METHOD FOR DETECTING A TACKLE ROLLER AND DEVICE FOR THIS

Abstract

A method and apparatus for detecting rack roll of a vehicle rack can perform operations that include: determining whether a fault is occurring with respect to a rack connected to a steering motor, using at least one motor current of the steering motor for steering control of a vehicle or a rack force; detecting abnormal behavior of the vehicle based on a yaw rate and a lateral acceleration of the vehicle; and detecting rack roll connected to the steering motor, based on determining whether a fault is occurring with respect to the rack and detecting the abnormal behavior of the vehicle.

Description

[0001] This application claims priority over Korean patent application No. 10-2024-0167699, filed with the Korean Intellectual Property Office on November 21, 2024, and No. 10-2025-0170535, filed there on November 12, 2025. BACKGROUND area

[0002] The present embodiments relate to a technology for detecting a rack rolling phenomenon occurring in a rack of a vehicle. Description of the related facts

[0003] Power steering is used in a vehicle's steering system to provide comfort during driving by assisting the effort exerted by a driver on a steering wheel. Power steering systems include hydraulic power steering, which uses hydraulic pressure; electro-hydraulic power steering, which uses hydraulic pressure and engine power; and electric power steering, which uses engine power only.

[0004] A steer-by-wire (SBW) steering system was recently developed. The steer-by-wire system has no mechanical connection between the steering wheel and a wheel, such as a steering shaft, universal joint, or pinion shaft, and incorporates an electric motor for steering the vehicle.

[0005] However, since the steer-by-wire steering system has no mechanical connection between the steering shaft and the wheel, the driver's steering input cannot be transferred to the rack in the event of engine failure, and the rack can be rotated by the torque of a ball nut, thus worsening steering stability.

[0006] In particular, if a problem occurs, such as a breakage of the anti-rotation element that prevents the rotation of the rack, there is a problem in that it is difficult to accurately detect the rack rotation problem in the steer-by-wire system or R-EPS. SUMMARY

[0007] The present embodiments propose a method and a device for detecting a rack rolling phenomenon occurring in a rack of a vehicle.

[0008] According to the present embodiments, a method can be provided which includes: determining whether a fault occurs with respect to a rack connected to a steering motor, using at least one motor current of the steering motor for steering control of a vehicle or a rack force; detecting abnormal behavior of the vehicle based on a yaw rate and a lateral acceleration of the vehicle; and detecting rolling of the rack connected to the steering motor, based on determining whether the fault occurs with respect to the rack and detecting the abnormal behavior of the vehicle.

[0009] According to the present embodiments, a device for detecting rack rolling can be provided with a device configured to include a memory configured to store at least one instruction and a processor executing at least one instruction to perform operations that include: determining whether a fault is occurring with respect to a rack connected to a steering motor, using at least one motor current of the steering motor for steering control of a vehicle or a rack force; detecting abnormal behavior of the vehicle based on a yaw rate and a lateral acceleration of the vehicle; and detecting rolling of the rack connected to the steering motor based on determining whether the fault is occurring with respect to the rack and detecting the abnormal behavior of the vehicle.

[0010] According to the present embodiments, in a non-volatile, computer-readable recording medium that stores computer instructions which, when executed by a processor, cause an operating operation to be carried out, the operating operation comprises: determining whether a fault is occurring with respect to a rack connected to a steering motor, using at least one motor current of the steering motor for steering control of a vehicle or a rack force; detecting abnormal behavior of the vehicle based on a yaw rate and a lateral acceleration of the vehicle; and detecting any rolling of the rack connected to the steering motor, based on determining whether the fault is occurring with respect to the rack and detecting the abnormal behavior of the vehicle.

[0011] According to the present embodiments, a steer-by-wire system can be provided which includes: a ball nut coupled to a rack via balls, which rotates the rack and displaces it in an axial direction; a first nut pulley provided on an outer circumferential surface of the ball nut; a second nut pulley provided on an outer circumferential surface of the ball nut; a first motor pulley coupled to a first motor and connected to the first nut pulley by a first belt; a second motor pulley coupled to a second motor and connected to the second nut pulley by a second belt;and a controller that controls an output value which is transmitted to the first motor and the second motor using an electrical signal as an input value, wherein the controller determines whether a fault occurs with respect to the rack, using at least one motor current of a steering motor for steering control of the vehicle or a rack force, detects abnormal behavior of the vehicle based on a yaw rate and a lateral acceleration of the vehicle, and detects a roll of a rack connected to the steering motor based on a determination of whether the fault occurs with respect to the rack and a detection of the abnormal behavior of the vehicle.

[0012] The present embodiments provide the effect of enabling fast and accurate detection of a rack rolling phenomenon occurring in a rack of a vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other aspects, features and other advantages of the present disclosure will become clearer from the following detailed description in conjunction with the accompanying drawings: Fig. Figure 1 is a schematic view that schematically illustrates a steering device according to an embodiment of the present disclosure; Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. Figure 7 are partial views illustrating a steering device according to embodiments of the present disclosure; Fig. Figure 8 is a schematic view that schematically illustrates a steering device according to an embodiment of the present disclosure; Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17 to Fig. Figure 18 are partial views illustrating a steering device according to one embodiment of the present disclosure; Fig. Figure 19 is a diagram illustrating a method for estimating a rack position according to a difference between first rotation information of a first motor and second rotation information of a second motor according to an embodiment of the present disclosure; Fig. Figure 20 is a diagram illustrating a rack rolling detection method according to one embodiment. Fig. Figure 21 is a diagram illustrating an operating procedure for determining whether a fault occurs with respect to a rack, according to one embodiment. Fig. Figure 22 is a diagram illustrating an example of a rack rolling detection operation according to one embodiment. Fig. Figure 23 is a diagram to illustrate another example of a rack rolling detection operation according to one embodiment. Fig. Figure 24 is a diagram illustrating a configuration of a rack rolling detection device according to one embodiment. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0014] In the following description of examples or embodiments of the present disclosure, reference is made to the accompanying drawings, which show, for illustrative purposes, specific examples or embodiments that can be implemented and in which the same reference numerals and symbols can be used to designate the same or similar components, even if they are shown in different accompanying drawings. Furthermore, in the following description of examples or embodiments of the present disclosure, detailed descriptions of well-known functions and components included herein are omitted where it is determined that such a description may render the subject matter rather unclear in some embodiments of the present disclosure.The terms used here, such as "including," "include," "contain," "form," "train," and "trained," are generally intended to allow the addition of other components, unless the terms are used with the term "only." As used here, singular forms are intended to include plural forms unless the context clearly indicates otherwise.

[0015] Terms such as "first," "second," "A," "B," "(A)," or "(B)" may be used here to describe elements of revelation. Each of these terms is not used to define any essentiality, order, sequence, or number of elements, etc., but is merely used to distinguish the respective element from other elements.

[0016] When it is mentioned that a first element is "connected or coupled" to a second element, "this contacted or overlapped with it," etc., it should be interpreted that the first element can not only be "directly connected or coupled" to the second element, or "this contacted or overlapped with it," but that a third element can also be "arranged" between the first and second elements, or that the first and second elements can be "connected or coupled" to each other via a fourth element, "this contacted or overlapped with it," etc. Here, the second element can be contained within at least one of two or more elements that are "connected or coupled," "contacted or overlapped," etc.

[0017] When temporally relative terms such as "after", "subsequent", "next", "before", and the like are used to describe processes or operations of elements or configurations or sequences or steps in operational, processing, or manufacturing procedures, these terms may be used to describe non-consecutive or non-sequential processes or operations unless the term "direct" or "immediate" is used together.

[0018] Additionally, if any dimensions, relative sizes, etc., are mentioned, it should be considered that numerical values ​​for an element or feature, or corresponding information (e.g., level, range, etc.), include a tolerance or error range that may be caused by various factors (e.g., process factors, internal or external influences, noise, etc.), even if a relevant description is not specified. Furthermore, the term "could" fully encompasses all meanings of the term "may."

[0019] Unlike a conventional steering system, which uses a mechanical link between the steering wheel and the vehicle's wheels, a steer-by-wire system allows a vehicle to move according to the driver's steering input using an electronic signal transmitted via a wire. This wire-based vehicle motion control can be applied to various components, such as the brakes. However, steer-by-wire systems require robust technical support, as a potential problem arises where the vehicle becomes uncontrollable due to an interruption in the electronic signals. Furthermore, technological advancements in miniaturization and cost reduction are also necessary.

[0020] Several embodiments of the present disclosure propose various structures and control technologies that can improve stability, miniaturization, and production cost reduction in the steer-by-wire steering device. For example, in certain embodiments of the present disclosure, a plurality of motors may be provided to move a rack to ensure redundancy and generate adequate torque. Exemplary embodiments of the arrangement and positions of the motor and rack are described with reference to the drawings.

[0021] In certain embodiments of the present disclosure, a pinion may not be included in a steer-by-wire steering device configured for cost reduction and miniaturization. However, in these embodiments, a rack can rotate when the rack is moved by the motor. Accordingly, various embodiments of the present disclosure may provide a structure to prevent the rack from rotating.

[0022] Furthermore, it is important to estimate the absolute position of the rack of the steer-by-wire steering system to accurately steer the vehicle. However, a sensor for estimating the absolute position of the rack can be susceptible to damage from impact, dust, water immersion, and similar environments. Additionally, a multitude of sensors may be required to ensure redundancy. Various embodiments of the present disclosure can provide configurations for estimating the position of the rack using an absolute angle sensor configured to estimate the position of the rack, or using a sensor provided in a motor or the like. Additionally, some embodiments of the present disclosure can perform a process for estimating the position of the rack when the position of the rack is estimated relatively.

[0023] The structure, motor, anti-rotation element, sensor, control process, and the like of the steering device disclosed in the present disclosure can be implemented as different embodiments for each part. Several embodiments for each part can be applied to a steering device in any combination thereof.

[0024] First, embodiments of configurations of the overall structure of a steer-by-wire steering device are described.

[0025] Fig. Figure 1 is a schematic view that schematically illustrates a steering device according to an embodiment of the present disclosure, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6 to Fig. 7 are partial views of a steering device according to embodiments of the present disclosure, Fig. Figure 8 is a schematic view that schematically illustrates a steering device according to an embodiment of the present disclosure, and Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17 to Fig. Figure 18 shows partial views of a steering device according to embodiments of the present disclosure.

[0026] A steering device according to one embodiment of the present disclosure comprises a ball nut 141, a first nut pulley 143a, a second nut pulley 143b, a first motor pulley 142a, a second motor pulley 142b, and an electronic control unit 110. The ball nut 141 can be rotatably coupled to a rack 130 by means of balls 144 and can be configured to displace the rack 130 in an axial direction by rotating the ball nut 141. The first nut pulley 143a can be provided on an outer circumferential surface of the ball nut 141, and the second nut pulley 143b can be provided on an outer circumferential surface of the first ball nut 141. The first motor pulley 142a can be coupled to a first motor 145 (e.g.,The first motor 145 may be attached to a shaft of the first motor 145 or be formed directly on a rotatable part of the first motor 145 and connected to a first belt 143a by a first belt 149a. The second motor 142b may be coupled to a second motor 147 (e.g., attached to a shaft of the second motor 147) or formed directly on a rotatable part of the second motor 147 and connected to the second belt 143b by a second belt 149a. The electronic control unit 110 may include one or more controllers or processors and may be configured to control the first and second motors 145 and 147. For example, the electronic control unit 110 outputs one or more control signals to the first motor 145 and the second motor 147 in response to one or more electrical signals.

[0027] With reference to Fig. 1 In a steering device according to the present disclosure, an angle sensor 105 and a torque sensor 107 can be coupled to a side of a steering shaft 103 which is connected to a steering wheel 101 or arranged around the steering shaft 103.

[0028] In an autonomous driving mode, in which an autonomous driving system drives the vehicle, or in a driver assistance mode, in which a driver assistance system, such as an Advanced Driver Assistance System (ADAS), assists a driver in operating the vehicle, the electronic control unit 110 controls a steering shaft motor 120, the first motor 145 and the second motor 147 by transmitting one or more control signals to the steering shaft motor 120, the first motor 145 and the second motor 147 in response to electrical signals transmitted by various sensors that are installed in or on or associated with a vehicle.

[0029] In a driver driving mode, the electronic control unit 110 controls the steering shaft motor 120, the first motor 145 and the second motor 147 by outputting one or more control signals to the steering shaft motor 120, the first motor 145 and the second motor 147 in response to electrical signals transmitted by the angle sensor 105, which detects an actuation or rotation angle of the steering wheel 101 by the driver, electrical signals transmitted by the torque sensor 107, and electrical signals transmitted by various other sensors that are installed in or on the vehicle or associated with it.

[0030] In a Fig. In the illustrated embodiment 1, the angle sensor 105 and the torque sensor 107 are provided as two separate and individual sensors. Alternatively, the angle sensor 105 and the torque sensor 107 can be integrated into a single sensor, such as a torque angle sensor.

[0031] The steering shaft motor 120 may be connected to or associated with a speed reducer configured to reduce the rotational speed of the steering shaft motor 120, including, for example, but not limited to, one or more gears, one or more pulleys and / or one or more belts.

[0032] During normal driving, the steering shaft motor 120 provides the driver with appropriate steering feedback by supplying a reaction force to the steering shaft 103, so that the driver can feel a steering reaction force against the driver's input of the steering wheel 101. The steering shaft motor 120 can also be referred to as a reaction force motor. However, as described below, the steering shaft motor 120 can not only provide the reaction force but also operate according to autonomous steering principles when the steering shaft motor 120 is operating in autonomous driving mode.

[0033] Additionally, the steering shaft motor 120 rotates the steering shaft 103, so that autonomous steering can be carried out under the control of the electronic control unit 110 without the involvement of driving or the intention of the driver when the steering shaft motor 120 is operating in autonomous driving mode.

[0034] Furthermore, in a steer-by-wire steering device, since the steering wheel 101 is not mechanically connected to the rack 130 and a wheel 131, a device for mechanically restricting or limiting a rotation range of the steering wheel 101 may be included to prevent the steering shaft 103 from rotating infinitely when the driver operates the steering wheel 101.

[0035] For example, a rotation angle limiting device 125 may be provided to limit or restrict a rotation range of the steering wheel 101 to prevent the steering shaft 103 from rotating infinitely.

[0036] The first motor 145 and the second motor 147 move the rack 130 or cause the rack 130 to move by means of a rack-and-pinion motion device 140 in order to steer the wheels 131 which are provided or connected to two opposite sides of the rack 130 by means of tie rods 133 and kingpin arms 135 by moving the rack 130.

[0037] The rack and pinion motion device 140 comprises the ball nut 141, the first nut pulley 143a, the second nut pulley 143b, the first motor pulley 142a, and the second motor pulley 142b. The ball nut 141 can be rotatably coupled to the rack 130 by means of the balls 144 and configured to displace the rack 130 in the axial direction of the rack and pinion motion device 140 by rotating the ball nut 141. The first nut pulley 143a can be provided on one side of the outer circumferential surface of the ball nut 141, and the second nut pulley 143b can be provided on the other side of the outer circumferential surface of the ball nut 141. The first motor pulley 142a can be coupled to the first motor 145 (e.g.,The first motor pulley 142b can be coupled to the second motor 147 (e.g., attached to a shaft of the first motor 145) or formed directly on a rotatable part of the first motor 145 and connected to the first nut pulley 143a by the first belt 149a. The second motor pulley 142b can be coupled to the second motor 147 (e.g., attached to a shaft of the second motor 147) or formed directly on a rotatable part of the second motor 147 and connected to the second nut pulley 143b by the second belt 149a.

