JP2020114710A - Vehicle control system - Google Patents

Abstract

To prevent a vehicle from coming into contact with an obstacle outside a traveling lane as a result of steering intervention by a driver when the steering intervention is performed during automatic steering control.SOLUTION: The vehicle control system performs the following operations: determining whether or not a lateral distance DL from a vehicle M to an obstacle OB is less than a first threshold TH1 (step S14); when this determination result is affirmative, determining whether or not a steering direction of a driver is a direction of the obstacle OB (step S18); when this determination result is affirmative, executing change processing of an assist torque gain Ga (step S20); in the change processing, when an absolute value of a vertical relative distance DRC from the vertical M to the obstacle OB is less than a second threshold value TH2, setting the assist torque gain Ga so that the value lowers more as the absolute value comes nearer to 0.SELECTED DRAWING: Figure 5

Description

The present invention relates to a vehicle control system.

Japanese Patent Laying-Open No. 2016-107750 discloses a system for performing automatic steering control of a vehicle. This conventional system calculates the steering reaction torque according to the running condition of the vehicle and applies it to the steering wheel during the automatic steering control. Examples of the traveling situation include a time required for the vehicle to depart from the traveling lane (margin time) and a distance from the white line to the vehicle (lateral position deviation).

When the traveling situation is represented by a margin time, the steering reaction force torque is set to a larger value as the margin time is shorter. When the traveling situation is represented by a lateral position deviation, the steering reaction force torque is set to a larger value as the lateral position deviation is smaller when the lateral position deviation is less than a set value. Therefore, according to the conventional system, a larger steering reaction torque is applied to the steering wheel as the vehicle is more likely to depart from the traveling lane.

JP, 2016-107750, A

However, the conventional system does not assume a case where the driver performs manual steering (steering intervention) during automatic steering control. The fact that steering intervention occurs may mean that the current steering situation is not a desirable situation for the driver. Therefore, it is not always appropriate to apply the steering reaction torque set according to the automatic steering control to the steering wheel, even though the steering intervention is performed.

On the other hand, if the steering intervention is performed, there is a risk that the vehicle comes into contact with an obstacle existing outside the traveling lane. However, such obstacles are not always present. Therefore, it is necessary to devise to refrain from steering intervention only when the presence of such an obstacle is confirmed.

An object of the present invention is to prevent the vehicle from coming into contact with an obstacle outside the traveling lane as a result of the steering intervention when the driver performs the steering intervention during the automatic steering control. With the goal.

The present invention is a vehicle control system for solving the above-mentioned problems and has the following features.
The vehicle control system includes an electric power steering device, a control device, and a steering information acquisition device.
The control device permits manual steering by a driver and performs automatic steering control for controlling the electric power steering device so that the vehicle travels along a target travel path.
The steering information acquisition device acquires a manual steering torque input from a driver.
The control device further comprises
Based on the manual steering torque, detects the manual steering during the automatic steering control,
When the manual steering is detected, an assist control for assisting the manual steering is executed,
The control device, in the assist control,
Based on the manual steering torque and the variable gain, calculate a steering control amount for assisting the manual steering,
Based on the peripheral information, it is determined whether or not there is an obstacle that can come into contact with the vehicle outside the traveling lane of the vehicle,
If it is determined that the obstacle does not exist, set the variable gain to a default value,
When it is determined that the obstacle is present, it is determined whether the lateral distance from the obstacle to the vehicle is less than a first threshold value,
When it is determined that the lateral distance is equal to or greater than the first threshold value, the variable gain is set to a value equal to or greater than the default value,
When it is determined that the lateral distance is less than the first threshold, it is determined whether the vertical distance from the obstacle to the vehicle is less than a second threshold,
When it is determined that the vertical distance is equal to or greater than the second threshold value, the variable gain is set to a value equal to or greater than the default value,
When it is determined that the vertical distance is less than the second threshold, the variable gain is set to a value less than the default value.

According to the present invention, when the manual steering is performed during the automatic steering control, the steering control amount for assisting the manual steering is calculated based on the lateral and vertical distances from the obstacle to the vehicle. The variable gain used is set. When it is determined that the horizontal distance is less than the first threshold and the vertical distance is less than the second threshold, the variable gain is set to a value less than the default value. When the variable gain is set to a value less than the default value, the steering control amount for assisting the manual steering becomes smaller than when the variable gain is set to the default value. Therefore, it becomes possible for a driver who feels uncomfortable in steering to recognize the risk of contact with an obstacle. Therefore, it is possible to prevent the vehicle from coming into contact with the obstacle as a result of the manual steering.

