JP2007066261A - Driving support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To warn of access of other vehicles without being influenced of update cycle of GPS data. <P>SOLUTION: A driving support device detects a travelling environment around a own-vehicle at a crossing (step S2); computes a communication range of an inter-vehicle communication device (step S3) based on the travelling environment around the own-vehicle and the position of the own-vehicle; corrects positions of other vehicles received by the inter-vehicle communication device based on the above communication range (step S5); and warns of the access of other vehicles at the crossing based on the corrected positions of other vehicles (step S6). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a driving support device that provides driving assistance by informing a driver of the presence of an approaching vehicle.

As a conventional example of a system using inter-vehicle communication, there are technologies described in Patent Document 1, Patent Document 2, and Patent Document 3. In the technique described in Patent Document 1, when the host vehicle approaches an area where the line of sight is not good, the map is enlarged and displayed on the in-vehicle display device. At this time, the display priority is changed based on the degree to which the driver should pay attention.
Further, in the technique described in Patent Document 2, an intersection that is difficult to communicate with an approaching vehicle due to a building or the like is detected, and when such an intersection is detected, the presence of a vehicle in the front-rear direction of the host vehicle is transmitted. This enables information communication at intersections where vehicle-to-vehicle communication is difficult.

The technique described in Patent Document 3 proposes a method for more accurately estimating the diffraction of radio waves by a building.
JP 2004-77281 A JP 2004-246458 A JP 2004-356680 A

By the way, in an encounter scene at an intersection, when the vehicle is approaching the intersection from a non-priority road (branch road), information on the vehicle approaching the intersection from the priority road side is received by inter-vehicle communication. A system that provides information on the presence of vehicles approaching the intersection from the priority road to the driver of the host vehicle traveling near the intersection can be considered.
However, in general, in a vehicle-to-vehicle communication system,
(1) When a vehicle-to-vehicle communication system uses a radio wave of a gigahertz band with high straightness, data may not be transmitted or received at an intersection where the line of sight is unobtrusive in a building or the like until approaching just before that.
(2) In the vehicle-to-vehicle communication system, the vehicle position is detected by GPS (Global Positioning System), and the detection result is transmitted and received between vehicles to detect the position of the other vehicle. On the other hand, GPS that is generally commercialized has a data update cycle (vehicle position update cycle) of about 1 second.

From these, vehicle-to-vehicle communication is almost possible immediately before the intersection, but when the vehicle-to-vehicle communication becomes possible before updating the GPS data of the other vehicle, it is transmitted from the other vehicle. Since the position data of the other vehicle coming will be the one before update (previous update data), the actual position of the other vehicle is closer to the own vehicle or the intersection than the position data obtained by inter-vehicle communication. there is a possibility. That is, even when the vehicle-to-vehicle communication is disabled, the position data of the other vehicle received by the vehicle may be shifted due to the GPS update cycle. . Therefore, even if the driver of the own vehicle is alerted to the approach of another vehicle based on such position data, the alerting timing may not be appropriate.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a driving support device that can alert an approach of another vehicle without being affected by a data update period in GPS.

The driving support device according to claim 1 communicates with another vehicle including vehicle position detecting means for detecting the vehicle position and updating the vehicle position at a predetermined cycle, and notifies the driver of the own vehicle of the other vehicle. It is a driving support device that provides information.
The driving support device includes: a communication unit that receives the position of the other vehicle detected by the vehicle position detection unit through communication with the other vehicle; and the own vehicle based on the position of the other vehicle received by the communication unit. Information providing means for providing information to the driver of the vehicle, detecting the position of the own vehicle by the own vehicle position detecting means, detecting the traveling environment around the own vehicle at the intersection by the own vehicle surrounding traveling environment detecting means, Based on the position of the host vehicle detected by the host vehicle position detection unit and the travel environment around the host vehicle detected by the host vehicle surrounding travel environment detection unit, the communicable range calculation unit of the communication unit is determined. The position of the other vehicle received by the communication unit is corrected based on the communicable range calculated by the communicable range calculation unit.

  According to the driving support apparatus of claim 1, the position of the other vehicle received by the communication unit is corrected based on the communicable range of the communication unit obtained in consideration of the traveling environment around the host vehicle at the intersection. Thus, an appropriate position of another vehicle approaching the intersection can be provided.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
The present embodiment is a vehicle equipped with the driving support apparatus according to the present invention. As shown in FIG. 1, the vehicle includes a vehicle-to-vehicle communication device 1, a host vehicle position detection unit 2, a travel environment detection unit 3, a communicable range calculation unit 4, an other vehicle position correction unit 5, and information as a driving support device. A providing device 6 is mounted.

