JP2021075234A - Steering apparatus - Google Patents

Abstract

To provide a steering apparatus that is able to reduce uncomfortable feeling given to a driver.SOLUTION: A steering apparatus 10 includes a steering shaft 21, a reaction force motor 22, and a reaction force control unit. The steering shaft 21 is separated from turning wheels of a vehicle in terms of power transmission. In addition, the steering shaft 21 rotates in conjunction with an operation of a steering wheel 11. The reaction motor 22 generates a steering reaction force to be applied to the steering shaft 21. The reaction force control unit controls power supply to the reaction force motor 22. If it is necessary to adjust a rotated position of the steering wheel 11 through the control of the reaction force motor 22 when the power source of the vehicle is switched from OFF to ON, the reaction force control unit notifies, through an on-vehicle notification device before the execution of the start of the adjustment, that the start of the adjustment is executed.SELECTED DRAWING: Figure 4

Description

The present invention relates to a steer-by-wire type steering device.

Conventionally, there is a so-called steer-by-wire type steering device in which the power transmission between the steering wheel and the steering wheel is separated. The steering device is a steering mechanism having a reaction force mechanism having a reaction force motor which is a source of steering reaction force applied to the steering shaft and a steering mechanism having a steering motor which is a source of steering force for steering the steering wheels. And have. When the vehicle is running, the control device of the steering device generates a steering reaction force through power supply control to the reaction force motor, and steers the steering wheel through power supply control to the steering motor.

In the steer-by-wire type steering device, the steering wheel is not restricted by the steering mechanism. Therefore, when some external force is applied to the steering wheel while the power of the vehicle is turned off, the steering wheel may rotate. At this time, since the steering wheel does not operate, the positional relationship between the steering wheel and the steering wheel differs from the original positional relationship according to the predetermined steering angle ratio. Incidentally, the steering angle ratio means the ratio between the steering angle of the steering wheel and the steering angle of the steering wheel.

Therefore, for example, in the steering device of Patent Document 1, when the power of the vehicle is switched from off to on, the initialization process of the steering wheel is executed. The control device of the steering device calculates an ideal steering angle according to the actual steering angle by multiplying the steering angle detected through the steering angle sensor by a predetermined steering angle ratio. The control device compares the ideal steering angle with the actual steering angle detected through the steering angle sensor, and if they do not match, through the actuator so that the actual steering angle matches the ideal steering angle. Rotate the steering wheel.

Japanese Unexamined Patent Publication No. 2004-51094

According to the steering device of Patent Document 1, the deviation of the positional relationship between the steering wheel and the steering wheel is certainly improved. However, in order to correct the positional relationship between the steering wheel and the steering wheel, the steering wheel automatically rotates at the timing when the power of the vehicle is turned on. The driver may feel uncomfortable with the automatic rotation of the steering wheel.

An object of the present invention is to provide a steering device capable of reducing a sense of discomfort given to a driver.

The steering device capable of achieving the above object is a steering shaft in which power transmission between the steering wheel and the steering wheel of the vehicle is separated and rotates in conjunction with the operation of the steering wheel, and the steering direction is opposite to that given to the steering shaft. It includes a motor that generates a steering reaction force that is torque in the direction, and a control device that controls power supply to the motor. When the power of the vehicle is switched from off to on, the control device starts executing the adjustment before starting the execution of the adjustment when it is necessary to adjust the rotational position of the steering wheel through the control of the motor. Notify through the in-vehicle notification device.

While the vehicle is turned off, the steering wheel may rotate due to external force. In such a case, it is necessary to adjust the rotation position of the steering wheel. Since the rotation position of the steering wheel can be adjusted through the control of the motor, the driver of the vehicle may feel uncomfortable with the automatic rotation of the steering wheel. In this regard, according to the above-mentioned steering device, it is notified that the adjustment of the rotation position of the steering wheel is started before the adjustment is started. Therefore, the driver's discomfort can be reduced.

In the above-mentioned steering device, when the control device executes the adjustment of the rotation position of the steering wheel, when the adjustment is completed, the control device may notify to that effect through the notification device.

