JP2009190464A - Lane keeping support system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lane keeping support system capable of performing highly accurate control of reducing the control quantity of a target control torque when a driver steering torque caused by actual steering operation of a driver and the target control torque by lane keeping control interferes with each other in controlling. <P>SOLUTION: The lane keeping support system 71 controls the steering torque to cause the vehicle to run with keeping the lane. The lane keeping support system comprises: a target control torque calculation means 72 for calculating the target control torque of the steering torque based on a plurality of detection elements indicating an advancing direction, a lateral position and/or a behavior of the vehicle; a torque sensor 20 for detecting a driver steering torque when the driver makes steering operation; and a control quantity reduction calculation means 76 for calculating the control reduction quantity of each of the plurality of the detection elements for determining the target control torque to reduce the target control quantity of the target control torque when the steering direction of the target control torque is different from the steering direction of the driver steering torque to cause interference in control. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lane keeping assist device, and more particularly to a lane keeping assist device that calculates a target control torque and controls a steering torque so that the vehicle travels while keeping the lane.

2. Description of the Related Art Conventionally, in a steering assist device that applies steering torque to a steering mechanism so that a vehicle travels along a travel path based on an image of a travel path ahead of the vehicle, the steering direction of the steering torque and the driver's When the steering direction is different from the steering direction, steering assist control is performed so that the steering torque does not increase, and the driver is prevented from feeling uncomfortable with the steering wheel operation, so that a good steering feeling can be maintained. An apparatus is known (see, for example, Patent Document 1).
JP 2007-38697 A

  However, in the configuration described in Patent Literature 1 described above, when the driver's steering wheel steering and the steering assist control interfere with each other, the control for preventing the steering torque from increasing is performed only on the final steering torque. Therefore, effective control may not always be performed.

  In other words, when calculating the steering torque for performing the steering assist control, the curvature of the road, the vehicle position, the direction of the vehicle with respect to the white line, and the like are detected based on the image information of the road, and these are multiplied by a predetermined gain. Although the steering torque is calculated by performing a predetermined calculation, these individual detection elements do not necessarily have the same effect as the control for reducing the control amount.

  Therefore, the present invention sets the control amount of the target control torque when the driver steering torque that the driver actually steers is different from the target control torque calculated for the lane keeping control and the control interference occurs. It is an object of the present invention to provide a lane keeping support device that performs high-precision lane keeping support control that performs control to be reduced on each detection element and does not give an uncomfortable feeling to the driver's steering.

In order to achieve the above object, a lane keeping assist device according to a first invention is a lane keeping assist device that controls a steering torque so that a vehicle travels while maintaining a lane,
Target control torque calculating means for calculating a target control torque of the steering torque based on a plurality of detection elements indicating the traveling direction, lateral position and / or behavior of the vehicle;
A torque sensor for detecting a driver steering torque when the driver steers,
The target control torque is determined so that a target control amount of the target control torque is reduced when a steering direction of the target control torque is different from a steering direction of the driver steering torque and control interference occurs. Control reduction amount calculation means for calculating a control reduction amount of each of the plurality of detection elements.

  As a result, it is possible to individually control the plurality of detection elements that determine the target control torque to reduce the target control amount, and in accordance with the state of the vehicle, the gain of the detection element is effective at a rate effective for reducing the target control amount. Thus, it is possible to realize control that does not give the driver a sense of incongruity even under various circumstances.

A second invention is the lane keeping assist device according to the first invention,
The plurality of detection elements include a yaw angle and an offset indicating an amount of deviation from a target position in the traveling lane.

  Accordingly, the target control torque is determined based on the lateral position in the relationship between the yaw angle indicating the traveling direction of the vehicle and the lane, and when control interference occurs, the detection element that is effective in reducing the control amount among these is detected. Therefore, it is possible to perform control for greatly reducing the target control amount, and to perform highly accurate control.

A third invention is the lane keeping assist device according to the second invention,
The control reduction amount calculation means controls the yaw angle control reduction amount to be larger than the offset control reduction amount.

  Thereby, in the normal state, the driver often places more importance on the steering assist on the yaw angle than on the steering assist on the offset, so in the normal state, by increasing the control reduction amount of the yaw angle larger than the offset, Delicate control that does not give a sense of incongruity according to the driver's intention can be realized.

