JP6737136B2 - Driving support device - Google Patents

Description

The present invention relates to either a gripping driving state in which a driver grips a steering wheel (steering wheel) to drive a vehicle, or a release driving state in which a driver drives a vehicle without gripping the steering wheel. The present invention relates to a driving support device having a function of determining whether or not the driving state is occurring.

Like the lane keeping control (LKA: lane keeping assist control), the lateral driving support control (hereinafter referred to as “lateral driving control” that automatically controls the lateral position of the vehicle in the traveling lane by steering steered wheels. A driving support device that performs "direction driving support control" is also known. This lateral driving support control is different from so-called "automatic driving" and is control for supporting (assisting) the steering operation of the driver. Therefore, in principle, this driving assistance device executes the lateral driving assistance control only when the driver is driving the vehicle while holding the steering wheel. Therefore, the driving support device needs to confirm that a state in which the driver is driving while gripping the steering wheel (hereinafter, also referred to as “grasping driving state”) has occurred. In other words, the driving support device needs to detect that a state in which the driver is driving without gripping the steering wheel (hereinafter, also referred to as “hand-over driving state”) occurs.

On the other hand, there has been proposed an electrostatic capacitance type contact detection sensor for detecting whether or not a driver is gripping a steering wheel (for example, refer to Patent Document 1). The electrostatic capacitance type contact detection sensor responds to the contact state of the driver with the steering wheel by utilizing the fact that the electrostatic capacitance of the steering wheel changes depending on whether or not the driver touches the steering wheel. A signal that changes as a result (hereinafter, also referred to as “contact state signal”) is output. Hereinafter, the sensor that outputs such a contact state signal is also referred to as a “contact detection sensor” or a “touch sensor”.

JP, 2014-190712, A

However, when it is determined whether or not the gripping driving state is generated using only the contact detection sensor, it is erroneously determined that the gripping driving state is generated even though the driver is not gripping the steering wheel. A situation arises in which the judgment is made. Such a situation is, for example, the following situation.
-When the steering wheel is accidentally touching a "conductive object" other than the driver's human body.
When the driver pretends to be holding the steering wheel by intentionally sticking a "conductive object (for example, a metal plate)" on the steering wheel.

On the other hand, a technique is also known in which the steering torque is detected and it is determined that the grip operation state is occurring when the detected steering torque is equal to or more than a threshold value. However, even when the driving support device adopts such a technique, it is erroneously determined that the gripping driving state is occurring even though the driver does not grip the steering wheel. The situation occurs. Such a situation is, for example, the following situation.

When the driver intentionally attaches a weight to the steering wheel to generate steering torque in the direction opposite to the direction in which the steering wheel tries to rotate due to the torque from the road surface.

When such an erroneous determination occurs, it is determined that the gripping driving state has occurred, and therefore, for example, no alarm is issued to inform the driver that the hand-released driving state has occurred, or the hand-held driving state has been generated. There arises a problem that the lateral driving support control that should be stopped is continued. The present invention has been made to address such problems.

The driving support device of the present invention (hereinafter, also referred to as “device of the present invention”) is
A driving assistance device that executes lateral driving assistance control that automatically steers the wheels of a vehicle to adjust the lateral position of the vehicle in the lane in which the vehicle is traveling (step 540),
A contact detection sensor (13) that outputs a contact state signal indicating a contact state of a driver of the vehicle with a steering wheel (SW) of the vehicle;
A steering torque sensor (14) for detecting a steering torque generated on a steering shaft (SS) connected to the steering handle (SW);
Any one of a gripping driving state in which the driver is driving the vehicle while gripping the steering wheel, and a hand-over driving state in which the driver is driving the vehicle without gripping the steering wheel A controller (10) for determining whether a state has occurred,
Equipped with.

Further, the controller (10) is
A first condition (step 610) that the contact state signal indicates that the driver is in contact with the steering wheel, and the magnitude of the detected steering torque is not less than a first threshold value. And a second condition (step 615), the first means (step 620) for determining that the grip operation state has occurred,
When the lateral driving support control is being executed and it is determined by the first means that the gripping driving state has occurred, a state in which neither the first condition nor the second condition is satisfied is Second means (step 655) for determining that the hand-over operation state has occurred when the third condition of continuing for one threshold time or longer is satisfied (step 645),
Equipped with.

As described above, the device of the present invention uses both the contact detection sensor and the steering torque sensor to determine which of the gripping driving state and the hand-released driving state is occurring.

That is, the device of the present invention determines that the gripping driving state has occurred when any one of the first condition and the second condition is satisfied, and is in a state where such a determination is made, and the lateral direction driving support. When the control is being executed, if the “state in which neither the first condition nor the second condition is satisfied” continues for the first threshold time or longer (that is, if the third condition is satisfied), the hand-released operation state occurs. It is judged that it did.

The third condition is satisfied when the condition indicating that the steering wheel is gripped (that is, the condition in which at least one of the first condition and the second condition is satisfied) does not occur for the first threshold time or longer. It is a condition to do.

Normally, the first condition is satisfied if the driver holds the steering wheel. However, for example, when the driver is holding the steering wheel while wearing gloves, the contact state signal output from the contact detection sensor may not indicate “contact of the steering wheel by the driver”. Even in such a case, if the driver holds the steering wheel, the steering torque becomes the first threshold value or more within the “certain time (first threshold time)”, so the second condition is satisfied. .. This is for the following reason. That is, since it is extremely rare that an actual road is a completely straight road that extends over an extremely long distance, it is possible that the lateral driving support control for adjusting the lateral position of the vehicle in the driving lane is performed. Also the lateral position of the vehicle deviates from the target position. As a result, it becomes necessary for the driver to steer the steering wheel within the “certain time (first threshold time)”, and the steering torque increases accordingly. Therefore, if the second condition is satisfied, it can be determined that the grip operation state has occurred.

Further, the controller of the device of the present invention includes at least one of “third means or fourth means” described later.

As described above, when a "conductive object" other than the human body of the driver accidentally touches the steering wheel, and the driver intends the "conductive object (for example, a metal plate)" as the steering wheel. In the case where it is assumed that the steering wheel is being gripped by affixing it, the first condition is satisfied. Therefore, in such a case, it is determined that the gripping operation state is generated by the first means even though the gripping operation state is not actually present.

The third means is a means for coping with such a case. The third means determines the magnitude of the steering torque detected when the lateral driving support control is being executed (step 605) and when it is determined by the first means that the grip operation state has occurred (step 660). When the fourth condition that the state in which is less than the second threshold time continues for “the second threshold time longer than the first threshold time” or more continues (step 685), it is determined that the hand-release operation state has occurred.

Even if the first condition is satisfied by the contact of the conductive object with the steering wheel when the driver is not actually touching the steering wheel, in that situation, the steering torque does not increase. Therefore, if the detected steering torque is less than the predetermined value (second threshold value), it can be determined that the hand-released driving state has occurred. However, it is necessary to consider that the situation in which the steering torque may not be generated by the lateral driving support control may continue to some extent. Therefore, the above-mentioned fourth condition is set so that the state where the magnitude of the detected steering torque is less than the second threshold value continues for “the second threshold time period longer than the first threshold time period” or more. ing. As a result, in the case where the device of the present invention includes the third means, even if the first condition is satisfied by the contact of the conductive object with the steering wheel when the driver is not actually touching the steering wheel, It can be determined that the hand-released driving state is occurring when the second threshold time has elapsed.