It is a block diagram showing an example of composition of a vehicle control system concerning an embodiment of the invention. It is a block diagram showing an example of composition of an automatic steering control part. It is a figure explaining a problem when there is steering intervention. It is a figure explaining the assist control which concerns on embodiment. 6 is a flowchart illustrating a flow of a characteristic control process according to the embodiment. It is a figure explaining the 1st example of a change process of assist torque gain. It is a figure explaining the 2nd example of a change process of assist torque gain. It is a figure explaining the 3rd example of a change process of assist torque gain. It is a figure explaining the 4th example of a change process of assist torque gain.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in the following embodiments, when reference is made to the number of each element, the number, the amount, the range, etc., the reference is made unless otherwise specified or in principle clearly specified by the number. The present invention is not limited to the number. Further, the structures, steps, and the like described in the following embodiments are not necessarily essential to the present invention, unless otherwise specified or clearly specified in principle.

1. Configuration of Vehicle Control System 1.1 Overall Configuration of System FIG. 1 is a block diagram showing a configuration example of a vehicle control system according to an embodiment of the present invention. The vehicle control system 100 shown in FIG. 1 is installed in a vehicle. A vehicle in which the vehicle control system 100 is mounted (hereinafter, also referred to as “vehicle M”) is, for example, a vehicle powered by an internal combustion engine such as a diesel engine or a gasoline engine, an electric vehicle powered by an electric motor, an internal combustion engine. It is a hybrid vehicle equipped with an engine and an electric motor. The electric motor is driven by a battery such as a secondary battery, a hydrogen fuel cell, a metal fuel cell, and an alcohol fuel cell.

In FIG. 1, among the various functions of the vehicle control system 100, the functions particularly related to the steering function are illustrated. As shown in FIG. 1, the vehicle control system 100 includes an EPS (Electronic Power Steering) device 10. The EPS device 10 includes a steering wheel 12, left and right steered wheels 14, 14, a steering mechanism 16, an electric motor 18, and a motor driver 20.

The steering mechanism 16 includes a steering column shaft, a gear mechanism, and a link mechanism. The rotation operation of the steering wheel 12 is input to the steering column shaft. The gear mechanism increases the steering force generated by the rotational operation input to the steering shaft. The link mechanism transmits the steering force transmitted from the gear mechanism to the left and right steered wheels 14, 14.

The electric motor 18 receives a command current from the motor driver 20 to generate torque, and applies the torque to the steering mechanism 16. In FIG. 1, the electric motor 18 transmits the generated torque to the rack shaft of the gear mechanism. That is, the EPS device 10 is configured as a rack assist type EPS device. However, the EPS device 10 may be configured as a column assist type EPS device that transmits the generated torque to the steering column shaft. The EPS device 10 may be configured as a pinion assist type EPS device that transmits the generated torque to the pinion shaft of the gear mechanism.

The vehicle control system 100 also includes a plurality of sensors and a control device 30. The plurality of sensors measure physical quantities related to steering control. The torque sensor 22 is included in the plurality of sensors. The torque sensor 22 measures the amount of twist of the torsion bar in the steering column shaft and converts it into torque. The torque sensor 22 measures a steering angle in addition to the steering torque. The torque sensor 22 transmits steering torque and steering angle information to the control device 30.

The plurality of sensors further includes a GPS (Global Positioning System) device and internal and external sensors. The GPS device acquires the position information of the vehicle M and transmits it to the control device 30. The internal sensor acquires information regarding the traveling state of the vehicle M (that is, internal sensor information) and transmits the information to the control device 30. The internal sensor includes a vehicle speed sensor, an acceleration sensor and a yaw rate sensor. The external sensor acquires the peripheral information of the vehicle M (that is, external sensor information) and transmits it to the control device 30. External sensors include cameras, radars and lidars.

The control device 30 is connected to a plurality of sensors directly or via a communication network built inside the vehicle M. The control device 30 is an ECU (Electronic Control Unit) having at least one memory and at least one processor. Various programs and maps used for steering control are stored in the memory. Various functions related to steering control are realized by the processor reading out and executing the program from the memory. The control device 30 may be composed of a plurality of ECUs.

