JP2015020633A - Lane keeping assist system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lane keeping assist system capable of easily and accurately detecting an inadequate situation to continue lane keeping assist control.SOLUTION: A lane keeping assist system comprises: lane detection means for detecting a lane where a vehicle travels thereon; an actuator which generates a force to change a direction of the vehicle; and a control device which performs lane keeping assist control to activate the actuator in a manner that allows the vehicle to travel in the lane. The control device curbs the lane keeping assist control when steering operation of a driver is not detected and a steering angular rate is not less than a predetermined rate under a situation that the actuator is activated through the lane keeping assist control.

Description

  The present disclosure relates to a lane keeping assist device.

  2. Description of the Related Art Conventionally, there is known a lane departure prevention device that applies a steering force to a steering mechanism so as to prevent a departure from the traveling lane of the host vehicle (for example, see Patent Document 1). In this lane departure prevention apparatus, the friction coefficient of the road surface is detected, and the pulsed steering force applied to the steering mechanism is reduced in accordance with the decrease in the friction coefficient. Patent Document 1 discloses only a friction coefficient detection method using various parameters such as vehicle speed, steering wheel angle, yaw rate, and a given vehicle motion model.

JP 2010-023605

  However, the friction coefficient detection method using various parameters such as vehicle speed, steering wheel angle, yaw rate, and a given vehicle motion model formula has a problem that the detection method is complicated and the processing load increases.

  Therefore, an object of the present disclosure is to provide a lane keeping assist device that can easily and accurately detect a non-conforming situation for continuing the lane keeping assist control.

According to one aspect of the present disclosure, lane detection means for detecting a lane in which the vehicle travels;
An actuator that generates a force that changes the direction of the vehicle;
A control device for performing lane keeping support control for operating the actuator so that the vehicle travels in the lane,
The control device suppresses the lane keeping support control when the driver's steering operation is not detected and the steering angular velocity is equal to or higher than a predetermined speed under the situation where the actuator is operated by the lane keeping support control. A lane keeping assist device is provided.

  According to the present disclosure, it is possible to obtain a lane keeping assist device that can easily and accurately detect a non-conforming situation for continuing lane keeping assist control.

It is a figure which shows the system configuration | structure of the lane maintenance assistance apparatus 100 by one Example. 4 is a block diagram illustrating an example of a control calculation unit 15. FIG. 5 is a flowchart illustrating an example of nonconforming environment determination processing by an abnormality determination unit 18; 10 is a flowchart illustrating another example of nonconforming environment determination processing by the abnormality determination unit 18; It is a flowchart which shows an example of the nonconforming environment determination process by EPS-ECU21. It is explanatory drawing of an example of the setting aspect of predetermined threshold value Th3 '.

  Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating a system configuration of a lane keeping assist device 100 according to an embodiment.

  The lane keeping assist device 100 includes an LKA (Lane Keeping Assist) -ECU (Electronic Control Unit) 10. The LKA-ECU 10 may be configured by a microcomputer or the like.

  An EPS (Electric Power Steering) system 20 is connected to the LKA-ECU 10 via an appropriate bus such as a CAN (controller area network). The EPS system 20 includes an EPS-ECU 21. The EPS-ECU 21 includes a torque sensor 22 that detects a steering torque of the steering shaft (hereinafter referred to as a driver steering torque) by the driver, and a steering sensor 24 that detects a steering angle of the steering shaft (or steering wheel) by the driver. And are connected.

  Further, a steering actuator 26 is connected to the EPS-ECU 21. The EPS-ECU 21 generates a control torque output according to the steering assist request torque from the LKA-ECU 10 and controls the steering actuator 26. Thereby, the steering torque according to the steering assistance request torque from the LKA-ECU 10 is generated.

  The steering actuator 2 may have any configuration that generates a steering torque (steering force). The steering actuator 26 may be a motor used in assist control that applies assist torque in the steering direction of the driver. For example, the steering actuator 26 may be provided coaxially with a steering rack (not shown) in the steering gear box. In this case, the steering actuator 26 may be engaged with the steering rack via a ball screw nut. In this case, the steering actuator 26 assists the movement of the steering rack by the driving force.

  The torque sensor 22 and the steering sensor 24 are connected to the LKA-ECU 10 via an appropriate bus such as CAN. The LKA-ECU 10 directly acquires information on the driver steering torque and steering angle from the torque sensor 22 and the steering sensor 24. Information on the driver steering torque and steering angle may be acquired indirectly via the EPS-ECU 21.

