JP2005059643A - Steering control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a steering control in response to a traveling tendency of a driver. <P>SOLUTION: The steering control device has a lane recognition means recognizing a lane shape, an own vehicle position detection means detecting an own vehicle position, a basic vehicle travel line calculation means calculating the basic vehicle travel line determined by the lane shape, a travel tendency learning means learning that the driver has a tendency to travel which position of the lane width direction based on the own vehicle position information detected with the own vehicle position detection means, a driver travel tendency correction amount calculation means calculating the driver travel tendency correction amount based on the driver travel tendency information obtained with the travel tendency learning means, a post correction vehicle travel line calculation means calculating the post correction vehicle travel line by correcting the basic vehicle travel line with the driver travel tendency correction amount, and a steering control means performing the steering control of the vehicle so as to travel on the post correction vehicle travel line. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a steering control device in consideration of a driving tendency of a driver.

In Patent Document 1, a lateral deviation amount between the position in the width direction of the traveling lane where the vehicle is located after a predetermined time and the center point of the traveling lane is calculated, and the steering control torque is set so as to reduce the lateral deviation amount. A vehicle driver assistance system to be set is disclosed.
JP-A-7-104850

  However, which position in the lane width direction travels depends on the driver's preference. For example, when a driver who likes to travel to the right side from the center of the lane drives a vehicle to which the vehicle driver assistance system disclosed in Patent Document 1 is applied, the driver who tries to travel to the right side of the lane In response to this steering operation, steering control is performed against the driver's intention to bring the vehicle to the left side of the lane (the center of the lane), which may cause the driver to feel uncomfortable.

  Therefore, as means for solving the above-described problems, the steering control device in this application includes, as shown in FIG. 1, lane recognition means for recognizing the lane shape in the traveling direction of the own vehicle, and self-control in the width direction of the lane. Driving based on own vehicle position detecting means for detecting the vehicle position, basic vehicle running line calculating means for calculating a basic vehicle running line determined by the lane shape, and own vehicle position information detected by the own vehicle position detecting means Driving tendency learning means for learning which position in the lane width direction the driver tends to drive, and driving for calculating the driver driving tendency correction amount based on the driver driving tendency information obtained by the driving tendency learning means And a corrected vehicle travel line calculating means for calculating the corrected vehicle travel line by correcting the basic vehicle travel line using the driver travel tendency correction amount. And the steering control means for performing the steering control of the vehicle so as to travel on the corrected vehicle travel line, the steering control amount is corrected in accordance with the driving tendency of the driver. It is possible to reduce the uncomfortable feeling given to the driver by the steering control.

  The traveling tendency learning means learns the driving tendency of the driver in this curve when the vehicle travels on a curve having a predetermined curvature or more, and the steering control means has a curve in which the vehicle has a predetermined curvature or more. When the vehicle is traveling, the vehicle steering control is performed so that the vehicle travels on the corrected vehicle travel line. In this case, it is possible to perform the steering control by the steering control means in accordance with the driving tendency of the driver on the curve.

  And when the locus | trajectory which the vehicle actually drive | worked differs from the corrected vehicle travel line, you may make it correct | amend a driver | operator driving | running | working tendency correction amount. When the driver makes a steering input different from the steering control, for example, when the steering wheel is operated in the opposite direction to the steering control by the steering control means, the driver traveling tendency information stored in the traveling tendency learning means and the driver's It is determined that the driving tendency is different. Thus, by rewriting the driver travel tendency information based on the new driver's travel tendency, steering control that matches the driver's travel tendency can be performed.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is an explanatory diagram showing a schematic configuration of an electric power steering device to which the steering control device according to the present invention is applied.

  A steering shaft 2 to which the steering wheel 1 is coupled is connected to an output shaft 4 via a torsion bar 3. The output shaft 4 is provided with a pinion (not shown), and meshes with the rack provided on the steering rack 5. Left and right front wheels 6L and 6R are connected to both ends of the steering rack 5, respectively. That is, when the output shaft 4 is rotated, the steering rack 5 performs a linear motion based on the relationship between the pinion and the rack, and thereby the directions of the left and right front wheels 6L and 6R can be changed (steered). The pinion of the output shaft 4 is assisted by the steering force from the steering wheel 1 by an electric motor 9 as a steering actuator that is driven and controlled by an actuator drive circuit 8 that receives a command from the control ECU 7. .

