JP6670226B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that controls the running of a vehicle.

  A so-called lane, in which lane markings and the like are recognized from images captured by an on-board camera, and based on the recognition result, a steering control amount such as a steering torque and a steering angle of a steering device is controlled so that the vehicle can travel along the lane. Maintenance control has been proposed. In such control, a lane detecting device such as a camera or a sensor acquires a state quantity indicating a running state of the vehicle such as a lateral position or a yaw angle of the vehicle in the lane, and is obtained from the state quantity and a predetermined target value. The steering control amount is feedback-controlled based on the deviation. Further, the calculation of the steering control amount generally includes an operation element for integrating the deviation to eliminate a steady error in the output of the lane detecting device.

  Here, in a lane detecting device such as a vehicle-mounted camera, there is a possibility that a temporary erroneous detection may occur due to various factors. When the detection accuracy is reduced due to the erroneous detection, an erroneous steering control amount is calculated, so that inappropriate steering may occur and the vehicle may fluctuate. Therefore, for example, in the device described in Patent Document 1, the irradiation state of the headlamp is used as an index of the detection accuracy of the own lane, and the control sensitivity of the steering control amount is weakened when the degree of goodness of the irradiation state of the headlamp is small. Controlling. This prevents the control state of the steering control amount from deteriorating in a situation where the detection accuracy of the own lane is poor.

JP 2008-308091 A

  However, even when the control sensitivity of the steering control amount is weakened when the detection accuracy of the own lane is reduced, the calculation of the steering control amount has been executed, and the steering of the vehicle occurs accordingly. For example, by continuously executing the integral calculation of the deviation, the deviation calculated as an erroneous value due to the erroneous detection is sequentially accumulated as an integral value, and the steering control amount is calculated based on the integral value. As a result, with an increase in the error in the steering control amount, inappropriate steering may occur, and the vehicle may wander.

  The present invention has been made in view of the above problems, and has as its object to provide a vehicle control device capable of appropriately controlling a steering control amount.

  The present invention is applied to a vehicle including a lane detection device that detects a lane of a road, and a steering device that performs steering of the vehicle, and is a vehicle control device that performs steering control by the steering device. A deviation calculator for acquiring a state quantity indicating the running state of the vehicle based on an output of the detection device, and calculating a deviation between the state quantity and a predetermined target value; and a steering control amount based on an integral operation of the deviation. A control amount calculation unit that calculates the steering control amount so as to eliminate the deviation, a reliability calculation unit that calculates the reliability of the output of the lane detecting device, and A processing change unit that changes a processing mode in the integration operation.

  In the lane keeping control, generally, the steering control amount is controlled by a feedback control based on a deviation between a state amount of the vehicle acquired by the lane detecting device (such as a lateral position and a yaw angle of the own vehicle in the own lane) and a predetermined target value. Is done. At this time, integral control is performed to eliminate a steady error in the output of the lane detecting device. However, in a lane detecting device such as a camera or a sensor that detects a lane, a temporary erroneous detection may occur due to various factors. When the detection accuracy decreases due to the erroneous detection, the deviation is calculated as an erroneous value, and the deviation is accumulated as a successively integrated value. As a result, an erroneous steering control amount is calculated, thereby causing inappropriate steering and possibly causing the vehicle to wander.

  In the above configuration, a state quantity indicating the traveling state of the vehicle is obtained based on the output of the lane detecting device, a deviation between the state quantity and a predetermined target value is calculated, and furthermore, an operation including an integral operation of the deviation is performed. Calculate the steering control amount. Then, the processing mode in the integration calculation is changed based on the reliability of the output of the lane detecting device. That is, unlike the case where the integral calculation is performed uniformly irrespective of the lane detection accuracy, the processing mode in the integral calculation is taken into account that the lane detection accuracy differs depending on the reliability of the output of the lane detection device. Was changed. As a result, occurrence of inappropriate steering can be suppressed, and wobbling of the vehicle can be suppressed. As a result, steering control of the vehicle can be properly performed.

The figure which shows the schematic structure of a lane keeping control system. The figure explaining the state quantity of the vehicle acquired by ECU. The figure for demonstrating calculation of a steering control amount. The figure for demonstrating the behavior of the own vehicle in the conventional control. 6 is a timing chart showing an aspect of conventional control. 5 is a flowchart illustrating a procedure of steering control according to the embodiment. FIG. 4 is a diagram for explaining the behavior of the host vehicle in the embodiment. 5 is a timing chart showing a mode of steering control in the embodiment. 9 is a flowchart illustrating a procedure of steering control in the second embodiment. 9 is a timing chart illustrating a mode of steering control according to the second embodiment.

