JP4349066B2 - VEHICLE DRIVE OPERATION ASSISTANCE DEVICE AND VEHICLE HAVING VEHICLE DRIVE OPERATION ASSISTANCE DEVICE - Google Patents

Description

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

  A conventional driving operation assisting device for a vehicle changes an operation reaction force of an accelerator pedal based on a distance between the preceding vehicle and the host vehicle (for example, Patent Document 1). This device alerts the driver by increasing the reaction force of the accelerator pedal as the inter-vehicle distance decreases.

Prior art documents related to the present invention include the following.
Japanese Patent Laid-Open No. 10-166889 Japanese Patent Laid-Open No. 10-166890 JP 2000-54860 A JP-A-9-286313

  In the vehicle driving operation assist device as described above, the driver is informed of the risk around the host vehicle, and the behavior of the host vehicle is controlled in consideration of the possibility of contact between the host vehicle and the obstacle. Is desired.

Vehicle driving assist system according to the present invention, the obstacle detection means for detecting a vehicle around the obstacle, the vehicle speed detecting means for detecting a vehicle speed, the vehicle and the obstacle which thus is detected obstacle detecting means The first risk representing the degree of approach of the host vehicle to the obstacle based on the inter-vehicle distance and relative speed with the object, and the host vehicle and the obstacle based on the host vehicle speed detected by the inter-vehicle distance and host vehicle speed detecting means a risk calculation means for calculating a second risk representing the possibility of contact, based on the first risk calculated by the risk calculating means, for controlling the operation reaction force generated when operating the driving operation device Based on the second risk calculated by the operation reaction force control means and the risk calculation means, the braking torque correction means for increasing the braking torque generated in the host vehicle, and the operation reaction force by the operation reaction force control means Please, and a control means for controlling to perform with priority either control the braking torque by the braking torque correction means.

Vehicle driving assist system according to the present invention, the obstacle detection means for detecting a vehicle around the obstacle, the vehicle speed detecting means for detecting a vehicle speed, the vehicle and the obstacle which thus is detected obstacle detecting means A risk potential calculating means for calculating a risk potential representing the degree of approach of the host vehicle to the obstacle based on the distance between the vehicle and the relative speed, and a driving operation device based on the risk potential calculated by the risk potential calculating means. Obstacles around the host vehicle based on the operating reaction force control means for controlling the operating reaction force generated when operating, the inter-vehicle distance detected by the obstacle detecting means and the own vehicle speed detected by the own vehicle speed detecting means . A contact prediction means for predicting the possibility of contact with the vehicle, and a brake pedal operation amount detection means for detecting an operation amount of the brake pedal; When it is predicted that the possibility of contact with an obstacle is high by the brake control means that generates a braking torque corresponding to the brake pedal operation amount and the contact prediction means, the relationship of the braking torque to the brake pedal operation amount is increased. Braking torque correction means for correcting.

  Prioritize either the control of the reaction force due to the potential risk of the host vehicle or the correction of the braking torque based on the risk of contact between the host vehicle and the obstacle. It is possible to appropriately assist the deceleration operation of the host vehicle while informing the person intuitively.

  Control the reaction force of the driver's operating device according to the risk potential around the host vehicle, and increase the braking torque generated for the brake pedal operation amount when the possibility of contact between the host vehicle and the obstacle is high Therefore, when the possibility of contact is high, the deceleration operation of the host vehicle can be appropriately assisted while the risk potential is transmitted through the reaction force.

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

  First, the configuration of the vehicle driving assistance device 1 will be described. The laser radar 10 is attached to a front grill part or a bumper part of the vehicle, and scans the front area of the vehicle by irradiating infrared light pulses in the horizontal direction. The laser radar 10 measures the reflected wave of the infrared light pulse reflected by a plurality of reflectors in front (usually the rear end of the front vehicle), and determines the distance between the plurality of front vehicles from the arrival time of the reflected wave. Detect the distance and its direction. The detected inter-vehicle distance and presence direction are output to the controller 50. In the present embodiment, the presence direction of the front object can be expressed as a relative angle with respect to the host vehicle. The forward area scanned by the laser radar 10 is about ± 6 deg with respect to the front of the host vehicle, and a forward object existing within this range is detected.

  The vehicle speed sensor 20 detects the vehicle speed of the host vehicle by measuring the number of rotations of the wheels and the number of rotations on the output side of the transmission, and outputs the detected host vehicle speed to the controller 50.

  The controller 50 includes a CPU and CPU peripheral components such as a ROM and a RAM, and controls the vehicle driving operation assisting device 1 as a whole. The controller 50 determines the obstacle situation around the own vehicle, for example, the relative distance and relative speed between the own vehicle and each obstacle, from the own vehicle speed inputted from the vehicle speed sensor 20 and the distance information inputted from the laser radar 10. Judgment is made on the running state of the object. The controller 50 calculates the risk potential of the host vehicle for each obstacle based on the obstacle situation. Furthermore, the controller 50 performs the following control based on the risk potential for the obstacle.

  The vehicular driving operation assisting apparatus 1 according to the first embodiment of the present invention controls the reaction force generated when the accelerator pedal 62 and the brake pedal 92 are depressed, thereby allowing the driver to apply the own vehicle. It assists the deceleration operation and assists the driver's driving operation appropriately. Therefore, the controller 50 calculates the reaction force control amount in the vehicle front-rear direction based on the risk potential for the obstacle ahead of the host vehicle from the obstacle situation. The controller 50 outputs the calculated reaction force control amount in the front-rear direction to the accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 90.

  The accelerator pedal reaction force control device 60 controls the torque generated by the servo motor 61 incorporated in the link mechanism of the accelerator pedal 62 according to the reaction force control amount output from the controller 50. The servo motor 61 controls the reaction force generated according to the command value from the accelerator pedal reaction force control device 60, and can arbitrarily control the pedaling force generated when the driver operates the accelerator pedal 62.

  The brake pedal reaction force control device 90 controls the torque generated by the servo motor 91 incorporated in the link mechanism of the brake pedal 92 according to the reaction force control amount output from the controller 50. The servo motor 91 controls the reaction force generated according to the command value from the brake pedal reaction force control device 90, and can arbitrarily control the pedal force generated when the driver operates the brake pedal 92. Here, the reaction force of the brake pedal is controlled by the servo motor 91. However, the present invention is not limited to this. For example, the brake assist force can be generated using oil pressure by computer control.

  The brake pedal stroke sensor 94 detects the operation amount of the brake pedal 92 converted into the rotation angle of the servo motor 91 via the link mechanism. The brake pedal stroke sensor 94 outputs the detected brake pedal operation amount to the controller 50 and the braking force control device 93, respectively.

  The braking force control device 93 outputs a brake fluid pressure command. FIG. 3 shows a block diagram of the braking force control in the braking force control device 93. FIG. 4 shows a characteristic map that defines the relationship between the brake pedal operation amount SB and the driver-requested braking force Fdb. The braking force control device 93 calculates a driver required braking force Fdb according to the brake pedal operation amount SB using a map as shown in FIG. Then, the braking force control device 93 calculates a target braking force by adding a braking force correction value ΔDb described later to the driver requested braking force Fdb. The brake fluid pressure controller of the braking force control device 93 outputs a brake fluid pressure command according to the target braking force. In response to a command from the brake fluid pressure controller, a brake device 95 provided on each wheel operates.

  FIG. 5 is a block diagram showing the internal and peripheral configuration of the controller 50. The controller 50 includes, for example, an obstacle state recognition unit 51, a risk potential calculation unit 52, a driving operation reaction force calculation unit 53, a contact possibility prediction unit 54, a driving operation reaction force correction unit 55, and a braking force depending on the software form of the CPU. The correction amount calculation unit 56 is configured.

  The obstacle recognizing unit 51 inputs signals from the laser radar 10 and the vehicle speed sensor 20 and recognizes an obstacle state ahead of the host vehicle. Specifically, the inter-vehicle distance and relative speed with the preceding vehicle are calculated, and the own vehicle speed is detected. The risk potential calculation unit 52 calculates the risk potential of the host vehicle with respect to the front obstacle based on the recognition result of the obstacle recognition unit 51. The driving operation reaction force calculation unit 53 calculates a reaction force control command for the accelerator pedal 62 and a reaction force control command for the brake pedal 92 from the risk potential calculated by the risk potential calculation unit 52.

  Based on the recognition result of the obstacle recognition unit 51, the contact possibility prediction unit 54 predicts whether or not there is a high possibility that the host vehicle is in contact with an obstacle ahead. The driving reaction force correction unit 55 is based on the possibility that the obstacle predicted by the contact possibility prediction unit 54 and the host vehicle come into contact with the driving operation reaction force calculated by the driving operation reaction force calculation unit 53. To correct. The braking force correction amount calculation unit 56 calculates the correction amount of the braking force of the host vehicle when the contact possibility prediction unit 54 determines that there is a possibility of contact.

