JP2013203186A - Preceding vehicle attitude detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preceding vehicle attitude detecting device 11 which acquires the attitude of a preceding vehicle and detects its travelling state without depending on a marker.SOLUTION: A preceding vehicle attitude detecting device 11 for detecting a travelling state from the attitude of a preceding vehicle includes: an inclination (angle) detecting means 12 which detects inclination of a vehicle body as the attitude of the preceding vehicle based on image data of the preceding vehicle imaged by an imaging means 21; a preceding vehicle information acquiring means 13 which extracts a group the preceding vehicle belongs to based on the image data, and acquires a distance between a center of gravity of the vehicle body and a roll center, a distance in a vehicle width direction of the center of gravity and a suspension for supporting the vehicle body, and a spring constant of the suspension as vehicle information corresponding to the extracted group; and a centrifugal force calculating (acquiring) means 14 which calculates centrifugal force acting on the vehicle body (the travelling state) in travelling a curve by the preceding vehicle based on the inclination of the vehicle body and the vehicle information of the preceding vehicle.

Description

  The present invention relates to a preceding vehicle posture detection device that detects a running state from the posture of a preceding vehicle that runs ahead of a host vehicle.

  There has been proposed a method for detecting the attitude angle of a preceding vehicle by photographing a marker provided at the rear portion of the preceding vehicle (see Patent Document 1, etc.).

JP 2001-202497 A

  However, in the case of Patent Document 1, in order to acquire the attitude angle of the preceding vehicle, the preceding vehicle needs to be provided with a marker, and the attitude angle is acquired for the preceding vehicle not provided with the marker. I can't.

  Therefore, a problem to be solved by the present invention is to provide a preceding vehicle posture detection device that can acquire the posture of a preceding vehicle and detects its running state regardless of the marker.

The present invention is a preceding vehicle attitude detection device that detects a traveling state from the attitude of a preceding vehicle,
Inclination detecting means for detecting the inclination of the vehicle body as the posture of the preceding vehicle based on the image data of the preceding vehicle imaged by the imaging means;
Based on the image data, the group to which the preceding vehicle belongs is extracted, and the vehicle information corresponding to the extracted group includes the distance between the center of gravity of the vehicle body and the roll center, and the suspension vehicle that supports the center of gravity and the vehicle body. Preceding vehicle information acquisition means for acquiring a distance in the width direction and a spring constant of the suspension;
And a centrifugal force calculating means for calculating, as the running state, a centrifugal force acting on the vehicle body when traveling on the curve of the preceding vehicle based on the inclination and the vehicle information.

  According to this, the inclination of the vehicle body can be acquired as the posture of the preceding vehicle based on the image data of the preceding vehicle imaged from the own vehicle using the imaging means, and the vehicle information of the preceding vehicle (the center of gravity of the vehicle body and the roll center). Distance, the center of gravity of the vehicle body and the distance in the vehicle width direction of the suspension, and the spring constant of the suspension), the centrifugal force acting on the vehicle body of the preceding vehicle when traveling on the curve of the preceding vehicle, It can be calculated as a representation. According to the calculated centrifugal force, it is possible to grasp the roll state (running state) of the preceding vehicle.

In the present invention, the preceding vehicle information acquisition means acquires the weight of the vehicle body as the vehicle information,
It is preferable to have first curvature calculation means for calculating a first curvature of the curve based on the speed of the preceding vehicle acquired by the preceding vehicle speed acquisition means, the centrifugal force, and the weight.

  According to this, the curvature (first curvature) of the curved road on which the preceding vehicle is traveling can be acquired. This first curvature can also be considered as a kind of traveling state of the preceding vehicle. Since the vehicle travels immediately after the preceding vehicle travels, the vehicle (the driver) can acquire the first curvature of the curve road in advance immediately before traveling and prepare for the travel. be able to. Further, the first curvature can be calculated regardless of the distance between the host vehicle and the preceding vehicle, and can be calculated as needed.

In the present invention, the group is a vehicle type,
Each vehicle type has a database having vehicle type image data that can be matched with the image data of the preceding vehicle, and the vehicle information,
The preceding vehicle information acquisition means extracts the vehicle type corresponding to the vehicle type image data matching the image data of the preceding vehicle from the database, and reads the vehicle information corresponding to the extracted vehicle type from the database. When there is no vehicle type image data that matches the image data of the preceding vehicle, it is preferable to obtain vehicle information defined in advance.

