JP2004110347A - 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 a 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 assistance correcting means 50 for correcting the ratio of longitudinal driving operation assistance to lateral driving operation assistance to the driver 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]
Japanese Patent Application Laid-Open No. Hei 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 was 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. A driving state detecting means for detecting a driving state of the own vehicle, and a ratio of front-rear driving assistance and left-right driving assistance to the driver is corrected in accordance with the traveling state detected by the traveling state detection means. And an operation assist correction means for assisting the driver's operation.
[0005]
【The invention's effect】
Depending on the driving condition of the host vehicle, the ratio of operation assistance to the driver in the front-rear direction and left-right direction is corrected, and correction is performed so that operation instructions from important directions are increased, so that more important information is provided to the driver. The information can be transmitted in an easy-to-understand manner, and the driving operation can be appropriately assisted.
[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 control reaction force 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 according to the risk potential. It assists the driver in accelerating / decelerating and steering the host vehicle and appropriately assists the driver in driving. However, in the case where the operation reaction force in the vehicle front-rear direction and the left-right direction is similarly controlled, it may be difficult for the driver to understand from which direction the information is more important.
[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, the front / rear / left / right ratio of the risk potential distribution around the vehicle is corrected (deformed) according to the driving state, and the driving is performed so that particularly important information can be easily understood. Make people feel.
[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, the relative distance and the relative angle to the preceding vehicle detected by the laser radar 10, and 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 vehicle traveling ahead are read, and further, the relative distance and the relative angle to the traveling vehicle existing behind the adjacent lane based on the image input from the rear camera 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. The allowance time TTCk with respect to the obstacle k is obtained by the following (Equation 1).
(Equation 1)
TTCk = (Dk−σ (Dk)) / (Vrk + σ (Vrk)) (Equation 1)
Here, Dk: relative distance from the own vehicle to the obstacle k, Vrk: relative speed of the obstacle k with respect to the own vehicle, σ (Dk): variation in relative distance, σ (Vrk): variation in relative speed, respectively Show.
[0027]
The variation σ (Dk) and σ (Vrk) of the relative distance and the relative speed are sensors that recognize the obstacle k in consideration of the uncertainty of the detector and the degree of influence when an unexpected situation occurs. 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 lateral risk potential 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 running state data read in step S101, it is determined how to correct the front-rear direction reaction force control amount and the left-right direction reaction force control amount according to the current running state. Here, as shown in FIG. 6, the current running state is determined under the following three conditions, and a method of correcting the reaction force control amount is determined. (1) Conditions for correcting so that operation assistance in the vehicle front-rear direction is increased.
When the traveling speed of the own vehicle is equal to or higher than a predetermined speed, for example, 70 km / h.
(2) Conditions for correcting so that the operation assistance in the vehicle left-right direction is increased.
When your vehicle is traveling in an urban area.
(3) Conditions for correcting so that the absolute value of the risk potential RP becomes large.
a. When the driver is tired.
b. When the driving environment of the host vehicle is poor. For example, bad weather such as rain or fog, or when driving at night.
[0039]
The determination of the condition (2) can be made according to, for example, map information by a navigation system or the own vehicle speed. When the determination is made based on the own vehicle speed, when the own vehicle speed is running at a predetermined vehicle speed, for example, 40 km / h or less, it is determined that the vehicle is running in an urban area. The driver's fatigue state under the condition (3a) can be determined based on, for example, continuous running time. Specifically, when the time from when the ignition switch is turned on to when it is turned off is a predetermined time, for example, two hours or more, the driver can be determined to be in a fatigue state. For the traveling environment under the condition (3b), for example, it is determined whether it is rainy based on the wiper operation state, and it is determined whether fog is generated based on the lighting state of the fog lamp. Also, for example, it is determined whether or not it is nighttime based on the lighting state of the headlight.
[0040]
When increasing the absolute value of the risk potential RP, the absolute values of both the longitudinal risk potential RPlongitudinal and the lateral risk potential RPlateral are increased, and the operational assistance in both the longitudinal direction and the lateral direction is increased.
[0041]
The calculation of the front-rear direction reaction force control amount and the left-right direction reaction force control amount are performed in steps S108 and S109, respectively. Here, a gain for correcting each reaction force control amount is set according to the traveling state. Keep it.
