Control device and control method for electric power steering system, and electric power steering system

Abstract

The embodiment relates to a control device and a control method of an electric power steering system, and the electric power steering system. A control device according to an embodiment may include: a steering controller configured to control rotation of a motor connected to a steering wheel; and a wake-up circuit configured to wake up the steering controller using a back electromotive force generated in a case where the motor is forced to rotate by an external force in an ignition-off state of the vehicle, in which the steering controller may apply a reaction torque to the motor after the wake-up to suppress the forced rotation of the motor.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a control device and a control method of an electric power steering (EPS, hereinafter referred to as "EPS") system and an electric power steering system. More specifically, embodiments of the present disclosure relate to a control device and a control method capable of waking up an electronic control unit (ECU) by motor rotation in a steer-by-wire (SBW) type EPS system and suppressing rapid steering of a steering wheel. Background Art

[0002] A steering device or a steering system is used as a device for controlling the traveling direction of a vehicle. Recently, an electric power steering (EPS) system is widely used, in which a steering motor provides necessary steering force through electronic control.

[0003] The EPS system or EPS device is operable to rotate a steering shaft of a steering column or move a rack rod connected thereto by driving a steering motor according to a steering torque applied to a steering wheel by a driver.

[0004] As an example of such an EPS system, there is a steer-by-wire (SBW) steering system which is a SBW type EPS system.

[0005] SBW steering systems may include structures that eliminate mechanical coupling devices, such as steering columns, universal joints, or pinion shafts between the steering wheel and the vehicle wheels.

[0006] The SBW steering system may generally include an upper device and a lower device that are mechanically separated from each other and a control circuit for controlling the upper device and the lower device.

[0007] In the case of the SBW steering system, since the upper device connected to the steering wheel and the lower device connected to the rack rod are mechanically separated, the steering wheel interlocked therewith can be rotated or the wheels can be steered even if the reaction force motor or the steering motor is turned off due to the vehicle ignition being turned off.

[0008] That is, even if the reaction force motor of the upper device is turned off due to the vehicle ignition being turned off, the steering wheel and the steering column are separated from the lower device, and thus the steering wheel can be rotated arbitrarily.

[0009] In addition, even if the steering motor of the lower device is turned off due to the vehicle ignition being turned off, the rack bar connected thereto can be moved left and right, so the wheels can be turned arbitrarily.

[0010] Therefore, in the SBW steering system, a locking device for forcibly locking the reaction force motor or the steering motor when the ignition of the vehicle is turned off is also required.

[0011] The locking device may be implemented as part of a steering control circuit included in a SBW steering system and may have a configuration in which, in the event of a condition requiring motor restraint, rotation of the three-phase motor is prevented by shorting the multi-phase windings of the steering motor to the same potential.

[0012] That is, in a locked state such as a case where the vehicle ignition is off, the lock circuit may operate to prevent rotation of the reaction motor or the steering motor, thereby preventing rotation of the steering wheel.

[0013] In the case of using such a lock circuit, there is a disadvantage that power consumption occurs because the lock circuit is required to operate even when the vehicle ignition is turned off and power is required.

[0014] Additionally, the control device of the EPS may be complicated because a separate locking circuit needs to be provided.

[0015] Therefore, a simple and low-power device is needed to suppress the rotation of the steering wheel of the EPS when the vehicle ignition is off. Summary of the invention

[0016] In this context, embodiments of the present disclosure provide a control device and a control method of an EPS system and an electric power steering system that can suppress the rotation of a steering wheel under a condition where the vehicle ignition is off in an electric power steering system of a vehicle.

[0017] Embodiments of the present disclosure provide a control device and a control method of an EPS system and an electric power steering system capable of restricting rotation of a steering wheel using back electromotive force generated by forced rotation of a motor included in the electric power steering system in a state where an ignition of a vehicle is off.

[0018] An embodiment of the present disclosure provides a control device and a control method for an EPS system and an electric steering system, which can, when the vehicle ignition is turned off, wake up an electronic control unit using a back electromotive force generated by forced rotation of a motor included in the electric steering system, and control the electronic control unit to provide a reaction force to the motor to limit the rotation of the steering wheel.

[0019] According to one aspect of the present disclosure, a control device for an electric steering system may be provided, the control device comprising: a steering controller configured to control the rotation of a motor connected to a steering wheel; and a wake-up circuit configured to wake up the steering controller when the ignition is off in a vehicle, using a back electromotive force generated when the motor is forced to rotate due to an external force, wherein the steering controller is configured to apply a reaction torque to the motor after waking up to suppress the forced rotation of the motor.

[0020] After waking up, the steering controller may determine a non-driving state of the vehicle based on vehicle state information received from a sensor, and apply the reaction torque to the motor only in the non-driving state.

[0021] In this case, the vehicle status information may include at least one of vehicle ignition information, vehicle speed information, vehicle door lock information, vehicle door opening information, driver boarding information, seat belt fastening information, and theft alarm function activation information.

[0022] In addition, the steering controller may include: a regulator configured to regulate a voltage from a power supply; an inverter configured to supply a control current to a winding included in the motor; a gate driver configured to control the operation of the inverter; and a microcontroller unit (MCU) configured to be driven by a driving voltage supplied from the regulator and to control the operation of the gate driver.

[0023] Furthermore, the wake-up circuit may include: a rectifier circuit configured to rectify the back electromotive force and output a DC output voltage; and a switch circuit configured to enable the regulator according to the output voltage of the rectifier circuit.

[0024] The rectifier circuit may rectify a sinusoidal back electromotive force generated during forced rotation of the motor into a DC voltage and output the output voltage.

[0025] In addition, the switching circuit may include: a first switching unit, which is turned on according to the output voltage; and a second switching unit, which is turned on when the first switching unit is turned on, and inputs a wake-up signal to an enable terminal of the regulator through the voltage of the power supply.

[0026] Meanwhile, the electric power steering system may be a steer-by-wire steering system including: an upper device including a reaction motor connected to the steering wheel; and a lower device mechanically separated from the upper device and including a steering drive motor connected to the wheels of the vehicle. In this case, the motor connected to the steering wheel may be the reaction motor included in the upper device.

[0027] In this case, the reaction torque may be a torque for rotating the reaction motor in a direction opposite to a forced rotation direction of the reaction motor.

[0028] After waking up, the steering controller may provide the reaction torque to the motor for a specific holding time and then may shut down or enter a sleep mode, and the holding time may be set to a period of 2 to 5 seconds.

[0029] According to another aspect of the present disclosure, a control method for an electric steering system may be provided, the control method comprising the following steps: a wake-up circuit wakes up a steering controller using a back electromotive force generated when a motor connected to a steering wheel is forced to rotate by an external force; and a reaction torque is generated by the steering controller during the wake-up and the reaction torque is applied to the motor to suppress the forced rotation of the motor.

[0030] In this case, the wake-up step may include the following steps: rectifying the sinusoidal back electromotive force generated during the forced rotation of the motor into a DC voltage and outputting an output voltage; and inputting a wake-up signal generated by the voltage of the power supply to an enable terminal of a regulator included in the steering controller by a switching circuit turned on by the output voltage.

[0031] The control method of the electric power steering system may further include the following steps: determining a non-driving state of the vehicle based on vehicle state information received from a sensor. In this case, the generating and applying steps may include the following steps: applying the reaction torque to the motor only in the non-driving state of the vehicle.

[0032] Additionally, the generating and applying steps may include providing the reaction torque to the motor for a specific hold time and then shutting down or entering a sleep mode.

[0033] According to another aspect of the present disclosure, an electric steering system may be provided, comprising: a motor connected to a steering wheel of a vehicle; a steering controller configured to control the rotation of the motor; and a wake-up circuit configured to wake up the steering controller when the ignition is off of the vehicle, using a back electromotive force generated when the motor is forced to rotate by an external force, wherein the steering controller is configured to apply a reaction torque to the motor after waking up to suppress the forced rotation of the motor.

