JP6617503B2 - Vehicle control apparatus and vehicle control method - Google Patents

Description

  The present invention relates to a vehicle control device and a vehicle control method.

  Conventionally, an idling stop-and-start control technology that temporarily stops an engine when a predetermined engine stop condition is satisfied and restarts the engine when a predetermined engine restart condition is satisfied during operation of the vehicle engine is known. It's being used.

  For example, Patent Document 1 confirms the driver's intention to decelerate or stop based on the depression amount of the driver's brake pedal and confirms that the vehicle is in a stopped state based on the detection value of the vehicle speed sensor. In such a case, a technique is disclosed in which the engine is automatically stopped and the engine is automatically restarted when the driver's intention to start is confirmed based on the amount of depression of the brake pedal.

  Further, in Patent Document 1, when the engine is automatically stopped, the automatic transmission is automatically switched to the neutral state to cut off the engine power, and the brake is generated so as to generate a braking force for maintaining the vehicle in the stopped state. A technique for automatically controlling the apparatus is disclosed.

JP2013-129378A

  However, when the brake device is automatically controlled using the technique of Patent Document 1 described above so that the braking force for maintaining the vehicle in a stopped state is generated, the minimum amount of braking force that can be generated is the vehicle. It is difficult to predict in advance whether it can be maintained in a stopped state.

  In addition, it may be possible to detect whether the vehicle is in a stopped state and further increase the braking force when the vehicle is not in a stopped state. The vehicle slips down at.

  The present invention has been made in view of the above problems, and its problem is to prevent the vehicle from moving when executing an idling stop on a slope or the like, and to prevent the vehicle from moving in a place where the vehicle stops. It is an object to provide a vehicle control device and a vehicle control method that can easily determine a braking force required to achieve the above.

  In order to solve the above-described problem, the vehicle control device according to the present invention is configured such that the brake pressure generated when the shift stage is the traveling stage and the brake pedal is depressed during the operation of the vehicle engine is the first brake. When a predetermined engine stop condition that includes greater than the pressure is satisfied, an automatic stop control unit that temporarily stops the engine, and a second brake pressure that is greater than the first brake pressure is generated when the brake pedal is depressed, In addition, when the engine is temporarily stopped in a state where the shift stage is the traveling stage, the braking device for braking the vehicle is controlled to maintain the second brake pressure, and after the engine is temporarily stopped, the traveling stage is changed to neutral. A brake control unit that maintains the brake pressure at a constant pressure equal to or higher than the second brake pressure when the shift operation is received.

  The vehicle control method of the present invention is a predetermined control method including that a gear position is a traveling speed during operation of a vehicle engine and a brake pressure generated by depressing a brake pedal is greater than a first brake pressure. When the engine stop condition is satisfied, an automatic stop control step for temporarily stopping the engine, a second brake pressure larger than the first brake pressure is generated by depressing the brake pedal, and the shift speed is the travel speed. When the engine is temporarily stopped in a certain state, the brake device that brakes the vehicle is controlled to maintain the second brake pressure, and after the engine is temporarily stopped, the shift operation from the travel stage to the neutral is accepted. And a braking control step of maintaining the brake pressure at a constant pressure equal to or higher than the second brake pressure.

  According to the present invention, it is possible to prevent a vehicle from moving when executing an idling stop on a slope or the like, and to easily determine a braking force necessary to prevent the vehicle from moving when the vehicle stops. be able to.

It is a figure showing an example of composition of vehicles concerning one embodiment of the present invention. It is a flowchart which shows an example of the process sequence of the vehicle control process which concerns on one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an example of a configuration of a vehicle 1 according to an embodiment of the present invention. The vehicle 1 is, for example, a vehicle such as a truck or a bus.

  As shown in FIG. 1, a vehicle 1 includes an engine 2, a transmission 3 connected to the engine 2 via a clutch, a braking device 4 that applies a braking force to the vehicle 1, and a driver for braking the vehicle 1. A brake pedal 9 that accepts a depression operation, a brake valve 10 that transmits air pressure according to the depression amount of the brake pedal 9, an engine 2, a transmission 3, and a vehicle control device 11 that controls the braking device 4 are provided.

  The engine 2 is started by a starter, and operates by injecting fuel into a combustion chamber by an injector.

  The transmission 3 has a plurality of selectable shift stages such as a driving stage such as a drive (D), neutral (N), and parking (P), and is connected to the engine 2 via a clutch (not shown). Then, the power of the engine 2 is transmitted to wheels (not shown). In the following description, the traveling stage is described as being a drive, but the present invention can also be applied to other traveling stages.