  The inter-vehicle communication device 1 performs data transmission / reception with another vehicle (not shown). The received data includes at least other vehicle position data related to position coordinates on the map of other vehicles and vehicle speed data of other vehicles. Here, the update cycle of the other vehicle position data is 1 second, and the update cycle of the vehicle speed data of the other vehicle is 0.1 second. The update cycle is not limited to this. For example, the value of 1 second of the update cycle of other vehicle position data is determined on the assumption that the data update cycle of GPS (Global Positioning System) that constitutes the vehicle position detection means of the other vehicle is 1 second. There is, but is not limited to this.

The inter-vehicle communication device 1 outputs the received data to the other vehicle position correction unit 5.
The own vehicle position detection unit 2 is equipped with a GPS (Global Positioning System), receives signals from GPS satellites, and the position coordinates of the own vehicle (hereinafter referred to as own vehicle position coordinates) and the traveling direction of the own vehicle. (Hereinafter, referred to as the own vehicle traveling direction) is detected. And the own vehicle position detection part 2 is updating the detected own vehicle position coordinate with a predetermined period. Here, the predetermined period is about 1 second, which is a data update period (own vehicle position update period) in GPS. The vehicle position detection unit 2 outputs detection data to the travel environment detection unit 3, the communicable range calculation unit 4, and the information providing device 6.

The traveling environment detection unit 3 detects the presence / absence of an intersection, the road type and the road width, and the presence / absence of a building around the host vehicle as information ahead of the host vehicle from the host vehicle position coordinate data and the host vehicle traveling direction data. . Then, the travel environment detection unit 3 outputs the detection data to the communicable range calculation unit 4.
Here, for example, the detection data is as follows.
For example, linear data (road shape data) around the road as shown in FIG. Here, the linear data corresponds to, for example, the number of the road on which the host vehicle is traveling and the number of the surrounding road (link number) Ln (n = 0, 1, 2, 3,...) And the link number. The node number (node number) Nn included in the link (connecting to another link), the coordinates (xn, yn) of the node, and the angle formed by the road at the node (link connected to the node) Angle between them) θ, the number of branches, and the like are included.

The road type data indicates the type of road (link) and corresponds to each link number Ln. The road width data indicates the width of the road (link) and corresponds to each link number Ln. Further, the building data around the host vehicle indicates the presence or absence of a building adjacent to the road (link). Specifically, the presence or absence of a building on the right side of the road with respect to the traveling direction of the host vehicle and the left side of the road Indicates whether there is a building. The building data around the host vehicle corresponds to the link number.
The communicable range calculation unit 4 is based on the own vehicle position coordinate data and own vehicle traveling direction data from the own vehicle position detection unit 2, and various data from the traveling environment detection unit 3. Calculate the communicable range by. Then, the communicable range calculation unit 4 outputs the calculation result to the other vehicle position correction unit 5.

The other vehicle position correction unit 5 receives the data from the vehicle-to-vehicle communication device 1, that is, the other vehicle transmitted from the other vehicle when the vehicle-to-vehicle communication with the other vehicle becomes possible. The position data and the communicable range calculated by the communicable range calculation unit 4 are compared. If the other vehicle position is outside the communicable range, the other vehicle position is corrected to a value that falls within the communicable range. Here, as described above, the other vehicle position data is data that is updated with an update cycle of 1 second. The other vehicle position correction unit 5 outputs the corrected other vehicle position or the other vehicle position that is not corrected in some cases to the information providing device 6.
The information providing device 6 occupies driving assistance information according to the other vehicle position (an information other vehicle distance for information provision calculation) corrected by the other vehicle position correcting unit 5, the own vehicle position and the own vehicle speed from the own vehicle position detecting unit 2. To provide.

Next, a series of processes performed by the respective components of the driving support apparatus will be described using the flowchart illustrated in FIG. 3, and processes of the respective components will be described in more detail.
Here, a description will be given assuming a specific traveling scene. For example, a traveling scene as shown in FIG. 4 is assumed. As shown in FIG. 4, the front of the host vehicle 100 is a T-shaped road, and there is a temporary stop mark M in front of it. The road on which the host vehicle 100 travels is a non-priority road (branch road) 200, and an approaching vehicle (another vehicle) 101 approaches the T-shaped road from the right side of the priority road 201 when viewed from the host vehicle 100. In addition, near the intersection, there are buildings on both sides of the travel path (branch road) 200 of the host vehicle 100 and on the other side of the priority road 201 when viewed from the host vehicle 100. And the driver of the own vehicle 100 wants to turn left at the T-junction. Therefore, in such a travel scene, vehicle-to-vehicle communication with the approaching vehicle 101 that travels in the same lane as the host vehicle after a left turn is required.

