JP2004110346A - Vehicle driving operation assist device, vehicle driving operation assist method, and vehicle applying the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle driving operation assist device capable of appropriately assisting driving operation by allowing a driver to accurately recognize risk potential in longitudinal and lateral directions. <P>SOLUTION: This vehicle driving operation assist device 1 has obstruction detecting means 10, 20, 21 for detecting obstructions existing around the own vehicle; a risk potential computing means 50 for computing the risk potential of the own vehicle to the obstructions based on signals from the obstruction detecting means 10, 20, 21; vehicle equipment control means 60, 80, 90 for controlling the operation of vehicle equipment to urge the driver to perform driving operation related to the longitudinal motion and lateral motion of the own vehicle based on signals from the risk potential computing means 50; a traveling state detecting means 30 for detecting the traveling state of the own vehicle; and an operation assist direction control means 50 for limiting the control of the vehicle equipment by the vehicle equipment control means 60, 80, 90, only to either one of the longitudinal direction and lateral direction according to the traveling state detected by the travel state detecting means 30. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a driving assist system for a vehicle that assists a driver's operation.
[0002]
[Prior art]
A conventional driving assist system for a vehicle detects a situation (obstacle) around the vehicle and obtains a potential risk potential at that time (for example, see Patent Document 1). The vehicle driving assist system controls the steering assist torque based on the calculated risk degree, thereby suppressing a steering operation that may lead to an unexpected situation.
Prior art documents related to the present invention include the following.
[Patent Document 1]
JP-A-10-212886
[Patent Document 2]
JP-A-10-166889
[Patent Document 3]
JP-A-10-166890
[0003]
[Problems to be solved by the invention]
However, the vehicle driving assist system as described above promotes prohibition of operation in a specific inappropriate situation, and in a complicated situation where both steering and acceleration / deceleration are required, driving is difficult. It is also expected that it is difficult to prompt the operation in an appropriate direction.
[0004]
[Means for Solving the Problems]
The vehicle driving assist system according to the present invention calculates an obstacle potential of an own vehicle with respect to an obstacle based on a signal from the obstacle detecting means for detecting an obstacle existing around the own vehicle and an obstacle detecting means. Risk potential calculation means, based on a signal from the risk potential calculation means, vehicle equipment control means for controlling the operation of the vehicle equipment, so as to prompt the driver to perform a driving operation related to the front-back movement and left-right movement of the vehicle. Controlling the vehicle equipment by the vehicle equipment control means according to the traveling state detected by the traveling state detecting means for detecting the traveling state of the own vehicle and the traveling state detected by the traveling state detecting means only in one of the front-back direction and the left-right direction. And assisting the driver's operation.
[0005]
【The invention's effect】
Depending on the running state of the host vehicle, the operation control of the vehicle equipment is limited to only the more important one of the front and rear direction and the left and right direction, and the operation instruction from the vehicle equipment is transmitted to the driver only from the more important direction Therefore, it is possible to appropriately assist the driving operation while preventing confusion of the driver.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
<< 1st Embodiment >>
A vehicle driving assist system 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 assist system 1 according to a first embodiment of the present invention. FIG. 1 is a configuration diagram of a vehicle to which a driving operation assisting method is applied.
[0007]
First, the configuration of the vehicle driving assist system 1 will be described. The laser radar 10 is attached to a front grill portion or a bumper portion of a vehicle, and scans an infrared light pulse in a horizontal direction. The laser radar 10 measures the reflected wave of the infrared light pulse reflected by a plurality of reflectors ahead (usually, the rear end of the preceding vehicle), and calculates the distance between the plurality of preceding vehicles based on the arrival time of the reflected wave. Detect the distance and its existing direction. The detected inter-vehicle distance and existence direction are output to the controller 50. In the present embodiment, the direction in which the front object exists can be represented as a relative angle with respect to the host vehicle. The front area scanned by the laser radar 10 is about ± 6 deg with respect to the front of the vehicle, and a front object existing within this range is detected. The laser radar 10 detects not only the inter-vehicle distance to the vehicle in front and the direction of its existence, but also the relative distance to obstacles such as pedestrians in front of the vehicle and the direction of its existence.
[0008]
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 road ahead as an image, and outputs the image to the controller 50. The detection area of the front camera 20 is about ± 30 deg in the horizontal direction, and the front road scenery included in this area is captured as an image.
[0009]
The rear side camera 21 is two small CCD cameras or CMOS cameras mounted near the left and right ends of the upper portion of the rear window. The rear side camera 21 detects an image of a road behind the own vehicle, particularly a situation on an adjacent lane, and outputs the image to the controller 50.
[0010]
The vehicle speed sensor 30 detects the traveling vehicle speed of the own vehicle from the number of revolutions of the wheels and the like, and outputs the detected traveling speed to the controller 50.
[0011]
The controller 50 controls the entire vehicle driving assist system 1. The controller 50 uses the vehicle speed input from the vehicle speed sensor 30, the distance information input from the laser radar 10, and the image information around the vehicle input from the front camera 20 and the rear side camera 21 to determine the surroundings of the vehicle. Obstacle situation is detected. The controller 50 detects an obstacle situation around the own vehicle by performing image processing on image information input from the front camera 20 and the rear side camera 21. Here, the obstacle situation around the host vehicle includes the following distance between the host vehicle and another vehicle traveling in front of the host vehicle, the presence / absence of the other vehicle approaching the adjacent lane from the rear of the host vehicle, and the lane identification line (white line). , That is, the relative position and angle of the host vehicle, and the shape of the lane identification line. In addition, pedestrians and motorcycles crossing the front of the host vehicle are also detected as obstacle situations.
[0012]
The controller 50 calculates the risk potential of the own vehicle with respect to each obstacle based on the detected obstacle situation. Further, the controller 50 calculates the overall risk potential around the own vehicle by integrating the risk potentials for the respective obstacles, and performs control according to the risk potential as described later.
[0013]
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 according to a command from the controller 50. The servomotor 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.