[0034] In this case, the electric steering system may be a steer-by-wire steering system comprising an upper device and a lower device, the upper device comprising a reaction motor connected to the steering wheel, the lower device being mechanically separated from the upper device and comprising a steering drive motor connected to the wheels of the vehicle, and the motor connected to the steering wheel may be a reaction motor included in the upper device.

[0035] According to an embodiment of the present disclosure, the rotation of the steering wheel may be restricted under the condition that the ignition of the vehicle is turned off.

[0036] In addition, according to the embodiment of the present disclosure, the steering wheel may be prevented from rotating using a counter electromotive force generated by forced rotation of a motor included in the electric power steering system in the vehicle ignition-off state.

[0037] In addition, according to an embodiment of the present disclosure, when the vehicle ignition is off, the back electromotive force generated by the forced rotation of the motor included in the electric steering system can be used to wake up the electronic control unit, and the electronic control unit can be controlled to provide a reaction force to the motor to limit the rotation of the steering wheel.

[0038] Therefore, according to the embodiments of the present disclosure, random rotation of the steering wheel in a vehicle ignition-off state can be prevented, thereby preventing vehicle theft and maintaining vehicle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 An example of a schematic configuration of an electric power steering system is shown.

[0040] Figure 2 A schematic configuration of a SBW steering system to which the embodiments may be applied is shown.

[0041] Figure 3 A functional block diagram of a steering control device according to an embodiment is shown.

[0042] Figure 4 An example of a detailed configuration of a steering control device according to an embodiment is shown.

[0043] Figure 5 A detailed configuration of a rectifier circuit included in a wake-up circuit according to an embodiment is shown.

[0044] Figure 6 An example of a waveform of a back electromotive force generated by forced rotation of a motor is shown.

[0045] Figure 7 An example of a waveform of a DC output voltage generated by rectifying the back electromotive force by a rectifier circuit is shown.

[0046] Figure 8 An example of a detailed configuration of a switch circuit included in a wake-up circuit according to an embodiment is shown.

[0047] Fig. 9 A flowchart showing a control method of an electric power steering system according to an embodiment of the present disclosure is shown.

[0048] Fig.10 A configuration of a SBW steering system is shown, which is an example of an electric power steering system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0049] In the following description of examples or embodiments of the present disclosure, reference will be made to the accompanying drawings, in which specific examples or embodiments that can be implemented are illustrated in a schematic manner, and in the accompanying drawings, the same reference numerals and symbols may be used to indicate the same or similar components, even if they are shown in different drawings from each other. In addition, in the following description of examples or embodiments of the present disclosure, when it is determined that a detailed description of the well-known functions and components incorporated herein may make the subject matter in some embodiments of the present disclosure unclear, the description will be omitted. Terms such as "including", "having", "containing", "consisting of", "consisting of", and "formed of" used herein are generally intended to allow the addition of other components unless the term is used together with the term "only". As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise.

[0050] Terms such as "first", "second", "A", "B", "(A)" or "(B)" may be used herein to describe elements of the present disclosure. Each of these terms is not used to define the nature, order, sequence or quantity of an element, but is merely used to distinguish the corresponding element from other elements.

[0051] When it is mentioned that a first element is “connected or coupled to”, “contacts or overlaps”, etc. a second element, it should be interpreted that not only the first element may be “directly connected or coupled to” or “directly contact or overlaps” the second element, but also a third element may be “interposed” between the first element and the second element, or the first element and the second element may be “connected or coupled to”, “contacts or overlaps”, etc. each other via a fourth element. Here, the second element may be included in at least one of the two or more elements that are “connected or coupled to”, “contacts or overlaps”, etc. each other.

[0052] When time-related terms such as “after,” “subsequently,” “next,” “before,” etc. are used to describe a process or operation of an element or configuration, or a flow or step in an operation, process, or method of manufacture, these terms may be used to describe a non-sequential or non-sequential process or operation unless the terms “directly” or “immediately” are used together.

[0053] Furthermore, when any dimension, relative dimension, etc. is mentioned, it should be considered that the numerical value of an element or feature, or corresponding information (e.g., level, range, etc.) includes a tolerance or error range that may be caused by various factors (e.g., process factors, internal or external impact, noise, etc.), even when no relevant description is specified. In addition, the term "may" fully encompasses all meanings of the term "can".

[0054] Figure 1 An example of a schematic configuration of an electric power steering system is shown.

[0055] A steering device or a steering system may be used as a device for controlling a driving direction of a vehicle, and recently, an electric power steering (EPS) system in which a steering motor provides necessary steering force through electronic control is widely used.

[0056] The EPS system or EPS device is operable to rotate a steering column or move a rack rod connected to the steering column by driving an EPS steering motor according to a steering torque applied to a steering wheel by a driver.

[0057] The EPS system in which the steering motor rotates the steering column can be referred to as a column-type EPS system or a C-type EPS system. In the C-type EPS system, the steering column can be connected to a universal joint and a pinion gear, and the pinion gear can be coupled to a rack of a rack bar connected to the wheels of the vehicle.

[0058] Figure 1 A C-type EPS system is shown, and may include a steering column 30 connected to a steering wheel 20, a sensor unit 40 mounted on the steering column, a steering motor 70 for rotating the steering column, and an electronic control unit (ECU) 10 as a steering controller or a steering control circuit for controlling the steering motor. A specific speed reducer may be connected to the steering motor, and the speed reducer may be interlocked between the steering column and the steering motor.

[0059] The steering column 30 may be coupled to the steering wheel 20 and may rotate together with the steering wheel 20. The shape of the steering column 30 may be cylindrical.

[0060] Although not shown, the steering column 30 may be interlocked with one or more speed reducers, and any one of the plurality of speed reducers may be coupled to the outer peripheral surface of the steering column 30 .

[0061] The sensor unit 40 may include a steering angle sensor, a torque sensor, and a vehicle speed sensor.

[0062] The steering angle sensor may detect a steering angle generated by rotation of the steering wheel 20. In addition, the steering angle sensor may output a steering angle signal indicating information on the steering angle.

[0063] The torque sensor may detect a steering torque generated by the rotation of the steering wheel 20. In addition, if the steering torque is detected, the torque sensor may output a steering torque signal indicating information about the steering torque.

[0064] Here, the steering torque may refer to a rotation torque acting on a torsion bar existing between an input shaft and an output shaft of the steering column 30. Therefore, the steering torque may be detected even if the steering wheel 20 is not rotated.

[0065] The vehicle speed sensor may detect the speed of the vehicle and output a vehicle speed signal indicating information about the vehicle speed.

[0066] The steering controller or ECU 10 may receive the steering information, calculate a target rack position for providing a steering assist force based on the steering information, and output a command current corresponding to the rack position to the steering motor 70. Here, the steering information may include one or more of a steering angle signal output by a steering angle sensor, a steering torque signal output by a torque sensor, and a vehicle speed signal output by a vehicle speed sensor.

[0067] The ECU 10 may be implemented with hardware and software including a micro control unit (MCU), an inverter, a printed circuit board (PCB), and the like.

[0068] The steering motor 70 may receive a command current from the ECU 10 and be driven at a torque and a rotation speed according to the command current. Although not shown, the steering motor 70 may be coupled to a speed reducer provided on the steering column 30. The rotation of the steering motor 70 may rotate the speed reducer and the steering column interlocked with the steering column 30.

[0069] Meanwhile, the steering column may be rotated by the rotation of the steering motor 70 , and thus, the rack bar connected to the pinion gear at the output end of the steering column may move left and right.

[0070] Therefore, the vehicle can be steered by moving the wheels connected to both ends of the rack bar to the left or right.

