JP4063170B2 - VEHICLE DRIVE OPERATION ASSISTANCE DEVICE AND VEHICLE HAVING VEHICLE DRIVE OPERATION ASSISTANCE DEVICE - Google Patents

Description

  The present invention relates to a driving operation assisting device for a vehicle that assists a driver's operation.

  Conventional vehicle driving assistance devices detect the situation (obstacles) around the vehicle and determine the potential risk potential at that time (see, for example, Patent Document 1). This vehicular driving operation assisting device controls the steering assist torque based on the calculated risk potential, thereby suppressing a steering operation that leads to an unexpected situation.

Prior art documents related to the present invention include the following.
Japanese Patent Application Laid-Open No. 10-211886 Japanese Patent Laid-Open No. 10-166889 Japanese Patent Laid-Open No. 10-166890

  In such a vehicle driving operation assisting device, the driver can easily understand which obstacle is the target of reaction force control, and the risk potential around the host vehicle is adjusted to the operational response of the vehicle operating device. It is desired that the power be reliably transmitted to the driver.

A vehicle driving operation assistance device according to the present invention includes an imaging unit that images a front area of a host vehicle, a preceding vehicle candidate detection unit that detects a preceding vehicle candidate from an image of the front area captured by the imaging unit, and a driving operation. In the vehicular driving operation assisting device having the operation reaction force control means for controlling the operation reaction force of the vehicle operating device related to the vehicle, the preceding vehicle candidate detecting means has two vertical lines extending from the lower end of the image as the preceding vehicle. The lowermost position detecting means for detecting the lengths of the two vertical lines to the intersection intersecting with the lowermost position of the candidate, and the lengths of the two vertical lines detected by the lowermost position detecting means are less than a predetermined value. And a preceding vehicle detection means for determining that the preceding vehicle candidate is a preceding vehicle when the vehicle is substantially the same, the operation reaction force control means is arranged before and after the own vehicle based on the determination result of the preceding vehicle detection means. Vehicle operation related to driving in the direction Comprising a front-back direction actuation reaction force control means for controlling the operation reaction force of the device, the two vertical lines, two horizontal direction in the image corresponding to the two obstacle detection directions set in order to detect an obstacle Each line extends vertically from the position.

  In the image of the front area of the host vehicle imaged by the imaging means, the lengths of the two vertical lines to the lowermost position of the preceding vehicle candidate are detected, the lengths of the two vertical lines are equal to or less than a predetermined value, and When it is substantially the same, it determines with a preceding vehicle candidate being a preceding vehicle. Since the operation reaction force control in the vehicle front-rear direction is performed based on the determination result of the preceding vehicle detection means, the operation reaction force control for the preceding vehicle can be performed with a simple method based only on the image of the front area of the host vehicle. .

<< First Embodiment >>
A vehicle operation assistance device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing a configuration of a vehicle driving assistance device 1 according to the first embodiment of the present invention, and FIG. 2 is a configuration diagram of a vehicle on which the vehicle driving assistance device 1 is mounted. .

First, the configuration of the vehicle driving assistance device 1 will be described.
The front camera 20 is a small CCD camera, a CMOS camera, or the like attached to the upper part of the front window, detects the state of the front road as an image, and outputs it to the controller 50. The detection area by the front camera 20 is about ± 30 deg in the horizontal direction with respect to the front surface of the host vehicle, and the front road scenery included in this area is captured as an image.

  The vehicle speed sensor 30 detects the vehicle speed of the host vehicle by measuring the number of rotations of the wheels and the number of rotations on the output side of the transmission, and outputs the detected host vehicle speed to the controller 50. The steering angle sensor 40 detects the steering angle of the steering wheel 62. The detected steering angle is output to the controller 50.

  The controller 50 includes a CPU and CPU peripheral components such as a ROM and a RAM, and performs overall control of the vehicle driving assistance device 1. The controller 50 detects an obstacle situation around the host vehicle from the host vehicle speed input from the vehicle speed sensor 30 and the image information around the vehicle input from the front camera 20. The controller 50 detects an obstacle situation around the host vehicle by performing image processing on the image information input from the front camera 20.

  The controller 50 calculates the risk potential of the host vehicle for each obstacle based on the detected obstacle situation, and performs reaction force control of the vehicle operating device according to the risk potential. The image processing executed in the controller 50 and the reaction force control using the image processing recognition result will be described later.

  The steering reaction force control device 60 is incorporated in the steering system of the vehicle and controls the torque generated by the servo motor 61 in response to a command from the controller 50. The servo motor 61 controls the torque generated according to the command value from the steering reaction force control device 60, and can arbitrarily control the steering reaction force generated when the driver operates the steering wheel 62.

  The accelerator pedal reaction force control device 80 controls the torque generated by the servo motor 81 in accordance with a signal from the controller 50. The servo motor 81 controls the torque and rotation angle generated according to the command value from the accelerator pedal operation reaction force control device 80, and arbitrarily controls the operation reaction force generated when the driver operates the accelerator pedal 82. can do.

  A normal accelerator pedal reaction force characteristic when the accelerator pedal reaction force control is not performed is set such that, for example, the accelerator pedal reaction force F increases linearly as the accelerator pedal operation amount increases. The normal accelerator pedal reaction force characteristic can be realized by the spring force of a torsion spring (not shown) provided at the center of rotation of the accelerator pedal 82, for example.

  The brake pedal reaction force control device 90 controls the brake assist force generated by the brake booster 91 in response to a command from the controller 50. The brake booster 91 controls the brake assist force generated according to the command value from the brake pedal reaction force control device 90, and can arbitrarily control the pedaling force generated when the driver operates the brake pedal 92. . As the brake assist force increases, the brake pedal operation reaction force decreases, and the brake pedal 92 is easily depressed.

Next, the operation of the vehicle driving assistance device 1 according to the first embodiment will be described. The outline of the operation will be described below.
The controller 50 calculates the risk potential for obstacles around the host vehicle, for example, the preceding vehicle and the lane marker. Then, the steering reaction force, the accelerator pedal reaction force, and the brake pedal reaction force are controlled in accordance with the risk potential, and the reaction force control in the vehicle front-rear direction and the left-right direction is performed.

  Here, for example, consider a case where the risk potential is calculated for each obstacle present in the 360 ° range around the host vehicle. In this case, the total risk potential in the front-rear direction and the left-right direction can be calculated by integrating the risk potential for all obstacles around the host vehicle for each component in the front-rear direction and the left-right direction. Continuous reaction force control in the front / rear / left / right direction can be performed by the reaction force control amount corresponding to the overall risk potential in the front / rear direction and the left / right direction.

  However, if all obstacles around the vehicle are detected in this way and the reaction potential control for front / rear / left / right is performed by integrating the risk potential for each obstacle, it is actually subject to reaction force control. It becomes difficult for the driver to understand what the obstacle is. Further, the process for calculating the overall risk potential in the front-rear direction and the left-right direction becomes complicated, and it is difficult to appropriately set the balance of reaction force control in the front-rear direction and the left-right direction.

  Therefore, in the first embodiment of the present invention, two directions for detecting an obstacle are set in front of the host vehicle, and risk potentials for obstacles existing in the set obstacle detection direction are respectively calculated. To do. And the risk potential with respect to two obstacles is compared, and the balance of the reaction force control amount of the front-back direction and the left-right direction is set appropriately.

  FIG. 3 shows an outline of the operation reaction force control in the first embodiment. As shown in FIG. 3, in the first embodiment, when a preceding vehicle is detected in two obstacle detection directions based on image information from the front camera 20, the front and rear of the vehicle according to the risk potential for the preceding vehicle. Control direction reaction force. On the other hand, when a lane marker is detected in two obstacle detection directions, or when a lane marker and a preceding vehicle are detected respectively, depending on the risk potential for each obstacle present in the two obstacle detection directions, Performs reaction force control in both direction and left / right direction.

  Hereinafter, in the first embodiment, how to determine the reaction force control amount, that is, the reaction force control command value when performing the steering reaction force control, the accelerator pedal reaction force control, and the brake pedal reaction force control. This will be described with reference to FIG. FIG. 4 is a flowchart showing a processing procedure of the driving operation assist control processing in the controller 50 according to the first embodiment. This processing content is continuously performed at regular intervals, for example, every 50 msec.

-Processing flow of controller 50 (Fig. 4)-
First, the travel state is read in step S101. Here, the host vehicle speed V detected by the vehicle speed sensor 30 and the steering angle STR detected by the steering angle sensor 40 are read. In step S102, image information of the vehicle front area detected by the front camera 20 is read.

  In step S103, the detection position of the horizontal edge in the detection image of the front camera 20, that is, the obstacle detection direction is determined. Specifically, as shown in FIG. 5, a center angle θc for determining the center line in the two obstacle detection directions and an opening angle α formed by the center line and each detection direction are calculated. Specifically, the approximate traveling direction of the host vehicle is estimated from the host vehicle speed V detected in step S101 and the steering angle STR, and an angle substantially coincident with the traveling direction with respect to the front surface of the host vehicle is set as the central angle θc. Since the traveling direction of the host vehicle is proportional to the steering angle STR and is approximately inversely proportional to the host vehicle speed V, the center angle θc increases as the steering angle STR increases, and conversely, the center angle θc decreases as the host vehicle speed V increases.

