Δd × sinθ) is calculated,
In this method, the current position output data (Px, Py) is obtained by adding the components Δx, Δy to the previous position output data (Px ′, Py ′).

[0003] Incidentally, there is a disadvantage that errors included in the obtained estimated position data are accumulated due to errors inherently possessed by the traveling distance sensor and the azimuth sensor. Assuming that the vehicle travels, the estimated position data obtained by the dead reckoning navigation is compared with road map data stored in a memory in advance, and a deviation amount of the estimated position data from the road is calculated as a cumulative error. A map matching method has been put to practical use in which the estimated position data is corrected for the accumulated error so that the estimated position data matches the road data (JP-A-63-148115,
JP-A-64-53112).

In both the dead reckoning navigation and the map matching method, a roadside antenna is arranged beside a road in order to improve the accuracy of distance data and azimuth data. A roadside beacon system has been proposed in which a signal including direction data is radiated only in a relatively narrow range and the signal is received by an on-vehicle antenna mounted on the vehicle to calibrate the position and direction of the vehicle.

[0005] In addition, GPS (Global Positioning System)
m) to measure the propagation delay time of radio waves emitted from three or four orbiting satellites to determine the absolute position of the vehicle. as mentioned above,
Regardless of which method is adopted, it is necessary to mount a device (hereinafter, referred to as a navigation device) for realizing the position detection method on the vehicle in order to know the position and orientation of the vehicle.

[0006] If the navigation device as described above is mounted on a vehicle, the driver can grasp the current position of the vehicle. Therefore, even when traveling on an unknown road, the driver can travel without getting lost. Can be. In the above navigation apparatus, the driver must determine the route to be taken to reach the destination by looking at a map or the like, even if the driver can grasp the current position of the vehicle.

In order to save the trouble of judging a route by looking at a map or the like, a method has been developed in which a computer automatically calculates a route to the destination if the destination is set, and shows the route to the driver. This method will be described. In accordance with the setting of a destination point or the like by a driver, road map data in a range including a starting point and a destination point is read from a road map memory, and a route from the starting point to the destination point is determined based on the road map data. The most economical route (optimal route) can be determined. As a method of calculating the route from the departure point to the destination, there is a so-called Dijkstra method ("Development research report of emergency vehicle travel guidance system" Japan Traffic Management Technology Association, March 1986, DirckVon Vliet, "Improved Shortest
Path Algorithm for Transportation Network ", Trans-p
ortation Research, Vol. 12, 1978). In this method, the route to be calculated is divided into a number of routes, the node or link closest to the departure point is set as the start point, the node or link closest to the destination is set as the end point, and the tree of links from the start point to the end point is formed. This is a method in which link costs of all routes constituting a tree are sequentially added to calculate a link sequence having the lowest cost to reach a destination.
Here, items to be evaluated when calculating the link cost include the travel distance, travel time, use of an expressway, the number of right and left turns, the probability of running on a main road, avoiding accident-prone zones,
Other items are set according to the driver's preference.

However, performing the above-described route calculation requires a large-capacity road map memory for storing a wide range of road map data and a computer for performing complicated calculations, resulting in a significant increase in cost. There is. Also,
When a new road is opened, the contents of the road map memory must be updated accordingly. In order to improve this problem, the types of roads included in the road map data are narrowed down to main roads (for example, national roads, motorways, general national roads, and major local roads) to reduce the memory capacity and shorten the calculation time. It is possible that
Even though the route along the main road can be calculated, the route cannot be calculated to the general road. Therefore, there is a disadvantage that the driver does not know the approximate route to the destination but cannot know the detailed route to the destination.

On the other hand, for a driver, especially when traveling on a general road close to the destination, the driver is required to show a detailed route to the destination, and to be more accurate at a required point (for example, at an intersection) during traveling on the road. Once you get the guidance, you can often reach the destination safely with your own memory and can. Since such route guidance does not display all routes to be traveled, it will be referred to as “simple route guidance”.