[0038] Furthermore, the balls 144 are rotatably arranged between a rack screw groove formed on an outer circumferential surface of the rack 130 and a nut screw groove formed on an inner circumferential surface of the ball nut 141, so that the rack 130 can be moved in the axial direction of the rack motion device 140 by the rotation of the ball nut 141.

[0039] In the embodiments of the present disclosure described above, however, the angle sensor 105 and the torque sensor 107 are provided on or around the steering shaft 103, and the steering device according to one embodiment of the present disclosure may include a vehicle speed sensor 102, an ultrasonic sensor 104, and an image sensor 106 for transmitting steering information to the electronic control unit 110. Various types of sensors, such as radar and lidar, may also be added to an embodiment of the present disclosure.

[0040] In a steer-by-wire steering device, since the steering wheel 101 is not mechanically connected to the rack 130 and the wheel 131, a device for mechanically limiting the rack 130 may be included to prevent the rack 130 from rotating due to a torque of the ball nut 141, which is rotated by the rack motion device 140.

[0041] For example, a rotation prevention element 150 is configured to support the axial displacement of the rack 130 and to prevent the rotation of the rack 130.

[0042] In a Fig. In the illustrated embodiment 1, a single anti-rotation element 150 is provided on one side of the rack 130.

[0043] Alternatively, a number of anti-rotation elements 150 can be provided to support the rack 130. The number of anti-rotation elements 150, the axial position of the anti-rotation element 150, or the like can vary depending on the configuration and required operation of the first and second motors 145 and 147 and the required torque of the ball nut 141 of the rack motion device 140.

[0044] In a Fig. In the illustrated embodiment, the first motor 145 and the second motor 147 are arranged such that they face each other, so that a shaft 145a of the first motor 145 and a shaft 147a of the second motor 147 are aligned coaxially and arranged parallel to a central axis of the rack 130.

[0045] In another in Fig. In the illustrated embodiment 2, the first motor 145 is arranged on one side of the rack 130 and the second motor 147 is arranged on the other side of the rack 130, so that the rack 130 is positioned between the shaft 145a of the first motor 145 and the shaft 147a of the second motor 147, and the shaft 145a of the first motor 145 and the shaft 147a of the second motor 147 are arranged parallel to the central axis of the rack 130 and are located on two opposite sides of the central axis of the rack 130.

[0046] As described above, the exemplary arrangements of the first and second motors 145 and 147 and the rack 130, which are shown in Fig. 1 and Fig. 2 are illustrated, reducing the package size of the steering device, which makes it more compact in volume, and simplifying the process of assembling the steering device, the first motor 145, the first belt 149a, the second motor 147 and the second belt 149b.

[0047] With reference to Fig. 3. The outer diameter mD1 of the first motor pulley 142a and the outer diameter mD2 of the second motor pulley 142b can be different from each other, and the outer diameter nD1 of the first mother pulley 143a and the outer diameter nD2 of the second mother pulley 143b can be the same.

[0048] This means that the first nut pulley 143a and the second nut pulley 143b rotate while maintaining the same phase angle without a phase difference between them when the first motor 145 and the second motor 147 are operating. The first motor pulley 142a and the second motor pulley 142b rotate while a phase difference between them gradually changes when the first motor 145 and the second motor 147 are operating.

[0049] In a Fig. In the illustrated embodiment 3, the first nut pulley 143a and the second nut pulley 143b are provided separately and connected to one section and the other section of the outer circumferential surface of the ball nut 141. However, as shown in Fig. Figure 4 illustrates that the first nut pulley 143a and the second nut pulley 143b are integrated as a single piece with the same outer diameter. This is described below.

[0050] The first motor 145 can have a first motor sensor 145s configured to detect a rotational position of the shaft 145a of the first motor 145, and the second motor 147 can have a second motor sensor 147s configured to detect a rotational position of the shaft 147a of the second motor 147.

[0051] When the first motor 145 is operating, the first motor sensor 145s detects a direction and angle of rotation of the shaft 145a of the first motor 145, and the first motor sensor 145s outputs a signal indicating the direction and angle to the electronic control unit 110.

[0052] When the second motor 147 is operating, the second motor sensor 147s detects the direction and angle of rotation of the shaft 147a of the second motor 147, and the second motor sensor 147s outputs a signal indicating the direction and angle of rotation of the shaft 147a of the second motor 147 to the electronic control unit 110.

[0053] Therefore, the electronic control unit 110 can determine a linear position of the rack 130 based on a first position of the shaft 145a of the first motor 145, which is detected by the first motor sensor 145s, and a second position of the shaft 147a of the second motor 147, which is detected by the second motor sensor 147s, and output a control signal to the first motor 145 and the second motor 147.

[0054] This means that the electronic control unit 110 sets an angle between a reference point on the shaft 145a of the first motor 145 when the first motor 145 is stopped and a reference point on the shaft 147a of the second motor 147 when the second motor 147 is stopped, to a reference position value. The electronic control unit 10 sets an angle between the reference point on the shaft 145a of the first motor 145 and the reference point on the shaft 147a of the second motor 147 after the first and second motors 145 and 147 have been operated, to an operating position value. The electronic control unit 10 determines the linear position of the rack 130 based on the difference between the reference position value and the operating position value.

[0055] For example, the difference between the reference position value and the operating position value can be set from 0° to 360°. A maximum displacement of the rack 130 is set within this range. The electronic control unit 110 determines the displacement position of the rack 130 based on at least one of the following: a rotation ratio between the first motor pulley 142a and the first nut pulley 143a, a rotation ratio between the second motor pulley 142b and the second nut pulley 143b, an outer diameter and an inner diameter of the ball nut 141, an outer diameter of the rack 130, or a helix angle between the rack bolt groove and the nut bolt groove.

[0056] Additionally, the electronic control unit 110 can determine the linear position of the rack 130 by setting the difference between the reference position value and the operating position value to a motion value and comparing the motion value with preset data. For example, the motion value can be set from 0° to 360°, and the maximum displacement of the rack 130 can be set within this range.

[0057] The preset data can be data that includes the displacement amount of the rack 130, which corresponds to the movement value determined on the basis of at least one of the outer diameters of the first and second motor pulleys 142a and 142b, the outer diameters of the first and second nut pulleys 143a and 143b, the outer and inner diameters of the ball nut 141 and / or the outer diameter of the rack 130.

[0058] For example, the first motor pulley 142a and the second motor pulley 142b have different outer diameters, and the first nut pulley 143a and the second nut pulley 143b have the same outer diameter, so that the electronic control unit 110 can determine the displacement position of the rack 130 based on the first position of the shaft 145a of the first motor 145, which is detected by the first motor sensor 145s, and the second position of the shaft 147a of the second motor 147, which is detected by the second motor sensor 147s, and output a signal to control the first motor 145 and the second motor 147.

[0059] With reference to Fig. 4. The first nut pulley 143a and the second nut pulley 143b can be integrated into a single piece with the same outer diameter.

[0060] In an example where the first mother pulley 143a and the second mother pulley 143b are integrated into a single piece with the same outer diameter, the first belt 149a is coupled to one section of the integrated pulley, and the second belt 149b is coupled to the other section of the integrated pulley, so that the first belt 149a and the second belt 149b can each be connected to the first motor pulley 142a and the second motor pulley 142b, respectively.

[0061] Furthermore, the first motor 145 can have the first motor sensor 145s, which is configured to detect the rotational position of the shaft 145a of the first motor 145, and the second motor 147 can have the second motor sensor 147s, which is configured to detect the rotational position of the shaft 147a of the second motor 147.

[0062] When the first motor 145 is operating, the first motor sensor 145s detects the direction and angle of rotation of the shaft 145a of the first motor 145, and the first motor sensor 145s transmits the direction and angle to the electronic control unit 110.

[0063] When the second motor 147 is operating, the second motor sensor 147s detects the direction and angle of rotation of the shaft 147a of the second motor 147, and the second motor sensor 147s transmits a signal indicating the direction and angle to the electronic control unit 110.

[0064] Therefore, the electronic control unit 110 can determine the linear position of the rack 130 based on the first position of the shaft 145a of the first motor 145, which is detected by the first motor sensor 145s, and the second position of the shaft 147a of the second motor 147, which is detected by the second motor sensor 147s, and output a signal to control the first motor 145 and the second motor 147.

[0065] In an exemplary embodiment, which is described in Fig. As illustrated in Figure 5, the outer diameter mD1 of the first motor pulley 142a and the outer diameter mD2 of the second motor pulley 142b can be the same, and the outer diameter nD1 of the first mother pulley 143a and the outer diameter nD2 of the second mother pulley 143b can be different.

[0066] The first nut pulley 143a, the second nut pulley 143b, and the ball nut 141 rotate at the same speed. Therefore, the first nut pulley 143a and the second nut pulley 143b maintain the same phase angle and rotate without a phase difference when the first motor 145 and the second motor 147 are operating. However, the first motor pulley 142a and the second motor pulley 142b rotate with a gradually changing phase difference.

[0067] Furthermore, the first motor 145 can have the first motor sensor 145s, which is configured to detect the rotational position of the shaft 145a of the first motor 145, and the second motor 147 can have the second motor sensor 147s, which is configured to detect the rotational position of the shaft 147a of the second motor 147.

[0068] When the first motor 145 is operating, the first motor sensor 145s detects the direction and angle of rotation of the shaft 145a of the first motor 145, and the first motor sensor 145s outputs a signal indicating the direction and angle of rotation of the shaft 145a of the first motor 145 to the electronic control unit 110.

[0069] Furthermore, when the second motor 147 is operating, the second motor sensor 147s detects the direction and rotation angle of the shaft 147a of the second motor 147, and the second motor sensor 147s transmits the direction and rotation angle of the shaft 147a of the second motor 147 to the electronic control unit 110.

[0070] Therefore, the electronic control unit 110 can output a signal to control the first motor 145 and the second motor 147 by determining the linear position of the rack 130 by the above-mentioned determination process based on the first position of the shaft 145a of the first motor 145, which is detected by the first motor sensor 145s, and the second position of the shaft 147a of the second motor 147, which is detected by the second motor sensor 147s.

[0071] In an exemplary embodiment, which is described in Fig. As shown in Figure 6, the outer diameter mD1 of the first motor pulley 142a and the outer diameter mD2 of the second motor pulley 142b can be different from each other, and the outer diameter nD1 of the first mother pulley 143a and the outer diameter nD2 of the second mother pulley 143b can also be different from each other.

[0072] Even in this case, the first nut pulley 143a, the second nut pulley 143b, and the ball nut 141 rotate at the same speed. Therefore, the first nut pulley 143a and the second nut pulley 143b maintain the same phase angle and rotate without a phase difference when the first motor 145 and the second motor 147 are operating.

[0073] Furthermore, the first motor pulley 142a and the second motor pulley 142b rotate while a phase difference is gradually changed when the first motor 145 and the second motor 147 are operating.

[0074] The first motor 145 can have the first motor sensor 145s, which is configured to detect the rotational position of the shaft 145a of the first motor 145, and the second motor 147 can have the second motor sensor 147s, which is configured to detect the rotational position of the shaft 147a of the second motor 147.

[0075] Therefore, the electronic control unit 110 can output a signal to control the first motor 145 and the second motor 147 by determining the linear position of the rack 130 by the above-mentioned determination process based on the first position of the shaft 145a of the first motor 145, which is detected by the first motor sensor 145s, and the second position of the shaft 147a of the second motor 147, which is detected by the second motor sensor 147s.

[0076] In an exemplary embodiment of Fig. 7. First motor pulley teeth 142-1 are provided on an outer circumferential surface of the first motor pulley 142a, and first nut pulley teeth 143-1 are provided on an outer circumferential surface of the first nut pulley 143a. The first motor pulley teeth 142-1 and the first nut pulley teeth 143-1 can be coupled to first belt teeth 149-1, which are provided on an inner circumferential surface of the first belt 149a.

[0077] Since the first engine pulley teeth 142-1 and the first nut pulley teeth 143-1 are coupled with the first belt teeth 149-1 to transmit power, the first engine pulley teeth 142-1 and the first nut pulley teeth 143-1 are the same size as the first belt teeth 149-1.

[0078] Second motor pulley teeth 142-2 are provided on an outer circumferential surface of the second motor pulley 142b, and second nut pulley teeth 143-2 are provided on an outer circumferential surface of the second nut pulley 143b. The second motor pulley teeth 142-2 and the second nut pulley teeth 143-2 can be coupled to second belt teeth 149-2, which are provided on an inner circumferential surface of the second belt 149b.

[0079] Since the second motor pulley teeth 142-2 and the second nut pulley teeth 143-2 are coupled with the second belt teeth 149-2 to transmit power, the second motor pulley teeth 142-2 and the second nut pulley teeth 143-2 can be the same size as the second belt teeth 149-2.

[0080] Furthermore, the number of teeth on the first motor pulley 142-1 and the number of teeth on the second motor pulley 142-2 can be different, and the number of teeth on the first nut pulley 143-1 and the number of teeth on the second nut pulley 143-2 can be the same.

[0081] The first motor pulley teeth 142-1 and the second motor pulley teeth 142-2 have the same circumferential pitch, different pitch circle diameters, and a different number of teeth. The first nut pulley teeth 143-1 and the second nut pulley teeth 143-2 have the same circumferential pitch, the same pitch circle diameter, and a different number of teeth.

[0082] The first motor 145 can have the first motor sensor 145s, which is configured to detect the rotational position of the shaft 145a of the first motor 145, and the second motor 147 can have the second motor sensor 147s, which is configured to detect the rotational position of the shaft 147a of the second motor 147.

[0083] Therefore, the electronic control unit 110 can determine the linear position of the rack 130 based on the first position of the shaft 145a of the first motor 145, which is detected by the first motor sensor 145s, and the second position of the shaft 147a of the second motor 147, which is detected by the second motor sensor 147s, and output a signal to control the first motor 145 and the second motor 147.

[0084] This means that, as in the determination method mentioned above, the difference between the reference position value and the operating position value can be set from 0° to 360°, and the maximum displacement of the rack 130 is set within this range. The electronic control unit 110 determines the displacement position of the rack 130 based on at least one of the following: a pitch circle diameter ratio or a tooth number ratio between the first motor pulley 142a and the first nut pulley 143a, a pitch circle diameter ratio or a tooth number ratio between the second motor pulley 142b and the second nut pulley 143b, the outer and inner diameters of the ball nut 141, or the outer diameter of the rack 130.

[0085] Additionally, similar to the determination method mentioned above, the electronic control unit 110 can determine the displacement position of the rack 130 by setting the difference between the reference position value and the operating position value to the movement value and comparing the movement value with preset data. In this case, the movement value can be set from 0° to 360°, and the maximum displacement of the rack 130 is set within this range.

