KR101257861B1 - Steering apparatus of electric drive vehicle - Google Patents

Abstract

A steering system of an electric drive vehicle is provided. According to an embodiment, the steering system includes a steering angle detection unit for detecting a rotation angle of the steering wheel and outputting it as a detection signal, a control unit receiving the detection signal of the steering angle detection unit and outputting a control signal for steering, and a control signal of the control unit. According to the present invention, there are a plurality of motors, each of which operates in accordance with a plurality of wheels, which are rotated by each of the motors.

Description

Steering system of electric drive vehicle {STEERING APPARATUS OF ELECTRIC DRIVE VEHICLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering system of an electric drive vehicle. More particularly, the steering system uses wheel assemblies such as a plurality of wheels (Active Split Offset Caster (ASOC)) having an electric drive type to independently steer the steering angle of each wheel. The invention relates to a steering system of an electric drive vehicle for creating a replacement for an existing steering system.

In general, the steering device of the vehicle is to arbitrarily change the traveling direction of the driving vehicle by switching the alignment state of the steering wheel, and may adjust the driving direction of the vehicle by adjusting the front wheel, the rear wheel, or the four wheels of the vehicle at a suitable angle, respectively. In general, the steering operation force of the steering wheel by the driver is transmitted to the steering gear and the link to change the direction of travel of the vehicle by rotating the knuckle arm of the wheel. On the other hand, as the problem of environmental pollution due to the burning of fossil fuels and the problem of alternative energy due to the consumption of fossil fuels has recently emerged, the development of electric drive vehicles using electricity as a driving source has been actively progressed.

In this way, the electric vehicle is driven using the driving force of the motor. The steering system of the electric drive vehicle is configured to be driven by an electric signal using a motor by modifying an existing mechanical steering system. . However, the conventional electric drive vehicle not only increases the consumption of electricity by increasing the weight of the vehicle when using the conventional mechanical steering system, but also increases the manufacturing cost of the vehicle, thereby causing obstacles to commercialization.

In addition, the conventional electric drive vehicle has a problem that it is difficult to design the appearance of the vehicle freely due to the adoption of the conventional mechanical steering system, and thus has a difficulty in implementing the appearance and refined design suitable for the use and function of the vehicle. In addition, the conventional electric drive vehicle has a problem that it is difficult to implement the minimization of the turning radius by having a limit in the steering angle generation of the mechanical steering system.

In order to solve the conventional problems as described above, the present invention is to remove the mechanical steering device applied to the existing vehicle by performing the driving and steering together using the electric drive method, and thus the weight of the vehicle and the consumption of electricity It is possible to reduce the design, to realize the appearance and refined design suitable for the use and function of the vehicle, and to free the structural design.

In addition, the present invention solves the difficulty of reducing the turning radius due to the limitation of the steering angle generation of the existing mechanical steering device to increase the steering angle of the wheel to implement a small turning radius, the system to be suitable for network-based control of the vehicle Allows you to configure These tasks are presented by way of example, and the scope of the present invention is not limited by these tasks.

According to one aspect of the present invention, a steering system of an electric drive vehicle is provided. A steering angle detector for detecting a rotation angle of a steering wheel and outputting the detected steering signal is provided. The control unit receives the detection signal of the steering angle detector and outputs a control signal for steering. It has a plurality of motors each operating in accordance with the control signal of the control unit, a plurality of wheels to be rotated in parallel by each of the motor is provided side by side, the rotation axis is provided between the wheels so that the wheel to rotate at an angle for steering Wheel assembly is provided.

The steering angle detection unit, the reaction force unit is installed to transfer the reaction force from the wheel to the steering wheel; And / or an encoder for detecting a rotation angle of the steering wheel through the reaction force unit and outputting a detection signal to the controller.

The wheel assembly may include a plurality of first and second wheels, wherein the plurality of wheels are first and second wheels, and the plurality of motors are respectively mounted inside the first and second wheels and connected to each other by a connecting shaft. It consists of, the rotation axis may be connected perpendicular to the connecting shaft.

The wheel assembly may be vertically connected such that the rotation shaft is offset to the connecting shaft forward or backward.

The wheel assembly may have an offset length at which the rotating shaft is spaced apart from the connecting shaft and corresponds to one-half the length of the connecting shaft.

The controller may control steering of the first and second in-wheel motors so as to change rotation directions of the first and second wheels.

The controller may control steering of the first and second in-wheel motors so as to vary rotation speeds of the first and second wheels.

The wheel assembly may be provided in plurality in the electric drive vehicle.

The electronic device may further include a first communication unit configured to transfer the detection signal of the steering angle detector to the controller by CAN communication or FlexRay communication.