As an example of a simple route guidance system, it is conceivable to give an instruction to the driver to turn right or left at the intersection when the distance to the next intersection to be turned is equal to or less than a predetermined value (Japanese Patent Laid-Open No. Sho 64). -16915).

[0011]

However, even in this case, the navigation device must store at least all the intersections in the middle of the route, and store in advance which intersection and which instruction should be issued. For this reason, it is necessary to input a route in order to memorize intersections and instruction contents. However, it is troublesome for a driver to manually input a route before driving, and when calculating by a computer, a large scale Device.

[0012] In addition, if traffic regulation is performed and traffic regulation information is not stored in the memory, an erroneous instruction may be given, and the driver cannot drive only by using the navigation device. The present invention has been made in view of the above-described problems, and as long as the destination and the current vehicle position are known, it is effective to rely on the driver's judgment to some extent without inputting or calculating a route. It is an object of the present invention to provide a destination guidance device that can provide guidance.

[0013]

According to a first aspect of the present invention, there is provided a destination guiding apparatus for detecting a current position of a vehicle using a distance sensor and a direction sensor. Destination setting means for setting a traveling destination; a distance D from the current position of the vehicle to the destination set by the destination setting means; a traveling direction of the vehicle; and a direction from the current position of the vehicle to the destination. Relative angle θ which is the difference between
Calculating means for calculating a traveling direction projection L = Dcos θ of the distance D to the destination, and a sign of the relative angle θ when the traveling direction projection L of the distance D calculated by the calculating means falls below the reference value L0. And guiding the driver that the destination is on the right or left side in the vehicle traveling direction.

Further, according to the present invention, the reference value L0
Is a function of the speed of the vehicle. According to the third aspect of the present invention, when it is detected that the absolute value of the relative angle .theta. Exceeds a certain angle .theta.3 larger than 90.degree. Notification means for notifying the user that the destination is behind.

According to a fourth aspect of the present invention, the driver is provided with predetermined guidance by the detection means for detecting that the vehicle has completed a right turn, left turn or turning, and the destination guidance means or the notification means, and thereafter the detection means When the vehicle detects that the vehicle has completed a right turn, a left turn, or a turn, the vehicle further includes a guidance stop unit that stops guidance to the driver.

According to a fifth aspect of the present invention, the distance D from the current position of the vehicle to the destination set by the destination setting means is set.
However, when the vehicle falls below a reference value D1 at which the vehicle can be considered to have arrived at the destination, a guidance function stopping means for stopping the function of the destination guiding means or the notifying means is further provided.

[0017]

According to the configuration of the first aspect, as shown in FIG. 1, simply by detecting the current position of the vehicle and setting the destination, the distance D from the current position of the vehicle to the destination and the relative angle are set. is automatically calculated, and when the projection L in the traveling direction of the distance D to the destination falls below the reference value L0, the presence or absence of an intersection, etc.
Guides the driver to the destination regardless of the surrounding road conditions.

According to the configuration of claim 2, the reference value L0
Is a function of the speed of the vehicle, so that the timing to guide the destination can be adjusted according to the vehicle speed.
According to the configuration of claim 3, the absolute value of the relative angle θ is the angle θ
When it is detected that the distance exceeds 3 or the traveling direction projection L becomes negative than the value L3, the driver passes the destination and travels for a while and looks backward, so the driver is informed. I can let you know.

According to the fourth aspect of the present invention, the guidance is stopped when the vehicle completes a right turn, a left turn, or a turn, so that the driver is not provided with unnecessary guidance. According to the configuration of claim 5, when the distance D to the destination becomes the distance D1 at which the vehicle can be regarded as having arrived at the destination, the destination guidance is not performed. It is considered that there is no need to provide guidance and guide the driver even in such a case.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 2 is a block diagram showing an electrical configuration for implementing the destination guidance device of the present invention. This destination guidance device is included in a so-called vehicle navigation device mounted on a vehicle.

