JP2008308120A - Vehicle steering gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle steering gear whose safety is improved by placing a limit on the rotation speed of a steering member when a part of a passenger's body is near the steering member. <P>SOLUTION: The vehicle steering gear includes a steering mechanism 1 for performing a steering operation according to the rotating operation of a steering wheel 30, an electric motor 6 for applying a steering force to the steering mechanism 1, and a steering control section 7 for controlling the drive of the motor 6. When an obstacle is detected in the rotation area of a steering wheel 30, the mechanism 1 places a limit on the steering angular velocity of the steering wheel 30 linked to the mechanism 1 through a steering shaft 3 by putting a limit on the rotation speed of the motor 6 for operating the mechanism 1. Thereby, a part of the passenger's body can be prevented from being entangled in the rotation of the steering wheel 30, thus improving safety. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle steering apparatus configured to be capable of automatic steering.

  Steering of a vehicle is performed by operating a steering mechanism in accordance with an operation of a steering member such as a steering wheel, and changing a steering angle of a steering wheel by the operation of the steering mechanism. In recent years, as a vehicle steering device for performing such steering, a vehicle steering device including an actuator capable of applying a steering force to a steering mechanism regardless of the operation of a steering member has been proposed. (See Patent Document 1).

In this vehicle steering apparatus, for example, a target turning angle is determined based on an image captured by an in-vehicle camera, and the steering mechanism is operated by driving the actuator so as to obtain the determined target turning angle. Automatic steering that automatically performs steering is possible. However, during this automatic steering, the steering member moves regardless of the operation of the driver, and there is a possibility that the passenger is surprised or uncomfortable. Therefore, in the vehicle steering device disclosed in Patent Document 1, when a touch sensor is provided on the steering member and the contact of the occupant is detected by the touch sensor, the upper limit value of the rotation speed of the steering member is limited. It is configured.
JP 2004-203117 A

  However, in the vehicle steering apparatus disclosed in Patent Document 1, the rotational speed of the steering member is limited to a low value only when the driver is in contact with the steering member during automatic steering. Part of the body is near the steering member and contacts with the rotation of the steering member during automatic steering. There is a risk of getting involved in rotation.

  The present invention has been made in view of such circumstances, and safety can be improved by limiting the rotational speed of the steering member when a part of the occupant's body is in the vicinity of the steering member. An object of the present invention is to provide a vehicle steering apparatus.

  A vehicle steering apparatus according to a first aspect of the present invention includes a steering mechanism that performs a steering operation in response to a rotation operation of a steering member, an actuator that applies a steering force to the steering mechanism, and a control unit that controls driving of the actuator. The vehicle steering apparatus includes a detecting unit that detects an obstacle in a rotation region of the steering member, and the control unit limits driving of the actuator when the detecting unit detects the obstacle. It is configured as described above.

  According to a second aspect of the present invention, there is provided the vehicle steering apparatus according to the first aspect, wherein the control means limits the drive of the actuator so as to decelerate the rotation speed of the steering member when an obstacle is detected by the detection means. It is comprised so that it may carry out.

  According to a third aspect of the present invention, there is provided the vehicle steering apparatus according to the first or second aspect, wherein the detecting means receives a light from the light emitting section that emits light that crosses the rotation region of the steering member in the radial direction, and light from the light emitting section. The steering member is provided with a light receiving portion capable of performing the above.

  According to a fourth aspect of the present invention, there is provided a vehicle steering apparatus according to any one of the first to third aspects, further comprising alarm means for issuing an alarm, wherein the control means is configured to detect an obstacle by the detection means. The alarm means is configured to operate.

  According to the first invention, when an obstacle is detected in the rotation region of the steering member by the detection means, the driving of the actuator that operates the steering mechanism is limited. When the hand is put in, the movement of the steering member is restricted according to the restriction of the drive of the actuator, so that the occupant's hand can be prevented from being caught by the rotation of the steering member, and safety is improved. be able to.

  According to the second aspect of the present invention, when an obstacle is detected in the rotation region of the steering member, the rotation speed of the steering member is reduced by limiting the drive of the actuator that operates the steering mechanism. So that the passengers do not feel uncomfortable.

  According to the third aspect of the present invention, the light emitting unit such as a light emitting diode that emits light that traverses the rotation region of the steering member in the radial direction and the light receiving unit such as a photodiode disposed so as to be able to receive light from the light emitting unit are provided. Since it is provided on the steering member and the presence or absence of an obstacle is determined by a change in an output signal accompanying light reception by the photodiode, the obstacle can be accurately detected with a simple configuration.

