JP2010058690A - Steering support device - Google Patents

Abstract

Provided is a steering assist device that appropriately ends integral control when a steering force applied to a steering mechanism interferes with a steering operation of a driver.
A steering assist device includes an environment recognition unit, a target travel position setting unit, a host vehicle lateral position recognition unit, a vehicle lateral position deviation calculation unit with respect to the target travel position, and a deviation integration. Means 150, target steering force setting means 180 based on the integrated value of the deviation, steering control means 190 for applying a steering force to the steering mechanism based on the target steering force, steering operation force detecting means 23, and target steering force The steering force setting means 180 includes an integration stop means 181 for stopping the addition of the integral value by the deviation integration means 150 when the direction and the direction of the steering operation force are different, and an external force estimation means 170 in the host vehicle. After the deviation integration means stops adding the integral value, the steering force based on the integral value is reduced after a predetermined integration stop time has elapsed, and the integration stop time is increased according to the increase in lateral external force. A configuration in which the length.
[Selection] Figure 1

Description

  The present invention relates to a steering assist device that is provided in a vehicle such as an automobile and applies a steering force to a steering mechanism so that the host vehicle travels along a target travel position.

The steering assist device recognizes the lane shape in front of the host vehicle using environment recognition means such as a stereo camera, and applies steering force to the steering mechanism so that the host vehicle travels along the lane. For example, the steering assist device applies a steering force so as to reduce a deviation between the target travel position set in the lane and the lateral position of the host vehicle.
In such a steering assist device, disturbances such as a lateral inclination (cant) of the road surface cause deterioration of convergence to the target course. 2. Description of the Related Art Conventionally, as a technique for improving the deterioration of convergence due to disturbance, integration control is known in which a steering target value is set by integrating the deviation of the vehicle lateral position with respect to a target travel position.
However, in the above-described integral control, the input when the driver intentionally shifts the lateral position of the vehicle is also regarded as a disturbance, causing interference with the driver's steering operation, resulting in a hindrance to the operation and a sense of incongruity.
On the other hand, for example, in Patent Literature 1, in the steering assist device, when the direction of the applied steering torque is different from the steering operation direction of the driver, the integration is stopped, and the integrated value and the applied steering are given. It is described that the torque is not increased.
JP 2007-38697 A

However, in the technique described in Patent Document 1, since the application of the steering force based on the integral value is continued for a while after the integration is stopped, the driver wants to travel a position that deviates from the target travel position. Will continue to interfere with driver operations.
Patent Document 1 (paragraph 0060 and the like) describes that the integral value is decreased based on the elapsed time or the travel distance from the time point when the steering operation in the direction opposite to the steering assist is detected. However, if the timing at which the steering assist is weakened by decreasing the integral value is inappropriate, the disturbance acting on the host vehicle is large, or if the lateral position of the host vehicle is close to the lane edge If the steering assist is weakened, the course and behavior may be disturbed and the vehicle may deviate from the lane.
The subject of this invention is providing the steering assistance apparatus which complete | finishes integral control appropriately at the time of interference with the steering force provided to a steering mechanism, and a driver's steering operation.

The present invention solves the above-described problems by the following means.
The invention according to claim 1 is a steering assist device that applies a steering force to the steering mechanism so that the host vehicle travels along the travel lane, and recognizes an environment in front of the host vehicle including the travel lane of the host vehicle. Recognition means; target travel position setting means for setting the target travel position of the host vehicle in the travel lane of the host vehicle using the environment recognition means; host vehicle lateral position recognition means for recognizing the lateral position of the host vehicle; Deviation calculating means for calculating a deviation of the lateral position of the host vehicle with respect to the target travel position, deviation integrating means for calculating an integrated value of the deviation, and target steering given to the steering mechanism based on the integrated value of the deviation A steering force setting means for setting a force; a steering control means for applying a steering force to the steering mechanism based on the target steering force; a steering operation force detection means for detecting a steering operation force input by a driver; and the target Steering force direction and front An integral stopping means for stopping the addition of the integral value by the deviation integrating means when the direction of the steering operation force is different; and an external force estimating means for estimating a lateral external force received by the host vehicle, the steering force setting And a means for reducing the steering force based on the integral value after elapse of a predetermined integration stop time after the deviation integrating means stops adding the integral value, and for integrating the integral in response to an increase in the lateral external force. A steering assist device that extends a stop time.
According to a second aspect of the present invention, in the steering assist device according to the first aspect, the steering force setting means further extends the integration stop time in accordance with an increase in the deviation.

