JP2012006534A - Device and method for vehicle travel support - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for vehicle travel support, capable of reducing a sense of incongruity imparted to a driver, in steering support when traveling in a narrow passage.SOLUTION: Travel support torque being torque in the inverse direction of steering torque is calculated based on an approach degree to an obstacle of one's own vehicle V in at least one of both sides in the vehicle width direction of the one's own vehicle V and the steering torque input by the driver to a steering wheel 16 possessed by the one's own vehicle V, and the calculated travel support torque is output to the steering wheel 16. When a deviation between the travel support torque and the steering torque is a preset torque deviation threshold value or more, output of the travel support torque is stopped.

Description

  The present invention relates to a vehicle travel support apparatus and a travel support method that appropriately control steering operation support while reflecting the driver's intention, and is applied to, for example, steering operation support during narrow road travel.

2. Description of the Related Art Conventionally, there is a travel support device that provides a travel support torque for assisting a steering operation to a driver via a steering wheel (steering wheel) for the purpose of positioning the host vehicle in a travel lane. As such a driving assistance apparatus, there exists a thing described in patent document 1, for example.
The travel support apparatus described in Patent Document 1 detects the steering angle of the steering wheel by a steering angle sensor. When it is detected that the steering angle of the steering wheel is steered by a predetermined allowable angle or more in the direction opposite to the white line forming the outer frame of the travel lane, the control for adding the travel assist torque to the steering wheel is gradually performed. It has been released. Thereby, the delay of the judgment performed by the driver who has received the driving assistance torque and the uncomfortable feeling given to the driver are reduced.

JP 2002-154451 A

  However, in the travel support device described in Patent Document 1, it is detected only by the steering angle sensor that the steering wheel has been steered by a predetermined allowable angle or more. For this reason, the control for adding the travel assist torque to the steering wheel is released in a state where the direction of the host vehicle is directed toward the center of the travel path (road). Therefore, for example, on a road where the distance between the white line or the like and the center side of the road is short, such as a narrow road having a narrow width with respect to the host vehicle, it is difficult to avoid risk to the center of the road. There is a possibility that a problem that the uncomfortable feeling given to the person increases will occur.

  The present invention has been made paying attention to the problems as described above, and in the steering assistance during traveling when the vehicle is directed from the outside of the traveling road to the center of the traveling road, the driver feels uncomfortable to the center of the traveling road. It is an object of the present invention to provide a vehicle travel support device and a travel support method that can be reduced.

  In order to solve the above-described problem, the present invention detects the degree of proximity of an own vehicle to an obstacle and the driver's steering torque on at least one of both sides in the vehicle width direction of the own vehicle. Then, based on the detected proximity degree and the steering torque, a travel support torque that is a torque in a direction opposite to the steering torque is calculated, and the calculated travel support torque is output to the steering wheel. Further, when the deviation between the driving support torque and the steering torque is equal to or greater than a preset torque deviation threshold, the output of the driving support torque is stopped.

  According to the present invention, when the host vehicle is traveling on a narrow road, the control for outputting the driving assistance torque to avoid the obstacle is stopped based on the driver's intention estimated using the driver's steering torque. It becomes possible to make it. For this reason, in the steering assistance at the time of driving | running | working on a narrow road, it becomes possible to reduce the discomfort given to a driver | operator.

It is a figure which shows schematic structure of the own vehicle provided with the driving assistance apparatus of this invention. It is a figure which shows the specific structure of a steering controller. It is a figure which shows the detailed structure of a motor command value calculation part. It is a figure which shows the behavior of the own vehicle provided with the driving assistance apparatus of this invention. It is a flowchart which shows the general process which the driving assistance device of this invention performs. It is a flowchart which shows the process which judges the necessity of the control which outputs a driving assistance torque to a steering wheel among the processes which a control start / end determination part performs. It is a flowchart which shows the detailed process which determines whether a driver | operator has the intention to stop the control which outputs driving assistance torque. It is a flowchart which shows the process which a control start / end determination part and a motor command value calculation part perform.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
Hereinafter, a first embodiment of the present invention (hereinafter referred to as the present embodiment) will be described with reference to the drawings.

(Constitution)
FIG. 1 is a diagram showing a schematic configuration of a host vehicle V provided with a travel support device 1 of the present embodiment.
As shown in FIG. 1, the driving support device 1 includes a left obstacle detection unit 2, a right obstacle detection unit 4, a vehicle speed detection unit 6, a steering torque detection unit 8, a steering angle detection unit 10, A steering controller 12 and torque applying means 14 are provided.

  The left obstacle detection means 2 is formed using, for example, a sonar capable of transmitting and receiving sound waves, and is arranged on the left side in the vehicle width direction on the front side of the host vehicle V. Further, the left obstacle detection means 2 transmits a sound wave toward the left side in the vehicle width direction of the host vehicle V. When the left obstacle detection means 2 receives the sound wave transmitted and reflected by the obstacle or the like, the left obstacle detection means 2 outputs an information signal including the transmission time and reception time of the sound wave to the steering controller 12.

  The right obstacle detection means 4 is formed using, for example, a sonar capable of transmitting and receiving sound waves, and is disposed on the right side in the vehicle width direction on the front side of the host vehicle V, as with the left obstacle detection means 2. Further, the right obstacle detection means 4 transmits sound waves toward the right side in the vehicle width direction of the host vehicle V. When the right obstacle detection means 4 receives the sound wave transmitted and reflected by the obstacle or the like, the right obstacle detection means 4 outputs an information signal including the transmission time and reception time of the sound wave to the steering controller 12.

  Therefore, the left obstacle detection means 2 and the right obstacle detection means 4 are formed so as to be able to detect the degree of proximity of the host vehicle V to the obstacle (wall W or the like) on both sides of the host vehicle V in the vehicle width direction. .

The vehicle speed detection unit 6 detects the vehicle speed of the host vehicle V and outputs an information signal including the detected vehicle speed to the steering controller 12.
The steering torque detecting means 8 is attached to, for example, a steering column 18 that rotatably supports the steering wheel 16. Further, the steering torque detection means 8 detects the steering torque input by the driver to the steering wheel 16 and outputs an information signal including the detected steering torque to the steering controller 12.

  The steering angle detection means 10 is attached to the steering column 18, for example, similarly to the steering torque detection means 8. Further, the steering angle detection means 10 detects the steering angle of the steering wheel 16 by the driver, and outputs an information signal including the detected steering angle to the steering controller 12.

  The steering controller 12 receives input of information signals output from the left obstacle detection means 2, right obstacle detection means 4, vehicle speed detection means 6, steering angle detection means 10, and steering torque detection means 8. In addition, the input / output of the information signal between each detection means (2, 4, 6, 8, 10) and the steering controller 12 is performed via vehicle-mounted networks, such as CAN (Controller Area Network), for example.

  Further, the steering controller 12 outputs a control signal including torque to be output to the steering wheel 16 based on various information signals input from the detection means (2, 4, 6, 8, 10). Output to. A specific configuration of the steering controller 12 will be described later. The torque output to the steering wheel 16 is a torque that the electric power steering outputs to the steering wheel 16 as a normal operation in addition to the driving support torque for assisting the driver with the steering operation. There is torque.

Here, the driving support torque is a torque in the opposite direction to the steering torque detected by the steering torque detecting means 8.
In the present embodiment, as an example, when the vehicle speed of the host vehicle V detected by the vehicle speed detection means 6 is 30 [km / h] or less, the steering controller 12 outputs a travel assist torque to the steering wheel 16. It is assumed that the control is performed. This is because, in a traveling state where the vehicle speed is high, it is difficult to assist the steering operation by the travel assist torque on a narrow road (for example, a road having a width of 4 m or less) narrow with respect to the host vehicle V.

  The torque applying means 14 is formed using, for example, a known electric power steering, and has an electric motor (not shown) that can output torque to the steering wheel 16. In the present embodiment, an electronically controlled power steering, which is a general configuration as a booster for assisting the driver's steering operation, is used as the electric power steering that forms the torque applying means 14. However, the configuration for forming the torque applying means 14 is not limited to electric power steering, and may be hydraulic control power steering, for example.

