JP5136918B2 - Shift-by-wire system - Google Patents

Description

  The present invention relates to a shift-by-wire system that switches a shift range of an automatic transmission.

  2. Description of the Related Art Conventionally, in the field of vehicle control, a by-wire system in which an actuator that changes a vehicle state is electrically controlled by a by-wire control circuit according to a command from a vehicle driver has been put into practical use. For example, a shift-by-wire system that switches the shift range of an automatic transmission of a vehicle according to a driver's command is known. In the shift-by-wire system, for example, the shift range is switched by rotating an electric actuator to drive a transmission mechanism of an automatic transmission. The actuator used here has a motor unit that rotates at a high speed and a deceleration unit that decelerates and outputs the rotation of the motor unit. In addition, when a brushless motor such as an SR motor is employed as the motor unit, the actuator is generally provided with an incremental encoder that outputs a pulse signal corresponding to a change in the rotation angle of the motor unit. This encoder enables optimum excitation energization control of the motor unit.

Japanese Patent No. 4248290

  By the way, in order to accurately drive the speed change mechanism part of the automatic transmission by the rotation of the actuator, the absolute rotation position (absolute position) of the output shaft of the speed reduction part of the actuator is detected, and the actuator is operated based on the detected absolute position. Need to rotate. As a method of detecting the absolute position of the output shaft, if it is a non-contact type, a method of setting a linear output sensor on the output shaft or an absolute encoder that outputs the absolute value of the rotation angle of the output shaft is considered. It is done. If it is a contact type, the method of setting the neutral switch etc. which were conventionally mounted in the automatic transmission etc. on the output shaft can be considered. The absolute position of the output shaft can also be detected by setting an absolute type encoder capable of multiple rotations on the motor section of the actuator.

  However, the contact type is inferior in terms of reliability and durability, and even if the rotation position of the output shaft can be detected, the rotation angle cannot be detected. Absent. In addition, the absolute encoder has a complicated structure and high cost, and there is a further tendency in the case of multi-rotation. Also, linear output sensors tend to be relatively expensive.

  Patent Document 1 discloses a shift-by-wire system that switches a shift range to either a “P range” that is a parking range or a “non-P range” that is a range other than the P range. In this shift-by-wire system, a reference position corresponding to the absolute position of the output shaft of the actuator is learned using only an incremental encoder for energization control of the motor unit, and based on the learned reference position and a predetermined rotation amount. The absolute position of the output shaft is set and detected. In this way, the cost of the system is reduced by using only an incremental encoder to detect the absolute position of the output shaft.

  In the shift-by-wire system of Patent Document 1, when the vehicle power supply is turned on, a reference position corresponding to at least one (absolute position of the output shaft) of both end ranges (P range or non-P range) of the shift range of the automatic transmission is set. learn. Here, whether to learn the reference position of the P range or the non-P range is determined according to the state (vehicle speed) of the vehicle when the vehicle power supply is turned on. This makes it possible to return the vehicle to a normal control state safely and promptly even when the power supply is restored (power-on) after a momentary interruption of the vehicle power supply.

  However, since the technique disclosed in Patent Document 1 is based on the assumption that the shift range of the automatic transmission is two (P range and non-P range), the technique is referred to as, for example, “P range (of both end ranges). 1), an automatic transmission including four ranges of an R range that is a reverse range, an N range that is a neutral range, and a D range that is a forward range (the other of both end ranges). When applied directly to the switching control, various problems may occur. For example, when the actual range is the N range (when the driving torque is not transmitted to the wheels), when the vehicle power supply is interrupted and then the power is restored, the shift range is set to the D range or the P range by learning control. The vehicle suddenly moves forward or stops (reversing and stopping) by entering the vehicle, which may cause the driver to feel danger or anxiety. Further, for example, when the actual range is the R range (during reverse travel), when the vehicle power supply is momentarily interrupted, and then the power supply is restored, the vehicle suddenly advances due to the shift range entering the D range or P range by learning control. (Reverse run) or stop, which may cause the driver to feel dangerous or anxious.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a shift-by-wire system that can safely return to a normal control state even if the vehicle power supply is momentarily interrupted with a simple configuration. It is in.

  The invention according to claim 1 is a shift-by-wire system that switches a shift range of an automatic transmission in accordance with a signal from a shift selection means operated by a vehicle driver, and controls an actuator, a detent plate, and a detent spring. A part. The actuator includes a motor unit that is rotated by electric power, an incremental encoder that outputs a pulse signal in accordance with the rotation of the motor unit, and a deceleration unit that decelerates and outputs the rotation of the motor unit. The detent plate is rotationally driven by the actuator by being provided so as to be connected to the deceleration portion of the actuator, and has a first recess, a second recess, and a plurality of intermediate recesses. The first recess is formed on one side in the rotational direction of the detent plate. The second recess is formed on the other side in the rotation direction of the detent plate. The plurality of intermediate recesses are formed between the first recess and the second recess. The detent spring has a restricting portion, and the restricting portion fits into the first recessed portion, the plurality of intermediate recessed portions, or the second recessed portion to restrict the rotation of the detent plate, thereby fixing the shift range of the automatic transmission. It is. The control unit has target range determination means for determining a target range based on a signal from the shift selection means, and rotates the actuator so that the shift range of the automatic transmission becomes the target range determined by the target range determination means. Control. More specifically, the target range determination means determines the target range based on the signal from the shift selection means, the brake signal, the vehicle speed signal, and the like.

  Here, the first concave portion corresponds to the P range which is a parking range. The first recess has a first wall on the side opposite to the second recess. The second recess corresponds to “D range or lowest speed range” which is a forward range. The second recess has a second wall on the side opposite to the first recess. The plurality of intermediate recesses respectively correspond to an R range that is a reverse range, an N range that is a neutral range, or a “forward range other than the lowest speed range”.

  The control unit has first position learning means and second position learning means. The first position learning means rotates the actuator in a direction in which the rotation of the actuator is restricted when the detent spring restricting portion comes into contact with the first wall of the first recess, and counts the pulse signal output from the encoder at this time The first reference position of the actuator corresponding to the P range is learned by detecting a state in which the minimum value or the maximum value does not change for a predetermined time. The second position learning means rotates the actuator in a direction in which the rotation of the actuator is regulated when the regulating part of the detent spring comes into contact with the second wall of the second recess, and counts the pulse signal output from the encoder at this time The second reference position of the actuator corresponding to the D range or the lowest speed range is learned by detecting a state in which the maximum value or the minimum value does not change for a predetermined time.

  The control unit learns the first reference position or the second reference position, for example, a plurality of predetermined values stored in advance (from the first reference position or the second reference position to the position corresponding to each shift range). The rotation position of the actuator corresponding to each shift range is obtained by calculation based on a predetermined value indicating the rotation amount of the actuator) and the first reference position or the second reference position, and the actuator is rotated so as to be the rotation position obtained by the calculation By doing so, the actual range can be switched to a desired shift range.

  In the present invention, for example, when the vehicle power is turned off when the actual range is the P range and the target power range is the P range when the vehicle power is turned on, the first reference position is detected by the first position learning unit. To learn. Usually, when the actual range is the P range, the vehicle is considered to be in a stopped state. Therefore, at this time, for example, even if learning of the first reference position is started by turning on the vehicle power supply after the vehicle power supply is momentarily interrupted, the actual range remains the P range (the vehicle remains in a stopped state). The first reference position can be learned safely and the normal control state can be restored.

