JPH10329742A - Steering control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimize the steering control when the steering position of a steering handle and the turning position of turning wheels are noncoincident by driving a steering shaft driving means in the steering position direction when an engine is started, and controlling the steering shaft driving means and a turning shaft driving means in response to the load state of the steering shaft driving means. SOLUTION: For the turning position control of turning wheels 21, a controller 30 calculates the target tuning position based on the actual steering position detected by a steering angle sensor 14. It calculates the duty value of the drive voltage applied to a turning shaft motor 23 based on the deviation between the target turning position and the actual turning position detected by a stroke sensor 25, and it outputs the corresponding control signal to the turning shaft motor 23. When an engine is started, the controller 30 judges whether the phase relations of the actual steering position and the actual turning position coincide with each other or not. If they do not coincide, the controller 30 drives a steering shaft motor 13 in the steering position direction, detects the load state based on the drive current value, and controls the steering shaft motor 13 and turning shaft motor 23 in response to the load state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering control device in which a steering mechanism and a turning mechanism are mechanically separated from each other, and the connecting mechanism is replaced with an electric control device.

[0002]

2. Description of the Related Art An example of a steering control device for electrically controlling the operations of a steering mechanism and a turning mechanism is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-233170. This steering control device detects a steering position of a steering wheel by an encoder provided on a steering shaft, and detects a traveling direction of the vehicle by a yaw rate gyro. Then, the turning control of the steered wheels is performed so that the deviation between the travel change instruction value based on the detected steering position and the actual travel direction change amount based on the yaw rate gyro detection result becomes zero.

[0003]

As described above, since the steering control of the steered wheels is performed based on the operation of the steering wheel,
For example, if the steering wheel is operated to another steering position between turning off the ignition key and stopping the engine and turning on the ignition key again to start the engine, the steering is started when the engine is started. The position relationship between the steering position of the steering wheel and the steering position of the steered wheels does not match. In such a case, how to execute the steering control is described in the above-mentioned JP-A-1-2331.
No. 70 does not disclose anything.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a method in which the steering position of a steering wheel does not coincide with the steering position of a steered wheel when the engine is started. It is an object of the present invention to provide a steering control device capable of suitably performing steering control according to the intention of the present invention.

[0005]

According to a first aspect of the present invention, there is provided a steering control device for steering a steered wheel in conjunction with a steering wheel, wherein the steering position detecting means detects a steering position of the steering wheel. A steering shaft driving means for driving a steering shaft connected to the steering wheel; a load state detecting means for detecting a load state of the steering shaft driving means; and a mechanically separated steering shaft and connected to the steered wheels. A steered shaft, a steered shaft driving means for driving the steered shaft, a steered position detecting means for detecting a steered position of a steered wheel, and a steering shaft in a steering position direction corresponding to the steered position when the engine is started. A first control unit for driving the driving unit, a second control unit for controlling the driving of the steering shaft driving unit and the turning shaft driving unit according to the load state of the steering shaft driving unit driven by the first control unit; It comprises.

[0006] When the engine is started, the first control means drives the steering shaft driving means to apply a rotational force to the steering wheel. At this time, when the driver holds the steering wheel against this rotational force or operates the steering wheel in the direction opposite to the direction of the rotational force, the load state of the steering shaft driving means becomes large. Further, when the driver releases his / her hand from the steering wheel or operates the steering wheel in the forward direction along the direction of the rotational force, the load state of the steering shaft driving means becomes small.
The second control means responds to the magnitude of such a load state,
The drive control of the steering shaft drive means and the steered shaft drive means is performed.

According to a second aspect of the present invention, there is provided a steering control device, wherein the second control means determines whether the load state of the steering shaft driving means is large or small, and determines whether the load state of the steering shaft driving means is large. A third control unit that performs drive control of the steered shaft driving unit and turns the steered wheels to a steered position corresponding to the steering position; and a third control unit that controls the steering shaft driving unit when the load state of the steering shaft driving unit is small. And fourth control means for performing drive control and rotating the steering wheel to a steering position corresponding to the steering position.

