JP2005170327A - Automatic steering control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic steering control device for a vehicle capable of performing steering control smoothly before intruding into a curve and after it. <P>SOLUTION: The automatic steering control device for the vehicle works with such steps as setting the first ahead attention point P<SB>1</SB>farther from the vehicle concerned with higher vehicle speed (Step S5), correcting the first ahead attention point P<SB>1</SB>before intruding to the curve and thereby lessening the transverse deviation Y<SB>E</SB>of the first ahead attention point P<SB>1</SB>in the curve from the reference path (Steps S6-S8), and calculating the steering amount of the vehicle concerned so that it runs along the reference path on the basis of the corrected transverse deviation Y<SB>E</SB>(Step S9). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automatic steering control device for a vehicle that performs automatic steering of the vehicle.

As an automatic steering control device for a vehicle, a device has been proposed that performs tracing by sequentially comparing a known route with the current vehicle position. For example, in the technique disclosed in Patent Document 1, two gazing points are provided to detect an error between the position of the vehicle and the route, and the gazing points are set farther as the vehicle speed increases. I am doing so. This enables automatic steering close to the driver's feeling.
JP 2000-122719 A

In such a conventional automatic steering control device for a vehicle, even when decelerating and entering a curve, if the vehicle speed is still high immediately before the curve, the front gazing point distance remains long. In this case, the forward gazing point set immediately before the curve may be extended to a radius of curvature R that is so small that it cannot pass through the curve. As a result, an unnecessarily large steering amount is commanded. . When such processing is performed, when the vehicle decelerates and enters the curve at an appropriate vehicle speed, and the front gaze distance becomes the length that matches the curve corresponding to the vehicle speed, the automatic steering control Therefore, the amount of steering control for this will change suddenly. If the steering control amount changes abruptly in this way, the automatic steering control performed immediately before is wasted, and the automatic steering is not smooth.
The present invention has been made in view of the above-described problems, and an object thereof is to provide an automatic steering control device for a vehicle that can smoothly perform steering control before and after entering a curve.

  The automatic steering control device for a vehicle according to claim 1 sets a forward gazing point set ahead of the host vehicle to a position farther from the host vehicle as the host vehicle speed increases, and the forward gazing point and a reference route that forms a travel target route An automatic steering control device for a vehicle that calculates a steering amount based on an error. The automatic steering control device for a vehicle corrects the error based on the forward gazing point set in front of the curve so as to be close to the error based on the forward gazing point set when entering the curve.

  According to a second aspect of the present invention, there is provided a vehicle automatic steering control device that sets a front gazing point in front of the host vehicle and calculates a steering amount based on an error between the front gazing point and a reference route that forms a travel target route. This is an automatic steering control device. The vehicle automatic steering control device sets the forward gazing point farther from the host vehicle by the forward gazing point setting means as the host vehicle speed increases, and the forward gazing point set by the front gazing point setting means and the reference route The error is detected by the error detection means, and is corrected by the error correction means so that the error with respect to the reference path at a predetermined position in the curve road is reduced at least before entering the curve, and the error correction means corrects the error. Based on the error, the steering amount calculation unit calculates the steering amount of the host vehicle so that the host vehicle travels along the reference route.

  According to the present invention, the error based on the forward gazing point set in front of the curve is corrected so as to be close to the error based on the forward gazing point set when entering the curve, so that before and after the curve approach smoothly. Steering control can be performed.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention, where 1FL, 1FR, 1RL and 1RR are a left front wheel, a right front wheel, a left rear wheel and a right rear wheel, respectively. The rear wheels 1RL and 1RR are drive wheels through which the driving force of the engine 2 is transmitted in order through the automatic transmission 3, the propeller shaft 4, the final reduction gear 5, and the axle 6. The front wheels 1FL and 1FR are steering wheels connected to the steering wheel 9 via the steering gear 7 and the steering shaft 8. A steering actuator 10 composed of an electric motor is coupled to the steering shaft 8. The steering actuator 10 is configured to control the steering direction, steering angle, and steering speed of the front wheels 1FL and 1FR according to the steering control amount δC output from the controller 17.

  Further, the vehicle is equipped with wheel speed sensors 11FL to 11RR that output wheel speeds VFL to VRR having frequencies corresponding to the rotational speeds of the wheels 1FL to 1RR. The vehicle is also equipped with a longitudinal acceleration sensor 12 that detects longitudinal acceleration Xg, a lateral acceleration sensor 13 that detects lateral acceleration Yg, and a yaw rate sensor 14 that detects yaw rate φ. The vehicle also includes a GPS (Global Positioning System) 15 that receives satellite radio waves transmitted from an artificial satellite and detects the current position of the vehicle, and a CD-ROM or DVD-ROM that stores road map information in a predetermined area. And a storage unit 16 mounted with the information storage medium.

  The wheel speeds VFL to VRR detected by the wheel speed sensors 11FL to 11RR described above, the longitudinal acceleration Xg detected by the longitudinal acceleration sensor 12, the lateral acceleration Yg detected by the lateral acceleration sensor 13, and the self detected by the GPS 15 The vehicle position information and the road map information stored in the storage unit 16 are input to the controller 17 constituted by, for example, a microcomputer. The controller 17 controls the output of the steering control amount δC for the steering actuator 10 described above by constantly executing the steering control process, and causes the host vehicle to travel along the reference route that forms the travel target route by automatic steering. It is configured. FIG. 2 shows the contents of the steering control process.

First, in step S1, the controller 17 reads the road map information stored in the storage unit 16 in accordance with the vehicle position detected by the GPS 15. The road map information is information representing a road shape as a plurality of node data (X, Y). And the controller 17 is within the range of the predetermined distance before and behind on the basis of the present position of the own vehicle 100 among the node data (X, Y) which comprises the read road map information, as shown in FIG. (N + 1) node data (X ₀ , Y ₀ ) to (X _n , Y _n ) are always held in the buffer. If the coordinates of these node data (X ₀ , Y ₀ ) to (X _n , Y _n ) are connected, the shape of the reference path is obtained.

Further, the predetermined distance on the front side of the vehicle is set to, for example, a larger one of a value (Vc × t1) obtained by multiplying the vehicle speed Vc by a predetermined time t1 and a minimum value (predetermined value) obtained in advance.
Subsequently, in step S2, the controller 17 reads the wheel speeds VFL to VRR, the longitudinal acceleration Xg, the lateral acceleration Yg, and the yaw rate φ output from various sensors.
Subsequently, in step S3, the controller 17 calculates the vehicle speed Vc from the average of the wheel speeds VFL to VRR.