  According to a third aspect of the present invention, there is provided a steering assist device that applies a steering force to a steering mechanism so that the host vehicle travels along the traveling lane, and an environment for recognizing an environment ahead of the host vehicle including the traveling lane of the host vehicle. Recognition means; target travel position setting means for setting the target travel position of the host vehicle in the travel lane of the host vehicle using the environment recognition means; host vehicle lateral position recognition means for recognizing the lateral position of the host vehicle; Deviation calculating means for calculating a deviation of the lateral position of the host vehicle with respect to the target travel position, deviation integrating means for calculating an integrated value of the deviation, and target steering given to the steering mechanism based on the integrated value of the deviation A steering force setting means for setting a force; a steering control means for applying a steering force to the steering mechanism based on the target steering force; a steering operation force detection means for detecting a steering operation force input by a driver; and the target Steering force direction and front Integration stop means for stopping the addition of the integral value by the deviation integration means when the direction of the steering operation force is different, and the steering force setting means stops the addition of the integral value by the deviation integration means Then, the steering assist device is characterized in that the steering force based on the integral value is reduced after a predetermined integral stop time has elapsed, and the integral stop time is extended in accordance with the increase in the deviation.

According to a fourth aspect of the present invention, there is provided a steering assist device that applies a steering force to a steering mechanism so that the host vehicle travels along the travel lane, and an environment for recognizing an environment ahead of the host vehicle including the travel lane of the host vehicle. Recognition means; target travel position setting means for setting the target travel position of the host vehicle in the travel lane of the host vehicle using the environment recognition means; host vehicle lateral position recognition means for recognizing the lateral position of the host vehicle; Deviation calculating means for calculating a deviation of the lateral position of the host vehicle with respect to the target travel position, deviation integrating means for calculating an integrated value of the deviation, and target steering given to the steering mechanism based on the integrated value of the deviation A steering force setting means for setting a force; a steering control means for applying a steering force to the steering mechanism based on the target steering force; a steering operation force detection means for detecting a steering operation force input by a driver; and the target Steering force direction and front An integral stopping means for stopping the addition of the integral value by the deviation integrating means when the direction of the steering operation force is different; and an external force estimating means for estimating a lateral external force received by the host vehicle, the steering force setting The means reduces the steering force based on the integral value at a predetermined decrease rate after the predetermined integration stop time has elapsed after the deviation integrating means decreases the addition of the integral value, and increases the lateral external force. Accordingly, the steering assist device is characterized in that the rate of decrease in the steering force based on the integrated value is reduced.
According to a fifth aspect of the present invention, in the steering assist according to the fourth aspect, the steering force setting means further reduces a decrease rate of the steering force based on the integral value in accordance with the increase in the deviation. Device.

  The invention according to claim 6 is a steering assist device that applies a steering force to the steering mechanism so that the host vehicle travels along the travel lane, and recognizes an environment in front of the host vehicle including the travel lane of the host vehicle. Recognition means; target travel position setting means for setting the target travel position of the host vehicle in the travel lane of the host vehicle using the environment recognition means; host vehicle lateral position recognition means for recognizing the lateral position of the host vehicle; Deviation calculating means for calculating a deviation of the lateral position of the host vehicle with respect to the target travel position, deviation integrating means for calculating an integrated value of the deviation, and target steering given to the steering mechanism based on the integrated value of the deviation A steering force setting means for setting a force; a steering control means for applying a steering force to the steering mechanism based on the target steering force; a steering operation force detection means for detecting a steering operation force input by a driver; and the target Steering force direction and front Integration stop means for stopping the addition of the integral value by the deviation integration means when the direction of the steering operation force is different, and the steering force setting means reduces the addition of the integral value by the deviation integration means After the predetermined integration stop time has elapsed, the steering force based on the integral value is decreased at a predetermined decrease rate, and the decrease rate of the steering force based on the integral value is reduced as the deviation increases. This is a steering assist device.

According to the present invention, the following effects can be obtained.
(1) After the deviation integration means stops adding the integral value, the steering force based on the integral value is reduced after a predetermined integral stop time has elapsed, and the integral stop time is extended in accordance with an increase in lateral external force. Accordingly, when the lateral external force is large, it is possible to lengthen the time until the steering force is reduced based on the integrated value, and to prevent the behavior of the vehicle and the disturbance of the course when the steering force is reduced.
(2) After the deviation integration means stops adding the integral value, the steering force based on the integral value is reduced after the predetermined integration stop time has elapsed, and the integral stop time is extended in accordance with the increase in deviation. When the deviation of the vehicle's lateral position from the target travel position is large and there is little time to depart from the lane, the lane departure is prevented by increasing the time until the steering force based on the integration is reduced. be able to.
(3) The steering force based on the integral value is increased when the lateral external force is large by reducing the reduction rate for decreasing the steering force based on the integral value in accordance with the increase in the lateral external force after the integration stop time has elapsed. The vehicle behavior and the course can be prevented from being disturbed by a decrease in the steering force based on the integrated value.
(4) By reducing the rate of decrease in the steering force based on the integrated value after the integration stop time has elapsed in accordance with the increase in the deviation, the deviation of the vehicle's lateral position from the target travel position is large, and When the time margin is small, the steering force based on the integrated value can be gradually reduced, and the vehicle can be prevented from deviating from the lane due to the decrease in the steering force based on the integrated value.