4th invention is the lane maintenance assistance apparatus which concerns on 2nd or 3rd invention,
The offset is detected based on an image captured by a white line recognition camera,
When a malfunction occurs in the white line recognition camera, the control reduction amount calculation unit performs control so that the control reduction amount of the offset is larger than the control reduction amount of the yaw angle.

  As a result, when it is raining or when the white line on the road is blurred and the white line is difficult to see and the white line recognition camera is likely to malfunction, it is possible to control appropriately by lowering the weight of detection by the white line recognition camera. Therefore, it is possible to perform highly accurate lane keeping support control appropriately corresponding to such a case.

A fifth aspect of the present invention is the lane keeping assist device according to any one of the first to fourth aspects of the invention,
The plurality of detection elements include a yaw rate and / or a lateral acceleration.

  As a result, even if the number of detection elements for determining the target control torque increases, highly accurate lane keeping assist control that does not give the driver a sense of incongruity becomes possible.

  According to the present invention, it is possible to perform highly accurate lane keeping assist control that does not contradict the driver's intention and does not give a sense of incongruity even under various circumstances.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of a lane keeping support system including a lane keeping assist device 71 according to an embodiment to which the present invention is applied and related components. In FIG. 1, a lane keeping assist device 71 according to the present embodiment is built in a lane keeping assist ECU (Electronic Control Unit) 70. Since the lane keeping assist device 71 performs various arithmetic processes for performing lane keeping assist control, the lane keeping assist device 71 may be configured, for example, as a part of a lane keeping assist ECU equipped with a CPU (Central Processing Unit). The lane keeping assist device 71 may be configured by a predetermined electronic circuit or ASIC (Application Specific Integrated Circuit), and various means may be applied as long as arithmetic control is possible. In this case, the lane keeping assist device 71 can be configured separately from the lane keeping assist ECU 70, and may be configured as such. In the lane keeping assist device 71 according to FIG. 1, an example configured as a part of the lane support assist ECU 70 will be described.

  The lane keeping assist device 71 is a control means having a lane keeping assist function. The lane keeping assist device 71 normally sets a target yaw rate necessary for traveling along the center line of the lane, and uses the steering torque applying means 80 to generate an output torque for generating the target yaw rate. Append to For this purpose, the lane keeping assist device 71 includes, as related components, a vehicle speed detection means 10, a steering torque detection means 20, a white line recognition camera 30, a brake switch 40, a blinker switch 50, a main switch 60, a steering wheel. A torque applying means 80, an alarm buzzer 90, and a meter 100 may be provided.

  The vehicle speed detecting means 10 is means for detecting the speed of the vehicle. The vehicle speed detection means 10 transmits the detected vehicle speed to the lane keeping assist ECU 70 as a vehicle speed signal.

  The steering torque detecting means 20 is a sensor that detects the steering torque input from the steering wheel. The steering torque detecting means 20 uses the detected steering torque as a steering torque signal to the lane keeping assistance device 71 in the lane keeping assistance ECU 70. Send.

  The white line recognition camera 30 includes a camera and an image processing unit (not shown). Various types of cameras may be applied to the camera, for example, a CCD (Charge Coupled Device) camera. The camera may be attached in front of a vehicle on which the lane keeping assist device 71 is mounted, and may be incorporated in a rearview mirror, for example. At this time, the camera is attached so that the optical axis direction thereof coincides with the traveling direction of the vehicle. The camera captures a road ahead of the vehicle and acquires the captured image. In the camera, data of the captured image is transmitted to the image processing unit as an imaging signal. As the camera, a camera that has a wide imaging range in the left-right direction and that can sufficiently capture the left and right (a pair of) white lines indicating the traveling lane is applied. The camera only needs to be able to acquire an image capable of recognizing a white line on the road, and may be a color camera or a monochrome camera.

  The image processing unit captures an imaging signal from the camera, and recognizes a pair of white lines (partition lines) indicating the lane in which the vehicle is traveling from the captured image data of the imaging signal. Hereinafter, the function of the white line recognition sensor 30 will be described with reference to FIG.

