JP2012097620A - Vehicle control apparatus and vehicle control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To limit the acceleration or the start-up of a vehicle attributable to simultaneous depression of both an accelerator pedal and a brake pedal without installing a sensor for detecting the amount of depression operation applied to the brake pedal.SOLUTION: The pitching correction value corresponding to the attitude change of a vehicle 10 caused by the pitching phenomenon is calculated. The depression operation force applied to the brake pedal 17 is estimated on the basis of the pitching correction value, the output torque of an internal combustion engine 11 calculated by an engine ECU (Electronic Control Unit) 31, and the acceleration of the vehicle 10 detected by an acceleration sensor 34. When the estimated depression operation force applied to the brake pedal 17 is equal to or more than a second evaluation value, and the amount of the depression operation applied to the accelerator pedal 22 detected by an accelerator sensor 33 is equal to or more than a first evaluation value, the output torque of the internal combustion engine 11 is limited.

Description

  The present invention relates to a vehicle control device and a vehicle control method for limiting drive torque transmitted to an axle when an accelerator pedal and a brake pedal are simultaneously depressed.

  In recent years, the occurrence of an event in which the accelerator pedal and the brake pedal are depressed simultaneously has been reported, for example, when the brake pedal is depressed while the accelerator pedal is caught on the floor mat. In this case, if the amount of depression of the accelerator pedal is large, the vehicle may accelerate or start even though the brake pedal is depressed by the occupant.

  Conventionally, in Patent Document 1, when the accelerator pedal and the brake pedal are simultaneously operated, the depression amount of the brake pedal detected by the sensor (or its index value [for example, brake operating pressure]) is larger than the determination value. Sometimes it has been proposed to limit the output of an in-vehicle internal combustion engine. The determination value is set to a value corresponding to a brake pedal depressing operation amount that cannot normally be taken when both pedals are intentionally depressed by the occupant.

  According to such a device, even if the accelerator pedal and the brake pedal are accidentally depressed at the same time, if the amount of depression of the brake pedal increases, the depression of the accelerator pedal is intended by the occupant. In other words, the brake pedal depressing operation is given priority, and the output of the in-vehicle internal combustion engine is limited. As a result, acceleration and start of the vehicle due to simultaneous depression of the accelerator pedal and the brake pedal can be suppressed.

JP 2005-291030 A

  Here, in order to reduce the manufacturing cost of the vehicle, it has been studied to omit a sensor for detecting the operation amount of the brake pedal. In this case, simply omitting the sensor makes it impossible to grasp the amount of depression of the brake pedal at that time, so that the acceleration and start of the vehicle due to the simultaneous depression of the accelerator pedal and the brake pedal described above can be suppressed. It becomes impossible.

  As is clear from the fact that the vehicle decelerates due to the depression of the brake pedal, there is a correlation between the depression operation force (depression force) of the brake pedal and the vehicle acceleration. For this reason, in a vehicle equipped with an acceleration sensor, the pedal effort of the brake pedal is estimated based on the vehicle acceleration detected by the acceleration sensor, and the estimated value is calculated based on the depression amount of the brake pedal detected by the dedicated sensor. It can be considered that it is used instead of. Thus, by using the estimated value of the pedal effort of the brake pedal, it becomes possible to suppress acceleration and start of the vehicle due to simultaneous depression of the accelerator pedal and the brake pedal. However, in this case, the following inconvenience may occur.

  Generally, as an acceleration sensor mounted on a vehicle such as an automobile, a sensor having one axis or two axes of detection axes (the number of directions in which acceleration can be accurately detected) is employed. The acceleration sensor is attached to the vehicle so that its detection axis coincides with the traveling direction of the vehicle. When the vehicle travels, a phenomenon occurs in which the front part of the vehicle sinks into the rear part of the vehicle or the rear part of the vehicle sinks into the front part of the vehicle (so-called pitching phenomenon). There is. When the pitching phenomenon occurs, the posture of the vehicle with respect to the traveling road surface changes, so that the posture of the acceleration sensor attached to the vehicle also changes. Therefore, at this time, the detection axis of the acceleration sensor and the traveling direction of the vehicle (specifically, the direction parallel to the road surface when traveling on a flat road) are shifted, and the actual acceleration and acceleration sensor in the traveling direction of the vehicle There will be a deviation from the detected acceleration. The change in the detection value of the acceleration sensor due to the occurrence of such a pitching phenomenon is a cause of lowering the estimation accuracy when the pedal effort of the brake pedal is estimated based on the detection value of the acceleration sensor as described above. .

  The present invention has been made in view of such circumstances, and an object of the present invention is to accelerate a vehicle caused by simultaneous depression of an accelerator pedal and a brake pedal without providing a sensor for detecting a depression amount of a brake pedal. Another object of the present invention is to provide a vehicle control device and a vehicle control method capable of accurately suppressing vehicle start.

In the following, means for achieving the above object and its operational effects will be described.
The vehicle control device of the present invention includes an internal combustion engine (11) as a drive source, an acceleration sensor (34) that detects vehicle acceleration, and an accelerator sensor (33) that detects the amount of depression of an accelerator pedal (22). An output calculation means (31, S104) that is applied to the vehicle (10) provided to calculate the output torque of the internal combustion engine (11), and pitching correction according to the posture change of the vehicle (10) due to the pitching phenomenon Correction value calculation means for calculating values (32, S109, S110, S111), the vehicle acceleration detected by the acceleration sensor (34), the output torque calculated by the output calculation means (31, S104), and Based on the pitching correction value calculated by the correction value calculating means (32, S109, S110, S111), the brake pedal (1 ), The pedaling force estimation means (32, S107, S108, S112, S115) for estimating the pedaling operation force, and the pedaling operation amount detected by the accelerator sensor (33) is greater than or equal to a first determination value, and the pedaling force When the stepping operation force estimated by the estimation means (32, S107, S108, S112, S115) is greater than or equal to a second determination value, the driving torque transmitted from the internal combustion engine (11) to the axle (13) is calculated. The gist is to include torque limiting means (32, S116, S117) for limiting.

  According to the above configuration, the actual acceleration of the vehicle can be detected by the acceleration sensor, and the acceleration (engine acceleration) of the vehicle obtained by the operation of the internal combustion engine can be grasped based on the output torque of the internal combustion engine. . Therefore, based on the relationship between the actual acceleration and the engine acceleration, it is possible to grasp the amount of change in the vehicle's acceleration due to the depression of the brake pedal. It can be estimated with high accuracy. In addition, when there is a deviation between the actual acceleration detected by the acceleration sensor and the actual acceleration detected by the acceleration sensor due to the change in the attitude of the vehicle due to the occurrence of the pitching phenomenon, the pitching correction corresponding to the change in the attitude of the vehicle The estimated value of the brake pedal depression force (brake pedal force estimation value) can be corrected by the value. Therefore, the brake pedal force estimated value can be accurately estimated while suppressing a decrease in estimation accuracy due to the occurrence of such a pitching phenomenon. Accordingly, it can be accurately determined that the pedal effort of the brake pedal is equal to or greater than the second judgment value based on the brake pedal effort estimated value. Therefore, the simultaneous depression of the accelerator pedal and the brake pedal is accurately performed based on the determination based on the estimated brake pedal force and the determination that the accelerator pedal depression amount detected by the accelerator sensor is equal to or greater than the first determination value. After the determination, it is possible to accurately limit the drive torque transmitted from the internal combustion engine to the axle. Therefore, it is possible to accurately suppress acceleration and start of the vehicle due to simultaneous depression of the accelerator pedal and the brake pedal without providing a sensor for detecting the depression amount of the brake pedal.

  In the vehicle control apparatus according to the present invention, the vehicle (10) preferably includes a speed sensor (36) for detecting a traveling speed thereof, and the correction value calculation means (32, S109, S110, S111) is the vehicle. In the traveling of (10), it is preferable to calculate the pitching correction value based on the transition of the traveling speed detected by the speed sensor (36).

  The pitching phenomenon while the vehicle is traveling occurs with a change in the traveling speed of the vehicle. As the degree of change in the vehicle traveling speed increases, the amount of change in the attitude of the vehicle when the pitching phenomenon occurs increases. As a result, while the vehicle is traveling, the amount of change in the vehicle posture caused by the occurrence of the pitching phenomenon based on the transition of the traveling speed in the traveling direction of the vehicle (the direction parallel to the road surface when traveling on a flat road). It can be said that it becomes possible to grasp.