If the load state determined by the determining means is large, it is determined that the driver intends to turn the steered wheels, and the third control means having received the determination result,
The drive control of the steered shaft driving means is performed so that the steered wheels are steered to the position corresponding to the steering position of the steered steering wheel. When the load state determined by the determination means is small, it is determined that there is a driver's will to permit the rotation of the steering wheel up to the steering position corresponding to the steered position of the steered wheels. The fourth control unit that receives the result performs drive control of the steering shaft driving unit so that the steering wheel rotates to the steering position corresponding to the steering position of the steered wheel at that time.

According to a third aspect of the present invention, there is provided a steering control device, wherein the load state detecting means according to the first or second aspect detects a current sensor for detecting a driving current of the steering shaft driving means and a steering torque applied to the steering wheel. Of the torque sensor to be used.

[0010] The magnitude of the load on the steering shaft driving means corresponds to the magnitude of the driving current of the steering shaft driving means or the magnitude of the steering torque applied to the steering shaft. Therefore, by detecting the current value or the magnitude of the steering torque with the current sensor or the torque sensor, the load state of the steering shaft driving unit can be detected.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the accompanying drawings.

FIG. 1 schematically shows the configuration of a steering control device according to this embodiment. This steering control device includes a master unit 10 operated by a driver, a slave unit 20 for turning a steered wheel 21, and a controller 30 for electrically controlling the master unit 10 and the slave unit 20.

The master unit 10 includes a steering shaft 12 on which a steering wheel 11 is mounted, and a steering shaft motor 13 for rotating the steering shaft 12. The steering shaft 12 detects a steering position of the steering wheel 11. Steering angle sensor 14
And a torque sensor 15 for detecting a steering torque applied to the steering wheel 11. Further, the steering shaft motor 13 is provided with a current sensor 16 for detecting a drive current flowing through the steering shaft motor 13.

The slave section 20 includes a steered shaft motor 23 which serves as a drive source when the steered shaft 22 is displaced.
Between the steered shaft motor 23 and the steered shaft 22, the rotational motion of the steered shaft motor 23 is
Is provided along the axis direction.
On both sides of the steered shaft 22, reaction force sensors 26 for detecting an axial force (steering reaction force) applied from the steered wheels 21 to the steered shaft 22 side.
Is provided. The steered shaft 22 has the steered shaft 22.
A stroke sensor 25 for detecting the displacement position of the steering wheel 22 is provided. Since the displacement position of the steered shaft 22 corresponds to the steered position of the steered wheels 21, the displacement sensor of the steered shaft 22 is detected by the stroke sensor 25. Thus, the steered position of the steered wheels 21 is detected.

The controller 30 includes a steering angle sensor 14,
The detection results of the torque sensor 15, the current sensor 16, the stroke sensor 25, and the reaction force sensor 26 are given, and based on these detection results, the steering shaft motor 13 and the turning shaft motor 2 are used.
3 is performed.

Hereinafter, each control process performed by the controller 30 will be described.

The control of the reaction force applied to the steering wheel 11 is performed as follows. Based on the deviation between the steering torque T detected by the torque sensor 15 and the steering reaction force F detected by the reaction sensor 26, the duty value V1 of the drive voltage applied to the steering shaft motor 13 is calculated by the following equation (1). And outputs a control signal corresponding to the calculated Duty value to the steering shaft motor 13. In the equation (1), K1 is a gain coefficient indicating the gain of the control signal. V1 = K1 · (T−F) (1)

The steering position control of the steered wheels 21 is performed as follows. Actual steering position θr detected by steering angle sensor 14
Is calculated based on the target steering position Xm, which is the steering position of the steered wheels 21 corresponding to the actual steering position θr. Then, based on the deviation between the actual turning position Xr detected by the stroke sensor 25 and the calculated target turning position Xm, the turning shaft motor 2
3, the duty value V2 of the drive voltage applied to
It calculates by the formula and outputs a control signal corresponding to the calculated Duty value to the steered shaft motor 23. In the equation (2), K2 is a gain coefficient indicating the gain of the control signal. V2 = K2 · (Xm−Xr) (2)

Further, when the phase relationship between the actual steering position θr of the steering wheel 11 and the actual steering position Xr of the steered wheels 21 does not match when the engine is started, the controller 30 adjusts the positional relationship between the two. Is carried out.