[0086] In this case, the preset data can be data that includes the displacement amount of the rack 130, which corresponds to the movement value determined on the basis of at least one of the pitch circle diameters and the number of teeth of the first and second motor pulleys 142a and 142b, the pitch circle diameters and the number of teeth of the first and second nut pulleys 143a and 143b, the outer and inner diameters of the ball nut 141 and / or the outer diameter of the rack 130.

[0087] As described above, the number of teeth on the first motor pulley 142-1 and the number of teeth on the second motor pulley 142-2 are different, while the number of teeth on the first nut pulley 143-1 and the number of teeth on the second nut pulley 143-2 are the same. The electronic control unit 110 can output a signal to control the first motor 145 and the second motor 147 by determining the displacement position of the rack 130 based on the first position of the shaft 145a of the first motor 145, detected by the first motor sensor 145s, and the second position of the shaft 147a of the second motor 147, detected by the second motor sensor 147s.

[0088] Additionally, the number of teeth on the first motor pulley 142-1 and the number of teeth on the second motor pulley 142-2 can be the same, and the number of teeth on the first nut pulley 143-1 and the number of teeth on the second nut pulley 143-2 can be different.

[0089] The first motor pulley teeth 142-1 and the second motor pulley teeth 142-2 have the same circumferential pitch, the same pitch circle diameter, and the same number of teeth. The first nut pulley teeth 143-1 and the second nut pulley teeth 143-2 have the same circumferential pitch but different pitch circle diameters and different numbers of teeth.

[0090] Furthermore, the first motor 145 can have the first motor sensor 145s, which is configured to detect the rotational position of the shaft 145a of the first motor 145, and the second motor 147 can have the second motor sensor 147s, which is configured to detect the rotational position of the shaft 147a of the second motor 147.

[0091] Therefore, the electronic control unit 110 can output a signal to control the first motor 145 and the second motor 147 by determining the displacement position of the rack 130 by the above-mentioned determination process based on the first position of the shaft 145a of the first motor 145, which is detected by the first motor sensor 145s, and the second position of the shaft 147a of the second motor 147, which is detected by the second motor sensor 147s.

[0092] Additionally, the number of teeth on the first motor pulley 142-1 and the number of teeth on the second motor pulley 142-2 may be different, and the number of teeth on the first nut pulley 143-1 and the number of teeth on the second nut pulley 143-2 may be different.

[0093] This means that the first motor pulley teeth 142-1 and the second motor pulley teeth 142-2 can have the same circumferential pitch but different pitch circle diameters and a different number of teeth. Similarly, the first nut pulley teeth 143-1 and the second nut pulley teeth 143-2 have the same circumferential pitch but different pitch circle diameters and a different number of teeth.

[0094] Furthermore, the first motor 145 can have the first motor sensor 145s, which is configured to detect the rotational position of the shaft 145a of the first motor 145, and the second motor 147 can have the second motor sensor 147s, which is configured to detect the rotational position of the shaft 147a of the second motor 147.

[0095] Therefore, the electronic control unit 110 can output a signal to control the first motor 145 and the second motor 147 by determining the displacement position of the rack 130 by the above-mentioned determination process based on the first position of the shaft 145a of the first motor 145, which is detected by the first motor sensor 145s, and the second position of the shaft 147a of the second motor 147, which is detected by the second motor sensor 147s.

[0096] In an exemplary embodiment of Fig. 8 To prepare for a case in which one of the first motor sensor 145s and the second motor sensor 147s is not functional, a rotary gear 139, rotatably engaged with a rack thread 130b provided on the rack 130, can be rotatably coupled to the rack 130, and a rotary angle sensor 137s can be configured to detect a rotary angle of the rotary gear 139.

[0097] The rotary gear 139 can be configured to rotate while supported on a rack housing by means of a bearing. The rotation angle sensor 137s can be installed on or around a shaft 137 of the rotary gear 139 and configured to detect a rotation angle of the rotary gear 139 and transmit the rotation angle of the rotary gear 139 to the electronic control unit 110.

[0098] Therefore, even if one of the first motor sensor 145s and the second motor sensor 147s is not functional, the electronic control unit 110 can output a signal to control the first motor 145 and the second motor 147 by determining the displacement position of the rack 130 based on the pre-stored transmission ratio between the rack thread 130b and the rotary gear 139 and the rotation angle of the rotary gear 139 received from the rotation angle sensor 137s.

[0099] Furthermore, various embodiments of a rotation prevention element or means in the steering device mentioned above can be provided below.

[0100] Some embodiments of the anti-rotation element 150 are described in more detail below with reference to Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17 to Fig. 18 described.

[0101] As in Fig. As illustrated in Figure 9, the anti-rotation element 150 can be coupled to one radial side and the other radial side of the rack 130 and support two opposite sides of the rack 130, thus preventing the rack 130 from rotating.

[0102] The anti-rotation element 150 can include a shaft 230 configured to support a support surface 130-1 formed on the outer circumferential surface of the rack 130, and a support yoke 240 configured to support the outer circumferential surface of the rack 130 opposite or corresponding to a position where the shaft 230 is supported.

[0103] The support surface 130-1, which is formed on the outer circumferential surface of the rack 130, can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0104] The support surface 130-1 can be recessed from the outer circumferential surface of the rack 130 and can be designed as a curved surface, a flat surface or a combination thereof.

[0105] The support surface 130-1 extends in an axial direction of the rack 130 in order to be supported by the shaft 230 when the rack 130 moves in the axial direction of the rack 130.

[0106] Optionally, a coating layer can be provided on the support surface 130-1 and made of a low-friction material with a low coefficient of friction, such as fluorinated resin or ceramic, to minimize or reduce friction with the shaft 230.

[0107] The shaft 230, which supports the support surface 130-1 of the rack 130, can include an upper end support section 231, a body section 233 and a lower end support section 235.

[0108] When the rack 130 moves, the shaft 230 is held in place by a rack housing (e.g. 160 made of Fig. 10) supported and is configured to be rotatable, so that the body section 233 supports the support surface 130-1 of the rack 130, thereby preventing the rack 130 from rotating.

[0109] A needle bearing 236 can be coupled to the body section 233 to minimize or reduce friction with the support surface 130-1 of the rack 130.

[0110] The upper end support section 231, which has a larger diameter than the body section 233, can be provided above the body section 233, and an upper end bearing 234 can be coupled to the upper end support section 231 to be rotatably supported on the rack housing.

[0111] An upper plug 232 can be coupled to a top surface of the upper end support section 231 to prevent foreign substances from being introduced into the rack housing.

[0112] The lower end support section 235, which has a smaller diameter than the body section 233, can be provided below the body section 233, and a lower end bearing 238 can be coupled to the lower end support section 235 to be rotatably supported on the rack housing.

[0113] The support yoke 240, which supports the outer circumferential surface of the rack 130 opposite a position where the shaft 230 is supported, supports the rack 130 in the direction of the shaft 230 when the rack 130 moves, thus preventing the rack 130 from rotating.

[0114] A support section 241 with a curved surface can be formed at an end section of the support yoke 240 and can be supported on the outer circumferential surface of the rack 130, making close contact with it. The support section 241 with a curved surface can have a curved surface that is identical to the outer circumferential surface of the rack 130.

[0115] The support yoke 240 can have a predetermined stiffness and elasticity and can be made from one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0116] An elastic ring 245 can be coupled to an outer circumferential surface of the support yoke 240 to prevent rattling noises with the rack housing.

[0117] One or more elastic rings 245 can be coupled to the outer circumferential surface of the support yoke 240.

[0118] The elastic ring 245 can be made of a material capable of absorbing vibrations and noise and exhibiting predetermined elasticity and stiffness. For example, the elastic ring 245 can be made of one or more materials selected from a group consisting of natural rubber (NR), nitrile butadiene rubber (NBR), chloroprene rubber (CR), ethylene propylene terpolymer (EPDM), fluororubber (FPM), styrene butadiene rubber (SBR), chlorosulfonated polyethylene (CSM), urethane, and silicone, all of which possess the aforementioned properties.

[0119] A yoke plug 243 can be coupled to an end section of the support yoke 240, press-fitted or screwed to the rack housing and fix the support yoke 240.

[0120] Furthermore, an elastic body can be coupled between the support yoke 240 and the yoke plug 243 and elastically support the support yoke 240 in the direction of the rack 130.

[0121] As in Fig. As illustrated in Figure 10, the anti-rotation element 150 can be coupled to one radial side and the other radial side of the rack 130 and support two opposite sides of the rack 130, thus preventing the rack 130 from rotating.

[0122] The anti-rotation element 150 can include a needle bearing 220 configured to support the support surface 130-1 formed on the outer circumferential surface of the rack 130, a support yoke 225 rotatably coupled to the needle bearing 220, and a rack bushing 229 configured to support the outer circumferential surface of the rack 130 opposite a position where the needle bearing 220 is supported.

[0123] The support surface 130-1 can be formed on the outer circumferential surface of the rack 130. For example, the support surface 130-1 can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0124] The support surface 130-1 can be recessed into the outer circumferential surface of the rack 130. The support surface 130-1 can be designed as a curved surface or a flat surface.

[0125] The support surface 130-1 extends longitudinally in the axial direction of the rack 130. And the support surface 130-1 can be supported by the needle bearing 220 when the rack 130 moves in the axial direction of the rack 130.

[0126] A coating layer can be provided on the support surface 130-1 and made of a low-friction material, such as fluorinated resin or ceramic, to minimize or reduce friction with the needle bearing 220.

[0127] The needle bearing 220 can be configured to support the support surface 130-1 of the rack 130, the needle bearing 220 can have a support shaft 221 provided on a central section of the needle bearing 220, and the support shaft 221 is attached to the support yoke 225 so that the needle bearing 220 can be rotatably supported by the support yoke 225.

[0128] An outer ring 222 of the needle bearing 220 is supported on the support surface 130-1 and is configured to rotate when the rack 130 moves, in order to prevent the rack 130 from rotating.

[0129] The outer ring 222 of the needle bearing 220 can be arranged in a position that projects from an end section of the support yoke 225, so that the outer ring 222 can be supported on the support surface 130-1.

[0130] The support yoke 225 supports the needle bearing 220 in the direction of the support surface 130-1 when the rack 130 moves, in order to prevent the rack 130 from rotating.

[0131] The support yoke 225 can have a predetermined stiffness and elasticity and can be made from one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0132] An elastic ring 226 can be coupled to the outer circumferential surface of the support yoke 225 to prevent rattling noises with the rack housing 160.

[0133] One or more elastic rings 226 can be coupled to the outer circumferential surface of the support yoke 225.

[0134] The elastic ring 226 can be made of a material capable of absorbing vibrations and noise and exhibiting predetermined elasticity and stiffness. Therefore, the elastic ring 226 can be made of one or more materials selected from a group consisting of natural rubber (NR), nitrile butadiene rubber (NBR), chloroprene rubber (CR), ethylene propylene terpolymer (EPDM), fluororubber (FPM), styrene butadiene rubber (SBR), chlorosulfonated polyethylene (CSM), urethane, and silicone, all of which possess the aforementioned properties.

[0135] A yoke plug 227 can be coupled to one end of the support yoke 225, press-fitted or screwed to the rack housing 160, and configured to fix the position of the support yoke 225.

[0136] Furthermore, an elastic body 228 can be coupled between the support yoke 225 and the yoke plug 227 and elastically support the support yoke 225 by exerting an elastic force in the direction of the rack 130.

[0137] The rack bushing 229, which supports the outer circumferential surface of the rack 130 against another outer circumferential surface of the rack 130, which supports the needle bearing 220, can be formed in a semi-cylindrical shape, which is produced by cutting a part of an outer circumferential surface thereof.

[0138] The rack bushing 229 supports the rack 130 in the direction of the needle bearing 220 in the radial direction of the rack bushing 229 when the rack 130 moves, thus preventing the rack 130 from rotating.

[0139] The rack bushing 229 can have a curved surface that is identical to or corresponds to the outer circumferential surface of the rack 130, so that it is in close contact with and supported on the outer circumferential surface of the rack 130.

[0140] A bushing coupling groove 166-1, with which the rack bushing 229 is coupled, can be formed on an inner circumferential surface of the rack housing 160.

[0141] The rack bushing 229 can have a fastening projection 229a formed on or around an end section of an outer circumferential surface of the rack bushing 229 to prevent the axial position of the rack bushing 229 from being separated or rotated when the rack 130 moves.

[0142] A fastening groove 166-2 can be formed on the inner circumferential surface of the rack housing 160, and the fastening projection 229a of the rack bushing 229 can be coupled to the fastening groove 166-2 of the rack housing 160.

[0143] The rack bushing 229 can have a predetermined stiffness and elasticity and can be made from one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0144] In a Fig. In the illustrated embodiment 11, the anti-rotation element 150 can be configured to prevent the rack 130 from rotating about its central axis. The anti-rotation element 150 supports the outer circumferential surface of the rack 130 and can also be supported on the inner circumferential surface of the rack housing 160.

[0145] The anti-rotation element 150 can include a support element 210, one end section of which is arranged or supported in a rack support groove 132 formed on the outer circumferential surface of the rack 130, and the other end section of which is arranged or supported in a housing groove 162 formed on the inner circumferential surface of the rack housing 160, and an elastic element 212 coupled to the support element 210 and configured to elastically support the inner circumferential surface of the rack housing 160.

[0146] The rack support groove 132, which is formed on the outer circumferential surface of the rack 130, can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0147] The rack support groove 132 can be recessed into the outer circumferential surface of the rack 130. The rack support groove 132 can have a curved surface or a flat surface.

[0148] The rack support groove 132 can extend longitudinally in the axial direction of the rack 130 and be supported by the support element 210 when the rack 130 moves in the axial direction of the rack 130.

[0149] A coating layer can be provided on the rack support groove 132 and made of a low-friction material, such as fluoropolymer or ceramic, to reduce or minimize friction with the support element 210.

[0150] The housing groove 162, in which the other end section of the support element 210 is supported, can be formed in a position that faces the rack support groove 132 in the radial direction of the rack 130.

[0151] For example, the housing groove 162 can be formed by machining or grinding the inner circumferential surface of the rack housing 160.

[0152] The housing groove 162 can be recessed into the inner circumferential surface of the rack housing 160 and have a curved surface or a flat surface, so that the support element 210 can prevent the rotation of the rack 130 when the rack 130 moves in the axial direction of the rack 130.

[0153] One end section and the other end section of the support element 210 are coupled to the rack support groove 132 and the housing groove 162 respectively, and a coupling groove 211, with which the elastic element 212 is coupled, is formed on the other end section of the support element 210.

[0154] The support element 210 can have a predetermined stiffness and elasticity and can be made of one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0155] The elastic element 212 is coupled to the coupling groove 211 of the support element 210, supports the support element 210, and is configured to exert an elastic force in the direction of the rack 130 while being elastically supported on the inner circumferential surface of the rack housing 160. This ensures that the support element 210 maintains a predetermined distance to avoid colliding with the inner circumferential surface of the rack housing 160 when the rack 130 moves axially. Therefore, rattling noises between the support element 210 and the rack housing 160 are prevented.

