Steering control device

Abstract

An embodiment of the present disclosure relates to a steering control device comprising a risk determination unit that receives a steering input value from a sensor of a Steering Feedback Actuator (SFA), calculates a steering inertia value using the steering input value when a hands-off state for the steering wheel is determined based on the steering input value, and determines whether there is a risk to the steering wheel by comparing the steering inertia value with a preset range.

Description

Technology Field

[0001] These embodiments relate to a steering control device. Background Technology

[0002] A conventional vehicle steering system is a device that allows a driver to select and operate the direction of travel of the vehicle, and is equipped with a steering wheel operated directly by the driver and a steering mechanism that transmits the direction of operation and operating force of the steering wheel to the wheels.

[0003] For example, power steering systems have been developed and applied to assist the driver's steering wheel operation and provide convenience in driving; these systems have been sequentially developed and applied, including hydraulic types utilizing hydraulic pressure, electro-hydraulic types utilizing both hydraulic pressure and motor power, and electric types utilizing only motor power.

[0004] Meanwhile, in order to reduce the weight of the vehicle, a steer-by-wire system (SbW) is being developed that electronically connects a steering shaft (or column) including a steering wheel and reaction force motor and an actuator including a wheel and rack bar to transmit the driver's steering force.

[0005] Such steer-by-wire systems may include a Steering Feedback Actuator (SFA) that detects the driver's steering intention via a torsion bar, but there are side effects that may occur due to disturbances in the steering wheel, and thus a method to ensure driving stability is required. The problem to be solved

[0006] The embodiments may provide a steering control device that determines whether there is a risk to the steering wheel in an autonomous driving mode of a vehicle equipped with an SBW system. means of solving the problem

[0007] In one aspect, the embodiments may provide a steering control device comprising: a receiving unit that receives a steering input value from a sensor of a steering wheel in an autonomous driving mode of a vehicle equipped with an SBW system; a calculating unit that calculates a steering inertia value using the steering input value when a hands-off state for the steering wheel is determined based on the steering input value; and a risk determining unit that determines whether there is a risk to the steering wheel by comparing a preset range with the steering inertia value. Effects of the invention

[0008] According to the embodiments, a steering control device can be provided to determine whether there is a risk to the steering wheel in an autonomous driving mode of a vehicle equipped with an SBW system. Brief explanation of the drawing

[0009] FIG. 1 is a block diagram schematically illustrating a steering control system according to one embodiment. FIG. 2 is a drawing for explaining a steering control device according to one embodiment. FIG. 3 is a flowchart illustrating a method for determining whether there is a risk of a steering wheel according to one embodiment. Specific details for implementing the invention

[0010] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the exemplary drawings. In assigning reference numerals to the components of each drawing, the same components may have the same reference numeral as much as possible, even if they are shown in different drawings. Furthermore, in describing the embodiments, if it is determined that a detailed description of related known components or functions may obscure the essence of the technical concept, such detailed description may be omitted. Where terms such as "comprising," "having," or "consisting of" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it may include a plural unless otherwise specified.

[0011] Additionally, terms such as first, second, A, B, (a), (b), etc., may be used to describe the components of the present disclosure. These terms are used merely to distinguish the components from other components, and the nature, order, sequence, or number of the components are not limited by such terms.

[0012] In describing the positional relationship of components, where it is stated that two or more components are "connected," "combined," or "joined," it should be understood that while the two or more components may be directly "connected," "combined," or "joined," they may also be "connected," "combined," or "joined" with other components "intervened." Here, the other components may be included in one or more of the two or more components that are "connected," "combined," or "joined" with one another.

[0013] In describing the temporal flow relationship regarding components, methods of operation, or methods of production, for example, when the temporal or sequential relationship is described using "after," "following," "next," or "before," it may include cases where the relationship is not continuous unless "immediately" or "directly" is used.

[0014] Meanwhile, where numerical values ​​or corresponding information regarding a component (e.g., levels, etc.) are mentioned, even without separate explicit notation, the numerical values ​​or corresponding information may be interpreted as including a range of error that may occur due to various factors (e.g., process factors, internal or external shocks, noise, etc.).

[0015] Below, an embodiment of a steering control system (1) that can perform the function of a steering control device (100) and performs the function of controlling the steering of a vehicle is described.

[0016] FIG. 1 is a block diagram schematically showing a steering control system (1) according to one embodiment.

[0017] Referring to FIG. 1, a steering control system according to one embodiment may include a steering control device, a Steering Feedback Actuator (SFA), and a Road Wheel Actuator (RWA).

