WO2012029773A1

WO2012029773A1 - Vehicle control device and vehicle control method

Info

Publication number: WO2012029773A1
Application number: PCT/JP2011/069595
Authority: WO
Inventors: 陽介橋本; 陽介大森; 雪生森; 政義武田
Original assignee: 株式会社アドヴィックス
Priority date: 2010-08-30
Filing date: 2011-08-30
Publication date: 2012-03-08
Also published as: JP5776153B2; CN103228514B; JP2012047153A; DE112011102870B4; CN103228514A; DE112011102870T5

Abstract

A vehicle control device including a first control unit (55, S12, S13) and a second control unit (55) is provided. The first control unit permits the automatic stop of an engine (12) when a stop condition of the engine (12) is satisfied, and permits the restart of the engine (12) when a restart condition of the engine (12) is satisfied. The second control unit (55, S32, S33) performs first braking control for increasing braking force for wheels (FR, FL, RR, RL) when detecting that the start of the engine (12) is in a bad condition after the restart of the engine (12) is permitted. Then, the second control unit performs second braking control for holding the braking force for the wheels (FR, FL, RR, RL). The first control unit (55, S12, S13, S31, S34) prohibits the restart of the engine (12) during the execution of the first braking control, and permits the restart of the engine (12) during the execution of the second braking control.

Description

Vehicle control apparatus and vehicle control method

The present invention is a control apparatus for a vehicle that permits automatic stop of the engine when a stop condition of the engine of the vehicle is satisfied, and permits restart of the engine when a restart condition of the engine is satisfied. The present invention relates to a control method of a vehicle.

In recent years, it has a so-called idle stop function that automatically stops the engine during or immediately before the stop of the vehicle for the purpose of improving the fuel efficiency of the vehicle, etc., and automatically restarts the engine upon start operation by the driver. Development of control devices for vehicles is underway. For example, in the vehicle control device described in Patent Document 1, braking is performed such that the negative pressure in the booster for assisting the braking operation by the driver becomes less than a predetermined threshold when the engine is automatically stopped. Allows engine restart when it detects that an operation has been performed. The booster is connected to an intake manifold that generates negative pressure when the engine is driven. The booster uses the pressure difference between the negative pressure generated in the intake manifold and the atmospheric pressure to boost the operation force of the brake pedal by the driver.

By the way, when the storage amount of the battery mounted on the vehicle is small, or when the starter motor that operates when starting the engine is malfunctioning, it takes time until the restart of the engine is completed, It may not be possible to restart the engine. Such a state is also referred to as "engine start failure state".

When the engine is in the start-up malfunction state, the driver may repeatedly perform the stepping operation and releasing operation of the brake pedal to prompt the restart of the engine. Then, the negative pressure in the booster decreases due to the repetition of the stepping and releasing operations of the brake pedal, and the braking force on the wheel decreases due to the insufficient negative pressure in the booster. As a result, when the vehicle is located on a slope, the vehicle may start moving against the driver's intention.

In addition, when the engine is automatically stopped while the vehicle is decelerating, the negative pressure in the booster decreases due to the adjustment of the operation amount of the brake pedal by the driver for the purpose of adjusting the vehicle deceleration after the engine stops. There is something to do. In this case, the negative pressure in the booster may be reduced immediately before the vehicle stops. Therefore, when the vehicle is located on a slope, there is a possibility that the vehicle can not be stopped against the driver's intention due to the insufficient braking force to the wheels caused by the insufficient negative pressure in the booster.

Therefore, in the control device described in Patent Document 1, when the start-up malfunction of the engine is detected, the pump of the brake actuator is operated to increase the braking force on the wheels. As a result, the movement of the vehicle against the driver's intention is suppressed. Then, in a state where the safety of the vehicle is secured as described above, control for restarting the engine is performed.

JP 2003-13768 A

By the way, in the control device for a vehicle described in Patent Document 1, when the start-up malfunction of the engine is detected, the restart of the engine is permitted even while the braking force on the wheels is increased. Therefore, there is a possibility that the braking control for increasing the braking force on the wheels and the control for restarting the engine may overlap in time. In this case, power is supplied from the battery to the pump of the brake actuator that operates to increase the braking force on the wheels, and to the starter motor that operates to start the engine, increasing the load on the battery. There was a risk of

An object of the present invention is to provide a control apparatus and a control method of a vehicle capable of restarting an engine in a state in which the safety of the vehicle is secured while reducing a load of a battery mounted on the vehicle. It is in.

In order to achieve the above object, according to one aspect of the present invention, there is provided a control device of a vehicle including a first control unit (55, S12, S13) and a second control unit (55). The first control unit permits the automatic stop of the engine (12) when the stop condition of the engine (12) of the vehicle is satisfied and the restart condition of the engine (12) is satisfied. Allow the engine (12) to restart. The second control unit adjusts a braking force on wheels (FR, FL, RR, RL) provided in the vehicle. The second control unit (55, S32, S33) detects the start failure of the engine (12) after permitting the restart of the engine (12), the wheels (for stopping the vehicle) A first braking control is performed to increase the braking force on FR, FL, RR, and RL). Thereafter, the second control unit performs a second braking control for holding the braking force on the wheels (FR, FL, RR, RL). The first control unit (55, S12, S13, S31, S34) prohibits restart of the engine (12) during execution of the first braking control, and executes the second braking control. During this time, the engine (12) is allowed to restart.

According to the above-mentioned configuration, when the engine starting malfunction is detected, the restart of the engine is inhibited and the braking force on the wheels is increased to stop the vehicle. Thereafter, when the braking force on the wheels is maintained, engine restart is permitted. That is, overlapping in time between braking control for increasing the braking force on the wheels and control for restarting the engine is avoided. In addition, even if the negative pressure in the booster is reduced, the engine is restarted with the braking force applied to the wheels that can stop the vehicle. Therefore, it is possible to restart the engine while securing the safety of the vehicle while reducing the load of the battery mounted on the vehicle.

Preferably, during the execution of the second braking control, the second control unit (55, S32, S33, S37) reduces the amount of operation of the brake pedal (15) provided to the vehicle, or The third braking control for permitting the movement of the vehicle by decreasing the braking force on the wheels (FR, FL, RR, RL) when detecting that the brake pedal (15) has become inoperative Do.

The case where the operation amount of the brake pedal is reduced or the brake pedal is not operated is considered to be the case where the driver permits the movement of the vehicle due to inertia. Therefore, in the present invention, when it is detected that the operation amount of the brake pedal is reduced or the brake pedal is not operated in a state in which the vehicle is kept stopped by the second braking control, The braking force is reduced and movement of the vehicle due to inertia is permitted. Then, for example, when the vehicle is located on a slope, the vehicle moves downward in the inclination direction. That is, even if the engine is in a start-up malfunction, the behavior of the vehicle can be made in accordance with the driver's intention.

