KR20230162304A - Emergency steering apparatus using rear wheel steering apparatus of vehicle and control method thereof - Google Patents

Abstract

The present invention relates to an emergency steering apparatus using a rear wheel steering apparatus of a vehicle, wherein the emergency steering apparatus includes: a steering angle sensor module outputting a front wheel steering command generated by reflecting a gear ratio on steering angle information of a steering wheel detected by a steering angle sensor; a yaw rate sensor module detecting a yaw rate of the vehicle; and a processor, when receiving a front wheel failure signal from a front wheel drive module, starting the operation of an emergency steering mode by a rear wheel steering apparatus, thereby controlling only the rear wheel steering apparatus without controlling a front wheel steering apparatus to steer the vehicle in a direction according to the control of a steering wheel. Therefore, the present invention is capable of improving user safety by allowing a vehicle to be moved from a dangerous area to a safe zone.

Description

Emergency steering device and control method using the rear wheel steering device of a vehicle {EMERGENCY STEERING APPARATUS USING REAR WHEEL STEERING APPARATUS OF VEHICLE AND CONTROL METHOD THEREOF}

The present invention relates to an emergency steering device and a control method using the rear-wheel steering device of a vehicle. More specifically, when the front-wheel steering device loses function or malfunctions, the rear-wheel steering device (RWS) is switched to emergency steering mode to drive the rear wheel steering device. It relates to an emergency steering device using a rear wheel steering device of a vehicle and a method of controlling the same, which allows the vehicle to be steered through control of the steering device.

Active front steering (AFS), which is generally applied to vehicles, has a steering gear ratio variable device between the steering wheel and the steering actuator, receives the steering angle of the steering wheel and outputs the changed rotation angle to the AFS actuator. By varying the steering gear ratio, front-wheel steering responsiveness and driving stability are provided.

In addition, the rear wheel steering (RWS: Real Wheel Steering) determines the rear wheel angle by receiving inputs such as the steering angle and vehicle speed, and controls the rear wheel angle by driving the RWS actuator to provide rear wheel steering responsiveness and driving stability.

As described above, the rear-wheel steering system improves rear-wheel steering responsiveness by narrowing the turning radius by steering the rear wheels in the opposite direction to the steering direction of the front wheels when the vehicle is traveling at low speeds, and also improves rear-wheel steering responsiveness when the vehicle is traveling at high speeds by steering the rear wheels in the opposite direction to the steering direction of the front wheels. It provides driving stability by reducing the yaw rate by steering in the same direction as the steering direction.

As described above, in the past, the rear wheel steering device simply assisted the operation of the front wheel steering device, giving priority to steering responsiveness when driving at low speeds, and controlling the rear wheels to prioritize driving stability when driving at high speeds.

However, in SBW (Steer By Wire) vehicles where the mechanical connection structure between the steering wheel and the rack bar is lost, if a malfunction occurs in the front wheel steering system, there is a problem that a situation may occur in which steering (or steering) in the driver's intended direction is impossible. there is. Therefore, when a loss of function or malfunction of the front-wheel steering device occurs as described above, there is a need for the development of technology that can control the rear-wheel steering device to steer (or steer) as intended by the driver.

The background technology of the present invention is disclosed in Republic of Korea Patent No. 10-2277285 (registered on July 8, 2021, rear-wheel steering control device and method).

According to one aspect of the present invention, the present invention was created to solve the above problems, and when the function of the front wheel steering system is lost or a malfunction occurs, the rear wheel steering system (RWS) is switched to the emergency steering mode to control the rear wheel steering system. The purpose is to provide an emergency steering device using a rear wheel steering device of a vehicle and a method of controlling the same, which allows the vehicle to be steered through control of .

An emergency steering device using a rear-wheel steering device of a vehicle according to an aspect of the present invention includes a steering angle sensor module that outputs a front-wheel steering command generated by reflecting a gear ratio to steering angle information of the steering wheel detected by a steering angle sensor; A yaw rate sensor module that detects the yaw rate of the vehicle; And when a front wheel failure signal is received from the front wheel drive module, the operation of the emergency steering mode by the rear wheel steering device is initiated, so that only the rear wheel steering device is controlled without controlling the front wheel steering device at all, and the direction according to the operation of the steering wheel is controlled. Characterized in that it includes a processor that steers the vehicle.