  Below, operation | movement of the driving operation assistance apparatus 1 for vehicles by 1st Embodiment is demonstrated in detail. FIG. 6 shows a flowchart of the processing procedure of the driving operation assist control processing in the controller 50 of the first embodiment. This processing content is continuously performed at regular intervals, for example, every 50 msec.

  First, the travel state is read in step S100. Here, the traveling state is information regarding the traveling state of the host vehicle including the obstacle state ahead of the host vehicle. Therefore, the inter-vehicle distance D to the front obstacle detected by the laser radar 10 and the existing direction, and the traveling vehicle speed Vh detected by the vehicle speed sensor 20 are read. The brake pedal operation amount SB detected by the brake pedal stroke sensor 94 is also read.

  In step S200, the situation of the front obstacle is recognized based on the driving state data read and recognized in step S100. Here, the relative position of the obstacle with respect to the host vehicle detected before the previous processing cycle and stored in the memory of the controller 50, its moving direction / speed, and the current running state data obtained in step S100 Thus, the relative position of the current obstacle with respect to the host vehicle, the moving direction and the moving speed thereof are recognized. Then, it is recognized how the obstacle is arranged in front of the host vehicle and how it moves relative to the traveling of the host vehicle.

In step S300, the risk potential RP for the obstacle is calculated. The risk potential RP for the obstacle is calculated as follows.
First, an allowance time TTC (Time To Contact) for the recognized obstacle is calculated. Here, the margin time TTC for the obstacle is obtained by the following (Equation 1).
TTC = D / Vr (Formula 1)
Here, D: the inter-vehicle distance between the host vehicle and the preceding vehicle, and Vr: the relative speed between the host vehicle and the preceding vehicle, respectively.

Then, the risk potential RP for the vehicle ahead is calculated using the calculated margin time TTC. The risk potential RP for the vehicle ahead is calculated by the following (Formula 2).
RP = 1 / TTC (Formula 2)
As shown in (Expression 2), the risk potential RP is expressed as a function of the allowance time TTC using the reciprocal of the allowance time TTC, and the greater the risk potential RP, the greater the degree of approach to the obstacle. ing.

  In step S400, the reaction force control command value FA output to the accelerator pedal reaction force control device 60 and the reaction force control command value FB output to the brake pedal reaction force control device 90 are obtained from the risk potential RP calculated in step S300. calculate. With respect to the accelerator pedal 62, the control reaction force is generated in the direction in which the accelerator pedal 62 is returned as the risk potential RP increases. As for the brake pedal 92, the control reaction force is generated in a direction in which the brake pedal 92 is more easily depressed as the risk potential RP is larger.

  FIG. 7 shows the relationship between the risk potential RP and the accelerator pedal reaction force control command value FA. As shown in FIG. 7, when the risk potential RP is smaller than the predetermined value RPmax, the accelerator pedal reaction force control command value FA is calculated so as to generate a larger accelerator pedal reaction force as the risk potential RP increases. When the risk potential RP is larger than the predetermined value RPmax, the accelerator pedal reaction force control command value FA is fixed to the maximum value FAmax so that the maximum accelerator pedal reaction force is generated.

  FIG. 8 shows the relationship between the risk potential RP and the brake pedal reaction force control command value FB. As shown in FIG. 8, when the risk potential RP is larger than the predetermined value RPmax, the brake pedal reaction force control command value FB is generated so that the smaller the risk potential RP, the smaller the brake pedal reaction force, that is, the larger brake assist force. Is calculated. When the risk potential RP becomes larger than the predetermined value RP1, the reaction force control command value FB is fixed to FBmin so as to generate the minimum brake pedal reaction force. When the risk potential RP is smaller than the 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.

  As shown in FIGS. 7 and 8, when the risk potential RP is smaller than the predetermined value RPmax, the accelerator pedal reaction force characteristic is changed, and the driver is notified of the magnitude of the risk potential RP as the accelerator pedal operation reaction force. On the other hand, when the risk potential RP is larger than the predetermined value RPmax, the accelerator pedal reaction force control command value FA is maximized to prompt the driver to release the accelerator pedal 62. Further, the brake pedal reaction force control command value FB is decreased so that the brake pedal 92 is easily depressed when the driver shifts to the brake operation.

In step S500, it is predicted whether or not there is a possibility that the obstacle and the host vehicle come into contact with each other. The processing performed here will be described with reference to the flowchart of FIG.
In order to determine the possibility of contact, first, an inter-vehicle time THW is calculated in step S501. The inter-vehicle time THW can be calculated from the following (Equation 3) using the inter-vehicle distance D between the host vehicle and the obstacle and the host vehicle speed Vh.
THW = D / Vh (Formula 3)

  In step S502, the flag Flg_A indicating the contact possibility determined in the previous cycle is stored as the past value Flg_Az.

  In step S503, the inter-vehicle time THW calculated in step 501 is compared with a threshold value Th. If the inter-vehicle time THW is equal to or greater than the threshold value Th (THW ≧ Th), it is determined that the vehicle is unlikely to contact the front obstacle, and the process proceeds to step S504, where the contact possibility flag Flg_A is set to 0. To do. On the other hand, when the inter-vehicle time THW is smaller than the threshold value Th (THW <Th), it is determined that the host vehicle may come into contact with a front obstacle, and the process proceeds to step S505 where the contact possibility flag Flg_A is set to 1. Set.

After predicting the possibility of contact in step S500 as described above, the process proceeds to step S600.
In step S600, the driving reaction force corresponding to the risk potential RP calculated in step S400 is corrected based on the possibility of contact with the obstacle predicted in step S500. The processing performed here will be described in detail with reference to FIGS.

  In step S610 of FIG. 10, a correction coefficient h for correcting the accelerator pedal reaction force control command value FA and the brake pedal reaction force control command value FB is calculated. A method for calculating the correction coefficient h will be described with reference to FIG.

  In step S611, it is determined whether or not the host vehicle may come into contact with a front obstacle, that is, whether or not the contact possibility flag Flg_A set in step S500 is 1. If a positive determination is made in step S611, the process proceeds to step S612. In step S612, it is determined whether or not the correction coefficient hz calculated in the previous cycle is larger than the difference between the correction coefficient maximum value hmax and a preset correction coefficient increment Δh (hz> hmax−Δh).

  If an affirmative determination is made in step S612, the process proceeds to step S613, where the correction coefficient maximum value hmax is set as the correction coefficient h, and the process ends (h = hmax). On the other hand, if a negative determination is made in step S612, the process proceeds to step S614, and the correction coefficient increment Δh is added to the correction coefficient hz calculated in the previous cycle to obtain the current correction coefficient h (h = hz + Δh).

  If the determination in step S611 is negative and the possibility that the host vehicle is in contact with the front obstacle is low, the process proceeds to step S615. In step S615, it is determined whether or not the correction coefficient hz of the previous cycle is smaller than a value obtained by adding 1 to the correction coefficient increment Δh (h <1 + Δh). If a positive determination is made in step S615, the process proceeds to step S616. In step S616, the current correction coefficient h is set to 1 and the process ends (h = 1). On the other hand, if a negative determination is made in step S615, the process proceeds to step S617, and the correction coefficient increment Δh is subtracted from the previous correction coefficient hz to obtain the current correction coefficient h (h = hz−Δh).

  FIG. 12 shows changes in the correction coefficient h in time series. When the contact possibility flag Flg_A is 1, that is, when it is determined that there is a possibility of contact, the correction coefficient h is gradually increased from 1 to the correction coefficient maximum value hmax. When the contactable positive flag Flg_A is 0, that is, when the possibility of contact is low, the correction coefficient h is gradually decreased to 1. In this way, when there is a possibility of contact, the correction coefficient k is increased, and when the possibility of contact is low, the correction coefficient k is decreased, so that the amount of change in the driving reaction force against the risk potential RP can be contacted. Correct according to. Further, since the correction coefficient h is gradually changed, a smooth reaction force change can be realized without the driving operation reaction force changing stepwise.

After calculating the correction coefficient h in step S610 as described above, the process proceeds to step S620.
In step S620, a pulse reaction force Fp applied to the accelerator pedal 62 and the brake pedal 92 is calculated. A method of calculating the pulse reaction force Fp will be described with reference to FIG.

