JPH06336163A - Control device for automatic steering device - Google Patents

Abstract

PURPOSE:To secure the maneuverability of manual steering after a failure and improve safety in a fail-safe control system cutting a motor power source when a steering control motor fails during automatic steering control. CONSTITUTION:The steering device 10 of a vehicle 1 is provided with a gear ratio changing mechanism 25 having a steering control motor 36 and a torque control motor 38 for automatic steering. When the steering control motor 36 fails, a motor power source is cut off to stop the motor operation, and the torque control motor 38 is controlled and corrected by an automatic steering control unit so that a handle and tires coincide in phase. A free sun gear 31 on the motor side of the gear ratio changing mechanism 25 is mechanically fixed by a gear lock means 60 via the thrusting action of a driver, and manual steering can be made after the failure of the steering control motor 36 while the handle and the tires are invariably kept in the same phase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic steering device which is used in a driving assistance system (ADA) of a vehicle such as an automobile and automatically electronically steers, and more particularly, when a steering control motor fails. Regarding fail-safe.

[0002]

2. Description of the Related Art In recent years, as a measure to drastically improve the safety of a vehicle, a technique for avoiding a collision against a collision damage reducing technique such as an airbag, that is, a driving operation system is actively assisted for safety. A comprehensive Active Drive Assist system (ADA) that automatically controls the side has been developed. This ADA system has cameras mounted in front of and behind the vehicle to recognize a road condition, another vehicle, and an external environment such as an obstacle three-dimensionally by a control unit.
The driver is provided with the same autonomous running capability as the driver, and the autonomous running capability is configured to automatically and properly operate various devices in the operation system such as the brake, throttle, and steering. Then, as functions aimed at by the ADA system, a collision prevention function and a limited automatic traveling function are considered. The collision prevention function is to automatically brake when there is a risk of a rear-end collision due to an error in driving operation or to correct the steering wheel in case of cross wind. The limited automatic traveling function is to perform automatic steering on behalf of the driver for lane following traveling, avoid obstacles automatically, and maintain a safe inter-vehicle distance.

The above ADA system will be described more specifically. For example, Japanese Patent Application No. 4-653 filed by the present applicant.
As shown in the application No. 47, the front scene and traffic environment are captured by a plurality of cameras mounted on the vehicle, the image is divided into small areas, and the distance is calculated by triangulation for each, and the entire screen is cubic. Obtain an image of the original distance distribution. Then, lanes, vehicles in front, obstacles, etc. are separated and detected from the distance image. Left and right white lines, road shapes, etc. are recognized from the lane. For a forward vehicle or an obstacle, what kind of object the object is, the relative distance to the obstacle, the speed, and the like are recognized to obtain various image data.

As a system for automatically steering using the above-mentioned image data, as shown in the application of Japanese Patent Laid-Open No. 3-238809, a planetary gear type system having a steering control motor and a torque control motor in a steering system of a steering device is used. A gear ratio variable mechanism is provided. Then, the steering angle along the white line of the lane is calculated from the image data, etc., and a steering signal corresponding to this steering angle is output to the steering control motor to operate the gear ratio variable mechanism, thereby automatically adjusting the tire side. It is considered to steer the vehicle and autonomously follow the lane. This system has been made more concrete by the development of the most important image recognition technology, and it is necessary to further develop the technology in various points in order to put it into practical use.

In the automatic steering mode, the front wheels are steered only by operating the steering control motor. For this reason, if the motor goes out of control or the harness breaks, the steering wheel may be steered in an unexpected direction. Therefore, it is necessary to ensure fail-safe when the steering control motor fails and to ensure proper maneuverability when traveling by manual steering after the failure.

Conventionally, as a fail-safe at the time of motor failure, it is considered that the control unit determines whether or not there is a motor failure, and when it fails, the motor power supply is cut off.

[0007]

By the way, in the above-mentioned prior art, since the motor power is simply turned off when the motor fails, the danger due to the malfunction of the motor in the automatic steering control can be eliminated. However, maneuverability in the case of manual steering after a failure cannot be ensured. That is, in the automatic steering control system, when the power of the steering control motor is turned off, the gear ratio variable mechanism is put in the idling state, and the manual steering by the steering wheel operation becomes impossible. Therefore, it is possible to connect the handle directly to the tire using mechanical means when the motor fails.
In this case, the steering wheel and the tire are out of phase with each other, so that the steering wheel cannot be steered properly.
Therefore, in the case of manual steering after a motor failure,
It is required to properly deal with the idling property of the gear ratio variable mechanism and the phase shift between the steering wheel and the tire.