  The opening angle α is determined according to the host vehicle speed V. FIG. 6 shows the relationship between the vehicle speed V and the opening angle α. The opening angle α indicates a change in the traveling direction of the host vehicle that is predicted when the steering angle STR changes by a minute angle. Since the change in the traveling direction with respect to the change in the steering angle STR is smaller as the host vehicle speed V increases, the opening angle α is set to decrease as the host vehicle speed V increases, as shown in FIG.

  The controller 50 determines two obstacle detection directions θL and θR with respect to the front surface of the host vehicle from the calculated center angle θc and opening angle α. In the traveling state shown in FIG. 5, the right obstacle detection direction θR = θc + α and the left obstacle detection direction θL = α−θc are represented.

  In step S104, the image information of the front area of the host vehicle read in step S102 is subjected to image processing, and an obstacle is detected by detecting a horizontal component in the image, that is, a horizontal edge. FIG. 7 is an image (camera screen) of the front area of the host vehicle detected by the front camera 20, and shows an example in which a preceding vehicle is present in front of the host vehicle. In the camera screen shown in FIG. 7, the X axis is taken in the horizontal direction and the Y axis is taken in the vertical direction. The controller 50 determines the X coordinates XL and XR corresponding to the two obstacle detection directions θL and θR set in step S103 on the camera screen.

The X coordinate values XL and XR corresponding to the two lane boundary detection directions θL and θR can be set using the following (Expression 1) and (Expression 2).
XL = k · θL (Formula 1)
XR = k · θR (Formula 2)
In (Expression 1) and (Expression 2), k is a constant for converting the angles θL and θR into the X coordinate of the camera screen.

  Then, the controller 50 detects the vertical position from the lower end of the horizontal edge in the X coordinate values XL and XR on the camera screen, that is, the Y coordinate values YL and YR of the obstacle, respectively. As a horizontal edge on the camera screen, for example, an obstacle having a horizontal component on the screen such as a shadow of a preceding vehicle or a lane marker is detected as shown in FIG.

  In subsequent step S105, it is determined whether or not the Y coordinate values YL and YR of the horizontal edge at the detection position that coincides with the two obstacle detection directions detected in step S104 are substantially the same. When the Y coordinate values YL and YR of the horizontal edge are substantially the same (YL≈YR), the process proceeds to step S106. In step S106, it is determined whether or not the Y coordinate values YL and YR of the horizontal edge are both equal to or smaller than a predetermined value Ya. If the determination in step S106 is affirmative and the Y coordinate values YL and YR of the two horizontal edges on the camera screen are substantially the same and not more than the predetermined value Ya, it is determined that the horizontal edge on the camera screen is due to the preceding vehicle. . That is, it is determined that the preceding vehicle is detected in the two obstacle detection directions, and the process proceeds to step S120 in order to perform the operation reaction force control for the preceding vehicle.

  The predetermined value Ya is appropriately set in advance as a value for determining whether or not a preceding vehicle candidate that forms a horizontal edge on the camera screen is regarded as a target of the reaction force control for the preceding vehicle. For example, when the Y coordinate values YL and YR of the horizontal edge are larger than a predetermined value Ya, even if the Y coordinate values YL and YR are substantially the same, the preceding vehicle exists far away, or the preceding vehicle candidates are on both sides of the own vehicle. Lane marker. In such a case, the Y coordinate values YL and YR of the horizontal edge are compared with a predetermined value Ya so that the preceding vehicle candidate forming the horizontal edge is excluded from the target of the reaction force control for the preceding vehicle.

  On the other hand, if a negative determination is made in step S105 or S106, it is determined that the horizontal edge on the camera screen is not due to the preceding vehicle. That is, it is determined that the lane marker or the lane marker and the preceding vehicle are detected in the two obstacle detection directions. Therefore, the process proceeds to step S110 in order to perform an operation reaction force control on the lane marker.

  In step S110, margin times TTC (Time To Contact) for obstacles existing in the two obstacle detection directions are calculated. In order to calculate the margin time TTC for the obstacle, the controller 50 first calculates the distance D to the obstacle in the two obstacle detection directions. Here, the distance D and the margin time TTC to the obstacle in the right obstacle detection direction are respectively DR and TTCR, and the distance D and the margin time TTC to the obstacle in the left obstacle detection direction are respectively DL and TTCR. Let TTCL. Hereinafter, a method for calculating the distances DL and DR to the obstacle will be described in detail with reference to FIGS. Here, a case where the distance D to the lane marker position 60 ahead of the host vehicle is calculated will be described as an example.

  FIG. 8 is a side view showing the positional relationship between the host vehicle and the lane marker position 60. FIG. 9 shows a camera screen of the front camera 20. The lane marker position 60 is represented as an intersection of the vertical line of the coordinate value X0 and the lane marker on the camera screen shown in FIG. The actual distance D from the host vehicle to the lane marker can be calculated using the length of the vertical line of the coordinate value X0 on the camera screen, that is, the Y coordinate value YE of the lane marker position 60.

The parameters used when calculating the distance D to the lane marker position 60 are as follows.
Hc: Mounting height of the front camera 20 (m, fixed value).
D0: Distance in the front-rear direction between the front end of the vehicle body and the mounting position of the front camera 20 (m, fixed value).
DC: Distance from front camera 20 to lane marker position 60 (m).
Y0: Y coordinate value (fixed value) indicating a point at infinity (horizontal direction) in the camera screen.
YE: Y coordinate value of the lane marker position 60 in the camera screen.
dY: A relative Y coordinate value with respect to the infinity point of the lane marker position 60 in the camera screen.

Hc, D0, and Y0 are fixed values and are stored in the memory of the controller 50 in advance. The distance DC and the Y coordinate value dY are represented by the following (formula 3) and (formula 4), respectively.
DC = D + D0 (Formula 3)
dY = Y0−YE (Formula 4)

Here, when the angular resolution Δθ (rad) per Y coordinate value of the front camera 20 is used, the following (Equation 5) is established from the geometric relationship shown in FIGS. 8 and 9.
dY = Hc / DC / Δθ (Formula 5)
By arranging (Equation 3) to (Equation 5), the following (Equation 6) is obtained.
D = HC / (Y0−YE) / Δθ−D0 (Expression 6)

  Using the Y coordinate values Y0 and YE obtained from the camera screen, the distance D to the lane marker position 60 can be calculated from (Equation 6). As described above, the controller 50 calculates the distances DL and DR to the obstacle for the X coordinate values XL and XR corresponding to the two obstacle detection directions.

Further, the controller 50 calculates margin times TTC for the obstacles in the two obstacle detection directions, using the calculated distances DL and DR. When the lane marker exists in the two obstacle detection directions, the controller 50 divides the distance D (DL, DR) to the lane marker by the own vehicle speed V, thereby obtaining a margin time TTC (TTCL) from the following (Equation 7). , TTCR) can be calculated.
TTC = D / V (Expression 7)

  The margin time TTC is a physical quantity indicating the current degree of approach of the host vehicle to the obstacle, and indicates the time until the host vehicle reaches the obstacle separated by the distance D. The margin time TTC for the lane marker can be calculated by dividing the distance D by the vehicle speed V because the lane marker is fixed to the road. When calculating the margin time TTC for the preceding vehicle, the relative speed Vr between the host vehicle and the preceding vehicle is used instead of the host vehicle speed V, as will be described later.

  In step S111, the left and right margin times TTCR and TTCL calculated in step S110 are compared to determine whether the margin time TTC for the left or right lane marker is small. If the margin time TTCR for the right lane marker is smaller than the margin time TTCL for the left lane marker, the process proceeds to step S112.

  In step S112, the risk potential RPlateral in the left-right direction is calculated based on the margin time TTCR on the smaller right side. FIG. 10 shows the relationship between the margin time TTC and the left-right direction risk potential RPlateral. As shown in FIG. 10, the left-right risk potential RPlateral increases as the margin time TTC decreases and the degree of approach between the host vehicle and the lane marker increases. When the margin time TTC is smaller than the predetermined value TTC1, the left-right risk potential RPlateral is fixed to the predetermined value RPm.

  In subsequent step S113, it is determined whether or not the larger left side margin time TTCL is smaller than a predetermined value T0. If the left margin time TTCL is smaller than the predetermined value T0, the process proceeds to step S114. In step S114, the risk potential RPlongitudinal in the front-rear direction is calculated based on the left margin time TTCL. FIG. 11 shows the relationship between the margin time TTC and the longitudinal risk potential RPlongitudinal. As shown in FIG. 11, the front-rear risk potential RPlongitudinal increases as the margin time TTC decreases and the degree of approach between the host vehicle and the lane marker increases. When the margin time TTC is smaller than the predetermined value TTC2, the front-rear direction risk potential RPlongitudinal is fixed to the predetermined value RPn.

