Apparatus for controlling electric power steering system

Abstract

An apparatus for controlling an electric power steering system is disclosed. The present embodiment relates to a control device and method for an electric power steering (EPS) system, and an EPS system including the same. A control device according to an embodiment may include a steering controller configured to control rotation of a motor linked to a steering wheel or a wheel of a vehicle, and a wake-up circuit configured to wake up the steering wheel or the wheel of the vehicle in a fire-off state of the vehicle. The steering controller is waken up using a change in current consumption of the motor rotation detecting element due to forced rotation of the motor by an external force, in which the steering controller may apply a reaction torque to the motor to suppress forced rotation of the motor after waking up.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a control device for an electric power steering (EPS; hereinafter may be abbreviated as "EPS") system and an electric power steering system including the control device. More specifically, embodiments of the present disclosure relate to a control device and 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 a traveling direction of a vehicle. Recently, an electric power steering (EPS) system has been widely used, in which a steering motor provides necessary steering force through electronic control.

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

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

[0005] The SBW steering system may include a structure that removes a mechanical coupling device (e.g., a steering column, a universal joint, or a pinion shaft) between a steering wheel of a vehicle and wheels.

[0006] The SBW steering system generally may 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 are mechanically separated, even if a reaction force motor or a steering motor is turned off due to vehicle ignition off, the steering wheel interlocked therewith may rotate or the wheels may be steered.

[0008] That is, even if the reaction force motor of the upper device is turned off due to vehicle ignition off, since the steering wheel and the steering column are separated from the lower device, the steering wheel may rotate arbitrarily.

[0009] In addition, even if the steering motor of the lower device is turned off due to vehicle ignition off, the rack linked thereto may move left and right, so that the wheels may be steered arbitrarily.

[0010] Therefore, in the SBW steering system, a locking device may also be required to forcibly lock the reaction force motor or the steering motor in the case of vehicle ignition off.

[0011] The locking device can be implemented as part of a steering control circuit included in an SBW steering system and can have a configuration in which, in the case of a motor restraint condition, rotation of a three-phase motor is prevented by short-circuiting the multiphase windings of the steering motor to the same potential.

[0012] That is, in a locked condition such as when the vehicle ignition is turned off, the locking circuit can 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 locking circuit, there is a drawback in that power consumption occurs because the locking circuit needs to operate even when the vehicle ignition is turned off and power is required for it.

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

[0015] Therefore, in the case of the vehicle ignition being turned off, a simple and low-power device is needed to restrict rotation of the steering wheel of the EPS. SUMMARY OF THE INVENTION

[0016] In this context, embodiments of the present disclosure aim to provide a control device and method for an EPS system and an electric power steering system including the control device and method, which can restrain rotation of the steering wheel or any steering of the vehicle wheels in an electric steering system of a vehicle when the ignition of the vehicle is turned off.

[0017] Embodiments of the present disclosure aim to provide a control device and method for an EPS system and an electric power steering system including the control device and method, which can, in a state where the vehicle ignition is turned off, use a change in current consumption of a motor rotation detection element included in the electric power steering system to restrain rotation of the steering wheel or any steering of the vehicle wheels.

[0018] Embodiments of the present disclosure aim to provide a control device and method for an EPS system and an electric power steering system including the control device and method, which can, in a state where the vehicle ignition is turned off, use a change in current consumption of a motor rotation detection element caused by forced rotation of a motor included in the steering system to wake up an electronic control unit.

[0019] According to one aspect of the present disclosure, a control device for an electric power steering system can be provided. The control device includes a steering controller and a wake-up circuit. The steering controller is configured to control the rotation of a motor linked to a vehicle's steering wheel or wheels. The wake-up circuit is configured to, in a state where the vehicle's ignition is off, use a change in current consumption of a motor rotation detection element caused by forced rotation of the motor by an external force to wake up the steering controller. Wherein, the steering controller is configured to apply a reaction torque to the motor to suppress the forced rotation of the motor after waking up.

[0020] If the motor does not rotate, the motor rotation detection element can generate a first consumption current, and when the motor rotates, it can generate a second consumption current that is larger than the first consumption current.

[0021] In addition, the wake-up circuit can include one or more switching elements and one or more resistance elements connected between a power supply and the motor rotation detection element.

[0022] Specifically, the resistance elements of the wake-up circuit can include a first resistor connected to the power supply and a second resistor connected between the first resistor and the motor rotation detection element.

[0023] In addition, the switching element of the wake-up circuit can include a source terminal, a gate terminal, and a drain terminal. The source terminal is connected to a first node between the power supply and the first resistor, the gate terminal is connected to a second node between the first resistor and the second resistor, and the drain terminal is connected to the steering controller.

[0024] In this case, in the case of generating the second consumption current, the voltage difference between both ends of the first resistor can be larger than the conduction threshold voltage of the switching element.

[0025] The steering controller can include a regulator, an inverter, a gate driver, and a micro control unit (MCU). The regulator is configured to regulate the voltage from the power supply. The inverter is configured to supply a control current to the windings included in the motor. The gate driver is configured to control the operation of the inverter. The micro control unit is configured to be driven by the driving voltage supplied from the regulator and control the operation of the gate driver.

[0026] In the case of generating the second consumption current, a wake-up signal can be transmitted from the drain terminal of the switching element to the enable terminal of the regulator.

[0027] In addition, the wake-up circuit can further include a third resistor and a fourth resistor. The third resistor is provided between the drain terminal of the switching element and the enable terminal of the regulator. The fourth resistor is connected between the enable terminal and one end of the third resistor and the ground.

[0028] Meanwhile, after awakening, the steering controller can determine the non-driving state of the vehicle based on the vehicle state information received from the sensors, and apply a reaction torque to the motor only in the case of the non-driving state.

[0029] In this case, the vehicle state information can include at least one of vehicle ignition information, vehicle speed information, vehicle door lock information, door open information, driver getting on information, seat belt fastening information, and anti-theft alarm function activation information.

[0030] Meanwhile, the electric power steering system can be a steer-by-wire type steering system, which includes an upper device and a lower device. The upper device includes a reaction motor linked to the steering wheel, and the lower device is mechanically separated from the upper device and includes a steering drive motor linked to the wheels of the vehicle.

[0031] In this case, the motor linked to the steering wheel can be the reaction motor included in the upper device.

[0032] Furthermore, after awakening, the steering controller can supply a reaction torque to the motor for a specific holding time and then turn off or enter the sleep mode. In this case, the holding time can be set to a time period between 2 seconds and 5 seconds.

[0033] As an example, the motor rotation detection element can be a motor position sensor connected to the motor and having the function of measuring the rotational speed of the rotor of the motor.

[0034] According to another aspect of the present disclosure, a control method for an electric power steering system can be provided. The control method includes: in the state where the ignition of the vehicle is turned off, waking up the steering controller by the wake-up circuit using the change in the current consumption of the motor rotation detection element caused by the forced rotation of the motor linked to the steering wheel or the wheels of the vehicle by an external force; and generating a reaction torque by the awakened steering controller and applying the reaction torque to the motor to suppress the forced rotation of the motor.

[0035] According to another aspect of the present disclosure, an electric power steering system can be provided. The electric power steering system includes a motor, a steering controller, and a wake-up circuit. The motor is linked to the steering wheel or the wheels of the vehicle. The steering controller is configured to control the rotation of the motor. The wake-up circuit is configured to wake up the steering controller using the change in the current consumption of the motor rotation detection element caused by the forced rotation of the motor in the state where the vehicle ignition is turned off, wherein the steering controller is configured to apply a reaction torque to the motor to suppress the forced rotation of the motor after awakening.