The control unit may further include a second communication unit for transmitting the control signal to the motor by CAN communication or FlexRay communication.

According to the steering system of an electric drive vehicle according to an embodiment of the present invention, by performing the driving and steering together by using the electric drive method, it is possible to remove the mechanical steering device applied to the existing vehicle, thereby reducing the weight and It is possible to reduce the consumption of electricity, to realize the appearance and refined design suitable for the use and function of the vehicle and to free the structural design.

The present invention solves the limitation of the reduction of the turning radius due to the limitation of the steering angle generation of the existing mechanical steering device, thereby making the steering angle of the wheel larger, thereby realizing a small turning radius, and configuring the system to be suitable for network-based control of the vehicle. can do.

In addition, the present invention can implement steering by using the power difference of the driving device for driving even without a separate steering system.

In addition, the present invention can implement the front wheel steering by using a pair of two wheels (Active Split Offset Caster, ASOC) with an electric drive method, it can be configured to replace the existing front wheel using two sets In addition, by configuring four wheels to replace all the wheels of the existing vehicle, the vehicle can move in all directions in place, thereby moving sideways to allow parking in a narrow space.

1 is a block diagram showing a steering system of an electric drive vehicle according to an embodiment of the present invention.
2 is a view for explaining the operation of the wheel assembly provided in the steering system of the electric drive vehicle according to an embodiment of the present invention.
3 is a side view illustrating a wheel assembly provided in a steering system of an electric drive vehicle according to another embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. In the drawings, the components may be exaggerated or reduced in size for convenience of description.

1 is a block diagram showing a steering system of an electric drive vehicle according to an embodiment of the present invention.

As shown in FIG. 1, a steering system 100 of an electric drive vehicle according to an embodiment of the present invention includes a steering angle detector 110 and a steering angle detector for detecting a rotation angle of a steering wheel 1. The controller 120 may receive the detection signal of the 110 and a wheel assembly 130 controlled by the controller 120 to allow steering.

The steering angle detecting unit 110 detects the rotation angle of the steering wheel 1 and outputs a detection signal. The steering angle detection unit 110 includes a steering angle encoder for directly detecting the rotation angle of the steering wheel 1 or the wheel ( 133, 134 detects the rotation angle of the steering wheel (1) through the reaction unit 111 is installed to transmit the reaction force to the steering wheel (1), and through the reaction force unit 111 to detect the detection signal to the control unit 120 The encoder 112 may be output. In addition, the steering angle detection unit 110 may include a steering wheel control unit for vehicle communication and reaction force control.

The reaction force unit 111 may include, for example, an actuator driven to allow the driver to feel the steering reaction force according to the speed, yaw speed, acceleration, etc. of the vehicle detected through the speed sensor installed in the vehicle. It can be made of a motor. Encoder 112 is a steering wheel (1) by detecting the rotation angle of the rotating body rotated by the rotation axis of the reaction force providing motor or the reaction force providing motor when the reaction force unit 111 includes a reaction force providing motor It is also possible to detect the rotation angle of.

The control unit 120 receives the detection signal of the steering angle detection unit 110, specifically, the encoder 112, and outputs a control signal for steering. For example, the control unit 120 calculates a steering angle of the steering wheel 1 based on the detection signal of the encoder 112, and for each of the steering angles corresponding to the steering angle, the motors 131 and 132 are preset rotation directions and rotations. The motors 131 and 132 are controlled to have a speed or a rotation amount.

The wheel assembly 130 has a plurality of motors 131 and 132 that operate in accordance with the control signal of the controller 120, and the wheels 133 and 134 rotated by the motors 131 and 132, respectively, are arranged in parallel. The rotating shaft 135 is provided between the wheels 133 and 134 so that the wheels 133 and 134 rotate at an angle for steering.

The wheel assembly 130 has a number for the motors 131 and 132 to correspond to the wheels 133 and 134, for example, two motors 131 and 132 and two wheels 133 and 134. In addition, as shown in the present embodiment, the plurality of wheels 133 and 134 may be formed of the first and second wheels 133 and 134, and the plurality of motors 131 and 132 may be the first. And first and second in-wheel motors 131 and 132 mounted on the inner side of the second wheels 133 and 134, respectively, and connected to each other by a connecting shaft (135a of FIG. 2), and the rotating shaft 135 is connected to the second wheel 133 and 134. It may be connected perpendicular to the axis (135a).

Meanwhile, the meaning that the rotating shaft 135 is connected perpendicularly to the connecting shaft 135a is not limited to that the rotating shaft 135 is connected to form the 90 degrees with respect to the connecting shaft 135a, and is connected to form an angle close to 90 degrees. It includes. On the other hand, the rotating shaft 135 is rotatably coupled between the connecting shaft (135a) via a bearing or the like, or coupled to form an integral with the connecting shaft (135a) is rotated via a bearing or the like to the vehicle body of the electric drive vehicle It can be installed possibly. By installing an encoder in the rotatable portion, steering stability may be secured through feedback control configured to measure whether the rotation angle of the wheel assembly 130 is rotated at a desired angle and transmit the same to the controller 120.

