JPH1129061A - Steering controller of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a driver recognize the approaching state to guidelines by imparting torque to a steering means of a vehicle and giving an alarm to the driver based on the approaching state to the guidelines on the traveling course of the vehicle. SOLUTION: A guideline recognition means M1 supplies road images that the front road of the advancing direction of a vehicle is image picked up from camera, processes these road images and recognizes guidelines such as white lines and yellow no-passing lines at the center of the road or the side of the road. The approaching state to the guidelines of the vehicle is detected by a steering control means M2 from the recognition result of the guidelines. Based on the detected approaching state, an alarm torque imparting means 4 imparts torque to a steering means M3 to be a front wheel steering mechanism of the vehicle and gives an alarm to the driver. Thus, the driver can be made to recognize the approaching state to the guidelines.

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 that recognizes a traveling path ahead of a vehicle and performs steering control so as not to deviate from the traveling path.

[0002]

2. Description of the Related Art Conventionally, for the purpose of running a vehicle stably, a guideline such as a white line on a road is recognized to recognize a travel route of an own vehicle, and an alarm is issued when the vehicle is likely to deviate from the travel route. A device has been proposed. For example, Japanese Patent Application Laid-Open No. 4-293109 discloses a video camera mounted on a vehicle and capturing an image of a road ahead of the vehicle, image processing means for performing image processing on a road image captured from the video camera, A processing area setting means for setting an area in an image to be processed by the processing means and a driving lane recognizing means for recognizing a driving lane by using a processing result of the image processing means are output from a driving lane tracking device. Position recognizing means for recognizing the position of the vehicle in the driving lane using the recognition result of the driving lane, and the possibility of the vehicle deviating from the lane from the position of the vehicle in the lane recognized by the vehicle position recognizing means. Lane departure determination means for determining
A traveling lane departure warning device is provided that includes a warning device that warns a driver when the lane departure determination unit determines that the vehicle may deviate from the traveling lane.

[0003]

In the conventional apparatus, when the vehicle exceeds the preset threshold value and the vehicle approaches the guideline and is about to deviate from the driving lane, the operation is performed. There is a problem that the driver is not considered to be aware of whether the vehicle is being operated.

The present invention has been made in view of the above points, and provides a vehicle capable of causing a driver to recognize a state of approach to a guideline by applying torque to steering means based on the state of approach to the guideline. It is an object of the present invention to provide a steering control device.

[0005]

According to the first aspect of the present invention, there is provided a guideline recognizing means M1 for recognizing a guideline on a traveling path of a vehicle, and a steering control means M2 uses the guideline of the vehicle based on the recognition result of the guideline. A steering control device for a vehicle that detects an approaching state and performs steering control, and includes a warning torque providing unit M4 that applies a torque to a steering unit M3 of the vehicle based on the approaching state with respect to the guideline and warns a driver. .

As described above, since the torque applied to the steering means changes based on the state of approach to the guideline,
The driver can know the approach state to the guideline from the torque. The invention described in claim 2 is the first invention.
In the vehicle steering control device described above, the warning torque applying unit increases the torque as the vehicle approaches a guideline.

For this reason, the driver can know that the guideline is approached as the magnitude of the torque applied to the steering means increases. The third aspect of the present invention is the first aspect.
Alternatively, in the vehicle steering control device according to the second aspect, the warning torque applying unit varies the torque according to a curve.

As described above, by varying the torque according to the curve, for example, the torque near the guide line outside the curve, where the vehicle is likely to deviate, is increased, and a large warning that the vehicle deviates outside the curve can be issued. . Claim 4
According to the invention described in claim 1, in the vehicle steering control device according to claim 1, a traveling situation detecting unit that detects a traveling situation of the vehicle, and a torque applied by the warning torque applying unit based on the detected traveling situation is corrected. And a torque correction unit that performs the operation.

