JP2012107657A - Shift-by-wire system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shift-by-wire system safely restorable to an ordinary control state, even if a vehicle power source is instantly disconnected, with a simple constitution.SOLUTION: When the vehicle power source is turned on and when a power source-on discriminating means discriminates that the on-state is by ordinary turning-on operation by a driver, an SBW-ECU 13 leans a first reference position by a first position learning means. Meanwhile, when the vehicle power source is turned on and when the power source-on discriminating means discriminates that the on-state is by a return after the vehicle power source is instantly disconnected, the SBW-ECU 13 notifies the driver to "stop the vehicle when switching a shift range, and turn on the vehicle power source again after turning off the vehicle power source once", and maintains an actual range of that time without driving an actuator 30.

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 premise 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 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 power-on determination 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 control unit learns the first reference position, for example, a plurality of predetermined values stored in advance (predetermined values indicating the amount of rotation of the actuator from the first reference position to the position corresponding to each shift range). Based on the first reference position, the rotation position of the actuator corresponding to each shift range is obtained by calculation, and the actual range is switched to the desired shift range by rotating the actuator so that the rotation position obtained by the calculation is obtained. Can do.

When the vehicle power supply is turned on, the power-on determination means determines whether the turn-on is due to a normal on-operation by the driver or a return after the vehicle power supply is momentarily interrupted.
In the present invention, when the vehicle power supply is turned on, when the power-on determination means determines that the turn-on is due to a normal on-operation by the driver, the control section performs the first reference by the first position learning means. Learn position. When the vehicle power is turned on by a normal on operation, the actual range is normally the P range, and the vehicle is considered to be in a stopped state. Therefore, at this time, even if learning of the first reference position is started, the actual range remains the P range (the vehicle remains in a stopped state), so the first reference position can be learned safely, and the normal control state Can be migrated to. For example, when the vehicle power supply is turned off for some reason when the actual range is a range other than the P range such as the D range, and then the vehicle power supply is turned on by a normal on operation by the driver, the vehicle is in a stopped state. There is no inconvenience even if the wheel is locked (P-locked) by starting learning of one reference position.

  On the other hand, when the vehicle power supply is turned on, when the power-on determination means determines that the on-state is due to a return after the vehicle power supply is momentarily interrupted, the control unit determines that the vehicle is stopped when the shift range is switched. Then, after turning off the vehicle power supply, the driver is notified to turn on the vehicle power supply again, and the actual range at that time is maintained by not driving the actuator.

  With the above configuration, in the present invention, when the power is turned on after the vehicle power supply is momentarily interrupted, the actual range at that time is maintained. Further, at this time, the control unit does not accept the shift range switching request, but “the driver stops the vehicle when the shift range is switched, turns off the vehicle power, and then turns on the vehicle again”. Therefore, the confusion of the driver can be avoided. Here, when the driver stops the vehicle, once turns off the vehicle power, and then turns on the vehicle power again, the power-on discrimination means determines that the on is due to a normal on operation by the driver. The first reference position is learned in a state where the vehicle is stopped. As a result, the shift-by-wire system returns to the normal control state. When the driver performs an off operation, the detent spring is restricted on the first wall of the first recess until the minimum value or maximum value of the count value of the pulse signal output from the encoder does not change for a predetermined time. If the actuator is rotated in the direction in which the rotation of the actuator is regulated by the contact of the part and then enters the vehicle power-off sequence, the vehicle power supply in the state where the actual range is the P range when the next vehicle power-on operation is performed. Is turned on.

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.
Further, since the shift-by-wire system according to the present invention is relatively simple after the determination by the power-on determination means, the entire system and control software (program) can be easily constructed.

  According to a second aspect of the present invention, when there is a shift range switching request, the vehicle further comprises warning means for warning the driver that the shift range cannot be switched. In the present invention, when the vehicle power supply is turned on, if it is determined that the turn-on is due to the return after the vehicle power supply is momentarily interrupted, the shift range switching request cannot be accepted. When there is a shift range switching request from the driver, the warning means can warn the driver that the shift range cannot be switched, thereby avoiding driver confusion.

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 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 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 actuator 30 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 to which a plurality of coils 36 arranged in the rotation direction are connected. 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 is obtained by calculation based on the learned reference position and a predetermined rotation amount (control constant; first predetermined value described later). 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) 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 this embodiment, it is assumed that learning of the first reference position is performed as learning of the reference position of the actuator 30. 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.

  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.