Preferably, in the third braking control, a braking force for the wheels (FR, FL, RR, RL) is set such that a vehicle body speed (VS) of the vehicle is less than a preset permission reference value (VSth). It is control to adjust.

In the case of engine start failure, there is a high possibility that the negative pressure in the booster has dropped. In this case, a sufficiently large braking force can not be applied to the wheels by the driver's operation of the brake pedal. Therefore, in the present invention, during the third braking control, the braking force on the wheels is adjusted such that the vehicle speed becomes less than the permission reference value. Therefore, it is possible to restart the engine while securing the safety of the vehicle, because it is possible to suppress the vehicle body speed of the vehicle from becoming too high.

Preferably, the vehicle includes a wheel cylinder (32a, 32b, 32c, 32d) for applying a braking force corresponding to fluid pressure generated inside the wheel cylinder to the wheel (FR, FL, RR, RL); And a brake actuator (31) for adjusting the fluid pressure in the cylinders (32a, 32b, 32c, 32d). The brake actuator (31) is a pump (42, 43) that operates to increase fluid pressure in the wheel cylinder (32a, 32b, 32c, 32d), and the wheel cylinder (32a, 32b, 32c, 32d) Control valves (35a, 35b) operated to adjust the fluid pressure in the The permission reference value is set to a value equal to or less than a control threshold (VSth) for permitting execution of the braking control accompanied by the operation of the pump (42, 43).

Preferably, the second control unit (55, S32, S33, S37) detects that the operation amount of the brake pedal (15) is increased during execution of the third braking control. And performing the first braking control.

According to the above configuration, even when the third braking control is being performed, when it is detected that the operation amount of the brake pedal is increased, the braking force on the wheels is increased to stop the vehicle. This is because that the operation amount of the brake pedal is increased, it is determined that the driver has the intention to stop the vehicle. Moreover, while the first braking control is performed to increase the braking force on the wheels, the restart of the engine is prohibited. Therefore, the vehicle can be stopped according to the driver's intention while reducing the load of the battery mounted on the vehicle.

Preferably, the first control unit (55, S12, S13, S31, S34) executes the number of restarts of the engine (12) after permitting the restart of the engine (12), or In the case where the engine (12) is not restarted even if the elapsed time after allowing the engine (12) to restart becomes equal to or more than a set number of times reference value (CTth) or time reference value (Tth), A start failure of the engine (12) is detected.

Preferably, a vehicle speed acquisition unit (55, S24) for acquiring a vehicle speed (VS) of the vehicle is further included. The first control unit (55, S12, S13, S31, S34) is a vehicle speed (VS) acquired by the vehicle speed acquisition unit (55, S24) after permission of restart of the engine (12). When the engine (12) is not restarted even if the vehicle speed exceeds a preset vehicle speed threshold (VSth), a start failure of the engine (12) is detected.

In a further aspect of the present invention, there is provided a control method of a vehicle comprising a stopping step (S12) and a restarting step (S13). The stop step (S12) permits the automatic stop of the engine (12) when the stop condition of the engine (12) of the vehicle is satisfied. The restart step (S13) permits restart of the engine (12) when a restart condition of the engine (12) is satisfied. The restart step includes a first step (S31, S32) and a second step (S33, S34). The first step (S31, S32) prohibits the restart of the engine (12) when the start failure of the engine (12) is detected after the permission of the restart of the engine (12). At the same time, the braking force on the wheels (FR, FL, RR, RL) provided on the vehicle to stop the vehicle is increased. The second step (S33, S34) holds the braking force on the wheel (FR, FL, RR, RL) after the execution of the first step (S31, S32), and the engine (12) Allow the restart of the

According to the above configuration, it is possible to obtain the same operation and advantage as the control device for the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows an example of the vehicle carrying the control apparatus which concerns on one Embodiment of this invention. FIG. 2 is a block diagram showing an example of the braking device of FIG. 1; The map which shows an example of the relationship between frequency reference value and a grade equivalent value. The flowchart which demonstrates an idle stop process routine. The flowchart (the first half part) explaining engine restart processing routine. The flowchart (second half part) explaining engine restart processing routine. The timing chart which shows change of engine number of rotations, body speed, frequency counter value, and target oil pressure. The map which shows an example of the relationship of the time reference value and gradient equivalent value in another embodiment.

An embodiment of the present invention will now be described with reference to FIGS. 1 to 7. In the following description of the present specification, the traveling direction (forward direction) of the vehicle will be described as the front (vehicle front).

The vehicle according to the present embodiment automatically stops the engine according to the establishment of a predetermined stop condition during traveling of the vehicle in order to improve the fuel efficiency performance and the emission performance, and then the engine according to the establishment of the predetermined start condition Has a so-called idle stop function that automatically restarts the Therefore, in this vehicle, the engine is automatically stopped during deceleration or stop by the driver's brake operation.

Next, an example of a vehicle having an idle stop function will be described.

As shown in FIG. 1, among the plurality of (four in this embodiment) wheels (right front wheel FR, left front wheel FL, right rear wheel RR and left rear wheel RL), the front wheels FR, FL are drive wheels. It is a so-called front wheel drive car that functions as Such a vehicle transmits a driving force generated by the driving force generator 13 to the front wheels FR, FL, and a driving force generator 13 having an engine 12 that generates a driving force according to the amount of operation of the accelerator pedal 11 by the driver. And a driving force transmission device 14. The vehicle is also provided with a braking device 16 for applying a braking force corresponding to the amount of operation of the brake pedal 15 by the driver to each of the wheels FR, FL, RR, and RL.

The driving force generation device 13 is provided with a fuel injection device (not shown) which is disposed in the vicinity of an intake port (not shown) of the engine 12 and has an injector for injecting fuel to the engine 12. The driving force generator 13 is driven based on control of an engine ECU 17 (also referred to as an “engine electronic control device”) having a CPU, a ROM, a RAM, and the like (not shown). The engine ECU 17 is electrically connected to an accelerator pedal operation amount sensor SE1 disposed in the vicinity of the accelerator pedal 11, and for detecting an operation amount of the accelerator pedal 11 by the driver, that is, an accelerator operation amount. . Then, the engine ECU 17 calculates the accelerator pedal operation amount based on the detection signal from the accelerator pedal operation amount sensor SE1, and controls the driving force generator 13 based on the calculated accelerator pedal operation amount and the like.