  Further, the torque applying means 14 drives the electric motor based on the control signal input from the steering controller 12 and outputs torque (running support torque, steering support torque) to the steering wheel 16.

(Specific configuration of the steering controller 12)
Hereinafter, a specific configuration of the steering controller 12 will be described.
FIG. 2 is a diagram illustrating a specific configuration of the steering controller 12.
As shown in FIG. 2, the steering controller 12 includes a control start / end determination unit 20, a steering assist current calculation unit 22, and a motor command value calculation unit 24.

  The control start / end determination unit 20 is based on information signals output from the left obstacle detection means 2, the right obstacle detection means 4, the vehicle speed detection means 6, the steering angle detection means 10, and the steering torque detection means 8, and the steering wheel. The necessity of control for outputting the driving support torque to 16 is determined. In addition to this, the control start / end determination unit 20 sets a control mode in the control for outputting the travel assist torque to the steering wheel 16. A description regarding the control mode will be described later.

Here, the determination of the necessity of control for outputting the driving support torque to the steering wheel 16 is the determination of (X) or (Y) described below.
(X): Judgment whether or not to start control for outputting the travel support torque to the steering wheel 16 in a state where the travel support torque is not output to the steering wheel 16. Hereinafter, the determination of (X) may be described as “determination of whether to start control”.
(Y): Judgment whether or not to stop the control to output the travel support torque to the steering wheel 16 in the state where the travel support torque is output to the steering wheel 16. Hereinafter, the determination of (Y) may be described as “determination of whether to stop control”.

Further, the control start / end determination unit 20 that has determined the necessity of the control for outputting the travel assist torque to the steering wheel 16 outputs an information signal including the determination result to the motor command value calculation unit 24. In addition to this, the control start / end determination unit 20 that has set the control mode outputs an information signal including the set control mode to the motor command value calculation unit 24.
The process when the control start / end determination unit 20 determines the necessity of control for outputting the travel assist torque to the steering wheel 16 and the process when the control mode is set will be described later.

  The steering assist current calculator 22 calculates a steering assist torque to be output to the steering wheel 16 based on the information signal output by the vehicle speed detector 6 and the steering torque detector 8, and a current corresponding to the calculated steering assist torque. The steering assist current is calculated. Further, the steering support current calculation unit 22 that has calculated the steering support current outputs an information signal including the calculated steering support current to the motor command value calculation unit 24.

  The motor command value calculation unit 24 calculates the torque output to the steering wheel 16. This calculation is performed on the information signals output from the left obstacle detection means 2, the right obstacle detection means 4, the steering angle detection means 10, the steering torque detection means 8, the control start / end determination section 20, and the steering assist current calculation section 22. Based on.

  The motor command value calculation unit 24 that has calculated the torque to be output to the steering wheel 16 calculates a motor command current value that is a current corresponding to the calculated torque, and outputs a control signal including the calculated motor command current value. Output to the torque applying means 14.

(Detailed configuration of motor command value calculation unit 24)
Hereinafter, a detailed configuration of the motor command value calculation unit 24 will be described.
FIG. 3 is a diagram showing a detailed configuration of the motor command value calculation unit 24.
As shown in FIG. 3, the motor command value calculation unit 24 includes a feedback error calculation unit 26, a system intervention control command value calculation unit 28, a steering assist actual current calculation unit 30, an addition processing unit 32, a rate limiter. 34 is provided.

  The feedback error calculation unit 26 calculates a feedback error based on information signals input from the left obstacle detection unit 2, the right obstacle detection unit 4, and the control start / end determination unit 20. Then, the feedback error calculation unit 26 that calculated the feedback error outputs an information signal including the calculated feedback error to the system intervention control command value calculation unit 28.

Here, the “feedback error” is the difference between the transmission time and the reception time of the sound wave in the left obstacle detection means 2 and the right obstacle detection means 4, respectively. The value to be reflected.
The feedback error calculation performed by the feedback error calculation unit 26 is based on the determination result that the control signal for outputting the driving support torque to the steering wheel 16 is necessary based on the information signal input from the control start / end determination unit 20. Do it if included.

  The system intervention control command value calculation unit 28 determines the driving support torque to be output to the torque applying unit 14 based on the information signals input from the left obstacle detection unit 2, the right obstacle detection unit 4 and the feedback error calculation unit 26. The control command value that is the command value is calculated. Then, the system intervention control command value calculation unit 28 that has calculated the control command value outputs an information signal including the calculated control command value to the addition processing unit 32.

  Here, when the system intervention control command value calculation unit 28 calculates the control command value, the distance between the current host vehicle V and the obstacle detected by the left obstacle detection means 2 and the right obstacle detection means 4. Is corrected using a feedback error. The distance between the host vehicle V and the obstacle decreases, that is, as the position of the host vehicle V approaches the obstacle, the magnitude of rotating the steering wheel 16 in a direction in which the position of the host vehicle V moves away from the obstacle, and Calculate the control command value in the rotation direction.

  That is, the system intervention control command value calculation unit 28 calculates a driving support torque that is a torque in a direction opposite to the steering torque. This calculation is performed based on the degree of proximity of the host vehicle V to the obstacle detected by the left obstacle detection means 2 and the right obstacle detection means 4 and the steering torque detected by the steering torque detection means 8.

  The steering assist actual current calculation unit 30 corresponds to the steering assist torque based on the information signals output from the steering angle detection unit 10, the steering torque detection unit 8, the control start / end determination unit 20, and the steering support current calculation unit 22. Calculate the actual current value. Then, the steering assist actual current calculation unit 30 that has calculated the actual current value according to the steering assist torque outputs an information signal including the calculated actual current value to the addition processing unit 32.

The actual current value is calculated according to the following procedure.
When the information signal input from the control start / end determination unit 20 includes a determination result indicating that the control for outputting the driving support torque to the steering wheel 16 is necessary, the steering support current calculation unit 22 calculates the information. Calculate the reduction ratio with respect to the steering assist current. Then, the calculated reduction ratio is multiplied by the steering assist current calculated by the steering assist current calculator 22, and the multiplied value is set as an actual current value corresponding to the steering assist torque.

  Here, the reduction ratio with respect to the steering assist torque is calculated using the current steering angle detected by the steering angle detection means 10 and the current steering torque detected by the steering torque detection means 8.

  On the other hand, when the information signal input from the control start / end determination unit 20 includes a determination result indicating that the control for outputting the driving support torque to the steering wheel 16 is not necessary, the steering support current calculation unit 22 calculates the information. The rate of decrease with respect to the steering assist current is not calculated. In this case, the steering assist current calculated by the steering assist current calculator 22 is set as an actual current value corresponding to the steering assist torque.

The addition processing unit 32 adds the actual current value according to the steering support torque calculated by the steering support actual current calculation unit 30 to the control command value calculated by the system intervention control command value calculation unit 28, and the steering wheel A torque current value corresponding to the torque output to 16 is calculated.
Then, the addition processing unit 32 that has calculated the torque current value corresponding to the torque output to the steering wheel 16 outputs an information signal including the calculated torque current value to the rate limiter 34.

  That is, as described above, when the information signal output from the control start / end determination unit 20 includes a determination result indicating that the control for outputting the driving support torque is not necessary, the addition processing unit 32 calculates the information. The torque current value is the steering assist current calculated by the steering assist current calculator 22.

  The rate limiter 34 performs filtering on the torque current value based on the information signal input from the addition processing unit 32 and the control start / end determination unit 20, and corrects the torque current value to a value that changes smoothly (continuously). To do. The filtering on the torque current value is performed in order to suppress a sudden change in the torque current value when the control mode is changed, and to suppress a sudden behavior in the steering wheel 16. For this reason, when the control mode included in the information signal input from the control start / end determination unit 20 has not changed, the rate limiter 34 does not perform filtering on the torque current value.

  Then, the rate limiter 34 that has corrected the torque current value outputs an information signal including the corrected torque current value to the torque applying means 14. When the control mode has not changed, the rate limiter 34 outputs an information signal including an uncorrected torque current value to the torque applying means 14.

  The correction of the torque current value by the rate limiter 34 includes a determination result that is determined to require control for outputting the driving support torque to the steering wheel 16 in the information signal input from the control start / end determination unit 20. Do it if it is. The control mode is changed in accordance with the control mode set by the control start / end determination unit 20 included in the information signal input from the control start / end determination unit 20.