  According to the fourth aspect of the invention, since an alarm is issued when an obstacle is detected by the detecting means, it is possible to urge the occupant to avoid an action for avoiding contact with the steering member. The property can be further improved.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a schematic diagram showing a configuration of a vehicle steering apparatus according to the present invention.

  The illustrated vehicle steering apparatus includes a rack and pinion type steering mechanism 1. A rack and pinion type steering mechanism 1 includes a rack shaft 10 that is supported in an axially movable manner in a rack housing 11 that extends in the left-right direction of a vehicle body (not shown), and crosses the rack housing 11 in the middle. And a pinion shaft 2 rotatably supported inside the pinion housing 20.

  Both ends of the rack shaft 10 projecting outward from both sides of the rack housing 11 are connected to left and right front wheels 13 and 13 as steering wheels via separate tie rods 12 and 12, respectively. Further, the upper end of the pinion shaft 2 protruding outside from the pinion housing 20 is connected to a steering wheel 30 as a steering member via the steering shaft 3. A pinion (not shown) is integrally formed at a lower portion of the pinion shaft 2 extending inside the pinion housing 20, and the pinion is formed in an intermediate portion of the rack shaft 10 at an intersection with the rack housing 11. Meshed with the rack.

  The steering shaft 3 is rotatably supported inside a cylindrical housing 31 and is attached to the interior of a passenger compartment (not shown) with the front facing down through the housing 31. The pinion shaft 2 is connected to the lower end of the steering shaft 3 that projects downward from the housing 31, and the steering wheel 30 is fixed to the upper end of the steering shaft 3 that projects upward from the housing 31.

  With the above configuration, the steering shaft 3 is rotated by the rotation operation of the steering wheel 30 for steering, and this rotation is transmitted to the pinion shaft 2, and the rotation of the pinion shaft 2 is performed at the meshing portion of the pinion and the rack. The movement of the shaft 10 is converted into the movement in the axial length direction, and such movement of the rack shaft 10 is transmitted to the left and right front wheels 13 and 13 via the separate tie rods 12 and 12 for steering.

  In the middle of the housing 31 that supports the steering shaft 3, a torque sensor 4 that detects a steering torque applied to the steering shaft 3 by a rotation operation of the steering wheel 30 is provided. A steering angle sensor 5 for detecting a steering angle, which is a rotation angle of the steering shaft 3 corresponding to the turning angle of the front wheels 13, 13, is arranged in parallel below the torque sensor 4. An electric motor 6 as an actuator is attached at a lower position.

  The electric motor 6 is attached to the outside of the housing 31 with its axis substantially orthogonal, and for example, a worm fixed to an output end extending inside the housing 31 is engaged with a worm wheel that is externally fixed to the steering shaft 3. Thus, the rotation of the electric motor 6 is decelerated by the worm and the worm wheel and transmitted to the steering shaft 3.

  The electric motor 6 attached in this way is driven in accordance with a control command given from the steering control unit 7 via a motor drive circuit (not shown). The steering control unit 7 is given a detected value of the steering torque by the torque sensor 4 and a detected value of the steering angle by the steering angle sensor 5, respectively.

  The steering control unit 7 obtains the target assist force using the detection values of the torque sensor 4 and the steering angle sensor 5, and performs an assist control operation for driving the electric motor 6 to generate the obtained target assist force. This operation assists the steering performed as described above.

  The steering control unit 7 is connected to a steering mode changeover switch 71 and an automatic parking switch 72 that are respectively provided at appropriate locations in the vehicle compartment. An output signal corresponding to the operation of the steering mode changeover switch 71 is given to the steering control unit 7, and the steering control unit 7 performs an assist mode for performing the assist control operation described above in accordance with the output signal and an automatic steering mode described later. A switching operation for switching between and is performed. Similarly, an output signal corresponding to the operation of the automatic parking switch 72 is given to the steering control unit 7, and the steering control unit 7 starts an automatic parking control operation to be described later according to the output signal.

  Further, the steering control unit 7 is given an image captured by an in-vehicle camera 73 provided at an appropriate part of the vehicle and a vehicle speed detected by the vehicle speed sensor 74, respectively. The steering control unit 7 performs an automatic steering control operation or an automatic parking control operation, which will be described later, using these detection results.

