METHOD AND DEVICE FOR DIAGNOSING AND REMEDYING THE SEIZING OF AN MOTOR IN A SHIFT-BY-WIRE SYSTEM

Abstract

Method for diagnosing and remedying the seizing of a motor (16a) in a shift-by-wire (SBW) system in which a shift range change of an automatic transmission by a motor (16a) is implemented, the method comprising: (a) when an actuation of a gearshift lever (11) is detected, determine whether a current position of the engine (16a) matches a target position or not; (b) if the current position does not match the target position, rotating the motor (16a) in a direction towards the target position; (c) re-determining whether the current position of the motor (16a) matches the target position or not after the motor (16a) has been rotated; (d) if it is determined that the current position does not correspond to the target position, diagnose whether or not the engine (16a) has seized; (e) if it is diagnosed that the motor (16a) is stuck, enabling the motor (16a) to be switched to a free-rotating mode in which the motor (16a) is freely rotatable by temporarily interrupting the current applied to the motor (16a) at the time of diagnosis; and (f) Selecting either a first remediation strategy or a second remediation strategy depending on whether the position of the motor (16a) changes after switching to free rotation mode or not, so that the stuckness of the motor (16a) is resolved.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] The present application claims priority over Korean patent application No. 10-2021-0049337, which was filed on April 15, 2021, and the entire contents of which are incorporated herein by reference for all purposes. AREA

[0002] The present disclosure relates to a method for diagnosing and remedying a motor seizure phenomenon occurring in a shift-by-wire (SBW) system, and a method and device for diagnosing and remedying the seizure of a motor, wherein a seized motor condition is diagnosed by means of a change in the motor position and current during a switching range change in a shift-by-wire system, and at the time of diagnosis of the motor seizure, the motor seizure is remedied or overcome by controlling the increase of a motor power value. BACKGROUND

[0003] In the shift-by-cable (SBC) method, a conventional automatic transmission's range-selective system, a detent plate rotates via a cable when the shift lever is moved. This causes a manual valve to move, opening the P, R, N, and D flow paths on a valve body and thus shifting into the desired range. However, because the conventional SBC method requires careful consideration of the cable's position and arrangement, it has significant design limitations and disadvantages regarding assembly and mass production.

[0004] One method for replacing the conventional SBC (Single Brake Control) system is the shift-by-wire (SBW) system. The SBW system is a technology that simplifies operation and increases safety by using a motor to rotate a detent plate instead of a cable connected to a gearshift lever at the driver's seat. This system is designed so that the operating state of the gearshift lever is detected by a sensor or switch, and the detent plate is then rotated by a motor to actuate a manual valve.

[0005] In such a self-locking brake (SBW) system, the detent plate is equipped with several switching ranges in which a detent roller can be statically stabilized by a detent spring. In response to the driver's request to change the switching range, the motor rotates the detent plate to a suitable position, corresponding to the driver's operation of the gearshift lever. This ensures the specific mechanical state of the vehicle system and thereby establishes the state desired by the driver, such as parking, driving, etc.

[0006] The motor operates under the control of a controller (SBW controller) when a request to change the gear range is received by actuating the gearshift lever. If a user request for a gear range change is received while driving, the controller calculates the power that can be precisely converted into the requested specific gear range based on a signal received from a motor Hall sensor and a gearshift lever sensor, and controls the motor accordingly.

[0007] In a drive unit with a motor (a detent plate synchronized with the motor and rotating in a forward / reverse direction within a predetermined angular range, a detent roller restricting the detent plate to a predetermined switching range, and a rotating shaft mechanically connecting the detent plate and the motor, etc.), a situation can occur with a seized motor in which the motor is mechanically restricted and cannot be driven due to the ingress of foreign matter or the increase in friction between peripheral devices due to aging.

[0008] For example, if a foreign object adheres to a section at a specific position on the track (a surface defining the switching area with a curved, wave-like shape that extends around the outer circumference of the detent plate), along which the detent roller rolls in close contact with the detent spring, a fault will occur due to a seized motor. In this case, the current applied to the motor gradually increases, which can lead to damage to the motor due to overcurrent or to a situation where a gear change cannot be performed.

[0009] Therefore, there is a need for a method that can accurately diagnose and overcome or resolve engine jamming in the conventional shift-by-wire system.

[0010] The foregoing statements are intended only to contribute to an understanding of the background of the present disclosure and are not to be interpreted as meaning that the present disclosure falls within the area of ​​prior art which is already known to the person skilled in the art.

[0011] Known shift-by-wire systems are described, for example, in patent applications CN 1 04 702 167 A and KR 10 2019 0 067 404 A. Patent application KR 10 2019 0 135 214 A discloses a method for diagnosing a seized gearbox. SUMMARY

[0012] In one aspect, a method and a device for diagnosing and remedying the seizing of a motor are provided, which can diagnose a seized motor condition by means of a change in motor position and current during a shift range change according to the request of a driver in a shift-by-wire system, and at the time of diagnosis of the seized motor, remedy or overcome the seized motor by controlling the increase of a motor power value.

[0013] In one aspect, a method for diagnosing and correcting the seizure of a motor in a shift-by-wire (SBW) system is provided, in which a shift range change of an automatic transmission is implemented by a motor, wherein the method comprises the following: (a) when a gearshift lever actuation is detected, determine whether the current position of the engine matches a target position or not; (b) if the current position does not correspond to the target position, rotate the engine in a direction towards the target position; (c) re-determining whether the current position of the engine matches the target position or not after the engine has been rotated; (d) if in step (c) it is determined that the current position does not match the target position, diagnose whether or not the engine has seized; (e) if the motor is diagnosed as being stuck, enabling the motor to be switched to a free-rotating mode in which the motor can rotate freely by temporarily interrupting the current applied to the motor at the time of diagnosis; and (f) Selecting either a first remediation strategy or a second remediation strategy depending on whether the position of the motor changes after switching to free rotation mode or not, so that the motor seizing is resolved.

[0014] As a result of the determination using steps (a) and (c), if the current position and the target position match, it can be recognized that the switching range has been changed normally, and the process can be terminated in the corresponding step without further progress.

[0015] Furthermore, in step (d), if there is no change in the output of a position sensor for detecting the direction and angle of rotation of the motor, it can be diagnosed that the motor is stuck.

