JP2003014479A - Car navigation device and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a car navigation device capable of improving accuracy for specifying the position of a vehicle, even if the vehicle travels in the range wherein road shapes or the like are not stored as map information. SOLUTION: This car navigation device 1 is constituted mainly of a CPU 2 for controlling the whole device, an azimuth sensor 8 for detecting the azimuth of the traveling direction of the vehicle as azimuth data, a GPS receiver 9 for receiving a position specification signal, and a speed sensor 7 for detecting the running speed of the vehicle. When the vehicle runs in an automotive type multistory parking lot, the CPU 2 estimates the present position of the vehicle from the azimuth data and the moving distance, and simultaneously determines whether the vehicle advances to an ordinary road guiding from a spot A to a spot B, and specifies a position un-specifiable range. In this case, the CPU 2 corrects the azimuth data θ by adding 180 degrees to an azimuth constant θ1 when the vehicle enters the position un-specifiable range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a car navigation device and a program for specifying a current position of a vehicle by performing map matching processing.

[0002]

2. Description of the Related Art Conventionally, the current position of a vehicle is specified by using a map matching process.
There is a car navigation device such as a vehicle traveling position display device disclosed in Japanese Patent No. 48. The map matching process is a system that corrects the current location on an appropriate road by comparing the trajectory that has been driven up to the present time based on the information of the current location with the corresponding road shape stored in the map memory. Is shown. That is, the car navigation device stores travel locus information generated from vehicle azimuth data obtained from a gyro sensor or the like and distance data obtained from a vehicle speed sensor or the like, and stored in a storage medium such as a CD-ROM or a DVD-ROM. The current vehicle position can be specified by determining the correlation of the shape with the road shape information or the like based on the existing map memory.

[0003]

At this time, when the vehicle travels in a place where the road shape and the like are not stored in the map memory, the car navigation device determines the position of the vehicle derived from the traveling locus information in the map memory. Since it does not correspond to the inside road shape, the map matching process cannot be performed correctly. When a vehicle equipped with such a car navigation device travels in a place where the map memory does not store the road shape and the like, the position may not be specified. Therefore, when traveling in such a place, it is conceivable to identify the current position of the vehicle based on the traveling locus information.

However, when the vehicle continuously travels for a long distance in a place where the road shape and the like are not stored in the map memory, the azimuth error is particularly accumulated. To give an example,
There is an opportunity to park on a rooftop where the distance from the entrance of a self-propelled multi-storey car park is long. This kind of self-propelled parking lot
It may be newly constructed in the center of the city, and the map memory may not store the road shape of the self-propelled multi-storey parking lot. At this time, the azimuth data of the vehicle obtained from the gyro sensor, etc. is designed to calculate the azimuth data by integrating the azimuth change amount with respect to the reference direction. There are many opportunities to turn, and even if the error included in the azimuth change amount is small, the azimuth change is large, so that the errors are integrated and an azimuth error is likely to occur when the azimuth data is calculated.

When a heading error occurs, even if the vehicle subsequently moves to a place where the road shape or the like is stored in the map memory, that is, a place where map matching processing is possible,
Since the travel trajectory information is derived from the azimuth data in which the azimuth error has occurred, an error will occur in the assumed travel trajectory information, and even if the corresponding map information is searched, a highly correlated road shape can be found. Can not. For this reason, the car navigation device cannot perform the map matching process and may not be able to specify the position of the vehicle. Moreover, there is a tendency for many self-propelled multi-storey parking lots to be installed in the center of the city from the viewpoint of effective use of land, and there are frequent opportunities for vehicles to be parked in the self-propelled multi-storey parking lot, which causes a problem. There is a circumstance that it is becoming easier.

The present invention has been made in view of the above circumstances, and an object of the present invention is to accurately determine the position of a vehicle thereafter even if the vehicle travels in a range in which road shapes and the like are not stored as map information. (EN) Provided is a car navigation device and a program that can improve the performance.

