JPH04204110A - Vehicle-borne navigation apparatus - Google Patents

Abstract

PURPOSE:To improve responsiveness of an apparatus by providing a load time determining means which makes an external auxiliary storage means start loading of map data on an internal storage means when it is detected that a vehicle goes across a load boundary. CONSTITUTION:In a position estimating device 3, the current position of a vehicle is estimated with reference to the previous position of the vehicle, a running distance obtained by a sensor unit 1, the amount of change in azimuth and map data stored in an internal storage device 7. Next, it is determined by a load time determining device 4 whether or not the vehicle goes across a load boundary which is formed outside the boundary of a unit section of the map data wherein it is present, and when it goes beyond the load boundary, the load boundary is shifted to around a section becoming the center afresh, by a load boundary shifting device 5. Subsequently, the section loaded on the device 7 is referred to in a load section decision device 6 and the map data on the section to be loaded afresh are loaded on the device 7 from an external auxiliary storage device 2. Then, the current position of the vehicle is displayed 9 on a display control device 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a map data loading device in an on-vehicle navigation device that displays the location of a vehicle and map information of its surroundings.

(Prior Art) In conventional in-vehicle navigation devices, map data of a slightly wider range than the map data required for displaying a map around the vehicle's current location can be accessed at high speed in advance from an external auxiliary storage means such as an optical disk. (By this, even if the position of the vehicle moves slightly,
It was configured so that map display changes could be made quickly without having to reload map data.

That is, as shown in the block diagram of FIG. 5, there is a sensor unit 1 that measures the traveling distance and direction of the vehicle, and an external auxiliary storage device 2 such as an optical disk that stores map data divided into rectangular unit sections. , a display device 9 that is controlled by a display control device 8 and displays a map and the current position of the vehicle, and a unit section a in which the vehicle currently exists and its section a, as shown in FIGS. 3 and 4 a. An internal storage device 7 that can be accessed at high speed stores map data for unit sections b-i on eight adjacent sides around A position estimation device 3 estimates the current position of the vehicle by referring to the stored map data, and a position estimation device 3 detects whether the vehicle has crossed the boundary of the unit section a of the map data and detects a new unit where the vehicle exists. It is equipped with a load determining device 4 that determines the start of the loading operation of the map data of the section and the eight surrounding sections from the external auxiliary storage device 2 to the internal storage device 7.

(Problem to be Solved by the Invention) In such a conventional in-vehicle navigation device, map data is loaded the moment the vehicle crosses the boundary of the unit section a, so the loading process as shown in FIG. 4a is performed. When the vehicle moves across a plurality of unit sections as shown by the trajectory 21, the vehicle crosses the section boundaries P2, P2, P5, P,
As shown in FIG. 4, loading processing is performed frequently every time the number exceeds . In particular, when a vehicle travels near the boundary of a unit area, crossing the boundary occurs frequently, which increases the load process of map data to the internal storage device 7, and as a result, other processes are interrupted. There was a problem in that the execution speed decreased and the responsiveness of the entire device deteriorated.

The present invention was devised to solve these problems, and aims to improve the responsiveness of the device by reducing the number of times or frequency of loading map data into the internal storage device. .

(Means for Solving the Problems) A sensor and a unit that detect vehicle position information, an external auxiliary storage means that divides and stores map data of a plurality of sections, and a section that includes the current position of the vehicle and the section of the section. Perimeter 8
The map data of the section of the plane is loaded in advance (an internal storage means, a means for determining the map data to be loaded into the internal storage means, a display means for displaying the map and the position of the vehicle, and a display means for displaying the map and the position of the vehicle. a display control means for controlling a display control device; and means for forming a load boundary outside a boundary of a central section among the sections loaded in the internal storage means; The present invention is configured to include a load timing determining means for starting loading of map data when it is detected that the map data has exceeded the limit.

(Operation) According to the present invention, by providing a hysteresis characteristic to the boundary for determining that it is time to load map data from the external auxiliary storage device to the internal storage device, the vehicle runs near the boundary of the unit section. Even in this case, the frequency of operations to load map data can be reduced.

(Embodiment) As shown in the block diagram of FIG. 1, the in-vehicle navigation device of the present invention includes a sensor unit 1 that measures the traveling distance and direction of the vehicle, and a sensor unit 1 that divides map data into rectangular unit sections. It includes an external auxiliary storage device 2 such as a stored optical disk, and a display device 9 that is controlled by a display control device 8 and displays a map and the current position of the vehicle.

