JP2017161020A - Vehicle control device and vehicle control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle behavior per intention of a driver in a reverse inhibiting control.SOLUTION: A controller 4 executes deceleration assist control that controls a reverse clutch 31 into a slip state when a brake operation is conducted at less than a prescribed vehicle speed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to reverse inhibit control for maintaining a reverse fastening element in a released state when an R range is selected when a vehicle is moving forward at a predetermined vehicle speed or higher.

  In an automatic transmission, based on a range (also called mode or position) such as P (parking), R (reverse), D (forward), and N (neutral) selected by a selector (select lever, select switch, etc.) The direction of travel of the vehicle intended by the driver is judged. When it is judged that the vehicle is moving forward, the forward fastening element is fastened. When it is judged that the vehicle is going backward, the reverse fastening element is fastened. The rotation direction is set in accordance with the traveling direction.

  However, if the R range is selected and the reverse fastening element is fastened when the vehicle is moving forward at a predetermined vehicle speed or higher, the torque converter may reversely rotate and the engine may stall. For this reason, in such a situation, even if the R range is selected, the reverse inhibit that maintains the reverse fastening element in the released state is executed.

JP 2000-249220 A

  When the reverse inhibit control is executed, the vehicle continues to move forward even if the driver wants to reverse the vehicle once until the reverse inhibit is released and the reverse fastening element is engaged.

  For this reason, for example, in a scene where there is not enough space in front of the vehicle at a U-turn or at a turn and turning is necessary, even if the driver wants to reverse the vehicle once while the vehicle is moving forward, In the inhibit control, even if the driver selects the R range, the reverse inhibit is continued until the vehicle speed drops below a predetermined vehicle speed, and the vehicle continues to move forward.

  The present invention has been made in view of such a technical problem, and an object of the present invention is to realize vehicle behavior in accordance with the driver's intention in reverse inhibit control.

  According to an aspect of the present invention, the engine, the selector that selects one range from a plurality of ranges including the R range, and the engine and the driving wheel are disposed, and when the R range is selected. And an automatic transmission having a reverse fastening element to be fastened, wherein the reverse range is selected when the R range is selected at a speed lower than a predetermined vehicle speed and a brake operation is performed. There is provided a control device for a vehicle, comprising a control unit that executes a deceleration assist control for controlling the fastening element for slipping into a slip state.

  According to another aspect of the present invention, the engine, a selector for selecting one range from a plurality of ranges including the R range, and the engine and the drive wheel are arranged, and the R range is selected. And an automatic transmission having a reverse fastening element that is fastened in the case where the R range is selected below a predetermined vehicle speed and a brake operation is being performed. A vehicle control method is provided, wherein deceleration assist control for controlling the reverse fastening element to a slip state is executed.

  If the R range is selected at least below the predetermined vehicle speed and the brake operation is being performed, it is considered that the driver intends to decelerate the vehicle quickly toward the reverse of the vehicle.

  According to the above aspect, in such a situation, the deceleration assist control is executed and the reverse fastening element is controlled to the slip state, and the deceleration force thereby acts on the vehicle, so the vehicle speed can be quickly reduced, As a result, the fastening timing of the reverse friction element, that is, the timing at which the vehicle starts to reverse can be advanced.

  Further, during the deceleration assist control, the reverse fastening element is controlled to the slip state, so that the torque transmitted from the drive wheel side to the engine side is limited, and the engine may stall due to the reverse rotation of the torque converter. Can be prevented.

1 is a schematic configuration diagram of a vehicle to which a control device according to an embodiment of the present invention is applied. It is the flowchart which showed the content of the reverse inhibit control which a controller performs. It is a time chart which showed a mode that reverse inhibit control was performed.

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

  FIG. 1 shows a schematic configuration of a vehicle 100 to which a control device according to an embodiment of the present invention is applied.