  According to the above configuration, the pitching correction value can be calculated on the basis of a transition of the vehicle traveling speed detected by the speed sensor, that is, a value correlated with the posture change amount while the vehicle is traveling. Therefore, the brake pedal force estimated value can be accurately calculated while suppressing a decrease in the estimated accuracy caused by the posture change by the pitching correction value.

In the vehicle control device of the present invention, the vehicle acceleration calculated based on the traveling speed detected by the speed sensor can be used as the transition of the vehicle traveling speed.
In the vehicle control apparatus of the present invention, the correction value calculation means (32, S109, S110, S111) corrects the pitching based on the driving torque transmitted to the axle (13) when the vehicle (10) is stopped. It is preferable to calculate the value.

  The pitching phenomenon when the vehicle is stopped is generated by the driving torque transmitted to the axle. As the drive torque increases, the change in the attitude of the vehicle when the pitching phenomenon occurs increases. From this, it can be said that when the vehicle is stopped, the change in the posture of the vehicle due to the occurrence of the pitching phenomenon can be grasped based on the driving torque transmitted to the axle.

  According to the above configuration, when the vehicle is stopped, the pitching correction value can be calculated based on the driving torque transmitted to the axle, that is, the value correlated with the posture change. Therefore, the brake pedal force estimated value can be accurately calculated while suppressing a decrease in the estimated accuracy caused by the posture change by the pitching correction value.

In the vehicle control device of the present invention, the drive torque transmitted to the axle can be calculated based on the output torque calculated based on the output calculation means.
The vehicle control method of the present invention includes an internal combustion engine (11) as a drive source, an acceleration sensor (34) for detecting vehicle acceleration, and an accelerator sensor (33) for detecting a depression operation amount of an accelerator pedal (22). A method for controlling the vehicle (10), wherein an output calculation step (S104) for calculating an output torque of the internal combustion engine (11), and a pitching correction value corresponding to a posture change amount of the vehicle (10) due to a pitching phenomenon. Correction value calculation step (S109, S110, S111) to be calculated, the vehicle acceleration detected by the acceleration sensor (34), the output torque calculated in the output calculation step (S104), and the correction value calculation step ( Depressing the brake pedal (17) based on the pitching correction value calculated in S109, S110, S111) The step force estimation step (S107, S108, S112, S115) for estimating the effort, the stepping operation amount detected by the accelerator sensor (33) is equal to or greater than a first determination value, and the step force estimation step (S107, S115) A torque limiting step (S116) for limiting the driving torque transmitted from the internal combustion engine (11) to the axle (13) when the stepping operation force estimated in S108, S112, S115) is equal to or greater than a second determination value. , S117).

  According to the control method, the same operation and effect as the vehicle control device can be obtained.

1 is a schematic diagram showing a schematic configuration of a vehicle to which a first embodiment of the present invention is applied. Sectional drawing which shows the cross-section of a brake booster. Explanatory drawing for the detection error of the vehicle acceleration which generate | occur | produces by a pitching phenomenon. The flowchart which shows the execution procedure of the torque limitation process of 1st Embodiment. The flowchart which shows the execution procedure of the torque limitation process. The flowchart which shows the execution procedure of the torque limitation process of 2nd Embodiment. The flowchart which shows the execution procedure of the torque limitation process of 3rd Embodiment.

(First embodiment)
Hereinafter, a first embodiment embodying the vehicle control device of the present invention will be described.
As shown in FIG. 1, the vehicle 10 is equipped with an internal combustion engine 11 as a drive source. The output torque of the internal combustion engine 11 is transmitted to the wheels 14 via a multi-stage automatic transmission 12 having a plurality of shift stages and an axle 13. The vehicle 10 has so-called front wheels in which the front wheels 14 function as driving wheels 14A to which the output torque of the internal combustion engine 11 is transmitted, and the rear wheels 14 function as driven wheels 14B to which the output torque is not transmitted. It is a driving car.

  The vehicle 10 is provided with a brake booster 18 that doubles and transmits the depressing operation force (stepping force) of the brake pedal 17 by using the intake negative pressure generated downstream of the throttle valve 16 in the intake passage 15 of the internal combustion engine 11. It has been. The vehicle 10 is also provided with a master cylinder 19 that generates a brake fluid pressure (master cylinder pressure) in accordance with the depression force of the brake pedal 17 boosted by the brake booster 18. Further, the vehicle 10 is provided with a brake actuator 21 that operates according to the brake fluid pressure generated by the master cylinder 19 and applies a braking force to the disc brake device 20 provided on each wheel 14.

  Further, the vehicle 10 is provided with an electronic control unit (engine ECU 31) that controls the operation of the internal combustion engine 11 and an electronic control unit (brake ECU 32) that controls the operation of the brake actuator 21.

  The engine ECU 31 and the brake ECU 32 are input with detection signals of sensors and switches for detecting the driving situation of the vehicle 10. For example, the engine ECU 31 receives a detection signal from an accelerator sensor 33 that detects a depression operation amount of the accelerator pedal 22 (accelerator depression amount Othr). Further, the brake ECU 32 receives a detection signal of an acceleration sensor 34 that detects acceleration (actual acceleration G) acting in the front-rear direction of the vehicle 10 and a signal of a brake switch 35 that detects whether the brake pedal 17 is depressed. ing. Further, the brake ECU 32 includes a detection signal from a speed sensor 36 that detects the rotational speed (wheel speed VSO) of each wheel 14 and a pressure sensor that detects a negative pressure (booster negative pressure Pv) formed inside the brake booster 18. 37 detection signals are also input.

  As the acceleration sensor 34, one having a single detection axis (specifically, a direction in which acceleration can be detected with high accuracy) is employed, and the acceleration sensor 34 includes the detection axis and the traveling direction of the vehicle 10. It is attached to the vehicle 10 so that (specifically, the front-rear direction) matches. One speed sensor 36 is provided for each wheel 14.

  Various information is communicated between the engine ECU 31 and the brake ECU 32 through data communication. As such data, in addition to information detected by sensors and switches, the internal combustion engine ascertained based on the gear position (gear position Pgear) selected in the automatic transmission 12 and the operating state of the internal combustion engine 11. 11 output torque (engine torque Teng) and the like. The engine torque Teng is obtained by calculation from the opening of the throttle valve 16, for example.

  The engine ECU 31 executes operation control of the internal combustion engine 11 in accordance with the operation status of the vehicle 10 that is grasped from the detection results of various sensors and switches. In addition, the brake ECU 32 operates a control solenoid of the brake actuator 21 to execute operation control of a brake system such as ABS (anti-lock brake system), brake assist, and ESC (electronic stability control).

Hereinafter, the structure of the brake booster 18 will be described in detail.
As shown in FIG. 2, two pressure chambers, a constant pressure chamber 23 and a variable pressure chamber 24, are formed in the brake booster 18. The constant pressure chamber 23 is communicated with an intake passage 15 (see FIG. 1) of the internal combustion engine 11 via a check valve (not shown), and negative pressure (specifically, atmospheric pressure) is generated therein due to intake negative pressure. Lower pressure) is introduced. The booster negative pressure of the brake booster 18 is a negative pressure in the constant pressure chamber 23 (a differential pressure between the atmospheric pressure and the pressure in the constant pressure chamber 23).

  The brake booster 18 is provided with two valves, a vacuum valve 25 and an atmospheric valve 26. When the vacuum valve 25 is opened, the constant pressure chamber 23 and the variable pressure chamber 24 communicate with each other, and when the vacuum valve 25 is closed, the communication between the constant pressure chamber 23 and the variable pressure chamber 24 is blocked. When the atmospheric valve 26 is opened, the variable pressure chamber 24 is opened to the atmosphere.

  Further, a piston 27 is disposed inside the brake booster 18. The piston 27 partitions the constant pressure chamber 23 and the variable pressure chamber 24. The piston 27 is connected to the brake pedal 17 and is disposed so as to be movable as the brake pedal 17 is depressed.