Subsequently, in step S4, the controller 17 determines a road radius through which the vehicle can pass (hereinafter referred to as a passable road radius) Rn_limit based on the vehicle speed Vc calculated in step S3 and the lateral G value Yg_limit allowed by the curve. Is calculated. For example, it is calculated by the following equation (1).
Rn_limit = Vc ² / Yg_limit (1)
Here, the lateral G value Yg_limit is a fixed value. For example, the lateral G value Yg_limit is set to 0.3.
In step S5 Subsequently, the controller 17, the driver (also referred to as a FB (Feedback) fixation point, hereinafter referred to as the first forward fixed point.) And expected vehicle front forward gaze point gazing setting the P ₁ To do. For example, as shown in FIG. 4, as the vehicle speed Vc increases larger such forward observation point distance (hereinafter, referred to as a first look-ahead point distance.) In D1, setting the first forward gaze point P _1.

Subsequently, in step S6, the controller 17, the road radius at the first forward observation point P ₁ set in step S5 (hereinafter referred to as the first forward gaze point position road radius.) Is calculated Rn_road. Specifically, it is calculated by the following procedure. This will be described with reference to FIG.
First, as shown in FIG. 5, nodes located at a predetermined distance D _S in the front-rear direction from the first forward gazing point P ₁ are P _F (hereinafter referred to as the most recent node P _F ) and P _R (hereinafter referred to as the most recent node). that P _R.) to select the.
Here, the predetermined distance _{D S} is the vehicle speed Vc, for example, a predetermined time (for example, about 1 second) value obtained by multiplying t2 (Vc × t2). Note that, as a predetermined distance _{D S} is not too short, the minimum value in advance to prepare the _{D MIN,} the value _(D S = V × be calculated on the basis of this minimum value _{D MIN} to the vehicle speed V and the predetermined time t2 the larger of t2), it may be set to the final predetermined distance D _S.

Subsequently, the line segment _P 1 _{P R} connecting the front nearest node _{P F} and the first forward fixed point _{P 1,} and the line segment _P 1 _{P F} connecting the rear nearest node _{P F} first and forward fixed point _{P 1} angle theta, and calculates the distance d between the front nearest node P _F and the rear nearest node P _R.
Here, the first forward gazing point P ₁ in comparison with the node is specifically a node corresponding to the first forward gazing point P ₁ . That is, when a straight line that passes through the first forward gazing point P ₁ and is perpendicular to the speed vector V of the host vehicle is drawn, the intersection Q between the straight line and the reference route or the nearest node from the intersection Q is the first is to say that the forward gaze point P _1. Therefore, the first forward gazing point P ₁ is not a node, but is compared with a node for the purpose of calculating a road radius, etc., and the first forward gazing point set at a position shifted from the actual reference route. it is assumed that refers to the point of view _{P 1.} In the following description, such a relationship is handled in the same manner.

Here, before the nearest node _{P F,} the center point O of the arc through the first forward observation point _{P 1} and the rear nearest node _{P R} has a vertical bisector A which passes through the middle point a of the line segment _P 1 _{P F} , the intersection of the vertical bisector B passing through the middle point b of the line segment _P 1 _{P R.} For this reason, the angle θ is, the vertical bisector B passing through the middle point b of the line segment P ₁ P perpendicular bisector passing through the midpoint a of _F A and the line segment P ₁ P _R It is obtained as the angle of eggplant aOb.
Then, the angle of the pre-nearest node _{P F} and the line segment formed by the center O _{P F} O and the rear nearest node _P line _R and a center point O forms _{P R} O and forms ∠P _F OP _R, the It becomes twice the angle θ of ∠aOb.
From the above relationship, the first forward gazing point position road radius Rn_road can be calculated based on the angle θ and the distance d using the following equation (2).
Rn_road = d / 2 × sinθ (2)

Subsequently, in step S7, the controller 17 compares the passable road radius Rn_limit calculated in step S4 with the first forward gazing point position road radius Rn_road calculated in step S6, thereby comparing the first forward gazing point P _1. Correct.
Specifically, based on the comparison result between the passable road radius Rn_limit and the first forward gazing point position road radius Rn_road, the forward gazing point (hereinafter referred to as the corrected _first gazing point P1) corrected for the position of the first forward gazing point P1. This is called forward gaze point.) P ₁ ′ is calculated. More specifically, when the passable road radius Rn_limit is less than the first forward watch point position road radius Rn_road (Rn_limit <Rn_road), the forward watch point setting limit point P_limit corresponding to the passable road radius Rn_limit in the reference route (point of the vehicle and the line containing the first and forward fixed point P _1, the same applies hereinafter.) assuming the first set based on a first look-ahead point distance D1 above its forward fixed point setting limit point P_limit When the forward gazing point P ₁ is far from the host vehicle, the corrected first gazing point P ₁ ′ is set as the forward gazing point setting limit point P_limit (P ₁ ′ = P_limit).

In other cases, the corrected first forward gazing point P ₁ ′ is set to the first forward gazing point P ₁ (P ₁ ′ = P ₁ ). That does not perform a first correction of the forward fixed point P _1. For example, even if the passable road radius Rn_limit is less than the first forward gaze point position road radius Rn_road (Rn_limit <Rn_road), forward fixed point setting limit points P_limit than the first headway point P ₁ from the vehicle If it is far away, the corrected first forward gazing point P ₁ ′ is set to the first forward gazing point P ₁ (P ₁ ′ = P ₁ ).
Thereby, as shown in FIG. 6, the corrected first forward gazing point P ₁ ′ is set in front of the host vehicle 100.

Subsequently, in step S8, the controller 17 calculates the lateral deviation Y _E for the first forward observation point P _{1 'after} correction obtained in step S7. Specifically, it is calculated by the following procedure.
First, the vehicle slip angle θ _S is calculated. Specifically, the slip angle θ _{S of the} vehicle is calculated based on the longitudinal acceleration Xg and the lateral acceleration Yg by the following equation (3).
θ _S = tan ⁻¹ (Yg / Xg) (3)
Further, as shown in FIG. 6, a yaw angle ε ₁ and a deviation angle ε _T are defined. The yaw angle ε ₁ is the yaw angle of the host vehicle 100 with respect to the reference coordinates. Further, the deviation angle ε _T draws a straight line C that passes through the corrected first forward gazing point P ₁ ′ and is perpendicular to the speed vector V of the host vehicle 100, and is relative to the reference coordinates at the intersection point Q of the straight line C and the reference route. This is the deviation angle of the reference path.

