JP5895907B2 - Vehicle shift control device - Google Patents

Description

  The present invention relates to a vehicle shift control device having a hill hold function.

  Conventionally, as a well-known technique, hill hold (also called hill start assist) is known as an assist function for a driver when starting from a vehicle stop state on a slope. This hill hold is used to generate a brake pressure by, for example, driving a hydraulic pump when the brake operation is released while the brake pedal is depressed on a slope, and the accelerator operation is performed after the brake operation is released. It is possible to prevent the vehicle from sliding down the slope due to the brake pressure until

JP 2006-306300 A JP 2007-326416 A

By the way, the hill hold has only to be executed for a short time from when the brake operation is released to when the accelerator operation is performed. For example, the hill hold is automatically released after 2 seconds.
In normal driving operation, the time from the release of the brake operation to the accelerator operation is short, and the accelerator operation is performed before the hill hold is released. Can be started smoothly.

  However, for example, if the driver loses consciousness due to poor physical condition when the vehicle is stopped by a brake operation on a slope, an abnormal state where the accelerator operation or the brake operation is not performed even though the brake operation is released. May be. In such an abnormal state, the hill hold is released without performing the accelerator operation or the brake operation, so that the vehicle may slide down the slope.

  On the other hand, as a technique similar to hill hold, it has been proposed to apply a braking force to driving wheels by driving an electric parking brake (hereinafter referred to as EPKB) (see Patent Documents 1 and 2). In this case, when the vehicle stops, the EPKB is driven according to the depression amount of the tilt sensor or the brake pedal, and the EPKB is released according to the accelerator operation, so that the vehicle can be started smoothly. By using such a technique, for example, even when the driver loses consciousness, it is possible to prevent the vehicle from sliding down the slope.

  However, since EPKB uses an auxiliary stopping device called a parking brake, a braking force is generated on the driving wheels by driving a motor with a large output and pressing a brake pad against the disc rotor. Yes. For this reason, when EPKB is adopted as a hill hold, it is necessary to continue driving the EPKB in order to maintain the vehicle stationary state for a long time. The motor driver for driving the motor generates heat or a large amount of electric power. Consuming may cause a decrease in battery life. For this reason, it is difficult to adopt EPKB as a substitute for hill hold.

  The present invention has been made in view of the above circumstances, and its purpose is to execute hill hold control until a hill hold cancellation condition is satisfied when a hill hold condition is satisfied when the vehicle is stopped on a slope. An object of the present invention is to provide a vehicle shift control device that can prevent a vehicle from slipping down even when hill hold control is released.

For example, when the hill hold condition is satisfied when the vehicle is stopped by a braking operation on an uphill, the hill hold control is executed until the hill hold release condition is satisfied, so that the vehicle is prevented from slipping down. Accordingly, the vehicle can be started smoothly by performing the accelerator operation after releasing the brake operation. However, for example, if the driver loses consciousness when the vehicle is stopped, the accelerator operation is not performed even though the hill hold release condition is satisfied, so the hill hold control is released and the vehicle slips. There is a risk of falling. However, according to the present invention, since the parking condition is established prior to the establishment of the hill hold cancellation condition, the parking control is performed. Thus, since the transmission is switched to the parking lock state before the hill hold control is released, it is possible to reliably prevent the vehicle from slipping down.

The block diagram which shows the shift control apparatus for vehicles in one Embodiment of this invention. Perspective view showing parking gear and parking lock Flow chart showing operation of brake ECU Flow chart showing operation of SBW / ECU

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a shift-by-wire vehicle shift control device mounted on a hybrid vehicle, for example. A shift-by-wire ECU (Electronic Control Unit; hereinafter referred to as SBW / ECU) 1 (corresponding to a shift-by-wire control means and a parking means) is mainly composed of a microcomputer including a CPU, a ROM, and a RAM. In other words, a general shift control device for an engine-equipped vehicle is configured to control the transmission by hydraulic control that generates a predetermined hydraulic pressure according to the shift range, but the hybrid vehicle is not hydraulic control but electric control. The shift-by-wire system is adopted because the transmission is controlled by the control.

  As the shift range of the shift device 2, a P (parking) range, an R (reverse) range, an N (neutral) range, a D (drive) range, and an H (home) range are set. In the present embodiment, the shift lever of the shift device 2 is located in the H range in the non-operating state, and outputs shift information indicating the shift range by operating from the H range to the desired shift range. When released, it automatically returns to the H range. Depending on the vehicle type, there is a configuration in which the P range is not set as the shift range, and shift information indicating the P range is output by a pressing operation on the parking button, for example.

