JP4179229B2 - Lane departure prevention device - Google Patents

Description

  The present invention relates to a lane departure prevention device for preventing a running vehicle from deviating from a lane in a driving assistance device that performs driving assistance of the vehicle.

  There is a vehicle having a lane departure prevention function for preventing a vehicle traveling on a road on which a lane is drawn from deviating from the lane. As an apparatus having such a lane departure prevention function, for example, there is an apparatus disclosed in JP-A-7-104850. This device tracks the center line between lanes, and when the vehicle deviates from the center line, an electric motor coupled to the steering mechanism applies torque to the vehicle steering mechanism to bring the vehicle to the center line position. It is to return.

A vehicle steering control device disclosed in Japanese Patent Application Laid-Open No. 11-91606 is provided with this type of lane departure prevention function. This vehicle steering control device determines whether or not the driver has consciously led the vehicle to the control area, and restricts the generation of return torque for returning the vehicle when it is determined that the driver has consciously led. is there.
JP-A-7-104850 JP-A-11-91606

  However, in the device disclosed in Patent Document 1, when the vehicle deviates from the center line, a return torque is applied to the steering mechanism of the vehicle, so that when the driver operates the steering to return to the center of the lane. This extra torque may be redundant. On the other hand, in the vehicle steering control device disclosed in Patent Document 2, it is determined whether or not the driver is consciously guiding the vehicle, and when it is consciously guided, the return torque is canceled. Application of a return torque can be eliminated.

  However, when the vehicle is traveling on a steep curve, the driver generally travels unconsciously by repeating delicate correction steering in the left-right direction. If such left and right correction steering is repeated, hunting occurs between the restriction (operation prohibited state) and the non-restricted (operable state) of the return torque (steering torque). There is a problem in that it is uncomfortable when the driver is notified of the change by sound or display.

  In addition, lane departures often occur mainly during so-called blurred driving. However, when driving on a sharp curve and when the generation of return torque is restricted, the driver is consciously guiding the vehicle, so there is a high possibility that the vehicle is running silently. Very low. If lane departure prevention support is performed in such a state, there is a problem that useless alarm operation may occur.

  Accordingly, an object of the present invention is to provide a lane departure prevention device that can prevent hunting between the restriction and non-limitation of the generation of steering torque to reduce the uncomfortable feeling given to the driver and prevent the occurrence of useless alarm operation. It is to provide.

The lane departure prevention apparatus according to the present invention that has solved the above-described problems is input from the steering wheel while preventing a lane departure by activating a departure warning by causing the vehicle to deviate when it is determined that the running vehicle departs from the lane. When the steering torque is equal to or higher than a steering torque predetermined value that prohibits the operation of the departure warning, in the lane departure prevention device that performs the operation prohibition determination for prohibiting the operation of the departure warning, when the operation of the departure warning is in a prohibited state, When the steering torque input from the steering is less than the steering torque predetermined value, it is determined that the deviation warning is to be returned from the operation prohibited state to the operable state, and the vehicle is determined to be traveling straight ahead. When the driving condition is not satisfied, a return prohibition determination is performed to prohibit the return alarm from returning from the operation prohibited state to the operable state.

  The lane departure prevention apparatus according to the present invention makes a return prohibition determination based on the straight traveling condition of the vehicle when the operation of the departure warning is prohibited. For this reason, even if the driver is driving on a sharp curve and does not satisfy the straight traveling condition unintentionally, right and left corrective steering is performed, hunting between the disabled state and the ready state can be prevented. it can.

  Also, when the vehicle is driving a sharp curve and does not satisfy the straight driving condition, the driver is consciously driving and it is unlikely that the driver is driving dimly. The need to emit is low. In such a case, it is possible to reduce a sense of incongruity given to the driver by maintaining the departure warning in the operation prohibited state.

Here, the case where the straight traveling condition is not satisfied can be an aspect in which the curve R of the road on which the vehicle travels is not greater than or equal to a predetermined value.