Further, the third means, when the fifth condition that the magnitude of the detected steering torque is equal to or greater than the second threshold value is satisfied, the hand-release operation state determined to be caused by the satisfaction of the fourth condition is It is determined that the process is completed (steps 665 and 670).

This is because the first condition is satisfied by "contact of a conductive object other than the human body of the driver with the steering wheel" when it is determined that the hand-released driving state is generated because the fourth condition is satisfied. This is because there is a high possibility that an erroneous determination is very high in determining that the gripping operation state has occurred due to the establishment of the first condition.

On the other hand, as described above, depending on the driver, a weight may be attached to the steering wheel to generate steering torque in the direction opposite to the direction in which the steering wheel is about to rotate due to the torque from the road surface. In this case, the second condition that the magnitude of the detected steering torque is equal to or greater than the first threshold value may be satisfied, and thus the first means determines that the vehicle is in the gripping operation state (in other words, the release operation is performed). There is a possibility that it is not judged to be the operating state).

Therefore, the fourth means determines the steering torque detected when the lateral driving support control is being executed and it is determined by the first means that the gripping operation state has occurred due to the establishment of the second condition. The third threshold is a state in which the magnitude is between the “first value equal to or larger than the first threshold” and the “second value larger than the first value by a predetermined value” and the steering torque generation direction does not change. When the sixth condition that it occurs over time is satisfied, it is determined that the hand-over operation state has occurred (steps 920 to 970).

When the lateral driving assistance control is being executed, it is extremely rare that a substantially constant steering torque must be applied to the steering wheel for a long time. In other words, the steering torque must be steered to some extent even when the lateral driving support control is being executed in order to maintain the vehicle at an appropriate position in the driving lane. The orientation and size of the will not remain substantially unchanged. Therefore, when the sixth condition is satisfied, it is considered that the steering torque is generated in the direction opposite to the direction in which the steering wheel is about to rotate due to the torque from the road surface by attaching a weight to the steering wheel. .. Therefore, the fourth means determines that the hand-over operation state has occurred when the sixth condition is satisfied. As a result, it is possible to invalidate the act of delaying the generation of an alarm or continuing the lateral driving support control by abusing the steering torque sensor.

In the above description, in order to help understanding of the present invention, the names and/or reference numerals used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each component of the present invention is not limited to the embodiment defined by the name and/or code.

FIG. 1 is a schematic configuration diagram of a driving support device (first device) according to the first embodiment of the present invention. FIG. 2 is a front view of the steering handle shown in FIG. FIG. 3 is a cross-sectional view of the steering handle shown in FIG. 2 taken along a plane along line 1-1. FIG. 4 is a graph showing the relationship between the duration time during which the steering torque is not detected and the ratio (probability) of the number of occurrences and the cumulative value of the number of occurrences to the whole during the execution of the lateral driving assistance. FIG. 5 is a flowchart showing a routine executed by the driving support ECU of the first device. FIG. 6 is a flowchart showing a routine executed by the driving support ECU of the first device. FIG. 7 is a flowchart showing a routine executed by the driving support ECU of the first device. FIG. 8 is a flowchart showing a routine executed by the driving support ECU of the driving support device (second device) according to the second embodiment of the present invention. FIG. 9 is a flowchart showing a routine executed by the driving support ECU of the second device. FIG. 10 is a flowchart showing a routine executed by the driving support ECU of the second device.

Hereinafter, a driving support device according to each embodiment of the present invention will be described with reference to the drawings. In all the drawings of the respective embodiments, the same or corresponding parts are designated by the same reference numerals.

<First Embodiment>
(Constitution)
The driving support device according to the first embodiment of the present invention (hereinafter sometimes referred to as “first device”) is mounted on a vehicle (not shown). As shown in FIG. 1, the first device includes a driving assistance ECU 10, a steering ECU 30, and a warning ECU 40. The driving assistance ECU 10 is also referred to as a “controller 10” for convenience.

In the present specification, the ECU is an abbreviation of an electric control unit (Electric Control Unit) including a microcomputer as a main part. The microcomputer includes a CPU, ROM, RAM, non-volatile memory, interface I/F and the like. The CPU implements various functions by executing instructions (programs, routines) stored in the ROM. The driving support ECU 10, the steering ECU 30, and the warning ECU 40 are connected to each other via a CAN (Controller Area Network) (not shown) so that information can be transmitted and received. Some or all of these ECUs may be integrated into one ECU.

The steering wheel (steering wheel) SW is well known and has an annular shape in a front view, and its center is connected to the steering shaft SS. The driver of the vehicle can change the steering angle of the steered wheels (steer the steered wheels) by rotating the steering wheel SW.

The steering shaft SS is known and constitutes a part of a known steering mechanism (not shown). The steering shaft SS transmits the force generated by the rotating operation of the steering wheel SW to a well-known steering gear (not shown) to change the turning angle.

The driving support ECU 10 is a main part that constitutes the first device. The driving support ECU 10 is connected to the sensors, switches, devices, and the like described below, and receives signals from these.

Radar sensor 11: The radar sensor 11 acquires information about a road ahead of the vehicle and a three-dimensional object existing on the road. The three-dimensional objects represent, for example, moving objects such as pedestrians, bicycles and automobiles, and fixed objects such as electric poles, trees and guardrails. Hereinafter, these three-dimensional objects may be referred to as “targets”. The radar sensor 11 includes a “radar transmitting/receiving unit and a signal processing unit”, which are not shown. The radar transmitter/receiver unit emits millimeter-wave band radio waves (hereinafter, referred to as “millimeter waves”) to the surrounding area of the vehicle including the area in front of the vehicle and the millimeter waves reflected by the target existing within the radiation range. Receive a wave (ie, a reflected wave). The signal processing unit is configured to detect each target object based on the phase difference between the transmitted millimeter wave and the received reflected wave, the attenuation level of the reflected wave, and the time from transmitting the millimeter wave to receiving the reflected wave. For each time, information indicating a relative relationship such as an inter-vehicle distance (longitudinal distance), a relative speed (relative vertical speed), a lateral distance, and a relative lateral speed is acquired every predetermined time.

Camera device 12: The camera device 12 includes a “stereo camera and an image processing unit” which are not shown. The stereo camera captures a pair of left and right image data by capturing a landscape of a left side region and a right side region in front of the vehicle. The image processing unit calculates and outputs information indicating the presence or absence of the target and the relative relationship between the vehicle and the target based on the pair of left and right image data captured by the stereo camera.