The driving force transmission device 14 controls the automatic transmission 18, the differential gear 19 for appropriately distributing the driving force transmitted from the output shaft of the automatic transmission 18 and transmitting it to the front wheels FR and FL, and the automatic transmission 18 And an AT ECU (not shown). The automatic transmission 18 includes a hydraulic drive power transmission mechanism 20 having a torque converter 20 a as an example of a fluid coupling, and a transmission mechanism 21.

In the vehicle of the present embodiment, the torque converter 20a is provided in the torque transmission path from the engine 12 to the drive wheels (front wheels FR, FL), so a creep phenomenon occurs. The creep phenomenon is a phenomenon in which, in a vehicle having an automatic transmission 18, when the shift lever is in the traveling position, the vehicle moves forward slowly without depressing the accelerator pedal 11, and this phenomenon is an idle of the engine 12 Sometimes, torque converter 20a generates a slight amount of driving force to transmit to front wheels FR and FL. And, a part of power transmitted to the front wheels FR, FL is called "creep torque".

As shown in FIGS. 1 and 2, the braking device 16 includes a hydraulic pressure generating device 28 having a master cylinder 25, a booster 26 and a reservoir 27, and a brake actuator 31 having two hydraulic circuits 29, 30 (in FIG. 2). (Indicated by a two-dot chain line). The respective

hydraulic circuits

29, 30 are connected to the master cylinder 25 of the hydraulic pressure generating device 28, respectively. A wheel cylinder 32a for the right front wheel FR and a wheel cylinder 32d for the left rear wheel RL are connected to the first hydraulic circuit 29, and a wheel for the left front wheel FL is connected to the second hydraulic circuit 30. A cylinder 32b and a wheel cylinder 32c for the right rear wheel RR are connected.

In the fluid pressure generating device 28, the booster 26 is connected to an intake manifold (not shown) that generates negative pressure when the engine 12 is driven. Then, the booster 26 boosts the operating force of the brake pedal 15 by the driver using the pressure difference between the negative pressure generated in the intake manifold and the atmospheric pressure.

Master cylinder 25 generates a master cylinder pressure (hereinafter also referred to as “MC pressure”) as a fluid pressure according to the operation of brake pedal 15 by the driver (hereinafter also referred to as “brake operation”). As a result, the master cylinder 25 supplies brake fluid as an example of fluid into the wheel cylinders 32a to 32d via the

hydraulic circuits

29, 30. Then, a braking force corresponding to the wheel cylinder pressure (also referred to as "WC pressure") in the wheel cylinders 32a to 32d is applied to the wheels FR, FL, RR, and RL.

In the brake actuator 31, the

hydraulic circuits

29, 30 are respectively connected to the master cylinder 25 via

connection paths

33, 34, and the

connection paths

33, 34 are normally open linear solenoid valves (

adjustment Valves

35a and 35b are provided respectively. The

linear solenoid valves

35a and 35b include a valve seat, a valve body, an electromagnetic coil, and a biasing member (eg, a coil spring) for biasing the valve body away from the valve seat, and the valve body will be described later It is displaced according to the magnitude of the current supplied from the brake ECU 55 to the electromagnetic coil, that is, the current value. That is, the WC pressure in the wheel cylinders 32a to 32d is maintained at a hydraulic pressure corresponding to the current value to the

linear solenoid valves

35a, 35b.

In addition, in one of the connection paths 33 and 34 (in the present embodiment, the connection path 33), the MC pressure in the master cylinder 25 is detected in a portion closer to the master cylinder 25 than the linear solenoid valve 35a. Pressure sensor SE8 is provided. The pressure sensor SE8 outputs a detection signal corresponding to the MC pressure to the brake ECU 55.

In the first hydraulic circuit 29, a right front wheel path 36a connected to the wheel cylinder 32a and a left rear wheel path 36d connected to the wheel cylinder 32d are formed. Further, in the second hydraulic circuit 30, a left front wheel path 36b connected to the wheel cylinder 32b and a right rear wheel path 36c connected to the wheel cylinder 32c are formed. Further, in the paths 36a to 36d, the WC pressures are set as pressure increase valves 37a, 37b, 37c, and 37d, which are normally open solenoid valves that operate when regulating the WC pressure increase in the wheel cylinders 32a to 32d.

Pressure reducing valves

38a, 38b, 38c, and 38d, which are normally closed solenoid valves that operate when reducing the pressure, are provided.

In the

hydraulic circuits

29, 30,

reservoirs

39, 40 for temporarily storing the brake fluid which has flowed out from the wheel cylinders 32a-32d via the pressure reducing valves 38a-38d, and a pump operated based on the rotation of the motor 41. 42 and 43 are connected. The

reservoirs

39 and 40 are connected to the pumps 42 and 43 through the

suction flow channels

44 and 45, and connected to the

connection paths

33 and 34 through the

master flow channels

46 and 47 more than the

linear solenoid valves

35a and 35b. It is connected to a portion near the master cylinder 25. The pumps 42 and 43 are connected to

connection portions

50 and 51 between the pressure increasing valves 37a to 37d and the

linear solenoid valves

35a and 35b in the

hydraulic circuits

29 and 30 through the

supply flow paths

48 and 49, respectively. There is. Then, when the motor 41 rotates, the pumps 42 and 43 suck the brake fluid from the

reservoirs

39 and 40 and the master cylinder 25 via the

suction flow paths

44 and 45 and the master

side flow paths

46 and 47, respectively. The brake fluid is discharged into the

supply channels

48, 49.

Next, the brake ECU 55 (also referred to as “brake electronic control device”) that controls the drive of the brake actuator 31 will be described.

As shown in FIG. 2, at the input side interface of the brake ECU 55, wheel speed sensors SE3, SE4, SE5, SE6 for detecting the wheel speeds of the respective wheels FR, FL, RR, RL, and the longitudinal direction of the vehicle An acceleration sensor (also referred to as a "G sensor") SE7 for detecting an acceleration at the point s. Is electrically connected. In addition, a brake switch SW1 disposed in the vicinity of the brake pedal 15 for detecting whether the brake pedal 15 is operated and a pressure sensor SE8 are electrically connected to the input side interface of the brake ECU 55. It is done. The

valves

35a, 35b, 37a to 37d, 38a to 38d and the motor 41 are electrically connected to the output side interface of the brake ECU 55. The acceleration sensor SE7 outputs a signal that gives a positive value when the center of gravity of the vehicle moves rearward, while a signal that gives a negative value when the center of gravity of the vehicle moves forward Is output.