Then, based on the yaw angle ε ₁ and the deviation angle ε _T defined as above, the yaw angle ε _R is calculated by the following equation (4).
ε _R = ε _T −ε ₁ (4)
Further, as shown in FIG. 6, the lateral deviation between the reference route and the current traveling position of the host vehicle 100 is represented by Y _U , the lateral deviation Y _S according to the vehicle posture, and the corrected first front gazing point P ₁ ′. Define a distance D1 '. Then, based on the lateral deviation Y _U , the corrected distance D1 ′ to the first forward gazing point P ₁ ′, the yaw angle ε _R and the slip angle θ _S , the lateral deviation Y _S is calculated by the following equation (5).
Y _S = Y _U + D1 ′ × tan (ε _R + θ _S ) (5)

It is also assumed that the vehicle is making a steady circular turn. Assuming this way, it is possible to ignore the slip rate to calculate the lateral deviation Y _P obtained from the vehicle turning state by the following equation (6).
Y _P = D1 ′ × tan β (6)
Here, β is expressed by the following equation (7).
β = 1/2 × sin ⁻¹ (D1 ′ × ε ₁ / Xg) (7)
Then, as shown in the following equation (8), by adding the lateral deviation Y _S and the lateral deviation Y _P by calculating the lateral deviation Y _E of the reference path.
Y _E = Y _S + Y _P (8)
In this way, the lateral deviation Y _E from the reference route at the corrected first forward gazing point P ₁ ′ is calculated.

Subsequently, in Step S9, the controller 17, based on the lateral deviation Y _E calculated in step S8, to calculate a first steering amount δ1 by the following equation (9).
δ1 = K1 × Y _E + K2 × (dY _E / dt) (9)
Here, K1 and K2 are coefficients. For example, it is desirable that K1 and K2 are obtained by experiments as optimum values so that the follow-up error does not increase with respect to disturbance during straight running.
Subsequently, in step S10, the controller 17 outputs the first steering amount δ1 calculated in step S9 to the steering actuator 10 as the final steering control amount δC. Thereby, the steering control is performed so that the host vehicle travels along the reference route at the corrected first forward gazing point P ₁ ′.
The above is the steering control process by the controller 17.

That is, node data (X ₀ , Y ₀ ) to (X _n , Y _n ) within a predetermined distance range are stored based on the position of the host vehicle 100, and each wheel speed VFL to VRR The acceleration Xg, the lateral acceleration Yg, and the yaw rate φ are read, and the vehicle speed Vc is calculated (steps S1 to S3). Then, a passable road radius Rn_limit is calculated based on the calculated vehicle speed Vc and the lateral G value Yg_limit allowed by the curve (step S4).
Then, first set the forward gaze point P ₁ in accordance with the vehicle speed Vc, calculates a first forward gaze point position road radius Rn_road at the first forward observation point P ₁ (step S5, step S6).

Subsequently, the passable road radius Rn_limit and the first forward gazing point position road radius Rn_road are compared to obtain a corrected first forward gazing point P ₁ ′ after correction (step S7). Specifically, when the passable road radius Rn_limit is less than the first forward gazing point position road radius Rn_road (Rn_limit <Rn_road), the first forward gazing point P ₁ is more than the forward gazing point setting limit point P_limit. In the case of being far from the position, the corrected first forward gazing point P ₁ ′ is set as the forward gazing point setting limit point P_limit (P ₁ ′ = P_limit). In other cases, the corrected first forward gazing point P ₁ ′ is set to the first forward gazing point P ₁ (P ₁ ′ = P ₁ ).

Then, a lateral deviation Y _E from the reference route at the corrected first forward gazing point P ₁ ′ is calculated, a first steering amount δ1 corresponding to the calculated lateral deviation Y _E is obtained, and the first steering amount δ1 is obtained. Is output to the steering actuator 10 as a steering control amount δC (steps S8 to S10).
The controller 17 repeats this process at a predetermined time interval, that is, obtains the steering control amount δC sequentially at the predetermined time interval, and outputs the obtained steering control amount δC to the steering actuator 10. ing. Thereby, the steering control is performed so that the host vehicle travels along the reference route at the corrected first forward gazing point P ₁ ′.

Next, effects of the first embodiment will be described.
As described above, _'has been steering control so as to travel along a reference path in its corrected first forward gaze point P _1' first forward observation point P ₁ after correction passable road This is obtained based on the comparison result between the radius Rn_limit and the first forward gazing point position road radius Rn_road (step S7). That is, if passable road radius Rn_limit is less than the first forward gaze point position road radius Rn_road (Rn_limit <Rn_road), and said first forward gaze point P ₁ than forward fixed point setting limit point P_limit is far from the vehicle In this case, the corrected first forward gazing point P ₁ ′ is set as the forward gazing point setting limit point P_limit. Otherwise, the first forward observation point P _{1 'is} set to the first forward fixed point P ₁ after correction, that is not carried out first correction of forward fixed point P _1. Specifically, even if passable road radius Rn_limit is less than the first forward gaze point position road radius Rn_road (Rn_limit <Rn_road), the forward fixed point setting limit points P_limit than the first headway point P ₁ when in the distant from the vehicle, the first front watch point P ₁ as the first forward observation point P _{1 'after} correction, and using the first forward observation point P ₁ as it is.

Here, as described above, the first look-ahead point distance D1 or the first forward observation point P ₁ is determined according to the vehicle speed Vc, in particular so as to become distant as the vehicle speed Vc is higher Yes. That is, the first look-ahead point distance D1 or the first forward observation point P ₁ is determined according to the same manner as the vehicle speed Vc and conventional techniques. On the other hand, as described above, the passable road radius Rn_limit is a road radius through which the vehicle can pass, and is specifically determined based on the vehicle speed Vc and the lateral G value Yg_limit allowed by the curve.

From the relationship described above, when the first forward gaze point P ₁ determined according to the vehicle speed Vc is from the vehicle than the forward fixed point setting limit point P_limit distant, and passable road radius Rn_limit first forward When the gazing point position road radius is less than Rn_road, the corrected first forward gazing point P ₁ ′ is set as the forward gazing point setting limit point P_limit.
That is, as shown in FIG. 7, is set forward fixed point P ₁ as a control target based on the first look-ahead point distance D1 would otherwise Based on the vehicle speed Vc is more standards in the forward gaze point P1 the place of calculating the lateral deviation Y _E of a path, passable road radius Rn_limit is the case of less than the first forward gaze point position road radius Rn_road is forward fixed point setting limit point on the near side of the forward fixed point P ₁ P_limit _'by setting a forward gaze point P _1' forward observation point P ₁ which becomes a control target lateral deviation is suppressed from traveling in front, a reference path at its forward gaze point P _{1 '} and calculates the Y _E. Then it is performed the steering control by the steering control amount based on the lateral deviation Y _E.