In the present invention, the processor actively controls the rear-wheel steering device in response to the current yaw rate of the vehicle by directly receiving the current yaw rate of the vehicle that changes as the rear-wheel steering device is controlled. Do it as

In the present invention, the emergency steering mode by the rear wheel steering device is a mode that allows the yaw rate control command to be generated through front wheel steering in a normal situation in which a front wheel failure does not occur to be generated by controlling only the rear wheel steering device. It is characterized by what it means.

In the present invention, when the processor starts operation of the emergency steering mode, it generates a yaw rate control command corresponding to the driver's steering wheel steering based on the front wheel steering command and pre-stored vehicle parameter information, It is characterized by outputting a RWS (Rear Wheel Steering) control command for controlling the rear wheel drive device based on a yaw rate command.

In the present invention, the vehicle parameter information is characterized as information reflecting wheel characteristics and gear characteristics for each vehicle.

In the present invention, the processor receives the current yaw rate of the vehicle detected through a yaw rate sensor module, corrects the yaw rate control command based on the current yaw rate of the vehicle, and then adjusts the yaw rate control command based on the current yaw rate of the vehicle. Characterized in that an RWS control command for controlling the rear-wheel drive device is output based on a control command.

A method of controlling an emergency steering device using a rear wheel steering device of a vehicle according to another aspect of the present invention includes the steps of having a processor receive a front wheel failure signal from a front wheel drive module; And upon receiving the front wheel high-altitude signal, the processor initiates the operation of the emergency steering mode by the rear wheel steering device, thereby controlling only the rear wheel steering device without controlling the front wheel steering device at all, and steering in the direction according to the operation of the steering wheel. Characterized in that it includes a step of steering the vehicle.

In the present invention, in the step of controlling only the rear-wheel steering device, the processor directly receives the current yaw rate of the vehicle, which changes as the rear-wheel drive device is controlled, and responds to the current yaw rate of the vehicle by directly receiving the yaw rate of the vehicle. It is characterized by actively controlling the rear-wheel drive system.

In the present invention, the emergency steering mode by the rear wheel steering device is a mode that allows the yaw rate control command to be generated through front wheel steering in a normal situation in which a front wheel failure does not occur to be generated by controlling only the rear wheel steering device. It is characterized by what it means.

In the present invention, when the operation of the emergency steering mode is initiated, the processor generates a yaw rate control command corresponding to the driver's steering wheel steering based on the front wheel steering command and pre-stored vehicle parameter information, A rear wheel steering (RWS) control command for controlling the rear wheel drive device is output based on the yaw rate command.

In the present invention, the vehicle parameter information is characterized as information reflecting wheel characteristics and gear characteristics for each vehicle.

In the present invention, in the process of generating the yaw rate control command, the processor receives the current yaw rate of the vehicle detected through the yaw rate sensor module and controls the yaw rate based on the current yaw rate of the vehicle. After correcting the command, an RWS control command for controlling the rear-wheel drive device is output based on the corrected yaw rate control command.

According to one aspect of the present invention, when a malfunction or malfunction of the front wheel steering device occurs, the rear wheel steering device (RWS) is switched to an emergency steering mode to steer the vehicle through control of the rear wheel steering device, User safety can be improved by allowing the vehicle to be moved from a dangerous area to a safe area.

1 is an exemplary diagram showing the schematic configuration of an emergency steering device using a rear wheel steering device of a vehicle according to an embodiment of the present invention.
Figure 2 is an example diagram showing a more detailed configuration of the processor in Figure 1.
Figure 3 is a flowchart illustrating a method of controlling a rear wheel steering device of a vehicle according to the first embodiment of the present invention.
Figure 4 is an example diagram shown in Figure 3 to explain the effect of allowing the vehicle to move to a safe area by controlling only the rear wheel steering system in a situation where the front wheel steering system cannot be controlled at all due to a malfunction.
Figure 5 is a flowchart illustrating a method of controlling a rear wheel steering device of a vehicle according to a second embodiment of the present invention.
6 shows that in FIG. 5, in a situation where the front wheel steering device cannot be controlled at all due to a malfunction and it is difficult to steer the front wheels forward by rear wheel steering due to the large friction force caused by the twisted angle of the front wheels, the vehicle is rotated An example shown to explain the operation of turning the rear wheels forward and then controlling the rear wheel steering to move the vehicle to a safe area.

