Methods and systems for controlling the stationary turning patterns of four-wheel independent steering vehicles

Abstract

This invention relates to a method and system for controlling the stationary turning mode of a four-wheel independent steering vehicle. The method for controlling the stationary turning mode of a four-wheel independent steering vehicle includes: when the vehicle's stationary turning mode is executed, using a controller to perform a wheel rotation operation to rotate the wheels according to the stationary turning mode; when the steering wheel is turned, using the controller to perform a target rotation angle calculation operation based on the steering angle of the steering wheel to calculate a target rotation angle for the vehicle; and when an accelerator pedal is depressed, using the controller to perform a rotation control operation to control the vehicle to rotate at the same angle as the target rotation angle.

Description

Technical Field

[0001] This invention relates to a method and system for controlling the stationary rotation mode of a four-wheel independent steering vehicle. Background Technology

[0002] Because conventional vehicles operate their wheels in only two modes (straight driving and left / right turning), they can be intuitively driven using only a small number of operating systems. On the other hand, a four-wheel independent steering (4WS) system can independently control each wheel to achieve a variety of vehicle behaviors.

[0003] refer to Figure 1A and Figure 1B The description explains that in typical front-wheel drive and rear-wheel drive modes, the degree of wheel rotation is the same as the degree of steering wheel rotation, and the degree of acceleration is the same as the degree of pressing the accelerator pedal, allowing the vehicle to steer while moving forward. In this case, since it is possible to determine whether to rotate the rear wheels in the opposite direction to the front wheels based on vehicle speed or steering angle, it can help reduce the turning radius during U-turns.

[0004] In addition, in such Figure 1C In the diagonal motion mode shown, the rear wheels are controlled in phase with the front wheels, preventing the vehicle from yawing. This is advantageous when the vehicle is changing lanes or overtaking other vehicles.

[0005] In addition, in such Figure 1D In the parallel motion mode shown, each of the front and rear wheels can rotate 90°, which facilitates parallel parking.

[0006] In addition, in such Figure 1E In the stationary turn mode shown, each of the front and rear wheels can rotate 45°, allowing the vehicle to make U-turns in narrow alleys.

[0007] On the other hand, the stationary driving mode is one of the least common driving modes of the 4WS system, as is the parallel motion mode. Because the stationary driving mode is uncommon, it can differentiate the vehicle from existing models and attract customers; however, the stationary driving mode has the following problems.

[0008] First, the stationary turning mode is a mode in which only the vehicle yaws, and the driver is not familiar with this yaw behavior, which may make the driver feel uncomfortable with such vehicle behavior.

[0009] Secondly, in stationary turning mode, the vehicle's direction of movement is not aligned with the driver's field of vision. Therefore, because the driver must turn their entire body to ensure visibility and is driving in a state of anxiety about when to stop turning, there are issues of difficult driving operation and increased accident risk.

[0010] The above statements are merely intended to help understand the background technology of the present invention, and are not intended to imply that the present invention falls within the scope of prior art known to those skilled in the art. Summary of the Invention

[0011] This invention relates to a method and system for controlling the stationary turning mode of a four-wheel independent steering vehicle. Specific embodiments relate to a method and system for controlling the stationary turning mode of a four-wheel independent steering vehicle, which enables easy and simple operation of the vehicle's stationary turning behavior to reduce driving anxiety and accident risk.

[0012] Accordingly, in view of the problems that have arisen in the related technologies, the embodiments of the present invention have been made. The embodiments of the present invention provide a method and system for controlling the stationary turning mode of a four-wheel independent steering vehicle, which can easily and simply operate the stationary turning behavior of the vehicle to reduce driving anxiety and accident risk.

[0013] According to one embodiment, a control method is provided, the control method comprising: when a vehicle is in a stationary rotation mode is executed, using a controller to perform a wheel rotation operation for turning and rotating the wheels according to the stationary rotation mode; when the steering wheel is turned, using the controller to perform a target rotation angle calculation operation for calculating a target rotation angle of the vehicle based on the steering angle of the steering wheel; and when an accelerator pedal is depressed, using the controller to perform a rotation control operation for controlling the vehicle to rotate at the same angle as the target rotation angle.

[0014] In the target rotation angle calculation operation, the target rotation angle can be divided for each step according to the steering wheel's steering angle range, and the target rotation angle can be set for each step.

[0015] The steering angle range can be set by successively extending the predetermined angle range.

[0016] The target rotation angle calculation can be performed through the operation of a separately configured mechanism.

[0017] In the target rotation angle calculation operation, a separate step-by-step rotation mode button can be set on the side of the gear shift lever, and the target rotation angle can be calculated when the step-by-step rotation mode button is activated.

[0018] In the target rotation angle calculation operation, the target rotation angle can be calculated when a specific button in the shift button is pressed a predetermined number of times or more, or is pressed for a predetermined period of time or a longer period of time.