Similar to the host vehicle 100, the other vehicle 101 also serves as a driving support device as the inter-vehicle communication device 1, the host vehicle position detection unit 2, the travel environment detection unit 3, the communicable range calculation unit 4, and the other vehicle position correction unit. 5 and the information providing device 6 are installed. Thereby, vehicle-to-vehicle communication is possible between the host vehicle 100 and the other vehicle 101.
In such a traveling scene, first, in step S1, the communicable range calculation unit 4 acquires the own vehicle position coordinates (xn, yn) detected by the own vehicle position detection unit 2, and the own vehicle position coordinates (xn). , Yn) is stored as Ph (xh, yh).

  Further, the communicable range calculation unit 4 acquires road shape data, road type data, road width data, and building data ahead of the host vehicle from the traveling environment detection unit 3. Then, the communicable range calculation unit 4 stores the link number as Ln, stores the road type data of the road corresponding to the link as TPL (Ln), and stores the road width corresponding to the link as WDTH (Ln). The coordinates of the node Nn are stored as Nn (xn, yn), the angle formed by the links at the node Nn is stored as θ (Nn), and the number of branch paths at the node Nn is stored as NLD (Nn). . Here, the road type data is stored in TPL (Ln) as 1 for a highway, 2 for a national road, 3 for a general road, and 4 for a narrow road.

  The communicable range calculation unit 4 stores the right building presence / absence data as KR (Ln) and the left building presence / absence data as KL (Ln) for the building data. Here, the link located near the host vehicle is stored as a target. The building presence / absence data is stored in the building presence / absence data KR (Ln) or KL (Ln), where 0 is no building and 1 is building. Further, the communicable range calculation unit 4 stores the host vehicle speed obtained from a vehicle speed sensor (not shown) as Vh.

  Subsequently, in step S2, the communicable range calculation unit 4 determines whether there is an intersection ahead of the host vehicle. Specifically, using the data stored in step S1, the number of branches (NLD (Nn)) at that node is detected in order from the closest node ahead of the host vehicle, and the presence or absence of an intersection is determined. . For example, in the driving scene as shown in FIG. 4, since the data as shown in FIG. 2 is obtained, the number of branches (NLD (N1)) of the node N1 that is closer to the front from the host vehicle is calculated based on the data. Detect and determine whether it is an intersection. Here, since NLD (N1) = 1 and the number of branches is 1, it is determined that the node is at the intersection.

  Subsequently, in step S3, the communicable range calculation unit 4 sets a communicable range with another vehicle based on the presence or absence of a building near the intersection. Specifically, using the data stored in step S1, particularly the building presence / absence data KR (Ln), KL (Ln), it is determined whether radio waves are difficult to reach based on the presence / absence of the building at the intersection. Set the communicable range according to the difficulty of delivery.

  FIG. 5 shows the traveling environment of the host vehicle constructed based on the data stored in the communicable range calculation unit 4. That is, since the data is obtained in the traveling scene as shown in FIG. 4, the node N1 corresponding to the intersection just before the own vehicle has a link L1 indicating the traveling path of the own vehicle and the right side of the intersection as viewed from the own vehicle. A link L2 indicating a priority road is connected to a link L3 indicating a priority road on the left side of the intersection as viewed from the host vehicle. Here, it is assumed that the angle θ12 formed by the link L1 and the link L2 is 270 °, and the angle θ13 formed by the link L1 and the link L3 is 90 °. Further, according to the building presence / absence data KR (Ln) and KL (Ln), there are buildings A and C on both sides of the link L1, and buildings B and D are on the other side of the links L2 and L3 when viewed from the host vehicle. There is.

  Then, a communicable range is set based on such stored data. Here, since the driver is going to turn left, it is necessary to detect a vehicle on the link L2 that will travel in the same lane as the host vehicle 100 after the left turn. For this reason, it is only necessary to pay attention to the vehicle on the link L2, and therefore the presence or absence of the buildings C and D on the left side of the host vehicle that is considered not to affect the inter-vehicle communication with the vehicle does not matter ( Not detected). On the other hand, since vehicle-to-vehicle communication with the vehicle on the link L2 is necessary, the presence or absence of the buildings A and B on the right side of the host vehicle is detected. And the communicable range of communication between vehicles is set based on the presence or absence of the buildings A and B.