The control device 30 gives a controlled variable to the motor driver 20. This control amount is a control amount of the EPS device 10 (hereinafter, also referred to as “EPS control amount”). The EPS control amount is represented by current or torque. The control device 30 controls the steering torque applied from the electric motor 18 to the steering mechanism 16 by adjusting the EPS control amount given to the motor driver 20.

1.2 Configuration of Control Device As illustrated by a block in FIG. 1, the control device 30 includes an information acquisition unit 32, an assist control unit 34, and an automatic steering control unit 36. The assist control unit 34 includes a basic assist control amount calculation unit 34a and an assist torque gain setting unit 34b.

The information acquisition unit 32 acquires signals from various sensors. The information acquisition unit 32 acquires various kinds of information by using these signals or by processing these signals. The information acquired by the information acquisition unit 32 includes steering torque information, steering angle information, camera information, internal and external sensor information, and GPS information (that is, position information of the vehicle M). The information acquired by the information acquisition unit 32 also includes map information. The map information is acquired from the map database. The map database is stored in a predetermined storage device (eg, hard disk, flash memory).

The assist control unit 34 executes assist control. The assist control is a steering control that operates the EPS device 10 so as to assist the driver's operation of the steering wheel 12 (that is, manual steering). As a function for executing the assist control, the assist control unit 34 includes a basic assist control amount calculation unit 34a and an assist torque gain setting unit 34b.

The basic assist control amount calculator 34a calculates the basic assist control amount. The basic assist control amount is a basic control amount for causing the electric motor 18 to generate assist steering torque for assisting the manual steering by the driver. The calculation of the basic assist control amount is performed, for example, by referring to a control map that defines the relationship between the manual steering torque TD and the basic assist control amount. The manual steering torque TD is the steering torque of the driver detected by the torque sensor 22 and is included in the steering torque information.

The assist torque gain setting unit 34b sets an assist torque gain Ga (hereinafter, also simply referred to as "gain Ga"). The gain Ga is a gain by which the basic assist control amount is multiplied. The gain Ga is variably set based on whether or not the driver holds the steering wheel 12, whether or not the obstacle OB is detected. For example, when the driver does not hold the steering wheel 12, the gain Ga is set to 0. When the driver is holding the steering wheel 12, the gain Ga is set to 1 (default value). The gain Ga is set to 1 also when the driver holds the steering wheel 12 and the obstacle OB is not detected. Details of such a process of changing the gain Ga will be described later. The basic assist control amount multiplied by the gain Ga is output from the assist control unit 34 as a final steering control amount.

The automatic steering control unit 36 executes automatic steering control. The automatic steering control is a steering control that operates the EPS device 10 so that the vehicle M travels along the target traveling track. The automatic steering control unit 36 calculates an automatic steering control amount. The automatic steering control amount is a control amount for causing the electric motor 18 to generate an automatic steering torque for the vehicle M to travel along the target traveling path. The automatic steering control amount calculated by the automatic steering control unit 36 is added to the multiplication value of the basic assist control amount output from the assist control unit 34 and the gain Ga. The control amount obtained by the summation is given to the motor driver 20 as an EPS control amount.

1.3 Configuration of Automatic Steering Control Unit FIG. 2 is a block diagram showing a configuration example of the automatic steering control unit 36. 2, the automatic steering control unit 36 includes a lateral deviation gain multiplication unit 36a, a yaw angle deviation gain multiplication unit 36b, an FF (Feedforward) control unit 36c, and an FB (Feedback) control. The unit 36d and the system gain multiplication unit 36e are provided.

When the lateral deviation gain multiplication unit 36a receives the lateral deviation of the vehicle M with respect to the target traveling trajectory from the information acquisition unit 32, the lateral deviation gain multiplication unit 36a multiplies the lateral deviation by a predetermined gain to convert the lateral deviation into a steering angle. The lateral deviation is the shortest distance from the vehicle M to the target traveling track. This shortest distance is calculated using camera information, GPS information, map information, and the like.

When the yaw angle deviation gain multiplication unit 36b receives the yaw angle deviation of the vehicle M with respect to the target traveling trajectory from the information acquisition unit 32, the yaw angle deviation gain multiplication unit 36b multiplies the yaw angle deviation by a predetermined gain to convert the yaw angle deviation into a steering angle. The yaw deviation is an angle (declination angle) formed by a tangent line passing through a point on the target traveling path that is the shortest from the vehicle M and the traveling direction of the vehicle M. This argument is calculated using camera information, GPS information, yaw rate, and the like.