  Therefore, when the information signal output from the control start / end determination unit 20 includes a determination result indicating that the control for outputting the driving support torque is not necessary, the information signal is output from the rate limiter 34 to the torque applying unit 14. The information signal has the following contents. That is, when the control for outputting the driving assistance torque is not necessary, the motor command current value included in the information signal output from the rate limiter 34 to the torque applying means 14 is the steering assistance current calculated by the steering assistance current calculator 22. Become.

Here, the change in the control mode described above will be described.
The change in the control mode refers to, for example, the control gain depending on the detection state of the obstacle, such as when there is an obstacle on both sides of the traveling road on which the host vehicle V is traveling, or when there is an obstacle only on one side of the traveling road. This is done when the design is designed to make changes. This is based on the assumption that, for example, an obstacle that was originally on both sides of the travel path becomes only one side during travel.

  In such a case, if correction by the filter (rate limiter 34) is not performed, a large torque change occurs and the driver feels uncomfortable. Therefore, for example, the above-described process of gradually bringing the output to the electric motor closer to the target value with a certain time constant by multiplying the current instruction value by a gain of a first-order delay system that changes with time is effective. In order to perform this processing, correction by the rate limiter 34 is performed.

  Therefore, the motor command value calculation unit 24 outputs the travel support torque calculated by the system intervention control command value calculation unit 28 in the direction opposite to the steering torque to the steering wheel 16 via the torque applying means 14.

  As described above, the information signal finally output from the motor command value calculation unit 24 to the torque applying unit 14 indicates the difference between the control target position for avoiding the collision with the obstacle and the current position of the host vehicle V. Calculated based on Further, the information signal finally output from the motor command value calculation unit 24 to the torque applying means 14 is determined by addition with the assist current calculated from the steering torque input by the driver, and the weight of each control signal is determined. Is appropriately calculated according to the distance between the host vehicle V and the obstacle.

  Further, as described above, the steering controller 12 has a function of controlling the controller of the electronic control type power steering, that is, a function of outputting the steering assist torque, in addition to the function of outputting the travel assist torque to the steering wheel 16. is doing.

(Process for determining whether to stop control by the control start / end determination unit 20)
Hereinafter, of the processes performed by the control start / end determination unit 20, a process for determining whether to stop the control will be described in detail.
In the present embodiment, a process of determining the intention of the driver using the relationship between the above-described driving support torque and the steering torque, and determining whether to stop the control based on the determined intention of the driver. Will be described.

  Here, whether or not to stop the control is determined in a state where the driving support torque is output to the steering wheel 16 and the driver and the driving support device 1 cooperate with each other through the steering of the steering wheel 16. Do.

  In the following description, the driving support torque may be described as “Tsys”. Similarly, in the following description, the steering torque may be described as “Tdr”. Here, the steering torque (Tdr) is detected by the steering torque detection means 8. In addition to this, the steering torque (Tdr) may be detected using the steering assist torque calculated by the steering assist current calculator 22.

Here, the relationship between the travel support torque and the steering support torque is roughly classified into the following three types (R1 to R3).
R1: Tsys <Tdr (the steering torque detected by the steering torque detecting means 8 is the torque in the counterclockwise direction)
R2: Tsys> Tdr (the steering torque detected by the steering torque detecting means 8 is the clockwise torque)
R3: Tsys≈Tdr (the steering torque detected by the steering torque detecting means 8≈0)

  Hereinafter, when the relationship between the driving support torque and the steering torque is the relationship of R1, the driver's intention is determined, and whether or not the control is stopped is determined based on the determined driver's intention. The process of performing will be described.

  Here, the case where the relationship between the driving support torque and the steering torque is the relationship of R1 is a case where the deviation between the driving support torque and the steering torque is equal to or greater than a preset torque deviation threshold. The “predetermined torque deviation threshold value” is a preset value, and is an allowable value of the steering torque that becomes a reference when the control for outputting the travel assist torque to the steering wheel 16 is finished.

  The case where the relationship between the travel support torque and the steering torque is the relationship of R1 is a state where the travel support torque is less than the steering support torque, and as a result, the steering wheel 16 rotates counterclockwise. It is in a state. This is a state in which the host vehicle V is moving forward in a direction approaching the obstacle.

  When the relationship between the travel support torque and the steering torque is the relationship of R1 described above, the control start / end determination unit 20 does not require control for outputting the travel support torque, or is aware of an obstacle. Judged to have no intention. The case where the driver does not need the control for outputting the driving assistance torque is, for example, a case where the host vehicle V is stopped and parked at a position close to the obstacle (wall).

  If it is determined that the driver does not need the control for outputting the driving assistance torque or has an intention such as not being aware of the obstacle, the control start / end determination unit 20 causes the driving torque to be output by the driver. It is determined whether or not there is an intention to stop the output control.

  Here, whether or not the driver intends to stop the control for outputting the driving assistance torque is determined by determining the driving assistance torque or the sign of the current value for generating the driving assistance torque and the steering torque detection. This is performed when the sign of the steering torque detected by the means 8 is opposite.

  Then, the control start / end determination unit 20 uses the steering torque detected by the steering torque detection means 8 to determine that the driver intends to stop the control for outputting the driving assistance torque (steering override). Specifically, when the steering torque detected by the steering torque detecting means 8 is large and the state where the steering torque is large continues for a preset specified time or longer, the driver stops the control for outputting the driving assistance torque. It is determined that there is an intention.

  When it is determined that the driver intends to stop the control for outputting the driving support torque, the control start / end determination unit 20 stops after suppressing the driving support torque, and then shifts to the control for outputting the steering support torque. Perform the process. This is because if the driver does not need the control for outputting the driving assistance torque, the control for outputting the driving assistance torque may be continued, which may cause a sense of incongruity.

  The process of “suppressing” the driving support torque is specifically a process of gradually decreasing (weakening) the driving support torque. The process of “stopping” the travel support torque is a process of stopping the control for outputting the travel support torque when the gradually decreased travel support torque becomes “0”.

  On the other hand, when it is determined that the driver does not intend to stop the control for outputting the driving assistance torque, the control start / end determination unit 20 performs a process of continuing the control for outputting the driving assistance torque.

Next, when the relationship between the driving support torque and the steering torque is the relationship of R2, the intention of the driver is determined, and whether or not to stop the control based on the determined driver's intention. A process for making the determination will be described.
Here, when the relationship between the driving support torque and the steering torque is the relationship of R2, the deviation between the driving support torque and the steering torque is equal to or greater than a preset torque deviation threshold, as in the relationship of R1. This is the case.

  Further, the case where the relationship between the travel support torque and the steering torque is the relationship of R2 is a state where the travel support torque is larger than the steering support torque, and as a result, the steering wheel 16 rotates in the clockwise direction. It is in a state. This is a state in which the host vehicle V is moving forward in a direction away from the obstacle.

  When the relationship between the driving support torque and the steering torque is the relationship of R2 above, the driver has noticed an obstacle and loosened the gripping force of the steering wheel 16 or has released his hand from the steering wheel 16 for some reason. It is determined that it has an intention such as. Note that the case where the driver releases his hand from the steering wheel 16 for some reason, for example, when the own vehicle V suddenly vibrates in the vertical direction due to a step or the like, or in front of the own vehicle V, a vehicle, personnel, etc. This is the case when the

  If the driver recognizes an obstacle and determines that the gripping force of the steering wheel 16 has been loosened, the control start / end determination unit 20 determines that the driver is maintaining a calm mental state and suppresses the driving support torque. Perform the process. Further, the control start / end determination unit 20 performs a process of shifting to control for outputting the steering assist torque after the suppressed travel assist torque becomes “0” and the control for outputting the travel assist torque is stopped. Thus, the control shifts from the control for outputting the driving support torque to the control for outputting the steering support torque, and the control right of the steering wheel 16 is delivered to the driver without a sense of incongruity.

  On the other hand, when it is determined that the driver has released his hand from the steering wheel 16 for some reason, the control start / end determination unit 20 is in a situation where the driver is in a panic or does not know what to do. Is determined.