[0156] For example, the elastic element 212 can be designed as a curved thin plate.

[0157] A plug bolt 215 can be arranged at an axial end of the support element 210, can be configured to prevent separation of the support element 210, and can be coupled to the inner circumferential surface of the rack housing 160. For example, the plug bolt 215 can be press-fitted and coupled to the inner circumferential surface of the rack housing 160.

[0158] The plug bolt 215 includes a support section 215a, which is configured to support the support element 210 in the axial direction of the rack 130, and a fixing section 215b, which extends from the support section 215a and is fixed to the inner circumferential surface of the rack housing 160.

[0159] The outer circumferential surface of the fixing section 215b has a threaded section which is screwed to the inner circumferential surface of the rack housing 160.

[0160] Furthermore, a fixing element 217 can be coupled to an axial end of the plug bolt 215 to prevent the plug bolt 215 from being loosened and separated.

[0161] A fixing projection 217a, which projects in the radial direction of the rack housing 160, can project from an outer circumferential surface of the fixing element 217.

[0162] A fixing groove 164 can be formed on the inner circumferential surface of the rack housing 160, and the fixing projection 217a of the fixing element 217 can be inserted into the fixing groove 164 and supported by it.

[0163] In one embodiment of Fig. 12 The anti-rotation element 150 can be supported on the outer circumferential surface of the rack 130 and the inner circumferential surface of the rack housing and prevent the rack 130 from rotating about the central axis.

[0164] The anti-rotation element 150 can include a support bushing 205 configured to support the support surface 130-1 formed on the outer circumferential surface of the rack 130, a bushing holder 200 coupled to the outer circumferential surface of the rack 130 and having an inner circumferential surface on which the support bushing 205 is supported, and an elastic element 207 coupled between the bushing holder 200 and the support bushing 205 and configured to elastically support the support bushing 205 by exerting an elastic force in the direction of the rack 130.

[0165] For example, the support surface 130-1, which is formed on the outer circumferential surface of the rack 130, can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0166] The support surface 130-1 can be recessed from the outer circumferential surface of the rack 130 and can have a curved surface or a flat surface.

[0167] The support surface 130-1 extends longitudinally in the axial direction of the rack 130 and is supported by the support bushing 205 when the rack 130 moves in the axial direction.

[0168] A coating layer can be provided on the support surface 130-1 and made of a low-friction material, such as fluoropolymer or ceramic, to minimize or reduce friction with the support bushing 205.

[0169] The housing groove 162, with which the bushing holder 200 is coupled and in which it is supported, is formed on the inner circumferential surface of the rack housing 160 and is positioned so that it faces the support surface 130-1 in the radial direction of the rack 130.

[0170] For example, the housing groove 162 can be formed by machining or grinding the inner circumferential surface of the rack housing 160.

[0171] The housing groove 162 can be recessed from the inner circumferential surface of the rack housing 160 and can have a curved surface or a flat surface.

[0172] Additionally, a stepped projection section 163 with a larger diameter can be formed at an end section of the housing groove 162 on the inner circumferential surface of the rack housing 160, and an end section of the stepped projection section 163 can have an opening in the axial direction of the rack 130.

[0173] The bushing holder 200 has a cylindrical shape. For example, the bushing holder 200 can have a cut-out section, which is produced by cutting a radial side of the bushing holder 200, and a projecting inner circumferential surface 201 that projects radially inwards.

[0174] Furthermore, a bushing coupling groove 203, with which the support bushing 205 is coupled, can be formed on the projecting inner circumferential surface 201. A flange section 206, which projects radially, is supported by or on the stepped projection section 163 of the rack housing 160 and can be formed at an axial end of the bushing holder 200.

[0175] The flange section 206 is supported by or on the stepped projection section 163 to prevent the bushing holder 200 from separating when the rack 130 moves in the axial direction.

[0176] The support bushing 205, which is coupled to the bushing coupling groove 203 of the bushing holder 200, includes a projecting support section 205a that projects from a central section of the support bushing 205, and the elastic element 207 is coupled to the projecting support section 205a.

[0177] For example, the elastic element 207 can be formed in a ring shape and in a conical shape, in which an inner circumferential surface and an outer circumferential surface of the elastic element 207 are stepped in the axial direction, so that the protruding support section 205a can be coupled to an inner circumferential surface of the elastic element 207.

[0178] The elastic element 207 elastically supports the support bushing 205 to exert an elastic force in the direction of the rack 130, and the elastic element 207 can be positioned between the bushing holder 200 and the support bushing 205, forming a gap or space 202 so that the support bushing 205 cannot collide with the bushing holder 200 when the rack 130 moves in the axial direction, in order to prevent or reduce rattling noises between the support bushing 205 and the bushing holder 200.

[0179] The bushing holder 200 and the support bushing 205 can have a predetermined stiffness and elasticity and can be made of one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0180] In one embodiment of Fig. 13 The anti-rotation element 150 can support the outer circumferential surface of the rack 130 to prevent the rack 130 from rotating about the central axis of the anti-rotation element 150, and can be supported by the inner circumferential surface of the rack housing 160.

[0181] The anti-rotation element 150 can include a rack bushing 250, comprising an inner circumferential support section 251, which is inserted into and supported by the rack support groove 132 formed on the outer circumferential surface of the rack 130, and an outer circumferential support section 253, which is inserted into and supported by the housing groove 162 formed on the inner circumferential surface of the rack housing 160, and an elastic element 252, which is coupled to the outer circumferential surface of the rack bushing 250 and is configured to elastically support the rack bushing 250.

[0182] For example, the rack support groove 132, which is formed on the outer circumferential surface of the rack 130, can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0183] The rack support groove 132 can be recessed from the outer circumferential surface of the rack 130 and can have a curved surface or a flat surface.

[0184] The rack support groove 132 extends longitudinally in the axial direction of the rack 130 in order to be supported by the rack bushing 250 when the rack 130 moves in the axial direction.

[0185] A coating layer can be provided on the rack support groove 132 and made of a low-friction material, such as fluoropolymer or ceramic, to minimize or reduce friction with the rack bushing 250.

[0186] The inner circumferential support section 251 projects radially inwards from the inner circumferential surface of the rack bushing 250 at a position facing the rack support groove 132.

[0187] The outer circumferential support section 253 projects radially outwards from the outer circumferential surface of the rack bushing 250 and is coupled to the housing groove 162.

[0188] For example, the housing groove 162 can be formed by machining or grinding the inner circumferential surface of the rack housing 160.

[0189] The housing groove 162 can be recessed from the inner circumferential surface of the rack housing 160 and can have a curved surface or a flat surface.

[0190] Two or more outer circumferential support sections 253 can be formed on the outer circumferential surface of the rack bushing 250 and be spaced apart from each other in a circumferential direction.

[0191] For example, a pair of outer circumferential support sections 253 can be formed on the outer circumferential surface of the rack bushing 250 in the circumferential direction at a position corresponding to the inner circumferential support section 251.

[0192] The rack bushing 250 can have a predetermined stiffness and elasticity and can be made from one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0193] The elastic element 252 can be coupled to the outer circumferential surface of the rack bushing 250 and can have a ring shape.

[0194] The elastic element 252 can be made of a material capable of absorbing vibrations and noise and exhibiting predetermined elasticity and stiffness. Therefore, the elastic element 252 can be made of one or more materials selected from a group consisting of natural rubber (NR), nitrile butadiene rubber (NBR), chloroprene rubber (CR), ethylene propylene terpolymer (EPDM), fluororubber (FPM), styrene butadiene rubber (SBR), chlorosulfonated polyethylene (CSM), urethane, and silicone, all of which possess the aforementioned properties.

[0195] A coupling groove 252-1, with which the elastic element 252 is coupled, can be formed on the outer circumferential surface of the rack bushing 250.

[0196] The rack bushing 250 can have a cut-out section 254 that is cut in the axial direction, so that the rack bushing 250 is deformable in the radial direction.

[0197] Two or more cut-out sections 254, spaced apart from each other in the circumferential direction, may be provided.

[0198] The cut-out sections 254 can be designed such that one end or the other end of the rack bushing 250 is open at a position where the cut-out section 254 is formed.

[0199] The cut-out sections 254, which are open at one end of the rack bushing 250, and the cut-out section 254, which is open at the other end of the rack bushing 250, can be spaced apart from each other in the circumferential direction and formed in an offset manner.

[0200] Therefore, the rack bushing 250 is elastically supported in the radial direction by an elastic force of the elastic element 252, so that the rack bushing 250 cannot collide with the rack housing 160 when the rack 130 moves in the axial direction, in order to prevent or reduce rattling noises between the rack bushing 250 and the rack housing 160.

[0201] In a Fig. In the illustrated embodiment 14, the anti-rotation element 150 can support the outer circumferential surface of the rack 130 to prevent the rack 130 from rotating about the central axis of the rack 130, and can be supported by the inner circumferential surface of the rack housing 160.

[0202] The anti-rotation element 150 can include a rotary element 191 configured to support the support surface 130-1 formed on the outer circumferential surface of the rack 130, and a support bushing 190 coupled to the housing groove 162 formed on the inner circumferential surface of the rack housing 160, and configured such that the rotary element 191 is rotatably coupled to the support bushing 190.

[0203] For example, the support surface 130-1, which is formed on the outer circumferential surface of the rack 130, can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0204] The support surface 130-1 can be recessed from the outer circumferential surface of the rack 130 and can have a curved surface or a flat surface.

[0205] The support surface 130-1 extends longitudinally in the axial direction of the rack 130 in order to be supported by the rotary element 191 when the rack 130 moves in the axial direction.

[0206] Two or more support surfaces 130-1 can be formed on the outer circumferential surface of the rack 130 and be spaced apart from each other in the circumferential direction of the rack 130.

[0207] For example, a pair of support surfaces 130-1 can be formed on opposite sides of the rack 130 with respect to the center of the rack 130.

[0208] The rotating elements 191 can be configured as a roller or ball that is movably arranged in an inner surface of the support bushing 190 (e.g. within one or more elongated holes of the support bushing 190) and is configured to be rotatable or rollable while supported on the support surface 130-1 of the rack 130.

[0209] The rotating elements 191 can be rotatably supported on both the inner and outer surfaces of the support bushing 190.

[0210] A coating layer can be provided on the support surface 130-1 and made of a low-friction material, such as fluoropolymer or ceramic, to reduce or minimize friction with the rotating element 191.

[0211] The housing groove 162, in which the support bushing 190 is arranged, is formed on the inner circumferential surface of the rack housing 160 at a position that faces a support surface 130-1 of the rotating element 191 in the radial direction.

[0212] The support bushing 190 is coupled to the housing groove 162 of the rack housing 160, and the rotary element 191 is rotatably coupled to the support bushing 190.

[0213] The support bushing 190 can have a predetermined stiffness and elasticity and can be made from one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0214] For example, the housing groove 162 can be formed by machining or grinding the inner circumferential surface of the rack housing 160.

[0215] The housing groove 162 can be recessed from the inner circumferential surface of the rack housing 160 and can have a curved surface or a flat surface.

[0216] In a Fig. In the illustrated embodiment 15, the anti-rotation element 150 can support the outer circumferential surface of the rack 130 to prevent the rack 130 from rotating about the central axis and is supported by the inner circumferential surface of the rack housing.

[0217] The anti-rotation element 150 can include a rack bushing 180, which includes one or more rotation support sections 183 rotatably arranged between the rack support groove 132 formed on the outer circumferential surface of the rack 130 and the housing groove 162 formed on the inner circumferential surface of the rack housing 160, an elastic support section 185 arranged between the rack support groove 132 formed on the outer circumferential surface of the rack 130 and the housing groove 162 formed on the inner circumferential surface of the rack housing 160 and elastically supported by it, and a connecting section 181 connecting the rotation support section 183 and the elastic support section 185.

[0218] The rack support groove 132 can be formed on the outer circumferential surface of the rack 130. For example, the rack support groove 132 can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0219] The rack support groove 132 can be recessed from the outer circumferential surface of the rack 130 and can have a curved surface or a flat surface.

[0220] The rack support groove 132 extends longitudinally in the axial direction of the rack 130 and is supported by the rotary support section 183 and the elastic support section 185 when the rack 130 moves axially. The rotary support section 183 and the elastic support section 185 can be arranged in the rack support groove 132.

[0221] The housing groove 162 is formed on the inner circumferential surface of the rack housing 160 at the position that faces or corresponds to the rack support groove 132 in the radial direction.

[0222] For example, the housing groove 162 can be formed by machining or grinding the inner circumferential surface of the rack housing 160.

[0223] The housing groove 162 can be recessed from the inner circumferential surface of the rack housing 160 and can have a curved surface or a flat surface.

[0224] A coating layer can be provided on the rack support groove 132 and the housing groove 162 and can be made of a low-friction material, such as fluoropolymer or ceramic, to minimize or reduce friction with the rack bushing 180.

[0225] The rack bushing 180 can have two or more rotary support sections 183 and / or two or more elastic support sections 185.

[0226] Balls can be coupled to the rotary support sections 183, and the balls can be spaced apart from each other in the axial direction.

[0227] The elastic support section 185 can have a substantially cylindrical shape. The elastic support section 185 can have an opening on one side.

[0228] The rack bushing 180 is elastically supported by the rack support groove 132 and the housing groove 162 by an elastic deformation force of the elastic support section 185, thereby maintaining a predetermined interval so that the rack bushing 180 does not collide with the rack housing 160 when the rack 130 moves in the axial direction, in order to prevent rattling noises between the rack bushing 180 and the rack housing 160.

[0229] In a Fig. In the illustrated embodiment 16, the anti-rotation element 150 can support the outer circumferential surface of the rack 130 to prevent the rack 130 from rotating about the central axis, and the anti-rotation element 150 can be supported by the inner circumferential surface of the rack housing 160.

[0230] The anti-rotation element 150 can include a rack bushing 170 having a first support section 171 and a second support section 175. The first support section 171 can be configured to support the support surface 130-1 formed on the outer circumferential surface of the rack 130. The second support section 175 can extend from or be connected to the first support section 171, can be configured to support the outer circumferential surface of the rack 130, and can have an outer circumferential surface on which a locking projection 173, coupled to the housing groove 162, is formed on the inner circumferential surface of the rack housing 160.

[0231] For example, the support surface 130-1, which is formed on a part of the outer circumferential surface of the rack 130, can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0232] The support surface 130-1 can be recessed from the outer circumferential surface of the rack 130 and can have a curved surface or a flat surface.

[0233] The support surface 130-1 extends longitudinally in the axial direction of the rack 130 in order to be supported by the first support section 171 when the rack 130 moves in the axial direction.

[0234] An inner circumferential surface 171a of the first support section 171 can be in close contact with and supported by the support surface 130-1 of the rack 130, and an outer circumferential surface of the first support section 171 can be spaced away from the inner circumferential surface of the rack housing 160.

[0235] A coating layer can be provided on the support surface 130-1 and the outer circumferential surface of the rack 130 and can be made of a low-friction material, such as fluoropolymer or ceramic, to minimize or reduce friction with the rack bushing 170.