[0019] In the target rotation angle calculation operation, the target rotation angle can be continuously changed and set to correspond to the steering wheel angle.

[0020] In the rotation control operation, when the vehicle is stationary and turning, the steering wheel can be turned in the opposite direction of the vehicle's rotation by the same angle as the vehicle's rotation.

[0021] In the rotation control operation, while the vehicle is rotating, the steering wheel can be rotated in the opposite direction to the vehicle's rotation angle. When the vehicle's rotation stops, the steering wheel can be reset and rotated in the opposite direction to the vehicle's rotation angle by the same angle, thus enabling the identification of the termination point of the stationary rotation.

[0022] In the rotation control operation, when the vehicle is stationary and turning, the steering wheel can be turned in the opposite direction to the vehicle's rotation direction by the same angle as the driver's turn of the steering wheel.

[0023] In the rotation control operation, while the vehicle is rotating, for the vehicle's stationary rotation, the steering wheel can be rotated in the opposite direction to the vehicle's rotation direction according to the steering angle of the driver's steering wheel. When the vehicle's rotation stops, the steering wheel can be reset and rotated in the opposite direction to the vehicle's rotation direction by the same angle as the driver's steering wheel, thereby enabling the identification of the termination point of the stationary rotation.

[0024] In rotation control operation, during the vehicle's stationary rotation, when the steering wheel is additionally turned in the vehicle's rotation direction, the vehicle can further rotate by the same angle as the additional steering angle of the steering wheel.

[0025] In rotation control operation, the rotation angle of the vehicle can be guided by notifying the components.

[0026] The notification unit can display the vehicle's rotation angle on the instrument cluster or guide the vehicle's rotation angle via voice.

[0027] While the vehicle is stationary, the notification unit can temporarily set different steering feel for the steering wheel at each predetermined rotation angle.

[0028] In rotation control operation, the vehicle's rotation speed can be determined based on the amount of pressure applied to the accelerator pedal, thereby causing the vehicle to rotate.

[0029] In rotation control operation, during the initial stage of vehicle rotation, the rotational acceleration can be gradually increased within the range of the accelerator pedal's depress amount.

[0030] In rotation control operation, the rotational acceleration can be gradually reduced at the end of the vehicle rotation phase, before the target rotation angle is reached.

[0031] In rotation control operation, pressing the brake pedal while the vehicle is rotating can reduce the vehicle's rotation speed.

[0032] According to another embodiment, a system for controlling the stationary turning mode of a four-wheel independent steering vehicle is provided, the system comprising: a controller configured to turn and rotate a steering wheel when the stationary turning mode of the vehicle is executed; calculating a target turning angle of the vehicle based on the steering angle of the steering wheel when the steering wheel is turned; and controlling the vehicle to turn at the same angle as the target turning angle when an accelerator pedal is applied. Attached Figure Description

[0033] The above and other objects, features, and other advantages of the invention will become clearer from the following detailed description presented in conjunction with the accompanying drawings, in which:

[0034] Figures 1A to 1F It is a schematic diagram used to describe the steering rotation of the wheels and the vehicle behavior of each driving mode of a four-wheel independent steering vehicle.

[0035] Figure 2 This is a block diagram illustrating a control system for a four-wheel independent steering vehicle according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram illustrating the operation of rotating a vehicle in place by dividing and setting the rotation in 30° increments according to an embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram illustrating the operation of rotating a vehicle in place by dividing and setting the rotation in 45° increments according to an embodiment of the present invention.

[0038] Figure 5 and Figure 6 This is a schematic example diagram illustrating a mode switching mechanism applied to a four-wheel independent steering vehicle according to an embodiment of the present invention;

[0039] Figure 7 This is a step-by-step schematic diagram illustrating the rotational behavior of the steering wheel and the vehicle during a stationary rotation of the vehicle according to an embodiment of the present invention;

[0040] Figure 8This is an operational schematic diagram illustrating how a change in the feel of the operator indicates a change in the angle of rotation in place, as described in an embodiment of the present invention; and

[0041] Figure 9 This is a flowchart illustrating the entire process of controlling the stationary rotation mode of a four-wheel independent steering vehicle according to an embodiment of the present invention. Detailed Implementation

[0042] Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0043] Figure 2 This is a block diagram illustrating a control system for switching driving modes in a four-wheel independent steering vehicle according to an embodiment of the present invention.

[0044] Referring to the accompanying drawings, the four-wheel steering system applicable to the present invention includes: a driving mode switching mechanism 10, a steering wheel 20, an accelerator pedal 30, a brake pedal 40, a controller 50 (electronic control unit or ECU), steering angle modules 60a, 60b, 60c and 60d for independent steering of the wheels, and a drive component 70.