  If it is determined that the driver is in a panic or the situation is not clear what to do, the control start / end determination unit 20 immediately sets the driving support torque to “0” and outputs the driving support torque. To immediately stop the control to be performed.

  Here, when determining the difference between whether the driver is in a calm mental state, the driver is in a panic, or not sure what to do, the control start / end determination unit 20 Performs the following processing. That is, the difference is determined with reference to at least one of the change rate of the steering torque detected by the steering torque detection means 8 and the steering angle detected by the steering angle detection means 10.

  In general, the steering operation of the steering wheel 16 in a situation where the driver is not calm is more complicated than a situation where the driver is calm. For this reason, when the driver is not calm, at least one of the change rate of the steering angle and the change rate of the steering torque tends to increase.

  Therefore, when the allowable change rate for at least one of the change rate of the steering angle and the change rate of the steering torque is equal to or less than the specified value, the control right of the steering wheel 16 is handed over to the driver as described above. Performs control processing. On the other hand, when the allowable change rate for at least one of the change rate of the steering angle and the change rate of the steering torque is equal to or greater than the allowable change rate, a process of immediately stopping the control for outputting the driving support torque is performed.

  Next, in the case where the relationship between the driving support torque and the steering torque is the relationship of R3, whether the driver intends is determined, and whether or not to stop the control based on the determined driver intention. A process for making the determination will be described.

  When the relationship between the travel support torque and the steering torque is the relationship of R3, the travel support torque and the steering support torque are in a balanced state. As a result, the steering wheel 16 is not rotating. Or, it is rotating at a very low speed. Here, the state where the relationship between the driving support torque and the steering torque is the relationship of R3 includes a state where the steering angle of the steering wheel 16 by the driver is within the play range of the steering wheel 16. It is.

  When the relationship between the driving support torque and the steering torque is the relationship of R3, it is difficult to clearly predict the driver's intention. For this reason, the control start / end determination unit 20 continues the control for outputting the driving support torque.

  As described above, the control start / end determination unit 20 stops the output of the driving support torque Tsys when the deviation between the driving support torque Tsys and the steering torque Tdr is equal to or larger than a preset torque deviation threshold. Forming means.

  Further, in the present embodiment, as described above, the process of stopping the output of the travel support torque Tsys is performed by referring to the change in the steering torque in addition to the change in the steering angle.

This is due to the following reason.
In the conventional technique, the control for applying the steering assist torque to the steering wheel 16 is gradually released, and the control is finally terminated (for example, refer to the background art described above). In addition, as a conventional technique, there is an LDP (Lane Departure Prevention) system or the like, and this system is a system for reducing a delay in judgment made by the driver from the system and an uncomfortable feeling given to the driver. Further, the release and end of the control described above are performed by detecting that the steering angle of the steering wheel 16 has been steered in a direction opposite to the white line forming the outer frame of the traveling lane by a predetermined allowable angle or more.

  Based on the same concept as the LDP system described above, if the control end determination is made on the condition that the steering angle passes (crosses) the reference angle in the control end determination, the control end determination will be delayed. This will give the driver a sense of incongruity. Note that the delay in determining the end of control occurs because the steering angle required for avoiding an obstacle is large. In addition, the above-described control end determination is performed in a system that supports narrow road traveling that operates at a lower vehicle speed than the LDP system.

  Therefore, the inventors of the present invention, as a method for solving the problem of giving the driver a sense of incongruity, determines whether to end the control by referring not only to the change in the steering angle but also to the change in the steering torque. Devised. With this method, it is possible to estimate the driver's intention quickly and accurately, and therefore it is possible to determine the end of the control reflecting the driver's intention.

  In general, the value of torque output to the steering wheel 16 can be measured prior to the change of the steering angle. For this reason, it is because it becomes possible to stop the output of the driving support torque Tsys more quickly and reliably than the determination of the end of control based only on the change of the steering angle, reflecting the driver's intention.

(Operation)
Next, an example of an operation performed by the travel support device 1 of the present embodiment will be described with reference to FIGS. 1 to 3 and FIGS. 4 to 8.
FIG. 4 is a diagram illustrating the behavior of the host vehicle V provided with the travel support device 1 of the present embodiment. Specifically, it is a diagram illustrating a state in which the driver is receiving steering assistance from the traveling support device 1 in a state where the host vehicle V including the traveling support device 1 is traveling forward on a narrow road.

  The travel support apparatus 1 according to the present embodiment travels appropriately in order to avoid contact and collision with an obstacle (in the situation shown in FIG. 4, a wall W) when the host vehicle V travels forward on a narrow road. The assist torque is output to the steering wheel 16 to assist the steering. In addition to the wall W, the obstacle is, for example, an object having a certain height from the ground (road surface) such as a guard rail or a road shoulder.

  Specifically, as shown in FIG. 4, when there are walls W on both sides in the vehicle width direction of the host vehicle V, the driving support device 1 determines the distance between the host vehicle V and the walls W on both sides. Each is detected by means such as a sensor (such as sonar using sound waves). In FIG. 4, the left wall W in the vehicle width direction of the host vehicle V is indicated as “wall WL”, and the right wall W in the vehicle width direction of the host vehicle V is indicated as “wall WR”. .

  In order to avoid contact / collision with the wall W on the side close to the host vehicle V, control is performed to output a travel assist torque to the steering wheel 16. FIG. 4 shows a state in which the left wall WL among the walls W on both sides is the wall W closer to the host vehicle V. The following description is made on the assumption that the host vehicle V traveling forward on a narrow road is approaching the left wall WL, which is an obstacle, as shown in FIG.

  In other words, the driving support device 1 determines that the host vehicle V is on the left side based on the distance between the host vehicle V and the left wall WL as the host vehicle V traveling forward on the narrow road approaches the left wall WL. A driving assistance torque for rotating the steering wheel 16 in a direction away from the wall WL is output. This prompts the driver of the host vehicle V to perform a steering operation (steering operation in the clockwise direction) for avoiding an obstacle. In this case, the direction in which the steering wheel 16 is rotated is the clockwise direction.

Next, processing performed by the driving support device 1 of the present embodiment when the host vehicle V performs the behavior shown in FIG. 4 will be described.
FIG. 5 is a flowchart showing general processing performed by the driving support device 1 of the present embodiment. The detailed operation (processing) in each step described below will be described later.

  The flowchart shown in FIG. 5 starts from a state in which a switch for operating the driving support device 1 is operated (ON) by the driver of the host vehicle V when the host vehicle V travels forward (see “ Start. Note that the switch that operates the driving support device 1 is disposed in the driver's seat, for example, in the vicinity of the steering column 18, and the driver who has determined that the travel path on which the vehicle V will travel from now on is a narrow path. This switch is operated manually. When the flowchart shown in FIG. 5 is started, the process performed by the driving support device 1 proceeds to the process of step S100.

  In step S100, the steering controller 12 receives the input of the information signal output from each detection means (2, 4, 6, 8, 10), and reads each information signal ("reading each signal" shown in step S100). . Each information signal is read by the steering controller 12 at a predetermined sampling time such as every 10 [msec]. When each information signal is read in step S100, the process performed by the driving support device 1 proceeds to step S102.

  In step S102, the steering assist current calculator 22 calculates a steering assist torque to be output to the steering wheel 16, and calculates a steering assist current that is a current corresponding to the calculated steering assist torque. That is, in step S102, the torque that the electric power steering outputs to the steering wheel 16 as a normal operation is calculated ("calculate a normal power steering support command current value" shown in step S102). Then, the steering assist current calculator 22 that has calculated the steering assist current outputs an information signal including the calculated steering assist current to the motor command value calculator 24. When the steering assist current is calculated in step S102, the process performed by the travel support apparatus 1 proceeds to the process in step S104.

In step S104, the control start / end determination unit 20 determines the necessity of control for outputting the travel assist torque to the steering wheel 16 ("is control necessary?" Shown in step S104).
If it is determined in step S104 that there is a need for control to output the travel support torque to the steering wheel 16 ("Yes" shown in the figure), the processing performed by the travel support device 1 proceeds to step S106.

