Method for controlling a switched reluctance motor for an electric gearshift system

Abstract

A method for controlling a switched reluctance motor for an electric shift lever system comprising a switched reluctance motor, the method comprising the following method steps: Determine whether a current gear and a target gear match or not; Rotate the motor towards the target gear if the current gear and the target gear do not match; Performing an OFF control of the engine if the current gear and the target gear match; Executing a reverse control if a difference between a current position and a target position of the motor is below a first setpoint; and Switching off the motor if the difference between the current position and the target position of the motor is below a second setpoint, wherein the reverse drive operation time control is carried out such that an operation time and time period are determined based on a rotational speed of the engine, and, if a value of the engine speed is below a third target value, a first reverse drive operating time control is executed, and, if the magnitude of the engine speed is below a fourth setpoint, a second reverse drive operating time control is executed, wherein, if the reverse drive duty cycle controller uses a duty step of 2.5 ms and a cycle period is 10 ms, the reverse drive duty cycle controller with a duty of 50% performs an output with two ON and two OFF duty times, and the reverse drive duty cycle controller with the duty cycle of 25% performs an output with one ON and three OFF duty cycles.

Description

Field of the invention

[0001] The present invention relates to a method for controlling a switched reluctance motor for an electric shift lever system (ie, shift-by-wire, also called SBW shift system), in particular, wherein simulation control of a pulse width modulation waveform (hereinafter referred to as PWM waveform) is performed to solve the problems of generation of shock and noise in the control operation of a motor. State of the art

[0002] A transmission is a core component for driving a motor vehicle, which can be used to increase or decrease the torque of an internal combustion engine depending on the driving situation of the motor vehicle and thus to transfer the driving force generated by the internal combustion engine to the wheels.

[0003] Transmissions are usually classified into manual and automatic transmissions depending on the shifting method, although automatic transmissions have recently been used for the majority of vehicles as their operation is very convenient because there is no need to operate a clutch separately, and they also have the advantage of allowing the vehicle to start smoothly.

[0004] Furthermore, depending on the shifting method, automatic transmissions are also classified into those with a mechanical shift lever system, in which the shifting is carried out by means of a linkage structure via a wire, and those with an electric shift lever system, in which the shifting can be carried out by utilizing the electrical signals by means of a substrate instead of such a linkage structure.

[0005] Unlike the mechanical shift lever system, the electric shift lever system, despite the disadvantage of its high price, enables the transmission of information about a driver-selected gear as electrical signals without the mechanical connection between the transmission and the shift lever. Therefore, it has the advantage of significantly reducing shock and vibration compared to the conventional mechanical shift lever system. Due to this advantage, vehicles adopting the electric shift lever system, or shift-by-wire, have recently become increasingly common.

[0006] In the electric shift lever system, a shift unit includes a detent plate rotationally driven primarily by an electric motor; a manual selector valve engageably mounted in the detent plate to set a shift range of the automatic transmission to a shift range corresponding to a rotational position of the detent plate; and a detent spring having a supportable restricting means and restricting rotation of the detent plate by being fitted into a concave portion formed in the detent plate and limiting the shift range within a certain range.

[0007] However, the electric gearshift system also requires that an electric actuator, i.e. an electric motor, is driven in rotation, which is why the occurrence of shocks and vibrations cannot be completely prevented.

[0008] Fig. 9 is a diagram illustrating a state in which the motor positions are controlled according to the prior art.

[0009] In relation to Fig. 9, the motor can be accelerated by the shape of the locking plate and the elastic reaction force of the locking spring. In this process, the accelerated motor causes shock and noise in a process in which one end of the locking spring engages the locking plate, causing the motor to generate heat during long-term use, thereby affecting its durability.

[0010] In order to reduce the shocks and noises generated during such a process in the conventional electric shift lever system, a control strategy is also used by which the motor is controlled to be held at 90% for a certain period of time (e.g. 100 ms) when a target position (e.g. concave section) is reached and then its drive is released (OFF).

[0011] However, despite these efforts to reduce shocks and noise, it is still difficult to meet the requirements of low-vibration properties and low noise for the vehicle.

[0012] US 2017 / 0 307 074 A1 discloses a shift range control device for switching a shift range by controlling a shift range switching device including a motor and a driven target rotated by the torque of the motor.

[0013] A shift-by-wire system which is installed in a vehicle and operates an actuating object by driving a manual shaft on the basis of a shift operation is known from DE 11 2010 000 065 T5.