Thus, since the lateral deviation Y _E is smaller corrected before entering a curve, the lateral deviation Y _E is, enters the curve the host vehicle is decelerated, the forward gaze point set corresponding to the vehicle speed It is, would be set to a value close to the lateral deviation Y _E obtained based on the forward fixed point that is the setting. Thus, the steering control amount does not change suddenly before and after entering the curve, and the steering control can be performed smoothly.

Next, a second embodiment will be described.
In the second embodiment, the content of the steering control process is different from that of the first embodiment. FIG. 8 shows the contents of the operation control process in the second embodiment. As shown in FIG. 8, instead of step S6, steps S21 and S22 are provided between steps S5 and S7.
In step S21, the controller 17, forward fixed point for predicting the steering amount of the future (also referred to as a fixation point FF (feed forward), hereinafter referred to as a second forward fixed point.) Setting the P _2.

The second forward fixed point P ₂ is set as the forward fixed point different from the first forward fixed point P ₁ set in step S5. Specifically, the second headway point P _2, as shown in FIG. 9, the forward gaze point distance (hereinafter, referred to as a second forward observation point distance.) Is set larger as the vehicle speed Vc is higher . Then, the second forward observation point P _2, at the same speed as than the first look-ahead point distance D1 and the second look-ahead point distance D2 increases, i.e., from the vehicle than the first headway point P ₁ Set to be far away.

Subsequently, in Step S22, the controller 17, the road in the second forward observation point P ₂ radius (hereinafter, referred to as a second forward gaze point position road radius.) Is calculated Rff. The procedure for calculating the second forward gazing point position road radius Rff is basically the same as the procedure for calculating the first forward gazing point position road radius Rn_road in step S6 in the first embodiment described above.
That is, first, as shown in FIG. 10, selects a pre-nearest node P _F and the rear nearest node P _R a node in the longitudinal direction of the predetermined distance D _S from the second forward observation point P _2.
Subsequently, the line segment _P 2 _{P R} connecting the front nearest node _{P F} and the second forward fixed point _{P 2,} and the line segment _P 2 _{P F} connecting the rear nearest node _{P F} and the second forward fixed point _{P 2} angle theta, and calculates the distance d between the front nearest node P _F and the rear nearest node P _R.

Here, before the nearest node _{P F,} the center point O of the arc through the second forward observation point _{P 2} and the rear nearest node _{P R} has a vertical bisector A which passes through the middle point a of the line segment _P 2 _{P F} , the intersection of the vertical bisector B passing through the middle point b of the line segment _P 2 _{P R.} For this reason, the angle θ is, the vertical bisector B passing through the middle point b of the line segment P ₂ P perpendicular bisector passing through the midpoint a of _F A and the line segment P ₂ P _R It is obtained as the angle of eggplant aOb.
Then, the angle of the pre-nearest node _{P F} and the line segment formed by the center O _{P F} O and the rear nearest node _P line _R and a center point O forms _{P R} O and forms ∠P _F OP _R, the It becomes twice the angle θ of ∠aOb.

From the above relationship, the second forward gazing point position road radius Rff can be calculated based on the angle θ and the distance d using the following equation (10).
Rff = d / 2 × sinθ (10)
Subsequently, in step S7, the controller 17 corrects the forward gazing distance.
In the step S5, as in the first embodiment described above, the first forward fixed point P ₁ is also set. However, in the step S7, it corrects only the second forward observation point P ₂ set in step S21.

Specifically, based on a result of comparison between the passable road radius Rn_limit and second forward gaze point position road radius Rff, forward fixed point obtained by correcting the second position of the forward fixed point P ₂ (hereinafter, corrected second This is referred to as a forward gazing point.) P ₂ ′ is calculated. More specifically, the forward gazing point setting limit point P_limit corresponding to the passable road radius Rn_limit in the reference route when the passable road radius Rn_limit is smaller than the second forward gazing point position road radius Rff (Rn_limit <Rff). assuming, the second forward observation point P ₂ than the forward fixed point setting limit point P_limit in a second look-ahead point distance D2 is the vehicle when in the distance, the second forward gaze point P ₂ after correction thereof The corrected second forward gazing point P ₂ ′ as a value is set as the forward gazing point setting limit point P_limit (P ₂ ′ = P_limit).

In other cases, the corrected second forward gazing point P ₂ ′ is set to the second forward gazing point P ₂ (P ₂ ′ = P ₂ ). That is, otherwise, not perform the second correction of the forward fixed point P _2. For example, even if the passable road radius Rn_limit is smaller than the second forward gaze point position road radius Rff (Rn_limit <Rff), forward fixed point setting limit points than the second headway point P ₂ P_limit from vehicle If it is far away, the corrected second front gazing point P ₂ ′ is set to the second front gazing point P ₂ (P ₂ ′ = P ₂ ).

As a result, when the passable road radius Rn_limit is smaller than the second forward gazing point position road radius Rff (Rn_limit <Rff), the road radius at the corrected second forward gazing point P ₂ ′ (hereinafter referred to as the corrected second forward gazing point). Pff 'is the passable road radius Rn_limit. In other cases, the corrected second forward gazing point position road radius Pff' is the second forward gazing point position road radius Rff.

Subsequently, in step S8 and step S9, the controller 17 calculates the lateral deviation Y _E based on the corrected first forward gazing point P ₁ ′, and calculates the first steering amount δ1.
Incidentally, the second corrected only forward observation point P ₂ in step S7, since no correction of the first headway point P _1, the corrected first forward gaze point P _{1 'is} first forward used herein Note point of view _{P 1} is the thing. Therefore, the corrected first is a forward gaze point P ₁ on the basis of the first forward fixed point P _{1 ',} as in the first embodiment described above, using the (3) to (9), A first steering amount δ1 is calculated.

In the second embodiment, in step S9, the controller 17 calculates the second steering amount δ2 based on the corrected second forward gazing point position road radius Rff ′. Specifically, based on the corrected second forward gazing point position road radius Rff ′ (ρ) and the wheel base L of the vehicle, the second steering amount δ2 is calculated by the following equation (11).
δ2 = L / ρ (11)
The second steering amount δ2 calculated by the equation (11) is a steering amount that is geometrically necessary for turning on the travel path of the corrected second forward gazing point position road radius Rff ′.

