JP7202897B2 - vehicle controller - Google Patents

Description

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

2. Description of the Related Art In recent years, from the viewpoint of assisting the driving operation of a vehicle, the use of a brake hold function that keeps the vehicle in a stopped state is increasing (see Patent Documents 1 to 3). In a vehicle having a brake hold function, a brake caliper or the like is automatically controlled by an electric actuator. By using this brake hold function, even if the brake operation is released when the vehicle is stopped in a traffic jam or on a slope, the vehicle can be kept stopped until the accelerator operation is performed.

Japanese Patent Application Laid-Open No. 2008-116002 JP 2010-208462 A JP 2015-30293 A

By the way, when the road surface slope is large or the load is large, it may be difficult to keep the vehicle stopped by the brake hold function. Therefore, it is required to appropriately hold the stopped state by the brake hold function.

SUMMARY OF THE INVENTION An object of the present invention is to appropriately maintain a stopped state by a brake hold function.

A control device for a vehicle according to the present invention is a control device for a vehicle having a brake hold function for holding a vehicle in a stopped state. and a parking lock control unit that controls the parking lock mechanism to a locked state when a parking range is selected by a driver's selection operation. The parking lock control unit operates when the vehicle, held in a stopped state, starts to move without the driver's starting operation in a state in which the driving range is selected by the driver's selection operation. and the parking lock control unit controls the parking lock mechanism to be in a locked state when the vehicle starts to move, and thereafter, when the vehicle continues to move, the parking lock mechanism is locked. to the released state.

According to the present invention, the parking lock control unit allows the vehicle held in a stopped state to start moving without the driver's starting operation in a state where the driving range is selected by the driver's selection operation. In this case, the parking lock mechanism is controlled to be locked. As a result, the stopped state of the vehicle can be appropriately maintained by the brake hold function.

1 is a schematic diagram showing a configuration example of a vehicle provided with a vehicle control device according to an embodiment of the present invention; FIG. 4 is a flowchart showing an example of a procedure for executing brake hold control; 4 is a flowchart showing an example of a procedure for executing brake hold control; (A) and (B) are diagrams showing operating states of an electric parking brake and a parking lock mechanism in brake hold control.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Vehicle configuration]
FIG. 1 is a schematic diagram showing a configuration example of a vehicle 11 equipped with a vehicle control device 10 according to one embodiment of the present invention. As shown in FIG. 1 , a vehicle 11 is equipped with a powertrain 15 having an engine 12 , a torque converter 13 and a transmission 14 . Further, the transmission 14 incorporates a forward/reverse switching mechanism 16 and a transmission mechanism 17 such as an automatic transmission mechanism. Further, the transmission 14 is provided with a valve unit 18 that supplies working oil to the forward/reverse switching mechanism 16, the transmission mechanism 17, and the like.

Wheels 23 are connected to an output shaft 19 of the transmission mechanism 17 via a propeller shaft 20, a differential mechanism 21, a drive shaft 22, and the like. That is, the power transmission path 24 connected to the wheels 23 is composed of the output shaft 19, the propeller shaft 20, the differential mechanism 21, the drive shaft 22, and the like. The forward/reverse switching mechanism 16 is a mechanism for switching the rotation direction of the input shaft 25 of the transmission mechanism 17, and is configured by a planetary gear train, a forward clutch, a reverse brake, and the like (not shown).

The transmission 14 is provided with a parking lock mechanism 30 that stops rotation of the power transmission path 24 described above. The parking lock mechanism 30 has a parking gear 31 provided on the output shaft 19 , a lock lever 32 that swings between a meshing position and a retracted position, and a lock actuator 34 that has a rod 33 that contacts the lock lever 32 . are doing. The lock lever 32 is urged by a spring (not shown) to a meshing position where it meshes with the parking gear 31 . By controlling the lock actuator 34 with a controller 50, which will be described later, the rod 33 can be extended and retracted to control the lock lever 32 between the meshing position and the retracted position.

That is, by contracting the rod 33 of the lock actuator 34, the spring force of the spring can move the lock lever 32 to the meshing position where it meshes with the parking gear 31. As shown in FIG. Thereby, the parking lock mechanism 30 is controlled to the locked state, and the rotation of the power transmission path 24 can be prohibited. On the other hand, by extending the rod 33 of the lock actuator 34, the lock lever 32 can be moved to the retracted position where it is disengaged from the parking gear 31 against the spring force. Thereby, the parking lock mechanism 30 is controlled to be in the released state, and the power transmission path 24 is allowed to rotate.

