JPH10197272A - Car navigation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a car navigation system in which fuel consumption up to a goal can be known with high accuracy and a decision can be made whether a car can arrive at the goal without replenishing fuel. SOLUTION: Altitude data of a node constituting a road is stored in a CD- ROM along with the longitude and latitude data thereof and a guide course up to a goal is searched thus preparing a three-dimensional guide course data. A fuel consumption coefficient (ratio of fuel consumption with regard to average conditions) is then set depending on the type of road, i.e., urban road, rural road or highway, and the fuel consumption coefficient is corrected depending on flat road, uphill or downhill. On the other hand, the quantity of fuel required for arriving at a goal is calculated based on the fuel consumption rate, the fuel consumption coefficient for each section and the traveling distance between sections. Furthermore, the fuel consumption coefficient or the fuel consumption rate is corrected as the car moves thus calculating the required quantity of fuel more accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle navigation device having a function of detecting whether or not a vehicle can reach a destination with fuel loaded thereon, and more particularly to an electric vehicle having a limited fuel supply location. The present invention relates to a suitable in-vehicle navigation device.

[0002]

2. Description of the Related Art An on-vehicle navigation device is a map data storage device such as a CD-ROM or an IC card in which map data is recorded, a monitor such as a liquid crystal display, a gyro, a GPS (Global Positioning System) and a vehicle speed sensor. It has a vehicle movement detecting device for detecting the current position and current direction of the vehicle, reads map data including the current position of the vehicle from the map data storage device, and monitors a map image around the vehicle position based on the map data. In addition to drawing on the map, the vehicle position mark (location) is displayed superimposed on the map image, and the map image is scrolled according to the movement of the vehicle, or the vehicle position mark is moved while the map image is fixed on the screen. Then, it is possible to see at a glance where the vehicle is currently traveling.

[0003] In addition, usually, a car navigation system is equipped with a route guidance function that allows a user to easily travel to a desired destination without making a mistake on a road. According to this route guidance function, the lowest cost route from the starting point to the destination using the map data is automatically searched by performing a simulation calculation such as the horizontal search method or the Dijkstra method, and the searched route is guided. The route is stored as a route, and during driving, the guidance route is drawn on the map image in a different color from the other roads and displayed thicker, or displayed on the screen, or a certain distance to the intersection where the vehicle should change the route on the guidance route When the vehicle approaches, the user is guided to the destination by displaying an arrow indicating the course at an intersection where the course on the map image should be changed.

The cost is a value obtained by multiplying a constant according to a road width, a road type (such as a general road or an expressway), a right turn, a left turn, and the like based on the distance, a predicted traveling time of the vehicle, and the like. , The degree of appropriateness as a guidance route is quantified. Even if there are two routes having the same distance, the cost differs depending on whether the user specifies, for example, whether to use a toll road, or gives priority to distance or time.

A map stored in a map data storage device such as a CD-ROM has a longitude width of an appropriate size according to a scale level such as 1/12500, 1/25000, 1/50000, and 1/100000. Roads and the like are stored as a coordinate set of vertices (nodes) represented by longitude and latitude. A road is formed by connecting two or more nodes, and a portion connecting the two nodes is called a link. The map data includes (1) a road layer including a road list, a node table, an intersection configuration node list, and the like; (2) a background layer for displaying roads, buildings, facilities, parks, rivers, and the like on a map screen; (3) It is composed of character / symbol layers for displaying characters such as names of administrative divisions such as municipalities, road names, intersection names, building names, etc., map symbols, and the like.

[0006]

In the conventional on-vehicle navigation device, since it is not known how much fuel is consumed before arriving at the destination, the driver takes the fuel to the destination while considering the distance to the destination. It is necessary to determine whether or not it is sufficient. In particular, in recent years, electric vehicles, which are required to be put to practical use because they are non-polluting, are limited in places where they can be charged (hereinafter referred to as charging stations). It is necessary to determine whether to stop at the charging station even if you make a detour.

Normally, not only gasoline vehicles but also electric vehicles are provided with a fuel gauge (battery remaining capacity meter), and the fuel gauge allows the driver to know the approximate mileage. However, the fuel consumption of a vehicle varies greatly when traveling on flat roads and on sloped roads, and fuel consumption also increases when traveling on urban roads and highways. Consumption changes drastically. Therefore, it is difficult for the user to accurately determine whether or not the user can reach the destination without refueling only by knowing the remaining fuel amount with the fuel gauge.