Further, the brake ECU 55 is a digital computer including a CPU, a ROM, and a RAM (not shown), a valve driver circuit (not shown) for operating the

valves

35a, 35b, 37a to 37d and 38a to 38d, and a motor 41. (Not shown) for driving the motor. In the ROM of the digital computer, various control processes (idle stop process described later, etc.), various maps (map shown in FIG. 3 etc.), various threshold values, etc. are stored in advance. In addition, while the ignition switch (not shown) of the vehicle is on, the RAM stores various types of information that can be appropriately rewritten.

In the vehicle of the present embodiment, the ECUs including the engine ECU 17 and the brake ECU 55 are connected to one another via a bus 56 so as to transmit and receive various information and various control commands as shown in FIG. For example, from the engine ECU 17, information on the accelerator opening degree of the accelerator pedal 11, information on success / failure of restart of the engine 12, and the like are appropriately transmitted to the brake ECU 55. On the other hand, from the ECU 55 for brakes, a stop permission command for permitting the automatic stop of the engine 12, a restart permission command for permitting the automatic restart of the engine 12 and a reactivation for prohibiting the restart A start prohibition instruction or the like is transmitted to the engine ECU 17.

Next, various maps stored in the ROM of the brake ECU 55 will be described based on FIG.

Even if it is attempted to restart the engine 12 automatically, the engine 12 can not be restarted due to insufficient storage of a battery (not shown) mounted on the vehicle or malfunction of a starter motor (not shown). is there. In such a case, control for restarting the engine 12 is repeatedly performed. If the engine 12 can not be restarted even if the control for restarting the engine 12 is continuously performed, it is determined that the engine 12 is in the start-up malfunction state.

The map shown in FIG. 3 sets the frequency reference value CTth, which is an example of a reference value for determining whether or not the engine 12 is in a malfunctioning state, to a value according to the gradient of the road surface where the vehicle is located. Is an example of a map of The number-of-times reference value CTth is an upper limit value of the number of times of continuously executing control processing in the engine ECU 17 for restarting the engine 12. Further, the gradient equivalent value Ag is a value corresponding to the gradient of the road surface on which the vehicle is located. That is, when the gradient equivalent value Ag is substantially "0 (zero)", the road surface on which the vehicle is located is a road surface substantially parallel to the horizontal plane. The road surface in the case where the gradient equivalent value Ag is a positive value is an uphill, and the road surface in the case where the gradient equivalent value Ag is a negative value is a downhill.

In the present embodiment, as shown in FIG. 3, the frequency reference value CTth is set to a larger value in the case where the slope of the road surface is gentle than in the case where the slope is steep. For example, when the gradient equivalent value Ag is “0”, the frequency reference value CTth is set to the maximum value CTmax (for example, five times). When the gradient equivalent value Ag is less than "0" and larger than the first value Ag1 (<0 (zero)), the frequency reference value CTth is set to a smaller value as the gradient equivalent value Ag decreases. Ru. Similarly, when the gradient equivalent value Ag is larger than "0" and less than the second value Ag2 (> 0 (zero)), the frequency reference value CTth is set to a smaller value as the gradient equivalent value Ag becomes larger. Ru. When the gradient equivalent value Ag is less than or equal to the first value Ag1, and when the gradient equivalent value Ag is greater than or equal to the second value Ag2, the frequency reference value CTth is set to the minimum value CTmin (for example, twice). Ru. The absolute value of the second value Ag2 is equal to the absolute value of the first value Ag1.

Next, the idle stop processing routine executed by the brake ECU 55 of the present embodiment will be described based on the flowchart shown in FIG. The idle stop processing routine is a processing routine for setting the timing for permitting the automatic stop of the engine 12, the timing for permitting the automatic restart of the engine 12, and the like.

The brake ECU 55 executes the idle stop processing routine every predetermined cycle (for example, 0.01 second cycle) set in advance. In the idle stop processing routine, the brake ECU 55 acquires the MC pressure Pmc in the master cylinder 25 based on the detection signal from the pressure sensor SE 8 (step S10). Subsequently, the brake ECU 55 determines whether the engine 12 is stopped based on the information received from the engine ECU 17 (step S11).

If the determination result is negative, the brake ECU 55 executes engine stop processing because the engine 12 is being driven (step S12). That is, the brake ECU 55 allows the MC pressure Pmc acquired in step S10 to automatically stop the engine 12 when the vehicle body speed of the vehicle is equal to or less than a predetermined speed (for example, 20 km / h) set in advance. If it is equal to or greater than the determination value for determining whether or not it is determined that the driver has the intention to stop the vehicle. And ECU55 for brakes transmits stop permission instruction | command to ECU17 for engines. Therefore, in the present embodiment, step S12 corresponds to the stop step of permitting the automatic stop of the engine 12 when the stop condition of the engine 12 is satisfied. Thereafter, the brake ECU 55 temporarily terminates the idle stop processing routine.

On the other hand, if the determination result in step S11 is affirmative, the brake ECU 55 performs an engine restart process because the engine 12 is stopped (step S13). In this engine restart process, although the details will be described later, the braking forces on the wheels FR, FL, RR, and RL are adjusted, and a restart permission command and a restart prohibition command are transmitted to the engine ECU 17. In this respect, in the present embodiment, step S13 corresponds to a restart step of permitting automatic restart of the engine 12 when the restart condition of the engine 12 is satisfied. Further, the brake ECU 55 functions as a first control unit. And ECU55 for brakes once complete | finishes an idle stop process routine, after execution of an engine restart process.

Next, the engine restart process (engine restart process routine) will be described based on the flowcharts shown in FIGS. 5 and 6 and the timing chart shown in FIG. FIG. 7 is a timing chart when the vehicle travels on a slope.

Now, in the engine restart process routine, the brake ECU 55 determines whether the MC pressure Pmc acquired in step S10 is less than a preset MC pressure reference value Pmcth (step S20). The MC pressure reference value Pmcth is a determination value for determining whether to permit the restart of the engine 12 and a determination value for determining whether to permit the automatic stop of the engine 12. It is set to a smaller value. The MC pressure reference value Pmcth may be set to a value according to the gradient of the road surface on which the vehicle is located.

If the determination result in step S20 is negative (Pmc P Pmcth), the brake ECU 55 resets the number counter value CT described later to "0 (zero)" because the restart condition of the engine 12 is not satisfied. (Step S21), the engine restart processing routine is ended. On the other hand, if the determination result in step S20 is affirmative (Pmc <Pmcth), the brake ECU 55 transmits a restart permission command to the engine ECU 17 because the restart condition of the engine 12 is satisfied (step S22). The engine ECU 17 that has received the restart permission command performs control for starting the engine 12. Then, the engine ECU 17 outputs information on success / failure of restart of the engine 12 to the brake ECU 55.