The sum of the steering angle converted from the lateral deviation and the steering angle converted from the yaw angle deviation is set as the target steering angle. When the FF control unit 36c receives the target steering angle, the FF control unit 36c multiplies the target steering angle by a predetermined gain to convert the target steering angle into a control amount. The control amount output from the FF control unit 36c is a feedforward term (hereinafter, also referred to as “FF control amount”) of the automatic steering control amount given to the motor driver 20 from the automatic steering control unit 36.

Upon receiving the difference between the target steering angle and the actual steering angle, the FB control unit 36d performs PID control on this difference. The actual steering angle is included in the steering angle information. The control amount obtained by the PID control is a feedback term (hereinafter, also referred to as “FB control amount”) of the automatic steering control amount given from the automatic steering control unit 36 to the motor driver 20.

The FF control amount output from the FF control unit 36c and the FB control amount output from the FB control unit 36d are added together. This summed control amount is the automatic steering control amount. Upon receiving this automatic steering control amount, the system gain multiplication unit 36e multiplies it by the system gain Gs (hereinafter, also simply referred to as "gain Gs"). The gain Gs is variably set based on the presence or absence of driver's steering intervention. The gain Gs is set to 1 when there is no steering intervention. If there is steering intervention, the gain Gs is set to zero. The automatic steering control amount obtained by multiplying the gain Gs is output from the automatic steering control unit 36 as the final automatic steering control amount.

2. Characteristic Control of Embodiment 2.1 Problems during Steering Intervention According to the function of the control device 30, assist control and automatic steering control are cooperatively performed. That is, when the driver holds the steering wheel 12, assist control is performed and automatic steering control is not performed. On the contrary, when the driver does not hold the steering wheel 12, the automatic steering control is performed and the assist control is not performed. When there is steering intervention by the driver during the automatic steering control, the automatic steering control ends and the assist control starts. When this steering intervention ends, the assist control ends and the automatic steering control starts.

However, the following problems occur when steering intervention is performed. FIG. 3 is a diagram illustrating a problem when steering intervention is performed. In the example of FIG. 3, the vehicle M are traveling on the lane which is defined by the left white line LWL and the right white line RWL at a speed V _M. Another lane exists to the left of this driving lane. The steering wheel 12 is operated according to automatic steering control. The target travel track (broken line) is set along the center of the travel lane.

In the example of FIG. 3, steering intervention that deviates from the target travel path is performed. At time t0, the driver starts steering the steering wheel 12. Then, the gain Ga is changed from 0 to 1, and the assist control is started accordingly. The automatic steering control ends with the start of the assist control. When the driver turns the steering wheel 12 to the left at time t1, the manual steering torque TD increases and the steering angle increases with a slight delay. The signs of the manual steering torque TD and the steering angle are represented by “positive” in the left direction.

In the example of FIG. 3, the obstacle OB exists outside the traveling lane. The obstacle OB includes vehicles, motorcycles and bicycles on the lane next to the driving lane. The obstacle OB also includes a pedestrian on the sidewalk next to the driving lane. The obstacle OB also includes a roadside object installed adjacent to the traveling lane. In the example of FIG. 3, it is assumed that the obstacle OB is moving at the relative speed VR in the same direction as the traveling direction of the vehicle M. Relative velocity VR is a speed obtained by subtracting the velocity _{V M} of the vehicle M from the velocity _{V OB} obstacle _{OB (VR = V OB -V M} ).

In the example of FIG. 3, it is assumed that the driver who started the manual steering before recognizing the obstacle OB recognizes the obstacle OB immediately after the start of the manual steering. When the driver starts the manual steering, the assist steering torque corresponding to the magnitude of the manual steering torque TD is generated with the start of the assist control. Upon recognizing the sudden approach to the obstacle OB immediately after the time t1, the driver performs the turning-back steering for avoiding the abnormal approach to the obstacle OB after the time t2. Further, the driver performs steering for returning to the center of the traveling lane after time t3.

2.2 Change in Assist Torque Gain As described above, when steering intervention is performed, there is a risk that the vehicle M contacts the obstacle OB. Therefore, in the present embodiment, when the steering intervention is performed during the automatic steering control, the gain Ga is changed based on the information of the obstacle OB. This "obstacle OB information" includes the lateral distance DL from the vehicle M to the obstacle OB and the vertical relative distance DRC from the vehicle M to the obstacle OB. The sign of the relative distance DRC represents “positive” when the obstacle OB is located in front of the vehicle M. "Information obstacle OB" further relative velocity VR, may include the speed _{V OB} speed _{V M} and the obstacle OB of the vehicle M.

