JP7155668B2 - Steering control device and steering control method - Google Patents

Description

The present disclosure relates to a steering control device and a steering control method.

For example, Patent Literature 1 discloses a steering system that includes an actuator that applies a rotational force to a steering shaft. This steering system applies an assisting force by driving an actuator to a steering shaft that rotates as a steering wheel is rotated. In addition, the steering system applies a rotational force to the steering shaft by driving the actuator, for example, during automatic driving or when the driver cannot normally rotate the steering wheel.

JP 2015-140102 A

In the steering system described above, there is a demand to give priority to steering by the driving force of the actuator over steering by rotating the steering wheel.

An object of the present disclosure is to provide a steering control device and a steering control method that can give priority to steering using the driving force of an actuator over steering based on turning operation of a steering wheel.

A steering control device according to an aspect of the present disclosure includes a steering shaft connected to a steering wheel, an actuator that applies a rotational force to the steering shaft, and a steering shaft provided between the steering wheel and the actuator. and a power connecting/disconnecting mechanism, wherein the state of the driver detected by a detection device in the vehicle interior when the power connecting/disconnecting mechanism is in the connected state. a determination unit that determines whether or not an abnormal state has occurred in which the driver cannot normally rotate the steering wheel based on the information indicating that the driver is in the abnormal state and a control unit for switching the power connection/disconnection mechanism from the connected state to the disconnected state.

A steering control method according to an aspect of the present disclosure includes a steering shaft connected to a steering wheel, an actuator that applies a rotational force to the steering shaft, and a steering shaft provided between the steering wheel and the actuator. A steering control method for controlling a steering device of a vehicle, comprising: a power connecting/disconnecting mechanism; and a state of a driver detected by a detection device in the vehicle interior when the power connecting/disconnecting mechanism is in a connected state. based on the information indicating whether or not the driver is in an abnormal state in which the driver cannot normally rotate the steering wheel, and if the driver is in the abnormal state, the connected state is switched to the disconnected state.

According to the present disclosure, it is possible to give priority to steering using the driving force of the actuator over steering based on rotating operation of the steering wheel.

Schematic diagram showing an example of a configuration of a steering system according to an embodiment of the present disclosure 1 is a block diagram showing an example configuration of a steering control device according to an embodiment of the present disclosure; FIG. Flowchart showing an example of the operation of the steering control device according to the embodiment of the present disclosure Schematic diagram showing an example of a configuration of a steering device according to a modified example of the present disclosure

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

First, the configuration of a steering device 1 according to an embodiment of the present disclosure will be described using FIG. 1 . FIG. 1 is a schematic diagram showing an example of the configuration of the steering device 1. As shown in FIG. In FIG. 1, FR indicates the front of the vehicle, and UP indicates the upper side of the vehicle.

A steering device 1 is mounted on a vehicle having a cabin 2 . The vehicle is, for example, a cab-over type vehicle (eg, truck, bus, van, etc.) having a cabin 2 above an internal combustion engine (not shown).

The steering device 1 includes a steering wheel 3, a first steering shaft 4, a first joint portion 5, a second steering shaft 6, a second joint portion 10, a third steering shaft 11, a power steering unit 12, a pitman arm 13, and a drag link. 14 , a coaxial motor 20 and a clutch 30 .

The steering wheel 3 is a device that is rotated by the driver when steering the vehicle.

The first steering shaft 4 is a rotatable rod-shaped member, one end of which is connected to the steering wheel 3 and the other end of which is connected to the first joint portion 5 .

The first joint portion 5 connects the first steering shaft 4 and the second steering shaft 6 at a predetermined angle.

The periphery of the first steering shaft 4 is covered with a tubular upper cover (also called a steering cowl) 8 . On the other hand, the periphery of the first joint portion 5 is covered with a tubular lower cover (also called a column cover or a column boot) 9 . The upper end of the lower cover 9 is connected to the lower end of the upper cover 8 , and the lower end of the lower cover 9 is fixed to the floor (bottom) 7 of the passenger compartment 2 . Note that the upper cover 8 and the lower cover 9 may not be provided.

The second steering shaft 6 is a rotatable rod-shaped member. For example, a shaft (not shown) and a cylindrical member (not shown) surrounding the shaft are connected so as to be relatively slidable in the axial direction. It is a shaft that is made telescopic.

The second steering shaft 6 has one end connected to the first joint portion 5 and the other end connected to a second joint portion 10 provided below the floor portion 7 (outside the vehicle compartment 2). Specifically, the other end of the second steering shaft 6 is inserted through an opening (not shown) formed in the floor portion 7 and connected to the second joint portion 10 .

A clutch 30 (an example of a power connection/disconnection mechanism) is interposed on the second steering shaft 6 . As the clutch 30, for example, a multi-plate clutch or a two-way clutch can be used.

When the clutch 30 is in the engaged state, the torque generated by rotating the steering wheel 3 is transmitted to the power steering unit 12 via the first steering shaft 4 , the second steering shaft 6 and the third steering shaft 11 .

When the clutch 30 is in the disengaged state (disconnected state), the torque generated by operating the steering wheel 3 is blocked by the second steering shaft 6 and is not transmitted to the third steering shaft 11 and the power steering unit 12 .