[0071] The steering motor 70 included in the C-type EPS system may be a three-phase motor, but is not limited thereto.

[0072] The ECU 10 may perform the following functions: receive power from a power supply unit (not shown); generate a target current to be supplied to each winding of the steering motor using an inverter; and supply the target current to the steering motor.

[0073] In the C-type EPS system, when the steering motor 70 rotates the steering column 30 to apply steering assist force, the steering assist force can be transmitted to the rack bar 12 through the pinion-rack gear. When the rack bar moves left and right, the wheels connected thereto can be steered left and right.

[0074] Meanwhile, an EPS system in which a steering motor directly moves a rack bar connected to a wheel may be referred to as a rack-type EPS system or an R-type EPS system.

[0075] In the R-type EPS system, the steering motor and the rack bar can be connected by a belt or gear, and a speed reducer such as a ball nut is connected between them. When the steering motor rotates, the ball nut speed reducer connected to the rack bar rotates, and the rack bar can move left and right according to the rotation of the speed reducer to steer the wheel.

[0076] Figure 2 A schematic configuration of a SBW steering system to which the embodiments may be applied is shown.

[0077] As an example of the EPS system, there is a steer-by-wire (SBW) steering system which is a SBW type EPS system.

[0078] The SBW steering system may include a configuration in which a mechanical coupling device such as a steering column, a universal joint, or a pinion shaft between the steering wheel and the wheels is removed.

[0079] Reference Figure 2 , the SBW steering system to which the embodiments of the present disclosure may be applied may include an upper device 110 and a lower device 120 that are mechanically separated from each other, and a control device 130 for controlling the upper device 110 and the lower device 120 .

[0080] The upper device 110 may include a steering wheel 112, a steering column 113 connected to the steering wheel, a torque sensor 155 for detecting torque applied to the steering wheel, a reaction motor 117 as a motor device for providing a reaction force torque to the steering wheel through a lower rack bar according to steering, and an upper ECU 119 for controlling the reaction force motor. The upper device 110 may be referred to as a steering feedback actuator (SFA).

[0081] In addition, the lower device 120 may include a rack bar 122 connected to a wheel 128 of the vehicle, a steering drive motor 127 for moving the rack bar left and right, and a lower ECU 129 for controlling the steering drive motor.

[0082] The lower ECU 129 of the lower device 120 may generate a steering assist torque signal proportional to the steering torque applied to the steering wheel, and generate a drive signal for moving the rack bar of the tie rod connected to the wheel leftward and rightward by using the steering assist torque signal.

[0083] The lower device 120 may control the steering drive motor through the ball nut reducer based on the drive signal. The lower device may be referred to as a travel wheel actuator (RWA).

[0084] That is, in the SBW steering system, the upper device including the steering wheel, steering column and reaction force motor and the lower device including the rack bar drive device (ie, pinion gear, ball nut and steering drive motor) can be independently operated without intermediate mechanical connection.

[0085] Therefore, in order to provide the driver with a steering feel, it is necessary to rotate the steering wheel connected to the upper device according to the movement of the rack bar of the lower device that performs the actual steering. In this case, the force or torque applied to the steering wheel can be defined as a reaction force or reaction torque.

[0086] Meanwhile, when the engine of the vehicle is turned off or in a case where the ignition of the vehicle is turned off, the steering system is required not to operate.

[0087] That is, if the steering wheel is rotated in a state where the vehicle engine is turned off or the vehicle ignition is turned off to allow the wheels to rotate, a problem may arise in which the wheels of the stopped or parked vehicle are arbitrarily turned.

[0088] Therefore, if the steering wheel is turned with the vehicle ignition off, the vehicle may be turned, which may make vehicle theft easier and reduce the stability of a parked vehicle.

[0089] Therefore, when the engine of the vehicle is turned off or with the ignition of the vehicle turned off, it is necessary to lock the steering wheel.

[0090] At the same time, in the C-type EPS system or the R-type EPS system, even if the steering motor is turned off due to the vehicle ignition being turned off, the steering wheel can be automatically locked because the mechanical structures such as the steering column, rack rod and reducer are interlocked between the steering wheel and the wheels.

[0091] However, in the case of the SBW steering system, the upper device connected to the steering wheel and the lower device connected to the rack bar are mechanically separated. Therefore, even if the reaction force motor or the steering motor is turned off due to the vehicle ignition being turned off, the steering wheel connected to the upper device can be rotated or the wheels connected to the lower device can be steered.

[0092] That is, even if the reaction force motor of the upper device is turned off due to the vehicle ignition being turned off, the steering wheel and the steering column are separated from the lower device, and thus the steering wheel can be rotated arbitrarily.

[0093] In addition, even if the steering motor of the lower device is turned off due to the vehicle ignition being turned off, the rack bar connected thereto can be moved left and right, so that the wheels can be steered arbitrarily.

[0094] That is, unlike the C-type EPS system or the R-type EPS system, in the case of the SBW steering system, when the vehicle ignition is turned off, a lock function that restricts the rotation of the steering wheel or the movement of the rack bar needs to be implemented separately.

[0095] Therefore, the SBW steering system needs to have a locking device that forcibly locks the reaction force motor or the steering motor when the vehicle ignition is turned off.

[0096] As an example of such a locking device, a separate clutch device may be provided to mechanically connect the upper device and the lower device.

[0097] As another example of a locking device, a key locking solenoid device may be provided for locking the steering column with the vehicle ignition turned off.

[0098] As another example of the locking device, a locking device including a locking circuit for limiting the rotation of the motor can be used. In this case, the locking circuit can be powered regardless of whether the vehicle ignition is turned off, and the locking circuit can prevent the motor from rotating by short-circuiting the winding of the motor.

[0099] Generally, a motor used in a steering system may be a three-phase motor including a u-phase, a v-phase, and a w-phase and corresponding u-phase coils, v-phase coils, and w-phase coils.

[0100] In the case of such a three-phase motor, if the input terminal of each phase coil is floating, the three-phase motor can rotate arbitrarily.

[0101] Therefore, with the vehicle ignition turned off, the input terminal of the three-phase steering motor (particularly the SBW steering motor) included in the EPS system may float, and the steering motor rotates arbitrarily accordingly, causing a problem with vehicle stability.

[0102] Therefore, it is possible to provide a lock circuit capable of preventing the motor from rotating by short-circuiting the input terminals of the three-phase coils of the reaction force motor or the steering motor included in the SBW steering system to the same potential when the vehicle ignition is turned off.

[0103] Meanwhile, the EPS system including the SBW steering system may include a steering control circuit for controlling a steering motor.

[0104] Specifically, in order to drive / control the steering motor, the SBW steering controller may include a power supply unit and a steering control circuit to supply a driving current to the steering motor.

[0105] The steering control circuit can also be expressed as a steering controller, a steering ECU, etc.

[0106] Generally, a steering control circuit included in an EPS system may include an inverter composed of a plurality of switching devices or switching elements and an inverter driving circuit or a gate driving circuit for controlling the inverter.

[0107] In particular, the steering control circuit included in the SBW steering system may include, in addition to the inverter and the inverter drive circuit (or gate drive circuit), a locking circuit for preventing rotation of the steering motor or the reaction force motor when the vehicle ignition is turned off, as described above.

[0108] Such a lock circuit can be turned on by a lock signal provided from a steering controller in a state where the vehicle ignition is off, and can prevent the motor from rotating by short-circuiting a multi-phase winding of a reaction motor or a steering motor.

[0109] The lock circuit needs to operate when the vehicle ignition is turned off, and thus there is a disadvantage in that power for operating the lock circuit is consumed even if the vehicle ignition is turned off.

[0110] Furthermore, since a separate locking circuit needs to be provided, the steering control device of the electric power steering system may be complicated.

[0111] Therefore, hereinafter, a steering control device is proposed which is simple and can be operated with low power consumption to restrict the rotation of an EPS steering wheel with the ignition of the vehicle turned off.