The driving support ECU 10 combines the information indicating the relative relationship between the vehicle and the target obtained by the radar sensor 11, and the information indicating the relative relationship between the vehicle and the target obtained by the camera device 12. Thus, the information indicating the relative relationship between the vehicle and the target (target information) is determined. Further, the driving assistance ECU 10 is based on a pair of left and right image data (road image data) captured by the camera device 12, and lane markers (white lane markers) on the left and right of the road (lane in which the vehicle is traveling, lane). Hereinafter, simply referred to as "white line") is recognized. Based on the recognized white line, the driving assistance ECU 10 further determines the shape of the traveling lane (for example, the radius of curvature indicating the degree of bending of the traveling lane) and the position of the vehicle in the traveling lane (for example, the left and right white lines). The lateral position, which is the deviation between the center position and the center position of the vehicle in the left-right direction, etc. is acquired.

Contact detection sensor 13: The contact detection sensor 13 is a “capacitance type contact detection sensor” provided on the steering wheel SW. The contact detection sensor 13 has a “capacitance detection unit 13a and a measurement circuit 13b” described in detail later. The contact detection sensor 13 is used when the driver holds the steering wheel SW (when a part of the human body of the driver touches the steering wheel SW) and when the driver does not hold the steering wheel SW ( A signal representing a different electrostatic capacitance is output depending on whether a part of the human body of the driver is not in contact with the steering wheel SW). That is, the contact detection sensor 13 outputs the electrostatic capacitance of the electrostatic capacitance detection unit 13a, which changes according to the contact state of the driver to the steering wheel SW, as a contact state signal using the measurement circuit 13b.

Steering torque sensor 14: The steering torque sensor 14 is provided on the steering shaft SS, detects the steering torque Tr applied to the steering shaft SS that rotates together with the steering wheel SW, and outputs a signal indicating the steering torque Tr (for example, Patent No. 1). See Japanese Patent No. 3055752, Japanese Patent No. 2830992, etc.). The steering torque sensor 14 outputs a steering torque generated when the steering wheel SW is rotated counterclockwise as a positive value, and outputs a steering torque generated when the steering wheel SW is rotated clockwise as a negative value.

Steering angle sensor 15: The steering angle sensor 15 detects the steering angle θ of the steering wheel SW and outputs a signal representing the steering angle θ. The steering angle θ becomes zero when the steering wheel SW is in the neutral position (the neutral position for moving the vehicle straight), has a positive value when the steering wheel SW is rotated counterclockwise from the neutral position, and is rotated clockwise from the neutral position. Will be negative.
Vehicle speed sensor 16: The vehicle speed sensor 16 detects the traveling speed (vehicle speed) SPD of the vehicle and outputs a signal representing the vehicle speed SPD.

Operation switch 17: The operation switch 17 is a switch operated by a driver and outputs a signal according to an operation state. By operating the operation switch 17, the driver can select whether or not to execute the lane keeping control.

The steering ECU 30 is an ECU of a known electric power steering system, and is connected to a motor driver 31. The motor driver 31 is connected to the steering motor 32. The steered system motor 32 is incorporated in a steering mechanism (not shown). The steered motor 32 can generate a torque by the electric power supplied from the motor driver 31, and can apply steering assist torque to the steering mechanism by this torque to steer the steered wheels. When the steering ECU 30 receives from the driving assistance ECU 10 the target amount of the steering angle of the steered wheels required to execute the lane keeping control, the steering ECU 30 uses the motor driver 31 so that the actual steering angle matches the target amount. And drives the steering motor 32. As a result, the vehicle can travel while maintaining the running lane.

The alarm ECU 40 is connected to the buzzer 41 and the display (display) 42. The warning ECU 40 sounds a buzzer 41 in response to an instruction from the driving support ECU 10 as a “hand-off warning”, and lights a warning symbol (for example, a warning lamp) on the display 42 to notify the driver. To call attention to. Further, the warning ECU 40 displays another warning message on the display 42 or displays the operation status of the driving support in accordance with the instruction from the driving support ECU 10.

<Structure of steering wheel and contact detection sensor>
Hereinafter, the steering handle SW and the contact detection sensor 13 will be further described. As described above, the contact detection sensor 13 includes the capacitance detection unit 13a and the measurement circuit 13b.

As shown in FIG. 3, the inside of the steering wheel SW of the vehicle shown in FIG. 2 is mainly composed of an upper electrode 21, a lower electrode 22, a core portion 23, and a dielectric (insulator) 24. The capacitance detection unit 13a is composed of an upper electrode 21 and a lower electrode 22.

The upper electrode 21 and the lower electrode 22 extend over substantially the entire circumference of the steering handle SW. As shown in FIG. 3, the upper electrode 21 and the lower electrode 22 have a core portion 23 that has an arc shape in a sectional view, has a circular cross section, and has an annular outer shape that follows the shape of the steering wheel SW. They face each other across. Further, the upper electrode 21 and the lower electrode 22 are housed in the cover portion 25. A dielectric (insulator) 24 is filled in the cover portion 25. In other words, the steering wheel SW has a core portion 23/dielectric 24/upper electrode 21 or lower electrode 22 (capacitance detection portion 13a)/dielectric (insulator) 24 from the center to the outside in a sectional view. /Has a structure in which the cover portion 25 is arranged.

The measurement circuit 13b shown in FIGS. 1 and 2 is connected to each of the pair of upper electrode 21 and lower electrode 22. The measurement circuit 13b includes a stray capacitance between each of the pair of upper electrodes 21 and lower electrodes 22 and an object that can be regarded as a ground such as "vehicle body, human body (hand), and conductive object other than human body", Also, a capacitance that is the sum of the capacitances of the measurement circuit 13b itself is detected, and a signal indicating the capacitance (that is, a contact state indicating a contact state of a part of the human body of the driver with the steering wheel SW) is detected. Signal) to the driving assistance ECU 10. Specifically, when the human body (hand) of the driver comes into contact with the steering wheel SW, the electrostatic capacitance detected by the contact detection sensor 13 decreases.

The driving support ECU 10 determines whether or not it can be considered that the driver holds the steering wheel SW, based on the signal indicating the capacitance transmitted from the measurement circuit 13b. That is, the driving support ECU 10 determines whether or not the capacitance exceeds a predetermined threshold value based on the signal indicating the capacitance received from the measurement circuit 13b. Then, the driving support ECU 10 determines that the conductive object (including the human body of the driver) is not in contact with the steering wheel SW when the electrostatic capacitance is equal to or larger than a predetermined threshold value, and the electrostatic capacitance is determined. Is less than a predetermined threshold value, it is determined that a conductive object (including the driver's human body) is in contact with the steering wheel SW.

<Outline of operation>
Next, an outline of the operation of the first device will be described. The driving assistance ECU 10 of the first device executes the lane keeping control when the operation switch 17 is operated to execute the lane keeping control and the vehicle speed SPD is equal to or higher than the predetermined vehicle speed SPDth.

The lane keeping control is well known, but steering assist torque is steered so that the lateral position of the vehicle is maintained near the target traveling line in the "lane in which the vehicle is traveling (lane or lane)". This is control for adjusting the steered angle of the steered wheels by applying it to the steering mechanism by the motor 32. That is, the lane keeping control is a control that automatically adjusts the lateral position of the vehicle in the traveling lane, and is a control that assists the driver's steering operation. Details of the lane keeping control are described in, for example, JP 2008-195402A, JP 2009-190464A, JP 2010-6279A, and JP 4349210A. In addition to the lane keeping control, the control for controlling the lateral position of the vehicle includes lane departure prevention control (that is, when the vehicle deviates from the lane, the steered wheels are steered to control the lateral position of the vehicle within the lane. Adjustment control), and is also collectively referred to as “lateral driving support control”.