Subsequently, the brake ECU 55 determines whether the restart of the engine 12 has failed based on the information received from the engine ECU 17 after the transmission of the restart permission command (step S23). If the determination result is negative, the ECU 55 for a brake shifts the process to step S21 described above since the restart of the engine 12 is successful. On the other hand, if the determination result in step S23 is affirmative, the ECU 55 for brakes acquires the vehicle body speed VS of the vehicle because the restart of the engine 12 has failed (step S24). Specifically, the brake ECU 55 calculates the wheel speeds of the wheels FL, FR, RL, and RR based on the detection signals from the wheel speed sensors SE3 to SE6, and calculates the wheel speeds of the wheels FL, FR, RL, and RR. The wheel acceleration is obtained by temporally differentiating at least one of the wheel speeds. Then, the brake ECU 55 integrates the wheel acceleration with respect to the vehicle speed acquired at the previous timing, and sets the integration result as the vehicle speed VS. Therefore, in the present embodiment, the brake ECU 55 also functions as a vehicle speed acquisition unit.

Then, the ECU 55 for brakes determines whether or not the vehicle body speed VS acquired in step S24 is less than a preset vehicle body speed threshold value and a vehicle body speed reference value VSth (for example, 7 km / h) as a control threshold (step S25). The vehicle speed reference value VSth is a reference value for determining whether or not the execution of the braking control to operate the pumps 42 and 43 of the brake actuator 31 is permitted. In addition, antilock brake control, anti-slip control (ESC: Electronic Stability Control), etc. are mentioned as an example of braking control accompanying operation of pumps 42 and 43.

If the determination result in step S25 is negative (VS ≧ VSth), the brake ECU 55 shifts the process to step S31 described later. On the other hand, if the determination result in step S25 is affirmative (VS <VSth), the brake ECU 55 increments the count value CT, which is a measurement value of the number of times the engine 12 has continuously failed to restart, by "1". (Step S26). Subsequently, the brake ECU 55 acquires an acceleration G (hereinafter, also simply referred to as “vehicle body acceleration”) G in the front-rear direction of the vehicle based on the detection signal from the acceleration sensor SE7 (step S27). Then, the brake ECU 55 time-differentiates the vehicle speed VS acquired in step S24 to acquire a vehicle speed differential value (actual acceleration of the vehicle) DVS (step S28). The brake ECU 55 may use the wheel acceleration obtained at the time of the processing in step S24 as the vehicle speed differential value DVS.

Subsequently, the brake ECU 55 subtracts the vehicle speed differential value DVS calculated in step S28 from the vehicle acceleration G calculated in step S27, and sets the subtraction result as the gradient equivalent value Ag (step S29). Here, the vehicle body acceleration G calculated based on the detection signal from the acceleration sensor SE7 includes an actual acceleration component of the vehicle and an acceleration component corresponding to the gradient of the road surface on which the vehicle travels. The "actual acceleration component of the vehicle" is a vehicle speed differential value DVS which is a differential value of the vehicle speed VS, and the gradient equivalent value Ag is obtained by removing the actual acceleration component of the vehicle from the vehicle acceleration G. Ru. Therefore, in the present embodiment, the brake ECU 55 also functions as a slope equivalent value acquisition unit.

Then, the brake ECU 55 sets the number-of-times reference value CTth corresponding to the gradient equivalent value Ag acquired in step S29 based on the map shown in FIG. Then, the brake ECU 55 determines whether or not the number-of-times counter value CT updated in step S26 is equal to or greater than the set recovery reference value CTth (step S30). If the determination result is negative (CT <CTth), the brake ECU 55 proceeds to step S22 described above. On the other hand, if the determination result in step S30 is affirmative (CT ≧ CTth), the brake ECU 55 determines that the engine 12 is in the start-up malfunction state, and shifts the process to step S31 described later.

In step S31, the brake ECU 55 transmits a restart prohibition command to the engine ECU 17. The engine ECU 17 that has received the restart inhibition command does not perform control for restarting the engine 12. Subsequently, the brake ECU 55 performs a first braking control process to operate the pumps 42 and 43 (that is, the motor 41) of the brake actuator 31 and the

linear solenoid valves

35a and 35b in order to stop the vehicle (step S32). Therefore, in the present embodiment, the first step is configured by steps S31 and S32. Further, the brake ECU 55 that performs the first braking control to increase the braking force on the wheels FR, FL, RR, and RL to stop the vehicle also functions as a second control unit.

When the first braking control process ends, the brake ECU 55 performs a second braking control process for holding the WC pressure Pwc in each of the wheel cylinders 32a to 32d (step S33). Specifically, the brake ECU 55 stops the pumps 42 and 43 of the brake actuator 31 and operates the

linear solenoid valves

35a and 35b to hold the WC pressure Pwc in the wheel cylinders 32a to 32d. Subsequently, since the brake ECU 55 has stopped the operation of the pumps 42 and 43, the brake ECU 55 transmits a restart permission command to the engine ECU 17 (step S34). The engine ECU 17 that has received the restart permission command appropriately performs control for restarting the engine 12. Therefore, in the present embodiment, the second step is configured by steps S33 and S34.

Here, as shown in the timing chart of FIG. 7, when the engine 12 is automatically stopped at the first timing t1, the engine rotational speed Ne drops sharply. Further, since the creep torque is not transmitted to the front wheels FR and FL which are driving wheels, the rate of change of the vehicle speed VS also becomes large. Then, when the restart condition of the engine 12 is satisfied at the second timing t2 at which the vehicle speed VS becomes less than the vehicle speed reference value VSth (more specifically, the vehicle stops), the engine 12 is restarted. Control is performed.

However, when the restart of the engine 12 fails, the number counter value CT is incremented by “1”. Then, at the third timing t3 after the second timing t2, since the vehicle speed VS is less than the vehicle speed reference value VSth, control for restarting the engine 12 is performed again. If the restart of the engine 12 fails again this time, the number counter value CT is incremented again by “1”. At this time, when the number counter value CT becomes equal to or more than the number reference value Ctth, it is determined that the engine 12 is in the start-up malfunction state, and the restart of the engine 12 is prohibited. On the other hand, when the number counter value CT is less than the number reference value Ctth, it is not determined at this timing that the engine 12 is in the start failure state.

That the control for restarting the engine 12 is repeatedly performed means that the MC pressure Pmc in the master cylinder 25 is reduced, that is, the braking force on the wheels FR, FL, RR, RL is reduced. Means. This is because the condition for permitting restart of the engine 12 includes that the MC pressure Pmc is less than the MC pressure reference value Pmcth (see FIG. 5). Therefore, when the road surface on which the vehicle is located is a downhill, there is a possibility that the vehicle moves forward due to insufficient braking force on the wheels FR, FL, RR, and RL caused by the decrease in the MC pressure Pmc. In addition, when the road surface on which the vehicle is located is an uphill, the vehicle may move rearward.