  The LKA-ECU 10 is connected to a vehicle speed detection means 30, a front camera 32, a main switch 34, and the like.

  The vehicle speed detection means 30 may be a wheel speed sensor, for example. The vehicle speed may be calculated based on the number of rotations of the output shaft of the transmission, a history of vehicle position measurement results by a global navigation satellite system (GNSS) receiver, and the like.

  The front camera 32 may be a monocular or compound eye camera that mainly captures the vehicle periphery including a predetermined range in front of the vehicle. The photoelectric conversion element of the front camera 32 may be a charge-coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or the like. The front camera 32 may output image data obtained by photographing the front of the vehicle to the LKA-ECU 10.

  The main switch 34 is a switch operated by the user, and may be arranged at an arbitrary place in the vehicle interior. The main switch 34 may be a mechanical switch or a touch switch. The main switch 34 is an interface for the user to input to the lane keeping assist device 100 an intention of performing lane keeping assist control described later. Here, as an example, it is assumed that the main switch 34 is turned on when there is an intention to perform lane keeping assist control. It should be noted that a display notifying the on / off state of the main switch 34 (that is, the on / off state of the lane keeping assist function) may be output to the meter (not shown).

  The LKA-ECU 10 may recognize a lane marking from the image data of the front camera 32 and calculate road information. A lane marking is a road marking that divides (defines) a driving lane (lane). The lane marking is a linear marking object formed by applying paint that can be distinguished from a road surface, such as white, in a linear manner along the road. There are also white lines formed in chromatic colors such as yellow and orange according to road regulations and countries. Further, the lane markings include not only those formed in a line but also dotted lines and broken lines provided with a non-painted portion for each predetermined length. Furthermore, when a traveling lane is divided not by paint but by a three-dimensional object such as botsdots such as the United States, such a three-dimensional object is also a lane marking. In addition, when a traveling lane is divided by arranging a light emitting element such as a cat's eye or a lamp along the road, these are also lane markings.

  The road information may include an angle (yaw angle) φ formed by the direction of the vehicle lane and the vehicle longitudinal axis, a lateral displacement X from the center of the vehicle lane to the vehicle center, and a curvature β of the vehicle lane. . Note that the curvature β of the traveling lane is determined by scanning the luminance information in the horizontal direction at predetermined intervals in the vertical direction of the image data, detecting an edge with a predetermined intensity or more in the horizontal direction, and detecting the position of the detected edge. It may be derived by applying curve fitting (eg, least square method).

  The LKA-ECU 10 performs lane keeping support control based on road information in cooperation with the EPS-ECU 21. The lane keeping support control may include alarm control via an information output device such as a buzzer or a meter, and intervention control for changing the direction of the vehicle via the steering actuator 26. Alternatively, the lane keeping support control may be only intervention control. In the following, the intervention control will be described as LKA (Lane Keeping Assist) that assists the driver's steering so as to travel while maintaining the travel lane, but operates when a deviation from the travel lane is detected. It may be an LDW (Lane Departure Warning) or other kind of control. In LKA, steering torque is steadily supported according to the lateral displacement or yaw angle from the target travel line (the center of the travel lane), and when a deviation tendency is detected, the steering torque for suppressing deviation is detected. To suppress deviations. In the LDW, when a deviation tendency from the traveling lane is detected, the deviation is suppressed by the steering torque for suppressing the deviation. During intervention control, both steering torque and yaw moment by a brake actuator (not shown) may be generated, or only steering torque may be generated.

  As shown in FIG. 1, the LKA-ECU 10 may output a steering support request flag and a steering support request torque to the EPS-ECU 21. When the steering support request flag is on, the lane keeping support function is on, and the LKA-ECU 10 outputs an operation request instruction (steering support request torque) to the EPS-ECU 21. The off state of the steering assist request flag means that the lane keeping assist function is off, that is, the system is stopped. The EPS-ECU 21 may generate a steering torque corresponding to the steering support request torque when the steering support request torque is received in a state where the steering support request flag is in an on state.

  As shown in FIG. 1, LKA-ECU 10 includes a control calculation unit 15 and an abnormality determination unit 18.