[0014]
The accelerator pedal reaction force control device 80 controls a torque generated by a servomotor 81 incorporated in a link mechanism of the accelerator pedal 82 according to a command from the controller 50. The servo motor 81 controls a reaction force generated according to a command value from the accelerator pedal operation reaction force control device 80, and can arbitrarily control a pedal force generated when the driver operates the accelerator pedal 82. .
[0015]
The brake pedal reaction force control device 90 controls the brake assist force generated by the brake booster 91 according to a command from the controller 50. The brake booster 91 controls the brake assist force generated according to a 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. . The greater the brake assist force, the smaller the brake pedal operation reaction force, and the easier it is to depress the brake pedal 92.
[0016]
Next, the operation of the vehicle driving assist system 1 according to the first embodiment will be described. The outline of the operation is described below.
The controller 50 controls the traveling speed of the host vehicle, the relative position of the host vehicle with other vehicles existing in front of and behind the host vehicle, the moving direction thereof, and the relative position of the host vehicle with respect to the lane identification line (white line). Recognize obstacles around the vehicle. The controller 50 obtains a risk potential of the own vehicle with respect to each obstacle based on the recognized obstacle situation. The controller 50 further calculates the reaction force control amount in the front-rear direction and the reaction force control amount in the left-right direction by adding the risk potential for each obstacle for each component in the front-rear and left-right directions.
[0017]
The calculated longitudinal reaction force control amount is output to the accelerator pedal reaction force control device 80 and the brake pedal reaction force control device 90 as a longitudinal reaction force control command value. The accelerator pedal reaction force control device 80 and the brake pedal reaction force control device 90 control the servomotor 81 and the brake booster 91 in accordance with the input reaction force control command values, respectively, to thereby control the accelerator pedal reaction force characteristics and the brake force. Change the pedal reaction force characteristics. By changing the accelerator pedal / brake pedal reaction force characteristic, the actual accelerator pedal operation amount and the brake pedal operation amount of the driver are controlled to be promoted to appropriate values.
[0018]
On the other hand, the calculated left / right direction reaction force control amount is output to the steering reaction force control device 60 as a left / right direction reaction force control command value. The steering reaction force control device 60 changes the steering reaction force characteristic by controlling the servo motor 61 according to the input reaction force control command value. By changing the steering reaction force characteristic, the actual steering angle of the driver is controlled to be promoted to an appropriate steering angle.
[0019]
As described above, the vehicle driving assist system 1 according to the first embodiment controls the reaction force generated when the accelerator pedal / brake pedal is depressed or the steering wheel is operated, whereby the driver's own vehicle can be controlled. This assists the driver's acceleration / deceleration operation and steering operation, and appropriately assists the driver's driving operation. However, the driver may be confused by simultaneously controlling the operation reaction forces in the front-rear direction and the left-right direction of the vehicle.
[0020]
For example, when the own vehicle approaches a corner by traveling alone, the operation reaction force in the front-back direction and the left-right direction is controlled according to the approach state to the corner. When the vehicle is relatively far from the corner, the risk potential in the front-rear direction is mainly transmitted to the driver as the reaction force of the accelerator / brake pedal, and as the vehicle approaches the corner, the risk potential in the left-right direction gradually increases as the steering reaction force. To be communicated to others. After the vehicle enters the corner, the risk potential mainly in the left-right direction is transmitted to the driver.
[0021]
On the other hand, when the own vehicle follows the preceding vehicle and approaches the corner, before entering the corner, the risk potential mainly in the front-rear direction is transmitted as a pedal reaction force according to the degree of approach to the preceding vehicle. If the vehicle enters the corner while following the preceding vehicle, a risk potential related to the corner is generated in addition to the risk potential of the preceding vehicle in the front-rear direction. Therefore, it is difficult to determine whether the risk potential in the front-rear direction transmitted as the pedal reaction force is due to the preceding vehicle or the corner. In this state, the risk potential of the preceding vehicle is the most important information, so the driver tends to consider that the risk potential at this point is entirely due to the preceding vehicle. Therefore, if the risk potential in the left-right direction is transmitted as the steering reaction force after entering the corner, it becomes difficult for the driver to understand what the steering reaction force is due to.
[0022]
Therefore, in the first embodiment of the present invention, it is determined whether to limit the reaction force control to only one of the front-rear direction and the left-right direction or to perform both control depending on the traveling state of the vehicle. Then, the front / rear / left / right reaction force control amounts are calculated. That is, the direction of the reaction force control is limited so that the driver is not confused, and more important information is transmitted to the driver according to the traveling state.
[0023]
Hereinafter, how to determine the reaction force characteristic command value, that is, the reaction force control command value in the first embodiment, will be described with reference to FIG. FIG. 3 is a flowchart illustrating a processing procedure of a driving operation assisting control process in the controller 50 according to the first embodiment. This processing content is continuously performed at regular intervals, for example, every 50 msec.
[0024]
-Processing flow of controller 50 (Fig. 3)-
First, the running state is read in step S101. Here, the traveling state is information on the traveling state of the own vehicle including the obstacle state around the own vehicle. Specifically, a relative distance and a relative angle to the vehicle traveling ahead detected by the laser radar 10 are read. Also, the relative position of the white line with respect to the own vehicle based on the image input from the front camera 20 (that is, the displacement and the relative angle in the left-right direction), the shape of the white line, the relative distance and the relative angle to the front running vehicle, and the rear side camera The relative distance and the relative angle to the traveling vehicle located behind the adjacent lane based on the image input from 21 are read. Further, the host vehicle speed detected by the vehicle speed sensor 30 is read. In addition, based on the images detected by the front camera 20 and the rear side camera 21, the type of the obstacle existing around the own vehicle, that is, whether the obstacle is a four-wheeled vehicle, a two-wheeled vehicle, a pedestrian, or others is determined. recognize.