  FIG. 2 is an explanatory diagram of information recognized by the white line recognition camera 30 of FIG. As shown in FIG. 2, the image processing unit calculates a lane width W and a line passing through the center of the pair of white lines (that is, the lane center line CL) from the recognized pair of white lines. Further, the image processing unit calculates a curve radius R (road curvature = 1 / R) of the lane center line CL. Further, the image processing unit includes an angle (yaw angle θ) formed between the tangential direction of the center line CL of the lane and the center axis in the front-rear direction of the vehicle, and a lateral shift amount (offset) D) is calculated. Then, the image processing unit transmits the information of the recognized pair of white lines and the calculated information as image signals to the lane keeping assist device 71 in the lane keeping assist ECU 70.

  Note that the curve radius R, the yaw angle θ, and the offset D recognized by the white line recognition camera 30 are represented by plus / minus values, and the sign indicates the direction. For the curve radius R, a positive value indicates a right curve and a negative value indicates a left curve. As for the yaw angle θ, a positive value is a right deflection angle, and a negative value is a left deflection angle. In the offset D, a positive value is a right offset, and a negative value is a left offset.

  Next, returning to FIG. 1, other components will be described.

  The brake switch 40 is a switch that detects whether or not the brake pedal has been depressed by the driver. Whether the brake pedal has been depressed may be detected by turning the brake pedal on / off. When the driver performs the brake operation, it is predicted that the driver himself needs to perform steering such as danger avoidance. Therefore, it is preferable to leave the operation to the driver without assistance. Therefore, when performing such control, the brake switch 40 may transmit ON / OFF of the brake pedal to the lane keeping assist device 71 as a brake signal.

  The blinker switch 50 is a switch for inputting a direction instruction (right direction instruction ON, left direction instruction ON) by the driver. When the winker switch 50 is ON, the driver intends to change lanes. Therefore, if the lane keeping assist device 71 according to the present embodiment is functioned, there is a high probability that it is contrary to the driver's intention. May perform control to temporarily cancel the function of the lane keeping assist device 71.

  The main switch 60 is a switch for inputting ON / OFF of the lane keeping assist device 71 by the driver. The main switch 60 transmits the driver ON / OFF operation to the lane keeping assist device 71 as a main switch signal. The lane keeping assist device 71 starts when the main switch 60 is turned on, and stops when the main switch 60 is turned off.

  Although not shown, other wiper switch signals may be transmitted to the lane keeping assist device 71. When the wiper switch is ON, it is considered that it is raining. When it is raining, it is difficult to see the white line and the lane keeping support control may not be possible. In such a case, the lane keeping control device 71 Control for canceling the function may be performed. When such control is performed, a wiper switch signal is also transmitted to the lane keeping assist device 71.

  The steering torque applying means 80 is means for applying a steering torque for assisting the driver's steering based on the target control torque output by the lane keeping assist device 71. Various modes may be applied to the steering torque application unit 80, and for example, an electric power steering device may be applied. The electric power steering apparatus drives and controls a motor (not shown) by an EPS (Electric Power Steering) ECU (not shown), and assists the steering by the driver with the driving torque of the motor. In the EPS ECU, an assist torque is set based on the steering torque generated by the driver's steering, and the motor is driven and controlled in order to generate the assist torque by the motor driver. The driving torque by the motor is added to a steering mechanism (not shown), and the steering torque by the motor is applied to the steering mechanism in addition to the driver steering torque by the driver. The steering torque is represented by a plus value / minus value, and the sign indicates the direction. For each torque, a positive value indicates a torque in the left direction, and a negative value indicates a torque in the right direction.

  The alarm buzzer 90 is an alarm buzzer for the lane keeping assist device 71. The alarm buzzer 21 may receive an abnormal signal from the lane keeping assist ECU 70 and output a buzzer sound when the abnormal signal indicates abnormal.

  The meter 100 is a means for providing various information of the vehicle to the driver, and includes a measuring instrument such as a speedometer, a tachometer, and a fuel gauge, and a warning light for notifying the driver of various abnormalities. The meter 100 receives signals from various ECUs in the vehicle, operates each instrument in accordance with each signal, and turns on / off each warning light. In particular, the meter 100 may be provided with a warning light for the lane keeping assist device 71. When the abnormality signal is received from the lane keeping assist device 71 and indicated as abnormal, the warning light is turned on. You may make it make it.