Further, the case where the straight traveling condition is not satisfied can be an aspect in which the curve curvature of the road on which the vehicle travels is a predetermined value or less.

Furthermore, the case where the straight traveling condition is not satisfied can be an aspect in which the lateral acceleration in the vehicle traveling direction in the vehicle is a predetermined value or more.

The case where the straight running condition is not satisfied can be an aspect in which the yaw rate of the vehicle is a predetermined value or more.

  According to the lane departure prevention apparatus according to the present invention, it is possible to prevent the sense of discomfort given to the driver by preventing hunting between the restriction and non-restriction of the generation of the steering torque, and to prevent the occurrence of useless alarm operation.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a lane departure prevention apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the lane departure prevention apparatus 1 according to this embodiment includes a departure prevention support ECU 10. The departure prevention assisting ECU 10 is connected to a vehicle speed detecting means 11, a steering torque detecting means 12, a white line recognition camera 13, a brake switch 14, a blinker switch 15, and a main switch 16. In addition, a steering torque applying means 17, an alarm buzzer 18, and a meter 19 are connected to the ECU 10.

  The departure prevention assisting ECU 10 determines whether or not the vehicle departs from the lane based on information output from the vehicle speed detection means 11, the steering torque detection means 12, the white line recognition camera 13, and the like. As a result, when it is determined that the vehicle departs from the lane after a predetermined time, a predetermined signal is output to the steering torque applying means 17, the alarm buzzer 18, and the like. More detailed functions of the departure prevention support ECU 10 will be described later.

  The vehicle speed detection means 11 is attached to the front wheel portion of the vehicle, for example, and detects the vehicle speed when the host vehicle travels. The vehicle speed detection means 11 outputs the detected vehicle speed to the departure prevention assisting ECU 10.

  The steering torque detection means 12 is attached to, for example, a steering rod connected to the steering in the vehicle interior, and detects the steering torque input to the steering by the driver's steering operation. The steering torque detection means 12 outputs the detected steering torque to the departure prevention assist ECU 10.

  The white line recognition camera 13 is disposed, for example, in a position overlooking the outside of the vehicle from the upper part of the windshield in the vehicle interior, and images the situation outside the vehicle as seen through the windshield. The white line recognizing camera 13 outputs the captured outside situation to the departure prevention assisting ECU 10.

  The brake switch 14 is attached to, for example, a brake pedal in the passenger compartment, and detects the operation of the brake pedal by the driver. The brake switch 14 outputs a brake signal to the departure prevention assisting ECU 10 when the driver operates the brake pedal to cause the vehicle to perform a braking operation.

  The blinker switch 15 is attached to, for example, a blinker lever in the passenger compartment, and detects the operation of the blinker by the driver. The winker switch 15 outputs a winker signal to the departure prevention assisting ECU 10 when the driver tries to take out the winker by operating the winker lever.

  The main switch 16 is attached, for example, to a door on the driver's seat side in the passenger compartment. When a driver or the like performs an operation to turn on the main switch 16, the main switch 16 outputs an ON signal to the departure prevention assisting ECU 10. The departure prevention support ECU 10 receives the ON signal and starts departure prevention support.

  As the steering torque applying means 17, for example, an electric motor in an electric power steering device connected to a steering rod is used. The steering torque applying means 17 applies a predetermined steering torque, which is the alarm torque of the present invention, to the steering rod based on the applied signal output from the departure prevention assisting ECU 10.

  The alarm buzzer 18 is provided, for example, in an instrument panel portion in the passenger compartment, and issues an alarm of a predetermined volume that reaches the driver. The alarm buzzer 18 has a plurality of types of signals, and a predetermined type of alarm is output based on the alarm signal output from the departure prevention support ECU 10.

