JP5962478B2 - Shift-by-wire system - Google Patents

Description

  The present invention relates to a shift-by-wire system provided in a vehicle.

  Conventionally, there is a shift-by-wire system as a system for switching the shift range of an automatic transmission according to the operation of a shift lever by a driver. The shift-by-wire system is a system that electrically detects the shift position where the shift lever is operated without using a mechanical link mechanism, and drives the actuator so that the shift range corresponds to the detected shift position. is there.

  Usually, in the shift-by-wire system, a dead zone where the shift position is not determined is provided between a plurality of operation determination positions where the shift position is determined and the operation determination position within a range where the shift lever can be operated. In such a shift-by-wire system, when the shift lever is operated in this dead zone, it is considered that the shift range is determined to be an indefinite position and the shift range is controlled to a non-drive range (for example, N range). Furthermore, in the shift-by-wire system, when the shift lever stays at a shift indefinite position for a predetermined time or longer, a system that warns the driver as a halfway operation is considered (Patent Document 1).

JP 2009-216215 A

  In the shift-by-wire system as described above, even though the driver intends to operate the shift lever to the operation confirmation position, the shift lever is not actually operated to the operation confirmation position (that is, the shift lever is operated to the dead zone). It is possible. Therefore, although the driver recognizes that the shift range is the drive range (R range or D range), the shift range is actually set to the non-drive range by operating the shift lever in the dead zone. It can happen.

  In this way, when the vehicle is stopped on the slope with the shift lever operated in the dead zone, even if the driver depresses the accelerator to drive the vehicle, the torque is reduced because the shift range is the non-driving range. Does not appear. Therefore, the vehicle may slip down in the direction of going down the slope. In addition, as disclosed in Patent Document 1, even if the driver is warned, when the driver notices the warning and operates the shift lever, the torque is not generated because the non-driving range is set. The vehicle may slide down the slope.

  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 prevent a vehicle stopped on a slope from sliding down.

In order to achieve the above object, the present invention provides:
A shift-by-wire system that is mounted on a vehicle and switches a shift range of an automatic transmission according to an operation of a shift lever (21) by a driver,
The shift lever can be operated in at least three operation confirmation positions, and at least two dead zones provided adjacent to the operation confirmation positions.
Shift position determination means (S11) for acquiring a shift position signal indicating the position of the shift lever, and determining whether the position of the shift lever is at the operation confirmation position or the dead zone based on the shift position signal;
Obtain a vehicle speed signal indicating the speed of the vehicle and a gradient signal indicating the angle of the gradient of the location where the vehicle is present, and based on the vehicle speed signal and the gradient signal, whether the vehicle is stopped on a slope Vehicle status determination means (S14) for determining
If the vehicle status determining means determines that the vehicle is stopped on a slope, a gradient determining means for determining whether the vehicle is stopped on a downhill road or on an uphill road based on the gradient signal (S15). When,
When the shift position determining means determines that the position of the shift lever is in the operation confirmation position, the shift position corresponding to the position of the shift lever is determined regardless of the determination by the vehicle condition determining means, and the shift lever is determined by the shift position determining means. Is determined to be in the dead zone, and if it is determined by the gradient determining means that the vehicle is stopped on the downhill road, the shift range is fixed to the R range, and the position of the shift lever is set to the dead zone by the shift position determining means. Shift position determining means ( S18, S17, S21) for determining the shift range to the D range when it is determined that the vehicle is stopped on the uphill road by the gradient determining means. And

  As described above, when the position of the shift lever is in the dead zone and the vehicle is stopped on the downhill road, the torque can be generated in the reverse direction by determining the shift range to the R range. Therefore, although the driver recognizes that the shift range is the R range, in fact, even when the shift lever is operated in the dead zone, when the driver depresses the accelerator, or the driver When the shift lever is operated, the vehicle can be prevented from sliding down.

  Further, when the shift lever is in the dead zone and the vehicle is stopped on the uphill road, it is possible to generate torque in the forward direction by determining the shift range to the D range. Therefore, the driver recognizes that the shift range is the D range, but in fact, even when the shift lever is operated in the dead zone, when the driver depresses the accelerator, or the driver When the shift lever is operated, the vehicle can be prevented from sliding down.