  For example, when the vehicle power is turned off when the actual range is the D range and the vehicle power is turned on after that, when the target range is “range corresponding to the second recess”, To learn the second reference position. Normally, when the actual range is “range corresponding to the second recess (D range or lowest speed range)”, the vehicle is considered to be in a traveling (forward) state. Therefore, at this time, even if learning of the second reference position is started by turning on the vehicle power supply after the vehicle power supply is momentarily interrupted, the actual range remains the D range or the lowest speed range (the vehicle is maintained in the running state). Therefore, the second reference position can be learned safely and the normal control state can be restored.

  For example, when the actual range is other than “P range and“ range corresponding to the second recess ”,” the control unit turns off the vehicle power, and when the vehicle power is turned on, the target range is “P range and“ second range ”. If the range other than “range corresponding to 2 recesses” ”or indefinite, the actual range at that time is maintained by not driving the actuator. In this state, in the first shift range switching by the driver, the control unit accepts only a switching request to the P range or “range corresponding to the second recess” and controls the rotation of the actuator in response to the switching request to shift. When the switching request is a switching request to the P range, the first reference position is learned by the first position learning means, and the switching request is switched to the “range corresponding to the second recess”. If it is a request, the second position learning means learns the second reference position.

  With the above configuration, in the present invention, when the actual range before the vehicle power supply is momentarily interrupted is a range other than the “P range and the“ range corresponding to the second recess ””, The actual range before the momentary interruption is maintained without learning the first reference position or the second reference position. Therefore, for example, in a vehicle in which the shift range of an automatic transmission consists of four ranges of P range, R range, N range, and D range (the first recess corresponds to the P range and the second recess corresponds to the D range), When the vehicle power supply is interrupted when the range is the N range, the actual range is maintained at the N range even after the power supply is restored, so that “the actual range is changed to the P range to learn the first reference position”. Sudden reverse torque is generated when passing the R range at the time of transition ”,“ Suddenly entering the P range during travel causes ratcheting of the parking lock mechanism, and the parking lock mechanism is damaged, or traveling at low speed If the vehicle is in the middle, the vehicle suddenly stops (P-lock) ”or“ The actual range enters the D range and an unexpected forward torque is generated to learn the second reference position. It is possible to prevent a situation such as raw to ". Further, for example, when the vehicle power supply is interrupted when the actual range is the R range, the actual range is maintained in the R range even after the power supply is restored, so that “the actual range is about to learn the first reference position”. Can suddenly stop the vehicle (P lock) "or" the actual range enters the D range and the vehicle runs backward trying to learn the second reference position ".

  Thus, the shift-by-wire system according to the present invention can safely return to the normal control state even when the vehicle power supply is momentarily interrupted. In the present invention, since the incremental encoder is used to detect the rotational position of the actuator, the configuration of the entire system can be simplified. Therefore, downsizing and cost reduction of the shift-by-wire system can be achieved.

  The invention according to claim 2 further includes notification means for notifying the driver that only a request for switching to the P range or the “range corresponding to the second recess” can be accepted. In the present invention, when the vehicle power is turned on, if the target range is a range other than “P range and“ range corresponding to the second recess ”” or is indefinite, the first shift range switching by the driver is the P range or Only the request for switching to the “range corresponding to the second recess” is accepted. At this time, the notification means can only accept the request for switching to the P range or “the range corresponding to the second recess”. The driver's confusion can be avoided by notifying the driver.

  In the invention according to claim 3, when there is a request for switching to a range other than “P range and“ range corresponding to the second recess ””, other than “P range and“ range corresponding to the second recess ”” There is further provided warning means for warning the driver that switching to the range is not possible. In the present invention, when the vehicle power is turned on, if the target range is a range other than “P range and“ range corresponding to the second recess ”” or is indefinite, the first shift range switching by the driver is the P range or Only a request for switching to the “range corresponding to the second recess” is accepted, but at this time, if there is a request to switch to a range other than the “P range and“ range corresponding to the second recess ””, Warning means can warn the driver that switching to a range other than the “P range and“ range corresponding to the second recess ”” is not possible, thereby avoiding driver confusion.

In a fourth aspect of the present invention, the control unit further includes storage means and power-on target range setting means. The storage means stores the state and actual range of the actuator when the vehicle power supply is turned off. The power-on target range setting means sets “actual range stored in storage means” as the target range when the state of the actuator stored in the storage means is “stopped” when the vehicle power is turned on. If the actuator state stored in the storage means is “operating state”, “undefined” is set as the target range.
In the present invention, the target range when the vehicle power is turned on is set by the power-on target range setting means based on the operating state of the actuator when the vehicle power is turned off. Unmatching between the target range and actual range when the power is turned on can be prevented.

1 is a schematic diagram showing a vehicle control system including a shift-by-wire system according to a first embodiment of the present invention. Sectional drawing which shows the actuator of the shift-by-wire system by 1st Embodiment of this invention. The figure which shows the transmission mechanism part of the shift-by-wire system by 1st Embodiment of this invention, and its vicinity. The figure which shows the detent plate of the shift-by-wire system by 1st Embodiment of this invention. The figure which shows the processing flow regarding learning of the rotational position of the actuator by the shift-by-wire system by 1st Embodiment of this invention. The figure which shows the sub process flow of the process flow of FIG. The figure which shows the detent plate of the shift-by-wire system by 2nd Embodiment of this invention.

Hereinafter, a shift-by-wire system according to a plurality of embodiments of the present invention will be described with reference to the drawings. Note that, in a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted. In the following description, the electronic control unit is abbreviated as “ECU”.
(First embodiment)
FIG. 1 shows a vehicle control system 1 including a shift-by-wire system 3 according to a first embodiment of the present invention. For example, a vehicle control system 1 mounted on a four-wheeled vehicle includes an automatic transmission control system 2, a shift-by-wire system 3, an engine control system 4, an integrated ECU 10, and the like.

  The automatic transmission control system 2, the shift-by-wire system 3, and the engine control system 4 have an AT-ECU 12, an SBW-ECU 13, and an EC-ECU 14, respectively. The AT-ECU 12, the SBW-ECU 13, and the EC-ECU 14 are all electric circuits mainly composed of a microcomputer. The AT-ECU 12, the SBW-ECU 13 and the EC-ECU 14 are electrically or optically connected to each other via a LAN line 17 in the vehicle. Further, the AT-ECU 12, the SBW-ECU 13, the EC-ECU 14, and the integrated ECU 10 are electrically connected to a battery 18 that is a power source of the vehicle, and are operated by electric power supplied from the battery 18. The integrated ECU 10 controls the entire vehicle control system 1 in cooperation with the above-described AT-ECU 12, SBW-ECU 13 and EC-ECU 14. In the present embodiment, the SBW-ECU 13 corresponds to a “control unit” in the claims.