  The steering control unit 7 is given an output signal from the obstacle detector 8 provided on the steering wheel 30. The obstacle detector 8 is configured to operate according to an operation command from the steering control unit 7 based on output signals from the steering mode changeover switch 71 and the automatic parking switch 72. Further, an alarm device 9 such as a buzzer is connected to the steering control unit 7, and the alarm device 9 is configured to operate according to an operation command from the steering control unit 7 and issue a predetermined alarm. is there.

  FIG. 2 is a diagram showing the configuration of the obstacle detector 8. As shown in the figure, the steering wheel 30 includes a flat columnar hub 30a and an annular rim 30b that are coaxially fitted to the upper end of the steering shaft 3, and a plurality of spokes 30c, 30c. Are connected by three). The obstacle detector 8 includes a plurality of light emitting diodes 8a, 8a ... (eight in the figure) attached to the hub 30a and a plurality of photodiodes 8b, 8b ... (eight in the figure) attached to the rim 30b. I have.

  The light emitting diodes 8a, 8a,... Are equally distributed in the circumferential direction of the hub 30a and are attached so as to emit light radially outward from their respective positions. The photodiodes 8b, 8b... Are attached to the inner periphery of the rim 30b so as to face the light emitting diodes 8a, 8a. The light emitted from each of the light-emitting diodes 8a, 8a... Attached in this way is along an optical path crossing a region inside the rim 30b, that is, a rotation region of the steering wheel 30, as shown by a two-dot chain line in FIG. Are received by the opposing photodiodes 8b, 8b. The light emitting diodes 8a, 8a,... And the photodiodes 8b, 8b,... Are provided in a plurality in a uniform arrangement in the circumferential direction of the rotation region, so that the rotation region of the steering wheel 30 is covered radially.

  Since the output values of the photodiodes 8b, 8b... Change corresponding to the amount of received light, as shown in FIG. 2, when there is an obstacle 80 in the rotation region of the steering wheel 30, the light emitting diodes at the corresponding positions Light incident on the photodiode 8b from 8a is blocked, and the output value of the photodiode 8b decreases. Accordingly, by monitoring the output values of all the photodiodes 8b, 8b..., It can be determined whether or not there is an obstacle in the rotation region of the steering wheel 30. As a result, the steering control unit 7 can determine the presence / absence of an obstacle in the rotation region of the steering wheel 30 based on a change in the output signal accompanying light reception by the photodiodes 8b, 8b.

  The automatic steering control operation of the steering control unit 7 is performed so that the steering mechanism 1 is automatically operated to perform steering. This control operation is performed by, for example, controlling the electric motor 6 based on the front image taken by the in-vehicle camera 73 and the vehicle speed detected by the vehicle speed sensor 74 as described in Japanese Patent Application Laid-Open No. 2002-200985 by the present applicant. This is realized by driving control.

  Further, the automatic parking control operation of the steering control unit 7 is performed so as to automatically park the vehicle. For example, the control operation recognizes the current position and the parking position of the vehicle based on a rear image captured by the in-vehicle camera 73, and moves to move the vehicle between the current position and the parking position. This is realized by setting a route, determining a steering procedure for moving the vehicle along the moving route, and driving and controlling the electric motor 6 to perform steering according to this procedure.

  During the automatic steering and automatic parking control operations as described above, the steering control unit 7 performs the following danger avoidance control operation according to the output signal from the obstacle detector 8.

  FIG. 3 is a flowchart showing the contents of the danger avoidance control operation of the steering control unit 7. This control operation is executed as an interruption process during the automatic steering and automatic parking control operations. The steering control unit 7 takes in the output signal S of the photodiodes 8b, 8b... And the steering angle θ detected by the steering angle sensor 5 (steps S1, S2). Next, the steering angular velocity ω that is the rotational speed of the steering wheel 30 is calculated using the steering angle θ captured in step S2 (step S3).

  It is determined from the output signal S of the photodiodes 8b, 8b... Taken in step S1 whether there is an obstacle in the rotation region of the steering wheel 30 (step S4). When there is an obstacle in the rotation region of the steering wheel 30 (step S4: YES), an operation command is issued to the alarm device 9 to cause the alarm device 9 to issue an alarm (step S5). On the other hand, when there is no obstacle in the rotation region of the steering wheel 30 (step S4: NO), the danger avoidance control operation is terminated without performing any control operation.

Next, it is determined whether the steering angular velocity ω of the steering wheel 30 is greater than a predetermined value ω _Th (step S6). When the steering angular velocity ω of the steering wheel 30 is greater than the predetermined value ω _Th (step S6: YES), the steering angular velocity ω of the steering wheel 30 is set to the predetermined value ω _Th (step S7). On the other hand, when the steering angular velocity ω of the steering wheel 30 is equal to or less than the predetermined value ω _Th (step S6: NO), the danger avoidance control operation is terminated.

