JPH10302199A - Automatic steering device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely suppress and prevent the influence of the noise of detection transverse displacement, which is increased according as the relative speed to a magnet is increased, to obtain accuracy as well as responsiveness of automatic lane following-up steering. SOLUTION: For example, a rear wheel can be steered as assistant independently of a front wheel used for lane following-up control, and a target rear wheel steering angle δrd where the side slide speed in the magnetic sensor position is zero is set in accordance with a vehicle speed (v), a lane curvature ρ, etc., and feedback control is so performed that an actual rear wheel steering angle δr coincides with the target value, thereby reducing the noise component of detected transverse displacement. A transverse momentum adjustment device like a traction controller is used to control transverse momentum like a yaw moment, and the side slide speed in the magnetic sensor position is made zero in the same manner, and the noise component of detected transverse displacement is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic steering apparatus for a vehicle that automatically steers the vehicle so that the vehicle travels along a lane.

[0002]

2. Description of the Related Art An example of such a conventional automatic steering device for a vehicle is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-81602.

An automatic steering apparatus for a vehicle described in this conventional example defines steering characteristics so that more artificial steering is performed when traveling along various conditions related to steering, particularly, a curve. It is. As a result, a more natural driving feeling and a more comfortable ride are provided to the occupant.

[0004]

By the way, the vehicle automatic steering apparatus described in the above-mentioned publication discloses road information, more specifically, the state of a lane, that is, whether it is a straight road or a curved road, It is assumed that information such as the degree of curvature is obtained from image information of a camera or the like. On the other hand, a magnetic force source such as a magnet called a magnetic nail is buried along the lane and detected by a magnetic sensor attached to the vehicle, and the lateral displacement of the vehicle (lateral position information with respect to the magnetic force source, that is, Vehicle position information), and the detected lateral displacement matches the target lateral displacement.
In some cases, the front wheels or the rear wheels are steered by an actuator. Note that, in principle, the magnetic force source is buried in the center of the lane, and the relative positional relationship between the magnetic sensor and the vehicle does not change.

[0005] When the lateral displacement of the vehicle is detected in this way, the steering actuator is controlled so that the lateral displacement matches the target lateral displacement. However, if such an automatic steering device is mounted on an actual vehicle to perform automatic steering, the accuracy of control may be reduced. This is due to the fact that the noise of the detected lateral displacement changes according to the running state of the vehicle,
It has also been found that such automatic steering devices are involved in the construction of a discretized system.

The present invention has been developed in view of these problems. For example, a noise component of a detected lateral displacement, which is likely to occur in accordance with the running state of a vehicle, is accurately prevented and accurately controlled. It is an object of the present invention to provide an automatic steering device capable of improving the performance.

[0007]

In order to achieve the above object, an automatic steering apparatus for a vehicle according to a first aspect of the present invention includes a magnetic sensor for detecting a magnetic force source embedded along a lane, Lateral displacement detecting means for detecting a lateral displacement of the vehicle from a detection signal of a magnetic sensor, a steering actuator for steering a front wheel or a rear wheel, and a steering angle detection for detecting a steering angle of a front wheel or a rear wheel steered by the steering actuator Means, a steering control means for controlling the steering actuator so that the detected lateral displacement of the vehicle becomes a target lateral displacement, and a sensor lateral slip of the vehicle relative to a magnetic force source at the position of the magnetic sensor. And a skid speed reducing means for reducing the speed.

According to a second aspect of the present invention, there is provided an automatic steering apparatus for a vehicle according to the first aspect, wherein the side slip speed reducing means includes at least a front wheel or a rear wheel steered by the steering actuator. Auxiliary steering actuator for auxiliary steering of different rear wheels or front wheels, and traveling state information detecting means for detecting information on the traveling state of the vehicle,
An auxiliary steering control means for controlling the auxiliary steering actuator so as to reduce the sensor side skid speed according to the traveling state information detected by the traveling state information detecting means.

According to a third aspect of the present invention, there is provided an automatic steering apparatus for a vehicle according to the second aspect, wherein the auxiliary steering actuator detects a steering angle of a rear wheel or a front wheel assisted by the auxiliary steering actuator. With steering angle detection means,
The traveling state information detecting means includes a vehicle speed detecting means for detecting a vehicle speed, and a lane curvature detecting means for detecting a curvature of a lane. The auxiliary steering control means includes a vehicle speed and a lane curvature detected by the vehicle speed detecting means. Based on the lane curvature detected by the detecting means, a target steering angle of a rear wheel or a front wheel that is assisted by the auxiliary steering actuator, which is necessary to reduce the sensor side skid speed, is set. The auxiliary steering actuator is controlled such that the steering angle detected by the auxiliary steering angle detecting means coincides with the steering angle to be performed.

According to a fourth aspect of the present invention, in the automatic steering apparatus for a vehicle according to the third aspect of the present invention, the target steering angle of the rear wheel or the front wheel to be assisted is determined by a state estimator. It is characterized by setting.

According to a fifth aspect of the present invention, in the automatic steering apparatus for a vehicle according to the fourth aspect, the state estimator includes a Kalman filter.

According to a sixth aspect of the present invention, there is provided an automatic steering apparatus for a vehicle according to the first to fifth aspects.
The side slip speed reducing unit is a lateral momentum adjusting unit that can adjust a lateral momentum in a lateral direction generated in at least the vehicle,
Traveling state information detecting means for detecting information relating to the traveling state of the vehicle, and a lateral control means for controlling the lateral momentum adjusting means so as to reduce the sensor side skid speed according to the traveling state information detected by the traveling state information detecting means. And a momentum control means.

According to a seventh aspect of the present invention, there is provided an automatic steering apparatus for a vehicle according to the sixth aspect, wherein the lateral momentum detecting means detects the lateral momentum of the vehicle adjusted by the lateral momentum adjusting means. And the traveling state information detecting means includes a vehicle speed detecting means for detecting a vehicle speed, and a lane curvature detecting means for detecting a curvature of a lane, and the lateral momentum control means is detected by the vehicle speed detecting means. Based on the lane curvature detected by the vehicle speed and the lane curvature detection means, a target lateral momentum of the vehicle, which is necessary for reducing the sensor side slip speed and is adjusted by the lateral momentum adjustment means, is set. The lateral momentum adjusting means is controlled so that the lateral momentum detected by the lateral momentum detecting means coincides with the lateral momentum.

According to a seventh aspect of the present invention, in the vehicle automatic steering apparatus according to the seventh aspect, the target lateral momentum of the adjusted vehicle is set by a state estimator. It is characterized by the following.

According to a ninth aspect of the present invention, in the vehicle automatic steering apparatus according to the ninth aspect, the state estimator includes a Kalman filter.