  An object of the present invention is to provide a steering assist device that appropriately terminates integral control when a steering force applied to a steering mechanism interferes with a driver's steering operation. The problem was solved by changing the timing and rate of reduction of the steering force based on the integral control according to the position.

Embodiments of a steering assist device to which the present invention is applied will be described below.
The steering assist device according to the embodiment is provided, for example, in a four-wheeled vehicle such as a passenger car that steers the two front wheels.
FIG. 1 is a diagram illustrating a system configuration of a vehicle including a steering assist device according to an embodiment. This steering assist device applies a steering torque (steering force) to the steering mechanism 10.
The steering mechanism 10 performs steering by rotating the housing H that supports the front wheel FW about a predetermined steering axis (king pin).

The steering mechanism 10 includes a steering wheel 11, a steering shaft 12, a steering gear box 13, a tie rod 14, and the like.
The steering wheel 11 is an annular operation member through which a driver inputs a steering operation.
The steering shaft 12 is a rotating shaft that transmits the rotation of the steering wheel 11 to the steering gear box 13.
The steering gear box 13 includes a rack and pinion mechanism that converts the rotational movement of the steering shaft 12 into a straight movement in the vehicle width direction.
The tie rod 14 is a shaft-like member having one end connected to the rack of the steering gear box 13 and the other end connected to the knuckle arm of the housing H. The tie rod 14 steers by rotating the housing H by pushing and pulling the knuckle arm of the housing H.

  The vehicle also includes an electric power steering (EPS) control unit 20, a steering control unit 30, an engine control unit 40, a transmission (TM) control unit 50, a vehicle integration unit 60, and the like.

The EPS control unit 20 comprehensively controls an electric power steering device that generates a steering assist force in accordance with a driver's steering operation. The EPS control unit 20 is connected to an electric actuator 21, a steering angle sensor 22, a torque sensor 23, and the like.
The electric actuator 21 is, for example, an electric motor that is provided in the middle of the steering shaft 12 and applies a steering torque (steering force) to the steering mechanism 10 via a speed reduction mechanism.
The steering angle sensor 22 includes an encoder that detects the angular position of the steering shaft 12 (substantially equal to the angular position of the steering wheel 11).
The torque sensor 23 is inserted into the steering shaft 12 between the electric actuator 21 and the steering wheel 11 and detects torque acting on the steering shaft 12. Normally, the torque detected by the torque sensor 23 is substantially equal to the steering torque input to the steering wheel 11 by the driver.

The steering control unit 30 performs vehicle steering control and ABS control for individually controlling the braking force of each wheel brake. In vehicle stability control, when understeer or oversteer occurs, the braking force on the turning inner wheel side and the outer wheel side is made different to generate a yaw moment in the restoring direction. ABS control (anti-lock brake control) is for reducing and recovering the braking force of a wheel when the tendency of the wheel to lock is detected.
The steering control unit 30 is connected to a hydraulic control unit (HCU) 31, a vehicle speed sensor 32, a yaw rate sensor 33, a lateral acceleration (lateral G) sensor 34, and the like.

The HCU 31 is a device that individually controls the brake fluid hydraulic pressure applied to the hydraulic service brake of each wheel. The HCU 31 includes a motor pump that pressurizes the brake fluid, a solenoid valve that adjusts the pressure applied to the caliper cylinder of each wheel, and the like.
The vehicle speed sensor 32 is provided in a housing that holds the hub bearing of each wheel, and outputs a vehicle speed pulse signal corresponding to the wheel speed. The vehicle speed pulse signal is subjected to predetermined processing, whereby the traveling speed of the vehicle can be obtained.
The yaw rate sensor 33 and the lateral G sensor 34 include a MEMS sensor that detects a rotational speed around the vertical axis of the vehicle body and a lateral acceleration, respectively.

