JP2006232094A - Brake control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of starting a vehicle with stable acceleration by appropriately releasing braking force holding condition even in the case wherein an acceleration pedal is suddenly operated by wrong operation by an occupant during the condition wherein vehicle braking force is held. <P>SOLUTION: This braking force control device for a vehicle is provided with a braking force holding means for holding braking force to be given to wheels separately from brake operation by the occupant, an accelerator operating condition detecting means for detecting accelerator operating condition by the occupant, and a braking force releasing means for releasing the braking force holding condition by reducing braking force when the accelerator operating condition detecting means detects accelerator operation by the occupant. This brake control device is also provided with releasing speed changing means (S106-S110) for reducing quantity of reduction of braking force by the braking force releasing means as accelerator operating speed, which is detected by the accelerator operating condition detecting means, is higher in the condition wherein braking force is held by the braking force holding means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle braking control device that controls braking force applied to a vehicle wheel.

  Conventionally, by controlling the braking force of the vehicle in relation to the driving force of the vehicle or the output torque of the power source, for example, when starting on an uphill road, the vehicle is prevented from moving backward to start smoothly. ing. As an example, Patent Document 1 discloses an invention relating to a brake force holding device that continuously applies a braking force to a vehicle until the start driving force of the vehicle itself reaches a predetermined value even after the brake pedal depression operation is released. ing.

  According to the brake force holding device described in Patent Document 1, if the start driving force is increased by the depression operation of the accelerator pedal of the driver while the brake force is held, the start driving force becomes a predetermined value. Before reaching the value, the reduction of the braking force is started, and thereafter, the braking force is gradually reduced as the starting driving force increases. Therefore, since the braking force is not released at a time when starting, it is said that the driver does not receive a sudden feeling such as a shock at the time of starting or a feeling of catching of the brake at the time of starting.

  Further, Patent Document 2 discloses that the reverse force estimated by the reverse force estimating means when the vehicle stops on the slope for the purpose of preventing the vehicle stopped on the uphill regardless of the slope of the slope. And a stopping device configured to prevent the vehicle from moving backward on the slope by adding to the wheels a stopping force that balances with the backward force based on a deviation from the driving force estimated by the driving force estimating means. The invention is described.

  Further, Patent Document 3 describes a series of brake braking operations such as a clutch operation signal from a clutch pedal switch, an accelerator operation signal from an accelerator operation switch, a brake operation signal from a brake switch, and a shift signal from a forward / reverse shift switch. When a control signal and a vehicle stop signal from a vehicle speed sensor are detected, the hydraulic pressure of the brake wheel cylinder is maintained and the front and rear wheels are braked locked, and from that state, the clutch pedal is depressed, An invention relating to a brake hydraulic pressure control device configured to release the holding of the hydraulic pressure of the brake wheel cylinder when a control signal is detected by a series of start operations in which the shift lever is shifted to a predetermined position and the accelerator pedal is depressed. Is described.

In Patent Document 4, the distance between the host vehicle and the obstacle ahead of the traveling direction of the host vehicle is measured, and the distance between the host vehicle and the obstacle when the host vehicle is stopped or traveling at a low speed. An invention relating to a vehicle collision prevention control device configured to be restricted so that when the vehicle approaches a predetermined distance or less, the vehicle cannot start, cannot be accelerated, or is below a predetermined acceleration is described.
JP 2000-313321 A JP-A-7-69102 JP-A-10-250541 JP 2004-280489 A

  In each of the inventions described in Patent Documents 1 to 3, when the braking force is held on a slope or the like and the vehicle is stopped, the accelerator pedal is suddenly depressed by, for example, an erroneous operation of the driver. If this happens, the vehicle's driving force will increase rapidly, and the braking force will be held quickly or evenly released, making the vehicle's acceleration unstable when starting. As a result, the driver may feel uncomfortable or the vehicle may start at a large acceleration unintended by the driver.

  In that case, by providing a function similar to that of the vehicle collision prevention device described in Patent Document 4 above, an unintended start of the driver due to an erroneous operation or the like is performed, and a collision with an obstacle ahead is prevented. Although it is possible to avoid such a collision prevention function of such a vehicle, none of the inventions described in the above-mentioned Patent Documents 1 to 3 takes into consideration, and these points have not been improved yet. There was room.

  The present invention has been made paying attention to the above technical problem, and is a case where the accelerator pedal is suddenly depressed by an erroneous operation of the occupant while the braking force of the vehicle is maintained. Another object of the present invention is to provide a control device that can start the vehicle at a stable acceleration by appropriately releasing the holding state of the braking force.

