JP2734195B2 - Car navigation system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle navigation device that displays the position and orientation of a vehicle, map information around the vehicle, and the like.

2. Description of the Related Art Conventionally, in this type of on-vehicle navigation device, a straight traveling portion is detected from traveling data of a vehicle, and a road having a small azimuth difference with respect to the straight traveling is searched from an estimated area of the vehicle. When there is only one road, the road is determined as the traveling route of the vehicle, the vehicle position is corrected on the road, and the vehicle direction is corrected so that the detected straight traveling direction becomes the road direction.

However, in the above-described conventional on-vehicle navigation device, when the vehicle travels in an area with many roads such as an urban area, a plurality of roads may be included in the vehicle existence estimation area. Therefore, since the road is not unique, position correction and azimuth correction cannot be performed, and position errors in the traveling direction of the vehicle accumulate. For this reason, the existence estimation area becomes large, and as a result, there is a problem in that the vehicle may lose track of the current position and the current azimuth and become stray.

In addition, since the road data is not always accurate, when the road becomes unique, the position and azimuth of the wrong road were corrected, and it was not possible to return to the correct road later. There was a problem that the direction could be lost.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide an excellent in-vehicle navigation device capable of accurately calculating a current position and a current direction of a vehicle.

Means for Solving the Problems In order to achieve the above object, the present invention searches a virtual trajectory obtained by combining a plurality of straight trajectories connecting straight running detected from running data of a vehicle with a plurality of vectors and a vehicle existence estimation area when the straight running is detected. A virtual route is created by combining a plurality of straight roads connecting the roads, and a virtual locus and a virtual route are respectively extended to obtain a turning point, and an azimuth offset is calculated from the linear portion of the virtual locus and the virtual route. And the position offset is calculated from the turning point of the virtual route and is removed. The azimuth inconsistency and the position inconsistency are calculated from the azimuth difference and the position difference remaining even after the offset, and the azimuth inconsistency and the position are calculated. When the degree of inconsistency is equal to or less than the predetermined threshold, the rotational movement of the angle of the azimuth offset and the parallel movement of the distance of the position offset, This is performed for the current position and current direction.

Effects Therefore, according to the present invention, a virtual trajectory based on a combination of a plurality of vectors of a straight trajectory connected to straight ahead and a virtual path based on a combination of a plurality of vectors of a straight road connecting roads are created, and an azimuth offset and a position offset are created. By obtaining the true azimuth difference (azimuth mismatch degree) and the true position difference (position mismatch degree) after the elimination, the trajectory and the route pattern over a long distance can be compared. Even when a plurality of roads are included in the presence estimation area while traveling in an area with many vehicles, the probability that an accurate traveling route can be determined increases, and the possibility of losing the current position and current direction of the vehicle can be reduced.

In addition, since the rotational movement and the parallel movement for the offset are performed based on the comparison result of not only one piece of road data but also a plurality of vector patterns, even if the road data is locally incorrect, it is hardly affected by the vehicle. , The possibility of losing the current position and current direction of the camera can be reduced.

Embodiment FIG. 1 shows the configuration of an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes straight ahead detecting means for detecting straight running from running data of a vehicle, 2 denotes road searching means for searching for a road having a small azimuth difference with respect to straight running from a vehicle existence estimation area when straight running is detected, 3 A straight-line trajectory creating means for creating a long straight-line trajectory by connecting straight lines, a straight-line road creating means for creating a long straight-line road by connecting roads, and a virtual-line creating means for creating a virtual trajectory by combining a plurality of vectors of the straight trajectory. Trajectory creating means, 6 is a virtual route creating means for creating a virtual route by combining a plurality of vectors of a straight road, 7 is an intersection for calculating a turning point by extending a straight road constituting a virtual locus and a straight road constituting a virtual route. Calculating means, 8 is an azimuth offset calculating means for calculating the azimuth deviation from the virtual trajectory and the linear portion of the virtual route, and 9 is azimuth off for calculating coordinates excluding the azimuth offset. A position offset calculating unit that calculates a position shift from a virtual trajectory and a turning point of a virtual path; a position offset removing unit that calculates coordinates excluding a position offset; Azimuth inconsistency degree calculating means for calculating the remaining misorientation, 13 is a position inconsistency degree calculating means for calculating the remaining position difference even after excluding the position offset, and 14 is an azimuth inconsistency degree and a position inconsistency degree respectively determined. This is a position / azimuth correction unit that performs a rotational movement by an angle corresponding to the azimuth offset and a parallel movement by a distance corresponding to the position offset when the difference is equal to or smaller than the threshold value.