[0018] A steering control system (1) according to one embodiment may mean a system that controls the steering of a vehicle equipped with the steering control system (1) to change according to the rotation angle of the steering wheel (21) operated by the driver.

[0019] Depending on whether the steering control system (1) is coupled with a mechanical connection member (or linkage) between a steering input actuator and a steering output actuator, the force (torque) generated by the driver rotating the steering wheel (21) is transmitted to the steering motor (31) through a mechanical power transmission device (e.g., a linkage) and the front wheel (33) is steered by the driving of the steering motor (31). Alternatively, it may be a steer-by-wire (SbW) system that transmits power by transmitting and receiving electrical signals through wires, cables, etc. instead of a mechanical power transmission device. The steering control system (1) is described below based on an SbW system, but is not limited thereto.

[0020] The steering control system (1) according to the present disclosure illustrated in FIG. 1 can implement an SbW system using an SFA (20), a steering control device (100), and an RWA (30), etc. As described above, when the steering control system (1) is an SbW system, the SFA (20) and the RWA (30) can be mechanically separated.

[0021] SFA (20) may refer to a device that receives the steering input value intended by the driver. As described above, this SFA (20) may include a steering wheel (21), a steering shaft (22), and a reaction motor (23). Additionally, although not illustrated, it may further include a steering gear that transmits the rotational force of the reaction motor (23) to the steering shaft (22). Additionally, although not illustrated, it may further include a torsion bar existing between the input shaft and the output shaft of the steering shaft (22).

[0022] SFA (20) may include a steering angle sensor that detects the steering angle and column angle of the steering wheel, a torque sensor that detects the driver's steering torque, and a steering angle velocity sensor that detects the steering angle velocity of the steering wheel.

[0023] The steering control device (100) receives steering input values ​​from each sensor included in the SFA (20), calculates a steering inertia value or a first control value, and outputs an electrical signal indicating the first control value to the RWA (30). Here, the steering input value may refer to information including at least one of a steering angle, a steering angular velocity, and a driver torque.

[0024] Meanwhile, the steering control device (100) receives feedback on actual power information (e.g., rack position information) output from the RWA (30), calculates a second control value, and outputs an electrical signal indicating the second control value to the SFA (20) to provide a steering sensation (steering sensation) to the driver.

[0025] RWA (30) may refer to a device that drives the actual vehicle to steer. This RWA (30) may include a steering motor (31), a rack (32), a front wheel (33), a vehicle speed sensor, a rack position sensor, etc. Here, the front wheel (33) may be replaced with a rear wheel (not shown) depending on the driving method of the vehicle.

[0026] And, SFA (20) and RWA (30) may further include a motor torque sensor capable of detecting the motor torque of the reaction motor (23) and the steering motor (31).

[0027] Although not illustrated, the steering control system (1) may further include a clutch, etc. capable of separating or combining the SFA (20) and RWA (30). Here, the clutch may be operated by the control of the steering control device (100).

[0028] Meanwhile, when the steering control system (1) is an SbW system and the vehicle is driving in autonomous driving mode, the steering control system (1) can control only the RWA (30) to perform steering control of the vehicle, or control both the SFA (20) and the RWA (30) to perform steering control of the vehicle.

[0029] The steering control device according to the present disclosure receives a steering input value from a sensor of a Steering Feedback Actuator (SFA), and when it is determined that the steering wheel is in a hands-off state based on the steering input value, it calculates a steering inertia value using the steering input value and can determine whether there is a risk to the steering wheel by comparing the steering inertia value with a preset range.

[0030] In one embodiment, the steering control device may be an ADAS (Advance Driver Assistance Systems) that provides information to assist in driving the vehicle or assists the driver in controlling the vehicle.

[0031] Here, ADAS can refer to various types of advanced driver assistance systems, and driver assistance systems may include, for example, Autonomous Emergency Braking, Smart Parking Assistance System (SPAS), Blind Spot Detection (BSD) system, Adaptive Cruise Control (ACC) system, Lane Departure Warning System (LDWS), Lane Keeping Assist System (LKAS), and Lane Change Assist System (LCAS). However, it is not limited to these.

[0032] Hereinafter, a steering control device (100) according to one embodiment of the present disclosure will be described with reference to the attached drawings.

[0034] FIG. 2 is a drawing for explaining a steering control device (100) according to one embodiment.

[0035] Referring to FIG. 2, in an autonomous driving mode of a vehicle equipped with an SBW system, the steering control device (100) may include a receiving unit (110) that receives a steering input value from a sensor of an SFA (Steering Feedback Actuator), a calculation unit (120) that calculates a steering inertia value using the steering input value when a hands-off state is determined based on the steering input value, and a risk determination unit (130) that determines whether there is a risk to the steering wheel by comparing a preset range with the steering inertia value.