  In order to achieve the above object, the invention of claim 1 is directed to a braking force holding means for holding a braking force applied to a wheel separately from a passenger's brake operation, and an accelerator operation state detection for detecting an accelerator operation state of the passenger. And a braking force release means for reducing the braking force and releasing the holding state when the accelerator operation of the occupant is detected by the accelerator operation state detection means. Release speed changing means for reducing the amount of decrease in the braking force by the braking force releasing means as the accelerator operating speed detected by the accelerator operating state detecting means is faster while the braking force is being held by the holding means. It is the control device characterized by comprising.

  According to a second aspect of the present invention, in the first aspect of the invention, the release speed changing means detects an accelerator sudden operation in which the accelerator operation speed is higher than a predetermined speed determined in advance by the accelerator operation state detecting means. In this case, the control device includes means for reducing the amount of decrease in the braking force.

  Further, the invention according to claim 3 is the invention according to claim 1 or 2, wherein the release speed changing means detects the accelerator sudden operation by the accelerator operation state detecting means and is detected by the accelerator operation state detecting means. The control device further includes means for reducing the amount of decrease in the braking force when the accelerator operation amount is greater than a predetermined amount.

  On the other hand, the invention of claim 4 is the invention according to any one of claims 1 to 3, wherein the release speed changing means detects the accelerator sudden operation by the accelerator operation state detecting means, and then the accelerator operation amount is The control device includes means for reducing the amount of reduction of the braking force when the accelerator operation is detected once again after being reduced.

  The invention according to claim 5 is the invention according to any one of claims 1 to 3, further comprising obstacle detection means for detecting an obstacle ahead in the traveling direction of the vehicle, wherein the release speed changing means is the obstacle. The control device includes means for reducing the amount of decrease in the braking force when the obstacle is detected by the object detection means.

  According to the first aspect of the present invention, in the state where the braking force of the vehicle is maintained, for example, when the accelerator operation due to the depression operation of the accelerator pedal of the occupant is detected and the holding of the braking force is released, The accelerator operation state such as the accelerator pedal depression speed or depression amount is also detected. The faster the accelerator pedal depression speed, that is, the accelerator operation speed, the lower the braking force decrease when the braking force is released. The Therefore, when the accelerator operation speed is fast and the driving force increases rapidly, the faster the accelerator operation speed, the smaller the decrease in the braking force that is held, and the slower the braking force. In other words, the holding of the braking force can be released with a release speed slower than usual or a release time longer than usual while decreasing. As a result, even when the accelerator pedal is suddenly depressed due to, for example, an occupant's mistaken operation, the braking force holding state is gently released, so the vehicle starts with unstable acceleration. Alternatively, it is possible to avoid starting at an acceleration that is not intended by the occupant and to start the vehicle at a stable acceleration.

  According to the second aspect of the present invention, when the accelerator operation is detected and the holding of the braking force is released, the accelerator operation speed at the time of the accelerator operation is faster than a predetermined speed. Is detected, the amount of decrease in the braking force when the holding of the braking force is released is reduced. For this reason, even if the accelerator pedal is suddenly depressed due to a sudden accelerator operation, for example, an occupant's mistaken operation and the accelerator operation speed exceeds a predetermined speed, the amount of decrease in braking force that has been maintained is reduced. The braking force can be released while reducing the braking force gently, and the vehicle can be started with stable acceleration, avoiding starting with unstable acceleration or starting with unintended acceleration by the passenger. Can be started.

  Further, according to the invention of claim 3, when the accelerator operation is detected and the holding of the braking force is released, the accelerator operation speed at the time of the accelerator operation, and the depression amount or depression angle or depression pressure of the accelerator pedal When the accelerator operation amount is detected together, and the accelerator operation speed is faster than a predetermined speed and the accelerator operation amount is higher than the predetermined amount, the holding of the braking force is released. The amount of decrease in braking force is reduced. Therefore, it is possible to reliably detect a sudden accelerator operation due to, for example, an occupant's erroneous operation, and when the driving force increases rapidly due to such a sudden accelerator operation, the amount of decrease in the braking force that has been held is reduced. The holding of the braking force can be released while reducing the braking force gradually. As a result, even when a sudden accelerator operation is performed, it is possible to avoid starting with unstable acceleration or starting with unintended acceleration of the occupant and starting the vehicle with stable acceleration. it can.

  On the other hand, according to the invention of claim 4, for example, after the accelerator pedal is suddenly depressed, the amount of depression of the accelerator pedal is once reduced, and the accelerator pedal is depressed again at a normal depression speed, so If it is performed, that is, if the accelerator operation is detected and the accelerator operation amount due to the accelerator operation is once reduced, then the accelerator operation is detected again at the normal accelerator operation speed, the above claims The amount of decrease in the braking force when the holding of the braking force is released as in the control according to the first to third aspects is not reduced. In other words, even when the accelerator is suddenly operated, for example, when the accelerator pedal is depressed again at a normal depression speed, the amount of decrease in the braking force when the holding of the braking force is released The braking force holding state is released in a normal state, that is, at a normal release speed or a normal release time. Therefore, the holding of the braking force can be released in an appropriate state according to the operation state of the accelerator operation, and the vehicle can be started smoothly. In this case, in order to reduce the accelerator operation amount, for example, when the accelerator operation amount becomes “0”, or when the accelerator operation amount is reduced to a predetermined value or less, or the change tendency of the accelerator operation amount increases. It includes the case where it changes from to decrease.