The driving assistance ECU 10 performs the lateral driving assistance control when it is determined that the driver is driving the vehicle while gripping the steering wheel SW (that is, the gripping driving state occurs). When the driving support ECU 10 determines that the driver is driving the vehicle without gripping the steering wheel SW (that is, the hand-released driving state is generated), the driving support ECU 10 continues the lateral driving support control and outputs a predetermined alarm. Give a hand-over alarm over the implementation time. Further, the driving support ECU 10 stops the lateral driving support control unless it determines that the gripping driving state has occurred during the hand-off alarm.

The driving support ECU 10 repeatedly determines whether or not the “first condition and the second condition” described below are satisfied, and when it is determined that at least one of the “first condition and the second condition” is satisfied, the gripping operation is performed. Determine that a condition has occurred.

<First condition>
The contact state signal transmitted from the contact detection sensor 13 indicates that a conductive object including the human body of the driver is in contact with the steering wheel SW. The contact detection sensor itself cannot identify whether the object touching the steering wheel SW is the human body of the driver or another conductive object. Therefore, in the present specification, the fact that a contact state signal equivalent to the case where the human body of the driver is in contact with the steering wheel SW is obtained means that "the steering wheel SW is based on the signal from the contact detection sensor 13". (Driver's) contact with is detected.”
<Second condition>
The magnitude |Tr| of the steering torque (hereinafter also simply referred to as “detected steering torque”) Tr detected by the steering torque sensor 14 is equal to or larger than the first threshold value Tr1th. The first threshold value Tr1th is a positive predetermined value and is preferably set to a value equal to or larger than the maximum value of the detected steering torque generated by the torque input from the road surface when the driver is not gripping the steering wheel SW. ..

The driving support ECU 10 repeatedly determines whether or not a third condition described below is satisfied, and when it is determined that the third condition is satisfied, the hand-released operation state (normal hand-released operation state, that is, the first hand-released operation state). Is determined to have occurred.

<Third condition>
Along with the determination that one of the “first condition and the second condition” is established, it is in a state where it is determined that the grip operation state has occurred, and the lane keeping control as the lateral driving assistance control is executed. In this case, the state in which neither the first condition nor the second condition is satisfied continues for the first threshold time tm1th or longer.

Normally, the first condition is satisfied when the driver holds the steering wheel SW with his bare hand. However, for example, when the driver holds the steering wheel SW while wearing gloves, the contact state signal from the contact detection sensor 13 may not indicate “contact of the steering wheel with SW”. Even in such a case, if the driver holds the steering wheel SW, the detected steering torque Tr becomes the first threshold value Tr1th or more within “a certain time (first threshold time tm1th)”, and as a result, The second condition is satisfied. This is because even if the lane keeping control is executed, the vehicle laterally deviates from the running line desired by the driver due to the shape of the lane, the characteristics of the vehicle, the control delay, etc. This is because the steered wheels are steered using the SW. As can be understood from the above, when the third condition is satisfied, it can be determined that the hand-over operation state has occurred.

By the way, it is assumed that the driver intentionally attaches a "conductive object (for example, a metal plate)" to the steering wheel SW to pretend that the driver holds the steering wheel SW. In this case, since the first condition is satisfied, it is determined that the gripping operation state is occurring even though the driver is not actually gripping the steering wheel SW.

Therefore, the driving assistance ECU 10 repeatedly determines whether or not the fourth condition described below is satisfied, and when it is determined that the fourth condition is satisfied, the hand-released driving state (the hand-released driving state due to the misuse of the contact detection sensor, that is, It is determined that the second release operation state) has occurred.

<Fourth condition>
In the case where it is determined that the grip operation state has occurred with the determination that any of the “first condition and the second condition” is satisfied and the lateral direction driving support control is executed, the detection is performed. The state where the magnitude |Tr| of the steering torque Tr is less than the second threshold value Tr2th (hereinafter, also referred to as “fourth condition precondition state”) is “second threshold time tm2th longer than first threshold time tm1th” or more. continue. In this example, the second threshold value Tr2th is set to the same value as the first threshold value Tr1th, but may be a value different from the first threshold value Tr1th.

Even when the driver does not actually touch the steering wheel SW, even if the first condition is satisfied due to the contact of the steering wheel SW with “a conductive object other than the human body of the driver”, in that situation, the steering torque is reduced. Does not grow. Therefore, if the magnitude |Tr| of the detected steering torque Tr is less than a predetermined value (second threshold value Tr2th), it should be possible to determine that the hand-over driving state is occurring.

However, for example, when the lane keeping control as the lateral driving support control is executed on a straight road that continues for a relatively long time, the situation where the steering torque does not have to be generated may continue for a “some time”. .. Therefore, the above-mentioned fourth condition is set such that the state where the magnitude |Tr| of the detected steering torque Tr is less than the second threshold value Tr2th continues for the second threshold time tm2th or more.

As a result, when the driver does not actually touch the steering wheel SW, the driving assistance ECU 10 determines that the “first conductive condition other than the human body of the driver” is in contact with the steering wheel SW, and thus the first condition is satisfied. Even if it is established, it can be determined that the hand-over operation state has occurred at the time when the second threshold time tm2th has elapsed.

Here, a method of determining the second threshold time tm2th will be described with reference to FIG. FIG. 4 shows that the magnitude |Tr| of the detected steering torque Tr is the second threshold value when the "normal driver" is traveling the vehicle when the lane keeping control as the lateral driving assistance control is executed. The result of having investigated about the continuation time of the state which is not more than Tr2th (namely, the state where steering torque is not detected) is shown. Here, the normal driver refers to a driver who does not intentionally attach a conductive object (for example, a metal plate) other than the human body to the steering wheel SW. The bar graph represents the number of occurrences, and the circle plot represents the ratio of the total number of occurrences to the cumulative value of the number of occurrences up to the duration of interest (that is, the steering torque is detected by the time of interest). Probability).

As can be seen from FIG. 4, the longer the duration in which the steering torque is not detected, the more rapidly (exponentially) the number of occurrences thereof. Therefore, if the second threshold value Tr2th is set to the time tmx in FIG. 4, when the normal driver is driving the vehicle, the steering is performed with a very high probability (X%) before the time tmx elapses. The torque should be detected. In other words, if the second threshold value Tr2th is set to be extremely shorter than the time tmx in FIG. 4, when the normal driver is driving the vehicle in the gripping driving state, it is erroneously determined to be in the hand-over driving state. More likely. On the other hand, when the second threshold value Tr2th is set to be extremely longer than the time tmx in FIG. 4, “a conductive object other than the human body (for example, a metal plate)” is intentionally attached to the steering wheel SW and is released. Therefore, the timing of issuing a warning to the driver who is driving the vehicle that the vehicle is in the released driving state is excessively delayed. From such a viewpoint, the second threshold time tm2th is set to the time tmx. The time tmx naturally changes depending on how much the probability X(%) is set.