  The SBW • ECU 1 controls the transmission 4 to the shift range indicated by the shift information by driving the motor 3 based on the shift information input from the shift device 2. The transmission 4 is integrally provided with a parking mechanism 5. As shown in FIG. 2, the parking mechanism 5 includes a parking gear 6 that rotates in conjunction with a drive shaft of the vehicle, a parking lock 7 that is rotatably supported on the vehicle body by a shaft 7a, and the parking lock 7 And a motor 8 (corresponding to an actuator) that elastically applies a pressing force in the direction of arrow A. The SBW • ECU 1 executes parking control when the shift information indicates the P range, and cancels the parking control when the shift information indicates other than the P range. The parking control is performed by rotating the motor 8 in the forward direction, and the parking control is canceled by rotating the motor 8 in the reverse direction. When the motor 8 rotates forward, the parking lock state in which the rotation of the drive shaft is restricted by engaging the claw 7b of the parking lock 7 with the valley 6a of the parking gear 6 is established. When the motor 8 rotates in the reverse direction in the parking lock state, the parking lock 7 is disengaged from the parking gear 6 and the parking shaft unlocked state in which the rotation of the drive shaft is allowed. Note that the SBW • ECU 1 is configured to drive the motor 3 and switch the transmission 4 to the N range when performing the parking control.

On the other hand, the SBW • ECU 1 executes the above-described parking control even when it receives a parking command from the brake ECU 9 (corresponding to a hill hold means) as will be described later.
The SBW • ECU 1 outputs current range information indicating the current shift range to the meter ECU 10 (corresponding to notification means).
The meter ECU 10 displays the current shift range on the meter 11 based on the current range information input from the SBW / ECU 1.

The brake angle sensor 12 detects the depression amount with respect to the brake pedal and outputs it to the brake ECU 9.
The inclination sensor 13 detects the inclination of the vehicle in the front-rear direction with respect to the horizontal direction and outputs it to the brake ECU 9.
The vehicle speed sensor 14 detects the current speed of the vehicle and outputs it to the brake ECU 9.
The accelerator angle sensor 15 detects the depression amount with respect to the accelerator pedal and outputs it to the brake ECU 9.

  When the brake ECU 9 determines that a hill hold condition, which will be described later, is established based on information from the brake angle sensor 12, the tilt sensor 13, the vehicle speed sensor 14, and the accelerator angle sensor 15, as will be described later, the brake ECU 9 The hill hold control to be driven is executed, and the hill hold control is released when it is determined that a hill hold release condition described later is satisfied. During the hill hold control, the hydraulic pump 16 is driven and the brake pad is pressed against the disc rotor to generate a brake pressure on the brake 17. In this case, the brake ECU 9 outputs a parking command to the SBW • ECU 1 when a parking condition (described later) that is set to be satisfied before the hill hold cancellation condition is satisfied is satisfied. Yes.

Now, the operation of the SBW • ECU 1 will be described. As shown in FIG. 4, the SBW • ECU 1 determines whether a parking command has been received from the brake ECU 9 (S401: NO) or whether shift information has been received from the shift device 2 (S402: NO). When shift information is received from the shift device 2 (S402: YES), the transmission 4 is switched and controlled by controlling the motor 3 based on the shift information and the like (S404).
Next, the SBW • ECU 1 outputs current range information indicating the current shift range to the meter ECU 10 (S403). Thus, the meter ECU 10 displays the current shift range on the meter 11 based on the current range information received from the SBW • ECU 1.
By the operation as described above, the driver can switch the transmission 4 to a desired shift range by a shift operation on the shift device 2 and can check the current shift range by the meter 11.

Next, the operation of the brake ECU 9 will be described.
The brake ECU 9 determines whether the hill hold release condition is satisfied (S301: NO), whether the hill hold condition is satisfied (S303: NO), or the hill hold state (S305: NO). If it is not in the hill hold state, the hill hold continuation counter is cleared as being in the hill hold end state (S309). The hill hold condition is determined from the angle information of the inclination sensor 13 and the depression amount with respect to the brake pedal. Specifically, the front-rear direction of the vehicle detected by the inclination sensor 13 when the brake angle sensor 12 detects a stepping amount equal to or greater than a predetermined angle and the vehicle speed sensor 14 detects that the vehicle speed is 0 (the vehicle is stopped). The brake angle sensor 12 detects that the depression amount of the brake pedal is 0 (the brake operation is released) in a state where the inclination angle of the brake pedal is equal to or greater than a predetermined angle (for example, uphill or downhill with a gradient of 3%). That is, the brake operation is released when the vehicle is stopped by a brake operation on a slope. On the other hand, the hill hold cancellation condition is a case where, for example, 2 seconds (corresponding to the first predetermined time) elapses after the hill hold condition is satisfied, or the accelerator operation is performed until 2 seconds elapse.