From the above, it is an object of the present invention to provide an on-vehicle navigation device capable of knowing the fuel consumption amount to a destination with high accuracy and knowing whether it is possible to reach the destination without refueling. It is to provide.

[0009]

SUMMARY OF THE INVENTION The above object is achieved by searching for a guidance route from a departure place to a destination, and classifying roads by type in an in-vehicle navigation device for guiding a vehicle along the guidance route. Data storage means for storing the longitude, latitude and altitude data of the nodes constituting each road, and the fuel required for reaching the destination using the data stored in the data storage means. The problem is solved by an in-vehicle navigation device having a fuel consumption calculating means for calculating the amount.

[0010] The above-described problem is also solved by a vehicle-mounted navigation device that searches for a guidance route from a departure place to a destination and guides a vehicle along the guidance route, stores and classifies roads by type. Data storage means for storing the longitude and latitude of the nodes constituting each road and the fuel consumption coefficient between adjacent nodes; and a fuel required to reach the destination using the data stored in the data storage means. And a fuel consumption calculating means for calculating the amount of fuel consumption.

The operation of the present invention will be described below. In the in-vehicle navigation device of the present invention, the data of the longitude, latitude and altitude of the node are stored in the data storage means. The fuel consumption calculation means examines the road type (e.g., urban road, suburban road, expressway, etc.) of each section of the guidance route from this data, and detects a height difference or a road gradient for each section. Then, the fuel consumption for each section is determined using these results. As a result, the amount of fuel consumed until reaching the destination can be obtained with high accuracy.

Further, a fuel remaining amount detecting means for detecting the remaining fuel amount is provided, the actual fuel consumption amount is detected with the movement of the vehicle by using the fuel remaining amount detecting means, and the fuel consumption amount obtained by calculation is calculated. Is corrected, the fuel consumption until the vehicle arrives at the destination can be obtained with higher accuracy.
The ratio of the fuel consumption to the standard driving condition may be set for each node as the fuel consumption coefficient, and may be stored in the data storage means in advance.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a vehicle-mounted navigation device according to an embodiment of the present invention. Reference numeral 1 denotes a navigation device main body constituted by a microcomputer. The navigation device main body 1 is provided with a memory 1a for storing a guidance route, a fuel consumption coefficient and a fuel consumption rate which will be described later. Reference numeral 2 denotes a liquid crystal monitor, and the navigation device body 1 displays a map near the current position of the vehicle on the liquid crystal monitor 2, displays a guidance route from a departure point to a destination, a vehicle position mark, and other guidance information. I do.

Reference numeral 3 denotes a CD-ROM (or DVD: Digital Versatile Diode) storing map data composed of road layers, background layers, character / symbol layers, and the like for each scale.
sk). Reference numeral 4 denotes a GPS receiver for detecting the current position, vehicle direction, vehicle speed, etc. of the vehicle by satellite navigation, 7 a gyro for detecting the rotation angle of the vehicle, and 8 a vehicle speed pulse generated as the vehicle moves. It is a vehicle speed pulse detector. Reference numeral 9 denotes a key operation unit provided with various operation keys for operating the navigation device.

Reference numeral 5 denotes a remaining fuel amount detecting unit for detecting the remaining fuel amount. In the case of a gasoline-powered vehicle, the fuel remaining amount detection unit 5 is connected to, for example, a fuel gauge provided in a driver's seat or a sensor provided in a fuel tank. Detect the amount. Further, the fuel remaining amount detecting unit 5 detects the fuel remaining amount by attaching a flow meter in the middle of the fuel pipe and subtracting the amount of fuel actually consumed from the amount of fuel when the tank is full. Alternatively, these methods may be used in combination to detect the remaining fuel amount more accurately.

In the case of an electric vehicle, the fuel remaining amount detecting unit 5 may be a unit that measures a battery voltage and converts it to a remaining battery capacity. Alternatively, a current sensor may be provided, and the remaining capacity may be detected by monitoring the balance between the amount of current (ampere hours) when charging the battery and the amount of current when discharging the battery. Further, a specific gravity meter for measuring the specific gravity of the electrolytic solution may be attached to the battery, and the specific gravity of the electrolytic solution may be converted into the remaining capacity of the battery.The battery voltage, the temperature, and the vehicle speed may be measured.
The remaining capacity may be calculated by a microcomputer.