  In step S621, it is determined whether or not the host vehicle may come into contact with a front obstacle, that is, whether or not the contact possibility flag Flg_A set in step S500 is 1. If a positive determination is made in step S621, the process proceeds to step S622. In step S622, it is determined whether or not there was a possibility of contact in the previous time, that is, whether or not the previous contact possibility flag Flg_Az is 1. If an affirmative determination is made in step S622, the process proceeds to step S623, and a counter Cnt indicating the elapsed time since it is determined that there is a possibility of contact is counted up. When a negative determination is made in step S622 and the state where there is a possibility of contact is changed to the state where there is a possibility of contact, the counter Cnt is cleared to zero.

In step S625, it is determined whether or not the counter Cnt is smaller than a predetermined time Tp (for example, Tp = 0.2 sec). If a positive determination is made in step S625, the process proceeds to step S626. In step S626, the pulse reaction force height ΔFp is set to the pulse reaction force Fp so that the pulse reaction force is applied to the accelerator pedal 62 and the brake pedal 92, and the process ends. On the other hand, if a negative determination is made in step S625, the process proceeds to step S627, where the pulse reaction force Fp is set to 0, and the process ends.
If the determination in step S621 is negative and there is no possibility of contact, the process proceeds to step S628, in which the pulse reaction force Fp is set to 0 and the process ends.

  FIG. 14 shows changes in the pulse reaction force Fp in time series. When the contact possibility flag Flg_A changes from 0 to 1, that is, from a state where there is no possibility of contact to a state where there is a possibility of contact, the pulse reaction force Fp becomes the pulse height ΔFp. Then, the pulse reaction force Fp is generated until a predetermined time Tp elapses after changing to a state where there is a possibility of contact.

  By calculating the pulse reaction force Fp in this way, the driver is notified of a change from a state where there is no possibility of contact to a state where there is a possibility of contact by a change in the reaction force of the pedal. This can prompt the driver to perform an appropriate driving operation. Further, after the predetermined time Tp has elapsed, the pulse reaction force Fp is not generated, and the driving operation reaction force corresponding to the risk potential RP is restored, so that the driving operation of the driver is not disturbed.

After calculating the pulse reaction force Fp in step S620 as described above, the process proceeds to step S631.
In step S631, the accelerator pedal reaction force correction value FA_hosei is calculated from the correction coefficient h calculated in step S610 and the pulse reaction force Fp calculated in step S620 according to the following (Equation 4).
FA_hosei = h × FA + Fp (Formula 4)

In step S632, a brake pedal reaction force correction value FB_hosei is calculated from the correction coefficient h and the pulse reaction force Fp according to the following (Equation 5).
FB_hosei = h × FB−Fp (Formula 5)

FIGS. 15A to 15D show examples of time-series changes in the correction coefficient h, the risk potential RP, the accelerator pedal reaction force, and the brake pedal reaction force.
When the state is changed from the state where there is no possibility of contact to the state where there is a possibility of contact, the correction coefficient h gradually increases to the maximum value hmax as shown in FIG. Along with this, as shown in FIG. 15C, the accelerator pedal reaction force increases in a pulse shape, and thereafter, a larger accelerator pedal reaction force is generated than the reaction force corresponding to the risk potential RP indicated by the broken line. . Further, as shown in FIG. 15 (d), the brake pedal reaction force decreases in a pulse shape, and thereafter, a smaller brake pedal reaction force, that is, a larger brake assist force than the reaction force corresponding to the risk potential RP indicated by the broken line. appear.

  When the state where there is a possibility of contact is changed to a state where there is no possibility of contact, the correction coefficient h gradually decreases to 1. Along with this, the accelerator pedal reaction force that had increased with respect to the reaction force according to the risk potential RP gradually decreased, and the brake pedal reaction force that had decreased decreased gradually, according to the risk potential RP. Return to reaction force respectively.

Thus, after calculating the accelerator pedal reaction force correction value FA_hosei and the brake pedal reaction force correction value FB_hosei in step S600, the process proceeds to step S700.
In step S700, a correction amount of the braking force is calculated when there is a possibility that the host vehicle is in contact with a front obstacle. In calculating the correction amount, as shown in FIG. 16 (a), it is considered that a virtual elastic body is provided in front of the host vehicle, and this virtual elastic body hits the front vehicle and is compressed so that the virtual vehicle is simulated. Consider a model that generates running resistance. Here, the length l of the virtual elastic body is expressed by the following (formula 6) in association with the threshold value Th of the inter-vehicle time THW used for the determination of the contact possibility described above according to the own vehicle speed Vh. be able to.
l = Th × Vh (Formula 6)

The elastic constant k of the virtual elastic body is a control parameter that is adjusted so as to obtain an appropriate control effect. As shown in FIG. 16B, when the inter-vehicle distance D between the host vehicle and the preceding vehicle is short, the repulsive force Fc of the virtually provided elastic body is expressed by the following (formula 7).
Fc = k × (1-D) (Expression 7)
As shown in (Expression 7), the repulsive force Fc increases as the inter-vehicle distance D decreases with respect to the length l of the virtual elastic body, that is, as the risk of contact between the host vehicle and the preceding vehicle increases. When the inter-vehicle distance D between the host vehicle and the preceding vehicle is short, the repulsive force Fc calculated by (Equation 7) is set as the braking force correction amount. When the inter-vehicle distance D is equal to or longer than the length l of the elastic body, the repulsive force Fc = 0.

  Here, the length l of the virtual elastic body is calculated using the threshold Th of the inter-vehicle time THW, and when the inter-vehicle distance D is smaller than the length l of the virtual elastic body (l> D), the host vehicle I think there is a possibility of touching an obstacle ahead. That is, when calculating the correction amount of the braking force, it can be said that the possibility of contact is determined based on the inter-vehicle time THW.

The process performed in step S700 will be described with reference to the flowchart of FIG.
First, in step S701, the repulsive force Fc of the elastic body that is virtually provided according to (Expression 7) described above is calculated. In step S702, it is determined whether or not the brake pedal 92 is depressed based on the brake pedal operation amount SB read in step S100. If the brake pedal 92 is depressed, the process proceeds to step S703.

  In step S703, it is determined whether the sum (ΔDb_z + ΔFb) of the braking force correction amount ΔDb_z set in the previous cycle and the predetermined value ΔFb is smaller than the repulsive force Fc of the virtual elastic body calculated in step S701. If a positive determination is made in step S703, the process proceeds to step S704. In step S704, the sum of the previous value ΔDb_z of the braking force correction amount and the predetermined value ΔFb is set as the current braking force correction amount ΔDb (ΔDb = ΔDb_z + ΔFb). On the other hand, if a negative determination is made in step S703, the process proceeds to step S705, where the repulsive force Fc is set as the braking force correction amount ΔDb (ΔDb = Fc). The predetermined value ΔFb is a change amount when the braking force correction amount ΔDb is changed, and is set appropriately in advance.

  If a negative determination is made in step S702 and the brake pedal 92 is not depressed, the process proceeds to step S706. In step S706, it is determined whether or not the difference (ΔDb_z−ΔFb) between the previous value ΔDb_z of the braking force correction amount and the predetermined value ΔFb is greater than zero. If a positive determination is made in step S706, the process proceeds to step S707. In step S707, the difference between the previous value ΔDb_z of the braking force correction amount and the predetermined value ΔFb is set as the current braking force correction amount ΔDb (ΔDb = ΔDb_z−ΔFb). On the other hand, if the determination in step S706 is negative, the process proceeds to step S708, where 0 is set as the braking force correction amount ΔDb (ΔDb = 0).

  FIGS. 18A to 18C show time-series changes in the brake pedal operation amount SB, the braking force correction amount ΔDb, and the braking force. When the driver starts to depress the brake pedal 92 as shown in FIG. 18 (a), the braking force correction amount ΔDb gradually increases to the repulsive force Fc as shown in FIG. 18 (b). Accordingly, as shown in FIG. 18C, a braking force is generated by adding the braking force correction amount ΔDb to the required braking force Fdb corresponding to the brake pedal operation amount SB. When the driver releases the brake pedal 92, the braking force correction amount ΔDb gradually returns to 0 from that time, and the braking force gradually decreases. Thus, since it correct | amends in the direction where the braking force with respect to the operation quantity SB of the brake pedal 92 increases, a driver | operator will perceive it as the further deceleration behavior of the own vehicle.

  FIG. 19 is a diagram for explaining a braking force correction method. The abscissa of FIG. 19 shows the accelerator pedal operation amount SA and the brake pedal operation amount SB. The accelerator pedal operation amount SA increases as it proceeds from the origin 0 to the right, and the brake pedal operation amount SB increases as it proceeds to the left. Show. The vertical axis in FIG. 19 indicates the driving force and the braking force, and indicates that the driving force increases as it progresses upward from the origin 0, and the braking force increases as it progresses downward. In FIG. 19, the required braking force Fdb corresponding to the brake pedal operation amount SB is indicated by a one-point difference line, and the braking force corrected according to the contact possibility is indicated by a solid line. In FIG. 19, the required driving force corresponding to the accelerator pedal operation amount SA is also indicated by a one-dot chain line.