Furthermore, an internal storage device 7 that can be accessed at high speed stores map data of the unit section a where the vehicle currently exists and the unit sections b-i of eight surrounding areas adjacent to that section, and the mileage and distance obtained by the sensor unit 1. A position estimation device 3 that estimates the current position of the vehicle by referring to the amount of change in direction and map data stored in the internal storage device 7, and a boundary between the main map data section a as shown in FIG. A load timing determination device 4 detects whether the vehicle has crossed a road boundary 18 formed on the outside of the vehicle 20 and determines when map data should be loaded; When the vehicle is received, a new vehicle exists, and the new center zone and eight surrounding zones, that is, the boundary 17 of the zone that must be loaded, are determined, and the zone that should be loaded is determined. Among them, a load section determination device 6 that determines a unit section that has not been loaded into the internal storage device 7 and loads the map data of the unloaded unit section from the external auxiliary storage device 2 to the internal storage device 7; A load boundary changing device 5 is provided for setting a load boundary 18 around a section that has newly become the center as a result of reloading.

As the load boundary 18 of this map data, as shown in FIG. 3, a boundary 18 is set by adding left and right E8 in the horizontal direction and up and down E in the vertical direction from the boundary 20 of the unit area a where the vehicle currently exists. . Then, as a result of the update, the load boundary 18 is changed and set in the unit section of the map data that has become the new center, thereby imparting hysteresis characteristics to the load boundary.

Next, the operation will be explained with reference to the flowchart shown in FIG.

(Step 1) The position estimating device 3 estimates the current position of the vehicle by referring to the previous vehicle position, the distance traveled and the amount of change in direction obtained by the sensor unit 1, and the map data stored in the internal storage device 7. do.

(Step 2) The load timing determination device 4 determines whether the vehicle has crossed the road boundary 18 formed outside the boundary 20 of the unit section a of the map data where the vehicle is present.

(Step 7) If the vehicle does not cross the road boundary 18 of section a of the map data, the display control device 8 displays on the display device 9 a screen display area 19 containing a map around the current location of the vehicle. and return to step 1.

(Step 3) When the vehicle crosses the road boundary 18 of section a of the map data, the road boundary changing device 5
Change the load boundary around the newly centered parcel.

(Step 4) The load partition determination device 6
Specifies the partitions to be loaded into. The section specified here is
As shown in FIG. 3, this is a section within a boundary 17 consisting of a section a in which a vehicle exists and sections b to i surrounding eight sides thereof.

(Step 5) The load partition determination device 6 refers to the partitions currently loaded in the internal storage device 7 and determines the partition that needs to be newly loaded.

(Step 6) Load the map data of the section that needs to be loaded from the external auxiliary storage device 2 to the internal storage device.

(Step 7) The display control device M8 causes the display device 9 to display the current position of the vehicle within the screen display area 19 and a map of its surroundings, and the process returns to Step 1.

When such a series of loading processes is performed, the vehicle reaches P as shown in FIGS. 4a and 4c. Even if the vehicle moves from boundary P to P7, because the boundary is set as the road boundary 18, which is slightly wider than the boundary 20 of the unit area, the vehicle moves to boundary P,
, P2, P3, and P6, the map data is not loaded, and as shown in FIG. 4C, the map data is loaded only after moving to the boundary P. and,
Since the load boundary 18 is changed by the load boundary changing device 5, even if P6, P6, and P7 are reached thereafter, the map data is not loaded because the movement is inside the new load boundary 22.

(Effects of the Invention) As is clear from the description of the above embodiments, the present invention has the following advantages:
Even when the vehicle travels near the boundary of a unit area, the frequency of loading map data to the internal storage device 7 does not increase, so no matter which area on the map data the vehicle travels, the system as a whole remains stable. Responsiveness can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of an in-vehicle navigation device according to the present invention, FIG. 2 is a flowchart used to explain the operation of the device shown in FIG. 1, and FIG. FIG. 4 is an explanatory diagram used to explain the loading operation of the device shown in FIG. 1, and FIG. , is a block diagram showing an example of a conventional in-vehicle navigation device. 1...Sensor unit 2...External auxiliary storage device 3...Position estimation device 4...Load timing determination device 5...Load boundary change device 6...Load section determination device 7...Inside Storage device 8...Display 1 control device 9...Display device 17...Boundary 18 of the unit section to be loaded into the internal storage device...Load boundary 20 of map data...Map data where the vehicle exists Boundary 21 of the unit section...Traveling trajectory 22...3rd point before the loading boundary of the map data after the change

Claims (1)

[Claims] (1) A sensor unit that detects vehicle position information, an external auxiliary storage means that stores map data of a plurality of sections,
internal storage means for preloading map data of a section including the current location of the vehicle and sections surrounding the section; means for determining map data to be loaded into the internal storage means; In an in-vehicle navigation device comprising a display means for displaying a display and a display control means for controlling the display means, a loading boundary is set outside a boundary of a central section among the sections loaded in the internal storage means. and load timing determining means for starting loading of map data from the external storage means to the internal storage means when it is detected that the vehicle has crossed the road boundary. In-vehicle navigation device.