[0045] Specifically, the driving mode switching mechanism 10 can be implemented via a gear shift lever, the gear shift lever being operated as follows: Figure 5 Move within the shift slide as shown, or via, as... Figure 6 This is achieved using the shift button shown.

[0046] For example, in Figure 5 In the case of a shift lever type mechanism, a shift groove is formed along the movement path of the shift lever, and general driving modes and special driving modes are arranged along the movement path of the shift lever. The general driving modes include: P gear (parking gear) mode 11, D gear (drive gear) mode 12 and R gear (reverse gear) mode 13; the special driving modes include: diagonal driving mode 14, parallel movement mode 15 and stationary rotation mode 16.

[0047] In addition, Figure 6 In the case of a shift button type mechanism, each of the normal driving mode and the special driving mode can be arranged in the form of a button.

[0048] Additionally, refer to Figure 2 Since the steering angle sensor 21 is connected to the steering wheel 20, the steering angle is detected by the steering angle sensor 21 and sent to the controller 50. For reference, a steering reaction force mechanism that generates the steering reaction force of the steering wheel 20 can be optionally added.

[0049] The accelerator pedal 30 can operate the throttle valve. The accelerator pedal position sensor (APS) 31 detects the pedal pressure signal and sends the detected pedal pressure signal to the controller 50.

[0050] The brake pedal 40 is connected to and can operate the braking mechanism. The brake pedal 40 can also be pressed by a brake pedal stroke sensor (BPS) 41, and the detected pressing signal is sent to the controller 50.

[0051] Existing steering modules can be used as steering modules 60a, 60b, 60c, and 60d. However, to maximize the availability of four-wheel independent steering operations such as parallel parking and turn-on-the-spot maneuvers, large steering angle steering modules 60a, 60b, 60c, and 60d are suitable, with each steering angle reaching up to 90 degrees.

[0052] Each of the large steering angle modules 60a, 60b, 60c and 60d includes: a suspension system, a large camber angle drive axle or in-wheel system, and a steering actuator, the suspension system being capable of fully traversing wheel clearance, and the steering actuator being used to provide operating force to independently steer the large steering angle modules 60a, 60b, 60c and 60d.

[0053] Specifically, according to the embodiment of the present invention, when the vehicle's stationary rotation mode 16 is executed, the controller 50 rotates the wheels according to the stationary rotation mode 16, calculates the target rotation angle of the vehicle based on the steering angle of the steering wheel 20 when the steering wheel 20 is rotated, and controls the vehicle to rotate at the same angle as the target rotation angle when the accelerator pedal 30 is pressed.

[0054] For reference, the controller 50 according to an exemplary embodiment of the present invention may be an ECU.

[0055] Alternatively, the controller 50 can be implemented as an algorithm configured to control the operation of various components of the vehicle, a non-volatile memory (not shown) configured to store data related to software commands for reproducing the algorithm, or a processor (not shown) configured to perform operations described below using data stored in the corresponding memory. Here, the memory and processor can be implemented as separate chips. Alternatively, the memory and processor can be implemented as a single chip integrating the memory and processor. The processor can be in the form of one or more processors.

[0056] On the other hand, in embodiments of the present invention, the control method for the stationary rotation mode of a four-wheel independent steering vehicle using the controller 50 can broadly include: wheel rotation operation, target rotation angle calculation operation, and rotation control operation.

[0057] First, during wheel rotation operation, when the vehicle's stationary rotation mode is executed, the controller 50 turns and rotates the wheels according to the stationary rotation mode.

[0058] For example, when the driver selects the stationary turning mode through the driving mode switching mechanism 10, the stationary turning mode is executed, and when the stationary turning mode is executed, the controller 50 uses the cornering modules 60a, 60b, 60c and 60d suitable for stationary turning to turn and rotate the front and rear wheels.

[0059] In this case, such as Figure 1E As shown, preferably, the left front wheel and right rear wheel are turned 45° to the right, and the right front wheel and left rear wheel are turned 45° to the left. However, the front and rear wheels may turn and rotate as follows: Figure 1F The front and rear wheels can be manipulated in various ways to allow them to rotate in place.

[0060] In the target rotation angle calculation operation, when the steering wheel 20 is rotated, the controller 50 calculates the target rotation angle of the vehicle based on the steering angle of the steering wheel 20.

[0061] In other words, when the stationary rotation mode is executed, when the driver turns the steering wheel 20 in the desired stationary rotation direction, the target angle for the vehicle's stationary rotation is calculated based on the steering angle detected by the steering angle sensor 21.

[0062] In the rotation control operation, when the accelerator pedal 30 is pressed, the controller 50 can control the vehicle to rotate in place by the same angle as the target rotation angle.

[0063] In other words, after the target rotation angle is set, when the driver presses the accelerator pedal 30, the driving force is applied to the drive wheels to make the vehicle rotate in place.