[0236] The second support section 175 extends from the first support section 171 in the circumferential direction or is connected to it and surrounds the outer circumferential surface of the rack 130.

[0237] The fixing projection 173 extends radially from the outer circumferential surface of the second support section 175.

[0238] The housing groove 162 can be formed on the inner circumferential surface of the rack housing 160, and the fixing projection 173 of the second support section 175 can be inserted into or coupled to the housing groove 162, thereby preventing the rack bushing 170 from rotating.

[0239] For example, the housing groove 162 can be formed by machining or grinding the inner circumferential surface of the rack housing 160.

[0240] The housing groove 162 can be recessed from the inner circumferential surface of the rack housing 160 and can have a curved surface or a flat surface.

[0241] The rack bushing 170 can have a predetermined stiffness and elasticity and can be made from one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0242] In a Fig. In the illustrated embodiment 17, the anti-rotation element 150 can be supported by a guide cover 155 which is coupled to the rack housing 160, and can support the outer circumferential surface of the rack 130 to prevent the rack 130 from rotating about the central axis.

[0243] The anti-rotation element 150 can include a support element 151 coupled to the outer circumferential surface of the rack 130, wherein the guide cover 155 is coupled to the rack housing 160 and has an inner circumferential surface that supports the support element 151, and a fastening element 159 configured to fasten the guide cover 155 to the rack housing 160.

[0244] The support element 151 can be coupled to the outer circumferential surface of the rack 130. For example, the support element 151 can be coupled to a coupling groove 134 formed on the outer circumferential surface of the rack 130 by press fitting, bonding, or the like. The coupling groove 134 can be formed by machining or grinding the outer circumferential surface of the rack 130.

[0245] The coupling groove 134 can be recessed into the outer circumferential surface of the rack 130 and can have a curved surface or a flat surface.

[0246] The rack housing 160 can have an opening at a position facing or corresponding to the support element 151, and the guide cover 155 is coupled to and covers the opening of the rack housing 160.

[0247] The inner circumferential surface of the guide cover 155 can have a support groove 155-1 into which and through which the support element 151 is inserted and supported.

[0248] The support groove 155-1 of the guide cover 155 extends longitudinally in the axial direction of the rack 130, so that the support element 151 can be supported by the support groove 155-1 when the rack 130 moves in the axial direction.

[0249] The support groove 155-1 can, for example, without being limited to, have a trapezoidal shape with a width that increases in the direction of the support element 151.

[0250] The support element 151 can have a trapezoidal shape with a width that decreases from the outer circumferential surface of the rack 130 in the direction of the support groove 155-1.

[0251] Two opposing side surfaces of the support groove 155-1 can be in close contact with and supported by the support element 151, and an inner upper surface of the support groove 155-1, which is positioned between the two opposing side surfaces of the support groove 155-1, can be spaced away from one end of the support element 151.

[0252] A coating layer can be provided on the support groove 155-1 or the support element 151 and can be made of a low-friction material, such as fluoropolymer or ceramic, to reduce or minimize friction.

[0253] The support groove 155-1 may contain grease to minimize friction with the support element 151.

[0254] The guide cover 155 can be attached to the rack housing 160 by means of the fastening element 159.

[0255] Furthermore, an elastic element 157 can be arranged between the guide cover 155 and the rack housing 160, which is penetrated by the fastening element 159 and is configured to elastically support the guide cover 155 and the rack housing 160.

[0256] A sealing element or seal 158 can be applied to the ends of the guide cover 155 and the outer circumferential surface of the rack housing 160 to prevent moisture or dust from being introduced from the outside of the rack housing 160.

[0257] The support element 151 and the guide cover 155 can have a predetermined stiffness and elasticity and can be made of one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0258] In a Fig. In the illustrated embodiment 18, the anti-rotation element 150 can be supported by a housing cover 154, which is coupled to the rack housing 160, and the outer circumferential surface of the rack 130, thereby preventing the rack 130 from rotating about the central axis of the rack 130.

[0259] The anti-rotation element 150 can include the support element 151, which supports the outer circumferential surface of the rack 130, wherein the housing cover 154 is attached to the rack housing 160 and has the inner circumferential surface to which the support element 151 is coupled, and the fastening element 159, which is configured to fasten the housing cover 154 to the rack housing 160.

[0260] A rack support groove 134, through which the support element 151 is supported, is formed on the outer circumferential surface of the rack 130.

[0261] The rack support groove 134 extends longitudinally in the axial direction of the rack 130, so that the support element 151 can be supported by the rack support groove 134 when the rack 130 moves in the axial direction.

[0262] The rack support groove 134 can be recessed from the outer circumferential surface of the rack 130 and can have a curved surface or a flat surface.

[0263] The rack housing 160 can have an opening at a position corresponding to or facing the rack support groove 134, and the housing cover 154 is coupled to the opening of the rack housing 160.

[0264] A cover support groove 156, in which the support element 151 is positioned, can be formed on the inner circumferential surface of the housing cover 154.

[0265] The rack support groove 134 can, for example, but is not limited to, have a trapezoidal shape with a width that increases towards the housing cover 154.

[0266] The support element 151 can have a trapezoidal shape with a width that decreases from the cover support groove 156 towards the rack support groove 134.

[0267] Two opposing side surfaces of the rack support groove 134 can be in close contact with and supported by the support element 151, and an inner surface of the rack support groove 134, which is positioned between the two opposing side surfaces of the rack support groove 134, can be spaced away from the end of the support element 151.

[0268] A coating layer can be provided on the rack support groove 134 or the support element 151 and can be made of a low-friction material, such as fluoropolymer or ceramic, to reduce or minimize friction.

[0269] The rack support groove 134 can be greased or filled to reduce or minimize friction with the support element 151.

[0270] The housing cover 154 can be attached to the rack housing 160 by means of the fastening element 159.

[0271] The seal or sealing element 158 ​​can be applied to the end section of the housing cover 154 and the outer circumferential surface of the rack housing 160 to prevent moisture or dust from being introduced from the outside of the rack housing 160.

[0272] The support element 151 and the housing cover 154 can have a predetermined stiffness and elasticity and can be made of one or more materials selected from a group consisting of polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS) and phenolformaldehyde (PF).

[0273] As described above, a steer-by-wire steering device according to some embodiments of the present disclosure can include a plurality of motors and provide a steering force for a rack. Additionally, a steer-by-wire steering device according to some embodiments of the present disclosure can prevent unnecessary rotation of a rack, even though a means for preventing rack rotation is provided and the pinion is excluded.

[0274] The following describes various embodiments of a method for determining the position of a rack in a steer-by-wire steering system. Some embodiments of the rack-determining method described below can be applied independently of the motor configuration, position, and shape mentioned above. However, certain embodiments of the rack-determining method can be applied to the aforementioned motor configuration, position, and shape. Furthermore, the rack-determining method can be applied in exemplary embodiments of the steer-by-wire steering system that do not include the anti-rotation element, or it can be applied in any type of anti-rotation element.

[0275] In the steer-by-wire steering system, the electronic control unit 110 can control the operating processes of one or more drive motors (e.g., 145 and 147). For example, the electronic control unit 110 can receive information or one or more signals from one or more sensors assigned to the vehicle and control one or more drive motors based on the information or signals received from one or more sensors.

[0276] One or more sensors include various sensors, such as a steering angle sensor, a steering torque sensor, a vehicle speed sensor, a rack position sensor, and any type of sensor that is attached to or provided in the vehicle in connection with the vehicle's steering system. However, as described above, according to some embodiments of the present disclosure, the pinion may not be included in the steer-by-wire steering device if the rack is configured to be moved by the first motor and the second motor. In this case, the rack position sensor, which is configured to detect an absolute position of the rack, may not be included in the steer-by-wire steering device.Alternatively, the rack position sensor, configured to detect the absolute position of the rack, can be included in a gearbox configured to connect the first and / or second motor to the rack.

[0277] First, various embodiments for identifying the absolute position (or an absolute angle) of the rack are described. Then, an embodiment is described that includes an absolute angle sensor configured to detect the absolute position (or an absolute angle) of the rack.

[0278] The electronic control unit 110 can control the operation of the steering shaft motor 120. The electronic control unit 110 can be configured as a single, physically integrated chip. Alternatively, the electronic control unit 110 can be configured using a variety of chips. For example, each of the reaction force motor, drive motor, main control unit, and any component of the steer-by-wire steering system includes one or more chips to perform its necessary operations.

[0279] In addition, the electronic control unit 110 can control the direction of travel of the vehicle according to the driver's steering intention by controlling the operating processes of the multitude of drive motors (e.g. 145 and 147).

[0280] Multiple electronic control units 110 can be provided in the steer-by-wire steering system to ensure redundancy and to perform the same operation consistently or stably, even if any one of the multiple electronic control units 110 is abnormal or inoperative. Alternatively, the multiple electronic control units 110 include a master electronic control unit and a sub-electronic control unit. The master electronic control unit can control the operation of the steer-by-wire steering system when the master electronic control unit is in a normal state, and the sub-electronic control unit can control the operation of the steer-by-wire steering system when the master electronic control unit is abnormal or inoperative.

[0281] The electronic control unit 110 can control the vehicle's steering in response to various pieces of information. The steer-by-wire (SBW) system may require precise information regarding the position of the rack and pinion to accurately control the vehicle's steering, especially when multiple motors are used to drive the rack.

[0282] For this purpose, the electronic control unit 110 can receive the rack position information from the rack position sensor. Alternatively, the electronic control unit 110 can estimate the rack position using the positions of the multiple motors without the rack position sensor.

[0283] For example, the electronic control unit 110 can receive rotation information from each of the motors from the plurality of motor position sensors. In an exemplary embodiment of the present disclosure, the motor rotation information can include rotation information from the first motor and rotation information from the second motor. The rotation information of the first motor can be received from a first motor position sensor that is contained in or associated with the first motor. The rotation information of the second motor can be received from a second motor position sensor that is contained in or associated with the second motor.

[0284] The motor position sensor can detect rotational information from each of the motors. It can detect the rotation of a motor shaft. Alternatively, it can detect the rotation of any rotatable component or structure connected to or associated with the motor shaft. The sensor can detect a rotational position between 0 and 360 degrees relative to the motor's rotation. For example, it can measure the angle of rotation and / or the position of the motor.

[0285] For example, the motor position sensor can be an optical sensor or encoder configured to detect a position by emitting light onto a rotating plate or disk. Alternatively, the motor position sensor can be a magnetic sensor or encoder configured to measure the position of a rotor by detecting a magnetic field. Alternatively, the motor position sensor can be an incremental sensor or encoder configured to measure a change in the relative position of a rotor by outputting a predetermined pulse. Alternatively, the motor position sensor can be an absolute sensor or encoder configured to measure the absolute position of a rotor by outputting a unique value with respect to a given position. The motor position sensor according to certain embodiments of this disclosure can provide a precise position and / or speed of the motor.

[0286] For example, a Hall sensor that measures the position of a motor by detecting a change in the magnetic flux of a rotor to which a permanent magnet or magnetic material is attached or mounted can be used as the motor position sensor. The motor of the steer-by-wire steering device can be a brushless direct current (BLDC) motor, and three Hall sensors with a phase difference of 120 degrees or 60 degrees can be arranged or configured to detect the position of the motor. Additionally, the motor position sensor can be a resolver configured to measure a position analogously by using a change in voltage, or an inductive position sensor configured to detect a position using an electromagnetic induction principle. In the present disclosure, any type of sensor can be used as the motor position sensor.

[0287] The motor position sensor can measure an absolute position or an absolute angle value based on a specific position of the motor. Alternatively, the motor position sensor can detect a relative position with respect to a reference position. Alternatively, the motor position sensor can measure the electrical position of a rotor in a BLDC or permanent magnet synchronous motor (PMSM).

[0288] A rotation angle in a single revolution is an angle between 0 and 360 degrees, and therefore a rotation angle can only be represented in a single revolution. Consequently, the absolute position of the motor, which lies beyond 360 degrees, cannot be identified because the angle of the motor's rotor resets after a complete revolution. However, there is an absolute motor position sensor that can measure the motor's position over multiple revolutions, but it has a complex configuration and structure and is more expensive.

[0289] Without using an absolute motor position sensor, some embodiments of the present disclosure can detect an absolute position of the rack using at least two motor position sensors that measure a relative position.

[0290] For example, if two motors are moving the same rack and have different rotational speeds, the angles of rotation measured by the two motor position sensors of the two motors can range from 0 degrees to 360 degrees. If the motor position sensor is not an absolute angle sensor, the angle measured by the motor position sensor is not recorded or stored, and the angle of rotation detected by the motor position sensor of the first motor can be between 0 degrees and 360 degrees, and the angle of rotation detected by the motor position sensor of the second motor can also be between 0 degrees and 360 degrees.

[0291] The electronic control unit 110 can receive the rotation angle detected by the motor position sensor of the first motor and the rotation angle detected by the motor position sensor of the second motor. The electronic control unit 110 estimates the absolute position of the rack using the two rotation angles (i.e., motor positions) detected by each of the two motor position sensors of the two motors.

[0292] As described above, in certain embodiments of the present disclosure, the first motor and the second motor are operatively connected to a single ball nut, which is operatively coupled to the rack, and move the rack at different rotational speeds. Although the first motor and the second motor rotate at different speeds, they must therefore rotate the ball nut at the same speed. Therefore, the motor pulley of the first motor and the motor pulley of the second motor can be configured with different gear ratios.

[0293] The transmission ratio can refer, for example, but is not limited to, a ratio of the number of threads or diameters of pulleys. For instance, the transmission ratio can be the ratio between the number of threads or diameter of a motor pulley connected to a motor shaft of the first motor and the number of threads or diameter of a motor pulley connected to a motor shaft of the second motor. There can be a significant difference in the transmission ratio if the diameters of the motor pulleys are different.

[0294] The first motor and the second motor can rotate at different speeds, and the electronic control unit 110 can receive different motor rotation information from the motor position sensors of the first and second motors.

[0295] The electronic control unit 110 can determine the absolute position of the rack using preset information and motor rotation information from the first and second motors.

[0296] For example, the difference in rotational speed between the two motors can vary depending on the absolute position of the rack.

[0297] For example, the electronic control unit 110 can determine the absolute position of the rack by monitoring a change in the rotation information of the two motors. For example, the electronic control unit 110 can determine the position of the rack using equation 1. R=K360×θ+K×n

[0298] R represents a linear position of the rack, θ represents a phase difference between the first rotation information of the first motor and the second rotation information of the second motor, K represents a distance by which the rack is moved while a phase difference between the first rotation information and the second rotation information changes from 0 and becomes 0 again if the rack moves in one direction, and n represents the number of times the phase difference becomes 0 while the rack moves in one direction.

[0299] This means that the electronic control unit 110 can cumulatively identify the position of the rack by consistently monitoring the phase difference between the first rotation information of the first motor and the second rotation information of the second motor and recording the number of times the phase difference becomes 0.

[0300] In another example, the electronic control unit 110 can determine the position of the rack based on a preset reference value. The movable range of the rack is structurally limited. Therefore, the multitude of rack positions corresponding to the first rotation information from the first motor and the second rotation information from the second motor can be calculated in advance and stored in the memory of the electronic control unit 110 in the form of a table or other data formats.