[0007]

According to the invention of claim 1, the azimuth obtaining means and the distance obtaining means respectively obtain the azimuth and the moving distance of the vehicle with respect to the reference direction. The position specifying unit specifies the position of the vehicle, and the control unit, when the condition for specifying the current position of the vehicle is not satisfied at this time, based on the direction data of the direction acquiring unit and the moving distance of the distance acquiring unit. The current position of is estimated and the position unidentifiable range is specified. For example, when the position specifying signal cannot be received from the GPS receiver, it is determined that the condition for specifying the current position of the vehicle is not satisfied, and the condition is applied. Also, for example,
It is applied when the correlation with the road shape of the map information is low at the time of map matching calculation. The control means corrects the azimuth data when the condition for specifying the current position of the vehicle is satisfied, based on the azimuth data when the vehicle enters the position unidentifiable range. As a result, the accumulated error of the azimuth data, which is a cause of the error with respect to the traveling locus information, can be reduced as much as possible, and even if the vehicle travels in a range where the road shape and the like are not stored in the map data storage means, The accuracy of identifying the position of the vehicle can be improved.

According to a second aspect of the present invention, in the first aspect of the invention, when the control means determines that the positions of the vehicles substantially match before and after entering the position unidentifiable range, the following control is performed. The direction data when the condition for specifying the current position of the vehicle is satisfied is corrected in the opposite direction. As a result, the azimuth data including the accumulated error can be corrected with high accuracy, and even if the vehicle travels in a range where the current position of travel of the vehicle cannot be specified, the accuracy of identifying the subsequent position can be improved. .

According to the invention described in claim 3, in the invention described in claim 1 or 2, the control means determines whether or not the variation amount of the azimuth data acquired by the azimuth acquisition means is equal to or more than a predetermined value. Then, it is determined whether or not the movement distance by the distance acquisition unit is a predetermined multiple or more of a predetermined straight line distance within the position unidentifiable range. When both of these conditions are satisfied, the control means determines that the location in the position unidentifiable range is a self-propelled multi-storey parking lot. Thereby, without impairing the advantages of the invention according to claim 1 or 2,
It is also possible to set the car navigation device to the effect that the place where the vehicle has traveled is a self-propelled multi-storey parking lot.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to FIGS. 1 to 11 as an embodiment applied to a car navigation device 1 mounted on a vehicle traveling in a self-propelled multi-storey parking lot. FIG. 1 shows an electrical configuration of the car navigation device 1. The car navigation device 1
It is mainly composed of a CPU 2 as a control means for controlling the overall operation, and a ROM 3, a RAM 4 and an input / output circuit 5 are connected to the CPU 2. A control program is stored in the ROM 3, and the CPU 2 is configured to operate each component described below according to the control program. A work memory area for the CPU 2 to operate each component is secured in the RAM 4. The ROM 3 is composed of an EEPROM or ROM.

The input / output circuit 5 inputs / outputs data between each constituent element described below and the CPU 2. The input / output circuit 5 includes a vehicle speed sensor 7 as a distance acquisition unit for calculating the traveling distance by integrating the speed of the vehicle 6, and a gyro that detects the azimuth of the traveling direction of the vehicle 6 with respect to the reference direction as azimuth data. An azimuth sensor 8 as an azimuth acquisition means such as a scope, a GPS receiver 9 as a reception means for receiving a position specifying signal,
VICS that can capture congestion information wirelessly
(Vehicle Information & Communication System) Receiver 10, a map memory 11 as a map data storage means for storing map information, a switch group 12 for inputting corresponding to various operations, and a display device 14 such as an LCD. An LCD controller 13 that controls the contents to be displayed is connected. The LCD controller 13 has a display device 1
4 is connected.

The azimuth sensor 8 is composed of, for example, a gyroscope, and the azimuth of the traveling direction of the vehicle 6 with respect to the reference direction is integrated by detecting the azimuth change amount and detected as azimuth data .theta. Direction data θ is sent to CPU2
Configured to output to. Note that direction data θ
Is increased when the vehicle 6 makes a right turn, and decreases when the vehicle 6 makes a left turn, for example, based on 0 °. The azimuth sensor 8 may be one that obtains the azimuth by cumulatively calculating the steering angle of the vehicle 6 obtained from the rotation difference between the left and right steered wheels.

The vehicle speed sensor 7 is constructed so that the traveling distance of the vehicle 6 can be obtained by detecting and integrating the traveling speed of the vehicle 6.

The GPS receiver 9 is adapted to calculate the absolute position of the vehicle 6 by receiving a position specifying signal by radio waves transmitted from a GPS satellite (not shown).
The receiver 10 is configured to be able to wirelessly acquire, for example, traffic congestion information on highways and main roads.