[0025]
In step S102, the current vehicle surrounding situation is recognized based on the running state data read and recognized in step S101. Here, the relative position of each obstacle with respect to the own vehicle, the moving direction and the moving speed thereof, and the current running state data obtained in step S101, which are detected before the previous processing cycle and stored in the memory (not shown). Thus, the current relative position of each obstacle with respect to the own vehicle and its moving direction and moving speed are recognized. Then, it recognizes how other vehicles and white lines that are obstacles to the traveling of the own vehicle are arranged around the own vehicle and relatively move.
[0026]
In step S103, a time to collision TTC (Time To Collision) for each recognized obstacle is calculated for each obstacle. Here, the allowance time TTCk for the obstacle k is obtained by the following (Equation 1).
(Equation 1)
TTCk = (Dk−σ (Dk)) / (Vrk + σ (Vrk)) (Equation 1)
Here, Dk: the relative distance from the host vehicle to the obstacle k, Vrk: the relative speed of the obstacle k with respect to the host vehicle, σ (Dk), σ (Vrk): the relative distance, and the variation in the relative speed.
[0027]
The variation k of the relative distance (Dk) and the variation σ of the relative speed (Vrk) recognize the obstacle k in consideration of the uncertainty of the detector and the degree of influence when an unexpected situation occurs. The setting is made according to the type of the sensor and the type of the recognized obstacle k.
[0028]
The laser radar 10 has a correct detection distance, that is, a correct distance irrespective of the magnitude of the relative distance between the host vehicle and the obstacle, as compared with the detection of an obstacle by the front camera 20 or the rear side camera 21 using a camera such as a CCD. Can be detected. Therefore, for example, as shown in FIG. 4A, when the relative distance Dk to the obstacle k is detected by the laser radar 10, the variation σ (Dk) is set to a substantially constant value regardless of the relative distance Dk. I do. On the other hand, when the relative distance Dk is detected by the cameras 20 and 21, the variation σ (Dk) is set to increase exponentially as the relative distance Dk increases. However, when the relative distance Dk of the obstacle k is small, the relative distance can be more accurately detected by the camera as compared with the case where the relative distance Dk is detected by the laser radar, so that the relative distance variation σ (Dk) Set smaller.
[0029]
For example, when the laser radar 10 detects the relative distance Dk, the variation σ (Vrk) of the relative speed Vrk is set to increase in proportion to the relative speed Vrk as shown in FIG. On the other hand, when the relative distance Dk is detected by the cameras 20 and 21, the relative speed variation σ (Vrk) is set to increase exponentially as the relative speed Vrk increases. FIGS. 4A and 4B show an example in which the detected obstacle is a four-wheeled vehicle.
[0030]
When an obstacle situation is detected by the front camera 20 and the rear side camera 21, the type of the obstacle can be recognized by performing image processing on the detected image. Therefore, as shown in FIGS. 5A and 5B, when an obstacle situation is detected by the cameras 20 and 21, the variation σ (Dk) of the relative distance and the relative speed according to the type of the recognized obstacle. ) And σ (Vrk) are set. FIGS. 5A and 5B show variations σ (Dk) and σ (Vrk) when a four-wheeled vehicle, a two-wheeled vehicle, a pedestrian, and a lane marker (white line) are detected as the obstacle k. I have.
[0031]
Since the detection accuracy of the relative distance Dk by the cameras 20 and 21 is higher as the size of the obstacle k is larger, the relative distance Dk when the obstacle is a four-wheeled vehicle as shown in FIG. The variation σ (Dk) of the distance is set smaller than the variation σ (Dk) of a two-wheeled vehicle or a pedestrian. On the other hand, the variation σ (Vrk) of the relative speed is set such that the variation σ (Vrk) increases as the moving speed assumed for each obstacle k increases, as shown in FIG. 5B, for example. That is, since the moving speed of the four-wheeled vehicle is assumed to be higher than the moving speed of the two-wheeled vehicle or the pedestrian, the variation σ (Vrk) when the relative speed Vrk is the same and the obstacle k is the four-wheeled vehicle is , (Vrk) for a two-wheeled vehicle or a pedestrian. As shown in FIGS. 5 (a) and 5 (b), the relative distance to the lane marker and the variation in relative speed σ (Dk), σ (Vrk) are the relative distance to other obstacles and the variation in relative speed σ ( Dk) is set to be smaller than σ (Vrk).
[0032]
When the obstacle k is detected by both the laser radar 10 and the camera 20, for example, the margin time TTCk with respect to the obstacle k is calculated using the larger variation σ (Dk) or σ (Vrk). can do.
[0033]
In step S104, the risk potential RPk for each obstacle k is calculated using the allowance time TTCk calculated in step S103. Here, the risk potential RPk for each obstacle k is obtained by the following (Equation 2).
(Equation 2)
RPk = (1 / TTCk) × wk (Equation 2)
Here, wk indicates the weight of the obstacle k. As shown in (Equation 2), the risk potential RPk is expressed as a function of the allowance time TTCk using the reciprocal of the allowance time TTCk, and it is understood that the greater the risk potential RPk, the greater the degree of approach to the obstacle k. Is shown.
[0034]
The weight wk for each obstacle k is set according to the type of the detected obstacle. For example, if the obstacle k is a four-wheeled vehicle, a two-wheeled vehicle, or a pedestrian, the weight wk = 1 is set because the importance when the own vehicle approaches the obstacle k, that is, the influence is high. On the other hand, when the obstacle k is a lane marker, the importance when the own vehicle approaches or comes into contact with the obstacle is relatively smaller than other obstacles. Therefore, the weight wk is set to, for example, about 0.5. Further, even when the same lane marker has an adjacent lane on the other side of the lane marker, and when there is no lane on the other side of the lane marker and only the guardrail is used, the weight wk is different because the importance when the own vehicle is in proximity is different. It can be set as follows.
[0035]
The lane markers do not determine the direction in which the vehicle is located in one direction, but are distributed in a certain range of directions. Therefore, the lane markers around the own vehicle detected by the cameras 20 and 21 are divided into small angles based on the own vehicle, and respective risk potentials are calculated from the relative positions of the lane markers corresponding to the small angles. Further, the risk potential RPlane is calculated by integrating the risk potential for the minute angle in the existing direction range. That is, the risk potential RPlane for the lane marker is represented by the following (Equation 3).