[0016] Even more preferably, in step (d), if there is no change in the output of the position sensor for detecting the direction and angle of rotation of the motor and the output of a current sensor for detecting the strength of the current applied to the motor exceeds a predetermined limit for a predetermined duration, it can be diagnosed that the motor is stuck.

[0017] Furthermore, in step (f) the first correction strategy can be selected if there is no change in motor position after switching to free rotation mode, and the second correction strategy can be selected if a change in motor position is detected after switching to free rotation mode.

[0018] The first remediation strategy can involve, firstly, driving the motor in the opposite direction to the target position, thus positioning it in a recessed section of the adjacent switching ranges, and secondly, after setting a power value so that it increases by a predetermined increment, driving the motor towards the target position with the increased power value to resolve the motor's stuck position. Furthermore, the second remediation strategy can involve, after setting a power value so that it increases by a predetermined increment, driving the motor towards the target position with the increased power value to resolve the motor's stuck position.

[0019] The procedure for diagnosing and resolving a seized engine may further include the following: (g) Determine whether the engine seizure was resolved by the first or second remediation strategy; and (h) as a result of the determination with step (g), if the engine's stuck position has not been resolved, check the power value, and as a result of the check with step (h), if the power value is less than a predetermined maximum value, the process returns to step (e), and the subsequent steps are repeated so that after a further increase in the power value by the predetermined increment, the first remediation strategy or the second remediation strategy can be applied again.

[0020] Preferably, in step (g) it is possible to determine whether the engine seizure has been resolved or not by comparing a distance between the current engine position and the engine position at the time when the seizure was diagnosed based on the target position.

[0021] More precisely, if the absolute value of the difference between the target position and the current position is smaller than the absolute value of the difference between the target position and the stuck position (the position of the engine at the time of diagnosis of the stuck position), ( | target position - current position | < | target position - stuck position | ), it can be determined that the stuck engine is resolved.

[0022] As a result of the check in step (h), if the power value reaches the predetermined maximum value, this is determined to be a situation in which the engine seizure cannot be rectified, and a corresponding warning message may be issued via a means recognizable to the driver.

[0023] In another aspect, a device is provided for diagnosing and remedying the seizing of a motor in a shift-by-wire (SBW) system in which a shift range change of an automatic transmission by a motor is implemented, wherein the device comprises the following: a motor that generates a driving force to rotate a detent plate into a target position; a Hall sensor and a current sensor, designed to determine the position of a rotor inside the motor or the strength of a current applied to the motor; a position sensor designed to detect a signal change corresponding to the rotation of the motor and to output a PWM signal corresponding to a current switching range; and a shift-by-wire (SBW) controller designed to analyze a signal from a shift lever sensor, which detects a change in the position of a shift lever, to determine a target position, and to control the drive of the motor based on signals from the Hall sensor and the position sensor to rotate the detent plate towards the determined target position, wherein the SBW controller is designed to diagnose, based on the signals from the position sensor and the current sensor, whether or not the motor has seized, and if the motor is diagnosed as seized, to apply different recovery strategies depending on the position of the seized motor, so that the seized motor is recovered.

[0024] Preferably, the SBW controller may include: a data acquisition section that is operated to receive signals from the shift lever sensor and the position sensor and, based on the received signals, determines whether the current position of the motor corresponds to the target position; a motor seizure detection section that is operated to receive signals from the current sensor and the position sensor and, based on the received signals, diagnoses whether the motor has seized; a motor operating mode setting section that is operated to select different control modes, depending on the position of the seized motor, to resolve the seizure when the motor is diagnosed as seized in the motor seizure detection section;and a power application section that is operated in such a way as to apply to the motor a power that is determined depending on the control mode selected by the motor operating mode setting section.

[0025] If there is no change in the output of the position sensor for detecting the direction and angle of rotation of the motor, the section for determining motor seizure can preferably diagnose that the motor is seized.

[0026] If there is no change in the output of the position sensor for detecting the direction and angle of rotation of the motor, and the output of the current sensor for detecting the magnitude of the current applied to the motor exceeds a predetermined limit for a predetermined duration, the section for determining motor seizure can preferably diagnose that the motor is seized.

[0027] Furthermore, the motor operating mode selected by the Motor Operating Mode Setting section may include: a free rotation mode, which ensures a time and distance sufficient to obtain the torque required to resolve the motor's jamming; a reverse rotation mode, which, if it is impossible to ensure the time and distance sufficient to obtain the required torque using the free rotation mode, drives the motor in the opposite direction (the direction opposite to the target position direction), depending on the position of the jammed motor, so that the time and distance are ensured; and a target power increase mode, which gradually increases a target power proportional to the number of retries of the free rotation or reverse rotation mode.

[0028] Preferably, the motor operating mode setting section can select a remediation strategy that switches to free rotation mode so that the motor is free to rotate by temporarily interrupting the current applied to the motor at the time of diagnosis of the jamming, and depending on whether the motor position changes after switching to free rotation mode or not, switches directly to target power increase mode or switches to target power increase mode via the reverse rotation mode.

[0029] If there is no change in motor position after switching to free rotation mode, a corrective strategy can preferably be selected that switches to target power increase mode via reverse rotation mode, and if there is a change in motor position after switching to free rotation mode, a corrective strategy can be selected that switches directly to target power increase mode.

[0030] Furthermore, the SBW controller can determine whether the motor jam has been resolved or not by comparing a distance between the current motor position and the motor position at the time of diagnosis of the jam with respect to the target position based on the output of the position sensor.

[0031] One or more of the above steps can be performed using a processor or a controller.

[0032] More precisely, if the absolute value of the difference between the target position and the current position is smaller than the absolute value of the difference between the target position and the stuck position (the position of the engine at the time of diagnosis of the stuck position), ( | target position - current position | < | target position - stuck position | ), it can be determined that the stuck engine is resolved.

[0033] According to the embodiments described above, by using the free rotation mode it is possible to accurately determine the type of jamming (whether the jamming of the motor occurred during movement in one direction from the recess to the protrusion or during movement in one direction from the protrusion to the recess, relative to the position of a roller on a positioning surface of a detent plate) and to selectively apply a suitable strategy depending on the type of jamming.