For example, in order to secure steering control stability when the wheel assembly 130 is connected to the vehicle body, the wheel assembly 130 may include a encoder together with a bearing to transmit the steering angle of the wheel assembly 130 to the controller 120 to perform feedback control. have. Furthermore, the assembly 130 may further include a motor control unit for driving the in-wheel motor and communicating with the control unit 120.

The wheel assembly 130 may be provided in a plurality of, for example, two sets of the electric drive vehicle as in the present embodiment, and the present invention is not limited thereto. It may be provided to achieve, may be made of a number that replaces all the wheels of the electric drive vehicle, when at least three or more are provided in the electric drive vehicle to enable all directions steering of the electric drive vehicle.

The steering angle detection unit 110 and the control unit 120 may transmit and receive a detection signal by the first communication unit 140. In this case, the first communication unit 140 may communicate with a controller area network (CAN) or a real-time measurement control communication network. By using a FlexRay communication that supports high-speed communication, the steering angle detection unit 110, specifically, the detection signal output from the encoder 112 may be transmitted to the control unit 120.

The control unit 120 and the first and second in-wheel motors 131 and 132 may transmit and receive a control signal by the second communication unit 150. In this case, the second communication unit 150 may perform CAN communication or real time high speed communication. The control signal of the controller 120 may be transmitted to the first and second in-wheel motors 131 and 132 by supporting FlexRay communication.

As shown in FIG. 2, the control unit 120 of FIG. 1 controls the first and second in-wheel motors 131 and 132 so as to change the rotation directions of the first and second wheels 133 and 134 for steering. Steering can be achieved by controlling. For example, the controller 120 controls the first and second in-wheel motors 131 and 132 to rotate the first and second wheels 133 and 134 in opposite A and B directions, and thus, the first and second wheels 133 and 134. 2 wheels 133 and 134 to generate a moment to rotate in the direction C about the axis of rotation 135 so that steering is achieved.

The controller 120 may control steering of the first and second in-wheel motors 131 and 132 such that the rotation speeds of the first and second wheels 133 and 134 are different. That is, the controller 120 controls the relative rotation speed between the first and second wheels 133 and 134 so that the first and second wheels 133 and 134 induce a moment about the rotation axis 135 to steer. This can be done.

As shown in (a) of FIG. 3, the wheel assembly 230 according to another embodiment may be vertically connected such that the rotation shaft 235 is forwardly offset with the connection shaft 235a, or as shown in (b), The wheel assembly 330 according to another embodiment may be vertically connected so that the rotation shaft 335 is offset to the connecting shaft 335a to the rear. Accordingly, the wheel assemblies 230 and 330 may form an Active Split Offset Caster (ASOC).

In this case, the wheel assemblies 230 and 330 may have an offset length L at which the rotation shafts 235 and 335 are spaced apart from the connection shafts 235a and 335a and corresponds to one-half the length of the connection shafts 235a and 335a. Accordingly, the wheel assemblies 230 and 330 are excellent in isotropy capable of moving in all directions at 360 degrees in place. Meanwhile, the connecting shafts 235a and 335a may have a connecting portion or connecting member having a “b” shape having a bent portion for offset connection of the rotating shafts 235 and 335.

The operation of the steering system of the electric drive vehicle according to the present invention will be described.

When the driver rotates the steering wheel 1 for steering, the encoder 112 detects the rotation angle of the steering wheel 1 through the reaction unit 111 to the control unit 120 through the first communication unit 140. Output The control unit 120 receives the detection signal of the encoder 112 and is required for the rotation direction, the rotation speed, and the rotation amount of the first and second in-wheel motors 131 and 132 preset according to the rotation angle of the steering wheel 1. When the control signal is output to the first and second in-wheel motors 131 and 132 through the second communication unit 150, the first and second wheels are operated by the operations of the first and second in-wheel motors 131 and 132, respectively. By rotating 133 and 134, respectively, the first and second wheels 133 and 134 rotate about the rotation axis 135 at an angle required for steering.

As such, by performing both driving and steering by using the electric driving method, it is possible to remove the mechanical steering device applied to the existing vehicle, thereby reducing the weight and consumption of the vehicle, and to the purpose and function of the vehicle. The design of the structure can be freely made while enabling the appearance and the refined design. In addition, by solving the difficulty of reducing the turning radius due to the steering angle generation limit of the existing mechanical steering device, it is possible to implement a small turning radius by generating a large steering angle of the wheel, and to make the system suitable for network-based control of the vehicle Can be configured.