As described above, since the torque is corrected based on the traveling state, the torque can be increased in a traveling state in which the vehicle is likely to deviate from the traveling path, and a larger warning can be given to the driver. According to a fifth aspect of the present invention, in the vehicle steering control device according to the first aspect, a target position on a traveling path is set based on a recognition result of the guideline, and the steering means is configured to travel at the target position. A tracking torque applying means for applying torque is provided.

[0010] As described above, since the torque is applied to the steering means so as to travel at the target position, the vehicle can easily travel at the target position on the travel path, and the vehicle can be prevented from deviating from the travel path. According to a sixth aspect of the present invention, there is provided the steering control device for a vehicle according to the fifth aspect, wherein a traveling state detecting means for detecting a traveling state of the vehicle, and a target position for correcting the target position based on the detected traveling state. Correction means.

As described above, since the target position is corrected based on the traveling condition, a position on the traveling road according to the driver's preference can be set as the target position, and a stable traveling without discomfort can be performed. .

[0012]

FIG. 2 is a block diagram showing an embodiment of the apparatus according to the present invention. In the figure, a front wheel steering mechanism 10 as a steering means M3 has a steering handle 11, and this steering handle 11 is connected to a pinion gear in a steering gear box 13 via a steering shaft 12. The pinion gear meshes with the rack bar 14, and converts the rotational motion of the steering handle 11 into a reciprocating motion of the rack bar 14 and transmits it. Left and right tie rods 15a, 15b and left and right knuckle arms 16a, 16
The left and right front wheels FW1 and FW2 are steerably connected via b.

The front wheel steering mechanism 10 has an electric motor 21 such as a brushless motor as an actuator for steering the front wheels. The rotation shaft of the electric motor 21 is connected to a pinion gear in the steering gear box 13. A front wheel steering angle sensor 32, a yaw rate sensor 35, and a guideline recognition device 36 are connected to the electronic control circuit (ECU) 30. The steering angle sensor 32 as a traveling state detecting means detects the steering angles of the left and right front wheels FW1 and FW2, and the yaw rate sensor 35 detects the yaw rate of the own vehicle.

A guide line recognizing device 36 serving as a guide line recognizing means M1 is supplied from a camera 38 with a road image obtained by photographing a road ahead in the traveling direction of the vehicle. The road image is processed and white lines or yellow lines at the center or the road side of the road are processed. The driving lane is recognized based on the guideline such as the overtaking prohibition line, and the traveling lane is recognized based on the guideline. The vehicle offset amount E (n) from the center line of the traveling road indicated by the broken line in FIG. It detects the distance L _1, for detecting the curvature radius R of the curve of the road. Here, θ is the inclination angle of the vehicle with respect to the traveling path obtained from the image, 1 is the distance of the gazing point ahead (constant value), e is the current lateral shift amount, and E (n) = e + L ₁ (1) L1 ≒ 1 × θ (2) The above-described tilt angle θ, current lateral displacement amount e, vehicle offset amount E (n), and radius of curvature R are supplied to the ECU 30. The current lateral displacement amount e is positive on the right side of the travel road center line and negative on the left side.

The ECU 30 comprises a microcomputer as shown in FIG.
0, a read only memory (ROM) 52, a random access memory (RAM) 54, and an input port circuit 56
, An output port circuit 58, and a communication circuit 60, which are connected to each other by a bidirectional common bus 62.

The input port circuit 56 includes a steering angle sensor 3
2, a detection signal output from each of the yaw rate sensors 35 is supplied. Further, the detection amounts θ, e, E (n), and R output from the guideline recognition device 36 are supplied to the communication circuit 60. A control program is stored in the ROM 52. The CPU 50 performs various operations to be described later based on the control program, and at that time, the RAM 54 is used as a work area. A control signal generated by the CPU 50 executing the control program is supplied from the output port circuit 58 to the drive circuit 40. The drive circuit 40 drives the electric motor 21 to steer the front wheels FW1 and FW2.