[0036] The electric power steering system can be a steer-by-wire steering system, which includes an upper device and a lower device. The upper device includes a reaction motor linked to the steering wheel, and the lower device is mechanically separated from the upper device and includes a steering drive motor linked to the vehicle's wheels. In this case, the motor linked to the steering wheel can be the reaction motor included in the upper device.

[0037] The wake-up circuit can include a first resistor, a second resistor, and a switching element. The first resistor is connected to the power supply, the second resistor is connected between the first resistor and the motor rotation detection element, and the switching element includes a source terminal, a gate terminal, and a drain terminal. The source terminal is connected to a first node between the power supply and the first resistor, the gate terminal is connected to a second node between the first resistor and the second resistor, and the drain terminal is connected to the steering controller.

[0038] As will be described below, according to an embodiment of the present disclosure, the rotation of the steering wheel and the random steering of the wheels can be restricted in a situation where the vehicle ignition is turned off.

[0039] In addition, according to an embodiment of the present disclosure, in a state where the vehicle ignition is turned off, the rotation of the steering wheel or the random steering of the wheels can be suppressed by using a change in the current consumption of the motor rotation detection element due to the forced rotation of the motor included in the electric steering system.

[0040] In addition, according to an embodiment of the present disclosure, in a state where the vehicle ignition is turned off, a change in the current consumption of the motor rotation detection element due to the forced rotation of the motor included in the electric steering system can be used to wake up the electronic controller and control the electronic controller to provide a reaction force to the motor, thereby restricting the rotation of the steering wheel or the random steering of the wheels.

[0041] Therefore, according to an embodiment of the present disclosure, the random rotation of the steering wheel or the random steering of the wheels in a state where the vehicle ignition is turned off can be prevented, thereby preventing vehicle theft and maintaining vehicle stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 An example of the schematic configuration of the electric power steering system is shown.

[0043] Figure 2 A schematic configuration of the SBW steering system to which this embodiment can be applied is shown.

[0044] Figure 3 A functional block diagram of the steering control device according to an embodiment is shown.

[0045] Figure 4 An example of the detailed configuration of the steering control device according to an embodiment is shown.

[0046] Figure 5 Shows an example of a wake-up circuit according to an embodiment.

[0047] Figure 6 Shows the operating state of the wake-up circuit when the motor is not rotating.

[0048] Figure 7 Shows the operating state of the wake-up circuit when the current consumption of the motor rotation detection element changes due to forced rotation of the motor.

[0049] Figure 8 Shows a flowchart of a control method for an electric power steering system according to an embodiment of the present disclosure.

[0050] Figure 9 Shows the configuration of an SBW steering system as an example of an electric power steering system according to an embodiment of the present disclosure. Detailed Description

[0051] 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 shown by way of illustration, and in which the same reference numerals and symbols may be used to represent the same or similar components even when they are shown in different drawings. Further, in the following description of examples or embodiments of the present disclosure, when it is determined that the description may make the subject matter in some embodiments of the present disclosure quite unclear, detailed descriptions of well-known functions and components included herein will be omitted. Terms such as "comprising", "having", "including", "constituting", "composing", and "formed of" used herein generally intend to allow the addition of other components, unless these terms are 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.

[0052] 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 does not limit the nature, order, sequence, or number, etc. of the element, but is only used to distinguish the corresponding element from other elements.

[0053] When referring to a first element being "connected or coupled to", "contacting or overlapping", etc. a second element, it should be construed that not only can the first element be "directly connected or coupled to" or "directly contacting or overlapping" the second element, but also a third element can be "interposed" between the first element and the second element, or the first element and the second element can be "connected or coupled to", "contacting or overlapping", etc. each other via a fourth element. Here, the second element may be included in at least one of two or more elements that are "connected or coupled", "contacting or overlapping", etc. with each other.

[0054] When time-related terms such as "after", "subsequently", "next", "before" are used to describe a process or operation of an element or configuration, or a flow or step in an operation, process, manufacturing method, these terms can be used to describe a discontinuous or non-sequential process or operation, unless the terms "directly" or "immediately" are used together.

[0055] In addition, when referring to any dimension, relative dimension, etc., it should be considered that the numerical value or corresponding information (e.g., level, range, etc.) for an element or feature includes a tolerance or error range that may be caused by various factors (e.g., process factors, internal or external influences, noise, etc.), even if no relevant description is specified. In addition, the term "may" fully encompasses all meanings of the term "might".

[0056] Figure 1 An example of a schematic configuration of an electric power steering system is shown.

[0057] A steering device or a steering system can be used as a device for controlling the traveling direction of a vehicle, and recently, an electric power steering (EPS) system has been widely used, in which a steering motor provides necessary steering force through electronic control.

[0058] An EPS system or an EPS device can rotate a steering column or move a rack connected thereto by driving an EPS steering motor according to a steering torque applied by a driver to a steering wheel.

[0059] An EPS system in which a steering motor rotates a steering column can be represented as a column type EPS system or a C-type EPS system. In this C-type EPS system, the steering column can be connected to a universal joint and a pinion, and the pinion can be coupled to a rack gear of a rack connected to a wheel of the vehicle.

[0060] Figure 1 A C-type EPS system is shown, and this C-type EPS system can 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 serving as a steering controller or a steering control circuit for controlling the steering motor. A specific speed reducer can be connected to the steering motor, and this speed reducer can be interlocked between the steering column and the steering motor.

[0061] The steering column 30 can be coupled to the steering wheel 20 and can rotate together with the steering wheel 20. The shape of the steering column 30 can be cylindrical.

[0062] Although not shown, the steering column 30 may be interlocked with one or more reduction gears, and any one of the plurality of reduction gears may be coupled to the outer peripheral surface of the steering column 30.

[0063] The sensor unit 40 may include a steering angle sensor, a torque sensor, and a vehicle speed sensor.

[0064] The steering angle sensor may detect the steering angle generated by the rotation of the steering wheel 20. In addition, the steering angle sensor may output a steering angle signal indicating information about the steering angle.

[0065] The torque sensor may detect the 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.

[0066] Here, the steering torque may refer to the rotational torque acting on the torque rod existing between the input shaft and the output shaft of the steering column 30. Therefore, even if the steering wheel 20 does not rotate, the steering torque can be detected.

[0067] The vehicle speed sensor may detect the speed of the vehicle and output a vehicle speed signal indicating information about the vehicle speed.

[0068] The steering controller or ECU 10 may receive 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 target rack position to the steering motor 70. Here, the steering information may include one or more of the steering angle signal output by the steering angle sensor, the steering torque signal output by the torque sensor, and the vehicle speed signal output by the speed sensor.

[0069] The ECU 10 may be implemented with hardware and software including a micro control unit (MCU), an inverter, a printed circuit board (PCB), etc.

[0070] The steering motor 70 may receive the command current from the ECU 10 and be driven with a torque and a rotational speed according to the command current. Although not shown, the steering motor 70 may be coupled to a reduction gear provided on the steering column 30. The rotation of the steering motor 70 may cause the reduction gear interlocked with the steering column 30 and the steering column to rotate.

[0071] At the same time, the steering column may rotate by the rotation of the steering motor 70, and thus, the rack linked to the pinion at the output end of the steering column may move left and right.

[0072] Therefore, the vehicle may be steered by moving the wheels connected to both ends of the rack left or right.