  The automatic transmission control system 2 drives the automatic transmission 20 of the vehicle by hydraulic pressure. The automatic transmission control system 2 includes a hydraulic circuit 21 that switches a shift range and a gear position of the automatic transmission 20. In the present embodiment, the automatic transmission 20 includes a D range that is a forward range as a travel range and an R range that is a reverse range, and a P range and a neutral range that are parking ranges as a non-travel range. N range is set. The hydraulic circuit 21 has a manual valve 22 that is a spool valve as a range position selection mechanism. The manual valve 22 switches the hydraulic circuit 21 by moving in the axial direction. When the manual valve 22 switches the hydraulic circuit 21, the automatic transmission 20 is set to one of the above shift ranges. The automatic transmission 20 includes a plurality of friction engagement elements that are fastened in any shift range. The plurality of solenoid valves 23 installed in the hydraulic circuit 21 drives the corresponding friction engagement elements by hydraulic pressure. Thereby, each friction engagement element is fastened or released by the hydraulic pressure supplied from the electromagnetic valve 23.

  The AT-ECU 12 is electrically connected to electrical elements such as the electromagnetic valve 23 of the hydraulic circuit 21. Thereby, the AT-ECU 12 electrically controls the output hydraulic pressure from each electromagnetic valve 23. By controlling the output hydraulic pressure from the electromagnetic valve 23 by the AT-ECU 12, each friction engagement element of the automatic transmission 20 is fastened or released. In the present embodiment, the AT-ECU 12 is electrically connected to a vehicle speed sensor 24 that detects the speed of the vehicle based on, for example, the rotational speed of the output shaft of the automatic transmission 20. The AT-ECU 12 receives the detection signal output from the vehicle speed sensor 24, detects the vehicle speed, and controls each electromagnetic valve 23.

The shift-by-wire system 3 includes the manual valve 22 of the automatic transmission control system 2, the actuator 30 that drives the parking lock mechanism 70 (FIG. 3), the transmission mechanism 31, and the like. The SBW-ECU 13 is one of the elements that constitute the shift-by-wire system 3. The electromagnetically driven actuator 30 includes a motor unit 32, an encoder 34, a speed reduction unit 33, and the like.
Here, the actuator 30 will be described. In the present embodiment, the motor unit 32 is a switched reluctance (SR) motor, and is a brushless motor that generates a driving force without using a permanent magnet. As shown in FIG. 2, the motor unit 32 includes a stator 35 into which a plurality of coils 36 arranged in the rotation direction are fitted. The motor unit 32 has a rotor 37 inside the stator 35. The rotor 37 has a shaft member 38 at the center, and is rotatably supported by the housing of the actuator 30.

The SBW-ECU 13 sequentially energizes the plurality of coils 36 of the motor unit 32 at a predetermined timing to rotate the rotor 37 and the shaft member 38.
In the present embodiment, the encoder 34 is provided in the housing of the actuator 30. The encoder 34 is configured by a magnet that rotates integrally with the rotor 37, a Hall IC for magnetic detection, and the like that is mounted on a substrate fixed to the housing and is opposed to the magnet to detect the passage of the magnetic flux generation part in the magnet. Has been. The encoder 34 outputs a pulse signal according to the change in the rotation angle of the motor unit 32 (rotor 37).

As described above, the encoder 34 in the present embodiment is an incremental encoder that outputs a pulse signal in accordance with the rotation of the motor unit 32. The SBW-ECU 13 decreases (counts down) or increases (counts up) the count value (count value) according to the pulse signal output from the encoder 34. Thereby, SBW-ECU13 can detect the rotation state of the motor part 32 (rotor 37). The SBW-ECU 13 can rotate the motor unit 32 at high speed without stepping out by detecting the rotation state of the motor unit 32 with the encoder 34. It should be noted that every time the vehicle power is turned on (every time the shift-by-wire system 3 is started), an initial stage for energized energized phase learning of the motor unit 32 (count value and energized phase synchronization according to the pulse signal output from the encoder 34). Drive control is performed. With this initial drive control, the rotation of the actuator 30 can be appropriately controlled.
The deceleration unit 33 decelerates the rotational motion of the motor unit 32 (shaft member 38) and transmits the reduced rotational motion to the transmission mechanism unit 31. The transmission mechanism unit 31 transmits the rotational driving force output from the speed reduction unit 33 to the manual valve 22 and the parking lock mechanism 70.

  As shown in FIG. 3, the transmission mechanism unit 31 includes a manual shaft 51, a detent plate 52, a detent spring 55, and the like. The manual shaft 51 is connected to the speed reduction unit 33 of the actuator 30 and is rotationally driven by the rotational driving force of the motor unit 32. The detent plate 52 extends radially outward from the manual shaft 51 and is configured integrally with the manual shaft 51. Thereby, the detent plate 52 is rotationally driven by the actuator 30 integrally with the manual shaft 51. The detent plate 52 is provided with a pin 54 that protrudes in parallel with the manual shaft 51. The pin 54 is connected to the manual valve 22. As a result, when the detent plate 52 rotates together with the manual shaft 51, the manual valve 22 reciprocates in the axial direction. That is, the speed change mechanism 31 converts the rotational driving force of the actuator 30 into a linear motion and transmits it to the manual valve 22.

  As shown in FIG. 4, the detent plate 52 has a first recess 61, an intermediate recess 62, an intermediate recess 63, and a second recess 64 on the radially outer side of the manual shaft 51. The first recess 61 is formed on one side in the rotational direction of the detent plate 52. The second recess 64 is formed on the other side in the rotational direction of the detent plate 52. The intermediate recess 62 and the intermediate recess 63 are formed between the first recess 61 and the second recess 64.

  In the present embodiment, the first recess 61 is formed corresponding to the “P range” that is the shift range of the automatic transmission 20. Further, the first recess 61 has a first wall 65 on the opposite side to the second recess 64. The intermediate recess 62 is formed corresponding to the “R range”. The intermediate recess 63 is formed corresponding to the “N range”. The second recess 64 is formed corresponding to the “D range”. Further, the second recess 64 has a second wall 66 on the opposite side to the first recess 61.

  The detent spring 55 has a detent roller 53 as a restricting portion at the tip. When a predetermined rotational force is applied to the detent plate 52 via the manual shaft 51, the detent roller 53 passes over the convex portions formed between the concave portions 61 to 64 as shown in FIG. It moves to the recessed parts 61-64. As a result, when the manual shaft 51 is rotated by the actuator 30, the position of the manual valve 22 in the axial direction and the state of the parking lock mechanism 70 are changed, and the shift range of the automatic transmission 20 is changed.

By restricting the rotation of the detent plate 52 by fitting the detent roller 53 into one of the first recess 61, the intermediate recess 62, the intermediate recess 63, and the second recess 64, the position of the manual valve 22 in the axial direction, and Then, the state of the parking lock mechanism 70 is determined. Thereby, the shift range of the automatic transmission 20 is fixed.
In the present embodiment, as shown in FIG. 4, when the shift range is switched from the “P range” side to the “R range”, “N range”, and “D range” side, the direction in which the speed reduction unit 33 of the actuator 30 rotates is changed. , Defined as the positive rotation direction. On the other hand, the direction in which the deceleration unit 33 of the actuator 30 rotates when the shift range is switched from the “D range” side to the “N range”, “R range”, and “P range” side is defined as the reverse rotation direction. .