  As shown in FIG. 2, the meter 19 is provided with a speed meter 21 and a tachometer 22. The display portion of the speed meter 21 includes a departure prevention support execution display 23 represented by characters “LKA”, a steering control execution display 24, a white line recognition display 25, a radar cruise display 26, and a radar cruise set speed display 27. Is displayed. These display portions are appropriately displayed based on a display signal output from the departure prevention assisting ECU 10. Specifically, the departure prevention support execution display 23 is lit while the departure prevention support is being performed. In the white line recognition display 25, during the deviation prevention support, a thick line display is displayed when the application of the steering torque is prohibited, and a thin line display is displayed when the application of the steering torque is not prohibited.

  The operation | movement and effect | action in the lane departure prevention apparatus 1 in this embodiment which have the above structure are demonstrated. In this embodiment, when performing lane departure prevention support, there is a feature in the pattern of steering torque applied to the steering torque applying means 17 when performing lane departure prevention. Before detailed description regarding this feature, driving support control is performed. The whole will be described. FIG. 3 is a flowchart showing a control procedure of the lane departure prevention apparatus 1 according to this embodiment.

  In the lane departure prevention apparatus 1 according to the present embodiment, the departure prevention support ECU 10 confirms that the main switch 16 is turned on as pre-processing for starting driving support. If the main switch 16 is ON, white line information processing for extracting a white line from an image taken by the white line recognition camera 13 is performed, and the white line of the lane in which the host vehicle travels is recognized. Then, white line recognition processing is performed, and flag processing based on the detection result of the white line is performed. After performing the white line information processing, it is determined whether steering assistance is possible (S1). Whether or not steering assistance is possible is determined based on vehicle speed information output from the vehicle speed detection unit 11, information on whether or not a white line is recognized by white line information processing, and the like.

  After determining whether or not steering assistance is possible, a driver operation determination is performed (S2). The driver's operation determination is made based on a steering torque signal output from the steering torque detection means 12, a brake signal output from the brake switch 14, a winker signal output from the winker switch 15, and the like. When the steering torque signal indicates a predetermined torque amount, it is determined that the driver has operated the steering. When a brake signal is output from the brake switch 14, it is determined that the driver has performed a brake operation. When a winker signal is output from the winker switch 15, it is determined that the driver has performed a blinker operation. Based on the determination results of these driver operations, it is determined whether or not to continue driving support.

  When the driver operation determination is performed, the deviation mitigation control operation amount is calculated (S3). Here, the target torque required to return the vehicle to the lane is calculated. The deviation mitigation control operation amount is calculated using the turning radius of the host vehicle and the vehicle speed of the host vehicle that are determined based on the turning angle of the steering. A predetermined upper limit value is set for the deviation mitigation control operation amount. The calculation of the deviation mitigation control manipulated variable will be further described later.

  After calculating the departure mitigation control operation amount, lane departure determination is performed (S4). Here, it is determined whether or not the vehicle departs from the lane after a lapse of a predetermined time, for example, about 1 second, and whether or not the steering torque applying means 17 is requested to be operated based on the determination result of lane departure. Make a decision. The lane departure determination is performed based on the steering support availability state, the white line detection state, the offset amount of the host vehicle with respect to the lane, the yaw angle, the estimated road R, the lane width, and the like.

  Now, it is assumed that the host vehicle M is traveling on the road R as shown in FIG. Here, based on the speed of the own vehicle M, the yaw angle, the offset amount with respect to the road R, etc., the travel route of the own vehicle M for about 1 second is calculated. As a result, when it is determined that the travel route C1 of the host vehicle M travels on the white line W, the steering torque calculated in the subsequent process is applied by the steering torque application means 17 so that, for example, the travel route C2 is obtained. . In this way, control is performed to change the travel route. In this way, by changing the travel route from C1 to C2, it is possible to lengthen the departure margin time until the vehicle departs from the white line. By extending the departure margin time, a steering torque is applied to the steering, and the driver is notified of the danger of departure, thereby preventing lane departure.

  Furthermore, in this lane departure determination, based on the steering torque given by the driver operating the steering, it is determined whether to prohibit the application of steering torque to the steering rod, and when it is determined not to prohibit, Allow application of steering torque. For example, when the steering torque given by the driver operating the steering is large, the application of the steering torque to the steering rod is prohibited.