  According to the invention of claim 5, when the accelerator operation is detected and the holding of the braking force is released, for example, when an obstacle is detected in the forward direction of the vehicle such as another stopped vehicle, The amount of decrease in braking force when the holding of power is released is reduced. Therefore, when the holding of the braking force is released and the vehicle starts, if there is an obstacle ahead in the traveling direction of the vehicle, the holding state of the braking force is gently released, so that a sudden driving force Can be suppressed, and collision with an obstacle can be avoided.

  Next, an embodiment of the present invention will be described with reference to the drawings. First, a vehicle drive system to which the present invention is applied is shown in FIG. FIG. 3 shows an example in which the vehicle Ve to which the present invention is applied is an FR (front engine / rear drive) type two-wheel drive vehicle Ve. In the vehicle Ve shown in FIG. 3, a transmission 2 for shifting the rotational output of the power source 1 is disposed on the output side of the power source 1, and the transmission 2 is transmitted from the transmission 2 to the output side of the transmission 2. A drive shaft 5 that transmits the drive force to the drive wheels 3 and 4 is provided.

  As the power source 1, for example, at least one of an internal combustion engine and an electric motor can be used. As the internal combustion engine, an internal combustion engine having a mechanism capable of electrically controlling an output such as an electronic throttle valve is preferably used. . As the electric motor, for example, a motor generator having a power running function for converting electric energy into kinetic energy and a regeneration function for converting kinetic energy into electric energy can be used. In this embodiment, the case where an engine 1 such as a gasoline engine, a diesel engine, or a natural gas engine having an electronic throttle valve 1a is used as the power source 1 will be described.

  As the transmission 2, various transmissions such as a manual transmission, an automatic transmission, or a continuously variable transmission can be used. The drive shaft 5 is connected to the left and right rear wheel drive shafts 7 and 8 via the rear differential 6. The rear wheel drive shafts 7 and 8 have wheels (drive wheels) 3 serving as left and right rear wheels. , 4 are connected. The wheels 9 and 10 that are the left and right front wheels are provided as non-driving wheels 9 and 10 that themselves do not generate a driving force.

  The output torque of the engine 1 is transmitted to the drive wheels 3 and 4 through the power transmission system formed by each mechanism. Here, the operation of the electronic throttle valve 1a that controls the output torque of the engine 1 is controlled by the electronic control device 100 described later. That is, the electronic control device 100 controls the operation of the electronic throttle valve 1a to increase / decrease the output torque of the engine 1 and to increase / decrease the driving force generated by the drive wheels 3 and 4. Therefore, the driving force of the driving wheels 3 and 4 can be controlled based on the signal output from the electronic control device 100.

  Each wheel 3, 4, 9, 10 is provided with a braking device 11 respectively. Further, in the hydraulic system of the hydraulic fluid that connects the wheel cylinder 12 that constitutes the braking device 11 and the master cylinder 13, the hydraulic pressure in the wheel cylinder 12 is increased or decreased separately from the driver's brake operation. A brake actuator 14 for controlling the braking force applied to the wheels 3, 4, 9, 10 is provided.

  FIG. 4 schematically shows the configuration of the brake actuator 14. The brake actuator 14 is configured so that the hydraulic pressure can be controlled independently for each braking device 11 of each of the wheels 3, 4, 9, and 10. FIG. The structure of the brake actuator 14 regarding one wheel among 3, 4, 9, and 10 is shown typically. Accordingly, the other wheels have the same configuration.

  The hydraulic system constituting the brake actuator 14 is provided with a hydraulic pump 21 that is rotationally driven by a motor 20. The hydraulic pump 21 functions as a hydraulic pressure source when controlling the braking force, and the discharge port 21 a of the hydraulic pump 21 is connected to a pipe between the shut-off valve 23 and the holding valve 24 via a pipeline 22. It is connected to the path 25. A check valve 26 is provided on the discharge port 21 a side of the hydraulic pump 21 to block the flow of hydraulic fluid in the direction opposite to the discharge direction of the hydraulic pump 21.