  The lane keeping assist ECU 70 may include a CPU, a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and may be configured to control the lane keeping assist device 71 in an integrated manner. The lane keeping assist ECU 70 starts when the main switch signal from the main switch 60 indicates ON, and stops when the main switch signal indicates OFF. When activated, the lane keeping assist ECU 70 takes in the image signal from the white line recognition camera 30 and takes in the detection signals from the sensors 10 and 20 and the signals from the switches 40 and 50 at regular intervals.

  The lane keeping assist device 71 according to the present embodiment may be configured to provide a driver's lane keeping assist in cooperation with other components in the system configuration as shown in FIG. 1, for example.

  Next, a specific configuration of the lane keeping assist device 71 according to the present embodiment will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of a control configuration of the lane keeping assist device 71 according to the present embodiment.

  In FIG. 3, the lane keeping assist device 71 according to the present embodiment includes a target control torque calculation unit 72, a control interference determination unit 75, a control reduction amount calculation unit 76, and an addition unit 79.

  The target control torque calculation means 72 performs target lane keeping support control, and therefore, a target control torque that becomes a target value of steering torque for assisting the driver based on a plurality of detection elements detected by the detection means such as the white line recognition camera 30. Is a means for calculating. The target control torque calculation means 72 includes a feedback gain calculation means 73 and a feed forward gain calculation means 74. When calculating the target control torque only by feedback control, only the feedback gain calculation means 73 is provided. It may be configured.

  As described with reference to FIG. 2, the yaw angle θ, the offset D, and the curve radius R of the vehicle traveling in the traveling lane can be detected using the white line recognition camera 30. The feedback gain calculation means 72 and the feed forward gain calculation means 73 perform a process for calculating a control gain for each of these detection elements. In FIG. 3, among the above-described three detection elements, the yaw angle θ and the offset D are used for feedback control and are input to the feedback gain calculation means 73. The curve radius R is used for Ford forward control and is input to the feed forward gain calculation means 74. These can be variously combined depending on the application, but FIG. 3 illustrates an example of such a combination.

  The feedback gain calculation means 73 calculates the control gain for the yaw angle θ and the offset D, and calculates the target control torque of the steering torque from the yaw angle θ and the offset D using each of the gains. That is, with respect to the yaw angle θ and the offset D, the gain value after the gain is multiplied and calculated for each term is calculated for each term, and each term of the target control torque is calculated. For example, the target control torque is calculated by calculating a target yaw rate for each term, converting the target yaw rate into a lateral acceleration based on this and the vehicle speed detected by the vehicle speed detecting means 10, and calculating a steering torque corresponding to this. You may do it.

  On the other hand, the feedforward gain calculation means 74 calculates a control gain for the curve radius R, and calculates a target control torque of the steering torque from the curve radius R using this. That is, for the detected curve radius R, the gain value after being calculated by multiplying the gain is calculated, and the target control torque is calculated. For example, similarly to the above, the target yaw rate is calculated, the target yaw rate is converted into the lateral acceleration based on this and the vehicle speed detected by the vehicle speed detecting means 10, and the steering torque corresponding to this is calculated. Good.

  The target control torques of these terms are added together and output as the final target control torque of the target control torque calculation means 72 and sent to the control interference determination means 75. On the other hand, the target control torque for the yaw angle term and the target control torque for the offset term are respectively sent to the input and output of the control reduction amount calculation means 77 and 78 for each term. The target control torque of the feedforward term is sent to the adding means 79 that outputs the final steering torque.

  The control interference determination unit 75 compares the target control torque calculated by the target control torque calculation unit 72 with the driver steering torque at which the driver actually steers the steering, and determines whether or not control interference has occurred. Means. That is, the control interference determination unit 75 determines whether or not the target control torque set by the lane keeping assist device 71 is set against the driver's intention. Therefore, both the driver steering torque detected by the steering torque detection unit 20 and the target control torque calculated by the target control torque calculation unit 72 are input to the control interference determination unit 75.

  Specifically, the control interference determination by the control interference determination means 75 is performed when the driver steering torque and the target control torque are different and it is determined whether or not there is a difference greater than or equal to a predetermined value. Determines that control interference has occurred. For example, when the difference between the driver steering torque and the target control torque is about 0.3 to 0.5 [N · m] or more, the control interference is generated. You may determine that you are doing. Strictly speaking, if the driver steering torque and the target control torque are different, it can be determined that the control interference has occurred, but a dead zone is provided in consideration of the accuracy error of the steering torque detecting means 20, It is preferable to determine that control interference has occurred when the difference between the driver steering torque and the target control torque is equal to or greater than a predetermined value.