Further, the driving assistance ECU 10 repeatedly determines whether or not a fifth condition described below is satisfied, and when it is determined that the fifth condition is satisfied, the hand-release that is determined to be caused by the satisfaction of the fourth condition is released. It is determined that the operating state has ended.

<Fifth condition>
The magnitude |Tr| of the detected steering torque Tr is not less than the second threshold value Tr2th (is not less than the second threshold value Tr2th).

This is because the first condition is highly likely to be satisfied when it is determined that the hand-released operating state (the hand-released operating state due to incorrect use of the contact detection sensor) has occurred due to the establishment of the fourth condition. This is because it is highly likely that an erroneous determination is made when it is determined that the gripping operation state has occurred due to the establishment of the first condition. That is, when it is determined that the hand-released driving state has occurred due to the incorrect use of the contact detection sensor, the contact state signal from the contact detection sensor 13 has low reliability. Therefore, the driving assistance ECU 10 determines that the fourth condition is satisfied until the detected steering torque Tr reaches “a torque (second threshold value Tr2th) generated when the driver surely holds the steering wheel SW”. When the hand-over driving state determined to have occurred has ended, it is not determined during lane keeping control.
However, when the ignition key switch is turned off or the lane keeping control is stopped by the operation switch 17, the driving assistance ECU 10 temporarily terminates the lane keeping control, but the hand-released driving state occurs. Cancel the judgment.

<Specific operation>
Next, the specific operation of the first device will be described. When the ignition key switch of the vehicle (not shown) is turned on, the CPU of the driving support ECU 10 (which may be simply referred to as “CPU”) operates according to the flowcharts of FIGS. 5 to 7 every time a predetermined time elapses. Execute the indicated routine.

(Lane maintenance control)
The CPU starts the process from step 500 of FIG. 5 at a predetermined timing, proceeds to step 510, and determines whether or not to execute the lane keeping control by the operation switch 17. When the determination in step 510 is “Yes”, the CPU proceeds to step 520 to determine whether the vehicle speed SPD is equal to or higher than the threshold vehicle speed SPDth. When it is determined to be “Yes” in step 520, the CPU proceeds to step 530 to determine whether or not the value of the prohibition flag Xkinshi described later is “0”. The value of the inhibition flag Xkinshi is set to "0" in the initial routine executed by the CPU when the ignition key switch is changed from off to on.

When the value of the inhibition flag Xkinshi is "0", the CPU proceeds to step 540 to execute the lane keeping control (LKA) as the lateral driving assistance control described above, and proceeds to step 595 to end the present routine tentatively. ..

On the other hand, if the determination is “No” in any of steps 510, 520, and 530, the CPU proceeds to step 550 to stop the lane keeping control (LKA). Therefore, when the value of the prohibition flag Xkinshi is "1", the lane keeping control is prohibited (not executed). After that, the CPU proceeds to step 595 to end the present routine tentatively.

(Determination of gripping operation status/hand-over operation status)
The CPU starts the process from step 600 of FIG. 6 at a predetermined timing and proceeds to step 605 to determine whether or not the lane keeping control is currently executed. If the lane keeping control is not currently executed, the CPU makes a “No” determination at step 605 to directly proceed to step 695 to end the present routine tentatively.

If the lane keeping control is currently executed, the CPU makes a “Yes” determination at step 605 to proceed to step 610, at which a contact with the steering wheel SW is detected based on a signal from the contact detection sensor 13. (Hereinafter, simply expressed as "whether contact is detected".) Judgment. That is, the CPU determines in step 610 whether or not the first condition is satisfied. When the contact is detected, the CPU determines “Yes” in step 610, sequentially performs the processes of steps 620 to 630 described below, and proceeds to step 660.

On the other hand, if no contact is detected, the CPU makes a “No” determination at step 610 to proceed to step 615 to determine whether or not the magnitude |Tr| of the detected steering torque Tr is equal to or greater than a first threshold value Tr1th. judge. That is, the CPU determines in step 615 whether or not the second condition is satisfied. When the magnitude |Tr| of the detected steering torque Tr is equal to or larger than the first threshold value Tr1th, the CPU determines “Yes” in step 610, sequentially performs the processes of steps 620 to 630 described below, and proceeds to step 660. move on.

Step 620: The CPU sets the value of the grip flag X1h to “1”. When the value of the grip flag X1h is “1”, it indicates that the CPU determines that “a grip operation state is occurring”, and when the value is “0”, the CPU determines that the grip flag is “1”. It means that it is not determined that "the operating state has occurred". Incidentally. The value of the grip flag X1th is set to "1" in the above-mentioned initial routine.

Step 625: The CPU sets the value of the first release flag X1t to “0”. When the value is "1", the first release flag X1t indicates that the CPU determines that "the first release operation state is occurring", and when the value is "0". , Indicates that the CPU has not determined that the “first hand-over driving state has occurred”. Incidentally. The value of the first release flag X1t is set to "0" in the above-mentioned initial routine.

Step 630: The CPU sets the value of the first timer tm1 to “0”. As will be described later, the first timer tm1 is a timer that indicates (measures) the duration of a state in which neither the first condition nor the second condition is satisfied. Incidentally. The value of the first timer tm1 is set to "0" in the above-mentioned initial routine.

On the other hand, when the magnitude |Tr| of the detected steering torque Tr is not equal to or smaller than the first threshold Tr1th (less than) at the time when the CPU executes the process of step 615, the CPU determines “No” in step 615. .. Then, the CPU proceeds to step 635 to determine whether or not the value of the grip flag X1h is “1”. When the value of the grip flag X1h is not “1”, the CPU determines “No” in step 635, directly proceeds to step 695, and ends this routine once.

On the other hand, when the value of the grip flag X1h is “1”, the CPU determines “Yes” in step 635, proceeds to step 640, and increases the value of the first timer tm1 by a predetermined value dt. .. As described above, as for the value of the first timer tm1, the contact is not detected (step 610: “No”) and the magnitude |Tr| of the detected steering torque Tr is less than the first threshold value Tr1th (step 615: “No”) indicates the duration of the state.

Next, the CPU proceeds to step 645 and determines whether or not the first timer tm1 is equal to or longer than the first threshold time tm1th. If the first timer tm1 is not equal to or longer than the first threshold time tm1th, the CPU makes a “No” determination at step 645 to proceed directly to step 695 to end the present routine tentatively.

On the other hand, when the first timer tm1 is equal to or longer than the first threshold time tm1th, the CPU determines “Yes” in step 645, performs the processes of step 650 and step 655 described below, and proceeds to step 660. ..
Step 650: The CPU sets the value of the grip flag X1h to “0”.
Step 655: The CPU sets the value of the first release flag X1t to "1".

When the CPU proceeds to step 660, it determines whether or not the value of the first release flag X1t is “1”. If the value of the first release flag X1t is not "1", the CPU makes a "No" determination at step 660 to directly proceed to step 695 to end the present routine tentatively. On the other hand, when the value of the first release flag X1t is “1”, the CPU determines “Yes” in step 660 and proceeds to step 665, where the magnitude |Tr| of the detected steering torque Tr is the second value. It is determined whether it is smaller than the threshold value Tr2th.