[Equation 3]
RPlane = ∫ ((1 / TTClane) × wane) dL (Equation 3)
[0036]
In step S105, components in the vehicle longitudinal direction are extracted and added from the risk potential RPk for each obstacle k calculated in step S104, and a total longitudinal risk potential for all obstacles around the vehicle is calculated. . The longitudinal risk potential RPlongitinal is calculated by the following (Equation 4). Note that the risk potential RPk for each obstacle k includes the risk potential RPlan for the lane marker.
(Equation 4)
RPlongitudinal = Σ _k (RPk × cos θk) (Equation 4)
Here, θk: indicates the direction in which the obstacle k is present with respect to the own vehicle. If the obstacle k is in the front direction of the vehicle, that is, in front of the own vehicle, θk = 0, and the obstacle k is in the rear direction of the vehicle. , Θk = 180.
[0037]
In step S106, the components in the vehicle left-right direction are extracted and added from the risk potential RPk for each obstacle k calculated in step S104, and the total left-right direction risk potential for all obstacles around the vehicle is calculated. I do. The horizontal risk degree RPlateral is calculated by the following (Equation 5).
(Equation 5)
RPlateral = Σ _k (RPk × sin θk) (Equation 5)
[0038]
In step S107, based on the traveling state data read in step S101, it is determined whether or not the current traveling state of the vehicle meets predetermined traveling conditions. Here, the following four running conditions are determined.
(1) When the vehicle speed is equal to or lower than a first predetermined vehicle speed, for example, 30 km / h.
(2) When the vehicle speed is equal to or higher than a second predetermined vehicle speed, for example, 100 km / h.
(3) When the longitudinal acceleration is equal to or more than a predetermined value.
(4) When the lateral acceleration is equal to or more than a predetermined value.
The longitudinal acceleration and the lateral acceleration are detected by, for example, a longitudinal acceleration sensor and a lateral acceleration sensor (not shown).
[0039]
If the current running state of the vehicle satisfies any of the conditions (1) to (4), an affirmative determination is made in step S107, and the process proceeds to step S108 in order to limit the control to the front-rear or left-right reaction force control. . In step S108, as shown in FIG. 6, it is determined whether to limit the reaction force control in the front-rear direction or the left-right direction according to the running state of the vehicle.
[0040]
When the traveling state matches the traveling condition (1), the vehicle speed is slow and the steering reaction force control has little effect, so that the control is limited to the longitudinal reaction force control. In the case of the condition (2), since the own vehicle speed is high, the control is limited to the reaction force control in the left-right direction so as to prompt the lane keeping of the own vehicle. In the case of the condition (3), it is determined that the pedal operation is performed by the driver's intention, and the control is limited to the reaction force control in the left-right direction. In the case of the condition (4), for example, a sharp turn is performed, it is determined that the steering operation is performed by the driver's intention, and the control is limited to the reaction force control in the front-rear direction.
[0041]
If the running state of the vehicle matches the condition (1) or the condition (4), the process proceeds to step S109 in order to limit the control to the reaction force in the front-rear direction. In step S109, a longitudinal direction control command value, that is, a reaction force control command value FA to be output to the accelerator pedal reaction force control device 80, and an output to the brake pedal reaction force control device 90, from the longitudinal risk potential RPlongitinal calculated in step S105. The calculated reaction force control command value FB is calculated. In accordance with the risk potential RPlongitudinal in the front-rear direction, as the risk potential increases, the accelerator pedal 82 generates a control reaction in the direction in which the accelerator pedal 82 is returned, and the brake pedal 92 controls in such a direction that the brake pedal 92 is easily depressed. Generates reaction force.
[0042]
FIG. 7 shows the relationship between the longitudinal risk potential RPlongitinal and the accelerator pedal reaction force control command value FA. As shown in FIG. 7, when the longitudinal risk potential RPlongitudinal is smaller than a predetermined value RPmax, the accelerator pedal reaction force control command value FA is calculated so as to generate a greater accelerator pedal reaction force as the longitudinal risk potential RPlongitudinal is larger. I do. If the longitudinal risk potential RPlongitinal is equal to or greater than a predetermined value RPmax, the accelerator pedal reaction force control command value FA is fixed at the maximum value FAmax so as to generate the maximum accelerator pedal reaction force.
[0043]
FIG. 8 shows the relationship between the longitudinal risk potential RPlongitinal and the brake pedal reaction force control command value FB. As shown in FIG. 8, when the longitudinal risk potential RPlongitudinal is equal to or greater than a predetermined value RPmax, the brake pedal reaction force control is performed such that the larger the longitudinal risk potential RPlongitudinal, the smaller the brake pedal reaction force, that is, the greater the brake assist force. The command value FB is calculated. When the longitudinal risk potential RPlongitudinal becomes larger than a predetermined value RP1, the reaction force control command value FB is fixed at FBmin so as to generate the minimum brake pedal reaction force. When the longitudinal risk potential RPlongitinal is smaller than a predetermined value RPmax, the brake pedal reaction force control command value FB is set to zero, and the brake pedal reaction force characteristic is not changed.
[0044]
When the reaction force control is performed only in the front-rear direction, as shown in FIGS. 7 and 8, the accelerator pedal reaction force control command value FA and the brake pedal reaction force control command value FB according to the front-rear risk potential RPlongitudinal. Is calculated respectively. In addition. As can be seen from FIGS. 7 and 8, the greater the risk potential RPlongitudinal in the front-rear direction, the greater the accelerator pedal reaction force and the smaller the brake pedal reaction force, thereby prompting the driver to operate from the accelerator pedal operation to the brake pedal operation. ing.
[0045]
In step S111, the longitudinal direction control command values FA and FB calculated in step S109 are output to the accelerator pedal reaction force control device 80 and the brake pedal reaction force control device 90.