It is a block diagram which shows schematic structure of a shift-by-wire system. It is a front view which shows schematic structure of a shift lever. It is drawing which shows schematic structure of a shift sensor. It is a flowchart which shows the processing operation of a shift-by-wire system. It is drawing which shows the relationship between each sensor and shift range of a shift-by-wire system. It is drawing which shows the relationship between each sensor at the time of a hill stop of a shift-by-wire system, and a shift range. It is a time chart which shows the shift range judgment process at the time of the hill stop of a shift-by-wire system. It is a flowchart which shows the processing operation of the shift-by-wire system in a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the present embodiment, the shift-by-wire system of the present invention includes an ECU (Electronic Control Unit) 10 mounted on a vehicle. The ECU 10 switches the shift range of the automatic transmission by driving an actuator such as a DC motor as a device for switching the shift range of the automatic transmission according to the operation of the shift lever 21 by the driver. In this embodiment, as an example, automatic switching that can be switched to P range (parking range), R range (reverse range), N range (neutral range), D range (forward range), and B range (regenerative brake range). A transmission is used.

  The ECU 10 mainly includes an arithmetic processing device, a memory, an interface, and the like. As shown in FIG. 1, the ECU 10 includes a shift determination unit 11, a vehicle state determination unit 12, and a torque calculation unit 13 as functional blocks. Further, as shown in FIG. 1, the ECU 10 electrically includes a shift sensor 20, a shift lever 21, a gradient sensor 30, a vehicle speed sensor 40, an accelerator sensor 50, and an actuator control device 60 via a signal line (electric signal line). It is connected.

  The shift sensor 20 detects the position of the shift lever 21 and outputs a shift position signal indicating the detected position of the shift lever 21. In the present embodiment, as shown in FIG. 3, a shift sensor 20 including eight sensors P, R, N, D, B, FD, RV, and MJ is employed. The ECU 10 acquires a shift position signal from the shift sensor 20.

  The shift lever 21 is a lever used by the driver for switching the shift range, and can be operated in at least three operation confirmation positions and at least two dead zones provided adjacent to the operation confirmation positions. As shown in FIG. 2, the shift lever 21 of the present embodiment includes a P position indicating the P range, an R position indicating the R range, an N position indicating the N range, a D position indicating the D range, and a B position indicating the B range. And can be operated in the dead zone.

  The P position, the R position, the N position, the D position, and the B position are operation confirmation positions at which the shift position (shift lever position) is confirmed. In other words, the operation confirmation position is a position where the range indicated by the shift lever 21 can be confirmed. On the other hand, a region (intermediate position PR) between the P position and the R position is a dead zone (shift indefinite position) where the shift position is not fixed. Further, the intermediate positions P and R are dead zones adjacent to the R position. Similarly, a region between the R position and the N position (intermediate position R · N) is a dead zone in which the shift position is not fixed. Further, the intermediate position R · N is a dead zone adjacent to the R position. Furthermore, the region between the N position and the D position (intermediate position N · D) is also a dead zone where the shift position is not fixed. This intermediate position N · D is a dead zone adjacent to the D position.

  In addition, the area | region (intermediate position D * B) between D position and B position in FIG. 2 is not a dead zone, as shown in FIG. When the shift lever 21 is present at the intermediate position D / B, the D range or the B range is determined depending on the vehicle condition. Specifically, when the shift lever 21 is at the intermediate position D / B and the previous shift range is other than the D range and the B range, the shift range of the automatic transmission is fixed to the D range. On the other hand, when the shift lever 21 is at the intermediate position D / B and the previous shift range is the D range or the B range, the shift range of the automatic transmission is held at the previous shift range. That is, when the shift lever 21 is at the intermediate position D · B and the previous shift range is the D range, the shift range of the automatic transmission is fixed to the D range. Further, when the shift lever 21 is at the intermediate position D / B and the previous shift range is the B range, the shift range of the automatic transmission is fixed to the B range.

  Further, as shown in FIGS. 3 and 5, the shift sensor 20 outputs a plurality of sensor values as shift position signals in accordance with the position of the shift lever 21. For example, when the shift lever 21 is at the P position, the shift sensor 20 outputs P and MJ as sensor values, and does not output the other sensor values R, N, D, B, FD, and RV. As described above, in the shift-by-wire system, the position of the shift lever 21 is transmitted to the ECU 10 by an electrical signal.