The map memory 11 is a large-capacity storage device for inputting map data as a storage medium such as a CD-ROM or a DVD-ROM, and stores map information described below. As this map information, for example, map data of a predetermined range such as Tokyo, Aichi prefecture or Tokai region, and road shape data in which the shape of the road is written are stored. The map data is data for reproducing the map such as road shape, road width, road name, building, place name, and topography.

The LCD controller 13 is adapted to control the display of the display device 14 connected thereto, and the CPU
The map data transferred from 2 is reproduced as a map on the screen of the display device 14, and the information indicating the traveling locus of the vehicle 6 (hereinafter referred to as traveling locus information) transmitted from the CPU 2 is displayed on the currently displayed map. Is configured to display.

The switch group 12 is provided with various switches for the driver to input a destination and to select a desired map to be displayed on the display device 14.

FIG. 2 is a perspective view of a self-propelled multi-storey parking lot P in which map information such as road shapes is not stored in the map memory 11. The self-propelled multi-storey parking lot faces the general road D, and the general road D has the above-mentioned information stored in the map memory 11. The self-propelled multi-storey parking area P faces south on the north side of the general road D, for example, in a section of about 50 m square.
The first floor to the fourth floor (4F) and the rooftop are built. On a part of the west side facing the south of the first floor of the self-propelled multi-storey car park P, an entrance and an exit are installed in substantially parallel with each other.

FIG. 3 schematically shows a plan view of the self-propelled multi-storey car park P from (a) 1st floor to 2nd floor (b) 2nd floor to 3rd floor, and FIG. The floor plan of (c) 3rd floor of a multi-storey car park P to 4th floor (d) 4th floor to the roof is schematically shown.

When the vehicle 6 enters from the entrance of the self-propelled multi-storey car park P, it is 2 from the first floor of the self-propelled multi-storey car park P on the west road.
The self-propelled multi-storey parking garage P is configured so that you can go up the floor and then turn right to drive on the north side road, and then turn right on the second floor east side road, south side road, west side road in a spiral fashion in order. There is. The west side road, the east side road, the south side road and the west side road are, for example, about 30 m long.

The self-propelled multi-storey parking garage P is constructed so that the vehicle 6 can go up from the west side road on the second floor to the third floor and turn right sequentially to spirally travel from the third floor to the fourth floor to the rooftop. .
The road inside the self-propelled multi-storey car park P is from the entrance on the first floor to the fourth floor,
One lane is provided on each side of the roof, and the opposite lane of the lane in which the vehicle 6 travels when going from the entrance to the roof can be lowered from the roof to the first floor. Then, the vehicle 6 can advance to the general road D from the exit installed substantially parallel to the entrance. As described above, the map information of the general road D from the point A to the point B shown in FIG. 3A is stored in the map memory 11, but the map information of the self-propelled multi-storey parking lot P is stored in the map memory. It is not stored in 11.

The operation of the above configuration will be described with reference to FIGS.
The description will be made with reference to FIG. 5 to 7 are flowcharts showing the main control contents of the CPU 2 when the vehicle 6 equipped with the car navigation device 1 travels in the self-propelled multi-storey parking lot P.

Further, in FIG. 8, (a) the vehicle 6 is on the general road D
From the vehicle to the self-propelled multi-storey parking lot P and traveling northward on the west side road on the first floor (b) The vehicle 6 is traveling in the east direction on the north side road on the second floor of the self-propelled multi-storey parking lot P and the vehicle. FIG. 9 schematically shows the current position of No. 6 and FIG. 9 shows that (c) the vehicle 6 is traveling in the south direction on the second floor east side road of the self-propelled multi-storey parking lot P (d) the second floor south side road is west. 1 schematically shows the locus of traveling in the direction and the current position of the vehicle 6. In this embodiment, the operation of the vehicle 6 being parked from the point A on the general road D to the roof of the self-propelled multi-storey parking lot P and exiting again to the point B on the general road D will be described.

FIG. 10 shows the relationship between the direction data θ obtained from the direction sensor 8 from the point A to the point B of the vehicle 6 and the position of the vehicle 6 in the self-propelled multi-storey parking garage P. . When the vehicle 6 travels on the general road D and approaches the vicinity of the point A where the road shape is stored, the CPU 2 of the car navigation device 1 sets the absolute position obtained from the GPS receiver 9 as an initial value, and the direction detected by the direction sensor 8. The data θ is calculated, the traveling speed is calculated by integrating the speed of the vehicle 6 of the vehicle speed sensor 7, and the map matching processing is performed (step S1). The CPU 2 determines that it exists at the point A set on the map memory 11 by the map matching process. Then, the CPU 2 performs a multistory parking lot determination process (step S2).