  In the state where the application of the steering torque is prohibited, the return prohibition determination is made as to whether or not the return is prohibited when returning from the prohibited state based on the straight traveling condition of the vehicle. The return prohibition determination performed here will be further described later.

  After performing the lane departure determination, the departure mitigation control target torque is calculated (S5). Here, the waveform of the steering torque actually applied by the steering torque applying means 17 with respect to the deviation mitigation operation amount is calculated. A steering torque having such a waveform is applied to the steering rod from the electric motor in the electric power steering apparatus.

  When the departure mitigation control target torque is calculated, a buzzer sounding process is performed to notify the driver that departure prevention support is to be performed (S6). In the lane departure determination process, when it is determined that the vehicle departs from the lane and the steering torque is applied by the steering torque application means 17, a warning of a predetermined sound is output from the alarm buzzer 18. In the present embodiment, the straight traveling condition is determined based on the curve R, which is a value related to the steering torque applied to the steering wheel and the curve radius.

  Further, a buzzer sounding process is performed and an alarm display process is performed (S7). In the lane departure determination process, when it is determined that the vehicle departs from the lane and the steering torque is applied by the steering torque application means 17, the departure prevention support execution display 23 and the white line recognition display are performed on the meter 19. The The application of the steering torque, the buzzer, and the departure prevention support execution display correspond to the departure warning operation of the present invention.

  Then, driving support is completed by performing a predetermined data output process (S8).

  Now, the return prohibition determination as to whether or not the return from the state where the application of the steering torque is prohibited to the state where the application of the steering torque is permitted is prohibited performed in step S4 of the above flowchart will be described. FIG. 5 is a flowchart showing a procedure for determining whether to prohibit return.

  First, it is determined whether or not the steering operation flag is ON (S11). When the steering operation flag is ON, the application of the steering torque is prohibited and the operation is prohibited. Therefore, when the steering operation flag is not ON, the application of the steering torque is not prohibited, so that it is not necessary to determine the return from the application prohibition. Therefore, when the steering operation flag is not ON, the return prohibition determination from the prohibition of application ends.

  On the other hand, when the steering operation flag is ON, application of steering torque is prohibited. At this time, it is determined whether or not the steering torque is equal to or greater than a predetermined value in order to determine whether or not to return (S12). As the predetermined value of the steering torque here, a steering torque is set to such an extent that the driver feels that he is consciously steering.

  As a result, when it is determined that the steering torque is greater than or equal to the predetermined value, the state where the steering operation flag is turned on is continued (S15), and the steering torque can be applied from the operation prohibited state where the application of the steering torque is prohibited. Is prohibited from returning to the proper operational state.

  If the return prohibition is not performed when the steering torque is greater than or equal to a predetermined value, hunting between an operation prohibited state and an operable state may occur on a curved road. Such hunting may cause the driver to feel uncomfortable. Further, when such hunting occurs, the display of the thick line and the thin line in the white line recognition display 25 may flicker due to this hunting, which may give the driver a sense of incongruity.

  On the other hand, in this embodiment, when it is considered that the driver is performing a conscious operation, the state where the steering operation flag is turned on is continued and the operation is returned from the operation prohibited state to the operable state. Is prohibited. In addition, when the steering torque is equal to or greater than a predetermined value, it is considered that the driver is performing a conscious operation, and the possibility of performing a so-called blurred operation is low. Therefore, flickering of the white line recognition display 25 can be prevented while the driver is performing conscious steering and the necessity of returning to the operable state is low.

  If it is determined in step S12 that the steering torque is equal to or less than a predetermined value, it is determined whether the curve R is equal to or greater than a predetermined value, for example, 200R (S13). It is obtained based on the curvature of the white line obtained by performing image processing on the image photographed by the white line recognition camera 13.

  As a result, when it is determined that the curve R is not a predetermined value or more and is a steep curve, the state where the steering operation flag is turned on is continued (S15), and the return from the operation prohibited state to the operable state is performed. Ban. Even when the vehicle is running on a sharp curve, hunting between the operation-disabled state and the operable state is prevented, as in the case where the steering torque is increased, and the uncomfortable feeling given to the driver by hunting is reduced. Thus, flickering between the thick line and the thin line in the white line recognition display 25 can be prevented.