The road layer in the map data stored in the CD-ROM 3 has the configuration shown in FIG. The road list RDLT includes, for each road, data such as the type of the road, the total number of nodes forming the road, the positions of the nodes forming the road on the node table NDTB, and the road width to the next node. I have. The intersection configuration node list CRLT is, for each intersection on the map, a set of positions on the node table NDTB of the other end of the link (referred to as an intersection configuration node) connected to the intersection.

The node table NDTB is a list of all nodes on the map, and stores longitude, latitude, and altitude as coordinates of each node. If the node is an intersection (if the intersection identification flag is "1")
A pointer (Pn) or the like indicating the position (Qi) on the intersection configuration node list CRLT and indicating the position of the road to which the node belongs on the road list if it is not an intersection (if the intersection identification flag is “0”). Have.

FIG. 3 is a flowchart showing the operation of the navigation device according to the present embodiment. First, in step S1, the user sets a destination in the navigation device. Then, the navigation device proceeds to step S2, and performs a horizontal search method or the like as in the related art.
Using the road data recorded on the CD-ROM 3,
Search for a guidance route from the current position of the vehicle to the destination.
Then, three-dimensional guidance route data as shown in FIG. 4 is created. Further, the navigation device sets the fuel consumption coefficient of each section constituting the guidance route using the road data in the CD-ROM 3.

That is, the navigation device reads the altitude difference between the starting point and the ending point of each link constituting the guidance route from the node table NDTB, and if the gradient is within a certain range, sets it as a flat road. If it exceeds, it shall be an up slope or a down slope. Then, for example, as shown in Table 1 below, the fuel consumption coefficient is set according to the type of road and whether it is a flat road, an uphill slope, or a downhill slope. The fuel consumption coefficient indicates the ratio of the fuel consumption to the average running condition, assuming that the average running condition is 1. The navigation device may determine whether the road is an urban road or a suburban road based on the number of traffic signals existing per unit area.

[0021]

[Table 1]

The navigation device has a memory 1a.
Read fuel consumption rate from. The fuel consumption rate is a traveling distance per unit fuel under an average traveling condition.
Input the fuel efficiency when driving in the 0 mode or the 15 mode. This fuel consumption rate is corrected as the vehicle travels, as described later. Here, it is assumed that the fuel consumption rate is set to 10 (km / liter) in advance.

Next, the navigation device performs step S
Proceed to 3 to check whether the vehicle has arrived at the destination. If the vehicle has arrived at the destination, the process ends. If the vehicle has not arrived, the process proceeds to step S4. Step S4
Then, the fuel consumption for each section is calculated from the distance to the destination, the fuel consumption coefficient, and the fuel consumption rate, and the amount of fuel required to reach the destination is calculated. For example, in the example shown in FIG. 4, the fuel required from the point of departure to the point of destination is 14 liters as shown in the following equation (1). {(1.3 x 10) + (1.0 x 10) + (1.2 x 20) + (0.8 x 10) + (1.0 x 5) + (1.2 x 50) + (1.0 x 20)} / 10 = 14 (liter) ... (1) Next, in step S5, the navigation device
The remaining fuel of the vehicle is read from the remaining fuel detector 5. Then, the process proceeds to step S6 to check whether the remaining fuel amount has changed. If the remaining fuel amount has changed in step S6, that is, if the vehicle is running, the process proceeds to step S7. If the remaining fuel amount has not changed, that is, if the vehicle is stopped, the process proceeds to step S9. .

In step S7, it is checked whether or not the actual fuel consumption detected by the remaining fuel amount detector 5 matches the fuel consumption calculated in step S4. If they do not match, the fuel consumption rate or the fuel consumption coefficient is changed based on the distance actually traveled and the amount of fuel actually consumed, and then the process returns to step S3. Step S7
If the actual fuel consumption is equal to the calculated fuel consumption, the process proceeds to step S9.

In step S9, the remaining fuel amount read in step S5 and the amount of fuel required to arrive at the destination calculated in step S4 are displayed on the monitor 2. At this time, an alarm may be issued when the remaining fuel amount is smaller than the amount required before reaching the destination. Thereafter, the process returns to step S3, and the above processing is continued until the vehicle reaches the destination.

As described above, in the present embodiment, the amount of fuel required to reach the destination is calculated and notified to the user based on the remaining fuel amount, the distance to the destination, and the state of the road. Since the fuel consumption rate or fuel consumption coefficient is corrected by checking the amount of fuel actually consumed during traveling, it is possible to detect with high accuracy whether the fuel loaded on the vehicle can reach the destination. it can.