According to this configuration, the driver can recognize that the adjustment of the steering wheel is completed. Therefore, the driver can smoothly start driving the vehicle.
The steering device has a sensor for detecting a steering angle which is a rotation angle of the steering shaft, and the control device turns off the power of the vehicle when the power of the vehicle is switched from on to off. The steering angle detected through the sensor immediately before may be stored as a reference steering angle. The control device rotates the steering wheel by comparing the steering angle detected through the sensor immediately after the power of the vehicle is switched from off to on with the reference steering angle stored by itself. The necessity of adjusting the position may be determined.

When the steering wheel rotates while the power of the vehicle is turned off, the steering angle immediately before the power of the vehicle is turned off and the steering angle immediately after the power of the vehicle is turned on are different values. Therefore, it is determined whether or not it is necessary to adjust the rotation position of the steering wheel by comparing the reference steering angle, which is the steering angle immediately before the power of the vehicle is turned off, with the steering angle immediately after the power of the vehicle is turned on. Is possible.

In the above steering device, the control device is used when the reference steering angle, which is the steering angle immediately before the power of the vehicle is turned off, and the steering angle immediately after the power of the vehicle is turned on do not match, or when the power of the vehicle is turned on. When the difference between the reference steering angle, which is the steering angle immediately before turning off, and the steering angle immediately after the vehicle is turned on is a value outside the defined allowable range, the rotation position of the steering wheel is adjusted. When it is determined that the steering wheel needs to be adjusted and the rotation position of the steering wheel needs to be adjusted, the steering angle detected through the sensor is the steering angle immediately before the power of the vehicle is turned off. The drive of the motor may be controlled so as to match the steering angle.

According to this configuration, the rotational position of the steering wheel can be returned to the rotational position immediately before the power of the vehicle is turned off.
In the above-mentioned steering device, the notification device may appeal to at least one of auditory and visual messages to notify that the adjustment of the rotation position of the steering wheel is started.

With this configuration, the driver of the vehicle can more clearly recognize that the adjustment of the rotational position of the steering wheel is initiated through at least one of auditory and visual.

In the above-mentioned steering device, the notification device may notify that the adjustment of the rotation position of the steering wheel is started by emitting a pseudo mechanical sound.

According to this configuration, the driver of the vehicle can easily recognize that the vehicle system is operating through a pseudo mechanical sound.

According to the steering device of the present invention, it is possible to reduce the discomfort given to the driver.

The block diagram which shows one Embodiment of a steering apparatus. (A) to (c) are block diagrams showing a series of flows when adjusting the rotation position of the steering wheel in the comparative example. The flowchart which shows the processing procedure which adjusts the rotation position of the steering wheel in one Embodiment. (A) to (e) are block diagrams showing a series of flows when adjusting the rotation position of the steering wheel in one embodiment.

Hereinafter, an embodiment in which the steering device is embodied will be described.
As shown in FIG. 1, the vehicle steering device 10 includes a reaction force unit 20 that applies a steering reaction force to the steering wheel 11 of the vehicle, and a steering unit 30 that steers the steering wheels 12 and 12 of the vehicle. ing. The steering reaction force is a torque acting in a direction opposite to the operating direction of the steering wheel 11 by the driver. By applying the steering reaction force to the steering wheel 11, it is possible to give the driver an appropriate feeling of response.

The reaction force unit 20 includes a steering shaft 21 to which the steering wheel 11 is connected, a reaction force motor 22, a reduction mechanism 23, a rotation angle sensor 24, a torque sensor 25, a steering angle sensor 26, and a reaction force control unit 27. ..

The reaction force motor 22 is a source of steering reaction force. As the reaction force motor 22, for example, a three-phase brushless motor is adopted. The reaction force motor 22 is connected to the steering shaft 21 via the reduction mechanism 23. The torque generated by the reaction force motor 22 is applied to the steering shaft 21 as a steering reaction force.

The rotation angle sensor 24 is provided on the reaction force motor 22. The rotation angle sensor 24 detects _{the rotation angle θ a of the reaction force motor 22.}
The torque sensor 25 is provided in a portion of the steering shaft 21 between the reduction mechanism 23 and the steering wheel 11. The torque sensor 25 detects the steering torque T _h applied to the steering shaft 21 through the rotational operation of the steering wheel 11.