[0046]
On the other hand, when the running state of the vehicle matches the condition (2) or the condition (3), the process proceeds to step S110 in order to limit the reaction control to the left-right direction. In step S110, a left / right direction control command value, that is, a steering reaction force control command value FS to the steering reaction force control device 60 is calculated from the left / right risk potential RPlateral calculated in step S106. In accordance with the left and right risk potential RPlateral, the greater the risk potential, the greater the steering reaction force in the direction to return the steering wheel steering angle, that is, in the direction to return the steering wheel to the neutral position.
[0047]
FIG. 9 shows the relationship between the left-right risk potential RPlateral and the steering reaction force control command value FS. In FIG. 9, when the left and right risk potential RPlateral is positive, it indicates a right risk potential, and when the left and right risk potential RPlateral is negative, it indicates a left risk potential. ing.
[0048]
As shown in FIG. 9, when the absolute value of the lateral risk potential RPlateral is smaller than the predetermined value RPmax, the steering reaction force in the direction of returning the steering wheel to the neutral position increases as the absolute value of the risk potential increases. A steering reaction force control command value FS is set. When the absolute value of the left-right risk potential RPlateral is equal to or greater than a predetermined value RPmax, the maximum steering reaction force control command value FSmax is set so as to quickly return the steering wheel to the neutral position.
[0049]
In step S111, the left / right direction control command value FS obtained in step S110 is output to the steering reaction force control device 60.
[0050]
On the other hand, when a negative determination is made in step S107, the process proceeds to step S112 to perform the reaction force control in both the front-rear direction and the left-right direction. In step S112, the accelerator pedal reaction force control command value FA and the brake pedal reaction force control command value FB are calculated based on the longitudinal risk potential RPlongitudinal according to FIGS. At this time, the gain set in advance is integrated to calculate the actual front-rear direction control command value. In the following step S113, a steering reaction force control command value FS is calculated according to FIG. 9 based on the left and right risk potential RPlateral. At this time, a predetermined gain is integrated to calculate an actual left-right direction control command value.
[0051]
In step S111, the front / rear direction control command values FA and FB calculated in step S112 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 S113 is steered. Output to the reaction force control command value 60. Thus, a series of processing ends.
[0052]
As described above, in the first embodiment described above, the following effects can be obtained.
(1) The controller 50 determines the relative position and the moving direction (relative speed) of the other vehicle existing in front of and behind the own vehicle, the running speed of the own vehicle, and the running condition such as the relative position of the own vehicle to the white line. Recognize and calculate the risk potential RP for each obstacle based on the driving situation. The controller 50 controls the operation of the vehicle device based on the risk potential RP so as to encourage the driver to perform a driving operation related to the longitudinal movement and the lateral movement of the own vehicle. At this time, the operation control of the vehicle equipment is limited to only the more important one of the front-rear direction and the left-right direction according to the traveling state of the host vehicle. That is, since the operation instruction from the vehicle device is transmitted only from the more important direction, it is possible to appropriately urge the driving operation in the direction in which the risk potential RP becomes lower while preventing the driver from being confused. .
(2) The direction of operation control of the vehicle device is limited according to the own vehicle speed, and an operation instruction in a more important direction is transmitted by the operation of the vehicle device. Specifically, when the own vehicle speed is equal to or lower than a first predetermined vehicle speed, the control is limited to the front-rear direction. When the own vehicle speed is equal to or higher than a second predetermined vehicle speed that is higher than the first predetermined vehicle speed, the control is performed in the left-right direction. Therefore, appropriate driving operation can be prompted without confusing the driver.
(3) The direction of the operation control of the vehicle device is limited according to at least one of the longitudinal acceleration and the lateral acceleration. For example, when the longitudinal acceleration is equal to or more than a predetermined value, the control is limited to the left-right direction, and when the left-right acceleration is equal to or more than the predetermined value, the control is limited to the longitudinal direction. Thereby, an appropriate driving operation can be prompted without confusing or annoying the driver.
(4) When the traveling state of the host vehicle matches the predetermined traveling conditions (1) to (4), the controller 50 limits the control direction of the vehicle device to the front-back direction or the left-right direction, and If they do not match, control in both the front-rear direction and the left-right direction is performed. Thus, under predetermined traveling conditions, only an operation instruction in a more important direction is issued, and an appropriate driving operation can be prompted without disturbing the driver. On the other hand, when the vehicle does not meet the predetermined traveling conditions, the operation instruction is issued from the front / rear / left / right directions. Even when complicated driving operations such as steering and acceleration operations are required, the driver is prompted to perform an appropriate driving operation. Can be.
(5) Since the operation reaction force generated on the accelerator pedal 82 is controlled in order to promote the driving operation related to the longitudinal movement of the host vehicle, the acceleration / deceleration operation by the driver can be appropriately assisted.
(6) Since the operation reaction force generated on the brake pedal 92 is controlled in order to promote the driving operation related to the longitudinal movement of the own vehicle, the acceleration / deceleration operation by the driver can be appropriately assisted.
(7) Since the steering reaction force of the steering wheel is controlled to promote the driving operation related to the left-right movement of the vehicle, the steering operation by the driver can be appropriately assisted.
(8) The risk potential RP was calculated as a function of the time to collision TTC, and the longitudinal component RPlongitudinal and the lateral component RPlateral of the risk potential RP were calculated. Since the front-rear control amount and the left-right control amount are set based on the front-rear component RPlongitudinal and the left-right component RPlateral, the driver's vehicle front-rear direction and the vehicle front-rear direction can be set according to the distribution of the risk potential RPk generated by each obstacle k. The driving operation in the left-right direction can be appropriately assisted.
[0053]
<< 2nd Embodiment >>
Next, a vehicle driving assist system according to a second embodiment of the present invention will be described. The configuration of the driving assist system for a vehicle according to the second embodiment is the same as that of the first embodiment shown in FIGS. 1 and 2, and therefore the description thereof is omitted. Here, differences from the first embodiment will be mainly described.