[0073] The steering motor 70 included in the C-type EPS system may be a three-phase motor, but is not limited thereto.

[0074] The ECU 10 may perform the following functions: receive power from a power supply unit (not shown); generate target currents to be supplied to each winding of the steering motor using an inverter; and supply the target currents to the steering motor.

[0075] In the C-type EPS system, when the steering motor 70 rotates the steering column 30 to apply a steering assist force, the steering assist force may be transmitted to the rack 12 through a pinion rack. When the rack moves left and right, the wheels connected thereto may be steered left and right.

[0076] Meanwhile, an EPS system in which the steering motor directly moves the rack connected to the wheels may be referred to as a rack-type EPS system or an R-type EPS system.

[0077] In the R-type EPS system, the steering motor and the rack may be connected by a belt or a gear, and a speed reducer such as a ball nut is linked therebetween. As the steering motor rotates, the ball nut speed reducer linked to the rack rotates, and the rack may move left and right according to the rotation of the speed reducer to steer the wheels.

[0078] Figure 2 A schematic configuration of an SBW steering system to which the present embodiment may be applied is shown.

[0079] As an example of an EPS system, there is an SBW steering system which is an EPS system of a steer-by-wire (SBW) type.

[0080] The SBW steering system may include a structure in which mechanical coupling devices such as a steering column, a universal joint, or a pinion shaft between the steering wheel and the wheels are removed.

[0081] Refer to 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.

[0082] 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 the torque applied to the steering wheel; a reaction motor 117 as a motor device for providing a reaction force torque to the steering wheel according to the steering through the lower rack; and an upper ECU 119 for controlling the reaction motor. The upper device 110 may be referred to as a steering feedback actuator (SFA).

[0083] In addition, the lower device 120 may include: a rack 122 connected to the vehicle's wheel 128; a steering drive motor 127 for moving the rack left and right; and a lower ECU 129 for controlling the steering drive motor.

[0084] 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 of the tie rod connected to the wheel left and right by using the steering assist torque signal.

[0085] The lower device 120 may control the steering drive motor based on the drive signal through a ball screw reducer. The lower device may be referred to as a road wheel actuator (RWA).

[0086] That is, in the SBW steering system, the upper device including the steering wheel, the steering column, and the reaction force motor and the lower device including the rack drive device (i.e., the pinion, the ball nut, and the steering drive motor) can operate independently without an intermediate mechanical connection.

[0087] Therefore, in order to provide a steering feeling to the driver, it is necessary to rotate the steering wheel connected to the upper device according to the movement of the rack of the lower device that actually performs the steering. In this case, the force or torque applied to the steering wheel may be defined as a reaction force or a reaction force torque.

[0088] Meanwhile, when the vehicle's engine is turned off or when the vehicle ignition is off, it is necessary for the steering system not to operate.

[0089] That is, if the steering wheel is rotated to allow the wheels to rotate in a state where the vehicle engine is turned off or the vehicle ignition is off, there may be a problem that the wheels of the stopped or parked vehicle are arbitrarily steered.

[0090] Therefore, if the steering wheel is rotated in a state where the vehicle ignition is off, the vehicle can be steered, which may make vehicle theft easier and reduce the stability of the parked vehicle.

[0091] Therefore, when the vehicle's engine is turned off or when the vehicle ignition is off, it is necessary to lock the steering wheel.

[0092] Meanwhile, 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 off, the steering wheel can be automatically locked because of the mechanical structures such as the steering column, the rack, and the reducer being interlocked between the steering wheel and the wheels.

[0093] However, in the case of an SBW steering system, the upper device connected to the steering wheel and the lower device connected to the rack 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 linked to the upper device can rotate, or the wheels linked to the lower device can be steered.

[0094] 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 can rotate arbitrarily because the steering wheel and the steering column are separated from the lower device.

[0095] In addition, even if the steering motor of the lower device is turned off due to the vehicle ignition being turned off, the rack linked to it can move left and right, enabling the wheels to be steered arbitrarily.

[0096] That is, different from a C-type EPS system or an R-type EPS system, in the case of an SBW steering system, a locking function needs to be separately implemented to restrict the rotation of the steering wheel or the movement of the rack when the vehicle ignition is turned off.

[0097] Therefore, when the vehicle ignition is turned off, the SBW steering system needs to have a locking device that forcibly locks the reaction force motor or the steering motor.

[0098] As an example of such a locking device, a separate clutch device can be provided to mechanically connect the upper device and the lower device.

[0099] As another example of the locking device, a key-lock solenoid device can be provided to lock the steering column when the vehicle ignition is turned off.

[0100] As another example of the locking device, a locking device including a locking circuit for restricting the rotation of the motor can be used. In this case, regardless of whether the vehicle ignition is turned off, power can be supplied to the locking circuit, and the locking circuit can prevent the motor from rotating by short-circuiting the windings of the motor.

[0101] Generally, the motor used in the steering system can be a three-phase motor, which includes a u-phase, a v-phase, and a w-phase, as well as corresponding u-phase coils, v-phase coils, and w-phase coils.

[0102] In the case of such a three-phase motor, if the input terminals of each phase coil are floating, the three-phase motor can rotate arbitrarily.

[0103] Therefore, when the vehicle ignition is turned off, the input terminals of the three-phase steering motor, especially the SBW steering motor, included in the EPS system can be floating, and the steering motor rotates arbitrarily accordingly, resulting in vehicle stability problems.

[0104] Therefore, a locking circuit can be provided that can prevent the motor from rotating by shorting 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.

[0105] Meanwhile, the EPS system including the SBW steering system may include a steering control circuit for controlling the steering motor.

[0106] 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 drive current to the steering motor.

[0107] The steering control circuit may also be represented as a steering controller, a steering ECU, etc.

[0108] Generally, the steering control circuit included in the EPS system may include an inverter composed of a plurality of switching devices or switching elements and an inverter drive circuit or a gate drive circuit for controlling the inverter.

[0109] In particular, as described above, the steering control circuit included in the SBW steering system may include a locking circuit in addition to the inverter and the inverter drive circuit (or gate drive circuit) to prevent the rotation of the steering motor or the reaction force motor when the vehicle ignition is turned off.

[0110] In a state where the vehicle ignition is turned off, such a locking circuit can be turned on by a locking signal provided from the steering controller, and can prevent the motor from rotating by shorting the multi-phase windings of the reaction force motor or the steering motor.

[0111] The locking circuit is required to operate when the vehicle ignition is turned off. Therefore, a possible disadvantage is that power is consumed for operating the locking circuit even when the vehicle ignition is turned off.

[0112] In addition, since a separate locking circuit needs to be provided, the steering control device of the electric power steering system may be complex.

[0113] Therefore, hereinafter, a simple steering control device that can operate with low power consumption is proposed to restrict the rotation of the EPS steering wheel when the vehicle ignition is turned off.

[0114] Figure 3 A functional block diagram of a steering control device according to an embodiment is shown.

[0115] Refer to Figure 3, the steering control device according to the embodiment may include: a steering controller 200 that controls the rotation of a motor 400 linked to a steering wheel or a wheel of a vehicle; and a wake-up circuit 300 that wakes up the steering controller by using a change in current consumption of a motor rotation detection element 410 linked to the motor 400.

[0116] The wake-up circuit 300 may wake up the steering controller by using a change in current consumption of the motor rotation detection element due to forced rotation of the motor by an external force in a state where the vehicle ignition is off.

[0117] As an example, the wake-up circuit 300 may include a switching element that conducts according to a change in current consumption of the motor rotation detection element 410 and one or more resistance elements.