The steering angle sensor 26 is provided in a portion of the steering shaft 21 between the torque sensor 25 and the steering wheel 11. The steering angle sensor 26 is an absolute angle sensor, and detects the steering angle θ _s , which is the rotation angle of the steering shaft 21, at an absolute angle in the range exceeding 360 °.

Reaction force control unit 27 executes the reaction force control for generating the steering reaction force corresponding to the steering torque T _h through drive control of the reaction force motor 22. Reaction force control unit 27 calculates the target steering reaction force based on the steering torque T _h which is detected through a torque sensor 25, the target steering angle of the steering wheel 11 based on the target steering reaction force and the steering torque T _h is the operational Is calculated. _{The reaction force control unit 27 obtains the difference between the actual steering angle θ s} detected through the steering angle sensor 26 and the target steering angle, and controls the power supply to the reaction force motor 22 so as to eliminate the difference. The reaction force control unit 27 vector-controls the reaction force motor 22 by using _{the rotation angle θ a} of the reaction force motor 22 detected through the rotation angle sensor 24.

The steering unit 30 includes a steering shaft 31, a steering motor 32, a reduction mechanism 33, a pinion shaft 34, a rotation angle sensor 35, and a steering control unit 36.
The steering shaft 31 extends along the vehicle width direction (left-right direction in FIG. 1). The left and right steering wheels 12 and 12 are connected to both ends of the steering shaft 31 via tie rods 13 and 13, respectively.

The steering motor 32 is a source of steering force. As the steering motor 32, for example, a three-phase brushless motor is adopted. The steering motor 32 is connected to the pinion shaft 34 via a reduction mechanism 33. The pinion teeth 34a of the pinion shaft 34 are meshed with the rack teeth 31a of the steering shaft 31. The torque generated by the steering motor 32 is applied to the steering shaft 31 as a steering force via the pinion shaft 34. The steering shaft 31 moves along the vehicle width direction (left-right direction in FIG. 1) according to the rotation of the steering motor 32. As the steering shaft 31 moves, the steering angles θ _w of the steering wheels 12 and 12 are changed.

The rotation angle sensor 35 is provided on the steering motor 32. The rotation angle sensor 35 detects _{the rotation angle θ b of the steering motor 32.}
The steering control unit 36 executes steering control for steering the steering wheels 12 and 12 according to the steering state through the drive control of the steering motor 32. _{The steering control unit 36 calculates the rotation angle θ p} of the pinion shaft 34 based on _{the rotation angle θ b} of the steering motor 32 detected through the rotation angle sensor 35. Further, the steering control unit 36 calculates the target rotation angle of the pinion shaft 34 by using the target steering angle calculated by the reaction force control unit 27. However, the target rotation angle of the pinion shaft 34 is calculated from the viewpoint of achieving a predetermined steering angle ratio. Steering control unit 36 calculates the difference between the actual rotation angle theta _p between the target rotation angle of the pinion shaft 34, and controls the power supply for the steering motor 32 so as to eliminate the difference. The steering control unit 36 vector-controls the steering motor 32 by using _{the rotation angle θ b} of the steering motor 32 detected through the rotation angle sensor 35.

Here, in the steer-by-wire type steering device 10, since the steering wheel 11 is not restricted by the steering unit 30, the following events may occur.

As shown in FIG. 2A, the steering wheel 11 and the steering wheels 12 and 12 are synchronized when the vehicle power is turned on. That is, the positional relationship between the steering wheel 11 and the steering wheels 12 and 12 is maintained in a positional relationship according to a predetermined steering angle ratio.

As shown in FIG. 2B, when some external force is applied to the steering wheel 11 while the vehicle power is off, the steering wheel 11 may rotate. At this time, since the steering shaft 31 does not operate, a situation occurs in which the positional relationship between the steering wheel 11 and the steering wheels 12 and 12 is different from the original positional relationship according to the predetermined steering angle ratio.

Therefore, it is conceivable that the steering device 10 has a function of automatically adjusting the position of the steering wheel 11 as an initial operation when the vehicle power is turned on again.
As shown in FIG. 2C, when the steering wheel 11 is rotated counterclockwise (positive direction) by an angle + α during the period when the vehicle power is turned off, when the vehicle power is turned on again, the steering wheel is steered. Rotate the wheel 11 clockwise (negative) by an angle −α. As a result, the positional relationship between the steering wheel 11 and the steering wheels 12 and 12 returns to the original positional relationship according to the predetermined steering angle ratio.