  As shown in FIG. 4, in this embodiment, the rotatable range of the detent plate 52 is from the position where the first wall 65 and the detent roller 53 abut to the position where the second wall 66 and the detent roller 53 abut. It becomes the range. However, since the rotatable range shown in FIG. 4 is the rotatable range of the detent plate 52 in relation to the detent roller 53, the detent includes the amount of deflection and extension of the detent spring 55 and the amount of twist of the manual shaft 51. The absolute rotatable range of the plate 52 is larger than the rotatable range shown in FIG.

  FIG. 3 shows a state of the parking lock mechanism 70 when the shift range is the “D range”, that is, when the shift range is a range other than the “P range”. In this state, the parking gear 74 is not locked by the parking lock pole 73. Therefore, rotation of the vehicle wheel is not hindered. From this state, when the speed reduction portion 33 of the actuator 30 rotates in the reverse rotation direction, the rod 71 is pushed in the direction of the arrow X shown in FIG. 3 via the detent plate 52, and the taper portion 72 provided at the tip of the rod 71. Pushes up the parking lock pole 73 in the direction of arrow Y shown in FIG. As a result, the parking lock pole 73 meshes with the parking gear 74, and the parking gear 74 is locked. As a result, the rotation of the wheel is restricted. At this time, the detent roller 53 of the detent spring 55 is fitted in the first recess 61 of the detent plate 52, and the actual range (hereinafter referred to as “actual range”) of the automatic transmission 20 is “P range”. It is.

The SBW-ECU 13 is electrically connected to the motor unit 32 and the encoder 34 of the actuator 30, the selector sensor 46 of the range selector 45 serving as a shift selection means, and the like.
The selector sensor 46 detects a range commanded by the driver of the vehicle by operating the range selector 45 (hereinafter referred to as “command range”). The selector sensor 46 outputs the detected signal to the SBW-ECU 13.

  The SBW-ECU 13 determines the target range based on the signal related to the command range output from the selector sensor 46. More specifically, in this embodiment, the target range is determined based on a signal from the selector sensor 46, a brake signal, a signal from the vehicle speed sensor 24, and the like. Here, the SBW-ECU 13 functions as “target range determining means” in the claims.

  The SBW-ECU 13 controls the rotation of the actuator 30 so that the shift range of the automatic transmission 20 becomes the target range determined by the target range determining means. As a result, the actual range of the automatic transmission 20 is switched to the range intended by the driver.

  Since the encoder 34 of this embodiment is an incremental encoder, it can only detect the relative rotational position of the motor unit 32. Therefore, when the shift range is switched to a desired range by rotating the actuator 30, it is necessary to learn a reference position corresponding to the absolute position of the deceleration unit 33 of the actuator 30. After learning the reference position of the actuator 30, the rotation position of the actuator 30 corresponding to each shift range based on the learned reference position and a predetermined rotation amount (control constant; first predetermined value and second predetermined value described later). Is obtained by calculation, and the actual range can be switched to a desired shift range by rotating the actuator 30 so that the rotation position obtained by the calculation is obtained. In the present embodiment, the SBW-ECU 13 learns the reference position of the actuator 30 corresponding to the end portion (P range or D range) of the rotatable range of the detent plate 52.

Further, after learning the reference position, the SBW-ECU 13 performs the calculation based on the reference position, the predetermined rotation amount, and the count value of the pulse signal from the encoder 34 (rotation position of the motor unit 32). The actual range can be detected indirectly. In the present embodiment, the SBW-ECU 13 displays information on the detected actual range on the display device 47 provided in front of the driver's seat of the vehicle via the integrated ECU 10. As a result, the driver can check the actual range at that time.
In the present embodiment, the corresponding actual range is based on the rotational position of the motor unit 32 when the center of the detent roller 53 is located within each of the shift ranges (P, R, N, D) shown in FIG. Can be detected. The above-mentioned “learning of the reference position of the actuator 30” will be described in detail later.

  The EC-ECU 14 is electrically connected to a throttle 41 of an internal combustion engine (hereinafter referred to as “engine”) 40 of the vehicle, an injector 42, and an accelerator sensor 44 of an accelerator pedal 43. The throttle 41 adjusts the flow rate of intake air flowing through the intake passage of the engine 40. The injector 42 adjusts the amount of fuel injected into the intake passage of the engine 40 or each cylinder. The accelerator sensor 44 detects the amount of operation of the accelerator pedal 43 by the driver of the vehicle, and outputs the detected signal to the EC-ECU 14. With such a configuration, when the accelerator pedal 43 is operated by the driver of the vehicle, the EC-ECU 14 electrically controls the throttle 41, the injector 42, and the like based on the operation. As a result, the EC-ECU 14 adjusts the rotational speed and output torque of the engine 40.

  Next, “learning of the reference position of the actuator 30” by the SBW-ECU 13 will be described. In the present embodiment, it is assumed that learning of the reference position of the actuator 30 is performed by learning the first reference position and learning the second reference position. Here, the first reference position is a rotational position of the actuator 30 in a state where the detent roller 53 of the detent spring 55 is in contact with the first wall 65 of the first recess 61 as shown in FIG. It is a position corresponding to the P range in the range. The second reference position is a rotational position of the actuator 30 in a state where the detent roller 53 is in contact with the second wall 66 of the second recess 64, and is a position corresponding to the D range in the shift range. .

  When the SBW-ECU 13 learns the first reference position, first, the direction in which the rotation of the actuator 30 is restricted by the contact of the detent roller 53 of the detent spring 55 with the first wall 65 of the first recess 61, that is, Then, the actuator 30 is rotated in the reverse rotation direction (see FIG. 4). As a result, the detent roller 53 starts to bend as the detent roller 53 comes into contact with the first wall 65 and is pressed. Then, the SBW-ECU 13 detects the state in which the minimum value or the maximum value of the count value of the pulse signal output from the encoder 34 does not change for a predetermined time, thereby rotating the detent plate 52 and the actuator 30 (the motor unit 32). Determined to have stopped. Whether the minimum value or the maximum value of the count value is monitored is set according to the characteristics of the encoder 34. In any case, the fact that the minimum value or the maximum value does not change for a predetermined time indicates that the detent plate 52 has stopped moving. The SBW-ECU 13 stores the count value at this time as a value corresponding to the first reference position of the actuator 30 in a volatile memory such as a RAM in the storage unit 15 (see FIG. 1). Thereby, learning of the first reference position of the actuator 30 is completed. Here, the SBW-ECU 13 functions as “first position learning means” in the claims.

  The storage unit 15 stores in advance a plurality of predetermined values (hereinafter referred to as “first predetermined values”) indicating the amount of rotation of the motor unit 32 from the first reference position to the position corresponding to each shift range. Yes. Therefore, after the SBW-ECU 13 learns the first reference position by the first position learning means, each shift range (P range, R range, N range) is based on the first reference position and each first predetermined value. The normal range can be switched to a desired shift range by calculating the rotational position of the actuator 30 corresponding to the D range) and rotating the actuator 30 so that the rotational position obtained by the calculation is obtained. State.