[0034] In other words, one advantage is that the jamming can be resolved by the strategy of efficient motor movement, and the power value is gradually increased proportionally to the number of attempts to resolve the jamming, so that if the degree of jamming is not severe, the jamming problem can be solved even in a low-power range before maximum power (100%) is applied, thus reducing unnecessary energy consumption in the jamming resolution process.

[0035] Further aspects are described below. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view illustrating a range switching mechanism of a shift-by-wire (SBW) system used in an automatic transmission; Fig. Figure 2 is a block diagram that schematically illustrates the design of a device for diagnosing and remedying the jamming of a motor in an SBW system according to an embodiment of the present disclosure; Fig. 3A and Fig. 3B are exemplary operating diagrams illustrating strategies for resolving a seized engine, which are selected differently depending on the seized position of the engine; and Fig. Figure 4 is a flowchart illustrating a method for diagnosing and remedying the seizure of a motor in an SBW system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] Preferred embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0037] The terms used here serve only to describe certain embodiments and are not intended to limit the present disclosure. As used here, an element expressed in the singular includes multiple elements unless the context clearly indicates otherwise.

[0038] Furthermore, it is understood that the term “comprehensive” or “inclusive” indicates the presence of a mentioned feature, number, step, operation, element, part or combination thereof, but does not exclude the presence or addition of one or more further features, numbers, steps, operations, elements, parts or combinations thereof.

[0039] Terms like "first," "second," etc., can also be used to describe different elements, but these terms should not restrict the elements. The terms mentioned above are used only to distinguish one component from another.

[0040] Furthermore, terms such as "...part", "...unit", "...module", etc., as described in the description, denote a unit that performs at least one function or operation that can be implemented by hardware or software or a combination of hardware and software.

[0041] Furthermore, the control logic of the present disclosure can be implemented as a non-volatile, computer-readable medium on a computer-readable medium containing executable program instructions that are executed by a processor, a controller, or the like. Examples of computer-readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer-readable medium can also be distributed across networked computer systems, such that the computer-readable medium is stored and executed in a distributed manner, for example, by a telematics server or a controller area network (CAN).

[0042] It is understood that the term "vehicle" or "vehicle-" or any other similar term as used herein includes motor vehicles in general, such as passenger cars including SUVs, buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft and the like, and also hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other vehicles with alternative fuels (e.g. fuels derived from resources other than petroleum). As stated herein, a hybrid vehicle is a vehicle with two or more propulsion sources, e.g. a gasoline-powered and an electric-powered vehicle.

[0043] In the description with reference to the accompanying drawings, it should be noted that identical elements in the drawings are marked with the same reference numerals, and a repeated description for the same configuration is omitted. Furthermore, a detailed description of known functions and configurations that could obscure the core of this disclosure is omitted.

[0044] First, a mechanical design of a switching range switching mechanism of a shift-by-wire (SBW) system is described based on Fig. 1. Illustrated schematically.

[0045] Fig. Figure 1 is a perspective view illustrating a range switching mechanism of a shift-by-wire system used in an automatic transmission.

[0046] Referring to Fig. 1 comprises a switching range switching mechanism 13, a detent plate 15 which is locked to determine a position of the coil 42a of a hand valve 42, and a switching actuator 16 for generating a driving force to rotate the detent plate 15. The switching actuator 16 can be an electric actuator and is operated like a starter (not shown) with current from a battery attached to the vehicle.

[0047] The switching range change mechanism 13 is connected to a parking mechanism 17 by mutual engagement. The detent plate 15 of the switching range change mechanism 13 is rotated by the switching actuator 16 such that it incrementally pushes and pulls the coil 42a of the manual valve 42 or a parking rod 17c of the parking mechanism 17 to determine the position. Here, a detent mechanism consists of the detent plate 15, a rotating shaft 15a, and the detent spring 15b.

[0048] The detent spring 15b can be held on a valve body 42b of the manual valve 42, and the detent plate 15 can be essentially fan-shaped. The section serving as the pivot point of the detent plate 15 is mechanically connected to the switching actuator 16 via the rotating shaft 15a, so that the detent plate 15 rotates synchronously with a motor 16a of the switching actuator 16.

[0049] A surface defining the switching range (hereinafter referred to as the "positioning surface"), which forms a continuously curved waveform, is formed on the outer circumference of the detent plate 15. A roller 15c of the detent spring 15b is arranged in a recess at a specific position of the positioning surface such that the positioned state (the switching range change state) is maintained.

[0050] Preferably, four recesses can be formed in the positioning surface, corresponding to the respective locked positions (P, R, N, D) of the manual valve 42. Furthermore, raised areas are formed between the respective recesses and adjacent recesses, for example, between a recess of the P area and a recess of the R area, or between a recess of the R area and a recess of the N area. In this case, the raised areas are to be understood as boundaries between adjacent switching areas.

[0051] Since the distances between the depressions that define the positions of the respective switching regions and the adjacent depressions are equal, the distances between the raised areas that serve as boundaries between adjacent switching regions and the adjacent raised areas are also equal. Of course, in some cases the distance between the depression of the P region and the depression of the R region is greater than the distances between other depressions, so that the distances between all depressions are not substantially equal.

[0052] When a driver operates the shift lever 11, the shift actuator 16 is driven, and accordingly, a roller 15c of the detent spring 15b is positioned in one of the four recesses (the recesses that determine the positions for each of the P, R, N, and D ranges). In this way, the detent plate 15 is held in a state in which it is arranged in positions corresponding to the respective positions of the hand valve 42.

[0053] The switching actuator 16 can include an electric motor 16a (hereinafter referred to as "motor" for the sake of simplicity), a reduction mechanism 16b for slowing down the motor rotation, and a position sensor 16c that detects the direction and angle of rotation according to the rotation of the motor 16a and outputs a corresponding electrical signal to an SBW controller 14, which will be described later.

[0054] The rotating shaft 15a can be rotatably connected to an output shaft (not shown) of the reduction mechanism 16b via keyways or similar means, and the parking mechanism 17 serves to switch an output shaft 10 of an automatic transmission 1 into a non-rotatable, locked state or a rotatable, unlocked state. In this case, the parking mechanism 17 can comprise a parking gear 17a on the outer surface of the output shaft 10, a parking pawl 17b, a parking rod 17c, and the like.

[0055] The basic operation of the switching range switching mechanism 13, which is designed as described above, will now be briefly described.