However, a driver who does not know that such an initial operation is executed may feel uncomfortable with the automatic rotation of the steering wheel 11.
Therefore, in the present embodiment, the steering device 10 has the following configuration from the viewpoint of reducing the driver's discomfort due to the automatic rotation of the steering wheel 11.

As shown in FIG. 1, the reaction force control unit 27 has a storage device 27a. When the power supply of the vehicle is switched from on to off, the reaction force control unit 27 stores the steering angle θ _s detected by the steering angle sensor 26 as the reference steering angle θ ₀ in the storage device 27a immediately before that. This reference steering angle θ ₀ serves as a reference for determining whether or not the steering wheel 11 is rotating during the period when the vehicle power is off.

When the power of the vehicle is switched from off to on, the reaction force control unit 27 _{detects the reference steering angle θ 0} stored in the storage device 27a and the steering angle sensor 26 immediately after the power of the vehicle is turned on. The necessity of adjusting the position of the steering wheel 11 is determined by comparing with the steering angle θ _s. When it is determined that the position of the steering wheel 11 needs to be adjusted, the reaction force control unit 27 notifies that the position of the steering wheel 11 is adjusted through the notification device 28 mounted on the vehicle, and then the steering wheel 11. The position of the wheel 11 is adjusted.

By the way, the notification device 28 is provided in the vehicle interior. The notification device 28 performs a notification operation determined based on a command from the reaction force control unit 27. As the notification operation, for example, issuing a voice message can be mentioned. Further, the position adjustment of the steering wheel 11 means adjusting the rotation position which is a position in the rotation direction of the steering wheel.

<Processing procedure for initial operation>
Next, the processing procedure of the initial operation executed by the reaction force control unit 27 will be described with reference to the flowchart of FIG. The processing of the flowchart of FIG. 3 is started when the power of the vehicle is turned on. _{Further, the storage device 27a stores the steering angle θ s} immediately before the power of the vehicle is turned off as the reference steering angle θ ₀ .

_{As shown in the flowchart of FIG. 3, the reaction force control unit 27 reads the reference steering angle θ 0} stored in the storage device 27a when the vehicle power supply is switched from off to on (step S101). _{Further, the reaction force control unit 27 detects the steering angle θ s} detected through the steering angle sensor 26 immediately after the vehicle power supply is switched from off to on (step S102).

Next, the reaction force control unit 27 compares the _{reference steering angle θ 0} captured in step S101 with the steering angle θ _{s detected in step S102.} Specifically, the reaction force control unit 27 determines whether or not the _{steering angle θ s} detected in step S102 is equal to the reference steering angle θ _{0 (step S103).}

The reaction force control unit 27 ends the process when it is determined that the _{steering angle θ s} detected in step S102 is equal to the reference steering angle θ _{0 (YES in step S103).} By the steering angle theta _s just after the reference steering angle theta ₀ and the vehicle power supply is a steering angle theta _s just before the vehicle power is turned off is turned on again coincide with each other, from the vehicle power supply is turned off _{It can be seen that the steering angle θ s} has not changed and the steering wheel 11 has not rotated during the period until the vehicle power is turned on again. Therefore, it is not necessary to adjust the position of the steering wheel 11.

_{When it is determined that the steering angle θ s} detected in step S102 is not equal to the reference steering angle θ ₀ (NO in step S103), the reaction force control unit 27 executes the position adjustment of the steering wheel 11 through the notification device 28. Notify that it will start (step S104).

After that, the reaction force control unit 27 executes the position adjustment of the steering wheel 11 (step S105). The reaction force control unit 27 obtains, for example _{, the difference between the reference steering angle θ 0 and the steering angle θ s} immediately after the vehicle power is turned on, and controls the power supply to the reaction force motor 22 so as to eliminate the difference. When the reference steering angle θ ₀ and the current steering angle θ _s coincide with each other, the position adjustment of the steering wheel 11 is completed.

When the position adjustment of the steering wheel 11 is completed, the reaction force control unit 27 notifies through the notification device 28 that the position adjustment of the steering wheel 11 is completed (step S106), and ends the process.