(1st Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiment embodies a lane keeping control system mounted on a vehicle having a steering device. In this system, an electronic control unit (hereinafter, referred to as an ECU) is used as a center, and a steering control amount is controlled so that the own vehicle can travel at a desired position (for example, the center of the vehicle) in the lane when traveling in the lane. I have.

  First, a schematic configuration of a vehicle lane keeping control system according to the present embodiment will be described with reference to FIG. The host vehicle 50 mainly includes various detection units such as a vehicle-mounted camera 10, a yaw rate sensor 11, a vehicle speed sensor 12, and a steering angle sensor 13, an ECU 20, and a steering device 30.

  The in-vehicle camera 10 acquires a captured image ahead of the own vehicle 50 in the traveling direction, and detects a lane based on the captured image. The on-vehicle camera 10 is a device including a monocular camera or a stereo camera such as a CCD image sensor, a CMOS image sensor, or a near-infrared sensor, and is mounted, for example, near the upper end of the windshield of the vehicle 50 and near the center in the vehicle width direction. Have been.

  Further, the vehicle-mounted camera 10 detects the position of a lane marking that separates the left and right lanes of the lane in which the host vehicle 50 travels, based on the acquired captured image. Specifically, the in-vehicle camera 10 extracts edge points by applying a sobel filter or the like to the image, performs Hough transform or the like on the extracted edge points, and detects edge points forming left and right division lines. Then, the coordinates of the edge points of the division line on the image plane are calculated, and the calculated coordinates are set as the position of the division line. Then, the vehicle-mounted camera 10 transmits the detected position of the lane marking to the ECU 20 at a predetermined cycle. Note that the dividing line includes a solid line and a broken line, and each line may be colored in white, yellow, blue, or the like.

  The yaw rate sensor 11 detects an angular velocity (yaw rate) of the vehicle 50 in the turning direction. The yaw rate sensor 11 has a vibrator, and detects a distortion generated in the vibrator based on the yaw moment of the host vehicle 50, thereby detecting the yaw rate of the host vehicle 50. The detected yaw rate is output to the ECU 20.

  The vehicle speed sensor 12 is attached to, for example, a wheel, and detects the vehicle speed V of the host vehicle 50 based on the rotation speed of the wheel. The detected vehicle speed V is output to the ECU 20.

  The steering angle sensor 13 detects a steering amount of the steering device 30. The steering angle sensor 13 is attached to the steering shaft 32 and detects the rotation angle (steering angle) of the steering wheel 31. The detected steering angle is output to the ECU 20.

  The ECU 20 is mainly configured by a computer having a CPU, various memories, and the like. The ECU 20 detects the lane in which the host vehicle 50 travels based on the lane marking information output from the on-board camera 10. In the detection of the lane, for example, the center coordinates in the width direction of the lane divided by the left and right lane markings detected by the in-vehicle camera 10 and the state quantity indicating the running state of the vehicle are acquired.

  FIG. 2 is a diagram illustrating a state quantity of the vehicle acquired by the ECU 20. In the present embodiment, the ECU 20 acquires the yaw angle θ that is the inclination of the center line with respect to the traveling direction of the host vehicle 50 and the lateral position y of the host vehicle 50 in the host lane as the state quantities. Here, the lateral position y is acquired as a shift amount from the center line in the lane width direction. That is, when the center line is set as the target lateral position, the lateral position y and the lateral position deviation Δy are acquired as the same value. The center line is a line passing through the center in the width direction of the lane divided by the left and right division lines. The state quantity of the vehicle is also referred to as a roadway parameter.

  Further, the ECU 20 performs feedback control of the steering control amount δ based on the deviation between the acquired state quantity and the predetermined target value and the integral of the deviation so that the host vehicle 50 can travel at a desired position in the lane. ing. Specifically, the ECU 20 calculates the steering control amount δ according to the control configuration shown in FIG.

  In FIG. 3, first, a deviation between each state quantity (for example, the yaw angle θ and the lateral position y) of the vehicle and each target value is calculated. More specifically, for example, the yaw angle deviation Δθ is calculated by subtracting the yaw angle θ from the target yaw angle (for example, 0 °). Further, the lateral position deviation Δy is calculated by subtracting the lateral position y from the target lateral position (for example, 0 if the center line of the lane is the target lateral position).

  Next, an integral value is obtained by integrating the calculated deviation. In FIG. 3, an integral value z (that is, ∫Δydt) is calculated by performing an integral operation on the lateral position deviation Δy. In this case, the integrated value z of the lateral position deviation Δy is used for feedback control in order to eliminate the steady deviation of the lateral position y caused by the influence of disturbance such as cant.