  When the brake pedal 17 is not depressed (when the brake is not operated), the vacuum valve 25 is opened and the atmospheric valve 26 is closed. At this time, the constant pressure chamber 23 and the variable pressure chamber 24 communicate with each other, and the intake negative pressure of the internal combustion engine 11 is introduced into these, so that the pressure in the constant pressure chamber 23 and the pressure in the variable pressure chamber 24 become substantially equal.

  On the other hand, when the brake pedal 17 is depressed (when the brake is operated), the vacuum valve 25 is closed and the atmospheric valve 26 is opened. At this time, the communication between the constant pressure chamber 23 and the variable pressure chamber 24 is blocked, and the internal pressure of the variable pressure chamber 24 gradually approaches the atmospheric pressure, so that the pressure in the constant pressure chamber 23 becomes higher than the pressure in the variable pressure chamber 24. Then, when the piston 27 is pressed by the pressure difference between the constant pressure chamber 23 and the variable pressure chamber 24, the depression operation of the brake pedal 17 is assisted.

  When the brake pedal 17 and the accelerator pedal 22 are accidentally depressed simultaneously, the vehicle 10 limits the output of the internal combustion engine 11 in order to suppress acceleration and start of the vehicle 10 due to this. System (BOS [Brake Override System]). In this system, the accelerator depression amount Othr is equal to or greater than the first determination value α, and the depression force of the brake pedal 17 (specifically, the estimated value of the master cylinder pressure [master pressure estimated value PesPm described later)] is the second determination value β. When this is the case, the output torque of the internal combustion engine 11 is limited. Thereby, acceleration and start of the vehicle 10 due to simultaneous depression of the brake pedal 17 and the accelerator pedal 22 are suppressed.

  Here, in the vehicle 10, a sensor for detecting the depression force of the brake pedal 17 is omitted in order to reduce the manufacturing cost. If the sensor is simply omitted, the pedaling force of the brake pedal 17 at that time cannot be grasped, so that acceleration and start of the vehicle 10 caused by simultaneous depression of the brake pedal 17 and the accelerator pedal 22 can be suppressed by the BOS. It will disappear.

  Therefore, in the present embodiment, the pedal effort of the brake pedal 17 is estimated based on the output torque of the internal combustion engine 11 (the engine torque Teng) calculated by the engine ECU 31 and the actual acceleration G detected by the acceleration sensor 34. ing. The brake ECU 32 limits the output of the internal combustion engine 11 based on the estimated value (specifically, a master pressure estimated value PesPm described later).

  As is clear from the fact that the vehicle 10 is decelerated by the depression operation of the brake pedal 17, there is a correlation between the depression force of the brake pedal 17 and the acceleration of the vehicle 10. Based on this point, in the present embodiment, the master pressure estimated value PesPm is calculated based on the actual acceleration G detected by the acceleration sensor 34, and the master pressure estimated value PesPm is used in the BOS.

  The calculation of the master pressure estimated value PesPm is specifically performed based on the following idea. First, the actual acceleration G of the vehicle 10 is detected by the acceleration sensor 34, and the acceleration (engine acceleration) of the vehicle 10 obtained by the operation of the internal combustion engine 11 is grasped based on the engine torque Teng. Based on the relationship between the actual acceleration G and the engine acceleration, the acceleration change of the vehicle 10 due to the depression operation of the brake pedal 17 is grasped. Further, the master pressure estimated value PesPm is calculated by converting the acceleration change amount into the depression force of the brake pedal 17 by a conversion coefficient determined by the characteristics of the vehicle 10.

  In the present embodiment, it can be accurately determined that the depression force of the brake pedal 17 is equal to or greater than the second determination value β based on the master pressure estimated value PesPm. Therefore, the brake pedal 17 and the accelerator pedal 22 are simultaneously depressed based on the determination based on the master pressure estimated value PesPm and the determination that the accelerator depression amount Othr detected by the accelerator sensor 33 is equal to or greater than the first determination value α. Is accurately determined, and the output of the internal combustion engine 11 can be accurately limited. Therefore, acceleration or start of the vehicle 10 due to simultaneous depression of the brake pedal 17 and the accelerator pedal 22 can be suppressed without providing a sensor for detecting the depression operation amount of the brake pedal 17.

  The brake booster 18 has a structure in which the booster negative pressure approaches the atmospheric pressure when the brake pedal 17 is depressed. Therefore, if the depression operation of the brake pedal 17 is repeatedly performed in a short time, the booster negative pressure is almost lost (a state where the pressure is almost atmospheric), and the brake pedal 18 is hardly assisted by the brake booster 18. It will be the situation where 17 is stepped on. In this case, since the degree of deceleration of the vehicle 10 due to the depression operation of the brake pedal 17 is reduced, the actual depression force of the brake pedal 17, the output torque (engine torque Teng) of the internal combustion engine 11, and the actual acceleration of the vehicle 10. The relationship with G changes, leading to a decrease in the estimation accuracy of the above-described master pressure estimated value PesPm.

  In view of this point, in the present embodiment, the booster negative pressure Pv detected by the pressure sensor 37 is used as one of the estimation parameters of the estimated master pressure value PesPm. Thereby, it is possible to accurately calculate the estimated master pressure value PesPm while considering the influence of the change in the booster negative pressure Pv.

  Even if the brake pedal 17 is depressed with the same force, the actual deceleration degree of the vehicle 10 varies depending on the weight of the vehicle 10. Therefore, it can be said that the relationship between the actual depression force of the brake pedal 17, the output torque of the internal combustion engine 11 (engine torque Teng), and the actual acceleration G of the vehicle 10 changes according to the weight of the vehicle 10. The vehicle weight changes in accordance with the weight of the load placed on the vehicle 10, the remaining amount of fuel in the internal combustion engine 11, the number of passengers, and the like. Therefore, there is a possibility that the estimation accuracy of the master pressure estimated value PesPm is lowered due to such a change in the weight of the vehicle 10.

  Therefore, in the present embodiment, the weight of the vehicle 10 is estimated, and the estimated value (loading amount estimated value PesW described later) is used as one of the estimation parameters of the master pressure estimated value PesPm. Thereby, the said master pressure estimated value PesPm can be estimated accurately, considering the influence by the change of the weight of the vehicle 10. FIG.

  Further, when the master pressure estimated value PesPm is calculated based on the actual acceleration G detected by the acceleration sensor 34 and the master pressure estimated value PesPm is used in the BOS as in the present embodiment, the following inconveniences are caused. May occur.

  In the present embodiment, the acceleration sensor 34 is attached to the vehicle 10 so that the detection axis of the acceleration sensor 34 coincides with the longitudinal direction of the vehicle 10. When the vehicle 10 is traveling, there is a phenomenon (so-called pitching phenomenon) in which the front part of the vehicle sinks with respect to the rear part of the vehicle or the rear part of the vehicle sinks with respect to the front part of the vehicle as the traveling speed changes. May occur. When such a pitching phenomenon occurs, the posture of the acceleration sensor 34 attached to the vehicle 10 also changes because the posture of the vehicle 10 with respect to the traveling road surface changes.

  Therefore, as shown in FIG. 3, the detection axis of the acceleration sensor 34 and the traveling direction of the vehicle 10 (specifically, the direction parallel to the road surface when traveling on a flat road) are shifted from each other. There is a difference between the actual acceleration in the traveling direction of the vehicle 10 (value indicated by arrow A in the figure) and the actual acceleration G (value indicated by arrow B in the figure) detected by the acceleration sensor 34. FIG. 3 shows an example of the relationship between the actual acceleration G and the actual acceleration in the vehicle traveling direction in a state where the rear portion of the vehicle is depressed with respect to the front portion of the vehicle. As can be seen from the figure, when the pitching phenomenon occurs, the actual acceleration G detected by the acceleration sensor 34 becomes smaller than the actual acceleration in the vehicle traveling direction. The change in the detection value (actual acceleration G) of the acceleration sensor 34 caused by the occurrence of such a pitching phenomenon reduces the calculation accuracy when the estimated master pressure value PesPm is calculated based on the actual acceleration G as described above. It becomes a cause. FIG. 3 exaggerates the deviation between the detection axis of the acceleration sensor 34 and the traveling direction of the vehicle 10 in order to facilitate understanding of the change in the actual acceleration G.