According to a tenth aspect of the present invention, in the vehicle automatic steering apparatus according to the sixth or ninth aspect, the lateral momentum adjusting means adjusts the traction of each wheel so that the vehicle can be controlled. It is a traction adjustment means for adjusting the generated yaw moment.

[0017]

Thus, according to the automatic steering apparatus for a vehicle according to the first aspect of the present invention, the magnetic force of the magnetic force source embedded along the lane is detected by the magnetic sensor, and the detection signal is obtained from the detection signal. When detecting the lateral displacement of the vehicle and automatically steering the front wheel or the rear wheel by controlling the steering actuator so that the detected lateral displacement coincides with the target lateral displacement, the magnetic sensor at the position of the magnetic sensor Since the configuration is such that the sensor side slip speed in the lateral direction of the vehicle is reduced, the relative speed between the vehicle, that is, the magnetic sensor and the magnetic force source is reduced by that amount. It is possible to suppress the noise component of the lateral displacement generated due to the configuration, and improve the accuracy of the control.

Further, according to the automatic steering apparatus for a vehicle according to the second aspect of the present invention, the rear wheels or the front wheels, which are different from the front wheels or the rear wheels mainly steered by the steering actuator, can be assisted by the auxiliary steering actuator. By controlling the auxiliary steering actuator in accordance with the traveling state information of the vehicle, the kinetic characteristics of the vehicle can be controlled, and the magnetic force at the position of the magnetic sensor cannot be reduced only with the front or rear wheels that are mainly steered. It is possible to more accurately and reliably reduce the sensor skid speed in the lateral direction of the vehicle with respect to the source.

According to the third aspect of the present invention, the target steering angle of the rear wheel or the front wheel to be assisted is set based on the detected vehicle speed and lane curvature. With this configuration, the target steering angle can be set to a value at which the sensor side slip speed of the vehicle in the lateral direction with respect to the magnetic force source at the position of the magnetic sensor becomes zero or substantially zero. Since the auxiliary steering actuator is controlled so that the steering angle detected matches the steering angle, the sensor skid speed can be reduced more accurately and reliably.

Further, according to the automatic steering apparatus for a vehicle according to claim 4 of the present invention, while accurately estimating the state quantity of the vehicle using the state estimator, the auxiliary steering of the rear wheel or the front wheel is performed. Since the target steering angle is set, if the steering angle of the rear wheel or the front wheel is assisted to follow the steering angle, the sensor skid speed can be reduced more accurately and reliably.

Further, according to the automatic steering apparatus for a vehicle according to claim 5 of the present invention, since the state estimator is constituted by a Kalman filter, the estimated state amount of the vehicle is:
Since the correction is made in accordance with the output error and becomes more accurate, the target steering angle can be set more accurately, and the sensor skid speed can be more accurately and reliably reduced.

According to the automatic steering apparatus for a vehicle according to the sixth aspect of the present invention, the lateral momentum generated in the vehicle in the lateral direction can be adjusted, and the lateral momentum adjusting means can be adjusted according to the traveling state information of the vehicle. By controlling the vehicle, it is possible to control the motion characteristics of the vehicle, mainly the steering wheel can not be reduced only by the front wheel or the rear wheel, the sensor skid speed in the lateral direction of the vehicle with respect to the magnetic force source at the position of the magnetic sensor, It is possible to reduce more accurately and reliably.

According to the automatic steering apparatus for a vehicle according to the seventh aspect of the present invention, since the target lateral momentum of the vehicle adjusted based on the detected vehicle speed and lane curvature is set. The target lateral momentum can be set to a value at which the sensor side slip speed of the vehicle in the lateral direction with respect to the magnetic force source at the position of the magnetic sensor becomes zero or substantially zero, and the target lateral momentum is detected. Since the lateral momentum adjusting means is controlled so that the lateral momentums to be adjusted coincide with each other, the sensor side slip speed can be reduced more accurately and reliably.

Further, according to the automatic steering apparatus for a vehicle according to claim 8 of the present invention, while accurately estimating the state quantity of the vehicle using the state estimator, the target lateral position of the adjusted vehicle is obtained. Since the momentum is set, if the lateral momentum of the vehicle is adjusted so as to follow the momentum, the sensor skid speed can be more accurately and reliably reduced.

According to the ninth aspect of the present invention, since the state estimator is constituted by a Kalman filter, the estimated state amount of the vehicle is:
Since the correction is made in accordance with the output error and becomes more accurate, the target lateral momentum can be set more accurately, and the sensor skid speed can be more accurately and reliably reduced.

According to the automatic steering apparatus for a vehicle according to claim 10 of the present invention, the lateral momentum adjusting means comprises traction adjusting means, and the yaw generated in the vehicle by adjusting the traction of each wheel. By making the moment adjustable, the automatic steering device according to claim 4 or 5 can be implemented.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. Here, an automatic steering device that mainly steers the front wheels will be described.

FIG. 1 is a schematic diagram showing an automatic steering apparatus according to a first embodiment of the present invention. Reference numeral 12 in the figure denotes front left and right wheels, and reference numeral 15 denotes rear right and left wheels. The front left and right wheels 12 are provided with a very common rack and pinion type steering mechanism. The steering mechanism includes a rack 11 connected to a steering shaft (tie rod) of front left and right wheels 12, a pinion 10 meshing with the rack 11, and a steering wheel 1
And a steering shaft 9 rotated by the steering torque given to the steering shaft 4.

The steering shaft 9 includes
An automatic steering mechanism for automatically steering the front left and right wheels 12 is also added. The automatic steering mechanism includes a driven gear 8 coaxially mounted on the steering shaft 9, a drive gear 7 meshing with the driven gear 8, and a motor 5 for rotating the drive gear 7. Note that a clutch mechanism 6 is interposed between the motor 5 and the drive gear 7, and the clutch mechanism 6 is connected only during automatic steering control. Otherwise, the clutch mechanism 6 is separated and the torque of the motor 5 is increased. Is not input to the steering shaft 9. The automatic steering mechanism including the motor 5 is controlled by a control signal from an automatic steering control unit 13 described later.

On the other hand, in this embodiment, an auxiliary steering mechanism for assisting the rear left and right wheels 15 is also added. The auxiliary steering mechanism includes a rack 19 mounted coaxially with a steering rod 20 for connecting the rear left and right wheels 15, and meshes with the rack 19 and moves the rack 19 forward by the rotational driving force of the motor 17 to move the rear left and right wheels. And a gear 18 for assisting steering of the gear 15. The auxiliary steering mechanism including the motor 17 is also controlled by a control signal from an automatic steering control unit 13 described later.