  Now, for example, when the driver depresses the brake pedal due to traffic jam while traveling on an uphill, the vehicle is stopped, and when the brake operation is released to start the vehicle from the vehicle stopped state, the brake ECU 9 satisfies the hill hold condition. (S303: YES), the hill hold control is started and the hill hold state is set (S304). In other words, the hydraulic pump 16 is driven and the brake pad is pressed against the disc rotor to generate the brake pressure on the brake 17, so that the vehicle is stopped so that the vehicle does not slide down on the slope. In such a hill hold state (S305: YES), the hill hold state duration time is counted by incrementing the hill hold continuation counter at a predetermined interval (S310). In normal driving operation, the accelerator operation is performed until the hill hold continuation counter exceeds a certain value, that is, until 1.8 seconds (second predetermined time) when the parking condition described later is satisfied. Since the hill hold cancellation condition is satisfied (S301: YES), the hill hold end state is entered and the hill hold continuation counter is cleared (S302). Thereby, since the drive with respect to the hydraulic pump 16 is cancelled | released, a brake pressurizing force is cancelled | released and a vehicle can be started smoothly.

By the way, for example, when the driver is in a physical condition with the vehicle stopped by a brake operation on a hill and loses consciousness, the accelerator operation or the brake operation is not performed even though the brake operation is released. May occur. In such an abnormal state, since the hill hold state is released after 2 seconds, the vehicle may slide down the hill.
In such a case, the brake ECU 9 determines that the parking condition is satisfied when the hill hold continuation counter is equal to or greater than a certain value (S306: YES), that is, when the hill hold state continues for 1.8 seconds, the process proceeds to SBW • ECU1. After outputting the parking command (S307), the hill hold continuation counter is cleared assuming that the hill hold end state is reached (S308).

  As described above, since the parking command is output to the SBW • ECU 1 immediately before the brake ECU 9 cancels the hill hold control, the SBW • ECU 1 receives the parking command from the brake ECU 9 (S401: YES). Parking control is executed (S405). In this parking control, the motor 3 is controlled to switch the transmission 4 to the N range, and at the same time, the motor 8 is controlled to lock the parking mechanism 5. As a result, the parking lock 7 is engaged with the parking gear 6 of the parking mechanism 5 so that the transmission 4 enters the parking lock state. The time for which the SBW • ECU 1 performs the parking control is short, and once the transmission 4 is in the parking lock state, the parking lock state of the transmission 4 can be maintained without driving the motor 8. Even when the drive is released, the vehicle can be prevented from slipping down.

  Next, the SBW • ECU 1 outputs current range information indicating the P range to the meter ECU 10 (S403). The meter ECU 10 displays on the meter 11 that the current shift range is the P range to the driver. As a result, the driver who has returned to consciousness can recognize that the current shift range is the P range, and thus can perform a shift operation from the P range to the intended shift range. In this case, since the shift device 2 is in the P range, the driver needs to perform a shift operation from the P range to another desired range while performing a brake operation. When the shift device 2 is operated from the P range to another shift range in the brake operation state, the transmission 4 is switched from the parking lock state to the parking unlock state. For example, after switching to the D range, the brake operation is released. The accelerator operation is performed following this. In this case, since the hill hold control is performed when the brake operation is released, the driver can be assisted and the convenience of the driver is not impaired.

According to such an embodiment, the following effects can be produced.
The brake ECU 9 outputs a parking command to the SBW • ECU 1 when the parking condition is satisfied prior to releasing the hill hold control, and the SBW • ECU 1 turns off the transmission 4 when receiving the parking command from the brake ECU 9. Since the parking lock state is set, for example, even when the driver loses consciousness when the vehicle is stopped on a slope and the brake operation is released, the vehicle does not slip. It can be surely prevented from falling.
Since the SBW • ECU 1 executes the parking control for switching the transmission 4 to the parking lock state, the SBW • ECU 1 can be easily implemented using the parking lock function originally provided in the SBW • ECU 1.

  The brake ECU 9 outputs a parking command to the SBW • ECU 1 1.8 seconds after the start of the hill hold control. When the SBW • ECU 1 receives the parking command from the brake ECU 9, the brake ECU 9 puts the transmission 4 in the parking lock state. Since the switching is performed, the parking control can be executed without the SBW • ECU 1 determining that the parking condition is satisfied. In other words, the brake ECU 9 only needs to output a parking command 1.8 seconds after the start of the hill hold control performed by the brake ECU 9, so that the configuration is simpler than the configuration in which the SBW • ECU 1 independently determines that the parking condition is satisfied. Parking control can be implemented with the configuration.