FIG. 6 is a flowchart showing the multistory parking lot determination processing. The CPU 2 determines whether the azimuth data θ obtained from the azimuth sensor 8 is (θ1 + 1080 ° −ε) or more or (θ1−1080 ° + ε) or less (step T1). That is, it is determined whether or not the change amount of the azimuth data is equal to or more than a predetermined value. Where 108
The reason why 0 ° is adopted as the determination criterion is to determine that the azimuth of the vehicle has rotated by three rotations or more. Also, ε
Indicates a predetermined error allowable amount (positive value). Vehicle 6
When traveling on the general road D from the point A to the multi-storey parking lot, the CPU 2 does not store the constant θ1 in the RAM 4, so that, for example, this processing is ignored and “the self-propelled multi-storey parking lot is traveling. "No" (step T2).
The CPU 2 causes the RAM 4 to store the fact that the vehicle is not traveling in the self-propelled multi-storey parking lot as a flag, and ends the multi-storey parking lot determination process.

The CPU 2 determines whether or not a departure determination has been made in the map matching process in step S1 (step S3). While the vehicle 6 is traveling on the general road D from the point A to the point B, the map matching process is normally performed and the CPU 2 determines that the departure determination is not made in the map matching process without the departure determination (step S
3: NO), and it is determined whether or not it is determined that the vehicle travels in the self-propelled multi-storey parking lot (step S4).

The CPU 2 refers to the flag stored in the RAM 4 and determines that the vehicle 6 is "not traveling in the self-propelled multi-storey parking lot" (step S4: NO), and step S
The process shifts to 1 and the map matching process is performed again. CP
At this time, U2 determines that it is heading to the point B from the current position and the map information, and outputs the current position of the vehicle 6 reaching the point B from the input / output circuit 5 to the LCD controller 13,
It is displayed on the display device 14.

As described above, while the vehicle 6 is traveling from the point A to the general road D toward the multi-storey parking lot, the CPU 2 determines the departure in the map matching process during the process of steps S1 to S3 to S4 to S1. Instead, it is determined that "the vehicle is not traveling in the self-propelled multi-storey parking lot". Vehicle 6
When turning left from the general road D and entering the self-propelled multi-storey parking lot P, the radio waves transmitted from the GPS satellites are blocked by the walls, ceiling, etc. of the self-propelled multi-storey parking lot P, and the GPS receiver 9 receives the position specifying signal. Cannot be received.

The CPU 2 causes the RAM 4 to store the absolute position where the vehicle 6 exists based on the position specifying signal immediately before the position specifying signal from the GPS receiver 9 cannot be received.

The CPU 2 executes steps S1 to S3 to S4
When the process in S1 is repeated, the position determination signal cannot be received in the map matching process in step S1. The CPU 2 determines in step S3 that the map matching process has determined the departure (step S3: Yes), and calculates the position unidentifiable range S (step S5).

FIG. 7 is a flowchart showing the calculation processing of the position unidentifiable range. The CPU 2 determines whether or not the calculation processing of the position unidentifiable range is the first time (step U1), and when it is the first time, the direction data θ at the time of the departure determination is calculated as the direction constant θ1. Is stored in RAM4 and the traveling distance K1 at that time is R
It is stored in AM4 (step U2).

The CPU 2 uses the heading data of the heading sensor 8 and the traveling distance obtained based on the vehicle speed sensor 7 to determine the vehicle 6
The current position of the vehicle is estimated, and the range from the point where the departure is determined to the general road D is the initial range of the unlocatable range S (see FIG. 8).
In (a), it is stored in the RAM 4 as a two-dimensional absolute position range indicated by Xa and Ya. The calculation processing of the position unidentifiable range ends, and the process proceeds to step S1.

When the vehicle 6 goes up from the first floor to the second floor, C
PU2 repeatedly executes the processing in steps S1 to S3 to S5. At this time, the CPU 2 determines the departure by the map matching process in step S1 and the azimuth data θ.
Update processing is performed, and the azimuth data θ does not satisfy the condition shown in step T1 in the multistory parking lot determination processing in step S2, it is determined that “the vehicle is not traveling in the self-propelled multistory parking lot”, and the flag is set. Update sequentially.