  When the brake pedal 92 is depressed, the braking force is corrected in the increasing direction based on the correction amount ΔDb. That is, the relationship between the braking force and the brake pedal operation amount SB is corrected in the increasing direction. Accordingly, the characteristic of the braking force is corrected so that the running resistance of the vehicle as a whole increases corresponding to the correction amount, that is, the repulsive force Fc of the virtual elastic body.

After calculating the braking force correction amount in step S700 as described above, the process proceeds to step S800.
In step S800, the accelerator pedal reaction force correction value FA_hosei and the brake pedal reaction force correction value FB_hosei calculated in step S600 are output to the accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 90, respectively. The accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 90 control the accelerator pedal reaction force and the brake pedal reaction force according to the command values input from the controller 50, respectively.

  In step S900, the braking force correction amount ΔDb calculated in step S700 is output to the braking force control device 93. The braking force control device 93 calculates a target braking force from the braking force correction amount ΔDb and the required braking force Fdb, and controls the brake fluid pressure controller to generate the target braking force.

  Thereby, pedal reaction force based on the risk potential RP around the host vehicle and the possibility of contact with a front obstacle is generated in the accelerator pedal 62 and the brake pedal 92, respectively. Further, when the inter-vehicle distance D is short and there is a possibility that the host vehicle and the preceding vehicle are in contact with each other, the braking force is increased using a correction amount corresponding to the repulsive force Fc of the virtual elastic body in front of the host vehicle. Make corrections.

Thus, in the first embodiment described above, the following operational effects can be achieved.
(1) The controller 50 determines the potential first risk of the host vehicle with respect to the obstacle and the second risk regarding the possibility of contact between the host vehicle and the obstacle based on the obstacle situation around the host vehicle. Is calculated. Then, the reaction force control of the driving operation device is performed based on the first risk, and the braking force control is performed so as to increase the braking torque generated in the host vehicle based on the second risk. The controller 50 performs control so as to give priority to either the operation reaction force control or the braking force control. Specifically, in the first embodiment, the risk potential RP around the host vehicle is calculated as the first risk, and the accelerator pedal reaction force control and the brake pedal reaction force control are performed according to the risk potential RP. . Further, as a second risk, the difference (1-D) between the length l of the virtual elastic body set in front of the host vehicle and the inter-vehicle distance D between the host vehicle and the preceding vehicle was calculated. The difference (1-D) is increased, and the braking torque is corrected so as to increase as the risk of contact between the host vehicle and the preceding vehicle increases. As described above, when the inter-vehicle distance D is greater than the length l of the virtual elastic body and the risk of contact between the host vehicle and the preceding vehicle is small, priority is given to reaction force control according to the risk potential RP, The braking force is not corrected. As a result, when the possibility of contact between the host vehicle and the preceding vehicle is low, by performing reaction force control according to the risk potential RP, the potential risk around the host vehicle can be intuitively determined through the operation reaction force. You can inform the driver. In addition, when the possibility of contact between the host vehicle and the preceding vehicle is high, the braking force is corrected so as to increase, so the driver is given a feeling of deceleration and alerted, and the driver's deceleration operation is properly performed. Can assist.
(2) The controller 50 calculates the risk potential RP for the obstacle, and performs accelerator pedal reaction force control and brake pedal reaction force control based on the risk potential RP. Further, the possibility of contact between the host vehicle and the obstacle is predicted, and when the possibility of contact is high, the relationship of the braking torque to the brake pedal operation amount SB is corrected in the increasing direction as shown in FIG. In this way, by performing the reaction reaction force control of the accelerator pedal 62 and the brake pedal 92 according to the risk potential RP, the risk potential RP around the host vehicle through the driving operation device that the driver always contacts and operates. Can be transmitted intuitively to the driver. Further, since the braking torque is increased when the possibility of contact is high, the driver can be alerted by giving the driver a feeling of deceleration. In the first embodiment, the possibility of contact for calculating the braking force correction amount ΔDb is set to the length l of the elastic body virtually set in front of the host vehicle, and the host vehicle and the preceding vehicle. And the difference from the inter-vehicle distance D (1-D).
(3) When it is predicted that the possibility of contact between the host vehicle and the obstacle is high, the controller 50 changes the operation reaction force with respect to the risk potential RP compared to the case where the possibility of contact with the obstacle is low. The reaction force is corrected so that becomes larger. Specifically, as shown in FIGS. 15A to 15D, when there is a possibility of contact, the accelerator pedal reaction force corresponding to the risk potential RP is increased and the brake pedal reaction force is decreased. As a result, the driver can be made sure of the possibility of contact.
(4) When shifting from a state where the possibility of contact with an obstacle is low to a high state, an additional force is applied to the driving operation device. Specifically, as shown in FIGS. 15A to 15D, a pulse reaction force Fp is added to the accelerator pedal reaction force and the brake pedal reaction force, respectively. Thus, the driver can be surely notified that there is a possibility that the host vehicle may come into contact with the obstacle. In the first embodiment, the additional force is generated as the pulse reaction force Fp. However, the present invention is not limited to this, and for example, vibration can be generated.
(5) Since the accelerator pedal operation reaction force increases as the risk potential RP around the host vehicle increases, the driver can be surely notified of the risk potential RP.
(6) Since the brake pedal operation reaction force decreases as the risk potential RP around the host vehicle increases, the driver's deceleration operation can be assisted when the driver performs the brake pedal operation.

<< Second Embodiment >>
Next, a vehicle driving assistance device according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 20 is a system diagram showing a configuration of the vehicle driving assistance device 2 according to the second embodiment of the present invention, and FIG. 21 is a configuration diagram of a vehicle on which the vehicle driving assistance device 2 is mounted. . 20 and 21, the same reference numerals are given to portions having the same functions as those of the first embodiment described with reference to FIGS. 1 and 2. Here, differences from the first embodiment will be mainly described.

  In the second embodiment, as in the first embodiment described above, the accelerator pedal operation reaction force and the brake pedal operation reaction force are controlled according to the risk potential RP around the host vehicle, and the brake pedal 92 is also controlled. The braking force of the host vehicle generated when the is operated is corrected. Further, the driving force generated when the accelerator pedal 62 is operated is also corrected. Therefore, the vehicle driving operation assistance device 2 according to the second embodiment further includes a driving force control device 63 and an accelerator pedal stroke sensor 64.

  The accelerator pedal stroke sensor 64 detects the operation amount of the accelerator pedal 62 converted into the rotation angle of the servo motor 61 via the link mechanism. The accelerator pedal stroke sensor 64 outputs the detected accelerator pedal operation amount to the controller 50 </ b> A and the driving force control device 63.

  The driving force control device 63 calculates a control command to the engine. FIG. 22 is a block diagram of driving force control in the driving force control device 63. FIG. 23 shows a characteristic map that defines the relationship between the accelerator pedal operation amount SA and the driver required driving force Fda. The driving force control device 63 calculates a driver required driving force Fda according to the accelerator pedal operation amount SA using a map as shown in FIG. Then, the driving force control device 63 calculates a target driving force by adding a driving force correction amount ΔDa described later to the driver required driving force Fda. The engine controller of the driving force control device 63 calculates a control command to the engine according to the target driving force.

  FIG. 24 is a block diagram showing a configuration inside and around the controller 50A of the vehicle driving assistance device 2. As shown in FIG. The controller 50A includes, for example, an obstacle situation recognition unit 51, a risk potential calculation unit 52, a driving operation reaction force calculation unit 53, a contact possibility prediction unit 54, a driving operation reaction force correction unit 55, and a control according to the software form of the CPU. A driving force correction amount calculation unit 57 is configured.

  The obstacle recognizing unit 51 inputs signals from the laser radar 10 and the vehicle speed sensor 20 and recognizes an obstacle state ahead of the host vehicle. Specifically, the inter-vehicle distance and relative speed with the preceding vehicle are calculated, and the own vehicle speed is detected. The risk potential calculation unit 52 calculates the risk potential of the host vehicle with respect to the front obstacle based on the recognition result of the obstacle recognition unit 51. The driving operation reaction force calculation unit 53 calculates a reaction force control command for the accelerator pedal 62 and a reaction force control command for the brake pedal 92 from the risk potential calculated by the risk potential calculation unit 52.