[0014] Furthermore, JP H07 - 81 448 A describes a position determining device which determines the specific range position of the following range switching valve on the basis of a learning value. Prior art literaturePatent document

[0015] Patent publication 0001: US 8 620 537 B2: “Shiftby-wire system”. Disclosure of the inventionObject of the invention

[0016] In the generic switched reluctance motor (SR motor), on-off control is mostly performed because PWM control used in DC motor or brushless DC motor cannot be easily achieved.

[0017] Unlike DC motors or brushless DC motors, switched reluctance motors do not use a permanent magnet, but rather a rotor composed of a static transfer switch (STS) or similar device. Therefore, a certain period of time is required for the motor to magnetize. Therefore, it has traditionally been considered difficult to apply PWM control, in which on-off switching is repeated in a short period, to the control of switched reluctance motors.

[0018] According to various embodiments of the present invention, the shock and noise generated when controlling a motor are to be reduced by performing simulation control of a PWM waveform, which is difficult to apply to the conventional switched reluctance motor. Solution to the problem of the invention

[0019] According to various embodiments of the present invention, a method for controlling a switched reluctance motor for an electric shift lever system (ieA shift-by-wire shifting system comprising a switched reluctance motor is provided, the method comprising the steps of: deciding whether or not a current gear and a target gear agree with each other; rotating the motor toward the target gear if the current gear and the target gear do not agree with each other; executing an OFF control of the motor if the current gear and the target gear agree with each other; executing a reverse drive operation timing control if a difference between a current position and a target position of the motor is below a first target value; and turning off the motor if the difference between the current position and the target position of the motor is below a second target value.The reverse drive timing control is executed such that an operation time and duration are determined based on a motor speed. If a magnitude of the motor speed is below a third set value, a first reverse drive timing control is executed. If the magnitude of the motor speed is below a fourth set value, a second reverse drive timing control is executed. If the reverse drive timing control uses a duty step of 2.5 ms and a cycle period is 10 ms, the reverse drive timing control with a 50% duty time executes an output with two ON and two OFF duty times, and the reverse drive timing control with the 25% duty time executes an output with one ON and three OFF duty times.

[0020] In this case, the method can be characterized in that the OFF control of the motor is carried out depending on one of the phases of the motor into which this motor is divided based on a shape of a locking plate of the electric shift lever system.

[0021] Here, the method can be characterized in that the second reverse drive operating time control is carried out in combination with the first reverse drive operating time control.

[0022] In contrast, according to the various embodiments of the present invention, the method for controlling a switched reluctance motor for an electric shift lever system with a switched reluctance motor may also include the following method steps: executing an OFF control of the motor in the ON state of the motor; and executing a reverse drive operation timing control based on a difference between the current position and the target position of the motor and a magnitude of a current motor speed in the method step for executing the OFF control of the motor. The reverse drive operation timing control is carried out such that an operation time and duration are determined based on a speed of the motor. If a magnitude of the motor speed is below a third target value, a first reverse drive operation timing control is executed.If the motor speed is below a fourth setpoint, a second reverse drive timing is executed. If the reverse drive timing uses a duty cycle of 2.5 ms and a cycle period of 10 ms, the reverse drive timing with a duty cycle of 50% executes an output with two ON and two OFF cycles, and the reverse drive timing with a duty cycle of 25% executes an output with one ON and three OFF cycles.

[0023] According to one embodiment, the method may be characterized in that the reverse drive operating time control is carried out in such a way that by comparing the difference values between the current position and the target position of the motor, it is decided whether the reverse drive operating time control is started or ended, wherein a duty cycle of the reverse drive operating time control is determined proportional to the size of the motor speed. Effect of the invention

[0024] With the method for controlling a motor according to the various embodiments of the present invention, it can be provided that the shocks and noises in the electric shift lever system are reduced, which can lead to increased satisfaction of a driver.

[0025] With the method for controlling a motor according to the various embodiments of the present invention, the advantage is further achieved that a switching period based on the OFF control of a motor can be significantly shortened.