FIG. 4 is a diagram explaining the assist control according to the present embodiment. In the example of FIG. 4, the steering angle after the time t0, the traveling path of the vehicle M, and the path of the obstacle OB are the same as those in the example of FIG.

In the example of FIG. 3, the gain Ga was changed from 0 to 1 at the time t0, and was maintained at 1 after that. On the other hand, in the example of FIG. 4, the gain Ga is changed from 1 to 0 at the time t1, and is maintained at 0 until the time t4. Further, the gain Ga is changed from 0 to 1 at time t4 and is maintained at 1 until time t5. Further, the gain Ga is changed from 1 to 0 at time t5 and is maintained at 0 until time t3. Further, the gain Ga is changed from 0 to 1 at the time t3, and is maintained at 1 thereafter.

As shown in FIG. 4, at times t1 to t4, the manual steering torque TD (solid line) becomes larger than the manual steering torque TD (broken line). The reason is that the gain Ga is changed to a value smaller than 1 at times t1 to t4 (solid line). When the gain Ga is changed to a value smaller than 1 (solid line), the steering control amount output from the assist control unit 34 is smaller than when the gain Ga is maintained at 1 (broken line). That is, at times t1 to t4, the driver is required to input more steering force than in the normal time.

Similar to the times t1 to t4, the manual steering torque TD (solid line) becomes larger than the manual steering torque TD (broken line) also at the times t5 to t3. Therefore, even at times t5 to t3, the driver is required to input more steering force than in the normal state. Therefore, the driver feels uncomfortable in steering during time t1 to t4 and during time t5 to t3. This makes it easier for the driver who feels uncomfortable in steering to recognize that the risk that the vehicle M contacts the obstacle OB is increased.

During times t0 to t1 and during times t4 to t5, the manual steering torque TD (solid line) matches the manual steering torque TD (broken line). The reason for this is that the risk of the vehicle M coming into contact with the obstacle OB has not increased so much between times t0 and t1. This is also because steering is performed in the return direction between times t4 and t5, and the risk that the vehicle M contacts the obstacle OB is reduced. The steering in the turning-back direction is determined based on the inversion of the sign of the steering angle.

2.3 Specific Process of Characteristic Control FIG. 5 is a flowchart illustrating a flow of a process of the characteristic control according to the present embodiment. The processing routine shown in FIG. 5 is repeatedly executed at a predetermined control cycle during the automatic steering control.

In the processing routine shown in FIG. 5, first, it is determined whether steering intervention has been performed (step S10). The determination in step S10 is made based on the manual steering torque TD. When the manual steering torque TD is less than the specified value, it is determined that there is no steering intervention. This specified value is set to, for example, a value with which it is possible to determine the start of holding the steering wheel 12 by the driver.

When the determination result of step S10 is affirmative, the information of the obstacle OB is acquired (step S12). As described above, the information on the obstacle OB includes the distance DL, the relative distance DRC, and the relative speed VR. The information on the obstacle OB is acquired through calculation using camera information, internal and external sensor information, GPS information, map information and the like.

Following step S12, it is determined whether the distance DL is less than the first threshold TH1 (step S14). The first threshold TH1 is, for example, the shortest distance from the target travel trajectory during automatic steering control to the white line (that is, the left white line LWL or the right white line RWL) that divides the travel lane on the side where the obstacle OB is detected. Is. This shortest distance is calculated using camera information, GPS information, map information, and the like.

If the determination result of step S14 is negative, that is, if it is determined that the distance DL is equal to or greater than the first threshold value TH1, the gain Ga is set to 1 (step S16). The reason is that it can be estimated that the risk of the vehicle M contacting the obstacle OB is not so high when the distance DL is equal to or greater than the first threshold value TH1.

When the determination result of step S14 is affirmative, it is determined whether the steering direction of the driver is the direction of the obstacle OB (step S18). The determination process of step S18 is performed based on the sign of the steering angle. For example, when the obstacle OB is located on the left side of the vehicle M, when the sign of the steering angle is positive, it is determined that the steering direction matches the direction of the obstacle OB. When the sign of the steering angle is negative, it is determined that the steering is in the turning direction.