  On the other hand, the suction port 21b of the hydraulic pump 27 is connected to the reservoir 28 via the conduit 27, and the flow of hydraulic fluid in the direction opposite to the suction direction of the hydraulic pump 21 is blocked in the conduit 27. Check valves 29 and 30 are provided. The pipe line 27 between the check valves 29 and 30 is connected to the reservoir tank 32 through the pipe line 31, and the hydraulic fluid in the reservoir tank 32 is supplied to the hydraulic pump 21 through the pipe line 27. It is configured to be inhaled. A suction valve 33 of a normally closed type (a type that opens when energized) is provided in the middle of the pipe 31 to open and close the pipe 31.

  The pipe 25 connecting the master cylinder 13 and the wheel cylinder 12 is provided with a normally open type (a type that closes when energized) shut-off valve 23, and hydraulic pressure control of the hydraulic fluid is executed. At this time, the valve 25 is closed, and the conduit 25 between the master cylinder 13 and the wheel cylinder 12 is shut off. Further, a normally open type holding valve 24 is provided in the pipe line 25 closer to the wheel cylinder 12 than the shutoff valve 23, and when the holding valve 24 is closed, the holding valve 24 and the wheel cylinder 12 are closed. The hydraulic system on the side is closed, that is, the hydraulic pressure of the hydraulic system on the wheel cylinder 12 side is maintained from the holding valve 24.

  Therefore, by controlling the holding valve 24 to the closed state, the hydraulic pressure of the hydraulic system on the wheel cylinder 12 side from the holding valve 24, that is, the brake hydraulic pressure can be held. , 9 and 10 can be held respectively.

  The conduit 25 between the holding valve 24 and the wheel cylinder 12 is connected to the reservoir 28 by a conduit 34. The pipe 34 is provided with a normally closed pressure reducing valve 35. The pressure reducing valve 35 is constituted by an electromagnetic valve such as a linear solenoid valve or a duty solenoid valve, for example, and the communication state of the pipe line 34 can be changed according to the duty ratio by driving the pressure reducing valve 35 with a duty ratio. .

  Therefore, by controlling the open / close state of the pressure reducing valve 35, the communication state of the pipe line 34 can be changed, and the hydraulic pressure (brake hydraulic pressure) of the hydraulic system on the wheel cylinder 12 side from the holding valve 24 can be changed. . For example, as described above, the pressure reducing valve 35 is controlled to be opened from the state in which the brake fluid pressure is maintained, that is, the state in which the braking force applied to each of the wheels 3, 4, 9, and 10 is retained. Then, the holding state of the braking force applied to each of the wheels 3, 4, 9, and 10 can be released by bringing the pipe line 34 into a communicating state and reducing the brake fluid pressure. Further, when the brake fluid pressure is reduced, the brake fluid pressure is reduced (speed reduction time) by controlling the duty ratio of the pressure reducing valve 35 driven by the duty ratio, that is, the brake force holding speed release speed (release). Time) can be appropriately controlled.

  As described above, the operation of the brake actuator 14 constituted by the hydraulic pump 21 and various valve devices is controlled by the electronic control device 100. That is, the operation of the brake actuator 14 is controlled by the electronic control device 100, and the hydraulic pressure in the wheel cylinder 12 of the braking device 11 is controlled to increase or decrease. Therefore, based on the signal output from the electronic control unit 100, the braking device 11 provided on each wheel 3, 4, 9, 10 is controlled, that is, added to each wheel 3, 4, 9, 10. Each braking force can be controlled.

  FIG. 5 schematically shows the configuration of the electronic control device 100. The electronic control unit 100 includes a wheel speed sensor 101 that detects the rotational speeds of the wheels 3, 4, 9, and 10, a shift position sensor 102 that detects the shift position of the shift lever, and a depression amount (depression angle) of the brake pedal 36. ) Or a brake pedal sensor 103 for detecting the depression pressure, an accelerator pedal sensor 104 for detecting the depression amount (depression angle) or depression pressure or depression time of an accelerator pedal (not shown), and an electronic throttle valve provided in the engine 1 A throttle valve sensor 105 that detects the throttle opening of 1a, a drive torque sensor 106 that detects the drive torque of each of the drive wheels 3 and 4, a longitudinal acceleration sensor 107 that detects the longitudinal acceleration of the vehicle Ve, and an inclination angle of the road surface Detecting tilt angle sensor 08, a steering angle sensor 109 for detecting the steering direction and steering angle of a steering wheel (not shown), a data processing device 110 having a radar for detecting an obstacle ahead of the traveling direction of the vehicle Ve, or an image having a CCD camera Various sensors such as the processing device 111 are provided, and an output signal of each sensor is input to the electronic control device 100.

  Various types of data are stored in the electronic control device 100, and the electronic throttle valve 1a and the brake are transmitted from the electronic control device 100 based on the signal input to the electronic control device 100 and the stored data. A signal for controlling the actuator 14 is output.