[0064] As described above, according to an embodiment of the present invention, the target rotation angle is set to correspond to the amount of steering wheel 20 operated by the driver, and the vehicle rotates in place at the same angle as the set target rotation angle, thereby enabling the driver to easily and conveniently operate the vehicle's in-place rotation function, thereby reducing driving anxiety and accident risk.

[0065] On the other hand, the target rotation angle calculation operation of the present invention embodiment can be divided into steps according to the steering angle range of the steering wheel 20, and the target rotation angle can be set for each step.

[0066] In other words, as an exemplary implementation for calculating the target rotation angle, the vehicle's rotation angle can be gradually identified based on the amount of steering wheel 20 turned by the driver in order to set the target rotation angle.

[0067] For example, Figure 3 This is a schematic diagram illustrating the operation of rotating a vehicle in place by dividing and setting the rotation in 30° increments according to an embodiment of the present invention. Figure 3 An example is shown where a 90° rotation angle is divided into 30° units and set as three steps.

[0068] Therefore, when the driver turns the steering wheel 20 at an angle within the range of 30° to 60°, the target rotation angle is set to 30°, so that the vehicle can rotate in place at an angle of only 30°.

[0069] As another example, Figure 4 This is a schematic diagram illustrating the operation of rotating a vehicle in place by dividing and setting the rotation in 45° increments according to an embodiment of the present invention. Figure 4 An example is shown where a 180° rotation angle is divided into 45° units and set as four steps.

[0070] Therefore, when the driver turns the steering wheel 20 at an angle within the range of 45° to 90°, the target rotation angle is set to 45°, so that the vehicle can rotate in place at an angle of only 45°.

[0071] As described above, according to an embodiment of the present invention, the steering angle range can be set by successively extending a predetermined angle range.

[0072] In other words, the steering angle range for each step can be set as follows: Figure 3 The 30° angle shown is in units or set as follows: Figure 4 The angle shown is 45° in units.

[0073] Figure 3 and Figure 4 The rotation angles and steps shown are merely examples for gradually setting the target rotation angle, and therefore the rotation angles and steps can be changed according to various implementation schemes.

[0074] Therefore, the vehicle's rotation angle can be precisely controlled by rotating the vehicle at a preset angle, without considering when the driver stops. This prevents accidental operation of the steering wheel 20 due to dizziness during rotation, thereby reducing the risk of accidents.

[0075] However, in the above-mentioned method for setting the target rotation angle, the stationary rotation angle required by the driver may not be accurately reflected in the vehicle's rotation angle.

[0076] Therefore, according to an embodiment of the present invention, the calculation of the target rotation angle at each step can be configured to be performed by a separate operation.

[0077] For example, in the case of a shift lever type mechanism, a step-by-step rotation mode button 17 is separately provided on the side of the upper end of the shift lever, so that when the driver operates the step-by-step rotation mode button 17, the target rotation angle for each step can be calculated.

[0078] As another example, in the case of a shift button type mechanism, when the stationary rotation mode button is pressed two or more times in succession, or when the stationary rotation mode button is pressed for a predetermined time or longer, the target rotation angle for each step can be calculated.

[0079] For example, in the case of the concept that the vehicle turns in four steps at a 30° angle, even if the driver tries to turn the steering wheel 20 to turn the vehicle by 100°, the target rotation angle is 90°, so that the vehicle only turns by 90°.

[0080] Therefore, since the target rotation angle for each step is calculated only when the step rotation mode button 17 is operated, the convenience of the vehicle's stationary rotation function can be improved even if it cannot accurately reflect the driver's intention.

[0081] In addition, as another example of the target rotation angle calculation operation, the target rotation angle can be set to change continuously in response to the steering angle of the steering wheel 20.

[0082] In other words, when the steering wheel 20 is rotated 100°, the target rotation angle is also set to 100°, so that the vehicle rotates 100° in place.

[0083] Therefore, it can accurately reflect the driver's intention to turn the vehicle while stationary.

[0084] on the other hand, Figure 7 This is a step-by-step schematic diagram illustrating the rotational behavior of the steering wheel 20 and the vehicle during a stationary rotation of the vehicle according to an embodiment of the present invention.

[0085] Referring to the attached diagram, during the rotation control operation, when the vehicle is rotating in place, the steering wheel 20 can rotate in the opposite direction to the vehicle's rotation direction by the same angle as the vehicle's rotation angle.

[0086] Specifically, while the vehicle is rotating, the steering wheel 20 can be rotated in the opposite direction to the vehicle's rotation angle. When the vehicle's rotation stops, the steering wheel 20 can be rotated in the opposite direction to the vehicle's rotation angle to reset, thus identifying the point at which the rotation stops in place.

[0087] In other words, when the vehicle is in stationary rotation mode, when the driver turns the steering wheel 20 degrees clockwise, the vehicle rotates clockwise by the same angle as the target rotation angle.