  FIG. 2 is a block diagram illustrating an example of the control calculation unit 15. In the example illustrated in FIG. 2, the control calculation unit 15 includes a departure determination unit 121, a target trace line creation unit 122, a target lateral acceleration calculation unit 123, and a target steering torque calculation unit 124.

  The departure determination unit 121 determines whether or not the vehicle departs from the travel lane. The departure determination may be realized by an arbitrary method. For example, the departure prediction time is calculated based on the change mode of the lateral displacement X of the vehicle, and it is detected that there is a departure tendency (departs) when the departure prediction time becomes equal to or less than a threshold value.

  The target trace line creation unit 122 creates a target trace line for suppressing the departure when it is determined that the departure is made. The target trace line may include two lines, a first line and a second line. In this case, the first line may be a target trace line for suppressing deviation, and the second line may be a target trace line for correcting the direction of the vehicle after deviation suppression. The second line may be set to a substantially straight line near the curve exit.

When it is determined that the target lateral acceleration calculating unit 123 deviates, the target lateral acceleration calculating unit 123 calculates the target lateral acceleration so that the vehicle travels on the target trace line. For example, the target lateral acceleration may be calculated as follows, for example.
Target lateral acceleration ^{Gx = G1 · V 2 · β} + G2 · φ + G3 · X
Here, G1 is a feedforward operator (gain), G2 is a feedback operator, and G3 is a feedback operator. Note that such a calculation method is an example. For example, the calculation may be performed only from the lateral displacement X and the yaw angle φ, or the speed may be included in the feedback term of the yaw angle φ. Further, it may be simply read out from a map in which the target lateral acceleration Gx is associated with the yaw angle φ and the lateral displacement X.

The target steering torque calculator 124 calculates a target steering torque according to the target lateral acceleration. For example, the gain K is determined according to the vehicle speed, and the target steering torque is calculated by the following equation based on the gain K and the target lateral acceleration.
Target steering torque ST = K · Gx
The gain K is a function of the vehicle speed determined in consideration that the steering torque required for tracing the target trace line varies depending on the vehicle speed.

  The target steering torque calculated by the target steering torque calculator 124 in this way is output to the EPS-ECU 21 as the steering assist request torque.

The intervention control may be realized by a braking force instead of or in addition to the steering assist request torque. In this case, the control calculation unit 15 may calculate, for example, the target cylinder pressure difference ΔPf for the front wheels and the target cylinder pressure difference ΔPr for the rear wheels based on the target lateral acceleration.
ΔPf = 2 · Cf · (Gx−Th) / Tr
ΔPr = 2 · Cr · Gx / Tr
Here, Tr is the tread length, and Cf and Cr are conversion coefficients when the lateral acceleration is converted into the wheel cylinder pressure. Further, Th is a constant for making the target cylinder pressure difference ΔPf of the front wheels smaller than that of the rear wheels. In the case of an outside deviation, the target wheel cylinder pressure of the front wheel of the outer ring (left side in the case of the left curve) is made larger by ΔPf than the target wheel cylinder pressure of the front wheel of the inner ring, and the target wheel cylinder pressure of the rear wheel of the outer ring is set behind the inner ring. ΔPr larger than the target wheel cylinder pressure of the wheel. Thereby, an inward yaw moment is generated and deviation can be suppressed. In the case of internal deviation, the target wheel cylinder pressure of the front wheel of the outer wheel (right side in the case of the left curve) is made larger by ΔPf than the target wheel cylinder pressure of the inner front wheel, and the target wheel cylinder pressure of the rear wheel of the outer wheel is set to the inner side. ΔPr larger than the target wheel cylinder pressure of the rear wheel. Thereby, an outward yaw moment is generated and deviation can be suppressed.

  FIG. 3 is a flowchart illustrating an example of the nonconforming environment determination process performed by the abnormality determination unit 18. The process shown in FIG. 3 may be repeatedly executed at predetermined intervals while the steering assist request torque is being output (that is, during intervention control).

