Apparatus and method for controlling a steer-by-wire system

Abstract

Proposed is an apparatus and method for controlling a steer-by-wire system, the apparatus including a steering angle sensor configured to detect a steering angle position, a steering position control command receiver configured to receive a steering position control command y2 from a designated external module, a processor configured to generate a steering angle position signal y1 based on the steering angle position from the steering angle sensor, calculate a compensation gain x corresponding to a column torque or motor current of a steering force actuator (SFA) when a driver engagement occurs, calculate a final steering position control command Y by reflecting the compensation gain x to the steering angle position signal y1 and the steering position control command y2, and output the final steering position control command Y to the steering force actuator (SFA). With the apparatus and method, it is possible to prevent a driver from perceiving a sense of being hit and it is possible to prevent a collision from occurring.

Description

Technical Field

[0001] Exemplary embodiments of this disclosure relate to an apparatus and method for controlling a steer-by-wire system, and more specifically, to an apparatus and method for controlling a steer-by-wire system capable of detecting driver involvement during steering angle position control during automatic parking, and compensating for steering angle position control in a steer-by-wire (SBW) system where the steering force actuator (SFA) and road wheel actuator (RWA) are not mechanically connected to each other. With this apparatus and method, the driver can prevent the feeling of being impacted and collisions can be prevented. Background Technology

[0002] Power steering systems are typically developed and installed in vehicles as vehicle steering devices (or steering systems) to assist drivers in operating the steering wheel, thereby providing convenience for drivers when driving. These power steering systems include hydraulic power steering systems that use hydraulic pressure, electro-hydraulic power steering systems that use both hydraulic and electric motor power, and electric power steering systems that use only electric motor power.

[0003] In recent years, steer-by-wire (SBW) systems have been developed and installed on vehicles. In SBW systems, vehicle steering is performed using an electric motor (such as an electric motor), rather than eliminating the mechanical connection between the steering wheel and the wheels (i.e., the vehicle's drive wheels) (such as a steering column, universal joint, or pinion shaft).

[0004] A Side-Wheel Steering (SBW) system is a steering system in which the steering wheel and the front-wheel steering mechanism (i.e., the frame connecting the drive wheels) are mechanically disconnected from each other. The SBW system receives steering wheel rotation signals from the electronic control unit (ECU) via a communication line (e.g., direct CAN) and operates the steering motor connected to the frame according to the input steering wheel rotation signals, thereby steering the vehicle.

[0005] In recent years, parking assist (PA) systems have been installed in vehicles. A parking assist (PA) system transmits position control signals (i.e., steering position control signals) to the steering system, thereby controlling the position of the wheels (i.e., steering position) to assist in automatic parking.

[0006] In this configuration, for the Parking Assist (PA) system to function properly, the steering system performs feedback control in accordance with steering angle control commands. During normal operation, the steering system performs reaction force control. However, when the steering system receives a position control activation signal, it switches to position control mode, thereby following position commands.

[0007] More specifically, as position control (i.e., steering position control), feedback control is performed using the difference between the position based on the steering position control command and the current steering position.

[0008] However, in related technologies, there is no method for determining and compensating for driver involvement when a parking assist (PA) system performs steering control.

[0009] Therefore, when the driver intervenes during steering position control, the difference between the position according to the steering position control command and the current steering position increases, generating a large force to compensate for the difference. Consequently, the driver oversteers due to the sensation of a collision. There is a problem that oversteer increases the likelihood of a vehicle accident.

[0010] In a steering-by-wire system, the mechanical connection structure (i.e., the connection between the steering wheel and the front wheel steering mechanism) used in related technologies is eliminated. In this case, a technology is needed to precisely control the front wheel steering mechanism (e.g., the front wheel steering actuator) in a manner that corresponds to steering position control commands, such as steering wheel rotation signals (corresponding to steering wheel operations performed by the driver).