In step S10, the controller 17 outputs the added value of the first steering amount δ1 and the second steering amount δ2 calculated in step S9 to the steering actuator 10 as the final steering control amount δC (= δ1 + δ2). . The steering control amount δC may be obtained as an average value ((δ1 + δ2) / 2) of the first steering amount δ1 and the second steering amount δ2.
The above is the steering control processing of the controller 17 in the second embodiment.

That is, node data (X ₀ , Y ₀ ) to (X _n , Y _n ) within a predetermined distance range are stored based on the position of the host vehicle 100, and each wheel speed VFL to VRR The acceleration Xg, the lateral acceleration Yg, and the yaw rate φ are read, and the vehicle speed Vc is calculated (steps S1 to S3). Then, a passable road radius Rn_limit is calculated based on the calculated vehicle speed Vc and the lateral G value Yg_limit allowed by the curve (step S4).

Then, set the first forward observation point P ₁ in accordance with the vehicle speed Vc. (Step S5). Incidentally, since no correcting the position of the first forward gaze point P _1, the calculation of the first forward gaze point position road radius Rn_road at the first forward observation point P ₁ that are required when the correction (step S6) is not performed.
On the other hand, the second set the forward gaze point _{P 2,} calculates a second forward gaze point position road radius Rff at the second forward observation point _{P 2} (step S21, step S22).

Subsequently, passable road radius Rn_limit and by comparing the second forward gaze point position road radius Rff, by correcting the second position of the forward fixed point P _2, second forward after correction after correction gaze point P ₂ 'Is obtained (step S7). Specifically, passable road radius Rn_limit second forward gaze point position road in the case of less than the radius Rff (Rn_limit <Rff), and second forward observation point P ₂ is the vehicle than forward fixed point setting limit point P_limit If it is far from the position, the corrected second forward gazing point P ₂ ′ is set as the forward gazing point setting limit point P_limit (P ₂ ′ = P_limit). In other cases, the corrected second forward gazing point P ₂ ′ is set to the second forward gazing point P ₂ (P ₂ ′ = P ₂ ).

Then, to calculate the lateral deviation Y _E of the reference path at the first forward observation point P _{1 'after} correction, to calculate a first steering amount δ1 corresponding to the calculated lateral deviation Y _E. Further, the second steering amount δ2 is calculated based on the corrected second forward gazing point position road radius Pff ′ at the corrected second forward gazing point P ₂ ′ (steps S8 and S9).
Then, the addition value of the first steering amount δ1 and the second steering amount δ2 is output to the steering actuator 10 as the final steering control amount δC (step S10).
The controller 17 repeats this process at a predetermined time interval, that is, obtains the steering control amount δC sequentially at the predetermined time interval, and outputs the obtained steering control amount δC to the steering actuator 10. ing.

Next, the effect in 2nd Embodiment is demonstrated.
As described above, the second forward gaze point P ₂ is set remote from the first forward fixed point vehicle than P _1, is positioned far as possible from the vehicle the second headway point P _2, the second front gazing point P ₂ in consideration of the second headway point P _{2 'after} the correction that corrects have automatic steering control. Here, the corrected second forward gazing point P ₂ ′ is obtained based on the comparison result between the passable road radius Rn_limit and the second forward gazing point position road radius Rff (step S7). That is, passable road radius Rn_limit is in the case of less than the second forward gaze point position road radius Rff at the second forward observation point P ₂ (Rn_limit <Rff), and second forward Note than the forward gaze point set limit point P_limit when the viewpoint P ₂ is distant from the vehicle, and sets the second forward observation point P _{2 'to} forward fixed point setting limit points P_limit corrected. Otherwise, a second forward gaze point P _{2 'is} set to the second forward fixed point P ₂ after correction, that is, does not perform a second correction of the forward fixed point P _2. Specifically, passable road radius Rn_limit even when less than the second forward gaze point position road radius Rff (Rn_limit <Rff), the forward fixed point setting limit points P_limit than second headway point P ₂ If it is forward, the second headway point P ₂ as the second forward observation point P _{2 'after} the correction, and using the second front watch point P ₂ as it is.

Thus, for example, as shown in FIG. 11, the place where the forward gaze point P ₂ as a control target based on a second look-ahead point distance D2 would otherwise be set, passable road radius Rn_limit second front If it is less than the gazing point position road radius Rff is to prevent the forward gaze point P ₂ is advanced to the front side, the control target forward fixed point setting limit points P_limit the front of the forward fixed point P ₂ This is set as the forward gazing point P ₂ ′.
On the other hand, passable road radius Rn_limit is larger than the second forward gaze point position road radius Rff, without correcting the forward gaze point P _2, the steering amount or the steering control amount based on the forward fixed point P ₂ Has been decided.

Thus, the second front watch point P ₂ affects the steering amount by setting remote from the first vehicle than forward fixed point P _1, the far traveling path than the first headway point P ₁ The steering amount required in the future is predicted. Thereby, for example, even when the first forward gazing point P ₁ (corrected first forward gazing point P ₁ ′) is set at a relatively short distance from the host vehicle, the amount necessary in the future is also taken into account according to the road shape. Thus, the steering amount can be determined.
Further, as described above, when the predetermined condition is satisfied, the second forward gazing point P ₂ (corrected second forward gazing point P ₂ ′) is set as the forward gazing point setting limit point P_limit. By suppressing the viewpoint P ₂ (corrected second forward gazing point P ₂ ′) from proceeding forward, the steering control amount can be reduced before and after entering the curve, as in the first embodiment. Steering control can be performed smoothly without sudden change.

Next, a third embodiment will be described.
In the third embodiment, the contents of the steering control process are different from those of the first and second embodiments described above. FIG. 12 shows the contents of the operation control process in the third embodiment. As shown in FIG. 12, in the comparison with the operation control process of the first embodiment described above, the process of step S6 and step S7 is omitted, while a new step is performed between step S8 and step S9. The process of S31 is provided.
Processing of step S6 and step S7, since a process for correcting the first look-ahead point P _1, by omitting these processes, the first forward gaze point after correction P _{1 'is} corrected a first forward fixed point P ₁ which is not.
Thus, in step S8, leading to calculation of a lateral deviation Y _E based on the first headway point P _1.