  In step 300, based on the driver steering torque information from the torque sensor 22, it is determined whether the driver steering torque is equal to or less than a predetermined threshold value Th1. The predetermined threshold Th1 may be set in an arbitrary manner. For example, the predetermined threshold Th1 may correspond to the maximum value of the range that can be taken by the driver steering torque when the driver is not substantially steering, and may be adapted by a test or the like. If the driver steering torque is equal to or less than the predetermined threshold Th1, the process proceeds to step 302. Otherwise, the count of abnormal time (described later) is reset to 0 (step 303), and step 300 is performed in the next processing cycle. Start with

  In step 302, based on the steering angle information from the steering sensor 24, it is determined whether or not the steering angular velocity is equal to or greater than a predetermined threshold Th2. The steering angular velocity is a time change (for example, a differential value) of the steering angle, and may be simply a difference from the previous value (or a value obtained by dividing the difference by the detection cycle), or the detected values at the latest three time points or more. May be calculated based on The predetermined threshold Th2 may be set in an arbitrary manner. For example, the predetermined threshold Th2 is a road environment that is incompatible with the execution of intervention control (for example, a low μ road, a road with a steep cant, etc., and hereinafter also simply referred to as “non-conforming environment”). May correspond to the minimum value of the range of steering angular velocities that can be taken when the intervention control is executed in a state where the hand is substantially released from the steering wheel, and may be adapted by testing or the like. Further, the predetermined threshold Th2 may be a fixed value, but may be varied according to, for example, the steering assist request torque currently being output. In this case, the predetermined threshold value Th <b> 2 may be varied so as to decrease as the steering assist request torque decreases. If the steering angular velocity is greater than or equal to the predetermined threshold value Th2, the process proceeds to step 304. Otherwise, the abnormal time (described later) count is reset to 0 (step 303), and starts from step 300 in the next processing cycle. To do.

  In step 304, the abnormal time is counted up. The abnormal time corresponds to the duration when the driver steering torque is equal to or less than the predetermined threshold Th1 and the steering angular velocity is equal to or greater than the predetermined threshold Th2.

  In step 306, it is determined whether or not the abnormal time is greater than or equal to a predetermined threshold Th3. The predetermined threshold Th3 may be set arbitrarily. For example, the predetermined threshold Th3 may be appropriately adapted from the viewpoint of detecting the nonconforming environment as early as possible and the viewpoint of enhancing robustness against noise or the like. If the abnormal time is equal to or greater than the predetermined threshold Th3, the process proceeds to step 308. Otherwise, the abnormal time count is not reset, and the process starts from step 300 in the next processing cycle.

  In step 308, the lane keeping support function is stopped (system stop). Specifically, the steering support request flag is turned off and the output of the steering support request torque is stopped.

  By the way, in a road environment unsuitable for intervention control such as a low μ road or a road with a steep cant, the steering angular velocity can be increased when the steering torque corresponding to the steering assist request torque is generated. On the other hand, even in a road environment where intervention control is properly executed, such as a road with a normal coefficient of friction, if the driver operates the steering wheel himself (giving the driver steering torque), steering The angular velocity increases as well.

  In this regard, according to the process shown in FIG. 3, in a situation where the driver steering torque is equal to or less than a predetermined threshold Th1, when the steering angular velocity is equal to or higher than the predetermined threshold Th2, it is determined that the environment is incompatible. Intervention control (output of steering support request torque) is stopped. As a result, it is possible to accurately detect the nonconforming environment under the situation where the driver is not performing the steering operation, and appropriately prevent the intervention control from being executed in the nonconforming environment. Further, since the nonconforming environment is determined using the driver steering torque information and the steering angle information, a simple determination process can be realized.

  If the lane keeping support function is stopped in step 308 in FIG. 3, the lane keeping support function is maintained for a predetermined time thereafter, and then a negative determination is made in step 300 or step 302. The function may be restored (provided that the main switch 34 is on).

  Note that the processing shown in FIG. 3 is executed by the LKA-ECU 10, but may be executed by the EPS-ECU 21 instead. In this case, in step 308, the EPS-ECU 21 may stop the lane keeping support function by invalidating the steering support request torque from the LKA-ECU 10. The invalidation may be realized in an arbitrary manner. For example, invalidation may be realized simply by not responding to the steering assist request torque from the LKA-ECU 10 (for example, by not generating a control torque output). Alternatively, as invalidation processing, the EPS-ECU 21 notifies the LKA-ECU 10 that a non-conforming environment has been detected, thereby stopping the output of the steering support request torque from the LKA-ECU 10 (and turning off the steering support request flag). ) May be requested.