Subsequently, the obtained deviations of the state quantities and their integrated values (Δθ, Δy, z) are multiplied by the corresponding control gains (G1, G2, G3). Then, a steering control amount δ is calculated based on the obtained values. That is, the steering control amount δ is calculated based on the following equation (1).
Steering control amount δ = −G1 × Δθ−G2 × Δy−G3 × z (1)
The calculated steering control amount δ is output from the ECU 20 to an EPS (Electric Power Steering) controller 21.

  The EPS controller 21 is a well-known computer including a CPU, a ROM, and a RAM (not shown), and is connected to the motor 34 of the steering device 30. The EPS controller 21 controls the motor 34 based on the steering control amount δ output from the ECU 20, and changes the steering angle and the steering torque.

  The steering device 30 is, for example, an electric steering device, and applies a steering torque to a steering shaft 32 connected to the steering wheel 31 by rotation of a motor 34 to set the steering of the host vehicle 50. A pinion gear 35 is provided at the tip of the steering shaft 32. This pinion gear 35 meshes with a rack gear 36. A pair of wheels are rotatably connected to both ends of the rack gear 36 via tie rods or the like. Further, a motor 34 is attached to the steering shaft 32 via a reduction gear 33.

  In the lane keeping control, the steering control amount is controlled so that the host vehicle 50 can travel along the lane detected by a lane detecting device such as a camera or a sensor. Specifically, the steering control amount is feedback-controlled based on the deviation between the state quantity of the vehicle acquired by the lane detecting device and a predetermined target value. In general, the calculation of the steering control amount includes a calculation element for performing an integration calculation of the deviation. That is, the detection accuracy of the lane is closely related to the steering control.

  On the other hand, the lane detection device may cause erroneous detection temporarily due to various factors such as road surface conditions and weather. Then, when the detection accuracy of the lane is reduced due to the erroneous detection, an incorrect steering control amount is calculated, which may cause inappropriate steering. In such a case, it is conceivable that the running of the vehicle becomes unstable, for example, the vehicle fluctuates. FIG. 4 shows the behavior of the host vehicle 50 when the host vehicle 50 runs along the center of the lane by the conventional lane keeping control. In addition, a guardrail is installed as a roadside stationary object beside the left lane marking.

  Here, in the sections P11, P12, and P13, if the guardrail is temporarily recognized as a lane marking, the own lane in the section is erroneously detected. That is, in the sections P11, P12, and P13, the own lane is detected to be spread to the left, and as a result, the center of the own lane is shifted to the left. Then, by performing the steering control so as to travel along the center of the detected own lane, the own vehicle 50 meanders right and left as shown in FIG. That is, due to the erroneous detection of the own lane, an inappropriate steering control amount occurs, and the own vehicle 50 fluctuates.

  FIG. 5 shows a timing chart in the case where the vehicle 50 exhibits the behavior shown in FIG. Between the timings t11 and t12, the lateral position deviation Δy is erroneously calculated due to the erroneous detection of the own lane in the sections P11, P12, and P13. In each of these sections, the integral value z increases, and the integral control amount G3z also increases due to the integration operation of the lateral position deviation Δy. That is, by executing the integration operation, the lateral position deviation Δy calculated as an erroneous value is sequentially accumulated as the integration value z, and the error of the integration control amount G3z increases.

  Thereafter, after the timing t12, when the erroneous detection of the own lane is eliminated, the lateral position deviation Δy converges to zero by performing the steering control along the center of the own lane. Accordingly, the integral value z and the integral control amount G3z also converge to zero. However, since the error of the integral control amount G3z is large at the timing t12, it takes time for the host vehicle 50 to return to the center of the host lane (timing t13). As described above, in the conventional control, there is a concern that vehicle control may be deteriorated such as inappropriate steering due to erroneous detection of the own lane.

  Therefore, in the present embodiment, the ECU 20 acquires a state quantity indicating the traveling state of the vehicle 50 based on the output of the on-board camera 10, calculates a deviation between the state quantity and a predetermined target value, and further calculates The steering control amount is calculated by an operation including an integral operation of the deviation. Then, based on the reliability of the output of the in-vehicle camera 10, the processing mode in the integration operation is changed. That is, by changing the processing mode in the integration operation based on the reliability of the output of the on-vehicle camera 10, the accumulation of erroneous values due to erroneous detection as an integral value is suppressed, and as a result, the steering control amount is reduced. Can be controlled appropriately. Here, the change of the processing mode specifically includes a stop process of the integral calculation and a change of the integral value.