[0042]
When the current running state satisfies the condition (1), the front-rear direction gain Glongitinal is corrected to be large, for example, Glongitinal = 1.5 is set, and the operation reaction force control amount in the front-rear direction is corrected. When the current traveling condition satisfies the condition (2), the left-right direction gain Glatalal is corrected to be large, for example, Glatal = 1.5, and the left-right direction operation reaction force control amount is corrected. When the current driving state satisfies the condition (3), the longitudinal gain Glongitinal and the lateral gain Glatinal are corrected so as to increase respectively, and, for example, Glongitinal = 1.5 and Glatral = 1.5 are set, and And correct the operation reaction force control amount in the left-right direction. If the current running state does not satisfy any of the conditions (1) to (3) (normal state), the front-rear direction gain Glongitinal = 1 and the left-right direction gain Glatalal = 1 are set, and the operation reaction force control is performed. No volume correction is made.
[0043]
In step S108, a longitudinal 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 a brake pedal reaction force control device 90 are output from the longitudinal risk potential RPlongitudinal calculated in step S105. And a reaction force control command value FB to be 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. Thus, the driver's operation is promoted from the operation of the accelerator pedal to the operation of the brake pedal.
[0044]
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.
[0045]
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.
[0046]
Further, a predetermined front-rear direction gain Glongitinal is integrated with the calculated front-rear direction reaction force command values FA and FB to obtain an actual reaction force command value. If the current running state satisfies the condition (1) or the condition (3), the actual reaction force command value is calculated using the corrected longitudinal gain Glongitinal = 1.5. On the other hand, when the current running state satisfies the condition (2) and in the normal state, the actual reaction force command value is calculated using the longitudinal gain Glongitinal = 1.
[0047]
In step S109, 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.
[0048]
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.
[0049]
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.
[0050]
Further, a predetermined left-right direction gain Glatal is integrated with the calculated steering reaction force control command value FS to obtain an actual reaction force command value. If the current running state satisfies the condition (2) or the condition (3), an actual reaction force command value is calculated using the corrected lateral gain Glatal = 1.5. On the other hand, when the current traveling state satisfies the condition (1) and in the normal state, the actual reaction force command value is calculated using the lateral direction gain Glatal = 1.
[0051]
In step S110, the front / rear direction control command values FA and FB calculated in step S108 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 S109 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 ratio of the operation assistance in the front-rear direction and the left-right direction for the driver is corrected according to the traveling state of the host vehicle. That is, since the correction is made so that the operation instruction from the important direction becomes large, more important information can be transmitted to the driver in an easy-to-understand manner, and the driving operation can be appropriately promoted in the direction in which the risk potential RP decreases.
(2) The front-rear and left-right operation assistance is corrected by correcting the front-rear control amount and the left-right control amount of the vehicle device according to the traveling state. As a result, operation instructions from important directions can be easily transmitted to the driver.
(3) The longitudinal control amount and the lateral control amount of the vehicle equipment are corrected according to the own vehicle speed. Specifically, when the own vehicle speed is equal to or higher than a predetermined vehicle speed, the control amount is corrected so that the longitudinal control amount is increased, so that the risk potential RP from a more important direction is transmitted to the driver, and the driving operation is performed in an appropriate direction. Can be encouraged.
(4) The control amount in the front-rear direction and the control amount in the left-right direction of the vehicle device are corrected depending on whether the own vehicle is traveling in an urban area. Specifically, since the control amount in the left / right direction is corrected so that the control amount in the left / right direction becomes large while traveling in an urban area, it is possible to transmit the risk potential RP from a more important direction to the driver and prompt the driving operation in an appropriate direction. it can.
(5) The front-rear direction control amount and the left-right direction control amount of the vehicle equipment are corrected according to the degree of fatigue of the driver. Specifically, when the driver is tired, the absolute value of the risk potential RP is corrected so that the longitudinal control amount and the left-right control amount are both increased, so that the risk potential RP can be easily understood. It can be transmitted to the driver.
(6) The longitudinal control amount and the lateral control amount of the vehicle equipment are corrected according to the traveling environment of the host vehicle. Specifically, during bad weather such as rain or fog or during night driving, the absolute value of the risk potential RP is corrected so that both the longitudinal control amount and the left-right control amount are increased. It can be transmitted to the driver in an easy-to-understand manner.
(7) 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.
(8) 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 host vehicle, the acceleration / deceleration operation by the driver can be appropriately assisted.
(9) Since the steering reaction force of the steering wheel is controlled in order to encourage the driving operation related to the left-right movement of the vehicle, the steering operation by the driver can be appropriately assisted.