[0056] When a driver operates the gearshift lever 11 or the park switch 12, a range is selected from the park (P), reverse (R), neutral (N), and drive (D) ranges of the automatic transmission 1. A signal is then output by the gearshift lever sensor 103 or the park switch 12, and the SBW controller 14 receives the output signal and recognizes the selected target position (or target range, P, R, N, D).

[0057] The SBW controller 14 determines a command value (a power value as a control value including the direction and angle of rotation) of the switching actuator 16 based on information about the distance between the current position and the newly detected target position (P, R, N, D) and rotates the motor 16a in a forward or reverse direction at a predetermined angle at a time set based on the determined command value. Accordingly, the rotating shaft 15a and the detent plate 15 are rotated at a predetermined angle.

[0058] Here, the timing is determined by a Hall sensor 16d, which uses a Hall element installed inside the motor and has a magnetic current effect. The position sensor 16c detects a signal change corresponding to the rotation of the motor 16a and supplies a PWM signal corresponding to the current switching range to the SBW controller 14. Furthermore, the SBW controller 14 controls the motor 16a based on the signals from the position sensor 16c and the Hall sensor 16d.

[0059] For example, if the shift lever 11 is moved from the neutral position N to the driving position D, the target position signal changes from N to D. Upon receiving this signal, the SBW controller 14 sets a target rotation angle corresponding to the selected target position D, determines a corresponding command value (power value), and allows the motor 16a to be powered according to the determined command value.

[0060] When motor 16a is driven by the power supply, causing its output shaft to rotate, the SBW controller 14 also receives a signal corresponding to the angle of rotation from the position sensor 16c in real time. The SBW controller then uses the received signal from the position sensor 16c to determine the angle and direction of rotation of motor 16a in real time in order to control motor 16a so that its angle of rotation matches the target angle of rotation.

[0061] According to this control, the roller 15c of the detent spring 15b comes out of the recess “N” when the detent plate 15 in the drawing rotates counterclockwise at a predetermined angle, and then engages in the recess “D” on the adjacent side via an adjacent protrusion. As a result, the coil 42a of the hand valve 42 slides in the axial direction, and the area of ​​the hand valve 42 changes from N to D.

[0062] When the driver manually activates the parking switch 12, selecting parking position P, a parking rod 17c is pushed in accordance with the rotation of the detent plate 15, and a parking pawl 17b is raised so that one claw 17d of it is positioned between the teeth of a parking gear 17a. This blocks the output shaft 10 of the automatic transmission 1 and simultaneously stops the manual valve 42 in position “P”.

[0063] As already mentioned in the BACKGROUND section, the switching range switching mechanism 13, operated in this manner, may be subject to a situation in which the motor is mechanically blocked and cannot be driven due to the ingress of foreign matter into the mechanism, an increase in friction between the peripheral components due to aging, or the like. If a fault occurs due to the motor seizing, the amount of current applied to the motor gradually increases, leading to damage to the motor due to overcurrent or a situation in which switching cannot be carried out.

[0064] A device for diagnosing and remedying the seizing of a motor in a shift-by-wire system according to an embodiment of the present disclosure is designed to precisely diagnose a condition in which the motor is seized by means of a change in the motor position and current during a shift range change according to the request of a driver, and at the time of diagnosis of the seizing of the motor, to remedy or overcome the seizing of the motor by controlling the increase of a motor power value.

[0065] The following describes a device for diagnosing and remedying the seizing of a motor according to an embodiment of the present disclosure, which is used in a shift-by-wire (SBW) system with the above-mentioned switching range switching mechanism.

[0066] Fig. Figure 2 is a block diagram that schematically shows the design of a device for diagnosing and remedying the jamming of a motor in an SBW system according to an embodiment of the present disclosure.

[0067] Referring to Fig. 2 The device for diagnosing and remedying the jamming of a motor according to an embodiment of the present disclosure comprises the above-mentioned motor 16a, sensors (a Hall sensor, a position sensor and a current sensor) and an SBW controller 14. The motor 16a rotates the locking plate 15 into a target position under the control of the SBW controller 14, and the SBW controller 14 detects the current position of the locking plate 15 and whether the locking plate is moving into the target position or not, based on the signals from the sensors 16c, 16d and 16e.

[0068] As mentioned above, when the shift lever 11 is actuated, the SBW controller 14 analyzes a signal output by the shift lever sensor 103 and sets a target position. The SBW controller then controls the motor 16a so that the detent plate 15 is rotated in the direction of the set target position. More precisely, the SBW controller detects the rotation angle of the motor 16a based on the signal from the position sensor 16c and then controls the motor 16a so that the rotation angle matches the target rotation angle.

[0069] In the present disclosure, the SBW controller 14 uses the signals from the position sensor 16c and the current sensor 16e to diagnose whether the motor is seized or not during a shift range change in response to the driver's request to change the shift range (actuation of the gearshift lever). If the motor is then diagnosed as seized, various remediation strategies are applied to resolve the seizure, depending on the seizure position (seize position relative to the detent plate).

[0070] More precisely, the SBW controller 14 comprises several processors programmed to apply different rectification strategies depending on the positions at which the roller 15c of the detent spring 15b described above is stopped in various types of motor jamming at several protrusions and indentations (convex sections and concave sections) formed in the detent plate 15 to subdivide several switching areas, thereby rectifying the motor jamming.

[0071] Preferably, the processors comprise the following: a data acquisition section 140, which is operated in such a way as to receive signals from the shift lever sensor 103 and the position sensor 16c and, based on the received signals, determines whether the current position of the motor corresponds to the target position or not; a section 142 for determining whether the motor is stuck, which is operated in such a way as to receive signals from the current sensor 16e and the position sensor 16c and, based on the received signals, diagnoses whether the motor has seized or not.

[0072] Furthermore, the processors include the following: a motor operating mode setting section 144, which is operated to set the operating mode of the motor 16a depending on the diagnostic result of section 142 for determining whether the motor is stuck, such that different control modes are selected depending on the position of the motor when it is diagnosed as stuck, in order to resolve the motor's stuckness; and a power application section 146, which is operated to apply to the motor a power that is determined depending on the control mode selected by the motor operating mode setting section 144.