  In the present embodiment, an alternate type (also referred to as a position holding type) shift lever 21 is employed. However, the present invention is not limited to this. Even a momentary type shift lever (also called an automatic return type that returns to the neutral position) can be employed. However, in the momentary type shift lever, a dead zone is provided between the neutral position and each operation confirmation position. For the momentary shift lever, refer to FIG. 2 of Patent Document 1.

  The gradient sensor 30 outputs a gradient signal indicating the angle of the gradient where the vehicle is present. In other words, the gradient signal can be rephrased as indicating the angle of inclination of the vehicle. This gradient signal is a signal for determining whether the vehicle is on a downhill road, an uphill road, or a flat place. The downhill road indicates a slope where the front side of the vehicle is below the rear side of the vehicle. On the other hand, the uphill road indicates a slope where the rear side of the vehicle is lower than the front side of the vehicle. The ECU 10 acquires a gradient signal from the gradient sensor 30. For example, the ECU 10 determines that the vehicle is on a slope when the absolute value of the value indicated by the gradient signal is equal to or greater than a predetermined value, and the vehicle is flat when the absolute value of the value indicated by the gradient signal is not equal to or greater than the predetermined value. It is determined that Further, the ECU 10 determines that the vehicle is on a downhill road when the value indicated by the gradient signal is negative (the gradient is negative) and the absolute value of the value indicated by the gradient signal is greater than or equal to a predetermined value. On the other hand, the ECU 10 determines that the vehicle is on an uphill road when the value indicated by the gradient signal is positive (the gradient is positive) and the absolute value of the value indicated by the gradient signal is greater than or equal to a predetermined value.

  In the present embodiment, the ECU 30 employs an example in which the gradient signal is acquired from the gradient sensor 30 to determine whether the vehicle is on a downhill road, an uphill road, or a flat place. Yes. However, the present invention is not limited to this. The ECU 10 acquires, for example, road gradient information (including a gradient angle) from a navigation device (not shown) and current position information indicating the current position of the vehicle from a current position detection device (not shown). It may be. The ECU 10 may determine whether the vehicle is on a downhill road, an uphill road, or a flat place from the gradient information and the current position detection device.

  The vehicle speed sensor 40 outputs a vehicle speed signal indicating the current vehicle speed. The ECU 10 acquires a vehicle speed signal from the vehicle speed sensor 40. The accelerator sensor 50 outputs an accelerator opening signal indicating the current accelerator opening. The ECU 10 acquires an accelerator opening signal from the accelerator sensor 50.

  When the ECU 10 acquires signals from the various sensors 20 to 50 in this way, the ECU 10 executes shift determination, vehicle status determination, torque calculation, and the like.

  The shift determination unit 11 determines a shift range to be determined based on a vehicle status signal acquired from a vehicle status determination unit 12 described later in addition to the shift position signal acquired from the shift sensor 20. Then, the shift determination unit 11 outputs a shift range signal corresponding to the shift range to be determined to the torque calculation unit 13.

  More specifically, as shown in FIG. 5, the shift determination unit 11 determines that the shift lever 21 is P from the combination of P, R, N, D, B, FD, RV, and MJ sensor values acquired from the shift sensor 20. It is determined whether the position, R position, N position, D position, B position, or dead zone has been operated. In other words, the shift determination unit 11 determines the shift range (P range, R range, NJ) of the automatic transmission from the combination of the sensor values of P, R, N, D, B, FD, RV, MJ acquired from the shift sensor 20. Range, D range, or B range) is determined. As described above, the combination of sensor values is not only a combination indicating that the shift lever 21 is at the P position, the R position, the N position, the D position, and the B position, but also a combination indicating that the shift lever 21 is a dead zone. is there.

  When the shift determination unit 11 determines that the shift lever 21 is operated in any of the P position, the R position, the N position, the D position, and the B position, the range of the automatic transmission corresponds to the position of the shift lever 21. Confirm the shift range to be used. On the other hand, when the shift determination unit 11 determines that the shift lever 21 is operated in the dead zone, the shift determination unit 11 determines the shift range to be determined based on the vehicle status signal acquired from the vehicle status determination unit 12. That is, the shift determination unit 11 determines the shift range to be determined when the vehicle is stopped on the downhill road or the uphill road, based on the vehicle state signal acquired from the vehicle state determination unit 12. This will be described later.