  Further, the nonconforming environment determination process shown in FIG. 3 may be executed independently in both the LKA-ECU 10 and the EPS-ECU 21. As a result, even if the LKA-ECU 10 cannot detect the non-conforming environment due to some abnormality, the lane keeping support function can be stopped on the EPS-ECU 21 side, and the fail sale function is improved.

  FIG. 4 is a flowchart showing another example of the nonconforming environment determination process by the abnormality determination unit 18 of the LKA-ECU 10. The processing shown in FIG. 4 may be repeatedly executed at predetermined intervals while the steering assist request torque is being output (that is, during intervention control). The nonconforming environment determination process shown in FIG. 4 is suitable to be executed by the LKA-ECU 10 in a configuration in which the nonconforming environment determination process is executed in parallel in both the LKA-ECU 10 and the EPS-ECU 21. In this case, the EPS-ECU 21 may execute the nonconforming environment determination process shown in FIG.

  The non-conforming environment determination process shown in FIG. 4 is different in that the process of step 300 of the non-conforming environment determination process shown in FIG. 3 is omitted, and the other cases may be the same. Thereby, the LKA-ECU 10 can detect the non-conforming environment at a timing earlier than that of the EPS-ECU 21. In this case, since the LKA-ECU 10 determines the nonconforming environment without considering the driver steering torque, the nonconforming environment is detected even when the driver is operating the steering wheel. There is a case. Considering this point, the EPS-ECU 21 also stops the lane keeping support function only when the non-conforming environment is detected (that is, only when the non-conforming environment is detected in both the LKA-ECU 10 and the EPS-ECU 21). You may do it.

  FIG. 5 is a flowchart illustrating an example of the nonconforming environment determination process performed by the EPS-ECU 21. The nonconforming environment determination process shown in FIG. 5 is executed by the EPS-ECU 21 in a configuration in which the nonconforming environment determination process is executed in parallel in both the LKA-ECU 10 and the EPS-ECU 21. In this case, the LKA-ECU 10 may execute the nonconforming environment determination process shown in FIG. 3 or the nonconforming environment determination process shown in FIG.

  In step 500, based on the driver steering torque information from the torque sensor 22, it is determined whether or not the driver steering torque is equal to or less than a predetermined threshold Th1 ′. The predetermined threshold Th1 ′ may be set in an arbitrary manner. For example, the predetermined threshold Th1 ′ may be the same value as the predetermined threshold Th1 used in Step 300 of FIG. 3, but is preferably a value smaller than the predetermined threshold Th1. If the driver steering torque is equal to or less than the predetermined threshold value Th1 ′, the process proceeds to step 502; otherwise, the process proceeds to step 512.

  In step 502, based on the steering angle information from the steering sensor 24, it is determined whether or not the steering angular velocity is equal to or greater than a predetermined threshold value Th2 ′. The predetermined threshold Th2 ′ may be set in an arbitrary manner. For example, the predetermined threshold Th2 ′ may be the same value as the predetermined threshold Th2 used in step 302 in FIG. 3, but is preferably a value larger than the predetermined threshold Th2. If the steering angular velocity is equal to or greater than the predetermined threshold Th2 ′, the process proceeds to step 504, and otherwise, the process proceeds to step 512.

  In step 504, the abnormal time is counted up. The abnormal time corresponds to the duration when the driver steering torque is equal to or less than the predetermined threshold Th1 ′ and the steering angular velocity is equal to or greater than the predetermined threshold Th2 ′.

  In step 506, it is determined whether or not the abnormal time is greater than or equal to a predetermined threshold Th3 ′. The predetermined threshold Th3 ′ may be set in an arbitrary manner. For example, the predetermined threshold Th3 ′ may be the same value as the predetermined threshold Th3 used in step 306 in FIG. 3, but is preferably a value larger than the predetermined threshold Th3. An example of how to set the predetermined threshold Th3 ′ will be described later. If the abnormal time is equal to or greater than the predetermined threshold Th3 ′, the process proceeds to step 508. Otherwise, the abnormal time count is not reset, and the process starts from step 500 in the next processing cycle.