When the SBW • ECU 1 sets the transmission 4 in the parking lock state in response to the parking command from the brake ECU 9, the SBW • ECU 1 confirms that the shift range is the P range even though the shift information is not received from the shift device 2. Since the present current range information is output to the meter ECU 10, the driver may recognize that the P range is in the case where the shift range is arbitrarily switched to the P range in order to execute the parking control. it can.
The SBW • ECU 1 switches the transmission 4 from the P range to the shift range indicated by the shift information when receiving the shift information from the shift device 2 under the condition of the brake operation after executing the parking control. Therefore, the operation similar to the normal operation is performed. Thus, the parking lock state can be released.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and may be modified or expanded as follows, each modified example may be combined with the above-described embodiment, or each modified example may be combined.
Although the parking command is output from the brake ECU 9, the parking command may be output via another ECU. Further, other ECUs (for example, engine ECUs) may perform the determination of the establishment of the hill hold condition and the establishment of the hill hold release condition and the measurement of the duration time of the hill hold state.
In order to prevent the SBW ECU 1 from receiving the parking command from the brake ECU 9 after the hill hold control in the D range, for example, the driver assumes the D range and erroneously depresses the accelerator pedal during the parking control. The driver may be alerted with a warning sound or the like when the parking control is performed.

Although the parking command is output only once, the parking command may be continuously output a plurality of times in order to improve robustness.
In addition to the shifter information, the SBW / ECU 1 may comprehensively determine the shift range switching from other information such as the amount of depression of the brake pedal and the vehicle speed.
Even if the shift device 2 does not directly output the shift information to the SBW • ECU 1, another ECU (for example, engine ECU) receives the shift information and outputs a P, R, N, D range switching command to the SBW • ECU 1. Thus, the SBW • ECU 1 may be operated.

The SBW • ECU 1 may only perform parking control (switching to other than the P range and P range), and the AT / ECU may perform switching of the D, N, and R ranges.
The shift lever of the shift device 2 is of a type that returns to the N range, but may be of a type that is positioned to the shifted shift range in the same manner as a general shift lever. In this case, if the shift lever is provided with an actuator for moving from another shift range to the P range, and the SBW • ECU 1 performs the parking control, the shift lever needs to be moved to the P range by the actuator.
The present invention is not limited to a hybrid vehicle, but may be applied to a transmission of an electric vehicle or an engine-driven vehicle and a shift-by-wire transmission.

  In the drawings, 1 is an SBW / ECU (shift-by-wire control means, parking means), 2 is a shift device, 4 is a transmission, 8 is a motor (actuator), 9 is a brake ECU (hill hold means), and 10 is a meter ECU ( Notification means).

Claims (5)

A vehicle shift control device comprising a shift device (2) for outputting shift information indicating a shift range, and a shift-by-wire control means (1) for switching the transmission (4) to the shift range indicated by the shift information from the shift device. In
Hill hold means for executing the hill hold control by driving the actuator (8) to generate brake pressure when the hill hold condition is satisfied, and releasing the hill hold control when the hill hold release condition is satisfied. (9) and
Parking means (1) for executing a parking control for switching the transmission to a parking lock state when a parking condition set to be satisfied before the hill hold cancellation condition is satisfied is provided. ,
The hill hold condition is that the brake operation is released,
The hill hold release condition is that the first predetermined time has elapsed since the brake operation was released,
The vehicle shift control device , wherein the parking condition is that a second predetermined time shorter than the first predetermined time has elapsed . The hill hold means is provided to determine whether the parking condition is satisfied, and outputs a parking command to the parking means when the parking condition is satisfied,
2. The vehicle shift control device according to claim 1, wherein the parking unit determines that the parking condition is satisfied when a parking command is received from the hill hold unit.   The vehicle shift control apparatus according to claim 2, wherein the shift-by-wire control means includes the parking means.   4. The apparatus according to claim 1, further comprising an informing unit that informs a driver that the shift range is a parking range when the parking unit performs the parking control. 5. The vehicle shift control device described.   When the shift means receives the shift information from the shift device after the parking means performs the parking control, the shift-by-wire control means moves the transmission to a shift range indicated by the shift information on condition that a brake operation is being performed. The vehicle shift control device according to any one of claims 1 to 4, wherein the vehicle is switched from a parking lock state.

Images