FIG. 5 is a flowchart of a first embodiment of a steering control process performed by the ECU 30 as the steering control means M2. This process is repeated at predetermined time intervals. In FIG. 12, in step S12, the vehicle offset amount E (n), the current lateral displacement amount e, and the curvature radius R (curve R) of the traveling road as the traveling situation output from the guide line recognition device 36 are read. Next, in step S14, it is determined whether or not the guideline recognition device 36 has recognized the guideline of the traveling path. When the guideline is recognized, the vehicle offset amount E (n) is a numerical value within a predetermined range, and when the guideline is not recognized, the vehicle offset amount E (n) is set as a specific value outside the predetermined range. Given.

Here, if the guideline has been recognized, the process proceeds to step S16, and if not, the process ends. In step S16, the guideline recognition device 3
Based on the curve R obtained from Step 6, it is determined whether or not the currently traveling road is a straight road. And in the case of straight road proceeds to step S18, it obtains the position control gain kp _1. The position control gain kp ₁ is obtained by using the current lateral displacement amount e and referring to the map shown in FIG.

Next, in step S20, a steering control amount θ and a steering torque T are obtained. The steering control amount is calculated using equation (3). θ = kp ₁ × e + kd × de (3) where kd is a predetermined coefficient (constant), and de is a differential value of the current lateral displacement amount e, that is, the value of the present e and the value of the previous e. This is the difference from. The steering torque T is equal to the current lateral displacement amount e.
By referring to the map shown in FIG. Thereafter, the process proceeds to step S22.

On the other hand, if it is not a straight road in step S16, the process proceeds to step S26, and it is determined whether or not it is a left curve. The value of the curve R output by the guideline recognition device 36 is assumed to be positive for a right curve and negative for a left curve. In the case of a left curve, the process proceeds to step S28, and the position control gain k is determined by referring to the map shown in FIG.
seek p _1. Next, in step S30, the steering control amount θ and the steering torque T are obtained. The steering control amount θ is calculated using equation (3). The steering torque T is obtained by first calculating the current lateral displacement amount e as shown in FIG.
The steering torque gain kt is determined by referring to the map shown in FIG. 9 using the curve R and the map shown in FIG.

T = TL × kt (4) Thereafter, the process proceeds to step S22. For right curve proceeds to step S32, the current lateral deviation e in determining the position control gain kp ₁ with reference to the map shown in FIG. Next, in step S34, the steering control amount θ and the steering torque T are obtained. The steering control amount θ is calculated using equation (3). Steering torque T
First, the torque TR is obtained by referring to the map shown in FIG. 10 based on the current lateral shift amount e, and then the steering torque gain kt is obtained by using the curve R and the map shown in FIG. .

T = TR × kt (5) Thereafter, the process proceeds to step S22. In step S22, a signal based on the steering control amount θ and the steering torque T is output to the drive circuit 40. As a result, the electric motor 21 is driven to rotate, and the front wheels FW1 and FW2 are steered. Thereafter, the process ends. The above steps S16 to S22 correspond to the warning torque applying means M4.

As described above, when the position of the vehicle on the road approaches the guide line, the torque applied to the steering means M3 increases, and this torque is transmitted to the driver through the steering handle 11, and the driver receives the torque. Can know the approach status to the guideline. Also, by varying the torque according to the direction of the curve and the curve R, the torque near the guide line outside the curve, where the vehicle is likely to deviate from the running path, is increased, and a large warning is given that the vehicle deviates outside the curve. it can.

FIG. 11 is a flowchart of a second embodiment of the steering control process executed by the ECU 30 as the steering control means M2. This process is repeated at predetermined time intervals.
In the figure, in step S42, the guideline recognition device 36
, The vehicle offset E (n), the current lateral displacement e, and the radius of curvature R (curve R) of the traveling road as the traveling situation are read. Next, in step S44, it is determined whether or not the guideline recognition device 36 has recognized the guideline of the traveling path. When the guideline is recognized, the vehicle offset amount E (n) is a numerical value within a predetermined range, and when the guideline is not recognized, the vehicle offset amount E (n) is set as a specific value outside the predetermined range. Given.