  When a negative determination is made in step S113 and the larger left side margin time TTCL is equal to or greater than the predetermined value T0, the front-rear risk potential RPlongitudinal is not calculated. That is, when the margin time TTC is equal to or greater than the predetermined value T0, it is determined that the degree of approach between the host vehicle and the lane marker is small, and reaction force control in the front-rear direction is not performed. Here, the predetermined value T0 is set to about 7 seconds, for example.

  On the other hand, if it is determined in step S111 that the margin time TTCL for the left lane marker is equal to or less than the margin time TTCR for the right lane marker, the process proceeds to step S115. In step S115, the risk potential RPlateral in the left-right direction is calculated based on the left side margin time TTCL. Here, similarly to step S112, the left-right risk potential RPlateral corresponding to the left margin time TTCL is calculated using the map of FIG.

  In subsequent step S116, it is determined whether or not the larger right margin time TTCR is smaller than a predetermined value T0. If the right margin time TTCR is smaller than the predetermined value T0, the process proceeds to step S117. In step S117, the risk potential RPlongitudinal in the front-rear direction is calculated based on the right margin time TTCR. Here, similarly to step S114, the longitudinal risk potential RPlongitudinal corresponding to the right margin time TTCR is calculated using FIG. When a negative determination is made in step S116 and the larger right side margin time TTCR is equal to or greater than the predetermined value T0, the front-rear risk potential RPlongitudinal is not calculated, and the reaction force control in the front-rear direction is not performed.

  When an affirmative determination is made in step S106 and the process proceeds to step S120, an allowance time TTC for the preceding vehicle is calculated in order to perform an operation reaction force control for the preceding vehicle. Here, as in step S110 described above, in order to calculate the margin time TTC, first, the distance D to the preceding vehicle is calculated. The controller 50 calculates the distance D to the preceding vehicle from (Equation 6) described above using the Y coordinate values YL and YR of the lowermost position of the preceding vehicle on the camera screen as shown in FIG. Since the Y coordinate values YL and YR of the horizontal edge in the two obstacle detection directions are substantially equal, the distance D to the preceding vehicle can be calculated using one of the Y coordinate values. Further, the controller 50 calculates the relative speed Vr between the host vehicle and the preceding vehicle, for example, from the time change of the calculated distance D to the preceding vehicle.

The controller 50 calculates a margin time TTC for the preceding vehicle from the calculated distance D to the preceding vehicle and the relative speed Vr. As described above, the margin time TTC is a physical quantity representing the current degree of approach of the host vehicle to the obstacle. The margin time TTC for the preceding vehicle indicates how many seconds later the inter-vehicle distance D becomes zero and the host vehicle and the preceding vehicle come into contact with each other when the current traveling state continues, that is, when the relative vehicle speed Vr is constant. The margin time TTC for the preceding vehicle can be calculated by the following (Equation 8).
TTC = D / Vr (Formula 8)

  In step S121, it is determined whether the margin time TTC calculated in step S120 is smaller than a predetermined value T0. If the determination in step S121 is affirmative and the margin time TTC is less than the predetermined value, the process proceeds to step S122. In step S122, the risk potential RPlongitudinal in the front-rear direction is calculated based on the margin time TTC for the preceding vehicle using the map of FIG. 11 as in step S114 or S117 described above.

  If a negative determination is made in step S121 and the margin time TTC for the preceding vehicle is equal to or greater than the predetermined value T0, the longitudinal risk potential RPlongitudinal is not calculated, and the operation reaction force control in the vehicle longitudinal direction and the lateral direction is not performed.

  In step S130, based on the longitudinal risk potential RPlongitudinal calculated in step S114, S117, or S122, the longitudinal control command value, that is, the reaction force control command value FA output to the accelerator pedal reaction force control device 80, and the brake pedal reaction The reaction force control command value FB output to the force control device 90 is calculated. In accordance with the longitudinal risk potential RPlongitudinal, the greater the risk potential, the more the control reaction force is generated in the direction in which the accelerator pedal 82 is returned, and the control reaction force is generated in the direction in which the brake pedal 92 is easily depressed. This prompts the driver to operate from the accelerator pedal to the brake pedal.

  FIG. 12 shows the relationship between the longitudinal risk potential RPlongitudinal and the accelerator pedal reaction force control command value FA. As shown in FIG. 12, the accelerator pedal reaction force control command value FA increases so that the accelerator pedal reaction force increases as the front-rear risk potential RPlongitudinal increases. When the front-rear risk potential RPlongitudinal is equal to or greater than a predetermined value RPmax, the accelerator pedal reaction force control command value FA is fixed to the maximum value FAmax so as to generate the maximum accelerator pedal reaction force.

  FIG. 13 shows the relationship between the longitudinal risk potential RPlongitudinal and the brake pedal reaction force control command value FB. As shown in FIG. 13, the brake pedal reaction force control command value FB decreases as the brake pedal reaction force decreases, that is, the brake assist force increases, as the front-rear risk potential RPlongitudinal increases above a predetermined value RPmax.

  When a negative determination is made in step S113, S116, or S121, the reaction force control in the front-rear direction is not performed, and normal pedal reaction forces corresponding to the respective operation amounts are generated in the accelerator pedal 82 and the brake pedal 92.

  In step S131, the left-right direction control command value, that is, the steering reaction force control command value FS output to the steering reaction force control device 60 is calculated from the left-right risk potential RPlateral calculated in step S112 or S115. In accordance with the left-right risk potential RPlateral, the greater the risk potential, the greater the steering reaction force is generated in the direction to return the steering wheel 62 to the neutral position.

  FIG. 14 shows the relationship between the left-right risk potential RPlateral and the steering reaction force control command value FS. As shown in FIG. 14, the steering reaction force control command value FS increases as the left-right risk potential RPlateral increases, and the steering reaction force in the direction to return the steering wheel 62 to the neutral position increases. In FIG. 14, the left-right risk potential RPlateral for the obstacle present in the right obstacle detection direction is shown in a positive region, and the left-right risk potential RPlateral for the obstacle present in the left obstacle detection direction is Shown in the negative area.

  In step S132, the front-rear direction control command values FA and FB calculated in step S130 are output to the accelerator pedal reaction force control device 80 and the brake pedal reaction force control device 90, and the left-right direction control command value FS calculated in step S131 is steered. Output to reaction force control command value 60. Thus, the current process is terminated.

  FIGS. 15A and 15B are diagrams for explaining the operation of the first embodiment. FIG. 15A shows a state where the host vehicle is traveling on a straight road, and FIG. 15B shows a state where the host vehicle is traveling on a curved road. FIGS. 15 (a) and 15 (b) both show a case where a lane marker existing in two obstacle detection directions is detected.

  In the traveling situation shown in FIG. 15 (a), the host vehicle goes straight on the left side of the host lane. Since the traveling direction of the host vehicle is substantially in front of the host vehicle, the center angle θc is 0, and the opening angle α is α ° to the left and right with respect to the front of the host vehicle. On the two obstacle detection directions set by the center angle θc and the opening angle α, there are lane markers on the right and left sides of the host vehicle. Therefore, the controller 50 calculates margin times TTCR and TTCL for each lane marker.

  As shown in FIG. 15 (a), the host vehicle travels to the left of the host lane, so the margin time TTCL for the left lane marker is smaller than the margin time TTCR for the right lane marker. Therefore, the controller 50 calculates the left-right risk potential RPlateral based on the left margin time TTCL, and controls the steering reaction force according to the left-right risk potential RPlateral. On the other hand, when the right margin time TTCR is smaller than the predetermined value T0, the controller 50 calculates the front-rear risk potential RPlongitudinal based on the surplus time TTCR, and the accelerator pedal reaction force control and brake according to the front-rear risk potential RPlongitudinal. Perform pedal reaction force control.

  As a result, a steering reaction force corresponding to the risk potential RP for the left lane marker is generated, and an accelerator pedal reaction force and a brake pedal reaction force corresponding to the risk potential RP for the right lane marker are generated. In this way, an operation reaction force in which the front-rear and left-right balances are appropriately set is generated, and the driving operation of the driver is urged in an appropriate direction. Note that, in the traveling state as shown in FIG. 15A, the margin time TTCR on the right side is relatively large, so the reaction force control amount in the vehicle front-rear direction is small. Therefore, an operation reaction force that prevents the driver from operating the accelerator pedal and the brake pedal is not generated by performing the reaction force control.

  In the traveling situation shown in FIG. 15B, the host vehicle is about to depart from the host lane while traveling on a curved road. Since the traveling direction of the host vehicle is substantially in front of the host vehicle, the center angle θc is 0, and the opening angle α is α ° to the left and right with respect to the front of the host vehicle. On the two obstacle detection directions set by the center angle θc and the opening angle α, there is a lane marker on the left side of the own lane. Therefore, the controller 50 calculates margin times TTCR and TTCL for the two lane markers in the obstacle detection direction.