[0112] Figure 3 A functional block diagram of a steering control device according to an embodiment is shown.

[0113] Reference Figure 3 , a steering control device according to an embodiment may include: a steering controller 200 that controls rotation of a motor 400 connected to a steering wheel; and a wake-up circuit 300 that wakes up the steering controller using back electromotive force.

[0114] The wake-up circuit 300 may wake up the steering controller using the back electromotive force generated when the motor is forced to rotate by an external force in a vehicle ignition-off state.

[0115] More specifically, the wake-up circuit 300 may include: a rectifier circuit 310, which is used to rectify the three-phase back electromotive force (EMF) voltage of the sinusoidal wave and output a direct current (DC) voltage higher than a specific threshold; and a switching circuit 330, which is turned on using the output signal from the rectifier circuit to wake up the steering controller.

[0116] Reference below Figure 6 An example of a detailed configuration of the wake-up circuit 300 is described in more detail.

[0117] In addition, the steering controller 200 may determine the non-driving state of the vehicle based on the vehicle state information I_state received from the sensor 500 after waking up.

[0118] In this case, the steering controller 200 may apply the reaction torque to the motor 400 only when it is determined that the vehicle is in a non-driving state.

[0119] In this case, the vehicle status information may include at least one of vehicle ignition information, vehicle speed information, vehicle door lock information, vehicle door opening information, driver boarding information, seat belt fastening information, and theft alarm function activation information.

[0120] Therefore, the sensor 500 may include a vehicle ignition detection sensor, a vehicle speed sensor, a door sensor, a weight detection sensor or an image sensor for detecting a driver getting on the vehicle, a seat belt fastening detection sensor, a theft alarm detection sensor, and the like.

[0121] The vehicle status information may be transmitted to the steering controller 200 via a vehicle controller area network (CAN) communication network connected to each sensor.

[0122] Specifically, the steering controller 200 can determine that the vehicle is in a non-driving state if at least one of the following conditions is met: the vehicle ignition information indicates that the ignition is off, the vehicle speed information indicates that the vehicle is stopped, and the vehicle door lock information indicates that the door lock is locked, the vehicle door opening information indicates that one or more of the doors are open, the driver boarding information indicates that the driver or passenger is not in the vehicle, the seat belt fastening information indicates that the seat belt is not fastened, and the theft alarm function activation information indicates the activation state of the vehicle anti-theft device in the vehicle.

[0123] As an example, after waking up, the steering controller 200 may generate a reaction torque and apply the reaction torque to the motor only when the vehicle ignition is off and the vehicle is not driving.

[0124] As another example, if the vehicle status information indicates that the vehicle is in a non-driving state, a steering controller awakened in a vehicle ignition-off state may apply a reaction torque to the motor to prevent rotation of the steering wheel even if the vehicle is subsequently in a vehicle ignition-on state.

[0125] This is because, for example, in the case where the steering controller is awakened due to forced rotation of the steering wheel, if the vehicle is in an abnormal driving state, such as a vehicle stopped state, a vehicle door open state, a vehicle door locked state, an occupant absent state, a seat belt unfastened state, an activated state of a vehicle anti-theft device, then it is necessary to restrict the rotation of the steering wheel, even if the vehicle is subsequently in a vehicle ignition on state due to an unqualified person attempting to start the vehicle or attempting to remotely start the vehicle.

[0126] In addition, according to an embodiment, the determination of the vehicle non-driving state and the application of the reactive torque may be performed only within a specific period of time after the steering controller wakes up.

[0127] This is because, if the steering controller is awakened by forced rotation of the steering wheel, it is not necessary to determine the non-driving state and apply the reaction torque after entering the normal vehicle ignition-on state and starting normal driving of the vehicle.

[0128] For example, if the legitimate driver forcibly rotates the steering wheel before turning on the vehicle ignition, according to this embodiment, even if the steering controller is awakened, there is no need to apply reaction torque, so the non-driven state of the vehicle can be determined and reaction torque is only applied within a specific threshold time period.

[0129] Meanwhile, the steering controller 200 according to this embodiment may include a regulator (REG), an inverter, a gate driver, and a micro control unit (MCU). Figure 4 The detailed configuration of the steering controller 200 is described in more detail.

[0130] The electric steering system including the steering control device according to the present embodiment may be a general electric steering system, such as a C-type EPS system, an R-type EPS system, etc. In this case, the motor may be a steering motor for rotating a steering column or a rack bar to steer the wheels of the vehicle.

[0131] Alternatively, the steering control device according to the present embodiment may be applied to a steer-by-wire (SBW) type steering system.

[0132] In particular, the steering control device according to the present embodiment can be applied to an upper device constituting an SBW steering system. In this case, the motor can be a reaction motor included in the upper device of the SBW steering system.

[0133] For example, the electric power steering system according to the embodiment may be a steer-by-wire steering system including an upper device including a reaction motor connected to a steering wheel and a lower device that is mechanically separated from the upper device and includes a steering drive motor connected to a wheel of the vehicle. In this case, the motor connected to the steering wheel may be a reaction motor included in the upper device.

[0134] In this case, the reaction torque may be a torque for rotating the reaction motor in a direction opposite to the forced rotation direction of the reaction motor.

[0135] More specifically, if Figure 2As shown, the SBW steering system including the steering control device according to the embodiment may include an upper device 110 and a lower device 120 mechanically separated from each other and a control device 130 for controlling the upper device and the lower device. The control device 130 may be denoted as a domain control unit (DCU).

[0136] Specifically, the upper device 110 may include a steering wheel 112, a steering column 113 connected to the steering wheel, a torque sensor 115 for detecting the torque applied to the steering wheel, a reaction motor 117 as a motor device that provides a reaction torque to the steering wheel according to the steering through the rack rod, and an upper ECU 119 for controlling the reaction motor.

[0137] In addition, the lower device 120 may include a rack bar 122 connected to a wheel 128 , a steering drive motor 127 for moving the rack bar left and right, and a lower ECU 129 .

[0138] The lower ECU 129 of the lower device 120 may generate a steering assist torque signal proportional to the steering torque applied to the steering wheel, and use the steering assist torque signal to generate a drive signal to move the rack bar of the tie rod connected to the wheel left and right.

[0139] In particular, the steering control device according to the present embodiment can be applied to a structure such as Figure 2 The upper device 110 of the SBW steering system is shown.

[0140] In this case, the motor 400 may be the reaction motor 117 included in the upper device 110 of the SBW steering system, and the steering controller 200 may be the upper ECU 119 included in the upper device 110 of the SBW steering system.

[0141] That is, included in Figure 3 The motor 400 and the steering controller 200 in the steering control device shown may be respectively included in Figure 2 The reaction motor 117 and the upper ECU 119 in the upper device 110 of the SBW steering system are shown.

[0142] The present disclosure is not limited thereto, and the control device according to the embodiment may be applied to the lower device 120 of the SBW steering system.

[0143] In this case, including Figure 3 The motor 400 in the steering control device shown may be included in Figure 2 The steering drive motor 127 in the lower device 120 of the SBW steering system is shown.

[0144] In this case, the upper ECU 119 or the lower ECU 129 can be awakened by the back electromotive force generated when the steering drive motor 127 is forcibly rotated.

[0145] The awakened upper ECU 119 or lower ECU 129 may provide a reaction torque to the reaction motor 117 or the steering drive motor 127 to suppress forced rotation.

[0146] In the case of a parked vehicle with the vehicle ignition off, the wheels may be turned due to an abnormal change in the parking space (parking tower, etc.) or a vehicle theft attempt.

[0147] In this case, the steering drive motor 127 connected to the wheel may be forced to rotate, and thus, a counter electromotive force may be generated in the winding of the steering drive motor 127 .