The engine control unit 40 controls the engine, which is a driving power source for the vehicle, and its auxiliary equipment.
The transmission control unit 50 controls the automatic transmission that changes the output of the engine and transmits it to the differential gear of the drive shaft.
The vehicle integration unit 60 controls the electrical components of the vehicle other than those related to each unit.

Further, the steering assist device of the embodiment includes a steering assist control unit 100 described below.
The steering assist control unit 100 is connected to the above-described EPS control unit 20, the operation control unit 30, the engine control unit 40, the transmission control unit 50, and the vehicle integration unit 60 via an in-vehicle LAN such as a CAN communication system, for example. Various information and signals can be acquired.

  The steering assist control unit 100 includes an environment recognition unit 110, a target travel position setting unit 120, a host vehicle traveling path estimation unit 130, a deviation calculation unit 140, a deviation integration unit 150, a steering operation force detection unit 160, an external force estimation unit 170, a target Steering force setting means 180, steering control means 190, etc. are provided. Each of these means may be configured as independent hardware, or a part or all of them may be configured as common hardware.

The environment recognition unit 110 recognizes the shape of the traveling lane of the host vehicle based on image information obtained by capturing the front of the host vehicle.
FIG. 2 is a diagram illustrating an example of a planar arrangement of the host vehicle and the lane in the embodiment.
The environment recognition unit 110 is connected to a stereo camera 111, an image processing unit 112, and the like.
The stereo camera 111 includes, for example, a pair of main cameras and sub-cameras provided near the room mirror base at the upper end of the front window of the vehicle. Each of the main camera and the sub camera has a CCD camera. The main camera and the sub camera are installed apart from each other in the vehicle width direction. The main camera and the sub camera capture a reference image and a comparative image, respectively, and output image data related to these images to the image processing unit 112.
The image processing unit 112 performs A / D conversion on the image data of the reference image and the comparison image output from the stereo camera 111, performs predetermined image processing, and outputs the result to the environment recognition unit 110. This image processing includes, for example, correction of an attachment position error of each camera, noise removal, gradation optimization, and the like. The digitized image has, for example, a plurality of pixels arranged in a matrix in the vertical direction and the horizontal direction. Each of these pixels has a luminance value corresponding to the brightness of the subject.

  The environment recognition unit 110 detects the parallax of a pixel group that is a block composed of an arbitrary pixel or a plurality of pixels on the reference image based on the data of the reference image and the comparison image. This parallax is the amount of deviation between the position on the reference image and the position on the comparison image of a certain pixel or pixel group. Using this parallax, the distance from the vehicle to the subject corresponding to the pixel can be calculated based on the principle of triangulation.

Moreover, the environment recognition means 110 recognizes the shape of the white line WL arrange | positioned at the lane both ends ahead of the own vehicle. In this specification, claims, etc., the white line WL indicates a continuous line or a broken line drawn at the end in the width direction of the lane, and the actual color is other than white (for example, amber, etc.) This line is also included.
The environment recognition unit 110 detects a pixel group in the white line WL portion based on the luminance data of the pixel from the reference image data. The orientation of the pixel group of the white line WL portion with respect to the host vehicle is detected based on the pixel position on the image data. Specifically, an area corresponding to the pixel position in the vertical direction on the road surface is scanned in the horizontal direction, and a portion where the brightness value changes suddenly is recognized as the outline of the white line WL. Then, the position of the white line WL is detected by calculating the distance of the pixel group in the white line portion.
The environment recognition means 110 can continuously detect the position of the white line to set a plurality of lane candidate points in the traveling direction of the vehicle, ignore the lane candidate points that cannot be matched, and set the lane candidate points. The area that does not exist is subjected to a predetermined complement process to recognize the lane shape ahead of the host vehicle.

  The target travel position setting unit 120 sets the target travel position Xc at the center in the width direction of the travel lane of the host vehicle set by the environment recognition unit 110.

The own vehicle traveling path estimation means 130 is based on information from the environment recognition means 110, the running state of the vehicle detected by the steering angle sensor 22, the vehicle speed sensor 32, the yaw rate sensor 33, etc., and known vehicle specifications. The vehicle traveling path is estimated. The own vehicle traveling path estimating means 130 functions as the own vehicle lateral position recognizing means according to the present invention.
The own vehicle traveling path is estimated by, for example, calculating the lateral position Xe of the own vehicle OV at the gaze distance Z in front of the vehicle.
This will be described below using a coordinate system having an X-axis extending in the vehicle width direction and a Z-axis extending forward of the vehicle body with the center of gravity of the host vehicle OV as the origin.
The estimated lateral position Xe of the host vehicle's center of gravity at the gaze distance Z is obtained by the following equation 1 using the handle angle α.