[0088] Accordingly, while the vehicle is rotating in place, the steering wheel 20 is reset and rotated counterclockwise in the opposite direction of the vehicle's rotation by the same angle as the vehicle's rotation. Thus, when the vehicle's rotation reaches the target rotation angle, the absolute angle of the steering wheel 20 remains in the state before the vehicle rotated.

[0089] Therefore, since the steering wheel 20 is rotated to the same angle as the vehicle's rotation angle and thus resets, the steering direction before the vehicle turned can be maintained, and the driver is notified of the point at which the vehicle's stationary rotation ends. This allows the driver to easily identify the point at which the vehicle's stationary rotation ends, thereby improving the convenience of the stationary rotation function and reducing the risk of accidents.

[0090] However, in the target rotation angle calculation operation according to the embodiment of the present invention, when calculating the target rotation angle at each step, the angle of the vehicle's stationary rotation may be less than the steering angle of the driver turning the steering wheel 20, so that the reset rotation of the steering wheel 20 may not return to the position of the steering wheel 20 just before the vehicle's stationary rotation.

[0091] Therefore, according to an embodiment of the present invention, for stationary rotation, the steering wheel 20 can be controlled to reset and rotate the steering angle corresponding to the driver's rotation of the steering wheel 20.

[0092] refer to Figure 7 The above description explains that during the rotation control operation, when the vehicle is rotating in place, the steering wheel 20 can be rotated in the opposite direction to the vehicle's rotation direction by the same angle as the driver's steering angle.

[0093] Specifically, while the vehicle is rotating, for the vehicle's stationary rotation, the steering wheel 20 can be rotated in the opposite direction to the vehicle's rotation direction according to the steering angle of the driver's steering wheel 20. When the vehicle's rotation stops, the steering wheel 20 can be reset and rotated in the opposite direction to the vehicle's rotation direction by the same angle as the driver's steering wheel 20, thereby identifying the point at which the stationary rotation ends.

[0094] In other words, when the vehicle is in stationary rotation mode, when the driver turns the steering wheel 20 degrees clockwise, the vehicle rotates clockwise by the same angle as the target rotation angle.

[0095] Accordingly, while the vehicle is rotating in place, the steering wheel 20 is reset and rotated counterclockwise in the opposite direction of the vehicle's rotation by the same angle as the steering angle of the driver's steering wheel 20. Thus, when the vehicle's rotation reaches the target rotation angle, the absolute angle of the steering wheel 20 remains in the state before the vehicle rotates.

[0096] Therefore, since the steering wheel 20 is rotated to the same angle as the angle at which the driver manipulates and turns the steering wheel 20, thus resetting the vehicle, the original steering direction can be maintained, and the driver is notified of the point in time when the vehicle's stationary turning ends. This allows the driver to easily identify the point in time when the vehicle's stationary turning ends, thereby improving the convenience of the stationary turning function and reducing the risk of accidents.

[0097] In addition, during the rotation control operation, when the steering wheel 20 is turned additionally in the direction of rotation of the vehicle while the vehicle is stationary, the vehicle can be further rotated by the same angle as the additional steering angle of the steering wheel 20.

[0098] In other words, when the driver turns the steering wheel 20 clockwise to make the vehicle turn clockwise in place, when the driver further turns the steering wheel 20 clockwise (i.e., the direction of the vehicle's rotation), the vehicle further turns clockwise by the same angle as the steering wheel 20, so that the driver can make the vehicle turn by the required rotation angle.

[0099] On the other hand, in the rotation control operation of the embodiment of the present invention, the rotation angle of the vehicle can be guided by the notification component.

[0100] For example, as an exemplary implementation of the notification component, the vehicle's rotation angle can be displayed on the instrument cluster, or the vehicle's rotation angle can be guided by voice.

[0101] When the vehicle's rotation angle is displayed on the instrument cluster, suggestions for smooth operation of the accelerator pedal 30 can be provided along with the angle of the vehicle's rotation while stationary.

[0102] In addition, as another implementation of the notification component, a warning sound can be provided at a predetermined angle while the vehicle is rotating in place.

[0103] For example, such as Figure 3 As shown, a warning sound can be provided at each 30° angle when the vehicle rotates 30°.

[0104] In addition, as another implementation of the notification component, different operating sensations can be temporarily set for the steering wheel 20 at predetermined rotation angles while the vehicle is stationary.

[0105] For example, Figure 8 This is an operational schematic diagram used to describe how the change in the feel of operation in an embodiment of the present invention can be used to warn of the angle of rotation in place. When the vehicle rotates by 30° in each step, a sense of stop can be set for the steering wheel 20 at each 30° angle.

[0106] On the other hand, according to an embodiment of the present invention, in the rotation control operation, the rotation speed of the vehicle is determined based on the amount of pressure applied to the accelerator pedal 30, thereby enabling the vehicle to rotate in place.