  More specifically, the ECU 20 determines whether or not the reliability of the output of the on-vehicle camera 10 is smaller than a predetermined value, and stops the integration operation when the reliability is determined to be smaller than the predetermined value. . In this case, the value of the integral value is kept constant by stopping the integral calculation.

  Further, the ECU 20 determines the reliability of the output of the on-vehicle camera 10 as an index for improving the detection accuracy of the lane. The reliability indicates that the detection accuracy of the lane is high if the reliability is high, and the detection accuracy of the lane is low if the reliability is low. When the reliability is determined, a well-known method can be used. For example, a method of determining the accuracy of the lane marking recognized by the vehicle-mounted camera 10 can be used. For example, when the edge points of the lane markings detected with a predetermined continuity show a variation with a predetermined change or more, or when the length of the continuous section is too small, the reliability is determined to be low. be able to.

  In the present embodiment, it is assumed that one of the left and right lane markings is correctly recognized in the calculation of the reliability. That is, the ECU 20 calculates the reliability when one of the lane markings on the left and right sides of the lane is correctly recognized. In other words, the ECU 20 determines that, for example, when the edge points of the left and right division lines detected with predetermined continuity show variations with a variation of more than a predetermined value on both the left and right sides, that is, the detection accuracy is low on both the left and right sides of the division line. In this case, the reliability is not calculated. Therefore, in such a case, the ECU 20 does not execute the main control for changing the processing mode in the integration calculation.

  Next, a processing procedure of the steering control in the vehicle control device will be described with reference to a flowchart of FIG. This process is repeatedly executed by the ECU 20 at predetermined intervals.

  In step S11, a state quantity indicating the running state of the host vehicle 50 is acquired based on the output of the lane detecting device. Here, the ECU 20 acquires, for example, the yaw angle θ and the lateral position y as the state quantities based on the lane information output from the on-vehicle camera 10. In step S12, a deviation between the obtained state quantity and a predetermined target value is calculated. For example, the yaw angle deviation Δθ between the yaw angle θ of the host vehicle 50 and the target yaw angle and the lateral position deviation Δy between the lateral position y of the host vehicle 50 and the target lateral position are calculated. Steps S11 and S12 correspond to a “deviation calculator”.

  In step S13, the reliability of the output of the lane detecting device is calculated. Here, as described above, the reliability is calculated using the continuity of the edge points of the lane markings recognized by the vehicle-mounted camera 10. For calculating the reliability, a predetermined correlation map may be used. In step S14, it is determined whether or not the calculated reliability is greater than a threshold Th1. Here, the threshold value Th1 is a determination value for determining that the detection accuracy of the own lane has decreased. If step S14 is YES, the process proceeds to step S15, and the steering control amount δ is calculated by ordinary calculation processing. Step S13 corresponds to a “reliability calculating unit”, and step S14 corresponds to a “reliability determining unit”.

  In step S15, an integral operation of the deviation calculated in step S12 is performed. Here, for example, the integral value z is calculated by integrating the lateral position deviation Δy. Note that the integration operation is performed using values from the current time to a predetermined period before the current time. The lateral position deviation Δy calculated in the past is stored in a memory in the ECU 20, and the ECU 20 uses the lateral position deviation Δy calculated in the past and the lateral position deviation Δy calculated at the present time to calculate the integral value z. Is calculated.

  In step S16, a steering control amount δ is calculated based on the calculated deviation and the integrated value of the deviation. Here, the steering control amount δ is calculated based on the above equation (1). The steering control amount δ calculated by the ECU 20 is output to the EPS controller 21, and the steering control by the steering device 30 is performed. Steps S15 and S16 correspond to a “control amount calculation unit”.

  On the other hand, if step S14 is NO, it is considered that the detection accuracy of the own lane has decreased, and the processing mode in the integral calculation of the deviation is changed. As a change of the processing mode, in step S17, the integration calculation of the lateral position deviation Δy is stopped. By this processing, the integral value z is held at a constant value. In step S18, the sensitivity to the steering control amount δ in the integral calculation is changed. Specifically, the control gain G3 by which the integral value z is multiplied is changed to a smaller value. In this case, by changing the control gain G3 to a smaller value, the sensitivity of the integral calculation with respect to the steering control amount δ is reduced.

  As described above, when it is determined that the reliability (that is, the detection accuracy of the lane) is low, the ECU 20 stops the integral calculation and reduces the control gain G3 to thereby control the steering control amount δ exerted by the integral calculation. The effect on is reduced.