  As described above, the SBW-ECU 13 performs the first position learning so that the normal control of the shift-by-wire system 3 (control for changing the actual range based on the command range from the driver) is possible (normally). Control state). The first predetermined value is a design value, and is set in consideration of the angle between the recesses of the detent plate 52, the play between the engagement members, the amount of deflection of the detent spring 55, and the like. Further, since the first predetermined value is stored in a nonvolatile memory such as a ROM or an EEPROM in the storage unit 15, the first predetermined value is not erased even if the supply of vehicle power to the storage unit 15 is cut off.

  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, whereby the first reference position and the first predetermined value are detected. Based on the above, the rotational position of the actuator 30 corresponding to each shift range is obtained by computation, and the actual range can be switched to the desired shift range by rotating the actuator 30 so as to be the rotational position obtained by the computation.

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 FIG.
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 S102, the SBW-ECU 13 determines whether the power-on in S101 is due to a normal on-operation by the driver (normally on) or due to a recovery after the vehicle power supply is momentarily interrupted (on after an instantaneous power-off). To do. Here, the SBW-ECU 13 performs the determination by referring to “information about power-off” that has been stored in the storage unit 15 when the vehicle power was turned off last time. At this time, the SBW-ECU 13 and the storage unit 15 function as “power-on determination means” in the claims. Note that the process of storing “information about power-off” when the vehicle power is turned off will be described later in S107.

  If the power-on determining means determines that “the power-on in S101 is a normal on-operation by the driver (normally on)” (S102: YES), the process proceeds to S103. On the other hand, if it is determined that “the power-on in S101 is due to the recovery after the vehicle power supply is instantaneously interrupted (ON after the instantaneous power-off)” (S102: NO), the process proceeds to S111. After the determination, the SBW-ECU 13 erases (clears) the content of “information relating to power-off” before moving to S103 or S111.

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 S105, the SBW-ECU 13 performs normal control of the shift-by-wire system 3 (actuator 30). That is, the SBW-ECU 13 calculates the rotation position of the actuator 30 corresponding to each shift range from the first predetermined value stored in the storage unit 15 and the first reference position learned in S104, and calculates the calculated rotation. The actuator 30 is rotated to reach the 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 S111, the SBW-ECU 13 displays, via the integrated ECU 10, on the display device 47 such that “if the shift range is switched, the vehicle is stopped, the vehicle power is turned off, and then the vehicle power is turned on again”. To inform the driver. Here, the SBW-ECU 13 uses the speaker 48 (see FIG. 1) connected to the integrated ECU 10 to “stop when changing the shift range, turn off the vehicle power, and then turn on the vehicle again. The driver may be notified by voice so as to “do”. At this time, the SBW-ECU 13 maintains the actual range (range hold) by not driving the actuator 30.

  If it is determined in S111 that the driver has requested a shift range switching based on the signal from the selector sensor 46, the SBW-ECU 13 indicates that the shift range cannot be switched by the speaker 48. To warn. Here, the SBW-ECU 13 may warn the driver that “the shift range cannot be switched” 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 S112, the SBW-ECU 13 determines whether or not there has been a vehicle power-off operation by the driver. Here, “the operation of turning off the vehicle power by the driver” means, for example, that the driver stops the vehicle with a brake and turns off the vehicle power with an ignition key. When it is determined that the driver has turned off the vehicle power supply (S112: YES), the process proceeds to S113. On the other hand, when there is no vehicle power-off operation by the driver (S112: NO), the process returns to S111.

  In S113, the SBW-ECU 13 rotates the actuator 30 in the reverse rotation direction (see FIG. 4) until the count value of the pulse signal from the encoder 34 does not change for a predetermined time. As a result, the actual range is switched to the P range.

  In S106 after S105 and S113, when the vehicle power-off operation is performed by the driver, “information regarding power-off” indicates that “the vehicle power-off has been performed by a normal off operation (not an instantaneous interruption). The information indicating “)” is stored in the storage unit 15. Here, since “information about power-off” is stored in a rewritable nonvolatile memory such as an EEPROM in the storage unit 15, the information is not erased even if the power supply to the storage unit 15 is cut off. Absent. Note that the “information regarding power-off” stored here is referred to as information for determining the type of power-on in the processing after the vehicle power is turned on next time (S102 described above).

When the vehicle power is turned off in S107, 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 S107, the “information about power off” stored in the storage unit 15 in S106 is not deleted.

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

Further, in the present embodiment, the SBW-ECU 13 functions as a power-on determining unit, and when the vehicle power is turned on, whether the on is due to a normal on-operation by the driver or after the vehicle power is momentarily interrupted. Determine if it is due to return.
When the vehicle power supply is turned on, the SBW-ECU 13 learns the first reference position by the first position learning means when the power-on determination means determines that the turn-on is due to a normal on operation by the driver. To do. When the vehicle power is turned on by a normal on operation, the actual range is normally the P range, and the vehicle is considered to be in a stopped state. Therefore, at this time, even if learning of the first reference position is started, the actual range remains the P range (the vehicle remains in a stopped state), so the first reference position can be learned safely, and the normal control state Can be migrated to. For example, when the vehicle power supply is turned off for some reason when the actual range is a range other than the P range such as the D range, and then the vehicle power supply is turned on by a normal on operation by the driver, the vehicle is in a stopped state. There is no inconvenience even if the wheel is locked (P-locked) by starting learning of one reference position.

