JPH1029554A - Vehicular steering controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a vehicle from going out of its running lane by recognizing white lines and the like on roads with a reference-position change means provided for changing the reference position of the vehicle on the basis of the recognized results of a surroundings recognition means. SOLUTION: A vehicular steering controller comprises a vehicle-position recognition means M1 for recognizing the transverse position of the vehicle on a running lane, a steering control means M2 for controlling the steering of the vehicle to guide the vehicle to its reference position on the basis of the transverse reference position of the vehicle on the running lane and of the vehicle position obtained by the vehicle-position recognition means, a surroundings recognition means M3 for recognizing the surroundings of the vehicle on the running lane, and a reference-position change means M4 for changing the reference position on the basis of the recognized results of the surroundings recognition means. The control is thus optimized to elevate the safety and to run the vehicle along its running position which suits the feelings of the driver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle steering control device, and more particularly to a vehicle steering control device for recognizing a white line on a road and preventing a vehicle from deviating from a travel lane.

[0002]

2. Description of the Related Art Conventionally, for the purpose of driving a vehicle more safely, a vehicle which recognizes a white lane of a road or the like and recognizes a traveling lane of a vehicle and performs steering control so as not to deviate from the traveling lane. Steering control device has been proposed.

For example, Japanese Patent Application Laid-Open No. 6-255514 discloses a system in which a white line on a road is recognized, and the safe driving potential energy is set low in a driving lane inside the white line, and is set high near the white line as the vehicle approaches the white line. It is disclosed that auxiliary steering of rear wheels is performed so that the potential energy for safe driving is reduced.

[0004]

In the conventional device, the safe driving potential energy is increased near the white line as the vehicle approaches the white line, and the auxiliary steering is performed so that the safe driving potential energy decreases. The steering is controlled so as to travel in the center.

In consideration of the surrounding environment of the traveling lane of the vehicle, it is optimal to control the vehicle to travel in the center of the traveling lane as in the prior art, or to set the same left and right corrected steering characteristics. There was no problem. That is, it is desirable to perform steering control by offsetting to the higher safety level from the center to the left or right depending on the left and right sides of the traveling lane. Further, it is desirable that the steering amount toward the higher safety level be larger than the steering amount toward the lower safety level.

[0006] The present invention has been made in view of the above points,
An object of the present invention is to provide a vehicle steering control device that performs optimal and highly safe steering control by changing a reference position in the width direction of a traveling lane or a steering amount of steering control based on a surrounding environment of the traveling lane. I do.

[0007]

According to the first aspect of the present invention, as shown in FIG. 1A, there is provided a vehicle position recognizing means M1 for recognizing a vehicle position in a width direction of a traveling lane of the own vehicle. A vehicle steering system having a steering control unit M2 for performing steering control to guide a vehicle to the reference position based on a reference position in a width direction of a traveling lane of the own vehicle and a vehicle position obtained by the vehicle recognition unit. The control device includes a surrounding environment recognizing unit M3 for recognizing the surrounding environment of the traveling lane of the own vehicle, and a reference position changing unit M4 for changing the reference position based on the recognition result of the surrounding environment recognizing unit.

As described above, by changing the reference position according to the surrounding environment, that is, the number of lanes, the presence or absence of a sidewalk, etc., it is possible to drive the vehicle at a traveling position that is higher in safety and suits the driver's feeling. Can be optimized. As shown in FIG. 1 (B), the invention according to claim 2 has a vehicle position recognizing means M1 for recognizing a vehicle position in the width direction of the traveling lane of the own vehicle, and the vehicle in the width direction of the traveling lane of the own vehicle. A steering control unit M2 that performs steering control to guide the vehicle to the reference position based on the reference position of the vehicle and the vehicle position obtained by the vehicle recognition unit. The vehicle includes a surrounding environment recognizing unit M3 for recognizing a surrounding environment of the traveling lane, and a steering amount changing unit M5 for changing a left-right steering amount in the steering control based on the recognition result of the surrounding environment recognizing unit.

As described above, by changing the left and right steering amounts in accordance with the surrounding environment, that is, the number of lanes and the presence or absence of a sidewalk, it is possible to shorten the traveling time in the direction of high safety.