If the determination result of step S18 is negative, that is, if it is determined that the driver's steering direction is not the direction of the obstacle OB, the gain Ga is set to 1 (step S16). The reason is that it can be estimated that the risk of the vehicle M coming into contact with the obstacle OB is reduced if steering is performed in the return direction.

If the determination result of step S18 is affirmative, the process of changing the gain Ga is performed (step S20). FIG. 6 is a diagram illustrating a first example of a process of changing the gain Ga. In the first processing example, the first gain Ga (hereinafter, also referred to as “gain Ga1”) is obtained by referring to the gain map 40 using the relative distance DRC. The gain map 40 is a map that defines the relationship between the relative distance DRC and the gain Ga1.

The gain Ga1 shown in the gain map 40 is set to take a value from 0 to 1. When the absolute value of the relative distance DRC is less than the second threshold value TH2, the risk that the vehicle M contacts the obstacle OB increases. Therefore, in this case, the gain Ga1 is set so that the value decreases as the absolute value approaches 0. On the contrary, when the absolute value is the second threshold value TH2 or more, this risk is reduced. Therefore, in this case, the gain Ga1 is set to 1 (default value).

In the first processing example, in addition to the gain Ga1, the second gain Ga (hereinafter, also referred to as “gain Ga2”) and the third gain Ga (hereinafter, also referred to as “gain Ga3”) are obtained. The gain Ga2 is obtained by referring to the gain map 42 using the velocity V _OB . In the gain map 42, the gain Ga2 is set to the value A when the speed V _OB is larger than 0 (that is, when the obstacle OB is moving). On the contrary, when the speed V _OB is 0, the gain Ga2 is set to the value B. Gain Ga3 is determined by reference to the gain map 44 using the velocity _{V M.} In gain map 44, if the speed V _M is within a predetermined range increases with velocity V _M, the speed V _M is the gain Ga3 such that the maximum value equal to or larger than the predetermined value is set.

In the first processing example, the multiplication value of the gain Ga1, the gain Ga2, and the gain Ga3 is obtained as the final value of the gain Ga. This final gain Ga is multiplied by the basic assist control amount.

FIG. 7 is a diagram illustrating a second example of the process of changing the gain Ga. In this second processing example, a gain map 50 is used instead of the gain map 40 shown in FIG. The gain map 50 is a map that defines the relationship between the relative distance DRC and the relative velocity VR and the gain Ga1. FIG. 6 illustrates a case where the relative speed VR is 0 (solid line), a case where the relative speed VR is 0 or more (dashed line), and a case where the relative speed VR is less than 0 (broken line).

The gain Ga1 shown in the gain map 50 is set so as to take a value from 0 to 1 with reference to the case where the relative speed VR is 0. When the relative speed VR is 0, the gain Ga1 is set so that the absolute value of the relative distance DRC decreases as the absolute value approaches 0 from the third threshold value TH3. If the relative speed VR is less than 0 (i.e., when the velocity _{V M} is faster than the speed _{V OB),} increase the risk that the vehicle M comes into contact with the obstacle OB. Therefore, in this case, the gain Ga1 is set so that the relative distance DRC decreases from the fourth threshold value TH4 (>TH3). On the contrary, when the relative velocity VR is 0 or more, this risk is not so high. Therefore, in this case, the gain Ga1 is set so that the relative distance DRC decreases from the fifth threshold value TH5 (<TH3).

FIG. 8 is a diagram illustrating a third example of the process of changing the gain Ga. In this third processing example, a gain map 60 is used instead of the gain map 40 shown in FIG. The gain map 60 is a map that defines the relationship between the relative distance DRC and the relative velocity VR and the gain Ga1.

The value of the gain Ga1 shown in the gain map 60 is basically the same as the value of the gain Ga1 shown in the gain map 50. However, the gain map 60, the relative speed VR is less than 0, and, when the relative distance DRC is less than 0 (i.e., the speed _{V M} is faster than the speed _{V OB,} and, behind the obstacle OB is the vehicle M (When it is located at), the gain Ga1 is set to 1. The reason is that when the vehicle M moving at a relatively high speed overtakes the obstacle OB, the risk of the vehicle M contacting the obstacle OB is reduced.