Hereinafter, an embodiment of an emergency steering device and its control method using a rear wheel steering device of a vehicle according to the present invention will be described with reference to the attached drawings.

In this process, the thickness of lines or sizes of components shown in the drawing may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are terms defined in consideration of functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, definitions of these terms should be made based on the content throughout this specification.

FIG. 1 is an exemplary diagram showing a schematic configuration of an emergency steering device using a rear wheel steering device of a vehicle according to an embodiment of the present invention, and FIG. 2 is an exemplary diagram showing a more detailed configuration of the processor in FIG. 1. .

As shown in FIG. 1, the emergency steering device using the rear wheel steering device of a vehicle according to this embodiment includes a steering angle sensor module 110, a yaw rate sensor module 120, a processor 130, and a rear wheel drive module 140. ), and the processor 130 may include a yaw rate calculation module 131 and a Rear Wheel Steering (RWS) control module 132.

The steering angle sensor module 110 detects the steering angle of the steering wheel operated by the driver through the steering angle sensor and transmits it to the processor 130. More precisely, the steering angle sensor module 110 detects the steering angle information detected by the steering angle sensor. A front wheel steering command generated by reflecting the gear ratio is transmitted to the processor 130.

Meanwhile, although not specifically shown in the drawing according to this embodiment, if it is desired to control the rear-wheel steering system by reflecting the vehicle speed, a vehicle speed sensor (not shown) may be further included, and a front-wheel drive module (not shown) may be used. A front wheel failure can be detected and a front wheel failure signal can be transmitted to the processor 130. Additionally, a lane detection module (not shown) can detect the lane of the road on which the vehicle is traveling and transmit the corresponding lane information to the processor 130. You can.

The yaw rate sensor module 120 detects the current yaw rate of the vehicle and transmits it to the processor 130.

For example, by directly receiving the current yaw rate of the vehicle that changes as the processor 130 controls the rear-wheel drive module 140 (or rear-wheel drive device), the processor 130 controls the rear-wheel drive module 140 (or rear-wheel drive system) can be actively controlled.

Hereinafter, based on the information received by the processor 130 (e.g., front wheel failure signal, front wheel steering command, lane information, yaw rate), the processor 130 performs an emergency operation by the rear wheel steering device when the front wheel steering device fails. The steering mode operation method will be described in detail.

When the yaw rate calculation module 131 receives a front wheel failure signal, it initiates an emergency steering mode operation, and the front wheel steering command (or steering angle) generated and transmitted from the information detected by the steering angle sensor module 110 and the internal memory ( Based on vehicle parameter information (e.g., information reflecting wheel characteristics and gear characteristics for each vehicle) previously stored in the device (not shown), a yaw rate control command is generated to steer the vehicle in the direction and angle desired by the driver (i.e., In order to steer the vehicle in the direction and angle desired by the driver, a yaw rate control command corresponding to the driver's steering wheel is generated).

Additionally, the RWS control module 132 outputs an RWS control command for controlling the rear-wheel drive module 140 based on the yaw rate command generated by the yaw rate calculation module 131.

However, since the yaw rate control command is a command suitable for a normal state in which a front wheel failure does not occur, it is an unsuitable command in an abnormal state in which a current failure occurs as described above.

For example, the angle of the front wheel may be arbitrarily fixed depending on the abnormal state in which the front wheel failure occurs. For example, as shown in (a) of FIG. 6, the front wheel (F) may be fixed at 0 degrees facing forward, or as shown in (b) of FIG. 6, the front wheel (F) may be fixed at 0 degrees in the front. It may be fixed and twisted at an arbitrary angle to the left or right. Accordingly, since the degree of friction applied varies depending on the angle at which the front wheels are twisted, the vehicle may not be steered to the originally intended angle by a yaw rate command appropriate for the normal state.