When the vehicle body speed VS of the vehicle becomes equal to or higher than the vehicle body speed reference value VSth due to the movement of the vehicle due to such inertia, the restart of the engine 12 is prohibited (fourth timing t4). This is because when the vehicle speed VS becomes equal to or higher than the vehicle speed reference value VSth, the execution of the braking control to operate the pumps 42 and 43 of the brake actuator 31 is permitted. That is, there is a possibility that the control for restarting the engine 12 and the braking control accompanied by the operation of the pumps 42 and 43 may overlap in time.

Then, when the restart of the engine 12 is prohibited, the WC pressure Pwc (indicated by a broken line in FIG. 7) in the wheel cylinders 32a to 32d for the wheels FR, FL, RR, and RL becomes the target hydraulic pressure Pwcth. Then, the pumps 42 and 43 of the brake actuator 31 and the

linear solenoid valves

35a and 35b operate (first braking control). That is, the braking forces on the wheels FR, FL, RR, and RL are increased to stop the vehicle.

Thereafter, at a fifth timing t5 at which the WC pressure Pwc in the wheel cylinders 32a to 32d becomes approximately equal to the target hydraulic pressure Pwcth, the braking control switches from the first braking control to the second braking control. Then, in the brake actuator 31, the operation of the pumps 42, 43 is stopped, and the braking force on the wheels FR, FL, RR, RL is held by the operation of the

linear solenoid valves

35a, 35b (second braking control) . Then, restart of the engine 12 is permitted. When the restart condition of the engine 12 is satisfied in this state, control for restarting the engine 12 is performed (sixth timing t6).

Referring back to the flowchart of FIG. 6, the brake ECU 55 determines whether the restart of the engine 12 is successful based on the information received from the engine ECU 17 after the transmission of the restart permission command (step S34) (step S35). ). If the determination result is affirmative, the brake ECU 55 shifts the process to step S21 described above because the engine 12 is restarted. On the other hand, when the determination result in step S35 is negative, the brake ECU 55 has not restarted the engine 12 yet, so whether or not the brake switch SW1 is turned off, that is, the operation of the brake pedal 15 has been cancelled. It is determined whether or not it is (step S36). If the determination result is negative (SW1 = on), the brake ECU 55 shifts the process to step S35 described above.

On the other hand, if the determination result in step S36 is affirmative (SW1 = off), the brake ECU 55 determines that the driver permits the movement of the vehicle due to inertia, and performs the third braking control process (step S37). . Specifically, even if the vehicle moves due to inertia, the brake ECU 55 adjusts the WC pressure Pwc in the wheel cylinders 32a to 32d so that the vehicle speed VS of the vehicle does not become equal to or higher than the vehicle speed reference value VSth. . That is, while the brake ECU 55 does not operate the pumps 42 and 43, the brake ECU 55 adjusts the current value to the

linear solenoid valves

35a and 35b. At this time, the current values to the

linear solenoid valves

35a, 35b are set to be larger values as the gradient of the road surface on which the vehicle is located becomes steeper. That is, in the third braking control, the braking force on the wheel is reduced but not increased. Therefore, in the present embodiment, the vehicle speed reference value VSth is also the permission reference value. Even if the braking forces on the wheels FR, FL, RR, and RL are reduced as described above, the vehicle may not move depending on the slope of the road surface.

And ECU55 for brakes determines whether restart of the engine 12 was successful based on the information received from ECU17 for engines after the process of step S37 (step S38). If the determination result is affirmative, the brake ECU 55 shifts the process to step S21 described above because the engine 12 is restarted. On the other hand, if the determination result in step S38 is negative, the brake ECU 55 determines whether the brake switch SW1 has been turned on, that is, the brake pedal 15 has been operated again, since the engine 12 has not yet been restarted. It is determined (step S39). If the determination result is negative (SW1 = OFF), the brake ECU 55 shifts the process to step S38 described above. On the other hand, if the determination result in step S39 is affirmative (SW1 = on), the brake ECU 55 shifts the process to step S31 described above. That is, the restart of the engine 12 is prohibited (step S31), and thereafter, the first braking control process for stopping the vehicle is executed (step S32). Then, when the vehicle stops, the second braking control process is executed (step S33), and restart of the engine 12 is permitted (step S34).

When the engine 12 is restarted with the braking force applied to the wheels FR, FL, RR, and RL by the second braking control or the third braking control, the brake ECU 55 is a linear solenoid valve. The current values for 35a and 35b are gradually decreased (see FIG. 7).

Therefore, in the present embodiment, the following advantages can be obtained.

(1) If the start failure of the engine 12 is detected, the restart of the engine 12 is prohibited and the braking force on the wheels FR, FL, RR, and RL is increased to stop the vehicle. Thereafter, when the braking forces on the wheels FR, FL, RR, and RL are held, the restart of the engine 12 is permitted. That is, there is a temporal overlap between the braking control of the brake actuator 31 for increasing the braking force on the wheels FR, FL, RR, and RL and the drive control of the driving force generator 13 for restarting the engine 12 It is avoided. In addition, even if the negative pressure in the booster 26 is reduced, the engine 12 is restarted with the braking force applied to the wheels FR, FL, RR, and RL that can stop the vehicle. It will be done. Therefore, the engine 12 can be restarted while securing the safety of the vehicle while reducing the load of a battery (not shown) mounted on the vehicle.

(2) In order to increase the braking force on the wheels FR, FL, RR, and RL using the brake actuator 31, it is necessary to operate the pumps 42 and 43 (i.e., the motor 41). When the pumps 42 and 43 are operated, the amount of power consumed by the brake actuator 31 increases. If it is attempted to restart the engine 12 in this state, the load on the battery of the vehicle becomes very large. In particular, one of the causes of the malfunction of the engine 12 is that the storage amount of the battery is small. Therefore, when drive control is performed by the driving force generator 13 for restarting the engine 12 during braking control to operate the pumps 42 and 43, a starter motor (shown in FIG. There is a possibility that the amount of power supplied to the power supply can not be sufficiently secured. That is, the engine 12 can not be easily restarted only by unnecessarily consuming the storage amount of the battery.

In this respect, in the present embodiment, the control for restarting the engine 12 is not performed during the braking control for operating the pumps 42 and 43. Therefore, the load on the battery can be reduced. In addition, when the engine 12 is restarted, power can be sufficiently supplied to the starter motor, and thus the engine 12 can be restarted promptly.