Clutch 30 is normally in the connected state, but is controlled from the connected state to the disconnected state by steering control device 100 (see FIG. 2), which will be described later, when a preset disengagement condition is satisfied. The control processing of the steering control device 100 will be described later with reference to FIGS. 2 and 3. FIG.

The second joint portion 10 connects the second steering shaft 6 and the third steering shaft 11 at a predetermined angle.

A lower cover 9 covers a portion of the second steering shaft 6 positioned above the floor 7 (the portion positioned inside the vehicle interior 2 ).

The third steering shaft 11 is a rotatable rod-shaped member, one end of which is connected to the second joint portion 10, and the other end of which is connected to an input shaft (not shown) of a power steering unit (also referred to as a steering gear box) 12. It is An input shaft of the power steering unit 12 is provided coaxially with the third steering shaft 11 .

The power steering unit 12 is arranged below the floor 7 (in other words, outside the vehicle compartment 2). The power steering unit 12 converts the rotational force transmitted as described above into a large force that swings the pitman arm 13 . As a result, the pitman arm 13 swings, the drag link 14 is pushed and pulled, and the wheels (not shown) are steered via the knuckle arms and tie rods (both not shown).

The power steering unit 12 is of a hydraulic type, for example, and two oil pumps (not shown) of main and sub systems are connected via one or more oil passages. As a result, even if the main oil pump fails, the sub oil pump can cope with the problem, so the operation of the power steering unit 12 is continued. The oil pump connected to the power steering unit 12 may be of one system. Moreover, the power steering unit 12 is not limited to a hydraulic type, and may be an electric type.

A coaxial motor 20 (an example of an actuator) is provided directly above the power steering unit 12 and attached to the third steering shaft 11 . By providing the coaxial motor 20 below the floor 7 of the passenger compartment in this manner, the layout of the passenger compartment can be improved.

An output shaft (not shown) of the coaxial motor 20 is provided coaxially with the third steering shaft 11 . Since the input shaft of the power steering unit 12 is provided coaxially with the third steering shaft 11 as described above, the output shaft of the coaxial motor 20 is provided coaxially with the input shaft of the power steering unit 12. I can say

The coaxial motor 20 is driven under the control of an actuator control device (not shown) and imparts rotational force to the third steering shaft 11 . For example, the actuator control device drives the coaxial motor 20 so that a predetermined rotational force is applied to the third steering shaft 11 at a predetermined timing when the automatic driving function is executed. Automatic driving functions include, for example, automatic parking and lane keeping assist during cruise control. The actuator control device is implemented by, for example, an ECU (Electric Control Unit).

A rotational force applied to the third steering shaft 11 by driving the coaxial motor 20 is transmitted to the power steering unit 12 .

The configuration of the steering device 1 has been described above.

Next, the configuration of steering control device 100 according to the embodiment of the present disclosure will be described using FIG. FIG. 2 is a block diagram showing an example of the configuration of the steering control device 100. As shown in FIG. The steering control device 100 is mounted on a vehicle having the steering device 1 .

As shown in FIG. 2 , the steering control device 100 has a determination section 101 and a control section 102 .

Although not shown, the steering control device 100 includes, for example, a CPU (Central Processing Unit), a storage medium such as a ROM (Read Only Memory) storing a control program, a working memory such as a RAM (Random Access Memory), and It has a communication circuit. Functions of the determination unit 101 and the control unit 102, which will be described later, are realized by the CPU executing a computer program.

When the clutch 30 is in the engaged state, the determination unit 101 determines whether or not a preset disengagement condition relating to the running of the vehicle or the state of the driver of the vehicle is satisfied.

The disconnection condition is, for example, that automatic operation of the vehicle has started, or that the driver has fallen into a state in which the steering wheel 3 cannot be rotated normally (hereinafter referred to as an abnormal state).

For example, the determination unit 101 determines that the disconnection condition is satisfied when the driver performs an operation to instruct the start of automatic operation, or when a signal indicating the start of automatic operation is received from the ECU or the like. .

Also, for example, the determination unit 101 receives information indicating the state of the driver detected by a predetermined detection device, and determines whether the driver is in an abnormal state based on the information. Then, when the driver is in an abnormal state, the determination unit 101 determines that the disconnection condition is satisfied. Examples of the detection device include a camera that is installed in the vehicle interior 2 and captures the driver, and a sensor that is attached to the driver and acquires the driver's biological information.

The determination processing by the determination unit 101 described above is executed at any time, for example, when the vehicle starts running.

The control unit 102 switches the clutch 30 from the connected state to the disconnected state when the disconnection condition is satisfied.

The configuration of the steering control device 100 has been described above.

Next, operation of the steering control device 100 will be described with reference to FIG. FIG. 3 is a flow chart showing an example of the operation of the steering control device 100. As shown in FIG.

First, the determination unit 101 determines whether or not a preset cutting condition is satisfied (step S101).

If the disconnection condition is not satisfied (step S101: NO), the flow returns to step S101.