  The braking device 4 is a device that decelerates or stops the vehicle 1. Hereinafter, the brake device 4 will be described as a pneumatic type, but other types may be used. The braking device 4 includes a braking unit 5, an HSA valve 6, a relay valve 7, and a pressure sensor 8.

  The braking unit 5 is a service brake that exerts a braking force according to the magnitude of the brake pressure generated due to the depression of the brake pedal 9 and brakes the rotation of the wheels of the vehicle 1.

  The HSA (Hill Start Aid) valve 6 is used as a slope start assisting device, and operates when the vehicle starts on a slope, for example, to maintain the brake pressure, thereby causing the braking unit 5 to exert a braking force.

  The relay valve 7 sends air from an air tank (not shown) to the braking unit 5 according to the magnitude of the brake pressure transmitted from the brake valve 10 via the HSA valve 6, and exerts braking force on the braking unit 5. Let

  The pressure sensor 8 detects the brake pressure in the brake pipe between the HSA valve 6 and the relay valve 7. This brake pressure is referred to when determining whether or not the engine stop condition is satisfied. Note that the pressure sensor 8 may detect the brake pressure in the brake pipe between the brake unit 5 and the relay valve 7 as the brake pressure.

  The brake pedal 9 is depressed by the driver to operate the braking unit 5. When the brake pedal 9 is depressed by the driver, the braking force is exerted by the braking unit 5 according to the magnitude of the brake pressure caused by the depression of the brake pedal 9.

  The brake valve 10 releases the air in the air tank according to the depression amount of the brake pedal 9. The brake pressure generated due to the release of air is transmitted to the relay valve 7 via the HSA valve 6.

The vehicle control device 11 includes an engine control unit 12, an ISS (Idling Stop and
A start control unit 13, a shift control unit 16, and a braking control unit 17. Each of these control units is connected to a common bus and configured to be able to communicate with each other through the bus.

  The engine control unit 12 acquires information such as the rotation speed of the engine 2, performs start-up control of the engine 2, and controls fuel injection timing and fuel injection amount of the engine 2.

  The ISS control unit 13 performs idling stop and start control. The ISS control unit 13 includes an automatic stop control unit 14 and a restart control unit 15.

  The automatic stop control unit 14 outputs a temporary stop command of the engine 2 to the engine control unit 12 and stops the engine 2 to the engine control unit 12 when a predetermined engine temporary stop condition is satisfied during operation of the engine 2. Let

  The engine temporary stop condition includes, for example, a condition that the vehicle speed of the vehicle 1 is zero and the brake pressure generated by the depression of the brake pedal 9 is larger than a predetermined pressure.

  The restart control unit 15 restarts the engine 2 when a predetermined engine restart condition is satisfied while the engine 2 is temporarily stopped.

  The engine restart condition includes, for example, a neutral state in which the brake pedal 9 is not depressed or the brake pressure generated by the depression of the brake pedal 9 is smaller than a predetermined pressure when the engine 2 is temporarily stopped. This includes conditions such as a shift operation to the drive.

  The shift control unit 16 performs acquisition of information such as the current shift stage, and shift speed change control for the transmission 3. Here, the gear position is determined based on the operation of the shift lever by the driver or the automatic shift control according to the vehicle speed or the like.

The braking control unit 17 controls the braking device 4 to control the vehicle 1. In particular, when the engine 2 is temporarily stopped in a state where the gear position is the drive, the braking control unit 17
By controlling the SA valve 6 to maintain the brake pressure generated when the brake pedal 9 is depressed, and after the engine 2 is temporarily stopped, the brake pressure is increased when the driver performs a shift operation from drive to neutral. Continue to maintain.

  Here, the advantage of the brake pressure maintenance control will be described. For example, it is assumed that a condition that the brake pressure is greater than a is included in one of the conditions (conditions for executing idling stop) in which the engine 2 is temporarily stopped when the gear position is in the drive state.

  Further, it is assumed that the condition that the brake pressure is less than b (b <a) is included in one of the conditions for restarting the engine 2 in the temporarily stopped state (condition for returning from the idling stop).

  Here, as a result of the shift stage being a drive and the driver depressing the brake pedal 9, the brake pressure in the brake piping between the brake valve 10 and the HSA valve 6 becomes c (c> a), and the engine 2 Consider the case of a paused state.

  In this case, the HSA valve 6 is operated, and the brake pressure in the brake pipe between the relay valve 7 and the HSA valve 6 is maintained at c. As a result, a pressure corresponding to the brake pressure c is applied to the braking unit 5.