In addition, the vehicle traveling path estimation unit 130 estimates the lateral position using the yaw rate γ detected by the yaw rate sensor 33 as shown in the following equation 2, instead of estimating the lateral position using the steering wheel angle α. be able to.

Xe = Z ² γ / 2V (Formula 2)
Z: Gaze distance [m]
γ: vehicle yaw rate [rad / sec]

The deviation calculation means 140 is a deviation Δe (= Xc−Xe) in the lateral direction between the target travel position Xc set by the target travel position setting means 120 and the lateral position Xe of the own vehicle estimated by the own vehicle traveling path estimation means 130. Is calculated.
The deviation integrating unit 150 calculates an integrated value obtained by integrating the deviation Δe calculated by the deviation calculating unit 140.
The steering operation force detection means 160 detects the output value of the torque sensor 23 via the EPS control unit 20 and detects the torque input to the steering wheel 11 by the driver.

The external force estimation means 170 is for estimating an external force that acts on the host vehicle OV due to a disturbance such as a lateral inclination (cant) of the road surface.
The external force estimating means 170 is a reference lateral G which is a lateral acceleration (G) calculated based on the vehicle speed V of the host vehicle OV detected using the vehicle speed sensor 32 and the yaw rate γ detected using the yaw rate sensor 33. The disturbance estimated value Fx is calculated by comparing the actual lateral G detected by the lateral G sensor 34 with the actual lateral G. This disturbance estimated value Fx is an estimated value of the external force that acts on the center of gravity of the host vehicle OV due to the road surface cant.

The target steering force setting unit 180 sets a target steering torque to be applied to the steering mechanism 10 based on the deviation Δe calculated by the deviation calculation unit 140 and the integral value calculated by the deviation integration unit.
The target steering force setting means 180 adds the deviation control steering force obtained by multiplying the deviation Δe or a power value thereof by a predetermined gain, and the integral control steering force obtained by multiplying the integral value of the deviation by the predetermined gain. Further, a predetermined correction is performed to set the target steering torque.

The target steering force setting unit 180 includes an integration stop unit 181, an integration stop time setting unit 182, and a subtraction integral gain calculation unit 183.
The integral stopping means 181 is an integral value obtained by the deviation integrating means 150 when the direction of the target steering torque set by the target steering force setting means 180 and the direction of the driver input torque detected by the steering operation force detecting means 160 do not match. Is to stop the increase.

なお、本実施例では、各定数の設定は、例えば、ａ＝２，ｂ＝１，ｃ＝５，Ｆ＝５００としたが、これに限らず適宜変更することができる。 The integration stop time setting means 182 sets an integration stop time Tc, which is the time until the target steering force setting means 180 starts to decrease the integral control steering force after the integration stop means 181 stops increasing the integral value. Is. The integration stop time setting means 182 calculates the integration stop time based on the magnitude of the external force estimated by the external force estimation means 170 and the magnitude of the deviation Δe calculated by the deviation calculation means 140.
A formula for calculating the integration stop time Tc is shown in Formula 3.

In this embodiment, each constant is set to a = 2, b = 1, c = 5, F = 500, for example. However, the present invention is not limited to this and can be changed as appropriate.

FIG. 3 is a graph showing the correlation between the lateral position and disturbance estimated value and the integration stop time in the steering assist device of the embodiment. In FIG. 3, the horizontal axis represents the normalized deviation and the estimated disturbance value, and the vertical axis represents the estimated disturbance value. Deviation Δe is normalized by dividing by the lane width X _lane. Further, the disturbance estimated value Fx is normalized by dividing by a predetermined normalization reference value F.
As shown in FIG. 3, the integration stop time Tc is set to increase in proportion to the increase in the disturbance estimated value Fx and the deviation Δe.

なお、本実施例では、各定数の設定は、例えば、σ＝０．００１，ζ＝０．０００１，Ｆ＝５００としたが、これに限らず適宜変更することができる。 The subtraction integral gain calculation means 183 calculates a subtraction integral gain that is a decrease rate when the integral control steering force is decreased.
A formula for calculating the subtraction integral gain Gs is shown in Formula 4.

In this embodiment, the constants are set to, for example, σ = 0.001, ζ = 0.0001, and F = 500. However, the present invention is not limited to this and can be changed as appropriate.

FIG. 4 is a graph showing the correlation between the lateral position and disturbance estimated value and the subtraction integral gain in the steering assist device of the embodiment.
As shown in FIG. 4, the subtraction integral gain Gs is a negative value, and is set so that the absolute value becomes smaller (the steering force reduction becomes gentle) as the estimated disturbance value Fx and the deviation Δe increase. .