  Based on this point, in the present embodiment, a correction value (pitching correction value Gp) corresponding to the change in the attitude of the vehicle 10 due to the pitching phenomenon is calculated, and the pitching correction value Gp is estimated as the master pressure estimated value PesPm. It is used as one of the parameters.

  In the present embodiment, the pitching correction value Gp is calculated in a different manner between when the vehicle 10 is traveling and when it is stopped. Hereinafter, how to calculate such a pitching correction value Gp will be described.

First, a calculation mode of the pitching correction value Gp when the vehicle 10 is traveling will be described.
The pitching phenomenon during the traveling of the vehicle 10 occurs with a change in the traveling speed of the vehicle 10. Then, the greater the degree of change in the traveling speed of the vehicle 10, the greater the change in the attitude of the vehicle 10 when the pitching phenomenon occurs. From this, it can be said that during the traveling of the vehicle 10, it is possible to grasp the change in the posture of the vehicle 10 due to the occurrence of the pitching phenomenon based on the transition of the traveling speed in the traveling direction of the vehicle 10. .

  Therefore, in the present embodiment, when the vehicle 10 is traveling, the transition of the traveling speed in the traveling direction of the vehicle 10 (specifically, the vehicle 10 estimated based on the wheel speed VSO detected by each speed sensor 36). The pitching correction value Gp is calculated based on acceleration [estimated vehicle body acceleration ΔVref described later].

  Thus, the pitching correction value Gp is calculated based on a value correlated with the transition of the traveling speed of the vehicle 10 detected by the speed sensor 36, that is, the change in the attitude of the vehicle 10 due to the pitching phenomenon while the vehicle 10 is traveling. be able to. Then, the master pressure estimated value PesPm can be calculated with high accuracy while suppressing a decrease in estimation accuracy caused by the posture change by the pitching correction value Gp.

Next, how the pitching correction value Gp is calculated when the vehicle 10 is stopped will be described.
The pitching phenomenon when the vehicle 10 is stopped is generated by the driving torque transmitted from the internal combustion engine 11 to the axle 13. As the driving torque increases, the change in the attitude of the vehicle 10 when the pitching phenomenon occurs increases. From this, it can be said that when the vehicle 10 is stopped, it is possible to grasp the amount of change in the posture of the vehicle 10 due to the occurrence of the pitching phenomenon based on the driving torque transmitted to the axle 13.

  In view of this point, in the present embodiment, the pitching correction value Gp is calculated based on the drive torque transmitted to the axle 13 when the vehicle 10 is stopped. The driving torque includes the output torque of the internal combustion engine 11 (engine torque Teng), the gear ratio Rtgear of the automatic transmission 12 calculated based on the gear position Pgear, and the gear of the final gear provided integrally with the automatic transmission 12. It can be calculated based on the ratio Rfinal.

  Thereby, when the vehicle 10 is stopped, the pitching correction value Gp can be calculated based on the driving torque transmitted to the axle 13, that is, the value correlated with the attitude change of the vehicle 10 due to the pitching phenomenon. Then, the master pressure estimated value PesPm can be calculated with high accuracy while suppressing a decrease in estimation accuracy caused by the posture change by the pitching correction value Gp.

  Thus, in the present embodiment, there is a case where a deviation occurs between the actual acceleration G detected by the acceleration sensor 34 and the actual acceleration in the traveling direction of the vehicle 10 due to the attitude change of the vehicle 10 due to the occurrence of the pitching phenomenon. However, it is possible to accurately estimate the master pressure estimated value PesPm through correction using a value (pitching correction value Gp) corresponding to the posture change of the vehicle 10.

  In addition to the above-described inconvenience due to the occurrence of the pitching phenomenon, the following inconvenience may occur. The wheel 14 may slip when the vehicle 10 travels on a road surface with a low coefficient of friction (for example, an icy road) or when the driving torque transmitted to the axle 13 is large due to a large amount of depression of the accelerator pedal 22. When such a slip occurs, the driving state of the vehicle 10 (specifically, the relationship between the engine torque Teng, the actual acceleration G, and the depression force of the brake pedal 17) changes accordingly. The change of the driving state due to the presence or absence of slip of the vehicle 10 is estimated by the device that calculates the master pressure estimated value PesPm based on the driving state of the vehicle 10 like the device of the present embodiment. It will be a cause to reduce the accuracy.

  Therefore, in the present embodiment, the occurrence of slip of the vehicle 10 is determined, and when it is determined that the slip has occurred, execution of output restriction of the internal combustion engine 11 by the BOS is prohibited. Thereby, when the slip of the vehicle 10 occurs, that is, when the relationship between the engine torque Teng, the actual acceleration G, and the depression force of the brake pedal 17 changes, it is determined that the estimated accuracy of the master pressure estimated value PesPm is low. It can be avoided that the output of the internal combustion engine 11 is limited when the estimated value PesPm is large.

Hereinafter, the process of limiting the output torque of the internal combustion engine 11 by the BOS (torque limiting process) will be described in detail.
FIG. 4 and FIG. 5 are flowcharts showing specific execution procedures of the torque limiting process. The series of processes shown in the flowcharts is a predetermined process executed on condition that the brake switch 35 is turned on. The processing is performed by the brake ECU 32 as processing for each time (for example, several milliseconds).

As shown in FIG. 4, in this process, first, the wheel speed VSO of each wheel 14 is detected by the speed sensor 36 (step S101).
Then, an estimated value (estimated vehicle body speed Vref) for the traveling speed of the vehicle 10 is calculated based on each wheel speed VSO (step S102). Specifically, a value indicating the highest speed among the wheel speeds VSO is calculated as the estimated vehicle body speed Vref.

  Further, an estimated value (estimated vehicle acceleration ΔVref) for the acceleration of the vehicle 10 is calculated based on the estimated vehicle speed Vref (step S103). Specifically, the difference between the estimated vehicle speed Vref [i−1] at the previous execution of this process and the estimated vehicle speed Vref [i] at the current execution (= Vref [i] −Vref [i−1]). Is calculated as the estimated vehicle body acceleration ΔVref.

  Further, the accelerator depression amount Othr, the engine torque Teng, and the gear position Pgear that are detected (or calculated) and stored by the engine ECU 31 are read (step S104). In the present embodiment, the process of step S104 functions as an output calculation process.

  Thereafter, it is determined whether or not the accelerator pedal 22 is depressed (step S105). Specifically, in this process, it is determined that the accelerator pedal 22 is depressed when the accelerator depression amount Othr is equal to or greater than a predetermined amount.

  If it is determined that the accelerator pedal 22 is not depressed (step S105: NO), there is no possibility that the vehicle 10 is accelerated or started due to the simultaneous depression of the brake pedal 17 and the accelerator pedal 22 described above. As described above, after the output restriction flag is turned off (step S118), the process is temporarily terminated.

  On the other hand, when it is determined that the accelerator pedal 22 is depressed (step S105: YES), it is determined whether or not the vehicle 10 is in a slip state (step S106). In this process, the difference ΔVSO between the wheel speed VSO and the estimated vehicle body speed Vref is calculated for each wheel 14, and if any of the differences ΔVSO is greater than or equal to the determination value J1, the vehicle 10 is in the slip state. To be judged. The determination value J1 is a value that can accurately determine that any one of the wheels 14 is slipping to such an extent that the estimated master pressure value PesPm cannot be accurately calculated. Is obtained in advance based on the result of the above and stored in the brake ECU 32. If it is determined that the vehicle 10 is in the slip state (step S106: YES), since the master pressure estimated value PesPm cannot be accurately calculated at this time, the output torque of the internal combustion engine 11 is accurately limited. If the output restriction flag is turned off (step S118), the process is temporarily terminated.

  The output restriction flag is a flag that operates as follows. That is, when the output restriction flag is turned on, a signal indicating that the output torque of the internal combustion engine 11 needs to be restricted is output to the engine ECU 31. In response to this signal, the engine ECU 31 changes the operation control of the internal combustion engine 11 to the control mode during idle operation without depending on the accelerator depression amount Othr. As a result, the output torque of the internal combustion engine 11 is kept small, and the vehicle 10 is prevented from accelerating or starting against the braking force caused by the depression of the brake pedal 17. On the other hand, when the output restriction flag is turned off, the signal output to the engine ECU 31 is not performed, and the output torque of the internal combustion engine 11 is not restricted. Therefore, in this process, the output torque of the internal combustion engine 11 is not limited when the accelerator pedal 22 is not depressed or when the vehicle 10 is in a slip state.