  Steering force assistance by the electric motor 9 is performed based on a detection value from a torque sensor 11 that detects a steering torque from the torsion amount of the torsion bar 3 input to the control ECU 7.

  Here, the control ECU 7 is inputted with image information from the camera 12 disposed toward the front of the vehicle and a detection value of a vehicle speed sensor (not shown) for detecting the vehicle speed. The vehicle recognizes the vehicle position and the lane shape in the traveling direction of the vehicle. Then, when the vehicle is traveling at a predetermined speed or higher, the control ECU 7 is electrically operated so that the vehicle travels on the basic vehicle travel line (for example, the center of the lane) determined by the control ECU 7 from the recognized lane shape. It is possible to further control the motor 9. Further, when the vehicle travels a curve having a predetermined curvature or more, the control ECU 7 determines which position in the lane width direction the driver tends to travel when the vehicle travels a curve having a predetermined curvature or more. The above-described basic vehicle travel line is corrected according to the tendency.

  With reference to FIG. 3, the correction of the vehicle basic travel line corresponding to the driver travel tendency correction amount calculation means will be described. The control of the flowchart shown in FIG. 3 is performed every predetermined time while the vehicle is traveling.

  In step (hereinafter simply referred to as S) 1, the absolute value of the lane curvature value in front of the vehicle obtained by processing the image information from the camera 12 by the control ECU 7 is based on a predetermined curvature threshold value set in advance. If the absolute value of the lane curvature value is determined to be larger than the curvature threshold value, the process proceeds to S2, and the absolute value of the lane curvature value is determined to be equal to or less than the curvature threshold value. If so, go to S5. Here, the lane curvature value indicates the size of the curve (the curvature of the curve), and the positive or negative value indicates the direction of the curve (for example, the left curve is positive and the right curve is negative). It represents.

  In S2, the absolute value of the curvature (the size of the curve) and the sign of the curvature (the direction of the curve) are determined from the lane curvature value obtained in S1.

  In S3, the lateral displacement correction amount yofs currently stored in the control ECU 7 is read. The lateral displacement correction amount yofs is numerical information about the degree of preference indicating whether the driver tends to travel near the curve in or the curve out, in the present embodiment. Is positive when it tends to be in, and negative when it tends to be out.

  In S4, the lateral displacement correction amount yofs is multiplied by the steering torque coefficient k to calculate a correction command value Htrq as a driver travel tendency correction amount. Here, the correction command value Htrq is a torque converted value corresponding to the steering torque generated by the electric motor 9, and the steering torque coefficient K is determined depending on the direction of the curve currently being traveled.

  On the other hand, when it is determined in S1 that the absolute value of the lane curvature value is equal to or less than the curvature threshold value and the process proceeds to S5, the correction command value Htrq = 0.

  That is, when a driver's vehicle that tends to travel inward of the curve travels a curve having a predetermined curvature or more, as shown in FIG. 4, the curve in the travel lane width direction from the basic vehicle travel line (lane center), as shown in FIG. The electric motor 9 is controlled (steering control means) so that the vehicle travels at a position (corrected vehicle travel line calculation means) shifted by the lateral displacement correction amount yofs to the in side of the vehicle. More specifically, the control ECU 7 is electrically driven so that the electric motor 9 generates a value obtained by adding the correction command value Htrq to the basic steering torque that must be generated by the electric motor 9 in order for the vehicle to travel on the basic vehicle travel line. The motor 9 is controlled. At this time, since the generated steering torque takes into account the driving tendency of the driver, it is substantially equal to the steering input that is expected to be input at that time by the driver's steering operation, which makes the driver feel uncomfortable. There is nothing.

  FIG. 5 shows a control flow showing the above-described learning method of the lateral displacement correction amount yofs, and shows a control flow corresponding to the travel tendency learning means. The control of the flowchart shown in FIG. 5 is performed every predetermined time while the vehicle is traveling.

  In step 11, it is determined whether or not the absolute value of the lane curvature value in front of the vehicle obtained by processing the image information from the camera 12 by the control ECU 7 is larger than a predetermined curvature threshold value set in advance. If it is determined that the absolute value of the lane curvature value is larger than the curvature threshold value, the process proceeds to S12. If the absolute value of the lane curvature value is determined to be equal to or less than the curvature threshold value, the process proceeds to S16.