When the subtraction integral gain Gs is set, the target steering force setting unit 180 reduces the integral control steering force using the following formula 5, and finally sets the integral control steering force to zero.

Δτ = Gs · Δe (5)
Δτ: Decrease in integral control steering force Gs: Subtraction integral gain Δe: Deviation of target vehicle from target course

Next, stop of integral control in the steering assist device of the present embodiment will be described.
FIG. 5 is a flowchart showing the operation when the integral control is stopped. Hereinafter, the steps will be described step by step in FIG.
<Step S01: Acquisition of environmental information / vehicle information>
The target steering force setting means 180 uses the environment recognition means 110, the target travel position setting means 120, the own vehicle traveling path estimation means 130, etc., and the lane shape in front of the own vehicle, the lane width X _lane , the target travel position in the _lane Information on Xc, estimated lateral position Xe of the own vehicle, and the like is acquired.
Thereafter, the process proceeds to step S02.

<Step S02: Calculate the integrated value of the vehicle lateral position>
The deviation integrating unit 150 calculates an integrated value obtained by integrating the deviation Δe sequentially calculated by the deviation calculating unit 140.
Thereafter, the process proceeds to step S03.

<Step S03: Estimate lateral force disturbance value>
As described above, the external force estimating means 170 estimates the disturbance estimated value Fx, which is an external force acting in the lateral direction on the center of gravity of the host vehicle OV due to the road surface cant, based on the vehicle speed, the yaw rate, and the lateral acceleration. .
Thereafter, the process proceeds to step S04.

<Step S04: Control Target and Driver Input Torque Direction Judgment>
The target steering force setting means 180 compares the direction of the target steering torque that is the control target with the direction of the driver input torque detected by the steering operation force detection means 160. If they match, the process proceeds to step S11. If so, the process proceeds to step S05.

<Step S05: Integral value increase stop>
The integration stop unit 181 of the target steering force setting unit 180 stops the increase of the integral value in the deviation integration unit 150. Thus, the integral control steering torque in the target steering force setting means 180 is provisionally fixed to a constant value until the integration stop time Tc is satisfied.
Thereafter, the process proceeds to step S06.

<Step S06: Determination of integration stop time set>
The target steering force setting means 180 determines whether or not the integration stop time Tc has been set by the integration stop time setting means 182. If it has not been set, the process proceeds to step S07, and if it has been set, step S07. Is skipped and the process proceeds to step S08.

<Step S07: Calculation of integration stop time Tc based on lateral position and external force state>
The integral stop time setting means 182 of the target steering force setting means 180 sets the integral stop time Tc using the estimated disturbance value Fx and the deviation Δe using the above-described equation 3.
Thereafter, the process proceeds to step S08.

<Step S08: Increment integration stop timer>
The target steering force setting means 180 increments the timer value T of the integration stop timer.
Thereafter, the process proceeds to step S09.

<Step S09: Stop Time Determination>
The target steering force setting means 180 compares the timer value T of the stop determination timer with the integral stop time Tc set in step S07. If the timer value T is equal to or greater than the integral stop time Tc, the target steering force setting means 180 proceeds to step S09. Returns to step S04 and repeats the subsequent processing.

<Step S10: Calculate subtractive integral gain based on lateral position and external force>
The subtraction integral gain calculation means 183 of the target steering force setting means 180 calculates the subtraction integral gain Gs using the above-described equation 4 based on the estimated disturbance value Fx and the deviation Δe.
Thereafter, the process proceeds to step S13.

<Step S11: Clear integration stop timer T>
The target steering force setting means 180 clears the timer value T of the integration stop timer as zero.
Thereafter, the process proceeds to step S12.

<Step S12: Clear integration stop time Tc>
The target steering force setting means 180 clears the set value Tc of the integration stop time as 0.
Thereafter, the process proceeds to step S13.

<Step S13: Output integral control target value>
The target steering force setting unit 180 sets a target steering torque and transmits it to the steering control unit 190. The steering control means 190 drives the electric actuator 21 via the EPS control unit 20 based on the target steering torque, and applies the steering torque to the steering mechanism 10.
At this time, when the stop time determination is established in step S09 and the subtraction integral gain is set in step S10, the steering torque by the integral control is gradually decreased based on this and finally set to zero.
Thereafter, the series of processing is terminated (returned).