On the other hand, if it is determined in step S104 that there is no need for control to output the travel support torque to the steering wheel 16 ("No" shown in the figure), the processing performed by the travel support device 1 proceeds to step S108.
In step S106, the motor command value calculation unit 24 calculates a torque current value corresponding to the torque output to the steering wheel 16.

  Here, the process performed by the motor command value calculation unit 24 in step S106 is a process performed when it is determined in step S104 that there is a need for control for outputting the travel assist torque to the steering wheel 16. Therefore, in step S106, the motor command value calculation unit 24 calculates a torque current value corresponding to the travel support torque output to the steering wheel 16 ("calculates a torque current value corresponding to the travel support torque" shown in step S106). ) When the torque current value corresponding to the driving support torque is calculated in step S106, the processing performed by the driving support device 1 proceeds to step S108.

  In step S108, an information signal including the torque current value calculated by the motor command value calculation unit 24 in step S106 is output to the torque applying means 14 ("outputs a command signal to the EPS motor" shown in step S108). Thereby, in the torque provision means 14, the electric current supplied to an electric motor is controlled based on the command signal input from the motor command value calculation part 24. FIG.

  At this time, when the processing performed by the driving support device 1 proceeds from step S104 described above to step S108 via step S106, the torque output to the steering wheel 16 becomes the driving support torque. Therefore, the driver steers the steering wheel 16 in the direction away from the obstacle (clockwise direction) by the driving assistance torque output to the steering wheel 16. As a result, the host vehicle V moves in a direction away from the obstacle (the left wall WL) (the direction of the right wall WR).

  On the other hand, when the processing performed by the driving support device 1 shifts from step S104 described above to step S108 without passing through step S106, the torque output to the steering wheel 16 is the steering support torque. Therefore, the driver steers the steering wheel 16 in an arbitrary direction while being assisted by the steering assist torque output to the steering wheel 16.

  In step S108, when the information signal including the torque current value calculated by the motor command value calculation unit 24 is output to the torque applying means 14, the processing performed by the driving support device 1 is ended ("END" shown in FIG. 5). . Note that, when the state where the switch for operating the driving support device 1 is operated (ON) is maintained, the processing performed by the driving support device 1 proceeds to step S100. On the other hand, when the switch for operating the driving support device 1 is released (OFF), the operation of the driving support device 1 ends, and the host vehicle V shifts to normal driving (output of only the steering support torque).

  Next, the process of step S104 described above, that is, the process of determining the necessity of control for outputting the travel support torque to the steering wheel 16 performed by the control start / end determination unit 20 will be described in detail.

FIG. 6 is a flowchart showing a process of determining the necessity of control for outputting the driving support torque to the steering wheel 16 among the processes performed by the control start / end determination unit 20.
The flowchart shown in FIG. 6 starts from the state in which the steering assist current is calculated in step S102 of the flowchart shown in FIG. 5 (“START (CALL)” shown in FIG. 6). When the flowchart shown in FIG. 6 is started, the process performed by the driving support device 1 proceeds to the process of step S200.

  In step S200, it is determined whether or not the control for outputting the driving assistance torque to the steering wheel 16 is being executed (“cont_flag = 1?” Shown in step S200). That is, the state in which the control for outputting the travel assist torque to the steering wheel 16 is being performed is a state in which the control flag (“cont_flag”) is established (“1”).

If it is determined in step S200 that the control for outputting the driving support torque to the steering wheel 16 is being performed ("Yes" shown in the drawing), the processing performed by the driving support device 1 proceeds to step S202.
On the other hand, if it is determined in step S200 that the control for outputting the driving support torque to the steering wheel 16 is not being performed ("No" shown in the drawing), the processing performed by the driving support device 1 is ended and the process returns to step S200. ("END (Return)" shown in FIG. 6).

In step S202, whether or not the absolute value “| T |” [Nm] of the steering torque detected by the steering torque detector 8 is equal to or smaller than the end determination torque threshold “α” [Nm] (“| T | ≦ α? ”).
Here, the absolute value | T | of the steering torque detected by the steering torque detection means 8 is a deviation between the travel support torque Tsys and the steering torque Tdr, and is applied to both the case of R1 and the case of R2. Value.

  Further, the end determination torque threshold value α is a preset value, and is an allowable value of the steering torque that serves as a reference when the control for outputting the travel support torque to the steering wheel 16 is ended. That is, the end determination torque threshold value α corresponds to the above-described “preset torque deviation threshold value”.

  The end determination torque threshold α is set to a value larger than the noise value included in the information signal output by the steering torque detection means 8 when the host vehicle V is traveling forward, for example, thereby causing malfunction due to the noise value. It becomes possible to suppress. Further, for example, the termination determination torque threshold value α is adjusted to a value that does not give the driver a sense of incongruity under conditions that occupy most of the conditions for stopping the control for outputting the driving assistance torque to the steering wheel 16. Is preferred.

If it is determined in step S202 that the absolute value | T | of the steering torque is equal to or less than the end determination torque threshold value α (“Yes” in the drawing), the processing performed by the driving support device 1 proceeds to step S204.
On the other hand, if it is determined in step S202 that the absolute value | T | of the steering torque is less than the end determination torque threshold value α (“No” shown in the figure), the processing performed by the driving support device 1 ends and proceeds to step S200. Return ("END (Return)" shown in FIG. 6).

In step S204, it is determined whether or not the travel support torque Tsys exceeds the steering torque Tdr (“Tsys> Tdr?” Shown in step S204).
If it is determined in step S204 that the travel support torque Tsys exceeds the steering torque Tdr (“Yes” shown in the figure), the processing performed by the travel support device 1 proceeds to step S206.

  On the other hand, if it is determined in step S204 that the driving support torque Tsys is equal to or less than the steering torque Tdr ("No" shown in the figure), the processing performed by the driving support device 1 proceeds to step S210.

  In step S206, it is determined whether or not the driver intends to stop the control for outputting the driving assistance torque (“override_flag = 0?” Shown in step S206). Here, the state in which the driver does not intend to stop the control for outputting the driving support torque means that the override flag (“override_flag”) for stopping the control for outputting the driving support torque is not established (“0”). )) State. Detailed processing in step S206 will be described later.

  If it is determined in step S206 that the driver intends to stop the control for outputting the driving support torque ("Yes" shown in the drawing), the processing performed by the driving support device 1 is ended and the process returns to step S200 ( "END (Return)" shown in FIG.

  On the other hand, if it is determined in step S206 that the driver does not intend to stop the control for outputting the driving support torque ("No" shown in the figure), the processing performed by the driving support device 1 proceeds to step S208. .

  In step S208, the driving support torque is gradually weakened, and an information signal including a determination result that the control for outputting the driving support torque is ended is output to the motor command value calculation unit 24. That is, in step S208, the control for outputting the driving support torque is not stopped immediately, but is stopped while gradually decreasing the output of the driving support torque (“Normal_end = 1” shown in step S208). Control for gradually decreasing the output of the driving support torque is performed by smoothly changing the torque current value. When the control for gradually decreasing the driving support torque is performed, the torque output to the steering wheel 16 smoothly shifts from the driving support torque to the steering support torque, so that it is possible to suppress a sense of discomfort given to the driver. .

  In step S208, when the information signal for stopping the control for outputting the driving support torque is output while gradually decreasing the output of the driving support torque, the processing performed by the driving support device 1 proceeds to step S218.

  In step S210, the steering angular velocity “ω” per unit time is calculated using the steering angle of the steering wheel 16 by the driver detected by the steering angle detection means 10. Then, it is determined whether or not the calculated steering angular velocity ω is less than the allowable angular velocity “β” [degree / sec] (“ω <β?” Shown in step S210). Here, the allowable angular velocity β is a preset value, and is an allowable value of the steering angular velocity that serves as a reference when determining whether or not the driver is calm.

If it is determined in step S210 that the steering angular velocity ω is less than the allowable angular velocity β (“Yes” shown in the figure), the processing performed by the driving support device 1 proceeds to step S212.
On the other hand, when it is determined in step S210 that the steering angular velocity ω exceeds the allowable angular velocity β (“No” shown in the figure), the processing performed by the driving support device 1 proceeds to step S216.