Therefore, the processor 130 detects and immediately receives the current yaw rate of the vehicle through the yaw rate sensor module 120, corrects the yaw rate control command based on the current yaw rate of the vehicle, and corrects the yaw rate control command based on the current yaw rate of the vehicle. An RWS control command for controlling the rear-wheel drive module 140 is output based on the yaw rate control command.

That is, the processor 130 allows the yaw rate control command, which must be generated through front-wheel steering in a normal situation in which a front wheel failure does not occur, to be generated by controlling only the rear-wheel steering device.

FIG. 3 is a flowchart illustrating a method of controlling the rear-wheel steering device of a vehicle according to the first embodiment of the present invention, and FIG. 4 is a flow chart in FIG. 3 in a situation in which the front-wheel steering device cannot be controlled at all due to a malfunction. This is an example diagram shown to explain the effect of controlling only the rear wheel steering system to move the vehicle to a safe area.

Referring to FIG. 3, when the processor 130 receives a front wheel failure signal from a front wheel drive module (not shown) (i.e., when a failure of the front wheel steering device occurs) (example of S101), rear wheel steering is performed according to a predetermined algorithm. Emergency steering mode operation by the device is initiated (S102).

Here, the emergency steering mode by the rear-wheel steering device refers to a mode that allows the yaw rate control command to be generated through front-wheel steering in a normal situation in which a front wheel failure does not occur to be generated by controlling only the rear-wheel steering device.

When the emergency steering mode operation is initiated as described above, the processor 130 pre-stores the front wheel steering command (or steering angle) generated and transmitted from the information detected by the steering angle sensor module 110 in the internal memory (not shown). Based on the existing vehicle parameter information (e.g., information reflecting wheel characteristics and gear characteristics for each vehicle), a yaw rate control command for the vehicle is generated to steer the vehicle in the direction and angle desired by the driver (S103).

However, since the yaw rate control command is a command that does not reflect the state of the failed front wheel (e.g., the angle at which the front wheel is twisted), the processor 130 determines the current yaw rate value of the vehicle through the yaw rate sensor module 120. RWS control for detecting and transmitting (S104), correcting the yaw rate control command based on the current yaw rate value of the vehicle, and controlling the rear-wheel drive module 140 based on the corrected yaw rate control command. Output the command (S105).

As described above, in this embodiment, as shown in (a) of FIG. 4, when the vehicle cannot be steered due to a failure of the front wheel steering device, the vehicle cannot be steered in the desired direction, which may cause an accident. To improve the problem, as shown in (b) of FIG. 4, when a malfunction occurs in the front wheel steering device and the front wheels cannot be operated at all, the rear wheel steering device is controlled to steer the vehicle in the desired direction, thereby steering the vehicle in the desired direction. You can move it to a safe area (e.g. shoulder of the road).

FIG. 5 is a flowchart for explaining a method of controlling the rear-wheel steering device of a vehicle according to a second embodiment of the present invention, and FIG. 6 is a flowchart showing the control method of the rear-wheel steering device of a vehicle in a situation in which the front-wheel steering device cannot be controlled at all due to a malfunction in FIG. If it is difficult to steer the front wheels forward by rear-wheel steering due to the large friction caused by the twisted angle of the front wheels, turn the vehicle to point the rear wheels forward and then control the rear-wheel steering system to move the vehicle to a safe area. This is an example shown to explain the operation.

Referring to FIG. 5, the processor 130 receives a front wheel failure signal from a front wheel drive module (not shown) (i.e., a failure of the front wheel steering device occurs), and the angle of the front wheel (i.e., the angle at which the front wheel is twisted) changes. If the deviation exceeds the standard (example in S201), an emergency steering mode operation by the rear wheel steering device is initiated according to a pre-designated algorithm (S202).

Here, the angle of the front wheel (i.e., the angle at which the front wheel is twisted) is detected through a front wheel drive module (not shown), or detected through a yaw rate control command and the yaw rate sensor module 120 as described in FIG. 3. It can be detected indirectly by comparing the vehicle's current yaw rate value.

As described above, when the emergency steering mode operation is initiated in a state where the angle of the front wheels (i.e., the angle at which the front wheels are twisted) is deviated more than the standard, the processor 130 turns the rear wheels (R) toward the front (i.e., the desired driving direction). Rotate the direction in which the vehicle is facing (i.e., rotate the rear wheels in reverse so that the rear wheels face forward, so that the rear wheels (R) are dragged in front of the front wheels (F), thereby rotating the direction in which the vehicle is facing) (S203) (Figure (see (b) of 6).