[0301] When the first rotation information from the first motor and the second rotation information from the second motor are received, the electronic control unit 110 can estimate the absolute position of the rack by comparing the first rotation information from the first motor and the second rotation information from the second motor with pre-stored data. However, in this case, the first and second rotation information must be designed to have different values ​​within a linearly movable range of the rack. Therefore, a difference in the gear ratio between the first motor and the second motor must be set so that the first rotation information of the first motor and the second rotation information of the second motor do not overlap or correspond to two or more absolute positions of the rack.

[0302] For example, the electronic control unit 110 can estimate the absolute position of the rack using equation 2. A={(first rotation information+m)×first gear ratio}B={(second rotation information+m)×second gear ratio}Rack position R=intersection of A and B. Rack position R = intersection of A and B.

[0303] Here, m is a natural number equal to or greater than 1 and equal to or less than a maximum movement distance of the rack.

[0304] Fig. Figure 19 is a diagram illustrating a method for estimating the position of a rack using a difference between first rotation information from a first motor and second rotation information from a second motor. Fig. Figure 19 illustrates a relationship between the first rotation information of the first motor and the second rotation information of the second motor and a linear position of a rack within a movable range of 0 to 75 mm. As described above, the first and second gear ratios can be adjusted so that the first rotation information of the first motor and the second rotation information of the second motor do not overlap or correspond to multiple positions of the rack.

[0305] The electronic control unit 110 can include a configuration to prevent noise when estimating a precise rack position. For example, the electronic control unit 110 can use noise filtering technology, such as a Kalman filter, to reduce errors caused by noise or similar interference.

[0306] Therefore, without a rack position sensor, the position of the rack can be estimated precisely, reducing manufacturing costs and improving ease of implementation.

[0307] However, a sensor assembly configured to detect the rack position can be included if required. For example, a sensor configured to detect the absolute position of the rack can detect a gear assembly connected to the ball nut, which is operationally connected to the rack to determine the rack's absolute position. In this case, the gear assembly can be directly connected to the ball nut or to the ball nut's pulley. Alternatively, the gear assembly can include two or more gears, and the gear rotational speeds can be reduced to a suitable detection level by means of a gear ratio between the gears.

[0308] Alternatively, the gear assembly can be connected to the first motor or the second motor without being connected to the ball nut or the nut pulley. In contrast to an embodiment that has a rack position sensor connected to a pinion gear, according to another embodiment of the present disclosure, the rack position sensor can be connected to the motor or the ball nut in order to make the package size more compact.

[0309] If one of the motor position sensors fails, determining the absolute position of the rack can be difficult. The motor position sensor for detecting the absolute angle can be configured to provide redundancy in preparation for this eventuality.

[0310] Alternatively, the electronic control unit 110 can consistently or periodically monitor the initial rotation information of the first motor and / or the second rotation information of the second motor from a fail-safe perspective. For example, the electronic control unit 110 can determine whether the initial rotation information of the first motor or the second rotation information of the second motor is outside an offset range relative to a preset value.

[0311] For example, it is assumed that a rack stroke of 15 is required if the first rotation information from the first motor is 240 degrees and the second rotation information from the second motor is 120 degrees. The electronic control unit 110 can identify the rack stroke using preset data and using two sets of received rotation information from the first and second motors, i.e., 240 and 120 degrees.

[0312] However, a predetermined level of offset can be applied to ensure reliability and a smooth process for estimating the rack stroke position. For example, if the first rotation information from the first motor is 240 and the second rotation information from the second motor is 119, the rack stroke can be estimated assuming the second rotation information is 120. This is because the difference between the preset second rotation information of the second motor (120) and the received second rotation information of the second motor (119) is 1, which is less than a preset offset.

[0313] Therefore, the offset is calculated by determining a value that is represented in the diagram of Fig. 19 is permissible, which varies depending on the gear ratio. For example, the offsets for each rack stroke or motor rotation information can be set to different values. Alternatively, an offset for all rack stroke or motor rotation information can be set to the same value. Therefore, a small level of error caused by noise or a motor position sensor failure can be ignored when determining whether one of the motor position sensors is failing, thus improving the accuracy and responsiveness of the operation.

[0314] In yet another example, the electronic control unit 110 can identify a change in the occurrence of a fault by consistently monitoring the first and second rotation information. For example, the electronic control unit 110 can monitor the first and second rotation information, track the frequencies or occurrence of faults in the first and second rotation information, and identify whether the occurrence of the fault is increasing and whether faults are occurring more frequently, even within the offset range. If faults occur more frequently or the magnitude of faults increases within a predetermined period, the electronic control unit 110 can detect a risk of failure of the first and second motor position sensors of the first and second motors and issue a warning signal in advance.

[0315] Alternatively, the electronic control unit 110 can recognize that the rack stroke represents a movement of the rack in one dimension, and sudden changes in the position of the rack cannot occur due to physical limitations. For example, the rack stroke is assumed to be set to 30 if the first rotation information of the first motor is 160 and the second rotation information of the second motor is 128, and the rack stroke is assumed to be 70 if the first rotation information of the first motor is 162 and the second rotation information of the second motor is 130.In this case, if the first rotation information of the first motor is entered by 162 and the second rotation information of the second motor by 130, after the first rotation information of the first motor is entered by 160 and the second rotation information of the second motor by 128, the electronic control unit 110 can perform a fail-safe operation within a predetermined period of time, instead of determining that the rack stroke is changed from 35 to 70.

[0316] For example, the electronic control unit 110 can determine the linear position of the rack or the rack stroke within a time window that is set as a predetermined period. If the linear position of the rack or the rack stroke changes rapidly within the time window, and the rapid change in the linear position of the rack or the rack stroke is determined to be temporary or one-off, it can be identified as noise and ignored when estimating the linear position of the rack or the rack stroke.

[0317] However, if the electronic control unit 110 determines that the rack stroke has changed rapidly within the predetermined time window, and the rapid change in the linear position of the rack or rack stroke is determined to be non-temporary or non-isolated, the electronic control unit 110 may determine that an accident or system failure has occurred. For example, if the estimated rack stroke changes from 35 to 70 and then, within the preset time window, to 37 and 38, the estimated rack stroke of 70 may be determined to be noise and ignored. In contrast, if the rack stroke changes significantly from 35 to 70, 10, and 50 within a predetermined time window, the electronic control unit 110 may determine that an accident or failure has occurred.

[0318] When the occurrence of an accident or failure is determined, the electronic control unit 110 can report the occurrence of the accident or failure to a specific component or point (e.g. another electronic control unit or an output device such as a display or a warning lamp) by means of communication or a communicator.

[0319] The present disclosure relates to a technology for quickly and accurately identifying a situation in which a problem in the steering control occurs due to rack rolling when a rotation-prevention element that prevents rack rolling in a vehicle is damaged or an anomaly occurs.

[0320] The present disclosure can be applied to the steer-by-wire steering device mentioned above and can also be applied to R-EPS and RWA (Rear Wheel Actuator). The steer-by-wire steering device has been described above, and the following description focuses on a technology for detecting rack roll. The rack roll detection method described below can be applied without limitation to various steering devices, including not only the twin-motor steer-by-wire steering device mentioned above, but also single-motor and belt-driven steer-by-wire steering devices and R-EPS. Additionally, an anti-rotation element for preventing rack rotation can be configured in the various forms described above and is not limited to these structures.

[0321] The steering system provides power assistance or the entire steering force through the steering motor in response to a driver's steering input. The steering motor can be one or more units. The steering motor can be connected to a rack and pinion by a structure that converts the motor's rotary motion into a linear motion. The steering system transmits the driver's steering input to the wheels via a left-right linear movement of the rack, thus steering the vehicle. The steering system can be configured in various forms, such as R-EPS, where a steering motor is connected to the rack to provide power assistance, and steer-by-wire (SbW), where the driver's steering input is transmitted via electronic signals and a physically separate steering motor provides steering force to the rack.

[0322] A rotation-prevention element can be configured on the rack. This element prevents the rack from rotating, similar to a structure without a pinion. When the steering motor's rotational force is converted into a linear motion of the rack, if the rack rotates, the rotational force may not be converted into linear motion, or some of the force may leak. In this case, the driver's steering input may not be accurately transmitted to the rack, and a problem may occur in the steering system.

[0323] To prevent this, an anti-rotation element is installed on the rack. This element prevents the rack from rolling and ensures that the steering motor's rotational force is accurately reflected as a linear movement of the rack.

[0324] However, if the anti-rotation element is damaged or deformed for various reasons, a problem may occur with steering in that the rack cannot push the vehicle's wheel, even if the steering motor and reduction gear are working normally.

[0325] In particular, damage to or deformation of the anti-rotation element is not easily perceived by the driver and is not easily detected. If a sensor is present that directly detects the position of the rack, the occurrence of rack rolling can be detected. For example, if it is possible to detect the position of the rack, rack rolling can be detected by determining whether the rack reaches a target position, regardless of the presence or absence of rack rolling.

[0326] However, in a case where there is no sensor that directly detects the position of the rack, or in a case of a method for indirectly checking the position of the rack (using the Vernier algorithm mentioned above, etc.), there is a problem in that the occurrence of rack rolling cannot be detected.

[0327] The present disclosure provides a method and a device capable of easily and accurately detecting the occurrence of rack rolling, even in the absence of an absolute position sensing sensor that detects the position of a rack. The embodiments described below can be applied to the steering device mentioned above.

[0328] Fig. Figure 20 is a diagram illustrating a rack rolling detection method according to one embodiment.

[0329] With reference to Fig. 20. A method for detecting rack rolling of a rack of a vehicle may include determining whether a fault is occurring with respect to a rack connected to a steering motor, using at least one motor current of the steering motor for steering control of the vehicle or a rack force S2000.

[0330] For example, the rack and pinion roll detection method can determine whether a fault is occurring by using the motor current of the steering motor. In one example, the rack and pinion roll detection method calculates a first differential value, which is the difference between the motor current and a target motor current value as defined by the steering control, and determines whether a fault is occurring with respect to a rack by comparing the first differential value to a preset first threshold. For example, a fault can be detected if the first differential value exceeds the first threshold. In another example, the rack and pinion roll detection method can determine whether a fault is occurring with respect to a rack by determining whether a first filtered value, obtained by filtering the first differential value according to a preset filter frequency, exceeds the preset first threshold.The filter frequency can be dynamically changed according to vehicle speed. Additionally, performing filtering on the first differential value is an operational procedure to reduce any noise that may be contained in the first differential value, or to distinguish a temporary disturbance state in order to increase stability; in this case, the filter operation can be omitted.

[0331] Additionally, the rack and pinion roll detection method can determine whether a fault has occurred with respect to a rack connected to a steering motor by using a rack force. For example, the rack and pinion roll detection method can determine whether a fault has occurred with respect to a rack by using a second difference value between a rack force and a target rack force value as defined by the steering control, and a preset second threshold value. Again, the rack and pinion roll detection method can determine that a fault has occurred if the second difference value exceeds the second threshold value. Vehicle speed information can be used to measure the rack force and / or to estimate the target rack force value.In another example, the rack and pinion rolling detection method can determine that a fault has occurred when a second filtered differential value, obtained by filtering the second differential value according to a preset filter frequency, exceeds the preset second threshold. The filter frequency can be dynamically changed according to vehicle speed. Additionally, performing filtering on the second differential value is an operational procedure to reduce any noise that may be present in the second differential value or to distinguish a temporary disturbance state to increase stability; in these cases, the filtering operation can be omitted.

[0332] The rack rolling detection method can use at least one parameter, either motor current or rack force, to determine whether a fault occurs with respect to a rack, according to a setting. For example, the occurrence of a fault can be determined by an operating operation using only the motor current. Alternatively, the occurrence of a fault can be determined by an operating operation using only the rack force. Alternatively, the rack rolling detection method can determine the occurrence of a fault only if it is identified as a fault according to an operating operation using the motor current and also according to an operating operation using the rack force.Alternatively, the rack rolling detection method can determine the occurrence of a fault if it is identified as a fault in only one of an operating operation using the motor current and an operating operation using the rack force.

[0333] The method for detecting rack rolling may involve detecting abnormal vehicle behavior using the vehicle's yaw rate and lateral acceleration S2010.

[0334] The rack and pinion roll detection method can determine, using the yaw rate and lateral acceleration of the vehicle, whether an abnormality has occurred in the vehicle's behavior.

[0335] For example, the rack and pinion roll detection method can detect abnormal vehicle behavior based on a comparison result between the vehicle's yaw rate and a target yaw rate value, and a comparison result between the vehicle's lateral acceleration and a target lateral acceleration value.

[0336] In one example, the rack and pinion roll detection method can detect abnormal vehicle behavior by comparing a third filtered value—obtained by filtering the difference between the vehicle's yaw rate and a target yaw rate at a preset filter frequency—to whether it exceeds a preset third threshold. For instance, an abnormality in vehicle behavior can be determined if the third filtered value exceeds the third threshold. Filtering is used to reduce noise and the influence of transient disturbances, and in some cases, it may not be possible to apply the filter. In such cases, abnormal behavior can be detected by comparing the third difference value to the third threshold.

[0337] In another example, the rack and pinion roll detection method can detect abnormal vehicle behavior by comparing a fourth filtered value—obtained by filtering the fourth difference between the vehicle's lateral acceleration and a target lateral acceleration value at a preset filter frequency—to whether it exceeds a preset fourth threshold. For example, an abnormality in the vehicle's behavior can be determined if the fourth filtered value exceeds the fourth threshold. Filtering is used to reduce noise and the influence of temporary disturbances, and in some cases, it may not be possible to apply the filter. In such cases, abnormal behavior can be detected by comparing the fourth difference value to the fourth threshold.

[0338] Vehicle speed information can be used to determine a filter frequency and to estimate a target lateral acceleration value, and the filter frequency can be dynamically changed according to the vehicle speed.

[0339] The rack and pinion roll detection method can determine whether an abnormality in vehicle behavior has occurred by using a detection result for abnormal behavior based on lateral acceleration and a detection result for abnormal behavior based on yaw rate. For example, the rack and pinion roll detection method can ultimately determine that an abnormality in vehicle behavior has occurred only if abnormal behavior is detected in both lateral acceleration and yaw rate. Alternatively, the rack and pinion roll detection method can determine that an abnormality in vehicle behavior has occurred if abnormal behavior is detected in either lateral acceleration or yaw rate.

[0340] Furthermore, the rack and pinion roll detection method can dynamically adjust the aforementioned third and fourth thresholds according to the vehicle's trajectory. For example, if the vehicle is traveling on a curved track, the thresholds can be set higher to prevent frequent detection due to temporary abnormal vehicle behavior. Alternatively, the aforementioned filter frequency can be dynamically changed according to the vehicle's trajectory.

[0341] The method for detecting rack rolling may involve detecting the occurrence of rack rolling of a rack connected to the steering motor, based on a result of determining whether a fault is occurring with respect to a rack, and a result of detecting abnormal behavior (S2020).

[0342] The rack rolling detection method can ultimately determine whether a rack rolling phenomenon occurs in the rack by using the above-mentioned result of determining whether a fault occurs with respect to a rack and the result of detecting abnormal behavior.