  The determination result of the control interference determination unit 75 is sent to each of the yaw angle control reduction amount calculation unit 77 and the offset control reduction amount calculation unit 78 in the control reduction amount calculation unit 76.

  The limit reduction amount calculation means 76 is a means for calculating a control reduction amount individually for each term of the yaw angle θ and the offset D used for feedback control. Therefore, the control reduction amount calculation unit 76 includes a control reduction amount calculation unit 77 for the yaw angle θ and a control reduction amount calculation unit 78 for offset separately.

  The yaw angle control reduction amount calculation means 77 receives the target control torque of the yaw angle term, the driver steering torque, and the control interference determination result, and the control reduction of the target control torque of the yaw angle term according to the control interference determination result. A quantity is calculated. Specifically, when no control interference occurs, the target control torque of the yaw angle term is output as it is. On the other hand, when control interference occurs and a target control torque that is contrary to the driver's intention is set, the control reduction amount of the yaw angle term is calculated based on the driver steering torque and the target control torque of the yaw angle term. The Note that the control reduction amount may be calculated as a reduction gain coefficient. The calculated limit reduction amount (reduction gain coefficient) is multiplied by the target limit torque of the yaw angle term, and is output to the final adding means 79 as the steering torque of the yaw angle term.

  Similarly, the offset control reduction amount calculation unit 78 receives the target control torque of the offset term, the driver steering torque, and the control interference determination result, and reduces the control of the target control torque of the offset term according to the control interference determination result. A quantity is calculated. As described above, when no control interference occurs, the target control torque of the offset term is output as it is. On the other hand, when control interference occurs and a target control torque that is contrary to the driver's intention is set, the target control torque of the offset term is calculated based on the driver steering torque and the target control torque of the offset term. Note that the control reduction amount may be calculated as a reduction gain coefficient, similarly to the yaw angle term. The calculated limit reduction amount is multiplied by the target limit torque of the offset term, and is output to the final adding means 79 as the steering torque of the offset term.

  As described above, the control reduction amount calculation unit 76 includes the yaw angle control reduction amount calculation unit 77 and the offset control reduction amount calculation unit 78 individually for the yaw angle θ and the offset D of the plurality of detection elements. The individual steering torque is output to the adding means 79. An example of specific control contents of the control reduction amount calculation means 76 will be described later.

  The adding means 79 is means for adding the steering torque of each term output from the yaw angle control reduction amount calculating means 77, the offset control reduction amount calculating means 78, and the feedforward gain calculating means 74. The steering torque that has been controlled to reduce the control as necessary is finally output from the adding means 79 and sent to the steering torque applying means 80. Then, an appropriate steering torque is applied in the steering torque application means 80.

  FIG. 4 is a diagram illustrating a control configuration of a conventional lane keeping assist device. In FIG. 4, the driver control torque and the target control torque that has been summed up with each term are input to the control interference determination unit 175, and the control reduction amount calculation unit 176 calculates the control reduction amount according to the control interference determination result. It is configured. The control reduction amount (gain coefficient) calculated by the control reduction amount calculation unit 176 is multiplied by the target control torque and output as the final target control torque. As described above, since only control for reducing the control is performed on the entire target control torque, it is impossible to perform fine control on each detection element.

  On the other hand, in the lane keeping assist device 71 according to the present embodiment shown in FIG. 3, when the lane keeping assist control is being performed contrary to the driver's intention, the steering torque to be applied is applied in the same manner as in FIG. Although control to decrease is performed, at that time, the control amount is individually reduced for each of the detection elements that determine the steering torque, so that highly accurate control according to the situation becomes possible.

  In FIG. 3, the yaw angle θ and the offset D are given as the detection elements for calculating the control reduction amount. However, instead of or in addition to this, the yaw rate and the lateral acceleration may be used as the detection elements. . The yaw rate can be detected using a yaw rate sensor, and the lateral acceleration can be detected using an acceleration sensor. When these are added or replaced, a control line similar to the yaw angle θ or offset D shown in FIG. 3 may be added or replaced. If these detection elements are also added, control with higher accuracy can be performed.