FIG. 9 is a diagram illustrating a fourth example of the process of changing the gain Ga. In this fourth processing example, a gain map 70 is used instead of the gain map 40 shown in FIG. The gain map 60 is a map that defines the relationship between the relative distance DRC and the relative velocity VR and the gain Ga1.

The value of the gain Ga1 shown in the gain map 70 is basically the same as the value of the gain Ga1 shown in the gain map 50. However, in the gain map 70, when the relative distance DRC is equal to or greater than the threshold value of the relative speed VR (that is, the third threshold value TH3, the fourth threshold value TH4, or the fifth threshold value TH5), the gain Ga1 is set to a value of 1 or more. .. This is because the risk of the vehicle M contacting the obstacle OB is low if the distance between the obstacles OB is large. Therefore, when the driver performs steering intervention intended to change lanes, the lane change can be completed before the vehicle M overtakes the obstacle OB.

Returning to FIG. 5, the flow of the characteristic control processing will be described. Subsequent to step S20, the assist steering torque is determined (step S22). The assist steering torque is determined by multiplying the gain Ga set or the like in step S18 or S20 by the separately calculated basic assist control amount.

2.4 Effect of Characteristic Control According to the characteristic control described above, when the steering intervention is performed during the automatic steering control, the gain Ga is changed based on the distance DL and the relative distance DRC. Specifically, when the distance DL is equal to or greater than the first threshold, the gain Ga is set to 1. When the distance DL is less than the first threshold value, the gain Ga is set to a value less than 1. When the gain Ga is set to a value less than 1, the assist steering torque for assisting the manual steering becomes smaller than when the gain Ga is set to 1. Therefore, the driver who feels uncomfortable in steering can recognize the increased risk of contact with the obstacle OB.

3. Correspondence between Embodiment and Present Invention In the above embodiment, the torque sensor 22 corresponds to the “steering information acquisition device” of the present invention. The external sensor corresponds to the “peripheral information acquisition device” of the present invention. The gain Ga1 corresponds to the "variable gain" of the present invention.

4. Other Embodiments In the above embodiment, it is determined in step S18 of FIG. 5 whether or not the steering direction of the driver is the direction of the obstacle OB. However, the determination process of step S18 may be omitted. That is, if the determination result of step S14 is affirmative, the process may proceed to step S20 and the gain Ga changing process may be performed.

In the above embodiment, three types of gains Ga1 to Ga3 are calculated in the example of the process of changing the gain Ga, and the multiplication value of these is set as the final gain Ga. However, if at least the calculation of the gain Ga1 is completed, the calculation of the gains Ga2 and Ga3 may be omitted and the gain Ga1 may be set as the final gain Ga.

10 EPS device 22 Torque sensor 30 Control device 32 Information acquisition unit 34 Assist control unit 34a Basic assist control amount calculation unit 34b Assist torque gain setting unit 36 Automatic steering control unit 40, 42, 44, 50, 60, 70 Gain map 100 Vehicle Control system Ga Assist torque gain M Vehicle OB Obstacle LWL Left white line RWL Right white line

Claims (1)

An electric power steering device,
A control device that allows automatic steering by a driver, and that performs automatic steering control to control the electric power steering device so that the vehicle travels along a target travel path;
A steering information acquisition device that acquires a manual steering torque input from a driver,
A peripheral information acquisition device that acquires peripheral information of the vehicle,
A vehicle control system comprising:
The control device further comprises
Based on the manual steering torque, detects the manual steering during the automatic steering control,
When the manual steering is detected, an assist control for assisting the manual steering is executed,
The control device, in the assist control,
Based on the manual steering torque and the variable gain, calculate a steering control amount for assisting the manual steering,
Based on the peripheral information, it is determined whether or not there is an obstacle that can come into contact with the vehicle outside the traveling lane of the vehicle,
If it is determined that the obstacle does not exist, set the variable gain to a default value,
When it is determined that the obstacle is present, it is determined whether the lateral distance from the obstacle to the vehicle is less than a first threshold value,
When it is determined that the lateral distance is equal to or greater than the first threshold value, the variable gain is set to a value equal to or greater than the default value,
When it is determined that the lateral distance is less than the first threshold, it is determined whether the vertical distance from the obstacle to the vehicle is less than a second threshold,
When it is determined that the vertical distance is equal to or greater than the second threshold value, the variable gain is set to a value equal to or greater than the default value,
The vehicle control system, wherein when the vertical distance is determined to be less than the second threshold, the variable gain is set to a value less than the default value.

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