[0107] For example, if the vehicle's drive unit 70 is an engine, the throttle opening is adjusted to correspond to the amount by which the driver depresses the accelerator pedal 30, causing the vehicle to rotate. If the vehicle's drive unit 70 is an electric motor, the motor's output is determined to correspond to the amount by which the driver depresses the accelerator pedal 30, causing the vehicle to rotate.

[0108] However, in the rotation control operation, during the initial stage of vehicle rotation, the rotational acceleration can be gradually increased within the range of the accelerator pedal 30's depress amount.

[0109] In other words, when the driver excessively depresses the accelerator pedal 30 during the initial stage of turning in place, there are problems such as dizziness caused by the rapid turning of the vehicle, instability of vehicle behavior, and shortened lifespan of related chassis components.

[0110] Therefore, in the initial stage of vehicle rotation, the yaw acceleration is gradually increased within the range of the driver's accelerator pedal depressing 30, in order to achieve smooth rotational acceleration. Thus, rapid acceleration is prevented when the vehicle begins to rotate, thereby providing smooth ride comfort and allowing the vehicle to rotate safely. This rotational acceleration can be controlled by adjusting the throttle opening or by adjusting the motor output.

[0111] In addition, during the rotation control operation, the rotation acceleration can be gradually reduced at the end of the vehicle rotation phase, before the target rotation angle is reached.

[0112] In other words, in order to perform smooth deceleration at the beginning and end of the vehicle's rotation, the yaw acceleration is gradually reduced to prevent rapid deceleration and thus provide a smooth ride comfort.

[0113] Specifically, when controlling rotational acceleration at the end of the vehicle's rotation, instead of braking according to the driver's intention, the vehicle is controlled to stop automatically at the target rotation angle, thus making acceleration control simpler.

[0114] However, in an embodiment of the invention, the vehicle should stop when the driver depresses the brake pedal 40 while the vehicle is rotating.

[0115] Therefore, during the rotation control operation, when the brake pedal is pressed at 40° while the vehicle is rotating, the vehicle's rotation speed decreases.

[0116] In other words, when the driver presses the brake pedal 40 while the vehicle is turning, the vehicle decelerates because the driver can recognize the danger inside or outside the vehicle and wants to stop the vehicle.

[0117] Figure 9 This is a flowchart illustrating the entire process of controlling the stationary rotation mode of a four-wheel independent steering vehicle according to an embodiment of the present invention.

[0118] Referring to the accompanying drawings, when the driver operates the shift lever or shift button to select the stationary turning mode, it is determined whether the absolute value of the steering angle exceeds β (approximately 2 degrees) (S10).

[0119] Therefore, when the absolute value of the steering angle exceeds β, the steering angle modules 60a, 60b, 60c and 60d are used to turn the front and rear wheels by 45° each (S20).

[0120] Then, determine whether to select the step-by-step rotation mode button 17 (S30).

[0121] As a result of step S30, when the step rotation mode button 17 is selected, the steering angle is detected, and then the target rotation angle is set according to the steering angle range.

[0122] For example, when setting a three-step rotation in units of 30°, determine whether the absolute value of the steering angle exceeds 90° (S31). If the absolute value of the steering angle exceeds 90°, set the target rotation angle α to 90° (S32).

[0123] Otherwise, if the absolute value of the steering angle does not exceed 90°, determine whether the absolute value of the steering angle exceeds 60° (S33). If the absolute value of the steering angle exceeds 60°, set the target rotation angle α to 60° (S34).

[0124] In addition, when the absolute value of the steering angle does not exceed 60°, it is determined whether the absolute value of the steering angle exceeds 30° (S35). When the absolute value of the steering angle exceeds 30°, the target rotation angle α is set to 30° (S36).

[0125] However, as a result of step S30, when the step rotation mode button 17 is not selected, the steering angle is detected, and then the target rotation angle is set to the corresponding steering angle.

[0126] In other words, when the absolute value of the steering angle is 100°, the target rotation angle α is set to 100° (S37).

[0127] Then, it is determined whether the signal of the accelerator pedal 30 is turned on (S40). When the signal of the accelerator pedal 30 is turned on, it is determined whether the steering angle exceeds 0° (S50), and then the turning direction of the steering wheel 20 is determined.

[0128] For example, when the steering angle exceeds 0°, it is determined that the steering wheel 20 is turned to the right and the drive component 70 for rotating the vehicle rotates in the positive direction so that the vehicle rotates in place in the clockwise direction (S51).

[0129] Otherwise, when the steering angle does not exceed 0°, it is determined that the steering wheel 20 is turned to the left and the drive component 70 for rotating the vehicle rotates in the opposite direction so that the vehicle rotates in place in the counterclockwise direction (S52).