  As described above, a plurality of (eight in this case) sensors are provided as the shift sensor 20, and the position of the shift lever 21 is detected by a combination of a plurality of sensor values output from the plurality of sensors. This is to prevent erroneous detection of the position of the lever 21.

  The vehicle status determination unit 12 determines the vehicle status based on the gradient signal acquired from the gradient sensor 30 and the vehicle speed signal acquired from the vehicle speed sensor 40. More specifically, the vehicle state determination unit 12 determines whether or not the vehicle is stopped on a slope. Then, the vehicle status determination unit 12 outputs a signal including the determination result and the gradient signal acquired from the gradient sensor 30 to the shift determination unit 11 as a vehicle status signal indicating the current vehicle status.

  The torque calculation unit 13 calculates torque based on the shift range signal acquired from the shift determination unit 11 and the accelerator opening signal acquired from the accelerator sensor 50. Then, the torque calculation unit 13 outputs a torque output instruction signal that is a calculation result to the actuator control device 60. That is, the torque calculation unit 13 issues a torque output instruction to the actuator control device 60. Thus, the ECU 10 switches the shift range of the automatic transmission by driving the actuator via the actuator control device 60.

Here, the processing operation of the ECU 10 will be described with reference to FIG. ECU10 performs the process shown with the flowchart of FIG. 4 for every predetermined time.

  In step S10, shift range determination is performed. At this time, the shift determination unit 11 acquires the shift position signal acquired from the shift sensor 20 (shift position determination means). Then, based on the acquired shift position signal, the shift determination unit 11 determines whether the current position of the shift lever 21 is the P position, the R position, the N position, the D position, the B position, or the dead zone ( Shift position judging means).

  In step S11, it is determined whether or not the shift position is indefinite (shift position determination means). The shift determination unit 11 determines whether or not the determination result in step S10 is an indefinite shift position (dead zone). When the shift determination unit 11 determines that the shift position is not indefinite, that is, the position of the shift lever 21 is any of the operation confirmation positions in the P position, R position, N position, D position, and B position. Proceed to S18. On the other hand, if the shift determining unit 11 determines that the shift position is indefinite, the process proceeds to step S12.

  In step S18, the shift range is determined. When the shift determining unit 11 determines that the position of the shift lever 21 is any one of the P position, the R position, the N position, the D position, and the B position, the range of the automatic transmission corresponds to the position of the shift lever 21 ( Confirm the shift range to be applicable. That is, the shift determination unit 11 determines the range of the automatic transmission to a shift range corresponding to the determined position. And ECU10 complete | finishes the process of the flowchart shown in FIG.

  On the other hand, in step S12, a gradient signal is acquired from the gradient sensor 30 (vehicle condition determination means). In step S13, a vehicle speed signal is acquired from the vehicle speed sensor 40 (vehicle condition determination means). As described above, in steps S12 and S13, the vehicle state determination unit 12 acquires the gradient signal and the vehicle speed signal. Note that step S13 may be executed prior to step S12. In FIG. 4, the gradient signal is simply described as gradient, and the vehicle speed signal is simply described as vehicle speed.

  In step S14, it is determined whether or not the gradient is not less than a predetermined value and not more than a predetermined vehicle speed. Whether or not the gradient is equal to or greater than a predetermined value refers to whether or not the absolute value of the value indicated by the gradient signal is equal to or greater than a predetermined value. In step S14, the vehicle situation determination unit 12 determines whether or not the vehicle is stopped on a slope (vehicle situation determination means). When the vehicle state determination unit 12 determines that the gradient is equal to or greater than the predetermined value and equal to or less than the predetermined vehicle speed, the vehicle state is determined to be stopped on the downhill or uphill road, and the process proceeds to step S15. On the other hand, if the vehicle state determination unit 12 determines that the gradient is not less than the predetermined value and not more than the predetermined vehicle speed, the vehicle is not stopped or the vehicle is in a flat place (that is, on a downhill road or an uphill road) The process proceeds to step S19.

  In step S19, the N range is determined. As shown in FIG. 5, the shift determination unit 11 determines the range of the automatic transmission to the N range even when the position of the shift lever 21 is in the dead zone. And ECU10 complete | finishes the process of the flowchart shown in FIG.