Then, in step S31 newly provided, the controller 17 is corrected based on the lateral deviation Y _E calculated in step S8 in the path of passable roads radius Rn_limit calculated at step S4. The correction will be described with reference to FIG.
As described above, since the set of nodes forms the shape of the reference route, when the reference route constituted by the nodes is a curved road, the road radius R can be obtained for each node. For this reason, among the road radii R obtained for each node, the road radius R having the same value as the passable road radius R_limit calculated in step S4 is specified, and the G point that obtains the road radius R is obtained. (Node) is specified.

Then, a virtual circle having a radius R_vir equal to the passable road radius R_limit based on the specified G point is assumed, and a corrected lateral deviation (hereinafter referred to as a corrected lateral deviation) is based on the assumed virtual circle. .) Calculate Y _E '.
A specific method for calculating the corrected lateral deviation Y _E ′ will be described with reference to FIG.
13 shows a case where the reference route has a right curve, and FIG. 14 shows a case where the reference route has a left curve. However, the calculation of the corrected lateral deviation Y _E ′ described here is not influenced by the curve direction of the reference path.

In the calculation, first, the slip angle θ _{S of the} vehicle is calculated. Specifically, the vehicle slip angle θ _S is calculated based on the longitudinal acceleration Xg and the lateral acceleration Yg by the following equation (12).
θ _S = tan ⁻¹ (Yg / Xg) (12)
Further, as shown in FIG. 14, a yaw angle ε ₁ and a deviation angle ε _T ′ are defined. The yaw angle ε ₁ is the yaw angle of the host vehicle 100 with respect to the reference coordinates. The deviation angle ε _T ′ draws a straight line C passing through the corrected first forward gazing point P ₁ ′ and perpendicular to the speed vector V of the host vehicle 100, and the straight line C and the path of the virtual circle (hereinafter referred to as a virtual circular path). The deviation angle of the reference path with respect to the reference coordinates at the intersection point Q ′ with.

Then, based on the yaw angle ε ₁ and the deviation angle ε _T ′ defined in this way, the yaw angle ε _R ′ is calculated by the following equation (13).
ε _R '= ε _T ' -ε ₁ (13)
Further, as shown in FIG. 14, the lateral deviation between the reference route and the current travel position of the host vehicle 100 is Y _U , and the lateral deviation according to the vehicle posture based on the virtual circular route (hereinafter referred to as the virtual circular route reference lateral deviation). _YS ′ and the corrected distance D1 ′ to the first forward gazing point P ₁ ′ are defined. Then, based on the lateral deviation Y _U , the corrected distance D1 ′ to the first forward gazing point P ₁ ′, the yaw angle ε _R and the slip angle θ _S , the virtual circular path reference lateral deviation Y _S ′ is obtained by the following equation (14). Is calculated.
Y _S ′ = Y _U + D 1 ′ × tan (ε _R + θ _S ) (14)

It is also assumed that the vehicle is making a steady circular turn. This assumption, since negligible slip rate to calculate the lateral deviation Y _P obtained from the vehicle turning state by the following equation (15).
Y _P = D1 ′ × tan β (15)
Here, β is expressed by the following equation (16).
β = 1/2 × sin ⁻¹ (D1 ′ × ε ₁ / Xg) (16)
Then, as shown in the following equation (17), the lateral deviation relative to the virtual circle path by adding the lateral deviation Y _S and the lateral deviation Y _P is calculated (hereinafter, referred to. Virtual circle path reference lateral deviation) Y E _' .
Y _E '= Y _S ' + Y _P (17)
As described above, in step S31, the virtual circular path reference lateral deviation Y _E ′ at the corrected first forward gazing point P ₁ ′ is calculated using the virtual circular path as a reference.

If there is no road radius R that is equal to the passable road radius R_limit calculated in step S4 among the road radii R obtained for each node, the virtual circular path reference lateral deviation Y _E ′ is set as it may be set in the lateral deviation Y _E calculated at step S8.
Subsequently, in step S9, the controller 17 calculates the first steering amount (hereinafter referred to as virtual circular path reference first steering amount) by the following equation (18) based on the virtual circular path reference lateral deviation Y _E ′ calculated in step S31. ) Δ1 ′ is calculated.
δ1 ′ = K1 × Y _E ′ + K2 × (dY _E ′ / dt) (18)

Here, K1 and K2 are coefficients. For example, it is desirable that K1 and K2 are obtained by experiments as optimum values so that the follow-up error does not increase with respect to disturbance during straight running.
Subsequently, in step S10, the controller 17 outputs the virtual circle reference first steering amount δ1 ′ calculated in step S9 to the steering actuator 10 as the final steering control amount δC. Thus, the steering control is performed so that the host vehicle travels along the virtual circular route at the corrected first forward gazing point P ₁ ′.

The above is the steering control processing of the controller 17 in the third embodiment.
That is, node data (X ₀ , Y ₀ ) to (X _n , Y _n ) within a predetermined distance range are stored based on the position of the host vehicle 100, and each wheel speed VFL to VRR The acceleration Xg, the lateral acceleration Yg, and the yaw rate φ are read, and the vehicle speed Vc is calculated (steps S1 to S3). Then, a passable road radius Rn_limit is calculated based on the calculated vehicle speed Vc and the lateral G value Yg_limit allowed by the curve (step S4).

Subsequently, the first set forward fixed point _{P 1} in accordance with the vehicle speed Vc (Step S5). Incidentally, since no correcting the position of the first forward gaze point P _1, the calculation of the first forward gaze point position road radius Rn_road at the first forward observation point P ₁ that are required when the correction (step S6) is not performed.
Then, the lateral deviation Y _E from the reference route at the corrected first forward gazing point P ₁ ′ (= P ₁ ) is calculated (step S8).
On the other hand, a virtual circular route having a passable road radius Rn_limit is set, and a virtual circular route reference lateral deviation Y _E ′ with the virtual circular route at the corrected first forward gazing point P ₁ ′ is calculated (step S31). Then, the virtual circular path reference first steering amount δ1 ′ corresponding to the calculated virtual circular path reference lateral deviation Y _E ′ is obtained, and the virtual circular path reference first steering amount δ1 ′ is used as the steering control amount δC. It outputs to the actuator 10 (step S9, step S10).

Next, effects in the third embodiment will be described.
As described above, the virtual circle path reference lateral deviation Y _E ′ with the virtual circle path is calculated at the corrected first forward gazing point P ₁ ′, and the virtual circle is calculated based on the virtual circle path reference lateral deviation Y _E ′. By determining the route reference first steering amount δ1 ′, the steering control is performed so that the vehicle travels along the virtual circular route at the corrected first forward gazing point P ₁ ′. As described above, for each node constituting the reference route, a node having a passable road radius R_limit is specified, and a virtual circular route is set based on the node (point G).