Here, if the guideline has been recognized, the process proceeds to step S46, and if not, the process ends. In steps S46 and S48, the absolute value of the current lateral displacement amount e obtained from the guideline recognition device 36 is set to a predetermined value L
1, L2. As shown in FIG. 12, the predetermined value L1
Is a value for determining whether or not the vehicle is near the center position of the traveling road, for example, several tens of cm. The predetermined value L2 is a value for determining whether or not the vehicle has approached the guideline, and is about 1 m or several tens of cm corresponding to a width from the center of the traveling path to several tens of cm before the guideline.

If | e | ≦ L1 as a result of the discrimination in steps S46 and S48, kpa is set to the position control gain kp and kta is set to the torque control gain kt in step S50. If L1 <| e | ≦ L1 + L2, the position control gain kp is set to kpb and the torque control gain kt is set to ktb in step S52. If L1 + L2 <| e |, step S54
Sets the position control gain kp to kpc and the torque control gain kt to ktc.

The above control gain has the following relationship. kpb <kpa ≦ kpc (6) 0 ≦ ktb <kta <ktc (7) As described above, the control gain is set so that the driver is warned of the departure from the traveling road as the guideline is approached. . Step S50 described above corresponds to tracking torque applying means, and step S54 corresponds to warning torque applying means.

After executing any of steps S50, S52, and S54, the process proceeds to step S56, where the steering control amount θ and the steering torque T are calculated by the following equations. θ = kp × e + kd × de (8) T = kt × α (9) where α is a predetermined value. Thereafter, the process proceeds to step S58. In step S58, the steering control amount θ and the steering torque T
The driving circuit 40 is driven based on. Thus, the electric motor 21 is rotationally driven to steer the front wheels FW1 and FW2, and the post-processing ends.

As described above, when the vehicle is traveling at the center position of the traveling road, the steering control is performed so that the vehicle does not deviate from the vicinity of the center of the traveling road (lane tracking), and the traveling stability is improved. Note that this steering control is not an automatic operation but a manual operation, and even if the above-described steering control is performed, the steering control by the driver can override the steering control.

Incidentally, the torque control gain may be varied according to the steering angle and the steering angular velocity (or yaw rate). When the steering angle and the steering angular velocity (time differential value of the steering angle) are smaller than the respective thresholds, the torque control gain ktc is increased, and when the steering angle and the steering angular velocity are larger than the respective thresholds, the torque control gain ktc is reduced. I do. FIG. 13 shows a flowchart of a process for realizing this. This process is interrupted every predetermined time. In the figure, step S6
At step S62, the steering angle θ and the steering angular velocity Δθ are read, and at step S62, the steering angle θ is larger than the threshold α or the steering angular velocity Δ
It is determined whether θ is larger than the threshold β. And θ> α or Δθ
If> β, the torque control gain ktc is determined in step S64.
Is reduced, and when θ ≦ α and Δθ ≦ β, step S66
Increases the torque control gain ktc. As a result, when the steering angle and the steering angular velocity of the vehicle 70 are large as shown in FIG. 14, it is possible to easily change the traveling path, and to move to the adjacent lane like the vehicle 70A, and the steering angle and the steering speed are reduced. At this time, it becomes possible to maintain the traveling road like the vehicle 70B.