If the magnitude |Tr| of the detected steering torque Tr is not smaller than the second threshold value Tr2th, the CPU sequentially performs the processes of step 670 and step 675 described below, proceeds to step 695, and ends this routine once.

Step 670: The CPU sets the value of the second release flag X2t to “0”. When the value of the second release flag X2t is "1", the CPU determines that "the second release operation state (release operation state due to misuse of the contact detection sensor) has occurred". When the value is “0”, it means that the CPU has not determined that “the second hand-over driving state is occurring”. Incidentally. The value of the second release flag X2t is set to "0" in the above-mentioned initial routine.
Step 675: The CPU sets the value of the second timer tm2 to “0”. Incidentally. The value of the second timer tm2 is set to "0" in the above-mentioned initial routine.

On the other hand, when the magnitude |Tr| of the detected steering torque Tr is less than the second threshold value Tr2th at the time when the CPU performs the process of step 665, the CPU determines “Yes” in step 665 and proceeds to step 680. , The value of the second timer tm2 is increased by a constant predetermined value dt. As described above, the second timer tm2 is a timer that indicates (measures) the duration of the fourth condition precondition state.

Next, the CPU proceeds to step 685, and determines whether or not the second timer tm2 is equal to or longer than the second threshold time tm2th. If the second timer tm2 is not equal to or longer than the second threshold time tm2th, the CPU makes a “No” determination at step 685 to proceed directly to step 695 to end the present routine tentatively.

On the other hand, when the second timer tm2 is equal to or longer than the second threshold time tm2th, the CPU determines “Yes” in step 685 and proceeds to step 690 to set the value of the second release flag X2t to “1”. To do. After that, the CPU proceeds to step 695 to end the present routine tentatively.

(Release alarm)
The CPU starts the process from step 700 of FIG. 7 at a predetermined timing and proceeds to step 705 to determine whether or not the lane keeping control is currently executed. If the lane keeping control is currently being executed, the CPU makes a “Yes” determination at step 705 to proceed to step 710 to determine whether or not the value of the first release flag X1t is “1”. If the value of the first release flag X1t is not “1”, the CPU determines “No” in step 710, and proceeds to step 730 described later.

On the other hand, if the value of the first release flag X1t is “1”, the CPU determines “Yes” in step 710 and proceeds to step 715, where the value of the first release flag X1t changes from “0” to “ It is determined whether or not "the duration of the state in which the value of the first release flag X1t is "1" from the time of changing to "1" is less than or equal to a predetermined time (alarm execution time) Tk.

When the condition of step 715 is satisfied, the CPU proceeds to step 720 and issues a first hand-off alarm. At this time, the CPU causes the alarm ECU 40 to “ring the buzzer 41 and display the first alerting mark on the display 42” in a mode according to the first hand-off alarm. After that, the CPU proceeds to step 735 described later.

On the other hand, when the condition of step 715 is not satisfied (that is, the value of the first release flag X1t is "1" from the time when the value of the first release flag X1t changes from "0" to "1". If the “state duration” exceeds the predetermined time Tk), the CPU makes a “No” determination at step 715 to sequentially perform the processes of step 725 and step 730 described below, and proceeds to step 735.

Step 725: The CPU sets the value of the prohibition flag Xkinshi to “1”. As a result, the lane keeping control is stopped (see the determination of “No” in step 530 of FIG. 5).
Step 730: The CPU ends the first hand-off alarm. If the first hand-off alarm is not issued, the CPU maintains that state.

When the CPU proceeds to step 735, it determines whether or not the value of the second release flag X2t is “1”. If the value of the second release flag X2t is not "1", the CPU determines "No" in step 735, and proceeds to step 755 described later.

On the other hand, if the value of the second release flag X2t is "1", the CPU determines "Yes" in step 735 and proceeds to step 740, where the value of the second release flag X2t is changed from "0" to " It is determined whether or not "the duration of the state in which the value of the second release flag X2t is "1" from the time of changing to "1" is less than or equal to a predetermined time (warning execution time) Tk.

When the condition of step 740 is satisfied, the CPU proceeds to step 745 and issues a second hand-off alarm. At this time, the CPU causes the alarm ECU 40 to “ring the buzzer 41 and display the second alerting mark on the display 42” in a mode according to the second hand-off alarm. After that, the CPU proceeds to step 760 described later.

On the other hand, when the condition of step 740 is not satisfied (that is, the value of the second release flag X2t is "1" from the time when the value of the second release flag X2t changes from "0" to "1"). If the “state duration” exceeds the predetermined time Tk), the CPU makes a “No” determination at step 740 to sequentially perform the processing of step 750 and step 755 described below, and proceeds to step 760.

Step 750: The CPU sets the value of the prohibition flag Xkinshi to “1”. As a result, the lane keeping control is stopped (see the determination of “No” in step 530 of FIG. 5).
Step 755: The CPU ends the second hand-off alarm. When the second hand-off alarm is not issued, the CPU maintains that state.

When the CPU proceeds to step 760, whether the value of the prohibition flag is “1”, the value of the first release flag X1t is “0”, and the value of the second release flag X2t is “0”. To judge. When this determination condition is satisfied, the CPU determines “Yes” in step 760, proceeds to step 765, and sets the value of the inhibition flag Xkinshi to “0”. After that, the CPU proceeds to step 795 to end the present routine tentatively.

On the other hand, when the determination condition of step 760 is not satisfied, the CPU determines “No” in step 760, directly proceeds to step 795, and ends this routine once.

At the time when the CPU executes the process of step 705, if the lane keeping control is not currently executed, the CPU makes a “No” determination at step 705 to proceed to step 770 to proceed to the first and second steps. All the release warnings are terminated, and the respective values of the inhibition flag Xkinshi, the first release flag X1t, the second release flag X2t, the first timer tm1 and the second timer tm2 are set to "0". After that, the CPU proceeds to step 795 to end the present routine tentatively.

As described above, the first device uses both the contact detection sensor 13 and the steering torque sensor 14 to determine which of the grip operation state and the first hand-release operation state has occurred. Therefore, a more accurate determination can be performed as compared with an apparatus that performs the same determination using only one of the contact detection sensor 13 and the steering torque sensor 14.

Further, the first device monitors whether or not the fourth condition and the fifth condition are satisfied, so that the hand-release alarm and/or the lane keeping control can be reliably stopped even when the contact detection sensor 13 is misused. It can be carried out.

<Second Embodiment>
Next, a driving support device according to the second embodiment of the present invention (hereinafter, may be referred to as “second device”) will be described. Similarly to the first device, the second device repeatedly determines whether the “first condition and the second condition” are satisfied, and when it is determined that at least one of the “first condition and the second condition” is satisfied, It is determined that the grip operation state has occurred. Further, like the first device, the second device repeatedly determines whether or not the third condition is satisfied, and when it is determined that the third condition is satisfied, the hand-released operation state (normal hand-released operation state, that is, the first device). It is determined that the one-handed operation state) has occurred.

On the other hand, the second device does not determine the hand-released driving state using the fourth condition.
On the other hand, the second device repeatedly determines whether or not the sixth condition described below is satisfied, and when it is determined that the sixth condition is satisfied, the hand-released operating state (the hand-released operating state due to incorrect use of the torque sensor, that is, the first condition). It is determined that the (3 hand-released operation state) has occurred.