  Here, the reliability of the output of the in-vehicle camera 10 is determined based on, for example, the edge points of the lane marking in time series and the variation of the edge points. Even if it occurs, there is a possibility that a decrease in the detection accuracy of the own lane cannot be immediately determined. In other words, when it is determined that the reliability is low, it is considered that a certain amount of time may have already passed since an error occurred in the recognition of the lane marking. In such a case, the integration operation is performed as usual until the reliability is determined to be small. Therefore, at the time of the determination of the reliability, the erroneous value resulting from the erroneous detection has already been accumulated as the integrated value. Become. Then, for example, when the determination of the reliability is slow and the time during which the erroneous value is accumulated is long, the error of the integral control amount G3z based on the integral calculation increases, and thereby inappropriate steering actually occurs. It is considered to have occurred.

  Therefore, in the present embodiment, when it is determined that the reliability has decreased, the steering amount of the steering device 30 is calculated from the occurrence of the factor of the decrease in reliability to the determination of the decrease in reliability. Then, the integrated value is changed based on the calculated steering amount. Specifically, the actual steering amount that occurs during the period from the occurrence of the lane marking recognition error to the determination of the decrease in reliability is calculated. Then, when the calculated actual steering amount is smaller than the threshold Th2, the integral value z is changed to zero. That is, when the actual steering amount due to the erroneous detection is small, the error of the integral control amount G3z can be eliminated by resetting the integral value z to zero, and the steering control amount δ can be optimized.

  Also, a sudden change in the steering control amount δ may lead to a sudden steering occurrence and affect drivability. Therefore, when the actual steering amount is equal to or larger than the threshold Th2, the ECU 20 sets the integral value z to: The value is changed to a predetermined value larger than zero, that is, an intermediate value between zero and the integral value (previous value) immediately before stopping the integration operation. For example, the integral value z is changed to 1/2 or 1/3 of the previous value. That is, when the actual steering amount due to the erroneous detection is large, drivability is ensured so that sudden steering does not occur.

  The ECU 20 calculates the actual steering amount, for example, as follows. The ECU 20 stores the edge point of the lane marking line recognized by the vehicle-mounted camera 10 as a history, and actually uses the history of the edge point from the time T1 when it is determined that the reliability of the output of the vehicle-mounted camera 10 is low. The time point T0 at which the lane marking recognition error occurs is specified. Then, based on the steering angle detected by the steering angle sensor 13, the actual steering amount generated during the period (T0 to T1) is calculated. That is, the actual steering amount is a steering amount generated to correct the lateral position y of the host vehicle 50 with respect to the host vehicle lane.

  In the flowchart of FIG. 6, in step S19, the actual steering amount is calculated. Here, the actual steering amount is calculated by, for example, the above-described method. Step S19 corresponds to a “steering amount calculation unit”. In step S20, it is determined whether the actual steering amount is smaller than a threshold Th2. If step S20 is YES, the process proceeds to step S21, where the integral value z is changed to zero. Then, in step S16, the steering control amount δ is calculated. In this case, by changing the integral value z to zero, the integral control amount G3z becomes zero.

  On the other hand, if step S20 is NO, the process proceeds to step S22. In step S22, the integral value z is changed to a predetermined value. For example, the predetermined value is an intermediate value between zero and an integral value (previous value) immediately before stopping the integral operation. Then, in step S16, the steering control amount δ is calculated. Steps S17 to S22 correspond to a “processing change unit”.

  In steps S19 to S22, the integral value z may be changed based on any of the steering control amount δ, the integral control amount G3z, and the integral value z instead of the actual steering amount. In such a case, for example, the ECU 20 stores the calculated steering control amount δ as a history, and uses the history and the history of the edge points to reduce the reliability after the cause of the reliability reduction occurs. The steering control amount δ during the period until the effect is determined is calculated. In the present embodiment, the steering control amount δ, the integral control amount G3z, and the integral value z correspond to “parameters correlated with the actual steering amount”.

  Next, FIGS. 7 and 8 show the processing of FIG. 6 more specifically. FIG. 7 shows the behavior of the host vehicle 50 when the host vehicle 50 runs along the center of the lane in the present embodiment, and FIG. 8 shows a corresponding timing chart. Here, the control when step S20 in FIG. 6 is YES, that is, when the actual control amount is smaller than the threshold Th2 is shown. FIGS. 7 and 8 correspond to FIGS. 4 and 5, which describe the conventional control, and show the control when the own lane is erroneously detected in the sections P11, P12, and P13. .