Further, various sensors are mounted on the vehicle. Reference numeral 3 denotes a steering angle sensor which calculates the actual front wheel steering angle δ of the front left and right wheels 12 based on the rotation angle of the steering shaft 9.
_f is calculated and output to the automatic steering control unit 13. Reference numeral 4 in the figure denotes a vehicle speed sensor, for example, based on the rotation speed of the output shaft of the transmission, and the moving speed of the vehicle (vehicle speed)
v is calculated and output to the automatic steering control unit 13. Reference numeral 16 in the figure denotes a lane curvature detecting device that detects the curvature of the lane. For example, the lane curvature information wirelessly transmitted from the side of the lane is obtained, and the lane curvature ρ is output to the automatic steering control unit 13. The lane curvature detecting device may be softwareized so as to be configured by arithmetic processing executed in the control unit 13, and its brief contents will be described later. Reference numeral 21 in the drawing denotes an auxiliary steering angle sensor, and outputs the automatic steering control unit 13 indexes the actual rear wheel steering angle [delta] _r of the rear left and right wheels 15 from the amount of movement of the steering rod 20.

On the other hand, the magnetic force of a magnet (not shown) embedded along the lane as a magnetic force source is detected by a magnetic sensor 1 mounted at a lower front part of the vehicle. This magnetic sensor 1
Decomposes not only the magnitude of the magnetic force of the magnet but also its magnetic force vector into a vertical component corresponding to the vehicle vertical direction and a horizontal component corresponding to the vehicle width direction, and calculates the respective directions and magnitudes. Can be detected.

The detection signal of the magnetic sensor 1 is output to a lateral displacement detecting device 2 constituting a lateral displacement detecting means. The lateral displacement detecting device 2 calculates the direction and magnitude of the lateral displacement of the vehicle (strictly speaking, the magnetic sensor 1) with respect to the lane (strictly speaking, the magnet) based on the vertical and horizontal component ratio of the detected magnetic force vector based on the principle described later. Is detected (calculated). Since the lateral displacement detecting device 2 is constituted by a discrete digital system such as a microcomputer (not shown), the sampling of the lateral displacement as described above is performed only at a preset sampling timing. The lateral displacement y of the vehicle detected by the lateral displacement detecting device 2 is output to an automatic steering control unit 13 which constitutes a control means and performs automatic steering control.

The automatic steering control unit 13
Is composed of a discretized digital system such as a microcomputer (not shown). This digital system, like an existing microcomputer, has an input interface circuit for reading detection signals from the sensors, a storage device such as a ROM and a RAM for storing necessary programs and calculation results, and an actual storage device. An arithmetic processing unit such as a microprocessor unit which performs arithmetic processing and has a certain buffer mechanism, and outputs a control signal set by the arithmetic processing unit to the motor 5 of the automatic steering mechanism and the motor 17 of the auxiliary steering mechanism. And an output interface circuit for performing the operation.

In the present embodiment, a Kalman filter as a state estimator is constructed in a digital system such as a microcomputer in the automatic steering control unit 13. Here, the Kalman filter will be described. The Kalman filter estimates several state quantities based on the modern control theory according to a preset model, and assuming that feedback control is performed for each of them, consequently eliminates various chain-like responses, resulting in a single state. When the feedback control of the state quantity is facilitated and accurate, the model, that is, the estimated state quantity can be corrected according to the output error between the output estimated state quantity and the detected state quantity. is there. Specifically, the configuration shown in FIG. 2A is obtained.

Here, since the model in the Kalman filter of the present embodiment is a two-wheel model of a vehicle, this is expressed by the following equation 12 using a state space expression. However, in the two-wheel model shown in Formula 12, since the rear wheels can be steered and the yaw moment can be controlled by the traction of the rear wheels, the front wheels are mainly steered and the vehicle is steered as in the present embodiment. In the case of controlling the lateral displacement and assisting the rear wheel to reduce the lateral speed with respect to the magnet at the position of the magnetic sensor 12, that is, the sensor side slip speed, the yaw moment _Tr is set to zero. I just need.

[0037] Where a ₁₁ = − (C _r + C _f ) / (m · v) (12-1) a ₁₂ = (− 1+ (C _r · b−C _f · a)) / (m · v ²⁾ _{) ......... (12-2) a 21 =} (C r · b-C f · a) / I ......... (12-3) a 22 = - (C r · b 2 + C f · a 2) / (I · v)… (12-4) b ₁₁ = C _f / (m · v)… (12-5) b ₁₂ = C _r / (m · v) …… (12-6) ) b ₂₁ = C _f · a / I (12-7) b ₂₂ = −C _r · b / I (12-8) b ₂₃ = 1 / I (12-9) It is. Β: sideslip angle at the center of gravity of the vehicle r: yaw rate Δψ: yaw angle relative to the lane L _s : distance in plan view between the magnetic sensor and the center of gravity of the vehicle C _r : cornering stiffness of rear right and left two wheels C _f : front Cornering stiffness of right and left wheels m: vehicle mass b: distance between rear wheel axle and vehicle center of gravity in plan view a: distance between front wheel axle and vehicle center of gravity in plan view I: moment of inertia of vehicle.

In the above equation (12), in a steady running state, the left side, that is, the side slip angular velocity β '(' indicates a time differential value) at the center of gravity of the vehicle, the yaw angular acceleration r ', the yaw rate Δψ' Since it is considered that all the lateral displacement speeds y 'become zero, the following equation (14) is obtained by adding a suffix "0" to each physical quantity or state quantity at this time. Note that each state quantity in such a steady running state is defined as a state quantity around the equilibrium point.

[0039] Then, similarly to the first embodiment, the actually required steering angle and yaw moment are further corrected by a correction error generated due to a model error or the like when a steady steering angle or yaw moment around the equilibrium point is given. Is given as a feedback value, and the following equations 15-1 to 3-5 are given. Further, the same can be said for other state quantities. Equations (4) to (4) hold.

Δ_f= Δ_f0+ Δδ_f ……… (15-1) δ_r= Δ_r0+ Δδ_r ............ (15-2) T_r= T_r0+ ΔT_r ……… (15-3) β = β₀+ Δβ ……… (16-1) r = r₀+ Δr... (16-2) Δψ = Δψ₀+ Δ^Twoψ ……… (16-3) y = y₀+ Δy (16-4) Next, since there is no correction in the lane curvature ρ, Δρ is
Qualitatively zero (ie, ρ₀= Ρ)
Solving them together gives the following equation (17). In other words, the gain here
Vector x (corrected sideslip angle Δβ, corrected yaw
-Rate Δr, corrected yaw angle Δ^Twoψ, the corrected lateral displacement Δy) is
If it were accurate, we would have to correct from this vector.
Front wheel steering angle, that is, the corrected front wheel steering angle Δδ_fdOr, the corrected wheel rudder
Angle Δδ_rdAnd corrected yaw moment ΔT_rdEtc. can be calculated
You. Note that the yaw moment is not corrected as described above.
In the case of the present embodiment, the steady yaw moment
T _r0Or the corrected yaw moment ΔT_rdEtc. to all “0”
Just set it.