  Stores image data on the back of the vehicle and vehicle information (distance between the center of gravity of the vehicle body and the roll center, distance between the center of gravity of the vehicle body and the suspension in the vehicle width direction, suspension spring constant, weight of the vehicle body) for each vehicle type. The prepared database may be prepared in advance, and according to this, the centrifugal force and the first curvature can be obtained with high accuracy. Further, even if the vehicle type of the preceding vehicle is a vehicle type that is not stored in the database, the centrifugal force and the first curvature can be calculated using vehicle information that is defined in advance.

Moreover, in this invention, the 2nd curvature acquisition means which acquires the centripetal direction of the vehicle width direction in which the 2nd curvature of the said curve exists using the map information acquisition means which acquires the map information of the road where the own vehicle drive | works. When,
Direction comparison means for determining whether or not the centrifugal direction in the vehicle width direction to which the centrifugal force is directed matches the centripetal direction;
It is preferable to have an alerting means for urging the driver of the own vehicle to alert when the coincidence is determined.

  The centripetal direction to the center of the second curvature (radius) obtained from the map information obtained using the map information obtaining means such as the navigation system, and the center of the first curvature (radius) obtained from the preceding vehicle. The centripetal direction (the reverse direction of the centrifugal direction toward which the centrifugal force is directed) should normally be matched. In the case of a mismatch, the preceding vehicle has a curvature of the actual road due to some cause (for example, obstacle avoidance). There is a possibility of turning without regard. For this reason, when the centripetal direction of the second curvature and the first curvature are not coincident, that is, when the centripetal direction of the second curvature coincides with the opposite direction of the centrifugal direction to which the centrifugal force is directed, The driver can be alerted, and the driver can be prepared for unexpected situations such as obstacles avoided by the preceding vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, the attitude | position of a preceding vehicle can be provided which can acquire the attitude | position of a preceding vehicle irrespective of a marker and detects the driving state.

1 is a configuration diagram of a vehicle (own vehicle) equipped with a preceding vehicle attitude detection device according to an embodiment of the present invention. The preceding vehicle attitude | position detection apparatus which concerns on embodiment of this invention is a flowchart of the preceding vehicle attitude | position detection method implemented with the other apparatus with which both were mounted in the vehicle (own vehicle). It is the typical image (data) which imaged the back of the preceding vehicle which runs straight ahead of the own vehicle from the own vehicle. It is the typical image (data) which imaged the back of the preceding vehicle which turns and runs ahead of the own vehicle from the own vehicle.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 shows a configuration diagram of a vehicle (own vehicle) 10 equipped with a preceding vehicle posture detection device 11 according to an embodiment of the present invention. The vehicle (own vehicle) 10 includes a preceding vehicle attitude detection device 11, an imaging means 21 such as a camera, a preceding vehicle speed acquisition means 22, an inter-vehicle distance acquisition means 23, and a map information acquisition means 24 such as a car navigation system. have.

  Although details will be described later, the preceding vehicle posture detection device (control device) 11 detects the posture (tilt angle) of a preceding vehicle that runs ahead of the host vehicle 10 regardless of the marker, and the posture (tilt). From the corner, the traveling state (the centrifugal force acting on the vehicle body of the preceding vehicle when traveling on the curve of the preceding vehicle and the curvature of the curve on which the preceding vehicle travels) is detected. The preceding vehicle attitude detection device 11 may also serve as a control device that controls the traveling of the host vehicle 10.

  The imaging means 21 images the preceding vehicle from the back side. The imaging means 21 generates image data of the back surface of the preceding vehicle and transmits it to the preceding vehicle posture detection device 11.

  The preceding vehicle speed acquisition means 22 measures (acquires) the speed (vehicle speed) of the preceding vehicle using sound, light, or the like. Alternatively, the speed difference between the preceding vehicle and the own vehicle and the speed of the own vehicle may be measured, and the speed of the preceding vehicle may be calculated from the speed difference between the preceding vehicle and the own vehicle and the speed of the own vehicle. Then, the preceding vehicle speed acquisition unit 22 transmits the speed (value) of the preceding vehicle to the preceding vehicle attitude detection device 11.