The CPU 2 executes the process of calculating the position unidentifiable range, and since this process is not the first time (step U1: No), the position unidentifiable range S is updated (step U1). U3). CP in this way
U2 repeatedly executes the processing in steps S1 to S3 to S5.

When the vehicle 6 turns right and runs on the north side road on the second floor, the azimuth sensor 8 detects the azimuth data θ so as to increase by approximately 90 ° (the current position (a) (b) of the vehicle 6 shown in FIG. 10). )reference). In step U3, the CPU 2 sets the position unidentifiable range S to a rectangular X in FIG. 8B.
It is updated to the range shown by b and Yb and stored in the RAM 4.

Similarly, when the vehicle 6 travels on the east side road and the south side road on the second floor, the azimuth sensor 8 detects the azimuth data θ so as to increase by about 90 ° (the current position (c ) (D)), the CPU 2 executes step S5.
The position unidentifiable range S is updated at (FIG. 9C).
(See (d)). At this time, at the time point shown in FIG. 9D, the position unidentifiable range S is updated with the straight line distance Xd and the straight line distance Yd indicating the maximum range in which the vehicle 6 has traveled.

When the vehicle 6 travels while sequentially rotating from the first floor to the fourth floor in the self-propelled multi-storey parking lot P and reaches the rooftop, the azimuth data θ detected by the azimuth sensor 8 is approximately 1080 with respect to the azimuth constant θ1. The CPU 2 determines that the azimuth data θ is (θ1 + 1080 ° −ε) or more in the multi-storey parking lot determination process in step S2 (step T1: YES), and proceeds to step T3.

Here, the CPU 2 subtracts the previously stored traveling distance K1 from the traveling distance K2 at this time to calculate the traveling distance referred to in the present invention, and this traveling distance defines the position unidentifiable range. It is determined whether or not the straight line distance Xd is 5 times or more (step T3). When the moving distance is not more than 5 times the linear distance Xd (step T3: NO), the CPU 2 determines in step T2 that "the vehicle is not traveling in the multi-storey parking lot", and updates the flag. Further, in step T3, conversely, the movement distance is the linear distance X.
When it is more than 5 times d (step T3: YE
S), it is determined whether or not a departure determination has been made in the map matching process. If a departure determination has been made, it is determined in step T2 that "the vehicle is not traveling in the multi-storey parking lot", and the flag is updated.

Further, the CPU 2 determines whether or not the departure determination is made in the map matching process (step T).
4) If it is not determined to leave (step T4: N
O), it is determined that the vehicle is not traveling in the self-propelled multi-storey parking lot, and the flag is updated. If it is determined in step T4 that the vehicle has left the map matching process, it is determined that the vehicle travels in the self-propelled multi-storey parking lot (step T5), and the multi-storey parking lot determination process ends. Incidentally, the CPU 2 executes steps T1 to T
During the process of 5, it is determined whether the vehicle 6 has once parked on the roof of the self-propelled multi-storey parking lot P, and whether the vehicle 6 is traveling in the self-propelled multi-storey parking lot P is determined. You can
Further, the process of step T4 can be deleted.

When the vehicle 6 runs spirally from the first floor to the rooftop, the CPU 2 determines in step T1 that the azimuth data θ is (θ1 + 1080 ° -ε) or more, and the vehicle 6 is identical for about three revolutions. Suppose it has rotated in the direction.

In step T2, the CPU 2 determines the moving distance by the linear distance Xd for specifying the position unidentifiable range S.
Is 5 times or more. For example, if the linear distance Xd is 30 m and the moving distance is 250 m,
The condition of step T2 is satisfied. At this time, the straight line distance Xd that specifies the position unidentifiable range S is the straight line distance Yd.
But it is okay.

Since it is determined in step T4 that the CPU 2 has left the map matching process, the CPU 2 determines in step T5 that the vehicle is traveling in a self-propelled multi-storey parking lot.
Update the flag. In addition, in FIG. 2, the roof of the multi-story parking lot is open and the position specifying signal from the GPS satellite can be received, but the map information of the self-propelled multi-story parking lot P is stored in the ROM 3
Since it is not stored in the CPU, the CPU 2 determines the departure as the map matching process even when traveling on the rooftop.