Next, the operation of the above embodiment will be described with reference to FIGS. 2 and 3, a road map shown in FIG. 3, and a graph for determining a traveling route shown in FIG. In FIG. 2, it is assumed that the vehicle first advances from point A to point C, and that the error of the current position and the azimuth at the point A has been corrected. Only one road is included in the estimation area B. In this case, the vehicle position is corrected on the road, and the vehicle direction is corrected to the road direction, as in the related art. Then, as the vehicle travels on the road, errors in the traveling direction accumulate, so that the presence estimation area becomes longer in the traveling direction.

When the vehicle turns right and reaches the point C, the direction of the existence estimation area detected last time does not change, so that the existence estimation area that has long been extended in the traveling direction is now substantially orthogonal to the traveling direction. , And at this point C, the existence estimation area D includes a plurality of roads. From this point on, a straight running is detected by the straight running detecting means 1 and a road having a small azimuth difference is searched for by the road searching means 2 to obtain the straight running locus T1 and the straight road R1.
The information for creating 1, R12 is accumulated, and this is continued until the point E where the straight line ends.

At the point E, the existence estimation area becomes large as D1. Therefore, based on the accumulated information, the straight traveling trajectory creating means 3 creates the straight trajectory 1 connecting the straight ahead, and the straight road creating means 4 connects the straight line connecting the roads. Create roads R11 and R12. Then, until the vehicle reaches the point G from the point F which has detected the straight ahead again after passing the turn, the straight path T2 and the straight road R21, similar to the section CE, are distinguished from the previously detected points CE. The information for creating R22 is accumulated, and this is continued up to point G, which is immediately before the next turn. At this G point, based on the information accumulated in the FG section,
Create T2 and straight roads R21 and R22. Further, the information for creating the straight path T3 and the straight roads R31 and R32 is accumulated from the point H at which the vehicle has passed the corner and the straight ahead is detected again to the point I.

Thus, when the vehicle is at point F, point G, point H and I
When proceeding to the points, the existence estimation areas D2, D3, D4, D5 of each point,
Since the process gradually increases, at the point I where three or more straight trajectories are created, the virtual trajectory creation means 5 creates a virtual trajectory by combining a plurality of vectors of the accumulated straight trajectories T1, T2, and T3. The trajectory is created, and the accumulated straight roads R11, R12, R21, R2 are created by the virtual route creation means 6.
A virtual route is created by combining a plurality of vectors of 2, R31, and R32. Then, the virtual trajectory and the virtual route are each extended by a straight line portion, an intersection is obtained through the intersection calculation means 7, and the intersection is calculated by the provisional intersections U1, U2 in the virtual trajectory and the provisional intersections V11, V12, V21, V22, V13, V23, V31, and V32.

Then, the azimuth offset calculating means 8 calculates the azimuth difference θ _Rij −θ _Ti between the straight trajectory constituting the virtual trajectory and the straight road constituting the virtual route, and calculates the average value θ of the azimuth difference over the entire route.
_Offi is calculated by the following equation (1), and this is offset in the direction of the virtual route.

Then, the azimuth offset removing means 9 performs the rotational movement of the azimuth offset for each virtual path by the following equation (2), removes the azimuth offset, and converts the coordinates of the intersection on the virtual path.

Here, X _'Rij, Y' _Rij denotes the corrected position of the vehicle straight road R _ij, X _Rij, Y _Rij denotes the corrected previous position of the vehicle straight road R _ij.

Further, the position offset calculating means 10 calculates the position difference between the virtual intersection and the virtual intersection coordinates of the virtual route, and calculates the average value (X _Offi , Y _Offi ) of the position difference over the entire route as shown in (3) and (4) below. ), And this is used as the position offset of the virtual route.

Here, X _Ti, Y _Ti is the vehicle position of the straight line trajectory T _i.

Then, the position offset removing unit 11 performs parallel movement of the position offset for each virtual route, removes the position offset, and converts the coordinates of the intersection on the virtual route.