[0148] Therefore, in the same manner as described above, the upper ECU 119 of the upper device or the lower ECU 129 of the lower device can be awakened by using the back electromotive force generated in the winding of the steering drive motor 127.

[0149] When the steering wheel is forcibly rotated by external force, back electromotive force may be generated in the reaction motor 117 of the upper device 110 , and when the wheel is forcibly turned by external force, back electromotive force may be generated in the steering drive motor 127 of the lower device 120 .

[0150] Therefore, the control device according to the embodiment can use the back electromotive force generated from one of the reaction motor 117 or the steering drive motor 127 of the SBW steering system to wake up the upper ECU 119 or the lower ECU 129, and can provide a reaction torque to the reaction motor 117 or the steering drive motor 127 for suppressing forced rotation.

[0151] For example, if it is extremely necessary to suppress the rotation of the steering wheel when the vehicle ignition is off, the control device can use the back electromotive force generated from the reaction motor 117 or the steering drive motor 127 of the SBW steering system to wake up the upper ECU 119, and provide a reaction torque to the reaction motor 117 connected to the steering wheel to suppress the forced rotation.

[0152] Alternatively, if there is a greater need to suppress random steering of the wheels when the vehicle ignition is off, the control device can use the back electromotive force generated from the reaction motor 117 or the steering drive motor 127 of the SBW steering system to wake up the lower ECU 129, and provide a reaction torque to the steering drive motor 127 connected to the wheels for suppressing forced rotation.

[0153] Meanwhile, the steering controller 200 may include a regulator, an inverter, a gate driver and a microcontroller unit, and the wake-up circuit 300 according to the present embodiment may wake up the steering controller 200 by turning on the regulator included in the steering controller 200 and using the back electromotive force generated by the forced rotation of the motor.

[0154] The following will refer to Figure 4 An example of a detailed configuration of the steering controller 200 is described in more detail.

[0155] Meanwhile, the reaction torque applied to the motor 400 by the wake-up steering controller 200 may be a torque that rotates the reaction motor 400 in a direction opposite to the forced rotation direction of the motor 400 .

[0156] That is, the steering controller 200 awakened by the forced rotation of the motor in a vehicle ignition-off state may determine a reaction torque for suppressing the forced rotation of the motor, generate a command current corresponding to the reaction torque, and supply the command current to the winding of the motor.

[0157] The magnitude of the reaction torque may be proportional to the rotation torque caused by the forced rotation of the motor, and the direction of the reaction torque may be opposite to the direction of the rotation torque caused by the forced rotation of the motor. For example, the magnitude of the reaction torque may be determined to be proportional to the magnitude of the back electromotive force generated by the forced rotation of the steering wheel.

[0158] As a result, rotation of the steering wheel due to external force in the ignition-off state of the vehicle can be suppressed.

[0159] Additionally, after providing reaction torque to the motor for a specific hold time after being awakened, the steering controller may be shut down or may enter a sleep mode.

[0160] In this case, the holding time may be set to a period of 2 to 5 seconds.

[0161] The hold time can also be expressed as the latch delay time.

[0162] To provide the hold time, the steering controller 200 may include a separate latching circuit or a delay circuit.

[0163] By using the hold time, even if the back EMF disappears after the steering controller wakes up, stability can be further ensured by providing reaction torque to the motor and preventing the steering wheel from rotating for only a specific period of time.

[0164] Figure 4 An example of a detailed configuration of a steering control device according to an embodiment is shown.

[0165] The steering control device according to the embodiment may include a steering controller 200 for controlling the rotation of a motor 400 connected to a steering wheel, and a wake-up circuit 300 for waking up the steering controller 200 using a counter electromotive force generated by forced rotation of the motor due to an external force in a vehicle ignition-off state. In this case, the steering controller 200 may apply a reaction torque to the motor after waking up to suppress forced rotation of the motor.

[0166] Reference Figure 4 The steering controller 200 included in the steering control device according to the embodiment may be represented as an ECU, and may include a regulator 210 , an inverter 220 , a gate driver 230 , and a micro control unit (MCU) 240 .

[0167] The regulator 210 may receive a battery voltage V_BAT from a vehicle power source, and regulate the battery voltage to output a driving voltage for driving the MCU 440 .

[0168] The regulator 210 may include an enable terminal EN through which an enable signal for enabling the regulator is input.

[0169] The inverter 220 may perform a function of supplying a control current to a winding included in the motor 400 .

[0170] The inverter 220 may convert a battery voltage V_BAT of a battery serving as a vehicle power source into alternating current (AC), which is direct current (DC) or a driving voltage of a DC output from the regulator 210 , and may apply the converted AC voltage (or AC current) to the motor 400 .

[0171] As an example, the motor is a reaction motor ( Figure 2 117) and the vehicle is in a driving state, the inverter 220 can apply a driving current capable of providing a reaction torque to be applied to the steering wheel to the motor 400 so as to rotate the steering wheel in response to the steering of the wheels by the lower device.

[0172] The inverter may be controlled by a gate driver 230 , which will be described below, and the gate driver 230 may be controlled by an MCU 240 .

[0173] Meanwhile, the motor 400 controlled by the steering control device according to the embodiment of the present disclosure may be a three-phase motor having u-phase, v-phase, and w-phase.

[0174] In this case, if Figure 4As shown, the inverter 220 may include an H-bridge circuit for supplying u-phase driving current, v-phase driving current and w-phase driving current to the three-phase windings (u winding, v winding and w winding) of the motor 400, respectively.

[0175] The gate driver 230 may control driving of the inverter 220 .

[0176] Specifically, the gate driver 230 may input control signals to gate terminals of the u circuit switch, the v circuit switch, and the w circuit switch included in the inverter 220 to control the inverter 220 to supply u phase driving current, v phase driving current, and w phase driving current to the motor 400 .

[0177] The MCU 240 may control the operation of the gate driver 230 with the driving voltage supplied from the regulator 210 .

[0178] Specifically, the MCU 240 may generate a gate driver enable signal to activate the gate driver 230 and supply the gate driver enable signal to the gate driver 230 .

[0179] As a result, in a normal driving state of the vehicle, the MCU 240 can generate a control signal capable of generating a reaction torque corresponding to the wheel steering through the lower device of the SBW steering system, and transmit the control signal to the gate driver 230. The gate driver 230 can control the inverter 220 to supply a driving current corresponding to the reaction torque of the control signal to the motor 400.

[0180] Meanwhile, if the vehicle ignition is turned off, the battery voltage V_BAT may not be supplied to the regulator 210 , and thus the steering controller 200 is turned off.

[0181] In this case, the three-phase winding of the motor 400 may be in a floating state, so the rotor of the motor 400 may be freely rotated by an external force. Therefore, the steering wheel connected to the motor 400 may also be freely rotated, which may reduce the vehicle stability.

[0182] Therefore, the steering control device according to the embodiment of the present disclosure can wake up the steering controller 200 in the vehicle ignition-off state, and apply a reaction torque to the motor to suppress the rotation of the motor due to the external force, thereby preventing the rotation of the steering wheel.

[0183] Specifically, the wake-up circuit 300 may wake up the steering controller 200 in a shutdown state or a sleep state by using a back electromotive force generated when the motor is forcibly rotated by an external force.

[0184] The awakened steering controller 200 may apply a reaction torque for suppressing forced rotation of the motor to the motor.

[0185] Hereinafter, the wake-up circuit 300 and the wake-up operation of the steering controller using the wake-up circuit will be described.

[0186] Reference Figure 4 The wake-up circuit 300 may include a rectifier circuit 310 that rectifies the back electromotive force and a switch circuit 330 that generates and outputs a wake-up signal Swu to wake up the steering controller 200 according to an output voltage of the rectifier circuit.