  The vehicle 100 includes an engine 1, a torque converter 2, and an automatic transmission 3, and the output rotation of the engine 1 is transmitted to driving wheels (not shown) via the torque converter 2 and the automatic transmission 3. is there.

  The torque converter 2 is a torque converter with a lockup clutch 21. When the lockup clutch 21 is engaged, the input shaft and the output shaft of the torque converter 2 are directly connected, and transmission loss due to slipping can be reduced. The lockup clutch 21 is engaged when the vehicle speed VSP exceeds the lockup start vehicle speed (for example, 18 km / h), and the lockup release vehicle speed (for example, 15 km / h) set slightly lower than the lockup start vehicle speed. It is released when it falls below.

  The automatic transmission 3 is a stepped automatic transmission having a plurality of forward shift stages and one reverse shift stage. The gear position can be changed depending on the combination of the plurality of engagement elements (clutch, brake) disposed inside the automatic transmission 3, and at least when the reverse gear position is realized. The reverse clutch 31 is engaged.

  A controller 4 is connected to the engine 1, the lockup clutch 21 and the automatic transmission 3. The controller 4 includes a CPU, a ROM, a RAM, an input / output interface, a bus for connecting them, and the like. The controller 4 comprehensively controls the rotational speed Ne and torque of the engine 1, the engagement state of the lockup clutch 21, the shift stage of the automatic transmission 3, and the like based on detection values of sensors that detect the state of each part of the vehicle 100. To do.

  Examples of sensors that detect the state of each part of the vehicle 100 include a rotational speed sensor 41 that detects the rotational speed Ne of the engine 1, a throttle opening sensor 42 that detects the throttle opening TVO of the engine 1, and the acceleration of the vehicle 100. , An acceleration sensor 43 for detecting the input speed, an input rotation speed sensor 44 for detecting the input rotation speed of the automatic transmission 3, a vehicle speed sensor 45 for detecting the vehicle speed VSP, a brake switch 46 for detecting the operating state of the brake pedal 5, and a selector 6 An inhibitor switch 47 and the like for detecting which range (parking), R (reverse), N (neutral), or D (forward) is selected are included. The selector 6 may be any mechanism such as a shift lever, a column lever, a button switch, or a dial.

  By the way, when the R range is selected by the selector 6, the controller 4 normally engages the reverse clutch 31 and realizes the reverse gear, but the reverse clutch remains in a state where the vehicle 100 is moving forward. When 31 is fastened, the torque converter 2 may reversely rotate and the engine 1 may stall. Therefore, in such a situation, it is necessary to execute a reverse inhibit that maintains the reverse clutch 31 in the released state even if the R range is selected by the selector 6.

  However, in the conventional reverse inhibit control, when the vehicle speed is higher than the predetermined vehicle speed, the reverse inhibit is uniformly executed. Therefore, a scene (U In turn and turn at the turn), even if the driver wants to move the vehicle backward, the vehicle continues to move forward until the reverse inhibit is released, and the turn may not be performed smoothly.

  Therefore, the controller 4 executes reverse inhibit control in the manner described below, thereby enabling smooth switching in the scene.

  FIG. 2 is a flowchart showing the contents of reverse inhibit control executed by the controller 4.

  According to this, first, in step S1, the controller 4 determines whether or not the R range is selected by the selector 6. If it is determined that the R range is selected, the process proceeds to step S2, and if not, the determination in step S1 is repeated.

  In step S2, the controller 4 determines whether the vehicle speed VSP is less than the first vehicle speed V1 (for example, 8 km / h). The first vehicle speed V1 is an upper limit value of the vehicle speed VSP that can guarantee that the engine 1 will not stall due to the reverse rotation of the torque converter 2 even if the reverse clutch 31 is completely engaged.