In view of such a point, the present invention secures maneuverability of manual steering after a failure in a control system that is fail-safe so as to turn off the motor power of the steering control motor in the automatic steering control. The purpose is to improve safety.

[0009]

In order to achieve this object, the present invention provides a steering system for a vehicle, which is provided with a steering ratio control motor and a torque control motor, and is provided with a gear ratio variable mechanism for automatically steering. In the case of, the steering control motor is rotationally controlled by the image data in front of the vehicle, the vehicle speed, and the signal of the actual steering angle, and the torque control motor is torque-controlled so that the running vehicle follows the white line of the road without operating the steering wheel. In the automatic steering device that automatically steers, the control that determines whether or not the steering control motor has a failure, turns off the motor power when the motor fails, and rotates the torque control motor to control the phases of the steering wheel and the tire to match each other. A unit,
Gear locking means for mechanically fixing the motor-side gear of the gear ratio variable mechanism when the motor fails.

[0010]

In the present invention having the above-described structure, when the automatic steering mode is set while the vehicle is traveling, the instructed steering angle is changed based on the relationship between the white line on the road and the vehicle based on the image data in front of the vehicle, the vehicle speed, and the signal of the actual steering angle. The steering control motor of the variable gear ratio mechanism is calculated in accordance with the calculated steering angle, and at the same time, torque assist is performed by the torque control motor to cancel the steering torque. Therefore, the output shaft on the tire side rotates with the input shaft on the steering wheel side fixed, and the front wheels automatically steer even when the driver does not operate the steering wheel, and the vehicle can safely follow the lane along the white line.

When the steering control motor fails during the automatic steering, the control unit turns off the motor power to immediately stop the operation of the steering control motor, and fail-safe so as not to steer in an unexpected direction. When the motor fails, the control unit controls the rotation of the torque control motor, so that the handle rotates while the tire is fixed, and the phases of the handle and the tire are automatically controlled to match each other. Then, the driver operates the gear locking means to mechanically fix the motor-side gear, whereby the gear ratio variable mechanism can be operated by operating the handle. Therefore, when the driver operates the steering wheel after the motor fails, the tire is always steered in the same phase with respect to the steering wheel and manually steered, and the steering wheel can be safely steered to travel.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. An outline of the ADA system will be described with reference to FIG. First, the throttle valve 3 of the engine 2 of the vehicle 1 is provided with an actuator 11 that opens and closes by an electric signal,
An automatic brake hydraulic unit 12 that increases or decreases the brake pressure by an electric signal is provided in a brake device 8 that applies brake pressure to the wheel cylinders 7 of the front wheels 5 and the rear wheels 6 by operating the brake pedal 4 to perform braking. A CCD camera 13 for picking up a predetermined range in front of the vehicle 1 is arranged on the left and right sides of the vehicle 1, and an automatic steering power unit 1 for steering an electric signal to a steering device 10 having a steering wheel 9 is provided.
4 are provided.

As a control system, an image recognition control unit 15 to which an image pickup signal of the CCD camera 13 is input is provided, distances are calculated by a triangulation method based on the image pickup signals, and an image having a three-dimensional distance distribution is displayed on the entire screen. obtain. Then, lanes, vehicles in front, obstacles, etc. are separately detected from the distance image, and left and right white lines, road shapes, etc. are recognized from the lanes. For a forward vehicle or an obstacle, what kind of object the object is, the relative distance to the obstacle, the speed, and the like are recognized to obtain various image data. This image data is input to the inter-vehicle distance control unit 16 and the automatic steering control unit 17.

The inter-vehicle distance control unit 16 calculates the acceleration / deceleration so as to maintain a safe distance with respect to the preceding vehicle and obstacles on the road based on the image data and various other sensor signals, and an appropriate acceleration / deceleration based on this acceleration / deceleration is calculated. A throttle signal indicating the throttle opening is output to the actuator 11 for throttle control. Further, a brake signal having an appropriate brake pressure based on the acceleration / deceleration is output to the automatic brake hydraulic unit 12 for brake control. Even if the driver's brake operation is insufficient, a safe inter-vehicle distance can be maintained, a collision can be prevented, and the vehicle can travel safely. The automatic steering control unit 17 calculates the deviation between the white line on the road and the vehicle based on the image data and various other sensor signals, and outputs a steering signal based on this deviation to the automatic steering power unit 14 to perform steering control. Even if the driver does not operate the steering wheel, it is possible to safely follow the lane.