  On the other hand, when the second reference position is learned, the SBW-ECU 13 first restricts the rotation of the actuator 30 when the detent roller 53 of the detent spring 55 contacts the second wall 66 of the second recess 64. That is, the actuator 30 is rotated in the forward rotation direction (see FIG. 4). As a result, the detent roller 53 starts to extend as the detent roller 53 comes into contact with the second wall 66 and is pulled. Then, the SBW-ECU 13 determines that the rotation of the detent plate 52 and the actuator 30 has stopped by detecting a state where the maximum value or the minimum value of the count value of the pulse signal output from the encoder 34 does not change for a predetermined time. . The SBW-ECU 13 stores the count value at this time in a volatile memory such as a RAM in the storage unit 15 as a value corresponding to the second reference position of the actuator 30. Thereby, learning of the second reference position of the actuator 30 is completed. Here, the SBW-ECU 13 functions as “second position learning means” in the claims.

  The storage unit 15 stores in advance a plurality of predetermined values (hereinafter referred to as “second predetermined values”) indicating the rotation amount of the motor unit 32 from the second reference position to the position corresponding to each shift range. Yes. Therefore, after the SBW-ECU 13 learns the second reference position by the second position learning means, each shift range (P range, R range, N range) based on the second reference position and each second predetermined value. The normal range can be switched to a desired shift range by calculating the rotational position of the actuator 30 corresponding to the D range) and rotating the actuator 30 so that the rotational position obtained by the calculation is obtained. State.

  As described above, the SBW-ECU 13 performs the first position learning or the second position learning, so that the normal control of the shift-by-wire system 3 (control to change the actual range based on the command range from the driver) is performed thereafter. It becomes a possible state (normal control state). The first predetermined value and the second predetermined value are design values, and take into account the angle between the recesses of the detent plate 52, the play between the engagement members, the amount of deflection and the amount of extension of the detent spring 55, and the like. Is set. Further, since the first predetermined value and the second predetermined value are stored in a nonvolatile memory such as a ROM or an EEPROM in the storage unit 15, the first predetermined value and the second predetermined value are deleted even if the supply of vehicle power to the storage unit 15 is cut off. Never happen.

  As described above, in the present embodiment, although the absolute rotation position of the actuator 30 cannot be detected by the encoder 34, the SBW-ECU 13 learns the first reference position or the second reference position, thereby the first reference position. Alternatively, the rotational position of the actuator 30 corresponding to each shift range is obtained by calculation based on the second reference position and the first predetermined value or the second predetermined value, and the actuator 30 is rotated so as to be the rotational position obtained by the calculation. Thus, the actual range can be switched to a desired shift range.

Next, processing related to “learning the reference position of the actuator 30” by the SBW-ECU 13 will be described based on the processing flow shown in FIGS.
As shown in FIG. 5, in S101, the vehicle control system 1 is turned on when the vehicle power supply is turned on. Here, when the vehicle power is turned on, “the driver stops the vehicle, consciously turns off the vehicle power with the ignition key, and then turns on (normally on) again with the ignition key” and “driving” The case where the vehicle power supply is turned off due to some trouble or the like regardless of the intention of the person and automatically turns on again (turns on after a momentary interruption) is included.

In S200 following S101, a target range when the vehicle power supply is turned on is set. A series of processing of S200 is shown in FIG.
In S201, the SBW-ECU 13 determines whether or not the actuator 30 was stopped when the vehicle power supply was turned off last time. Here, the SBW-ECU 13 makes the determination by referring to the “state of the actuator 30” that has been stored when the vehicle power supply was turned off last time. When the stored “state of the actuator 30” is “stopped”, the SBW-ECU 13 determines that “the actuator 30 was stopped when the vehicle power was turned off last time”, and the stored “actuator 30 When the “30 state” is the “actuated state”, it is determined that “the actuator 30 was not in the stopped state (actuated) when the vehicle power supply was turned off last time”. Note that the process of storing the “state of the actuator 30” when the vehicle power supply is turned off will be described later in S106.

If it is determined that the actuator 30 when the vehicle power was turned off last time was in a stopped state (S201: YES), the process proceeds to S202. On the other hand, when it is determined that the actuator 30 when the vehicle power supply was turned off last time was in an operating state (S201: NO), the process proceeds to S203.
In S202, the SBW-ECU 13 sets “actual range” that has been stored when the vehicle power is turned off last time as the target range. Note that the process of storing the “actual range” when the vehicle power is turned off will be described later in S107.

In S203, the SBW-ECU 13 sets “undefined” as the target range. Here, the target range being “undefined” indicates that none of the ranges is determined as the target range.
After S202 or S203, the processing of S200 shown in FIG. 6 (processing for setting a target range when the vehicle power supply is turned on) is exited. After exiting the process of S200, the process proceeds to S102 shown in FIG.

  In S102, the SBW-ECU 13 determines whether or not the target range is the P range (a range corresponding to the first recess 61). Here, the SBW-ECU 13 makes the determination by referring to the value of the target range set in S202 or S203. If it is determined that the target range is the P range (S102: YES), the process proceeds to S103. On the other hand, when it is determined that the target range is not the P range (including “indefinite”) (S102: NO), the process proceeds to S110.

In S103, the SBW-ECU 13 performs initial drive control of the actuator 30. Thereby, rotation of the actuator 30 can be appropriately controlled. After S103, the process proceeds to S104.
In S104, the SBW-ECU 13 functions as a first position learning unit and learns the first reference position of the actuator 30. After S104, the process proceeds to S105.

  In S110, the SBW-ECU 13 determines whether or not the target range is the D range (a range corresponding to the second recess 64). Here, the SBW-ECU 13 makes the determination by referring to the value of the target range set in S202 or S203. If it is determined that the target range is the D range (S110: YES), the process proceeds to S111. On the other hand, when it is determined that the target range is not the D range (including “indefinite”) (S110: NO), the process proceeds to S120.

In S <b> 111, the SBW-ECU 13 performs initial drive control of the actuator 30. Thereby, rotation of the actuator 30 can be appropriately controlled. After S111, the process proceeds to S112.
In S112, the SBW-ECU 13 functions as a second position learning unit and learns the second reference position of the actuator 30. After S112, the process proceeds to S105.

  In S120, the SBW-ECU 13 maintains the actual range at that time (range hold) by not driving the actuator 30. At this time, the SBW-ECU 13 notifies the driver via the integrated ECU 10 by displaying on the display device 47 that “only a request for switching to the P range or D range can be accepted”. . Here, the SBW-ECU 13 informs the driver by voice that “only a request for switching to the P range or D range can be accepted” by the speaker 48 (see FIG. 1) connected to the integrated ECU 10. May be. At this time, the SBW-ECU 13, the integrated ECU 10, the display device 47, and the speaker 48 function as "notification means" in the claims.

  If it is determined in S120 that the driver has requested switching to a range other than the “P range and D range” based on the signal from the selector sensor 46, the SBW-ECU 13 causes the speaker 48 to “ The driver is warned that it is not possible to switch to a range other than “D range”. Here, the SBW-ECU 13 may warn the driver that “switching to a range other than the“ P range and D range ”is not possible” by displaying on the display device 47. At this time, the SBW-ECU 13, the integrated ECU 10, the speaker 48, and the display device 47 function as "warning means" in the claims.