  As shown in FIG. 15B, the host vehicle is about to deviate from the right curve to the left side, so that the left side margin time TTCL is smaller than the right side margin time TTCR. Therefore, the controller 50 calculates the left-right risk potential RPlateral based on the left margin time TTCL, and controls the steering reaction force according to the left-right risk potential RPlateral. On the other hand, when the right margin time TTCR is smaller than the predetermined value T0, the controller 50 calculates the front-rear risk potential RPlongitudinal based on the surplus time TTCR, and the accelerator pedal reaction force control and brake according to the front-rear risk potential RPlongitudinal. Perform pedal reaction force control. As a result, a steering reaction force corresponding to the risk potential RP for the lane marker in the obstacle detection direction on the left side close to the host vehicle is generated, and the risk potential RP for the lane marker in the right obstacle detection direction far from the host vehicle is generated. A corresponding accelerator pedal reaction force and brake pedal reaction force are generated.

  Therefore, as shown in FIG. 15B, when the host vehicle is about to depart from the curve, a steering reaction force is generated in the direction of returning the steering wheel 62, and the driver's driving operation is urged in an appropriate direction. At this time, when the right margin time TTCR is relatively large, the reaction force control amount in the vehicle longitudinal direction is small. When the host vehicle continues to move forward and further approaches the lane marker, both the left margin time TTCL and the right margin time TTCR are reduced, and the reaction force control amount in the vehicle left-right direction and the front-rear direction is increased. As a result, a steering reaction force is generated so that the host vehicle does not deviate from the curve, and a deceleration operation by the driver is urged. In this way, the reaction force control is performed by appropriately setting the balance between the front and rear and left and right reaction force control.

  The operation of the vehicular driving assist device 1 in each driving situation will be described with reference to FIGS. 16 to 21 showing more specific driving situations of the host vehicle and the preceding vehicle. 16 to 21, the arrow indicates the obstacle detection direction with respect to the host vehicle, the length of the arrow corresponds to the Y coordinate values YL and YR of the horizontal edge on the camera screen, and the obstacle in the obstacle detection direction from the host vehicle. Indicates the distance to the object.

  FIG. 16 shows a scene in which the host vehicle travels following the preceding vehicle while keeping the inter-vehicle distance short. In the situation shown in FIG. 16, the distance to the obstacle in the right obstacle detection direction and the distance to the obstacle in the left obstacle detection direction, that is, the Y coordinate values YR and YL of the horizontal edge on the camera screen are approximately. The Y coordinate values YR and YL are equal to or less than a predetermined value Ya. Therefore, the controller 50 determines that the obstacle existing in the two obstacle detection directions is the preceding vehicle. Therefore, the controller 50 calculates the margin time TTC based on the distance D to the preceding vehicle, and performs reaction force control in the vehicle longitudinal direction based on the margin time TTC for the preceding vehicle. At this time, the reaction force control in the vehicle left-right direction is not performed. Accordingly, an operation reaction force corresponding to the risk potential RP for the preceding vehicle is generated in the accelerator pedal 82 and the brake pedal 92, and the driver can be prompted to decelerate.

  FIG. 17 shows a scene in which the host vehicle travels following the preceding vehicle while maintaining a long inter-vehicle distance. In the situation shown in FIG. 17, the distance to the obstacle in the right obstacle detection direction and the distance to the obstacle in the left obstacle detection direction, that is, the Y coordinate values YR and YL of the horizontal edge on the camera screen are approximately. Although the same, the Y coordinate values YR and YL exceed the predetermined value Ya. Therefore, the controller 50 determines that the obstacle present in the obstacle detection direction is not the preceding vehicle. Therefore, the controller 50 calculates a margin time TTC based on the distance D to the lane marker, and performs reaction force control in the vehicle front-rear direction and the left-right direction based on the margin time TTC with respect to the lane marker.

  As a result, a reaction force corresponding to the risk potential RP with respect to the lane marker is generated in the accelerator pedal 82 or the brake pedal 92. However, since the margin time TTC with respect to the lane marker is longer than that in the traveling state shown in FIG. 16, the pedal reaction force that hinders the driving operation of the driver is not generated by performing the reaction force control. Further, the steering reaction force control is performed according to the risk potential RP for the lane marker, but the left and right risk potentials RP are balanced, and the substantial steering reaction force control amount FS becomes zero.

  FIG. 18 shows a scene in which the host vehicle travels to the left of the host lane while maintaining a long inter-vehicle distance from the preceding vehicle. As shown in FIG. 18, the right lane marker is detected in the right obstacle detection direction, and the left lane marker is detected in the left obstacle detection direction. The controller 50 calculates distances DR and DL to the right and left lane markers of the own lane, and calculates margin times TTCR and TTCL based on the calculated distances DR and DL, respectively. Then, the controller 50 performs reaction force control in the vehicle front-rear direction based on the larger margin time TTC, that is, the margin time TTCR for the right lane marker, and the smaller margin time TTC, that is, the lane marker on the left side of the own lane. Reaction force control in the vehicle left-right direction is performed based on the allowance time TTCL.

  As a result, a steering reaction force is generated in a direction in which the steering wheel 62 is returned to the neutral position in accordance with the risk potential RP for the left lane marker. Further, a pedal reaction force corresponding to the risk potential RP for the right lane marker is generated.

  FIG. 19 shows a scene in which the host vehicle travels closer to the left side of the host lane from the driving situation shown in FIG. As shown in FIG. 19, the preceding vehicle is detected in the right obstacle detection direction, and the lane marker on the left side of the own lane is detected in the left obstacle detection direction. The controller 50 calculates a distance DR to the preceding vehicle and a distance DL to the lane marker on the left side of the own lane, and calculates a margin time TTCR for the preceding vehicle and a margin time TTCL for the left lane marker. Then, the controller 50 performs reaction force control in the vehicle longitudinal direction based on the larger margin time TTCR, that is, the margin time TTCR for the preceding vehicle, and based on the smaller margin time TTCL, that is, the margin time TTCL for the left lane marker. To control the reaction force in the vehicle lateral direction.

  As a result, a steering reaction force is generated in a direction to return the steering wheel 62 to the neutral position in accordance with the risk potential RP for the left lane marker. Further, a reaction force corresponding to the risk potential RP for the preceding vehicle is generated in the accelerator pedal 82 or the brake pedal 92.

  FIG. 20 shows a scene in which the preceding vehicle approaches the left side of the own lane in a state where the distance between the own vehicle and the preceding vehicle is short. For example, the case where the vehicle ahead of the host vehicle is parked at the left end of the host lane is also included in the scene shown in FIG. As shown in FIG. 20, the right lane marker is detected in the right obstacle detection direction, and the preceding vehicle is detected in the left obstacle detection direction. The controller 50 calculates the distance DR to the right lane marker and the distance DL to the preceding vehicle, and calculates the margin time TTCR for the right lane marker and the margin time TTCL for the preceding vehicle. Then, the controller 50 controls the reaction force in the vehicle longitudinal direction based on the larger margin time TTCR, that is, the margin time TTCR for the right lane marker, and based on the smaller margin time TTCL, that is, the margin time TTCL for the preceding vehicle. To control the reaction force in the vehicle lateral direction.

  As a result, a steering reaction force corresponding to the risk potential RP for the preceding vehicle is generated, and a steering operation in a direction to avoid the preceding vehicle is urged. Further, a reaction force corresponding to the risk potential RP for the right lane marker is generated in the accelerator pedal 82 or the brake pedal 92.

  FIG. 21 shows a scene in which the host vehicle approaches the left side of the host lane in a state where the distance between the host vehicle and the preceding vehicle is short. As shown in FIG. 21, the preceding vehicle is detected in the right obstacle detection direction, and the lane marker on the left side of the own lane is detected in the left obstacle detection direction. The controller 50 calculates a distance DR to the preceding vehicle and a distance DL to the lane marker on the left side of the own lane, and calculates a margin time TTCR for the preceding vehicle and a margin time TTCL for the left lane marker. Then, the controller 50 performs reaction force control in the vehicle longitudinal direction based on the larger margin time TTCL, that is, the margin time TTCL for the left lane marker, and based on the smaller margin time TTCR, that is, the margin time TTCR for the preceding vehicle. To control the reaction force in the vehicle lateral direction.

  As a result, a steering reaction force corresponding to the risk potential RP for the preceding vehicle is generated, and a steering operation in a direction to avoid the preceding vehicle is urged. Further, a reaction force corresponding to the risk potential RP for the left lane marker is generated in the accelerator pedal 82 or the brake pedal 92.

  22 and 23 are diagrams for explaining other actions according to the first embodiment. Here, an operation in the case where the front-rear direction reaction force control is performed based on the distance to the obstacle detected from the image of the front camera 20 when the host vehicle travels on a slope will be described. 22 and 23 show an example in which a lane marker is detected as an obstacle ahead of the host vehicle. 22A to 22E show changes in the camera screen of the front camera 20 and changes in the front-rear direction control command value when the host vehicle travels uphill. FIGS. 23A to 23E show changes in the camera screen of the front camera 20 and changes in the front-rear direction control command value when the host vehicle travels downhill. FIGS. 22A to 22E and FIGS. 23A to 23E also show the operation of the third and fourth embodiments described later.