[0011] Examples of related technologies to this disclosure are disclosed in Korean patent application No. 10-2018-0065045, published on June 18, 2018, entitled "Steering Control Method in a Steer-by-Wire System". Summary of the Invention

[0012] Various embodiments relate to apparatus and methods for controlling a steer-by-wire system that can detect driver involvement during steering angle position control during automatic parking and compensate for steering angle position control in a steer-by-wire (SBW) system where the steering force actuator (SFA) and wheel actuator (RWA) are not mechanically connected to each other.

[0013] In one embodiment, the means for controlling the steer-by-wire system may include: a steering angle sensor configured to detect a steering angle position; a steering position control command receiver configured to receive a steering position control command y2 from a designated external module; and a processor configured to generate a steering angle position signal y1 based on the steering angle position from the steering angle sensor, calculate a compensation gain x corresponding to the column torque or motor current of the steering force actuator (SFA) when driver involvement occurs, calculate a final steering position control command Y by reflecting the compensation gain x in the steering angle position signal y1 and the steering position control command y2, and output the final steering position control command Y to the steering force actuator (SFA).

[0014] In this device, the designated external module includes a parking assist (PA) system.

[0015] In this device, the compensation gain x can be a compensation gain x used to compensate for steering position control initiated by the driver's participation in steering during automatic steering via the designated external module.

[0016] In this device, the processor can use a predetermined equation or lookup table to calculate the compensation gain x corresponding to the column torque or the motor current.

[0017] In this device, the processor can calculate the final steering position control command Y by subtracting the value obtained by multiplying the steering position control command y2 by "compensation gain x" from the value obtained by multiplying the steering angle position signal y1 by "1 - compensation gain x".

[0018] In this device, the final steering position control command Y is transmitted to the wheel actuator (RWA) via the steering force actuator (SFA).

[0019] In this device, when the driver participates in maintaining the position for a predetermined time or longer, the processor can stop the automatic steering position control of the designated external module and execute the steering control initiated by the driver.

[0020] In another embodiment, a method for controlling a steer-by-wire system may include: generating a steering angle position signal y1 by a processor based on a steering angle position from a steering angle sensor; receiving a steering position control command y2 from a designated external module by a steering position control command receiver; calculating a compensation gain x corresponding to the column torque or motor current of a steering force actuator (SFA) when driver involvement occurs; and calculating a final steering position control command Y by the processor by reflecting the compensation gain x into the steering angle position signal y1 and the steering position control command y2, and outputting the final steering position control command Y to the steering force actuator (SFA).

[0021] In this method, the designated external module may include a parking assistance (PA) system.

[0022] In this method, the compensation gain x can be a compensation gain x used to compensate for steering position control initiated by the driver's participation in steering during automatic steering via the designated external module.

[0023] In this method, when calculating the compensation gain x, the processor can use a predetermined equation or lookup table to calculate the compensation gain x corresponding to the column torque or motor current.

[0024] In this method, in order to calculate the final steering position control command Y, the processor can calculate the final steering position control command Y by subtracting the value obtained by multiplying the steering position signal y1 by "1 - compensation gain x" from the value obtained by multiplying the steering position control command y2 by "compensation gain x".

[0025] In this method, the final steering position control command Y can be transmitted to the wheel actuator (RWA) via the steering force actuator (SFA).

[0026] In this method, if the driver participates in maintaining the position for a predetermined time or longer, the processor can stop the automatic steering position control of the designated external module and execute the steering control initiated by the driver.

[0027] According to one aspect of the invention, the device and method are capable of detecting driver involvement during steering angle position control in automatic parking and compensating for steering angle position control in a steer-by-wire (SBW) system where the steering force actuator (SFA) and wheel actuator (RWA) are not mechanically connected to each other. Using this device and method, the driver can be prevented from perceiving a collision and collisions can be avoided. Attached Figure Description

[0028] Figure 1This is a diagram illustrating a schematic configuration of an apparatus for controlling a steer-by-wire system according to a first embodiment of the present disclosure.

[0029] Figure 2 This is a flowchart illustrating a method for controlling a steer-by-wire system according to a second embodiment of the present disclosure.