  On the other hand, in step S15, it is determined whether or not the gradient is negative (gradient determining means). At this time, the shift determination unit 11 determines whether or not the gradient is negative based on the gradient signal included in the vehicle status signal acquired from the vehicle status determination unit 12. If the shift determining unit 11 determines that the gradient is negative, the shift determining unit 11 regards the vehicle as stopping on a downhill road and proceeds to step S16 (gradient determining means). On the other hand, if the shift determining unit 11 determines that the gradient is not negative (that is, the gradient is positive), the shift determining unit 11 regards the vehicle as stopping on the uphill road and proceeds to step S20 (gradient determining means).

  In step S16, it is determined whether or not the shift position is intermediate between P and R (intermediate position P · R), or intermediate between R and N (intermediate position R · N). At this time, the shift determination unit 11 determines whether the shift lever 21 is at the intermediate position P · R or the intermediate position R · N based on the shift position signal acquired from the shift sensor 20. If the shift determination unit 11 determines that the shift lever 21 is at the intermediate position P • R or the intermediate position R • N, the shift determination unit 11 determines that the driver has an intention to move backward and proceeds to step S17. On the other hand, when the shift determining unit 11 determines that the shift lever 21 is not in the intermediate position P · R or the intermediate position R · N, the shift determining unit 11 regards that the driver has no intention to move backward and proceeds to step S22. Note that the intention to move backward indicates the intention to move the vehicle backward.

  As described above, the shift determination unit 11 estimates whether or not the driver intends to move the vehicle backward in step S16. If the shift lever 21 is in the dead zone adjacent to the R position, the shift determination unit 11 moves the vehicle backward. It can be paraphrased as presuming that there is a will (inference means). Further, the shift determination unit 11 determines the vehicle sliding direction and the driver traveling direction request from the vehicle tilt angle and the position of the shift lever 21, and from the vehicle sliding direction and the driver traveling direction request. In other words, the possibility of reverse travel is determined as the vehicle state.

  When the driver sets the shift lever 21 to the R position and attempts to set the shift range of the automatic transmission to the R range, the driver may move the shift lever 21 too much or the shift lever 21 may not move sufficiently. obtain. In such a case, it is considered that the shift lever 21 is operated to the intermediate position P · R or the intermediate position R · N. Therefore, when the shift lever 21 is in the intermediate position P · R or the intermediate position R · N, it can be considered that the driver has an intention to move backward.

  On the other hand, when the driver tries to set the shift lever 21 to the R position, the shift lever 21 is rarely operated in the dead zone other than the intermediate position P · R or the intermediate position R · N. Therefore, when the shift lever 21 is not in the intermediate position P · R or the intermediate position R · N, it can be considered that the driver does not intend to move backward.

  In step S17, the R range is determined (shift position determining means). The shift determination unit 11 determines the range of the automatic transmission to be the R range when it can be considered that the driver has the intention to move backward. That is, in this embodiment, as shown in FIG. 6, when the vehicle is a downhill road stop, the operation confirmation position (R range confirmation region) for the R range is expanded. In other words, the intermediate range P · R or the intermediate location R · N that is the dead zone is also set as the R range determination region.

  As described above, the shift determination unit 11 determines that the position of the shift lever 21 is in the dead zone, and in addition to determining that the vehicle is stopped on the downhill road, the shift determination unit 11 is willing to drive the vehicle backward. When it is estimated that there is, the shift range is fixed to the R range. In addition, ECU10 complete | finishes the process of the flowchart shown in FIG. 4, after the process of step S17 is complete | finished.

  As described above, when the shift lever 21 is at the intermediate position P / R or the intermediate position R / N and the vehicle is stopped on the downhill road, the torque is set in the reverse direction by determining the R range. Can be generated. Therefore, the vehicle can be prevented from sliding down in the direction opposite to the driver's intention.

  In step S22, the N range is determined. The shift determination unit 11 determines the range of the automatic transmission to be the N range when it can be considered that the driver does not intend to move backward. And ECU10 complete | finishes the process of the flowchart shown in FIG.

  In step S20, it is determined whether or not the shift position is between N and D (intermediate position N · D). At this time, the shift determination unit 11 determines whether or not the shift lever 21 is at the intermediate position N · D based on the shift position signal acquired from the shift sensor 20. When the shift determination unit 11 determines that the shift lever 21 is at the intermediate position N · D, the shift determination unit 11 determines that the driver has an intention to move forward and proceeds to step S21. On the other hand, if the shift determining unit 11 determines that the shift lever 21 is not at the intermediate position N · D, it is determined that the driver does not intend to move forward, and the process proceeds to step S19. Note that the intention to move forward indicates the intention to move the vehicle forward.