(3) When it is detected that the brake pedal 15 is not operated while the vehicle is kept stopped by the second braking control, it is determined that the driver permitted the vehicle to move due to inertia . Then, the braking force on the wheels FR, FL, RR, and RL is reduced. Then, when the vehicle is located on a slope, the vehicle moves downward in the inclination direction. That is, even when the start of the engine 12 is in a malfunction, the behavior of the vehicle can be made in accordance with the driver's intention.

(4) In the case where the start of the engine 12 is in a malfunction, there is a high possibility that the negative pressure in the booster 26 is reduced. In this case, since the MC pressure Pmc in the master cylinder 25 can not be made sufficiently high, a sufficiently large braking force can not be applied to the wheels FR, FL, RR, and RL by the operation of the brake pedal 15 by the driver. Therefore, in the present embodiment, during the third braking control, the braking force on the wheels FR, FL, RR, and RL is adjusted so that the vehicle speed VS does not become equal to or higher than the vehicle speed reference value VSth. Therefore, since the vehicle speed VS of the vehicle can be prevented from becoming too high, control for restarting the engine 12 can be performed while securing the safety of the vehicle.

Depending on the road surface where the vehicle is located, the vehicle may not move even if the third braking control is performed. In addition, “movement due to inertia of the vehicle” in the present embodiment means movement of the vehicle caused by applying a force (also referred to as “gradient acceleration”) according to the gradient to the vehicle located on a slope. It is a concept that includes

(5) In the present embodiment, during the third braking control, since the pumps 42 and 43 do not operate, restart of the engine 12 is permitted. Therefore, there is a possibility that the engine 12 may be restarted in response to the cancellation of the operation of the brake pedal 15 by the driver. That is, the engine 12 can be restarted at a timing at which the driver does not feel discomfort.

(6) Even during the third braking control, when the driver's operation of the brake pedal 15 is detected, the braking force on the wheels FR, FL, RR, and RL is increased to stop the vehicle. This is because that the brake pedal 15 is operated, it is determined that the driver has the intention to stop the vehicle. Therefore, the vehicle can be stopped according to the driver's intention.

(7) Further, when the braking force on the wheels FR, FL, RR, and RL is increased as described above, the restart of the engine 12 is prohibited. Therefore, the increase of the load of the battery can be suppressed.

(8) The frequency reference value CTth is set to a larger value when the slope of the road surface where the vehicle is located is slower than when the slope is steep. Therefore, when it is difficult for the vehicle to accelerate, that is, when the gradient equivalent value Ag is close to “0 (zero)”, the number of retries for restarting the engine 12 increases. This is because, even if the braking force on the wheels FR, FL, RR, and RL decreases due to the reduction of the negative pressure in the booster 26, the vehicle body can be obtained if the gradient equivalent value Ag is close to "0 (zero)". This is because it is difficult for the speed VS to be high. As described above, when the safety of the vehicle can be secured, the determination as to whether or not the engine 12 is in the start-up malfunction state can be delayed as much as possible. That is, before the execution of the first braking control, the possibility that the engine 12 can be restarted can be increased.

(9) In the present embodiment, even if the number counter value CT is less than the collection reference value CTth, restart of the engine 12 is prohibited when the vehicle body speed VS of the vehicle becomes equal to or higher than the vehicle body speed reference value VSth. And the brake actuator 31 is driven to increase the braking force on the wheels FR, FL, RR, and RL. This is because when the vehicle body speed VS of the vehicle becomes equal to or higher than the vehicle body speed reference value VSth, the execution of the braking control accompanied by the operation of the pumps 42 and 43 is permitted, so the braking control and the control for restarting the engine 12 And may overlap in time. Therefore, in the present embodiment, it is possible to contribute to the reduction of the possibility that the braking control accompanied by the operation of the pumps 42 and 43 and the control for restarting the engine 12 overlap in time.

Note that the embodiment may be changed to another embodiment as described below.

In the embodiment, the frequency reference value CTth may be a preset value (for example, 3) regardless of the magnitude of the gradient equivalent value Ag.

Further, it is not necessary to count the number of restart failures of the engine 12, that is, the number counter value CT. In this case, when the vehicle speed VS becomes equal to or higher than the vehicle speed reference value VSth while repeating the failure of the restart of the engine 12, it is determined that the engine 12 is in the start failure condition.

In the embodiment, when gradient information on the gradient of the road surface (ie, information on the gradient equivalent value Ag) is stored in the navigation device mounted on the vehicle, the gradient equivalent value Ag may be acquired from the navigation device .

In the embodiment, the elapsed time after the restart condition of the engine 12 is satisfied (in the above embodiment, after step S20 becomes affirmative) is measured, and the elapsed time becomes equal to or greater than the time reference value, When the engine 12 is not restarted, it may be determined that the engine 12 is in the start up failure state. In this case, it is preferable to prepare a map shown in FIG. This map is a map for setting the time reference value Tth to a value corresponding to the gradient equivalent value Ag. That is, the time reference value Tth is set to a larger value in the case where the gradient of the road surface is gentle than in the case where the gradient is steep.

When the vehicle is moving backward, braking control using the brake actuator 31 is not generally performed. In such a vehicle, when the vehicle moves backward, the determination process of step S25 may be omitted. Even in this configuration, the braking control accompanied by the operation of the pumps 42 and 43 of the brake actuator 31 and the driving control by the driving force generator 13 for restarting the engine 12 overlap in time. It can be avoided.

In the embodiment, in step S36, it may be determined whether the amount of operation of the brake pedal 15 has decreased. The operation amount of the brake pedal 15 is estimated based on the fluctuation of the MC pressure Pmc calculated based on the detection signal from the pressure sensor SE8.

Similarly, in step S39, it may be determined whether the operation amount of the brake pedal 15 has increased.

In the embodiment, in the third braking control, the wheels FR, FL, and RR are set such that the vehicle body speed VS of the vehicle is equal to or less than the permission reference value set to a value smaller than the vehicle body speed reference value (control threshold) VSth. , RL may be adjusted.

During execution of the third braking control, the slope of the road surface on which the vehicle travels may change. In particular, when the slope of the road surface becomes steeper than the slope at the start of the third braking control, the vehicle speed VS of the vehicle becomes high. This is because the current values for the

linear solenoid valves

35a, 35b are set by the gradient of the road surface at the start of the third braking control. As described above, when the vehicle speed VS becomes equal to or higher than the vehicle speed reference value VSth during execution of the third braking control, the restart inhibition command is sent to the engine regardless of the presence or absence of the operation of the brake pedal 15 of the driver. While transmitting to ECU17, you may perform a 1st damping | braking control process. According to this configuration, it is possible to avoid that the braking control accompanied by the operation of the pumps 42 and 43 of the brake actuator 31 and the driving control by the driving force generator 13 for restarting the engine 12 overlap in time. .