In FIG. 2, the automatic steering power unit 14 is shown.
The configuration of will be described. First, the steering shaft 20 is divided into an input shaft 21 and an output shaft 22.
A handle 9 is provided at one end of the shaft 1, the output shaft 22 is connected to the front wheels 5 via a hydraulic power steering 23, and a gear ratio variable mechanism 25 is connected between the shafts 21 and 22 by bypass. The gear ratio variable mechanism 25 includes the input and output shafts 21 and 2.
Two sets of gears 26, 27 and one set of planetary gears 30 are combined with two and a motor shaft 24 arranged in parallel therewith.

That is, in the first gear 26, a small-diameter drive gear 26a is integrally coupled to the input shaft 21, and a large-diameter driven gear 26b is rotatably provided on the motor shaft 24. In the second gear 27, the large-diameter drive gear 27a is the motor shaft 2
4, the driven gear 27b having a small diameter is integrally coupled to the output shaft 22. In the planetary gear 30, the sun gear 31 is integrally coupled to the motor shaft 24, the ring gear 32 is formed inside the drive gear 27 a of the second gear 27, and the pinion 33 that meshes with the sun gear 31 and the ring gear 32 is the driven gear of the first gear 26. It is supported by a carrier 34 integral with 26b. A steering control motor 36 is connected to one end of the motor shaft 24 via a reversibly rotatable worm gear 35, and a torque control motor 38 is also connected to the input shaft 21 via a similar worm gear 37.
Further, a large steering torque is input between the input shaft 21 and the output shaft 22 due to the collision of the tire with a curb, etc.
Stopper 39 that is directly connected when is rotated more than a predetermined angle
Is provided.

When the driver steers the handle 9 with the sun gear 31 of the motor shaft 24 fixed, the input shaft 21 and the first gear 26 rotate the carrier 34 of the planetary gear 30 to rotate the pinion 33 as a planet. The ring gear 32 and the second gear 27 rotate the output shaft 22 in the same direction as the steering wheel 9 to steer the output shaft 22. In this case, the rotations of the input and output shafts 22 are made substantially the same by selecting the number of gear teeth. Further, in a state where the torque control motor 38 fixes the input shaft 21 to perform torque assist so as to cancel the steering reaction force, the steering control motor 36 causes the sun gear 3 to rotate.
When 1 is rotated, the ring gear 32 is rotated by the rotation of the pinion 33.
And the output shaft 22 is rotated in the same direction via the second gear 27 and electrically steered.

As a control system, the input shaft 21 has a steering angle Qh.
Is provided with a steering angle sensor 40 for detecting the steering torque Th, and a steering angle sensor 42 for detecting the actual steering angle Qp is provided on the output shaft 22. Further, the motor shaft 24 of the gear ratio variable mechanism 25 is provided with a phase angle sensor 43 for detecting the phase angle Qs. Then, the image data of the image recognition control unit 15, the vehicle speed V of the vehicle speed sensor 44, and the signals of the sensors 40 to 43 are input to the automatic steering control unit 17 and electrically processed, and the steering signal is transmitted in the automatic steering mode. Output to the steering control motor 36,
It is configured to output a torque signal to the torque control motor 38.

The gear ratio variable mechanism 25 will be described in detail with reference to FIG. First, a column case 29 is provided in the middle of a column tube 28 that covers the input and output shafts 21 and 22, and the motor shaft 24 of the gear ratio variable mechanism 25 and the first and second gears 26 and 27 are provided inside the column case 29. , Planetary gears 30 and the like are housed. The input shaft 21 is divided into a handle shaft 21a having the handle 9 and a gear shaft 21b to which the gear 26a and the worm gear 37 of the torque control motor 38 are attached. Further, both shafts 21a and 21b are connected by a torsion rod 21c so as to have a predetermined handle play, and a steering torque sensor 41 is arranged between the handle shaft 21a and the gear shaft 21b. Therefore, as a fail-safe means at the time of motor failure, gear lock means 60 for mechanically fixing the sun gear 31 is projectingly provided at a position on the driver side of the column case 29.