[0041] This 17 equation is abbreviated according to the configuration diagram of the Kalman filter shown in FIG.

Dx / dt = Ax + Bu (11) That is, each vector, x, A,
B and u are summarized as follows.

[0043] Here, once away from the description of the configuration of the Kalman filter, the lane following, that is, the corrected front wheel steering angle Δδ for realizing the corrected lateral displacement Δy = 0 from the vector x of the state quantity.
_fd , the corrected rear wheel steering angle Δδ _rd and the corrected yaw moment ΔT _rd
In order to set, consider optimization control using an optimal regulator. Here, the constraint condition is the above equation 11, and the evaluation function J is given by the following equation 18.

J = ∫ (x ^T Qx + u ^T Ru) dt (18) where x ^T is the transposed vector of vector x, and u ^T is the transposed vector of vector u. Q is a symmetric non-negative definite matrix, and R is a symmetric positive definite matrix, which is generally called a weight. Since the corrected lateral displacement Δy in the vector x is the fourth row, to reduce the corrected lateral displacement Δy, it is sufficient to increase the 4-row, 4-column element of the symmetric non-negative definite matrix Q. However, it goes without saying that it is necessary to consider a trade-off in that the noise is more easily picked up by increasing the gain.

The resulting feedback law is:
According to the block diagram shown in FIG. 2B, it is expressed by the following 19 equations, and by listing each element, 20 equations are obtained. Note that K _R
Is a constant matrix.

U = −K _R · x (19) Here, when the target lateral displacement and [Delta] y _d, to the [Delta] y and [Delta] y _d is Becomes

[0047] That is, in this embodiment, for the wheel steering angle [delta] _r after controllable, until the feedback frequency is not corrected, that is, the target rear wheel steering angle [delta] _rd said stationary rear-wheel steering angle [delta]
_Since it is set to _r0 , the estimated corrected side slip angle Δβ, the corrected yaw rate Δr, the corrected yaw angle Δ ² ψ, and the corrected lateral displacement Δy
On the other hand, the corrected front wheel steering angle Δδ _fd is simply given by the following equation (21).

Δδ _fd = k ₁₁ · Δβ + k ₁₂ · Δr + k ₁₃ · Δ ² ψ + k ₁₄ · (Δy−Δy _d ) (21) The corrected side slip angle Δβ excluding the corrected lateral displacement Δy in the state estimator described above. , corrected yaw rate [delta] r, when the corrected yaw angle delta ² [psi can not be detected, if constituting a state estimator using reverse the correction lateral displacement Δy and the correction front wheel steering angle .DELTA..delta _f, to estimate the amount their state Can be.

On the other hand, returning to the description of the Kalman filter again, the estimated lateral displacement y ＾ (＾ indicates an estimated value) estimated as described above is obtained by adding the corrected front wheel steering angle Δδ _fd to the model described above. Substitution (In view of the straight running state, it seems that the target front wheel steering angle δ _fd should be substituted. However, the model before that, that is, the model around the equilibrium point corresponding to the steady turning state until then, will be described later. Is substantially substituted into the corrected front wheel steering angle Δ.
δ becomes _fd) to result tried, since an estimated value of the vehicle is achieved, which is referred to as estimated lateral displacement y _e. However,
There is always an error between the aforementioned model and the actual vehicle. Therefore, as shown in FIG. 2A, a deviation (hereinafter, simply referred to as an output error) ε between the estimated lateral displacement y _e and the actual lateral displacement y detected as in the first embodiment is obtained. over the output error feedback gain vector K _e to the error epsilon, it corrects the model in the state estimator. Here, in order to facilitate understanding, the notation of correcting the model is used. However, since there is no problem in directly correcting each state quantity, it is assumed that the state quantity is corrected in a broad sense. Handle.

Although the magnitude of the output error feedback gain vector K _e cannot be simply compared due to the characteristics of the vector, as is clear from the above description, if the gain characteristic is large, the state quantity can be corrected quickly. It can be seen that the responsiveness of control can be improved, but on the other hand, it is easily affected by noise components. Conversely, the smaller the gain characteristics of the output error feedback gain vector K _e is the correction effect of the state quantity decreases, it can be seen accuracy of control to prevent suppress the influence of noise components can be improved.

Next, the arithmetic processing of the present embodiment executed in the control unit 13 will be described with reference to the flowchart of FIG. Although this flowchart does not particularly include a step for exchanging information, the information read by the arithmetic processing unit, the physical quantity, or the calculated operation result is updated and stored in the storage device at any time. Necessary programs, maps, tables, and the like are read from the storage device to the buffer of the arithmetic processing device at any time.

This arithmetic processing is executed as a timer interrupt processing at every preset sampling time ΔT of, for example, 10 msec. First, the vehicle speed v from the vehicle speed sensor 4 is read in step S1.

Next, the process proceeds to step S2, where the lane curvature ρ from the lane curvature detector 16 is read. Next, the process proceeds to step S3, where the steady front wheel steering angle δ _{f0 is calculated} according to the following equation.
Is calculated. The calculation principle of the following equation will be described in detail later. This steady front wheel steering angle δ _f0 is equivalent to the state quantity around the equilibrium point expressed by the above equation (14) when the steady yaw moment T _r0 = 0, due to the linearity of the vehicle.

[0054] Next, the process proceeds to step S4 to calculate a steady rear wheel steering angle δ _r0 according to the following two equations. The calculation principle of the following two equations will be described in detail later. Also, this steady rear wheel steering angle δ
_r0 is a steady yaw moment _Tr0 =
It is equivalent to the state quantity around the equilibrium point expressed by the above equation (14) when it is set to 0.

[0055] At the next step S5, wheel steering angle after the front wheel steering angle [delta] _f and the auxiliary steering angle sensor 21 from the steering angle sensor 3 [delta]
Read _r .

[0056] and then proceeds to step S6, in accordance with the following 22 formula, the actual front wheel steering angle [delta] _f, and calculates a front wheel steering angle deviation .DELTA..delta _f from the steady front wheel steering angle [delta] _f0. Δδ _f = δ _f −δ _f0 (22) Next, the process proceeds to step S7, and at least the steady-state lateral displacement y ₀ corresponding at least around the equilibrium point is obtained from the vehicle speed v and the lane curvature ρ according to the above equation (14). calculate.

