JPH10100919A - Steering system with automatic steering mechanism - Google Patents

Abstract

(57) [Problem] To provide a steering device with an automatic steering mechanism that can quickly and reliably prioritize manual steering when automatic steering and manual steering interfere with each other. SOLUTION: A planetary gear device 5 is interposed in the middle of a steering shaft 4 connecting a steering wheel 2 and a steering gear 3, the steering shaft 4 is fixedly fixed to a sun gear 6, and a carrier 7 supporting a planet gear 8 is torqued. The ring gear 9 is supported on the vehicle body side by the engaging element 10 and can be rotated when the rotational force applied to the ring gear 9 exceeds a predetermined set force. Torque motor 15
When the automatic steering for rotating the steering shaft 4 by rotating the carrier 7 and the manual steering for rotating the steering shaft 4 by the steering wheel 2 interfere with each other, the engaging element 10 slides, and the manual steering is prioritized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a steering device with an automatic steering mechanism.

[0002]

2. Description of the Related Art As a vehicle steering mechanism, there is a steering apparatus with an automatic steering mechanism which can switch between steering by a driver (manual steering) and steering by an automatic steering mechanism (automatic steering). The automatic steering mechanism is provided with various sensors in the vehicle, sets each steering signal based on information from these sensors, drives a hydraulic motor, an electric motor, and the like to automatically control the steering mechanism. ing. Such a steering system is disclosed in, for example, JP-A-7-47969 and JP-A-6-336167.

[0003]

SUMMARY OF THE INVENTION In a steering device with an automatic steering mechanism, a driving substitute (automatic driving by a driver's intention) is performed.
In such a case, when the machine steering by the automatic steering and the manual steering by the driver interfere with each other, it is indispensable that the manual steering by the driver is promptly and reliably prioritized.

In a conventional steering apparatus with an automatic steering mechanism, after detecting interference between manual steering by a driver and machine steering by automatic steering by detecting means for detecting interference between manual steering and automatic steering, the automatic steering force is reduced. For example, the automatic steering force is weakened by operating a hydraulic relief valve to be set, or the automatic steering system is stopped to give priority to manual steering by the driver.

However, in such a method, the switching control from the automatic steering to the manual steering is performed by an electric signal. Therefore, if an electric trouble occurs in the control system for some reason, the manual steering by the driver is not performed. There is a possibility that priority will not be given. In addition, the structure of the steering control device is complicated, and a sensor such as a torque sensor for detecting the interference between the automatic steering and the manual steering is required when the interference occurs. .

[0006] The present invention has been made in view of the above point, and when automatic steering and manual steering interfere with each other,
It is another object of the present invention to provide a steering device with an automatic steering mechanism capable of reliably giving priority to manual steering.

[0007]

According to the present invention, there is provided a steering apparatus with an automatic steering mechanism for giving priority to manual steering when automatic steering and manual steering interfere with each other. A planetary gear device in which a steering shaft for connecting a steering wheel and a steering gear is fixedly penetrated to a sun gear, a ring gear of the planetary gear device is supported on a vehicle body side, and a rotational force applied to the ring gear is a predetermined value. The configuration includes an engagement element that allows the rotation of the ring gear when the set force is exceeded, and a motor that rotationally drives the carrier of the planetary gear device.

In the planetary gear device, when the sun gear rotates with the ring gear fixed, the carrier rotates in the same direction as the sun gear via the planet gear, and when the carrier rotates, the sun gear matches the carrier via the planet gear. Rotate in the direction. The ring gear is mechanically fixed to the vehicle body side by an engagement element. When the steering wheel is manually operated in this state, the sun gear rotates together with the steering shaft. The carrier rotates with the sun gear, and the motor rotates accordingly.

At the time of automatic traveling, the carrier is rotated by the motor, whereby the sun gear is rotated and the steering shaft is rotated. Thus, automatic steering is performed.
When the driver operates the steering during automatic steering, automatic steering and manual steering interfere. When the sun gear rotates by manual operation, a rotational force (torque) is applied to the ring gear. When the rotational force exceeds the set force of the engaging element, the engaging element starts to slide, and the ring gear starts rotating. When the ring gear rotates, the carrier idles, and the rotational force of the motor is not transmitted to the sun gear. As a result, priority is given to rotation of the sun gear, that is, manual steering. Thereby, when the automatic steering and the manual steering interfere with each other, the manual steering is quickly and reliably prioritized.