When the vehicle 6 is parked on the roof, the CPU 2 indicates that the vehicle 6 is in the position unidentifiable range S, for example, R
Store in EEPROM in OM3. After the vehicle 6 is parked on the roof and the car navigation device 1 mounted on the vehicle 6 starts to operate, the CPU 2 can receive the position specifying signal. The fact that it exists in S is stored, and a departure determination is made in the map matching processing in step S1.

When the vehicle 6 is once parked on the roof and the vehicle 6 gradually turns in the oncoming lane from the exit to the general road D while spirally turning, the CPU 2 determines the departure in the map matching process shown in step S1. It will not be done. In the multistory parking lot determination process shown in step S2, the CPU 2 determines that "the vehicle is not traveling in the self-propelled multistory parking lot", and updates the flag. CPU2, step S3
In step S4, it is determined that the departure determination has not been made in the map matching processing, and it is determined in step S4 whether or not the self-propelled multi-storey parking lot was determined to be traveling. The CPU 2 determines that “the self-propelled multi-storey parking lot has been determined to be traveling” from the state of the flag before the determination that the vehicle is leaving and the state is updated.
Is corrected (step S6).

FIG. 11 (e) schematically shows the locus and the current position of the vehicle 6 when the vehicle 6 advances on the general road D and deviates from the position unidentifiable range S. At this time, the azimuth data of the vehicle 6 deviates from the value (θ1 + 180 °) that should be originally shown due to the accumulation of the azimuth error (FIG. 1).
0, the current position of the vehicle 6 (e)).

The CPU 2 substitutes (θ1 + 180 °) into the bearing data θ to correct the bearing data. In this way, the azimuth data θ including the azimuth error is corrected.

The absolute position indicated by the position specifying signal immediately before the reception is stopped is stored in the RAM 4, and the CPU 2 uses the stored absolute position to determine whether or not the exit of the self-propelled multi-storey parking lot P is reached. It may be determined. At this time, the exit and entrance of the self-propelled multi-storey parking lot P are substantially coincident with each other, and when the vehicle 6 advances to the general road from the exit, the GPS receiver 9 receives the position specifying signal again and outputs it to the CPU 2. .

When the CPU 2 compares the absolute position indicated by the position specifying signal with the absolute position indicated by the position specifying signal immediately before reception becomes impossible, and confirms that they substantially match, the CPU 2 detects the reverse direction, that is, the azimuth data θ. (Θ1 + 180 °)
Will be fixed.

The CPU 2 uses the corrected azimuth data θ and travels on the general road D to perform map matching processing at the point B. That is, when the vehicle 6 reaches the exit of the self-propelled multi-storey parking lot P and then turns left, the azimuth sensor 8 acquires the azimuth data θ so as to be subtracted by about 90 °, and CP
Output to U2. After that, the vehicle 2 travels on the general road D, and at the point B, the CPU 2 normally performs the map matching process.

As described above, according to the car navigation system 1 of the present embodiment, the current position of the vehicle 6 is estimated from the azimuth data θ and the movement distance within the position unidentifiable range S, and the vehicle 6 is It is determined whether or not the vehicle has advanced to the general road D between the points A and B. If the vehicle 6 advances to the general road D, the direction data when the condition for specifying the current position of the vehicle 6 is satisfied by adding 180 ° to the direction constant θ1 when the vehicle 6 enters the position unidentifiable range S Correct θ. As a result, the cumulative error of the azimuth data θ, which is a cause of the error with respect to the traveling locus information, can be reduced as much as possible, and even if the vehicle 6 travels in a range where the road shape and the like are not stored in the map memory 11, The accuracy of identifying the position of the vehicle 6 can be improved.

Further, the CPU 2 causes the position unidentifiable range S
When it is determined that the absolute position of the vehicle 6 indicated by the position specifying signal received by the GPS receiver 9 before and after entering the vehicle is substantially the same,
After that, the azimuth data θ when the condition for specifying the current position of the vehicle 6 is satisfied is set to (θ1 + 180 °) and is corrected in the opposite direction. Alternatively, when the CPU 2 determines that the absolute position of the vehicle 6 substantially matches from the road shape of the map information, the azimuth data, and the moving distance before and after entering the position unidentifiable range S, the CPU 2 determines the current position of the vehicle 6 thereafter. The azimuth data θ when the specified condition is satisfied is set to (θ1 + 180 °) and corrected in the opposite direction. As a result, the azimuth data θ including the accumulated error can be accurately corrected, and even if the vehicle 6 travels in a range in which the current position of travel of the vehicle cannot be specified,
The accuracy of identifying the current position of the vehicle 6 thereafter can be improved.