[0026] According to the motor control method according to various embodiments of the present invention, holding control of a motor to reduce shock and noise in the conventional electric shift lever system is eliminated, and therefore, high-current control required for holding is eliminated, thus achieving the advantage of reducing the heat dissipation phenomenon of the motor / controller. As a result, if the heat dissipation phenomenon of the motor / controller can be reduced, the position changes of the lever do not need to be limited, thus achieving the advantage of maximizing the driver's comfort. Short description of the drawings

[0027] They show: Fig. 1 shows the components of a system for controlling a motor for an electric gearshift system according to the various embodiments of the present invention; Fig. 2 shows a locking plate and a locking spring of the electric shift lever system according to the various embodiments of the present invention in a perspective view; Fig. 3 (a) a state in which a locking spring is located in a groove of a locking plate, and Fig. 3 (b) a state in which the locking spring is located in a bulge of the locking plate; Fig. 4 is a block diagram illustrating a method for controlling a motor for an electric shift lever system according to various embodiments of the present invention; Fig. 5 is a diagram illustrating a method for output simulation of an operating time according to various embodiments of the present invention; Fig. 6 is a diagram illustrating a state in which the motor positions are controlled by the method for outputting simulation of an operation time according to various embodiments of the present invention; Fig. 7 is a block diagram illustrating a method for reverse drive operation timing control according to various embodiments of the present invention; Fig. 8 is a diagram illustrating the method for output simulation of an operating time according to the various embodiments of the present invention; and Fig. 9 is a diagram illustrating a state in which the motor positions are controlled according to the prior art. Preferred embodiments of the invention

[0028] First, it should be noted that the embodiments explained below are intended to enable a person skilled in the art to easily understand the technical concept of the present invention, and the present invention should not be limited to such embodiments. Furthermore, the objects expressed in the accompanying drawings are shown in diagrammatic representations for easy explanation of the embodiments of the present invention, and they may differ from their actually implemented forms.

[0029] Furthermore, if it is mentioned that a component is connected or attached to another component, then it may be directly connected or attached to the other component, but it should also be understood that another component may be interposed between such two components. Furthermore, if an element is "on" or "at" another element throughout this description, then this includes not only a case where one element is adjacent to another element, but also a case where another element is present between two elements.

[0030] With regard to the explanations of the drawings, similar components may also be designated by similar reference numerals. The singular expressions also include the plural meanings, unless the context requires otherwise. In this description, the expressions such as "a and / or b", "at least one of a and / or b", "a, b or c", or "at least one of a, b and / or c", etc., may include all possible combinations of the items listed together. Furthermore, the expressions such as "first", "second", etc., may only be used to designate corresponding components regardless of their order or importance and to distinguish one component from another. However, the corresponding components should not be limited to the above expressions. Furthermore, the expressions such as "A", "B", "C", etc., may only be used to identify corresponding components regardless of their order or importance, and to distinguish one component from another. However, the corresponding components should not be limited to the above expressions.

[0031] Furthermore, the singular expressions also include the plural meanings unless the context otherwise requires. Furthermore, expressions such as "comprise," "include," and "have," etc., should only mean that features, digits, steps, movements, components, parts, or combinations thereof are present in this description, and may be understood to include one or more other features, digits, steps, movements, components, parts, or combinations thereof.

[0032] However, it should be understood that the 'system' used in this description means a facility that has several structures.

[0033] An electric shift lever system according to various embodiments of the present invention will be explained in more detail below with reference to the drawings. Fig. 1 to 3, schematic components of the electric shift lever system according to the various embodiments of the present invention are first explained.

[0034] This shows Fig. 1 the components of a system for controlling a motor for an electric gearshift system according to the various embodiments of the present invention. Fig. Figure 2 shows a locking plate and a locking spring of the electric shift lever system according to the various embodiments of the present invention in a perspective view. Fig. 3 (a) a state in which a locking spring is located in a groove of a locking plate, and Fig. 3 (b) a state in which the locking spring is located in a bulge of the locking plate.

[0035] Here, the electric shift lever system (i.e., shift-by-wire shifting system) of the present invention may include a shift lever sensor 110 that detects a position of a shift lever 100 changed by the driver's operation and thus determines a target gear; an electric motor position sensor 210 that detects a current position of an electric motor 200 and thus determines a current gear; and a control unit 300 that receives information from the shift lever sensor 110 and electric motor position sensor 210 and thus adjusts the rotational speed of the electric motor 200 based on the received information and the pre-stored information about the shape of a detent plate 230.

[0036] The shift lever sensor 110 can be understood as the component attached to the shift lever 100 and capable of detecting the position change of the shift lever 100 based on the driver's operation. For example, if the driver operates the shift lever 100 and thus changes a gear from a "P mode" to a "D mode," the shift lever sensor 110 can detect the D mode gear as a targeted gear (hereinafter referred to as the target gear).