[0054]
As in the first embodiment, the controller 50 limits the reaction force control to only one of the front-rear direction and the left-right direction according to the traveling state. However, in the second embodiment, in addition to the running state of the vehicle such as the vehicle speed and acceleration of the own vehicle, it is determined whether the situation around the vehicle and the state of the driver match predetermined running conditions, and the reaction force control is performed. The direction of is limited. If the traveling state does not meet the predetermined traveling conditions, the longitudinal risk potential RPlongitinal and the lateral risk potential RPlateral are compared to limit the reaction force control in a more important direction.
[0055]
In such control, how to determine each reaction force control command value will be described below with reference to FIG. FIG. 10 is a flowchart illustrating a processing procedure of a driving operation assisting control process in the controller 50 according to the second embodiment of the present invention. This processing content is continuously performed at regular intervals, for example, every 50 msec.
[0056]
-Processing flow of controller 50 (Fig. 10)-
The processing in steps S201 to S206 is the same as the processing in steps S101 to S106 in the above-described flowchart of FIG.
[0057]
In step S207, based on the traveling state data read in step S201, it is determined whether or not the current traveling state meets predetermined traveling conditions. Here, the following six traveling conditions including the traveling conditions (1) to (4) used in the above-described first embodiment are determined. If the current running state does not match the running conditions (1) to (6), it is determined that (7) others.
(1) When the vehicle speed is equal to or lower than a first predetermined vehicle speed, for example, 30 km / h.
(2) When the vehicle speed is equal to or higher than a second predetermined vehicle speed, for example, 100 km / h.
(3) When the longitudinal acceleration is equal to or more than a predetermined value.
(4) When the lateral acceleration is equal to or more than a predetermined value.
(5) When the degree of approach to the preceding vehicle is equal to or greater than a predetermined value.
(6) When the driver does not operate the pedal.
(7) Other.
[0058]
The degree of approach to the preceding vehicle may be, for example, the reciprocal of the preceding vehicle and the time to contact TTC (relative speed Vr / inter-vehicle distance D). If there is a preceding vehicle, the controller 50 acquires the degree of approach to the preceding vehicle in advance. The traveling condition (6) is a case where neither the accelerator pedal 82 nor the brake pedal 92 is operated. The presence or absence of these pedal operations can be detected by, for example, a pedal operation detection switch, or can be determined from the pedal stroke amount.
[0059]
Then, as shown in FIG. 11, it is determined whether to limit the reaction force control in the front-rear direction or the left-right direction according to the traveling state. When the traveling state matches the traveling conditions (1) to (4), it is the same as in the above-described first embodiment.
[0060]
When the traveling state matches the traveling condition (5), the control is limited to the longitudinal direction control because the degree of approach to the preceding vehicle is large and the importance of performing the longitudinal reaction force control is high. In the case of the condition (6), since the accelerator pedal operation and the brake pedal operation are not performed and there is no effect of performing the pedal reaction force control, the control is limited to the left-right direction reaction force control.
[0061]
If the traveling state does not meet the conditions (1) to (6), the condition is (7) Other. In this case, the longitudinal risk potential RPlongitinal calculated in step S205 and the left-right risk potential RPlateral calculated in step S206 are compared, and the control is limited to the reaction force control in the direction in which the risk potential RP is high. That is, when the longitudinal risk potential RPlongitinal is equal to or more than the left-right risk potential RPlateral (RPlongitinal ≧ RPlateral), the condition (7A) is set, and the control is limited to the longitudinal reaction force control. On the other hand, when the longitudinal risk potential RPlongitinal is smaller than the left-right risk potential RPlateral (RPlongitinal <RPlateral), the condition (7B) is set, and the control is limited to the lateral reaction force control.
[0062]
If the traveling state matches any of the conditions (1), (4), (5), and (7A), the process proceeds to step S208 to limit the control to the reaction force in the front-rear direction. In step S208, the longitudinal direction control command value, that is, the reaction force control command value output to the accelerator pedal reaction force control device 80, from the longitudinal risk potential RPlongitudinal calculated in step S205, as in the above-described first embodiment. FA and a reaction force control command value FB to be output to the brake pedal reaction force control device 90 are calculated.
[0063]
In step S210, the command values FA and FB calculated in step S208 are output to the accelerator pedal reaction force control device 80 and the brake pedal reaction force control device 90, respectively.
[0064]
On the other hand, when the traveling state matches any of the conditions (2), (3), (6), and (7B), the process proceeds to step S209 in order to limit the reaction force control in the left-right direction. In step S209, a left-right control command value, that is, a reaction force control command value FS to be output to the steering reaction force control device 60 is calculated from the left-right risk potential RPlateral calculated in step S206, as in the first embodiment. I do.
[0065]
In step S210, the command value FS calculated in step S209 is output to the steering reaction force control device 60. Thus, the current process ends.
[0066]
As described above, in the second embodiment described above, the following effects can be obtained in addition to the effects of the above-described first embodiment.
(1) The controller 50 limits the control direction of the vehicle device according to the degree of approach to the preceding vehicle, for example, the reciprocal 1 / TTC of the allowance time. Specifically, when the degree of approach to the preceding vehicle is high, the control is limited to the forward and backward directions, so only the information in the more important direction is transmitted to the driver at that time, and the driving operation is performed in the appropriate direction. Can be encouraged.
(2) The control direction of the vehicle equipment is limited according to the operation state of the own vehicle by the driver.
For example, when the accelerator pedal 82 and the brake pedal 92 are not operated, the control is limited to the left-right direction, so that the driving operation can be prompted in an appropriate direction according to the operation state.
(3) The control direction of the vehicle device is limited based on the longitudinal component and the lateral component of the risk potential. Specifically, when RPlongitudinal ≧ RPlatal, the control is limited to the front-back direction, and when RPlongitudinal <RPlatal, the control is limited to the left-right direction. Thus, only the operation instruction in the more important direction is transmitted to the driver, and the driving operation can be prompted in an appropriate direction.