For example, the communicable range is set using the following table (table).
FIG. 6 shows the relationship between the right-side building presence / absence data KR (Ln) and the left-side building presence / absence data KL (Ln) and the presence / absence of the buildings A and B when attention is paid to inter-vehicle communication with the vehicle on the link L2. It is a table | surface which shows.

  According to FIG. 6, when buildings A and B exist, the right building presence / absence data KR (1) of link L1 becomes 1, the right building presence / absence data KR (2) of link L2 and the left building presence / absence Since the data KL (2) is 1, when such data is obtained, the communicable range with the vehicle on the link L2 is set to 25 m, for example. When only the building A exists, the right building presence / absence data KR (1) of the link L1 is 1, the right building presence / absence data KR (2) of the link L2 is 1, and the left side of the link L2 is built. Since the object presence / absence data KL (2) is 0, when such data is obtained, the communicable range with the vehicle on the link L2 can be set when the buildings A and B exist. It is smaller than the range, for example, 15 m. Further, if there is no building A, the right side building presence / absence data KR (1) of the link L1 is 0. Therefore, when such data is obtained, the presence / absence of the building B (the building presence / absence data of the link L2). Regardless of KR (2), KL (2)), the communicable range is not limited. Thus, when there is no building A, there is nothing to block communication radio waves for inter-vehicle communication, so the communication range is not limited. On the other hand, when there is a building A, depending on the presence or absence of the building B Each of the communication ranges is limited.

The communicable range here is a distance based on the intersection. That is, the distance from the other vehicle to the intersection when the host vehicle and the other vehicle can communicate near the intersection is set as a communicable range ΔRR (shown in FIG. 4).
For example, as shown in FIG. 4, when the host vehicle 100 is stopped at a distance x from the center of the intersection (point S in the figure) and the other vehicle 101 is slowly running, The coordinates of the other vehicle 101 when communication with the vehicle 101 can be obtained in advance through experiments or calculations. The distance ΔRR between the obtained coordinates of the other vehicle 101 and the coordinates of the center of the intersection (S point in the figure) is set as the communicable range here. Note that the communicable range shown in FIG.

Thus, FIG. 6 is for setting a communicable range with the vehicle on the link L2 in order for the host vehicle to turn left, but FIG. 7 shows a communicable range when the host vehicle turns to the right. A table (table) for setting is shown.
When the host vehicle turns right, it is necessary to detect vehicles on the link L2 and the link L3. For this reason, when the host vehicle turns to the right, it is necessary to detect the buildings C and D adjacent to the link L3 in addition to the buildings A and B adjacent to the link L2. FIG. It corresponds to the presence or absence of C and D.

  As shown in FIG. 7, when buildings C and D exist, the left side building presence / absence data KL (1) of link L1 becomes 1, the right side building presence / absence data KR (3) of link L3 and the left side building presence / absence Since the data KL (3) is 1, when such data is obtained, the communicable range with the vehicle on the link L3 is set to 25 m, for example. When only the building C exists, the left building presence / absence data KL (1) of the link L1 is 1, the left building presence / absence data KL (3) of the link L3 is 1, and the right side construction of the link L3. Since the object presence / absence data KR (3) is 0, when such data is obtained, the communicable range with the vehicle on the link L3 can be set when the buildings C and D exist. It is smaller than the range, for example, 15 m. Further, if there is no building C, the building presence / absence data KL (1) on the left side of the link L1 becomes 0. Therefore, when such data is obtained, the presence / absence of the building D (the building presence / absence data of the link L3) Regardless of KR (3), KL (3)), the communicable range is not limited. Thus, when there is no building C, there is nothing to block communication radio waves for inter-vehicle communication, so the communication range is not limited. On the other hand, when there is the building C, depending on the presence or absence of the building D Each of the communication ranges is limited.

  When the apparatus holds such FIG. 6 and FIG. 7 and it is determined that the driver of the own vehicle is going to turn left, for example, when the left turn signal is taken out before the intersection, the right building of the link L1 Based on the presence / absence data KR (1), the left side building presence / absence data KL (2) and the right side building presence / absence data KR (2) of the link L2, and the table of FIG. 6, the communicable range ΔRR with the vehicle traveling on the link L2 is obtained. Is calculated.

  Further, when it is determined that the driver of the own vehicle is going to turn right, for example, when the right turn signal comes out before the intersection, the communicable range ΔRR with the vehicle traveling on the link L2 is calculated as described above. In addition, the vehicle travels on the link L3 based on the left building presence / absence data KL (1) of the link L1, the left building presence / absence data KL (3) and the right building presence / absence data KR (3) of the link L3, and the table of FIG. A communicable range ΔRL with the vehicle to be operated is calculated.