[0130] Subsequently, it is determined whether the signal of the brake pedal 40 is open (S60). When the signal of the brake pedal 40 is not open, it is determined whether the absolute value of the vehicle's rotation angle is consistent with the preset target rotation angle, so as to determine whether the stationary rotation has achieved the driver's intention (S70).

[0131] Additionally, it determines whether the speed of the stationary vehicle is zero (S80), and terminates control when the speed of the stationary vehicle is zero.

[0132] Furthermore, as a result of step S60, even when a signal for the brake pedal 40 is applied, the process proceeds to step S80 to determine whether the speed of the stationary vehicle is zero, and when the speed of the stationary vehicle is zero, the control is terminated.

[0133] As described above, according to the embodiment of the present invention, the target rotation angle is set to correspond to the amount of steering wheel 20 operated by the driver, and the vehicle rotates in place at the same angle as the set target rotation angle, thereby precisely controlling the rotation angle of the vehicle. The driver can easily and conveniently operate the vehicle's in-place rotation function to reduce driving anxiety and prevent misoperation of the steering wheel 20 due to dizziness during rotation, thereby reducing the risk of accidents.

[0134] According to an embodiment of the present invention, the target rotation angle is set to correspond to the amount of steering wheel operation by the driver, and the vehicle rotates in place at the same angle as the set target rotation angle. This allows for precise control of the vehicle's rotation angle, and enables the driver to easily and conveniently operate the vehicle's in-place rotation function to reduce driving anxiety and prevent misoperation of the steering wheel due to dizziness during rotation, thereby reducing the risk of accidents.

[0135] On the other hand, although the invention has been described in detail with reference to the specific examples above, it will be apparent to those skilled in the art that various modifications and alterations can be made within the technical scope of the invention, and such modifications and alterations naturally fall within the scope of the appended claims.

Claims

1. A control method for a stationary turning mode of a four-wheel independent steering vehicle, the control method comprising: When the vehicle's stationary rotation mode is executed, wheel rotation operations are performed to make the wheels rotate, according to the stationary rotation mode. When the steering wheel is turned, a target rotation angle calculation operation is performed based on the steering angle of the steering wheel to calculate the target rotation angle of the vehicle, and the target rotation angle is set to the amount of steering wheel turning operated by the driver. When the accelerator pedal is pressed, a rotation control operation is performed to control the vehicle to rotate in place by the same angle as the target rotation angle. The system determines whether the brake pedal signal is engaged. If the brake pedal signal is not engaged, it checks whether the absolute value of the vehicle's rotation angle matches the preset target rotation angle. When the brake pedal signal is applied, it checks whether the vehicle's speed while stationary is zero. In the target rotation angle calculation operation, a separate step-by-step rotation mode button is provided on the side of the gear shift lever. When the step-by-step rotation mode button is activated, the target rotation angle for each step is calculated. When the step-by-step rotation mode button is not selected, the steering angle is detected, and then the target rotation angle is set to the corresponding steering angle. In the rotation control operation that controls the vehicle to rotate in place at the same angle as the target rotation angle, it is determined whether the steering angle exceeds 0°. When the steering angle exceeds 0°, the steering wheel is turned to the right so that the vehicle rotates in place in a clockwise direction. When the steering angle does not exceed 0°, the steering wheel is turned to the left so that the vehicle rotates in place in a counterclockwise direction.

2. The method according to claim 1, wherein, In the target rotation angle calculation operation, the target rotation angle is divided for each step according to the steering wheel's steering angle range, and the target rotation angle is set for each step.

3. The method according to claim 2, wherein, The steering angle range is set by successively extending the predetermined angle range.

4. The method according to claim 2, wherein, The target rotation angle calculation is performed through the operation of a separately configured mechanism.

5. The method according to claim 1, wherein, In the target rotation angle calculation operation, the target rotation angle is calculated when a specific button in the shift button is pressed a predetermined number of times or more, or is pressed for a predetermined period of time or a longer period of time.

6. The method according to claim 1, wherein, In the target rotation angle calculation operation, the target rotation angle is continuously changed and set to the steering angle corresponding to the steering wheel.

7. The method according to claim 1, wherein, In the rotation control operation, when the vehicle is rotating in place, the steering wheel rotates in the opposite direction to the vehicle's rotation by the same angle as the vehicle's rotation.

8. The method according to claim 7, wherein, In the rotation control operation, while the vehicle is rotating, the steering wheel is rotated in the opposite direction to the vehicle's rotation angle. When the vehicle's rotation stops, the steering wheel is reset and rotated in the opposite direction to the vehicle's rotation angle by the same angle, thereby enabling the identification of the termination point of the stationary rotation.

9. The method according to claim 1, wherein, In the aforementioned rotation control operation, when the vehicle is stationary and rotating, the steering wheel rotates in the opposite direction to the vehicle's rotation direction by the same angle as the driver's rotation of the steering wheel.