<Sixth condition>
The magnitude |Tr| of the detected steering torque Tr is in the state where it is determined that the gripping driving state has occurred in accordance with the determination that the second condition is satisfied, and the lateral driving assistance control is being executed. Is between the “first value equal to or larger than the first threshold value Tr1th” and the “second value larger than the first value by a predetermined value”, and the generation direction of the detected steering torque Tr does not change. State occurs over a third threshold time.

When the lane keeping control, which is the lateral driving support control, is being executed, it is extremely rare to apply a substantially constant steering torque (steering torque having a substantially constant direction and magnitude) to the steering wheel for a long time. is there. In other words, in order to maintain the vehicle at an appropriate position in the driving lane, the steering wheel must be steered to some extent even when the lane keeping control is being executed, so that the steering torque is long. It can never change significantly over time. Therefore, when the sixth condition is satisfied, the driver attaches a weight to the steering wheel SW to generate steering torque in the direction opposite to the direction in which the steering wheel is about to rotate due to the torque from the road surface. it is conceivable that.

Therefore, if the sixth condition is satisfied, the second device determines that the hand-released operating state (the hand-released operating state due to incorrect use of the torque sensor, that is, the third hand-released operating state) has occurred. When the second device determines that the hand-released driving state has occurred with the establishment of the sixth condition, it immediately stops the execution of the lane keeping control, and issues a third hand-release alarm for a predetermined time from that point. If the second device determines that the hand-released driving state has occurred due to the establishment of the sixth condition, the ignition key switch is turned off, the lane keeping control is stopped by the operation switch 17, or the detected steering torque Tr Until the magnitude |Tr| becomes equal to or larger than the “second value that is larger than the first value by a predetermined value”, it is determined that the hand-released driving state has been released and the gripping driving state has been restored. Does not.

<Specific operation>
The CPU of the driving assistance ECU 10 included in the second device executes the routine shown in FIG. 5 and the routines shown by the flowcharts in FIGS. 8 to 10 each time a predetermined time has elapsed. Since the routine of FIG. 5 has already been described, the specific operation of the second device will be described below according to the routines of FIGS. 8 to 10.

(Determination of gripping operation status/release operation status)
When the predetermined timing comes, the CPU starts the process from step 800 of FIG. The routine of FIG. 8 is a routine for performing the processing from step 605 to step 655 of the routine of FIG. 6 according to the flow. As a result, when either the first condition (see step 610) or the second condition (see step 615) is satisfied, the grip flag X1h is set to “1” (see step 620), and , The value of the first release flag X1t is set to "0" (see step 625).

Further, when the third condition (see step 645) is satisfied, the grip flag X1h is set to “0” (see step 650), and the value of the first release flag X1t is set to “1”. (See step 655).

(Judgment of hand-operated state due to incorrect use of torque sensor)
In addition, the CPU starts the process from step 900 of FIG. 9 at a predetermined timing and proceeds to step 905 to determine whether or not the lane keeping control is currently executed. If the lane keeping control is not currently executed, the CPU makes a “No” determination at step 905 to proceed directly to step 995 to end the present routine tentatively.

If the lane keeping control is currently executed, the CPU makes a “Yes” determination at step 905 to proceed to step 910 to determine whether the value of the grip flag X1h is “1”. If the value of the grip flag X1h is not "1", the CPU makes a "No" determination at step 910 to directly proceed to step 995 to end the present routine tentatively.

If the value of the grip flag X1h is “1”, the CPU determines “Yes” in step 910 and proceeds to step 915 to determine whether the magnitude |Tr| of the detected steering torque Tr is the first threshold value Tr1th or more. Determine whether or not. That is, the CPU determines in step 915 whether or not the second condition is satisfied. When the magnitude |Tr| of the detected steering torque Tr is not equal to or larger than the first threshold value Tr1th, the CPU makes a “No” determination at step 915 to directly proceed to step 995 to end the present routine tentatively.

If the magnitude |Tr| of the detected steering torque Tr is greater than or equal to the first threshold value Tr1th, the CPU determines “Yes” in step 915 and proceeds to step 920. It is determined whether or not | is a time point immediately after changing from a value less than the first threshold value Tr1th to a value greater than or equal to the first threshold value Tr1th (hereinafter, this time point is also simply referred to as “steering torque detection time point”). To do.

When the determination condition in step 920 is satisfied, the CPU proceeds from step 920 to step 925 and sets the value of the third timer tm3 to "0". Next, the CPU proceeds to step 930 to determine whether the detected steering torque Tr is “0” or more. When the detected steering torque Tr is equal to or greater than “0”, the CPU sequentially performs the processes of step 935 and step 940 described below, and proceeds to step 955. On the other hand, when the detected steering torque Tr is less than “0”, the CPU sequentially performs the processes of step 945 and step 950 described below, and proceeds to step 955. When the determination condition of step 920 is not satisfied, the CPU determines “No” in step 920 and directly proceeds to step 955.

Step 935: The CPU sets the detected steering torque Tr at that time as the lower limit value TdLim. The lower limit value TdLim set in step 935 is also referred to as a first value for convenience.
Step 940: The CPU sets, as the upper limit value TuLim, a value obtained by adding a constant positive value ΔTr to the lower limit value TdLim. The upper limit value TuLim set in step 940 is also referred to as a second value for convenience.

Step 945: The CPU sets the detected steering torque Tr at that time as the upper limit value TuLim. The upper limit value TuLim set in step 945 is also referred to as a second value for convenience.
Step 950: The CPU sets a value obtained by subtracting a constant positive value ΔTr from the upper limit value TuLim as the lower limit value TdLim. The lower limit value TdLim set in step 950 is also referred to as a first value for convenience.

When the CPU proceeds to step 955, it determines whether or not the detected steering torque Tr at that time is equal to or more than the lower limit value TdLim and equal to or less than the upper limit value TuLim. In other words, in step 955, the CPU determines that the direction of the detected steering torque Tr at the current time point is the same as the direction of the detected steering torque Tr immediately after the steering torque detection time point, and at the current time point. The magnitude |Tr| of the detected steering torque Tr in step S1 is equal to the magnitude (first value) of the detected steering torque Tr immediately after the steering torque is detected, and the second value larger by a predetermined value ΔTr than that. It is determined whether it is a value between.

When the determination condition of step 955 is satisfied, the CPU proceeds to step 960 and increases the value of the third timer tm3 by a constant predetermined value dt. The value of the third timer tm3 indicates the duration of the state in which the determination condition of step 955 is satisfied (see also step 975 described later).

Next, the CPU proceeds to step 965 to determine whether the third timer tm3 is equal to or longer than the third threshold time tm3th. If the third timer tm3 is not equal to or longer than the third threshold time tm3th, the CPU makes a “No” determination at step 965 to directly proceed to step 995 to end the present routine tentatively.