[0036] The hands-off state can be determined using steering input values ​​received from the vehicle's sensors, which will be described later. For example, the hands-off state can be determined by whether the driver is gripping the steering wheel using a sensor that measures the vehicle's steering torque. In this case, the hands-off state can be determined by utilizing the fact that steering torque fluctuations are detected differently when the steering wheel is being held compared to when the hands are released from the steering wheel. As another example, the hands-off state can be calculated according to a specific logic based on steering input values ​​received from the steering wheel's sensors. Additionally, the specific logic may be pre-set or may vary depending on the vehicle's operating speed. The embodiments in which the hands-off state is determined are not limited to the described embodiments and may be pre-set in various ways.

[0037] The steering control device (100) may include a receiving unit (110) that receives a steering input value from a sensor of an SFA (Steering Feedback Actuator).

[0038] For example, steering input values ​​may include steering angle, steering angular velocity, steering torque, and column angle.

[0039] For example, the steering angle may include the rotated angle of the steering wheel and the rotated angle of the top of the torsion bar. For instance, the rotated angle may refer to an angle rotated clockwise or counterclockwise relative to a specific point on the steering wheel. However, since the direction can be varied and set according to the movement of the vehicle, this embodiment is not limited thereto. Additionally, for convenience of explanation, the description has focused on the rotated angle of the steering wheel, but the rotated angle of the top of the torsion bar can also be operated and controlled in the same manner.

[0040] As another example, steering angular velocity may refer to the angular velocity of the vehicle's steering wheel. As yet another example, steering torque may refer to a value generated by converting the twisting angle of the torsion bar into a voltage signal when the driver operates the vehicle's steering wheel. As yet another example, the column angle may refer to the rotated angle of the lower part of the torsion bar. However, the steering input value is not limited to the aforementioned embodiments and may include various values. Additionally, the steering input value may vary over time and may be variably set according to the movement of the vehicle.

[0041] Meanwhile, the steering control device (100) may include a calculation unit (120) that calculates a steering inertia value using the steering input value when it is determined to be in a hands-off state based on the steering input value.

[0042] For example, the steering inertia value can be calculated according to preset conditions using at least one of the steering angle, steering angular velocity, steering torque, and column angle.

[0043] Preset conditions can be pre-set using Equation 1. The parameters of the preset conditions are described in detail with reference to Equation 1.

[0044]

[0046] Referring to mathematical formula 1, (unit: ) can mean the steering inertia value of the steering wheel. (unit: ) can refer to the steering angular acceleration value of the steering wheel. For example, the value is the steering angle ( It can be set to a value estimated through a Kalman filter based on ).

[0047] also, (unit: ) can refer to the damping coefficient of the steering wheel. (unit: ) may refer to the stiffness value of the torsion bar included in the SFA. (unit: ) may refer to the damping coefficient of the torsion bar included in the SFA. , , All can be set to constant values ​​in advance.

[0048] also, (unit: ) can refer to the steering angular velocity value of the steering wheel. This value is the steering angle ( It can be set to a value estimated through a Kalman filter based on ). Or, as described above, it may mean the steering angular velocity received by the steering angle sensor. ( ) may mean the value of the steering angle of the aforementioned steering wheel.

[0049] also, ( ) may mean the value of the aforementioned column angle.

[0050] also, (unit: ) may refer to the angular velocity value of the column (the bottom of the aforementioned torsion bar). This value is the column angle ( It can be set to a value estimated through a Kalman filter based on ).

[0051] also, (unit: ) may represent the value of the steering torque of the steering wheel. In this case, the value of the steering torque of the steering wheel may be the value of the friction torque of the steering wheel when the driver is in a hands-off state. Additionally, the initial value may be set to that value.

[0052] Referring to Equation 1, the product of the steering inertia value of the steering wheel and the steering angular acceleration value of the steering wheel can be calculated using the steering angular velocity value of the steering wheel, the deviation between the steering angle of the steering wheel and the column angle, the deviation between the steering angular velocity value of the steering wheel and the angular velocity value of the column, and the steering torque value of the driver's steering wheel. However, the preset conditions are not limited to Equation 1 and can be set in various ways.

[0054] Meanwhile, the steering control device (100) may include a risk determination unit (130) that determines whether there is a risk to the steering wheel by comparing a preset range with a steering inertia value.

[0055] For example, the risk determination unit (130) can determine whether the steering inertia value is included within a preset range and determine whether there is a risk to the steering wheel based on the determination result.