  As shown in FIG. 22A, when the host vehicle enters an ascending slope from a flat road, the infinity point (horizontal direction) on the camera screen of the front camera 20 is directed upward of the camera screen as indicated by an arrow. Moving. As a result, the horizontal edge in the obstacle detection direction on the camera screen, here, the Y coordinate value of the lane marker increases. As described above, the Y coordinate value of the lane marker is calculated from the lower end of the camera screen, and the Y coordinate value Y0 at the infinity point on the camera screen is a fixed value. Therefore, the distance D from the host vehicle to the lane marker in the obstacle detection direction, which is calculated using the Y coordinate value of the lane marker and the Y coordinate value of the infinity point, increases, and the margin time TTC to the lane marker also increases. Since the forward / rearward risk potential RPlongitudinal is reduced due to the increase in the margin time TTC, the forward / backward control command value is reduced.

  Therefore, when the host vehicle enters an uphill, the image state of the camera screen changes according to the road gradient, and the front-rear direction control command value is automatically reduced. As a result, the accelerator pedal reaction force generated when the accelerator pedal 82 is operated is reduced, and acceleration can be promoted when the host vehicle enters the uphill. As described above, the front-rear direction reaction force control is performed only when the margin time TTC for the obstacles in the two obstacle detection directions is less than the predetermined value T0.

  After the host vehicle has entered the uphill as shown in FIG. 22 (b), the vehicle body of the host vehicle becomes parallel to the road gradient, so that the infinity point on the camera screen is shown on the camera screen as indicated by the arrow. It returns almost to the middle. Along with this, the Y coordinate value of the lane marker increased when entering the uphill returns to a value that is not affected by the road gradient, that is, a normal value. As a result, the front-rear direction control command value that has decreased when approaching the uphill is restored to a normal value that is the same as when the host vehicle travels on a flat road.

  Therefore, as shown in FIG. 22B and FIG. 22C, when the host vehicle is traveling on the uphill, the Y coordinate value of the lane marker is calculated without being affected by the road gradient. Accordingly, the front-rear direction control command value is calculated using the accurate distance D to the lane marker, as in the case where the host vehicle is traveling on a flat road.

  As shown in FIG. 22D, when the host vehicle exits from the uphill, the infinity point on the camera screen of the front camera 20 moves downward as shown by the arrow. Along with this, the Y coordinate value to the lane marker decreases, and the margin time TTC for the lane marker decreases. In this way, when the host vehicle exits from the uphill, the image state of the camera screen changes according to the change in the road gradient, and the front-rear direction control command value automatically increases. As a result, the accelerator pedal reaction force generated when the accelerator pedal 82 is operated increases, and it is possible to prompt the vehicle to decelerate when shifting from an uphill to a flat road.

  As shown in FIG. 22 (e), after the vehicle leaves the uphill, the infinity point on the camera screen returns to the middle of the camera screen as indicated by the arrow, and the Y coordinate value up to the lane marker is normal. Return to value. Thereby, the front-rear direction control command value is calculated using the accurate distance D to the lane marker, and the front-rear direction control command value increased when getting out of the uphill is returned to the normal value.

  On the other hand, when the host vehicle enters a downhill from a flat road as shown in FIG. 23A, the infinity point on the camera screen of the front camera 20 moves downward as shown by the arrow. Along with this, the Y coordinate value of the lane marker decreases, the margin time TTC to the lane marker decreases, and the longitudinal control command value increases automatically. Thereby, the accelerator pedal reaction force increases, and it is possible to prompt the vehicle to decelerate when entering the downhill.

  After the host vehicle enters the downhill as shown in FIG. 23 (b), the infinity point on the camera screen returns almost to the middle as indicated by the arrow. As a result, the Y coordinate value of the lane marker returns to a normal value, and the front-rear direction control command value increased when entering the downhill returns to a normal value calculated from the accurate distance D to the lane marker.

  Therefore, as shown in FIGS. 23 (b) and 23 (c), when the host vehicle is traveling downhill, the Y coordinate value of the lane marker is calculated without being affected by the road gradient. As a result, the front-rear direction control command value is calculated using the accurate distance D to the lane marker as in the case of traveling on a flat road.

  As shown in FIG. 23D, when the host vehicle exits from the downhill, the point at infinity on the camera screen moves upward as shown by the arrow. Along with this, the Y coordinate value to the lane marker increases, the margin time TTC to the lane marker increases, and the longitudinal control command value automatically decreases. As a result, the accelerator pedal reaction force is reduced, and acceleration of the host vehicle can be promoted when getting out of the downhill.

  As shown in FIG. 23 (e), after the vehicle exits the downhill, the infinity point on the camera screen returns to the middle of the camera screen as indicated by the arrow, and the Y coordinate value up to the lane marker is normal. Return to value. As a result, the front-rear direction control command value is calculated using the accurate distance D to the lane marker, and the front-rear direction control command value decreased when getting out of the downhill returns to the normal value.

  The above-described change in the reaction force control command value due to the road gradient is the same when there is a preceding vehicle ahead of the host vehicle, and also applies to the reaction force control command value in the left-right direction as well as the front-rear direction. .

Thus, in the first embodiment described above, the following operational effects can be achieved.
(1) The controller 50 performs image processing on the image of the front camera 20 to recognize an obstacle existing ahead of the host vehicle, that is, a preceding vehicle candidate, and two vertical lines are displayed in the front image as shown in FIG. The lengths YL and YR of the two vertical lines up to the intersection that intersects with the lowermost position of the preceding vehicle candidate are detected. The controller 50 determines that the preceding vehicle candidate on the camera screen is the preceding vehicle when the lengths YL and YR of the two vertical lines are substantially the same and are equal to or less than the predetermined value Ya. Thereby, it can be simply determined based on the image information from the front camera 20 whether the preceding vehicle candidate ahead of the own vehicle is a preceding vehicle. Further, the controller 50 determines the vehicle operation equipment related to the driving operation in the front-rear direction of the host vehicle, such as the accelerator pedal 82 and the brake pedal 92, based on the preceding vehicle determination result using the lengths YL and YR of the two vertical lines. Control the reaction force. The accelerator pedal reaction force control device 80 and the brake pedal reaction force control device 90 perform reaction force control in the vehicle front-rear direction based on the distance D to the preceding vehicle candidate ahead of the host vehicle. Specifically, when it is determined that the preceding vehicle candidate is the preceding vehicle, the operation reaction force of the accelerator pedal 82 and the brake pedal 92 is controlled based on the distance D to the preceding vehicle. Thereby, the driving operation by the driver can be urged in an appropriate direction. When the lengths YL and YR of the two vertical lines are equal to or smaller than the predetermined value Ya, the preceding vehicle candidate on the camera screen is regarded as an object of the operation reaction force control for the preceding vehicle, and thus is calculated from the captured image of the front camera 20 Based on the accurate distance D to the preceding vehicle, the operation reaction force control in the vehicle longitudinal direction can be performed.
(2) When the lengths YL and YR of the two vertical lines on the camera screen are different or when the lengths YL and YR of the two vertical lines are greater than the predetermined value Ya, the controller 50 Is determined not to be a preceding vehicle. At this time, based on the distance D from the own vehicle to the preceding vehicle candidate, the operation reaction force of the vehicle operating device, for example, the steering wheel 62 related to the driving operation in the left-right direction of the own vehicle is controlled. When the obstacle ahead of the host vehicle is a lane marker, for example, the driver's operation can be urged in an appropriate direction by performing the steering reaction force control in addition to the accelerator pedal reaction force control and the brake pedal reaction force control. .
(3) The controller 50 uses the equation (6) to calculate the preceding vehicle candidate from the positional relationship between the horizontal line (infinity point) on the camera screen as shown in FIGS. 7 and 9 and the lowest position of the preceding vehicle candidate. Distance D is calculated. Accordingly, the distance D can be calculated based only on the captured image of the front camera 20 without providing a sensor or the like for detecting the distance to the preceding vehicle candidate. Further, the distance D can be calculated from the lengths YL and YR of the two vertical lines used for determining whether the preceding vehicle candidate is the preceding vehicle.
(4) When the controller 50 determines that the preceding vehicle candidate is the preceding vehicle, the controller 50 calculates a margin time TTC until the host vehicle contacts the preceding vehicle based on the distance D to the preceding vehicle. And operation reaction force control of the vehicle front-back direction is performed based on the allowance time TTC to a preceding vehicle. As a result, the degree of approach between the host vehicle and the preceding vehicle can be reliably transmitted to the driver as an accelerator pedal reaction force or a brake pedal reaction force.
(5) When the controller 50 determines that the preceding vehicle candidate is not a preceding vehicle, for example, when the preceding vehicle candidate is a lane marker, or when the preceding vehicle candidate is a preceding vehicle and a lane marker, The surplus times TTCL and TTCR until they come into contact with the obstacle are calculated. Then, operation reaction force control in the vehicle front-rear direction and the left-right direction is performed based on the surplus time TTCL, TTCR to the obstacle. Accordingly, both the vehicle reaction force control in the vehicle front-rear direction and the left-right direction can be achieved, and the driving operation by the driver in the front-rear direction and the left-right direction can be urged in an appropriate direction.
(6) The controller 50 performs reaction force control in the vehicle front-rear direction when the two margin times TTCL and TTCR are both smaller than the predetermined value T0. As a result, when the degree of approach between the host vehicle and the obstacle is large, the steering reaction force control is performed so as to return the steering angle and the deceleration operation is promoted, so that the driving operation of the driver can be guided in an appropriate direction. .
(7) The controller 50 sets the horizontal position of the two lowermost positions on the camera screen according to the traveling state of the host vehicle, that is, the two obstacle detection directions in front of the host vehicle. Candidates can be detected as appropriate, and the reaction force control according to the running situation can be performed. It should be noted that the angles θR and θL formed by the obstacle detection direction with respect to the front of the host vehicle are the horizontal position on the camera screen of the front camera 20, that is, the X coordinate values XL and XR, as shown in (Expression 1) and (Expression 2). Correspond.
(8) The controller 50 sets the opening angle α in the obstacle detection direction with respect to the traveling direction of the host vehicle, that is, the interval between the X coordinate values XL and XR on the camera screen, according to the host vehicle speed V. Thus, two horizontal positions on the camera screen can be set according to the traveling direction of the host vehicle predicted from the host vehicle speed V, and a preceding vehicle candidate that affects the traveling of the host vehicle can be detected appropriately.
(9) The controller 50 estimates the approximate traveling direction of the host vehicle based on the host vehicle speed V and the steering angle STR, and the central angle θc of the two obstacle detection directions according to the traveling direction, that is, the X coordinate on the camera screen The center of the values XL and XR is set. Thereby, the obstacle detection direction for detecting a preceding vehicle candidate can be set appropriately. In the above embodiment, the center angle θc is set based on the host vehicle speed V and the steering angle STR. However, the center angle θc can be set based on either one of them. However, the traveling direction of the host vehicle can be estimated more accurately by using both the host vehicle speed V and the steering angle STR.