10. The method according to claim 9, wherein, In the rotation control operation, while the vehicle is rotating, for the stationary rotation of the vehicle, the steering wheel is rotated in the opposite direction to the direction of vehicle rotation according to the steering angle of the steering wheel turned by the driver. When the rotation of the vehicle ends, the steering wheel is reset and rotated in the opposite direction to the direction of vehicle rotation by the same angle as the angle of the steering wheel turned by the driver, thereby enabling the identification of the end time of the stationary rotation.

11. The method according to claim 1, wherein, In the aforementioned rotation control operation, during the vehicle's stationary rotation, when the steering wheel is additionally rotated in the vehicle's rotation direction, the vehicle further rotates by the same angle as the additional steering angle of the steering wheel.

12. The method according to claim 1, wherein, In the rotation control operation, the vehicle's rotation speed is determined based on the amount of pressure applied to the accelerator pedal, so that the vehicle rotates.

13. The method according to claim 1, wherein, In the rotation control operation, during the initial stage of vehicle rotation, the rotational acceleration is gradually increased within the range of the accelerator pedal's depress amount.

14. The method according to claim 1, wherein, In the rotation control operation, at the end of the vehicle rotation phase, before reaching the target rotation angle, the rotation acceleration is gradually reduced.

15. The method according to claim 1, wherein, In the rotation control operation, when the brake pedal is pressed while the vehicle is rotating, the rotation speed of the vehicle is reduced.

16. A control method for a stationary turning mode of a four-wheel independent steering vehicle, the control method comprising: When the vehicle's stationary rotation mode is executed, wheel rotation operations are performed to make the wheels rotate, according to the stationary rotation mode. When the steering wheel is turned, a target rotation angle calculation operation is performed based on the steering angle of the steering wheel to calculate the target rotation angle of the vehicle, and the target rotation angle is set to the amount of steering wheel turning operated by the driver. When the accelerator pedal is pressed, a rotation control operation is performed to control the vehicle to rotate at the same angle as the target rotation angle, wherein the rotation angle of the vehicle is guided by a notification component in the rotation control operation. The system determines whether the brake pedal signal is engaged. If the brake pedal signal is not engaged, it checks whether the absolute value of the vehicle's rotation angle matches the preset target rotation angle. When the brake pedal signal is applied, it checks whether the vehicle's speed while stationary is zero. In the target rotation angle calculation operation, a separate step-by-step rotation mode button is provided on the side of the gear shift lever. When the step-by-step rotation mode button is activated, the target rotation angle for each step is calculated. When the step-by-step rotation mode button is not selected, the steering angle is detected, and then the target rotation angle is set to the corresponding steering angle. In the rotation control operation that controls the vehicle to rotate in place at the same angle as the target rotation angle, it is determined whether the steering angle exceeds 0°. When the steering angle exceeds 0°, the steering wheel is turned to the right so that the vehicle rotates in place in a clockwise direction. When the steering angle does not exceed 0°, the steering wheel is turned to the left so that the vehicle rotates in place in a counterclockwise direction.

17. The method according to claim 16, wherein, The notification component displays the vehicle's rotation angle on the instrument cluster or guides the vehicle's rotation angle via voice.

18. The method according to claim 16, wherein, While the vehicle is stationary, the notification component temporarily sets different operating sensations for the steering wheel at each predetermined rotation angle.

19. A vehicle comprising: Four wheels, configured to operate in a stationary turning mode in a four-wheel independent steering vehicle; steering wheel; Accelerator pedal; as well as The controller is configured to cause the wheels to turn and rotate according to the stationary turning mode when the vehicle's stationary turning mode is executed. When the steering wheel is turned, the target rotation angle of the vehicle is calculated based on the steering angle of the steering wheel, and the target rotation angle is set to correspond to the amount of steering wheel input by the driver. When the accelerator pedal is pressed, the vehicle is controlled to rotate in place by the same angle as the target rotation angle. The system checks whether the brake pedal is engaged. If the brake pedal is not engaged, it checks whether the absolute value of the vehicle's rotation angle matches the preset target rotation angle. If the brake pedal is engaged, it checks whether the vehicle's speed is zero. In calculating the target rotation angle, a separate step-by-step rotation mode button is provided on the side of the gear shift lever. When this button is activated, the target rotation angle for each step is calculated. If the step-by-step rotation mode button is not selected, the steering angle is detected, and the target rotation angle is set to correspond to the steering angle. In controlling the vehicle to rotate in place by the same angle as the target rotation angle, it checks whether the steering angle exceeds 0°. If the steering angle exceeds 0°, the steering wheel is turned to the right to rotate the vehicle clockwise. If the steering angle does not exceed 0°, the steering wheel is turned to the left to rotate the vehicle counterclockwise.

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