These communicable ranges ΔRR and ΔRL may be variable according to the distance between the host vehicle and the intersection, the road width, and the road type. For example, the communicable range may be increased as the intersection is approached or the road width is increased. The numerical value at this time is adjusted from the experimental results.
As described above, based on the presence / absence of buildings around the intersection, it is determined whether or not communication radio waves reach the vehicle-to-vehicle communication, and the communicable range is set.

Subsequently, in step S4, the information providing device 6 determines whether or not the own vehicle approaches the intersection and is temporarily stopped.
Here, the distance Lph from the own vehicle to the intersection center can be calculated by the following equation (1).
^{Lph = {(x1-x2)} 2 + (y1-y2) 2} 0.5 ··· (1)
Therefore, if the distance Lph calculated by the equation (1) is equal to or less than the distance determination threshold value Lcr and the own vehicle speed Vh is equal to or less than the vehicle speed determination threshold value Vstp, the information providing apparatus 6 It is determined that the vehicle is temporarily stopped just before the intersection. If it is determined that the host vehicle has stopped temporarily just before the intersection in this way, the information provision flag _fINF is set to 1 and information provision is started. After that, when the vehicle travels a predetermined distance, the information provision flag f _INF is cleared (f _INF = 0) because the _host vehicle has passed the intersection.

Here, the distance determination threshold value Lcr is determined by a driving experiment in consideration of a GPS error. The predetermined value Lcr may be variable based on the map matching state of the host vehicle. The speed determination threshold value Vstp is set based on the accuracy of the vehicle speed sensor of the host vehicle and the detection range on the low speed side.
Subsequently, in step S5, the other vehicle position correcting unit 5 corrects the other vehicle position. FIG. 8 is a flowchart showing details of the correction processing procedure. In this case as well, since the driver is about to turn left, a description will be given assuming a traveling scene in which another vehicle (vehicle on the link L2) approaches from the right side.

  First, in step S11, it is determined whether the inter-vehicle communication device 1 has been able to communicate with another vehicle. For example, based on the data reception state from the other vehicle of the inter-vehicle communication device 1, the communication state of the inter-vehicle communication device 1 with the other vehicle is determined. If the inter-vehicle communication device 1 can communicate with another vehicle, the process proceeds to step S12. If the inter-vehicle communication device 1 cannot communicate with the other vehicle, the process proceeds to step S13.

In step S13, the communication state determination flag f _CMN (k) is set to 0 (f _CMN (k) = 0) to indicate that the inter-vehicle communication device 1 cannot communicate with another vehicle. Then, the process shown in FIG. 8 ends (the process of step S11 is started again). On the other hand, in step S12, the communication state determination flag f _CMN (k) is set to 1 (f _CMN (k) = 1) to indicate that the inter-vehicle communication device 1 can communicate with another vehicle. Then, the process proceeds to step S14.
Note that k indicates the number of sampling times of the process (microcomputer) (k = 1, 2, 3,...).

In step S <b> 14, it is determined whether or not communication with another vehicle is possible and a possible state is reached. That is, the communication state determination flag f _CMN (k−1) at the time of the previous sampling is 0 (f _CMN (k−1) = 0), and the current communication state determination flag f _CMN (k) is 1 (f _CMN (k). ) = 1). Here, when the communication from the state in which communication with other vehicles is impossible becomes possible, the process proceeds to step S15. Otherwise, that is, when the communication is continuously possible, the process proceeds to step S19. .

In step S15, based on the other vehicle position coordinates Pt (xt (k), yt (k)) acquired from the other vehicle at the first timing when communication is possible, A distance Lpt to the intersection is calculated.
Lpt = {(x1−xt (k)) ² + (y1−yt (k)) ² } ^0.5 (2)
Here, (x1, y1) is the coordinates of the node at the intersection.

  Subsequently, in step S16, it is determined whether or not the distance Lpt calculated in step S15 is larger than the communicable range ΔRR set in step S3. Here, of the communicable range ΔRR and communicable range ΔRL, the reason why the communicable range ΔRR is used is that the driver of the host vehicle is going to turn left, so only the communicable range ΔRR needs to be considered. Because.

If the distance Lpt is larger than the communicable range ΔRR (Lpt> ΔRR), the process proceeds to step S17. If the distance Lpt is equal to or smaller than the communicable range ΔRR (Lpt ≦ ΔRR), the process proceeds to step S18.
In step S17, a communicable range ΔRR that is smaller than the distance Lpt is set in the information providing calculation other vehicle distance Lpti (Lpti = ΔRR). Then, the process proceeds to step S19.