<< Second Embodiment >>
Next, a vehicle driving assistance device according to a second embodiment of the present invention will be described. The configuration of the vehicle driving operation assistance device according to the second embodiment is the same as that of the first embodiment shown in FIG. 1 and FIG. Here, differences from the first embodiment will be mainly described.

  The image of the front area of the host vehicle captured by the front camera 20 changes according to the vehicle state of the host vehicle. That is, since the front camera 20 is fixed to the host vehicle, when the posture of the host vehicle with respect to the road changes, the image on the camera screen of the front camera 20 also changes with the posture of the host vehicle.

  FIG. 24 shows an image of the camera screen of the front camera 20 when the host vehicle is traveling on the right curve. In the camera screen of FIG. 24, the lane marker and infinity point (horizontal direction) when the host vehicle rolls are indicated by solid lines, and the lane marker and infinity point when the host vehicle is not rolled are indicated by dotted lines.

When the host vehicle travels on a right curve as shown in FIG. 24, a leftward lateral acceleration is generated in the host vehicle along with the curve, and the host vehicle rolls to the left, that is, counterclockwise. As a result, as shown in FIG. 24, on the camera screen of the front camera 20, the image rotates clockwise as shown by the solid line with respect to the image when not rolled as shown by the dotted line. As a result, the Y coordinate values of the lane marker positions in the two obstacle detection directions change. Specifically, the Y coordinate values YL and YR of the lane marker position in the X coordinate values XL and XR corresponding to the obstacle detection direction change as follows.
・ YL → YL '(increase)
・ YR → YR '(decrease)

  When the detected coordinate values YL and YR of the lane marker change according to the roll angle generated in the host vehicle, the distances DL and DR to the lane marker in each obstacle detection direction change. As a result, the margin times TTCL and TTCR change, and the reaction force control command values in the front-rear direction and the left-right direction also change. In the situation shown in FIG. 24, the accelerator pedal reaction force control command value FA decreases as the Y coordinate value YL increases. Further, the steering reaction force control command value FS increases as the Y coordinate value YR decreases.

  Therefore, in the second embodiment, the distance D to the lane marker and the margin time TTC calculated from the image information of the front camera 20 are corrected according to the roll angle generated in the host vehicle when traveling on a curve. Below, the correction | amendment method in case the own vehicle rolls is demonstrated in detail.

In order to calculate the roll angle φ generated in the host vehicle, first, the lateral acceleration YG generated in the host vehicle is calculated. The lateral acceleration YG while the host vehicle is turning is proportional to the product of the steering angle STR and the square of the host vehicle speed V. Therefore, the lateral acceleration YG can be estimated from the following (Equation 9) using the constant k1.
YG = k1 · STR · V ² (Equation 9)

The magnitude of the roll angle φ generated in the host vehicle is substantially proportional to the magnitude of the lateral acceleration YG. Therefore, the roll angle φ can be calculated from the following (Equation 10) using the constant k2.
φ = k2 / YG
^{= K2 · k1 · STR · V} 2 ··· ( Equation 10)

Using the roll angle φ calculated by (Equation 10), the detected coordinate values YL ′ and YR ′ of each lane marker obtained from the camera screen are corrected, and the Y coordinate values YL and YR of the lane marker excluding the influence of the roll angle φ. Is calculated. The corrected Y coordinate values YL and YR of the lane marker are shown in the following (Expression 11) and (Expression 12).
YL = YL′−XL · φ (Formula 11)
YR = YR ′ + XR · φ (Formula 12)

  The Y coordinate values YL ′ and YR ′ detected from the camera screen are substituted into (Equation 11) and (Equation 12), and the corrected Y coordinate values YL and YR are used as in the first embodiment ( The distances DL and DR from the equation 6) to the lane marker can be calculated.

Here, when the host vehicle rolls counterclockwise, the Y coordinate value YL ′ of the lane marker in the left obstacle detection direction increases, and the Y coordinate value YR ′ of the lane marker in the right obstacle detection direction decreases. The case of doing is described as an example. However, on the contrary, when the host vehicle rolls to the right, that is, clockwise, the Y coordinate values YL and YR of the lane marker can be similarly corrected. Further, when there is a preceding vehicle ahead of the host vehicle, the Y coordinate values YL and YR corresponding to the lower end of the preceding vehicle can be similarly corrected.
That is, when the Y coordinate value of the horizontal edge on the camera screen varies depending on the roll angle φ generated in the host vehicle, the product of the X coordinate value and the roll angle φ is added to the detected coordinate value Y ′ on the camera screen or By subtracting, the Y coordinate value of the horizontal edge in the obstacle detection direction can be corrected.

As described above, the following effects can be achieved in the second embodiment described above.
(1) The controller 50 corrects the distance D from the image state of the camera screen due to the change in the vehicle state of the host vehicle to the preceding vehicle candidate. Specifically, the controller 50 calculates the roll angle φ generated in the host vehicle from the host vehicle speed V and the steering angle STR, and the distance D to the preceding vehicle candidate based on the change in the image state of the camera screen due to the roll angle φ. Correct. Thereby, the exact distance D is computable irrespective of a vehicle state.
(2) The controller 50 corrects the lengths YL and YR of the two vertical lines in the image on the camera screen according to the roll angle φ generated in the host vehicle as shown in FIG. The distance D to is corrected. As a result, it is possible to calculate the accurate distance D regardless of the roll angle φ, and to calculate an accurate margin time TTC that is not affected by the roll angle φ.

<< Third Embodiment >>
Next, a vehicle driving assistance device according to a third embodiment of the present invention will be described. The configuration of the vehicle driving operation assistance device according to the third embodiment is the same as that of the first embodiment shown in FIGS. 1 and 2. Here, differences from the first embodiment will be mainly described.

  As described with reference to FIGS. 22A to 22E and FIGS. 23A to 23E in the first embodiment, the distance D to the obstacle is calculated using the image from the front camera 20. In this case, the Y coordinate value of the horizontal edge on the camera screen changes due to a change in the road gradient, and the front-rear direction control command value changes automatically.

  In the third embodiment, the reaction force control command value in the vehicle longitudinal direction is prevented from changing due to a change in road gradient. Specifically, when the vehicle exits from an uphill or downhill, the longitudinal control command value is not automatically changed according to the road gradient. When the host vehicle enters an uphill or downhill, the front / rear direction control command value is automatically changed according to the road gradient.

  In order to prevent the front-rear direction control command value from changing according to the road gradient of the own lane, the controller 50 corrects the distance D to the obstacle calculated from the image by the front camera 20. In the first embodiment described above, the Y coordinate value Y0 at the infinity point on the camera screen shown in FIG. 9 is set as a fixed value. In the third embodiment, when the vehicle exits from an uphill or downhill, the Y coordinate value Y0 at the infinity point on the camera screen is changed according to the road gradient. The correction of the distance D to the obstacle is performed when the margin time TTC for the obstacle is calculated in step S110 or step S120 in the flowchart of FIG.