[0073] If there is no change in the output of the position sensor 16c for detecting the direction and angle of rotation of the motor 16a in a state where the current position and the target position of the motor coincide, the motor seized detection section 142 can preferably diagnose that the motor is seized. In some cases, in addition to the above condition, the motor seized detection section can also diagnose that the motor is seized if the output of the current sensor 16e for detecting the magnitude of the current applied to the motor exceeds a predetermined limit for a predetermined duration.

[0074] In other words, even if a command is given to shift the shift range to the target position, which is determined according to the actuation of the shift lever 11, the section for determining the motor's stuck position can diagnose the motor as stuck if the motor does not rotate as fast as the set value (a state in which the target position is not reached) and stops (the state in which there is no change in the output of the position sensor 16c), and if the current state is added to the above state, the reliability of the diagnosis can be improved.

[0075] If the motor seizes in a state where it does not reach the target position, the current to rotate the motor to the target position is continuously applied, but the motor 16a cannot rotate due to the seizing condition, resulting in an overcurrent flowing through the motor. Therefore, in this disclosure, the change in the output of the position sensor 16c and the change in the output of the current sensor 16e, as well as the time of change, are used as a reference for diagnosing the seizing.

[0076] The motor operating mode, selected by the motor operating mode setting section 144, can be divided into a free rotation mode, a reverse rotation mode, and a target power increase mode. The free rotation mode is an operating mode to ensure the time and distance necessary to obtain the torque required to free a seized motor, and the reverse rotation mode is an operating mode to reverse the motor 16a to ensure the time and distance necessary to obtain the torque required to free a seized motor.

[0077] In free rotation mode, motor 16a can rotate freely by temporarily interrupting the current applied to it at the time the seizure is diagnosed. If it is not possible to ensure the time and distance required to achieve the necessary torque corresponding to the seizure position using free rotation mode, reverse rotation mode is also executed, rotating motor 16a in the opposite direction to the target position to ensure the aforementioned time and distance.

[0078] Furthermore, in target power increase mode, a target power (engine control value) is gradually (or stepwise) increased proportionally to the number of repeated attempts by the free rotation mode or the reverse rotation mode to resolve the jam.

[0079] For example, if motor jamming is diagnosed at an initial power of 40% during motor operation, after switching to free rotation or reverse rotation mode, a first attempt is made to resolve the jamming by increasing the motor power to 60% (increasing the motor torque) and rotating the motor again towards the target position. If the jamming is still not resolved, a second attempt is made to resolve the jamming by increasing the motor power again to 80%.

[0080] This will be discussed later in relation to the Fig. 3A and Fig. 3B is described in more detail.

[0081] Preferably, in the motor operating mode setting section 144, when motor seizure is diagnosed, the seized position is detected by means of a signal from the position sensor 16c at the time of the seizure diagnosis, and simultaneously the operating mode initially switches to the free rotation mode. Depending on whether the position of the motor 16a changes after switching to the free rotation mode, a corrective strategy is then selected, such that the operating mode switches directly to the target power increase mode or the operating mode switches to the target power increase mode via the reverse rotation mode.

[0082] Preferably, if no change in motor position is detected after switching to free rotation mode, a corrective strategy can be selected in which the target power increase mode is switched via the reverse rotation mode (hereinafter referred to as the “first corrective strategy”), and if a change in the position of motor 16a is detected after switching to free rotation mode, a corrective strategy (hereinafter referred to as the “second corrective strategy”) can be selected in which the target power increase mode is switched directly.

[0083] The positioning surface 150 of the locking plate 15 is formed in a curved wave shape in which, as described above, several protrusions and depressions alternately run through it. With such a structure, there are mainly two types of jamming situations. One is jamming that occurs while the aforementioned roller 15c moves from the protrusion (convex section) to the depression (concave section), and conversely, the other is jamming that occurs while the roller 15c moves from the depression (concave section) to the protrusion (convex section).

[0084] In the case of the type of seizing that occurs while the roller 15c moves from the depression (concave section) to the elevation (convex section), the motor 16a rotates in the opposite direction due to a recoil force from the detent spring 15b when the motor switches to free-rotation mode. Consequently, the roller 15c retracts to a previously passed inflection point of the depression (concave section), thus ensuring sufficient time and distance to achieve the torque required to release the seized motor.

[0085] Conversely, in the case of the type of seizing that occurs while the roller 15c moves from the raised section (convex part) to the recessed section (concave part), the rotational position of the motor does not change, even when the motor 16a switches to free rotation mode. Therefore, it is impossible to guarantee the time and distance required to achieve the torque necessary to resolve the motor seizure, unlike the type of seizing that occurs while the roller 15c moves from the recessed section (concave part) to the raised section (convex part).

[0086] Therefore, depending on the type of motor jamming (whether the roller 15c jams during movement from the depression (concave section) to the elevation (convex section) or vice versa during movement from the elevation (convex section) to the depression (concave section)), different strategies are required to resolve the jamming. In preferred aspects, either a first or a second resolution strategy is selectively applied, depending on whether the position of the motor 16a detected by the position sensor 16c changes after switching the operating mode to the free-rotation mode.

[0087] Fig. 3A and Fig. Figure 3B contains exemplary operating diagrams illustrating strategies for clearing a seized motor, which are selected differently depending on the seized position of the motor. The strategies for clearing a seized motor according to the types of seized motors mentioned above are now discussed with reference to the... Fig. 3A and Fig. 3B described in detail.

[0088] Fig. Figure 3A illustrates a process for resolving the stuck condition of the roller 15c of the detent spring 15b, which is detected during movement from a depression to a protrusion when the roller 15c moves into the target position for changing the switching range. Here, the process for resolving the stuck condition, in which the stuck condition is detected during the movement from the depression to the protrusion, consists of three steps.

[0089] With reference to Fig. Step 3A, the first step ①, represents a situation in which a jamming fault is detected at t1 after an initial attempt with a target power of 40% for access to a target switching range. Step 2� is the step to execute a free rotation mode, which is a process in which, after the jamming fault is detected, a torque is applied to resolve the jamming fault. In step 2�, the detent plate 15 and the motor 16a, which are synchronized with each other, rotate in opposite directions due to the recoil force of the detent spring 15b.