[0037] In the various embodiments of the present invention, the automatic transmission is configured such that a P range is set as a non-driving and parking range, an R range is set as a reversing range, an N range is set as a neutral range, and a D range is set as a drive range. The P range corresponds to a "P mode," the R range to an "R mode," the N range to an "N mode," and the D range to a "D mode." However, this is only an example of the gears set for clarity, and is not necessarily limited thereto.

[0038] For example, the D range can be divided into D-1, D-2, D-3, etc. depending on the speed or acceleration of the vehicle.

[0039] Furthermore, in all embodiments included in this description, it is intended that the respective areas and the respective sections of the corresponding locking plate 230 are described in the form of P, R, N and D, but they are not necessarily limited thereto, while a different order or an additional combination of other areas is rather possible depending on the embodiment.

[0040] Here, the locking plate 230 according to the various embodiments of the present invention may represent the element included in the switching unit according to the various embodiments of the present invention and may mean a structure that allows it to be locked by the locking spring 240 so that the switching can be carried out according to the driver's will.

[0041] The locking plate 230 may have an approximately flat plate shape and be fan-shaped overall when viewed axially from the front side. It may have a structure such that a plurality of concave and convex portions are alternately formed. The concave portions may be configured to correspond to the aforementioned grooves. The convex portions, on the other hand, are located between the respective grooves, and may also have an uneven shape and form the boundaries between the respective grooves.

[0042] Furthermore, the locking plate 230 can be configured as a single piece with a shaft. The locking plate 230 can be rotationally driven integrally with the shaft by the motor. According to one embodiment, the locking plate 230 and the shaft can be configured such that the two convert a rotary drive force of the motor 200 into a linear movement within the switching unit.

[0043] In contrast, the locking spring 240 is a long, elastically deformable element, and it may have a locking roller at one end as a restricting means. Furthermore, the locking spring 240 may be configured such that its locking roller can exert an elastic reaction force toward the center of the locking plate 230, i.e., toward a recess of the concave portion. Therefore, when the locking plate 230 is subjected to a force by the drive of the motor, the locking roller moves continuously through (i.e., passing over) a convex portion formed between the respective concave portions to the other concave portion. As a result, switching can occur.

[0044] Now, the concave portions of the locking plate can each correspond to the respective gear of the present invention, i.e., P, R, N, and D. The locking plate 230 is configured as grooves and ridges corresponding to the respective gears, i.e., P, R, N, and D. When one end of the locking spring 240 connected to a fixing member 250 is located in a groove of the locking plate 230 by rotating the locking plate 230, the corresponding gear becomes the current gear. Specifically, the end of the locking spring 240, i.e., the locking roller, is inserted into one of several concave portions, so that the rotation of the locking plate 230 is restricted, which can consequently lead to a shift range of the automatic transmission being set and then assisted.

[0045] For your information, according to the various embodiments of the present invention, a rotational direction of the locking plate 230 when changing the direction from the P side to the D side may represent a forward rotation, while the rotational direction of the locking plate 230 when changing the direction from the D side to the P side may represent a reverse rotation.

[0046] Furthermore, according to the various embodiments of the present invention, the electric motor position sensor 210 can be configured such that it is attached to the electric motor 200 and thus detects a current position of the electric motor 200. The current position of the electric motor 200 can be understood as a rotated angle of a rotational axis of the electric motor 200 at the current time.

[0047] The locking plate 230 is connected to the rotation axis 220 of the electric motor 200, so that the locking plate 230 can also be rotated based on the rotation of the rotation axis 220.

[0048] Furthermore, the information about the positions of the locking plate 230 and the locking spring 240 corresponding to the current position of the electric motor 200 can be mapped in a control unit 300 to be mentioned later, wherein, when the electric motor position sensor 210 detects the current position of the electric motor, then the information about a current gear of the vehicle can also be detected.

[0049] It is advantageously provided that the electric motor position sensor 210 comprises at least one of an encoder, an inhibitor switch and a Hall sensor for magnetic detection, but is not limited thereto, and any sensor that can measure a rotation angle of the electric motor 200 can be used for such an electric motor position sensor.

[0050] The electric motor position sensor 210 can output a pulse signal based on the change in the rotation angle of the electric motor.

[0051] A control unit 300 of the present invention will now be considered. The control unit 300 of the present invention may form a component for a central processing unit (CPU), a transmission control unit (TCU), or an engine control unit (ECU).

[0052] Therefore, the electric shift lever system according to the various embodiments of the present invention can be divided in detail into an automatic transmission control unit (not shown), a SBW (Shift-By-Wire) control unit (not shown) and an internal combustion engine control unit (not shown), wherein these control units each mean a small computer comprising the central processing unit as operation means, a read-only memory (ROM) and random access memory (RAM) as storage means, and the input / output means, etc.