  The vehicle speed VSP is not the detection value of the vehicle speed sensor 45 (the vehicle speed converted value of the vehicle speed pulse, that is, the current vehicle speed) itself, but the value detected by the vehicle speed sensor 45 and the acceleration of the vehicle 100 detected by the acceleration sensor 43. The vehicle speed estimated ahead based on a predetermined time (prefetch vehicle speed) is used. The predetermined time is set equal to the time from when the supply of hydraulic pressure to the reverse clutch 31 is started until the reverse clutch 31 starts generating the transmission torque capacity (engagement delay time). Set to 0 seconds. The transmission torque capacity is the maximum torque that can be transmitted by the clutch.

  If it is determined that the vehicle speed VSP is less than the first vehicle speed V1, the engine 1 will not stall even if the reverse clutch 31 is immediately engaged, so the process proceeds to step S3, and the controller 4 fully engages the reverse clutch 31. To do.

  On the other hand, when it is determined that the vehicle speed VSP is equal to or higher than the first vehicle speed V1, the process proceeds to step S4, and the controller 4 determines whether the vehicle speed VSP is less than the second vehicle speed V2 (for example, 30 km / h). The second vehicle speed V2 is an upper limit value of the vehicle speed VSP at which the driver may want to reverse the vehicle 100 once although the vehicle 100 is moving forward.

  If it is determined that the vehicle speed VSP is less than the second vehicle speed V2, that is, if the vehicle speed VSP is determined to be greater than or equal to the first vehicle speed V1 and less than the second vehicle speed V2, the process proceeds to step S5.

  In step S5, the controller 4 determines whether or not the brake switch 46 is ON (depressed state). If it is determined that the brake switch 46 is ON, the driver wants to prevent the vehicle 100 from moving forward. Therefore, the process proceeds to step S6, and the vehicle behavior intended by the driver, in this case, acts on the vehicle 100. Deceleration assist control using the reverse clutch 31 is executed so that the deceleration force increases.

  In step S6, the controller 4 increases the hydraulic pressure supplied to the reverse clutch 31 stepwise, closes the gap between the friction elements constituting the reverse clutch 31, and puts the reverse clutch 31 in a state immediately before the transmission torque capacity is generated ( Stuffed).

  In step S7, the controller 4 gradually increases the hydraulic pressure supplied to the reverse clutch 31 to gradually increase the transmission torque capacity of the reverse clutch 31, and controls the reverse clutch 31 to the slip state. As a result, a torque in the direction opposite to the rotational direction acts on the drive wheels, so that a deceleration force acts on the vehicle 100 (deceleration assist control). As described above, the preceding vehicle speed (pre-reading vehicle speed) is used as the vehicle speed VSP for the engagement delay time. Therefore, the timing at which the vehicle speed VSP becomes less than the second vehicle speed V2 and the timing at which the reverse clutch 31 starts to generate the transmission torque capacity are approximately. Match.

  On the other hand, since the torque transmitted from the drive wheel side to the engine 1 side is limited by controlling the reverse clutch 31 to the slip state, stalling of the engine 1 is prevented.

  During the deceleration assist control, the controller 4 monitors the vehicle speed VSP and the rotational speed Ne of the engine 1 (steps S8, S9, S11). If the vehicle speed VSP falls below the first vehicle speed V1, the process starts from step S8. In step S3, the reverse clutch 31 is completely engaged.

  When the rotational speed Ne of the engine 1 becomes lower than the first rotational speed (= idle rotational speed Nidle + α1), the process proceeds from step S9 to step S10, and the rotational speed of the engine 1 is prevented in order to prevent the engine 1 from stalling. The supplied hydraulic pressure to the reverse clutch 31 is gradually decreased until Ne becomes higher than the second rotation speed (= idle rotation speed Nidle + α2, α2> α1), and the transmission torque capacity of the reverse clutch 31 is gradually decreased.

  Thereby, during the deceleration assist control, the rotational speed Ne of the engine 1 is maintained between the first rotational speed and the second rotational speed. By the processing of steps S7 to S11, the transmission torque capacity of the reverse clutch 31 is appropriately controlled, and the engine 1 is prevented from being stalled. Further, as much deceleration force as possible can be applied to the vehicle 100 as long as the engine 1 does not stall.