  Thereafter, it is assumed that the driver reduces the amount of depression of the brake pedal 9 and the brake pressure in the brake pipe between the brake valve 10 and the HSA valve 6 becomes d (c> d> b). In this state, the brake pressure in the brake pipe between the relay valve 7 and the HSA valve 6 is maintained at c, and the engine 2 is also stopped.

  However, after that, when the driver changes the gear position from drive to neutral, if the maintenance of the brake pressure by the HSA valve 6 is released, the brake pressure in the brake pipe between the relay valve 7 and the HSA valve 6 is reduced. There is a possibility that the vehicle 1 will move on the slope because of the decrease from c to d.

  Therefore, in the present invention, even when the driver changes the gear position from drive to neutral, the maintenance of the brake pressure by the HSA valve 6 is not released and the brake pressure of c is maintained. Thereby, it can prevent that the vehicle 1 moves on a slope.

  The brake pressure c maintained here is a brake pressure when the driver depresses the brake pedal 9 and the engine 2 is temporarily stopped. The brake pressure c is set by the driver as a brake pressure necessary to prevent the vehicle 1 from moving when the vehicle 1 is stopped. The braking force corresponding to the brake pressure c is the vehicle 1. It can be said that the braking force is necessary to prevent the movement of the vehicle.

  In the present invention, by using the brake pressure c set by the driver, the braking force necessary for preventing the vehicle 1 from moving during the idling stop can be easily obtained without requiring a complicated calculation. Can be determined.

  Returning to the description of the brake control unit 17, the brake control unit 17 further ends the control for maintaining the brake pressure described above when the gear position is neutral and the brake pedal 9 is not depressed, and the brake pressure Is changed according to the depression amount of the brake pedal 9.

  As a result, the driver can easily release the control for maintaining the brake pressure simply by removing his / her foot from the brake pedal 9, and the convenience can be improved.

  When the driver lifts his / her foot from the brake pedal 9, the braking force is not applied to the vehicle 1, and the vehicle 1 moves on the slope, but the driver sets the gear position to neutral and the brake pedal 9 Since it is considered that the driver has allowed the vehicle 1 to move when the foot is lifted, such a state can be said to be consistent with the driver's intention.

  Next, an example of a processing procedure of vehicle control processing according to an embodiment of the present invention will be described. FIG. 2 is a flowchart illustrating an example of a processing procedure of a vehicle control process according to an embodiment of the present invention.

  First, the automatic stop control unit 14 establishes one of the engine stop conditions that the second brake pressure detected by the pressure sensor 8 is larger than the first brake pressure as a threshold, and other engine stop conditions are satisfied. It is determined whether or not it is established (step S11).

  If the second brake pressure is not greater than the first brake pressure or other engine stop conditions are not satisfied (NO in step S11), the process of step S11 is executed again.

  When the second brake pressure is greater than the first brake pressure and another engine stop condition is satisfied (YES in step S11), the automatic stop control unit 14 controls the engine 2 with respect to the engine control unit 12. A stop command is output, and the engine control unit 12 performs idling stop to stop the engine 2, and the brake control unit 17 operates the HSA valve 6 to maintain the second brake pressure (step S12).

  Next, the braking control unit 17 determines whether or not a shift operation from the drive (D) to the neutral (N) has been performed by the driver (step S13).

  When the shift operation from the drive to the neutral is not performed (NO in step S13), the process of step S13 is executed again.

  When a shift operation from the drive to the neutral is performed (YES in step S13), the brake control unit 17 continues to maintain the second brake pressure (step S14).

  Thereafter, the brake control unit 17 determines whether or not the brake pedal 9 is depressed by the driver based on the detection value of the pressure sensor 8 (step S15). This determination may be made based on the output of a switch or the like that detects depression of the brake pedal 9.

  When the brake pedal 9 is depressed by the driver (YES in step S15), the process of step S15 is executed again.

  When the brake pedal 9 is not depressed by the driver (NO in step S15), the braking control unit 17 releases the maintenance of the second brake pressure (step S16), and the braking force is not applied to the vehicle 1. State. Then, this vehicle control process is complete | finished.

  In the above-described embodiment, when the shift operation from the drive to the neutral is accepted after the engine 2 is temporarily stopped, the second brake pressure is maintained. The brake pressure may be maintained at a constant pressure that is larger than the brake pressure by a predetermined value. In this case, for example, by supplying air from the air tank, the brake pressure may be adjusted to be higher than the brake pressure maintained so far.