(10) The risk potential RP was calculated as a function of the time to collision TTC, and the longitudinal component RPlongitudinal and the horizontal 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]
The controller 50 corrects the operation reaction force control amounts in the front-rear direction and the left-right direction according to the traveling state, as in the first embodiment. However, in the second embodiment, the operation reaction force control amount is corrected by calculating the risk gain Grp according to the direction of each obstacle existing around the vehicle and correcting the risk potential RP.
[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 S203 is the same as the processing in steps S101 to S103 in the above-described flowchart of FIG.
[0057]
In step S204, a risk gain Grp for correcting the risk potential RP is calculated according to the running state and the direction of the obstacle. First, in order to correct the risk potential RP according to the traveling state and the obstacle direction, the current traveling state is determined based on the above-described conditions (1) to (3) (see FIG. 6), and the risk potential RP is corrected. That is, a method of correcting the operation reaction force control amount is determined. Then, in order to realize this correction, the risk gain Grp is set according to the existing direction θk of the obstacle k.
[0058]
FIG. 11 shows an example of the characteristic of the risk gain Grp with respect to the direction θk of the obstacle k. In FIG. 11, the horizontal axis represents the absolute value of the direction θk in which the obstacle k exists relative to the host vehicle, and the vertical axis represents the risk gain Grp. When the obstacle k exists in front of the vehicle, θk = 0 deg, when it exists behind the vehicle, θk = 180 deg. When the obstacle k exists on the right or left side of the vehicle, | θk | = 90 deg. .
[0059]
As shown in FIG. 11, when the traveling state is the condition (1), for example, when there is a preceding vehicle, the risk gain Grp = 2 when the direction θk = 0 of the obstacle k, and the direction θk of the obstacle k Increases, the risk gain Grp decreases. In addition, in the condition (1), when the obstacle k exists from the side to the rear and 90 ≦ | θk | ≦ 180, the risk gain Grp = 1. When the traveling state is the condition (2), for example, a motorcycle or the like exists on the left and right sides of the vehicle, the risk gain Grp = 2 when the direction | θk | The risk gain Grp decreases as the absolute value decreases or increases. In the condition (2), when the obstacle k exists in front of or behind the vehicle and | θk | = 0, 180 deg, the risk gain Grp = 1. When the traveling state is the condition (3), the risk gain Grp is 1.5 regardless of the direction θk of the obstacle k. If the running state is a normal state that does not satisfy any of the conditions (1) to (3), the risk gain Grp = 1.
[0060]
The controller 50 calculates a risk gain Grp according to the direction of existence θk of each obstacle k according to FIG. 11 according to the traveling state and the obstacle situation.
[0061]
In step S205, the risk potential RPk for each obstacle k is calculated using the margin time TTCk calculated in step S203 and the risk gain Grp calculated in step S204. Here, the risk potential RPk for each obstacle k is obtained by the following (Equation 6).
(Equation 6)
RPk = (1 / TTCk) × wk × Grp (Equation 6)
Here, wk indicates the weight of the obstacle k. The method of calculating the weight wk is the same as in the first embodiment. The risk potential RPk is corrected according to the traveling state and the direction of the obstacle by integrating the risk gain Grp, and the risk potential RPk increases as the risk gain Grp increases.
[0062]
In step S206, components in the vehicle longitudinal direction are extracted and added from the risk potential RPk for each obstacle k calculated in step S205, and a total longitudinal risk potential for all obstacles existing around the vehicle is calculated. . The longitudinal risk potential RPlongitinal can be calculated using (Equation 4) in the same manner as in the first embodiment.
[0063]
In step S207, the components in the vehicle left-right direction are extracted and added from the risk potential RPk for each obstacle k calculated in step S205, and the total left-right direction risk potential for all obstacles around the vehicle is calculated. . The left and right risk degree RPlateral can be calculated using (Equation 5) as in the first embodiment.
[0064]
The processing in subsequent steps S208 to S210 is the same as the processing in steps S108 to S110 in the above-described flowchart of FIG.
[0065]
Note that the risk gain characteristics shown in FIG. 11 can be expressed as shown in FIG. 12 corresponding to the vertical direction and the horizontal direction of the vehicle.
[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 risk potential RP is corrected in accordance with the traveling state, and the longitudinal and lateral control amounts of the vehicle equipment are set based on the corrected risk potential RP, whereby the longitudinal and lateral operation assistance is provided. to correct. As a result, operation instructions from important directions can be easily transmitted to the driver.