  In S121, based on the signal from the selector sensor 46, the SBW-ECU 13 determines whether or not the driver has requested to switch to the P range or D range. When it is determined that the driver has requested switching to the P range or D range (S121: YES), the process proceeds to S122. On the other hand, when the driver does not request switching to the P range or the D range (S121: NO), the process returns to S120.

  In S122, the SBW-ECU 13 sets the range requested to be switched in S121, that is, the P range or the D range, as the target range. The target range set at this time is determined based on the signal from the selector sensor 46, the brake signal, the signal from the vehicle speed sensor 24, and the like by the SBW-ECU 13 functioning as “target range determining means”. . After S122, the process returns to S102.

  In S105 after S104 or S112, the SBW-ECU 13 performs normal control of the shift-by-wire system 3 (actuator 30). That is, the SBW-ECU 13 learns from the first predetermined value stored in the storage unit 15 and the first reference position learned in S104, or learned from the second predetermined value stored in the storage unit 15 in S112. From the second reference position, the rotation position of the actuator 30 corresponding to each shift range is calculated each time, and the actuator 30 is rotated so as to be the calculated rotation position. In the normal control, the SBW-ECU 13 determines the target range based on the signal of the selector sensor 46, the signal of the brake, the signal of the vehicle speed sensor 24, etc. by functioning as “target range determining means”, and the automatic transmission 20 The rotation of the actuator 30 is controlled so that the shift range becomes the determined target range.

  In S106, the SBW-ECU 13 stores the state of the actuator 30 at that time in the storage unit 15. Specifically, the “actuator 30” stored in the storage unit 15 at the timing when the state of the actuator 30 shifts from the “stop state” to the “operation state” or when the state shifts from the “operation state” to the “stop state”. Rewrite “state” (value) to “operating state” or “stopped state”. Here, since the “state of the actuator 30” is stored in a rewritable non-volatile memory such as an EEPROM in the storage unit 15, the “actuator 30 state” is not erased even if the power supply to the storage unit 15 is cut off. Absent. Note that the “state of the actuator 30” stored last is referred to as the “state of the actuator 30” when the vehicle power is turned off in the processing after the vehicle power is turned on next time (S201 described above).

  In S107, the SBW-ECU 13 is based on the first reference position or the second reference position, the first predetermined value or the second predetermined value, and the count value of the pulse signal from the encoder 34 (the rotational position of the motor unit 32). The actual range at that time is always detected by calculation, and the actual range is stored in the storage unit 15. Specifically, every time the actual range is switched by the rotation of the actuator 30, the “real range” (value) stored in the storage unit 15 is rewritten. Here, since the “real range” is stored in a rewritable nonvolatile memory such as an EEPROM in the storage unit 15, the “real range” is not erased even if the power supply to the storage unit 15 is cut off. The “actual range” (value) stored last is referred to as the “actual range” when the vehicle power is turned off in the processing after the vehicle power is turned on next time (S202 described above).

When the vehicle power supply is turned off in S108, the series of processes shown in FIG. Here, when the vehicle power supply is turned off, “the driver stops the vehicle and, for example, the vehicle power supply is turned off consciously (normally off) by the ignition key” and “there is some trouble regardless of the driver's intention” The case where the vehicle power supply is turned off (instantaneous interruption off) due to the above.
Even if the vehicle power is turned off in S108, the “state of actuator 30” and “actual range” stored in storage unit 15 in S106 and S107 are not deleted.
The SBW-ECU 13 functions as “power-on target range setting means” in the claims in the series of processes of S200 to S203 described above. Further, the SBW-ECU 13 functions as “storage means” in the claims in the processing of S106 and S107 described above.

  As described above, in the present embodiment, the SBW-ECU 13 learns the first reference position or the second reference position of the actuator 30 to thereby store a plurality of first predetermined values or second predetermined values stored in advance. Based on (a predetermined value indicating the amount of rotation of the actuator 30 from the first reference position or the second reference position to the position corresponding to each shift range) and the first reference position or the second reference position, each shift range (P range, The rotational position of the actuator 30 corresponding to the R range, N range, and D range) is obtained by calculation, and the actual range is changed to a desired shift range by rotating the actuator 30 so that the rotation position obtained by the calculation is obtained. Can be switched.

  In the present embodiment, the SBW-ECU 13 turns off the vehicle power when the actual range is the P range, for example, and then turns on the target range when the vehicle power is turned on (the range corresponding to the first recess 61). If there is, the first reference position is learned by the first position learning means. Usually, when the actual range is the P range, the vehicle is considered to be in a stopped state. Therefore, at this time, for example, even if learning of the first reference position is started by turning on the vehicle power supply after the vehicle power supply is momentarily interrupted, the actual range remains the P range (the vehicle remains in a stopped state). The first reference position can be learned safely and the normal control state can be restored.

  For example, when the actual range is the D range, the SBW-ECU 13 is turned off when the vehicle power source is turned on, and then when the vehicle power source is turned on, the target range is “range corresponding to the second recess 64 (D range)”. Then, the second reference position is learned by the second position learning means. Normally, when the actual range is “range corresponding to the second recess 64 (D range)”, the vehicle is considered to be in a traveling (forward) state. Therefore, at this time, even if learning of the second reference position is started by turning on the vehicle power supply after the vehicle power supply is momentarily interrupted, the actual range remains the D range (the vehicle remains in the running state). The first reference position can be learned safely and the normal control state can be restored.

  In addition, the SBW-ECU 13 is configured such that, for example, when the actual range is other than the P range or the D range, the vehicle power supply is turned off. If the range other than "D range)" "or indefinite, the actual range at that time is maintained by not driving the actuator 30. In the first shift range switching by the driver, only the switching request to the P range or the “range corresponding to the second recess 64 (D range)” is accepted, and the rotation of the actuator 30 is controlled and shifted according to the switching request. When the switching request is a request to switch to the P range, the first reference position is learned by the first position learning means, and the switching request is “range corresponding to the second recess 64 (D range ) ", The second reference position is learned by the second position learning means.

  With the above configuration, in the present embodiment, when the actual range before the vehicle power supply is momentarily interrupted is a range other than the “P range and the“ range corresponding to the second recess 64 (D range) ”” or is indefinite. When the power is restored after an instantaneous interruption, the actual range before the instantaneous interruption is maintained without learning the first reference position or the second reference position. Therefore, in a vehicle in which the shift range of the automatic transmission 20 is composed of four ranges of P range, R range, N range, and D range (the first concave portion 61 corresponds to the P range and the second concave portion 64 corresponds to the D range). For example, when the vehicle power supply is momentarily interrupted when the actual range is the N range, the actual range is maintained in the N range even after the power supply is restored, so that “the actual range is about to learn the first reference position. When moving to the P range, an unexpected reverse torque is generated when passing through the R range. "" Suddenly entering the P range during travel causes ratcheting of the parking lock mechanism 70 and damages the parking lock mechanism 70. " Or, if the vehicle is traveling at low speed, the vehicle suddenly stops (P-lock) ”or“ The actual range enters the D range to learn the second reference position. It is possible to prevent the situation forward torque is generated unexpected ". Further, for example, when the vehicle power supply is interrupted when the actual range is the R range, the actual range is maintained in the R range even after the power supply is restored, so that “the actual range is about to learn the first reference position”. Can suddenly stop the vehicle (P lock) "or" the actual range enters the D range and the vehicle runs backward trying to learn the second reference position ".