  In S12, it is determined whether or not a sampling value is stored in a sampling value storage unit ybuf in which a sample value to be described later is stored (stored). If the sampling value is stored, the process proceeds to S13, and the sampling value is stored. Is not stored, the process proceeds to S14. The sampling value storage means ybuf is, for example, a RAM in the control ECU 7.

  In S13, it is determined whether or not the vehicle has traveled a predetermined distance from the point at which the previous sampling value was detected. If the vehicle has traveled a predetermined distance, the process proceeds to S14. Is terminated without storing in the sampling value storage means ybuf.

  In S14, the absolute value of the curvature (the size of the curve) and the sign of the curvature (the direction of the curve) are determined from the lane curvature value obtained in S11.

  In S15, the sampling value storage means ybuf samples the displacement amount Y in the width direction from the center of the own vehicle after inverting the sign depending on whether the vehicle is in or out of the curve. Store as a value.

  Specifically, as shown in FIGS. 6 and 7, when a vehicle that has traveled on the right curve travels on the inward side of the curve with respect to the basic vehicle travel line (the center of the lane), it is detected every predetermined distance. The displacement Y in the width direction from the center of the lane of the vehicle is positive when it is on the left side with respect to the center of the lane and negative when it is on the right side, and is −Y1, −Y2,. Here, based on the determination result of S14, it can be seen that the vehicle is traveling inward with respect to the curve. Therefore, the displacements obtained by inverting the signs (positive / negative) of the displacement amounts -Y1, -Y2, ... -Yn. The quantities Y1, Y2,... Yn are sequentially stored in the sampling value storage means ybuf as sampling values. The displacement amount Y is a value obtained by processing the image information from the camera 12 by the control ECU 7.

  On the other hand, if it is determined in S11 that the absolute value of the lane curvature value is equal to or less than the curvature threshold value and the process proceeds to S16, it is determined in S16 whether the sampling value is stored in the sampling value storage means ybuf. . If it is determined in S16 that the sampling value is stored in the sampling value storage means ybuf, the process proceeds to S17, and if not, the current routine ends.

  In S17, the lateral displacement correction amount yofs is updated using the sampling value stored in the sampling value storage means ybuf. Here, the initial value of the lateral displacement correction amount yofs is assumed to be zero. Further, the weighting of the sampling value with respect to the lateral displacement correction amount yofs may be any method such as addition averaging, frequency distribution, or always updating to the latest data. Then, the lateral displacement correction amount yofs updated in S17 is reflected from the next curve intrusion. Further, the lateral displacement correction amount yofs may be initialized every time the engine is started, or may be initialized every certain period (several days). Alternatively, manual reset means may be provided and initialized when the driver performs a manual reset operation.

  In S18, the sampling value stored in the sampling value storage means ybuf is cleared.

  In S13 of FIG. 5 described above, it is determined whether or not a predetermined time has elapsed since the previous sampling value was detected. If the predetermined time has elapsed, the process proceeds to S14, and if the predetermined time has not elapsed. This time, the sampling value may be terminated without being stored in the sampling value storage means ybuf.

  In this embodiment, it is possible to assist the steering force in accordance with the driving tendency of the driver. That is, when the vehicle is controlled so that the vehicle travels on the basic vehicle travel line that is uniquely determined by the lane shape, the travel line that the driver intends to travel matches the basic vehicle travel line. In this embodiment, the steering force can be assisted according to the driving tendency of the driver, so that the driver feels uncomfortable. The steering operation of the driver can be assisted.

  Note that the offset amount (lateral displacement correction amount yofs) from the lane center of the own vehicle, which is generally preferred by the driver, varies depending on the curvature of the curve, and the offset amount often increases as the curvature increases. In the embodiment, when the sampling value is stored in the sampling value storage unit ybuf in S15 of FIG. 5, the displacement amount Y is divided by the absolute value of the curvature obtained in S11 of FIG. 5 and stored in the sampling value storage unit ybuf. By making the sampling value non-dimensional, the correction command value Htrq may be obtained from the following equation (1) in S4 of FIG.