  First, at timing t21, if a lane is erroneously detected by the in-vehicle camera 10, an error occurs in the lateral position of the host vehicle 50, and the lateral position deviation Δy is incorrectly calculated. Then, by accumulating an erroneous value of the lateral position deviation Δy, the integral value z increases and the integral control amount G3z also increases. Thereafter, when the reliability of the output of the on-vehicle camera 10 decreases at timing t22, the integration calculation of the lateral position deviation Δy is stopped, and the integration value z is changed to zero. Accordingly, the integral control amount G3z also becomes zero.

  Thereafter, the erroneous detection and the normal detection of the own lane are alternately repeated. During this time, the integral value z is maintained at zero, and the integral control amount G3z also remains at zero. Then, when the erroneous detection of the own lane is resolved after the timing t23, the lateral position deviation Δy approaches zero, and at the timing t24, the lateral position deviation Δy becomes zero. That is, the lateral position y of the vehicle 50 returns to the center of the lane.

  On the other hand, the reliability of the output of the vehicle-mounted camera 10 is restored by improving the continuity of the edge points and the like. With the restoration of the reliability, the suspension of the integration calculation is released. That is, the integration operation is restarted. The recovery of the reliability may be determined based on the fact that the reliability obtained from the continuity of the edge points or the like has reached a predetermined value or more.

  Here, a comparison between the present control and the conventional control reveals that in this control, the integral calculation of the lateral position deviation Δy is stopped and the integral value z is changed to zero. The generation of quantity is suppressed. That is, the amount of steering that occurs when the vehicle deviates from the center of the own lane is smaller in the present control than in the conventional control. Further, in the present control, the accumulation of an inappropriate steering amount is suppressed, so that a state of deviating from the center of the own lane can be quickly eliminated. That is, the time from timing t23 to t24 in this control is shorter than the time from timing t12 to t13 in the conventional control.

  According to the embodiment described above, the following excellent effects can be obtained.

  In the above configuration, a state quantity indicating the running state of the vehicle 50 is acquired based on the output of the on-vehicle camera 10, a deviation between the state amount and a predetermined target value is calculated, and an integration operation of the deviation is further included. The steering control amount δ is calculated by calculation. Then, based on the reliability of the output of the in-vehicle camera 10, the processing mode in the integration operation is changed. That is, unlike the case where the integral calculation is performed uniformly regardless of the lane detection accuracy, the processing mode in the integral calculation is taken into account that the lane detection accuracy differs depending on the reliability of the output of the vehicle-mounted camera 10. Was changed. As a result, occurrence of inappropriate steering can be suppressed, and wobble of the host vehicle 50 can be suppressed. As a result, the steering control of the host vehicle 50 can be appropriately performed.

  Specifically, when the reliability of the output of the vehicle-mounted camera 10 is smaller than a predetermined value, the integration calculation of the lateral position deviation Δy is stopped. In this case, by stopping the integration operation, the integration value z is kept constant. That is, it is possible to prevent accumulation of an incorrect value of the lateral position deviation Δy due to the integration operation. As a result, occurrence of inappropriate steering due to erroneous detection can be suppressed.

  In addition, the integral calculation is stopped, and the integral value z of the lateral position deviation Δy is changed to a predetermined value. In this case, by changing the integral value z to a predetermined value, for example, a sudden change in the steering control amount δ can be suppressed. Thus, the occurrence of sudden steering can be suppressed, and deterioration of drivability can be prevented.

  On the other hand, when it is determined that the reliability of the output of the vehicle-mounted camera 10 is low, the lateral position deviation Δy calculated as an erroneous value may already be accumulated as the integral value z. In such a case, it is possible that inappropriate steering has actually occurred. In consideration of this point, in the above configuration, the integral calculation is stopped and the integral value z is changed to zero. In this case, by resetting the integral value z to zero, accumulation of erroneous values due to erroneous detection is eliminated. As a result, inappropriate steering can be suppressed.

  Further, when it is determined that the reliability of the output of the on-vehicle camera 10 has decreased, the actual steering amount of the steering device 30 from the time when the factor of the decrease in reliability occurs to the time when it is determined that the reliability has decreased is determined. Is calculated, and the value of the integral value is changed based on the actual steering amount. In this case, by changing the value of the integral value based on the erroneous actual steering amount caused by the erroneous detection of the on-vehicle camera 10, it is possible to suppress the occurrence of inappropriate steering while suppressing the occurrence of sudden steering. it can.