In the gear lock means 60, a stepped cylinder body 61 is integrally projectingly provided on the extension line of the motor shaft 24 having the sun gear 31 so as to be integrally coupled with the column case 29, and the operation button 62 is fixed to the cylinder body 61 so as not to rotate. It is mounted so that it can be moved back and forth.
A fixed rod 63 having a cross-shaped tapered convex portion 63a is attached to the operation button 62, and a concave portion 24a having the same shape as the convex portion 63a is formed at the end of the motor shaft 24. Further, the operation button 62 is provided with a spring 64 and a claw 65, and the cylindrical body 61 is provided with a protrusion 66.
Is moved to a retracted position and a forward position where the convex portion 63a and the concave portion 24a and the claw 65 and the protrusion 66 are engaged by a driver's pushing operation.

In FIG. 5, the automatic steering control unit 17
Will be described. First, it has a distance calculation unit 50 to which the image data from the image recognition control unit 15 is input.
As described above, the predetermined distance position D on the image is set. The target trajectory setting unit 51 sets the target trajectory L1 by the white line at the predetermined distance position D based on the image data. Further, the vehicle has a predicted trajectory calculating unit 52 for inputting the vehicle speed V and the turning angle ωp, and calculates a predicted trajectory L2 of the vehicle 1 when traveling at a predetermined distance position D with the current position, direction, and traveling state of the vehicle. To do. Furthermore,
It has a mode setting unit 53 for setting, for example, an automatic steering mode in which the power of the control system is turned on and a manual steering mode in which the power is turned off by turning the selection switch 45 on and off.

The above-described target trajectory L1, predicted trajectory L2 and mode signal are input to the deviation width calculator 54 to calculate the deviation width e between the target trajectory L1 and the predicted trajectory L2 in the automatic steering mode. The deviation width e is input to the steering angle calculation unit 55, and the indicated steering angle φ is calculated from the deviation width e and the proportional constant k. The instructed steering angle φ and the actual steering angle Qp are input to the control amount calculation unit 56,
The control amount C is calculated from the difference between the two, and the drive unit 57 supplies the steering control motor 36 with a current Ip corresponding to the control amount C. In the manual steering mode, the steering control motor 36 is supplied with a predetermined current Ip necessary for fixing the sun gear. The steering torque Th of the steering torque sensor 41 is input to the assist torque calculation unit 58, the steering torque Th corresponding to the steering reaction force acting on the steering wheel 9 side in the automatic steering mode is detected, and the steering reaction force is offset. Such assist torque Ta
Is calculated. Then, the drive unit 59 is configured to supply the current Is according to the torque Ta to the torque control motor 38.

In the above control system, a measure for fail-safe at the time of motor failure will be described. First, in the circuit of the battery 75 of the steering control motor 36, a normally closed switch 76,
A current sensor 77 for detecting the actual motor current Ip is provided. The automatic steering control unit 17 has a failure determination unit 70 to which the control amount C for motor control and the motor current Ip are input, and whether or not there is a failure in the steering control motor 36 due to motor runaway or harness breakage depending on the relationship between the two. If the motor fails, the switch 76 is turned off and an alarm 78 is displayed. Also two sensors 40, 4
2 has a phase shift calculator 71 for inputting the actual steering angle Qp and the steering angle Qh, and calculates the shift amount (Qp-Qh) and the shift direction of the phase between the steering wheel and the tire when the motor fails. The signals of the phase shift amount and the shift direction are input to the rotation control unit 72, and the rotation amount and the rotation direction corresponding to the phase shift amount and the shift direction are set under the safe condition that the vehicle speed V is equal to or less than the set value a, The drive unit 59 is configured to control the rotation of the torque control motor 38.

Next, the operation of this embodiment will be described. First, when the driver turns off the selection switch 45 while the vehicle is traveling, the automatic steering control unit 17 enters the manual steering mode, a predetermined current flows through the steering control motor 36, and the motor shaft 24 of the gear ratio variable mechanism 25 of the automatic steering power unit 14 is turned on. And the sun gear 31 is fixed. Further, the torque control motor 38 does not operate and the input shaft 21 of the handle 9 becomes free. Then, when the driver grips the steering wheel 9 to steer as shown in FIG. 8A, the output shaft 22 moves in the same direction by the operation of the planetary gear 30 with respect to the input shaft 21, the first and second gears 26 and 27, and the fixed sun gear 31. The front wheels 5 are freely steered left and right by the operation of the hydraulic power steering mechanism 23.