  In step 508, it is determined whether or not the steering request torque (> 0) is received from the LKA-ECU 10. If the steering request torque has been received, the process proceeds to step 510; otherwise, the process proceeds to step 512. In step 508, it may be determined whether or not the steering assist request flag is on instead of or in addition to whether the steering request torque is received from the LKA-ECU 10. In this case, when the steering request torque is received from the LKA-ECU 10 and the steering support request flag is on, the process may proceed to step 510, and otherwise, the process may proceed to step 512. Alternatively, in this case, if the steering request torque is received from the LKA-ECU 10 or the steering support request flag is on, the process proceeds to step 510, and otherwise, the process may proceed to step 512. .

  In step 510, it is determined that there is an abnormality in the LKA-ECU 10, and a diagnosis indicating the abnormality of the LKA-ECU 10 is generated (registered). Along with this, the EPS-ECU 21 stops the lane keeping support function by invalidating the steering support request torque from the LKA-ECU 10. The invalidation may be realized in an arbitrary manner. For example, the invalidation may be realized simply by not responding to the steering assist request torque from the LKA-ECU 10. Alternatively, as invalidation processing, the EPS-ECU 21 notifies the LKA-ECU 10 that a non-conforming environment has been detected, thereby stopping the output of the steering support request torque from the LKA-ECU 10 (and turning off the steering support request flag). ) May be requested.

  In step 512, it is determined that the LKA-ECU 10 is normal, and the process starts from step 500 in the next processing cycle. At this time, if the current value of the abnormal time is larger than 0, it is reset to 0.

  According to the non-conforming environment determination process shown in FIG. 5, since the non-conforming environment is redundantly determined in the EPS-ECU 21, even if the LKA-ECU 10 has an abnormality, the lane keeping support function can be stopped in the non-conforming environment. . That is, the fail safe function is improved. Further, the EPS-ECU 21 can detect that there is an abnormality in the LKA-ECU 10 and generate a diagnosis.

  Here, the EPS-ECU 21 performs the nonconforming environment determination process shown in FIG. 5 and the LKA-ECU 10 executes the nonconforming environment determination process shown in FIG. 3 or the nonconforming environment determination process shown in FIG. 4 in parallel. It is necessary to prevent the diagnosis from being registered by the processing of step 510 even though there is no abnormality in the LKA-ECU 10.

  Therefore, in the example shown in FIG. 5, preferably, the predetermined threshold Th1 ′ is smaller than the predetermined threshold Th1 used in Step 300 of FIG. 3, and the predetermined threshold Th2 ′ is used in Step 302 of FIG. The predetermined threshold value Th2 is larger than the predetermined threshold value Th2 and the predetermined threshold value Th3 ′ is larger than the predetermined threshold value Th3 used in step 306 in FIG. 3. Thereby, before LKA-ECU10 detects a nonconforming environment normally, it can suppress that the process of step 510 is performed by EPS-ECU21.

  In this regard, the predetermined threshold Th3 ′ may be set in consideration of a delay that occurs in the determination process of the LKA-ECU 10, a delay that occurs in communication with the EPS-ECU 21, a delay in the process in the EPS-ECU 21, and the like.

  FIG. 6 is an explanatory diagram of an example of a setting mode of the predetermined threshold Th3 ′. FIG. 6 shows various delay factors.

  First, communication interruption may occur during transmission from the steering sensor 24 (and the torque sensor 22) to the LKA-ECU 10 via, for example, CAN. In FIG. 6, a dotted arrow schematically represents a communication interruption. Therefore, a delay may occur at this stage by the time T1 corresponding to the communication cycle × the allowable number of disruptions.

  Next, at the time of calculation in the LKA-ECU 10, the number of determinations (for example, a time corresponding to a predetermined threshold Th1) and other delay times (for example, the reception timing and processing cycle from the steering sensor 24 as shown in FIG. 6). (Delay due to deviation). Therefore, a delay may occur at this stage by the time T2 considering these.

  Next, communication may be interrupted during communication from the LKA-ECU 10 to the EPS-ECU 21. In FIG. 6, a dotted arrow schematically represents a communication interruption. Accordingly, a delay may occur at this stage by the time T3 corresponding to the communication cycle × the allowable number of disruptions.

  Next, a delay time (for example, a delay due to a shift in reception timing from the LKA-ECU 10 and a processing cycle as shown in FIG. 6) may occur during calculation in the EPS-ECU 21. Therefore, a delay may occur at this stage by the time T4 considering these.

  In this case, the predetermined threshold Th3 ′ may be a time corresponding to the total of each time (= T1 + T2 + T3 + T4). Thereby, it is possible to appropriately prevent the diagnosis from being registered by the processing in step 510 even though the LKA-ECU 10 has no abnormality.