[0056] For example, a preset range can be set based on a specific steering inertia value. The preset range is the specific steering inertia value, 0.02 to 0.03 It can be set to a range of -50% to 50% based on. However, the specified steering inertia value and the preset range may be set differently depending on the type of vehicle and may be preset in various ways, not limited to this embodiment.

[0057] For example, the danger judgment unit (130) may determine that there is a danger to the steering wheel if it determines that the steering inertia value is not included within a preset range. Additionally, the steering control device (100) may transmit data to an MCU or ECU included in the vehicle so that a danger warning message is displayed on an information display device included in the vehicle.

[0058] For example, the risk determination unit (130) can determine that there is no risk to the steering wheel if the steering inertia value is included within a preset range.

[0059] For example, the risk determination unit (130) can determine whether there is a risk to the steering wheel by recalculating the steering inertia value when it is determined that there is no risk to the steering wheel, and comparing the recalculated steering inertia value with a preset range.

[0060] In this case, while the risk determination unit (130) determines whether there is a risk, a new steering input value may be received by the receiving unit. Therefore, if the risk determination unit (130) determines that there is no risk to the steering wheel, it is necessary to recalculate the steering inertia value using the newly received steering input value. Through this, it is possible to prepare for risks that may occur to the vehicle in response to the steering input value received in real time.

[0061] For example, if the risk judgment unit (130) determines that the steering inertia value is not included within the aforementioned preset range, it can further determine that there is a risk in the steering wheel by additionally calculating the number of times it is not included.

[0062] However, the risk determination unit (130) may determine whether there is a risk to the steering wheel, without being limited by the embodiments of the present disclosure. The operation of the risk determination unit (130) determining the risk is explained in detail through FIG. 2.

[0064] FIG. 3 is a flowchart illustrating a method for determining whether there is a risk of a steering wheel according to one embodiment.

[0065] An embodiment of the present disclosure is a flowchart regarding a method for determining whether there is a risk to the steering wheel of a steering control device, and the operation of the steering control device is explained primarily.

[0066] For example, a step of receiving steering input values ​​through a receiver may be performed (S210). At this time, the steering input values ​​may include a steering angle, a column angle, and a steering torque received through a sensor included in the SFA.

[0067] For example, a step of determining a hands-off state using a steering input value may be performed. (S220) An embodiment of the present disclosure is intended to determine whether there is a risk to the steering wheel when it is in a hands-off state. Accordingly, it is determined whether it is in a hands-off state, and if it is not in a hands-off state, the steering control device may stop operation in step S220.

[0068] If it is determined that the hands-off state is present, a step of calculating the steering inertia value may be performed (S230). The present embodiment may calculate the steering inertia value using values ​​included in the steering input value, and steering angular velocity values ​​and steering angular acceleration values ​​calculated through a Kalman filter or the like using the steering input value.

[0069] A step of comparing the calculated steering inertia value with a preset range may be performed (S240). The preset range may be set based on a specific steering inertia value, and this may be pre-set differently depending on the type of vehicle. At this time, if the steering inertia value is not included in the preset range, the steering control device may determine that there is a risk to the steering wheel. On the other hand, if the steering inertia value is included in the preset range, the steering control device may determine that there is no risk to the steering wheel.

[0070] The foregoing description is merely an illustrative explanation of the technical concept of the present disclosure, and those skilled in the art to which the present disclosure pertains may make various modifications and variations within the scope of the essential characteristics of the technical concept. Furthermore, since these embodiments are intended to explain, not limit, the scope of the technical concept is not limited by these embodiments. The scope of protection of the present disclosure shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present disclosure.

Claims

Claim 1 A steering control device comprising: a receiving unit that receives steering input values ​​including a steering angle, steering angular velocity, steering torque, and column angle from a sensor of an SFA (Steering Feedback Actuator) in an autonomous driving mode of a vehicle equipped with an SBW system; a calculating unit that calculates a steering inertia value according to a preset condition using at least one of the steering angle, steering angular velocity, steering torque, and column angle when a hands-off state regarding the steering wheel is determined based on the steering input values; and a risk judgment unit that determines whether the steering inertia value is included within a preset range and determines whether there is a risk to the steering wheel according to the determination result, wherein the risk judgment unit determines that there is a risk to the steering wheel when it determines that the steering inertia value is not included within the preset range, and determines that there is no risk to the steering wheel when the steering inertia value is included within the preset range. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A steering control device according to claim 1, wherein the risk determination unit, when it is determined that there is no risk to the steering wheel, recalculates the steering inertia value and compares the recalculated steering inertia value with the preset range again to determine whether there is a risk to the steering wheel.

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