[0010]

FIG. 2 is a block diagram showing an embodiment of the apparatus according to the present invention. In the figure, the front wheel steering mechanism A is a steering wheel 1
The steering wheel 11 is connected to a pinion gear 13 via a steering shaft 12. The pinion gear 13 meshes with a rack bar 14 to control the steering wheel 1.
1 is converted into a reciprocating motion of the rack bar 14 and transmitted. Left and right tie rods 15a, 15b and left and right knuckle arms 16a,
Left and right front wheels FW1 and FW2 are steerably connected via 16b.

Further, the rack bar 14 is driven by the left and right front wheels FW1, FW in accordance with the axial displacement caused by the rotation of the steering handle 11.
Steer 2 A control valve 17 composed of a four-way valve is mounted in the middle of the steering shaft 12. Control valve 17
Supplies hydraulic oil from a hydraulic pump 21 driven by an engine 18 to one oil chamber of a power cylinder 22 in accordance with a steering torque acting on a steering shaft 12.
It functions to discharge the hydraulic oil in the other oil chamber of the power cylinder 22 to the reservoir 23. Power cylinder 22
Assists the steering of the left and right front wheels FW1 and FW2 by driving the rack bar 14 in the axial direction according to the intake and discharge of the hydraulic oil.

The variable steering torque device 25 is a shock absorber (steering damper) for attenuating shocks transmitted directly from the road surface and vibrations of the steering system.
The steering torque is varied by varying the damping coefficient by varying the orifice diameter of the shock absorber.

The rear wheel steering mechanism B has a relay rod 31 that is displaced in the axial direction and steers the left and right rear wheels RW1 and RW2 similarly to the rack bar 14. The left and right tie rods 32a, 32b and the left and right knuckle arms 33a, 33 are provided at both ends of the relay rod 31, as in the case of the front wheel steering mechanism A.
The left and right rear wheels RW1 and RW2 are steerably connected via b.

The relay rod 31 is axially displaceably supported by a housing 34 supported by the vehicle body. A power cylinder 35 is formed in the housing 34.
The power cylinder 35 drives the relay rod 31 in the axial direction in accordance with the suction and discharge of hydraulic oil.
The left and right oil chambers 35b,
35c. These left and right oil chambers 35b, 3
5c has springs 36a and 36b incorporated therein so as to penetrate the relay rod 31 in a preloaded state, and the springs 36a and 36b urge the relay rod 31 to a neutral position by their elastic force. doing.

In the housing 34, a spool valve 37 constituting a hydraulic copying mechanism together with the power cylinder 35 is incorporated. The spool valve 37 includes a valve sleeve 37a accommodated in the housing 34 in a liquid-tight and slidable manner in the axial direction, and a valve sleeve 37b fixed to the housing 34. In accordance with the displacement, hydraulic oil from a hydraulic pump 38 driven by the engine 18 is supplied to the left oil chamber 35b of the power cylinder 35, and hydraulic oil in the right oil chamber 35c of the power cylinder 35 is supplied to the reservoir 23.
Discharge to When the valve sleeve 37a is displaced rightward, the spool valve 37 supplies the hydraulic oil from the hydraulic pump 38 to the right oil chamber 35c of the power cylinder 35, and supplies the hydraulic oil in the left oil chamber 35b of the power cylinder 35. Discharge to reservoir 23.

[0016] the right end portion of the valve sleeve 37a has a through hole 37a ₁ is provided, the lever 41 is in the through-holes 37a ₁ are through. The intermediate portion of the lever 41 is provided nodose ridges 41a of the spherical, lever 41 is tilted and slidably engaged with the inner peripheral surface of the through hole 37a ₁ at the outer peripheral surface of the nodular elevations 41a ing. Further, the lower end portion of the lever 41 is slidably fitted in the annular groove 35a ₁ provided on the outer periphery of the piston 35a to be rotatable and vertically, the lever 4
The upper end of 1 is rotatably connected to a pin 42.

Both ends of the pin 42 enter the support holes 34a and 34b provided in the housing 34 so as to be able to advance and retreat and not to rotate. In addition, rack teeth 42
a is formed, and the stepping motor 43 is provided on the rack teeth 42a.
The worm 44 fixed to the rotation shaft of the gear is engaged. In this case, when the step motor 43 rotates clockwise or counterclockwise, the pin 42 is displaced rightward or leftward.