<Action of the embodiment>
Next, the operation of the present embodiment will be described.
As shown in FIGS. 4A and 4B, as a premise state, the steering wheel 11 is rotated counterclockwise by an angle + α in a state where the vehicle power is switched from on to off. The positional relationship between the steering wheel 11 and the steering wheels 12 and 12 is maintained in a state different from the original positional relationship according to the predetermined steering angle ratio.

As shown in FIG. 4C, when the vehicle power is switched from off to on, it is notified that the position adjustment is executed prior to the execution of the position adjustment of the steering wheel 11. For example, a message such as "The steering wheel moved while the power was off, so adjust it." Is announced by voice. As a result, the driver of the vehicle can recognize that the position adjustment of the steering wheel 11 is executed.

As shown in FIG. 4D, after being notified that the position adjustment of the steering wheel 11 is executed, the steering wheel 11 rotates clockwise (negative direction) by an angle −α. As a result, the positional relationship between the steering wheel 11 and the steering wheels 12 and 12 returns to the original positional relationship according to the predetermined steering angle ratio. Since the driver of the vehicle recognizes that the position adjustment of the steering wheel 11 is executed before the steering wheel 11 actually rotates, the driver may feel a sense of discomfort even when the steering wheel 11 automatically rotates. Absent.

As shown in FIG. 4E, after the position adjustment of the steering wheel 11 is completed, a notification to that effect is given. For example, a message such as "Completed" is announced by voice. The driver of the vehicle can recognize that the position adjustment of the steering wheel 11 is completed as the initial operation of the steering device 10, and that the steering wheel 11 may be operated.

<Effect of embodiment>
Therefore, according to the present embodiment, the following effects can be obtained.
(1) When the reaction force control unit 27 needs to adjust the position of the steering wheel 11 when the power supply of the vehicle is switched from off to on, the reaction force control unit 27 executes the position adjustment of the steering wheel 11 through the notification device 28. After notifying, the position adjustment of the steering wheel 11 is started. Therefore, the driver of the vehicle can recognize in advance that the position adjustment of the steering wheel 11 is executed. Therefore, it is possible to reduce the discomfort given to the driver by the automatic rotation of the steering wheel.

(2) The reaction force control unit 27 also notifies that the position adjustment of the steering wheel 11 is completed through the notification device 28 even when the position adjustment of the steering wheel 11 is completed. Therefore, the driver of the vehicle can recognize that the position adjustment of the steering wheel 11 is completed. Therefore, the driver of the vehicle can smoothly start driving the vehicle after the position adjustment of the steering wheel 11 is completed.

(3) when the steering wheel 11 in the period in which the power supply of the vehicle is turned off is rotated, the steering angle theta _s just before the power supply of the vehicle is turned off, the steering angle theta _s just after the power source of the vehicle is turned on Have different values. Therefore, the reference steering angle theta ₀ is a steering angle theta _s just before the power supply of the vehicle is turned off, adjustment of the rotational position of the steering wheel 11 through comparison between the steering angle theta _s just after the power source of the vehicle is turned on It is possible to determine the necessity of.

(4) The notification device 28 notifies the driver that the adjustment of the rotation position of the steering wheel 11 is started by issuing a voice message and that the adjustment of the rotation position of the steering wheel 11 is completed. It appeals to the hearing and notifies. The driver of the vehicle can more clearly recognize that the adjustment of the rotation position of the steering wheel 11 is started and the adjustment of the rotation position of the steering wheel 11 is completed through hearing.

<Other embodiments>
The present embodiment may be modified as follows.
-The reaction force control unit 27 and the steering control unit 36 may be integrated and provided as a single control device.

The reaction force control unit 27 calculates the steering angle θ _{s using the rotation angle θ a} of the reaction force motor 22 detected through the rotation angle sensor 24, and uses the calculated steering angle θ _s to counteract. Force control may be performed. In this case, it is also possible to adopt a configuration in which the steering angle sensor 26 is omitted as the steering device 10. However, when the power of the vehicle is switched from on to off, the reaction force control unit 27 stores the steering angle θ _s calculated immediately before the power of the vehicle is turned off in the storage device 27a as the reference steering angle θ _0. .. Further, the reaction force control unit 27 calculates the steering angle θ _{s by using the rotation angle θ a} of the reaction force motor 22 as the process of step S102 in the flowchart of FIG. The rotation angle sensor 24 functions as a sensor for detecting the _{steering angle θ s.}

-The notification device 28 may turn on the warning light in the vehicle interior or display a warning or message on the display in the vehicle interior in addition to the voice message or instead of the voice message as the notification operation. .. The notification device 28 may appeal to at least one of the five senses of the driver, auditory and visual, to notify the start and completion of the adjustment of the rotation position of the steering wheel 11.