The navigation device of this embodiment detects the position of the vehicle using so-called dead reckoning,
We adopt a method of displaying it over the map,
As described above, a map matching method, a beacon method, or GPS may be employed to improve the position detection accuracy. The navigation device, as shown in FIG.
A console 1, a display 2, an azimuth sensor 3, a distance sensor 4, a road map memory 5 storing road map data, a memory drive 6 for reading stored data from the road map memory 5, a distance sensor 4, the travel distance detected by the azimuth sensor 3 and the travel direction change detected by the azimuth sensor 3 are integrated. The vehicle position is detected based on the integrated data, and guidance for guiding the destination in accordance with the procedure of the present invention. A position detection device 8 that outputs a signal, reads a road map in a predetermined range, edits destination guidance data for guiding a vehicle, controls a voice output device 10, controls a display 2, and controls a position detection device 8. And a navigation controller 9 for performing various controls such as control.

More specifically, the console 1 comprises:
It has a key input board (not shown) for starting / stopping the apparatus, moving a cursor on the screen, scrolling a road map displayed on the screen, and the like. The driver can use the keyboard to input the coordinates of the destination. The display 2 is provided with a transparent touch panel on a screen such as a CRT or a liquid crystal panel. Display 2
The position of the vehicle detected by the position detection device 8 is displayed on a screen together with a surrounding road map. The driver can also input the position of the vehicle and the position of the destination on the map using the touch panel.

The azimuth sensor 3 detects a change in azimuth accompanying the traveling of the vehicle, and may use a geomagnetic sensor, a gyro, or the like. The direction sensor 3
Is also used for the detection of turning right and left and turning, which will be described later. The distance sensor 4 detects the traveling distance based on the speed of the vehicle, the number of rotations of the wheels, and the like.
Wheel speed sensors, vehicle speed sensors, and the like can be used.

The road map memory 5 includes a large-capacity storage medium such as a CD-ROM, an IC memory card, and a memory such as a magnetic tape. The road map memory 5 divides the road map (including highway national roads, motorways, general national roads, major local roads, general prefectural roads, general city roads of designated cities, and other living roads) into a mesh shape. , Road map data consisting of a combination of nodes and links in each mesh unit, along with a high-level map containing data on highways (including highway national roads, motorways, general national roads, and major local roads), and highway maps It is stored separately from a lower-level map that also includes data on non-trunk roads (hereinafter, referred to as “general roads”) such as general prefectural roads, general city roads in designated cities, and other living roads.

Here, a node is generally a coordinate position for specifying an intersection or a turning point of a road. A node representing an intersection is referred to as an intersection node, and a turning point (excluding an intersection) of a road is referred to as a node. The represented node may be called an interpolation point node. The node data includes a node number, an address of a node of an adjacent mesh corresponding to the node, an address of a link connected to the node, and the like.

A link connecting the intersection nodes is a link. The link data includes the link number, the address of the start node and the end node of the link, the link distance, the direction of the link, the required time data in that direction, the standard curve frequency data of the link, the road type, the road width, one-way and toll roads, etc. Traffic regulation data. The position detection device 8
Based on the initial position and the initial azimuth of the vehicle set at the time of departure of the vehicle, travel trajectory data is calculated by integrating distance data detected by the distance sensor 4 and azimuth change data detected by the azimuth sensor 3 respectively. The current position and direction of the vehicle are detected, and a destination guidance signal is output to the navigation controller 9 according to a procedure described later.

The navigation controller 9 obtains the vehicle position from the position detecting device 8, displays the current position and the destination on the map in a superimposed manner, obtains the destination guidance signal, and displays the content on the display unit 2. Sound output device 1
Announce from zero. Specifically, it is composed of a microcomputer, a graphics processing processor, an image processing memory, etc., and displays a screen, searches a map, switches the scale, scrolls, displays the current position and direction of the vehicle, and displays a destination that is a landmark or a landmark. And display guidance to the destination.