[0343] In one example, the rack roll detection method can determine that rack roll has occurred if, based on the result of determining whether a fault has occurred with respect to a rack, it is determined that a fault has occurred, and based on the result of detecting abnormal vehicle behavior, it is determined that abnormal behavior has occurred. That is, the rack roll detection method can determine that a rack roll phenomenon has occurred if both a fault occurrence condition and an abnormal behavior condition are met. For this purpose, operational procedures for determining whether a fault has occurred with respect to a rack and for detecting abnormal behavior can be performed in parallel.

[0344] In another example, the rack and pinion roll detection method can perform an operational step to detect abnormal vehicle behavior if, based on the result of determining whether a fault has occurred with respect to the rack, it is determined that a fault has occurred, and can determine that rack and pinion roll has occurred if abnormal vehicle behavior is also detected. That is, in this case, determining whether a fault has occurred with respect to the rack is performed preferentially, and the detection of abnormal behavior can be carried out sequentially based on the corresponding determination result.

[0345] The aforementioned operating procedures enable the rack rolling detection method to determine whether rack rolling occurs, even in situations where no direct rack position detection sensor is present. Even without an absolute position detection sensor for the rack, it can be applied, thus providing cost reduction and improved safety.

[0346] Fig. Figure 21 is a diagram illustrating an operating procedure for determining whether a fault occurs with respect to a rack, according to one embodiment.

[0347] With reference to Fig. Based on a current value from a steering motor 2120, it can be determined whether a fault occurs with respect to a rack. For example, the steering motor 2120 may include an ECU 2100 for controlling a current and a motor 2110 driven according to the current control. Although RWA is described here as an example, a steering motor 2120 can be used in steer-by-wire (SbW) or R-EPS systems alike.

[0348] Based on the vehicle's yaw rate, lateral acceleration, vehicle speed information, and steering input from the driver, the ECU 2100 can calculate a target current input to the motor. When a drive current is input to the motor 2110 according to the target current, the motor 2110 performs a rotary motion according to the drive current.

[0349] The ECU 2100 can measure the actual current flowing through the motor 2110 according to the operation of the motor 2110 in order to obtain a measured current value.

[0350] The rack and pinion roll detection method receives a measured current value from the motor 2110 and a target current value to reflect actual steering intent. It can determine whether a rack-related fault is occurring by using a difference value between them. As described above, a difference value between the measured motor current and the target current value can be compared to a threshold value and used to determine whether a rack-related fault is occurring. If necessary, the difference value passes through a filter to reduce the influence of noise and temporary disturbances. A filtered value that has passed through the filter can then be compared to the threshold value and used to determine the occurrence of a fault.

[0351] Similarly, a rack force can also be used for rack roll detection based on a difference between an (estimated) rack force and a target rack force value.

[0352] The following describes the respective embodiments of the operating processes in the rack and pinion rolling detection method described above by classifying detection into parallel detection and sequential detection.

[0353] Fig. Figure 22 is a diagram illustrating an example of a rack rolling detection operation according to one embodiment.

[0354] With reference to Fig. 22 The rack rolling detection method can include a fault occurrence determination operation based on a motor current and a fault occurrence determination operation based on a rack force.

[0355] For example, the rack rolling detection method can measure an error value as a difference value between a measured motor current and a target motor current value, reflect this in a filter, and determine whether an error occurs with respect to a rack by comparing the filtered error value with a preset threshold value.

[0356] Similarly, the rack rolling detection method can calculate an error value as a difference value between an estimated or measured rack force and a target rack force value, reflect this in a filter, and determine whether an error occurs with respect to a rack by comparing the filtered error value with a preset threshold value.

[0357] An operation to detect whether a fault has occurred with respect to a rack, using both a motor current and a rack force, can only use one of these. That is, the occurrence of a fault can be determined using only a motor current, or it can be determined using only a rack force. Alternatively, it is possible to determine whether a fault has occurred with respect to a rack using either a motor current or a rack force, and a final determination of fault occurrence can be made when both operations confirm the occurrence of a fault.

[0358] A determination result as to whether a fault occurs with respect to a rack is used to determine a rack rolling.

[0359] Furthermore, the rack and pinion roll detection method can detect whether abnormal vehicle behavior occurs by comparing the vehicle's yaw rate with a target yaw rate value to calculate an error value as a difference value, filtering the error value, and comparing the filtered error value with a preset threshold value.

[0360] Similarly, the rack and pinion roll detection method can detect whether abnormal vehicle behavior occurs by comparing the vehicle's lateral acceleration with a target lateral acceleration value to calculate an error value as a difference value, filtering the error value, and comparing the filtered error value with a preset threshold value.

[0361] The yaw rate and lateral acceleration can be measured by sensors configured in the vehicle, or can be estimated using the vehicle speed and the like.

[0362] The rack roll detection process ultimately determines whether rack roll has occurred, using a result from determining whether a fault is occurring with respect to a rack, a detection result for abnormal behavior based on the yaw rate, and a detection result for abnormal behavior based on the lateral acceleration.

[0363] The three fault detection operations described above (where the use of motor current and rack force is selectively applicable) or four fault detection operations can run in parallel and be used for rack roll detection. The rack roll detection process can ultimately determine that rack roll has occurred if a fault is detected, abnormal behavior is detected according to the lateral acceleration, and abnormal behavior is detected according to the yaw rate.

[0364] These operational processes can run within a predetermined timeframe, and it can be determined that a rack rolling event has occurred if rack rolling is detected a predetermined number of times or for a predetermined time within a time window set within the predetermined period. This can reduce the influence of temporary errors and noise.

[0365] Furthermore, an operating procedure for changing the error value to a filtered error value can be omitted. Additionally, a filter frequency can be dynamically changed in conjunction with the vehicle speed.

[0366] Fig. Figure 23 is a diagram to illustrate another example of a rack rolling detection operation according to one embodiment.

[0367] With reference to Fig. Figure 23 shows an embodiment in which the rack rolling detection method is carried out according to sequential flags and not in parallel.

[0368] The fault detection operation 2200 can be performed within a predetermined period or continuously. As described above, a fault detection operation using a motor current and a fault detection operation using a rack force can be performed using only one of these, or both operations can be performed simultaneously.

[0369] If a fault is detected according to the operation described above, a flag can be issued that triggers operation 2210 to detect abnormal vehicle behavior. This means that whether a fault occurs with respect to a rack is first determined using motor current and / or rack force. If this is not determined to be a fault, the detection operation 2210 for abnormal vehicle behavior is not performed. If, according to the fault occurrence operation 2200, a fault is determined to have occurred, the detection operation 2210 for abnormal vehicle behavior is performed secondarily to determine whether there is also an abnormality in the vehicle's behavior. This effectively reduces computing power by preventing unnecessary continuous operations for determining abnormal behavior.Additionally, false detection and the like can be prevented by sequential operation.

[0370] If a flag is generated according to the fault detection operation 2200 and the detection operation 2210 is triggered for abnormal behavior, an operation to detect whether abnormal behavior is occurring is performed as described above, using a yaw rate and lateral accelerations.

[0371] The rack rolling detection process can determine that rack rolling has occurred if this is identified as a fault and is determined as abnormal behavior.

[0372] These operating procedures make it easy to detect a rack rolling phenomenon that may occur in the rack of a vehicle, without introducing additional sensors.

[0373] The following is a brief description of a device in which the rack and pinion rolling detection method described above can be carried out.

[0374] Fig. Figure 24 is a diagram illustrating a configuration of a rack rolling detection device according to one embodiment.

[0375] With reference to Fig. A rack and pinion roll detection device 2400 can be configured to include a memory that stores at least one instruction and a processor that executes at least one instruction. The processor determines whether a fault occurs with respect to a rack, using at least one motor current from a steering motor for steering control of the vehicle or a rack force; detects abnormal vehicle behavior using a yaw rate and a lateral acceleration of the vehicle; and detects the occurrence of rack and pinion roll of a rack connected to the steering motor, based on the result of a determination of whether a fault occurs with respect to a rack and the result of an abnormal behavior detection. A display and an input device are optional configurations and may or may not be connected to the rack and pinion roll detection device 2400.

[0376] The memory can include at least one of a main memory, a ROM, or a storage device.

[0377] A bus performs the role of transferring information between the processor and the memory and can be configured as vehicle-internal CAN communication and the like.

[0378] For example, the processor can determine if a fault occurs by using the steering motor's current. In one example, the processor calculates an initial differential value, which is the difference between the motor current and a target motor current value as defined by the steering control, and determines if a fault occurs with respect to a rack by comparing the initial differential value to a preset initial threshold. For example, a fault can be detected if the initial differential value exceeds the initial threshold. In another example, the processor can determine if a fault occurs with respect to a rack by determining if an initial filtered value, obtained by filtering the initial differential value according to a preset filter frequency, exceeds the preset initial threshold. The filter frequency can be dynamically changed according to vehicle speed.Additionally, performing filtering on the first difference value is an operational procedure to reduce any noise that may be contained in the first difference value, or to distinguish a temporary disturbance state in order to increase stability, and the filter operation can be omitted.

[0379] Additionally, the processor can determine whether a rack fault has occurred by using a rack force. For example, the processor can determine whether a rack fault has occurred by using a second difference value between a rack force and a target rack force value as determined by the steering control, and a preset second threshold value. Again, the processor can determine that a fault has occurred if the second difference value exceeds the second threshold value. Vehicle speed information can be used to measure the rack force and / or estimate the target rack force value.In another example, the processor can determine that a fault has occurred if a second filtered difference value, obtained by filtering the second difference value according to a preset filter frequency, exceeds the preset second threshold. The filter frequency can be dynamically changed according to vehicle speed. Additionally, performing filtering on the second difference value is an operational procedure to reduce any noise that may be present in the second difference value or to distinguish a temporary disturbance state to increase stability; in this case, the filter operation can be omitted.

[0380] The processor can use at least one of a motor current or a rack force to determine, according to a setting, whether a fault occurs with respect to a rack. For example, the occurrence of a fault can be determined by an operation using only the motor current. Alternatively, the occurrence of a fault can be determined by an operation using only the rack force. Alternatively, the processor can determine the occurrence of a fault only if it is determined as a fault by an operation using the motor current and by an operation using the rack force. Alternatively, the processor can determine the occurrence of a fault if it is determined as a fault in only one of an operation using the motor current and by an operation using the rack force.

[0381] Additionally, the processor can use the vehicle's yaw rate and lateral acceleration to determine whether an abnormality has occurred in the vehicle's behavior.

[0382] For example, the processor can detect abnormal vehicle behavior based on a comparison between the vehicle's yaw rate and a target yaw rate value, and a comparison between the vehicle's lateral acceleration and a target lateral acceleration value.

[0383] In one example, the processor can detect abnormal vehicle behavior by comparing a third filtered value—obtained by filtering the difference between the vehicle's yaw rate and the target yaw rate at a preset filter frequency—to whether it exceeds a preset third threshold. For instance, an abnormality in the vehicle's behavior can be determined if the third filtered value exceeds the third threshold. Filtering is used to reduce noise and the influence of temporary disturbances, and sometimes it may not be possible to apply the filter. In such cases, abnormal behavior can be detected by comparing the third difference value to the third threshold.

[0384] In another example, the processor can detect abnormal vehicle behavior by comparing a fourth filtered value—obtained by filtering the fourth difference between the vehicle's lateral acceleration and a target lateral acceleration value at a preset filter frequency—to whether it exceeds a preset fourth threshold. For example, an abnormality in the vehicle's behavior can be determined if the fourth filtered value exceeds the fourth threshold. Filtering is used to reduce noise and the influence of temporary disturbances, and sometimes it may not be possible to apply the filter. In such cases, abnormal behavior can be detected by comparing the fourth difference value to the fourth threshold.

[0385] Vehicle speed information can be used to determine a filter frequency and to estimate a target lateral acceleration value, and the filter frequency can be dynamically changed according to the vehicle speed.

[0386] The processor can determine whether an abnormality in the vehicle's behavior has occurred by using a detection result for abnormal behavior based on lateral acceleration and a detection result for abnormal behavior based on yaw rate. For example, the processor can ultimately determine that an abnormality in the vehicle's behavior has occurred only if abnormal behavior is detected in both lateral acceleration and yaw rate. Alternatively, the processor can determine that an abnormality in the vehicle's behavior has occurred if abnormal behavior is detected in either lateral acceleration or yaw rate.

[0387] Furthermore, the processor can dynamically adjust the aforementioned third and fourth thresholds according to the vehicle's trajectory. For example, if the vehicle is traveling on a curved track, the thresholds can be set higher to prevent frequent detection due to temporary abnormal vehicle behavior. Alternatively, the aforementioned filter frequency can be dynamically changed according to the vehicle's trajectory.

[0388] The processor can ultimately determine whether a rack rolling phenomenon occurs in the rack by using the aforementioned result of determining whether a fault occurs with respect to a rack and the result of detecting abnormal behavior.

[0389] In one example, the processor can determine that rack rolling has occurred if, based on the result of determining whether a fault has occurred with respect to a rack, it is determined that a fault has occurred, and based on the result of detecting abnormal vehicle behavior, it is determined that abnormal behavior has occurred. That is, the processor can determine that a rack rolling phenomenon has occurred if both a fault occurrence condition and an abnormal behavior condition are met. For this purpose, operations to determine whether a fault has occurred with respect to a rack and to detect abnormal behavior can be performed in parallel.

[0390] In another example, if a determination of whether a rack-related fault has occurred is successful, the processor performs an operation to detect abnormal vehicle behavior and can determine that rack rolling has occurred if abnormal vehicle behavior is also detected. That is, in this case, a determination of whether a rack-related fault has occurred is performed preferentially, and the detection of abnormal behavior can be carried out sequentially based on the corresponding determination result.

[0391] Furthermore, the present disclosure can refer to the information relating to the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17, Fig. 18 to Fig. The steer-by-wire system described in Section 19 can be applied. For example, the present disclosure can be applied to a steer-by-wire system configured to detect the absolute position of a rack, even if no sensor is present to detect the absolute position of the rack. In this case, since the absolute position of the rack cannot be detected, the rack roll detection method described above can be used to accurately detect whether a problem has occurred in an anti-rotation element. The electronic control device described above can be referred to below as a controller. Alternatively, the controller can be configured as a separate device from the electronic control device described above.

[0392] For example, the steer-by-wire system may include: a rack; a ball nut coupled to the rack via balls, which rotates the rack and displaces it in an axial direction; a first nut pulley provided on an outer circumferential surface of the ball nut; a second nut pulley provided on an outer circumferential surface of the ball nut; a first motor pulley coupled to a first motor and connected to the first nut pulley by a first belt; a second motor pulley coupled to a second motor and connected to the second nut pulley by a second belt; and a controller that manages an output value transmitted to the first and second motors using an electrical signal as an input value.

[0393] For example, the controller can use at least one motor current or rack force from each of the first or second motors to determine whether a rack fault is occurring, detect abnormal vehicle behavior using the vehicle's yaw rate and lateral acceleration, and detect rack roll based on the result of determining whether a rack fault is occurring and the above abnormal behavior detection result.