  Here, the transmission torque capacity of the reverse clutch 31 is controlled so that the rotational speed Ne of the engine 1 falls between the first rotational speed and the second rotational speed, but the rotational speed Ne of the engine 1 is idle. The transmission torque capacity of the reverse clutch 31 may be feedback-controlled so that the rotation speed is maintained at a predetermined rotation speed or higher.

  On the other hand, if the vehicle speed VSP is greater than or equal to the second vehicle speed V2 or less than the second vehicle speed V2 in step S4 and the brake switch 46 is OFF (no depression), the driver mistakenly operates the selector 6 and mistakenly R Most likely you have selected a range. In such a case, the controller 4 advances the process to step S12, sets the hydraulic pressure supplied to the reverse clutch 31 to zero, and maintains the reverse clutch 31 in a released state (reverse inhibit).

  Then, the controller 4 monitors the range selected by the selector 6 (step S13), and when the R range is selected and the vehicle speed VSP becomes lower than the first vehicle speed V1, the reverse inhibit is canceled and the river is The scratch 31 is completely fastened (step S14 → step S15).

  FIG. 3 is a time chart showing how the reverse inhibit control is executed. A solid line indicates an embodiment of the present invention. A broken line indicates a comparative example in which the detection value itself of the vehicle speed sensor 45 is used as the vehicle speed VSP, and the reverse inhibit is uniformly executed when the vehicle speed VSP is equal to or higher than the first vehicle speed V1.

  According to this, the throttle opening TVO is OFF (zero) at time t1, and the brake switch 46 is ON (depressed state) at time t2.

  When the range selected by the selector 6 is changed from the D range to the R range at time t3, the reverse clutch 31 is loosened in response to the fact that the vehicle speed VSP (read-ahead vehicle speed) is less than the second vehicle speed V2. Thereafter, the reverse clutch 31 is controlled to a slip state (deceleration assist control). As a result, a deceleration force acts on the vehicle 100.

  At time t3, the vehicle 100 is still moving forward, but the R range is selected and the brake pedal 5 is depressed. Therefore, the driver intends to decelerate the vehicle 100 and then move the vehicle 100 backward. it seems to do. In this embodiment, in such a situation, deceleration assist control is performed in addition to the braking force generated by depressing the brake pedal 5, and the vehicle 100 can be decelerated quickly.

  Further, if the transmission torque capacity of the reverse clutch 31 becomes excessive, the engine 1 may stall due to the reverse rotation of the torque converter 2. Regarding this point, in the present embodiment, during the deceleration assist control, the rotational speed Ne of the engine 1 is monitored, and the reverse clutch 31 is set so that the rotational speed Ne of the engine 1 falls within a predetermined range (Nidle + α1 ≦ Ne <Nidle + α2). Since the transmission torque capacity is controlled (time t4 to t5), stall of the engine 1 is prevented.

  When the vehicle speed VSP decreases to the first vehicle speed V1 at time t5, the deceleration assist control is released and the hydraulic pressure supplied to the reverse clutch 31 is increased. At time t6, the reverse clutch 31 is completely engaged, and then the traveling direction of the vehicle 100 turns backward.

  In comparison with the comparative example, in the comparative example, when the detected value of the vehicle speed sensor 45 becomes less than the first vehicle speed V1 at time t7, the reverse clutch 31 is loosened, and the reverse clutch 31 is engaged at time t8. In contrast, according to the present embodiment, the timing at which the reverse clutch 31 is engaged is advanced from time t8 to time t6, and the vehicle behavior (reverse) intended by the driver is realized at an earlier timing than in the comparative example. Smooth turn-back is possible in situations where turn-around or turning is necessary at a turn.

  The actions and effects of this embodiment are summarized as follows.