  On the other hand, when the vehicle power supply is turned on, when the power-on determination means determines that the ON is due to the return after the vehicle power supply is momentarily interrupted, the SBW-ECU 13 determines that “if the shift range is switched, Stop the vehicle, turn off the vehicle power, and notify the driver to turn on the vehicle again. The actuator 30 is not driven to maintain the actual range at that time.

  With the above configuration, in the present embodiment, the actual range at that time is maintained when the power is turned on after the vehicle power supply is momentarily interrupted. Further, at this time, the SBW-ECU 13 does not accept the shift range switching request, but operates so as to “stop the vehicle when switching the shift range, turn off the vehicle power, and then turn on the vehicle again”. Since the driver is notified, the confusion of the driver can be avoided. Here, when the driver stops the vehicle, once turns off the vehicle power, and then turns on the vehicle power again, the power-on discrimination means determines that the on is due to a normal on operation by the driver. The first reference position is learned in a state where the vehicle is stopped. As a result, the shift-by-wire system 3 returns to the normal control state. In the present embodiment, when the driver performs an off operation, the vehicle power is turned off after switching the actual range to the P range. Therefore, when the vehicle power is turned on next time, the actual range is in the P range. The vehicle power is turned on.

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 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.
Furthermore, since the shift-by-wire system 3 according to the present embodiment has a relatively simple process after discrimination by the power-on discrimination means, the entire system and control software (program) can be easily constructed.

  In the present embodiment, the SBW-ECU 13 functions as a warning unit that warns the driver that the shift range cannot be switched when there is a shift range switching request. In this embodiment, when the vehicle power supply is turned on, if it is determined that the on is due to a return after the vehicle power supply is momentarily interrupted, the shift range switching request cannot be accepted. When there is a shift range switching request from the driver, the warning means can warn the driver that the shift range cannot be switched, thereby avoiding driver confusion.

(Second Embodiment)
FIG. 6 shows one of the components (detent plate) of the shift-by-wire system according to the second embodiment of the present invention. The second embodiment differs from the first embodiment only in the detent plate as a physical configuration.

  As shown in FIG. 6, in the present 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. 6, 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. 6, in this 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. 6 is the rotatable range of the detent plate 57 in relation to the detent roller 53, the detent includes the amount of deflection, the amount of extension of the detent spring 55, the amount of twist of the manual shaft 51, and the like. The absolute rotatable range of the plate 57 is larger than the rotatable range shown in FIG.

Regarding the control relating to the learning of the first reference position in this embodiment, and other controls, the “D range” is set to the “L range” and the “first recess 61” is set to the “first” in the description of the first embodiment. If “second recess 64” is read as “second recess 76” in “1 recess 71”, 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 of the actuator 30, so that each shift range (P range) is based on a plurality of first predetermined values and first reference positions stored in advance. , R range, N range, D range, 2 range, and L range) by calculating the rotational position of the actuator 30 and rotating the actuator 30 to the rotational position determined by the calculation, The range can be switched to the desired shift range.
With the above configuration, 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-mentioned embodiment, the example which warns with respect to a driver | operator by the warning means was shown. On the other hand, in another embodiment of the present invention, the warning by the warning means may not be given to the driver.

In another embodiment of the present invention, no 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 determination means, torque control means, first position learning means, power-on determination 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

Claims (2)

A shift-by-wire system that switches a shift range of an automatic transmission according to a signal of a shift selection means operated by a driver of a vehicle,
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 “D range or lowest speed range” which is a forward range,
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
When the vehicle power is turned on, it has a power-on determination means for determining whether the on is due to a normal on operation by the driver or a return after the vehicle power is momentarily interrupted,
When the vehicle power supply is turned on, when the power-on determination means determines that the on is due to a normal on operation by the driver, the first position learning means learns the first reference position,
When the vehicle power supply is turned on, the power-on determination means determines that the turn-on is due to a return after the vehicle power supply is momentarily interrupted. The vehicle power supply is turned on again after turning off, and the shift range switching request is not accepted, and the actuator is not driven to maintain the actual range at that time. And shift-by-wire system.   The shift-by-wire system according to claim 1, further comprising warning means for warning a driver that the shift range cannot be switched when a shift range switching request is made.

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