When the selection switch 45 is turned on, the automatic steering mode is selected. Therefore, in the automatic steering control unit 17, the target trajectory L1 such as the white line at the predetermined distance position D is set by the image data from the image recognition control unit 15, and the predetermined distance position D of the vehicle 1 is set by the vehicle speed V and the actual steering angle Qp.
The predicted trajectory L2 at is calculated. Then, the instructed steering angle φ is calculated according to the deviation width e between the target trajectory L1 and the predicted trajectory L2, and the control amount C based on the instructed steering angle φ and the actual steering angle Qp is calculated.

Here, when the steering control motor 36 is normal, the steering control motor 36 is connected to the battery 75 when the switch 76 is turned on, and the rotation can be controlled. Further, the gear lock means 60 is in the retracted position, and the sun gear 31 of the gear ratio variable mechanism 25 can rotate the motor. Therefore, the drive unit 57 causes the electric current Ip corresponding to the control amount C to flow to the steering control motor 36 for rotation control, and therefore the worm gear 35, the motor shaft 24, and the sun gear 31 rotate in the gear ratio variable mechanism 25. At this time, since a large load is applied to the ring gear 32 on the tire side, the carrier 34 and the like reversely rotate, and the steering reaction force in this case acts on the steering wheel 9 side.

Then, the steering torque sensor 41 detects the steering reaction force in this case, the assist torque Ta for canceling the steering reaction force is calculated, and the current Ih corresponding to the torque Ta flows into the torque control motor 38. Then, the torque control motor 38 and the worm gear 37 are operated, and torque assist is performed to fix the input shaft 21, the first gear 26, the carrier 34, and the like. Therefore, the steering control motor 3
When the sun gear 31 is rotated by 6, the ring gear 32, the second gear 27, and the output shaft 22 rotate against the load on the tire side, and the front wheel 5 is released in a state where the steering wheel is released as shown in FIG. 8B.
Is automatically steered according to the steering signal. In this way, even if the driver does not operate the steering wheel 9, the front wheels 5 of the vehicle 1 are steered so as to follow the white line of the road, and the vehicle 1 safely follows the lane.

Control when the motor fails in the above-mentioned automatic steering control mode will be described with reference to the flowchart of FIG. First, when the automatic steering mode is determined in step S1, the process proceeds to step S2, the steering control motor 36 is rotationally controlled, and in step S3, the torque control motor 38 is torque-controlled to operate. After that, the process proceeds to step S4 and the motor current Ip of the steering control motor 36 causes the motor 3 to move.
It is judged whether or not there is a failure in No. 6, and if it is normal, the process returns to step S1. On the other hand, when it is determined that the steering control motor 36 has failed due to the abnormality in the motor current Ip, the motor power is turned off in step S5, the steering control motor 36 immediately stops operating, and it is prevented that the steering control motor 36 steers in an unexpected direction. .

By the way, when the motor fails, the sun gear 31 of the motor shaft 24 becomes free by disconnecting the motor power source,
For this reason, even if the driver operates the steering wheel in the manual steering after the motor failure, the variable gear ratio mechanism 25 is in the idling state, and the steering cannot be performed on the tire side. Therefore, in order to ensure the maneuverability in this case, the actual steering angle Qp on the tire side is compared with the steering angle Qh on the steering wheel side in step S6. If the phases of both are deviated, the process proceeds to step S7 to determine the traveling state. To do. Therefore, when the vehicle speed V is safely stopped at the set value a or less, the torque control motor 38 is rotationally controlled in step S8 according to the phase shift amount and the shift direction.