In addition, according to the present invention, steering may be implemented by using a power difference of a driving device for driving even without a separate steering system, and two combined wheels having an electric driving method (Active Split Offset Caster, ASOC) Front wheel steering can be implemented using one pair, two wheels can be configured to replace existing front wheels, and four wheels can be configured to replace all wheels of an existing vehicle. This allows the electric vehicle to move sideways, thereby allowing the electric drive vehicle to move to the side and parking in a narrow space. In other words, when the assembly of two front wheels is used, the vehicle can rotate with a small turning radius, and when all four wheels are adopted as the wheel assembly, omni-motion can be implemented, so that the vehicle can move in the lateral direction and implement the parking function. have.

The foregoing description of specific embodiments of the invention has been presented for purposes of illustration and description. Therefore, the present invention is not limited to the above embodiments, and various modifications and changes can be made by those skilled in the art within the technical spirit of the present invention in combination with the above embodiments. Do.

1: steering wheel 110: steering angle detection unit
111: reaction unit 112: encoder
120: control unit 130,230,330: wheel assembly
131: first in-wheel motor 132: second in-wheel motor
133: first wheel 134: second wheel
135,235,335: rotating shaft 135a, 235a, 335a: connecting shaft
140: first communication unit 150: second communication unit

Claims (14)

A steering angle detector 110 which detects a rotation angle of the steering wheel 1 and outputs it as a detection signal;
A control unit 120 receiving the detection signal of the steering angle detection unit 110 and outputting a control signal for steering; And
It has a plurality of motors (131, 132) that operate in accordance with the control signal of the control unit 120, respectively, and a plurality of wheels (133, 134) rotated by each of the motors (131, 132) are provided in parallel, Wheel assemblies (130, 230, 330) provided with rotating shafts (135, 235, 225) between the wheels (133, 134) so that the wheels (133, 134) rotate at an angle for steering;
Including,
The wheel assemblies 130, 230, and 330 may include the plurality of wheels 133 and 134 as first and second wheels 133 and 134, and the plurality of motors 131 and 132 as the first wheel. And first and second in-wheel motors 131 and 132 mounted on the inner side of the second wheels 133 and 134 and connected to each other by connecting shafts 135a, 235a, and 335a, respectively. , 225 is perpendicular to the connecting shaft (135a, 235a, 335a),
And the rotary shaft (135, 235, 225) is vertically connected to the connecting shaft (135a, 235a, 335a) to make an offset forward or rearward. The method of claim 1, wherein the steering angle detection unit 110,
And a reaction force unit (111) installed to transmit reaction force from the wheels (133, 134) to the steering wheel (1). The method of claim 2, wherein the steering angle detection unit 110,
And an encoder (112) for detecting a rotation angle of the steering wheel (1) through the reaction force unit (111) and outputting a detection signal to the control unit (120). delete delete The method of claim 1, wherein the wheel assembly (130, 230, 330),
The offset length of the rotary shafts 135, 235, and 225 spaced apart from the connection shafts 135a, 235a, and 335a corresponds to one-half the length of the connection shafts 135a, 235a, and 335a. Steering system. The method of claim 1, wherein the control unit 120,
A steering system, wherein the steering is achieved by controlling the first and second in-wheel motors (131, 132) to vary the rotational direction of the first and second wheels (133, 134). The method of claim 1, wherein the control unit 120,
A steering system, wherein steering is achieved by controlling the first and second in-wheel motors (131, 132) to vary the rotational speeds of the first and second wheels (133, 134). The steering system of claim 1, wherein the wheel assembly (130, 230, 330) is provided in plurality in the electric drive vehicle. The electric drive of claim 1, further comprising a first communication unit 140 for transmitting a detection signal of the steering angle detection unit 110 to the control unit 120 by CAN communication or FlexRay communication. Steering system of the vehicle. The electric drive of claim 1, further comprising a second communication unit 150 for transmitting a control signal of the control unit 120 to the motors 131 and 132 by CAN communication or FlexRay communication. Steering system of the vehicle. The wheel assembly of claim 1, wherein the wheel assemblies 130, 230, and 330 transmit the steering angles of the wheel assemblies 130, 230, 330 to the controller 120 when the wheel assemblies 130 are connected to the vehicle body. A steering system of an electric drive vehicle for performing feedback control. The steering system of claim 1, wherein the steering angle detection unit comprises a steering wheel control unit for vehicle communication and reaction force control. The steering system of claim 1, wherein the wheel assembly (130, 230, 330) comprises a motor control unit for driving an in-wheel motor (131, 132) and communicating with the control unit (120).

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