  As described above, the shift determination unit 11 estimates whether or not the driver intends to move the vehicle forward in step S20. If the shift lever 21 is in the dead zone adjacent to the D position, the shift determination unit 11 It can be paraphrased as guessing that there is an intention to move forward (guessing means). Further, the shift determination unit 11 determines the vehicle sliding direction and the driver traveling direction request from the vehicle tilt angle and the position of the shift lever 21, and from the vehicle sliding direction and the driver traveling direction request. In other words, the possibility of reverse travel is determined as the vehicle state.

  When the driver sets the shift lever 21 to the D position (or B position) and attempts to set the shift range of the automatic transmission to the D range (or B range), the shift lever 21 may not move sufficiently. obtain. In such a case, it is conceivable that the shift lever 21 is operated to the intermediate position N · D. Therefore, when the shift lever 21 is at the intermediate position N · D, it can be considered that the driver has an intention to move forward.

  On the other hand, when the driver tries to set the shift lever 21 to the D position, the shift lever 21 is rarely operated in a dead zone other than the intermediate positions N and D. Therefore, when the shift lever 21 is not in the intermediate position N · D, it can be considered that the driver has no intention of moving forward.

  In step S21, the D range is determined (shift position determining means). The shift determination unit 11 determines the range of the automatic transmission to be the D range when it can be considered that the driver has an intention to move forward. That is, in the present embodiment, as shown in FIG. 6, when the vehicle is on an uphill road, the operation confirmation position (D range confirmation region) for the D range is expanded. In other words, the intermediate range N · D, which is a dead zone, is also set as the D range determination region.

  As described above, the shift determination unit 11 determines that the position of the shift lever 21 is in the dead zone, and in addition to determining that the vehicle is stopped on the uphill road, the driver is willing to advance the vehicle. When it is estimated that there is a shift range, the shift range is fixed to the D range.

  FIG. 7 is a time chart when the driver of the vehicle operates the shift lever 21 from the P position to the intermediate position N / D between the N position and the D position when the vehicle is on an uphill stop. The ECU 10 obtains a gradient signal indicating plus 10 ° from the gradient sensor 30 and 0 km / h from the vehicle speed sensor 40. In this case, the ECU 10 determines that the vehicle is on an uphill stop. If the ECU 10 determines that the shift position is indeterminate, the ECU 10 determines the range of the automatic transmission to be the D range when it can be assumed that the driver has an intention to move forward. In addition, ECU10 complete | finishes the process of the flowchart shown in FIG. 4, after the process of step S21 is complete | finished.

  As described above, when the shift lever 21 is at the intermediate position N · D and the vehicle is stopped on the uphill road, the torque can be generated in the forward direction by determining the D range. Therefore, the vehicle can be prevented from sliding down in the direction opposite to the driver's intention.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not restrict | limited to the embodiment mentioned above at all, and various deformation | transformation are possible in the range which does not deviate from the meaning of this invention.

  In addition to the ECU 10, the shift-by-wire system of the present invention may include a shift sensor 20, a shift lever 21, and an electric signal line that electrically connects them. In the present embodiment, an example in which the N range is determined in steps S19 and S22 is employed. However, the present invention is not limited to this. In the present invention, the P range may be determined in steps S19 and S22. In other words, the present invention only needs to establish the non-driving range in steps S19 and S22.

(Modification)
Here, the shift-by-wire system in the modification will be described. The shift-by-wire system in the modification includes the ECU 10 mounted on the vehicle, as in the above-described embodiment. The shift-by-wire system in the modified example is different from the above-described embodiment in part of the processing operation. In the processing operation of the shift-by-wire system in the modification, the same step number is assigned to the same part as the processing operation of the shift-by-wire system in the above-described embodiment.