Next, a procedure for performing destination guidance using the above-described apparatus will be described with reference to a series of flowcharts (FIGS. 3 and 4). This procedure is executed by interrupting the main program for detecting the position of the vehicle at predetermined time intervals. First, the current position of the vehicle, the traveling direction α of the vehicle detected in step (1), and the direction β from the current position of the vehicle to the destination are obtained. In step (2), it is determined whether the vehicle is traveling on a curve based on the angular acceleration detected by the direction sensor 3.

If the vehicle is traveling on a curve, the interruption is terminated without entering the destination guidance procedure. If the vehicle is not running on a curve, the process proceeds to step (3) to calculate a relative angle θ = β−α which is a difference between the traveling direction α of the vehicle and the direction β from the current position of the vehicle to the destination. Instead of the traveling direction α of the vehicle, if the direction of the road is known by a map matching method or the like, the link direction α ′ of the road may be used.
In step (4), a distance D from the current position of the vehicle to the destination is calculated. Then, in step (5), the traveling direction component L = Dcos θ of the distance D is calculated.

In step (6), it is determined whether or not the traveling direction component L is greater than a value Lo = f (v) determined by the current speed v of the vehicle. Here, as illustrated in FIG. 5, the function f (v) takes a large value when the vehicle speed v is large, and takes a small value when the vehicle speed v is small. This is based on the experience that when the vehicle is running at a high speed, it is necessary to give guidance early. According to FIG. 5, if the speed v of the vehicle is smaller than 20 km / h, the function f (v) becomes a constant value 3
0m is taken because the signal to turn right or left is made at least 30m before. If the vehicle speed v is greater than 60 km / h, the function f
(v) has a constant value of 100 m because if the guidance is given too near, the vehicle will bend at the intersection before the target intersection. Note that the function f (v) is not limited to the form shown in FIG. For example, a constant value may be taken in all vehicle speed v ranges.

If the traveling direction component L is larger than the value f (v), the process proceeds to step (7), and all guide counters are cleared to zero. Here, the guidance counter means an arrival guidance counter, a turn guidance counter, a right-turn guidance counter, and a left-turn guidance counter, each of which is incremented by one. When the added value exceeds a threshold value, guidance is displayed on the display 2. The sound is output or an announcement is made from the audio output device 10.

If the traveling direction component L is smaller than the value f (v), the process proceeds to step (8), and it is determined whether or not the distance D is equal to or less than a fixed value D1. The constant value D1 is a distance that can be regarded as the vehicle has reached the destination, and is set, for example, to a minimum distance of 10 m between parallel roads. When the distance is shorter than the distance D1, it is considered that there is no need to provide guidance for traveling, and even if detailed guidance is provided, it will not be very useful.

Even if the distance D is larger than the distance D1, if it is considered that the arrival guidance may be performed earlier if the relative angle θ is smaller, the condition of step (8) is changed as shown in FIG. May be substituted. That is, the relative angle θ
It is determined whether or not the absolute value is equal to or smaller than a threshold value θ1 (for example, 10 °) (step (81)).
It is determined whether or not the distance D is equal to or less than the distance D2 longer than the distance D1. If the determination is NO in step (81), it is determined in step (83) whether the distance D is equal to or less than D1. If the determination in step (82) or step (83) is YES, step (9)
If the determination is NO, the process proceeds to step (10).

In step (9), the arrival guidance counter is set to +
Do one. In step (10), the absolute value | θ |
Is greater than θ3 (eg, θ3 = 150 °). As shown in FIG. 7, when the vehicle travels for a while after passing the intersection to be turned to the destination, | θ | exceeds θ3. At this time, the process proceeds to step (11), and the turning guide counter is incremented by one. Instead of the determination in step (10), it may be determined whether or not L exceeds a negative constant value L3 (for example, L3 = -100 m).

In step (12), it is determined whether the relative angle θ is positive. If it is positive, the destination is viewed to the right, and the right turn guidance counter is incremented by 1 in step (13). If the relative angle θ is negative, it means that the destination is looking to the left, and in step (15), the left turn guidance counter is set to +
Do one. In step (16), it is determined whether or not the number exceeds a threshold value (for example, 5) with reference to each guidance counter. The reason for this determination is that if the guidance counter is incremented once, there is a malfunction and it is uncertain whether the conditions for issuing the guidance are satisfied. by.