  Based on the recognition result of the obstacle recognition unit 51, the contact possibility prediction unit 54 predicts whether or not there is a high possibility that the host vehicle is in contact with an obstacle ahead. The driving reaction force correction unit 55 is based on the possibility that the obstacle predicted by the contact possibility prediction unit 54 and the host vehicle come into contact with the driving operation reaction force calculated by the driving operation reaction force calculation unit 53. To correct. The braking / driving force correction amount calculation unit 57 calculates the correction amount of the braking force and driving force of the host vehicle when the contact possibility prediction unit 54 determines that there is a possibility of contact.

  Below, operation | movement of the driving operation assistance apparatus 2 for vehicles by 2nd Embodiment is demonstrated in detail. FIG. 25 shows a flowchart of the processing procedure of the driving assist control processing in the controller 50A of the second embodiment. This processing content is continuously performed at regular intervals, for example, every 50 msec.

  The processing in steps S100 to S600 is the same as the processing in steps S100 to S600 in the flowchart of FIG. 6 described in the first embodiment, and thus description thereof is omitted. However, it is assumed that the accelerator pedal operation amount SA detected by the accelerator pedal stroke sensor 64 is also read in step S100.

  In step S700A, correction amounts for the braking force and the driving force are calculated when the host vehicle may come into contact with a front obstacle. In calculating the correction amount of the braking force and the driving force, the repulsive force Fc of the virtual elastic body when it is assumed that the virtual elastic body is provided in front of the host vehicle as shown in FIG. Use. Here, the length l of the virtual elastic body is calculated from the above-described (Equation 6) using the threshold Th of the inter-vehicle time THW, and the inter-vehicle distance D is smaller than the length l of the virtual elastic body (l> D) In the case, it is considered that the host vehicle may come into contact with a front obstacle. That is, when calculating the braking / driving force correction amount, it can be said that the possibility of contact is determined based on the inter-vehicle time THW.

The process performed in step S700A will be described with reference to the flowchart of FIG.
First, in step S1701, it is determined whether or not the accelerator pedal 62 is depressed based on the accelerator pedal operation amount SA read in step S100. If the accelerator pedal 62 is not depressed, the process proceeds to step S1702 to determine whether or not the accelerator pedal 62 is suddenly released. For example, if the operation speed of the accelerator pedal 62 calculated from the accelerator pedal operation amount SA is less than a predetermined value, it is determined that the accelerator pedal 62 has been slowly returned, and the process proceeds to step S1703. In step S1703, 0 is set as the driving force correction amount ΔDa, and in step S1704, the repulsive force Fc of the virtual elastic body calculated in (Equation 7) described above is set as the braking force correction amount ΔDb.

  On the other hand, if it is determined in step S1702 that the accelerator pedal 62 has been suddenly returned, the process proceeds to step S1705. In step S1705, the driving force correction amount ΔDa is gradually decreased, and in step S1706, the braking force correction amount ΔDb is gradually increased to the repulsive force Fc. Specifically, when the accelerator pedal 62 is suddenly returned, the driving force correction amount ΔDa (= −Fc) set to decrease the driving force by the repulsive force Fc during the operation of the accelerator pedal is set. As shown in FIG. 27A, it is gradually changed to 0. Further, as shown in FIG. 27B, after the accelerator pedal 62 is suddenly returned, the braking force correction amount ΔDb is gradually increased to the repulsive force Fc. Thus, when the accelerator pedal 62 is suddenly returned, the driving force correction amount ΔDa is finally changed to 0 and the braking force correction amount ΔDb is changed to Fc.

  On the other hand, if the determination in step S1701 is affirmative and the accelerator pedal 62 is depressed, the process proceeds to step S1707 to estimate the driver requested driving force Fda. In the controller 50, the same driver required driving force calculation map (FIG. 23) stored in the driving force control device 63 is prepared, and the driver required driving force Fda is estimated according to the accelerator pedal operation amount SA. To do.

  In step S1708, the magnitude relationship between the driver required driving force Fda and the repulsive force Fc estimated in step S1707 is compared. If the driver requested driving force Fda is greater than or equal to the repulsive force Fc (Fda ≧ Fc), the process proceeds to step S1709. In step S1709, -Fc is set as the driving force correction amount ΔDa, and 0 is set in the braking force correction amount ΔDb in step S1710. That is, since Fda−Fc ≧ 0, a positive driving force remains even after the driving force Fda is corrected by the repulsive force Fc. Therefore, the correction amount can be output only by the driving force control device 63. In this case, the vehicle is in a state where the driving force as expected can not be obtained even though the driver steps on the accelerator pedal 62. When the corrected driving force is larger than the running resistance, the driver feels that the acceleration is slow, and when the corrected driving force is smaller than the running resistance, the driver feels that the behavior is decelerating.

  On the other hand, when a negative determination is made in step S1708 and the driver required driving force Fda is smaller than the repulsive force Fc (Fda <Fc), the driving force control device 63 alone cannot output a target correction amount. Therefore, in step S1711, -Fda is set as the driving force correction amount ΔDa, and in step S1712, an insufficient amount of correction amount (Fc-Fda) is set as the braking force correction amount ΔDb. In this case, the driver perceives the deceleration behavior of the vehicle.

  FIG. 28 is a diagram illustrating a method for correcting the driving force and the braking force. The horizontal axis of FIG. 28 shows the accelerator pedal operation amount SA and the brake pedal operation amount SB. The accelerator pedal operation amount SA increases as it proceeds from the origin 0 to the right, and the brake pedal operation amount SB increases as it proceeds to the left. Show. The vertical axis in FIG. 28 indicates the driving force and the braking force, and indicates that the driving force increases as it progresses upward from the origin 0, and the braking force increases as it progresses downward.

  In FIG. 28, the required driving force Fda corresponding to the accelerator pedal operation amount SA and the required braking force Fdb corresponding to the brake pedal operation amount SB are indicated by one-dotted lines. Further, the driving force and the braking force corrected according to the contact possibility are indicated by solid lines.

  When the accelerator pedal operation amount SA is large and the required driving force Fda corresponding to the accelerator pedal operation amount SA is greater than or equal to the repulsive force Fc, the driving force is corrected in a decreasing direction according to the correction amount ΔDa. On the other hand, when the accelerator pedal operation amount SA is small and the required driving force Fda corresponding to the accelerator pedal operation amount SA is smaller than the repulsive force Fc, a correction amount ΔDa that does not generate a driving force is set to correct the driving force. To do. Further, the difference between the repulsive force Fc and the required driving force Fda is set as the correction amount ΔDb. Thereby, the gentle braking according to the accelerator pedal operation amount SA is performed.

  When the brake pedal 92 is depressed, the braking force is corrected in the increasing direction based on the correction amount ΔDb. Thereby, the characteristic of the braking / driving force is corrected so as to increase the running resistance of the vehicle as a whole corresponding to the correction amount, that is, the repulsive force Fc of the virtual elastic body.

Thus, after calculating the braking / driving force correction amount in step S700, the process proceeds to step S800.
In step S800, the accelerator pedal reaction force correction value FA_hosei and the brake pedal reaction force correction value FB_hosei calculated in step S600 are output to the accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 90, respectively. The accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 90 control the accelerator pedal reaction force and the brake pedal reaction force according to the command values input from the controller 50, respectively.

  In step S900A, the driving force correction amount ΔDa and the braking force correction amount ΔDb calculated in step S700A are output to the driving force control device 63 and the braking force control device 93, respectively. The driving force control device 63 calculates a target driving force from the driving force correction amount ΔDa and the required driving force Fda, and controls the engine controller to generate the calculated target driving force. The braking force control device 93 calculates a target braking force from the braking force correction amount ΔDb and the required braking force Fdb, and controls the brake fluid pressure controller so as to generate the target braking force.

  Thereby, pedal reaction force based on the risk potential RP around the host vehicle and the possibility of contact with a front obstacle is generated in the accelerator pedal 62 and the brake pedal 92, respectively. Further, when the inter-vehicle distance D is short and there is a possibility that the host vehicle and the preceding vehicle are in contact with each other, the driving force is reduced using a correction amount corresponding to the repulsive force Fc of the virtual elastic body in front of the host vehicle, Correction is performed to increase the braking force.