  Also in this case, the second brake pressure generated by the driver depressing the brake pedal 9 in order to prevent the vehicle 1 from moving when the vehicle 1 is stopped is set as a lower limit, and is constant larger by a predetermined value than that. Since the pressure is determined as the pressure to be maintained, it is possible to easily determine the braking force required to prevent the vehicle 1 from moving when the idling stop is performed without requiring a complicated calculation.

  As described above, according to the present embodiment, the automatic stop control unit 14 of the vehicle control device 11 is in the travel stage and the brake pedal 9 is depressed while the engine 2 of the vehicle 1 is in operation. When a predetermined engine stop condition including that the brake pressure generated by the above is greater than the first brake pressure is satisfied, the engine 2 is temporarily stopped and the brake control unit 17 is depressed by depressing the brake pedal 9. When a second brake pressure larger than the first brake pressure is generated and the engine 2 is temporarily stopped in a state where the shift speed is the traveling speed, the braking device 4 that brakes the vehicle 1 is controlled to control the second braking pressure. The brake pressure is maintained at a constant pressure equal to or higher than the second brake pressure when a shift operation from the travel stage to the neutral is accepted after the engine 2 is temporarily stopped. As a result, it is possible to prevent the vehicle from moving when executing idling stop on a slope or the like, and it is possible to easily determine a braking force necessary to prevent the vehicle from moving in a place where the vehicle stops. .

  Further, according to the present embodiment, the braking control unit 17 controls the braking device 4 to receive the second brake pressure when the shifting operation from the traveling stage to the neutral is received after the engine 2 is temporarily stopped. Maintain brake pressure. In this case as well, it is possible to prevent the vehicle from moving when performing idling stop on a slope or the like, and to easily determine the braking force necessary to prevent the vehicle from moving when the vehicle stops. it can.

  Further, according to the present embodiment, the braking control unit 17 ends the control to maintain the brake pressure at a constant pressure when the shift speed is neutral and the brake pedal 9 is no longer depressed, and the brake pressure Is changed according to the depression amount of the brake pedal 9. As a result, the driver can easily release the control for maintaining the brake pressure simply by removing his / her foot from the brake pedal 9, and the convenience can be improved.

  In this case, the braking force is not applied to the vehicle 1 and the vehicle 1 moves on the slope, but the driver sets the gear position to neutral and releases his foot from the brake pedal 9. It can be said that this situation is consistent with the driver's intention, since it is considered that 1 is allowed to move.

  The present invention can be used in a vehicle control device and a vehicle control method for maintaining a brake pressure at an idling stop when the shift speed is a traveling speed.

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 3 Transmission 4 Braking device 5 Braking part 6 HSA valve 7 Relay valve 8 Pressure sensor 9 Brake pedal 10 Brake valve 11 Vehicle control device 12 Engine control part 13 ISS control part 14 Automatic stop control part 15 Restart control part 16 Transmission control unit 17 Braking control unit

Claims (4)

When a predetermined engine stop condition is satisfied, including the fact that the shift speed is the travel speed and the brake pressure generated by depressing the brake pedal is greater than the first brake pressure during operation of the vehicle engine. An automatic stop control unit for temporarily stopping the engine;
When the brake pedal is depressed, a second brake pressure greater than the first brake pressure is generated, and the vehicle is braked when the engine is temporarily stopped in a state where the shift speed is the travel speed. The brake device is controlled to maintain the second brake pressure, and after a temporary stop of the engine, when a shifting operation from the travel stage to the neutral is accepted, the pressure is set to a constant pressure equal to or higher than the second brake pressure. A braking control unit for maintaining the brake pressure;
A vehicle control device comprising:   The brake control unit controls the brake device to maintain the brake pressure at the second brake pressure when a shift operation from the travel stage to the neutral is received after the engine is temporarily stopped. The vehicle control device according to 1. 3. The vehicle control according to claim 1, wherein the brake control unit ends the control for maintaining the brake pressure at the constant pressure when the shift speed is neutral and the brake pedal is not depressed. apparatus. When a predetermined engine stop condition is satisfied, including the fact that the shift speed is the travel speed and the brake pressure generated by depressing the brake pedal is greater than the first brake pressure during operation of the vehicle engine. An automatic stop control step for temporarily stopping the engine;
When the brake pedal is depressed, a second brake pressure greater than the first brake pressure is generated, and the vehicle is braked when the engine is temporarily stopped in a state where the shift speed is the travel speed. The brake device is controlled to maintain the second brake pressure, and after a temporary stop of the engine, when a shifting operation from the travel stage to the neutral is accepted, the pressure is set to a constant pressure equal to or higher than the second brake pressure. A braking control step for maintaining the brake pressure;
A vehicle control method.