  In step S212, a torque change rate “dT / dt” obtained by differentiating the steering torque detected by the steering torque detecting means 8 per unit time is calculated. Then, it is determined whether or not the calculated torque change rate dT / dt is less than the allowable torque change rate “γ” [Nm / sec] (“dT / dt <γ?” Shown in step S212). Here, the allowable torque change rate γ is a preset value, and is an allowable value of the torque change rate that serves as a reference when determining whether or not the driver is calm. That is, in step S210 and step S212, it is determined whether or not the steering angle of the steering wheel 16 is rapidly changed by the driver's steering operation.

If it is determined in step S212 that the torque change rate dT / dt is less than the allowable torque change rate γ (“Yes” shown in the figure), the processing performed by the driving support device 1 proceeds to step S214.
On the other hand, if it is determined in step S212 that the torque change rate dT / dt exceeds the allowable torque change rate γ (“No” in the figure), the processing performed by the driving support device 1 proceeds to step S216.

  In step S214, as in step S208, the driving support torque is gradually decreased, and an information signal including a determination result that the control for outputting the driving support torque is terminated is output to the motor command value calculation unit 24. That is, in step S214, the control for outputting the driving support torque is not stopped immediately, but is stopped while gradually decreasing the output of the driving support torque (“Normal_end = 1” shown in step S214). This control is performed by smoothly changing the torque current value as in step S208. In step S214, when the information signal for stopping the control for outputting the driving support torque is output while gradually decreasing the output of the driving support torque, the processing performed by the driving support device 1 proceeds to step S218.

  In step S216, the output of the driving support torque is immediately stopped, and an information signal including a determination result that the control for outputting the driving support torque is ended is output to the motor command value calculation unit 24. That is, in step S216, the control for outputting the driving assistance torque is immediately stopped (“Immediate_end = 1” shown in step S216). This control is performed by immediately setting the torque current value to “0”. When the control for outputting the driving support torque is immediately stopped, the output of the driving support torque to the steering wheel 16 is immediately stopped. Therefore, the behavior of the host vehicle V is not limited to the driver's intention. It is prevented that the torque is determined.

In step S216, when the information signal for immediately stopping the control for outputting the driving support torque is output, the processing performed by the driving support device 1 proceeds to step S218.
In step S 218, an information signal for stopping the control for outputting the driving assistance torque to the steering wheel 16 is output to the motor command value calculation unit 24. That is, in step S218, the control flag (“cont_flag”) described above is set to the unestablished (“0”) state (“cont_flag = 0” shown in step S218). Here, when the control for outputting the travel support torque to the steering wheel 16 is stopped, the electric power steering outputs the steering support torque to the steering wheel 16 as a normal operation.

  In step S218, when the information signal for stopping the control for outputting the driving support torque is output to the motor command value calculation unit 24, the processing performed by the driving support device 1 ends and returns to step S200 ("END shown in FIG. 6" (Return) ").

  Next, the processing in step S206 described above, that is, detailed processing for determining whether or not the driver intends to stop the control for outputting the driving assistance torque will be described.

FIG. 7 is a flowchart showing detailed processing for determining whether or not the driver intends to stop the control for outputting the driving assistance torque.
The flowchart shown in FIG. 7 starts from the state where it is determined in step S204 of the flowchart shown in FIG. 6 that the driving support torque Tsys exceeds the steering torque Tdr (“Yes” shown in the figure) (in FIG. 7). ("START (CALL)"). When the flowchart shown in FIG. 7 is started, the process performed by the driving support apparatus 1 proceeds to the process of step S300.

In step S300, it is determined whether or not the sign of the current value for generating the driving assistance torque is opposite to the sign of the steering torque detected by the steering torque detecting means 8 ("the sign is reversed?" Shown in step S300). judge.
If it is determined in step S300 that the sign of the current value for generating the driving support torque is opposite to the sign of the steering torque detected by the steering torque detecting means 8 ("Yes" shown in the figure), the driving support device The processing performed by 1 moves to step S302.

  On the other hand, if it is determined in step S300 that the sign of the current value described above and the sign of the steering torque described above are not opposite ("No" shown in the drawing), the processing performed by the driving support device 1 ends and the process proceeds to step S300. Return ("END (Return)" shown in FIG. 7).

  In step S302, whether or not the absolute value “| T |” [Nm] of the steering torque detected by the steering torque detector 8 is equal to or greater than the override determination torque threshold “A” [Nm] (“| T | ≧ A? ”). Here, the override determination torque threshold value A is a value that serves as a reference when determining that the driver intends to stop the control for outputting the driving assistance torque, and is the size of the host vehicle V or the steering ability (minimum). It is set in advance according to the turning radius or the like.

  If it is determined in step S302 that the absolute value | T | of the steering torque is equal to or greater than the override determination torque threshold A (“Yes” in the figure), the processing performed by the driving support device 1 proceeds to step S304.

  On the other hand, when it is determined in step S302 that the absolute value | T | of the steering torque is less than the override determination torque threshold A (“No” in the drawing), the processing performed by the driving support device 1 proceeds to step S306. .

  In step S304, the time during which the absolute value | T | of the steering torque is equal to or greater than the override determination torque threshold A is measured (counted) (“counter + 1” shown in step S304). In step S304, when the time during which the absolute value | T | of the steering torque is equal to or greater than the override determination torque threshold A is measured, the processing performed by the driving support device 1 proceeds to step S308.

  In step S306, unlike step S304, processing is performed in which the time during which the absolute value | T | of the steering torque is equal to or greater than the override determination torque threshold A is not measured ("counter = 0" shown in step S306). In step S306, when processing for not measuring the time during which the absolute value | T | of the steering torque is equal to or greater than the override determination torque threshold A is performed, the processing performed by the driving support device 1 proceeds to step S308.

  In step S308, whether or not the time that the absolute value | T | of the steering torque measured in step S304 is equal to or greater than the override determination torque threshold A is equal to or greater than the override determination time “B” [sec] (shown in step S308). “Counter ≧ B?”) Is determined. Here, the override determination time B is a threshold value used as a reference when it is determined that the driver intends to stop the control for outputting the driving assistance torque, and the size of the own vehicle V or the steering ability (minimum turning) It is set in advance according to the radius.

In step S308, when it is determined that the time during which the absolute value | T | of the steering torque is equal to or greater than the override determination torque threshold A is equal to or greater than the override determination time B ("Yes" in the drawing), the driving support device 1 performs. The process proceeds to step S310.
On the other hand, when it is determined in step S308 that the time during which the absolute value | T | of the steering torque is equal to or greater than the override determination torque threshold A is less than the override determination time B ("No" shown in the figure), the driving support device 1 The process performed by the process proceeds to step S312.

  In step S310, an override flag for stopping the control for the driver to output the driving assistance torque is established (“override_flag = 1” shown in step S310). In step S310, when the override flag is established, the processing performed by the driving support device 1 ends and returns to step S300 ("END (Return)" shown in FIG. 7).

  In step S312, unlike step S310, a process is performed in which the driver does not establish an override flag for stopping the control for outputting the driving assistance torque ("override_flag = 0" shown in step S312). If the process that does not establish the override flag is performed in step S312, the process performed by the driving support device 1 ends and returns to step S300 ("END (Return)" shown in FIG. 7).

Next, the processing performed by the motor command value calculation unit 24 among the processing performed by the above-described step S104 to step S108, that is, the processing performed by the control start / end determination unit 20 and the motor command value calculation unit 24 will be described in detail. .
FIG. 8 is a flowchart showing processing performed by the control start / end determination unit 20 and the motor command value calculation unit 24.

  The flowchart shown in FIG. 8 starts from the state in which the steering assist current is calculated in step S102 of the flowchart shown in FIG. 5 (“start” shown in FIG. 8). When the flowchart shown in FIG. 8 is started, the process performed by the driving support device 1 proceeds to the process of step S400.

  In step S <b> 400, the control start / end determination unit 20 determines the necessity of control for outputting the travel support torque to the steering wheel 16. Thereby, in step S400, it is determined whether or not a control start flag for starting control for outputting the travel assist torque to the steering wheel 16 is established ("control start flag?" Shown in step S400). That is, the process of step S400 is the same as the process of step S104 described above.