[0118] Specifically, if in a state where the vehicle ignition is off, the current consumption of the motor rotation detection element 410 changes from a first consumption current to a second consumption current according to forced rotation of the motor 400, the wake-up circuit 300 may operate, and the wake-up circuit 300 may wake up the steering controller 200 that is in an off or sleep mode.

[0119] The following will refer to Figures 5 to 7 Examples of the detailed configuration of the wake-up circuit 300 will be described in more detail.

[0120] The motor rotation detection element 410 used in the embodiment may be a sensor equipped with an electronic tachometer (ETC) function for counting the number of revolutions of the rotor of the motor.

[0121] As an example, the motor rotation detection element 410 may be one of an electronic tachometer sensor or a motor position sensor (MPS) having an electronic tachometer function.

[0122] In addition, the steering controller 200 may determine a non-driving state of the vehicle based on vehicle state information I_state received from a sensor 500 after waking up.

[0123] In this case, only when it is determined that the vehicle is in a non-driving state, the steering controller 200 may apply a reaction torque to the motor 400.

[0124] In this case, the vehicle state information may include at least one of vehicle ignition information, vehicle speed information, vehicle door lock information, door open information, driver getting on information, seat belt fastening information, and anti-theft alarm function activation information.

[0125] 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 the driver getting on the vehicle, a seat belt fastening detection sensor, an anti-theft alarm detection sensor, etc.

[0126] The vehicle state information may be transmitted to the steering controller 200 through a Controller Area Network (CAN) communication network connected to each sensor.

[0127] Specifically, if at least one of the following conditions is met: among them, the condition where the vehicle ignition information indicates the ignition-off state; the condition where the vehicle speed information indicates the vehicle stop state and the vehicle door lock information indicates the door lock locked state; the condition where the door open information indicates that one or more of the doors are open; the condition where the driver getting on information indicates that the driver or passenger is not in the vehicle; the condition where the seat belt fastening information indicates that the seat belt is not fastened; the condition indicating the activation information of the anti-theft alarm function indicates the activation state of the vehicle anti-theft device inside the vehicle, the steering controller 200 may determine that the vehicle is in a non-driving state.

[0128] 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 in a non-driving state.

[0129] As another example, if the vehicle state information indicates that the vehicle is in a non-driving state, even if the vehicle is in the vehicle ignition-on state thereafter, the steering controller woken up in the vehicle ignition-off state may apply a reaction torque to the motor to prevent the rotation of the steering wheel.

[0130] This is because, for example, in the case where the steering controller is woken up by the forced rotation of the steering wheel, if the vehicle is in an abnormal driving state (such as the vehicle stop state, the door open state, the door lock locked state, the passenger leaving state, the seat belt not fastened state, the activation state of the vehicle anti-theft device), even if the vehicle is in the vehicle ignition-on state thereafter due to an unqualified person attempting to start the vehicle or attempting to remotely start the vehicle, it is necessary to restrict the rotation of the steering wheel.

[0131] In addition, according to an embodiment, the determination of the vehicle non-driving state and the application of the reaction force torque may be performed only for a specific period of time after the steering controller wakes up.

[0132] This is because, if the steering controller is woken up by the forced rotation of the steering wheel, it is not necessary to determine the non-driving state and apply the reaction force torque after entering the normal vehicle ignition-on state and starting the normal driving of the vehicle.

[0133] For example, if the steering wheel is forcibly rotated just before the driver turns on the vehicle ignition, even if the steering controller is awakened according to the present embodiment, it is not necessary to apply a reaction torque. Therefore, the non-driving state of the vehicle can be determined, and the reaction torque is only applied for a specific threshold time period.

[0134] Meanwhile, the steering controller 200 according to the present embodiment may include a regulator, an inverter, a gate driver, and a micro control unit (MCU). The detailed configuration of the steering controller 200 will be described in more detail below with reference to Figure 4 the detailed configuration of the steering controller 200.

[0135] The electric power 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 to steer the wheels of the vehicle.

[0136] Alternatively, the steering control device according to the present embodiment may be applied to a steer-by-wire (SBW) steering system.

[0137] In particular, the steering control device according to the present embodiment may be applied to an upper device constituting the SBW steering system. In this case, the motor may be a reaction motor included in the upper device of the SBW steering system.

[0138] For example, the electric power steering system according to an embodiment may be a steer-by-wire steering system, which includes an upper device and a lower device. The upper device includes a reaction motor linked to the steering wheel, and the lower device is mechanically separated from the upper device and includes a steering drive motor linked to the wheels of the vehicle. In this case, the motor linked to the steering wheel may be a reaction motor included in the upper device.

[0139] 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.

[0140] More specifically, as Figure 2 shown in, the SBW steering system including the steering control device according to the embodiment 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 and the lower device. The control device 130 may be represented as a domain control unit (DCU).

[0141] 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 serving as a motor device to provide a reaction torque to the steering wheel according to steering via a rack; and an upper ECU 119 for controlling the reaction motor.

[0142] In addition, the lower device 120 may include a rack 122 connected to the wheels 128, a steering drive motor 127 for moving the rack left and right, and a lower ECU 129.

[0143] 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 of the tie rod connected to the wheels left and right.

[0144] In particular, the steering control device according to the present embodiment can be applied to the upper device 110 constituting the Figure 2 SBW steering system as shown.

[0145] 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.

[0146] That is to say, the motor 400 and the steering controller 200 included in the Figure 3 steering control device shown can be respectively the reaction motor 117 and the upper ECU 119 included in the Figure 2 upper device 110 of the SBW steering system shown.

[0147] In this case, a motor rotation detection element for detecting the rotation of the reaction motor 117 may be connected to the reaction motor 117. The wake-up circuit 300 can wake up the upper ECU 119 by operating based on the change in current consumption of the motor rotation detection element connected to the reaction motor 117 in the vehicle ignition-off state.

[0148] The awakened upper ECU 119 may generate a reaction torque command signal that suppresses the forced rotation of the reaction motor, and apply a reaction torque to the reaction motor 117 based on the reaction torque command signal.

[0149] The present disclosure is not limited to this, and the control device according to the embodiment can be applied to the lower device 120 of the SBW steering system.

[0150] In this case, included in theFigure 3 The motor 400 in the steering control device shown in Figure 2 may be the steering drive motor 127 included in the lower device 120 of the SBW steering system shown in

[0151] In this case, a motor rotation detection element for detecting the rotation of the steering drive motor 127 may be connected to the steering drive motor 127. The wake-up circuit 300 may operate by detecting a change in the current consumption of the motor rotation detection element connected to the steering drive motor 127 in a state where the vehicle ignition is off, to wake up the lower ECU 129.

[0152] The awakened lower ECU 129 may generate a reaction torque command signal for suppressing forced rotation of the steering drive motor, and apply reaction torque to the steering drive motor 127 based on the reaction torque command signal.

[0153] That is, the awakened upper ECU 119 or lower ECU 129 may provide reaction torque to suppress forced rotation of the reaction motor 117 or the steering drive motor 127.

[0154] When the parked vehicle is in a state where the vehicle ignition is off, the wheels may turn due to an abnormal change in the parking position (such as a parking tower) or an attempt to steal the vehicle.

[0155] In this case, the steering drive motor 127 linked to the wheels may be forced to rotate, and thus, the current consumption of the motor rotation detection element connected to the steering drive motor 127 may change, and the upper ECU 119 of the upper device or the lower ECU 129 of the lower device may be awakened using this change in current consumption.