Further, the control gain may be varied according to the vehicle position (current lateral deviation amount) on the traveling road and the steering direction.
When left-turn steering is detected while traveling on the left side of the traveling path, the position control gain kpc is increased and the torque control gain kt is increased.
increase c. Similarly, when right-turn steering is detected during traveling on the right side of the traveling road, the position control gain kpc and the torque control gain ktc are increased. The steering direction is determined to be left turning if the value obtained by subtracting the current steering angle from the previous steering angle is positive, and right if it is negative. FIG. 15 shows a flowchart of a process for realizing this. This process is interrupted every predetermined time. In the figure, step S70
Reads the current lateral displacement amount e, the previous steering angle θ (k−1), and the current steering angle θ (k), and determines in step S72 whether the difference steering angle θ (k−1) −θ (k) is positive. Determines left or right turn. If the difference steering angle is positive, step S74
Is turned left, and if the difference steering angle is negative, right turning is performed in step S76.

Next, in step S78, it is determined from the current lateral displacement amount e whether or not the vehicle position is on the left side of the traveling road (lane). If it is on the left side, it is determined in step S80 whether or not the steering direction is left turning. When turning left, the control gain kp is set in step S82.
If c and ktc are increased, and if it is turned right, the control gains kpc and ktc are set to normal settings in step S84. On the other hand, if the vehicle position is on the left side of the traveling road, it is determined whether or not the vehicle is turning left in step S86. If the vehicle is turning right, the control gains kpc and ktc are increased in step S82, and if the vehicle is turning left, control is performed in step S84. The gains kpc and ktc are normally set.
As a result, the running path holding ability of each of the vehicles 71 and 72 shown in FIG. 16 is increased.

If there is a vehicle within L1 + L2 shown in FIG. 12 and the absolute value of the steering angle is kept within a predetermined value θ ₀ for a predetermined time t ₀ (for example, several tens of seconds), FIG. As shown in the above, the predetermined value L1 may be shifted left and right by the average value of the current lateral displacement amount e, and the range in which the lane tracking is performed may be changed from near the center of the traveling road to the position where the vehicle is traveling stably. . FIG. 18 shows a flowchart of a process for realizing this. This process is interrupted every predetermined time. In the figure, the current lateral deviation amount e and the steering angle θ are read in step S90, it is determined whether the absolute value of the current lateral deviation amount e is within a predetermined value L1 + L2 in step S92, and further, in step S94, the absolute value of the steering angle θ is predetermined. to determine whether or not the value θ ₀ within. If step S92 or S94 is not satisfied, the timer t is reset to 0 in step S96. When steps S92 and S94 are satisfied, the timer t is counted up in step S98, and step S1 is executed.
At 00, it is determined whether or not the timer t has exceeded a predetermined value t ₀ ,
When it exceeds, the predetermined value L1 in step S102 is shifted left and right by the average value of the current lateral shift amount. As a result, the vehicle can travel at a position according to the driver's preference.

[0034]

As described above, the first aspect of the present invention provides
A steering control device for a vehicle, comprising: a guideline recognizing means M1 for recognizing a guideline on a traveling path of a vehicle, wherein a steering control means M2 detects an approach state of the vehicle to the guideline from a recognition result of the guideline and performs steering control. And a warning torque applying means M4 for applying a torque to the steering means M3 of the vehicle based on the approach state with respect to the guide line to warn the driver.

As described above, since the torque applied to the steering means changes based on the state of approach to the guideline,
The driver can know the approach state to the guideline from the torque. According to a second aspect of the present invention, in the vehicle steering control device according to the first aspect, the warning torque applying means increases the torque as the vehicle approaches the guideline.

Therefore, the driver can know that the guideline is approached as the magnitude of the torque applied to the steering means increases. According to a third aspect of the present invention, in the vehicle steering control device according to the first or second aspect, the warning torque applying means varies the torque according to a curve.

As described above, by varying the torque according to the curve, the torque near the guide line outside the curve, where the vehicle is likely to deviate, is increased, and a large warning that the vehicle deviates toward the outside of the curve can be issued. Claim 4
According to the invention described in claim 1, in the vehicle steering control device according to claim 1, a traveling situation detecting unit that detects a traveling situation of the vehicle, and a torque applied by the warning torque applying unit based on the detected traveling situation is corrected. And a torque correction unit that performs the operation.