If it is determined in step S400 that the control start flag is established (“Yes” shown in the figure), the processing performed by the driving support device 1 proceeds to step S402.
On the other hand, if it is determined in step S400 that the control start flag is not established ("No" shown in the figure), the processing performed by the driving support device 1 proceeds to step S420.

  In step S <b> 402, the feedback error calculation unit 26 calculates a feedback error based on the information signal input from the left obstacle detection unit 2 and the right obstacle detection unit 4. That is, in step S402, the feedback error calculation unit 26 calculates a feedback error (“feedback error calculation unit calculates feedback error” shown in step S402). When the feedback error is calculated in step S402, the process performed by the driving support device 1 proceeds to step S404.

  In step S404, the system intervention control command value calculation unit 28 performs control based on the feedback error calculated by the feedback error calculation unit 26 and the information signal input from the left obstacle detection unit 2 and right obstacle detection unit 4. Calculate the command value. That is, at step S404, the system intervention control command value calculation unit 28 calculates the control command value (“the system intervention control command value calculation unit calculates the control command value” shown at step S404). When the control command value is calculated in step S404, the process performed by the driving support device 1 proceeds to step S406.

  In step S <b> 406, the control start / end determination unit 20 determines whether or not the control mode in the control for outputting the travel assist torque to the steering wheel 16 has changed. Thereby, in step S406, it is determined whether or not a mode change flag indicating that the control mode is changed (“mode change flag?” Shown in step S406).

If it is determined in step S406 that the mode change flag is not satisfied ("No" shown in the figure), the processing performed by the driving support device 1 proceeds to step S408.
On the other hand, if it is determined in step S406 that the mode change flag is established (“Yes” shown in the figure), the processing performed by the driving support device 1 proceeds to step S410.

  In step S408, the rate limiter 34 sets “1” as the gain used when filtering the torque current value (“rate limiter gain = 1” shown in step S408). In step S408, when the gain used when filtering the torque current value is set to “1”, the process performed by the driving support device 1 proceeds to step S416.

  In step S410, the rate limiter 34 calculates a gain used when filtering the torque current value (“rate limiter gain calculation” shown in step S410). If the gain used when filtering with respect to a torque electric current value is calculated in step S410, the process which the driving assistance device 1 performs will transfer to step S412.

In step S412, it is determined whether or not the gain calculated in step S410 is “1” (“gain = 1?” Shown in step S412).
If it is determined in step S412 that the gain calculated in step S410 is “1” (“Yes” shown in the figure), the processing performed by the driving support device 1 proceeds to step S414.

  On the other hand, if it is determined in step S412 that the gain calculated in step S410 is not “1” (“No” shown in the figure), the processing performed by the driving support device 1 proceeds to step S416.

  In step S414, if the gain calculated in step S410 is “1” by the control start / end determination unit 20, the mode change flag is not substantially established (“mode change flag shown in step S414”). = 0 "). Thereby, in the rate limiter 34, the gain used when filtering the torque current value is set to “1”. If it is determined in step S414 that the mode change flag is not substantially established, the processing performed by the driving support device 1 proceeds to step S416.

  In step S 416, the steering support actual current calculation unit 30 multiplies the steering support current calculated by the steering support current calculation unit 22 by the decrease rate with respect to the steering support current calculated by the steering support current calculation unit 22, thereby obtaining the steering support torque. The actual current value corresponding to is calculated. That is, in step S416, the steering support actual current calculation unit 30 multiplies the steering support current by the reduction rate with respect to the steering support current (see “Decrease with respect to the steering support current in the steering support actual current calculation unit 30” Multiply the steering assist current by the ratio "). In step S416, when the steering support current is multiplied by the decrease rate with respect to the steering support current, the processing performed by the travel support device 1 proceeds to step S418.

  In step S418, the addition processing unit 32 adds the control command value calculated in step S404 and the actual current value calculated in step S416, and calculates a torque current value corresponding to the torque output to the steering wheel 16. To do. Further, the rate limiter 34 performs filtering by multiplying the torque current value calculated by the addition processing unit 32 by a gain and corrects the torque current value to a value that changes smoothly. That is, in step S418, the torque current value obtained by adding the control command value and the actual current value is multiplied by the gain by the rate limiter 34 (the current value obtained in S404 and the current value obtained in S416 shown in step S418). Add and multiply with the rate limiter value ”). When the torque current value is corrected in step S418, the process performed by the driving support device 1 proceeds to step S420. That is, the processing from step S402 to step S418 is the same as the processing of step S106 described above.

  In step S420, an information signal including the torque current value corrected in step S418 is output to the torque applying means 14 ("outputs a command signal to the EPS motor" shown in step S420). Thereby, in the torque provision means 14, the electric current supplied to an electric motor is controlled based on the command signal input from the motor command value calculation part 24. FIG. That is, the process of step S420 is the same as the process of step S108 described above.

In step S420, when the information signal including the corrected torque current value is output to the torque applying means 14, the processing performed by the driving support device 1 is ended (“END” shown in FIG. 8).
As described above, in the processing shown in FIG. 8, when the control mode is changed in the processing from step S406 to step S414, the rate limiter 34 corrects the torque current value to a value that smoothly changes. As a result, a sudden change in the torque current value is suppressed, and a sudden behavior in the steering wheel 16 is suppressed.

  As described above, the driving support method implemented by the operation of the driving support device 1 according to the present embodiment calculates the driving support torque that is a torque in the direction opposite to the steering torque of the driver, and calculates the calculated driving support torque. Is output to the steering wheel 16. Then, when the deviation between the driving support torque and the steering torque is equal to or greater than a preset torque deviation threshold, the output of the driving support torque is stopped. Here, the driving assistance torque is calculated based on the degree of proximity of the host vehicle V to the obstacle (wall W) on at least one of both sides in the vehicle width direction of the host vehicle V and the steering torque.

  As described above, the left obstacle detection means 2 and the right obstacle detection means 4 correspond to the proximity degree detection means, and the system intervention control command value calculation unit 28 corresponds to the driving assistance torque calculation means. The motor command value calculation unit 24 and the torque application unit 14 correspond to a travel support torque output unit, and the control start / end determination unit 20 corresponds to a travel support torque stop unit.

(Effects of the first embodiment)
(1) When the driving support torque stopping means has a deviation between the driving support torque output from the driving support torque output means and the steering torque detected by the steering torque detecting means equal to or greater than a preset torque deviation threshold, Stop the output of.

  Therefore, when the host vehicle is traveling on a narrow road, the control for outputting the driving assistance torque to avoid the obstacle is stopped based on the driver's intention estimated by using the steering torque input by the driver. Is possible.

  As a result, it is possible to perform control that reflects the driver's intention by using the steering torque that can be detected prior to the change in the steering angle, and the driver feels uncomfortable when steering on narrow roads. Can be reduced.

(2) The driving support torque stopping unit stops the output of the driving support torque when the steering torque detected by the steering torque detecting unit is greater than or equal to the driving support torque output by the driving support torque output unit.

  As a result, safety can be improved in situations where the driver is expected to maintain a calm mental state, in situations where the driver is in a panic or does not know what to do. It becomes possible.

(3) The driving assist torque stopping means has a steering angular velocity of the steering hole by the driver less than a preset allowable angular speed, and a rate of change of the steering torque detected by the steering torque detecting means is less than a preset allowable torque change rate. In this case, the driving is stopped after the output of the driving support torque is suppressed.

  As a result, in a state where the driver is predicted to maintain a calm mental state, the control right of the steering wheel can be delivered to the driver without a sense of incongruity.

(4) The driving support torque stop means is at least a steering angular velocity of the steering hole by the driver equal to or higher than a preset allowable angular speed and a steering torque change rate detected by the steering torque detection means is at least a preset allowable torque change rate or higher. When one is established, the output of the driving support torque is immediately stopped.

  As a result, it is possible to prevent the behavior of the vehicle from being determined by the driving assistance torque regardless of the driver's intention in situations where the driver is in a panic or does not know what to do. It becomes.

(5) Time when the steering assist torque detecting unit detects that the steering torque detected by the steering torque detecting unit is less than the driving support torque output by the driving support torque output unit, and the deviation is equal to or greater than a preset override determination torque threshold value. Is over the preset override determination time, it stops after suppressing the output of the driving support torque.