Further, the CPU 2 sets the azimuth data θ within the position unidentifiable range S from the azimuth constant θ1 (1080 ° -ε).
The travel distance calculated by determining whether or not the travel distance has increased and subtracting the travel distance K1 from the travel distance K2 is a distance that is five times or more the linear distance Xd specified within the position unidentifiable range S. Or not. CPU2 is
When both of these conditions are satisfied and the departure determination is made in the map matching processing, it is determined that the location in the position unidentifiable range S is the self-propelled multi-storey parking lot P. As a result, the fact that the place where the vehicle has traveled is the self-propelled multi-storey parking lot P can be set in, for example, the EEPROM or the RAM 4 of the car navigation device 1.

(Modification) The configuration of the car navigation system 1 described above can also be applied to a self-propelled multi-storey parking lot P having different entrances and exits as shown below. For example, as shown in FIG. 12 (f), the entrance faces the south general road D between points A and B, and the exit faces the east general road D between points B and C. Is. The general road D between the points B and C intersects the general road D between the points A and B at a substantially right angle. The road shape and the like intersecting at right angles are stored in the map memory 11. This self-propelled multi-storey parking lot P can spirally climb from the first floor facing the south general road D to the roof as in the first embodiment, and spirally descends from the roof to the exit on the east side. It is configured to be able to advance to the road D.

Incidentally, FIG. 12 (f) corresponds to FIG. 9 (e), and when the vehicle 6 advances to the general road D from the point B to C and deviates from the position unidentifiable range S. Shows the state of.

The vehicle 6 ascends from the first floor to the rooftop and is parked on the rooftop as in the above embodiment. Then, the vehicle 6 is again 1
When it spirally descends to the floor, it is determined that the vehicle has traveled within the self-propelled multi-storey parking garage P in the flowcharts of FIGS. 5 to 7 from the operation of the above-described embodiment, and the azimuth data θ is corrected. C
The PU 2 determines that it has advanced to the general road D from the point B to C, and determines that it has deviated from the position unidentifiable range S. The CPU 2 refers to the data stored in the map memory 11, and refers between the points A and B and the points B and C where the departure is determined.
Since it intersects at a right angle between and, the azimuth data θ is corrected to (θ1 + 90 °). Then, when the vehicle 6 travels toward the point C, the CPU 2 normally performs the map matching process at the point C.

According to such a modified example, it can be applied even when the vehicle 6 equipped with the car navigation system 1 travels in a self-propelled multi-storey parking lot P having different entrances and exits.
That is, by adding 90 ° to the azimuth constant θ1 when the vehicle 6 enters the position unidentifiable range S, the vehicle 6
The azimuth data θ when the condition for specifying the current position of is satisfied is corrected. As a result, the cumulative error of the azimuth data θ, which is a cause of the error with respect to the traveling locus information, can be reduced as much as possible, and even if the vehicle 6 travels in a range where the road shape and the like are not stored in the map memory 11, The accuracy of identifying the position of the vehicle 6 can be improved.

In the above embodiment, the azimuth data θ is corrected when it is determined that the vehicle 6 has traveled in the self-propelled multi-storey parking garage P. Even if it is determined that the vehicle is not traveling, the CPU 2 may correct the azimuth data θ if the departure determination is made as the map matching process.

In the above-mentioned embodiment, the embodiment is shown for the multi-story parking lot that turns right from the first floor to the rooftop, but it is also applicable to a multi-story parking lot that turns left.

[Brief description of drawings]

FIG. 1 is an electrical configuration diagram of a car navigation device showing an embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of a self-propelled multi-storey car park.

[Fig. 3] (a) First floor to second floor (b) of a self-propelled multi-storey car park
2nd floor to 3rd floor schematic plan view

[Figure 4] (c) 3rd floor to 4th floor (d) of self-propelled multi-storey parking lot
Schematic plan view from the 4th floor to the rooftop

FIG. 5 is a flowchart (part 1) showing the subject of the control contents of the CPU.