  In the present embodiment, the controller 4 (control unit) controls the reverse clutch 31 to the slip state when the vehicle speed VSP is less than the second vehicle speed V2 (less than a predetermined vehicle speed) and a brake operation is being performed. Execute deceleration assist control.

  When the vehicle speed VSP is less than the second vehicle speed V2 and the R range is selected and the brake operation is performed, it is considered that the driver has an intention to quickly decelerate the vehicle 100 toward the reverse of the vehicle.

  According to the present embodiment, in such a situation, the deceleration assist control is executed and the reverse clutch 31 is controlled to the slip state, and the deceleration force due to this is applied to the vehicle 100. As a result, the vehicle speed VSP can be quickly reduced toward the reverse of the vehicle (effect corresponding to claims 1 and 4).

  Further, during the deceleration assist control, the reverse clutch 31 is controlled to the slip state, so that the torque transmitted from the drive wheel side to the engine 1 side is limited, and the engine 1 stalls due to the reverse rotation of the torque converter 2. This can also be prevented (effect corresponding to claims 1 and 4).

  Furthermore, the controller 4 reduces the transmission torque capacity of the reverse clutch 31 when the rotational speed Ne of the engine 1 becomes less than the first rotational speed during the deceleration assist control. As a result, the rotational speed Ne of the engine 1 can be increased, thereby further preventing the engine 1 from stalling (effect corresponding to claim 2).

  Further, the controller 4 increases the transmission torque capacity of the reverse clutch 31 when the rotational speed Ne of the engine 1 becomes equal to or higher than the second rotational speed higher than the first rotational speed after the transmission torque capacity of the reverse clutch 31 is decreased. . As a result, during deceleration assist, stalling of the engine 1 can be prevented, and as much deceleration force as possible can be applied to the vehicle 100 to accelerate the engagement timing of the reverse clutch 31 (effect corresponding to claim 3).

  The embodiment of the present invention has been described above, but the above embodiment is merely one example of application of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. is not.

  For example, in the above embodiment, the vehicle speed VSP (prefetched vehicle speed) estimated from the current vehicle speed and acceleration is used as the vehicle speed VSP used for the reverse inhibit control. However, this configuration is not an essential configuration, but a vehicle speed sensor. 45 detection values may be used instead.

  In addition, the “brake operation” in the claims refers to a depression operation in the case of a depression type brake pedal as in this embodiment, but the braking force is applied to the vehicle when the pedal and lever are operated in a specific direction. In the case of acting on, the operation in the specific direction corresponds to the “brake operation” in the claims.

1 Engine 3 Automatic transmission 4 Controller (control part)
5 Brake pedal 6 Selector 31 Reverse clutch (reverse engagement element)
100 vehicles

Claims (4)

An engine, a selector for selecting one range from a plurality of ranges including the R range, and a reverse fastening element that is disposed between the engine and the driving wheel and is fastened when the R range is selected. A vehicle control device comprising an automatic transmission,
A vehicle comprising: a control unit that executes deceleration assist control for controlling the reverse fastening element to a slip state when the R range is selected at a speed lower than a predetermined vehicle speed and a brake operation is performed. Control device. The vehicle control device according to claim 1,
The control unit reduces the transmission torque capacity of the reverse fastening element when the rotational speed of the engine becomes less than a first rotational speed during the deceleration assist control.
A control apparatus for a vehicle. The vehicle control device according to claim 2,
The controller reduces the transmission torque capacity of the reverse fastening element when the rotational speed of the engine becomes equal to or higher than a second rotational speed higher than the first rotational speed after reducing the transmission torque capacity of the reverse fastening element. increase,
A control apparatus for a vehicle. An engine, a selector for selecting one range from a plurality of ranges including the R range, and a reverse fastening element that is disposed between the engine and the driving wheel and is fastened when the R range is selected. A vehicle control method comprising an automatic transmission,
When the R range is selected at a speed lower than a predetermined vehicle speed and a brake operation is being performed, a deceleration assist control for controlling the reverse fastening element to a slip state is executed.

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