[0187] As an example, the switch circuit 330 may be turned on by the DC output voltage output from the rectifier circuit 310 , and generate a wake-up signal Swu for enabling the regulator 210 included in the steering controller 200 , and input the wake-up signal Swu to the enable terminal EN of the regulator 210 .

[0188] The following will refer to Figures 5 to 8 An example of a detailed configuration of the wake-up circuit 300 is described in more detail.

[0189] Figure 5 shows a detailed configuration of a rectifier circuit included in a wake-up circuit according to an embodiment, Figure 6 An example of a waveform of the back electromotive force generated by the forced rotation of the motor is shown, Figure 7 An example of a waveform of a DC output voltage generated by rectifying the back electromotive force by the rectifier circuit is shown.

[0190] Reference Figure 5 The rectifier circuit 310 included in the wake-up circuit according to the embodiment may be connected to the three-phase windings of the motor and may receive sinusoidal back electromotive force signals SIN_u, SIN_v, and SIN_w generated by forced rotation of the motor from each winding.

[0191] The rectifier circuit 310 may include two diodes corresponding to each phase and a plurality of resistance elements in order to rectify the sinusoidal back-EMF signal of each phase SIN_u, SIN_v, and SIN_w.

[0192] Reference Figure 5 Each of the sinusoidal back electromotive force signals SIN_u, SIN_v, and SIN_w generated in each phase of the motor may be rectified by a rectifier circuit element including two diodes to generate an output signal DC, which is a direct current voltage V_DC.

[0193] Hereinafter, as an example, a case where forced rotation of the motor occurs due to an external force 0.5 seconds after ignition is turned off will be described.

[0194] Reference Figure 6, when the motor is not forced to rotate, a back electromotive force close to 0 is generated. After the forced rotation of the motor due to external force occurs (at a time point of about 0.5 seconds), sinusoidal back electromotive force signals SIN_u, SIN_v, and SIN_w with an amplitude of about 0.6V and a period of about 0.2 seconds can be generated from the winding of each phase of the motor.

[0195] If the sinusoidal back-EMF signals SIN_u, SIN_v and SIN_w generated in each phase winding are Figure 5 The rectifier circuit shown in FIG. 1 generates a direct current (DC) voltage V_DC having a voltage above a specific threshold voltage of 0.4 V. Figure 7 shown.

[0196] In this case, the amplitude and period of the sinusoidal back electromotive force signal generated from each phase winding may be varied according to the rotation speed, change in angular velocity, or rotation torque of the forced rotation of the motor.

[0197] Furthermore, the amplitude of the DC voltage V_DC rectified by the rectifier circuit 310 (ie, the amplitude of the output signal DC) may also vary according to the rotation speed of the motor forced rotation, the change in angular velocity or the rotation torque, and the resistance value of the resistance element.

[0198] However, the magnitude of the DC voltage V_DC rectified by the rectifier circuit 310 (ie, the potential difference of the output signal DC of the rectifier circuit 310 ) may be greater than a threshold voltage capable of turning on the first switching unit TR1 of the switch circuit 330 , which will be described below.

[0199] Figure 8 An example of a detailed configuration of a switch circuit included in a wake-up circuit according to an embodiment is shown.

[0200] Reference Figure 8 , the switch circuit 330 included in the wake-up circuit according to the present embodiment may include: a first switch unit TR1, which is turned on according to the output voltage DC of the rectifier circuit 310; a second switch unit TR2, which is turned on in response to the turning on of the first switch unit; and a plurality of resistance elements.

[0201] When the first switching unit TR1 is turned on, the second switching unit TR2 may be turned on, and the wake-up signal Swu is input to the steering controller 200 through the voltage V_BAT of the power source to wake up the steering controller 200 .

[0202] Specifically, the second switching unit TR2 may transmit the wake-up signal Swu corresponding to the battery voltage V_BAT as the voltage of the power supply unit to the enable terminal EN of the regulator 210 included in the steering controller 200 .

[0203] In addition, the first switching unit TR1 and the second switching unit TR2 may be transistors or FETs having a gate terminal, a source terminal, and a drain terminal, but are not limited thereto.

[0204] As an example, a gate terminal of the first switching unit TR1 included in the switching circuit 330 may be connected to an output terminal of the rectifier circuit 310 to receive the output signal DC of the rectifier circuit 310 .

[0205] The second switching unit TR2 may be connected to the first switching unit TR1 , and may be turned on when the first switching unit TR1 is turned on.

[0206] As an example, Figure 8 As shown, a source terminal of the second switching unit TR2 may be connected to the battery voltage V_BAT of the power supply unit, and a drain terminal of the second switching unit TR2 may be connected to an enable terminal of the regulator 210 included in the steering controller 200 .

[0207] In addition, a drain terminal of the first switching unit TR1 may be connected to a gate terminal of the second switching unit TR2 , and a source terminal of the first switching unit TR1 may be grounded.

[0208] In this switching circuit 330 , if a counter electromotive force is generated due to forced rotation of the motor, the output signal DC of the rectifier circuit 310 higher than a certain threshold voltage may be input to the gate terminal of the first switching unit TR1 .

[0209] In this case, the threshold voltage may be a gate-source threshold voltage capable of turning on the first switching unit TR1 .

[0210] If the voltage of the output signal DC of the rectifier circuit 310 is less than the threshold voltage of the first switch unit TR1, a separate boost circuit may be further provided to boost the output signal DC to be higher than the threshold voltage. For example, a boost circuit (not shown) may be provided between the rectifier circuit 310 and the first switch unit TR1, and may boost the voltage of the output signal DC from the rectifier circuit 310 to be higher than the gate-source threshold voltage of the first switch unit TR1.

[0211] In this case, the output signal of the rectifier circuit 310 may be input to the boost circuit, and the output signal of the boost circuit may be input to the gate terminal of the first switching unit TR1 of the switch circuit 330 .

[0212] Therefore, the first switching unit TR1 may be turned on, and a voltage signal higher than a certain level may also be applied to the gate terminal of the second switching unit TR2.

[0213] The second switching unit TR2 may also be turned on, and the battery voltage V_BAT of the power supply unit may be input to the enable terminal of the regulator 210 connected to the drain terminal of the second switching unit TR2 .

[0214] If the regulator 210 is enabled, as Figure 4 As shown, the driving voltage rectified from the regulator may be applied to the MCU 240 to wake up the steering controller 200 .

[0215] After waking up, the steering controller 200 may determine a non-driving state of the vehicle based on vehicle state information I_state received from the sensor.

[0216] In this case, the steering controller 200 may apply a reaction torque opposite to the external force causing the forced rotation of the motor to the motor only when it is determined that the vehicle is in a non-driving state.

[0217] As a result, even if forced rotation of the motor is attempted by external force in the vehicle ignition-off state, the steering wheel can be prevented from rotating arbitrarily.

[0218] Fig. 9 A flowchart showing a control method of an electric power steering system according to an embodiment of the present disclosure is shown.

[0219] Reference Fig. 9 According to an embodiment, a control method of an electric steering system may include step S910 and step S930, in which the wake-up circuit wakes up the steering controller using the back electromotive force generated when the motor connected to the steering wheel is forced to rotate by an external force, and in step S930, the awakened steering controller generates a reaction torque for suppressing the forced rotation of the motor and applies the reaction torque to the motor.

[0220] In addition, the control method of the electric power steering system according to the embodiment may further include step S920, in which the awakened steering controller determines a non-driving state of the vehicle based on vehicle state information received from the sensor.

[0221] In this case, if it is determined in step S920 that the vehicle is in a non-driving state, step S930 of applying a reaction torque to the motor may be performed.

[0222] The vehicle status information may be one or more of vehicle ignition information, vehicle speed information, vehicle door lock information, vehicle door opening information, driver entry information, seat belt fastening information, and theft alarm function activation information.