[0030] Figure 3 It shows the control with Figure 1 The flowchart shows the method for adjusting the turning position by compensating for changes in gain x. Detailed Implementation

[0031] As is customary in the relevant art, some exemplary embodiments may be illustrated in drawings according to functional blocks, units, and / or modules. Those skilled in the art will understand that these blocks, units, and / or modules are physically implemented via electronic (or optical) circuitry, such as logic circuits, discrete components, processors, hardwired circuitry, memory elements, wiring connections, etc. When blocks, units, and / or modules are implemented by processors or similar hardware, they can be programmed and controlled using software (e.g., code) to perform the various functions discussed herein. Alternatively, each block, unit, and / or module may be implemented by dedicated hardware, or as a combination of dedicated hardware performing some functions and processors performing other functions (e.g., one or more programmed processors and associated circuitry). Without departing from the scope of the inventive concept, each block, unit, and / or module of some exemplary embodiments may be physically separated into two or more interacting and discrete blocks, units, and / or modules. Furthermore, blocks, units, and / or modules of some exemplary embodiments may be physically combined into more complex blocks, units, and / or modules without departing from the scope of the inventive concept.

[0032] The apparatus and method for controlling a steer-by-wire system according to the first and second embodiments of the present disclosure will now be described with reference to the accompanying drawings.

[0033] For clarity and convenience, the thickness of lines and the size of components may be exaggerated in the accompanying drawings. Furthermore, terms defined by consideration of the function of the components according to this disclosure will be used hereinafter and may vary depending on the intent of the user or administrator or practice in the art. Therefore, the terminology should be defined in the context of this specification.

[0034] Figure 1 This is a diagram illustrating a schematic configuration of an apparatus for controlling a steer-by-wire system according to a first embodiment of the present disclosure. Figure 3 It shows the control with Figure 1 The flowchart shows the method for adjusting the turning position by compensating for changes in gain x.

[0035] like Figure 1As shown, the device 100 for controlling a steer-by-wire system according to the first embodiment includes a steering angle sensor (not shown), a steering position control command receiver (receiving unit) 120, and a processor 110. The processor 110 includes a steering angle position signal calculation unit 111, a compensation gain calculation unit 112, and a steering position command calculation unit 113.

[0036] The steering angle position signal calculation unit 111 uses a steering angle sensor (not shown) included in the steering force actuator (SFA) to calculate the current steering angle position, thereby outputting a steering angle position signal y1.

[0037] Steering position control command receiver 120 receives steering position control command y2 from a designated external module (e.g., a parking assist (PA) system).

[0038] The compensation gain calculation unit 112 calculates the compensation gain x corresponding to the column torque or motor current of the steering force actuator (SFA). The compensation gain x here is a compensation gain x used to compensate for steering position control (i.e., steering angle position control) through driver involvement (i.e., driver-assisted steering) during automatic steering via a specified external module (e.g., a parking assist (PA) system).

[0039] The compensation gain calculation unit 112 uses a predetermined equation or lookup table to calculate the compensation gain x corresponding to the column torque or motor current.

[0040] The steering position command calculation unit 113 calculates the final steering position control command Y by reflecting the compensation gain x to the steering angle position signal y1 and the steering position control command y2, and outputs the final steering position control command Y to the steering force actuator (SFA).

[0041] More specifically, the steering position command calculation unit 113 calculates the final steering position control command Y by subtracting the value obtained by multiplying the steering position control command y2 by the compensation gain x (i.e., y2*x) from the value obtained by multiplying the steering angle position signal y1 by "1-compensation gain x".

[0042] Therefore, when the compensation gain x is 1, the steering angle position signal y1 is multiplied by 0. This achieves a state where driver intervention does not occur. Thus, the designated external module (e.g., the parking assist (PA) system) performs automatic steering position control only on a 100% basis. When the compensation gain x is 0, the steering angle position signal y2 is multiplied by 0. Therefore, the automatic steering position control performed by the designated external module (e.g., the parking assist (PA) system) is interrupted, and driver-initiated steering control is performed only on a 100% basis (see [link to relevant documentation]).Figure 3 )。In addition, when the compensation gain x satisfies 0 < x < 1, steering position control for compensating the steering position is performed (refer to the inclined portion in Figure 3 ).