  ECU10 in a modification performs the processing operation shown in FIG. As shown in FIG. 8, after the determination in step S15, the ECU 10 proceeds to step S17 or step S21 without determining which dead zone the shift lever 21 is in. That is, in step S15, when the shift determining unit 11 in the modification determines that the gradient is negative, it is determined that the vehicle is stopped on the downhill road and proceeds to step S17, and when the gradient is determined not negative. Considers that the vehicle is stopped on the uphill road and proceeds to step S21. Therefore, the shift determination unit 11 in the modified example determines the range of the automatic transmission to the R range when determining that the gradient is negative, and sets the range of the automatic transmission to the D range when determining that the gradient is not negative. To confirm. Thus, even if the shift-by-wire system of the present invention does not make the determinations in step S16 and step S20, the vehicle stopped on the slope can be prevented from sliding down.

  In other words, the driver recognizes that the shift range is the R range, but in fact, even when the shift lever 21 is operated in the dead zone, when the driver depresses the accelerator, When the person operates the shift lever, the vehicle can be prevented from sliding down. In addition, the driver recognizes that the shift range is the D range. Actually, even when the shift lever 21 is operated in the dead zone, when the driver depresses the accelerator, When a person operates the shift lever 21, the vehicle can be prevented from sliding down.

  DESCRIPTION OF SYMBOLS 10 ECU, 11 Shift judgment part, 12 Vehicle condition judgment part, 13 Torque calculation part, 20 Shift sensor, 21 Shift lever, 30 Gradient sensor, 40 Vehicle speed sensor, 50 Acceleration sensor, 60 Actuator control apparatus

Claims (3)

A shift-by-wire system that is mounted on a vehicle and switches a shift range of an automatic transmission according to an operation of a shift lever (21) by a driver,
The shift lever can be operated in at least three operation confirmation positions and at least two dead zones provided adjacent to the operation confirmation positions.
Shift position determination means (S10, S11) which acquires a shift position signal indicating the position of the shift lever and determines whether the position of the shift lever is in the operation fixed position or the dead zone based on the shift position signal. )When,
Whether a vehicle speed signal indicating the speed of the vehicle and a gradient signal indicating the angle of the gradient of the place where the vehicle is present are acquired, and whether the vehicle is stopped on a slope based on the vehicle speed signal and the gradient signal Vehicle status judging means (S12 to S14) for judging whether
Gradient determination means for determining whether the vehicle is stopped on a downhill road or on an uphill road based on the gradient signal when the vehicle status determination means determines that the vehicle is stopped on a slope. S15)
When the shift position determining means determines that the position of the shift lever is in the operation confirmed position, the shift position determining means determines the shift range corresponding to the position of the shift lever regardless of the determination by the vehicle status determining means. If the shift lever position is determined to be in the dead zone, and the gradient determination means determines that the vehicle is stopped on the downhill road, the shift range is fixed to the R range, and the shift position determination means determines the shift lever. Shift position determining means ( S18, S17, S21) for determining the shift range to the D range when it is determined that the position of the vehicle is in the dead zone and the gradient determining means determines that the vehicle is stopped on the uphill road. ,
A shift-by-wire system comprising: The shift lever can be operated in a D position that is an operation confirmation position indicating the D range, a dead zone adjacent to the D position, an R position that is an operation confirmation position indicating the R range, and a dead band adjacent to the R position. Yes,
Inferring whether the driver is willing to advance or retreat the vehicle, and if the shift lever is in the dead zone adjacent to the D position, the driver is willing to advance When the shift lever is in a dead zone adjacent to the R position, the shift lever includes an estimation means (S16, S20) for estimating that there is an intention to reverse the vehicle,
The shift position determining means includes
In addition to the shift position determining means determining that the position of the shift lever is in the dead zone and the gradient determining means determining that the vehicle is stopped on the downhill road, the estimating means determines that the vehicle is When it is estimated that there is an intention to reverse, the shift range is fixed to the R range,
The shift position determining means determines that the position of the shift lever is in the dead zone, and the gradient determining means determines that the vehicle is stopped on the uphill road. The shift-by-wire system according to claim 1, wherein the shift range is fixed to the D range when it is estimated that there is an intention to move forward. The shift position determining means includes
In addition to the shift position determining means determining that the position of the shift lever is in the dead zone and the gradient determining means determining that the vehicle is stopped on the downhill road, the estimating means determines that the vehicle is When it is estimated that there is no intention to move backward, the shift range is fixed to the non-drive range,
The shift position determining means determines that the position of the shift lever is in the dead zone, and the gradient determining means determines that the vehicle is stopped on the uphill road. The shift-by-wire system according to claim 2, wherein when it is estimated that there is no intention to move forward, the non-driving range is determined.

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