  The controller 50 performs image processing on the image captured by the front camera 20 and detects two or three lane markers (lane boundaries) in the camera screen. Then, a virtual point on the camera screen that is assumed to intersect the detected road boundary at a far road, that is, a vanishing point is calculated, and the Y coordinate value of the vanishing point is set as the Y coordinate value Y0 of the infinity point on the camera screen. As described above, the controller 50 calculates the Y coordinate value of the point at infinity according to the change in the image state of the camera image due to the road gradient.

  The controller 50 calculates the distance D to the obstacle from (Equation 6) from the calculated Y coordinate value Y0 of the infinity point and the Y coordinate value of the horizontal edge in the obstacle detection direction. As a result, an accurate distance D that is not affected by the road gradient can be calculated. As a result, when the vehicle exits from the uphill or downhill, as shown in FIGS. 22 (d) (e) and 23 (d) (e), the longitudinal control command value is influenced by the change in the road gradient. It becomes a normal value not receiving.

  Thus, by correcting the distance D to the obstacle according to the road gradient, the accurate distance D can be calculated regardless of the road gradient. As a result, the front-rear direction control command value can be prevented from changing automatically when the host vehicle exits from an uphill or downhill. In other words, the accelerator pedal reaction force automatically increases when the host vehicle comes out of the uphill to accelerate deceleration, and the accelerator pedal reaction force automatically decreases when the host vehicle gets out of the downhill. There is no prompting, and the driving operation by the driver is not hindered.

  On the other hand, when the host vehicle goes uphill or downhill, the longitudinal control command value automatically changes according to the road gradient. When entering a slope, it is possible to prompt the vehicle to decelerate.

Thus, the following effects can be achieved in the third embodiment described above.
The controller 50 detects the change in the road gradient of the own lane, and corrects the distance D to the preceding vehicle candidate according to the change in the road gradient. As a result, it is possible to calculate the exact distance D to the preceding vehicle candidate regardless of the road gradient, and further to calculate the accurate margin time TTC independent of the road gradient to perform the operation reaction force control. The controller 50 can estimate the road gradient of the own lane from the change in the image state on the camera screen of the front camera 20.

<< Fourth Embodiment >>
Next, a vehicle driving assistance device according to a fourth embodiment of the present invention will be described.
In the third embodiment described above, the distance D to the obstacle is set so that the front-rear direction control command value does not automatically change according to the road gradient when the host vehicle exits from the uphill or downhill. Corrected. In the fourth embodiment, even when the host vehicle enters an uphill or downhill, the distance D to the obstacle calculated from the image of the front camera 20 is corrected, and the longitudinal control command value is determined according to the road gradient. Will not change automatically.

  As in the third embodiment described above, the controller 50 changes the Y coordinate value Y0 of the infinity point on the camera screen according to the road gradient. Then, using the changed Y coordinate value Y0 of the point at infinity and the Y coordinate value of the horizontal edge in the obstacle detection direction, the distance D from the host vehicle to the obstacle is calculated from (Equation 6).

  As a result, as shown in FIGS. 22A to 22E and FIGS. 23A to 23E, when the host vehicle enters an uphill or downhill, and when it gets out of an uphill or downhill. The front-rear direction control command value is a normal value that is not affected by the change in the road gradient.

  Thus, by correcting the distance D to the obstacle according to the road gradient, the accurate distance D can be calculated regardless of the road gradient. Thereby, when the own vehicle enters an uphill or a downhill, and when it exits, it is possible to prevent the front-rear direction control command value from automatically changing. That is, even when the road gradient changes, the front-rear direction control command value based on the accurate distance D to the obstacle can be generated as in the case where the host vehicle is traveling on a flat road.

Thus, in the fourth embodiment described above, the following operational effects can be achieved.
The controller 50 detects the change in the road gradient of the own lane, and corrects the distance D to the preceding vehicle candidate according to the change in the road gradient. As a result, it is possible to calculate the exact distance D to the preceding vehicle candidate regardless of the road gradient, and further to calculate the accurate margin time TTC independent of the road gradient to perform the operation reaction force control. The controller 50 can estimate the road gradient of the own lane from the change in the image state on the camera screen of the front camera 20.

  In the first to fourth embodiments described above, when the Y coordinate values YL and YR of the horizontal edge at the horizontal position corresponding to the two obstacle detection directions on the camera screen are substantially the same and not more than the predetermined value Ya. Furthermore, it was determined that the detected horizontal edge was due to the preceding vehicle. Then, as shown in FIG. 3, when a preceding vehicle is detected in two obstacle detection directions, reaction force control for the preceding vehicle, that is, reaction force control in the vehicle longitudinal direction is performed. Therefore, when detecting a preceding vehicle in one obstacle detection direction and detecting a lane marker in the other obstacle detection direction as shown in FIG. 3, reaction force control for the lane marker, that is, the vehicle front-rear direction and the left-right direction The reaction force was controlled. However, the embodiment of the driving assistance device for a vehicle according to the present invention is not limited to this.

  For example, as shown in FIG. 25, when both lane markers are detected in two obstacle detection directions, reaction force control in the vehicle front-rear direction and the left-right direction is performed on the lane marker. On the other hand, if a preceding vehicle is detected in both obstacle detection directions, or if a preceding vehicle is detected in one obstacle detection direction and a lane marker is detected in the other obstacle detection direction, Only the direction reaction force control can be performed.

  As described above, when detecting a preceding vehicle existing in one of the obstacle detection directions and performing the reaction force control in the front-rear direction with respect to the preceding vehicle, two obstacles are used by using a well-known image processing method. The type of obstacle existing in the object detection direction is determined. That is, if the two horizontal edges on the camera screen are due to a preceding vehicle or a lane marker and are individually determined by a well-known image processing technique and the horizontal edge due to the preceding vehicle is detected, Perform reaction force control in the front-rear direction.

  In the first embodiment described above, as shown in FIG. 9, the Y coordinate value YE of the horizontal edge on the camera screen and the Y coordinate value Y0 of the infinity point (horizontal direction) are used. Further, the distance D between the host vehicle and the obstacle was calculated. However, the embodiment according to the present invention is not limited to this. For example, the distance D between the host vehicle and the preceding vehicle can be calculated using the vehicle width of the preceding vehicle.

  Specifically, the width of the preceding vehicle on the camera screen is measured, and the distance D to the preceding vehicle is calculated from the actual vehicle width of the preceding vehicle and the width of the preceding vehicle on the camera screen. Usually, the width of the preceding vehicle is detected using the vertical direction component on the camera screen, that is, the distance between the two tires where the vertical edge occurs most stably. In this case, the change in the width of the vertical edge on the camera screen corresponds to the change in the distance D between the host vehicle and the preceding vehicle. In order to calculate the inter-vehicle distance D from the vehicle width of the preceding vehicle, it is necessary to measure the actual vehicle width of the preceding vehicle in advance. Therefore, for example, in a steady state in which the host vehicle follows the preceding vehicle at a constant speed, the inter-vehicle distance D to the preceding vehicle is calculated from (Equation 6) described above, and the calculated inter-vehicle distance D and the time at that time are calculated. The vehicle width of the preceding vehicle on the camera screen, that is, the width between tires is stored. Then, the change in the inter-vehicle distance D is calculated from the change in the vehicle width of the preceding vehicle on the camera screen, and the inter-vehicle distance D to the preceding vehicle at each time point is calculated.

  In the second embodiment, the distance D to the preceding vehicle candidate obtained from the image of the front camera 20 is corrected according to the roll angle φ generated in the host vehicle. Moreover, in the said 3rd and 4th embodiment, the distance D to the preceding vehicle candidate obtained from the image of the front camera 20 was correct | amended according to the road gradient of the own lane. It is also possible to correct the distance D to the preceding vehicle candidate obtained from the image of the front camera 20 by combining a correction method according to the roll angle φ generated in the own vehicle and a correction method according to the road gradient of the own lane. .

  That is, the controller 50 corrects the distance D to the preceding vehicle candidate obtained from the image of the front camera 20 and further the allowance time TTC based on the state of the image that changes depending on the vehicle state. Thereby, the distance D to the preceding vehicle candidate can be calculated regardless of the vehicle state, and the driving operation by the driver can be urged in a more appropriate direction by the reaction force control of the vehicle operating device.

  In the first to fourth embodiments, the configuration is such that the movement in the front-rear direction of the vehicle is controlled using the accelerator pedal reaction force control device 80 and the brake pedal reaction force control device 90. However, the present invention is not limited to this. For example, only one of them can be used. In the first to fourth embodiments, the brake assist force is generated by the brake booster 91 using the negative pressure of the engine. However, the present invention is not limited to this. For example, the hydraulic pressure by computer control is increased. It can also be used to generate a brake assist force.