  Here, based on the accelerator pedal depression amount (depression angle) detected by the accelerator pedal sensor 104, the depression pressure, the depression time, or the throttle opening of the electronic throttle valve 1a detected by the throttle valve sensor 105, That is, for example, the accelerator pedal depression speed is calculated by the electronic control unit 100 performing arithmetic processing based on the detected value of the accelerator pedal depression amount (depression angle), depression pressure, depression time, or throttle opening of the electronic throttle valve 1a. It is possible to detect the accelerator operation state of the passenger. Therefore, the electronic control unit 100, the accelerator pedal sensor 104, and the throttle valve sensor 105 function as an accelerator operation state detection unit in the present invention. Further, the data processing device 110 provided with a radar that detects an obstacle ahead of the traveling direction of the vehicle Ve, or the image processing device 111 provided with a CCD camera functions as an obstacle detection means in the present invention.

  Further, the brake cylinder constituted by the wheel cylinder 12, the master cylinder 13, the brake actuator 14, the hydraulic system connecting them, and the like, and a control signal are output to the brake apparatus. Thus, the electronic control unit 100 that controls the holding / release state of the braking force applied to each of the wheels 3, 4, 9, and 10 functions as the braking force holding means and the braking force releasing means in the present invention.

  As described above, according to the present invention, even when the accelerator pedal is suddenly depressed due to an erroneous operation of the occupant when the braking force of the vehicle Ve is maintained, the vehicle Ve can be stably accelerated. Therefore, the control device of the present invention is configured to execute the following control.

(First control example)
FIG. 1 is a flowchart for explaining the first control example, and the routine shown in this flowchart is repeatedly executed every predetermined short time. In FIG. 1, first, it is determined whether or not the vehicle Ve is in a stopped state by a brake operation at the will of the occupant (step S101). Specifically, a brake operation at the will of the occupant, for example, an operation of depressing the brake pedal 36 by the occupant is performed, and the depression amount (depression angle) of the brake pedal 36 detected by the brake pedal sensor 103 at that time, or the brake pedal A braking force is applied to each of the wheels 3, 4, 9, and 10 based on the master cylinder pressure of the master cylinder 13 that generates pressure according to the amount of depression (depression angle) of 36, and the vehicle Ve is caused by the braking force. It is determined whether or not the vehicle is stopped. In this case, the determination of the stop state of the vehicle Ve is, for example, that the detection results of the wheel speed sensor 101 that detects the rotational speeds of the wheels 3, 4, 9, 10 are all equal to or lower than a predetermined vehicle speed (for example, approximately 0 km / h). Therefore, it can be determined.

  If the vehicle Ve is not in a stopped state, for example, if at least one of the detection results of the wheel speed sensors 101 is not less than or equal to the predetermined vehicle speed, a negative determination is made in this step S101, the subsequent control is not executed. End this routine once

  On the other hand, if the vehicle Ve is in a stopped state and the determination in step S101 is affirmative, the process proceeds to step S102, the road surface gradient is calculated, and the data is stored. This road surface gradient calculation processing can be obtained from the detection result of the inclination angle sensor 108 mounted on the vehicle Ve, for example. Or it can also estimate based on the detection result of the longitudinal acceleration of the vehicle Ve according to the road surface gradient obtained by the longitudinal acceleration sensor 107. It is also possible to estimate from the change state of the rotational speed of each wheel 3, 4, 9, 10 obtained by the wheel speed sensor 101. Alternatively, it can be estimated based on geographic information obtained from a navigation system (not shown).

  Subsequently, based on the road surface gradient data obtained in step S102, the driving torque necessary for the vehicle Ve to start is calculated, and the throttle opening of the electronic throttle valve 1a for generating the driving torque is calculated. It is set (step S103).

  Then, the braking force of the vehicle Ve is maintained (step S104). Specifically, a braking force necessary for maintaining the stopped state of the vehicle Ve is obtained, and the braking force is held in a state where the braking force is applied to the wheels 3, 4, 9, and 10. That is, as described above, the brake fluid pressure is held by controlling the holding valve 24 of the brake actuator 14 to be closed, and the braking force applied to each of the wheels 3, 4, 9, and 10 is controlled. Are held respectively.

  When the braking force of the vehicle Ve, that is, the braking force applied to each of the wheels 3, 4, 9, and 10 is maintained, it is determined whether or not the occupant is willing to start (step S105). Regarding the determination of the occupant's intention to start, for example, the depression state of the brake pedal 36 by the occupant, the shift position or gear position of the transmission 2 selected by operating a shift lever (not shown), and the accelerator pedal. The presence or absence of the occupant's intention to start is determined based on the depression state (not shown).

  The determination of the depression state of the brake pedal 36 in this case can be made based on the detection result of the depression amount or depression angle of the brake pedal 36 or depression pressure detected by the brake pedal sensor 103, for example, When the depression amount of the pedal 36 is equal to or greater than a predetermined amount, it can be determined that the occupant has no intention to start.