In step S18, the distance Lpt calculated in step S15 is set as the information providing calculation other vehicle distance Lpti (Lpti = Lpt). Then, the process proceeds to step S19.
In step S19, the current other vehicle position coordinates Pt (xt (k), yt (k)) and the other vehicle position coordinates Pt (xt (k-1), yt (k)) at the previous sampling match. That is, it is determined whether or not the GPS coordinates of the other vehicle (other vehicle position data held by the host vehicle) have been updated (whether there is a change in the other vehicle position). Here, the current other vehicle position coordinates Pt (xt (k), yt (k)) and the other vehicle position coordinates Pt (xt (k−1), yt (k)) at the previous sampling match. If the GPS coordinates of the other vehicle are not updated, the process proceeds to step S23. If not, that is, if the GPS coordinates of the other vehicle are updated, the process proceeds to step S20.

In step S20, Lpt is calculated from the distance from the other vehicle to the intersection according to the equation (2). That is, using the other vehicle position coordinates Pt (xt (k), yt (k)) at the timing when the GPS coordinates of the other vehicle are updated, the distance Lpt from the other vehicle to the intersection is calculated by the equation (2). To do.
Subsequently, in step S21, it is determined whether the distance Lpt calculated in step S20 is less than the other vehicle distance Lpti for information provision calculation. Here, the information providing calculation other vehicle distance Lpti is set to the value set in step S17 (Lpti = ΔRR) or in step S18 when communication with another vehicle is disabled. When the set value (Lpti = Lpt) is reached and the communication with the other vehicle is disabled, the communication is enabled. After that, the communication enabled state is maintained. Value.

Here, if the distance Lpt is less than the information providing calculation other vehicle distance Lpti (Lpt <Lpti), the process proceeds to step S22. If the distance Lpt is greater than or equal to the information providing calculation other vehicle distance Lpti (Lpt ≧ Lptti), step S23 is performed. Proceed to
In step S22, the distance Lpt calculated in step S20, that is, a value Lpt smaller than the information providing calculation other vehicle distance Lpti used for comparison in step S21 is set in the information providing calculation other vehicle distance Lpti (Lpti = Lpt).

In step S23, the information providing calculation other vehicle distance Lpti set in step S17, step S18 or step S23 is updated by the following equation (3).
Lpti = Lpti−ΔT · Vt (3)
Here, ΔT is a sampling time.
Thus, the position of the other vehicle is interpolated using the speed of the other vehicle until the GPS coordinates of the other vehicle are updated.

By the above steps S11 to S23 (step S5), the following processing becomes possible.
If communication with another vehicle is impossible, the communication state determination flag f _CMN (k) is set to 0 (steps S11 and S13). On the other hand, in a state where communication with another vehicle is possible, the communication state determination flag f _CMN (k) is set to 1 (steps S11 and S12).

Subsequently, when communication with another vehicle is possible (f _CMN (k) = 1), when the state is from a state where communication with the other vehicle is impossible, the communication is The distance Lpt from the other vehicle to the intersection is calculated based on the other vehicle position coordinates Pt (xt (k), yt (k)) acquired at the timing when it becomes possible (steps S14 and S15). When the calculated distance Lpt is larger than the communicable range ΔRR, the communicable range ΔRR is set as the other vehicle distance Lpti for information provision calculation. When the calculated distance Lpt is less than the communicable range ΔRR, the information provision computation The distance Lpt is set as the other vehicle distance Lpti (steps S16 to S18). That is, the other vehicle distance Lpti for information provision calculation is always set to a value not more than the communicable range ΔRR.

  Subsequently, when the GPS coordinates of the other vehicle are updated in a state where communication with the other vehicle is maintained, the updated other vehicle position coordinates Pt (xt (k), yt (k) ) Is used to calculate the distance Lpt from the other vehicle to the intersection, and when the calculated distance Lpt is less than the other vehicle distance Lpti for information provision calculation, the distance Lpt is set to the other vehicle distance Lpti for information provision calculation And the other vehicle distance Lpti for the said information provision calculation is updated (the said step S20-step S23).

  On the other hand, if the GPS coordinates of the other vehicle are not updated in a state where communication with the other vehicle is maintained, the other vehicle distance Lpti for information provision calculation is updated. That is, the information providing calculation other vehicle distance Lpti is updated by interpolation using the other vehicle speed until the GPS coordinates of the other vehicle are updated next time (steps S19 and S23). When the GPS coordinates of the other vehicle are updated, the distance Lpt from the other vehicle to the intersection is calculated based on the updated other vehicle position coordinates Pt (xt (k), yt (k)) ( If the calculated distance Lpt is less than the information providing calculation other vehicle distance Lpti obtained by the interpolation, the information providing calculation other vehicle distance Lpti is replaced with the distance Lpt (see the equation (2)). Steps S19 to S22).