[0010] In the second aspect, the engagement element fixes the ring gear when a rotational force applied to the ring gear is smaller than the predetermined set force, and when the rotational force exceeds the predetermined set force. This is a friction clutch that allows the ring gear to rotate when it starts to slide. The friction clutch fixes the ring gear to the vehicle body when no rotational force is applied to the ring gear. At the time of automatic steering, the steering wheel is manually operated to apply a rotational force to the ring gear via the sun gear. When this rotational force exceeds a predetermined set force, it starts to slide and allows rotation of the ring gear. The ring gear is mechanically supported on the vehicle body side by a friction clutch, and is rotatable when the applied rotational force exceeds a predetermined set force, thereby establishing a mechanical fail-safe.

According to a third aspect of the present invention, there is further provided an engagement element interposed between the carrier and the motor for connecting or disconnecting the two. During manual steering, the carrier rotates with the rotation of the sun gear, and the motor rotates with the rotation. When the motor rotates, the feeling during steering deteriorates. At this time, the engagement element is released to release the connection between the carrier and the motor. This prevents rotation of the motor during manual steering,
Feeling becomes good.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below by way of examples. FIG. 1 shows a skeleton diagram of a steering device with an automatic steering mechanism to which the present invention is applied. The steering device 1 is provided with a planetary gear device 5 in the middle of a steering shaft 4 that connects a steering wheel 2 and a steering gear (not shown) housed in a steering gear box 3. The planetary gear set 5 includes a centrally arranged sun gear 6.
And a carrier 7 arranged coaxially with the sun gear 6 and rotatably relative thereto, and arranged at a predetermined interval in the circumferential direction around the sun gear 6 and rotatably supported by the carrier 7 to mesh with the sun gear 6. A plurality of planet gears 8 revolve around the sun gear 6, and a ring gear 9 disposed concentrically with the sun gear 6 outside of the planet gears 8 and meshing with each planet gear 8.

The steering shaft 4 penetrates through the sun gear 6 and the carrier 7 and is integrally fixed to the sun gear 6 and has the carrier 7 loosely fitted therein. That is, the steering shaft 4 rotates integrally with the sun gear 6 and is relatively rotatable with the carrier 7. One end surface of the ring gear 9 is supported by a disk-shaped bracket 11 via an annular clutch (engaging element) 10, and the bracket 11 is fixed to the vehicle body. The steering shaft 4 is
A hole formed in the center of the bracket 11 is loosely fitted. Since the planetary gear set 5 is arranged coaxially with the steering shaft 4, the space property is extremely good.

When the rotational force (torque) applied to the ring gear 9 is smaller than a predetermined rotational force (set force), the clutch 10 fixes the ring gear 9 to the bracket 11 to prevent the rotation thereof, and When it exceeds, the bracket 9 slides out and the rotation of the bracket 9 is allowed. That is, the clutch 10 fixes the ring gear 9 by a mechanical pressing force (set force), and when the rotational force applied to the ring gear 9 exceeds the pressing force, the clutch 10 slides out and enables its rotation.
By mechanically and uniquely setting the pressing force for restraining the ring gear 9 (that is, the pressing force is not controlled electrically or hydraulically), a fail-safe as a mechanism is established, and trouble is solved. Prevent occurrence. The clutch 10 is constituted by a friction clutch, for example, a multi-plate friction clutch.

The clutch 10 does not need to be annular, and a plurality of clutches 10 may be arranged at appropriate intervals in the circumferential direction between the ring gear 9 and the bracket 11. In this case, the plurality of clutches uniformly support the ring gear 9,
Moreover, it is preferable to arrange them at equal intervals in order to smooth the rotation. Also, the outer peripheral surface of the ring gear 9 and the bracket 11
And may be arranged between them. However, the space property is improved by disposing it between the end face of the ring gear 9 and the bracket 11 as in the embodiment.