[0223] The wake-up circuit for performing step S910 of waking up the steering controller may include a rectifier circuit that rectifies the back electromotive force and a switch circuit that enables the regulator according to an output voltage of the rectifier circuit.

[0224] For example, in step S910 of waking up the steering controller, a rectifier circuit included in the wake-up circuit may rectify a sinusoidal back electromotive force generated during forced rotation of the motor into a direct current DC voltage to output an output voltage.

[0225] Furthermore, the step S910 of waking up the steering controller may include the step of inputting a wake-up signal generated by the power supply voltage to an enable terminal of a regulator included in the steering controller through a switch circuit turned on by the output voltage.

[0226] To this end, the switching circuit may include a first switching unit that is turned on according to the output voltage and a second switching unit that is turned on in response to the turning on of the first switching unit and inputs a wake-up signal to an enable terminal of the regulator based on the voltage of the power supply.

[0227] In addition, in the step of applying the reaction torque to the motor S930, the wake-up steering controller may provide the reaction torque to the motor for a specific holding time and then shut down or enter a sleep mode (S940, S950).

[0228] In this case, the holding time may be expressed as a latching delay time, and may be set to a period of approximately 2 seconds to 5 seconds.

[0229] Meanwhile, the electric power steering system to which the method according to the present embodiment is applied may be a SBW steering system.

[0230] That is, the electric steering system or the electric power steering system may include an upper device and a lower device, the upper device including a reaction motor connected to the steering wheel, the lower device being mechanically separated from the upper device and including a steering drive motor connected to the wheels. The motor connected to the steering wheel may be a reaction motor included in the upper device.

[0231] At the same time, according to an embodiment of the present disclosure, an electric steering system can be provided, which includes a motor connected to a steering wheel of a vehicle, a steering controller for controlling the rotation of the motor, and a wake-up circuit, which wakes up the steering controller when the vehicle ignition is turned off by the back electromotive force generated when the motor is forced to rotate by external force.

[0232] In this case, the steering controller may apply a reaction torque to the motor after waking up to suppress forced rotation of the motor.

[0233] Since specific configurations of the steering controller and the wake-up circuit included in the electric steering system may correspond to the configuration of the control device of the above-mentioned electric steering system, description is omitted to avoid redundancy.

[0234] However, the electric steering system to which an embodiment of the present disclosure is applied may be an SBW steering system, which includes an upper device and a lower device, the upper device including a reaction motor connected to a steering wheel, the lower device being mechanically separated from the upper device and including a steering drive motor connected to the wheels, which will be described in more detail below.

[0235] Fig.10 A configuration of a SBW steering system is shown, which is an example of an electric power steering system according to an embodiment of the present disclosure.

[0236] Reference Fig.10 According to an embodiment, the electric steering system may be a steer-by-wire steering system including an upper device 1100 including a reaction motor 1170 connected to a steering wheel 1120 and a lower device 1200 that is mechanically separated from the upper device and includes a steering drive motor 1270 connected to the wheels of the vehicle.

[0237] The detailed configuration of the upper device 1100 and the lower device 1200 may correspond to Figure 2 The configuration described in .

[0238] The reaction motor 1170 of the upper device 1100 may provide a steering reaction torque to the steering wheel according to the steering of the wheels by the lower device 1200. The steering reaction torque is used to rotate the steering wheel so that the driver can feel the steering degree of the wheels.

[0239] The upper device 1100 may include an upper ECU 1190 for controlling the reaction motor 1170 , and the upper ECU may be a steering controller according to an embodiment of the present disclosure.

[0240] The wake-up circuit 1140 may be connected to the upper ECU 1190 .

[0241] The wake-up circuit 1140 may wake up the upper ECU 1190 by using a counter electromotive force generated when the reaction motor 1170 is forcibly rotated by an external force when the vehicle is in an ignition-off state.

[0242] The upper ECU 1190 can prevent the forced rotation of the steering wheel by applying a reaction torque for suppressing the forced rotation of the reaction motor 1170 to the motor after waking up.

[0243] The wake-up circuit 1140 may include a rectifier circuit and a switch circuit, such as Figures 5 to 8 described.

[0244] As Figure 4The steering controller 200 shown, the upper ECU 1190 may include: a regulator for regulating the voltage from a power supply; and an inverter for supplying a control current to a winding included in the reaction motor 1170; a gate driver for controlling the operation of the inverter; and a micro control unit (MCU) for controlling the operation of the gate driver using the drive voltage supplied from the regulator.

[0245] In addition, the wake-up circuit 1140 may include: a rectifier circuit that rectifies a back electromotive force voltage generated by forced rotation of the reaction motor and outputs a DC output voltage; and a switch circuit that enables a regulator according to the output voltage of the rectifier circuit.

[0246] The rectifier circuit of the wake-up circuit 1140 may rectify the sinusoidal back electromotive force voltage generated during the forced rotation of the reaction motor 1170 into a direct current DC voltage to output an output voltage.

[0247] In addition, the switching circuit of the wake-up circuit 1140 may include: a first switching unit which is turned on according to the output voltage; and a second switching unit which is turned on when the first switching unit is turned on and inputs a wake-up signal to an enable terminal of the regulator based on the driving voltage of the power supply.

[0248] In addition, the upper ECU 1190 can determine the non-driving state of the vehicle based on the vehicle state information received from the sensor after being awakened by the awakening circuit 1140, and can apply reaction torque to the reaction motor 1170 only in the non-driving state of the vehicle.

[0249] In this case, the vehicle status information may be one or more of vehicle ignition information, vehicle speed information, vehicle door lock information, vehicle door opening information, driver entry information, seat belt fastening information, and theft alarm function activation information.

[0250] After waking up, the upper ECU 1190 may provide reaction torque to the reaction motor 1170 for a specific hold time and then may shut down or enter a sleep mode.

[0251] Hereinabove, an example has been described in which the embodiment is applied to the upper device of the SBW steering system, but the present disclosure is not limited thereto.

[0252] As an example, the control device according to the embodiment can be applied to Fig.10 The lower device 1200 or both the upper device 1100 and the lower device 1200 of the SBW steering system are shown.

[0253] The lower device 1200 may also include a wake-up circuit 1240 connected to the lower ECU 1290 .

[0254] In this case, the upper ECU 1190 or the lower ECU 1290 may be awakened by the back electromotive force generated when the steering drive motor 1270 is forcibly rotated.

[0255] The awakened upper ECU 1190 or lower ECU 1290 may provide a reaction torque to the reaction motor 1170 or the steering drive motor 1270 to suppress forced rotation.

[0256] With the vehicle ignition off, the steering wheel can be forced to turn or the wheels can be forced to turn by external force.

[0257] In this case, the reaction motor 1170 connected to the steering wheel or the steering drive motor 1270 connected to the wheel may be forced to rotate, and thus, a counter electromotive force may be generated in a winding of the reaction motor 1170 or the steering drive motor 1270 .

[0258] Therefore, in the same manner as described above, by using the back electromotive force generated in the windings of the reaction motor 1170 or the steering drive motor 1270, the wake-up circuit 1140 of the upper device or the wake-up circuit 1240 of the lower device can wake up the upper ECU 1190 of the upper device or the lower ECU 1290 of the lower device.

[0259] That is, when the steering wheel is forcibly rotated by external force, a back electromotive force can be generated in the reaction motor 1170 of the upper device 1100, and when the wheel is forcibly turned by external force, a back electromotive force can be generated in the steering drive motor 1270 of the lower device 1200.

[0260] Therefore, the control device according to the embodiment can use the back electromotive force generated from the reaction motor 1170 or the steering drive motor 1270 of the SBW steering system to wake up the upper ECU 1190 or the lower ECU 1290, and can provide a reaction torque to the reaction motor 1170 or the steering drive motor 1270 to suppress forced rotation.