FIG. 2 shows the actual steering position θ of the steering wheel 11.
3 is a flowchart illustrating a process of determining a phase relationship between r and the actual turning position Xr of the steered wheels 21. First, in step 101 (hereinafter, step is referred to as “S”), it is determined whether or not an ignition switch is turned on. If the ignition switch is turned on (“Yes” in S101),
In 103, the actual steering position θr as the detection result of the steering angle sensor 14 and the actual turning position Xr as the detection result of the stroke sensor 25 are read.

Next, in S105, a target turning position Xm as a turning position of the steered wheels 21 corresponding to the actual steering position θr is calculated from the read actual steering position θr. In subsequent S107, it is determined whether or not the target turning position Xm calculated in S105 matches the actual turning position Xr read in S103. When it is determined in S107 that the target turning position Xm matches the actual turning position Xr, the phases of the actual steering position θr of the steering wheel 11 and the actual turning position Xr of the steered wheels 21 match. Therefore, the phase adjustment is not necessary, and the control flow ends.

On the other hand, if it is determined in step S107 that the target turning position Xm does not match the actual turning position Xr, the phase between the actual steering position θr of the steering wheel 11 and the actual turning position Xr of the steered wheels 21 is determined. The relationship does not match. In this case, the process proceeds to S200, and the phase adjustment control for matching the phase relationship between the actual steering position θr of the steering wheel 11 and the actual steering position Xr of the steered wheels 21 is performed.

FIG. 3 shows a flowchart of the phase adjustment control performed in S200.

First, in S201, a target steering position θm of the steering wheel 11 corresponding to the actual steering position Xr is calculated from the actual steering position Xr at that time based on the detection result of the stroke sensor 25.

Next, in S203, the actual steering position θr of the steering wheel 11 is changed to the target steering position θm based on the target steering position θm calculated in S201 and the actual steering position θr detected by the steering angle sensor 14. The steering shaft motor 13 is rotationally driven so as to move. At this time, the steering shaft motor 1
3, the duty value of the drive voltage applied to the steering wheel 3 is predetermined, whereby the turning force is applied to the steering wheel 11 by the predetermined output torque, and the direction of the turning force is determined by the target steering wheel 11 The direction is toward the position θm.

In step S205, the current value I of the drive current of the steering shaft motor 13, which is the detection result of the current sensor 16, is read, and the load state of the steering shaft motor 13 at this time is detected. In the following S207, the current value I read at this time is compared with a preset threshold value Is. If the current value I is smaller than the threshold value Is ("Yes" in S207), the steering shaft is adjusted. The load state of the motor 13 is small. In this case, it is assumed that the driver releases his / her hand from the steering wheel 11 or operates the steering wheel along the direction of the rotational force applied to the steering wheel 11. In such a case, it is determined that there is a driver's intention to permit the rotation of the steering wheel 11 to a position corresponding to the steered position of the steered wheels 21, and the steering shaft motor 13 driven in S203 is continued. Drive.

In step S209, it is determined whether the actual steering position θr of the rotationally driven steering wheel 11 matches the target steering position θm calculated in step S201. When it is determined that the actual steering position θr of the steering wheel 11 does not coincide with the target steering position θm (“No” in S209), the processing from S205 is repeated again. And
If it is determined in S209 that the actual steering position θr of the steering wheel 11 matches the target steering position θm (S209
"Yes"), the actual steering position θr of the steering wheel 11 and the actual steering position Xr of the steered wheels 21 match, and this phase adjustment control ends.

On the other hand, if the read current value I is equal to or greater than the threshold value Is in S207 ("No" in S207), the load state of the steering shaft motor 13 is large,
In this case, the driver holds the steering wheel 11 against the turning force applied to the steering wheel 11, or
It is assumed that the steering wheel is operated in a direction opposite to the rotational force. In such a case, it is determined that there is a driver's intention to steer the steered wheels 21, and the actual steered position Xr of the steered shaft 22 is determined in S105 of FIG.
The steering shaft motor 23 is driven toward the target steering position Xm calculated by the above. Also in this case, the steering shaft motor 13 driven in S203 is continuously driven.