An electronic control circuit (ECU) 50 detects a steering torque sensor 51, a rear wheel steering angle sensor 54, a turn signal switch 60, a guideline recognition means 62 as a traveling environment detecting means, a vehicle speed sensor 65, and a front wheel steering angle. The steering angle sensor 67 is connected.

The steering torque sensor 51 detects the torque applied to the steering shaft 12 and outputs a signal representing the steering torque MT to the EC.
Supply to U50. The rear wheel steering angle sensor 54 measures the rotation angle of the step motor 43 and supplies a signal representing the rear wheel steering angle θr to the ECU 50. The turn signal switch 60 is turned on when the turn signal is operated, and the on / off signal is set to EC.
Supply to U50.

A guide line recognizing means 62 serving as a vehicle position recognizing means M1 and a surrounding environment recognizing means M3 is supplied from a camera 64 with a road image obtained by photographing a road ahead in the traveling direction of the vehicle. Or, recognize guidelines such as roadside white lines and yellow no-pass lines,
The travel lane is recognized based on these guidelines, and the vehicle offset E (n) from the travel lane center line indicated by the dashed line in FIG. 4 is detected. In addition, traveling environment information such as the number of lanes on the road and the presence or absence of a sidewalk or a median strip is also detected. Here, θ is the inclination angle obtained from the image, l is the forward fixation point distance (constant value), e is the current lateral shift amount, and is expressed as E (n) = e + e ′ e ′ ≒ l × θ. The vehicle offset amount E (n) and the traveling environment information ECU 50 are supplied.

As shown in FIG. 3, the electronic control unit 50 is composed of a microcomputer and has a central processing unit (CP).
U) 70, a read only memory (ROM) 72, a random access memory (RAM) 74, an input port circuit 76, an output port circuit 78, and a communication circuit 80. They are connected to each other by 82.

The input port circuit 76 includes the rear wheel steering angle sensor 54, the turn signal switch 60, the vehicle speed sensor 65,
A detection signal output from each of the steering angle sensors 67 is supplied. The communication circuit 80 includes the guideline recognition means 62.
Is output as the vehicle offset amount E (n). R
The OM 72 stores a control program. CPU
70 performs various operations to be described later based on the control program, and at that time, the RAM 74 is used as a work area.

FIGS. 5 to 7 show a flowchart of one embodiment of the steering control process executed by the ECU 50 of the device of the present invention. This process is repeatedly executed at predetermined time intervals. In FIG. 5, in step S10, it is determined whether or not the steering of the steering wheel 11 is the driver's unconscious steering based on whether or not the turn signal switch 60 is off. If the turn signal switch 60 is off and the steering is unconscious, the process proceeds to step S12,
If not, the processing cycle ends.

In step S12, it is determined whether or not the travel lane has been recognized by the guideline recognition means 62. When the traveling lane can be recognized, the process proceeds to step S14,
If it cannot be recognized, the processing cycle ends. In step S14, the vehicle speed V output from the vehicle speed sensor 65, the steering angle MA output from the steering sensor 67, the vehicle offset amount E (n) output from the guideline recognition means 62, and traveling environment information are read. The vehicle offset amount E (n) is a value based on the center of the traveling lane.

Next, in step S16 of FIG. 6, it is determined whether or not the road is one lane on one side based on the traveling environment information. If the road is one lane on one side, it is determined in step S18 whether there is a sidewalk. If there is a sidewalk, the vehicle offset amount is shifted to the right by ER and the rightward steering gain ΔKR is increased in step S20 according to the following equation.

E (n) = E (n) + ER ΔKR = ΔKR × k where k is a real number of 1 or more. This is because the existence of the sidewalk on the left side of the traveling lane is taken into consideration, and control is performed more in accordance with the driver's feeling.

If there is no sidewalk in step S18, the process proceeds to step S22, and the leftward steering gain ΔKL is increased while the vehicle offset amount E (n) remains unchanged. E (n) = E (n) [Delta] KL = [Delta] KL * k This is because the oncoming vehicle passing on the right side of the lane in which the own vehicle runs is taken into account, and control is performed more in accordance with the driver's feeling.