[0261] For example, if there is a greater need to suppress the rotation of the steering wheel when the vehicle ignition is off, the control device can use the back electromotive force generated from the reaction motor 1170 or the steering drive motor 1270 of the SBW steering system to wake up the upper ECU 1190, and can provide a reaction torque for suppressing forced rotation to the reaction motor 1170 connected to the steering wheel.

[0262] Alternatively, if there is a greater need to suppress the steering of the wheels when the vehicle ignition is off, the control device can use the back electromotive force generated from the reaction motor 1170 or the steering drive motor 1270 of the SBW steering system to wake up the lower ECU 1290, and can provide a reaction torque for suppressing forced rotation to the steering drive motor 1270 connected to the wheels.

[0263] As described above, the embodiments of the present disclosure may be applied to the SBW steering system, and may selectively prevent forced rotation of the steering wheel caused by an external force or forced steering of the wheels caused by an external force.

[0264] In addition, according to the embodiment of the present disclosure, in the ignition-off state of the vehicle, by using the counter electromotive force generated by the forced rotation of the motor included in the electric power steering system, the rotation of the steering wheel or the arbitrary turning of the wheels can be suppressed.

[0265] In addition, according to an embodiment of the present disclosure, the back electromotive force generated when the motor included in the electric steering system is forced to rotate can be used to wake up the electronic controller, and a reaction force can be provided to the motor through the electronic control unit, thereby suppressing the rotation of the steering wheel or preventing arbitrary turning of the wheels.

[0266] Therefore, according to the embodiments of the present disclosure, it is possible to prevent vehicle theft in an ignition-off state and maintain the stability of the vehicle while using a simple device with low power consumption.

[0267] It should be noted that although all or some of the configurations or elements included in the above one or more embodiments have been combined to form a single configuration or component or operate in a combined manner, the present disclosure is not necessarily limited to this. That is, within the scope of the purpose or spirit of the present disclosure, all or some of the configurations or elements included in one or more embodiments may be combined to form one or more configurations or components, or operate with such a combined configuration or component. In addition, each configuration or element included in one or more embodiments may be implemented by an independent hardware configuration; however, some or all of these configurations or elements may be selectively combined and implemented by one or more computer programs having one or more program modules, which perform some or all functions from one or more combined hardware configurations. Those skilled in the art can easily generate codes or code segments constituting a computer program. When a computer program stored in a computer-readable medium is read and executed by a computer, an embodiment of the present disclosure may be implemented. The medium for storing a computer program may include, for example, a magnetic storage medium, an optical recording medium, and a carrier medium.

[0268] In addition, unless otherwise specified herein, the terms "including", "comprising", "consisting of", "having", etc. described herein mean that one or more other configurations or elements may be further included in the corresponding configuration or element. Unless otherwise defined herein, all terms (including technical and scientific terms) used herein have the same meaning as understood by those skilled in the art. Commonly used terms (such as those defined in dictionaries) should be interpreted as having the same meaning as in the context of the relevant technology, and should not be interpreted as an ideal or overly formal meaning, unless otherwise defined herein.

[0269] The above description is given to enable those skilled in the art to implement and use the technical ideas of the present disclosure, and is provided in the context of specific applications and their requirements. Various modifications, additions and substitutions to the described embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. The above description and accompanying drawings provide examples of the technical ideas of the present disclosure for illustrative purposes only. That is, the disclosed embodiments are intended to illustrate the scope of the technical ideas of the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiments shown, but is consistent with the widest scope consistent with the claims. The scope of protection of the present disclosure should be interpreted based on the attached claims, and all technical ideas within the scope of their equivalents should be interpreted as included within the scope of the present disclosure.

[0270] CROSS-REFERENCE TO RELATED APPLICATIONS

[0271] This application claims priority to Korean Patent Application No. 10-2023-0154451 filed on November 9, 2023, which is hereby incorporated by reference for all purposes as if fully set forth herein.

Claims

1. A device for controlling an electric power steering system, the device comprising: a steering controller configured to control a motor operatively connected to a steering wheel; as well as a wake-up circuit configured to wake up the steering controller using a back electromotive force generated by the rotation of the motor caused by an external force when the ignition of the vehicle is turned off, The steering controller is configured to control the application of a reaction torque to the motor after being awakened, so as to suppress the rotation of the motor caused by the external force.

2. The device according to claim 1, wherein: The steering controller is configured to, after being awakened, determine whether the vehicle is in a non-driving state based on vehicle state information received from a sensor, and perform control to apply the reaction torque to the motor only when the vehicle is in the non-driving state, The vehicle status information includes at least one of vehicle ignition information, vehicle speed information, vehicle door lock information, vehicle door opening information, driver boarding information, seat belt fastening information or theft alarm function activation information.

3. The device according to claim 1, wherein: The steering controller comprises: a regulator configured to regulate a voltage from a power supply; an inverter configured to supply a control current to a winding of the motor; a gate driver configured to control the inverter; and A micro control unit is configured to be driven by the driving voltage supplied from the regulator and to control the gate driver.

4. The device according to claim 3, wherein: The wake-up circuit comprises: a rectifier circuit configured to rectify a sinusoidal back electromotive force generated during rotation of the motor caused by the external force into a DC voltage to output a DC output voltage; and a switching circuit configured to enable the regulator according to the DC output voltage of the rectifier circuit, Wherein, the switching circuit includes: a first switching unit, which is configured to be turned on in response to the DC output voltage; and a second switching unit, which is configured to be turned on in response to turning on the first switching unit, and input a wake-up signal to an enable terminal of the regulator through the voltage of the power supply.

5. The device according to claim 1, wherein: The motor is a reaction motor connected to the steering wheel, and The electric power steering system comprises a steer-by-wire steering system comprising an upper device including the reaction motor connected to the steering wheel and a lower device which is not mechanically connected to the upper device and comprises a steering drive motor connected to the wheels of the vehicle.

6. A method for controlling an electric power steering system, the method comprising the following steps: waking up the steering controller by a wake-up circuit using a back electromotive force generated by rotation of a motor caused by an external force, the motor being operatively connected to a steering wheel; and After the steering controller is awakened by the awakening circuit, the steering controller controls application of a reaction torque to the motor to suppress rotation of the motor caused by the external force.

7. The method according to claim 6, wherein: The step of waking up the steering controller comprises the following steps: rectifying a sinusoidal back electromotive force generated during rotation of the motor caused by the external force into a DC voltage to output an output voltage; and After the switch circuit is turned on, a wake-up signal is input to an enable terminal of a regulator included in the steering controller by the switch circuit through the voltage of a power supply.

8. An electric power steering system, comprising: a motor operatively connected to a steering wheel of the vehicle; a steering controller configured to control rotation of the motor; as well as a wake-up circuit configured to wake up the steering controller using a back electromotive force generated by the rotation of the motor caused by an external force when the ignition of the vehicle is turned off, The steering controller is configured to control the application of a reaction torque to the motor after being awakened, so as to suppress the rotation of the motor caused by the external force.

9. The electric power steering system according to claim 8, wherein: The steering controller comprises: a regulator configured to regulate a voltage from a power supply; an inverter configured to supply a control current to a winding of the reaction motor; a gate driver configured to control the inverter; and A micro control unit is configured to be driven by the driving voltage supplied from the regulator and to control the gate driver.

10. The electric power steering system according to claim 9, wherein: The wake-up circuit comprises: a rectifier circuit configured to rectify a sinusoidal back electromotive force generated during rotation of the motor caused by the external force into a DC voltage to output a DC output voltage; and a switching circuit configured to enable the regulator according to the DC output voltage of the rectifier circuit, Wherein, the switching circuit includes: a first switching unit, which is configured to be turned on in response to the DC output voltage; and a second switching unit, which is configured to be turned on in response to turning on the first switching unit, and input a wake-up signal to an enable terminal of the regulator through the voltage of the power supply.

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