  On the other hand, when it is determined that the accelerator pedal 22 is depressed (step S105: YES) and it is determined that the vehicle 10 is not in a slip state (step S106: NO), the simultaneous operation of both pedals 17 and 22 is performed. The following processing is executed assuming that the vehicle 10 may be accelerated or started and the master pressure estimated value PesPm can be accurately calculated.

  That is, first, based on the engine torque Teng, the gear ratio Rtgear of the automatic transmission 12 calculated based on the gear position Pgear, and the gear ratio Rfinal of the final gear provided integrally with the automatic transmission 12, the following relational expression From this, the drive torque (shaft drive torque Taxle) transmitted from the internal combustion engine 11 to the axle 13 is calculated (step S107).

Taxle = Teng × Rtgear × Rfinal

Then, this shaft driving torque Taxle is converted into a value (driving torque equivalent acceleration Gdrv) corresponding to the acceleration of the vehicle 10 through the conversion coefficient Ctg (step S108). Specifically, the driving torque equivalent acceleration Gdrv (= Taxle × Ctg) is calculated by multiplying the shaft driving torque Taxle by the conversion coefficient Ctg. This conversion coefficient Ctg is a value for converting the driving torque transmitted to the axle 13 into the acceleration of the vehicle 10 and is a constant value determined from the specifications of the vehicle 10 and the like. The conversion coefficient Ctg is obtained in advance and stored in the brake ECU 32.

  Thereafter, as shown in FIG. 5, it is determined whether or not the vehicle 10 is stopped (step S109). Here, it is determined that the vehicle 10 is stopped when the estimated vehicle body speed Vref is “0” (or almost “0”).

  When it is determined that the vehicle 10 is stopped (step S109: YES), the pitching correction value Gp is calculated from the calculation map based on the shaft drive torque Taxle (step S110). In the present embodiment, the relationship between the value (pitching correction value Gp) that can accurately correct the detection error of the actual acceleration G caused by the occurrence of the pitching phenomenon and the shaft driving torque Taxle when the vehicle is stopped is the result of experiments and simulations. Based on the result, it is obtained in advance and stored in the brake ECU 32 (specifically, the calculation map). As the shaft driving torque Taxle is larger, a larger value is calculated as the pitching correction value Gp.

  On the other hand, when it is determined that the vehicle 10 is not stopped and traveling (step S109: NO), the pitching correction value Gp is calculated from the calculation map based on the estimated vehicle body acceleration ΔVref (step S111). In the present embodiment, the relationship between the value (pitching correction value Gp) that can accurately correct the detection error of the actual acceleration G caused by the occurrence of the pitching phenomenon and the estimated vehicle body acceleration ΔVref during vehicle travel is the result of experiments and simulations. It is obtained in advance based on the result and stored in the brake ECU 32 (the calculation map). As the absolute value of the estimated vehicle body acceleration ΔVref is larger, a larger value is calculated as the pitching correction value Gp. In the present embodiment, the processes in steps S109 to S111 function as a correction value calculation process.

  After the pitching correction value Gp is calculated according to the traveling state of the vehicle 10 in this way, the brake is calculated from the following relational expression based on the actual acceleration G, the driving torque equivalent acceleration Gdrv, the rolling resistance Gk, and the pitching correction value Gp. A value (brake equivalent acceleration Gbrk) corresponding to the acceleration generated by the depression operation of the pedal 17 is calculated (step S112).

Gbrk = G−Gdrv−Gk + Gp

As the rolling resistance Gk, a constant value determined by the specifications (specifically, size and material) of the standard tire set for each vehicle type is stored in the brake ECU 32 in advance.

  Thereafter, a negative pressure correction coefficient Cvc is calculated from the calculation map based on the booster negative pressure Pv detected by the pressure sensor 37 (step S113). In the present embodiment, the relationship between the correction value (negative pressure correction coefficient Cvc) that can accurately calculate the booster negative pressure Pv and the master pressure estimated value PesPm is obtained in advance based on the results of experiments and simulations, and the brake ECU 32 (Details are described in the calculation map). As the booster negative pressure Pv is smaller, a larger value is calculated as the negative pressure correction coefficient Cvc.

  Further, the loading correction coefficient Cwe is calculated from the calculation map based on the estimated value of the vehicle weight (the estimated loading amount PesW) (step S114). In the present embodiment, the relationship between the estimated load amount PesW and the correction value (load correction coefficient Cwe) that can accurately calculate the master pressure estimated value PesPm is obtained in advance based on the results of experiments and simulations, and the brake ECU 32 (Details are described in the calculation map). As the load amount estimation value PesW is larger, a larger value is calculated as the load correction coefficient Cwe.

The load amount estimated value PesW is calculated through a process (load amount estimation process) different from the main process and stored in the brake ECU 32, and the stored value is read when the main process is executed. The processing for calculating and storing the load amount estimated value PesW in the load amount estimation processing is executed when all of the following execution conditions are satisfied.
The load amount is estimated during a period from when the operation switch (not shown) is turned on to start the operation of the vehicle 10 to when the operation switch is turned off to stop the operation of the vehicle 10 (so-called trip). There is no history in which the value PesW has been calculated.
The brake pedal 17 is not depressed (specifically, the brake switch 35 is turned off).
The vehicle 10 is traveling (specifically, the estimated vehicle body speed Vref is equal to or higher than a predetermined speed).

  The calculation of the estimated load amount PesW is executed as follows. That is, when the actual acceleration G detected by the acceleration sensor 34 is [a] and the engine torque Teng is the force [F] applied to the vehicle 10, the weight [V] of the vehicle 10 that satisfies the equation of motion [F = ma] [ m] is calculated as the estimated load amount PesW. Thus, in the present embodiment, the estimated load amount PesW is calculated with high accuracy based on the equation of motion [F = ma].

  After the negative pressure correction coefficient Cvc (step S113) and the load correction coefficient Cwe (step S114) are calculated, the following relational expression is based on the brake equivalent acceleration Gbrk, the conversion coefficient Cgp, the negative pressure correction coefficient Cvc, and the load correction coefficient Cwe. From this, a master pressure estimated value PesPm is calculated (step S115).

PesPm = Gbrk × Cgp × Cvc × Cwe

The conversion coefficient Cgp is a value for converting the acceleration of the vehicle 10 into the depression force of the brake pedal 17, and is a constant value determined from the specifications of the vehicle 10. The conversion coefficient Cgp is obtained in advance and stored in the brake ECU 32. In the present embodiment, steps S107, S108, S112, and S115 function as a treading force estimation step.

Thereafter, it is determined whether or not both of the following [Condition A] and [Condition B] are satisfied (step S116).
[Condition A] The accelerator depression amount Othr is greater than or equal to the first determination value α.
[Condition B] The master pressure estimated value PesPm is greater than or equal to the second determination value β.

  As the first determination value α and the second determination value β, it is appropriately determined that the vehicle 10 may accelerate or start due to simultaneous depression of the brake pedal 17 and the accelerator pedal 22. Possible values are obtained and set in advance based on the results of experiments and simulations.

  If both [Condition A] and [Condition B] are satisfied (Step S116: YES), the vehicle 10 may be accelerated or started due to simultaneous depression of both pedals 17 and 22. The output restriction flag is turned on (step S117). Thereby, the output torque of the internal combustion engine 11 is limited, and acceleration and start of the vehicle 10 due to simultaneous depression of both pedals 17 and 22 are suppressed. In the present embodiment, the processes of steps S116 and S117 function as a torque limiting process.

  On the other hand, when one of [Condition A] and [Condition B] is not satisfied (Step S116: NO), the output restriction flag is turned off (Step S118). In this case, the output torque of the internal combustion engine 11 is not limited.

In this way, after the output restriction flag is operated based on the estimated master pressure value PesPm, this process is temporarily terminated.
As described above, according to the present embodiment, the effects described below can be obtained.