In step (17), if there is a counter exceeding the threshold, the guidance content is displayed on the display unit 2 or an announcement is made from the voice output device 10 in step (18). You may use both together. As described above, the timing at which the guidance is issued is when the traveling direction component L of the distance D to the destination falls below the reference value L0.
The guidance will be provided at a distance L0 before the vehicle must perform some operation such as turning left or right. Therefore, the vehicle only has to prepare for a right turn or a left turn before the vehicle travels straight for the distance L0, so that no burden is imposed on the vehicle even if such guidance is given.

It should be noted that there is a case where the vehicle cannot travel in accordance with the guidance. For example, as shown in FIG. 8, there is no road to turn right at the destination. Even in this case, predetermined guidance is provided. Thereby, the driver can know that the destination exists on the right side where the vehicle is traveling as shown in FIG. Needless to say, the driver can determine by himself that traveling as instructed is not possible immediately, and even if such guidance is given, the driver will not be erroneously operated. On the contrary, since the driver can make a right turn decision at the next intersection as indicated by the arrow e by the guidance, the present invention can provide guidance that is very useful for the driver.

Next, returning to FIG. 4, it is determined whether the driver has operated the vehicle according to the guidance (step (19)). This judgment is made for turn guidance, right turn guidance or left turn guidance,
For example, whether or not the vehicle has traveled a curve and then changed to straight traveling is determined from the gyro output if the azimuth sensor 3 is a gyro, and is determined from a signal obtained by differentiating the output if the azimuth sensor 3 is a terrestrial magnetism sensor. In the case of arrival guidance, it is performed by detecting that the vehicle has stopped or the like from the output of the distance sensor 4.

When it is determined that the operation of the vehicle has been completed,
In step (20), all the guidance counters are cleared to 0, and the process returns to the beginning. An example in which the above procedure is applied to an actual road will be described. FIG. 9 shows a case where a destination is located on a narrow street. The vehicle receives right turn guidance from the destination guidance device when it comes to a point A before the intersection a while traveling on the main road. The driver passes the intersection a knowing that he cannot turn right during construction. In this regard, when the conventional route guidance device is used, when information during construction is not input, the intersection a is designated as a point to be turned right, so a driver who cannot make a right turn at the intersection a may be stuck. However, as in the present invention, the driver is only informed that the destination is on the right side and should turn right, so that the driver can deal with a margin. The driver knows that it is not possible to make a right turn during construction and will continue to receive right turn guidance even after passing intersection a, so he will turn right at the next intersection b. After the right turn at the intersection b, the guidance ends, and if the vehicle proceeds as it is, a right turn guidance is received at a point C before the intersection c.
Turn right at intersection c according to the guidance, the guidance ends,
The destination can be seen at the corner of the intersection d. Because the destination is near, the destination guidance device no longer provides any guidance. The driver brings the vehicle to the destination according to his own judgment.

As described above, the destination guidance according to the present invention, which provides guidance to reach a destination but does not give specific instructions on what to do at an intersection, and a driver's guidance in accordance with the actual conditions of road regulation. By properly combining the judgment with the above, it is possible to efficiently reach the destination. It should be noted that the present invention is not limited to the above-described embodiment.If the number of cases in which the driver does not follow the guidance exceeds the standard, an alarm is provided or the destination guidance function is automatically stopped. You may.

The navigation device may have the above-described route calculation function. If there is a route calculation function, the present invention may seem unnecessary. However, as described above, when the information that is the basis of the route calculation is changing every day, the route guidance and the simple route guidance according to the present invention are used. By using together, more reliable guidance can be provided. In addition, when the target of the route calculation is only the main road, the vehicle cannot be guided on the outermost street, so that the use of the present invention is particularly effective.