Next, the flow shifts to step S8, where the lateral displacement y from the lateral displacement detecting device 2 is read. Next, step S9
Then, the lateral displacement deviation Δy is calculated from the detected actual lateral displacement y and the steady lateral displacement y ₀ according to the following equation (23). Note that when the front-wheel automatic steering based on state estimation has already been started, the calculated steady-state lateral displacement y ₀ is substantially zero, and the detected lateral displacement y is a feedback amount for correcting the model error described above. Therefore, the detected lateral displacement y may be directly set to the lateral displacement deviation Δy.

Δy = y−y ₀ (23) Next, the process proceeds to step S 10, where each state quantity is estimated by a Kalman filter composed of the above formula (17).
The state estimation vector x is calculated.

Next, the flow shifts to step S11, where
From Equations (21) and (21), the corrected front wheel steering angle Δδ _fdIs calculated. next
The process proceeds to step S12, and the following formulas 24 and 25 are used.
Thus, the calculated corrected front wheel steering angle Δδ_fd, Steady front wheel rudder
Angle δ_f0From the target front wheel steering angle δ_fdOr steady front wheel steering angle δ
_r0From the target rear wheel steering angle δ_rdAre calculated respectively.

Δ _fd = δ _f0 + Δδ _fd (24) δ _rd = δ _r0 (25) Next, the process proceeds to step S13, where the actual front wheel steering is set to the set target front wheel steering angle δ _fd. to then creates a control signal for feedback control to match the angular [delta] _f output.

[0061] and then proceeds to step S14, returns to the main program and the by creating a set control signal of the feedback control to the target rear wheel steering angle [delta] _rd match Migo wheel steering angle [delta] _r outputs I do.

Next, the principle of calculation of the above equations 1 and 2 will be described. The equation of motion when the rear wheels are steered as in the present embodiment is expressed by the following equations 5 and 6 using a two-wheel model.

M · v · (r + β ′) = C _f · (δ _f − (ar + v · β) / v) + C _r · (δ _r − (v · β−br) / v) (5) I · r ′ = a · C _f · (δ _f − (a · r + v · β) / v) −b · C _r · (δ _r − (v · β−br) / v) (6) where β ': side slip angular velocity at the center of gravity of the vehicle, r': yaw angular acceleration.

The yaw rate r in the steady state of the turning motion is expressed by the following equation from the lane curvature ρ and the vehicle speed v. r = ρ · v (7) Further, in the steady state of the turning motion, both the sideslip angular velocity β ′ and the yaw angular acceleration r ′ at the center of gravity of the vehicle are zero.

[0065] β '= r' = 0 ......... (8) In addition, side-slip velocity v _s of the magnetic sensor position are those given by the following formula (9) by using the yaw rate [psi 'and slip angle beta.

V _s = L _s · r + v · β (9) The front wheel steering angle δ _f of the above formulas (5) and (6) is set to the steady front wheel steering angle δ _f0 in the steady state, and the rear wheel steering angle δ _{Let r be the} steady rear wheel steering angle δ _r0 in the steady state, and solve Equations 5 to 9 for each of them to obtain Equations 1 and 2. Such a calculation principle is the same as the principle for deriving the state quantity around the change point, that is, each state quantity in a steady state, so that the steady front wheel steering angle δ _f0
It can be understood that the steady rear wheel steering angle δ _r0 is equivalent to those of Equations 1 and 2 respectively. This is due to the linearity of the vehicle.

The corrected front wheel steering angle Δδ _fd is considered to be a correction by feedback control of the lateral displacement y when the steady front wheel steering angle δ _f0 is given, and is determined according to the so-called PID control in classical control theory. May be set.

Next, the operation of the present embodiment will be described. Here, when a magnet is used as a magnetic force source, the principle of detecting the lateral displacement of the vehicle with respect to the lane based on the magnetic force from the magnet will be briefly described. When the line of magnetic force from the magnet is generated as shown in FIG. 9, the level (height) of the magnetic sensor is constant. Therefore, if the ratio of the vertical and horizontal components of the detected magnetic force vector is known, the magnetic sensor, that is, the vehicle, You can see how far the magnets, or lanes, are displaced laterally. In other words, if the magnetic sensor is directly above the magnet, the ratio of the vertical and horizontal components of the detected magnetic force vector becomes 1: 0, and the more it is shifted in the horizontal direction, the more the horizontal component of the detected magnetic force vector is shifted. Becomes large, and the vertical component becomes small. Further, it can be determined from the direction in which the lateral component of the magnetic force vector is generated, which of the magnetic sensor, that is, the vehicle, is deviated from the magnet, that is, the lane.

Next, the timing for detecting the lateral displacement of the vehicle with respect to the lane using this principle will be briefly described. Now, assuming that the magnetic sensor attached to the vehicle is not displaced in the lateral direction with respect to the magnet as described with reference to FIG.
Assuming that the distance between the magnetic sensor and the magnet is D as shown in FIG. 0a, the relationship between the distance D and the magnetic force appears as shown in FIG. 10b.
That is, when the magnetic sensor comes closest to the magnet, the detected magnetic force also becomes maximum. Therefore, when the detected magnetic force becomes the maximum, it becomes possible to accurately detect the lateral displacement of the vehicle from the vertical and horizontal component ratio of the magnetic force vector.

Therefore, when the steering actuator is controlled using the detected lateral displacement so as to coincide with the target lateral displacement as described above, the output error can be corrected in the present embodiment as described above. A noise component is removed using an observer (state estimator) such as a Kalman filter.

Next, the noise component of the lateral displacement y detected as described above will be described. In a method of detecting the magnetic force of a magnetic force source such as a magnet buried along the lane with a magnetic sensor to detect the lateral displacement of the vehicle with respect to the lane,
There are many noises (including error components) in the lateral displacement detected by the actual vehicle. This has been considered to be because, for example, as shown in FIG. 10, a magnetic force source such as a magnet is not accurately embedded in the center of the lane corresponding to the center of two white lines indicating the width of the lane. That is, if a magnetic force source such as a magnet, which should be originally located at the center of the lane, is buried with a lateral shift, the detected lateral displacement is, as shown in FIG. Even if you move along the center,
It is erroneously recognized as if it is shifted in the horizontal direction.

However, the detected noise component of the lateral displacement y also includes the following noise components. That is, the automatic steering apparatus for a vehicle as described above generally includes a digital system that is discretized because it requires advanced arithmetic processing. Therefore, for example, as described above, there is a possibility that the sampling timing when the magnetic force of the magnet is detected by the magnetic sensor differs from the timing when the magnetic sensor actually comes closest to the magnet. This possibility increases as the relative speed between the magnet and the magnetic sensor, that is, the vehicle, increases.