In the above-described embodiment, a case has been described in which the map data stores altitude data in addition to the longitude and latitude as the coordinates of the node. However, instead of this, each road list RDLT is stored in each road list RDLT. The fuel consumption coefficient between the nodes may be stored in advance, and the fuel consumption for each section may be obtained using this information. That is, as shown in FIG. 5, the fuel consumption coefficient of each node is recorded in the road list RDLT. After searching for the guidance route, the navigation device sums up the product of the distance between each node constituting the guidance route and the fuel consumption coefficient and divides the result by the fuel consumption rate to obtain the necessary information before reaching the destination. Calculate the fuel quantity Then, by correcting the fuel consumption rate in accordance with the traveling of the vehicle, the amount of fuel required until reaching the destination is calculated more accurately. In this case, the same effect as in the above embodiment can be obtained.

[0028]

As described above, according to the on-vehicle navigation device of the present invention, the data storage means stores the data of the longitude, latitude and altitude of the node, and the fuel consuming means derives from the data. In addition to examining the road type (e.g., urban road, suburban road, expressway, etc.) of each section of the route, detecting the height difference or road gradient for each section,
Since the fuel consumption until reaching the destination is calculated using these results, the amount of fuel required until reaching the destination can be determined with high accuracy.

Further, a fuel remaining amount detecting means for detecting the remaining fuel amount is provided, and the amount of fuel consumed by the actual movement of the vehicle is detected by using the remaining amount detecting means, and the fuel consumption amount obtained by calculation is calculated. By correcting the amount, the amount of fuel consumed until reaching the destination can be obtained with higher accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a vehicle-mounted navigation device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of a road layer.

FIG. 3 is a block diagram illustrating an operation of the vehicle-mounted navigation device according to the embodiment of the present invention.

FIG. 4 is a schematic diagram showing three-dimensional guidance route data.

FIG. 5 is a schematic diagram showing another example of a road layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Navigation apparatus main body 1a Memory 2 Monitor 3 CD-ROM 4 GPS 5 Fuel remaining amount detection part 7 Gyro 8 Vehicle speed pulse detection part 9 Key operation part

Claims (4)

[Claims] An in-vehicle navigation device for searching for a guidance route from a departure point to a destination and guiding a vehicle along the guidance route stores and classifies roads by type and configures each road. Data storage means for storing data of the longitude, latitude and altitude of the node; and fuel consumption calculation means for calculating an amount of fuel required to reach the destination using the data stored in the data storage means And an on-vehicle navigation device. 2. An on-vehicle navigation device that searches for a guidance route from a departure point to a destination and guides a vehicle along the guidance route, classifies and stores roads by type and configures each road. A data storage unit that stores data of longitude, latitude and altitude of the node; a vehicle position detection unit that detects a position of the vehicle; a remaining fuel amount detection unit that detects a remaining fuel amount of the vehicle; The moving distance of the vehicle is detected based on the position detection result, the fuel consumption is detected based on the fuel remaining amount detection result by the fuel remaining amount detecting means, and these detection results are stored in the data storage means. And a fuel consumption calculating means for calculating an amount of fuel required to reach the destination using the obtained data. 3. An in-vehicle navigation device that searches for a guidance route from a departure point to a destination and guides a vehicle along the guidance route, classifies and stores roads by type and configures each road. A data storage unit storing the longitude and latitude of the node and a fuel consumption coefficient between adjacent nodes; and calculating an amount of fuel required to reach the destination using the data stored in the data storage unit. An on-vehicle navigation device comprising: a fuel consumption calculating unit. 4. An on-vehicle navigation device for searching for a guidance route from a departure place to a destination and guiding a vehicle along the guidance route stores and classifies the roads by type and stores each road. Data storage means for storing the longitude and latitude of the node and the fuel consumption coefficient between adjacent nodes; vehicle position detection means for detecting the position of the vehicle; remaining fuel detection means for detecting the remaining fuel of the vehicle; The travel distance of the vehicle is detected based on the position detection result by the vehicle position detection means, and the fuel consumption is detected based on the fuel remaining amount detection result by the fuel remaining amount detection means. A fuel consumption calculating means for calculating an amount of fuel required to reach the destination using the data stored in the storage means; Apparatus.