  (1) Based on the relationship between the actual acceleration G of the vehicle 10 detected by the acceleration sensor 34 and the acceleration (engine acceleration) of the vehicle 10 obtained by driving the internal combustion engine 11 based on the engine torque Teng, The acceleration change of the vehicle 10 due to the depression operation of the brake pedal 17 can be grasped. Then, the master pressure estimated value PesPm can be accurately calculated based on the acceleration change. Moreover, even if there is a difference between the actual acceleration in the traveling direction of the vehicle 10 and the actual acceleration G detected by the acceleration sensor 34 due to the change in the posture of the vehicle 10 due to the occurrence of the pitching phenomenon, the vehicle 10 The master pressure estimated value PesPm can be accurately estimated through correction by the pitching correction value Gp corresponding to the posture change. Therefore, based on the determination that the master pressure estimated value PesPm is greater than or equal to the second determination value β and the determination that the accelerator depression amount Othr detected by the accelerator sensor 33 is greater than or equal to the first determination value α, It is possible to accurately limit the output of the internal combustion engine 11 after accurately determining the simultaneous depression of the pedal 17 and the accelerator pedal 22. Therefore, acceleration or start of the vehicle 10 due to simultaneous depression of the brake pedal 17 and the accelerator pedal 22 can be suppressed without providing a sensor for detecting the depression operation amount of the brake pedal 17.

  (2) When the vehicle 10 is traveling, the pitching correction value Gp is calculated based on the estimated vehicle body acceleration ΔVref estimated based on the wheel speed VSO detected by the speed sensor 36. Therefore, the pitching correction value Gp can be calculated on the basis of the transition of the traveling speed of the vehicle 10, that is, a value correlated with the change in posture of the vehicle 10 due to the pitching phenomenon. Therefore, it is possible to calculate the master pressure estimated value PesPm with high accuracy while suppressing a decrease in estimation accuracy due to the posture change by the pitching correction value Gp.

  (3) When the vehicle 10 is stopped, the pitching correction value Gp is calculated based on the shaft driving torque Taxle calculated based on the engine torque Teng. Therefore, the pitching correction value Gp can be calculated based on the driving torque transmitted to the axle 13, that is, a value correlated with the change in the posture of the vehicle 10 due to the pitching phenomenon. Therefore, it is possible to calculate the master pressure estimated value PesPm with high accuracy while suppressing a decrease in estimation accuracy due to the posture change by the pitching correction value Gp.

(Second Embodiment)
Hereinafter, a second embodiment in which the vehicle control device of the present invention is embodied will be described focusing on differences from the first embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the first embodiment, when the vehicle 10 is in a slip state, execution of output restriction of the internal combustion engine 11 by the BOS is prohibited. On the other hand, in the present embodiment, even when the vehicle 10 is in a slip state, when the rotational speed difference ΔV between the driving wheel 14A and the driven wheel 14B of the vehicle 10 is equal to or larger than the determination value J2, the internal combustion by the BOS is performed. The output restriction of the engine 11 is not prohibited. According to such an apparatus of the present embodiment, acceleration and start of the vehicle 10 due to simultaneous operation of the brake pedal 17 and the accelerator pedal 22 can be accurately suppressed. The reason will be described below.

  In the vehicle 10, the output torque of the internal combustion engine 11 is transmitted only to the drive wheels 14 </ b> A, whereas the braking force due to the depression operation of the brake pedal 17 acts on both the drive wheels 14 </ b> A and the driven wheels 14 </ b> B. Therefore, if slip occurs during the simultaneous operation of the brake pedal 17 and the accelerator pedal 22, the difference between the rotational speed of the drive wheel 14A and the rotational speed of the driven wheel 14B increases. And this rotational speed difference becomes so large that the depression amount of the accelerator pedal 22 is large.

  In view of this point, in the apparatus of the present embodiment, even when the estimation accuracy of the estimated master pressure value PesPm is low because the vehicle 10 slips during simultaneous operation of both pedals 17 and 22, the same is true. It can be accurately determined that the vehicle 10 may be accelerated or started at this time due to the large rotational speed difference between the drive wheels 14A and the driven wheels 14B of the vehicle 10. And since the output limitation of the internal combustion engine 11 can be executed based on such a determination, acceleration and start of the vehicle 10 caused by simultaneous depression of both the pedals 17 and 22 can be accurately suppressed.

Hereinafter, the torque limiting process according to the present embodiment including the process of determining based on the rotational speed difference will be described with reference to FIG.
As shown in FIG. 6, when it is determined that the vehicle 10 is in a slip state (step S106: YES), a rotational speed difference ΔV between the driving wheel 14A and the driven wheel 14B of the vehicle 10 is calculated (step S106). S201). Specifically, the rotation speed difference ΔV is calculated by subtracting the average value of the wheel speeds VSO of the two driven wheels 14B from the average value of the wheel speeds VSO of the two drive wheels 14A.

Thereafter, it is determined whether or not both [Condition A] and the following [Condition C] are satisfied (step S202).
[Condition C] The rotational speed difference ΔV between the drive wheel 14A and the driven wheel 14B is equal to or greater than the determination value J2.

  Note that the determination value J2 is a value that can accurately determine that the vehicle 10 may be accelerated or started by simultaneous operation of both pedals 17 and 22 based on the results of experiments and simulations. It is obtained and stored in the brake ECU 32. In the present embodiment, when [Condition C] is satisfied, the rotational speed of the drive wheel 14A is higher than the rotational speed of the driven wheel 14B by the simultaneous operation of the brake pedal 17 and the accelerator pedal 22, and the rotational speed difference is It is possible to accurately determine that the vehicle is large, that is, the vehicle 10 may be accelerated or started due to simultaneous operation of both the pedals 17 and 22.

  If it is determined that both [Condition A] and [Condition C] are satisfied (step S202: YES), the vehicle 10 may be accelerated or started due to simultaneous depression of both pedals 17 and 22. As a result, the output restriction flag is turned on (step S117). Thereby, the output torque of the internal combustion engine 11 is limited, and acceleration and start of the vehicle 10 due to simultaneous depression of both pedals 17 and 22 are suppressed.

  On the other hand, when one of [Condition A] and [Condition C] is not satisfied (Step S202: NO), the output restriction flag is turned off (Step S118). In this case, the master pressure estimated value PesPm cannot be calculated with high accuracy, and the rotational speed difference ΔV may cause acceleration or start of the vehicle 10 due to simultaneous depression of both pedals 17 and 22. As a result, the output torque of the internal combustion engine 11 is not limited.

In this way, after the output restriction flag is operated based on the rotational speed difference ΔV between the drive wheel 14A and the driven wheel 14B, this process is temporarily terminated.
On the other hand, when it is determined that the vehicle 10 is not in the slip state (step S106: NO), the master pressure estimated value PesPm can be accurately calculated at this time, and the processing after step S107 described above (FIG. 4). And (see FIG. 5).

As described above, according to the present embodiment, the same effects as those described in (1) to (3) above can be obtained.
(Third embodiment)
Hereinafter, a third embodiment that embodies the vehicle control device of the present invention will be described focusing on differences from the first embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the first embodiment, the negative pressure correction coefficient Cvc is calculated based on the booster negative pressure Pv detected by the pressure sensor 37, and the negative pressure correction coefficient Cvc is used as an estimation parameter for the master pressure estimated value PesPm. It is done. In contrast, in the present embodiment, the pressure sensor 37 is not provided. Therefore, the negative pressure correction coefficient Cvc is not calculated, and the master pressure estimated value PesPm is estimated without using the negative pressure correction coefficient Cvc. In the present embodiment, when the execution frequency of the depression operation of the brake pedal 17 detected by the brake switch 35 becomes equal to or higher than the determination value, the second determination value β in [Condition B] is changed to a small value. I am doing so. According to such a configuration, the following operation can be obtained.

  As described above, when the depression of the brake pedal 17 is repeatedly performed in a short period of time and the booster negative pressure is almost eliminated (substantially atmospheric pressure), the brake pedal 17 is hardly assisted by the brake booster 18. It will be the situation where 17 is stepped on. In this case, since the degree of deceleration of the vehicle 10 with respect to the actual depression force of the brake pedal 17 becomes small, the master pressure estimated value PesPm becomes a small value (a value indicating a low pressure) accordingly.