FIG. 9 shows the change over time of the distance between the other vehicle and the intersection (other vehicle distance Lpti for information provision calculation) obtained by the processes in steps S11 to S23 described above.
The smaller value between the distance Lpt and the communicable range ΔRR obtained based on the other vehicle position coordinates Pt (xt (k), yt (k)) acquired at the timing when communication with the other vehicle becomes possible. The other vehicle distance Lpti for information provision calculation is updated by interpolation using the other vehicle speed as an initial value (circle mark in the figure). And when the GPS coordinate of the other vehicle is updated in the state where the communicable state is maintained, the above-mentioned obtained based on the updated other vehicle position coordinate Pt (xt (k), yt (k)) The information provision calculation other vehicle distance Lpti is updated by interpolation using the other vehicle speed, with the smaller value of the distance Lpt and the information provision calculation other vehicle distance Lpti at that time as an initial value. That is, the other vehicle distance Lpti for information provision calculation is constantly updated as a smaller value.

As described above, the position of the other vehicle is corrected in step S5 (the other vehicle distance Lpti for information provision calculation is obtained).
Subsequently, in step S6, the information providing device 6 determines whether or not to alert the driver. Here, in the alarm determination, for example, the arrival time TTC (= Lpti / Vt) to the intersection of the other vehicle is calculated from the information providing calculation other vehicle distance Lpti obtained in step S5 and the vehicle speed Vt of the other vehicle. When the arrival time TTC is equal to or shorter than a predetermined time (for example, 3 seconds) and the host vehicle is moving (Vh ≠ 0), an alarm is given. The alarm alerts the driver that another vehicle is approaching the intersection, for example, by driving a buzzer (not shown).

The outline of the series of processes as described above is as follows.
First, the communicable range calculation unit 4 acquires the vehicle position coordinates (xn, yn) detected by the vehicle position detection unit 2, and stores the vehicle position coordinates as Ph (xh, yh) (see above). Step S1). Further, the communicable range calculation unit 4 acquires road shape data, road type data, road width data, and building data ahead of the host vehicle from the traveling environment detection unit 3. Then, the communicable range calculation unit 4 determines the presence / absence of an intersection in front of the host vehicle based on the information thus acquired (step S2), and determines whether there is a building near the intersection. A communicable range with the vehicle is set (step S3).

  Subsequently, when the own vehicle temporarily stops at the intersection, the information providing device 6 starts providing necessary information (step S4). On the other hand, the other vehicle position correction unit 5 corrects the other vehicle position (the other vehicle distance Lpti for information provision calculation) based on the communicable range set by the communicable range calculation unit 4 (step S5). Then, the information providing device 6 issues a warning based on the other vehicle position (the information providing calculation other vehicle distance Lpti) corrected by the other vehicle position correcting unit 5 (step S6).

Next, effects in the embodiment will be described.
As described above, the position of the other vehicle received by the inter-vehicle communication device 1 (the other vehicle distance Lpti for calculation of information provision) is obtained by considering the traveling environment around the own vehicle at the intersection. Correction is performed based on the communicable range ΔRR. As a result, even when the position of another vehicle received by the inter-vehicle communication device 1 is corrected, the correction can be performed in a direction in which the accuracy increases.

  Further, as described above, the other vehicle distance Lpti for information provision calculation is always set to be equal to or smaller than the communicable range ΔRR and is updated in a smaller direction. Thereby, since the information provision apparatus 6 is performing the warning based on such other vehicle distance Lpti for information provision calculation, the warning is always performed on the safe side. For example, information on other vehicles approaching the intersection can be provided to the driver of the host vehicle earlier.

Further, as described above, the information providing calculation other vehicle distance Lpti is updated by interpolation using the vehicle speed of the other vehicle. Thereby, it is possible to accurately estimate the position of the other vehicle during the period until the position of the other vehicle is updated next time. Thereby, the information of the other vehicle approaching the intersection can be provided more accurately to the driver of the own vehicle.
Further, as described above, the traveling environment detection unit 3 acquires information on road shapes and buildings as information on the traveling environment around the host vehicle, and the communicable range calculation unit 4 based on the acquired information. A communicable range ΔRR is calculated. Therefore, the calculated communicable range ΔRR becomes more accurate data. As a result, the position of the other vehicle received by the inter-vehicle communication device 1 can be corrected in a direction in which the accuracy is further increased.