When the direction in which the vehicle is facing is rotated as above, the rear wheels face forward and the front wheels face rearward, so the driver must operate the steering wheel while facing rearward, so turn the steering wheel in the opposite direction to the direction in which you want to drive the vehicle. It is inconvenient to operate it.

Accordingly, when the user precedes automatic steering (i.e., an automatic steering mode that can be selected when the direction the vehicle is facing is reversed due to a turn), the processor 130 detects through a lane detection module (not shown). Lane information is received, and based on the lane information, vehicle parameter information (e.g., information reflecting wheel characteristics and gear characteristics for each vehicle) previously stored in the internal memory (not shown) is applied in a designated direction (e.g., outside the lane). Generates a yaw rate control command for the vehicle to steer the vehicle in the shoulder direction (S204).

At this time, if there is no shoulder or the shoulder is too narrow, the user can intervene (i.e., operate the steering wheel) to change the automatic steering direction to a designated direction (e.g., the direction of the shoulder outside the lane).

In addition, when the automatic steering direction is changed during the automatic steering or by user intervention, the processor 130 detects and receives the current yaw rate value of the vehicle through the yaw rate sensor module 120 (S205), The yaw rate control command is corrected based on the current yaw rate value of the vehicle, and an RWS control command for controlling the rear-wheel drive module 140 is output based on the corrected yaw rate control command (S206).

As described above, in this embodiment, as shown in (a) of FIG. 6, when the vehicle cannot be steered due to a failure of the front wheel steering device, the vehicle cannot be steered in the desired direction, which may cause an accident. To improve the problem, as shown in (b) of FIG. 4, when a malfunction occurs in the front wheel steering device and the front wheels cannot be operated at all, the rear wheel steering device is controlled to steer the vehicle in the desired direction, thereby steering the vehicle in the desired direction. You can move it to a safe area (e.g. shoulder of the road).

As shown in (a) of FIG. 6, the front wheel (F) is not fixed at 0 degrees facing forward, but the front wheel (F) is fixed at a random angle to the left or right from the front, so a friction force acts. If the vehicle is not steered at the originally intended angle, as shown in (b) of FIG. 6, rotate the direction in which the vehicle is facing so that the rear wheels (R) face forward (i.e., the direction in which you want to drive). By rotating the rear wheels in reverse so that the rear wheels face forward, the direction in which the vehicle is facing is rotated so that the rear wheels (R) are dragged in front of the front wheels (F), and then automatic steering based on lane information or manual steering through driver intervention. By this, in a situation where the failed front wheel cannot be operated at all, only the rear wheel steering device is controlled to steer the vehicle in the desired direction, allowing the vehicle to be moved to a safe area (e.g., shoulder of the road).

As described above, this embodiment switches the rear wheel steering system (RWS) to emergency steering mode when the front wheel steering system loses function or malfunctions, allowing the vehicle to be steered through control of the rear wheel steering system, thereby ensuring safety from dangerous areas. It has the effect of improving user safety by allowing vehicles to be moved to the area.

As described above, the present invention has been described with reference to the embodiments shown in the drawings, but these are merely illustrative, and various modifications and equivalent embodiments can be made by those skilled in the art. You will understand the point. Therefore, the scope of technical protection of the present invention should be determined by the scope of the patent claims below. Implementations described herein may also be implemented as, for example, a method or process, device, software program, data stream, or signal. Although discussed only in the context of a single form of implementation (eg, only as a method), implementations of the features discussed may also be implemented in other forms (eg, devices or programs). The device may be implemented with appropriate hardware, software, firmware, etc. The method may be implemented in a device such as a processor, which generally refers to a processing device including a computer, microprocessor, integrated circuit, or programmable logic device. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants (“PDAs”) and other devices that facilitate communication of information between end-users.