When this is reproduced in an actual vehicle, for example, as the vehicle speed v increases or the lane curvature ρ increases, the noise component of the detected lateral displacement increases, and as a result, the accuracy of the automatic steering control decreases. I do. Among these, the increase in the lane curvature ρ means that the angle between the moving direction of the vehicle that is to move along the lane center line and the direction in which the vehicle is actually facing, that is, the yaw angle, as shown in FIG. Is large, which means that the skid speed of the magnetic sensor is large at the same time. During a steady turning motion, the two can be evaluated as equivalent to each other. However, the difference between the magnetic force sampling timing and the closest approach timing of the magnetic sensor described above is due to the magnet and the magnetic sensor,
That is, assuming that the noise is caused by the relative speed with respect to the vehicle, the noise component of the detected lateral displacement increases as the sideslip speed of the magnetic sensor increases.

Of the relative speed between the magnet and the magnetic sensor, that is, the vehicle, the speed component in the front-rear direction of the vehicle, that is, the direction orthogonal to the sensor side slip speed, which is equivalent to the so-called vehicle speed, is the one that the vehicle desires This is a speed component that cannot be changed or should not be changed in order to move. Thus, in the present embodiment, the sensor side slip speed is reduced, preferably to zero, to reduce the noise component of the detected lateral displacement. However, in a vehicle that steers only the front wheels, such as a normal vehicle, the sensor skid speed at the position of the magnetic sensor cannot be controlled depending on the vehicle characteristics. That is, the sensor sideslip speed (same as the sideslip speed of the vehicle) is uniquely determined by the vehicle characteristics when the steering angle and the vehicle speed are given (of course,
Disturbance elements such as the road surface μ and the shape of the road surface are individual elements).

Therefore, in this embodiment, the front wheel to be steered is mainly responsible for the lane following control, and the rear wheel is further assisted to reduce the sensor skid speed, preferably to zero. At this time, the target steering angle of the rear wheel to be assisted is stabilized using the steady rear wheel steering angle δ _r0 while stabilizing the behavior of the vehicle while approaching the sensor side skid speed to zero. While providing a steady front wheel steering angle δ _f0 so that the vehicle can roughly follow the lane, the correction front wheel steering angle Δδ _fd is further provided to correct the small lateral displacement Δy to achieve complete lane following. That is, in the vehicle of the present embodiment,
As shown in FIG. 5, a vehicle turning motion slightly different from a general vehicle is achieved. Of course, since the sensor side slip speed is zero or substantially zero, the noise component of the detected lateral displacement y is reduced accordingly, and as a result, the accuracy of the automatic steering control is improved.

As described above, in the automatic steering apparatus according to the present embodiment, the sensor side slip speed can be reduced by mainly assisting the wheels other than the steered wheels, and the sensor side slip speed can be reduced to zero from the vehicle speed and lane curvature. By setting the target steering angle of the auxiliary steering wheel to be controlled and controlling the auxiliary steering wheel actuator so that the actual steering angle matches the target steering angle, the noise component of the detected lateral displacement can be effectively and significantly reduced. And the accuracy of the control can be improved.

As described above, the present embodiment is an embodiment of the vehicle automatic steering device according to claim 1 or 2 of the present invention, wherein the automatic steering mechanism constitutes a steering actuator of the present invention. Similarly, the lateral displacement detecting device and step S8 of the arithmetic processing in FIG. 3 constitute a lateral displacement detecting means, and the steering angle sensor 3 and step S5 of the arithmetic processing in FIG. 3 constitute a steering angle detecting means. Steps S9 to S13 of the arithmetic processing in FIG. 3 constitute the steering control means, the auxiliary steering mechanism constitutes the auxiliary steering actuator, and the auxiliary steering angle sensor 21 and the step S5 of the arithmetic processing in FIG. The vehicle speed sensor 4 and step S1 of the arithmetic processing of FIG. 3 constitute vehicle speed detecting means and running state information detecting means, and the lane curvature detecting device 16 and step S2 of the arithmetic processing of FIG. Steps S4 and S14 of the arithmetic processing shown in FIG. 3 constitute auxiliary steering control means, the auxiliary steering mechanism, the auxiliary steering angle sensor 21, the vehicle speed sensor 4, and the lane curvature. Steps S1, S2, and S4 of the detection device 16 and the arithmetic processing in FIG. 3 and steps S10 and S14 corresponding to a Kalman filter (state estimator) constitute a skid speed reduction unit.

In the first embodiment, a mechanism for assisting the rear wheel is provided. In the arithmetic processing shown in FIG. 3, it is possible to calculate a corrected rear wheel steering angle of the rear wheel with respect to the lateral displacement deviation. For the correction of the lateral displacement deviation, the rear wheel steering angle was not controlled, and only the steady rear wheel steering angle for setting the sensor side slip speed to zero was set as the target rear wheel steering angle. For this purpose, the rear wheel steering angle may be corrected. However, in this case, although the steady rear wheel steering angle is set to a value for setting the sensor side slip speed to zero, this is corrected to further correct the lateral displacement. It should be noted that speed convergence may be reduced. In this case, it is necessary to correct the state quantity for the output error of the sensor side slip speed or to provide an optimum regulator for the sensor side slip speed.

Next, an automatic steering system according to a second embodiment of the present invention will be described. First, as an outline of the automatic steering device provided in the vehicle, a traction adjustment mechanism constituting a lateral momentum adjustment means is attached instead of the auxiliary steering mechanism for the rear wheels in the first embodiment. This traction adjustment mechanism is configured by, for example, a traction control actuator 22 provided on each wheel, and adjusts the yaw moment generated in the vehicle by adjusting the traction (driving and braking force) of each wheel. More specifically, Japanese Patent Application Laid-Open No.
No. 1087, a rear-wheel drive power controller described in Japanese Patent Application Laid-Open No. 8-127258, or a known front-rear wheel drive power distribution control device alone or the like. They can be used in appropriate combination. For details of the specific control of the traction control actuator 22, reference is made to these documents. Here, a control signal for achieving the target yaw moment T _rd is transmitted from the control unit 13 to the control unit 13. When supplied to the traction control actuator 22, the actuators operate independently or mutually to achieve the target yaw moment T _rd . Other configurations are the same or substantially the same as those of the first embodiment, and the same reference numerals are given to the same components, and the detailed description thereof will be omitted.

In this embodiment, as in the first embodiment, a Kalman filter as a state estimator is constructed in a digital system such as a microcomputer in the automatic steering control unit 13.
However, in the two-wheel model shown in the above equation (12), since the rear wheels can be steered and the yaw moment can be further controlled, the lateral displacement of the vehicle is controlled by mainly steering the front wheels as in the present embodiment. Both control the yaw moment,
Lateral velocity with respect to the magnet at the position of the magnetic sensor 12,
That in the case of only one reducing sensor side-slip velocity may be set to zero wheel steering angle [delta] _r after in the equation (12).
Further, in the case of the present embodiment in which the rear wheel steering angle is not corrected, the steady rear wheel steering angle δ _{r0 in} Equations (14), (17) and (20) is used.
It is only necessary to set all the corrected wheel steering angles Δδ _{rd and the} like to “0”. Further, in the present embodiment, similarly to the description of the optimal regulator and the Kalman filter, the configuration in which the yaw moment _Tr can be estimated from the corrected lateral displacement Δy and the corrected front wheel steering angle Δδ _fd by the state estimator composed of the equation (12). It has become.