[0042]

As described above, according to the first aspect of the present invention, guidance is given a certain distance before a point to be turned to reach a destination without clearly indicating an intersection or a route. The rest can be left to the driver's judgment. Therefore, the amount of data to be stored is greatly reduced, and only simple processing is required, so that the apparatus can be simplified. By setting the reference value L0 appropriately, guidance can be provided at the most appropriate timing.

According to the second aspect of the present invention, the guide can be issued at a time slightly earlier than the time when the vehicle reaches the point to be guided according to the vehicle speed. The preparation time for operating the vehicle can be guaranteed from. According to the third aspect of the present invention, when the vehicle has passed a point to be guided considerably, it is possible to notify the driver of the fact that the vehicle should turn right or left or turn.

According to the fourth aspect of the present invention, the guidance is stopped when the vehicle completes a right or left turn, so that the driver does not make an erroneous determination after the right or left turn is completed. Claim 5
According to the configuration described above, when the distance D to the destination becomes the distance D1 at which the vehicle can be regarded as having arrived at the destination, unnecessary destination guidance need not be issued.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a vehicle and a destination for explaining the contents of the present invention.

FIG. 2 is a block diagram of a vehicle navigation device in which a destination guidance device is incorporated.

FIG. 3 is a flowchart illustrating a procedure of a destination guidance device.

FIG. 4 is a flowchart illustrating a procedure of a destination guidance device.

FIG. 5 is a graph showing a reference value L0 as a function f (v) of a vehicle speed.

FIG. 6 is a partially modified view of a flowchart showing a procedure of the destination guidance device.

FIG. 7 is a diagram illustrating a relationship between a vehicle and a destination when the vehicle passes an intersection.

FIG. 8 is a diagram illustrating a relationship between a vehicle and a destination when there is no intersection.

FIG. 9 is a diagram showing a vehicle traveling route when a destination is located on a narrow street.

[Explanation of symbols]

 2 Display 3 Orientation Sensor 4 Distance Sensor 5 Road Map Memory 8 Position Detector 9 Navigation Controller 10 Voice Output Device

────────────────────────────────────────────────── (5) References JP-A-2-198316 (JP, A) JP-A-60-107718 (JP, U) JP-A-4-43217 (JP, U) (58) Investigation Field (Int.Cl. ⁶ , DB name) G01C 21/00 G08G 1/0969

Claims (5)

(57) [Claims] 1. A position detecting means for detecting a current position of a vehicle using a distance sensor and an azimuth sensor, a destination setting means for setting a traveling destination, and a destination setting means for setting from a current position of the vehicle. The distance D to the destination, the relative angle θ that is the difference between the heading of the vehicle and the heading from the current position of the vehicle to the destination, and the projection L = Dcos θ of the distance D to the destination Calculation means for calculating, and the projection L in the traveling direction of the distance D calculated by the calculation means is a reference value L
When the value is less than 0, a destination guidance means for determining the sign of the relative angle θ and guiding the driver that the destination is on the right side or the left side in the vehicle traveling direction is included. Destination guidance device. 2. The destination guidance apparatus according to claim 1, wherein the reference value L0 is determined according to a current speed of the vehicle. 3. When the driver detects that the absolute value of the relative angle .theta. Has exceeded a certain angle .theta.3 greater than 90.degree., Or that the forward projection L has become less than a negative constant value L3, the driver is notified. 2. The destination guidance device according to claim 1, further comprising a notification unit that notifies that the destination is behind. 4. A detection means for detecting that the vehicle has completed a right turn, a left turn or a turn, and a predetermined guidance to the driver by the destination guidance means or the notification means, and thereafter, the vehicle is turned right or left by the detection means. 4. The destination guidance apparatus according to claim 1, 2, or 3, further comprising a guidance stopping means for stopping guidance to a driver when it is detected that the vehicle has completed turning. . 5. When the distance D from the current position of the vehicle to the destination set by the destination setting means is smaller than a reference value D1 which can be regarded as the arrival of the vehicle at the destination, the destination guidance means or the notification means. 3. The destination guidance device used for vehicle navigation according to claim 1, further comprising a guidance function stopping means for stopping a function of the means.