  The inter-vehicle distance acquisition unit 23 measures (acquires) the inter-vehicle distance between the preceding vehicle and the host vehicle using sound, light, or the like, and transmits the inter-vehicle distance (value) to the preceding vehicle attitude detection device 11.

  The map information acquisition unit 24 acquires map information including the curvature (second curvature) of the curved road located ahead of the road on which the host vehicle travels, and transmits the map information to the preceding vehicle attitude detection device 11. The curvature (second curvature) may be transmitted directly to the preceding vehicle posture detection device 11.

  The preceding vehicle attitude detection device 11 includes an attitude (tilt angle) detection means 12, a preceding vehicle information acquisition means 13, a centrifugal force calculation (acquisition) means 14, a first curvature calculation (acquisition) means 15, and a second curvature. The acquisition unit 16, the curvature (direction) comparison unit 17, and the alerting unit 18 are included.

  The attitude (inclination angle) detection unit 12 detects the inclination (angle) of the vehicle body as the attitude of the preceding vehicle based on the image data of the preceding vehicle imaged by the imaging unit 21.

  The preceding vehicle information acquisition means 13 has a first database 13a grouped according to vehicle type and a second database 13b grouped according to vehicle type. The preceding vehicle information acquisition unit 13 extracts a group to which the preceding vehicle belongs from the first database 13a or the second database 13b based on the image data of the preceding vehicle imaged by the imaging unit 21. The preceding vehicle information acquisition means 13 obtains the vehicle information corresponding to the extracted group from the first database 13a or the second database 13b, the distance between the center of gravity of the vehicle body and the roll center, and the vehicle width of the suspension supporting the center of gravity and the vehicle body. Get the distance in the direction, the spring constant of the suspension, and the weight of the car body.

  The first database 13a includes, for each vehicle type, vehicle type image data that can be matched with image data of a preceding vehicle and the vehicle information. Using the first database 13a, the preceding vehicle information acquisition unit 13 extracts the vehicle type corresponding to the vehicle type image data that matches the image data of the preceding vehicle from the first database 13a. The preceding vehicle information acquisition means 13 reads the vehicle information corresponding to the extracted vehicle type from the first database 13a and sets it as the vehicle information of the preceding vehicle. If there is no vehicle type image data that matches the image data of the preceding vehicle, vehicle information defined in advance may be acquired. The second database 13b can be used to obtain the vehicle information defined in advance.

  The second database 13b has a range of the size and the vehicle information for each group divided by the vehicle grade (the size of the back surface) of the vehicle. Using the second database 13b, the preceding vehicle information acquisition unit 13 extracts from the second database 13b a group of vehicle grades in a range including the size of the rear surface of the preceding vehicle. The preceding vehicle information acquisition means 13 reads the vehicle information corresponding to the extracted group of vehicle grades from the second database 13b and sets it as the vehicle information of the preceding vehicle. The size of the back surface of the preceding vehicle is calculated based on the size of the image of the back surface of the preceding vehicle measured from the image data and the distance between the preceding vehicle and the own vehicle measured by the inter-vehicle distance acquisition means 23. The Since the vehicles are grouped according to the vehicle grade (the size of the rear surface), the preceding vehicle can always belong to some group, and the vehicle information of the preceding vehicle can be determined. Specifically, it can be classified into groups such as small cars (light trucks), ordinary cars, large cars, trucks, and large trucks.

  The centrifugal force calculation (acquisition) means 14 determines the curve of the preceding vehicle based on the vehicle body inclination (angle) detected by the posture (inclination angle) detection means 12 and the vehicle information acquired by the preceding vehicle information acquisition means 13. Centrifugal force acting on the vehicle body when traveling is calculated.

  The first curvature calculation (acquisition) means 15 acquires the speed of the preceding vehicle acquired by the preceding vehicle speed acquisition means 22, the centrifugal force calculated by the centrifugal force calculation (acquisition) means 14, and the preceding vehicle information acquisition means 13 acquires. The curvature (first curvature) of the curve road is calculated based on the weight of the vehicle body of the preceding vehicle.