Next, the arithmetic processing of this embodiment executed in the automatic steering control unit 13 will be described with reference to FIG.
This will be described with reference to the flowchart of FIG. In this flowchart, although there is no particular step for transmitting and receiving information, the transmission and reception of information is executed at any time as in the first embodiment. This arithmetic processing is executed as a timer interrupt processing at every preset sampling time ΔT, for example, 10 msec., As in the first embodiment.

The arithmetic processing of this embodiment is similar to the arithmetic processing of the first embodiment shown in FIG.
5, S10, S12, and S14 are each performed in step S
Except for replacing 3 ', S4', S5 ', S10', S12 ', and S14, they are all the same as those in the first embodiment. Is omitted.

Of the changed steps, the step
In step S3 ', the steady front wheel steering angle?_f0To
calculate. The calculation principle of the following equation (26) is described later.
Will be described in detail. Also, this steady front wheel steering angle δ_f0The vehicle line
Steady rear wheel steering angle δ _r0The above 1 when = 0
This is equivalent to the state quantity around the equilibrium point expressed by Equation 4.

[0084] In step S4 ', a steady yaw moment _Tr0 is calculated according to the following equation (27). The calculation principle of the following equation (27) will be described in detail later. In addition, the steady yaw moment _Tr0 is determined by the steady rear wheel steering angle δ due to the linearity of the vehicle.
_This is equivalent to the state quantity around the equilibrium point expressed by the above equation (14) when _r0 = 0.

T _r0 = (a + b) · ρ · C _r (b + L _s ) + am · ρ · v ² (27) In step S 5 ′, the front wheel steering from the steering angle sensor 3 is simply performed. Read only the angle δ _f .

In step S10 ', the current yaw moment _Tr is estimated by the state estimator as described above, together with the state estimation by the Kalman filter. Also,
In step S12 ′, the target front wheel steering angle δ _fd is calculated according to the above equation (24), and the target yaw moment T _rd is calculated according to the following equation (28).

T _rd = T _r0 (28) In step S 14 ′, a control signal for feedback control for making the actual yaw moment T _r coincide with the set target yaw moment T _rd is generated and output. To return to the main program.

Next, the principle of calculation of the equations (26) and (27) will be described. The equation of motion when controlling the yaw moment of the vehicle as in the present embodiment is expressed by the following equations 29 and 30 using a two-wheel model.

M · v · (r + β ′) = C _f · (δ _f − (ar + v · β) / v) + C _r · (− (v · β−br) / v) 29) I · r ′ = a · C _f · (δ _f − (a · r + v · β) / v) −b · C _r · (− (v · β−br) / v) + T _r (30) where _Tr is the yaw moment of the four wheels generated in the vehicle.

Next, the operation of the present embodiment will be described. First, since the detected noise component of the lateral displacement y is the same as that described in the first embodiment, the description is omitted here.

In this embodiment, the lane following control is mainly performed by the steered front wheels, and the traction of each wheel is further adjusted to adjust the yaw moment generated in the vehicle. Is zero. At this time, for the target yaw moment _Trd , the steady-state yaw moment _Tr0 is used to stabilize the behavior of the vehicle while keeping the sensor side slip speed close to zero, while the front wheels have a steady front wheel steering angle _δf0 . While giving the vehicle roughly following the lane, a small lateral displacement Δy is further corrected by giving a corrected front wheel steering angle Δδ _fd to achieve complete lane following.
That is, also in the vehicle of the present embodiment, as an ideal turning motion, the side slip speed and the yaw angular speed of the magnetic sensor are zero as shown in FIG. 8, and the vehicle turns while maintaining a constant yaw angle. Of course, since the sensor side slip speed is zero or substantially zero, the noise component of the detected lateral displacement y is reduced accordingly, and as a result, the accuracy of the automatic steering control is improved.

As described above, in the automatic steering system according to the present embodiment, the lateral momentum of the vehicle such as the yaw moment can be adjusted by the lateral momentum adjusting device such as the traction adjusting device in addition to the steered wheels. Set the target lateral momentum such as the target yaw moment to make the sensor side slip speed zero based on the vehicle speed and lane curvature, and adjust the lateral momentum so that the actual lateral momentum matches the target lateral momentum. By controlling the device,
The noise component of the detected lateral displacement can be effectively and significantly reduced, and the control accuracy can be improved.

As described above, the present embodiment is an embodiment of an automatic steering apparatus for a vehicle according to claim 1 or 4 or 5 or 6 of the present invention, wherein the automatic steering mechanism includes a steering actuator of the present invention. Similarly, the lateral displacement detecting device and step S8 of the arithmetic processing of FIG. 7 constitute lateral displacement detecting means, and the steering angle sensor 3 and step S5 'of the arithmetic processing of FIG. 7, steps S9 to S13 of the arithmetic processing in FIG. 7 constitute steering control means, the traction adjustment mechanism constitutes a lateral momentum adjusting means, and step S10 'of the arithmetic processing in FIG. 7 constitutes a lateral momentum detecting means. The vehicle speed sensor 4 and the step S of the calculation processing of FIG.
1 constitutes a vehicle speed detecting means and a traveling state information detecting means,
Lane Curvature Detector 16 and Step S of Calculation Processing in FIG. 7
2 constitutes a lane curvature detecting means and a traveling state information detecting means.
4 'constitutes a lateral momentum control means, and corresponds to the traction adjustment mechanism, the vehicle speed sensor 4, the lane curvature detecting device 16, the steps S1, S2 and S4' of the arithmetic processing of FIG. 7, and a Kalman filter (state estimator). Steps S10 'and S14' constitute side skid speed reduction means.

The second embodiment has a mechanism for adjusting the yaw moment as the lateral momentum. Further, in the arithmetic processing shown in FIG. 7, it is possible to calculate a corrected yaw moment with respect to the lateral displacement deviation. The yaw moment was not controlled for the correction, and only the steady yaw moment for setting the sensor side slip speed to zero was set as the target yaw moment. Of course, even if the yaw moment was corrected to correct the lateral displacement, Good. However, in this case, while the steady yaw moment is set to a value for setting the sensor side slip speed to zero, this is corrected to further correct the lateral displacement. It should be noted that the convergence of the data may be reduced. In this case, it is necessary to correct the state quantity for the output error of the sensor side slip speed or to provide an optimum regulator for the sensor side slip speed.