  Thus, the shift-by-wire system 3 according to the present embodiment can safely return to the normal control state even when the vehicle power supply is momentarily interrupted. In the present embodiment, since the incremental encoder 34 is used to detect the rotational position of the actuator 30, the configuration of the entire system can be simplified. Therefore, downsizing and cost reduction of the shift-by-wire system 3 can be achieved.

  In the present embodiment, the SBW-ECU 13 functions as a notification means for notifying the driver that only a request for switching to the P range or the “range corresponding to the second recess 64 (D range)” can be accepted. To do. In the present embodiment, when the vehicle power is turned on, if the target range is a range other than “P range and“ range corresponding to the second recess 64 (D range) ””, or if it is indefinite, the first shift by the driver In the range switching, only a request for switching to the P range or the “range corresponding to the second recess 64 (D range)” is accepted. At this time, the notification means causes the P range or the “range corresponding to the second recess 64 (D The driver can be prevented from being confused by notifying the driver that only the switching request to “range” can be accepted.

  In the present embodiment, when there is a request for switching to a range other than the “P range and the“ range corresponding to the second recess 64 (D range) ””, the SBW-ECU 13 It functions as a warning means that warns the driver that switching to a range other than “range corresponding to the recess 64 (D range)” is impossible. In the present embodiment, when the vehicle power is turned on, if the target range is a range other than “P range and“ range corresponding to the second recess 64 (D range) ””, or if it is indefinite, the first shift by the driver In the range switching, only the switching request to the P range or the “range corresponding to the second recess 64 (D range)” is accepted. At this time, the driver inputs “P range and“ range corresponding to the second recess 64 ”(D When there is a request to switch to a range other than “range)” ”, the warning means indicates that switching to a range other than“ P range and “range corresponding to second recess 64 (D range)” ”is impossible. Warning to the driver can avoid driver confusion.

  In the present embodiment, the SBW-ECU 13 functions as a storage unit and a power-on target range setting unit. The storage means stores the state and actual range of the actuator 30 when the vehicle power supply is turned off. The power-on target range setting means, when the vehicle power is turned on, if the state of the actuator 30 stored in the storage means is “stopped”, the target range is set to “actual range stored in storage means”. If the state of the actuator 30 set and stored in the storage means is “operating state”, “undefined” is set as the target range.

  In this embodiment, since the target range when the vehicle power supply is turned on is set by the power-on target range setting means based on the operating state of the actuator 30 when the vehicle power supply is turned off, the vehicle power supply instantaneous interruption during the shift range switching is performed. It is possible to prevent an unmatch between the target range and the actual range when the power is turned on later.

(Second Embodiment)
One of the components (detent plate) of the shift-by-wire system according to the second embodiment of the present invention is shown in FIG. The second embodiment differs from the first embodiment only in the detent plate as a physical configuration.

  As shown in FIG. 7, in this embodiment, the detent plate 57 has a first recess 71, an intermediate recess 72, an intermediate recess 73, an intermediate recess 74, an intermediate recess 75, and a second recess 76 on the radially outer side of the manual shaft 51. have. The first recess 71 is formed on one side in the rotational direction of the detent plate 57. The second recess 76 is formed on the other side in the rotational direction of the detent plate 57. The intermediate recesses 72 to 75 are formed between the first recess 71 and the second recess 76.

  In the present embodiment, the first recess 71 is formed corresponding to the “P range” that is the shift range of the automatic transmission 20. The first recess 71 has a first wall 77 on the side opposite to the second recess 76. The intermediate recess 72 is formed corresponding to the “R range”. The intermediate recess 73 is formed corresponding to the “N range”. The intermediate recess 74 is formed corresponding to the “D range”. The intermediate recess 75 is formed corresponding to “2 range” which is the second range of the forward range of the automatic transmission 20. The second recess 76 is formed corresponding to the “L range” that is the lowest speed range of the forward range of the automatic transmission 20. The second recess 76 has a second wall 78 on the side opposite to the first recess 71.

Thus, in the present embodiment, the shift range of the automatic transmission is selected from the six ranges of “P range”, “R range”, “N range”, “D range”, “2 range”, and “L range”. The example applied to the vehicle which becomes.
In the present embodiment, as shown in FIG. 7, the direction in which the speed reduction unit 33 of the actuator 30 rotates when the shift range is switched from the “P range” side to the “L range” side is defined as the positive rotation direction. On the other hand, the direction in which the speed reduction unit 33 of the actuator 30 rotates when the shift range is switched from the “L range” side to the “P range” side is defined as the reverse rotation direction.

  As shown in FIG. 7, in the present embodiment, the rotatable range of the detent plate 57 is from the position where the first wall 77 and the detent roller 53 abut to the position where the second wall 78 and the detent roller 53 abut. It becomes the range. However, since the rotatable range shown in FIG. 7 is the rotatable range of the detent plate 57 in relation to the detent roller 53, including the amount of deflection of the detent spring 55, the amount of extension, the amount of twist of the manual shaft 51, etc. The absolute rotatable range of the plate 57 is larger than the rotatable range shown in FIG.

Regarding the control related to learning of the first reference position and the second reference position in this embodiment, and other controls, “D range” is set to “L range” and “first concave portion” in the description of the first embodiment. If “61” is read as “first recess 71” and “second recess 64” is read as “second recess 76”, the control is the same as in the first embodiment.
In other words, in the present embodiment, the SBW-ECU 13 learns the first reference position or the second reference position of the actuator 30 to thereby store a plurality of first predetermined values or second predetermined values stored in advance and the first reference position. Based on the position or the second reference position, the rotation position of the actuator 30 corresponding to each shift range (P range, R range, N range, D range, 2 range, and L range) is obtained by calculation, and is obtained by the calculation. The actual range can be switched to a desired shift range by rotating the actuator 30 so that the rotation position is reached.

  In the present embodiment, for example, when the actual range is the P range, the SBW-ECU 13 turns off the vehicle power, and when the vehicle power is turned on thereafter, the target range is the P range (a range corresponding to the first recess 71). In this case, the first reference position is learned by the first position learning means. Usually, when the actual range is the P range, the vehicle is considered to be in a stopped state. Therefore, at this time, for example, even if learning of the first reference position is started by turning on the vehicle power supply after the vehicle power supply is momentarily interrupted, the actual range remains the P range (the vehicle remains in a stopped state). The first reference position can be learned safely and the normal control state can be restored.

  For example, when the actual range is the L range, the SBW-ECU 13 turns off the vehicle power, and when the vehicle power is turned on, the target range is “range corresponding to the second recess 76 (L range)”. Then, the second reference position is learned by the second position learning means. Usually, when the actual range is “range corresponding to the second recess 76 (L range)”, the vehicle is considered to be in a traveling (forward) state. Therefore, at this time, even if learning of the second reference position is started by turning on the vehicle power supply after the vehicle power supply is momentarily interrupted, the actual range remains the L range (the vehicle remains in the running state). The second reference position can be learned safely and the normal control state can be restored.