[0156] In addition, when the steering wheel is forced to rotate by an external force, the current consumption of the motor rotation detection element connected to the reaction motor 117 of the upper device 110 may change. Alternatively, when the wheels are forced to turn by an external force, the current consumption of the motor rotation detection element connected to the steering drive motor 127 of the lower device 120 may change.

[0157] Therefore, the control device according to the embodiment can wake up the upper ECU 119 or the lower ECU 129 by using the change in the current consumption of the motor rotation detection element caused by the forced rotation of the reaction motor 117 or the steering drive motor 127 of the SBW steering system, and can provide reaction torque for suppressing forced rotation to the reaction motor 117 or the steering drive motor 127.

[0158] For example, if it is highly necessary to suppress the rotation of the steering wheel when the vehicle ignition is off, the control device can use the change in the current consumption of the motor rotation detection element caused by the forced rotation of 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 for suppressing the forced rotation to the reaction motor 117 linked to the steering wheel.

[0159] Alternatively, if it is more necessary to suppress the random steering of the wheels when the vehicle ignition is off, the control device can use the change in the current consumption of the motor rotation detection element caused by the forced rotation of 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 for suppressing the forced rotation to the steering drive motor 127 linked to the wheels.

[0160] The following will refer to Figure 9 Describe the implementation of the SBW steering system in more detail.

[0161] Meanwhile, the steering controller 200 can include a regulator, an inverter, a gate driver, and a micro control unit, and the wake-up circuit 300 according to the present embodiment can wake up the steering controller 200 by turning on the regulator included in the steering controller 200 and using the change in the current consumption of the motor rotation detection element caused by the forced rotation of the motor.

[0162] The following will refer to Figure 4 Describe an example of the detailed configuration of the steering controller 200 in more detail.

[0163] Meanwhile, the reaction torque applied by the awakened steering controller 200 to the motor 400 can be a torque that causes the reaction motor to rotate in a direction opposite to the forced rotation direction of the motor 400.

[0164] That is, the steering controller 200 awakened by the forced rotation of the motor in the vehicle ignition off state can determine the 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.

[0165] The magnitude of the reaction torque can be proportional to the rotational torque caused by the forced rotation of the motor, and the direction of the reaction force torque can be opposite to the direction of the rotational torque caused by the forced rotation of the motor. For example, the magnitude of the reaction torque can be determined to be proportional to the magnitude of the back electromotive force generated by the forced rotation of the steering wheel.

[0166] As a result, it is possible to suppress the rotation of the steering wheel or the steering of the wheels caused by external forces when the vehicle ignition is off.

[0167] Additionally, after being awakened, the steering controller can be turned off or enter the sleep mode after providing a reaction torque to the motor for a specific holding time.

[0168] In this case, the holding time can be set to a time period of 2 seconds to 5 seconds.

[0169] This holding time can also be expressed as a latching delay time.

[0170] To provide this holding time, the steering controller 200 can include a separate latching circuit or delay circuit.

[0171] By using the holding time, even if the back electromotive force disappears after the steering controller is awakened, stability can be further ensured by providing the reaction torque to the motor only for a specific period of time and preventing the rotation of the steering wheel.

[0172] Figure 4 An example of the detailed configuration of a steering control device according to an embodiment is shown.

[0173] The steering control device according to an embodiment may include: a steering controller 200 for controlling the rotation of a motor 400 linked to a steering wheel; and a wake-up circuit 300 for waking up the steering controller 200 by using a change in the current consumption of a motor rotation detection element 410 caused by the forced rotation of the motor in a state where the vehicle ignition is turned off. In this case, the steering controller 200 can apply a reaction torque to the motor to suppress the forced rotation of the motor after waking up.

[0174] Refer to Figure 4 and the steering controller 200 included in the steering control device according to an embodiment can be represented as an ECU, and the steering controller 200 can include a regulator 210, an inverter 220, a gate driver 230, and a micro control unit (MCU) 240.

[0175] The regulator 210 can receive a battery voltage V_BAT from a vehicle power supply and regulate the battery voltage to output a driving voltage for driving the MCU 240.

[0176] The regulator 210 can include an enable terminal EN through which an enable signal for starting the regulator is input.

[0177] The inverter 220 can perform a function of supplying a control current to a winding included in the motor 400.

[0178] The inverter 220 can convert the battery voltage V_BAT of the battery serving as the vehicle power source (which is direct current (DC)) or the drive voltage of the direct current output from the regulator 210 into alternating current (AC), and can apply the converted alternating voltage (or alternating current) to the motor 400.

[0179] As an example, when the motor is a reaction motor included in the upper device of the SBW steering system ( Figure 2 the 117 in), and the vehicle is in a driving state, the inverter 220 can apply a drive current capable of providing a reaction torque to be applied to the steering wheel to the motor 400 so that the steering wheel rotates in response to the steering of the steering wheel by the lower device.

[0180] The inverter can be controlled by the gate driver 230, which will be described below, and the gate driver 230 can be controlled by the MCU 240.

[0181] Meanwhile, the motor 400 controlled by the steering control device according to an embodiment of the present disclosure can be a three-phase motor having u, v, and w phases.

[0182] In this case, as Figure 4 shown in, the inverter 220 can include an H-bridge circuit for supplying a u-phase drive current, a v-phase drive current, and a w-phase drive current to the three-phase windings (u, v, w windings) of the motor 400, respectively.

[0183] The gate driver 230 can control the driving of the inverter 220.

[0184] Specifically, the gate driver 230 can input a control signal to the gate terminals of the u, v, and w circuit switches included in the inverter 220 to control the inverter 220 to supply a u-phase drive current, a v-phase drive current, and a w-phase drive current to the motor 400.

[0185] The MCU 240 can control the operation of the gate driver 230 by using the drive voltage supplied from the regulator 210.

[0186] Specifically, the MCU 240 can generate a gate driver enable signal to activate the gate driver 230 and supply the gate driver enable signal to the gate driver 230.

[0187] As a result, in the 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 drive current of the reaction torque corresponding to the control signal to the motor 400.

[0188] 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.

[0189] In this case, the three-phase windings of the motor 400 may be in a floating state, and thus the rotor of the motor 400 may rotate freely by an external force. Accordingly, the steering wheel linked to the motor 400 may also rotate freely, which may reduce vehicle stability.

[0190] Therefore, the steering control device according to an embodiment of the present disclosure can wake up the steering controller 200 in a vehicle ignition-off state and apply a reaction torque to the motor to suppress the rotation of the motor due to an external force, thereby preventing the rotation of the steering wheel or the random steering of the wheels.

[0191] Specifically, the wake-up circuit 300 can wake up the steering controller 200 in an off state or a sleep state by using a change in the current consumption of the motor rotation detection element due to the forced rotation of the motor by an external force.

[0192] The awakened steering controller 200 can apply a reaction torque for suppressing the forced rotation of the motor to the motor.

[0193] Hereinafter, the wake-up operation of the wake-up circuit 300 and the steering controller using the wake-up circuit will be described.

[0194] The wake-up circuit 300 may include a switching element that is turned on according to a change in the current consumption of the motor rotation detection element 410 and one or more resistor elements.

[0195] When the current consumption of the motor rotation detection element 410 changes from a first current consumption to a second current consumption, the switching element included in the wake-up circuit 300 may be turned on, and a wake-up signal Swu for starting the regulator 210 included in the steering controller 200 may be generated and input to the enable terminal EN of the regulator 210.

[0196] Hereinafter, reference will be made to Figures 5 to 8 An example of the detailed configuration of the wake-up circuit 300 will be described in more detail.

[0197] Figure 5 An example of the wake-up circuit according to an embodiment is shown.

[0198] As an example, as Figure 4 shown, the wake-up circuit 300 may include a first resistor R1 connected to the power supply of the vehicle and a second resistor R2 connected between the first resistor R1 and the motor rotation detection element 410.

[0199] In addition, the wake-up circuit 300 may include a switching element TR having a source terminal (S) connected to a first node N1 between the power supply and a first resistor R1, a gate terminal (G) connected to a second node N2 between the first resistor R1 and a second resistor R2, and a drain terminal (D) connected to the steering controller 200.

[0200] The switching element TR may be a PNP transistor or a P-channel field effect transistor (FET), but is not limited thereto.

[0201] A current of a specific magnitude may flow between the motor rotation detection element 410 and the wake-up circuit 300. In other words, whether the motor is rotating or not, the motor rotation detection element may consume a specific amount of current, which may be expressed as the consumed current or current consumption.

[0202] For example, if no external force is applied in the vehicle ignition-off state, the motor 400 does not rotate, and in this case, the motor rotation detection element 410 may consume a first consumed current.

[0203] Meanwhile, in the vehicle ignition-off state, if the steering wheel is forcibly rotated or the wheels are forcibly steered by an external force, the motor 400 may be forcibly rotated, and in this case, a second consumed current may flow through the motor rotation detection element 410.

[0204] In this case, the first consumed current and the second consumed current may be determined according to the specifications of the motor rotation detection element 410.

[0205] For example, the first current consumption may have a value of about several tens of μA to several hundreds of μA, and the second current consumption may have a value of about 4 mA to 10 mA.

[0206] In addition, both the first resistor R1 and the second resistor R2 may have a resistance value of several hundred ohms (Ω), but are not limited thereto. For example, the first resistor R1 and the second resistor R2 may have a resistance value of approximately 150 Ω.

[0207] When the motor is forcibly rotated, the second consumed current may flow between the motor rotation detection element 410 and the wake-up circuit 300. Therefore, the potential difference or voltage difference between both ends of the first resistor R1 may be greater than the conduction threshold voltage of the switching element TR or the gate-source threshold voltage of the switching element TR.

[0208] Therefore, the switching element TR may be turned on, and the battery voltage V_BAT of the power supply may be output through the drain terminal D of the switching element.

[0209] Therefore, the high-level wake-up signal Swu can be transmitted from the drain terminal (D) of the switching element TR to the enable terminal of the regulator 210 included in the steering controller 200.

[0210] In addition, as Figure 5 shown, the wake-up circuit 300 may further include a third resistor R3 disposed between the switching element TR and the steering controller 200.

[0211] Specifically, as Figure 5 shown, the third resistor R3 may be disposed between the drain terminal (D) of the switching element TR and the enable terminal EN of the regulator 210.

[0212] If the switching element TR conducts through the second quiescent current, the third resistor R3 may be configured to allow the wake-up current caused by the battery voltage V_BAT of the power supply to flow to the enable terminal of the regulator 210.

[0213] In addition, the wake-up circuit 300 may further include a fourth resistor R4 connected between one end of the third resistor R3 or the steering controller 200 and the ground.

[0214] Specifically, as Figure 5 shown, the fourth resistor R4 may be connected between the enable terminal EN of the regulator 210 or one end of the third resistor and the ground.

[0215] The fourth resistor R4 can prevent the enable terminal EN from floating, thereby allowing the wake-up signal Swu to be stably applied to the enable terminal EN.

[0216] Figure 6 The operating state of the wake-up circuit is shown when the motor is not rotating.

[0217] Hereinafter, it is assumed that the resistance values of the first resistor R1 and the second resistor R2 are both 150 Ω.

[0218] As Figure 6 shown, if there is no external force in the vehicle ignition-off state, the motor 400 does not rotate. In this case, the first quiescent current I1 may flow through the motor rotation detection element 410.

[0219] That is to say, if the motor does not rotate, the first quiescent current I1 flows between the motor rotation detection element 410 and the wake-up circuit 300, and the first quiescent current may have a value in the range of several tens of μA to several hundreds of μA.

[0220] For example, the first quiescent current I1 may be about 100 μA.

[0221] In this case, the gate-source voltage Vgs, which is the voltage between the gate terminal (G) and the source terminal (S) of the switching element (TR), is only several tens of mV, and the switching element TR may not turn on through this gate-source voltage value.

[0222] That is, in the state where the first consumption current flows, the gate-source voltage Vgs of the switching element TR is smaller than the turn-on threshold voltage or the gate-source threshold voltage of the switching element TR, so the switching element TR can be in the off state.

[0223] As an example, when the first consumption current I1 is 100 μA and the resistance value of the first resistor R1 is 150 Ω, the gate-source voltage Vgs of the switching element TR can be approximately 15 mV, and the switching element TR can be maintained in the off state through this gate-source voltage value.

[0224] Therefore, the battery voltage V_BAT of the power supply is blocked, and current does not flow to the regulator 210 of the steering controller 200, so a signal is not supplied to the enable terminal of the regulator 210.

[0225] Therefore, the steering controller 200 can be maintained in the off state or the sleep mode state, which is the default state in the vehicle ignition-off state.

[0226] Figure 7 The operating state of the wake-up circuit is shown in the case where the current consumption of the motor rotation detection element changes due to the forced rotation of the motor.

[0227] Refer to Figure 7 , if the motor 400 is forcibly rotated by an external force while the vehicle ignition is off, the motor rotation detection element 410 can detect the forced rotation of the motor using the second consumption current I2.

[0228] That is, if the motor is forcibly rotated, the second consumption current I2 can flow between the motor rotation detection element 410 and the wake-up circuit 300.

[0229] Since the resistance values of the first resistor R1 and the second resistor R2 are both 150 Ω, and the second consumption current has a value of approximately 4 mA to 10 mA, a voltage of approximately 0.6 V to 1.5 V can be applied across the first resistor R1.

[0230] Therefore, the gate-source voltage Vgs, which is the voltage between the gate terminal (G) and the source terminal (S) of the switching element TR, can be approximately 0.6 V to 1.5 V.

[0231] This gate-source voltage of 0.6 V to 1.5 V can be larger than the turn-on threshold voltage or the gate-source threshold voltage of the switching element TR.

[0232] For example, if the second consumption current I2 is 5 mA and both the first resistor R1 and the second resistor R2 are 150 Ω, the gate-source voltage Vgs of the switching element TR can be approximately 0.75 V.

[0233] This gate-source voltage of 0.75 V can be greater than the conduction threshold voltage or the gate-source threshold voltage of the switching element TR, so the switching element TR can be turned on.

[0234] When the switching element TR is turned on, the battery voltage V_BAT of the power supply can be output from the wake-up circuit 300.

[0235] That is to say, the drive current Is can flow through the third resistor R3 by the battery voltage V_BAT, and the wake-up signal Swu can be applied to the steering controller 200 accordingly.

[0236] Specifically, a high-level wake-up signal Swu can be applied to the enable terminal EN of the regulator 210 included in the steering controller.

[0237] Therefore, the regulator 210 can be turned on, and as Figure 4 shown, the power from the external power supply can be supplied to the MCU 240, and the steering controller 200 can be woken up.

[0238] After waking up, the steering controller 200 can determine the non-driving state of the vehicle based on the vehicle state information I_state received from sensors and the like.

[0239] In this case, only when it is determined that the vehicle is in a non-driving state, the steering controller 200 can apply a reaction torque opposite to the external force that causes the forced rotation of the motor to the motor.

[0240] As a result, even if an external force attempts to forcibly rotate the motor in the vehicle ignition-off state, any rotation of the steering wheel or any steering of the wheels can be prevented.

[0241] Figure 8 The flowchart showing the control method of the electric power steering system according to an embodiment of the present disclosure is shown.

[0242] Referring to Figure 8 , the control method of the electric power steering system according to the embodiment may include step S810 and step S830. In step S810, the wake-up circuit wakes up the steering controller by using the change in the current consumption of the motor rotation detection element caused by the forced rotation of the motor linked to the steering wheel or the wheels by an external force. In step S830, the woken-up steering controller generates a reaction torque for suppressing the forced rotation of the motor and applies the reaction torque to the motor.

[0243] In addition, the control method of the electric power steering system according to the embodiment may further include step S820, wherein the awakened steering controller determines the non-driving state of the vehicle based on the vehicle state information received from the sensor.

[0244] In this case, if it is determined in step S820 that the vehicle is in a non-driving state, step S830 of applying a reaction torque to the motor may be executed.

[0245] The vehicle state information may be one or more of vehicle ignition information, vehicle speed information, vehicle door lock information, vehicle door open information, driver getting on the vehicle information, seat belt fastening information, and anti-theft alarm function activation information.

[0246] The wake-up circuit for executing step S910 of waking up the steering controller may include: a first resistor connected to the power supply; a second resistor connected between the first resistor and the motor rotation detection element; and a switching element having a source terminal connected to a first node between the power supply and the first resistor, a gate terminal connected to a second node between the first resistor and the second resistor, and a drain terminal connected to the steering controller.

[0247] Therefore, in step S810 of waking up the steering controller, the switching element can be turned on by the second consumption current applied to the motor rotation detection element, and thus, a high-level wake-up signal Swu can be applied to the steering controller through the battery voltage V_BAT of the power supply.

[0248] Specifically, the steering controller 200 may include a regulator 210 for regulating the voltage from the power supply, and may transmit the high-level wake-up signal Swu to the enable terminal EN of the regulator to wake up the steering controller.

[0249] In addition, in step S830 of applying a reaction torque to the motor, the awakened steering controller may provide a reaction torque to the motor for a specific holding time, and then turn off or enter the sleep mode (S840, S850).

[0250] In this case, the holding time may be expressed as a latching delay time, and may be set to a time period of about 2 seconds to 5 seconds.

[0251] Meanwhile, the electric power steering system applying the method according to the present embodiment may be an SBW steering system.

[0252] That is to say, an electric power steering system or an electric power-assisted steering system may include an upper device and a lower device. The upper device includes a reaction motor linked to the steering wheel, and the lower device is mechanically separated from the upper device and includes a steering drive motor linked to the wheels. The motor linked to the steering wheel may be the reaction motor included in the upper device.

[0253] Meanwhile, according to an embodiment of the present disclosure, an electric power steering system may be provided, which includes a motor linked to the steering wheel or wheels of a vehicle, a steering controller for controlling the rotation of the motor, and a wake-up circuit. The wake-up circuit wakes up the steering controller by using the change in the current consumption of a motor rotation detection element caused by the forced rotation of the motor due to an external force in a state where the vehicle ignition is turned off.

[0254] In this case, the steering controller may apply a reaction torque to the motor to suppress the forced rotation of the motor after waking up.

[0255] Since the specific configurations of the steering controller and the wake-up circuit included in the electric power steering system may correspond to the configuration of the control device of the above electric power steering system, the description is omitted to avoid repetition.

[0256] However, the electric power steering system applying the embodiment of the present disclosure may be a steer-by-wire (SBW) steering system, which includes an upper device and a lower device. The upper device includes a reaction motor linked to the steering wheel, and the lower device is mechanically separated from the upper device and includes a steering drive motor linked to the wheels, which will be described in more detail below.

[0257] Figure 9 The configuration of an SBW steering system as an example of the electric power steering system according to an embodiment of the present disclosure is shown.

[0258] Referring to Figure 9 , according to an embodiment, the electric power steering system may be a steer-by-wire steering system, which includes an upper device 1100 and a lower device 1200. The upper device 1100 includes a reaction motor 1170 linked to the steering wheel 1120, and the lower device 1200 is mechanically separated from the upper device and includes a steering drive motor 1270 linked to the wheels of the vehicle.

[0259] The detailed configurations of the upper device 1100 and the lower device 1200 may correspond to the configurations described in Figure 2 .

[0260] 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 through the lower device 1200. The steering reaction torque is used to rotate the steering wheel so that the driver can feel the degree of steering of the wheels.

[0261] The upper device 1100 may include an upper ECU 1190 for controlling the reaction motor 1170 and an upper motor rotation detection element 1130 for detecting the rotation of the reaction motor 1170, and the upper ECU may be a steering controller according to an embodiment of the present disclosure.

[0262] The wake-up circuit 1140 may be connected to the upper ECU 1190.

[0263] The wake-up circuit 1140 may use a change in the current consumption of the upper motor rotation detection element 1130 that occurs when the reaction motor 1170 is forcibly rotated due to an external force in a state where the vehicle ignition is off to wake up the upper ECU 1190.

[0264] Specifically, if the reaction motor 1170 is forcibly rotated due to an external force, the wake-up circuit 1140 may operate through a second consumption current flowing through the upper motor rotation detection element 1130. The wake-up circuit 1140 generates a high-level wake-up signal and applies the wake-up signal to the upper ECU 1190, thereby waking up the upper ECU 1190.

[0265] After being woken up, the upper ECU 1190 may prevent the forced rotation of the steering wheel by applying a reaction torque that suppresses the forced rotation of the reaction motor 1170 to the motor.

[0266] As an example, as Figures 5 to 7 shown, the wake-up circuit 1140 may include a first resistor R1 connected to a power supply, a second resistor R2 connected between the first resistor R1 and the upper motor rotation detection element 1130, and a switching element TR, the switching element including a source terminal connected to a first node between the power supply and the first resistor, a gate terminal connected to a second node between the first resistor and the second resistor, and a drain terminal connected to the steering controller.

[0267] As Figure 4 shown in the steering controller 200, the upper ECU 1190 may include a regulator for regulating the voltage from the power supply, 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 a driving voltage supplied from the regulator.

[0268] In addition, after being woken up by the wake-up circuit 1140, the upper ECU 1190 may determine a non-driving state of the vehicle based on vehicle state information received from a sensor, and may apply a reaction torque to the reaction motor 1170 only in the non-driving state of the vehicle.

[0269] In this case, the vehicle state information may be one or more of vehicle ignition information, vehicle speed information, vehicle door lock information, door open information, driver getting-on information, seat belt fastening information, and anti-theft alarm function activation information.

[0270] After waking up, the upper ECU 1190 may provide reaction torque to the reaction motor 1170 for a specific holding time and then may be turned off or enter the sleep mode.

[0271] In the above, an example in which the present embodiment is applied to the upper device of the SBW steering system has been described, but the present disclosure is not limited thereto.

[0272] As an example, the control device according to the embodiment may be applied to Figure 9 the lower device 1200 of the SBW steering system shown in or both the upper device 1100 and the lower device 1200.

[0273] The lower device 1200 may further include a wake-up circuit 1240 connected to the lower ECU 1290 and a lower motor rotation detection element 1230 that detects the rotation of the steering drive motor 1270.

[0274] In this case, the upper ECU 1190 or the lower ECU 1290 may be woken up by a change in the current consumption of the lower motor rotation detection element 1230 that occurs when the steering drive motor 1270 is forcibly rotated.

[0275] The woken-up upper ECU 1190 or lower ECU 1290 may provide reaction torque to suppress the forced rotation of the reaction motor 1170 or the steering drive motor 1270.

[0276] In a state where the vehicle ignition is turned off, the steering wheel may be forcibly rotated, or the wheels may be forcibly steered by an external force.

[0277] In this case, the reaction motor 1170 linked to the steering wheel or the steering drive motor 1270 linked to the wheels may be forcibly rotated. Therefore, the current consumption of the motor rotation detection elements 1130 and 1230 connected to the reaction motor 1170 or the steering drive motor 1270 may change from a first consumption current to a second consumption current.

[0278] Therefore, in the same manner as described above, the wake-up circuit 1140 of the upper device or the wake-up circuit 1240 of the lower device may wake up the upper ECU 1190 of the upper device or the lower ECU 1290 of the lower device by using the change in the current consumption of the motor rotation detection elements 1130 and 1230 connected to the reaction motor 1170 or the steering drive motor 1270.

[0279] That is, when the steering wheel is forced to rotate due to an external force, the current consumption of the upper motor rotation detection element 1130 of the reaction motor 1170 connected to the upper device 1100 can change, and if the wheels are forced to turn by an external force, the current consumption of the lower motor rotation detection element 1230 of the steering drive motor 1270 connected to the lower device 1200 can also change.

[0280] Therefore, the control device according to the embodiment can use the change in the current consumption of the motor rotation detection element caused by the forced rotation of 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 suppress the forced rotation of the reaction motor 1170 or the steering drive motor 1270.

[0281] For example, if it is more necessary to suppress the rotation of the steering wheel in the vehicle ignition-off state, the control device can use the change in the current consumption of the motor rotation detection element caused by the forced rotation of 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 the forced rotation to the reaction motor 1170 linked to the steering wheel.

[0282] Alternatively, if it is more necessary to suppress the turning of the wheels in the vehicle ignition-off state, the control device can use the change in the current consumption of the motor rotation detection element caused by the forced rotation of 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 the forced rotation to the steering drive motor 1270 linked to the wheels.

[0283] As described above, the embodiments of the present disclosure can be applied to the SBW steering system and can selectively prevent the forced rotation of the steering wheel by an external force or the forced turning of the wheels by an external force.

[0284] In addition, according to the embodiments of the present disclosure, in the vehicle ignition-off state, the rotation of the steering wheel or any turning of the wheels can be suppressed by using the change in the current consumption of the motor rotation detection element caused by the forced rotation of the motor included in the electric power steering system.

[0285] In addition, according to the embodiments of the present disclosure, the change in the current consumption of the motor rotation detection element caused by the forced rotation of the motor included in the electric power steering system can be used to wake up the electronic controller, and a reaction force can be provided to the motor through the electronic control unit to suppress the rotation of the steering wheel or prevent any turning of the wheels.

[0286] Thus, according to an embodiment of the present disclosure, it is possible to prevent theft of a vehicle in an ignition-off state while using a simple device with low power consumption and maintain the stability of the vehicle.

[0287] It should be noted that although all or some of the configurations or elements included in one or more of the above embodiments have been combined to form a single configuration or component or operate in combination, the present disclosure is not necessarily limited thereto. 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 of the embodiments may be combined to form one or more configurations or components or operate in such a combined configuration or component. In addition, each of the configurations or elements included in one or more of the embodiments may be implemented by an independent hardware configuration; however, some or all of the configurations or elements may be selectively combined and implemented by one or more computer programs having one or more program modules that perform some or all of the functions from one or more combined hardware configurations. Those skilled in the art can easily generate the code or code segments constituting the computer program. Since the computer program stored in the computer-readable medium is read and executed by the computer, the embodiments of the present disclosure can be implemented. The medium for storing the computer program may include, for example, a magnetic storage medium, an optical recording medium, and a carrier medium.

[0288] In addition, unless otherwise specified herein, the terms "comprising", "including", "constituting", "having", etc., as used herein mean that one or more other configurations or elements may also be 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. Terms commonly used, such as those defined in a dictionary, should be interpreted as having the same meaning as in the context of the related art and should not be construed as having an ideal or overly formal meaning unless otherwise specified herein.

[0289] The above description is provided to enable those skilled in the art to implement and use the technical idea of the present disclosure and is provided in the context of a specific application and its 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 can be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. The above description and the drawings merely provide examples of the technical idea of the present disclosure for illustrative purposes. That is, the disclosed embodiments are intended to illustrate the scope of the technical idea of the present disclosure. Therefore, the scope of the present disclosure is not limited to the illustrated embodiments, but should be given the broadest scope consistent with the claims. The scope of protection of the present disclosure should be construed based on the claims, and all technical ideas within the equivalent scope should be construed as being included within the scope of the present disclosure.

[0290] Cross - reference to related applications

[0291] This application claims priority to Korean Patent Application No. 10 - 2023 - 0161617, filed on November 20, 2023, which is incorporated herein by reference for all purposes as if fully set forth herein.

Claims

1. A device for controlling an electric power steering system, the device for controlling an electric power steering system comprising: a steering controller configured to control a motor operatively connected to a steering wheel or wheels of the vehicle; as well as a wake-up circuit configured to wake up the steering controller using a change in current consumption of a motor rotation detector associated with rotation of the motor caused by an external force in an ignition-off state of the vehicle; The steering controller is configured to, after being awakened, perform control to apply a reaction torque to the motor, thereby suppressing rotation of the motor caused by the external force.

2. The device for controlling an electric power steering system according to claim 1, wherein: The motor rotation detector is configured to generate a first consumption current in response to non-rotation of the motor, and to generate a second consumption current greater than the first consumption current in response to rotation of the motor.

3. The device for controlling an electric power steering system according to claim 2, wherein: The wake-up circuit includes one or more switch elements and one or more resistor elements connected between a power source and the motor rotation detector.

4. The device for controlling an electric power steering system according to claim 3, wherein: The one or more resistor elements include a first resistor and a second resistor, the first resistor being connected to the power source, the second resistor being connected between the first resistor and the motor rotation detector, The switching element includes a source terminal, a gate terminal, and a drain terminal, the source terminal being connected to a first node between the power supply and the first resistor, the gate terminal being connected to a second node between the first resistor and the second resistor, and the drain terminal being connected to the steering controller.

5. The device for controlling an electric power steering system according to claim 4, wherein: The steering controller comprises: a regulator configured to regulate a voltage from the 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 MCU is configured to be driven by the driving voltage supplied from the regulator and to control the gate driver.

6. The device for controlling an electric power steering system according to claim 5, wherein: The switching element is configured such that, in response to the second consumption current, a wake-up signal is transmitted from the drain terminal of the switching element to an enable terminal of the regulator.

7. The device for controlling an electric power steering system according to claim 4, wherein: The resistor element further includes a third resistor connected between the drain terminal of the switch element and an enable terminal of a regulator, and a fourth resistor connected between the enable terminal and one end of the third resistor and ground.

8. The device for controlling an electric power steering system 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 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 anti-theft alarm function activation information.

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

10. The device for controlling an electric power steering system according to claim 1, wherein: The steering controller is configured to, after being awakened, control to provide the reaction torque to the motor for a holding time and then shut down or enter a sleep mode after the holding time.

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