The torque motor 15 has a built-in clutch (engagement element) 16 and a pinion 17 is fixed to a rotating shaft. The torque motor 15 is arranged near the ring gear 9 and fixed to the vehicle body via a bracket (not shown). On the other hand, a gear 18 is provided on one end surface of the carrier 9 over the entire circumference, and meshes with a pinion 17 of the torque motor 15. The gear 18 is formed of, for example, a ring-shaped rack. Torque motor 15
Is a low torque, high rotation type electric motor. The clutch 16 is, for example, an electromagnetic clutch, which is turned off (disengaged) when not energized, and turned on (connected) when energized. Note that the clutch 16 may be another clutch, for example, a hydraulic clutch.

FIG. 2 shows an automatic / manual steering control system. The automatic / manual steering control system includes an operation switching control unit (hereinafter, referred to as “ECU”) 20, an environment recognition system 21, an automatic operation switch 22, a steering angle sensor 23.
From the torque motor 15, the clutch 16
Control. The environment recognition system 21 sets a target course by recognizing a white line drawn on the road surface from image information in front of the vehicle captured by a camera mounted on the vehicle, and outputs an information signal of the target course. Automatic operation switch 22
Is a changeover switch that is turned on by the driver when performing automatic driving. The steering angle sensor 23 detects an actual steering angle and outputs a corresponding steering angle signal. ECU2
When the automatic operation switch 22 is turned on, the automatic operation switch 22 switches from manual operation to automatic operation, turns on (connects) the clutch 16, and sets the target steering according to the target course information input from the environment recognition system 21. Set the corner,
While controlling the torque motor 15 to perform steering angle control, the steering angle signal from the steering angle sensor 23 is fed back, steering control is performed along the target course, and the vehicle is automatically driven.

The operation will be described below. In FIG. 1, when the sun gear 6 rotates, the carrier 7 rotates in the same direction as the sun gear 6 because the ring gear 9 is stopped by being fixed by the clutch 10,
When the carrier 7 rotates, the sun gear 6 rotates in the same direction as the carrier 7. During manual operation, the automatic operation switch 22 is off, and the ECU 20 turns off the clutch 16 and stops the torque motor 15. Therefore, the carrier 7 is separated from the torque motor 15 and can idle.

When the driver operates the steering wheel 2, the steering shaft 4 rotates and is steered via the steering gear in the steering gear box 3. The sun gear 6 rotates in the same manner as the steering shaft 4. At this time, the planet gear 8 is rotated by the sun gear 6 and idles because the carrier 7 is in a state where it can idle. Therefore, the steering device 1 becomes a normal steering system. Moreover, there is no load on the torque motor 15 and no backlash of the gear system.

The clutch 16 is not always necessary, and the carrier 7 and the torque motor 15 may be directly connected by the pinion 17 and the gear 18. However, when the clutch 16 is not provided, the carrier 7 rotates with the operation of the steering wheel 2, and the torque motor 15 rotates with the rotation of the carrier 7, resulting in poor feeling. Accordingly, the clutch 16 that completely disconnects the carrier 7 and the torque motor 15 during manual steering is provided.
Is preferably provided. In this case, compactness can be achieved by using an integrated torque motor (clutch with torque motor) as in the embodiment.

When the automatic operation switch 22 is turned on, E
The CU 20 turns on (connects) the clutch 16 and
The drive of the torque motor 15 is controlled. When the clutch 16 is turned on, the torque of the torque motor 15
The power is transmitted to the carrier 7 of the planetary gear device 5 via the pinion 17 and the gear 18. The carrier 7 has a torque motor 15
To rotate the sun gear 6 via the planet gear 8. Then, the sun gear 6 is rotated at an increased speed in the same direction as the carrier 7. The steering shaft 4 rotates integrally with the sun gear 6 and controls a steering angle via a steering gear in the steering gear box 3.
Thereby, the vehicle is automatically driven along the target course. As described above, the responsiveness of the automatic steering is improved by using a low-torque high-rotation type motor as described above.

When the driver operates the steering wheel 2 to rotate the steering shaft 4 to control the steering angle during the automatic driving, torque is applied to the ring gear 9 fixed by the clutch 10 and the torque is applied. Exceeds the pressing force of the clutch 10, the clutch 1
0 starts to slide, and the ring gear 9 rotates. When the ring gear 9 rotates, the carrier 7 idles from this time, and the rotation of the sun gear 6 has priority. That is, when the manual steering by the hand truck interferes with the automatic steering, the clutch 10 slips, the automatic steering idles, and the manual steering has priority.