  In the present embodiment, in accordance with the change in the estimated master pressure value PesPm due to such a change in the booster negative pressure, a threshold value (second determination value) determined based on the estimated master pressure value PesPm. β) is changed to a smaller value. Thus, when the depression operation of the brake pedal 17 is repeatedly performed in a short time, that is, when the booster negative pressure is small, the internal combustion engine is in a situation where the master pressure estimated value PesPm is small compared to the case where the depression is not so. Execution of 11 output restrictions is permitted. Therefore, at this time, although the degree of deceleration of the vehicle 10 becomes small and the master pressure estimated value PesPm becomes small, the execution condition (specifically, [Condition B]) for the output restriction of the internal combustion engine 11 is adjusted accordingly. Therefore, the output of the internal combustion engine 11 can be limited accurately.

Hereinafter, the torque limiting process of the present embodiment will be described with reference to FIG.
As shown in FIG. 7, in this process, the brake equivalent acceleration Gbrk is calculated from the following relational expression based on the actual acceleration G, the driving torque equivalent acceleration Gdrv, the rolling resistance Gk, and the pitching correction value Gp (step S112). ).

Gbrk = G−Gdrv−Gk + Gp

Thereafter, a load correction coefficient Cwe is calculated based on the load amount estimated value PesW (step S114). Then, a master pressure estimated value PesPm is calculated from the following relational expression based on the brake equivalent acceleration Gbrk, the conversion coefficient Cgp, and the load correction coefficient Cwe (step S301).

PesPm = Gbrk × Cgp × Cwe

Thereafter, it is determined whether or not a change condition for changing the second determination value β is satisfied (step S302). Here, it is determined that the change condition is satisfied when the following [Condition D] is satisfied and any one of [Condition E] to [Condition G] is satisfied.
[Condition D] The accelerator depression amount Othr is not less than the first determination value α, and the change amount per unit time of the accelerator depression amount Othr is not more than a predetermined value.
[Condition E] The number of times the brake switch 35 is turned on while the condition [Condition D] is satisfied is continued a predetermined number of times (for example, three times) or more.
[Condition F] The brake switch 35 is turned on at an interval of less than a predetermined time (for example, 1 second) while the state in which the above [Condition D] is satisfied is continued.
[Condition G] The elapsed time after either [Condition E] or [Condition F] is satisfied in a state where [Condition D] is satisfied is less than a predetermined time.

  If the change condition is satisfied (step S302: YES), it is determined that the booster negative pressure is in a small state due to the depression operation of the brake pedal 17 with high frequency, and the second determination value β is predetermined. A value β1 is determined (step S303). Note that the predetermined value β1 is a value that can accurately determine through [Condition B] that there is a possibility that the vehicle 10 may be accelerated or started by simultaneous operation of the brake pedal 17 and the accelerator pedal 22. A value suitable for the situation where the booster negative pressure is reduced is obtained in advance based on the results of experiments and simulations and stored in the brake ECU 32.

  On the other hand, when the change condition is not satisfied (step S302: NO), it is unlikely that the booster negative pressure is in a low state, and the predetermined value β2 is set as the second determination value β (step S302). S304). The predetermined value β2 is a value that can accurately determine through the [Condition B] that the vehicle 10 may be accelerated or started by simultaneous operation of the brake pedal 17 and the accelerator pedal 22. A value suitable for a situation where the booster negative pressure is not small is obtained in advance based on the results of experiments and simulations and stored in the brake ECU 32. A value larger than the predetermined value β1 is set as the predetermined value β2.

After the second determination value β is set in this way, it is determined whether or not both [Condition A] and [Condition B] are satisfied (Step S116).
If both [Condition A] and [Condition B] are satisfied (Step S116: YES), the vehicle 10 may be accelerated or started due to simultaneous depression of both pedals 17 and 22. The output restriction flag is turned on (step S117). Thereby, the output torque of the internal combustion engine 11 is limited, and acceleration and start of the vehicle 10 due to simultaneous depression of both pedals 17 and 22 are suppressed.

  On the other hand, when one of [Condition A] and [Condition B] is not satisfied (Step S116: NO), the output restriction flag is turned off (Step S118). In this case, the output torque of the internal combustion engine 11 is not limited.

In this way, after the output restriction flag is operated based on the estimated master pressure value PesPm, this process is temporarily terminated.
As described above, according to the present embodiment, the same effects as those described in (1) to (3) above can be obtained.

(Other embodiments)
Each of the above embodiments may be modified as follows.
In each embodiment, the method of calculating the weight of the vehicle 10 (specifically, the estimated load amount PesW) is not limited to the method of calculating through the equation of motion, and any calculation method can be adopted. The calculation parameters used for calculating the vehicle weight include, for example, the number of passengers grasped based on the signals of the seating sensor and the seat belt switch, the fuel remaining amount in the fuel tank detected by the fuel remaining amount sensor, and the vehicle height sensor. The vehicle height detected by can be adopted. When these calculation parameters are employed, a heavier value may be calculated as the weight of the vehicle 10 as the number of passengers increases, the remaining amount of fuel increases, the vehicle height decreases.

In each embodiment, the stacking correction coefficient Cwe may be calculated based on a predetermined relational expression instead of being calculated through map calculation.
In each embodiment, instead of using the estimated load amount PesW as an estimation parameter for the estimated master pressure value PesPm, the second determination value β of [Condition B] is variably set according to the estimated load amount PesW. May be. In such a configuration, the smaller the loading amount estimated value PesW, the smaller the second determination value β may be set. According to the configuration, even when the brake pedal 17 is operated with the same pedal effort, the degree of deceleration of the vehicle 10 becomes smaller and the master pressure estimated value PesPm becomes smaller as the vehicle weight is heavier. The second determination value β can be changed in accordance with the change in the master pressure estimated value PesPm. Therefore, acceleration and start of the vehicle 10 due to simultaneous operation of the brake pedal 17 and the accelerator pedal 22 can be accurately suppressed.

  -In each embodiment, the structure which calculates loading amount estimated value PesW and the structure which uses loading amount estimated value PesW as an estimation parameter of master pressure estimated value PesPm can be abbreviate | omitted.

  In the first and second embodiments, instead of calculating the negative pressure correction coefficient Cvc based on the booster negative pressure Pv detected by the pressure sensor 37, the negative pressure based on the index value of the master cylinder pressure A correction coefficient may be calculated. The index value of the master cylinder pressure includes, for example, the depression operation timing of the brake pedal 17 detected by the brake switch 35, the duration of the depression operation of the brake pedal 17, and the elapsed time after the depression of the brake pedal 17 is released. Time etc. can be adopted.

In the first and second embodiments, the negative pressure correction coefficient Cvc may be calculated based on a predetermined relational expression instead of calculating through map calculation.
In the first and second embodiments, instead of using the booster negative pressure Pv as an estimation parameter for the master pressure estimated value PesPm, the second determination value β in [Condition B] is set according to the booster negative pressure Pv. It may be variably set. In the same configuration, the smaller the booster negative pressure Pv, that is, the smaller the differential pressure between the pressure in the constant pressure chamber 23 of the brake booster 18 and the atmospheric pressure, the smaller the second determination value β may be set. According to this configuration, even when the brake pedal 17 is operated with the same pedal effort, the degree of deceleration of the vehicle 10 decreases as the booster negative pressure Pv decreases, and the master pressure estimated value PesPm decreases. The second determination value β can be changed in accordance with the change in the master pressure estimated value PesPm. Therefore, acceleration and start of the vehicle 10 due to simultaneous operation of the brake pedal 17 and the accelerator pedal 22 can be accurately suppressed.

  -In 1st and 2nd embodiment, you may abbreviate | omit the structure which uses the booster negative pressure Pv detected by the pressure sensor 37 and the pressure sensor 37 as an estimation parameter of the master pressure estimated value PesPm.

  In the vehicle control device of each embodiment, the front wheel 14 functions as a driven wheel to which the output torque of the internal combustion engine 11 is not transmitted, and the rear wheel 14 functions as a drive wheel to which the output torque is transmitted. It can also be applied to so-called rear wheel drive vehicles.