  For example, when the transmission 2 mounted on the vehicle Ve is an automatic transmission, the shift position position of the transmission 2 selected by operating a shift lever or the like is in the D (drive) range or R (reverse). The state of the range can be a shift position position for starting. In particular, when the transmission is a stepped automatic transmission, in addition to these D range and R range, L (1 (Speed) range or 2nd (second speed) range can also be used as a shift position for starting. For example, when the transmission 2 mounted on the vehicle Ve is a manual transmission, a depression of a clutch pedal (not shown) of a predetermined amount or more is detected by, for example, a clutch pedal sensor (not shown), A state where the gear position of the transmission 2 selected by operating the shift lever or the like is shifted to a gear position such as a low gear or a reverse gear can be set as a gear position for starting.

  Further, the determination of the depression state of the accelerator pedal can be made, for example, based on the detection result of the depression amount or depression angle of the accelerator pedal, the depression pressure, or the depression time detected by the accelerator pedal sensor 104. When the amount of depression of the accelerator pedal is less than a predetermined amount, it can be determined that the occupant has no intention to start. In addition to the amount of operation of the accelerator pedal, such as the amount of depression of the accelerator pedal, for example, based on the amount of operation in a predetermined device that increases or decreases the throttle opening of the electronic throttle valve 1a according to the amount of operation such as the amount of operation of the accelerator lever. Thus, it is possible to determine whether or not the passenger is willing to start.

  Therefore, the brake pedal 36 is depressed more than a predetermined amount, that is, the brake pedal 36 is not released, or the shift position position or gear position of the transmission 2 is not the shift position position or gear position for starting. If the determination is negative in this step S105, for example, because the accelerator pedal is not depressed more than a predetermined amount, it is determined that the occupant is not yet ready to start, and the subsequent control is executed. Instead, this routine is terminated.

  The state where the shift position position or gear position of the transmission 2 is not a shift position position or gear position for starting is, for example, when the transmission 2 is an automatic transmission, the shift position position is N (neutral). ) Range or P (parking) range, etc., or when the transmission 2 is a manual transmission, the gear position is in a neutral state or the clutch pedal is depressed more than a predetermined amount. It is.

  On the other hand, the brake pedal 36 is not depressed more than a predetermined amount, that is, the brake pedal 36 is released, and the shift position position or gear position of the transmission 2 is changed to the shift position position or gear position for starting. If the determination is affirmative in step S105 because the setting is made and the accelerator pedal is depressed by a predetermined amount or more, the process proceeds to step S106, and the depression operation of the accelerator pedal at that time is performed suddenly. It is then determined whether or not it is a strong stepping operation.

  The determination of the rapid and strong depression of the accelerator pedal is performed by, for example, calculating the accelerator pedal calculated based on the detected values of the accelerator pedal depression amount (depression angle), depression pressure, depression time, and the like detected by the accelerator pedal sensor 104. An accelerator sudden operation in which the depression speed is faster than a predetermined speed A that is predetermined as a threshold for detecting a sudden operation of the accelerator pedal, that is, the accelerator pedal depression speed is faster than the predetermined speed A, and the accelerator pedal is detected. When the amount of depression of the accelerator pedal is greater than a predetermined amount B that is predetermined as a threshold for detecting a rapid and strong depression of the accelerator pedal, the depression operation of the accelerator pedal in that case is an abrupt and strong depression Judgment can be made.

  Therefore, if a negative determination is made in this step S106 because the accelerator pedal depression speed is equal to or less than the predetermined speed A, or the accelerator pedal depression amount is equal to or less than the predetermined amount B, the accelerator in that case It is determined that the pedal depressing operation is abrupt and not a strong depressing operation, that is, a normal accelerator operation, and the process proceeds to step S107, where the release speed when releasing the holding of the braking force is the release speed during the normal accelerator operation. (Normal release speed) is set, and then this routine is terminated.

  Specifically, as described above, when the pressure reducing valve 35 of the brake actuator 14 is controlled to be in the open state so that the pipe line 34 is in a communicating state and the brake hydraulic pressure is reduced, The pressure reducing valve 35 is duty-controlled so that the release speed when releasing the holding of the braking force becomes the normal pressure reduction speed (release speed). In other words, the pressure reducing valve 35 is duty-controlled so that the amount of decrease in the brake fluid pressure, that is, the amount of decrease in the braking force when releasing the holding of the braking force, becomes the amount of decrease (decrease) in the normal time.