  When the curve R is equal to or greater than the predetermined value and the host vehicle is traveling on a straight road, the steering operation flag is turned OFF (S14), and the operation is changed from the operation disabled state to the operation enabled state without prohibiting the return. Return. As described above, when driving on a straight road without applying a large steering torque to the steering, it is likely that a dull driving occurs. In such a case, departure prevention support can be suitably performed.

The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, as the straight traveling condition, yaw rate, lateral acceleration, navigation information, and the like can be used. The yaw rate and lateral acceleration can be detected by separately attaching a yaw rate sensor and a lateral acceleration sensor (G sensor) to the vehicle. The navigation information can be obtained from a navigation device attached to the vehicle.

  In the above embodiment, the curve R is used as a value related to the curve radius, but a curve radius (curvature radius) or a curve curvature may be used as the value related to the curve radius. When the curvature of the curve is used as a value related to the curve radius, the reciprocal of the curve R is obtained. Therefore, in step S13 in FIG. 5, when the curve curvature is equal to or less than a predetermined value, the sharp curve, that is, the curve R corresponds to a predetermined value or less. Therefore, the state where the steering operation flag is turned on is continued. On the other hand, when the curve curvature is less than or equal to a predetermined value, the curve R is equal to or greater than a predetermined value and a gentle curve, that is, the curve R is equal to or greater than a predetermined value, so the steering operation flag is turned OFF.

It is a block block diagram of the lane departure prevention apparatus which concerns on this invention. It is a front view of a meter. It is a flowchart which shows the control procedure of the lane departure prevention apparatus which concerns on this invention. It is a figure for demonstrating the driving | running route of the vehicle at the time of not performing when the deviation prevention assistance in the vehicle which drive | works a road is not performed. It is a flowchart which shows the procedure of a return prohibition judgment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lane departure prevention apparatus, 11 ... Vehicle speed detection means, 12 ... Steering torque detection means, 13 ... White line recognition camera, 14 ... Brake switch, 15 ... Winker switch, 16 ... Main switch, 17 ... Steering torque application means, 18 ... Alarm buzzer, 19 ... Meter, 21 ... Speed meter, 22 ... Tachometer, 23 ... Deviation prevention support execution display, 24 ... Steering control execution display, 25 ... White line recognition display, 26 ... Radar cruise display, 27 ... Radar cruise set speed display.

Claims (5)

When it is determined that the running vehicle departs from the lane, the departure torque is activated on the vehicle to prevent the departure from the lane, while the steering torque input from the steering prohibits the operation of the departure alarm. In the lane departure prevention apparatus that performs the operation prohibition determination for prohibiting the operation of the departure warning when the predetermined value or more ,
When the operation of the departure warning is in a prohibited state, when the steering torque input from the steering becomes less than a predetermined value of the steering torque, it is determined to return from the operation disabled state of the departure warning to the ready state. And
A lane for performing a return prohibition for prohibiting a return from an operation prohibited state to an operable state of the departure warning when a predetermined straight traveling condition for determining that the vehicle is traveling straight is not satisfied. Deviation prevention device. The lane departure prevention device according to claim 1 , wherein the case where the straight traveling condition is not satisfied is a case where a curve R of a road on which the vehicle travels is not a predetermined value or more . The lane departure prevention device according to claim 1, wherein the case where the straight traveling condition is not satisfied is a case where a curve curvature of a road on which the vehicle travels is a predetermined value or less. 2. The lane departure prevention device according to claim 1, wherein the case where the straight traveling condition is not satisfied is a case where a lateral acceleration in the vehicle traveling direction in the vehicle is a predetermined value or more. The lane departure prevention device according to claim 1, wherein the case where the straight traveling condition is not satisfied is a case where a yaw rate of the vehicle is a predetermined value or more.

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