As a result, for example, as shown in FIG. 13, the lateral deviation Y _E is obtained with reference to the reference route at the corrected first forward gazing point P ₁ ′, and the reference at the corrected first forward gazing point P ₁ ′. A reference lateral deviation Y _E ′ based on a virtual circular route having a road radius larger than the route is obtained. By doing so, as shown in FIG. 13, it is possible to calculate the steering control amount based on a small reference transverse deviation Y _{E 'than} the lateral deviation Y _E.

As a result, _'since it has become, the reference lateral deviation Y _E' lateral deviation Y _E is less corrected by the reference lateral deviation Y _E before entering the curve, enters the curve the host vehicle is decelerated The forward gazing point corresponding to the vehicle speed is set, and is set to a value close to the lateral deviation obtained based on the set forward gazing point. Thus, the steering control amount does not change suddenly before and after entering the curve, and the steering control can be performed smoothly.

In addition, by setting the virtual circular route to be the road radius Rn_limit through which the vehicle can pass, even when the lateral deviation is corrected to be small, an optimal steering amount can be obtained according to the road shape.
The embodiment of the present invention has been described above. However, the present invention is not limited to being realized as the above-described embodiment.
That is, in the above-described embodiment, the lateral G value Yg_limit as the lateral acceleration of the predetermined host vehicle is set to a fixed value, and specifically, the lateral G value Yg_limit is set to 0.3. However, it is not limited to this. For example, as shown in FIG. 15, the lateral G value Yg_limit may be decreased as the vehicle speed increases.

In the first embodiment described above, if passable road radius Rn_limit is less than the first forward gaze point position road radius Rn_road, and first forward observation point P ₁ than forward fixed point setting limit point P_limit own When the vehicle is far from the vehicle, the corrected first forward gazing point P ₁ ′ is set to the forward gazing point setting limit point P_limit that is closer to the vehicle than the first forward gazing point P ₁ . In this case, when considered in terms of absolute position, the corrected first forward gazing point P ₁ ′ at the time of the current calculation moves closer to the vehicle front side than the corrected first front gazing point P ₁ ′ at the time of the previous calculation. That is, the corrected first front gazing point P ₁ ′ may be reversed. You may perform the process which prevents such a return.

Specifically, we are substituting _'the previous value P _1' first forward observation point P ₁ the corrected during the previous operation on _old, first forward Note the corrected during the previous value P _{1 '_old} and current operation When the first forward gazing point P ₁ ′ after correction at the time of the current calculation is present at a position closer to the vehicle than the previous value P ₁ ′ _old, the _first point after correction at the time of the current calculation is compared with the viewpoint P ₁ ′. The forward gazing point P ₁ ′ is set to the previous value P ₁ ′ _old. This prevents the corrected first front gazing point P ₁ ′ from returning backward.

In addition, the same process may be performed when the corrected second forward gazing point P ₂ ′ is set in the _second embodiment. In other words, previously calculated time of _'the previous value P _2' second forward observation point P ₂ corrected gradually substituted for _old, the previous value P _{2 '_old} a current operation the second forward observation point after correction at P ₂ , And when the corrected second forward gazing point P ₂ ′ at the time of the current calculation is present at a position closer to the host vehicle than the previous value P ₂ ′ _old, the corrected first forward gazing point at the time of the current calculation P ₂ 'is set to the previous value P ₂ ' _old. This prevents the corrected second front gazing point P ₂ ′ from returning backward.

  In the above-described embodiment, the first front gazing point distance D1 and the second front gazing point distance D2 have been specifically described with reference to FIGS. However, it is not limited to this. For example, as shown in FIG. 16, when the second forward gazing distance D2 used in the second embodiment is increased corresponding to the vehicle speed, the first forward gazing distance D1 at a certain vehicle speed. You may make it cross.

In the second embodiment described above, if not corrected first position of the forward gaze point P _1, i.e. has been described a case of fixing the first position of the forward gaze point P _1. However, it is not limited to this. For example, for the first forward fixed point P _1, as in the first embodiment described above, it may be corrected according to a result of comparison between the passable road radius Rn_limit a first forward gaze point position road radius Rn_road . When the correction is performed in this way, the first steering amount δ1 obtained based on the corrected first forward gazing point P ₁ ′ corrected to the forward gazing point setting limit point P_limit and the corrected second forward gazing point P _{2 are obtained.} A control amount δC composed of an addition value with the second steering amount δ2 obtained based on 'can be obtained.

In the third embodiment described above, if not corrected first position of the forward gaze point P _1, i.e. has been described a case of fixing the first position of the forward gaze point P _1. However, it is not limited to this. For example, as in the first embodiment described above, may be corrected according to a result of comparison between the passable road radius Rn_limit a first forward gaze point position road radius Rn_road the first forward gaze point P _1. When the correction is performed in this way, the virtual circular path reference lateral deviation Y _E ′ with the virtual circular path is calculated at the corrected first forward gazing point P ₁ (corrected first forward gazing point P ₁ ′). Will be able to.
In the description of the above-described embodiment, the process of step S5 shown in FIG. 2 of the controller 17 realizes a first forward gazing point setting unit that sets the first forward gazing point farther from the host vehicle as the host vehicle speed increases. doing.

Further, as described above, based on the vehicle speed Vc, the forward gazing point P1, which is a control target, is set based on the first forward gazing point distance D1. the place where the lateral deviation Y _E is calculated, passable road radius Rn_limit is the case of less than the first forward gaze point position road radius Rn_road is to prevent the forward gaze point progresses to the front side, forward fixed point P1 and 'set as its forward fixed point P1' forward fixed point P1 to the forward gaze point set limit point P_limit the front side becomes a control target to calculate the lateral deviation Y _E of the reference path in than. That is, by correcting the headway point P1, it is corrected lateral deviation Y _E. Such processing includes error detection means for detecting a first error (lateral deviation Y _E ) between the first forward gazing point set by the first forward gazing point setting means and the reference path, and at least before entering the curve. An error correction unit that corrects the first error with respect to the reference route at a predetermined position on the curve traveling route to be small is realized. Here, the predetermined position is the forward gazing point P1.