If the disconnection condition is satisfied (step S101: YES), the control unit 102 switches the clutch 30 from the connected state to the disconnected state (step S102). As a result, the torque of the steering wheel 3 is no longer transmitted to the third steering shaft 11 and the power steering unit 12 .

The operation of the steering control device 100 has been described above.

Next, the effects of this embodiment will be described.

If the steering system 1 were not provided with the clutch 30, the rotational force of the steering wheel 3 would always be transmitted to the power steering unit 12, which would cause the following problems.

For example, if the unconscious driver falls onto the steering wheel 3 and rotates the steering wheel 3 as a result, the safety of driving may be impaired.

Further, for example, during automatic driving, the steering wheel 3 rotates even if the driver does not perform a rotating operation, so there is a risk that the driver's clothing or the like may get caught in the steering wheel 3 .

Therefore, as described above, the steering control device 100 is provided on the second steering shaft 6 between the steering wheel 3 and the coaxial motor 20 when automatic driving is executed or when the driver is in an abnormal state. The connected clutch 30 is switched from the connected state to the disconnected state. Thereby, it is possible to prevent the rotational force of the steering wheel 3 from being transmitted to the coaxial motor 20 . Therefore, steering by the driving force of the coaxial motor 20 can be given priority over steering by rotating the steering wheel 3 . As a result, the problems described above can be avoided.

The effects of the present embodiment have been described above.

It should be noted that the present disclosure is not limited to the embodiments described above, and can be modified as appropriate without departing from the gist of the present disclosure. Each modification will be described below.

[Modification 1]
Although the case where the clutch 30 is provided on the second steering shaft 6 has been described as an example in the embodiment, the present invention is not limited to this. In the configuration of FIG. 1 , the clutch 30 may be provided on the first steering shaft 4 or the third steering shaft 11 . Note that when the clutch 30 is provided on the third steering shaft 11 , the clutch 30 is provided on the third steering shaft 11 above the coaxial motor 20 .

[Modification 2]
In the embodiment, the case where the coaxial motor 20 is provided on the third steering shaft 11 has been described as an example, but the present invention is not limited to this. For example, the coaxial motor 20 may be provided on the first steering shaft 4 or the second steering shaft 6 .

FIG. 4 shows a configuration in which the coaxial motor 20 is provided on the first steering shaft 4. As shown in FIG. In this case, the clutch 30 is provided on the first steering shaft 4 above the coaxial motor 20, as shown in FIG.

Although illustration is omitted, when the coaxial motor 20 is provided on the second steering shaft 6 , the clutch 30 is provided on the first steering shaft 4 or the second steering shaft 6 above the coaxial motor 20 . be done.

[Modification 3]
In the embodiment, the case where the steering device 1 is of a ball screw type has been described as an example, but the present invention is not limited to this, and the steering device 1 may be of a rack and pinion type.

[Modification 4]
In the embodiment, the case where the actuator is the coaxial motor 20 has been described as an example, but the present invention is not limited to this. For example, the actuator may be a motor that applies rotational force to the third steering shaft 11 via a speed reducer.

[Modification 5]
The control unit 102 of the steering control device 100 may perform control to return the disconnected clutch 30 to the connected state. The timing at which this control is performed is, for example, when an instruction operation to return the clutch 30 to the engaged state is performed, when automatic driving is terminated, or when the vehicle stops running.

Each modification has been described above. In addition, each modification may be implemented in combination.

The steering control device and steering control method of the present disclosure can be applied to techniques for controlling steering.

REFERENCE SIGNS LIST 1 steering device 2 vehicle compartment 3 steering wheel 4 first steering shaft 5 first joint portion 6 second steering shaft 7 floor portion 8 upper cover 9 lower cover 10 second joint portion 11 third steering shaft 12 power steering unit 13 pitman arm 14 Drag link 20 Coaxial motor 30 Clutch 100 Steering control device 101 Determination unit 102 Control unit

Claims (3)

A vehicle comprising: a steering shaft connected to a steering wheel; an actuator that imparts a rotational force to the steering shaft; and a power connection/disconnection mechanism provided between the steering wheel and the actuator on the steering shaft. A steering control device for controlling a steering device,
When the power connection/disconnection mechanism is in the connected state, the driver cannot normally rotate the steering wheel based on the information indicating the driver's state detected by the detection device in the vehicle compartment. a determination unit that determines whether an abnormal state has occurred ;
a control unit that switches the power connection/disconnection mechanism, which is in a connected state, to a disconnected state when the driver is in the abnormal state ;
Steering control device. The actuator is
provided below the floor of the compartment of the vehicle,
A steering control device according to claim 1 . A vehicle comprising: a steering shaft connected to a steering wheel; an actuator that imparts a rotational force to the steering shaft; and a power connection/disconnection mechanism provided between the steering wheel and the actuator on the steering shaft. A steering control method for controlling a steering device,
When the power connection/disconnection mechanism is in the connected state, the driver cannot normally rotate the steering wheel based on the information indicating the driver's state detected by the detection device in the vehicle compartment. Determine whether an abnormal state has occurred,
When the driver is in the abnormal state, the power connection/disconnection mechanism, which is in the connected state, is switched to the disconnected state.
Steering control method.

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