Thus, in the second embodiment described above, the following operational effects can be obtained in addition to the effects of the first embodiment described above.
(1) When the possibility of contact between the host vehicle and the obstacle is high, the controller 50A corrects the relationship of the driving torque with respect to the accelerator pedal operation amount SA in a decreasing direction as shown in FIG. Thereby, the driver can be alerted by giving the driver a feeling of slowing down or slowing down the acceleration. In this case, the possibility of contact for calculating the correction amount ΔDa of the driving force is set to the length l of the elastic body virtually set in front of the host vehicle, and the inter-vehicle distance D between the host vehicle and the preceding vehicle. (1−D).
(2) When the accelerator pedal operation amount SA is smaller than a predetermined value, gentle braking is performed according to the accelerator pedal operation amount SA. Specifically, when the driver required driving force Fda corresponding to the accelerator pedal operation amount SA is smaller than the repulsive force Fc of the virtual elastic body, the difference (Fc−Fda) between the repulsive force Fc and the required driving force Fda is controlled. It outputs to the braking force control apparatus 93 as motive power correction amount (DELTA) Db. Thereby, even when the driving force according to the accelerator pedal operation amount SA is small, the driving operation of the driver can be assisted. Note that the gentle braking performed when the accelerator pedal operation amount SA is smaller than the predetermined value can be combined with the first embodiment. That is, when the possibility of contact is high, when the brake pedal 92 is operated, the braking torque is corrected to increase, and the accelerator pedal 62 is operated with the accelerator pedal operation amount SA being smaller than a predetermined value. In this case, the braking force correction amount ΔDb can be generated by the difference between the driver requested driving force Fda and the repulsive force Fc of the virtual elastic body.

<< Third Embodiment >>
Below, the driving operation assistance apparatus for vehicles by the 3rd Embodiment of this invention is demonstrated. The configuration of the vehicle driving operation assisting device according to the third embodiment is the same as that of the second embodiment shown in FIGS. Here, differences from the second embodiment will be mainly described.

  In the third embodiment, it is determined whether or not the host vehicle can avoid an obstacle ahead by a steering operation or a braking operation, and the correction amount of the braking / driving force is determined based on the determination result. That is, automatic braking control that automatically generates a braking force is performed based on the determination result of the avoidable determination.

  The operation of the vehicular driving assistance apparatus according to the third embodiment will be described in detail below. FIG. 29 shows a flowchart of the processing procedure of the driving operation assist control processing in the controller 50 of the third embodiment. This processing content is continuously performed at regular intervals, for example, every 50 msec.

  The processing in steps S100 to S700A is the same as the processing in steps S100 to S700A in the flowchart of FIG. 25 described in the second embodiment, and a description thereof will be omitted.

  In step S720, based on the situation of the front obstacle recognized in step S200, it is determined whether or not the host vehicle can avoid the front obstacle by the steering operation. Here, the lateral movement distance y required to avoid the front obstacle is calculated, and the avoidance possibility determination by steering is performed. When the host vehicle can avoid the front obstacle to the left or right by the steering operation, it is determined that steering can be avoided, and automatic braking control is not performed.

FIG. 30 shows the positional relationship between the host vehicle and the preceding vehicle. As shown in FIG. 30, the angles of the right end and the left end of the front obstacle with respect to the front of the host vehicle are θ1 and θ2, respectively. Thus, when there are two directions left and right (θ1, θ2) that can be avoided with respect to the front obstacle, the smaller value θ1 is selected. Then, the lateral movement distance y necessary for the host vehicle to steer in the θ1 direction to avoid the preceding vehicle is calculated. The lateral movement distance y can be calculated from the following (Equation 8).
y = D × sin (θ1) + lw / 2 (Expression 8)
Here, D: inter-vehicle distance, lw: vehicle width.

  Here, an example in which the laser radar 10 is attached to the center of the host vehicle has been described. If the laser radar 10 is mounted with an offset to the left or right from the center of the host vehicle, the offset of the mounting position of the laser radar 10 is added or subtracted as appropriate in the above (Equation 8).

  Further, when a detector that detects a front obstacle using a plurality of beams having a predetermined width is used, the direction of the front obstacle is within a certain range of widths θ1 to θ2 as shown in FIG. It is detected. In this case, the direction of the front obstacle is the minimum value θ1 in the existence range θ1 to θ2, and the lateral movement distance y necessary for avoidance is calculated using the above-described (Equation 8). In this case as well, when the radar is mounted offset to the left or right from the center of the vehicle, the offset of the radar mounting position is added or subtracted as appropriate in the above (Equation 8).

  By calculating the lateral movement amount y necessary for avoiding steering by the method as described above, even when the offset amount of the obstacle with respect to the own vehicle, that is, when the relative position in the left-right direction between the own vehicle and the preceding vehicle is different, The lateral movement amount y necessary for avoiding steering can be calculated according to the case. Therefore, it is possible to accurately calculate whether steering can be avoided or not.

Furthermore, the time ty required for the vehicle to move laterally by the lateral movement distance y necessary for avoidance is calculated. The steering characteristics of the vehicle are expressed as the following (Equation 9) and (Equation 10).
m × v × (r + dβ / dt) = 2Yf + 2Yr (Expression 9)
Iz * dr / dt = 2lf * Yf-2lr * Yr (Formula 10)
here,
m: vehicle weight Iz: inertia moment in vehicle yaw direction v: vehicle speed r: yaw rate β: vehicle body slip angle lf: distance from vehicle center of gravity to front wheel lr: distance from vehicle center of gravity to rear wheel

Yf and Yr are lateral forces generated by the front wheels and the rear wheels, respectively, and are expressed as in the following (Expression 11) and (Expression 12).
Yf = Ff {β + (lf / v) × r−θf} (Expression 11)
Yr = Fr {β- (lr / v) × r} (Formula 12)

Here, θf is the front wheel steering angle. In an emergency, it is assumed that the driver steers at the steering speed and the maximum steering amount as shown in FIG. 32, and the front wheel steering angle θf is set according to the characteristics shown in FIG.
Ff and Fr are functions representing the lateral force generated with respect to the tire slip angle, and are defined as a relationship as shown in FIG.

At this time, the lateral movement amount y is expressed as in (Equation 13) below.
y = ∫v × sin (∫r × dt + β) dt (Expression 13)
By solving the above (Formula 9) to (Formula 13), it is possible to calculate the time ty required for the vehicle to move laterally by the lateral movement distance y necessary for avoiding the front obstacle.

  Since it takes a very long time to execute the calculations of (Equation 9) to (Equation 13) online, these calculations are performed offline in advance, and the calculation results are mapped as shown in FIG. . FIG. 34 shows that when the lateral movement amount y required for steering avoidance is y1, the time ty required for avoidance is ty1. The necessary time ty is shorter as the host vehicle speed is higher, and is longer as the host vehicle speed is lower.

  When calculating the time ty required for the lateral movement by the lateral movement distance y necessary for avoidance, the calculation is performed with reference to the map values for the vehicle speed v and the lateral movement distance y shown in FIG.

  The lateral movement time ty calculated in this way is compared with an estimated time D / Vr (margin time TTC) until the host vehicle comes in contact with the front obstacle. When the surplus time D / Vr until contact is smaller than the lateral movement time ty (D / Vr <ty), it is determined that avoidance by steering is impossible.

  As described above, since the steering avoidance time ty is calculated according to the difference in the steering characteristics of the vehicle, can the front obstacle be avoided by steering regardless of the different steering characteristics for each vehicle or different steering characteristics in the vehicle speed range? Can calculate exactly what is impossible. In addition, since the steering avoidance time ty of the vehicle is calculated in consideration of the characteristics of the driver's emergency steering operation, the emergency steering avoidance time ty can be calculated more accurately.

Thus, after determining the possibility of avoidance by steering in step S720, the process proceeds to step S740.
In step S740, a determination of possibility of avoidance by braking is performed. Specifically, when the distance D between the host vehicle and the front obstacle recognized in step S200 and the relative speed Vr have the relationship shown in the following (formula 14), it is impossible to avoid the front obstacle by braking. It is judged that.
D <−Vr × Td + Vr ² / 2a (Expression 14)
Here, Td is a dead time until deceleration occurs when the driver operates the brake. For example, Td = 0.2 seconds. a is a deceleration generated by the driver's brake operation, and is set to, for example, a = 8.0 m / s ² .

  In step S760, the braking / driving force correction amount calculated in step S700A is corrected based on the result of the steering avoidability determined in step S720 and the brake avoidance possibility determined in step S740. The process performed in step S760 will be described with reference to the flowchart of FIG.

  In step S901, it is determined whether it is impossible to avoid a front obstacle by braking and steering. If it is determined that avoidance by braking is impossible and avoidance by steering is impossible, the process proceeds to step S902. In step S902, a braking force target value Ft by the braking force 2 shown in FIG. 36 is calculated. Specifically, as shown in FIG. 36, a braking force target value Ft that increases to a braking force 2 set in advance with a predetermined inclination is calculated.