  Further, the SBW-ECU 13 is configured such that, for example, when the vehicle power is turned off when the actual range is other than the P range or the L range, and then the vehicle power is turned on, the target range is “the range corresponding to the“ P range and the second recess 76 ( If the range other than “L range)” ”or indefinite, the actuator 30 is not driven to maintain the actual range at that time. In the first shift range switching by the driver, only the switching request to the P range or the “range corresponding to the second recess 76 (L range)” is accepted, and the rotation of the actuator 30 is controlled and shifted according to the switching request. When the switching request is a request to switch to the P range, the first reference position is learned by the first position learning means, and the switching request is “range corresponding to the second recess 76 (L range ) ", The second reference position is learned by the second position learning means.

With the above configuration, in the present embodiment, when the actual range before the vehicle power supply is momentarily interrupted is a range other than the “P range and the“ range corresponding to the second concave portion 76 (L range) ”” or indefinite. When the power is restored after an instantaneous interruption, the actual range before the instantaneous interruption is maintained without learning the first reference position or the second reference position. Therefore, the automatic transmission 20 has a shift range of six ranges of P range, R range, N range, D range, 2 range, and L range (first recess 71 corresponds to P range, second recess 76 has For example, if the vehicle power supply is interrupted when the actual range is the N range, the actual range is maintained in the N range even after the power supply is restored. When the actual range shifts to the P range, an unexpected reverse torque is generated when passing through the R range. ”“ Suddenly entering the P range during driving causes the parking lock mechanism 70 to ratchet and park. If the lock mechanism 70 is damaged or the vehicle is traveling at a low speed, the vehicle suddenly stops (P-lock) ”or“ actually trying to learn the second reference position ” Nji can be prevented a situation "forward torque abrupt occurs enters the D-range (2 range, L range). Further, for example, when the vehicle power supply is interrupted when the actual range is the R range, the actual range is maintained in the R range even after the power supply is restored, so that “the actual range is about to learn the first reference position”. Enters the P range and the vehicle suddenly stops (P lock) or “the actual range enters the D range (2 range, L range) and the vehicle reverses in an attempt to learn the second reference position”. Can be prevented.
As described above, the shift-by-wire system according to the present embodiment can safely return to the normal control state even if the vehicle power supply is momentarily interrupted, as in the first embodiment.

(Other embodiments)
In another embodiment of the present invention, the first recess corresponds to the P range, the second recess corresponds to the “D range or the lowest speed range (L range, etc.)”, and the intermediate recess corresponds to the R range and the N range. If it corresponds, how many intermediate | middle recessed parts may be formed. That is, the number of ranges of the automatic transmission to which the present invention can be applied is not limited to four or six.

  In the above-described embodiment, an example in which notification and warning are given to the driver by the notification unit and the warning unit has been described. On the other hand, in another embodiment of the present invention, either one of notification or warning may be given to the driver by either one of notification means or warning means. Alternatively, neither notification nor warning may be performed.

In another embodiment of the present invention, only one of the notification unit and the warning unit may be provided. Alternatively, neither the notification means nor the warning means may be provided.
The shift-by-wire system according to the present invention is used for range switching of a continuously variable transmission (CVT) and an automatic transmission (A / T) of an HV (hybrid vehicle) that switches four positions of P, R, N, and D. You can also.
Thus, the present invention is not limited to the above-described embodiment, and can be applied to various forms without departing from the gist thereof.

3... Shift-by-wire system 13... SBW-ECU (control unit, target range determining means, first position learning means, second position learning means)
20... Automatic transmission 30... Actuator 34... Encoder 45... Range selector (shift selection means)
52, 57 ... Detent plate 53 ... Detent roller (regulator)
55... Detent springs 61 and 71... First recesses 62, 63, 72, 73, 74, 75... Intermediate recesses 64 and 76. 1 wall 66, 78 ... 2nd wall

Claims (4)

A shift-by-wire system that switches a shift range of an automatic transmission in response to a signal from a shift selection means operated by a vehicle driver,
A motor unit that rotates by electric power, an incremental encoder that outputs a pulse signal according to the rotation of the motor unit, and an actuator that includes a deceleration unit that decelerates and outputs the rotation of the motor unit;
A first recess formed on one side in the rotational direction, a second recess formed on the other side in the rotational direction, and the first concave portion, which is rotationally driven by the actuator by being provided so as to be connected to the speed reduction unit. And a detent plate having a plurality of intermediate recesses formed between the second recesses and the second recesses,
The automatic transmission has a restricting portion, and the restricting portion fits into the first recessed portion, the plurality of intermediate recessed portions, or the second recessed portion to restrict the rotation of the detent plate, thereby fixing the shift range of the automatic transmission. Possible detent springs,
And a target range determining means for determining a target range based on a signal from the shift selecting means, and the rotation of the actuator so that the shift range of the automatic transmission becomes the target range determined by the target range determining means. And a control unit for controlling
The first recess corresponds to the P range which is a parking range, and has a first wall on the side opposite to the second recess,
The second recess corresponds to the “D range or minimum speed range” which is a forward range, and has a second wall on the side opposite to the first recess,
Each of the plurality of intermediate recesses corresponds to an R range that is a reverse range, an N range that is a neutral range, or “the forward range other than the lowest speed range”.
The controller is
The actuator is rotated in a direction in which the rotation of the actuator is restricted when the restricting portion comes into contact with the first wall. At this time, the minimum value or the maximum value of the count value of the pulse signal output from the encoder is predetermined. First position learning means for learning a first reference position of the actuator corresponding to the P range by detecting a state that does not change over time; and
The actuator is rotated in a direction in which the rotation of the actuator is restricted when the restricting portion comes into contact with the second wall. At this time, the maximum value or the minimum value of the count value of the pulse signal output from the encoder is predetermined. Second position learning means for learning a second reference position of the actuator corresponding to the D range or the lowest speed range by detecting a state that does not change over time;
When the vehicle power is turned on,
When the target range is the P range, the first reference position is learned by the first position learning means,
If the target range is “range corresponding to the second recess”, the second reference position is learned by the second position learning means,
When the target range is a range other than “the P range and“ the range corresponding to the second recess ””, or indefinite,
By not driving the actuator, the actual range at that time is maintained, and in the first shift range switching by the driver, only the switching request to the P range or the “range corresponding to the second recess” is accepted, In response to the switching request, the rotation of the actuator is controlled to switch the shift range,
If the switching request is a request to switch to the P range, the first position learning means learns the first reference position,
When the switching request is a switching request to “range corresponding to the second recess”, the second reference position is learned by the second position learning means.   2. The shift-by-wire system according to claim 1, further comprising notification means for notifying a driver that only a request for switching to the P range or the “range corresponding to the second recess” can be accepted. .   When there is a request for switching to a range other than “the P range and“ the range corresponding to the second recess ””, switching to a range other than “the P range and“ the range corresponding to the second recess ”” is performed. The shift-by-wire system according to claim 1, further comprising a warning unit that warns the driver that it is impossible. The controller is
Storage means for storing the state and actual range of the actuator when the vehicle power is turned off; and
When the state of the actuator stored in the storage means is “stopped” when the vehicle power is turned on, the “actual range stored in the storage means” is set as the target range, and the storage means The power-on target range setting means for setting "undefined" as the target range when the state of the actuator stored in (1) is "operating state". The shift-by-wire system as described in any one.

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