  Next, an operation example of the lane keeping assist device 71 according to the present embodiment will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of a processing flow executed in the lane keeping assist device 71 according to the present embodiment. In addition, about the component demonstrated until now, the same referential mark as the past is attached | subjected and the description is abbreviate | omitted.

  In step 100, it is determined whether the brake switch 40 and the blinker switch 50 are OFF. As described above, when the brake switch 40 is ON, it is considered that the vehicle is in an emergency state. When the blinker switch 50 is ON, it is considered that the driver is changing the lane. For safety reasons, it is preferable not to generate the steering torque. Therefore, in step 100, it is confirmed whether or not the brake switch 40 and the blinker switch 50 are in the OFF state. If not, the process ends. On the other hand, when it is in the OFF state, the process proceeds to step 110.

  In the processing flow of FIG. 5, step 100 is not essential, and may be provided as necessary.

  In step 110, the target control torque is calculated by the target control torque calculation means 72. At that time, the target control torque is calculated for each detection element of the yaw angle θ, the offset D, and the curve radius R, and the target control torque obtained by adding all of them is also calculated. Then, the target control torque for each term of the yaw angle θ and the offset D used for feedback control is sent to the input / output of the control reduction amount calculation means 77 and 78 for each corresponding term. Further, the target control torque calculated from the curve radius R used for the feedforward control is sent to the final adding means 79. On the other hand, the combined target control torque is sent to the control interference determination means 75 and the process proceeds to step 120.

  In step 120, the control interference determining means 75 determines whether or not control interference has occurred. This makes it possible to determine whether or not lane keeping support control that is contrary to the driver's intention is being performed. The determination may be made based on whether or not the difference between the steering torque when the driver steers the steering and the target control torque is equal to or greater than a predetermined value.

  When it is determined that the control interference has not occurred, the lane keeping assist control is being performed in accordance with the driver's intention, so the process proceeds to step 160 and the target control torque is output as the steering torque as it is. On the other hand, when it is determined that control interference has occurred, the process proceeds to step 130.

  In step 130, it is determined whether or not the white line recognition camera 30 is operating normally, that is, whether or not it is malfunctioning. The white line recognition camera 30 is normally operated when the shape and white of the lane markings on the road are clear and the weather is fine, but it is rainy or the white lines on the lane markings are difficult to recognize. In such a case, the white line may not be recognized normally and may malfunction. In step 130, it is determined whether or not the white line recognition camera is operating normally according to the environment in which the vehicle is placed. The determination may be made based on, for example, the contrast of the image captured by the white line camera. When the wiper switch is ON and the wiper is continuously operated, it is determined that it is heavy rain and this control is temporarily interrupted (may be determined in step 100), or the wiper moves If it is intermittent, it may be determined that the white line recognition camera 30 is in a malfunctioning state although the lane keeping support control itself is performed because it is light rain.

  If it is determined in step 130 that the white line recognition camera 30 is operating normally, the process proceeds to step 140. If it is determined that the white line recognition camera 30 is malfunctioning, the process proceeds to step 150.

  In step 140, the control reduction amount calculation means 76 calculates the control reduction amount when the white line recognition camera 30 is operating normally. Specifically, calculation of the control reduction amount that increases the control reduction amount of the yaw angle θ term and decreases the control reduction amount of the offset D term is performed by the yaw angle control reduction amount calculation unit 77 and the offset control reduction. Each is performed in the amount calculation means 78.

  The driver places more importance on the assist steering torque applied to the yaw angle θ than the assist steering torque applied to the offset. That is, it is more uncomfortable for the driver to feel that the vehicle is given a yaw angle that is contrary to his / her intention than an offset which is contrary to his / her intention. It can be said that the yaw angle θ has a greater influence on the driver's sense than the offset D. In such a normal state, by increasing the control reduction amount of the yaw angle θ and reducing the control reduction amount of the offset D, it is possible to reduce interference in accordance with the driver's feeling. In setting the control reduction amount, the ratio of the gain coefficient for performing the mode control in step 140 is determined in advance by the yaw angle control reduction amount calculation unit 77 and the offset control reduction amount calculation unit 78. Alternatively, the control reduction amount may be determined by various other control methods.