  FIG. 6 is a time chart showing changes in the throttle opening and the brake fluid pressure when the brake fluid pressure is reduced at the normal pressure reduction speed as described above. In FIG. 6, when the accelerator pedal is started to be depressed at a normal operation speed (depressing speed), the throttle opening TA starts to increase, and the throttle opening TA generates a driving torque necessary for starting the vehicle Ve. When reaching the target throttle opening degree TTA set as the throttle opening degree (time T1), the brake fluid pressure OP starts decreasing at the brake fluid pressure decreasing speed during normal accelerator operation. Note that the slope of the change state line of the throttle opening TA indicated by the angle α0 represents the operation speed of the accelerator pedal during normal accelerator operation, and the slope of the change state line of the brake hydraulic pressure OP indicated by the angle β0 is The brake fluid pressure reduction speed during normal accelerator operation is shown.

  On the other hand, if the accelerator pedal depression speed is faster than the predetermined speed A and the accelerator pedal depression amount is larger than the predetermined amount B, and if the determination in step S106 is affirmative, the accelerator pedal in that case is It is determined that the stepping operation is an abrupt and strong stepping operation, and the process proceeds to step S108, where the brake fluid pressure is reduced, that is, the brake force decrease is stopped for a predetermined time, or the brake force decrease amount is reduced. The pressure reduction speed, that is, the release speed when releasing the holding of the braking force is controlled to be slower than the normal pressure reduction speed (release speed). In other words, if it is determined that the accelerator pedal depressing operation is a rapid and strong depressing operation, the amount of decrease in the braking force when releasing the holding of the braking force is reduced, and the normal decompression time (release time) It is controlled to be longer.

  Subsequently, whether or not the accelerator pedal is depressed has been changed. Specifically, after the accelerator pedal is suddenly and strongly depressed, the accelerator pedal depression is temporarily released and the accelerator pedal is depressed again. It is determined whether or not the so-called accelerator pedal is depressed again (step 109).

  If the determination at step 109 is affirmative because the accelerator pedal has been depressed again, it is determined that the depression operation of the accelerator pedal is a normal accelerator operation, and the determination at step 106 is negative. As in the case of the above, the routine proceeds to step 107, where the release speed for releasing the holding of the braking force is set to the release speed at the time of normal accelerator operation (the release speed at the normal time), and then this routine is temporarily ended. To do.

  The change state of the throttle opening and the brake fluid pressure when the accelerator pedal is depressed again as shown above is shown in the time chart of FIG. In FIG. 7, when the accelerator pedal is depressed more rapidly than the predetermined speed A and the accelerator pedal is depressed more rapidly than the predetermined amount B, the throttle opening degree TA is set to the target throttle. Even if the opening degree TTA is reached, the brake fluid pressure OP is not reduced and the holding state is continued. Then, when the accelerator pedal is depressed again at the normal depression speed, the throttle opening TA starts to increase again by the depression, and when the throttle opening TA reaches the target throttle opening TTA (time T2 ), The brake fluid pressure OP is reduced at the brake fluid pressure reduction speed during normal accelerator operation.

  Note that the slope of the change state line of the throttle opening TA indicated by the angle α1 represents the accelerator pedal operating speed when a sudden and strong stepping operation is performed, and the change state of the throttle opening TA indicated by the angle α2. The slope of the line represents the operating speed of the accelerator pedal when the accelerator pedal is depressed again, and the slope of the change state line of the brake fluid pressure OP indicated by the angle β1 indicates that the accelerator pedal is depressed again. Represents the pressure reduction speed of the brake fluid pressure. At this time, angle α2≈angle α0 and angle β1≈angle β0. That is, when the accelerator pedal is depressed again by the normal accelerator operation after the accelerator sudden operation, the same control as that in the case of reducing the brake fluid pressure at the normal pressure reduction speed is executed.

  On the other hand, if a negative determination is made in step 109 because the accelerator pedal has not been depressed again, the routine proceeds to step 110, where the release speed when releasing the holding of the braking force is It is set to the release speed at the time of a sudden and strong stepping operation, and a warning sound is transmitted to make the occupant aware of this, or a warning is displayed, or both a warning sound and warning display are performed. Thereafter, this routine is once terminated.

  Specifically, as described above, when the pressure reducing valve 35 of the brake actuator 14 is controlled to be in the open state so that the pipe line 34 is in a communicating state and the brake hydraulic pressure is reduced, The pressure reducing valve 35 is duty-controlled so that the release speed when releasing the holding of the braking force becomes a pressure reduction speed (release speed) at a time when the accelerator pedal is suddenly and strongly depressed, which is slower than normal. In other words, the brake fluid pressure reduction amount, that is, the reduction amount of the braking force when releasing the holding of the braking force is less than the normal time, and the pressure reduction amount (decrease amount) at the time of the accelerator sudden operation is reduced. The valve 35 is duty controlled.