[0053] However, the automatic transmission, SBW, and internal combustion engine control units can be combined into the control unit 300 of the present invention. This means that the control unit 300 can be understood as an integrated central processing unit (CPU). The control unit 300 can be electrically connected to a power source of the vehicle, i.e., a battery (and / or alternator), and thus operated by electrical energy supplied by this battery.

[0054] Furthermore, the automatic transmission control unit can hydraulically drive the vehicle's automatic transmission. The automatic transmission control unit can be equipped with a hydraulic circuit that switches the shift ranges and gears of the automatic transmission, and with an electronic valve that serves to electronically control the hydraulic circuit.

[0055] A manual selector valve is installed in the hydraulic circuit and is thus moved axially, allowing the hydraulic circuit to be switched. By switching the hydraulic circuit, the manual selector valve allows the automatic transmission to be set to one of the shift ranges.

[0056] Furthermore, the automatic transmission control unit can receive a detection signal from a vehicle speed sensor that detects the speed of the vehicle and thus control the respective manual selector valve.

[0057] In contrast, the SBW control unit is provided with an actuator and switching mechanism, etc., which actuator and switching mechanism control the valves and brakes of the automatic transmission control system. The actuator may include the electric motor 200, electric motor position sensor 210, etc., as discussed above.

[0058] Through this SBW control unit, several coils that make up the electric motor are successively energized based on the set control times, so that a rotor and a shaft that make up the electric motor are rotated.

[0059] If the above descriptions are taken into account, the control unit 300 of the present invention may include the automatic transmission, SBW, and combustion control units, and may be used to control the electric motor based on the speed of the vehicle.

[0060] Furthermore, according to the various embodiments of the present invention, it may be provided that the control unit 300 consists, in terms of its functions, of a position information receiving unit 310, a compensation unit 320 and a decision unit 330.

[0061] First, the position information receiving unit 310 may receive the information of a target gear and a current gear from the shift lever sensor 110 and the electric motor position sensor 210, respectively.

[0062] By receiving the position information receiving unit 310 information about a current position (rotation angle) of the electric motor 200, the following situations can also be detected: in which of a bead and groove of the locking plate 230 the end of the locking spring 240 is located, at which point the end is located during the movement of the locking spring from the groove to the bead, or at which point the end is located during the movement of the locking spring from the bead to the groove.

[0063] Then, the compensation unit 320 can be configured to execute feedforward control and proportional-integral-derivative (PID) control based on the information received from the position information receiving unit 310, thus controlling the rotational speed of the electric motor 200. Specifically, the compensation unit 320 can execute feedforward control and PID control simultaneously or non-simultaneously. Therefore, a drive operating time of the electric motor 200 can be calibrated, so that a target operating time for rotating the electric motor 200 at a desired rotational speed can be calculated.

[0064] Furthermore, the compensation unit 320 can perform the feedforward control based on the information about the positions of the locking plate 230 and the locking spring 240 detected in the position information receiving unit 310. Here, the information about the positions of the locking plate 230 and the locking spring 240 refers to the information about the relative positions of the two to each other.

[0065] If the position of the locking spring 240 is changed by rotating the locking plate 230 from the groove to the bead, then a restoring force acts by means of the locking spring 240, so that a rotational speed of the locking plate 230 can slow down.

[0066] In this case, a positive feedforward control can be carried out by the compensation unit 320 according to the various embodiments of the present invention, so that the electric motor 200 can be controlled so that its rotational speed becomes even faster.

[0067] On the other hand, if the position of the end of the locking spring 240 is changed from the bead to the groove by rotating the locking plate 230, the restoring force acts in an opposite direction, so that the rotation speed of the locking plate 230 may become even faster, which may cause impact and noise between the locking plate 230 and the locking spring 240 in this process.

[0068] For this purpose, a negative feedforward control may be performed by the compensation unit 320 according to the various embodiments of the present invention, so that the electric motor 200 may be controlled so that its rotational speed becomes even slower.

[0069] That is, because the compensation unit 320 can perform such optimum value control, compensation control of the motor is made possible based on the positional relationships between the locking plate 230 and the end of the locking spring 240.

[0070] Finally, the decision unit 330 is configured such that, after the control of the electric motor 200 by the compensation unit 320 has been carried out, it compares a current position and a target position of the electric motor with each other, so that it then decides from this comparison whether a current gear (or a current lever position) and a target gear (or a target lever position) match each other.

[0071] If the current gear and the target gear do not match, then the decision unit 330 may cause the control strategy of the electric motor 200 to change, while if the current gear and the target gear match, then it may interrupt the control of the motor until the driver operates the gear lever 100 again.

[0072] Fig. 4 shows a block diagram illustrating a method for controlling a motor for an electric shift lever system according to various embodiments of the present invention. Fig. 5 is a diagram illustrating a method for output simulation of an operating time according to various embodiments of the present invention. Fig. 6 is a diagram illustrating a state in which the motor positions are controlled by the method for outputting simulation of an operation time according to various embodiments of the present invention. Fig. 7 is a block diagram illustrating a reverse drive operation timing control method according to various embodiments of the present invention. Fig. 8 is a diagram illustrating the method for output simulation of an operating time according to various embodiments of the present invention.

[0073] According to the various embodiments of the present invention, the electric motor can be a switched reluctance motor (SR motor).

[0074] Generally, the switched reluctance motor uses a rotor composed of a static transfer switch (e.g., a metal ground) or the like, which requires a certain period of time for the motor to magnetize. Therefore, it has been commonly considered difficult to apply PWM control, in which the on-off switching is repeated within a short period, to the control of the switched reluctance motor.

[0075] According to various embodiments of the present invention, the inventive method is characterized in that PWM simulation control is carried out for the switched reluctance motor to which PWM was difficult to apply, so that the shocks and noises in an OFF control of the motor are significantly reduced, which can consequently lead to the significant shortening of the switching period in the OFF control.

[0076] Specifically with regard to Fig. 4 illustrates a method for controlling an electric motor for an electric gearshift system according to the various embodiments of the present invention, the method for controlling an electric motor for an electric gearshift system (ieshift-by-wire shifting system) which comprises the following process steps: deciding whether a current gear and a target gear agree with each other or not (S100); rotating the motor towards the target gear if the current gear and the target gear do not agree with each other (S200 - 300); executing an OFF control of the motor if the current gear and the target gear agree with each other (S400); executing a reverse drive operation timing control if a difference between a current position and a target position of the motor is below a first target value (S500 - 600); and switching off the motor if the difference between the current position and the target position of the motor is below a second target value (S700).

[0077] A gearshift lever 100 operated by the driver can be electrically connected to a control unit 300 by means of a gearshift lever sensor 110.

[0078] Therefore, when the driver operates the shift lever 100, an intention of the driver is transmitted as an electrical signal to the control unit, so that an electric motor of the present invention is driven.

[0079] Therefore, when the driver operates the shift lever 100, the control unit 300 can calculate (operate) a target lever position of the driver. Here, the driver's target lever position can correspond to a target position of the engine.

[0080] The physical position changes of the shift lever 100 are input into the control unit 300 as an electrical signal form, and this control unit 300 can then drive the electric motor 200 of the present invention using these physical position changes, so that a relative position between the locking plate 230 and the end of the locking spring 240 can change.

[0081] Then, a decision is made as to whether the current gear and the target gear match. If the current gear and the target gear match, it is determined that the shift lever is positioned according to the driver's intention, and motor control is not executed. If the current gear and the target gear do not match, motor ON control is executed, rotating the motor toward the target gear.

[0082] When the target lever position expected by the driver's lever operation is calculated, the control unit 300 starts controlling the motor, and this control of the motor can be carried out differently depending on the shape of the locking plate.

[0083] Furthermore, the method for controlling an electric motor of the present invention according to the various embodiments is characterized in that the electric motor is accelerated in a controlled manner based on the unevenness of the locking plate connected to the motor via a rotation axis when the locking spring moves from the groove to the bead of the locking plate, while it is decelerated in a controlled manner when the locking spring moves from the bead to the groove of the locking plate.

[0084] Specifically, motor control begins when the target position of the motor is calculated, so that the motor can be accelerated or decelerated in a controlled manner based on the shape of the locking plate 230. Specifically, if the end (roller) of the locking spring 240 moves from the groove to the bead of the locking plate 230, the motor can be accelerated in a controlled manner, while if the end moves from the bead to the groove, the motor can be decelerated. Here, the acceleration or deceleration control can be performed by the compensation unit 320.

[0085] According to the various embodiments, it can be provided that a difference between the current position and the target position of the motor corresponds to the difference between the current position and the target position of the end of the locking plate 240. Furthermore, the difference between the current position and the target position of the motor can be converted into an absolute value. If converted into an absolute value, the difference value is evaluated based on whether it lies within a predetermined range or not.

[0086] After the motor is rotated by the motor ON control operation, it is again decided whether the current gear and the target gear agree with each other or not, wherein if the two gears do not agree with each other, then the motor ON control step continues, while if the two gears agree with each other, then the motor OFF control step can be executed.

[0087] According to various embodiments of the present invention, it may be arranged that a reverse drive operation timing control is carried out to reduce the shocks and noises in the OFF control operation of the motor.

[0088] The reverse drive operating time control can be understood as meaning that the speed of the motor is not reduced continuously but intermittently in the OFF control process.

[0089] The reverse drive timing control is executed when the difference between the current position and the target position of the motor is below a first setpoint. Of course, the first setpoint can be set differently depending on the specific embodiment, depending on the required accuracy. If the difference between the current position and the target position of the motor is above the first setpoint, the reverse drive timing control should be started too early, which can indicate that the sensitivity of the electric shift lever system to the driver's shift request is poor.

[0090] In contrast, the reverse drive operating time control can be interrupted when the difference between the current position and the target position of the motor is below a second set value, so that the control of the motor can be terminated.

[0091] In Fig. 5, as an example of a reverse drive duty time, a reverse drive duty time control method with a duty time of 50% is simulated.

[0092] For example, if a system using a 2.5 ms duty cycle measures the motor speed as -1000 rpm, the 50% duty cycle is continuously output for 10 ms, thus executing motor OFF control. Please note that the motor speed, which determines the reverse drive duty cycle, can be based on an absolute value.

[0093] According to the reverse drive duty control method with 50% duty, when one cycle period is 10 ms, the ON and OFF duty times can be output twice each.

[0094] If the motor control is carried out with these operating times, then the same result of the motor position control can be achieved as in Fig. 6 shown.

[0095] By executing the reverse drive operation time control, the generation of shocks and noises (or overshoots) in the OFF control of the generic switched reluctance motor as shown in Fig. 9, are suppressed.

[0096] On the other hand, with the method for controlling a motor according to the various embodiments of the present invention, it may be provided that the OFF control of the motor is carried out depending on one of the phases which is divided based on a shape of a locking plate of the electric shift lever system.

[0097] In this case, the regions having the respective gears of P, R, N and D depending on the boundaries between the grooves and the ridges of the locking plate 230 can be divided into a plurality of phases, wherein the method for controlling a motor according to the present invention can be carried out depending on one of these several divided phases.

[0098] In Fig. Figure 6 shows a state in which the engine OFF control according to the present invention is executed in one phase, and a resulting diagram is repeated until the target gear and the current gear coincide. For your information, it should be noted that the Fig. The sign of 'Phase = 1' shown in Fig. 4 means that a position of the motor (or a position of the roller of the locking spring) is in the limit of the phase in question, ie in the groove or bulge.

[0099] In contrast, the reverse drive timing control can be implemented such that an operating time and duration are determined based on the motor speed. If the start and end of the reverse drive timing control are determined based on the difference between the current position and the target position of the motor, i.e., the relative displacement of the motor based on the start and end times, then a duty ratio (%) and a running time of the reverse drive timing control can be based on the motor speed.

[0100] For example, if the speed of the motor at the time of entry of the reverse drive operation timing is relatively low, then the duty cycle can also be set to be relatively low.

[0101] In relation to Fig. 7, the method for controlling an electric motor according to the various embodiments of the present invention may, on the other hand, include a method for reverse drive operating time control, which has different operating times depending on the speed changes of the motor.

[0102] According to one embodiment, if the engine speed is below a third setpoint, a first reverse drive operating time control is executed. Furthermore, if the engine speed is below a fourth setpoint, a second reverse drive operating time control is executed. The third setpoint can be set, for example, to -1000 rpm and the fourth setpoint to -500 rpm.

[0103] Specifically, it may be provided that if the detected engine speed is measured at -1000 rpm, then the first reverse drive operation time control is executed with the operation time of 50%, while if the engine speed is reduced to -500 rpm by the first reverse drive operation time control, then the second reverse drive operation time control is executed with the operation time of 25%.

[0104] According to the method for controlling a motor according to an embodiment, the second reverse drive duty control with the duty time of 25% can be understood as outputting the ON duty time once and the OFF duty time three times as shown in Fig. 8 shown.

[0105] Furthermore, the method for controlling an electric motor according to the various embodiments of the present invention can be combined with the method for reverse drive operating time control, which has different operating times depending on the speed changes of the motor. Here, the combination with the method for reverse drive operating time control includes all cases in which at least two different methods for reverse drive operating time control are implemented not only stepwise but also alternatively depending on the time series.