[0090] In other words, from the perspective of the detent plate 15, the roller 15c of the detent spring 15b moves in the opposite direction to the target position upon entering the free-rotation mode due to the recoil force of the detent spring 15b. This free-rotation mode ends at time t2, i.e., at a time when the roller 15c of the detent spring 15b is positioned by a recoil force of the detent spring 15b at the apex of a specific switching range (shown in the drawing as the reversal range R).

[0091] Step 3 is the step for executing a power increase mode. In step 3, an attempt is made to resolve the seizure by applying a power value to the motor immediately after the end of the free-rotation mode at t2. This power value is higher than the target power of the previous attempt. In step 3, t3 signifies the end of the power increase mode and indicates the point in time at which the current motor position reaches a seizure point.

[0092] At time t3, as described later, it is checked whether the jamming has been resolved. If, as a result, it is determined that the jamming has not been resolved, as illustrated in the drawing, the time and distance are reset to obtain sufficient torque through the free-rotation mode up to t4, and a new attempt is made with higher power. If, as a result of the jamming status check at t3, the jamming has been resolved, a control operation is performed to reach the target position.

[0093] Fig. Figure 3B illustrates a process for resolving the stuck condition of the roller 15c of the detent spring 15b, which is detected during the movement from a protrusion to a depression as the roller 15c moves into the target position for changing the switching range. Here, the process for resolving the stuck condition, where the stuck condition is detected during the movement from the depression to the protrusion, consists of four steps because a reversing rotation mode is added.

[0094] With reference to Fig. Step 3B is the same as in the previous situation, where the jamming is detected during the movement from a depression to a protrusion. Step 2� is the step to perform a free rotation mode, which is a process in which, after the jamming fault is detected, a torque is applied to correct the jamming fault. In step 2�, unlike in the previous case of movement from protrusion to depression, the detent plate 15 and the motor do not rotate, not even with a recoil force from the detent spring 15b.

[0095] In other words, from the perspective of the detent plate 15, even upon entering the free rotation mode, there is no change in the position of the roller 15c of the detent spring 15b. Therefore, if there is no change in the position of the motor 16a at time t2 when the free rotation mode ends, it is recognized that the jamming is detected during the movement from a protrusion to a depression, and a different strategy is executed than in the case above, where the jamming is detected during the movement from the depression to the protrusion; namely, a reversal rotation mode, which is step 3.

[0096] In step 3, a preset reverse power value is applied to the motor 16a, positioning the roller 15c of the detent spring 15b at the apex of a specific switching range (shown in the drawing as parking range P), adjacent to the point where the jamming is diagnosed, and the process ends (time t3). Immediately after the reversing mode ends, the power increase mode is maintained until t4 (step 5). Here, t4 is the time at which the motor reaches the jamming point.

[0097] At time t4, as in the previous operating example, it is checked whether the jam has been resolved. If the jam is found to be unresolved, the time and distance are reset, as shown in the diagram, to achieve sufficient torque through the reverse rotation mode, and a new attempt is made with higher power. If the jam has been resolved as a result of the jam check at t4, a control operation is performed similarly to achieve the target position.

[0098] On the other hand, in the above-mentioned determination of the resolution of the jamming, an algorithm can be applied to determine the resolution of the jamming of the motor by comparing a distance between the current position of the motor 16a and the recorded motor position at the time of diagnosis of the jamming with respect to the target position based on the output of the position sensor 16c.

[0099] More precisely, if the absolute value of the difference between the target position and the current position is smaller than the absolute value of the difference between the target position and the stuck position (the position of the engine at the time of diagnosis of the stuck position), ( | Target position - current position | < | Target position - stuck position | ), it can be determined that the stuck engine is resolved, because when the stuck position is resolved, the distance from the current position to the target position decreases from that point on.

[0100] The following describes a method for diagnosing and remedying the seizure of an engine, which is carried out by the above-mentioned device for diagnosing and remedying the seizure of an engine in the shift-by-wire system according to the embodiment of the present disclosure, using the following: Fig. 4 described. To simplify the explanation, the above design, which is described in Fig. 1 and Fig. 2 is illustrated and described with the corresponding reference symbols.

[0101] Fig. Figure 4 is a flowchart illustrating a method for diagnosing and remedying the seizure of a motor in an SBW system according to an embodiment of the present disclosure.

[0102] Referring to Fig.4. The procedure for diagnosing and remedying the seizing of a motor begins with step S100, in which it is determined whether the current position of a motor 16a corresponds to a target position when an actuation of a shift lever is detected. When the shift lever 11 is actuated, a change in the physical position is converted into an electrical signal, thus generating a difference between the current position and the target position. In the present disclosure, this difference is used to determine whether the current position and the target position correspond or not.

[0103] As a result of the determination of step S100, if the current position and the target position do not match, it is determined that the range change to a target shift range selected by the gearshift lever actuation will not be carried out, and step S200 to rotate a motor in the target position direction will be carried out, and if the current position and the target position match, it is determined that the change of the shift range intended by a driver has been carried out normally, and the control is terminated.

[0104] After the motor has rotated in step S200, it is determined again whether the current position and the target position match (S300). As a result of step S300, if the current position and the target position match, it is determined that the change in the shift range intended by a driver was executed normally, and the control process is terminated. If the current position and the target position do not match, the process proceeds to step S400 to diagnose whether the motor is stuck or not.

[0105] Preferably, in step S400, if there is no change in the output of a position sensor 16c, which detects the direction and angle of rotation of the motor 16a, it can be diagnosed that the motor is stuck. More preferably, if there is no change in the output of the position sensor 16c, which detects the direction and angle of rotation of the motor 16a, and the output of the current sensor 16e, which detects the magnitude of the current applied to the motor 16a, exceeds a defined limit for a preset duration, it can be diagnosed that the motor has seized.

[0106] If the motor seizes in a state where it does not reach the target position, the current intended to rotate the motor 16a to the target position is continuously applied. However, due to the seizing condition, the motor 16a cannot rotate, resulting in an overcurrent flowing through the motor. Therefore, in this disclosure, the change in the output of the position sensor 16c and the change in the output of the current sensor 16e, as well as the time of these changes, are used as a reference for diagnosing the seizure.