As described above, since the torque is corrected based on the traveling state, the torque can be increased in a traveling state in which the vehicle is likely to deviate from the traveling path, and a larger warning can be given to the driver. According to a fifth aspect of the present invention, in the vehicle steering control device according to the first aspect, a target position on a traveling path is set based on a recognition result of the guide line, and the steering is performed so as to travel at the target position. A tracking torque applying means for applying torque to the means;

As described above, since the torque is applied to the steering means so as to travel at the target position, traveling at the target position on the traveling path is facilitated, and the vehicle can be prevented from deviating from the traveling path. According to a sixth aspect of the present invention, in the steering control device for a vehicle according to the fifth aspect, a traveling situation detecting means for detecting a traveling situation of the vehicle, and the target position is corrected based on the detected traveling situation. Target position correcting means.

As described above, since the target position is corrected on the basis of the driving situation, a position on the traveling road according to the driver's preference can be set as the target position, and a stable running without discomfort can be performed. .

[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 diagram showing a map of a position control gain on a straight road.

FIG. 7 is a diagram showing a map of steering torque on a straight road.

FIG. 8 is a diagram showing a map of a torque TL of a left curve.

FIG. 9 is a diagram showing a map of a steering torque gain.

FIG. 10 is a view showing a map of a torque TR of a right curve.

FIG. 11 is a flowchart of a steering control process.

FIG. 12 is a diagram for explaining a relationship between a current lateral shift amount and a control gain according to the present invention.

FIG. 13 is a flowchart of an interrupt process.

FIG. 14 is a diagram for explaining travel route change and travel route maintenance according to the present invention.

FIG. 15 is a flowchart of an interrupt process.

FIG. 16 is a diagram for explaining the holding of a traveling road according to the present invention.

FIG. 17 is a diagram illustrating a change of a predetermined value of the current lateral shift amount according to the present invention.

FIG. 18 is a flowchart of an interrupt process.

[Explanation of symbols]

 Reference Signs List 10 steering mechanism 11 steering handle 12 steering shaft 13 steering gear box 14 rack bar 15a, 15b tie rod 16a, 16b knuckle arm 20 rear wheel steering mechanism 21 electric motor 23 relay rod 30 ECU 32 steering angle sensor 34 yaw rate sensor 36 guideline recognition device 38 Camera 40 Drive circuit M1 Guideline recognition means M2 Steering control means M3 Steering means M4 Warning torque applying means

Claims (6)

[Claims] 1. A vehicle steering control device comprising: a guideline recognizing means for recognizing a guideline on a traveling path of a vehicle, and detecting a state of approach of the vehicle to the guideline from a recognition result of the guideline and performing steering control, A steering control device for a vehicle, comprising: a warning torque applying unit that applies a torque to a steering unit of the vehicle based on an approach state with respect to the guide line and warns a driver. 2. The vehicle steering control device according to claim 1, wherein the warning torque applying means increases the torque as the vehicle approaches a guide line. 3. The vehicle steering control device according to claim 1, wherein the warning torque applying means changes the torque according to a curve. 4. The steering control device for a vehicle according to claim 1, wherein a traveling state detecting unit that detects a traveling state of the vehicle, and a torque applied by the warning torque applying unit is corrected based on the detected traveling state. A steering control device for a vehicle, comprising: a torque correction unit. 5. The vehicle steering control device according to claim 1, wherein a target position on a traveling path is set based on a recognition result of the guideline, and torque is applied to the steering means so as to travel at the target position. A steering control device for a vehicle, comprising a tracking torque applying means. 6. The steering control device for a vehicle according to claim 5, further comprising: a traveling state detecting unit that detects a traveling state of the vehicle; and a target position correcting unit that corrects the target position based on the detected traveling state. A steering control device for a vehicle, comprising: