Control device and control method for controlling an electric power steering system and an electric power steering system comprising the same

Abstract

The present embodiments relate to a control device and a control method for an electric power steering (EPS) system and an EPS system incorporating therein. A control device according to one embodiment may comprise a steering control unit configured to control the rotation of a motor connected to a steering wheel, and a wake-up circuit configured to wake up the steering control unit when the vehicle is stationary by using a counter-electromotive force generated in the event of forced rotation of the motor by an external force, wherein the steering control may apply a reaction torque to the motor to suppress the forced rotation of the motor after wake-up.

Description

REFERENCE TO A RELATED APPLICATION

[0001] This application claims priority to Korean Patent Application No. 10-2023-0154451, filed on November 9, 2023, which is incorporated herein by reference for all purposes as if fully set forth herein. TECHNICAL FIELD

[0002] One embodiment of the present disclosure relates to a control device and a control method for an electric power steering (EPS; may be abbreviated as "EPS" hereinafter) system, and an electric power steering system including the same. More specifically, the 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 the steering wheel. BACKGROUND

[0003] A steering device or steering system is a device for controlling the direction of travel of a vehicle. Recently, an electric power steering (EPS) system has been widely used, in which a steering motor provides the required steering force through an electronic control unit.

[0004] The EPS system or device may rotate a steering shaft of a steering column or move an associated rack by driving a steering motor in response to a steering torque applied by a driver to a steering wheel.

[0005] An example of such an EPS system is an SBW steering system, which is a Steer-by-Wire (SBW) type EPS system.

[0006] The SBW steering system may include a structure that removes a mechanical coupling device such as a steering column, a universal joint, or a pinion shaft between a steering wheel and a wheel of a vehicle.

[0007] The SBW steering system may generally include an upper and a lower device that are mechanically separated from each other, and a control circuit for controlling the upper and lower devices.

[0008] In SBW steering, since the upper device connected to a steering wheel and the lower device connected to a rack are mechanically separated, a connected steering wheel can rotate or a wheel can be steered even if a reaction force motor or a steering motor is turned off due to a vehicle ignition being turned off.

[0009] 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 freely because the steering wheel and steering column are separated from the lower device.

[0010] In addition, the connected rack can move left and right, so that the wheels can be steered as desired, even if the steering motor of the lower device is turned off due to the vehicle ignition being turned off.

[0011] Accordingly, the SBW steering system may still require a locking device to forcibly lock the reaction force motor or the steering motor in the event of the vehicle ignition being turned off.

[0012] An interlock device may be implemented as part of the steering control circuitry in the SBW steering system and may be configured to prevent rotation of a three-phase motor by shorting the multi-phase windings of the steering motor to the same potential in the event of a condition requiring motor inhibition.

[0013] That is, in a locked condition, such as when the vehicle ignition is off, the lock circuit can be operated to prevent rotation of the reaction motor or the steering motor and thus prevent rotation of the steering wheel.

[0014] Since the locking circuit must be functional even when the vehicle ignition is switched off and a power source is required for this, the use of such a locking circuit has the disadvantage that power is consumed.

[0015] In addition, an EPS control device can be complicated because a separate locking circuit is required.

[0016] Therefore, a simple and power-saving device is needed to prevent the rotation of the steering wheel of an EPS in case the vehicle ignition is turned off. DEMOLITION

[0017] Against this background, embodiments of the present disclosure provide a control apparatus and a control method of an EPS system that can restrict the rotation of the steering wheel under conditions when the vehicle ignition is turned off in the electric steering system of a vehicle, and an electric power steering system incorporating the same.

[0018] Embodiments of the present disclosure are to provide a control apparatus and a control method for an EPS system that can limit the rotation of the steering wheel when the vehicle ignition is turned off using the counter electromotive force generated due to forced rotation of a motor included in the electric steering system, and an electric power steering system including the same.

[0019] Embodiments of the present disclosure are to provide a control apparatus and a control method for an EPS system capable of waking up an electronic control unit using the counter electromotive force generated by forced rotation of the motor included in the electric steering system when the vehicle ignition is turned off, and controlling the electronic control unit to supply a reaction force to the motor to prevent rotation of the steering wheel, and an electric power steering system including the same.

[0020] According to one aspect of the present disclosure, there may be provided a control device of an electric power steering system comprising a steering control unit configured to control rotation of a motor connected to a steering wheel, and a wake-up circuit configured to wake up the steering control unit using a counter electromotive force generated in the event of forced rotation of the motor by an external force when the vehicle ignition is turned off, wherein the steering control unit is configured to apply a reaction torque to the motor to suppress the forced rotation of the motor after the wake-up.

[0021] After waking up, the steering control unit can determine a stopped vehicle state based on the vehicle status information received from a sensor and apply the reaction torque to the motor only in the stopped state.

[0022] In this case, the vehicle status information may include at least one of the following information: vehicle ignition information, vehicle speed information, vehicle door locking information, vehicle door open information, driver entry information, seat belt fastening information, and anti-theft alarm activation information.

[0023] In addition, the steering control unit may include a regulator configured to regulate or control a voltage from a power supply, an inverter configured to supply a control current to the windings included in the motor, a gate driver configured to control the operation of the inverter, and a microcontroller (MCU) configured to be driven by a control voltage supplied by the regulator and to control the operation of the gate driver.

[0024] Furthermore, the wake-up circuit may comprise a rectifier circuit configured to rectify the counter electromotive force and output a DC output voltage, and a switch circuit configured to activate the regulator in response to the output voltage of the rectifier circuit.

[0025] The rectifier circuit can convert a sinusoidal counter electromotive force generated during the forced rotation of the motor into a DC voltage and output the output voltage.

[0026] Furthermore, the switching circuit may include a first switching unit that is turned on depending on the output voltage, and a second switching unit that turns on when the first switching unit is turned on and that provides a wake-up signal by the voltage of the power supply to an enable terminal of the regulator.

[0027] The electric power steering system may be a steer-by-wire steering system, comprising an upper assembly with a reaction motor connected to the steering wheel, and a lower assembly, mechanically separated from the upper assembly, containing a steering drive motor connected to a vehicle wheel. In this case, the motor connected to the steering wheel may be the reaction motor contained in the upper assembly.

[0028] In this case, the reaction torque may be a torque that rotates the reaction motor in a direction opposite to the direction of forced rotation of the reaction motor.

[0029] After being woken up, the steering control unit can deliver the reaction torque to the motor for a certain holding time and then be turned off or enter a sleep mode, where the holding time can be set to a period of 2 to 5 seconds.

[0030] According to another aspect of the present disclosure, there may be provided a control method for an electric power steering system, which comprises waking up a steering control unit by a wake-up circuit using a counter electromotive force generated in the event of forced rotation of a motor connected to a steering wheel by an external force, and generating and applying a reaction torque to the motor by the woken-up steering control unit to suppress the forced rotation of the motor.

[0031] In this case, the wake-up may include rectifying a sinusoidal counter electromotive force generated during the forced rotation of the motor into a DC voltage and outputting an output voltage, and, through a switch circuit turned on by the output voltage, inputting a wake-up signal by a voltage of a power supply to an enable terminal of a controller included in the steering control unit.

[0032] The control method of an electric power steering system may further include determining a stopped vehicle state based on vehicle status information received from a sensor. In this case, generating and applying the reaction torque to the motor may only be performed in the case of the stopped vehicle state.

[0033] In addition, generating and applying may involve providing the reaction torque to the motor for a specified holding time and then turning it off or entering a rest state.

[0034] According to another aspect of the present disclosure, there may be provided an electric power steering system comprising a motor connected to a steering wheel of a vehicle, a steering control unit configured to control rotation of the motor, and a wake-up circuit configured to wake up the steering control unit using a counter electromotive force generated in the event of forced rotation of the motor by an external force when the vehicle ignition is turned off, wherein the steering control unit is configured to apply a reaction torque to the motor to suppress the forced rotation of the motor after the wake-up.

[0035] In this case, the electric power steering may be a steer-by-wire steering system comprising an upper device having a reaction motor connected to the steering wheel and a lower device mechanically separated from the upper device and comprising a steering drive motor connected to a wheel of the vehicle, wherein the motor connected to the steering wheel may be the reaction motor included in the upper device.

[0036] According to an embodiment of the present disclosure, it is possible to limit the rotation of the steering wheel under the condition that the vehicle ignition is turned off.

[0037] Furthermore, according to an embodiment of the present disclosure, it is possible to prevent the rotation of the steering wheel when the vehicle ignition is turned off by utilizing the counter electromotive force generated by forced rotation of a motor included in the electric steering system.

[0038] Furthermore, according to an embodiment of the present disclosure, when the vehicle ignition is turned off, it is possible to wake up an electronic control unit using the counter electromotive force generated by forced rotation of a motor included in the electric steering system, and control the electronic control unit to supply a reaction force to the motor to restrict rotation of the steering wheel.

[0039] Therefore, according to embodiments of the present disclosure, it is possible to prevent accidental rotation of the steering wheel in a vehicle with the ignition off, thereby preventing vehicle theft and maintaining vehicle stability. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows an example of a schematic configuration of an electric power steering system. Fig. 2 shows a schematic configuration of an SBW steering system to which the embodiments can be applied. Fig. 3 shows a functional block diagram of a steering control device according to an embodiment. Fig. 4 shows an example of the detailed configuration of a steering control device according to an embodiment. Fig. 5 shows the detailed configuration of a rectifier circuit included in a wake-up circuit according to an embodiment. Fig. Figure 6 shows an example of a counter electromotive force waveform generated by the forced rotation of a motor. Fig. Figure 7 shows an example of the waveform of a DC output voltage generated by rectifying the counter electromotive force by a rectifier circuit. Fig. 8 shows an example of the detailed configuration of the switch circuit included in the wake-up circuit according to an embodiment. Fig. 9 shows a flowchart of a control method for an electric steering system according to an embodiment of the present disclosure. Fig. 10 shows the configuration of an SBW steering system, which is an example of an electric steering system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0040] In the following description of examples or embodiments of the present disclosure, reference is made to the accompanying drawings, in which specific examples or embodiments that may be implemented are shown for illustrative purposes, and in which the same reference numbers and characters may be used to designate the same or similar components even though they are shown in different accompanying drawings. Furthermore, in the following description of examples or embodiments of the present disclosure, detailed descriptions of known functions and components contained herein have been omitted in some embodiments of the present disclosure when it was determined that the description would be likely to obscure the subject matter.Terms such as "include," "comprise," "contain," "constitute," "made of," and "formed of" as used herein are generally intended to permit the addition of other components unless the terms are used with the phrase "only." As used herein, singular forms are intended to include plural forms unless the context clearly indicates otherwise.

[0041] Terms such as "first," "second," "A," "B," "(A)," or "(B)" may be used herein to describe elements of the disclosure. None of these terms are used to define an importance, order, sequence, or number of elements, etc., but are used merely to distinguish the corresponding element from other elements.

[0042] When it is said that a first element is "connected or coupled" to a second element, "contacts or overlaps" it, etc., this should be interpreted to mean that the first element may not only be "directly connected or coupled" to the second element, or "directly contact or overlap" it, but also that a third element may be "interposed" between the first and second elements, or that the first and second elements may be "connected or coupled" to each other, or "contact or overlap" 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," "contact or overlap," etc.

[0043] When time-related terms such as "after", "subsequent to", "following", "before" and the like are used to describe processes or sequences of elements or configurations, or sequences or steps in the operation, processing, or manufacturing process, these terms are used to describe non-consecutive or non-sequential processes or sequences unless the term "direct" or "immediate" is used.

[0044] When mentioning dimensions, relative sizes, etc., it should also be noted that numerical values ​​for an element or characteristic, or corresponding information (e.g., grade, range, etc.), include a tolerance or margin of error that may be caused by various factors (e.g., process factors, internal or external influences, noise, etc.), even if a relevant description is not specified. Furthermore, the term "could" includes all meanings of the term "may."

[0045] Fig. 1 shows an example of a schematic configuration of an electric power steering system.

[0046] A steering device or steering system can be used as a device for controlling the direction of travel of a vehicle, and recently an electric power steering (EPS) system has been widely used, in which a steering motor provides the required steering force through electronic control.

[0047] An EPS system or device may be used to rotate a steering column or move an associated rack and pinion by driving an EPS steering motor in response to steering torque applied by a driver to a steering wheel.

[0048] An EPS system in which a steering motor rotates a steering column may be referred to as a column EPS system or a C-type EPS system. In the C-type EPS system, a steering column may be connected to a universal joint and a pinion gear, and the pinion gear may be coupled to a gear of a rack connected to a vehicle wheel.

[0049] Fig. 1 shows a C-type EPS system. The C-type EPS system may include a steering column 30 connected to a steering wheel 20, a sensor unit 40 installed on the steering column, a steering motor 70 for rotating the steering column, and an electronic control unit (ECU) 10 as a steering control unit or steering control circuit for controlling the steering motor. A dedicated reduction gear may be connected to the steering motor, and the reduction gear may be interlocked between the steering column and the steering motor.

[0050] The steering column 30 may be connected to the steering wheel 20 and rotated together with the steering wheel 20. The shape of the steering column 30 may be cylindrical.

[0051] Although not shown, the steering column 30 may be interlocked with one or more reduction gears, and any one of a plurality of reduction gears may be connected to an outer peripheral surface of the steering column 30.

[0052] The sensor unit 40 may include a steering angle sensor, a torque sensor and a vehicle speed sensor.

[0053] The steering angle sensor can detect a steering angle generated by the rotation of the steering wheel 20. Furthermore, the steering angle sensor 40 can output a steering angle signal containing information about the steering angle.

[0054] The torque sensor can detect the steering torque generated by the rotation of the steering wheel 20. Furthermore, when the steering torque is detected, the torque sensor can output a steering torque signal containing information about the steering torque.

[0055] The steering torque can be understood here as a torque acting on a torsion bar located between an input shaft and an output shaft of the steering column 30. Therefore, the steering torque can be detected even when the steering wheel 20 is not rotating.

[0056] The vehicle speed sensor can detect the speed of a vehicle and output a vehicle speed signal that indicates information about the vehicle speed.

[0057] The steering control unit 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 control current corresponding to the rack position to the steering motor 70. The steering information may include one or more of a steering angle signal output from a steering angle sensor, a steering torque signal output from a torque sensor, and a vehicle speed signal output from a speed sensor.

[0058] The ECU 10 can be implemented with hardware and software including a microcontroller unit (MCU), an inverter, a printed circuit board (PCB), and the like.

[0059] The steering motor 70 can receive a control current from the ECU 10 and be driven with torque and speed corresponding to the control current. Although not shown, the steering motor 70 can be coupled to a reduction gear arranged on the steering column 30. The rotation of the steering motor 70 can rotate the reduction gear connected to the steering column 30 and the steering column.

[0060] Meanwhile, the steering column can be rotated by the rotation of the steering motor 70, and accordingly, the rack connected to the pinion at the output end of the steering column can move left and right.

[0061] Accordingly, the vehicle can be steered by moving the wheels connected to both ends of the rack to the left or right.

[0062] The steering motor 70 associated with the C-type EPS system may be, but is not limited to, a three-phase motor.

[0063] The ECU 10 may perform the function of receiving power from a power supply unit (not shown), generating a target current to be supplied to each winding of the steering motor using an inverter, and supplying the target current to the steering motor.

[0064] In the C-type EPS system, when the steering motor 70 rotates the steering column 30 to apply the steering assist force, the steering assist force can be transmitted to the rack 12 via the pinion. When the rack moves left and right, the wheels connected to it can be steered left and right.

[0065] An EPS system in which a steering motor directly moves a rack connected to a wheel may be referred to as a rack-and-pinion EPS system or an R-type EPS system.

[0066] In the R-type EPS system, the steering motor and the rack can be connected by a belt or gear, with a reduction gear such as a ball nut interposed. When the steering motor rotates, the ball nut reduction gear connected to the rack rotates, and the rack can move left and right according to the rotation of the gear to steer the wheels.

[0067] Fig. 2 shows a schematic configuration of an SBW steering system to which the embodiments can be applied.

[0068] An SBW steering system, which is a Steer-by-Wire (SBW) type EPS system, is an example of an EPS system.

[0069] The SBW steering system may include a structure in which the mechanical coupling devices such as a steering column, a universal joint, or a pinion shaft between a steering wheel and a wheel are removed.

[0070] As in Fig. 2, the SBW steering system to which an embodiment of the present disclosure is 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.

[0071] 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 force motor 117 as a motor device for providing a reaction force torque to the steering wheel in accordance with the steering by a lower rack, and an upper ECU 119 for controlling the reaction force motor. This upper device 110 may be referred to as a steering feedback actuator (SFA).

[0072] In addition, the lower device 120 may include a rack 122 connected to a wheel 128 of a vehicle, a steering drive motor 127 for moving the rack left and right, and a lower ECU 129 for controlling the steering drive motor.

[0073] The lower ECU 129 of the lower device 120 can generate a steering assist torque signal proportional to the steering torque applied to the steering wheel and generate a drive signal to move a rack connected to a tie rod of a wheel left and right using a steering assist torque signal.

[0074] The lower device 120 can control the steering drive motor via a ball-nut reduction gear based on the drive signal. The lower device can be referred to as a road wheel actuator (RWA).

[0075] That is, in the SBW steering system, the upper device, which includes a steering wheel, a steering column, and a reaction force motor, and the lower device, which includes a rack and pinion drive device (i.e., a pinion gear, a ball nut, and a steering drive motor), can operate independently of each other without any mechanical interconnection.

[0076] Therefore, to provide the driver with a steering feel, it is necessary to rotate the steering wheel connected to the upper device in accordance with the movement of the rack of the lower device, where the actual steering takes place. In this case, the force or torque acting on the steering wheel can be referred to as the reaction force or reaction force moment.

[0077] In the meantime, the steering system must not be in operation when the vehicle's engine is off or the ignition is off.

[0078] That is, if the steering wheel is turned in a state where the vehicle engine is off or the ignition is off to allow the wheels to turn, a problem may occur in which the wheels of a stopped or parked vehicle are steered randomly.

[0079] Turning the steering wheel with the ignition off may cause the vehicle to be steered, which may facilitate vehicle theft and reduce the stability of the parked vehicle.

[0080] Therefore, the steering wheel must be locked when the vehicle's engine is off or the ignition is off.

[0081] Meanwhile, in the C-type EPS system or 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 locked automatically because the mechanical structures such as a steering column, a steering rack, and a reduction gear are locked between the steering wheel and the wheel.

[0082] However, with SBW steering, the upper device connected to the steering wheel and the lower device connected to the rack are mechanically separated. Therefore, the steering wheel connected to the upper device can rotate or a vehicle wheel connected to the lower device can be steered even if the reaction force motor or steering motor is turned off due to the vehicle ignition being turned off.

[0083] 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 freely because the steering wheel and steering column are separated from the lower device.

[0084] In addition, the associated rack can move left and right even if the steering motor of the lower device is turned off due to the vehicle ignition being turned off, so that the vehicle wheels can be steered at will.

[0085] That is to say, in contrast to the EPS system of type C or type R, a separate locking function is required for the SBW steering system, which restricts the rotation of the steering wheel or the movement of the rack in the event of the vehicle ignition being switched off.

[0086] Accordingly, the SBW steering system must be provided with a locking device that forcibly blocks the reaction force motor or the steering motor in the event of the vehicle ignition being switched off.

[0087] As an example of such a locking device, a separate coupling device can be provided to mechanically connect the upper device and the lower device.

[0088] As a further example of a locking device, a solenoid can be provided for locking the steering column in the event of the vehicle ignition being switched off.

[0089] Another example of a locking device may be a locking device that includes a locking circuit for limiting motor rotation. In this case, the locking circuit may be powered independently of the vehicle's ignition being turned off, and the locking circuit may prevent the motor from rotating by short-circuiting the motor's windings.

[0090] Generally, a motor used in a steering system may be a three-phase motor, which includes a U-phase, a V-phase, and a W-phase, and corresponding U-phase, V-phase, and W-phase coils.

[0091] If one input terminal of each phase coil in such a three-phase motor is potential-free, the three-phase motor can rotate freely.

[0092] Therefore, when the vehicle ignition is turned off, the input terminal of the three-phase steering motor belonging to the EPS system, especially the SBW steering motor, may float and the steering motor rotates accordingly, causing vehicle stability problems.

[0093] Therefore, an interlock circuit capable of preventing motor rotation by short-circuiting an input terminal of a three-phase coil of a reaction force motor or a steering motor in the SBW steering system to the same potential when the vehicle ignition is turned off may be provided.

[0094] An EPS system including the SBW steering system may include a steering control circuit for controlling a steering motor.

[0095] To drive / control the steering motor, an SBW steering control unit may include a power supply unit and a steering control circuit to supply drive current to the steering motor.

[0096] The steering control circuit may also be referred to as a steering control unit, steering ECU, or similar.

[0097] In general, 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 driver circuit or a gate driver circuit for controlling the inverter.

[0098] In particular, the steering control circuit of the SBW steering system may include, in addition to the inverter and the inverter driver circuit (or gate driver circuit), a lock circuit to prevent rotation of the steering motor or the reaction force motor in the event of vehicle ignition, as described above.

[0099] Such an interlock circuit can be activated by an interlock signal provided by the steering control unit when the vehicle ignition is off, and can prevent the rotation of the motor by short-circuiting the multi-phase winding of the reaction motor or the steering motor.

[0100] The locking circuit must be in operation when the vehicle ignition is off, which can have the disadvantage that the power for operating the locking circuit is consumed even when the vehicle ignition is off.

[0101] In addition, since a separate interlock circuit must be provided, the electric steering control device can be complicated.

[0102] Therefore, a simple and low-power steering control device is proposed below that limits the rotation of the EPS steering wheel when the vehicle ignition is switched off.

[0103] Fig. 3 shows a functional block diagram of a steering control device according to an embodiment.

[0104] As in Fig. 3, a steering control device according to one embodiment may include a steering control unit 200 that controls the rotation of a motor 400 connected to a steering wheel, and a wake-up circuit 300 that wakes up the steering control unit using counter electromotive force.

[0105] The wake-up circuit 300 can wake up the steering control unit using the counter electromotive force generated when the engine is forced to rotate by an external force when the vehicle ignition is off.

[0106] More specifically, the wake-up circuit 300 may include a rectifier circuit 310 for rectifying the three-phase counter electromotive voltage of a sine wave and outputting a DC voltage above a certain threshold, and a switch circuit 330 that is turned on using an output signal of the rectifier circuit to wake up the steering control unit.

[0107] An example of the detailed configuration of this wake-up circuit 300 will be described below with reference to Fig. 6 described in more detail.

[0108] In addition, the steering control unit 200 may determine a stopped vehicle state based on the vehicle status information I_state received from a sensor 500 after wake-up.

[0109] In this case, the steering control unit 200 can apply the reaction torque to the motor 400 only when it is determined that the vehicle is in the stopped state.

[0110] In this case, the vehicle status information may include at least one of the following information: vehicle ignition information, vehicle speed information, vehicle door locking information, vehicle door open information, driver entry information, seat belt fastening information, and anti-theft alarm activation information.

[0111] Accordingly, the sensor 500 may include a vehicle ignition sensor, a vehicle speed sensor, a vehicle door sensor, a weight detection sensor, or an image sensor for detecting driver entry, a seat belt fastening sensor, an anti-theft alarm sensor, etc.

[0112] The vehicle status information can be transmitted to the steering control unit 200 via a CAN communication network connected to each sensor.

[0113] In particular, the steering control unit 200 may determine that the vehicle is in a stopped state if at least one of the following conditions exists: a state in which the vehicle ignition information indicates a vehicle off state, a state in which the vehicle speed information indicates a vehicle stopped state and the vehicle door lock information indicates a vehicle locked state, a state in which the vehicle door opening information indicates that one or more of the vehicle doors are open, a state in which the driver entry information indicates that the driver or passenger is not in the vehicle, a state in which the seat belt fastening information indicates that the seat belt is not fastened, a state in which the anti-theft alarm function activation information indicates,that the activation condition of the vehicle anti-theft device in the vehicle is met.,

[0114] For example, after wake-up, the steering control unit 200 may generate and transmit reaction torque to the engine only when the vehicle ignition is off and the vehicle is in the stopped state.

[0115] As another example, the steering control unit that wakes up when the vehicle ignition is off may apply the reaction torque to the motor when the vehicle status information indicates that the vehicle is in the stopped state, even if the vehicle is subsequently in a vehicle ignition on state, thereby preventing the steering wheel from turning.

[0116] This is because, for example, in the case where the steering control unit wakes up due to a forced rotation of the steering wheel, the rotation of the steering wheel must be restricted when the vehicle is in an abnormal driving state such as a stopped state, a vehicle door open state, a vehicle door locked state, an unoccupied state of the vehicle, a seat belt not fastened state, an activation state of an anti-theft device of the vehicle, even if the vehicle is thereafter in an ignition-on state because an unqualified person attempted to start the vehicle or start the vehicle remotely.

[0117] Furthermore, according to one embodiment, the determination of the stopped state and the application of the reaction force moment can only be carried out for a certain period of time after the steering control unit has been woken up.

[0118] Because when the steering control unit is awakened by a forced rotation of the steering wheel, it is not necessary to determine the stopped state and apply the torque of the reaction force after the vehicle enters the normal power-on state and starts normal driving.

[0119] For example, if an authorized driver forcibly turns the steering wheel before turning on the vehicle ignition, no reaction torque needs to be applied even if the steering control unit is woken up according to the embodiment, so that it is possible to determine the stopped vehicle state and apply the reaction torque only for a certain threshold period.

[0120] Meanwhile, the steering control unit 200 according to the embodiment may include a regulator, an inverter, a gate driver, and a microcontroller (MCU). A detailed configuration of the steering control unit 200 will be described below with reference to Fig. 4 described in more detail.

[0121] The electric power steering system having the steering control device according to this embodiment may be a general electric steering system, e.g., a C-type EPS system, an R-type EPS system, etc. In this case, the motor may be a steering motor that rotates the steering column or the rack to steer the vehicle wheels.

[0122] Alternatively, the steering control device shown in this embodiment can also be used in a steer-by-wire (SBW) steering system.

[0123] In particular, the steering control device according to this embodiment can be mounted on an upper device constituting the SBW steering system. In this case, the motor can be a reaction motor included in the upper device of the SBW steering system.

[0124] For example, according to one embodiment, the electric steering system may be a steer-by-wire steering system comprising an upper device with a reaction motor connected to the steering wheel, and a lower device mechanically separated from the upper device and comprising a steering drive motor connected to the wheel of the vehicle. In this case, the motor connected to the steering wheel may be the reaction motor included in the upper device.

[0125] In this case, the reaction torque may be a torque that rotates the reaction motor in a direction opposite to the forced rotation direction of the reaction motor.

[0126] More specifically, the SBW steering system including the steering control device according to an embodiment as shown in Fig. 2, an upper device 110 and a lower device 120, which 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 referred to as a DCU (Domain Control Unit).

[0127] 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 for providing a reaction torque to the steering wheel in accordance with the steering by the rack, and an upper ECU 119 for controlling the reaction motor.

[0128] In addition, the lower device 120 may include a rack 127 connected to a wheel 128, a steering drive motor 127 for moving the rack left and right, and a lower ECU 129.

[0129] 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 steering rack connected to the tie rod of the wheel left and right.

[0130] In particular, the steering control device according to this embodiment can be attached to the upper device 110 which implements the SBW steering system as shown in Fig. 2.

[0131] In this case, the motor 400 may be a reaction motor 117 included in the upper device 110 of the SBW steering system, and the steering control unit 200 may be an upper ECU 119 included in the upper device 110 of the SBW steering system.

[0132] That is, the motor 400 and the steering control unit 200, which are arranged in the Fig. 3, the reaction motor 117 and the upper ECU 119, respectively, which are included in the upper device 110 of the steering control device shown in Fig. 2 shown SBW steering system.

[0133] The present disclosure is not limited thereto, and the control device according to an embodiment may be applied to the lower device 120 of the SBW steering system.

[0134] In this case, the engine 400, which is in the Fig. 3, the steering drive motor 127 contained in the lower device 120 of the steering control device shown in Fig. 2 shown SBW steering system.

[0135] In this case, the upper ECU 119 or the lower ECU 129 may be awakened by the counter electromotive force generated when the steering drive motor 127 is forced to rotate.

[0136] The awakened upper ECU 119 or lower ECU 129 can provide a reaction torque to suppress the forced rotation of the reaction motor 117 or the steering drive motor 127.

[0137] When a vehicle is parked with the ignition off, the wheels may be steered due to unusual changes in the parking space (parking tower, etc.) or an attempted theft of the vehicle.

[0138] In this case, the steering drive motor 127 connected to the wheel can be forced to rotate, and accordingly, a counter electromotive force can be generated in the winding of the steering drive motor 127.

[0139] Therefore, the upper ECU 119 of the upper device or the lower ECU 129 of the lower device can be awakened in the same manner as described above by utilizing the counter electromotive force generated in the winding of the steering drive motor 127.

[0140] When the steering wheel is forced to rotate by an external force, a counter electromotive force can be generated in the reaction motor 117 of the upper device 110, and when the wheel is forced to steer by an external force, the counter electromotive force can be generated at the steering drive motor 127 of the lower device 120.

[0141] Therefore, the control device according to one embodiment may wake up the upper ECU 119 or the lower ECU 129 using the counter electromotive force generated by one of the reaction force motors 117 or the steering drive motor 127 of the SBW steering system, and may supply the reaction torque for suppressing the forced rotation to the reaction motor 117 or the steering drive motor 127.

[0142] For example, when it is necessary to suppress the rotation of the steering wheel when the vehicle ignition is turned off, the control device may wake up the upper ECU 119 by using the counter electromotive force generated by the reaction motor 117 or the steering drive motor 127 of the SBW steering system and provide the reaction motor 117 connected to the steering wheel with a reaction torque that suppresses the forced rotation.

[0143] Alternatively, when there is a greater need to suppress the voluntary steering of the wheels when the vehicle ignition is off, the control device may wake up the lower ECU 129 using the counter electromotive force generated by the reaction motor 117 or the steering drive motor 127 of the SBW steering system and supply the reaction torque to the steering drive motor 127 connected to the wheel to suppress the forced rotation.

[0144] Meanwhile, the steering control device 200 may include a regulator, an inverter, a gate driver, and a microcontroller, and the wake-up circuit 300 according to the embodiment may utilize the counter electromotive force generated by the forced rotation of the motor to wake up the steering control unit 200 by turning on the regulator included in the steering control unit 200.

[0145] An example of the detailed configuration of the steering control unit 200 will be described below with reference to Fig. 4 described in more detail.

[0146] Meanwhile, the reaction torque applied by the wake-up steering control unit 200 to the motor 400 may be a torque that rotates the reaction motor in a direction opposite to the forced rotation direction of the motor 400.

[0147] That is, the steering control unit 200, which is awakened by the forced rotation of the motor when the vehicle ignition is turned off, can determine the reaction torque for suppressing the forced rotation of the motor, generate a control current corresponding to the reaction torque, and supply the control current to the windings of the motor.

[0148] The magnitude of the reaction torque may be proportional to the rotational torque caused by the forced rotation of the motor, and the direction of the reaction torque may 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 may be determined to be proportional to the magnitude of the counter electromotive force generated by the forced rotation of the steering wheel.

[0149] This makes it possible to suppress the rotation of the steering wheel by an external force when the vehicle ignition is switched off.

[0150] In addition, the steering control device can be turned off or enter a sleep mode after the reaction torque is delivered to the motor for a certain holding time after waking up.

[0151] In this case, the hold time can be set to a period of 2 to 5 seconds.

[0152] The hold time can also be expressed as a release delay time.

[0153] To ensure the holding time, the steering control unit 200 may include a separate locking circuit or delay circuit.

[0154] By using the hold time, stability can be further ensured by giving reaction torque to the motor and preventing the steering wheel from turning only for a certain time, even if the counter electromotive force disappears after the steering control unit is awakened.

[0155] Fig. 4 shows an example of the detailed configuration of a steering control device according to an embodiment.

[0156] The steering control device according to one embodiment may include a steering control unit 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 control unit 200 using the counter electromotive force generated by forced rotation of the motor due to an external force when the vehicle ignition is turned off. In this case, the steering control unit 200 may apply a reaction torque to the motor to suppress forced rotation of the motor after wake-up.

[0157] According to Fig. 4, the steering control unit 200 included in the steering control device according to an embodiment may be expressed as an ECU and may include a controller 210, an inverter 220, a gate driver 230, and a microcontroller (MCU) 240.

[0158] The regulator 210 may receive a battery voltage V_BAT from a power supply of a vehicle and regulate the battery voltage to output a control voltage for driving the MCU 440.

[0159] The controller 210 may include an enable terminal EN through which an enable signal is input to activate the controller.

[0160] The inverter 220 can take over the task of supplying the winding of the motor 400 with control current.

[0161] The inverter 220 may convert the battery voltage V_BAT of a battery as a vehicle power supply, which is direct current (DC) or a control voltage of the DC output of the controller 210, into alternating current (AC) and apply the converted alternating voltage (or alternating current) to the motor 400.

[0162] For example, if the engine is a reaction engine (117 in Fig. 2) included in the upper device of the SBW steering system, and the vehicle is in a driving state, the inverter 220 may apply a drive current to the motor 400, which may provide a reaction torque to be applied to the steering wheel to rotate the steering wheel in response to the wheel steering by the lower device.

[0163] The inverter can be controlled by the gate driver 230, which is described below, and the gate driver 230 can be controlled by the MCU 240.

[0164] Meanwhile, the motor 400 controlled by the steering control device according to an embodiment of the present disclosure may be a three-phase motor having u, v, and w phases.

[0165] In this case, the inverter 220, as in Fig. 4, an H-bridge circuit for supplying the three-phase windings (u-, v-, w-windings) of the motor 400 with u-phase drive current, v-phase drive current and w-phase drive current, respectively.

[0166] The gate driver 230 can control the drive of the inverter 220.

[0167] In particular, the gate driver 230 may input control signals to the gate terminals of the u-, v-, and w-circuit switches of the inverter 220 to control the inverter 220 to supply the u-phase drive current, the v-phase drive current, and the w-phase drive current to the motor 400.

[0168] The MCU 240 can control the operation of the gate driver 230 with the control voltage supplied by the regulator 210.

[0169] In particular, the MCU 240 may generate a gate driver enable signal to enable the gate driver 230 and provide the gate driver enable signal to the gate driver 230.

[0170] As a result, in a normal driving state of a vehicle, the MCU 240 can generate a control signal capable of generating a reaction torque corresponding to the wheel steering by 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 the drive current for the reaction torque to the motor 400 according to the control signal.

[0171] When the vehicle ignition is turned off, the battery voltage V_BAT may not be supplied to the controller 210, so the steering control unit 200 is turned off.

[0172] In this case, the three-phase winding of the motor 400 may be in a floating state, allowing the rotor of the motor 400 to rotate freely under an external force. Accordingly, the steering wheel connected to the motor 400 may also rotate freely, which may affect vehicle stability.

[0173] Therefore, the steering control device according to the present embodiment can wake up the steering control unit 200 in the state where the vehicle ignition is turned off and apply a reaction torque to the motor to suppress the rotation of the motor due to an external force and thereby prevent the rotation of the steering wheel.

[0174] In particular, the wake-up circuit 300 can wake up the steering control unit 200 that is in an off state or sleep state by utilizing the counter electromotive force generated when the motor is forced to rotate by an external force.

[0175] The awakened steering control unit 200 may apply a reaction torque to the motor to suppress the forced rotation of the motor.

[0176] The wake-up circuit 300 and the wake-up operation of the steering control unit using the wake-up circuit are described below.

[0177] As in Fig. 4, the wake-up circuit 300 may include a rectifier circuit 310 that rectifies the counter electromotive force and a switch circuit 330 that generates and outputs a wake-up signal Swu to wake up the steering control unit 200 according to the output voltage of the rectifier circuit.

[0178] For example, the switching 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 activating the controller 210 included in the steering control unit 200 and input the wake-up signal Swu to the enable terminal EN of the controller 210.

[0179] An example of the detailed configuration of the wake-up circuit 300 is described below with reference to the Fig. 5 to 8 are described in more detail.

[0180] Fig. 5 shows the detailed configuration of a rectifier circuit included in a wake-up circuit according to an embodiment, Fig. Figure 6 shows an example of a waveform of the counter electromotive force generated by the forced rotation of a motor, and Fig. 7 shows an example of a waveform of a DC output voltage generated by rectifying the counter electromotive force by a rectifier circuit.

[0181] As in Fig. 5, the rectifier circuit 310 included in the wake-up circuit according to this embodiment may be connected to the three-phase winding of the motor and receive sinusoidal back electromotive force signals SIN_u, SIN_v and SIN_w generated by the forced rotation of the motor from each winding.

[0182] The rectifier circuit 310 may include two diodes corresponding to each phase and a plurality of resistive elements to rectify the sinusoidal back electromotive force signals of each phase SIN_u, SIN_v and SIN_w.

[0183] As in Fig. 5, each of the sinusoidal back electromotive force signals SIN_u, SIN_v and SIN_w generated in each phase of the motor can be rectified by a two-diode rectifying circuit element to generate an output signal DC which is a DC voltage V_DC.

[0184] The following describes a case where the forced rotation of the engine by an external force occurs 0.5 seconds after the ignition is turned off, as an example.

[0185] As in Fig. 6, in a state where there is no forced rotation of the motor, a back electromotive force close to 0 is generated. After the forced rotation of the motor by an external force (about 0.5 seconds), the sinusoidal back electromotive force signal SIN_u, SIN_v and SIN_w with an amplitude of about 0.6 V and a duration of about 0.2 seconds can be generated from the windings of each phase of the motor.

[0186] When the sinusoidal counter electromotive force signals SIN_u, SIN_v and SIN_w generated in each phase winding are combined in the rectifier circuit as shown in Fig. 5, a DC voltage V_DC with a voltage of a specific threshold voltage of 0.4 V or more is generated, as shown in Fig. 7 shown.

[0187] In this case, the amplitude and duration of the sinusoidal counter electromotive force signal generated by each phase winding can vary depending on the rotational speed of the forced rotation of the motor, the change in angular velocity or the torque.

[0188] In addition, the magnitude of the DC voltage V_DC rectified by the rectifier circuit 310 (i.e., the magnitude of the output signal DC) may also vary depending on the rotational speed of the forced motor rotation, a change in the angular velocity or torque, and the resistance value of the resistive element.

[0189] 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 the threshold voltage that can turn on the first switching unit TR1 of the switching circuit 330, which will be described below.

[0190] Fig. 8 shows an example of the detailed configuration of the switch circuit included in the wake-up circuit according to an embodiment.

[0191] As in Fig. 8, the switching circuit 330 included in the wake-up circuit according to the embodiment may include a first switching unit TR1 turned on according to the output voltage DC of the rectifier circuit 310, a second switching unit TR2 turned on in response to the first switching unit being turned on, and a plurality of resistance elements.

[0192] The second switching unit TR2 may be turned on when the first switching unit TR1 is turned on, and input the wake-up signal Swu to the steering control unit 200 through the voltage V_BAT of the power supply to wake up the steering control unit 200.

[0193] In particular, the second switching unit TR2 may transmit a wake-up signal Swu corresponding to the battery voltage V_BAT, which is the voltage of the power supply unit, to the enable terminal EN of the controller 210 in the steering control unit 200.

[0194] In addition, the first switching unit TR1 and the second switching unit TR2 may be, but are not limited to, a transistor or a field effect transistor (FET) having a gate terminal, a source terminal, and a drain terminal.

[0195] For example, the gate terminal of the first switching unit TR1 included in the switching circuit 330 may be connected to the output terminal of the rectifier circuit 310 to receive the output signal DC of the rectifier circuit 310.

[0196] 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.

[0197] As in Fig. 8, for example, the source terminal of the second switching unit TR2 may be connected to the battery voltage V_BAT of the power supply unit, and the drain terminal of the second switching unit TR2 may be connected to the enable terminal of the regulator 210 included in the steering control unit 200.

[0198] In addition, the drain terminal of the first switching unit TR1 may be connected to the gate terminal of the second switching unit TR2, and the source terminal of the first switching unit TR1 may be grounded.

[0199] In this switching unit 330, the output signal DC of the rectifier circuit 310 above a certain threshold voltage can be fed into the gate terminal of the first switching unit TR1 when a counter electromotive force is generated by the forced rotation of the motor.

[0200] In this case, the threshold voltage may be a gate-source threshold voltage with which the first switching unit TR1 can be turned on.

[0201] If the voltage of the DC output signal of the rectifier circuit 310 is below the threshold voltage of the first switching unit TR1, a separate amplifier circuit may also be provided to boost the DC output signal to a value above the threshold voltage. For example, an amplifier circuit (not shown) may be arranged between the rectifier circuit 310 and the first switching unit TR1 and increase the voltage of the DC output signal of the rectifier circuit 310 to more than the gate-source threshold voltage of the first switching unit TR1.

[0202] In this case, the output signal of the rectifier circuit 310 can be input to the amplifier circuit, and the output signal of the amplifier circuit can be input to the gate terminal of the first switching unit TR1 of the switching circuit 330.

[0203] Accordingly, the first switching unit TR1 can be turned on and a voltage signal above a certain level can also be applied to the gate terminal of the second switching unit TR2.

[0204] 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, which is connected to the drain terminal of the second switching unit TR2.

[0205] When the controller 210 is activated, as in Fig. 4, the control voltage rectified by the regulator can be applied to the MCU 240 to wake up the steering control unit 200.

[0206] After waking up, the steering control unit 200 can determine the stopped state of the vehicle based on the vehicle state information I_state received from a sensor.

[0207] In this case, the steering control unit 200 can apply a reaction torque to the motor to counteract the external force that causes forced rotation of the motor only when it is determined that the vehicle is in a stopped state.

[0208] This can prevent the steering wheel from turning randomly even if an external force is used to turn the engine when the vehicle is turned off.

[0209] Fig. 9 shows a flowchart of a control method for an electric steering system according to an embodiment of the present disclosure.

[0210] As in Fig. 9, a control method of the electric steering system according to an embodiment may include a step S910 in which the wake-up circuit wakes up the steering control unit using the counter electromotive force generated when the motor connected to the steering wheel is forced to rotate by an external force, and a step S930 in which the woken-up steering control unit generates a reaction torque for suppressing the forced rotation of the motor and applies the reaction torque to the motor.

[0211] Furthermore, the control method of the electric steering system according to an embodiment may include a step S920 in which the awakened steering control unit determines a stopped state of the vehicle based on the vehicle status information received from the sensor.

[0212] In this case, if it is determined in step S920 that the vehicle is in the stopped state, the reaction torque may be applied to the motor in step S930.

[0213] The vehicle status information may include one or more of vehicle ignition information, vehicle speed information, vehicle door locking information, vehicle door open information, driver entry information, seat belt fastening information, and anti-theft alarm activation information.

[0214] The wake-up circuit for performing step S910 of waking up the steering control unit may include a rectifier circuit that rectifies the counter electromotive force and a switch circuit that activates the regulator according to the output voltage of the rectifier circuit.

[0215] For example, in step S910 of waking up the steering control unit, the rectifier circuit in the wake-up circuit may convert the sinusoidal counter electromotive force generated during the forced rotation of the motor into a DC voltage to output an output voltage.

[0216] Furthermore, the step S910 of waking up the steering control unit may include a step in which the switching circuit turned on by the output voltage inputs a wake-up signal by the voltage of the power supply to the enable terminal of the controller included in the steering control unit.

[0217] For this purpose, the switching circuit may include a first switching unit that is turned on in response to the output voltage and a second switching unit that is turned on in response to the first switching unit being turned on and inputs a wake-up signal based on the voltage of the power supply to the enable terminal of the regulator.

[0218] Furthermore, in step S930 of applying a reaction torque to the motor, the wake-up steering control unit may apply the reaction torque to the motor for a certain holding time and then turn off or enter a sleep mode (S940, S950).

[0219] In this case, the hold time can be expressed as a release delay time and set to a period of approximately 2 to 5 seconds.

[0220] The electric steering system to which the method according to this embodiment is applied may be an SBW steering system.

[0221] That is, the electric steering system or electric power steering may include an upper device with 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 wheel. The motor connected to the steering wheel may be the reaction motor included in the upper device.

[0222] Meanwhile, according to an embodiment of the present disclosure, there may be provided an electric steering system comprising a motor connected to the steering wheel of a vehicle, a steering control unit for controlling rotation of the motor, and a wake-up circuit that wakes up the steering wheel of the vehicle by a back electromotive force generated by the steering control unit in the event of forced rotation of the motor by an external force when the vehicle ignition is turned off.

[0223] In this case, the steering control unit can apply a reaction torque to the motor to suppress the forced rotation of the motor after awakening.

[0224] Since the specific configuration of the steering control unit and the wake-up circuit in the electric steering system may be the same as the configuration of the steering control unit of the electric steering system described above, a description is omitted to avoid duplication of the content.

[0225] However, the electric steering system to which embodiments of the present disclosure are applied may be an SBW steering system comprising an upper device having a reaction motor coupled to the steering wheel and a lower device mechanically separated from the upper device and having a steering drive motor coupled to the wheel, as described in more detail below.

[0226] Fig. 10 shows the configuration of an SBW steering system, which is an example of an electric steering system according to an embodiment of the present disclosure.

[0227] According to Fig. 10, according to one embodiment, the electric steering system may be a steer-by-wire steering system comprising an upper device 1100 having a reaction motor 1170 connected to a steering wheel 1120, and a lower device 1200 mechanically separated from the upper device and comprising a steering drive motor 1270 connected to the wheel of the vehicle.

[0228] The detailed configuration of the upper device 1100 and the lower device 1200 can be found in Fig. 2 described configuration.

[0229] The reaction motor 1170 of the upper device 1100 can apply a steering reaction torque to the steering wheel according to the steering of the wheel by 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.

[0230] The upper device 1100 may include an upper ECU 1190 for controlling the reaction motor 1170, and the upper ECU may be a steering control unit according to the embodiment of the present disclosure.

[0231] A wake-up circuit 1140 may be connected to the upper ECU 1190.

[0232] The wake-up circuit 1140 can wake up the upper ECU 1190 by utilizing the back electromotive force generated when the reaction motor 1170 is forced to rotate by an external force when the vehicle is in an ignition-off state.

[0233] The upper ECU 1190 can prevent forced rotation of the steering wheel by applying a reaction torque to the motor after waking up to suppress the forced rotation of the reaction motor 1170.

[0234] The wake-up circuit 1140 may include a rectifier circuit and a switch circuit, as shown in Fig. 5 to 8.

[0235] The upper ECU 1190 can, as shown in Fig. 4, a regulator for regulating the voltage from the power supply and an inverter for supplying control current to the winding included in the reaction motor 1170, a gate driver for controlling the operation of the inverter, and a microcontroller (MCU) for controlling the operation of the gate driver with a control voltage supplied by the regulator.

[0236] In addition, the wake-up circuit 1140 may include a rectifier circuit that rectifies the counter electromotive force generated by the forced rotation of the reaction motor and outputs a DC output voltage, and a switch circuit that activates the regulator according to the output voltage of the rectifier circuit.

[0237] The rectifier circuit of the wake-up circuit 1140 can convert the sinusoidal counter electromotive force generated during the forced rotation of the reaction motor 1170 into a DC voltage to output the output voltage.

[0238] Furthermore, the switching circuit of the wake-up circuit 1140 may include a first switching unit that is turned on according to the output voltage and a second switching unit that is turned on when the first switching unit is turned on and that inputs a wake-up signal based on the control voltage of the power supply to the enable terminal of the regulator.

[0239] In addition, after being awakened by the awakening circuit 1140, the upper ECU 1190 may determine the stopped state of the vehicle based on the vehicle status information received from the sensor and apply the reaction torque to the reaction force motor 1170 only in the vehicle stopped state.

[0240] In this case, the vehicle status information may be one or more of vehicle ignition information, vehicle speed information, vehicle door locking information, vehicle door open information, driver entry information, seat belt fastening information, and anti-theft alarm activation information.

[0241] After wake-up, the upper ECU 1190 may supply the reaction torque to the reaction force motor 1170 for a certain holding time and then be turned off or enter a sleep mode.

[0242] In the above, an example in which the embodiment is applied to the upper device of the SBW steering system has been described, but the present disclosure is not limited thereto.

[0243] For example, according to one embodiment, the control device may be attached to the lower device 1200 or to both the upper device 1100 and the lower device 1200 of the Fig. 10 shown SBW steering system.

[0244] The lower device 1200 may also include a wake-up circuit 1240 connected to a lower ECU 1290.

[0245] In this case, the upper ECU 1190 or the lower ECU 1290 may be awakened by the counter-electromotive force generated when the steering drive motor 1270 is forced to rotate.

[0246] The awakened upper ECU 1190 or lower ECU 1290 may provide reaction torque to the reaction motor 1170 or the steering drive motor 1270 to suppress the forced rotation.

[0247] When the vehicle ignition is turned off, the steering wheel may be forcibly turned or the wheels may be forcibly steered by an external force.

[0248] In this case, the reaction motor 1170 connected to the steering wheel or the steering drive motor 1270 connected to the wheel can be forced to rotate, and accordingly, the counter electromotive force can be generated in the winding of the reaction motor 1170 or the steering drive motor 1270.

[0249] 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 can wake up the upper ECU 1190 of the upper device or the lower ECU 1290 of the lower device by utilizing the counter electromotive force generated in the winding of the reaction motor 1170 or the steering drive motor 1270.

[0250] That is, when the steering wheel is forcibly rotated by an external force, a counter electromotive force can be generated in the reaction motor 1170 of the upper device 1100, and when the wheel is forcibly steered by an external force, the counter electromotive force can be generated in the steering drive motor 1270 of the lower device 1200.

[0251] Therefore, the control device according to one embodiment may wake up the upper ECU 1190 or the lower ECU 1290 by using the counter electromotive force generated by the reaction motor 1170 or the steering drive motor 1270 of the SBW steering system, and may provide a reaction torque to suppress the forced rotation of the reaction motor 1170 or the steering drive motor 1270.

[0252] For example, if there is a greater need to suppress the rotation of the steering wheel when the vehicle ignition is off, the controller may wake up the upper ECU 1190 using the counter electromotive force generated by the reaction motor 1170 or the steering drive motor 1270 of the SBW steering system and provide a reaction torque to the reaction motor 1170 connected to the steering wheel to suppress the forced rotation.

[0253] Alternatively, when there is a greater need to suppress the steering of the wheels when the vehicle ignition is off, the controller may wake up the lower ECU 1290 using the counter electromotive force generated by the reaction motor 1170 or the steering drive motor 1270 of the SBW steering system and provide a reaction torque to the steering drive motor 1270 connected to the vehicle wheel to suppress the forced rotation.

[0254] As described above, the present embodiment can be applied to the SBW steering system and selectively prevent forced rotation of the steering wheel by an external force or forced steering of the wheel by an external force.

[0255] Furthermore, according to embodiments of the present disclosure, it is possible to suppress the rotation of the steering wheel or the arbitrary steering of the wheels by utilizing the counter electromotive force generated by the forced rotation of the motor included in the electric steering system when the vehicle ignition is turned off.

[0256] Furthermore, according to embodiments of the present disclosure, it is possible to wake up the electronic control device using the counter electromotive force generated when the motor included in the electric steering system is forced to rotate and supply the reaction force to the motor through the electronic control unit, thereby suppressing the rotation of the steering wheel or preventing arbitrary steering of the wheels.

[0257] Accordingly, according to embodiments of the present disclosure, it is possible to prevent theft of a vehicle when the ignition is off and to maintain the stability of the vehicle using a simple device with low power consumption.

[0258] It should be noted that although all or some of the configurations or elements included in one or more of the embodiments described above 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 subject matter or spirit of the present disclosure, all or some of the configurations or elements included in the one or more embodiments may be combined to form one or more configurations or components, or operate in (at least) one such configuration or (at least) one such component.Furthermore, each of the configurations or elements included in one or more 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 of one or more combined hardware configurations. Codes or code segments constituting the (at least one) computer program may be readily produced by one skilled in the art. Embodiments of the present disclosure may be implemented as computer programs stored in computer-readable media, read by a computer, and executed.The media for storing computer programs may include, for example, a magnetic storage medium, an optical recording medium and a carrier wave medium.

[0259] Unless otherwise specified herein, terms "including," "comprising," "forming," "having," and the like described herein mean that one or more other configurations or elements may be further included in a corresponding configuration or element. Unless otherwise defined herein, all terms used herein, including technical and scientific terms, have the same meaning as understood by those skilled in the art. Commonly used terms, such as those defined in dictionaries, should be construed as having the same meanings in the context of the related art and should not be construed as having ideal or overly formal meanings unless otherwise defined herein.

[0260] The above description is presented to enable a person skilled in the art to implement and utilize the technical spirit of the present disclosure and is provided in the context of a particular application and its requirements. Various modifications, additions, and substitutions to the described embodiments will be readily 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 the accompanying drawings provide an example of the technical spirit of the present disclosure for illustrative purposes only. That is, the disclosed embodiments are intended to illustrate the scope of the technical spirit of the present disclosure.Thus, the scope of the present disclosure is not limited to the illustrated embodiments, but should be consistent with the broadest scope still consistent with the claims. The scope of the present disclosure should be interpreted based on the following claims, and all technical ideas within the scope of equivalents thereof should be construed as being included within the scope of the present disclosure. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] KR 10-2023-0154451

[0001]

Claims

[1] A device for controlling an electric power steering system, the device comprising: a steering control unit (200) configured to control a motor (400) operatively connected to a steering wheel (20); and a wake-up circuit (300) configured to wake up the steering control unit (200) when the vehicle ignition is turned off using a counter electromotive force generated by the rotation of the motor (400) caused by an external force, wherein the steering control unit (200) is configured to apply a reaction torque to the motor (400) after awakening to suppress the rotation of the motor (400) caused by the external force. [2] The apparatus of claim 1, wherein the steering control unit (200) is configured to determine, upon wake-up, whether the vehicle is in a stopped state based on vehicle status information (I_state) received from a sensor (500), and to apply the reaction torque to the motor (400) only when the vehicle is in the stopped state. [3] The device according to claim 2, wherein the vehicle status information (I_state) comprises at least one of the following information: vehicle ignition information, vehicle speed information, vehicle door locking information, vehicle door open information, driver entry information, seat belt fastening information, or anti-theft alarm function activation information. [4] Device according to one of the preceding claims, wherein the steering control unit (200) comprises: a regulator (210) arranged to regulate a voltage (V_BAT) from a power supply; an inverter (220) arranged to supply control current to the windings of the motor (400); a gate driver (230) configured to control the inverter (220); and a microcontroller (MCU) (240) configured to be driven by a drive voltage supplied by the regulator (210) and to control the gate driver (230). [5] The apparatus of claim 4, wherein the wake-up circuit (300) comprises: a rectifier circuit (310) arranged to rectify a sinusoidal counter electromotive force generated by the external force during rotation of the motor (400) into a DC voltage to output the DC output voltage; and a switch circuit (330) arranged to activate the regulator (210) in dependence on the DC output voltage of the rectifier circuit (310). [6] The device according to claim 5, wherein the switching circuit (330) comprises a first switching unit (TR1) configured to be turned on in response to the DC output voltage, and a second switching unit (TR2) configured to be turned on in response to the first switching unit (TR1) being turned on and inputting a wake-up signal (Swu) by the voltage (V_BAT) of the power supply to an enable terminal (EN) of the regulator (210). [7] Device according to one of the preceding claims, wherein: the motor (400) is a reaction motor (117) connected to the steering wheel (20), and the electric power steering system comprises a steer-by-wire (SBW) steering system comprising an upper device (110) having the reaction motor (117) connected to the steering wheel (20), and a lower device (120) not mechanically connected to the upper device (110) and comprising a steering drive motor (127) connected to a vehicle wheel. [8] Device according to one of the preceding claims, wherein the steering control unit (200) is arranged to supply the reaction torque to the motor (400) for a holding time after wake-up and then to switch off or enter a sleep mode after the holding time. [9] A method for controlling an electric power steering system, the method comprising: waking up a steering control unit (200) by a wake-up circuit (300) using a counter electromotive force generated by the rotation of a motor (400) caused by an external force, the motor (400) being operatively connected to a steering wheel (20); and after the steering control unit (200) is awakened by the wake-up circuit (300), controlling by the steering control unit (200) to apply a reaction torque to the motor (400) to suppress the rotation of the motor (400) caused by the external force. [10] The method of claim 9, further comprising, after the steering control unit (200) is woken up by the wake-up circuit (300), determining whether a vehicle is in a stopped state based on vehicle status information (I_state) received from a sensor (500), wherein the controlling to apply the reaction torque to the motor (400) is performed only when the vehicle is in the stopped state. [11] The method of claim 9 or 10, wherein waking up the steering control unit (200) comprises: rectifying a sinusoidal counter electromotive force generated by the external force during rotation of the motor (400) into a DC voltage to output an output voltage; and after switching on a switching circuit (330), inputting a wake-up signal through the switching circuit (330) by a voltage (V_BAT) of a power supply to an enable terminal (EN) of a controller (210) included in the steering control unit (200). [12] Electric power steering system comprising: a motor (400) operatively connected to a steering wheel (20) of a vehicle; a steering control unit (200) arranged to control the rotation of the motor (400); and a wake-up circuit (300) configured to wake up the steering control unit (200) when the vehicle ignition is turned off using a counter electromotive force generated by the rotation of the motor (400) caused by an external force, wherein the steering control unit (200) is configured to control a reaction torque to the motor (400) after awakening to suppress the rotation of the motor (400) caused by the external force. [13] An electric power steering system according to claim 12, wherein: the motor (400) is a reaction motor (117) connected to the steering wheel (20), and the electric power steering system comprises a steer-by-wire (SBW) steering system comprising an upper device (110) having the reaction motor (117) connected to the steering wheel (20), and a lower device (120) not mechanically connected to the upper device (110) and comprising a steering drive motor (127) connected to a vehicle wheel. [14] An electric power steering system according to claim 13, wherein the steering control unit (200) comprises: a regulator (210) arranged to regulate a voltage (V_BAT) from a power supply; an inverter (220) arranged to supply control current to the windings of the reaction motor (117); a gate driver (230) configured to control the inverter (220); and a microcontroller (MCU) (240) configured to be driven by a control voltage supplied by the regulator (210) and to control the gate driver (230). [15] An electric power steering system according to claim 14, wherein the wake-up circuit (300) comprises: a rectifier circuit (310) configured to rectify a sinusoidal counter electromotive force generated by the external force during rotation of the motor (400) into a DC voltage to output the DC output voltage; and a switch circuit (330) arranged to activate the regulator (210) in dependence on the DC output voltage of the rectifier circuit (310), wherein the switching circuit (330) comprises a first switching unit (TR1) configured to be turned on in response to the DC output voltage, and a second switching unit (TR2) configured to be turned on in response to the first switching unit (TR1) being turned on and to input a wake-up signal by the voltage (V_BAT) of the power supply to an enable terminal (EN) of the regulator (210).

Images