A brake device 40 for braking the wheels 23 has a disk rotor 41 fixed to the wheels 23 and a caliper 43 having pistons 42 for urging the brake pads. A master cylinder (not shown) or the like is connected to the caliper 43 via a brake pipe 44. When the driver depresses the brake pedal, brake fluid pressure is supplied from the master cylinder to the caliper 43, and the brake fluid The pressure pushes the piston 42 and brakes the disc rotor 41 .

Also, the caliper 43 is provided with a parking actuator 45 having an electric motor for pushing the piston 42 . By driving the parking actuator 45, the piston 42 can be pushed out toward the disc rotor 41, so that the disc rotor 41 can be braked even when the brake fluid pressure is not supplied. When the parking range (P range) is selected by operating a select lever, which will be described later, the parking actuator 45 is controlled by the controller 50, the piston 42 is pushed out, and the disk rotor 41 is braked. Thus, the brake device 40 having the parking actuator 45 functions as an electric parking brake.

[Control system]
As shown in FIG. 1, the vehicle control device 10 includes a controller 50 such as a microcomputer to control a power train 15, a brake device 40 (hereinafter referred to as an electric parking brake 40), a parking lock mechanism 30, and the like. have. The controller 50 includes an engine control unit 51 that controls the engine 12, a transmission control unit 52 that controls the valve unit 18 of the transmission 14, a parking lock control unit 53 that controls the parking lock mechanism 30, and an electric parking brake 40. A parking brake control unit 54 and a notification control unit 55 for notifying the driver of an abnormal situation, which will be described later, are provided.

Various sensors are connected to the controller 50 . Sensors connected to the controller 50 include an accelerator sensor 60 that detects the amount of operation of the accelerator pedal, a brake sensor 61 that detects the amount of operation of the brake pedal, a vehicle speed sensor 62 that detects the vehicle speed, and a slope sensor 63 that detects the road slope. etc. Furthermore, as a sensor connected to the controller 50, there is a position detection sensor 64 for detecting the operation position of a select lever 70, which will be described later, and a parking switch 65 operated by the driver when selecting the parking range (P range). There is

[Control range]
A plurality of control ranges for controlling the operating state of the power train 15 are set in the vehicle 11 . These control ranges include a forward range for forward travel (D range, travel range), a reverse range for reverse travel (R range, travel range), a neutral range for power cutoff (N range), and a parking range for parking. (P range). Of these control ranges, the D range, R range, and N range are selected by the driver operating a select lever 70, which will be described later. The P range is selected by operating the parking switch 65 by the driver.

As shown in FIG. 1, the vehicle control device 10 includes a lever unit 71 having a select lever 70 operated by the driver to select a control range (D range, R range, N range). is provided. For example, when the driver operates the select lever 70 to the forward position PD, the D range is selected as the control range. Also, when the driver operates the select lever 70 to the reverse position PR, the R range is selected as the control range. Furthermore, when the driver operates the select lever 70 to the neutral position PN, the N range is selected as the control range. The lever unit 71 is a so-called momentary lever unit in which the select lever 70 returns to the home position PH after manual operation.

When the D range is selected by the select lever operation (selection operation), the valve unit 18 is controlled by the controller 50, the forward clutch of the forward/reverse switching mechanism 16 is engaged, and the reverse brake is released. When the R range is selected by operating the select lever, the valve unit 18 is controlled by the controller 50, the forward clutch of the forward/reverse switching mechanism 16 is released, and the reverse brake is engaged. Further, when the N range is selected by operating the select lever or when the P range is selected by operating the parking switch, the controller 50 controls the valve unit 18 so that the forward clutch and reverse brake of the forward/reverse switching mechanism 16 are controlled. are released together.

Further, when the D range, R range, or N range is selected by operating the select lever, the lock actuator 34 is controlled by the controller 50, and the parking lock mechanism 30 is controlled to be released. Further, when the P range is selected by the parking switch operation (selection operation), the lock actuator 34 is controlled by the controller 50, and the parking lock mechanism 30 is controlled to be locked.

[Brake hold control]
Next, brake hold control by the controller 50 will be described. The vehicle control device 10 has a brake hold function for holding the stopped state when the vehicle is stopped in the D range. That is, the vehicle control device 10 controls the parking actuator 45 by the controller 50 when the driver depresses the brake pedal to stop the vehicle 11 while the D range, which is the driving range, is selected. By braking the disk rotor 41 with the caliper 43, the stopped state is maintained. Such brake hold control is also called auto brake hold control or hill hold control. By the way, when the road surface slope is large or the load is large, it may be difficult to maintain the stopped state by the brake hold control. Therefore, the vehicle control device 10, which is an embodiment of the present invention, executes the above-described brake hold control so as to maintain the stopped state even when the road surface slope is large or the load is large. are doing.