The embodiments of the present invention have been described above. However, the present invention is not limited to being realized as the embodiment.
That is, in the said embodiment, description based on the specific driving | running | working scene (FIG. 4 etc.) was performed. However, it is not limited to this. That is, as long as the present invention can be applied, other traveling scenes may be used.

  In the description of the embodiment, the inter-vehicle communication device 1 realizes a communication unit that receives the position of the other vehicle detected by the vehicle position detection unit (GPS mounted on the other vehicle) through communication with the other vehicle. The information providing device 6 realizes information providing means for providing information to the driver of the own vehicle based on the position of the other vehicle received by the communication means. The vehicle position detecting means for detecting the position of the own vehicle is realized, and the traveling environment detecting unit 3 realizes the surrounding environment detecting means for detecting the surrounding environment of the own vehicle at the intersection. The communicable range calculation unit 4 communicates with the communication unit based on the position of the host vehicle detected by the host vehicle position detection unit and the traveling environment around the host vehicle detected by the host vehicle surrounding traveling environment detection unit. Communication to calculate possible range The other vehicle position correcting unit 5 corrects the position of the other vehicle received by the communication unit based on the communicable range calculated by the communicable range calculating unit. Position correction means is realized.

It is a block diagram which shows the structure of the driving assistance apparatus which the vehicle of this embodiment mounts. It is the figure used for description of the road shape data which the driving environment detection part of the said driving assistance device detects. It is a flowchart which shows a series of processing procedures by the said driving assistance device. It is a figure which shows the example of the driving scene used by description of the said driving assistance apparatus. It is a figure which shows the driving environment of the own vehicle constructed | assembled based on the data memorize | stored in the communicable range calculating part of the said driving assistance apparatus. It is a figure which shows the example of the table which the said communicable range calculating part uses for the setting of a communicable range. It is a figure which shows the example of the other table which the said communication range calculation part uses for the setting of a communication range. It is a flowchart which shows the process sequence of the correction process of the other vehicle position by the other vehicle position correction | amendment part of the said driving assistance apparatus. It is a figure which shows the time-dependent change of the other vehicle distance Lpti for information provision calculation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inter-vehicle communication device 2 Own vehicle position detection part 3 Running environment detection part 4 Communication range calculation part 5 Other vehicle position correction part 6 Information provision apparatus

Claims (5)

In a driving support device that detects a vehicle position, communicates with another vehicle including vehicle position detection means for updating the vehicle position at a predetermined cycle, and provides information on the other vehicle to a driver of the own vehicle at an intersection ,
Communication means for receiving the position of the other vehicle detected by the vehicle position detecting means by communication with the other vehicle;
Information providing means for providing information to the driver of the host vehicle based on the position of the other vehicle received by the communication means;
Own vehicle position detecting means for detecting the position of the own vehicle;
A vehicle surroundings traveling environment detection means for detecting a traveling environment around the vehicle at the intersection;
A communicable range in which the communicable range of the communication unit is calculated based on the position of the host vehicle detected by the host vehicle position detection unit and the travel environment around the host vehicle detected by the travel environment detection unit around the host vehicle. A calculation means;
Other vehicle position correcting means for correcting the position of the other vehicle received by the communication means based on the communicable range calculated by the communicable range calculating means;
A driving support apparatus comprising:   2. The driving support apparatus according to claim 1, wherein the vehicle surroundings traveling environment detection means detects at least one of a road shape and a building around the host vehicle as the traveling environment around the host vehicle.   When the communication state of the communication means with the other vehicle changes from an impossible state to a possible state, the position of the other vehicle received by the communication means is outside the communicable range. The driving support device according to claim 1 or 2, wherein the position of the other vehicle is corrected to a value within the communicable range.   Until the position of the other vehicle is updated by the vehicle position detecting means in the other vehicle, the position of the other vehicle most recently updated by the vehicle position detecting means is used as an initial value, and interpolation is performed using the speed of the other vehicle. The other vehicle position prediction update means for predicting and updating the position of the other vehicle is provided, and the other vehicle position prediction update means enables the other vehicle position correction means to communicate the position of the other vehicle. 4. The driving support apparatus according to claim 3, wherein when the value is corrected to a value within the range, the position of the other vehicle is updated using the correction value as the initial value.   The other vehicle position prediction update means receives the new position of the other vehicle updated by the vehicle position detection means while the position of the other vehicle is being updated using the correction value as the initial value. In this case, the position of the other vehicle is updated using the position close to the own vehicle among the position of the new other vehicle and the position of the other vehicle obtained by updating the correction value as the initial value. The driving support apparatus according to claim 4.

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