In addition, the processing of step S9 and step S10 shown in FIG. Steering amount calculation means for calculating is realized.
Further, the process of step S4 shown in FIG. 2 of the controller 17 realizes a travelable road radius calculation means for calculating the road radius on which the host vehicle can travel, and the process of step S6 of the controller 17 shown in FIG. The road radius detection means for detecting the road radius of the travel path at the first forward gazing point is realized, and the processing of step S7 shown in FIG. 2 of the controller 17 is performed by the first forward gazing point detected by the road radius detection means. The comparison means for comparing the road radius and the road radius that can be traveled by the host vehicle calculated by the travelable road radius calculation means is realized. Further, the processing of step S7 shown in FIG. 2 of the controller 17 is performed when the comparison result of the comparison means is that the road radius on which the host vehicle can travel is less than the road radius at the first forward gazing point. When the first forward gazing point is located farther from the vehicle than the traveling road position having the correct road radius, the error correction unit changes the position of the first forward gazing point to the traveling road position having the road radius that can be traveled. Processing is realized.

It is a schematic block diagram of embodiment of this invention. It is a flowchart which shows the steering control process in 1st Embodiment. It is a figure explaining the structure (node data) of road map information. It is a characteristic diagram for setting the first forward gaze point P _1. It is a diagram used for explaining a method of calculating the first headway point position road radius Rn_road at the first forward observation point P _1. It is a diagram used for explaining a method of calculating the lateral deviation Y _E at the first forward observation point P _1. It is the figure used for description of the effect in 1st Embodiment. It is a flowchart which shows the steering control process in 2nd Embodiment. Is a characteristic diagram for setting the second forward gaze point P _2. It is a diagram used for explaining a method of calculating the second headway point position road radius Rff at the second forward observation point P _2. It is the figure used for description of the effect in 2nd Embodiment. It is a flowchart which shows the steering control process in 3rd Embodiment. It is the figure used for description of the setting of the virtual circular path | route used as the passable road radius R_limit. It is a diagram used for explaining a method of calculating the _'corrected lateral deviation Y _E' in first forward observation point P ₁ after the correction. It is a characteristic view for setting lateral G value Yg_limit according to vehicle speed. Is another characteristic diagram for setting the second forward gaze point P _2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Steering actuator 11FL-11RR Wheel speed sensor 12 Longitudinal acceleration sensor 13 Lateral acceleration sensor 14 Yaw rate sensor 15 GPS
16 Storage unit 17 Controller

Claims (10)

Automatic steering for vehicles that sets the front gazing point set in front of the host vehicle further from the host vehicle as the host vehicle speed increases, and calculates the steering amount based on the error between the front gazing point and the reference route that forms the travel target route In the control device,
An automatic steering control device for a vehicle, wherein the error based on a forward gazing point set in front of a curve is corrected so as to be close to the error based on a forward gazing point set when entering the curve. In a vehicle automatic steering control device that sets a forward gazing point in front of the host vehicle and calculates a steering amount based on an error between the forward gazing point and a reference route that forms a travel target route,
Forward gazing point setting means for setting the forward gazing point farther from the host vehicle as the host vehicle speed increases;
Error detecting means for detecting the error between the forward gazing point set by the forward gazing point setting means and the reference path;
Error correction means for correcting so that an error between the forward gazing point and the reference path at a predetermined position in the curve road is reduced at least before entering the curve;
Steering amount calculation means for calculating the steering amount of the host vehicle so that the host vehicle travels along the reference route based on the error corrected by the error correction unit;
An automatic steering control device for a vehicle, comprising: Road radius detection means for detecting the road radius of the travel path at the forward gazing point, travelable road radius calculation means for calculating the road radius on which the host vehicle can travel, and the forward gazing point detected by the road radius detection means And a comparison means for comparing the road radius that can be traveled by the host vehicle calculated by the travelable road radius calculation means,
The error correction means is a travel path in which the comparison result of the comparison means is the road radius that allows the vehicle to travel when the road radius on which the host vehicle can travel is less than the road radius at the front gazing point. When the forward gazing point is located farther from the vehicle than the position, the error is corrected by changing the position of the forward gazing point to a traveling road position that is the road radius where the vehicle can travel. The automatic steering control device for a vehicle according to claim 2.   The error correction means changes the position of the front gazing point to the position of the front gazing point used for the previous calculation of the steering amount or farther from the vehicle than the position. The automatic steering control device for a vehicle according to claim 3. A second forward gazing point setting means for setting a second forward gazing point farther from the vehicle than the forward gazing point;
The steering amount calculation means calculates the steering amount of the host vehicle based on the second forward gazing point set by the second forward gazing point setting unit so that the host vehicle travels along the reference route. The automatic steering control device for a vehicle according to any one of claims 2 to 4, wherein the automatic steering control device is used. Road radius detecting means for detecting the road radius of the traveling road at the second forward gazing point set by the second forward gazing point setting means, and travelable road radius calculating means for calculating the road radius on which the host vehicle can travel. Comparison means for comparing the road radius at the second forward gazing point detected by the road radius detection means with the road radius on which the host vehicle can be traveled calculated by the travelable road radius calculation means, and the comparison If the road radius in which the vehicle can travel is less than the road radius at the second forward gazing point and the vehicle is more than the travel road position that is the travelable road radius. And a second forward gazing point changing means for changing a position of the second forward gazing point to a travel path position having a radius capable of traveling when the second forward gazing point is present far away from the vehicle. And
The steering amount calculating means controls the steering amount of the host vehicle so that the host vehicle travels along the reference route based on the second forward gazing point whose position has been changed by the second forward gazing point changing unit. The vehicle automatic steering control device according to claim 5, wherein:   The second forward gazing point changing means is a second forward gazing point at the position of the second forward gazing point used by the steering amount calculation means for the previous calculation of the steering amount or farther from the host vehicle than the position. The vehicle automatic steering control device according to claim 6, wherein the position of the vehicle is changed. A travelable road radius calculation unit that calculates a road radius on which the host vehicle can travel, a travel path position that is a road radius calculated by the travelable road radius calculation unit, and a virtual curved path that is in contact with the identified position Virtual route setting means for setting
The error correction unit detects a second error between the forward gazing point set by the forward gazing point setting unit and the virtual curved path set by the virtual route setting unit, and the error correction unit detects the error. The automatic steering control device for a vehicle according to any one of claims 2 to 4, wherein the second error is changed.   The vehicle according to any one of claims 3 to 8, wherein the travelable road radius calculation means calculates a road radius on which the host vehicle can travel based on a predetermined lateral acceleration of the host vehicle. Automatic steering control device.   The automatic steering control device for a vehicle according to claim 9, wherein the lateral acceleration of the host vehicle changes according to the speed of the host vehicle.

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