According to the embodiment described above, the following effects can be obtained.
(1) After the deviation integration means 150 stops adding the integral value, the integral control steering force is reduced after a predetermined integration stop time Tc has elapsed, and the integration stop time Tc is extended in accordance with an increase in the estimated disturbance value Fx. By doing so, when the disturbance in the lateral direction is large, it is possible to lengthen the time until the integral value control steering force is lowered, and to prevent the behavior of the vehicle and the disturbance of the course when the steering force is reduced.
(2) After the integration of the deviation value is stopped by the deviation integrating means 150, the integral control steering force is reduced after the predetermined integration stop time Tc has elapsed, and the integration stop time Tc is extended in accordance with the increase in the deviation Δe. Therefore, if the deviation Δe of the host vehicle lateral position Xe with respect to the target travel position Xc is large and the time margin until the lane departure is small, the lane departure is reduced by increasing the time until the integral control steering force is reduced. Can be prevented.
(3) By reducing the subtraction integral gain Gs, which is a reduction rate for reducing the integral control steering force after the integration stop time Tc, according to the increase in the estimated disturbance value Fx, the integral control is performed when the lateral external force is large. It is possible to prevent the behavior and the course of the vehicle from being disturbed by a change in the steering force when the steering force is gradually reduced and the integral control steering force is reduced.
(4) By reducing the rate of decrease in the steering force based on the integrated value after the integration stop time has elapsed in accordance with the increase in the deviation, the deviation of the vehicle's lateral position from the target travel position is large, and When the time margin is small, the steering force based on the integrated value can be gradually reduced, and the vehicle can be prevented from deviating from the lane due to the decrease in the steering force based on the integrated value.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
(1) In the embodiment, the integration stop time is set based on the lateral external force and the deviation, but the present invention is not limited to this, and the integration stop time may be set based only on one of these.
(2) In the embodiment, the reduction rate of the steering force based on the integral value is set based on the lateral external force and the deviation. It may be set.
(3) In the embodiment, the environment recognition means detects the lane shape using a stereo camera. However, the present invention is not limited to this. For example, the map data prepared for the navigation device etc. The lane shape may be detected based on the positioning information. Further, the method for detecting the lateral position of the own vehicle and the yaw angle is not particularly limited.
(4) The configuration of the actuator that applies the steering torque to the steering mechanism is not limited to the column assist type as in the embodiment. For example, the pinion assist type that drives the pinion shaft connected to the steering shaft, the steering shaft A double pinion type that drives a pinion that is independent of the connected pinion, a rack direct-acting type that drives the steering rack itself in a straight direction, or the like may be used.

1 is a diagram showing a system configuration of a vehicle including an embodiment of a steering assist device to which the present invention is applied. It is a figure which shows an example of the planar arrangement | positioning of the own vehicle and lane in the steering assistance apparatus of an Example. It is a graph which shows the correlation with the disturbance estimated value and the own vehicle lateral position (deviation), and the integral stop time in the steering assistance apparatus of an Example. It is a graph which shows the correlation with the disturbance estimated value in the steering assistance apparatus of an Example, the own vehicle lateral position (deviation), and a subtraction integral gain. It is a flowchart which shows the operation | movement at the time of the integral control stop in the steering assistance apparatus of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Steering mechanism 11 Steering wheel 12 Steering shaft 13 Steering gear box 14 Tie rod FW Front wheel H Housing 20 Electric power steering (EPS) control unit 21 Electric actuator 22 Steering angle sensor 23 Torque sensor 30 Steering control unit 31 Hydraulic control unit (HCU) )
32 Vehicle speed sensor 33 Yaw rate sensor 34 Lateral acceleration (lateral G) sensor 40 Engine control unit 50 Transmission (TM) control unit 60 Vehicle integrated unit
DESCRIPTION OF SYMBOLS 100 Steering assistance control unit 110 Environment recognition means 111 Stereo camera 112 Image processing part 120 Target travel position setting means 130 Own vehicle travel path estimation means 140 Deviation calculation means 150 Deviation integration means 160 Steering operation force detection means 170 External force estimation means 180 Target steering Force setting means 181 Integration stop means 182 Integration stop time setting means 183 Subtraction integral gain calculation means 190 Steering control means OV Own vehicle WL White line

Claims (6)