[0394] The steer-by-wire system can include a controller that uses an electrical signal as its input to control an output value transmitted to the first and second motors. The controller can manage the operation of the first and second motors. Additionally, the controller can calculate the rack's displacement position using a first position value detected by a first motor sensor (which measures the rotational position of a shaft in the first motor) and a second position value detected by a second motor sensor (which measures the rotational position of a shaft in the second motor).

[0395] For example, the controller can estimate (determine) a displacement position without providing a separate steering rack position sensor to calculate an accurate absolute displacement position of the rack.

[0396] For example, the controller can calculate a displacement position of the rack using a preset Vernier algorithm with a first position value and a second position value.

[0397] For example, the controller can calculate a displacement position of the rack using a phase difference obtained from a first position value, which is motor rotation information from the first motor, and a second position value, which is motor rotation information from the second motor, and using information about how often the phase difference becomes zero.

[0398] In another example, the controller can calculate a rack displacement position corresponding to the first position value and the second position value using table information of rack displacement positions corresponding to preset motor position values.

[0399] For this purpose, the rotational ratios of the first and second motors can be set to be different. For example, the rotational ratio can be a ratio of the number of rotations of the motors or a ratio of angular velocities. For example, the number of teeth on a first motor pulley (or first nut pulley) provided on a first motor shaft of a first motor in a first drive unit can differ from the number of teeth on a second motor pulley (or second nut pulley) provided on a second motor shaft of a second motor in a second drive unit. Accordingly, the rotational ratio relating to the first motor and the rotational ratio relating to the second motor will differ from each other.In another exemplary embodiment, the outer diameter of a first nut pulley (or a first motor pulley) provided on the first motor shaft of the first motor of the first drive unit may differ from the outer diameter of a second nut pulley (or a second motor pulley) provided on the second motor shaft of the second motor of the second drive unit.

[0400] A Vernier algorithm can calculate a value using two related variables with different phases or time intervals. Due to the different rotational ratios of the first and second motors, the controller can identify a linear position of the rack using a phase difference between a position of the first motor, detected by a first motor position sensor, and a position of the second motor, detected by a second motor position sensor, which have different cycles.By using a Vernier algorithm based on different rotation ratios caused by configurations of a first motor pulley, a second motor pulley, and a driven pulley relating to a rack position and / or rack movement, the rack position can be determined without a learning algorithm to detect a linear rack position, an electronic rotation counter, or a linear position sensor.

[0401] Additionally, the controller can perform the operational processes of the rack rolling detection method described above. The controller for estimating the rack's displacement position by applying a current value to the motor or detecting a current value, and the controller for rack rolling detection, can be implemented by the same physical processor or by different processors.

[0402] Furthermore, the present disclosure can provide a non-volatile, computer-readable recording medium that stores computer instructions which, when executed by a processor, cause the performance of a rack-roll detection operation, wherein the rack-roll detection operation includes: determining whether a fault occurs with respect to a rack, using at least one motor current from a steering motor for steering control of the vehicle or a rack force; detecting abnormal behavior of the vehicle using a yaw rate and a lateral acceleration of the vehicle; and detecting the occurrence of rack-roll of a rack connected to the steering motor, based on a result of a determination of whether a fault occurs with respect to a rack and a result of a detection of abnormal behavior.

[0403] The computer commands of the non-volatile, computer-readable recording medium can be configured to perform operational operations at each stage according to the operation described above for detecting a rack roller. Accordingly, all operational operations of the rack roller detection method and device described above can be applied.

[0404] The electronic control unit may include a data processor. The electronic control unit may include a bus or other communication component or communicator for communicating data or information. The electronic control unit may include a processor or processing circuit that is communicatively or electronically connected to the bus to process data or information. The electronic control unit may include main memory, such as random-access memory (RAM) or other dynamic storage device, that is communicatively or electronically connected to the bus to store information and instructions to be executed by the processor. The main memory may include a data archive.The main memory can be configured to store positional information, temporary variables, or other intermediate information during the execution of instructions by the processor. The electronic control unit may also include read-only memory (ROM) or other static storage device, which is electronically or communicatively connected to the bus to store static information and instructions for the processor. A storage device, such as a solid-state device, a magnetic disk, or an optical disk, may be electronically or communicatively connected to the bus to store information and instructions permanently. The storage device may include or be part of the data archive.

[0405] The electronic control unit can be connected electronically or communicatively via the bus to a display, such as a liquid crystal display or an active matrix display, to output or display information to a user. An input device, such as a keyboard including alphanumeric and other keys, can be connected electronically or communicatively to the bus to communicate information and commands to the processor. The input device can include a touchscreen display. The input device can include cursor control, such as a mouse, trackball, or cursor keys, for receiving or communicating directional information and command selections to the processor and for controlling cursor movement on a display. The display can be part of a data processing system, a client computing device, or another component of a system.

[0406] The processes and procedures described here can be carried out by the processor executing instructions stored in main memory. Such instructions can be stored in main memory, which is read by another computer-readable medium, such as a storage device. The execution of the instructions stored in main memory causes the electronic control unit to carry out the processes or procedures described here. One or more processors in a multiprocessor arrangement can be included in the electronic control unit to execute the instructions stored in main memory. Hardwired circuitry can be used in conjunction with software instructions along with the systems and procedures described here. The systems and procedures described here are not limited to a specific combination of hardware and software.

[0407] Although an example of the electronic control device has been described, the operations described in this description may be implemented in other types of digital electronic circuitry or in computer software, firmware or hardware, including the structures disclosed in this description and their structural equivalents, or in combinations of one or more of these.

[0408] The terms "data processing system," "computing equipment," "component," or "data processing device" encompass various devices, facilities, and machines for processing data, including a programmable processor, a computer, a system-on-a-chip, or several or combinations of the foregoing. These terms may include specialized logic circuitry, such as an FPGA (field-programmable gate array) or an ASIC (application-specific integrated circuit). The terms may also include code that creates an execution environment for the computer program, such as code that forms processor firmware, a protocol stack, a database management system, an operating system, a cross-platform runtime environment, a virtual machine, or a combination of one or more of these.The device and the execution environment can implement various different computing model infrastructures, such as web services, distributed computing and network computing infrastructures.

[0409] A computer program (also known as a program, software, software application, app, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and can be used in any form, including as a standalone program or as a module, component, subroutine, object, or other entity suitable for use in a computing environment. A computer program can be implemented as a file in a file system. A computer program can be stored in a section of a file containing other programs or data (e.g., one or more scripts stored in a markup language document), in a single file associated with the program, or in multiple coordinated files (e.g., files containing one or more modules, subroutines, or portions of code).A computer program can be used to run on one computer or on multiple computers located at one site or distributed across multiple sites and connected by a communication network.

[0410] The processes and logic sequences described in this description can be performed by one or more programmable processors executing one or more computer programs (e.g., components of the data processing system) to perform actions by processing input data and generating output. The processes and logic sequences can also be performed by a specialized logic circuit, such as an FPGA (field-programmable gate array) or an ASIC (application-specific integrated circuit), and devices can also be implemented as such. Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, for example.Internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and memory may be supplemented by or contained within a special logic circuit.

[0411] According to some embodiments of the present disclosure, although there is no mechanical connection between a steering shaft and a wheel in a steer-by-wire steering device, the driver's steering intention can be stably transmitted to a rack and it can be prevented that the rack rotates due to a torque of a ball nut when the driver operates the steering wheel.

[0412] In addition, according to certain embodiments of the present disclosure, the position of a rack can be accurately estimated without a pinion shaft.

[0413] The subject matter and the processes described herein can be implemented in digital electronic circuits or in computer software, firmware, or hardware, including the structures disclosed herein and their structural equivalents, or in combinations of one or more of these. The subject matter described herein can be implemented as one or more computer programs, e.g., computer program instructions for one or more circuits, which are stored or encoded in one or more computer storage media for execution by one or more data processing devices or for controlling the operations of one or more data processing devices. Alternatively or additionally, the program instructions can be encoded on an artificially generated propagated signal, e.g.,A computer storage medium is a machine-generated electrical, optical, or electromagnetic signal produced to encode information for transmission to a suitable receiver for execution by a data processing device. A computer storage medium may be contained in a computer-readable storage device, a computer-readable storage substrate, a random-access or serial-access storage arrangement or device, or a combination of one or more of these. While a computer storage medium may not be a propagated signal itself, it may be a source or destination of computer program instructions encoded in an artificially generated propagated signal. The computer storage medium may be contained in one or more separate components or media (e.g., multiple CDs, disks, or other storage devices).The operational processes described in this description can be implemented as operations performed by a data processing device on data stored on one or more computer-readable storage devices or received from other sources.

[0414] The above description has been presented to enable any person skilled in the art to make and use the technical idea of ​​the present disclosure and has been provided in the context of a specific application and its requirements. Various modifications, additions, and substitutions of the described embodiments will be readily apparent to the person skilled in the art, and the general principles defined here can be applied to other embodiments and applications without departing from the fundamental idea and scope of the present disclosure. The above description and the accompanying drawings provide an example of the technical idea of ​​the present disclosure for illustrative purposes only. That is to say, the disclosed embodiments are intended to illustrate the scope of the technical idea of ​​the present disclosure.Therefore, the scope of the present disclosure is not limited to the embodiments shown, but is to be assigned to the broadest scope in accordance with the claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] KR 10-2024-0167699

[0001] KR 10-2025-0170535

[0001]

Claims

[1] Procedure, encompassing: Determine whether a fault is occurring with respect to a rack connected to a steering motor, using at least one of the motor currents of the steering motor for steering control of a vehicle or a rack force; Detecting abnormal vehicle behavior based on the vehicle's yaw rate and lateral acceleration; and Detecting any rolling of the rack connected to the steering motor, based on determining whether the fault is related to the rack and detecting the abnormal behavior of the vehicle. [2] Method according to claim 1, wherein determining whether the fault occurs with respect to the rack uses a first difference value between the motor current of the steering motor and a target motor current value according to the steering control to determine whether the fault occurs with respect to the rack. [3] Method according to claim 2, wherein determining whether the fault occurs with respect to the rack includes determining that the fault occurs with respect to the rack when a first filtered value obtained by filtering the first difference value according to a preset filter frequency exceeds a preset first threshold. [4] Method according to claim 1, wherein determining whether the fault occurs with respect to the rack uses a second difference value between the rack force and a target rack force value according to the steering control to determine whether the fault occurs with respect to the rack. [5] Method according to claim 4, wherein determining whether the fault occurs with respect to the rack includes determining that the fault occurs with respect to the rack when a second filtered differential value, obtained by filtering the second differential value according to a preset filter frequency, exceeds a preset second threshold. [6] Method according to claim 1, wherein the detection of the abnormal behavior of the vehicle includes detecting the abnormal behavior of the vehicle based on a comparison between the yaw rate of the vehicle and a target yaw rate value and a comparison between the lateral acceleration of the vehicle and a target lateral acceleration value. [7] Method according to claim 6, wherein the detection of the abnormal behavior of the vehicle includes detecting the abnormal behavior of the vehicle based on whether a third filtered value, obtained by filtering a third difference value between the yaw rate of the vehicle and the target yaw rate value according to a preset filter frequency, exceeds a preset third threshold. [8] Method according to claim 6, wherein the detection of the abnormal behavior of the vehicle includes detecting the abnormal behavior of the vehicle based on whether a fourth filtered value, obtained by filtering a fourth difference value between the lateral acceleration of the vehicle and the target lateral acceleration value according to a preset filter frequency, exceeds a preset fourth threshold. [9] Method according to claim 1, wherein detecting the rolling of the rack includes determining that the rack is rolling when, based on at least one of the motor current or the rack force, it is determined that the fault with respect to the rack occurs, and based on the yaw rate and lateral acceleration of the vehicle, it is determined that the abnormal behavior of the vehicle occurs. [10] Method according to claim 1, wherein the detection of the abnormal behavior of the vehicle is carried out when it is determined that the fault is related to the rack. [11] Device comprising: a memory configured to store at least one instruction; and a processor configured to execute at least one instruction to perform operational operations that include: Determine whether a fault is occurring with respect to a rack connected to a steering motor, using at least one of the motor currents of the steering motor for steering control of a vehicle or a rack force; Detecting abnormal vehicle behavior based on the vehicle's yaw rate and lateral acceleration; and Detecting any rolling of the rack connected to the steering motor, based on determining whether the fault is related to the rack and detecting the abnormal behavior of the vehicle. [12] Device according to claim 11, wherein the processor is configured to determine whether the fault occurs with respect to the rack, using a first differential value between the motor current of the steering motor and a target motor current value according to the steering control. [13] Device according to claim 11, wherein the processor is configured to determine whether the fault occurs with respect to the rack, using a second difference value between the rack force and a target rack force value according to the steering control. [14] Device according to claim 11, wherein the processor is configured to detect the abnormal behavior of the vehicle based on a comparison between the yaw rate of the vehicle and a target yaw rate value and a comparison result between the lateral acceleration of the vehicle and a target lateral acceleration value. [15] Device according to claim 11, wherein the processor is configured to detect the abnormal behavior of the vehicle when it is determined that the fault is related to the rack. [16] Steer-by-wire system, including: a ball nut rotatably coupled to a rack and is configured to move the rack linearly by rotating the ball nut; first and second nut pulleys provided on an outer surface of the ball nut; a first motor pulley of a first motor, which is operationally connected to the first nut pulley of the ball nut by a first belt; a second motor pulley of a second motor, which is operationally connected to the second nut pulley of the ball nut by a second belt; a controller configured to control the first motor and the second motor, and where the controller is configured to: Determine if a fault occurs with respect to the rack, using at least one motor current or rack force from each of the first motor or the second motor, Detecting abnormal vehicle behavior based on the vehicle's yaw rate and lateral acceleration, and Detecting rack rolling based on determining whether the fault is related to the rack and detecting abnormal vehicle behavior. [17] Steer-by-wire system according to claim 16, wherein the controller is configured to calculate a linear position of the rack using a first position detected by a first motor sensor configured to detect a rotational position of a shaft of the first motor, and a second position detected by a second motor sensor configured to detect a rotational position of a shaft of the second motor. [18] Steer-by-wire system according to claim 17, wherein the controller is configured to calculate the linear position of the rack using the first position of the first motor and the second position of the second motor with a Vernier algorithm. [19] Steer-by-wire system according to claim 16, wherein the rotational ratios of the first motor and the second motor are set to be different from each other. [20] Steer-by-wire system according to claim 16, wherein the controller is configured to determine whether the fault occurs with respect to the rack, using a first differential value between the motor current and a target motor current value according to the steering control. [21] Steer-by-wire system according to claim 16, wherein the controller is configured to determine whether the error occurs with respect to the rack, using a second difference value between the rack force and a target rack force value according to the steering control. [22] Steer-by-wire system according to claim 16, wherein the controller is configured to detect the abnormal behavior of the vehicle based on a comparison between the yaw rate of the vehicle and a target yaw rate value and a comparison between the lateral acceleration of the vehicle and a target lateral acceleration value. [23] Steer-by-wire system according to claim 16, wherein the controller is configured to detect the abnormal behavior of the vehicle when it is determined that the fault is related to the rack.

Images