It is of course possible to control the vehicle motion by combining the above two embodiments, but if there are two state quantities to be controlled, it is better to have two inputs to control. That is, it is easy to secure control accuracy by avoiding a so-called chain reaction.

Further, in the first and second embodiments, only the case where the lane curvature ρ is read as external information is described in detail. However, the lane curvature ρ is determined by the lateral displacement, the yaw rate, the yaw rate, and the yaw rate. Since it is well known that it is represented by equations of motion such as an angle and a vehicle speed, it is also possible to estimate using these.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a vehicle automatic steering apparatus according to a first embodiment of the present invention, in which FIG. 1A is a side view and FIG. 1B is a plan view.

FIG. 2A is a block diagram illustrating an example of a Kalman filter, and FIG. 2B is a block diagram illustrating an example of an arithmetic device that outputs a control amount from an estimated state amount.

FIG. 3 is a flowchart illustrating a calculation process executed by the automatic steering device for a vehicle in FIG. 1;

FIG. 4 is an explanatory diagram of a skid speed of a magnetic sensor.

FIG. 5 is an explanatory diagram of a skid speed achieved by the vehicle of FIG. 1;

FIGS. 6A and 6B are schematic diagrams showing a vehicle automatic steering apparatus according to a second embodiment of the present invention, in which FIG. 6A is a side view and FIG. 6B is a plan view.

FIG. 7 is a flowchart showing a calculation process executed by the automatic steering device for the vehicle in FIG. 6;

FIG. 8 is an explanatory diagram of a skid speed achieved by the vehicle of FIG. 6;

FIG. 9 is an explanatory diagram of a magnetic force vector from a magnet embedded in a lane.

FIG. 10 is an explanatory diagram for detecting a magnetic force of a magnet by a magnetic sensor attached to a vehicle.

FIG. 11 is an explanatory diagram of a magnet embedded in a lane.

FIG. 12 is an explanatory diagram of a vehicle lateral displacement obtained according to a detected magnetic force.

[Explanation of symbols]

1 is a magnetic sensor 2 is a lateral displacement detecting device (lateral displacement detecting means) 3 is a steering angle sensor (steering angle detecting means) 4 is a vehicle speed sensor (vehicle speed detecting means) 5 is a motor 6 is a clutch mechanism 7 is a drive gear 8 is a driven gear 9 is a steering shaft 10 is a pinion 11 is a rack 12 is front left and right wheels 13 is an automatic steering control unit (control means) 14 is a steering wheel 15 is rear right and left wheels 16 is a lane curvature detector (lane curvature detector) 17 is a motor 18 Is a gear 19 is a rack 20 is a steering rod 21 is an auxiliary steering angle sensor (auxiliary steering angle detecting means) 22 is a traction control actuator (traction adjusting means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G05D 1/02 G05D 1/02 W // B62D 101: 00 113: 00

Claims (10)

[Claims] 1. A magnetic sensor for detecting a magnetic source buried along a lane, a lateral displacement detecting means for detecting a lateral displacement of a vehicle from a detection signal of the magnetic sensor, and a steering actuator for steering a front wheel or a rear wheel. Steering angle detecting means for detecting a steering angle of a front wheel or a rear wheel steered by the steering actuator; and steering for controlling the steering actuator so that the detected lateral displacement of the vehicle becomes a target lateral displacement. An automatic steering apparatus for a vehicle, comprising: a control unit; and a skid speed reducing unit that reduces a sensor skid speed in a lateral direction of the vehicle with respect to a magnetic force source at a position of the magnetic sensor. 2. The vehicle according to claim 1, wherein the side slip speed reducing unit is configured to assist steering of at least a rear wheel or a front wheel different from a front wheel or a rear wheel steered by the steering actuator, and a traveling state detecting information on a traveling state of the vehicle. Information detecting means, and auxiliary steering control means for controlling the auxiliary steering actuator so as to reduce the sensor side skid speed according to the traveling state information detected by the traveling state information detecting means. The automatic steering device for a vehicle according to claim 1. 3. An auxiliary steering angle detecting means for detecting a steering angle of a rear wheel or a front wheel which is assisted by the auxiliary steering actuator, and a vehicle speed detecting means for detecting a vehicle speed as the traveling state information detecting means; Lane curvature detection means for detecting the curvature of the lane, wherein the auxiliary steering control means detects the sensor side slip speed based on the vehicle speed detected by the vehicle speed detection means and the lane curvature detected by the lane curvature detection means. The steering angle detected by the auxiliary steering angle detection means is set to a target steering angle of the rear wheel or the front wheel that is required to be reduced and that is auxiliary-steered by the auxiliary steering actuator. 3. The automatic steering apparatus for a vehicle according to claim 2, wherein the auxiliary steering actuator is controlled so as to match. 4. The automatic steering apparatus for a vehicle according to claim 3, wherein a target steering angle of the rear wheel or the front wheel to be assisted is set by a state estimator. 5. The automatic steering apparatus for a vehicle according to claim 4, wherein the state estimator includes a Kalman filter. 6. The vehicle according to claim 1, wherein the side slip speed reducing unit includes a lateral momentum adjusting unit configured to adjust at least a lateral momentum generated in the vehicle in a lateral direction, a traveling state information detecting unit detecting information on a traveling state of the vehicle, 6. A lateral momentum control means for controlling said lateral momentum adjusting means so as to reduce said sensor side skid speed according to the traveling state information detected by said traveling state information detecting means. An automatic steering device for a vehicle according to any one of the above. 7. A vehicle according to claim 1, further comprising a lateral momentum detecting means for detecting a lateral momentum of the vehicle adjusted by said lateral momentum adjusting means, and a vehicle speed detecting means for detecting a vehicle speed as said traveling state information detecting means; Lane curvature detection means for detecting, the lateral momentum control means, based on the vehicle speed detected by the vehicle speed detection means and the lane curvature detected by the lane curvature detection means, to reduce the sensor side skid speed A required lateral momentum of the vehicle adjusted by the lateral momentum adjusting means is set, and the lateral momentum adjustment is performed so that the target lateral momentum coincides with the lateral momentum detected by the lateral momentum detecting means. 7. The automatic steering apparatus for a vehicle according to claim 6, wherein the means is controlled. 8. The target lateral momentum of the vehicle to be adjusted is set by a state estimator.
An automatic steering device for a vehicle according to claim 1. 9. The automatic steering apparatus for a vehicle according to claim 8, wherein the state estimator includes a Kalman filter. 10. The traction adjusting device according to claim 6, wherein the lateral momentum adjusting device is a traction adjusting device that adjusts the traction of each wheel to adjust a yaw moment generated in the vehicle. Vehicle automatic steering system.