(4) When the traveling state matches a predetermined traveling condition, the control direction of the vehicle device is limited to the front-back direction or the left-right direction. In addition, the predetermined running conditions are limited to control of the vehicle equipment in either the front-rear direction or the left-right direction, and in order to clearly inform the driver of the direction in which the risk potential occurs, the own vehicle speed, the front-rear direction acceleration, the left-right It is set based on at least one of the directional acceleration, the degree of approach to the preceding vehicle, and the operating state of the vehicle by the driver. Thereby, only the operation instruction in the more important direction is transmitted to the driver, and the driving operation can be appropriately prompted.
[0067]
In the above embodiment, the risk potential RP is calculated by multiplying the reciprocal of the time to contact TTC by the weight w. However, the present invention is not limited to this. The risk potential RP is defined as a function of the allowance time TTC, and the same effect can be obtained as long as the allowance time TTC decreases as the risk potential RP increases. Furthermore, if the risk potential for an obstacle can be accurately indicated according to the obstacle situation around the host vehicle, the risk potential can be calculated without using the time to contact TTC.
[0068]
In calculating the margin time TTCk and the risk potential RPk, the relative distance to each obstacle k, the variation σ (Dk) and σ (Vrk) of the relative speed, and the weight wk of each obstacle k are considered. However, the present invention is not limited to this. For example, the margin time TTCk can be calculated without considering the variation σ, or the risk potential RPk can be calculated without considering the weight wk. Further, when setting the variation σ, the variation σ can be set according to only the type of the detector, or the variation σ can be determined by combining the type of the detector and the type of the obstacle. However, by determining the variation σ according to the type of the detector and the type of the obstacle, and considering the variation σ and the weight wk, it is possible to calculate a more accurate margin time and risk potential.
[0069]
In the second embodiment, the traveling state is applied to any of the seven traveling conditions (1) to (7), and is limited to the front-rear direction control or the left-right direction control. Is not limited to the above (1) to (7). For example, if the running state does not match the condition (4), the condition is classified as (7) regardless of other conditions, and the risk potential in the front / rear / left / right direction is compared regardless of the own vehicle speed or pedal operation. The control direction can be limited only by this. In other words, it is also possible to determine the traveling state by arbitrarily combining these traveling conditions and limit the control direction. In addition, if the control of the vehicle device can be limited to the front-back direction or the left-right direction and the direction in which the risk potential is generated can be easily transmitted to the driver, the driving state is determined based on the driving conditions other than (1) to (7). You can also.
[0070]
Further, although the reciprocal of the time to spare the preceding vehicle is used as the degree of approach to the preceding vehicle in the driving condition (5), the present invention is not limited to this. For example, a relative vehicle speed to the preceding vehicle may be used. Alternatively, the risk potential RPk for the preceding vehicle, which takes into account the relative distance variation σ (Dk), the relative speed variation σ (Vrk), and the weight wk of each obstacle, which is calculated in step S204 in FIG. 10, can be used.
[0071]
In the above-described embodiment, the vehicle is configured to control the longitudinal movement of the vehicle 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. Only one may be used. That is, in the present invention, not only the accelerator pedal 82, the brake pedal 92, or the steering wheel 62, but also the operation of various vehicle devices is controlled so that the driver can drive the vehicle in the front-rear direction and the left-right direction in appropriate directions. It just needs to be encouraged.
[0072]
In the above-described embodiment, the brake assist force is generated by using the negative pressure of the engine by the brake booster 91. However, the present invention is not limited to this. For example, the brake assist force is generated by using hydraulic pressure controlled by a computer. You can also.
[0073]
The vehicle to which the vehicle driving assist control method according to the present invention is applied is not limited to the configuration shown in FIG.
[0074]
In the above-described embodiment of the vehicle driving assist system according to the present invention, the laser radar 10, the front camera 20, the rear camera 21 and the vehicle speed sensor 30 are used as the obstacle detecting means. The present invention is not limited to this as long as obstacles existing in the surroundings can be detected. For example, a millimeter wave radar can be used. Further, although the controller 50 is used as the risk potential calculation means, the traveling state detection means, the operation assist direction control means, and the determination means, the vehicle operation assist apparatus according to the present invention is not limited thereto. For example, an image processing device that performs image processing on image signals input from the front camera 20 and the rear side camera 21 may be provided, and this may be used as an obstacle detection unit. In addition, a controller 50, a steering reaction force control device 60, an accelerator pedal reaction force control device 80, and a brake pedal reaction force control device 90 were used as vehicle device control means.
[Brief description of the drawings]
FIG. 1 is a system diagram of a vehicle driving assist system according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a vehicle equipped with the vehicle driving assist system shown in FIG.
FIG. 3 is a flowchart illustrating a processing procedure of a driving operation assist control program in the vehicle driving operation assist device according to the first embodiment;
FIGS. 4A and 4B are diagrams illustrating the magnitude of variation in relative distance according to sensor type, and FIGS. 4B and 4B are diagrams illustrating the magnitude of variation in relative speed according to sensor type.
5A is a diagram illustrating the magnitude of variation in relative distance according to obstacle type, and FIG. 5B is a diagram illustrating the magnitude of variation in relative speed according to obstacle type.
FIG. 6 is a diagram showing running conditions in the first embodiment.
FIG. 7 is a diagram showing characteristics of an accelerator pedal reaction force control command value with respect to a longitudinal risk potential.
FIG. 8 is a diagram showing characteristics of a brake pedal reaction force control command value with respect to a longitudinal risk potential.
FIG. 9 is a diagram illustrating characteristics of a steering reaction force control command value with respect to a risk potential in the left-right direction.
FIG. 10 is a flowchart illustrating a processing procedure of a driving operation assist control program in the vehicle driving operation assist device according to the second embodiment;
FIG. 11 is a diagram showing running conditions according to the second embodiment.