[0106] Furthermore, according to the various embodiments of the present invention, the method according to the invention can be the method for controlling an electric motor for an electric shift lever system with a switched reluctance motor, which simply comprises the following method steps: executing an OFF control of the motor in the ON state of the motor; and executing a reverse drive operating time control based on a difference between the current position and the target position of the motor and a value of a current motor speed in the method step for executing the OFF control of the motor.

[0107] The method can be characterized in that the reverse drive operating time control is carried out in such a way that by comparing the difference values between the current position and the target position of the motor, it is decided whether the reverse drive operating time control is started or ended, and that a duty cycle of the reverse drive operating time control is determined proportional to the size of the motor speed.

[0108] As mentioned above, with the method for controlling a motor according to the various embodiments of the present invention, it can be provided that the shocks and noises in the electric shift lever system are reduced, which can lead to increased satisfaction of a driver, achieving the advantage that a switching period based on the OFF control of a motor can be significantly shortened, as can be seen from Fig. 6 and Fig. 9 is recognizable.

[0109] In a conventional electric shift lever system, a motor holding control was implemented to reduce shock / noise and prevent the generation of overshoot. However, in the various embodiments of the present invention, the high-current control required for holding is eliminated, thus providing the advantage of reducing the heat dissipation phenomenon of the motor / controller. As a result, if the heat dissipation phenomenon of the motor / controller can be reduced, the lever position changes do not need to be limited, thus achieving the advantage of maximizing the driver's comfort.

[0110] Finally, it should be noted that the above-explained method for controlling an electric motor for an electric shift lever system (i.e., a shift-by-wire shift system) should not be limited by the above-described embodiments and the drawings. Rather, it will be apparent to a person skilled in the art that the inventive method can be variously replaced, modified, and altered within the technical scope of the present invention.

Claims

[1] A method for controlling a switched reluctance motor for an electric gear lever system comprising a switched reluctance motor, the method comprising the following method steps: Determine whether a current gear and a target gear match or not; Rotate the motor towards the target gear if the current gear and the target gear do not match; Performing an OFF control of the engine if the current gear and the target gear match; Executing a reverse control if a difference between a current position and a target position of the motor is below a first setpoint; and Switching off the motor if the difference between the current position and the target position of the motor is below a second setpoint, wherein the reverse drive operation time control is carried out such that an operation time and time period are determined based on a rotational speed of the engine, and, if a value of the engine speed is below a third target value, a first reverse drive operating time control is executed, and, if the magnitude of the engine speed is below a fourth setpoint, a second reverse drive operating time control is executed, wherein, if the reverse drive duty cycle controller uses a duty step of 2.5 ms and a cycle period is 10 ms, the reverse drive duty cycle controller with a duty of 50% performs an output with two ON and two OFF duty times, and the reverse drive duty cycle controller with the duty cycle of 25% performs an output with one ON and three OFF duty cycles. [2] Method according to claim 1, characterized bythat the OFF control of the motor is carried out according to one of the phases of the motor into which this motor is divided by a shape of a locking plate of the electric gearshift lever system. [3] Method according to claim 1 or 2, characterized by that the second reverse drive operation timing control is carried out in combination with the first reverse drive operation timing control. [4] A method for controlling a switched reluctance motor for an electric gear lever system with a switched reluctance motor, the method comprising the following method steps: performing OFF control of the engine in the ON state of the engine; and executing a reverse drive operation timing control based on a difference between the current position and the target position of the motor and a value of a current motor speed in the process step for executing the motor OFF control, wherein the reverse drive operating time control, the operating time and the time duration are determined based on the speed of the motor, and, if a value of the engine speed is below a third target value, a first reverse drive operating time control is executed, and, if the magnitude of the engine speed is below a fourth setpoint, a second reverse drive operating time control is executed wherein, if the reverse drive duty cycle controller uses a duty step of 2.5 ms and a cycle period is 10 ms, the reverse drive duty cycle controller with a duty of 50% performs an output with two ON and two OFF duty times, and the reverse drive duty cycle controller with the duty cycle of 25% performs an output with one ON and three OFF duty cycles. [5] Method according to claim 4, characterized bythat the reverse drive operating time control is carried out in such a way that by comparing the difference values between the current position and the target position of the motor, it is decided whether the reverse drive operating time control is started or ended, wherein a duty cycle of the reverse drive operating time control is determined proportional to the size of the motor speed.

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