FIG. 6 is a flowchart (part 2) showing the subject of the control contents of the CPU.

FIG. 7 is a flowchart (part 3) showing the subject of the control contents of the CPU.

[FIG. 8] (a) A vehicle enters a self-propelled multi-storey parking lot from a general road and is traveling northward on the first floor west road. (B) A vehicle is east on the second-floor north road of the self-propelled multi-storey parking lot. Diagram schematically showing the locus of traveling in the direction and the current position of the vehicle

[Fig. 9] (c) The vehicle is traveling southward on the east side road on the second floor of the self-propelled multi-storey parking lot. (D) The trajectory of the vehicle traveling westward on the south side road on the second floor and the current position of the vehicle are schematic. Shown in

FIG. 10 is a diagram showing the relationship between the azimuth data θ and the current position of the vehicle in the self-propelled multi-storey parking lot.

FIG. 11 (e) is a diagram schematically showing the locus and the current position of the vehicle when the vehicle departs from the position unidentifiable range by advancing between straight lines from point A to point B.

FIG. 12 (f) is a view corresponding to FIG. 11 (e) showing a modified example.

[Explanation of symbols]

1 is a car navigation device, 2 is a CPU (control means,
(Position specifying means), 6 is a vehicle, 7 is a vehicle speed sensor (distance acquisition means), 8 is a direction sensor (direction acquisition means), and 9 is GPS.
The receiver 11 is a map memory.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G08G 1/09 G08G 1/09 FF term (reference) 2C032 HB02 HB05 HB22 HB23 HB24 HC08 HD03 2F029 AA02 AB01 AB07 AB09 AC01 AC02 AC04 AC13 AD01 5H180 AA01 BB02 BB04 FF04 FF05 FF07 FF12 FF13 FF22 FF27 FF33 5J062 AA05 BB01 CC07 HH05

Claims (6)

[Claims] 1. A position specifying means for specifying the position of the vehicle, an azimuth acquiring means for acquiring the azimuth of the vehicle with respect to a reference direction as azimuth data, a distance acquiring means for acquiring the moving distance of the vehicle, and the position specifying means. When the condition for specifying the current position of the vehicle is not satisfied, the current position of the vehicle is estimated based on the azimuth data of the azimuth acquisition unit and the moving distance of the distance acquisition unit to specify the non-positionable range. At the same time, based on the azimuth data when the vehicle enters the position unidentifiable range, a control unit that corrects the azimuth data of the vehicle when a subsequent condition for specifying the current position of the vehicle is satisfied. A car navigation device comprising: 2. The control means, when it is determined that the current position of the vehicle substantially matches before and after entering the position unidentifiable range, and when the subsequent condition for specifying the current position of the vehicle is satisfied. 2. The car navigation system according to claim 1, wherein the azimuth data of is corrected in the opposite direction. 3. The amount of change in the azimuth data acquired by the azimuth acquisition means is a predetermined value or more, and the movement distance by the distance acquisition means is a predetermined multiple or more of a predetermined linear distance within the position unidentifiable range. The car navigation device according to claim 1 or 2, wherein when the distance is a distance, the control unit determines that the location in the position unidentifiable range is a self-propelled multi-storey parking lot. 4. The vehicle based on the azimuth data of the azimuth acquisition means and the moving distance of the distance acquisition means when the control means of the car navigation device does not satisfy the condition for specifying the current position of the vehicle corresponding to the map information. A procedure for estimating the current position of the vehicle and specifying a position unidentifiable range, and a condition for identifying the current position of the vehicle thereafter based on the azimuth data when the vehicle enters the position unidentifiable range. A program for executing the procedure for correcting the azimuth data when satisfied. 5. When the control means determines that the positions of the vehicle substantially match before and after entering the position unidentifiable range, and when the condition for specifying the current position of the vehicle thereafter is satisfied. The program according to claim 4, wherein a procedure for correcting the azimuth data in the reverse direction is executed. 6. The control means is configured such that the direction data acquired by the direction acquisition means is equal to or more than a predetermined value, and the movement distance by the distance acquisition means is a predetermined multiple of a predetermined linear distance within the position unidentifiable range. The program according to claim 4 or 5, wherein when the distance is equal to or more than the above distance, a procedure of determining that the place in the position unidentifiable range is a self-propelled multi-storey parking lot is executed.