[0043] The final steering position control command Y output from the steering position command calculation unit 113 is transmitted to the wheel actuator (RWA) through the steering force actuator (SFA), and then used to control the steering position.

[0044] At this time, when the driver's participation lasts for a predetermined time or longer, the processor 110 of the device 100 for controlling the steer-by-wire system according to the first embodiment stops the automatic steering position control by a designated external module (e.g., the parking assist (PA) system), and performs the driver-initiated steering control.

[0045] Figure 2 is a flowchart showing a method for controlling a steer-by-wire system according to a second embodiment of the present disclosure.

[0046] Refer to Figure 2 . In the method for controlling a steer-by-wire system according to the second embodiment, the steering angle position signal calculation unit 111 calculates the current steering angle position using a steering angle sensor (not shown) included in the steering force actuator (SFA), and outputs a steering angle position signal y1 (S101).

[0047] In addition, the steering position control command receiver 120 receives a steering position control command y2 from a designated external module (e.g., the parking assist (PA) system) (S102).

[0048] In addition, the compensation gain calculation unit 112 calculates a compensation gain x corresponding to the column torque or motor current of the steering force actuator (SFA) (S103).

[0049] The compensation gain x here is a compensation gain x that is used to compensate the steering position control (i.e., the steering angle position control) through the driver's participation (i.e., the driver participates in steering) during automatic steering by a designated external module (e.g., the parking assist (PA) system).

[0050] That is, the compensation gain calculation unit 112 calculates the compensation gain x corresponding to the column torque or motor current using a predetermined equation or a look-up table.

[0051] In addition, the steering position command calculation unit 113 calculates a final steering position control command Y by reflecting the compensation gain x to the steering angle position signal y1 and the steering position control command y2, and outputs the final steering position control command Y to the steering force actuator (SFA) (S104).

[0052] More specifically, the steering position command calculation unit 113 calculates the final steering position control command Y by subtracting the value obtained by multiplying the steering position control command y2 by the "compensation gain x" (i.e., y2 * x) from the value obtained by multiplying the steering angle position signal y1 by "1 - compensation gain x" (i.e., y1 * (1 - x)).

[0053] For example, when the compensation gain x is 1, the steering angle position signal y1 is multiplied by 0. Thus, a state where driver participation does not occur is achieved. Therefore, a specified external module (e.g., a parking assist (PA) system) performs automatic steering position control only on a 100% basis. When the compensation gain x is 0, the steering position control command y2 is multiplied by 0. Therefore, the automatic steering position control by the specified external module (e.g., a parking assist (PA) system) is interrupted, and the steering control initiated by the driver is performed on a 100% basis (refer to Figure 3 ).

[0054] Furthermore, when the compensation gain x is 0 < x < 1, steering position control for compensating the steering position is performed (refer to the inclined portion in Figure 3 ). That is, when the compensation gain x is 0 < x < 1, it should be noted that instead of performing automatic steering position control or driver-initiated steering control, steering control is performed using a numerical value for compensation.

[0055] The final steering position control command Y output from the steering position command calculation unit 113 is transmitted to the wheel actuator (RWA) through the steering force actuator (SFA), and then used to control the steering position.

[0056] At this time, when driver participation continues for a predetermined time or longer, the processor 110 for controlling the steer-by-wire system according to the first embodiment stops the automatic steering position control of the specified external module (e.g., a parking assist (PA) system) and performs the driver-initiated steering control (S105).

[0057] As described above, according to the second embodiment, in a steer-by-wire (SBW) steering system where the steering force actuator SFA is not mechanically connected, driver participation is detected during the steering angle position control of automatic parking, and then the steering angle position control is compensated. Thus, advantageous effects of preventing the driver from feeling being collided and preventing vehicle accidents can be achieved.