  Such control amount reduction control is performed by each of the yaw angle control reduction amount calculation unit 77 and the offset control reduction amount calculation unit 78 of the control reduction amount calculation unit 62 to calculate the target control torque of each term. Proceed to

  On the other hand, in step 150, the control reduction amount calculation means 76 calculates the control reduction amount when the white line recognition camera 30 malfunctions. Specifically, calculation of the control reduction amount that reduces the control reduction amount of the yaw angle θ term and increases the control reduction amount of the offset D term is performed by the yaw angle control reduction amount calculation unit 77 and the offset control reduction. Each is performed in the amount calculation means 78.

  When the white line recognition camera 30 malfunctions, the malfunction caused by the offset error is larger than the malfunction caused by the recognition error of the yaw angle θ. In other words, in the case of the yaw angle θ, the white line is used to calculate the angle difference from the direction of the white line on both sides, so if the overall directionality can be recognized, so much error will not occur, but in the case of offset Since the distance of the deviation is calculated from the white line as the starting point, erroneous recognition of the white line more directly affects the malfunction. Therefore, in such a case, if the control reduction amount of the yaw angle θ term is reduced and the control reduction amount of the offset D term is increased, the influence of malfunction is reduced and effective interference reduction for malfunction is reduced. It can be performed. Similarly to step 140, the control reduction amount is set in advance using the gain coefficient when the control of the mode of step 150 is controlled in advance by the yaw angle control reduction amount calculation means 77 and the offset control reduction amount calculation means 78. The ratio may be determined, or the control reduction amount may be determined by various other control methods.

  Such control amount reduction control is performed by each of the yaw angle control reduction amount calculation unit 77 and the offset control reduction amount calculation unit 78 of the control reduction amount calculation unit 62, and the target control torque of each term is calculated. Proceed to

  In step 160, the target control torque of each term is added by the adding means 79, and the final steering torque is output. By the above-described control processing, effective interference reduction control can be performed, and lane keeping support control can be performed within a range that is not contrary to the driver's intention.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

It is a lane maintenance support system block diagram containing the lane maintenance support apparatus 71 which concerns on a present Example. It is explanatory drawing of the information recognized with the white line recognition camera. It is a figure which shows an example of the control structure of the lane maintenance assistance apparatus 71 which concerns on a present Example. It is the figure which showed the control structure of the conventional lane maintenance assistance apparatus. It is the figure which showed the example of the processing flow by the lane maintenance assistance apparatus 71 which concerns on a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle speed detection means 20 Steering torque detection means 30 White line recognition camera 40 Brake switch 50 Winker switch 60 Main switch 70 Lane maintenance assistance ECU
71 Lane Maintenance Support Device 72 Target Control Torque Calculation Unit 73 Feedback Gain Calculation Unit 74 Feedforward Gain Calculation Unit 75 Control Interference Determination Unit 76 Control Reduction Amount Calculation Unit 77 Yaw Angle Control Reduction Amount Calculation Unit 78 Offset Control Reduction Amount Calculation Unit 79 Adding means 80 Steering torque applying means 90 Alarm buzzer 100 Meter

Claims (5)

A lane keeping assist device that controls steering torque so that a vehicle travels while keeping a lane,
Target control torque calculating means for calculating a target control torque of the steering torque based on a plurality of detection elements indicating the traveling direction, lateral position and / or behavior of the vehicle;
Steering torque detection means for detecting driver steering torque when the driver steers,
The target control torque is determined so that a target control amount of the target control torque is reduced when a steering direction of the target control torque is different from a steering direction of the driver steering torque and control interference occurs. And a control reduction amount calculating means for calculating a control reduction amount of each of the plurality of detection elements.   2. The lane keeping assist device according to claim 1, wherein the plurality of detection elements include a yaw angle and an offset indicating an amount of deviation from a target position in the traveling lane.   The lane keeping assist device according to claim 2, wherein the control reduction amount calculation unit performs control so that the control reduction amount of the yaw angle is larger than the control reduction amount of the offset. The offset is detected by a white line recognition camera,
The control reduction amount calculation unit controls the offset control reduction amount to be larger than the control reduction amount of the yaw angle when a malfunction occurs in the white line recognition camera. The lane keeping assist device according to 2 or 3.   The lane keeping assist apparatus according to any one of claims 1 to 4, wherein the plurality of detection elements include a yaw rate and / or a lateral acceleration.

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