In the following S213, it is determined whether or not the actual turning position Xr of the displaced and driven turning shaft 22 matches the target turning position Xm. When it is determined that the actual turning position Xr of the turning shaft 22 does not match the target turning position Xm (S213).
, “No”), and the processing after S205 is repeatedly performed again. Then, in S213, the actual steered position X of the steered shaft 22.
When it is determined that r matches the target turning position Xm (“Yes” in S213), the phases of the actual turning position θr of the steering wheel 11 and the actual turning position Xr of the steered wheels 21 match. That is, the phase adjustment control ends.

As described above, when the engine is started, the actual steering position θr of the steering wheel 11 and the actual steering position X of the steered wheels 21 are determined.
Even when a phase shift from r occurs, the controller 30 performs such a control process,
It is possible to execute the phase adjustment control that suits the driver's will.

In the above-described embodiment, in the phase determination flowchart in FIG. 2, the calculated target steered position Xm is compared with the actual steered position Xr of the steered wheels 21 to shift to the phase adjustment control in S200. For example, in S105, the target steering position θm corresponding to the actual steering position Xr is calculated based on the read actual steering position Xr, and in S107, the obtained target steering position θm is calculated.
May be configured so that the flow proceeds to the phase adjustment control in S200 when the actual steering position does not match the actual steering position θr.

Although the case where the current sensor 16 is provided to determine the load state of the steering shaft motor 13 has been described as an example, the present invention is not limited to this.
, The load state of the steering shaft motor 13 can be determined based on the detection result. In this case, for example, in S207, the detected steering torque is compared with a predetermined threshold, and if the detected steering torque is smaller than the threshold, the load state of the steering shaft motor 13 is small. , The load state of the steering shaft motor 13 is determined to be large. Then, similarly, drive control of the steering shaft motor 13 and the steered shaft motor 23 may be performed.

[0033]

As described above, according to the steering control apparatus of the present invention, the first control means drives the steering shaft driving means in the direction of the steering position corresponding to the steering position when the engine is started. From the load state of the steering shaft driving means at this time, the steered wheels are steered to a position corresponding to the steering position of the steering wheel, or the steering handle is rotated to a position corresponding to the steered position of the steered wheels. The driver's will can be determined. Further, the second control means controls the driving of the steering shaft driving means and the turning shaft driving means in accordance with the load state of the steering shaft driving means at this time. It becomes possible to execute phase adjustment control with the steering position.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a steering control device according to an embodiment.

FIG. 2 is a flowchart for determining a phase relationship between an actual steering position of a steering wheel and an actual steering position of a steered wheel.

FIG. 3 is a flowchart illustrating phase adjustment control between a steering position and a steered position.

[Explanation of symbols]

10: Master unit, 11: Steering handle, 12: Steering axis,
13: Steering shaft motor, 14: Steering angle sensor, 15: Torque sensor, 16: Current sensor, 20: Slave unit, 21
... Steering wheel, 22 ... Steering shaft, 23 ... Steering shaft motor, 25 ...
Stroke sensor.

Claims (3)

[Claims] 1. A steering control device for turning a steered wheel in conjunction with a steering wheel, a steering position detecting means for detecting a steering position of the steering wheel, and a steering for driving a steering shaft connected to the steering wheel. Shaft driving means, load state detecting means for detecting a load state of the steering shaft driving means, a steering shaft mechanically separated from the steering shaft and connected to the steered wheels, and driving the steering shaft Turning shaft driving means, turning position detecting means for detecting a turning position of the turning wheel, and first control for driving the steering shaft driving means in a steering position direction corresponding to the turning position when the engine is started. Means for controlling the steering shaft drive means and the steered shaft drive means according to the load state of the steering shaft drive means driven by the first control means. apparatus. 2. The steering device according to claim 1, wherein the second control unit determines whether the load state of the steering shaft driving unit is large or small, and drives the steering shaft driving unit when the load state of the steering shaft driving unit is large. Performing control, third control means for turning the steered wheels to a steering position corresponding to the steering position, and when the load state of the steering shaft drive means is small, performing drive control of the steering shaft drive means, The steering control device according to claim 1, further comprising: a fourth control unit configured to rotate the steering handle to a steering position corresponding to the steered position. 3. The load state detecting means is one of a current sensor for detecting a drive current of the steering shaft driving means and a torque sensor for detecting a steering torque applied to the steering wheel. Or the steering control device according to 2.