On the other hand, if it is determined in step S16 that the vehicle is not one lane on one side, the process proceeds to step S24, where it is determined whether or not the vehicle has two lanes on one side. It is determined whether it is medium or not. If the vehicle is traveling on the left end, it is determined in step S27 whether or not there is a sidewalk. If there is a sidewalk, the vehicle offset amount is shifted to the right by ER and the rightward steering gain ΔKR is increased in step S28 by the following equation.

E (n) = E (n) + ER ΔKR = ΔKR × k This is for performing the control more suited to the driver's sense in consideration of the existence of the sidewalk on the left side of the traveling lane. If there is no sidewalk, the vehicle offset amount E is determined in step S29.
(N) is shifted to the left by EL, and the leftward steering gain ΔKL is increased.

E (n) = E (n) -EL ΔKL = ΔKL × k When the vehicle is not traveling on the left end, that is, traveling on the right lane, the vehicle offset amount E (n) is determined in step S30.
And the left steering gain ΔKL is increased.

E (n) = E (n) ΔKL = ΔKL · k On the other hand, if it is not two lanes on one side in step S24, it is regarded as three lanes on one side, and in step S32 the own vehicle travels on the leftmost lane from the traveling environment information. It is determined whether it is medium or not. If the vehicle is traveling on the left end, it is determined in step S33 whether or not there is a sidewalk. If there is a sidewalk, the vehicle offset amount is shifted to the right by ER and the rightward steering gain ΔKR is increased in step S34 by the following equation.

E (n) = E (n) + ER ΔKR = ΔKR × k This is because the existence of the sidewalk on the left side of the traveling lane is taken into consideration, and control is performed in accordance with the driver's sense. If there is no sidewalk, the vehicle offset amount E is determined in step S35.
(N) is shifted to the left by EL, and the leftward steering gain ΔKL is increased.

E (n) = E (n) -EL ΔKL = ΔKL × k If the vehicle is not traveling on the left end, it is determined in step S36 whether or not the vehicle is traveling on the right lane. If the vehicle is traveling on the left side, the vehicle offset amount E (n) is left as it is in step S38, and the leftward steering gain ΔKL
And the rightward steering gain ΔKR is increased.

E (n) = E (n) ΔKL = ΔKL · k ΔKR = ΔKR · k Further, if the vehicle is traveling on the rightmost lane, the vehicle offset amount E (n) is left as it is in step S40 and leftward. The steering gain ΔKL is increased.

E (n) = E (n) ΔKL = ΔKL × k By changing the reference position in accordance with the surrounding environment, that is, the number of lanes, the presence or absence of a sidewalk, and the like, higher safety is achieved.
It is possible to travel at a traveling position that matches the driver's feeling,
Further, by changing the left and right steering amounts, it is possible to shorten the moving time in the direction of high safety.

Steps S20, S22, S28 corresponding to the reference position changing means M4 and the steering amount changing means M5.
After executing steps S30, S34, S35, S38, and S40, the process proceeds to step S44 in FIG. Step S44
Then, the rear wheel steering control amount D (n) is calculated by the following equation.

D (n) = D (n-1) + K1 × ｛E1
(N) -E1 (n-1)} where D (n-1) is the previous rear wheel steering control amount and E1 (n
-1) is the previous offset amount, and K1 is the rear wheel control gain (constant value). Thereafter, the process proceeds to step S46, in which the drive circuit 56 is driven based on the rear wheel steering control amount D (n), whereby the step motor 43 is driven to rotate and the rear wheels are steered. finish.

As a result, as shown in FIG. 8, a vehicle 104 running on a lane 102 having a sidewalk 100 on the left side with one lane on each side.
Travels toward the right side of the arrow from the center of the traveling lane 100 as indicated by the broken line, and can ensure the safety of pedestrians. FIG.
As shown in the figure, the vehicle 108 traveling on the central lane 106 of three lanes on one side travels in the center of the central lane 106 indicated by a broken line. At the same time, as shown in FIG. 10, the vehicle 112 traveling on the left end lane 110 without the three-lane sidewalk on one side is the left end lane 1
The vehicle 116 traveling on the left side of the arrow from the center indicated by the dashed line 10 and traveling in the rightmost lane 114 travels in the center indicated by the dashed line on the rightmost lane 114 and has a vehicle width interval with the vehicle traveling on the central lane 106. Can be increased, and highly safe traveling can be performed.