Here, FIGS. 2 and 3 are flow charts showing an example of the execution procedure of the brake hold control. The flow charts shown in FIGS. 2 and 3 are connected to each other at point A. FIG. As shown in FIG. 2, in step S10, it is determined whether or not the control range is the D range. When it is determined in step S10 that the control range is the D range, the process proceeds to step S11, in which it is determined whether or not the driver is performing a brake operation, that is, whether or not the brake pedal is depressed. be. If it is determined in step S11 that the brake operation is being performed, the process proceeds to step S12, in which it is determined whether or not the vehicle 11 is in a stopped state, that is, whether or not the vehicle speed is 0 [km/h]. be judged.

When it is determined in step S12 that the vehicle is stopped, the process proceeds to step S13, in which the piston 42 is pushed out by the parking actuator 45, and the electric parking brake 40 is controlled to the braking state. By controlling the electric parking brake 40 to the braking state in this manner, the stopped state can be maintained even when the brake operation is released, and the driving operation of the vehicle 11 can be simplified. Subsequently, in step S14, it is determined whether or not the accelerator operation (starting operation) is performed by the driver, that is, whether or not the accelerator pedal is depressed. When it is determined in step S14 that the accelerator operation is being performed, the process proceeds to step S15, the piston 42 is returned by the parking actuator 45, and the braking state of the electric parking brake 40 is released. In this manner, when the accelerator operation is performed by the driver, the braking state of the electric parking brake 40 is released in preparation for the start of the vehicle.

On the other hand, if it is determined in step S14 that the accelerator operation is not performed, the process proceeds to step S16, in which it is determined whether or not the vehicle speed exceeds a predetermined first threshold value V1 (for example, several km/h). be. If it is determined in step S16 that the vehicle speed is equal to or less than the first threshold value V1, that is, if it is determined that the vehicle is being stopped, the process proceeds to step S13, where the electric parking brake 40 continues to be applied. be. On the other hand, if it is determined in step S16 that the vehicle speed exceeds the first threshold value V1, that is, if it is determined that the vehicle 11 that has been held in a stopped state has started to move without operating the accelerator, 2, the control range is automatically switched to the P range, and the parking lock mechanism 30 is controlled to be locked.

Here, FIGS. 4A and 4B are diagrams showing operating states of the electric parking brake 40 and the parking lock mechanism 30 in brake hold control. As shown in FIG. 4A , when the vehicle 11 stops on an uphill or the like, the controller 50 outputs a braking command to the brake actuator, and the controller 50 outputs a release command to the lock actuator 34 . As a result, the piston 42 is pushed out by the parking actuator 45 and the wheels 23 are braked by the electric parking brake 40, so that the stopped state can be maintained even when the braking operation is released. In the situation shown in FIG. 4A, the parking lock mechanism 30 is controlled to be in the released state.

Subsequently, as indicated by an arrow α in FIG. 4B, when the vehicle 11 that has been held in a stopped state by the electric parking brake 40 starts to move, the controller 50 outputs a lock command to the lock actuator 34. be done. As a result, the lock actuator 34 moves the lock lever 32 to the engagement position, so that the parking lock mechanism 30 prohibits rotation of the power transmission path 24 . By controlling the parking lock mechanism 30 to the locked state in this manner, the vehicle 11 that has begun to move on an uphill or the like can be stopped again, and the stopped state by the brake hold function can be appropriately maintained.

Also, as shown in FIG. 3, when the parking lock mechanism 30 is controlled to be locked in step S17, the process proceeds to step S18, and the controller 50 notifies the driver of the abnormal situation. In other words, when the vehicle 11 starts to move, the driver is notified of a situation in which the parking lock mechanism 30 is controlled to the locked state, ie, an abnormal situation in which the electric parking brake 40 does not hold the stopped state. In step S18, the abnormal situation may be notified by emitting a warning sound, or may be notified by displaying a warning.

Next, in step S19, it is determined whether or not the driver is operating the accelerator. If it is determined in step S19 that the accelerator is being operated, the process proceeds to step S20, the control range is automatically switched to the D range, and the parking lock mechanism 30 is controlled to be released. That is, the controller 50 controls the parking lock mechanism 30 to the locked state when the vehicle 11 starts to move, and then controls the parking lock mechanism 30 to the released state when the driver operates the accelerator. Further, when it is determined in step S19 that the accelerator is being operated, the process proceeds to step S21 via step S20, the piston 42 is returned by the parking actuator 45, and the braking by the electric parking brake 40 is released. . In this manner, when the accelerator operation is performed by the driver, the locked state of the parking lock mechanism 30 and the braking state of the electric parking brake 40 are released in preparation for starting the vehicle.