The vehicle control apparatus according to the first and third embodiments can be applied to a vehicle in which all wheels are drive wheels, such as a four-wheel drive vehicle.
-In each embodiment, the method of determining that the vehicle 10 is a slip state can be changed arbitrarily. As conditions for determining that the vehicle 10 is in the slip state, for example, a condition that “the difference between the maximum value and the minimum value of the wheel speed VSO of each wheel 14 is a predetermined value or more”, or “each wheel 14 The condition that the difference between the average value of the wheel speeds VSO and the wheel speed VSO of any one of the wheels 14 is equal to or greater than a predetermined value can be set. The slip state is not limited to the method for determining the slip state based on the wheel speed VSO detected by the speed sensor 36, but the slip state is determined based on the relationship between the gear position Pgear of the automatic transmission 12 and the estimated vehicle body speed Vref. Is also possible.

  In the second embodiment, the change condition is arbitrarily changed as long as it can be determined that the execution frequency of the depression operation of the brake pedal 17 is increased when the brake pedal 17 and the accelerator pedal 22 are simultaneously operated. can do. For example, instead of [Condition D], a condition that “the accelerator depression amount Othr is equal to or greater than the first determination value α” can be set. [Condition G] may be omitted, or one of [Condition E] and [Condition F] may be omitted.

  In the first and third embodiments, the process of prohibiting execution of output restriction of the internal combustion engine 11 when the vehicle 10 is in the slip state (the process of step S106 in FIG. 4) may be omitted.

  The vehicle control device according to each embodiment is a vehicle in which the acceleration sensor is attached so that the detection axis of the acceleration sensor and the direction parallel to the road surface coincide with each other when the vehicle is stopped on a flat road. The present invention can also be applied to a vehicle that employs an acceleration sensor having a detection axis.

  In each embodiment, instead of calculating the estimated vehicle body acceleration ΔVref based on the wheel speed VSO, the rotational speed of the axle 13 may be detected and the estimated vehicle body acceleration may be calculated based on the detected value.

  In each embodiment, instead of using the value received from the engine ECU 31 as the engine torque Teng, the operating state of the vehicle 10 (specifically, the accelerator depression amount Othr, the engine rotation speed, the intake air amount, etc.) Based on the above, the engine torque may be calculated and used by the brake ECU 32.

In each embodiment, the pitching correction value Gp may be calculated based on a predetermined relational expression instead of calculating through a map calculation.
In each embodiment, an attitude angle sensor that detects the attitude angle of the vehicle 10 and a vehicle height sensor that detects the vehicle height are provided, and a change in the attitude of the vehicle 10 is detected based on a detection signal of the sensor, and the detection is performed. The pitching correction value Gp may be calculated based on the value.

In each embodiment, the pitching correction value Gp may be calculated only when either the vehicle stops or the vehicle travels.
The configuration of the second embodiment and the configuration of the third embodiment can be implemented in combination.

  In each embodiment, the output torque of the internal combustion engine 11 is limited by changing the operation control of the internal combustion engine 11 to the control mode during idle operation. Instead, an upper limit value may be set for the output torque of the internal combustion engine 11, or the operation of the internal combustion engine 11 (specifically, fuel injection or ignition operation) may be stopped. Further, instead of limiting the output torque of the internal combustion engine 11, the automatic transmission 12 may be in a neutral state. In short, by limiting the driving torque transmitted from the internal combustion engine 11 to the axle 13 of the vehicle 10, acceleration and start of the vehicle 10 due to simultaneous operation of the brake pedal 17 and the accelerator pedal 22 can be suppressed.

In each embodiment, instead of calculating the estimated vehicle speed Vref based on the wheel speed VSO, the rotational speed of the axle 13 may be detected as the estimated vehicle speed.
In each embodiment, instead of calculating the master pressure estimated value PesPm, an estimated value of the depression force itself of the brake pedal 17 may be calculated. In short, it is only necessary to estimate the depression force index value of the brake pedal 17 and the depression force itself, and determine the simultaneous depression of the brake pedal 17 and the accelerator pedal 22 based on the estimated value (brake depression force estimated value).

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... Internal combustion engine, 12 ... Automatic transmission, 13 ... Axle, 14 ... Wheel, 14A ... Driving wheel, 14B ... Drive wheel, 15 ... Intake passage, 16 ... Throttle valve, 17 ... Brake pedal, 18 ... Brake booster, 19 ... master cylinder, 20 ... disc brake device, 21 ... brake actuator, 22 ... accelerator pedal, 23 ... constant pressure chamber, 24 ... transformer chamber, 25 ... vacuum valve, 26 ... atmospheric valve, 27 ... piston, 31 ... Engine ECU (output calculating means), 32 ... brake ECU (correction value calculating means, pedaling force estimating means, torque limiting means), 33 ... accelerator sensor, 34 ... acceleration sensor, 35 ... brake switch, 36 ... speed sensor, 37 ... pressure Sensor.

Claims (6)

Applicable to a vehicle (10) provided with an internal combustion engine (11) as a drive source, an acceleration sensor (34) for detecting vehicle acceleration, and an accelerator sensor (33) for detecting a depression operation amount of an accelerator pedal (22) Being
Output calculation means (31, S104) for calculating the output torque of the internal combustion engine (11);
Correction value calculation means (32, S109, S110, S111) for calculating a pitching correction value corresponding to the amount of change in attitude of the vehicle (10) due to the pitching phenomenon;
The vehicle acceleration detected by the acceleration sensor (34), the output torque calculated by the output calculation means (31, S104), and the pitching correction calculated by the correction value calculation means (32, S109, S110, S111) Treading force estimation means (32, S107, S108, S112, S115) for estimating the depressing operation force of the brake pedal (17) based on the value;
The stepping operation amount detected by the accelerator sensor (33) is greater than or equal to a first determination value, and the stepping operation force estimated by the stepping force estimation means (32, S107, S108, S112, S115) is a second value. A vehicle control device comprising torque limiting means (32, S116, S117) for limiting the drive torque transmitted from the internal combustion engine (11) to the axle (13) when the value is equal to or greater than a determination value. The vehicle control device according to claim 1,
The vehicle (10) includes a speed sensor (36) for detecting the traveling speed,
The correction value calculating means (32, S109, S110, S111) calculates the pitching correction value based on the transition of the traveling speed detected by the speed sensor (36) when the vehicle (10) is traveling. A vehicle control device. The vehicle control device according to claim 2,
The correction value calculation means (32, S109, S110, S111) calculates the acceleration of the vehicle (10) based on the traveling speed detected by the speed sensor (36), and uses the acceleration as the traveling speed. A vehicle control device characterized by being used as a transition of the vehicle. In the vehicle control device according to any one of claims 1 to 3,
The correction value calculating means (32, S109, S110, S111) calculates a pitching correction value based on a driving torque transmitted to the axle (13) when the vehicle (10) is stopped. Vehicle control device. The vehicle control device according to claim 4, wherein
The correction value calculating means (32, S109, S110, S111) calculates the driving torque based on the output torque calculated based on the output calculating means (31, S104). . A control method for a vehicle (10) comprising an internal combustion engine (11) as a drive source, an acceleration sensor (34) for detecting vehicle acceleration, and an accelerator sensor (33) for detecting a depression operation amount of an accelerator pedal (22). There,
An output calculating step (S104) for calculating an output torque of the internal combustion engine (11);
A correction value calculation step (S109, S110, S111) for calculating a pitching correction value according to the posture change of the vehicle (10) due to the pitching phenomenon;
Based on the vehicle acceleration detected by the acceleration sensor (34), the output torque calculated in the output calculation step (S104), and the pitching correction value calculated in the correction value calculation step (S109, S110, S111). Treading force estimation step (S107, S108, S112, S115) for estimating the depressing operation force of the brake pedal (17),
The stepping operation amount detected by the accelerator sensor (33) is greater than or equal to a first determination value, and the stepping operation force estimated in the stepping force estimation step (S107, S108, S112, S115) is a second determination value. A vehicle control method including a torque limiting step (S116, S117) for limiting the drive torque transmitted from the internal combustion engine (11) to the axle (13) when the above is true.

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