After removing the azimuth and position offsets,
Regarding the remaining azimuth difference and position difference, the azimuth mismatch degree calculating means 12 and the position mismatch degree calculating means 13 find their absolute values, and average the azimuth difference and absolute value of the position difference over the entire route. the following (5), is calculated by equation (6), which is an azimuth mismatch F _theta and misalignment degree F _P of the path.

Also, as shown by the broken line in FIG. 4, thresholds F _θO and F _PO are set for each of the azimuth inconsistency and the position inconsistency, and if only one virtual route is less than any of the thresholds, the virtual route is Is determined as the traveling route, and the vehicle position and the vehicle direction are corrected by performing the rotational movement based on the azimuth offset and the parallel movement based on the position offset of the previously calculated route.

As described above, according to the above-described embodiment, the virtual trajectory obtained by combining a plurality of vectors of the straight trajectory connecting the straight ahead detected from the traveling data of the vehicle and the straight line connecting the road searched from the vehicle presence estimation area when the straight ahead is detected By creating a virtual route based on a combination of multiple vectors of roads and removing the azimuth and position offsets and calculating the azimuth and degree of position inconsistencies, it is possible to compare the trajectory and route patterns over a long distance. For example, even when the vehicle travels in an area with many roads such as an urban area and includes a plurality of roads in the presence estimation area, an accurate traveling route can be obtained with high probability. Therefore, it is possible to prevent the vehicle from losing sight of the current position and current direction of the vehicle and going astray.

In addition, not only one piece of road data but also a rotational movement and a parallel movement for an offset are performed based on a comparison result of a plurality of vector patterns. An accurate current position and current direction can be obtained with high probability.

As is clear from the above embodiment, the present invention provides a virtual trajectory obtained by combining a plurality of vectors of a straight trajectory connected to a straight line of a vehicle and a plurality of straight roads connected to a road searched from a presence estimation area when a straight line is detected. By creating a virtual route based on a combination of vectors, removing the azimuth offset and position offset, and calculating the azimuth inconsistency and position inconsistency and performing pattern matching, even if the vehicle travels in an area with many roads, The vehicle position and heading can be corrected by uniquely determining the exact travel route, thus preventing the current vehicle position and heading from being lost, and providing the vehicle driver with the correct vehicle position and heading. Can be announced.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an in-vehicle navigation device according to an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing the trajectory, road, position and direction correction in the device, and FIG. FIG. 4 is a diagram illustrating a direction-to-position mismatch degree for determining a traveling route of a vehicle according to the present invention. DESCRIPTION OF SYMBOLS 1 ... Straight running detection means, 2 ... Road search means, 3 ... Straight running locus creation means, 4 ... Straight running road creation means, 5 ... Virtual locus creation means, 6 ... Virtual route creation means, 7 ... Intersection calculation means, 8 ... Direction offset Calculation means, 9 ... azimuth offset removal means,
10 position offset calculating means, 11 position offset removing means, 12 azimuth mismatch degree calculating means, 13 position mismatch degree calculating means, 14 position azimuth correcting means.

Claims (1)

(57) [Claims] 1. A straight running detecting means for detecting straight running from running data of a vehicle, a road searching means for searching for a road with a small azimuth difference from an estimated area of the vehicle when the straight running is detected, and a straight running locus connected to the straight running. Straight trajectory creating means for creating, a straight road creating means for creating a straight road by connecting the roads, virtual trajectory creating means for creating a virtual trajectory by combining a plurality of straight trajectories with a plurality of vectors, Virtual route creating means for creating a virtual route in combination, straight-ahead forming the virtual locus, and intersection calculating means for extending a straight road constituting the virtual route to calculate a turning point; Azimuth offset calculating means for calculating azimuth deviation; azimuth offset removing means for calculating coordinates excluding the azimuth offset; Position offset calculating means for calculating the position shift, position offset removing means for calculating coordinates excluding the position offset, azimuth mismatch degree calculating means for calculating the azimuth difference remaining even after excluding the azimuth offset, A position inconsistency degree calculating means for calculating a position difference remaining even after excluding a position offset, and a rotational movement of an angle corresponding to the azimuth offset when the azimuth inconsistency degree and the position inconsistency degree are respectively equal to or less than a predetermined threshold. An in-vehicle navigation device comprising: a position / azimuth correcting means for performing parallel movement by a distance corresponding to a position offset.