On the other hand, if it is determined in step S19 that the accelerator operation is not performed, the process proceeds to step S22, in which it is determined whether or not the vehicle speed exceeds a predetermined second threshold value V2 (for example, several km/h). be. If it is determined in step S22 that the vehicle speed is equal to or less than the second threshold value V2, that is, if it is determined that the vehicle is kept stopped by the locked state of the parking lock mechanism 30, the process proceeds to step S17, and the parking lock is performed. The locked state of mechanism 30 continues. On the other hand, if it is determined in step S22 that the vehicle speed exceeds the second threshold value V2, that is, if it is determined that the vehicle 11 continues to move, the process proceeds to step S23, and the control range is automatically changed to the D range. , and the parking lock mechanism 30 is controlled to be in the released state.

In this way, the controller 50 controls the parking lock mechanism 30 to be locked when the vehicle 11 starts to move, and then controls the parking lock mechanism 30 to be released when the vehicle 11 continues to move. That is, when the vehicle speed increases and the rotation speed of the parking gear 31 increases, it is already difficult to control the parking lock mechanism 30 to the locked state. The parking lock mechanism 30 is controlled to be in the released state. In step S23, when the parking lock mechanism 30 is controlled to be in the released state, the driver is encouraged to depress the brake pedal by using a warning sound or the like.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. In the illustrated example, the parking lock mechanism 30 is provided inside the transmission 14 , but the present invention is not limited to this, and the parking lock mechanism 30 may be provided outside the transmission 14 . Further, in the illustrated example, a disk brake is used as the brake device 40, but the brake device 40 is not limited to this, and a drum brake may be used. Also, in the illustrated example, the parking actuator 45 is assembled integrally with the caliper 43 , but the present invention is not limited to this, and the parking actuator 45 may be separated from the caliper 43 . In this case, for example, the caliper 43 and the parking actuator 45 are connected via a cable, and the parking actuator 45 operates the cable to control the caliper 43 .

In the above description, the driver operates the parking switch 65 to select the P range as the control range, but the present invention is not limited to this, and the P range may be selected by operating the select lever. In the above description, the brake hold control is executed under the condition that the D range is selected. may be executed. Further, as shown in FIGS. 2 and 3, the first threshold V1 and the second threshold V2 are used in brake hold control, but the first threshold V1 and the second threshold V2 may be set to the same value. , the second threshold V2 may be set higher than the first threshold V1.

In the above description, the controller 50 is provided with the engine control unit 51, the mission control unit 52, the parking lock control unit 53, the parking brake control unit 54, and the notification control unit 55, but is not limited to this. For example, each control unit 51-55 may be provided in another controller, or each control unit 51-55 may be provided separately in a plurality of controllers.

10 vehicle control device 11 vehicle 23 wheel 24 power transmission path 30 parking lock mechanism 40 brake device (electric parking brake)
53 parking lock control unit 55 notification control unit

Claims (4)

A vehicle control device having a brake hold function for holding a stopped state,
A parking lock mechanism that is controlled into a locked state that prohibits rotation of a power transmission path connected to wheels and a released state that allows rotation of the power transmission path;
a parking lock control unit that controls the parking lock mechanism to a locked state when a parking range is selected by a driver's selection operation;
has
The parking lock control unit, when the vehicle held in a stopped state starts to move without the driver's starting operation in a state where the driving range is selected by the driver's selection operation, Control the parking lock mechanism to the locked state,
The parking lock control unit controls the parking lock mechanism to a locked state when the vehicle starts to move, and then controls the parking lock mechanism to a released state when the vehicle continues to move.
Vehicle controller. In the vehicle control device according to claim 1,
an electric parking brake that brakes the wheels to hold the vehicle in a stopped state when the vehicle is stopped by the driver's brake operation;
The parking lock control unit controls the parking lock mechanism to a locked state when the vehicle held in a stopped state by the electric parking brake starts to move.
Vehicle controller. In the vehicle control device according to claim 1 or 2 ,
The parking lock control unit controls the parking lock mechanism to a locked state when the vehicle starts to move, and then controls the parking lock mechanism to a released state when the driver operates the accelerator.
Vehicle controller. In the vehicle control device according to any one of claims 1 to 3 ,
a notification control unit that notifies a driver of an abnormal situation when the parking lock mechanism is controlled to be in a locked state by the vehicle starting to move;
Vehicle controller.

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