(Equation 1)
Htrq = k × yofs ₁ × C (1)
In the above equation (1), yofs ₁ is the dimensionless lateral displacement correction amount, and C is the absolute value of curvature of the curve during traveling (when the correction command value Htrq is calculated in S4 of FIG. 3).

  In this way, by making the sampling value and the lateral displacement correction amount dimensionless, even if the curvature of the curve that has passed this time is larger than the curvature of the curve learned so far, the correction according to the curvature of the curve The command value Htrq can be obtained with high accuracy.

  In the above-described embodiment, a plurality of lateral displacement correction amounts corresponding to the magnitude of the absolute value of the curvature of the curve are provided, and at the time of control, that is, in S4 of FIG. The correction command value Htrq may be calculated using the lateral displacement correction amount corresponding to the value. Specifically, for example, there are three lateral displacement correction amounts respectively corresponding to three categories of large curvature absolute value, medium curvature absolute value, and small curvature absolute value, and may be used properly according to the curvature of the curve. . In this case, the update of yofs in S17 of FIG. 5 is performed for the lateral displacement correction amount corresponding to the category into which the absolute value of curvature of the curve obtained in S11 of FIG. 5 is classified. In this way, by having a plurality of lateral displacement correction amounts corresponding to the magnitude of the absolute value of curvature of the curve, learning is performed so far as in the case where the sampling value and the lateral displacement correction amount are made dimensionless. Even when the curvature of the curve passing this time is larger than the curvature of the curved curve, the correction command value Htrq according to the curvature of the curve can be obtained with high accuracy.

  Next, in addition to the invention described in the claims, the invention that can be grasped from the above-described embodiment will be described together with the effects thereof.

  (A) In the configuration according to any one of claims 1 to 3, the steering force generated by the steering control means is substantially equal to the steering input expected to be input at that time by the steering operation of the driver. Thus, it is possible to prevent the driver from feeling uncomfortable when performing the steering operation.

  (B) In the configuration according to any one of claims 1 to 3 and (A), when the driver inputs a steering input different from the steering force generated by the steering control means, the driver traveling tendency correction is performed. The amount is corrected.

1 is a block diagram of a steering control device according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows schematic structure of the electric power steering apparatus with which the steering control apparatus which concerns on this invention was applied. The flowchart which shows the flow of control regarding correction | amendment of the vehicle basic travel line in the steering control apparatus which concerns on this invention. Explanatory drawing which showed typically the control content of the steering control apparatus which concerns on this invention. The flowchart which shows the flow of control regarding learning of the lateral displacement correction amount yofs in the steering control device according to the present invention. Explanatory drawing which showed typically the driving | running | working tendency of the driver | operator with respect to the vehicle center. The timing chart which shows the example of a detection result of the curvature and the own vehicle position in the vehicle which has an inward tendency at the time of a right curve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Steering wheel 2 ... Steering shaft 3 ... Torsion bar 4 ... Output shaft 5 ... Steering rack 7 ... Control ECU
DESCRIPTION OF SYMBOLS 9 ... Electric motor 10 ... Steering angle sensor 11 ... Torque sensor 12 ... Camera

Claims (3)

Lane recognition means for recognizing the lane shape in the traveling direction of the own vehicle, own vehicle position detection means for detecting the own vehicle position in the width direction of the lane,
Basic vehicle travel line calculating means for calculating a basic vehicle travel line determined by the lane shape;
Traveling tendency learning means for learning which position in the lane width direction the driver tends to travel based on the own vehicle position information detected by the own vehicle position detecting means;
A driver travel tendency correction amount calculating means for calculating a driver travel tendency correction amount based on the driver travel tendency information obtained by the travel tendency learning means;
A corrected vehicle travel line calculating means for calculating the corrected vehicle travel line by correcting the basic vehicle travel line using the driver travel tendency correction amount;
And a steering control unit that performs steering control of the vehicle so as to travel on the corrected vehicle travel line. The traveling tendency learning means learns the traveling tendency of the driver in this curve when the vehicle travels a curve having a predetermined curvature or more.
The steering control according to claim 1, wherein the steering control means performs steering control of the vehicle so as to travel on the corrected vehicle travel line when the vehicle is traveling on a curve having a predetermined curvature or more. apparatus. 3. The steering control device according to claim 1, wherein the driver travel tendency correction amount is corrected when the trajectory in which the vehicle actually travels is different from the corrected vehicle travel line. 4.

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