[0058] Embodiments of this disclosure are described with reference to the accompanying drawings only by way of example. Various other modifications and equivalents will be apparent to those skilled in the art to which this disclosure pertains. Therefore, the true technical scope of this disclosure should be determined by the technical solutions. The technical ideas of this disclosure described herein can be implemented in the form of, for example, methods, processes, apparatus, software programs, data streams, or signals. While the feature is described only in the context of implementation in a single form (e.g., described as implemented only as a method), it can also be implemented in different forms (e.g., as an apparatus or program). The apparatus can be implemented in the form of suitable hardware, software, firmware, etc. For example, the method can be implemented in an apparatus such as a computer, microprocessor, or processor (which generally refers to a processing device such as an integrated circuit or programmable logic device). These apparatuses also include computers, cellular phones, portable / personal information terminals (personal digital assistants (“PDAs”)), and other communication devices that facilitate information communication between end users.

Claims

1. An apparatus for controlling a steer-by-wire system, the apparatus being configured to detect driver involvement during steering angle position control during automatic parking and to compensate for the steering angle position control in the steer-by-wire system where the steering force actuator (SFA) and wheel actuator (RWA) are not mechanically connected to each other, the apparatus comprising: The steering angle sensor is configured to detect the steering angle position; A steering position control command receiver is configured to receive steering position control command y2 from a parking assist (PA) system; as well as The processor is configured to generate a steering angle position signal y1 based on the steering angle position from the steering angle sensor, calculate a compensation gain x corresponding to the column torque or motor current of the steering force actuator (SFA) when the driver engages, calculate a final steering position control command Y by reflecting the compensation gain x in the steering angle position signal y1 and the steering position control command y2, and output the final steering position control command Y to the steering force actuator (SFA).

2. The apparatus according to claim 1, wherein, The compensation gain x is used to compensate for the steering position control initiated by the driver's participation in steering during automatic steering via the parking assist (PA) system.

3. The apparatus according to claim 1, wherein, The processor uses a predetermined equation or lookup table to calculate the compensation gain x corresponding to the column torque or the motor current.

4. The apparatus according to claim 1, wherein, The processor calculates the final steering position control command Y by subtracting the value obtained by multiplying the steering position control command y2 by "compensation gain x" from the value obtained by multiplying the steering angle position signal y1 by "1 - compensation gain x".

5. The apparatus according to claim 1, wherein, The final steering position control command Y is transmitted to the wheel actuator (RWA) via the steering force actuator (SFA).

6. The apparatus according to claim 1, wherein, If the driver engages to maintain the position for a predetermined time or longer, the processor stops the automatic steering position control of the parking assist (PA) system and executes driver-initiated steering control.

7. A method for controlling a steer-by-wire system, the method comprising detecting driver involvement during steering angle position control during automatic parking and compensating for steering angle position control in the steer-by-wire system where the steering force actuator (SFA) and wheel actuator (RWA) are not mechanically connected to each other, the method comprising: The processor generates a steering angle position signal y1 based on the steering angle position from the steering angle sensor; The steering position control command y2 is received from the parking assist (PA) system by the steering position control command receiver; When the driver engages, the processor calculates a compensation gain x corresponding to the column torque or motor current of the steering force actuator (SFA); and The processor calculates the final steering position control command Y by reflecting the compensation gain x into the steering angle position signal y1 and the steering position control command y2, and outputs the final steering position control command Y to the steering force actuator (SFA).

8. The method according to claim 7, wherein, The compensation gain x is used to compensate for the steering position control initiated by the driver's participation in steering during automatic steering in the parking assist (PA) system.

9. The method according to claim 7, wherein, When calculating the compensation gain x, the processor uses a predetermined equation or lookup table to calculate the compensation gain x corresponding to the column torque or motor current.

10. The method according to claim 7, wherein, In order to calculate the final steering position control command Y, the processor calculates the final steering position control command Y by subtracting the value obtained by multiplying the steering position signal y1 by "1 - compensation gain x" from the value obtained by multiplying the steering position control command y2 by "compensation gain x".

11. The method according to claim 7, wherein, The final steering position control command Y is transmitted to the wheel actuator (RWA) via the steering force actuator (SFA).

12. The method according to claim 7, wherein, If the driver engages to maintain the position for a predetermined time or longer, the processor stops the automatic steering position control of the parking assist (PA) system and executes driver-initiated steering control.

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