  As a result, in the state where it is predicted that the driver intends to stop the control for outputting the driving assistance torque, the right to control the steering wheel can be delivered to the driver without a sense of incongruity.

(6) In the driving support method of the present embodiment, the output of the driving support torque is stopped when the deviation between the driving support torque and the steering torque is equal to or greater than a preset torque deviation threshold.

  Therefore, when the host vehicle is traveling on a narrow road, the control for outputting the driving assistance torque to avoid the obstacle is stopped based on the driver's intention estimated by using the steering torque input by the driver. Is possible.

  As a result, it is possible to perform control that reflects the driver's intention by using the steering torque that can be detected prior to the change in the steering angle, and the driver feels uncomfortable when steering on narrow roads. Can be reduced.

(Modification)
(1) In the driving support device 1 of the present embodiment, when the host vehicle V is traveling forward, the driver of the host vehicle V operates the switch that operates the driving support device 1 to operate the driving support device 1. Although configured, the present invention is not limited to this. That is, for example, the distance between the host vehicle V and the obstacle (the wall W or another vehicle) is detected by the left obstacle detection unit 2 and the right obstacle detection unit 4 with respect to the traveling path of the host vehicle V. And it is good also as a structure which makes the driving assistance device 1 operate | move automatically, when this detected distance is below the predetermined distance set beforehand.

  That is, the configuration of the driving support device 1 may include a narrow road determination unit. When the narrow road determination means determines that the width of the travel path on which the host vehicle V travels is equal to or less than a preset width with respect to the vehicle width of the host vehicle V, the narrow path determination means transmits the travel support torque to the travel support torque output means described above. A command signal for outputting torque to the steering wheel is output.

  The “predetermined predetermined distance (width)” is set according to the vehicle width of the host vehicle V, for example. Other than this, for example, when there are walls W on both sides in the vehicle width direction of the host vehicle V, when it is detected that the distance between the left wall WL and the right wall WR is 4 [m] or less. The driving support device 1 may be configured to automatically operate.

  In addition, the narrow road determination means is configured so that the width of the travel path on which the host vehicle V travels is equal to that of the host vehicle V only when the vehicle speed of the host vehicle V detected by the vehicle speed detection unit 6 is equal to or lower than a preset vehicle speed. It is good also as a structure which determines whether it is below the preset width with respect to the vehicle width.

  In this case, the above-mentioned “preset vehicle speed” is, for example, 30 [km / km] in consideration of the performance of the left obstacle detection means 2 and the right obstacle detection means 4 and ensuring safety when traveling on a narrow road. h].

(2) In the driving support device 1 of the present embodiment, the proximity detection means is formed by the left obstacle detection means 2 and the right obstacle detection means 4, but the present invention is not limited to this. That is, in addition to the left obstacle detection means 2 and the right obstacle detection means 4, a sound wave is transmitted forward of the host vehicle V in the front-rear direction of the host vehicle V and forward of the host vehicle V in the front-rear direction of the vehicle. A front obstacle detecting means capable of receiving the sound wave reflected on the head may be arranged. In this case, the front obstacle detection means may be singular or plural. Thereby, in addition to the left obstacle detection means 2 and the right obstacle detection means 4, the proximity detection means may be formed by the front obstacle detection means.

  In this case, it is possible to detect the distance between the host vehicle V and an obstacle (such as a stopped vehicle) existing in the forward direction of the host vehicle V in addition to both sides (sides) of the host vehicle V in the vehicle width direction. Thus, it is possible to improve the accuracy of the control performed by the driving support device 1.

(3) In the driving support device 1 of the present embodiment, the proximity degree detection means is formed by the left obstacle detection means 2 and the right obstacle detection means 4, but is not limited thereto. That is, the proximity detection means may be formed by the left obstacle detection means 2 or the right obstacle detection means 4. In this case, for example, in a vehicle used mainly in a country (such as Japan) where the vehicle is generally left-hand traffic, the proximity detection means is formed only by the left obstacle detection means 2. As a result, it is possible to detect the degree of proximity of the host vehicle V to the obstacle on at least the side where the obstacle is predicted to be close to the host vehicle V on both sides in the vehicle width direction of the host vehicle V.

DESCRIPTION OF SYMBOLS 1 Driving assistance apparatus 2 Left side obstacle detection means 4 Right side obstacle detection means 6 Vehicle speed detection means 8 Steering torque detection means 10 Steering angle detection means 12 Steering controller 14 Torque provision means 16 Steering wheel 18 Steering column 20 Control start / end determination unit 22 Steering support current calculation unit 24 Motor command value calculation unit 26 Feedback error calculation unit 28 System intervention control command value calculation unit 30 Steering support actual current calculation unit 32 Addition processing unit V Own vehicle W Wall (obstacle)

Claims (8)

Proximity degree detection means for detecting the degree of proximity of the own vehicle to the obstacle on at least one of both sides in the vehicle width direction of the own vehicle;
Steering torque detection means for detecting the steering torque of the driver;
Based on the proximity degree detected by the proximity degree detecting means and the steering torque detected by the steering torque detecting means, a driving assistance torque calculating means for calculating a driving assistance torque which is a torque in a direction opposite to the steering torque;
Travel support torque output means for outputting the travel support torque calculated by the travel support torque calculation means to a steering wheel;
The travel support torque that stops the output of the travel support torque when the deviation between the travel support torque output by the travel support torque output means and the steering torque detected by the steering torque detection means is greater than or equal to a preset torque deviation threshold. A vehicle travel support apparatus comprising: stop means;   The travel support torque stop means stops output of the travel support torque when the steering torque detected by the steering torque detection means is equal to or greater than the travel support torque output by the travel support torque output means. The vehicle travel support device according to claim 1.   The travel support torque stop means is a case where the steering torque detected by the steering torque detection means is greater than or equal to the travel support torque output by the travel support torque output means, and the steering angular velocity of the steering hole by the driver is When the steering torque change rate detected by the steering torque detecting means is less than a preset allowable torque change rate and less than a preset allowable angular velocity, stopping the output after suppressing the output of the driving support torque. The travel support device for a vehicle according to claim 2, wherein the travel support device is a vehicle.   The travel support torque stop means is a case where the steering torque detected by the steering torque detection means is greater than or equal to the travel support torque output by the travel support torque output means, and the steering angular velocity of the steering hole by the driver is When at least one of the preset allowable angular velocity and the change rate of the steering torque detected by the steering torque detecting means is equal to or greater than the preset allowable torque change rate, the output of the driving support torque is immediately stopped. The travel support device for a vehicle according to claim 2, wherein the travel support device is a vehicle.   The travel support torque stop means has a steering torque detected by the steering torque detection means that is less than the travel support torque output by the travel support torque output means, and the deviation is greater than or equal to a preset override determination torque threshold. 2. The vehicle travel support device according to claim 1, wherein when the time is equal to or greater than a preset override determination time, the vehicle travels after the output of the travel support torque is suppressed. Narrow path determination means for determining whether or not the width of the travel path on which the host vehicle travels is equal to or less than a preset width with respect to the vehicle width of the host vehicle;
The travel support torque output means outputs the travel support torque to a steering wheel when the narrow road determination means determines that the width of the travel path is equal to or less than the preset width. Item 6. The vehicle travel support device according to any one of Items 1 to 5. Vehicle speed detecting means for detecting the vehicle speed of the host vehicle,
When the vehicle speed of the host vehicle detected by the vehicle speed detection unit is equal to or lower than a preset vehicle speed, the narrow road determination unit sets the width of the travel path on which the host vehicle travels in advance with respect to the vehicle width of the host vehicle. The vehicle travel support apparatus according to claim 6, wherein it is determined whether or not the width is equal to or less than the determined width. Based on the degree of proximity of the host vehicle to the obstacle on at least one of both sides in the vehicle width direction of the host vehicle and the driver's steering torque, a driving support torque that is a torque in a direction opposite to the steering torque is calculated. And output the calculated driving assistance torque to the steering wheel,
A vehicle driving support method comprising: stopping output of the driving support torque when a deviation between the driving support torque and the steering torque is equal to or greater than a preset torque deviation threshold.

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