  If a negative determination is made in step S901, the process proceeds to step S903, where it is determined whether or not avoiding a front obstacle by braking or avoiding by steering is impossible. If it is determined that avoiding a front obstacle by braking or steering is impossible, the process proceeds to step S904. In step S904, a braking force target value Ft for the braking force 1 shown in FIG. 36 is calculated. Specifically, the braking force 1 smaller than the braking force 2 is calculated as the braking force target value Ft. The braking force 1 gradually increases from 0 with a constant inclination α. The gradient α of the braking force 1 is calculated so that the braking force difference p1 becomes equal to or less than a predetermined value when the braking force 1 shifts to the braking force 2. The slope α is calculated as follows.

First, a time T1 from when the braking force 1 starts to operate until the braking force 2 operates is estimated. In the case where it is impossible to avoid obstacles by steering after it becomes impossible to avoid obstacles ahead by braking, the time T1 is expressed by the following (formula 15) using the lateral movement time ty required for steering avoidance.
T1 = D / Vr−ty (Expression 15)

Further, when it becomes impossible to avoid the obstacle by braking after it becomes impossible to avoid the front obstacle by steering, the time T1 is expressed by the following (Equation 16).
T1 = − (D−Vr ² / 2a + Vr × Td) / Vr (Expression 16)
Here, Td is a dead time when the brake operation is performed by the driver, and a is a deceleration generated by the brake operation.

The slope α of the braking force 1 can be calculated from the following (Equation 17) using the time T1 calculated as described above and the difference p1 between the braking force 2 and the braking force 1. The braking force difference p1 used here is set to an appropriate value in advance.
α = p1 / T1 (Expression 17)

  When a negative determination is made in step S903 and both avoidance by braking and avoidance by steering are possible, the process proceeds to step S905, where the set braking force target value Ft is gradually reduced by a predetermined inclination, and finally The braking force target value Ft is set to zero.

  FIG. 37 shows a time-series change in the braking force target value Ft. When it is determined at time t = ta that a front obstacle cannot be avoided by braking or steering, the braking force target value Ft is gradually increased from 0 according to the braking force 1. If it is determined that the avoidance by braking and the avoidance by steering are impossible at time t = tb after the lapse of T1 from time t = ta, the braking force target value Ft is increased to the braking force 2 with a predetermined inclination until then, The braking force 1 is shifted to the braking force 2 and sudden braking is performed.

  In subsequent step S906, it is determined whether or not the braking force correction amount ΔDb calculated in step S700A is smaller than the braking force target value Ft calculated in steps S902, S904, or S905 (ΔDb <Ft). When the braking force correction amount ΔDb is smaller than the braking force target value Ft, the process proceeds to step S907, and the braking force target value Ft is set as the braking force correction amount ΔDb. In subsequent step S908, in order to set the driving force to 0, a value −Fda corresponding to the accelerator pedal operation amount SA is set as the driving force correction amount ΔDa. If a negative determination is made in step S906, the braking force correction amount ΔDb and the driving force correction amount ΔDa calculated in step S700A are used as they are.

  As described above, after correcting the driving force correction amount ΔDa and the braking force correction amount ΔDb in accordance with the possibility of avoiding the front obstacle in step S760, the process proceeds to step S780. In step S780, the operation reaction force is corrected according to the possibility of avoiding the front obstacle. The process performed in step S780 will be described with reference to the flowchart shown in FIG.

  In step S781, based on the possibility of steering avoidance determined in step S720 and the possibility of braking avoidance determined in step S740, whether or not a forward obstacle can be avoided by braking and whether avoidance by steering is impossible or not is determined. Determine. If it is impossible to avoid a front obstacle by steering and braking, the process proceeds to step S782, and the accelerator pedal reaction force correction value FA_hosei is set to the maximum value FAmax so as to generate the maximum accelerator pedal reaction force. In step S783, the brake pedal reaction force correction value FB_hosei is set to FBmin so as to generate the minimum brake pedal reaction force.

  If the determination in step S781 is negative and at least the front obstacle can be avoided by steering or braking, the reaction force correction values FA_hosei and FB_hosei calculated in step S600 are used as they are.

  The reaction force correction values FA_hosei and FB_hosei set in step S780 are output to the accelerator pedal reaction force control device 60 and the brake pedal reaction force control device 90 in step S800, respectively, and the accelerator pedal reaction force control and the brake pedal reaction force are output. Take control. As a result, when it is determined that avoiding a front obstacle is impossible by either steering or braking, the braking force is generated and the accelerator pedal reaction force and the brake assist force are set to predetermined values, that is, maximum values. Since the operation reaction force is maximized, the driver can be more surely aware of the possibility of avoidance, and can prompt the driver to perform a deceleration operation.

  In step S900A, the driving force correction amount ΔDa and the braking force correction amount ΔDb corrected in step S760 are output to the driving force control device 63 and the braking force control device 93, respectively, and braking / driving force control is performed. Thus, the current process is terminated.

Thus, in the third embodiment described above, the following operational effects can be obtained in addition to the effects of the first and second embodiments described above.
(1) When the controller 50A determines the possibility of avoiding an obstacle and determines that the host vehicle cannot avoid the obstacle, the controller 50A controls the braking force control device 93 to perform automatic braking. As a result, the host vehicle can be automatically decelerated to mitigate the influence of an unexpected situation.
(2) The controller 50A determines whether or not the host vehicle can avoid an obstacle only by braking and whether or not the obstacle can be avoided only by steering, and at least the obstacle cannot be avoided only by braking or steering. If so, perform automatic braking. As a result, when it is predicted that an obstacle cannot be avoided, it is possible to reduce the influence of an unexpected situation by performing automatic braking. In addition, as shown in FIG. 30, when a state in which an obstacle cannot be avoided by braking or steering is changed to a state in which an obstacle cannot be avoided by braking or steering, the braking force target value Ft increases from the braking force 1 to the braking force 2. To do. As a result, the braking force is automatically increased and sudden braking is automatically performed, and even when an unexpected situation occurs, the influence can be reduced.

  In the third embodiment, in the process of step S780, the reaction force correction values FA_hosei and FB_hosei are corrected to the maximum value in accordance with the possibility of avoiding the front obstacle. However, the present invention is not limited to this, and the reaction force correction values FA_hosei and FB_hosei corrected in step S600 can be used without correction according to the possibility of contact.

  In the first to third embodiments described above, the accelerator pedal operation reaction force and the brake pedal operation reaction force are determined based on the risk potential RP calculated using the margin time TTC. However, the present invention is not limited to this, and the risk potential RP for determining the operation reaction force is associated with the repulsive force Fc of the virtual elastic body used for determining the braking / driving force correction amounts ΔDa and ΔDb. You can also. For example, when the difference (1-D) between the length l of the virtual elastic body and the inter-vehicle distance D is greater than or equal to a predetermined value, the reaction force control according to the risk potential RP is performed. Thereby, when the difference (1-D) is large and the risk of contact between the host vehicle and the preceding vehicle is small, the operation reaction force control is preferentially performed over the braking / driving force control. On the other hand, when the difference (1-D) is small and the risk of contact between the host vehicle and the preceding vehicle is large, the braking / driving force control is performed with priority over the operation reaction force control.

  Further, in the above-described third embodiment, the reaction force control according to the risk potential RP, the braking / driving force control according to the possibility of contact with the front obstacle, and the possibility of avoiding the front obstacle. Although the corresponding braking force control is performed, the driving force control according to the possibility of contact may be omitted. For example, when there is a possibility of contact, the driving force correction amount ΔDb is appropriately set according to the brake pedal operation amount SB to increase the braking force, and further, when the obstacle cannot be avoided, the braking force is further increased. And sudden braking.

  In the first to third embodiments described above, the accelerator pedal reaction force control and the brake pedal reaction force control corresponding to the risk potential RP around the host vehicle are performed. However, the present invention is not limited to this, and accelerator pedal reaction force control or brake pedal reaction force control can also be performed.

  In the first to third embodiments described above, the laser radar 10 and the vehicle speed sensor 30 are used as the obstacle detection means, the risk calculation means, the risk potential calculation means, the control means, the contact prediction means, the operation reaction force. Controllers 50 and 50A were used as correction means, braking torque correction means, automatic braking control means, avoidance determination means, braking avoidance determination means, steering avoidance determination means, and operation reaction force setting means. Further, the controllers 50 and 50A, the accelerator pedal reaction force control device 60, and the brake pedal reaction force control device 90 are used as the operation reaction force control means and the additional force generation means. An accelerator pedal stroke sensor 64 is used as the accelerator pedal operation amount detection means, a brake pedal stroke sensor 94 is used as the brake pedal operation amount detection means, and a braking force control device 93 is used as the brake control means. However, the present invention is not limited thereto, and for example, another type of millimeter wave radar can be used as the obstacle detection means instead of the laser radar 10.