The operability at the time of manual priority is determined by the pressing force (set force) of the clutch 10 supporting the ring gear 9. Therefore, by using the clutch 10 capable of adjusting the pressing force of the clutch 10, a steering system capable of adjusting the degree of override of the driver can be established. Next, the control procedure will be described with reference to the flowchart of FIG.

In FIG. 3, the ECU 20 determines whether the automatic operation switch 22 is on (step S).
1) If it is not on, it is determined that the operation is manual operation and the control routine is terminated. If it is on, it is determined that it is automatic operation, the clutch 16 is turned on (connected) (step S2), and the torque motor 15 The carrier 7 of the planetary gear set 5 is connected. Thereby, rotation of the steering shaft 4 by the torque motor 15, that is, automatic steering becomes possible. Next, the ECU 20 controls the driving of the torque motor 15 based on the information from the environment recognition system 21 and the signal from the steering angle sensor 22 to control the steering angle (step S4). In this way, the automatic steering control is performed, and the vehicle automatically travels along the target course.

[0025]

As described above, according to the first aspect of the present invention, the planetary gear device is used as the steering mechanism, the steering shaft is fixedly fixed to the sun gear, the ring gear is fixed to the vehicle body with the engagement element, and the carrier is fixed. By driving with a torque motor, at the time of manual steering, it becomes exactly the same as a normal steering system, and when automatic steering and manual steering interfere with each other, priority is given to manual steering quickly and reliably. In addition, by using the planetary gear device as the steering mechanism, the structure is made robust and simple, and the cost is reduced. Further, by arranging the planetary gear device on the steering shaft, the space property is improved. Furthermore,
A torque sensor for detecting interference when automatic steering and manual steering interfere with each other by using an engagement element that permits rotation of the ring gear when a rotational force exceeding a predetermined set force is applied to the ring gear. Such a sensor becomes unnecessary, and the cost can be reduced.

According to the second aspect of the invention, by using the friction clutch as the engagement element, a mechanical fail-safe is established, and runaway of the automatic steering device is prevented. Further, the configuration is simple, and the cost can be reduced. According to the third aspect of the present invention, the carrier of the planetary gear device and the drive motor are further connected via an engagement element, and the manual engagement is released during manual steering to separate the carrier from the motor. Is prevented, and the feeling is improved.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of a steering device with an automatic steering mechanism according to the present invention.

FIG. 2 is a block diagram of an automatic / manual control system of the steering device with an automatic steering mechanism shown in FIG. 1;

FIG. 3 is a flowchart showing the operation of the steering apparatus with an automatic steering mechanism shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steering device with an automatic steering mechanism 2 Steering wheel 3 Steering gear box 4 Steering shaft 5 Planetary gear device 6 Sun gear 7 Carrier 8 Planet gear 9 Ring gear 10, 16 Clutch (engagement element) 11 Bracket 15 Torque motor 17 Pinion 18 Gear 20 Operation Switching control unit (ECU) 21 Environment recognition system 22 Automatic operation switch 23 Steering angle sensor

Continued on the front page (72) Inventor Tadashi Sugawara 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Norio Inoue 5-33-8 Shiba 5-chome, Minato-ku, Tokyo Mitsubishi Motors Industrial Inside the company (72) Inventor Yoshihide Nakane 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation

Claims (3)

[Claims] 1. A steering device with an automatic steering mechanism for giving priority to manual steering when automatic steering and manual steering interfere with each other, wherein a steering shaft connecting a steering wheel and a steering gear is fixedly penetrated by a sun gear. A gear device, an engagement element that supports the ring gear of the planetary gear device on the vehicle body side and allows rotation of the ring gear when a rotational force applied to the ring gear exceeds a predetermined set force; and the planetary gear. A steering device with an automatic steering mechanism, comprising: a motor that rotationally drives a carrier of the device. 2. The engaging element fixes the ring gear when a rotational force applied to the ring gear is smaller than the predetermined set force, and starts sliding when the rotational force exceeds the predetermined set force. The steering device with an automatic steering mechanism according to claim 1, wherein the steering device is a friction clutch that allows rotation of a ring gear. 3. The steering device with an automatic steering mechanism according to claim 1, further comprising an engagement element interposed between the carrier and the motor for connecting or disconnecting the two. Steering device with automatic steering mechanism.