(2) The risk potential RP for the obstacle is corrected according to the own vehicle speed and the direction of the obstacle. For example, when the vehicle speed is equal to or higher than the predetermined vehicle speed and there is a preceding vehicle, the gain Grp to be added to the risk potential RP for the preceding vehicle is set to be larger than that in the normal state. As a result, the control amount in the front-rear direction that is larger than that in the normal state is set, and the risk potential RP from a more important direction can be transmitted to the driver in an easy-to-understand manner to prompt the driver to perform the driving operation in an appropriate direction. Further, since the risk potential RP is corrected in accordance with the direction of existence θk of each obstacle k, a more appropriate operation instruction can be given according to the situation of each obstacle k.
(3) The risk potential RP for the obstacle is corrected based on the direction of the obstacle and whether or not the host vehicle is traveling in an urban area. For example, when a motorcycle or the like is present beside the vehicle while traveling in an urban area, the gain Grp to be added to the risk potential RP for the motorcycle is set to be larger than that in the normal state. As a result, the control amount in the left-right direction that is larger than that in the normal state is set, and the risk potential RP from a more important direction can be transmitted to the driver in an easy-to-understand manner, and the driving operation can be prompted in an appropriate direction. Further, since the risk potential RP is corrected in accordance with the direction of existence θk of each obstacle k, a more appropriate operation instruction can be given according to the situation of each obstacle k.
(4) The risk potential RP for the obstacle is corrected according to the degree of fatigue of the driver. Specifically, when the driver is tired, the gain Grp to be added to the risk potential RP is set larger than in the normal state. As a result, the control amount in the front-rear direction and the control amount in the left-right direction that are larger than those in the normal state are set, and the risk potential RP can be easily transmitted to the driver.
(5) The risk potential RP for the obstacle is corrected according to the traveling environment of the host vehicle. Specifically, during bad weather such as rain or fog and during night driving, the gain Grp to be added to the risk potential RP is set to be larger than that in the normal state. As a result, the control amount in the front-rear direction and the control amount in the left-right direction that are larger than those in the normal state are set, and the risk potential RP can be easily transmitted to the driver.
[0067]
In the above embodiment, when the current running state of the vehicle satisfies a plurality of conditions, the gains Glongitinal, Glateral, and Grp are set so as to provide the driver with the greatest operation assistance. For example, when the running state satisfies the conditions (1) and (3) in the first embodiment, the correction corresponding to the condition (3) is performed. Thereby, the operation assistance in the front-rear direction and the left-right direction becomes larger than in the normal state, and the risk potential RP can be easily transmitted to the driver.
[0068]
In the above embodiment, the traveling state is determined under three conditions, and the method of correcting the operation assistance is determined. However, if the risk potential from a more important direction can be transmitted to the driver in an easy-to-understand manner, the traveling state can be further increased. It is also possible to determine a correction method by making a determination on many or few conditions.
[0069]
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.
[0070]
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.
[0071]
In the above-described embodiment, the vehicle is configured to control the longitudinal movement of the vehicle by 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 can 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 perform driving operations in the vehicle front-rear direction and the left-right direction in appropriate directions. It just needs to be encouraged.
[0072]
In the above-described embodiment, the ratio of the front-back direction driving operation assistance and the left-right direction driving operation assistance is corrected by correcting the front-rear / left-right control amount or the risk potential RP according to the traveling state. However, by combining both corrections, for example, the risk potential RP is corrected according to the driving state, the longitudinal / lateral control amount is calculated based on the corrected risk potential RP, and further, the longitudinal / directional control amount is calculated according to the traveling state. The control amount in the left-right direction can also be corrected.
[0073]
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.
[0074]
The vehicle to which the vehicle driving assist method according to the present invention is applied is not limited to the configuration shown in FIG.
[0075]
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, the controller 50 was used as risk potential calculation means, running state detection means, operation assist correction means, operation amount correction means, and risk potential correction means. Further, 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 equipment control means. However, the vehicle driving assist system according to the present invention is not limited to these. 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.
[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 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 illustrating an example of a characteristic of a risk gain Grp with respect to a direction in which an obstacle exists.
FIG. 12 is a diagram illustrating an example of a characteristic of a risk gain Grp with respect to an existing direction of an obstacle.