When the vehicle speed VS becomes equal to or higher than the vehicle speed reference value VSth during execution of the third braking control, the brake actuator 31 is driven such that the vehicle speed VS becomes lower than the vehicle speed reference value VSth. May be However, it is preferable to prohibit the restart of the engine 12 while the brake actuator 31 is driven.

In the embodiment, when the driver's operation of the brake pedal 15 is canceled during the second braking control, the braking force on the wheels FR, FL, RR, and RL may be “0 (zero)”. Thereafter, when the vehicle speed VS becomes equal to or higher than the vehicle speed reference value VSth, the first braking control may be performed. The engine 12 may be allowed to restart while the braking forces on the wheels FR, FL, RR, and RL are "0 (zero)."

In the embodiment, the vehicle speed VS may be obtained from a navigation device mounted on a vehicle.

In the embodiment, in the first braking control process, the target hydraulic pressure Pwcth may be set to a higher pressure in the case where the gradient equivalent value Ag is larger than in the case where the gradient equivalent value Ag is small.

In the embodiment, when the first braking control process and the second braking control process are executed when the determination result in step S39 becomes affirmative (SW1 = on), the second braking control is performed. The restart permission command may be transmitted to the engine ECU 17 when the elapsed time since the start is equal to or longer than a predetermined time (for example, 10 seconds) set in advance. In this case, the power stored in the battery is not consumed for restarting the engine 12 for a predetermined time after the second braking control is performed, and the storage amount of the battery can be slightly increased. As described above, the increase in the storage amount of the battery increases the possibility of eliminating the start failure state of the engine 12 caused by the shortage of the storage amount of the battery.

When the vehicle includes the electric parking brake device, the electric parking brake device may be used instead of the brake actuator 31 in each of the first to third braking control processes, or the brake actuator 31 and the electric parking brake device And may be used together.

12: Engine, 15: Brake pedal, 31: Brake actuator, 32a to 32d: Wheel cylinder, 35a, 35b: Linear solenoid valve as adjusting valve, 42, 43: Pump, 55: First control unit, second Control unit, ECU for brake as vehicle speed acquisition unit, FR, FL, RR, RL: wheel, CT: number of execution times counter value, CTth: number of times reference value, Tth: time reference value, VS: vehicle speed, VSth: permission reference value, vehicle speed threshold, vehicle speed reference as control threshold.

Claims

In the control device of the vehicle,
The automatic stop of the engine (12) is permitted when the stop condition of the engine (12) of the vehicle is satisfied, and the restart condition of the engine (12) is satisfied when the restart condition of the engine (12) is satisfied. A first control unit (55, S12, S13) permitting start-up;
A second control unit (55) for adjusting a braking force on wheels (FR, FL, RR, RL) provided in the vehicle;
The second control unit (55, S32, S33) detects the start failure of the engine (12) after permitting the restart of the engine (12), the wheels (for stopping the vehicle) The first braking control is performed to increase the braking force on FR, FL, RR, and RL, and then the second braking control is performed to hold the braking force on the wheels (FR, FL, RR, and RL).
The first control unit (55, S12, S13, S31, S34) prohibits restart of the engine (12) during execution of the first braking control, and executes the second braking control. The control device of the vehicle which permits the restart of the said engine (12) in the inside.
During the execution of the second braking control, the second control unit (55, S32, S33, S37) reduces the amount of operation of the brake pedal (15) provided on the vehicle, or the brake pedal The third braking control for permitting the movement of the vehicle by reducing the braking force on the wheels (FR, FL, RR, RL) when detecting that (15) is in the non-operating state is performed. The control device of the vehicle according to 1.
The third braking control is a control for adjusting the braking force on the wheels (FR, FL, RR, RL) such that the vehicle body speed (VS) of the vehicle is less than a preset permission reference value (VSth). The control device of the vehicle according to claim 2.
The vehicle is provided with a wheel cylinder (32a, 32b, 32c, 32d) that applies a braking force corresponding to fluid pressure generated inside the wheel cylinder to the wheel (FR, FL, RR, RL), and the wheel cylinder (32a). , 32b, 32c, 32d), and a brake actuator (31) for adjusting the fluid pressure in the
The brake actuator (31) is a pump (42, 43) that operates to increase fluid pressure in the wheel cylinder (32a, 32b, 32c, 32d), and the wheel cylinder (32a, 32b, 32c, 32d) Control valve (35a, 35b) that operates to adjust the fluid pressure in the
The control system for a vehicle according to claim 3, wherein the permission reference value is set to a value equal to or less than a control threshold (VSth) for permitting execution of braking control accompanied by operation of the pump (42, 43).
The second control unit (55, S32, S33, S37) detects that the operation amount of the brake pedal (15) is increased during execution of the third braking control, The control device for a vehicle according to any one of claims 2 to 4, wherein the braking control of 1 is performed.
The first control unit (55, S12, S13, S31, S34) executes the number of restarts of the engine (12) after allowing the restart of the engine (12), or The engine (12) is not restarted even if the elapsed time after allowing the restart of the engine) exceeds a set number of times reference value (CTth) or time reference value (Tth). The control device of a vehicle according to any one of claims 1 to 5, which detects a start up malfunction of 12).
It further comprises a vehicle speed acquisition unit (55, S24) for acquiring the vehicle speed (VS) of the vehicle,
The first control unit (55, S12, S13, S31, S34) is a vehicle speed (VS) acquired by the vehicle speed acquisition unit (55, S24) after permission of restart of the engine (12). 7. A start failure of the engine (12) is detected when the engine (12) is not restarted even if the vehicle speed exceeds a preset vehicle speed threshold (VSth). Control device of a vehicle according to any one of the preceding claims.
In the control method of the vehicle,
A stop step (S12) of permitting automatic stop of the engine (12) when a stop condition of the engine (12) of the vehicle is satisfied;
And V. a restart step (S13) for permitting restart of the engine (12) when the restart condition of the engine (12) is satisfied.
The restart step (S13) prohibits the restart of the engine (12) when a malfunction in the start of the engine (12) is detected after permission to restart the engine (12), and A first step (S31, S32) of increasing the braking force on the wheels (FR, FL, RR, RL) provided on the vehicle to stop the vehicle;
After the execution of the first step (S31, S32), the second step (S33) allows the engine (12) to be restarted while holding the braking force for the wheels (FR, FL, RR, RL). , S34), and a control method of the vehicle.