-The notification device 28 may generate a pseudo mechanical sound or an electronic sound, which is a sound created as a warning sound, instead of the voice. The mechanical sound is, for example, a sound generated when a mechanical device operates. Electronic sound refers to sound generated electrically. In this way, it is possible to appeal to the hearing of the driver of the vehicle to notify that the vehicle system is adjusting the position of the steering wheel 11 as an initial operation when the power is turned on. Further, by emitting a pseudo mechanical sound or an electronic sound, the driver of the vehicle can easily recognize that the vehicle system is operating.

-The process of step S103 in the flowchart of FIG. 3 may be changed as follows. That is, the reaction force control unit 27 passes through the reference steering angle θ _{0 , which is the steering angle θ s} immediately before the vehicle power supply is switched from on to off, and the steering angle sensor 26 immediately after the vehicle power supply is switched from off to on. When the difference from the detected steering angle θ _s is out of the predetermined allowable range (NO in step S103), the process shifts to step S104. On the other hand, the reaction force control unit 27 _{ends the process when the difference between the reference steering angle θ 0} and the steering angle θ _s is within a predetermined allowable range (YES in step S103).

-The process of step S106 in the flowchart of FIG. 3 may be omitted. In this case, after the position adjustment of the steering wheel 11 in step S105 is completed, the reaction force control unit 27 ends the process without notifying that fact.

10 ... Steering device, 11 ... Steering wheel, 12 ... Steering wheel, 21 ... Steering shaft, 22 ... Reaction force motor, 24 ... Rotation angle sensor (sensor), 26 ... Steering angle sensor (sensor), 27 ... Reaction force control unit (Control device), 27a ... Storage device, 28 ... Notification device, θ _s ... Steering angle, θ ₀ ... Reference steering angle.

Claims (6)

The steering shaft, which is separated from the steering wheel of the vehicle and rotates in conjunction with the operation of the steering wheel,
A motor that generates a steering reaction force, which is a torque applied to the steering shaft in the direction opposite to the steering direction,
A control device for controlling power supply to the motor is provided.
When the power of the vehicle is switched from off to on, the control device starts executing the adjustment before starting the execution of the adjustment when it is necessary to adjust the rotational position of the steering wheel through the control of the motor. A steering device that notifies through an in-vehicle notification device. The steering device according to claim 1, wherein the control device notifies through the notification device when the adjustment of the rotation position of the steering wheel is executed and the adjustment is completed. It has a sensor for detecting the steering angle, which is the rotation angle of the steering shaft.
When the power of the vehicle is switched from on to off, the control device stores the steering angle detected through the sensor as a reference steering angle immediately before the power of the vehicle is turned off.
When the power of the vehicle is switched from off to on, it is necessary to adjust the rotational position of the steering wheel by comparing the steering angle detected through the sensor with the reference steering angle stored by the self. The steering device according to claim 1 or 2, which determines whether or not. The control device is used when the reference steering angle, which is the steering angle immediately before the vehicle is turned off, does not match the steering angle immediately after the vehicle is turned on, or immediately before the vehicle is turned off. When the difference between the reference steering angle, which is the steering angle, and the steering angle immediately after the vehicle is turned on is a value outside the specified allowable range, it is determined that the rotation position of the steering wheel needs to be adjusted. And
When it is determined that the rotation position of the steering wheel needs to be adjusted, the steering angle detected through the sensor is matched with the reference steering angle which is the steering angle immediately before the power of the vehicle is turned off. The steering device according to claim 3, wherein the driving of the motor is controlled. The steering according to any one of claims 1 to 4, wherein the notification device appeals to at least one of the auditory sense and the visual sense a message that the adjustment of the rotation position of the steering wheel is started. apparatus. The steering device according to any one of claims 1 to 4, wherein the notification device notifies that adjustment of the rotation position of the steering wheel is started by emitting a pseudo mechanical sound.

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