  The second curvature acquisition means 16 uses the map information acquisition means 24 to acquire map information including the curvature (second curvature) of the curved road located ahead of the road on which the vehicle travels. Based on the map information, the second curvature acquisition means 16 determines whether the center of the second curvature (radius) of the curved road is located on the right side or the left side of the preceding vehicle, that is, from the preceding vehicle to the center. Whether the centripetal direction of the vehicle is rightward or leftward in the vehicle width direction.

  The curvature (direction) comparison unit 17 determines whether or not the centrifugal direction in the vehicle width direction to which the centrifugal force calculated by the centrifugal force calculation (acquisition) unit 14 coincides with the centripetal direction.

  The alerting means 18 urges the driver of the own vehicle to alert when it is determined that they match. According to this, the driver can be prepared for an unexpected situation such as an obstacle avoided by the preceding vehicle.

  FIG. 2 shows a flowchart of a preceding vehicle posture detection method implemented by other devices 21 to 24 mounted on the vehicle (own vehicle) 10 by the preceding vehicle posture detection device 11 according to the embodiment of the present invention.

  First, in step S1, the imaging means 21 images the preceding vehicle from behind. The imaging means 21 acquires the image data of the preceding vehicle and transmits it to the preceding vehicle attitude detection device 11. Thereby, the preceding vehicle attitude | position detection apparatus 11 can acquire the image data of a preceding vehicle.

  FIG. 3 shows a schematic image (data) taken by the imaging means 21 from the own vehicle 10 on the back surface of the preceding vehicle (vehicle) 1 that runs straight ahead of the own vehicle 10. A center of gravity 2a of the vehicle body 2 and a roll center 2b of the vehicle body 2 exist on the vehicle body 2 (spring top) of the preceding vehicle 1. The vehicle body 2 (spring top) is supported by a suspension 3r (spring) disposed on the right side in the vehicle width direction in the traveling direction and a suspension 3l (spring) disposed on the left side. The suspension 3r is supported on the axle 5 in the vicinity of the wheel 4r. The suspension 3l is supported on the axle 5 in the vicinity of the wheel 4l. As shown in FIG. 3, the axle 5 of the wheel 4r and the axle 5 of the wheel 4l may be continuous or independent.

When the preceding vehicle (vehicle) 1 is running straight, forces fl and fr are applied to the vehicle body 2 from the left and right suspensions 3l and 3r, and the vehicle body 2 is kept horizontal. The distance between the point of action of the force fr by the suspension 3r and the roll center 2b and the distance of the point of action of the force fl by the suspension 3l and the roll center 2b are substantially equal to each other and can be set to L. At this time, the moments Ml (= −fl × L) and Mr (= fr × L) generated by the forces fl and fr around the roll center 2 b cancel each other and have the relationship of Formula 1. Due to this relationship, the vehicle body 2 is kept horizontal.
Ml + Mr = 0 (Formula 1)

FIG. 4 shows a schematic image (data) taken by the imaging means 21 from the own vehicle 10 on the back surface of the preceding vehicle 1 that bends and runs ahead of the own vehicle 10. When the preceding vehicle (vehicle) 1 is turning with a curvature R, a centrifugal force fc acts on the vehicle body 2. The action point of the centrifugal force fc can be regarded as the center of gravity 2a of the vehicle body 2. The center of gravity 2 a of the vehicle body 2 is located substantially immediately above the roll center 2 b of the vehicle body 2. The distance between the center of gravity 2a of the vehicle body 2 and the roll center 2b of the vehicle body 2 is H. The moment Mc created by the centrifugal force fc around the roll center 2b has the relationship of Formula 2.
Mc = −fc × H (Formula 2)

At this time, the moment Mc and the moments Ml and Mr that the centrifugal force fc and the forces fl and fr create around the roll center 2b cancel each other, and have the relationship of Formula 3. Equation 3 can be rewritten as Equation 4 using centrifugal force fc and forces fl and fr. Equation 4 can be rewritten as Equation 5.
Ml + Mr + Mc = 0 (Formula 3)
−fl × L + fr × L−fc × H = 0 (Expression 4)
fc = (− fl × L + fr × L) / H
= (Fr−fl) × L / H (Formula 5)