  Further, the sensitivity to the steering control amount δ in the integration calculation is changed according to the reliability. In this case, for example, when the reliability is low, by reducing the sensitivity to the steering control amount δ in the integral calculation, it is possible to reduce the influence of the integrated value z in which the erroneous value is accumulated on the steering control amount δ. it can.

(2nd Embodiment)
Next, a second embodiment will be described focusing on differences from the first embodiment. In the first embodiment, when the integral calculation of the deviation is stopped, the control gain G3 is changed, and the integral value z is changed to a preset value (zero or a predetermined value). On the other hand, in such a case, in the second embodiment, the control gain G3 is changed, and the integrated value z is changed (adjusted) so that the integrated control amount G3z becomes constant before and after the change of the control gain G3. That is, the integrated value z is changed so that the integrated control amount G3z becomes a continuous value before and after the control gain G3 is changed.

  Specifically, when the integral value z of the deviation is large at the time when the integral operation is stopped, the control gain G3 is reduced, and the integral value z is changed so that the integral control amount G3z is constant. When the integral value is large, for example, in addition to the deviation of the wrong value, the lateral position deviation Δy detected due to disturbances such as a bias error of the sensor or cant is accumulated as a normal value in the integral value z. Is the case. When the integral value z is large, there is a possibility that the steering control amount δ may change abruptly by changing the gain. In such a case, the integral control amount G3z is controlled to be constant.

  FIG. 9 is a flowchart illustrating a processing procedure of steering control according to the second embodiment. This process is repeatedly executed at predetermined intervals by the ECU 20 instead of the above-described FIG. In FIG. 9, the same processes as those in FIG. 6 are denoted by the same step numbers, and the description is simplified.

In FIG. 9, when it is determined that the reliability is equal to or less than the threshold Th1 (step S14: NO), the process proceeds to step S17, and the integration operation is stopped. In a succeeding step S18, the control gain G3 is changed. Here, the control gain G3 is changed to a smaller value. In step S31, the previous integral value z (i-1), that is, the integral value immediately before stopping the integration operation, is acquired. In step S32, it is determined whether or not the previous integration value z (i-1) is larger than a threshold Th3. If the previous integral value z (i-1) is larger than the threshold value Th3 (step S32: YES), in step S33, the integral value z is changed so that the integral control amount G3z becomes constant. In this case, for example, assuming that the control gain G3 before the change is G3a, the integrated value z before the change is za, the control gain G3 after the change is G3b, and the integrated value z after the change is zb, zb is given by the following equation (2). Is calculated based on
zb = G3a / G3b × za (2)
The value of the control gain G3b after the change varies depending on the vehicle speed and the like, and is determined by adaptation or the like.

  On the other hand, if the previous integral value z (i-1) is equal to or smaller than the threshold Th3 (Step S32: NO), the integral value z is changed to a preset value (for example, zero) in Step S34. Then, the steering control amount δ is calculated in step S16 using the integral value z changed in step S33 or step S34, respectively.

  Subsequently, FIG. 10 is a timing chart showing the processing of FIG. 9 more specifically. Here, it is determined that the reliability of the output of the on-vehicle camera 10 is low (step S14: NO), and it is determined that the previous integral value z (i-1) is larger than the threshold Th3. (Step S32: YES) is shown. In FIG. 10, as in FIG. 7, it is assumed that erroneous detection of the own lane occurs in a plurality of sections (P11, P12, P13).

  At timing t31, the lane is erroneously detected by the on-board camera 10, whereby the lateral position deviation Δy is erroneously calculated. As a result, the integral value z and the integral control amount G3z both increase. Then, at timing t32, when the reliability of the output of the on-vehicle camera 10 becomes equal to or less than the threshold Th1, the integration calculation of the lateral position deviation Δy is stopped, and the control gain G3 is changed to a smaller value. Further, at this timing t32, if the previous integral value z (i-1) is larger than the threshold Th3, the integral control amount G3z becomes constant before and after the change of the control gain G3, that is, the integral control amount G3z is continuous. The integral value z is changed so as to be a value. In this case, since the control gain G3 is changed to a smaller value, the integral value z is changed to a larger value according to the above equation (2). The subsequent control is the same as in FIG.

  According to the configuration described above, by adjusting the integral value z so that the integral control amount G3z is constant, it is possible to suppress a sudden change in the steering control amount δ that occurs when the control gain G3 is changed, and consequently, the occurrence of sudden steering. Ability can be kept good.

  The above embodiment may be changed as follows, for example.