[Explanation of symbols]
10: Laser radar
20: Front camera
21: Rear side camera
30: Vehicle speed 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)

Obstacle detection means for detecting an obstacle present around the own vehicle;
Based on a signal from the obstacle detection unit, a risk potential calculation unit that calculates a risk potential of the host vehicle with respect to the obstacle,
Vehicle equipment control means for controlling the operation of the vehicle equipment, based on a signal from the risk potential calculation means, so as to prompt the driver to perform a driving operation related to the longitudinal movement and the left and right movement of the own vehicle,
Traveling state detection means for detecting the traveling state of the vehicle,
Operation assist direction control means for limiting the control of the vehicle equipment by the vehicle equipment control means to only one of the front-rear direction and the left-right direction in accordance with the traveling state detected by the traveling state detection means. A driving assistance device for a vehicle, comprising: The vehicle driving assist system according to claim 1,
The traveling state detecting means detects the own vehicle speed as the traveling state,
The vehicle, wherein the operation assist direction control means limits the control by the vehicle equipment control means to only one of the front-rear direction and the left-right direction according to the own vehicle speed detected by the traveling state detection means. Driving operation assist device. The vehicle driving assist system according to claim 1,
The traveling state detection means detects at least one of the longitudinal acceleration and the lateral acceleration of the vehicle as the traveling state,
The operation assist direction control means limits the control by the vehicle equipment control means to only one of the front-rear direction and the left-right direction according to the acceleration of the host vehicle detected by the traveling state detection means. Driving assist device for vehicles. The vehicle driving assist system according to claim 1,
The running state detecting means detects an approach degree to a preceding vehicle on the own lane as the running state,
The vehicle, wherein the operation assisting direction control means limits the control by the vehicle equipment control means to only one of the front-rear direction and the left-right direction in accordance with the degree of approach detected by the traveling state detection means. Driving operation assist device. The vehicle driving assist system according to claim 1,
The traveling state detecting means detects an operation state of the own vehicle by a driver as the traveling state,
The vehicle, wherein the operation assist direction control means limits the control by the vehicle equipment control means to only one of the front-rear direction and the left-right direction according to the operation state detected by the traveling state detection means. Driving operation assist device. The vehicle driving assist system according to claim 1,
The running state detecting means calculates a front-rear component and a left-right component of the risk potential calculated by the risk potential calculating means according to a direction of the obstacle detected by the obstacle recognizing means,
The operation assisting direction control means limits the control by the vehicle device control means to only one of the front-rear direction and the left-right direction in accordance with the calculation result by the traveling state detection means, Auxiliary equipment. The vehicle driving assist system according to claim 1,
A determination unit configured to determine whether the traveling state detected by the traveling state detection unit matches a predetermined traveling condition;
(A) when the determining unit determines that the traveling state matches the predetermined traveling condition, the operation assisting direction control unit controls the vehicle device control unit in the front-rear direction according to the traveling state. And (B) when the determination unit determines that the traveling state does not meet the predetermined traveling condition, the vehicle device control unit transmits and receives the front and rear of the vehicle device. A driving assist system for a vehicle, characterized in that operation control is performed in both the left and right directions. The vehicle driving assist system according to claim 7,
The determination means includes: (1) the own vehicle speed is equal to or lower than a first predetermined vehicle speed, (2) the own vehicle speed is equal to or higher than a second predetermined vehicle speed which is higher than the first predetermined vehicle speed, and (3) Four running conditions in which the longitudinal acceleration is equal to or more than a predetermined value, and (4) the lateral acceleration is equal to or more than a predetermined value,
When the traveling state detected by the traveling state detection unit matches any of the four traveling conditions, the operation assist direction control unit controls the vehicle device control unit to control the front-rear direction and the left-right direction. A driving assistance device for a vehicle, characterized in that the driving assistance device is limited to only one of them. The vehicle driving assist system according to any one of claims 1 to 8, wherein the vehicle equipment control unit includes at least an accelerator pedal reaction force control unit that controls an operation reaction force generated on an accelerator pedal. Driving operation assisting device for a vehicle. The vehicle driving assist system according to any one of claims 1 to 9, wherein the vehicle device control means includes at least a brake pedal reaction force control means for controlling an operation reaction force generated on a brake pedal. Driving operation assisting device for a vehicle. The vehicle driving assist system according to any one of claims 1 to 10,
The vehicle operation control device according to claim 1, wherein the vehicle device control unit includes at least a steering reaction force control unit that controls a steering reaction force of a steering wheel. The vehicle driving assist system according to any one of claims 1 to 11,
The obstacle detection unit detects a relative distance and a relative speed to the obstacle, respectively.
The risk potential calculation means calculates a margin time obtained by dividing a relative distance to the obstacle by a relative speed, and calculates a risk potential for the obstacle as a function of the margin time,
The traveling state detecting means calculates a front-rear component and a left-right component of a risk potential calculated by the risk potential calculating means according to a direction toward the obstacle,
The vehicle equipment control means sets a longitudinal control amount and a lateral control amount of the vehicle equipment based on the longitudinal risk potential and the lateral risk potential calculated by the traveling state detecting means. Driving operation assist device for vehicles. Detects obstacles around the vehicle,
Based on the detected state of the obstacle, calculate a risk potential of the own vehicle with respect to the obstacle,
Based on the calculated risk potential, controlling the operation of the vehicle equipment, so as to prompt the driver to perform a driving operation related to the front-back movement and the left-right movement of the own vehicle,
Detecting the traveling state of the own vehicle,
It is determined whether the detected driving state matches a predetermined driving condition,
A driving operation assisting method for a vehicle, wherein the control of the vehicle device is limited to only one of a front-rear direction and a left-right direction when the traveling state matches the predetermined traveling condition. The driving assist control method according to claim 13,
The predetermined running conditions include: own vehicle speed, front-rear direction acceleration, left-right A driving operation assist control method for a vehicle, wherein the method is set based on at least one of a direction acceleration, a degree of approach to a preceding vehicle, and an operation state of the own vehicle by a driver. A vehicle to which the driving assist control method according to claim 13 or 14 is applied.

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