1 is a system diagram of a vehicle driving assistance device according to a first embodiment of the present invention. The block diagram of the vehicle carrying the driving operation assistance apparatus for vehicles shown in FIG. The figure explaining the outline | summary of braking force control. The figure which shows the relationship between the amount of brake pedal operations, and a request | requirement braking force. FIG. 2 is a block diagram showing an internal configuration of a controller 50. The flowchart which shows the process sequence of the driving operation assistance control program in 1st Embodiment. A map showing the relationship between risk potential and accelerator control reaction force command value. A map showing the relationship between the risk potential and the brake control reaction force command value. The flowchart explaining a contact possibility prediction process. The flowchart explaining the operation reaction force correction process. The flowchart explaining the calculation process of the operation reaction force correction coefficient. The figure explaining the operation reaction force correction coefficient in time series. The flowchart explaining the calculation process of a pulse reaction force. The figure explaining pulse reaction force in time series. (A)-(d) The figure explaining a correction coefficient, a risk potential, an accelerator pedal reaction force, and a brake pedal reaction force in time series, respectively. (A) (b) The figure explaining the concept of braking / driving force control. The flowchart explaining a braking force correction amount calculation process. (A)-(c) The figure which shows the time-sequential change of brake pedal operation amount, braking force correction amount, and braking force. The figure explaining the characteristic of braking force amendment. The system figure of the driving operation assistance apparatus for vehicles by the 2nd Embodiment of this invention. The block diagram of the vehicle carrying the driving operation assistance apparatus for vehicles shown in FIG. The figure explaining the outline | summary of driving force control. The figure which shows the relationship between an accelerator pedal operation amount and a request | requirement driving force. The block diagram which shows the structure inside the controller 50A. The flowchart which shows the process sequence of the driving operation assistance control program in 2nd Embodiment. The flowchart explaining a braking / driving force correction amount calculation process. (A) (b) The figure explaining the change of a driving force correction amount and a braking force correction amount, respectively. The figure explaining the characteristic of driving force correction and braking force correction. The flowchart which shows the process sequence of the driving operation assistance control program in 3rd Embodiment. The figure which shows the positional relationship of a front obstruction and the own vehicle at the time of using a scanning type laser radar as a front detection apparatus. The figure which shows the positional relationship of a front obstruction and the own vehicle at the time of using a multiple beam type laser radar as a front detection apparatus. The figure showing the steering characteristic of the driver in emergency. The figure showing the lateral force which generate | occur | produces with respect to a tire slip angle. The figure which shows the relationship between the lateral movement distance required for steering avoidance, and required time. The flowchart explaining a braking / driving force correction process. The figure which shows the braking force 1 and the braking force 2. FIG. The figure which shows the change of braking force target value in a time series. The flowchart explaining the operation reaction force setting process.

Explanation of symbols

10: Laser radar 20: Vehicle speed sensors 50, 50A: Controller 60: Accelerator pedal reaction force control device 63: Driving force control device 64: Accelerator pedal stroke sensor 90: Brake pedal reaction force control device 93: Braking force control device 94: Brake Pedal stroke sensor

Claims (15)

Obstacle detection means for detecting obstacles around the vehicle;
Own vehicle speed detecting means for detecting the own vehicle speed;
A first risk indicating the degree of the vehicle with respect to the obstacle based on the following distance and the relative speed between the vehicle and the obstacle is therefore detected in the obstacle detection means, the inter-vehicle distance and the self Risk calculating means for calculating a second risk representing the possibility of contact between the host vehicle and the obstacle based on the host vehicle speed detected by the vehicle speed detecting means ;
Based on the first risk calculated by the risk calculation means, an operation reaction force control means for controlling an operation reaction force generated when operating the driving operation device;
Braking torque correcting means for increasing braking torque generated in the host vehicle based on the second risk calculated by the risk calculating means;
A vehicle driving system comprising: control means for performing control so that priority is given to either the control of the operation reaction force by the operation reaction force control means or the control of the braking torque by the braking torque correction means. Operation assistance device. Obstacle detection means for detecting obstacles around the vehicle;
Own vehicle speed detecting means for detecting the own vehicle speed;
Based on the inter-vehicle distance and the relative speed between the vehicle and the obstacle is therefore detected in the obstacle detection means, and the risk potential calculating means for calculating a risk potential indicating the degree with respect to the obstacle of the vehicle,
An operation reaction force control means for controlling an operation reaction force generated when operating the driving operation device based on the risk potential calculated by the risk potential calculation means;
Contact predicting the possibility of contact between the obstacle around the host vehicle and the host vehicle based on the inter-vehicle distance detected by the obstacle detection unit and the host vehicle speed detected by the host vehicle speed detecting unit Prediction means,
Brake pedal operation amount detection means for detecting the operation amount of the brake pedal;
Brake control means for generating a braking torque according to the brake pedal operation amount;
And a braking torque correcting unit that corrects the relationship of the braking torque with respect to the brake pedal operation amount in an increasing direction when the contact predicting unit predicts that the possibility of contact with the obstacle is high. A vehicle driving operation assisting device. The vehicle driving operation assistance device according to claim 2,
The operation reaction force control means further comprises an operation reaction force correction means for correcting the operation reaction force controlled based on the risk potential.
When it is predicted that the operation reaction force correction means is likely to be in contact with the obstacle, the operation reaction force correction unit is configured to reduce the operation reaction force with respect to the risk potential as compared with a case in which the possibility of contact with the obstacle is low. A driving operation assisting device for a vehicle, wherein the operation reaction force is corrected so that a change amount becomes large. In the driving assistance device for a vehicle according to claim 2 or 3,
When the contact prediction unit determines that the state of low contact with the obstacle has shifted to a state of high contact with the obstacle, the contact prediction unit further includes additional force generation unit that applies additional force to the driving operation device. A driving operation assisting device for a vehicle. The vehicle driving operation assistance device according to claim 4,
The driving force assisting device for a vehicle, wherein the additional force generating means causes the driving operation device to generate a pulsed reaction force as the additional force. In the driving assistance device for a vehicle according to any one of claims 2 to 5,
Further comprising an accelerator pedal operation amount detection means for detecting an operation amount of the accelerator pedal;
The vehicular driving operation assisting device according to claim 1, wherein the brake control means performs gentle braking according to the accelerator pedal operation amount when the accelerator pedal operation amount is smaller than a predetermined value. In the driving assistance device for a vehicle according to any one of claims 2 to 6,
Avoidance determination means for determining the possibility of avoidance of the obstacle based on the detection result by the obstacle detection means;
A vehicle driving operation assistance device, further comprising: an automatic braking control unit that controls the brake control unit to perform automatic braking when it is determined by the avoidance determination unit that the obstacle cannot be avoided. The vehicle driving assistance device according to claim 7,
The avoidance determining means includes braking avoidance determining means for determining whether the obstacle can be avoided only by braking, and steering avoidance determining means for determining whether the obstacle can be avoided only by steering,
The automatic braking control means performs control so that the automatic braking is performed by the brake control means when it is determined that at least the braking avoidance determination means or the steering avoidance determination means cannot avoid the obstacle. Driving operation assist device for vehicles. The vehicle driving operation assistance device according to claim 8,
The vehicle driving further comprising an operation reaction force setting unit that sets the operation reaction force generated in the driving operation device to a predetermined value when it is determined by the avoidance determination unit that the obstacle cannot be avoided. Operation assistance device. In the driving assistance device for vehicles according to any one of claims 2 to 9,
The driving operation assisting device for a vehicle, wherein the driving operation device includes an accelerator pedal. The vehicle driving operation assistance device according to claim 10,
The driving reaction assisting device for a vehicle, wherein the operation reaction force control means controls the operation reaction force of the accelerator pedal to increase as the risk potential increases. In the driving assistance device for a vehicle according to any one of claims 2 to 11,
The driving operation assisting device for a vehicle, wherein the driving operation device includes at least a brake pedal. The vehicle driving assistance device according to claim 12,
The driving reaction assisting device for a vehicle, wherein the operation reaction force control means performs control so that the operation reaction force of the brake pedal decreases as the risk potential increases.   A vehicle comprising the vehicular driving assist device according to any one of claims 1 to 13.   The vehicle driving assist device according to claim 1,
  The control means only controls the operation reaction force by the operation reaction force control means when the possibility of contact is low, and in addition to the control of the operation reaction force when the possibility of contact is high. Then, the vehicle driving operation assisting device is controlled to control the braking torque by the braking torque correcting means.

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