  In the above-described embodiment, the yaw angle θ and the lateral position y are used as the vehicle traveling state quantities used for calculating the steering control amount δ. However, the present invention is not limited to this. For example, a lateral speed or a yaw rate can be used. Note that the lateral speed is obtained based on the yaw angle θ and the vehicle speed V detected by the vehicle speed sensor 12. The yaw rate is detected by the yaw rate sensor 11.

Further, the steering control amount δ may be calculated by using only the lateral position y as the vehicle traveling state amount. In this case, the steering control amount δ is calculated based on, for example, the following equation (3).
Steering control amount δ = −G2 × Δy−G3 × z (3)

  In the above-described embodiment, when it is determined that the reliability of the output of the on-vehicle camera 10 has decreased, the integral calculation of the lateral position deviation Δy is stopped and the control gain G3 is changed. May not be changed.

  In the first embodiment, when it is determined that the reliability of the output of the on-vehicle camera 10 has decreased, the integral calculation is stopped and the integral value z is changed based on the actual steering amount. May be changed. For example, the configuration may be such that, when it is determined that the reliability has decreased, the integral calculation is stopped and the integral value z is not changed. In such a configuration, the integral value z is maintained at the integral value (previous value) immediately before stopping the integration operation.

  Further, when it is determined that the reliability has decreased, the integral calculation may be stopped and the integral value z may be changed to a predetermined value regardless of the actual steering amount. For example, in FIG. 6, when step S14 is NO, only the steps S17 and S21 (or step S22) may be performed. According to this configuration, it is preferable from the viewpoint of a calculation load. In these configurations as well, by stopping the integration calculation, the occurrence of an inappropriate steering amount due to erroneous detection of the own lane is suppressed.

  -In 2nd Embodiment, it was set as the structure which determined whether to change integral value z so that integral control amount G3z might be fixed according to the value of integral value z. In this regard, the present invention is not limited to this. For example, according to the ratio of the control gain G3 to the total control gain (sum of G1, G2, and G3), whether to change the integral value z so that the integral control amount G3z is constant is determined. May be determined. For example, when the ratio of the control gain G3 to the total control gain is large, the integral value z can be changed so that the integral control amount G3z is constant. This can prevent the steering control amount δ from changing suddenly when the control gain G3 is changed.

  10: on-board camera, 20: ECU, 30: steering device, 50: own vehicle.

Claims (7)

A vehicle control device (20) that is applied to a vehicle including a lane detection device (10) that detects a lane of a road and a steering device (30) that performs steering of the vehicle (50), and that performs steering control by the steering device )
A deviation calculating unit that obtains a state quantity indicating the traveling state of the vehicle based on the output of the lane detecting device, and calculates a deviation between the state quantity and a predetermined target value.
A control amount calculation unit that includes a calculation element that calculates a steering control amount based on the integral calculation of the deviation, and calculates the steering control amount so as to eliminate the deviation;
A reliability calculation unit that calculates the reliability of the output of the lane detection device,
A reliability determination unit that determines whether the reliability is smaller than a predetermined value,
A processing change unit that changes a processing mode in the integration operation based on the reliability;
Equipped with a,
The vehicle control device , wherein the processing change unit stops the integration operation when the reliability is determined to be smaller than the predetermined value . Wherein the processing changing unit, when the reliability is determined to the smaller than the predetermined value, to stop the integral operation, to change the integral value obtained by integration calculation of the deviation to a predetermined value Item 2. The vehicle control device according to item 1 . The vehicle control device according to claim 2 , wherein the processing change unit stops the integration operation and changes the integration value to zero when the reliability is determined to be smaller than the predetermined value. The processing change unit stops the integration operation when the reliability is determined to be smaller than the predetermined value, and sets the integration value between zero and the previous value obtained in the previous integration operation. The vehicle control device according to claim 2 , wherein the vehicle control device changes the intermediate value between the values. When the reliability is determined to be smaller than a predetermined value, the actual steering amount of the steering device or the actual steering amount between the occurrence of the factor of the reliability reduction and the determination of the reliability reduction is determined. A steering amount calculating unit that calculates a parameter correlated with the steering amount,
5. The vehicle control device according to claim 2 , wherein the processing change unit changes the integral value based on the actual steering amount or a parameter correlated with the actual steering amount. The vehicle control device according to any one of claims 1 to 5 , wherein the processing change unit changes the sensitivity to the steering control amount in the integration operation according to the reliability. The processing change unit is to change the control gain by which the integral value of the deviation is multiplied as the change of the sensitivity, and before and after the change of the control gain, the control gain and the integral value of the deviation are changed. 7. The vehicle control device according to claim 6 , wherein the integrated value is adjusted so that the multiplied value becomes constant.

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