[0107] In step S400, the process returns to step S200 if the above-mentioned condition for a seized diagnosis (there is no change in the output of the position sensor 16c, and the output of the current sensor 16e, which detects the strength of the current applied to the motor, exceeds the set limit for the preset duration) is not met, and if the condition is met so that the seized motor is diagnosed, the position at the time of the seized diagnosis is stored as the seized position, and then the operating mode switches to a free rotation mode (S500).

[0108] In step S500, the motor 16a can rotate freely by temporarily interrupting the current applied to the motor at the time the motor's seizure is diagnosed. In the free-rotating mode, the motor may or may not rotate depending on the position in which the motor 16a is seized, more precisely, depending on the position of the roller 15c of the detent spring 15b on the positioning surface 150 of the detent plate 15.

[0109] As previously described, this is due to the fact that, in the type of jamming that occurs while the roller 15c moves from the depression (concave section) to the elevation (convex section) of the positioning surface 150, the motor 16a rotates in the opposite direction due to a recoil force of the detent spring 15b when the motor switches to free rotation mode, whereas in the type of jamming that occurs while the roller 15c moves from the elevation (convex section) to the depression (concave section), the motor 16a does not rotate even when the operating mode switches to free rotation mode.

[0110] Therefore, in step S600, performed after step S500, either a first or a second recovery strategy is selected to resolve the stuck state, depending on whether the position of motor 16a has changed after switching to free rotation mode (rotation state). Preferably, in step S600, the first recovery strategy S610 is selected if there is no change in motor position after switching to free rotation mode, and the second recovery strategy S620 is selected if a change in motor position is detected.

[0111] The first remediation strategy involves driving motor 16a in the opposite direction (reverse) to position it in the recess of the adjacent shift range. In this scenario, power is increased by a predetermined increment, and motor 16a is driven towards the target position with this increased power to resolve the jam. This strategy ensures sufficient time and distance to obtain the necessary torque for resolving the jam by reversing.

[0112] Furthermore, the second remediation strategy can be understood as a strategy in which, after increasing the power by a defined increment, the motor 16a is driven with the increased power towards the target position to resolve the jam. Here, with the type of jam that occurs during movement from a depression (concave section) to a protrusion (convex section), it is possible to ensure sufficient time and distance to obtain the torque required to resolve the jam simply by freely rotating the motor.

[0113] After the strategy to resolve the motor seizure in step S600 has been executed, it is determined whether the motor seizure was resolved by the first or second resolution strategy (S700). As a result of the determination in step S700, the process returns to step S100 if it is determined that the motor seizure was resolved, and if it is determined that the motor seizure was not resolved, the process proceeds to step S800 to verify the performance value.

[0114] In step S800, the power value last applied to the motor is compared to a maximum setpoint. If the comparison result is lower than the maximum setpoint, the process returns to step S500 and repeats the subsequent steps, increasing the power by a defined increment. Then, either the first or second remediation strategy is reapplied with the increased power. The maximum setpoint can be 100% power, but for safety reasons, it can also be set lower.

[0115] In step S700, by comparing the distance between the current motor position and the motor position at the time of diagnosis of the seizure against the target position, it can be determined whether the seizure has been resolved or not. More precisely, if the absolute value of the difference between the target position and the current position is less than the absolute value of the difference between the target position and the seized position (|target position - current position| < |target position - seized position|), it can be determined that the motor seizure has been resolved.

[0116] This is because the distance from the current position to the target position decreases once the stuck position is resolved.

[0117] If, on the other hand, the performance value reaches the maximum target value as a result of the check by step S800, it is determined that the engine seizure cannot be rectified, and a corresponding warning message may be issued via a means recognizable to the driver.

[0118] For example, if the maximum target value is 100% power, and the engine seizure has not been resolved even at 100% power in step S620, it will be recognized that the engine seizure cannot be resolved solely by power control, and a corresponding warning message can be issued via a suitable means recognizable to the driver (e.g. cluster or AVN) so that a rapid follow-up action can be taken.

[0119] According to the embodiments of the present disclosure discussed above, it is possible to accurately determine the type of jamming by using the free rotation mode (whether the jamming of the motor occurred during movement in one direction from the recess to the protrusion or during movement in one direction from the protrusion to the recess, with respect to a position of a roller on a positioning surface of a detent plate) and to selectively apply a suitable strategy depending on the type of jamming.

[0120] In other words, one advantage is that the jamming can be resolved by the strategy of efficient motor movement, with the power value gradually increasing proportionally to the number of attempts to resolve the jamming, so that if the degree of jamming is not severe, the jamming problem can be solved even in a low-power range before maximum power (100%) is applied, thus reducing unnecessary power consumption in the jamming resolution process.

[0121] The above detailed description of the present disclosure has only described certain embodiments. However, it should be understood that the present disclosure is not limited to the form mentioned in the detailed description, but rather includes all modifications, equivalents, and substitutions that pertain to the concept and scope of the present disclosure as defined in the claims.