The forces fl and fr can be expressed as Equations 6 and 7 using the spring constant k of the suspensions 3r and 3l and the lengths xl and xr of the suspensions 3r and 3l from the natural length. . By substituting Equation 6 and Equation 7 into Equation 5, Equation 8 can be obtained.
fl = k × xl (formula 6)
fr = k × xr (Expression 7)
fc = (k × xr−k × xl) × L / H
= K × (xr−xl) × L / H (Expression 8)

The value of (xr−xl) in Equation 8 has the relationship of Equation 9 when the inclination angle (posture) of the vehicle body 2 with respect to the road surface or the axle 5 is θ. From this, the value of (xr−xl) can be obtained by Expression 10. The inclination (angle) θ of the vehicle body 2 can be measured from the image data acquired in step S1.
tan θ = (xr−xl) / 2L (Expression 9)
(Xr−xl) = 2L × tan θ (Expression 10)

  Therefore, in step S2 of FIG. 2, the posture (tilt angle) detecting means 12 detects (measures) the tilt (angle) θ of the vehicle body 2 from the image data.

  In step S3, the preceding vehicle information acquisition unit 13 uses the first database 13a to extract the vehicle type of the preceding vehicle that matches the image data.

  In step S4, the preceding vehicle information acquisition unit 13 determines whether or not the vehicle type has been extracted. If it is determined that the vehicle type has been extracted (step S4, Yes), the process proceeds to step S6. If it is not determined that the vehicle type has been extracted (No in step S4), the process proceeds to step S5.

  In step S6, the preceding vehicle information acquisition means 13 uses the first database 13a to determine vehicle information corresponding to the vehicle type (k: spring constant of the suspension 3r, 3l, L: suspension 3l, The distance between the action point of the forces fl and fr by 3r and the roll center 2b, H: the distance between the center of gravity 2a and the roll center 2b, and m: the weight of the vehicle body 2) are acquired as vehicle information of the preceding vehicle 1.

  In step S5, the preceding vehicle information acquisition unit 13 acquires predetermined vehicle information (k, L, H, m). Step S5 has steps S51 to S54.

  In step S51, the inter-vehicle distance acquisition means 23 measures (acquires) the inter-vehicle distance between the preceding vehicle and the host vehicle, and the preceding vehicle posture detection device 11 acquires the inter-vehicle distance (value).

  In step S52, the preceding vehicle information acquisition unit 13 calculates the size of the preceding vehicle 1 from the inter-vehicle distance and the image data. As the size, the vehicle width, the area of the back surface of the vehicle body 2, the length of the diagonal line on the back surface of the vehicle body 2, and the like can be used.

  In step S53, the preceding vehicle information acquisition unit 13 extracts a group (vehicle grade) of a range to which the size belongs from the second database 13b based on the calculated size.

  In step S54, the preceding vehicle information acquisition unit 13 uses the second database 13b to obtain vehicle information (k, L, H, m) corresponding to the vehicle type based on the extracted vehicle case, and the preceding vehicle 1 As vehicle information.

In step S7, the centrifugal force calculation means 14 determines the inclination (angle) θ of the vehicle body 2 detected in step S2, the spring constant k of the suspension 3r, 3l of the vehicle information acquired in step S5 or S6, and the suspensions 3l, 3r. The centrifugal force fc acting on the preceding vehicle 1 is calculated by substituting the distance L between the action point of the forces fl and fr and the roll center 2b and the distance H between the center of gravity 2a and the roll center 2b into Expression 11. To do. Expression 11 can be obtained from Expression 8 and Expression 10.
fc = k × 2L × tan θ × L / H (Expression 11)

  In step S8, the preceding vehicle speed acquisition unit 22 measures (acquires) the speed (vehicle speed) v of the preceding vehicle 1, and the first curvature calculation (acquisition) unit 15 acquires this.

In step S9, the first curvature calculation (acquisition) means 15 calculates the speed v of the preceding vehicle 1, the centrifugal force fc calculated in step S7, and the weight m of the vehicle body 2 of the vehicle information acquired in step S5 or S6. By substituting into Equation 12, the curvature (first curvature) R of the curved road on which the preceding vehicle 1 is traveling is calculated.
R = m × v ² / fc (Formula 12)

  In step S <b> 10, the map information acquisition unit 24 acquires map information including the curvature (second curvature) of the curved road located ahead of the road on which the vehicle travels, and transmits the map information to the second curvature acquisition unit 16. The second curvature acquisition unit 16 acquires the map information.