[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 (18)

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,
A vehicle comprising: an operation assist correction unit that corrects a ratio of a front-back direction driving operation assist and a left-right direction driving operation assist to a driver in accordance with the traveling state detected by the traveling state detection unit. Driving operation assist device. The vehicle driving assist system according to claim 1,
The operation assistance correction unit includes an operation amount correction unit that corrects a control amount in the front-rear direction and a control amount in the left-right direction by the vehicle device control unit,
The driving operation assisting device for a vehicle, wherein the operation amount correcting means corrects the front-rear direction control amount and the left-right direction control amount in accordance with the traveling state to correct driving operation assistance for a driver. The vehicle driving assist system according to claim 2,
The traveling state detecting means detects the own vehicle speed as the traveling state,
The driving operation assisting device for a vehicle, wherein the operation amount correction unit corrects the front-rear direction control amount and the left-right direction control amount according to the own vehicle speed detected by the traveling state detection unit. The vehicle driving assist system according to claim 2,
The traveling state detection means detects whether the vehicle is in an urban area traveling state as the traveling state,
The driving operation assisting device for a vehicle, wherein the operation amount correction unit corrects the front-back direction control amount and the left-right direction control amount according to a detection result of the traveling state detection unit. The vehicle driving assist system according to claim 2,
The traveling state detecting means detects a degree of fatigue of the driver as the traveling state,
The driving operation assisting device for a vehicle, wherein the operation amount correction unit corrects the front-rear direction control amount and the left-right direction control amount according to a degree of fatigue detected by the traveling state detection unit. The vehicle driving assist system according to claim 2,
The traveling state detecting means detects a traveling environment of the host vehicle as the traveling state,
The driving operation assisting device for a vehicle, wherein the operation amount correction unit corrects the front-rear direction control amount and the left-right direction control amount according to a traveling environment detected by the traveling state detection unit. The vehicle driving assist system according to claim 1,
The operation assistance correction unit includes a risk potential correction unit that corrects the risk potential calculated by the risk potential calculation unit,
The risk potential correction means corrects the risk potential according to the running state, and causes the vehicle equipment control means to set a control amount in the front-rear direction and a control amount in the left-right direction based on the corrected risk potential, and perform driving. A driving operation assisting device for a vehicle, which corrects driving operation assistance for a driver. The vehicle driving assist system according to claim 7,
The obstacle detection means detects an existing direction of the obstacle,
The traveling state detecting means detects the own vehicle speed as the traveling state,
The risk potential correction means corrects the risk potential for the obstacle according to the own vehicle speed detected by the traveling state detection means and the direction of the obstacle detected by the obstacle detection means. Driving operation assisting device for vehicles. The vehicle driving assist system according to claim 7,
The obstacle detection means detects an existing direction of the obstacle,
The traveling state detection means detects whether the vehicle is in an urban area traveling state as the traveling state,
The risk potential correcting means corrects a risk potential for the obstacle according to a detection result of the traveling state detecting means and a direction in which the obstacle is detected by the obstacle detecting means. Driving operation assist device for vehicles. The vehicle driving assist system according to claim 7,
The traveling state detecting means detects a degree of fatigue of the driver as the traveling state,
The driving potential assist device for a vehicle, wherein the risk potential correcting means corrects a risk potential for the obstacle in accordance with a degree of fatigue detected by the running state detecting means. The vehicle driving assist system according to claim 7,
The traveling state detecting means detects a traveling environment of the host vehicle as the traveling state,
The driving potential assist device for a vehicle, wherein the risk potential correcting means corrects a risk potential for the obstacle in accordance with a traveling environment detected by the traveling state detecting means. The vehicle driving assist system according to any one of claims 1 to 11,
A vehicle driving assist system comprising: an accelerator pedal reaction force control unit configured to control at least an operation reaction force generated by an accelerator pedal. The vehicle driving assist system according to any one of claims 1 to 12,
The vehicle operation control device according to claim 1, wherein the vehicle device control means includes at least a brake pedal reaction force control means for controlling an operation reaction force generated on the brake pedal. The vehicle driving assist system according to any one of claims 1 to 13,
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 14,
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, calculates a risk potential for the obstacle as a function of the margin time, and calculates a risk potential for the obstacle according to a direction toward the obstacle. Calculating the longitudinal component and the lateral component of the risk potential,
The vehicle equipment control means sets a front-rear control amount and a left-right control amount of the vehicle equipment based on the front-rear risk potential and the left-right risk potential calculated by the risk potential calculation 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,
A driving operation assisting method for a vehicle, comprising: correcting a longitudinal control amount and a lateral control amount of the vehicle device according to a detected traveling state. 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,
Detecting the traveling state of the own vehicle,
According to the detected driving state, the risk potential is corrected,
A driving operation assisting method for a vehicle, comprising: controlling an operation of a vehicle device so as to prompt a driver to perform a driving operation related to a longitudinal motion and a lateral motion of the host vehicle based on the corrected risk potential. A vehicle to which the driving operation assisting method according to claim 16 or 17 is applied.

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