The steering angular speed ω of the steering wheel 30 is limited by the electric motor 6 that operates the steering mechanism 1 connected to the steering wheel 30 via the steering shaft 3 below the rotational speed corresponding to the predetermined value ω _Th. This is realized by controlling as described above. The warning by the warning device 9 is realized, for example, by sounding a buzzer in response to an operation command from the steering control unit 7. Note that the alarm device 9 is not limited to a buzzer and may be any means that can give a warning to an occupant, such as a speaker that outputs sound and a display that displays a warning.

  The vehicle steering apparatus according to the present invention configured as described above includes an electric motor 6 that operates the steering mechanism 1 when an obstacle is detected in the rotation region of the steering wheel 30 during automatic steering. By limiting the rotational speed, the steering angular speed of the steering wheel 30 connected to the steering mechanism 1 via the steering shaft 3 is limited, so that it is possible to prevent the steering wheel 30 from being caught in the rotation. , Can improve safety.

  Further, the obstacle detector 8 is provided on the hub 30a of the steering wheel 30 and faces the light emitting diodes 8a, 8a,... That emit light that crosses the rotation region of the steering wheel 30 in the radial direction, and the light emitting diodes 8a, 8a, respectively. In this manner, the optical sensor includes photodiodes 8b, 8b,... Provided on the rim 30b, and the presence or absence of an obstacle is determined by a change in an output signal accompanying light reception by the photodiodes 8b, 8b,. Therefore, it is possible to accurately detect an obstacle with a simple configuration.

  Further, when there is an obstacle in the rotation region of the steering wheel 30, the alarm device 9 operates in response to an operation command from the steering control unit 7 and issues a predetermined alarm, so that the occupant does not touch the steering wheel 30. Therefore, it is possible to take an avoidance action, and safety can be further improved.

  In the above embodiment, the steering angular velocity of the steering wheel 30 is limited to a predetermined value or less in the danger avoidance control operation according to the output signal from the obstacle detector 8. May be limited to 0, and the steering wheel 30 may be stopped.

  Further, the obstacle detector 8 is not limited to the configuration shown in the embodiment including the light emitting diodes 8a, 8a,... And the photodiodes 8b, 8b, but can appropriately detect obstacles in the rotation region of the steering wheel 30. It can be realized in the form of. For example, a camera is installed with the rotation area of the steering wheel 30 as an imaging field of view, and an image captured by the camera is analyzed to determine whether there is an obstacle between the hub 30a and the rim 30b. The obstacle detector 8 may be configured.

  In the above embodiment, the steering wheel 30 is used as the steering member. However, the present invention is not limited to this, and the steering member can transmit the rotation operation by the driver to the steering mechanism 1 via the steering shaft 3. It only has to be configured.

  Furthermore, the present invention can be carried out in other various forms within the scope of the matters described in the claims.

It is a mimetic diagram showing the composition of the steering device for vehicles concerning the present invention. It is a figure which shows the structure of an obstruction detector. It is a flowchart which shows the content of the danger avoidance control operation | movement of a steering control part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Steering mechanism, 6 Electric motor (actuator), 7 Steering control part (control means), 8 Obstacle detector (detection means), 8a Light emitting diode (light emission part, detection means), 8b Photodiode (light receiving part, detection) Means), 9 alarm device (alarm means), 30 steering wheel (steering member)

Claims (4)

  A steering apparatus for a vehicle, comprising: a steering mechanism that performs a steering operation according to a rotation operation of the steering member; an actuator that applies a steering force to the steering mechanism; and a control unit that controls driving of the actuator. Detecting means for detecting an obstacle in the rotation region, and the control means is configured to limit the drive of the actuator when the obstacle is detected by the detecting means. Vehicle steering system.   2. The vehicle steering apparatus according to claim 1, wherein when the obstacle is detected by the detection unit, the control unit is configured to limit the drive of the actuator so as to reduce a rotation speed of the steering member. .   The said detection means is equipped with the light-emitting part which emits the light which crosses the rotation area | region of the said steering member to radial direction, and the light-receiving part which can receive the light from this light-emitting part, The said steering member is equipped with the said steering member. Item 3. The vehicle steering device according to Item 2.   The alarm means which issues an alarm is provided, The said control means is comprised so that the said alarm means may be operated when an obstruction is detected by the said detection means. The steering apparatus for vehicles as described.

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