  In step S11, the second curvature acquisition unit 16 acquires the curvature of the curved road (second curvature) from the map information. In particular, the second curvature acquisition means 16 determines whether the center of the second curvature (radius) of the curve road is located on the right side or the left side of the preceding vehicle, that is, whether the curve road is clockwise or counterclockwise. Make it clear.

  In step S12, the curvature (direction) comparison unit 17 determines whether or not the first curvature substantially matches the second curvature. In particular, it is determined whether or not the first curvature and the second curvature coincide with each other in the clockwise direction or the counterclockwise direction. If it is determined that they match (step S12, Yes), the preceding vehicle posture detection method is stopped. If it is not determined that they match (step S12, No), the process proceeds to step S13.

  In step S13, the alerting means 18 prompts the driver of the host vehicle 10 to alert. According to this, the driver can be prepared for a situation where the curvatures do not match, such as an unexpected situation such as an obstacle avoided by the preceding vehicle 1.

1 vehicle (preceding vehicle)
2 Body 2a Center of gravity 2b Roll center 3r, 3l Suspension 4r, 4l Wheel 5 Axle 10 Vehicle (own vehicle)
11 Leading vehicle attitude detection device (control device)
12 posture (inclination angle) detection means 13 preceding vehicle information acquisition means 13a first database (vehicle type)
13b Second database (vehicle grade)
DESCRIPTION OF SYMBOLS 14 Centrifugal force calculation (acquisition) means 15 1st curvature calculation (acquisition) means 16 2nd curvature acquisition means 17 Curvature comparison means 18 Attention raising means 21 Imaging means (camera)
22 preceding vehicle speed acquisition means 23 inter-vehicle distance acquisition means 24 map information acquisition means (car navigation system, etc.)

Claims (4)

A preceding vehicle posture detection device that detects a traveling state from the posture of a preceding vehicle,
Inclination detecting means for detecting the inclination of the vehicle body as the posture of the preceding vehicle based on the image data of the preceding vehicle imaged by the imaging means;
Based on the image data, the group to which the preceding vehicle belongs is extracted, and the vehicle information corresponding to the extracted group includes the distance between the center of gravity of the vehicle body and the roll center, and the suspension vehicle that supports the center of gravity and the vehicle body. Preceding vehicle information acquisition means for acquiring a distance in the width direction and a spring constant of the suspension;
A preceding vehicle attitude detecting device, comprising: a centrifugal force calculating means for calculating, as the running state, a centrifugal force acting on the vehicle body when traveling on a curve of the preceding vehicle based on the inclination and the vehicle information. . The preceding vehicle information acquisition means acquires the weight of the vehicle body as the vehicle information,
The first curvature calculating means for calculating a first curvature of the curve based on the speed of the preceding vehicle acquired by the preceding vehicle speed acquiring means, the centrifugal force, and the weight. The preceding vehicle posture detection device according to 1. The group is a vehicle type,
Each vehicle type has a database having vehicle type image data that can be matched with the image data of the preceding vehicle, and the vehicle information,
The preceding vehicle information acquisition means extracts the vehicle type corresponding to the vehicle type image data matching the image data of the preceding vehicle from the database, and reads the vehicle information corresponding to the extracted vehicle type from the database. The preceding vehicle attitude detection device according to claim 1 or 2, wherein when there is no vehicle type image data that matches the image data of the preceding vehicle, vehicle information defined in advance is acquired. Second curvature acquisition means for acquiring a centripetal direction in the vehicle width direction in which the second curvature of the curve exists using map information acquisition means for acquiring map information of a road on which the vehicle travels;
Direction comparison means for determining whether or not the centrifugal direction in the vehicle width direction to which the centrifugal force is directed matches the centripetal direction;
The preceding vehicle posture detection device according to any one of claims 1 to 3, further comprising a warning means for urging the driver of the host vehicle to call attention when the coincidence is determined. .

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