In the above embodiment, the rear wheel steering control is performed. For example, the front wheel steering control may be performed when the switch is turned on, and the driver may steer the front wheel when the switch is turned off. It is not limited to the above embodiment. In the above embodiment, the traveling environment is detected by using the vehicle speed V, the radius of curvature R of the curve, and the steering angle MA. However, the driving environment is further divided by using various parameters such as the steering angular speed and the brake operation state. It may be configured to correspond to the set traveling environment.

[0040]

As described above, the first aspect of the present invention provides
The vehicle has a vehicle position recognizing means for recognizing a vehicle position in the width direction of the traveling lane of the own vehicle, based on the reference position in the width direction of the traveling lane of the own vehicle and the vehicle position obtained by the vehicle recognizing means. A vehicle steering control device having steering control means for performing steering control to guide the vehicle to the reference position, wherein a surrounding environment recognizing means for recognizing a surrounding environment of a traveling lane of the own vehicle; Reference position changing means for changing the reference position based on the recognition result.

By changing the reference position in accordance with the surrounding environment, that is, the number of lanes, the presence or absence of a sidewalk, and the like, it is possible to drive at a safer driving position that matches the driver's feeling and control. Can be optimized. Further, the invention according to claim 2 has a vehicle position recognizing means for recognizing a vehicle position in the width direction of the traveling lane of the own vehicle, wherein the reference position in the width direction of the traveling lane of the own vehicle and the vehicle recognition device are provided. And a steering control means for performing steering control to guide the vehicle to the reference position based on the vehicle position obtained by the means. There is provided an environment recognizing means, and a steering amount changing means for changing a left-right steering amount in the steering control based on a recognition result of the surrounding environment recognizing means.

As described above, by changing the left and right steering amounts in accordance with the surrounding environment, that is, the number of lanes, the presence or absence of a sidewalk, etc., it is possible to shorten the traveling time in the direction of high safety.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of the device of the present invention.

FIG. 3 is a block diagram of an ECU.

FIG. 4 is a diagram for explaining a vehicle offset amount.

FIG. 5 is a flowchart of a steering control process.

FIG. 6 is a flowchart of a steering control process.

FIG. 7 is a flowchart of a steering control process.

FIG. 8 is a diagram for explaining the present invention.

FIG. 9 is a diagram for explaining the present invention.

FIG. 10 is a diagram for explaining the present invention.

[Explanation of symbols]

 Reference Signs List 11 steering handle 21 hydraulic pump 22 power cylinder 23 reservoir 31 relay rod 32a, 32b left and right tie rod 35 power cylinder 37 spool valve 38 hydraulic pump 41 lever 50 ECU 51 steering torque sensor 54 rear wheel steering angle sensor 56, 57 drive circuit 60 turn signal switch 65 Vehicle speed sensor 67 Steering angle sensor M1 Vehicle position recognizing means M2 Steering control means M3 Ambient environment recognizing means M4 Reference position changing means M5 Steering amount changing means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B62D 119: 00 137: 00 (72) Inventor Yoshiaki Suzuki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Inside the corporation

Claims (2)

[Claims] 1. A vehicle position recognizing means for recognizing a vehicle position in a width direction of a traveling lane of an own vehicle, a reference position in a width direction of the driving lane of the own vehicle, and a vehicle obtained by the vehicle recognizing means. A vehicle-based steering control device having steering control means for performing steering control to guide the vehicle to the reference position based on the position, wherein a surrounding environment recognizing means for recognizing a surrounding environment of a traveling lane of the own vehicle; And a reference position changing means for changing the reference position based on a recognition result of the surrounding environment recognizing means. 2. A vehicle position recognizing means for recognizing a vehicle position in a width direction of a running lane of the own vehicle, a reference position in a width direction of the running lane of the own vehicle, and a vehicle obtained by the vehicle recognizing means. A vehicle-based steering control device having steering control means for performing steering control to guide the vehicle to the reference position based on the position, wherein a surrounding environment recognizing means for recognizing a surrounding environment of a traveling lane of the own vehicle; A steering amount changing unit that changes a left-right steering amount in the steering control based on a recognition result of the surrounding environment recognizing unit.