On the other hand, when the third timer tm3 is equal to or longer than the third threshold time tm3th, the CPU determines “Yes” in step 965 and proceeds to step 970 to set the value of the third release flag X3t to “1”. To do. Incidentally. The value of the third release flag X3t is set to "0" in the above-mentioned initial routine. After that, the CPU proceeds to step 995 to end the present routine tentatively. If the determination condition of step 955 is not satisfied when the CPU executes the process of step 955, the CPU proceeds to step 975 and sets the value of the third timer tm3 to “0”. Incidentally. The value of the third timer tm3 is set to "0" in the above-mentioned initial routine. After that, the CPU proceeds to step 995 to end the present routine tentatively.

(Release alarm)
The CPU starts the process from step 1000 of FIG. 10 at a predetermined timing and performs the processes of steps 705 to 730 according to the flow. The processing of steps 705 to 730 has already been described with reference to FIG. 7, and thus description thereof will be omitted here. As a result, as long as the value of the first release flag X1t is "1", the first release alarm is issued for a predetermined time Tk after the value of the first release flag X1t becomes "1", and thereafter, The value of the prohibition flag Xkinshi is set to "1".

When the CPU proceeds to step 1010 from either step 720 or step 730, the CPU determines whether or not the value of the third release flag X3t is “1”. When the value of the third release flag X3t is “1”, the CPU determines “Yes” in step 1010 and proceeds to step 1020, and the value of the third release flag X3t changes from “0” to “1”. It is determined whether or not the “duration time when the value of the third release flag X3t is “1”” from the point of time is equal to or less than a predetermined time (warning execution time) Tk.

When the condition of step 1020 is satisfied, the CPU sequentially performs the processes of step 1030 and step 1040 described below, and proceeds to step 1060.
Step 1030: The CPU issues a third hand-off alarm. At this time, the CPU causes the alarm ECU 40 to perform “ringing of the buzzer 41 and display of the third alerting mark on the display 42” in a mode according to the third hand-off alarm.
Step 1040: The CPU sets the value of the prohibition flag Xkinshi to “1”. As a result, the lane keeping control is stopped (see the determination of “No” in step 530 of FIG. 5).

On the other hand, when the condition of step 1020 is not satisfied (that is, the value of the third release flag X3t is “1” from the time when the value of the third release flag X3t changes from “0” to “1”). If the “duration” exceeds the predetermined time Tk), the CPU determines “No” in step 1020. Then, the CPU proceeds to step 1050 to end the third release warning. In this case, if the third hand-off alarm has not been issued, the CPU maintains that state.

If the value of the third release flag X3t is not “1” at the time when the CPU executes the process of step 1010, the CPU directly proceeds from step 1010 to step 1060.

In step 1060, the CPU determines whether the value of the inhibition flag Xkinshi is “1”, the value of the first release flag X1t is “0”, and the value of the third release flag X3t is “0”. Determine whether. When the determination condition in step 1060 is satisfied, the CPU determines “Yes” in step 1060, proceeds to step 1070, and sets the value of the inhibition flag Xkinshi to “0”. After that, the CPU proceeds to step 1095 to end the present routine tentatively. On the other hand, if the determination condition in step 1060 is not satisfied, the CPU determines “No” in step 1060, proceeds directly to step 1095, and ends this routine once.

If the lane keeping control is not being executed at the time when the CPU executes the process of step 705, the CPU makes a “No” determination at step 705 to proceed to step 1080. Then, in step 1080, the CPU ends the first release alarm and sets the respective values of the inhibition flag Xkinshi, the first release flag X1t, the first timer tm1 and the third timer tm3 to “0”. .. After that, the CPU proceeds to step 1095 to end the present routine tentatively.

As described above, like the first device, the second device uses both the contact detection sensor 13 and the steering torque sensor 14 to determine which of the grip operation state and the first hand-release operation state has occurred. To do. Therefore, a more accurate determination can be performed as compared with an apparatus that performs the same determination using only one of the contact detection sensor 13 and the steering torque sensor 14.

Further, the second device can reliably stop the hand-release alarm and/or stop the lane keeping control by monitoring whether the sixth condition is satisfied even when the steering torque sensor 14 is misused. ..

The present invention is not limited to the above embodiment, and various modifications can be adopted within the scope of the present invention. For example, the contact detection sensor 13 is not limited to a capacitance-type contact detection sensor, and may be a resistance-film type touch sensor, a membrane switch, a pressure detection sensor, or the like whose signal switches depending on whether or not there is a human body contact. good.

Further, the function of the second device (that is, the function of monitoring the satisfaction of the sixth condition and stopping the third hand-off alarm and lane keeping control when the sixth condition is satisfied) is added to the first device. May be.

Furthermore, the first threshold value Tr1th, the second threshold value Tr2th, the predetermined value ΔTr, the first threshold value time tm1th, the second threshold value time tm2th, and the third threshold value time tm3th depend on the environment (temperature, running place), date and time in which the vehicle exists. It may be changed based on each vehicle, or may be changed for each vehicle, each vehicle type, and each driver.

10... Driving support ECU (controller), 11... Radar sensor, 12... Camera device, 13... Contact detection sensor, 13a... Capacitance detection part, 13b... Measuring circuit, 14... Steering torque sensor, 17... Operation switch, 31 ... Motor driver, 32... Steering motor, 41... Buzzer, 42... Indicator.

Claims (1)

A driving assistance device that executes lateral driving assistance control for automatically steering a steering wheel of a vehicle to adjust a lateral position of the vehicle in a lane in which the vehicle is traveling,
A contact detection sensor that outputs a contact state signal indicating a contact state of the driver of the vehicle with the steering wheel of the vehicle;
A steering torque sensor that detects a steering torque generated on a steering shaft connected to the steering handle,
Any one of a gripping driving state in which the driver is driving the vehicle while gripping the steering wheel, and a hand-over driving state in which the driver is driving the vehicle without gripping the steering wheel A controller that determines if a condition is occurring,
Equipped with
The controller is
A first condition that the contact state signal indicates that the driver is in contact with the steering wheel, and a second condition that the magnitude of the detected steering torque is equal to or greater than a first threshold value. First means for determining that the gripping operation state has occurred when any one of the conditions is satisfied;
When the lateral driving support control is being executed and it is determined by the first means that the gripping driving state has occurred, a state in which neither the first condition nor the second condition is satisfied is Second means for determining that the hand-over operation state has occurred when a third condition of continuing for one threshold time or longer is satisfied;
Equipped with
The controller further comprises
A state in which the magnitude of the detected steering torque is less than a second threshold value when the lateral driving support control is being executed and the gripping operation state is determined to have occurred by the first means is When the fourth condition of continuing for a second threshold time longer than the first threshold time is satisfied, it is determined that the hand-released operating state has occurred, and the magnitude of the detected steering torque is the second threshold or more. And a third means for determining that the hand-released operation state has been determined to have occurred when the fourth condition is satisfied when the fifth condition is satisfied, or
The magnitude of the steering torque detected when the lateral driving support control is being executed and it is determined by the first means that the gripping operation state has occurred due to the satisfaction of the second condition. Is between a first value that is equal to or greater than the first threshold value and a second value that is greater than the first value by a predetermined value, and the direction in which the steering torque is generated does not change for a third threshold time. Fourth means for determining that the hand-over operation state has occurred when the sixth condition that occurs when
A driving support device including at least one of the above.

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