Claims

[1] Method for diagnosing and remedying the seizing of a motor (16a) in a shift-by-wire (SBW) system in which a shift range change of an automatic transmission by a motor (16a) is implemented, the method comprising: (a) when an actuation of a gearshift lever (11) is detected, determine whether a current position of the engine (16a) matches a target position or not; (b) if the current position does not match the target position, rotating the motor (16a) in a direction towards the target position; (c) re-determining whether the current position of the motor (16a) matches the target position or not after the motor (16a) has been rotated; (d) if it is determined that the current position does not correspond to the target position, diagnose whether or not the engine (16a) has seized; (e) if it is diagnosed that the motor (16a) is stuck, enabling the motor (16a) to be switched to a free-rotating mode in which the motor (16a) is freely rotatable by temporarily interrupting the current applied to the motor (16a) at the time of diagnosis; and (f) Selecting either a first remediation strategy or a second remediation strategy depending on whether the position of the motor (16a) changes after switching to free rotation mode or not, so that the stuckness of the motor (16a) is resolved. [2] Method according to claim 1, wherein, as a result of the determination by steps (a) and (c), when the current position and the target position coincide, it is recognized that the switching range has been changed normally and the process is terminated in the corresponding step without further progress. [3] Method according to claim 1 or 2, wherein in step (d) if there is no change in the output of a position sensor (16c) for detecting the direction and angle of rotation of the motor (16a), it can be diagnosed that the motor (16a) is stuck. [4] Method according to one of the preceding claims, wherein in step (d) if there is no change in the output of the position sensor (16c) for detecting the direction and angle of rotation of the motor (16a) and the output of a current sensor (16e) for detecting the magnitude of the current applied to the motor (16a) exceeds a predetermined limit for a predetermined duration, it can be diagnosed that the motor (16a) is stuck. [5] Method according to any of the preceding claims, wherein in step (f) the first rectification strategy is selected if there is no change in the motor position (16a) after switching to free rotation mode, and the second rectification strategy is selected if a change in the motor position (16a) is detected after switching to free rotation mode. [6] Method according to claim 5, wherein the first remedying strategy is a strategy in which, firstly, the motor (16a) is driven in the opposite direction to the direction of the target position, so that the motor (16a) is positioned in a recessed section of the adjacent switching areas, and secondly, after setting a power value, so that it increases by a predetermined increment, the motor (16a) is driven with the increased power value in the direction of the target position in order to remedy the jamming of the motor (16a), and The second remedy strategy is one in which, after setting a power value so that it increases by a predetermined increment, the motor is driven towards the target position with the increased power value in order to resolve the motor's stuck position. [7] The method of claim 6, further comprising: (g) Determine whether the engine seizure (16a) was resolved by the first or second remediation strategy; and (h) as a result of the determination with step (g), if the engine jam (16a) has not been resolved, check the power value, wherein as a result of the check with step (h), if the power value is less than a predetermined maximum value, the process returns to step (e) and the subsequent steps are repeated, so that after a further increase in the power value by the predetermined increment, the first remediation strategy or the second remediation strategy is applied again. [8] Method according to claim 7, wherein in step (g) it is possible to determine whether the jamming of the motor (16a) has been resolved or not by comparing a distance between the current motor position (16a) and the motor position (16a) at the time when the jamming was diagnosed based on the target position. [9] Method according to claim 7 or 8, wherein, as a result of the check in step (h), if the power value reaches the predetermined maximum value, this is determined as a situation in which the jamming of the motor (16a) cannot be rectified, and a corresponding warning message is issued by means recognizable to the driver. [10] Device for diagnosing and remedying the seizing of a motor (16a) in a shift-by-wire (SBW) system in which a shift range change of an automatic transmission by a motor (16a) is implemented, the device comprising: a motor (16a) that generates a driving force to rotate a detent plate (15) into a target position; a Hall sensor (16d) and a current sensor (16e) designed to determine the position of a rotor inside the motor (16a) and the strength of a current applied to the motor (16a), respectively; a position sensor (16c) designed to detect a signal change corresponding to the rotation of the motor (16a) and to output a PWM signal corresponding to a current switching range; and a shift-by-wire (SBW) controller (14) designed to determine a target position by analyzing a signal from a shift lever sensor that detects a change in the position of a shift lever (11) and controlling the drive of the motor (16a) based on signals from the Hall sensor (16d) and the position sensor (16c) to rotate the detent plate (15) in the direction of the determined target position, wherein the SBW controller (14) is designed to diagnose whether the motor (16a) has seized or not based on the signals from the position sensor (16c) and the current sensor (16e), and if the motor (16a) is seized, to apply different recovery strategies depending on the position of the seized motor (16a) so that the motor (16a) is recovered. [11] Device according to claim 10, wherein the SBW controller (14) comprises: a data acquisition section (140) which is operated in such a way that it receives signals from the gearshift sensor (103) and the position sensor (16c) and determines, on the basis of the received signals, whether the current position of the motor (16a) matches the target position or not; a section (142) for determining whether the motor (16a) is stuck, which is operated in such a way that it receives signals from the current sensor (16e) and the position sensor (16c) and, based on the received signals, diagnoses whether the motor (16a) has become stuck or not; a motor operating mode setting section (144) which is operated such that, when the motor (16a) is diagnosed as stuck in the section (142) for determining the stuckness of the motor (16a), it selects different control modes depending on a position of the stuck motor (16a) in order to remedy the stuckness of the motor (16a); and a power application section (146) which is operated to apply to the motor (16a) a power which is determined depending on the control mode selected by the motor operating mode setting section (144). [12] Device according to claim 11, wherein, if there is no change in the output of the position sensor (16c) for detecting the direction and angle of rotation of the motor (16a), the section (142) for determining the stuckness of the motor (16a) diagnoses that the motor (16a) is stuck. [13] Device according to claim 11 or 12, wherein if there is no change in the output of the position sensor (16c) for detecting the direction and angle of rotation of the motor (16a) and the output of the current sensor (16e) for detecting the magnitude of the current applied to the motor (16a) exceeds a predetermined limit for a predetermined duration, the section (142) for determining the stuckness of the motor (16a) diagnoses that the motor (16a) is stuck. [14] Device according to any one of claims 11 to 13, wherein the motor operating mode selected by the motor operating mode setting section (144) comprises: a free rotation mode which ensures a time and distance such that a torque is obtained that is required to remedy the jamming of the motor (16a); a reverse rotation mode which, if it is impossible to ensure the time and distance so that the required torque is obtained by the free rotation mode, drives the motor (16a) in the reverse direction (the direction opposite to the target position direction) depending on the position of the fixed motor (16a), so that the time and distance are ensured; and a target power increase mode that gradually increases a target power proportional to the number of retries of the free rotation mode or the reverse rotation mode. [15] Device according to claim 14, wherein the motor operating mode setting section (144) selects a remediation strategy that switches to free rotation mode so that the motor (16a) is free to rotate by temporarily interrupting the current applied to the motor (16a) at the time of diagnosis of the jamming, and depending on whether the motor position (16a) changes after switching to free rotation mode or not, switches directly to target power increase mode or switches to target power increase mode via reverse rotation mode. [16] Device according to claim 15, wherein, if there is no change in the motor position (16a) after switching to the free rotation mode, a corrective strategy is selected in which the device switches to the target power increase mode via the reverse rotation mode, and if there is a change in the motor position (16a) after switching to the free rotation mode, a corrective strategy is selected in which the device switches directly to the target power increase mode. [17] Device according to any one of claims 10 to 16, wherein the SBW controller (14) determines whether the jamming of the motor (16a) has been resolved or not by comparing a distance between the current motor position (16a) and the motor position (16a) at the time of diagnosis of the jamming with respect to the target position based on the output of the position sensor (16c).

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