A steering assist device that applies a steering force to a steering mechanism so that the host vehicle travels along a traveling lane,
Environment recognition means for recognizing the environment ahead of the host vehicle including the traveling lane of the host vehicle;
Target travel position setting means for setting a target travel position of the host vehicle in the travel lane of the host vehicle using the environment recognition unit;
Own vehicle lateral position recognition means for recognizing the lateral position of the own vehicle;
Deviation calculating means for calculating a deviation of the lateral position of the host vehicle with respect to the target traveling position;
Deviation integration means for calculating an integrated value of the deviation;
Steering force setting means for setting a target steering force to be applied to the steering mechanism based on the integral value of the deviation;
Steering control means for applying a steering force to the steering mechanism based on the target steering force;
Steering operation force detection means for detecting the steering operation force input by the driver;
Integration stop means for stopping the addition of the integral value by the deviation integrating means when the direction of the target steering force and the direction of the steering operation force are different;
An external force estimating means for estimating a lateral external force received by the host vehicle,
The steering force setting means reduces the steering force based on the integrated value after a predetermined integration stop time after the deviation integrating means stops adding the integral value, and increases the lateral external force. In response, the steering support device extends the integration stop time. The steering assist device according to claim 1, wherein the steering force setting unit further extends the integration stop time according to an increase in the deviation. A steering assist device that applies a steering force to a steering mechanism so that the host vehicle travels along a traveling lane,
Environment recognition means for recognizing the environment ahead of the host vehicle including the traveling lane of the host vehicle;
Target travel position setting means for setting a target travel position of the host vehicle in the travel lane of the host vehicle using the environment recognition unit;
Own vehicle lateral position recognition means for recognizing the lateral position of the own vehicle;
Deviation calculating means for calculating a deviation of the lateral position of the host vehicle with respect to the target traveling position;
Deviation integration means for calculating an integrated value of the deviation;
Steering force setting means for setting a target steering force to be applied to the steering mechanism based on the integral value of the deviation;
Steering control means for applying a steering force to the steering mechanism based on the target steering force;
Steering operation force detection means for detecting the steering operation force input by the driver;
Integration stop means for stopping the addition of the integral value by the deviation integration means when the direction of the target steering force and the direction of the steering operation force are different,
The steering force setting means reduces the steering force based on the integral value after a predetermined integration stop time has elapsed after the deviation integrating means stops adding the integral value, and responds to the increase in the deviation. A steering assist device that extends the integration stop time. A steering assist device that applies a steering force to a steering mechanism so that the host vehicle travels along a traveling lane,
Environment recognition means for recognizing the environment ahead of the host vehicle including the traveling lane of the host vehicle;
Target travel position setting means for setting a target travel position of the host vehicle in the travel lane of the host vehicle using the environment recognition unit;
Own vehicle lateral position recognition means for recognizing the lateral position of the own vehicle;
Deviation calculating means for calculating a deviation of the lateral position of the host vehicle with respect to the target traveling position;
Deviation integration means for calculating an integrated value of the deviation;
Steering force setting means for setting a target steering force to be applied to the steering mechanism based on the integral value of the deviation;
Steering control means for applying a steering force to the steering mechanism based on the target steering force;
Steering operation force detection means for detecting the steering operation force input by the driver;
Integration stop means for stopping the addition of the integral value by the deviation integration means when the direction of the target steering force and the direction of the steering operation force are different;
An external force estimating means for estimating the lateral external force received by the host vehicle,
The steering force setting means reduces the steering force based on the integral value at a predetermined decrease rate after a predetermined integration stop time after the deviation integrating means decreases the addition of the integral value, and A steering assist device that reduces the rate of decrease in steering force based on the integral value in response to an increase in external force. The steering assist device according to claim 4, wherein the steering force setting means further reduces the rate of decrease of the steering force based on the integral value in accordance with an increase in the deviation. A steering assist device that applies a steering force to a steering mechanism so that the host vehicle travels along a traveling lane,
Environment recognition means for recognizing the environment ahead of the host vehicle including the traveling lane of the host vehicle;
Target travel position setting means for setting a target travel position of the host vehicle in the travel lane of the host vehicle using the environment recognition unit;
Own vehicle lateral position recognition means for recognizing the lateral position of the own vehicle;
Deviation calculating means for calculating a deviation of the lateral position of the host vehicle with respect to the target traveling position;
Deviation integration means for calculating an integrated value of the deviation;
Steering force setting means for setting a target steering force to be applied to the steering mechanism based on the integral value of the deviation;
Steering control means for applying a steering force to the steering mechanism based on the target steering force;
Steering operation force detection means for detecting the steering operation force input by the driver;
Integration stopping means for stopping addition of the integral value by the deviation integrating means when the direction of the target steering force and the direction of the steering operation force are different, and
The steering force setting means reduces the steering force based on the integral value at a predetermined decrease rate after a lapse of a predetermined integration stop time after the deviation integration means decreases the addition of the integral value, and the deviation The steering assist device is characterized in that the rate of decrease in the steering force based on the integral value is reduced in accordance with the increase in the steering force.

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