110: Steering angle sensor module
120: Yaw rate sensor module
130: processor
131: Yaw rate calculation module
132: RWS (Rear Wheel Steering) control module
140: Rear-wheel drive module

Claims (12)

a steering angle sensor module that outputs a front wheel steering command generated by reflecting the gear ratio to the steering angle information of the steering wheel detected by the steering angle sensor;
A yaw rate sensor module that detects the yaw rate of the vehicle; and
When a front wheel failure signal is received from the front wheel drive module, the operation of the emergency steering mode by the rear wheel steering device is initiated, so that only the rear wheel steering device is controlled without controlling the front wheel steering device at all, and the vehicle is steered in the direction according to the operation of the steering wheel. An emergency steering device using a rear wheel steering device of a vehicle, comprising: a processor for steering.
The method of claim 1, wherein the processor:
By directly receiving the current yaw rate of the vehicle, which changes as the rear-wheel steering device is controlled, the rear-wheel steering device is actively controlled in response to the current yaw rate of the vehicle. Emergency steering device.
The method of claim 1, wherein the emergency steering mode by the rear wheel steering device is:
An emergency steering device using the rear wheel steering device of a vehicle, which means a mode that allows the yaw rate control command, which must be generated through front wheel steering in a normal situation in which a front wheel failure does not occur, to be generated by controlling only the rear wheel steering device. .
The method of claim 1, wherein the processor:
When the operation of the emergency steering mode is initiated, a yaw rate control command corresponding to the driver's steering wheel steering is generated based on the front wheel steering command and pre-stored vehicle parameter information, and the rear wheel drive is driven based on the yaw rate command. An emergency steering device using a rear wheel steering device of a vehicle, characterized in that it outputs RWS (Rear Wheel Steering) control commands to control the device.
The method of claim 4, wherein the vehicle parameter information is:
An emergency steering device using a rear-wheel steering device of a vehicle, characterized in that the information reflects the wheel characteristics and gear characteristics of each vehicle.
The method of claim 4, wherein the processor:
After receiving the current yaw rate of the vehicle detected through the yaw rate sensor module, correcting the yaw rate control command based on the current yaw rate of the vehicle, and then based on the corrected yaw rate control command, the rear-wheel drive device An emergency steering device using a rear wheel steering device of a vehicle, characterized in that it outputs an RWS control command to control.
A processor receiving a front wheel failure signal from a front wheel drive module; and
Upon receiving the front wheel high-phase signal, the processor initiates an operation of the emergency steering mode by the rear wheel steering device, thereby controlling only the rear wheel steering device without controlling the front wheel steering device at all, thereby steering the vehicle in the direction according to the operation of the steering wheel. A method of controlling an emergency steering device using a rear wheel steering device of a vehicle, comprising: steering.
The method of claim 7, wherein in the step of controlling only the rear wheel steering device,
The processor,
By directly receiving the current yaw rate of the vehicle that changes as the rear-wheel drive device is controlled, the rear-wheel drive device is actively controlled in response to the current yaw rate of the vehicle using a rear-wheel steering device. Control method of emergency steering device.
The method of claim 7, wherein the emergency steering mode by the rear wheel steering device is:
An emergency steering device using the rear wheel steering device of a vehicle, which means a mode that allows the yaw rate control command, which must be generated through front wheel steering in a normal situation in which a front wheel failure does not occur, to be generated by controlling only the rear wheel steering device. control method.
The method of claim 7, wherein when the operation of the emergency steering mode is initiated,
The processor,
Based on the front wheel steering command and pre-stored vehicle parameter information, a yaw rate control command corresponding to the driver's steering wheel is generated, and RWS (Rear Wheel Drive) is used to control the rear wheel drive device based on the yaw rate command. Steering) A control method of an emergency steering device using a rear wheel steering device of a vehicle, characterized by outputting a control command.
The method of claim 10, wherein the vehicle parameter information is:
A method of controlling an emergency steering device using a rear wheel steering device of a vehicle, characterized in that the information reflects the wheel characteristics and gear characteristics of each vehicle.
The method of claim 10, wherein in the process of generating the yaw rate control command,
The processor,
After receiving the current yaw rate of the vehicle detected through the yaw rate sensor module, correcting the yaw rate control command based on the current yaw rate of the vehicle, and then based on the corrected yaw rate control command, the rear-wheel drive device A method of controlling an emergency steering device using a rear wheel steering device of a vehicle, characterized in that outputting an RWS control command to control .

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