  Although each embodiment has been described in detail above, it is not limited to a specific embodiment, and various modifications and changes can be made within the scope described in the claims. It is also possible to combine all or a plurality of the components of the above-described embodiments.

  For example, in the above-described embodiment, the intervention control is realized using only the steering actuator 26. However, the intervention control may be performed using a brake actuator instead of or in addition to the steering actuator 26. It is. Here, there is no substantial difference in the nonconforming environment between the intervention control by the brake actuator and the intervention control by the steering actuator 26. Therefore, even in a configuration in which intervention control by the brake actuator is performed alone or in combination, the nonconforming environment determination process itself may be substantially the same as the above-described nonconforming environment determination process.

  Further, in the above-described embodiment, the presence or absence of the driver's steering operation is detected using the driver steering torque, but instead of or in addition to this, other sensors (for example, touch sensors provided on the steering wheel) Alternatively, the presence or absence of the driver's steering operation may be detected using an image sensor that captures the driving state of the driver.

  In the above-described embodiment, the lane detection means is realized by the front camera 11 and the white line recognition device 12. However, when a special infrastructure is provided, the lane is a magnetic sensor or the like. It may be detected by other means.

  Further, in the above-described embodiment, when a non-conforming environment is detected, the lane keeping support control is suppressed by stopping the lane keeping support control, but the lane keeping support control is suppressed in another aspect. Also good. For example, when a non-conforming environment is detected, the control target value of the intervention control may be reduced as compared with the same situation when the non-conforming environment is not detected. Note that the control target value for intervention control may be the target lateral acceleration Gx, the target steering torque ST, or the like in the example shown in FIG.

  In the above-described embodiment, the abnormal time is considered, but equivalently, the number of determinations may be considered. For example, in the example illustrated in FIG. 3, in step 306, it may be determined whether or not the number of determination periods (number of determinations) in which step 300 and step 302 are simultaneously determined to be affirmative is greater than or equal to a predetermined threshold value. As described above, the number of determination periods substantially represents the length of time, and thus is equivalent to considering the abnormal time.

10 LKA-ECU
21 EPS-ECU
22 Torque sensor 24 Steering sensor 26 Steering actuator 34 Main switch 100 Lane keeping support device

Claims (5)

Lane detection means for detecting the lane in which the vehicle travels;
An actuator that generates a force that changes the direction of the vehicle;
A control device for performing lane keeping support control for operating the actuator so that the vehicle travels in the lane,
The control device suppresses the lane keeping support control when the driver's steering operation is not detected and the steering angular velocity is equal to or higher than a predetermined speed under the situation where the actuator is operated by the lane keeping assistance control. A lane keeping support device.   The lane keeping assist device according to claim 1, wherein the driver's steering operation is detected based on a driver steering torque detected by a torque sensor.   In the case where the actuator is operated by the lane keeping assist control, the control device has a state where the driver steering torque is equal to or lower than a predetermined torque and the state where the steering angular speed is equal to or higher than the predetermined speed continues for a predetermined time or longer. The lane keeping assist device according to claim 2, further comprising suppressing lane keeping assist control. The control device includes a first control device that makes an operation request for the actuator, and a second control device that operates the actuator in response to the operation request for the actuator,
The second control device receives the actuation request for the actuator from the first control device, and when the predetermined second condition is satisfied, the second control device receives the actuator actuation request from the first control device. Invalidating the operation request and determining that there is an abnormality in the first control device;
When the first control device satisfies a predetermined first condition that is more easily satisfied than the second condition in a situation where an operation request for the actuator is output to the second control device, The lane keeping assist device according to claim 1, wherein an operation request for the actuator is stopped. The predetermined first condition is satisfied when the driver steering torque is equal to or lower than the first predetermined torque, and the steering angular speed is equal to or higher than the first predetermined speed but continues for the first predetermined time,
The predetermined second condition is satisfied when the driver steering torque is equal to or lower than the second predetermined torque, and the steering angular speed is equal to or higher than the second predetermined speed but continues for a second predetermined time,
5. The second predetermined torque is smaller than the first predetermined torque, the second predetermined speed is larger than the first predetermined speed, or the second predetermined time is longer than the first predetermined time. The lane keeping assist device described in 1.

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