  The vehicle provided with the vehicle driving operation assisting device according to the present invention is not limited to the configuration shown in FIG.

  In the first to fourth embodiments described above, the front camera 20 is used as the imaging means. Further, the preceding vehicle candidate detecting means, the lowest end position detecting means, the preceding vehicle candidate distance calculating means, the preceding vehicle detecting means, the preceding vehicle margin time calculating means, the preceding vehicle candidate margin time calculating means, the lowest end position detecting direction setting means, and The controller 50 was used as the distance correction means. The steering reaction force control device 60 was used as the left-right direction operation reaction force control means, and the accelerator pedal reaction force control device 80 and the brake pedal reaction force control device 90 were used as the front-rear direction operation reaction force control means. Further, the vehicle speed sensor 30, the steering angle sensor 40, and the controller 50 are used as the vehicle state detection means, and the vehicle speed sensor 30 and the steering angle sensor 40 are used as the traveling state detection means. However, the present invention is not limited thereto, and a device that performs image processing on the image signal from the front camera 20 can be provided independently of the controller 50. It is also possible to provide a sensor that directly detects the vehicle state, for example, the roll angle φ generated in the host vehicle or the road gradient of the host lane.

1 is a system diagram of a vehicle driving assistance device according to a first embodiment of the present invention. The block diagram of the vehicle carrying the driving operation assistance apparatus for vehicles shown in FIG. The figure which shows the outline | summary of the operation reaction force control in 1st Embodiment. The flowchart which shows the process sequence of the driving operation assistance control program in 1st Embodiment. The figure which shows the obstruction detection direction with respect to the own vehicle. The figure which shows the relationship between the own vehicle speed and the opening angle of an obstruction detection direction. The figure which shows the camera screen of the own vehicle front area | region obtained with a front camera. The side view which shows the positional relationship from the own vehicle to a lane marker detection position. The figure which shows the lane marker detection position in a camera screen. The figure which shows the relationship between the margin time of a smaller one, and the left-right direction risk potential. The figure which shows the relationship between the larger margin time and the front-back risk potential. The figure which shows the characteristic of the accelerator pedal reaction force control command value with respect to the front-back direction risk potential. The figure which shows the characteristic of the brake pedal reaction force control command value with respect to the front-back direction risk potential. The figure which shows the characteristic of the steering reaction force control command value with respect to the left-right direction risk potential. (A) (b) The figure for demonstrating the effect | action by the driving assistance device for vehicles of 1st Embodiment. The figure which shows the specific driving | running | working condition of the own vehicle and preceding vehicle in 1st Embodiment. The figure which shows the specific driving | running | working condition of the own vehicle and preceding vehicle in 1st Embodiment. The figure which shows the specific driving | running | working condition of the own vehicle and preceding vehicle in 1st Embodiment. The figure which shows the specific driving | running | working condition of the own vehicle and preceding vehicle in 1st Embodiment. The figure which shows the specific driving | running | working condition of the own vehicle and preceding vehicle in 1st Embodiment. The figure which shows the specific driving | running | working condition of the own vehicle and preceding vehicle in 1st Embodiment. (A)-(e) The figure for demonstrating the other effect | action of the driving assistance device for vehicles. (A)-(e) The figure for demonstrating the other effect | action of the driving assistance device for vehicles. The figure which shows the image state of the camera screen before and behind a roll generate | occur | produces in the own vehicle. The figure which shows another example of the outline | summary of the operation reaction force control in the driving operation assistance apparatus for vehicles.

Explanation of symbols

20: Front camera 30: Vehicle speed sensor 40: Steering angle sensor 50: Controller 60: Steering reaction force control device 80: Accelerator pedal reaction force control device 90: Brake pedal reaction force control device

Claims (15)

Imaging means for imaging a front area of the host vehicle;
A preceding vehicle candidate detecting means for detecting a preceding vehicle candidate from the image of the front area imaged by the imaging means;
In a vehicle driving operation assistance device having an operation reaction force control means for controlling an operation reaction force of a vehicle operation device related to a driving operation,
The preceding vehicle candidate detection means detects the length of the two vertical lines to the intersection where two vertical lines extending from the lower end of the image intersect with the lowermost position of the preceding vehicle candidate. When the lengths of the two vertical lines detected by the position detection means and the lowermost position detection means are equal to or less than a predetermined value and are substantially the same, it is determined that the preceding vehicle candidate is a preceding vehicle. Consisting of preceding vehicle detection means,
The operation reaction force control means includes a front-rear direction operation reaction force control means for controlling an operation reaction force of a vehicle operation device related to a driving operation in the front-rear direction of the host vehicle based on a determination result of the preceding vehicle detection means ,
The two vertical lines are lines extending vertically from two horizontal positions in the image corresponding to two obstacle detection directions set for detecting an obstacle, respectively. Operation assisting device. The vehicle driving assistance device according to claim 1,
Using the image, further comprising a preceding vehicle candidate distance calculating means for calculating a distance from the host vehicle to the preceding vehicle candidate;
The front-rear direction reaction reaction force control unit controls the operation reaction force in the front-rear direction based on the distance to the preceding vehicle candidate calculated by the preceding vehicle candidate distance calculation unit. Operation assisting device. The vehicle driving operation assistance device according to claim 2,
The front-rear direction operation reaction force control means, when the preceding vehicle detection means determines that the preceding vehicle candidate is the preceding vehicle, the up to the preceding vehicle calculated by the preceding vehicle candidate distance calculating means. A vehicle driving operation assisting device that controls the operation reaction force in the front-rear direction based on a distance. In the driving assistance device for a vehicle according to claim 2 or 3,
The operation reaction force control unit is configured to calculate the distance to the preceding vehicle candidate calculated by the preceding vehicle candidate distance calculating unit when the preceding vehicle detection unit determines that the preceding vehicle candidate is not the preceding vehicle. A vehicle driving operation assisting device, further comprising: a left-right operation reaction force control means for controlling an operation reaction force of a vehicle operating device related to a left-right driving operation of the host vehicle. In the vehicle driving assistance device according to any one of claims 2 to 4,
The preceding vehicle candidate distance calculating means calculates the distance to the preceding vehicle candidate from a positional relationship between a horizontal line in the image and the lowermost position of the preceding vehicle candidate. apparatus. In the driving assistance device for a vehicle according to claim 2 or 3,
Based on the distance calculated by the preceding vehicle candidate distance calculating unit, the vehicle further includes a preceding vehicle margin time calculating unit that calculates a margin time until the host vehicle contacts the preceding vehicle,
The front-rear direction operation reaction force control means controls the operation reaction force in the front-rear direction based on the margin time. The vehicle driving operation assistance device according to claim 4,
Based on the distance to the two points on the preceding vehicle candidate calculated by the preceding vehicle candidate distance calculating means, the margin time until the host vehicle contacts the two points on the preceding vehicle candidate is calculated. It further includes a preceding vehicle candidate margin time calculating means,
The front-rear direction reaction reaction force control unit and the left-right direction operation reaction force control unit are configured to perform the operation reaction force in the front-rear direction and the left-right direction based on the two margin times calculated by the preceding vehicle candidate margin time calculation unit. A driving operation assisting device for a vehicle that controls the operation reaction force in each direction. The vehicle driving assistance device according to claim 7,
The front-rear direction operation reaction force control means controls the operation reaction force in the front-rear direction only when the two margin times calculated by the preceding vehicle candidate margin time calculation means are smaller than a predetermined time. A driving operation assisting device for a vehicle. In the driving assistance device for a vehicle according to any one of claims 1 to 8,
Traveling state detecting means for detecting the traveling state of the host vehicle;
Depending on the detection result of the running state detection means, two of the said horizontal position the vehicle driving assist, characterized by further comprising a lowermost position detecting direction setting means for setting each of the lowest position in the image apparatus. The driving operation assisting device for a vehicle according to claim 9,
The lowermost position detection direction setting means sets the interval between the two horizontal positions according to the own vehicle speed detected by the traveling state detection means. In the driving assistance device for a vehicle according to claim 9 or 10,
The lowermost position detection direction setting means sets the center of two horizontal positions according to at least one of the own vehicle speed and the steering angle detected by the running state detection means. Driving assistance device. In the driving assistance device for a vehicle according to any one of claims 2 to 8,
Vehicle state detection means for detecting the vehicle state of the host vehicle;
A vehicle driving operation assisting device, further comprising distance correcting means for correcting the distance from the state of the image detected by the vehicle state detecting means to the preceding vehicle candidate. The vehicle driving assistance device according to claim 12,
The vehicle state detection means detects a roll angle generated in the host vehicle,
The distance correction means corrects the distance based on a state change of the image due to the roll angle of the host vehicle. The vehicle driving assistance device according to claim 12,
The vehicle state detection means detects a change in the road gradient of the own lane,
The distance correction means corrects the distance according to a change in the road gradient detected by the vehicle state detection means.   A vehicle comprising the vehicular driving assist device according to any one of claims 1 to 14.

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