Therefore, the variable gear ratio mechanism 25 operates as shown in FIG. That is, when the front wheels 5 are steered to the right as shown in the drawing, the input shaft 2 is driven by the torque control motor 38.
1, the gear 26a, and the handle 9 are rotated in the same right direction. Then, the carrier 34 of the planetary gear 30 rotates counterclockwise by the gear 26b. In this case, the load on the tire side is sufficiently larger than the load on the steering wheel side. Therefore, when the front wheel 5 and the ring gear 32 are fixed, the pinion 33 and the sun gear are fixed. The carrier 34 easily rotates counterclockwise while idly rotating 31.
In this way, the steering wheel 9 is rotated clockwise by the rotation of the torque control motor 38, and the phase shift between the steering wheel 9 and the front wheels 5 is automatically corrected.

When the actual steering angle Qp and the steering angle Qh match, the process proceeds from step S6 to step S9 and the driver operates the gear lock means 60. That is, the operation button 62 at the retracted position of the gear locking means 60 is strongly pushed against the spring 64 by the driver's finger as shown in FIG.
Then, the fixed rod 63 moves forward, the convex portion 63a at the tip engages with the concave portion 24a of the motor shaft 24 while being aligned,
At this time, the claw 65 of the operation button 62 is also the projection 66 of the cylindrical body 61.
And the free sun gear 31 engages with the column case 29.
Mechanically fixed to the side. Then, the gear ratio variable mechanism 25 becomes operable by operating the handle.

Therefore, after operating the gear lock means 60, the process proceeds from step S9 to step S10, and the driver operates the steering wheel to manually steer the gear ratio variable mechanism 25.
Causes the output shaft 22 to rotate in a 1: 1 relationship. In this case, since the phases of the steering wheel 9 and the front wheels 5 are already controlled to match each other, the front wheels 5 are always steered in the same phase according to the steering angle Qp of the steering wheel 9 and it is possible to travel safely.

Although the embodiment of the present invention has been described above, the invention can be applied to the case where the structure of the gear ratio variable mechanism is different.

[0034]

As described above, according to the present invention,
In the automatic steering system, when fail-safe to cut off the motor power source when the steering control motor fails, control is performed so that the steering wheel and tire phases match, and the gear on the motor side is mechanically fixed by the gear lock means. With this configuration, the steering wheel and the tire can be steered in the same phase during manual steering after a motor failure, and steering can be performed safely and accurately. The phase of the steering wheel and the tire can be corrected reliably and easily by controlling the rotation of the torque control motor. The gear lock means has a structure in which the sun gear is mechanically fixed to the column case side by the pushing operation of the driver, so that the operability is good and the sun gear can be firmly fixed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of an embodiment of a control device for an automatic steering device according to the present invention.

FIG. 2 is a configuration diagram showing an automatic steering power unit.

FIG. 3 is a sectional view specifically showing a portion of a gear ratio variable mechanism.

FIG. 4 is a cross-sectional view showing a locked state of the gear lock means.

FIG. 5 is a block diagram showing an automatic steering control system.

FIG. 6 is a conceptual diagram of automatic steering control.

FIG. 7 is a flowchart showing control when a motor fails in the automatic steering mode.

FIG. 8 is a diagram showing states of manual steering and automatic steering.

FIG. 9 is a diagram showing a state of a phase correction operation of the gear ratio variable mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 vehicle 9 steering wheel 10 steering device 14 automatic steering power unit 15 image recognition control unit 17 automatic steering control unit 21 input shaft 22 output shaft 25 gear ratio variable mechanism 36 steering control motor 38 torque control motor 60 gear lock means 70 failure determination unit 71 phase shift Calculation unit 72 Rotation control unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B62D 137: 00

Claims (2)

[Claims] 1. A steering device for a vehicle is provided with a gear ratio variable mechanism that is equipped with a steering control motor and a torque control motor to automatically steer, and image data, vehicle speed, and actual steering angle in front of the vehicle in the automatic steering mode. The steering control motor is rotationally controlled by the signal of, and the torque control motor is torque controlled,
In an automatic steering device that automatically steers a running vehicle along a white line on the road without operating the steering wheel, it determines whether the steering control motor has a failure, and when the motor fails, the motor power is turned off and the torque control motor is turned on. An automatic steering apparatus comprising: a control unit that rotates to control the steering wheel and the tire so that the phases thereof match each other; and a gear lock unit that mechanically fixes the motor-side gear of the gear ratio variable mechanism when the motor fails. Control device. 2. The automatic steering apparatus according to claim 1, wherein the gear locking means is configured to fix the sun gear connected to the steering control motor of the planetary gear to the column case side by a pushing operation of a driver. Control device.