  FIG. 8 is a time chart showing changes in the throttle opening and the brake fluid pressure when the brake fluid pressure is reduced at the pressure reduction speed when the accelerator pedal is suddenly and strongly depressed as described above. In FIG. 8, when the accelerator pedal is depressed more rapidly than the predetermined speed A and the accelerator pedal is depressed more rapidly than the predetermined amount B, the throttle opening degree TA is set to the target throttle. Even if the opening degree TTA is reached, the brake fluid pressure OP is not reduced and the holding state is continued for a predetermined time. Then, when the predetermined time has elapsed (time T3), the brake fluid pressure OP starts to be reduced at a brake fluid pressure reduction rate that is slower than the normal pressure reduction rate and during the sudden and strong depression of the accelerator pedal. The

  Note that the slope of the line TA representing the change in the throttle opening indicated by the angle α3 represents the operating speed of the accelerator pedal during a sudden and strong depression of the accelerator pedal, and the change in the brake fluid pressure indicated by the angle β3 The slope of the line OP representing the state represents the speed at which the brake fluid pressure is reduced when the accelerator pedal is suddenly and strongly depressed. That is, when the angle β3> the angles β0, β1, and when the accelerator pedal is suddenly and strongly depressed and the accelerator pedal is not depressed again, the brake fluid is slower than the normal decompression speed. Control for reducing the pressure is executed.

  If the brake pedal pressure is maintained while the brake fluid pressure is maintained and the accelerator pedal is suddenly and strongly depressed as described above, the brake force retention is released when the accelerator pedal is depressed. Then, the driving force of the vehicle Ve is suddenly increased by a sudden and strong depression operation of the accelerator pedal, and there is a possibility that the vehicle Ve starts in an unstable acceleration state or at an acceleration not intended by the occupant. Therefore, in the control according to the present invention, when the accelerator pedal is suddenly and strongly depressed as described above, the brake fluid pressure reduction, that is, the reduction of the braking force is temporarily stopped, and further the brake fluid pressure reduction is performed. The amount of braking, that is, the amount of decrease in braking force is reduced, and the brake hydraulic pressure reduction speed is slowed down, so that it is possible to avoid starting in an unstable state or starting at an unintended acceleration by the occupant. it can.

(Second control example)
FIG. 2 is a flowchart for explaining a second control example by the control device of the present invention. The second control example shown in the flowchart of FIG. 2 is a partial modification of the flowchart of FIG. The steps having the same control content as the control example shown in the flowchart of FIG. 1 are denoted by the same reference numerals as those in FIG. The routine shown in the flowchart of FIG. 2 is repeatedly executed every predetermined short time as in the first control example shown in FIG.

  In FIG. 2, similarly to the first control example shown in FIG. 1, when the control of steps S1 to S6 is executed and the determination in step S106 is affirmative, that is, the accelerator pedal depression speed is higher than the predetermined speed A. If it is determined that the accelerator pedal depressing operation is a rapid and strong depressing operation because the depressing amount of the accelerator pedal is higher than the predetermined amount B, the process proceeds to step S201, and the vehicle Ve progresses. An obstacle is detected forward in the direction, and it is determined whether or not an occupant avoiding operation is necessary.

  As for the forward obstacle detection process, for example, the presence or absence of a forward obstacle can be detected by the data processing device 110 including a laser radar on which the vehicle Ve is mounted. When a front obstacle is detected, the distance between the vehicle Ve and the front obstacle is measured at any time, and the moving speed of the front obstacle or the relative relationship between the front obstacle and the vehicle Ve is determined by the change in the distance and the distance. The speed is calculated, and based on the calculation result, it is determined whether an obstacle avoiding operation such as an occupant steering operation is necessary.

  In addition to the data processing device 110 provided with a radar, for example, an image processing device 111 provided with a CCD camera mounted on the vehicle Ve continuously collects images in front of the vehicle Ve at any time and analyzes the images. Can detect the presence or absence of a front obstacle. Further, in a dark environment such as at night, it is possible to detect a front obstacle as described above using, for example, an infrared camera (not shown).

  If no obstruction is detected in the forward direction of the vehicle Ve and no obstacle avoidance operation is required by the occupant, and if a negative determination is made in step S201, the process proceeds to step S107 to maintain the braking force. The release speed at the time of release is set to the release speed at the time of normal accelerator operation (normal release speed), and then this routine is once ended.

  On the other hand, if an obstacle is detected in front of the traveling direction of the vehicle Ve and it is determined that an occupant avoiding operation is necessary, the process proceeds to step S202. It is determined whether an obstacle avoidance operation has been performed by a passenger. The determination of the presence or absence of an obstacle avoidance operation by the occupant can be made based on, for example, a detection value by the steering angle sensor 109 or a control signal such as a turn signal switch (turn signal switch) (not shown).

  If an affirmative determination is made in step S202 because the obstacle avoidance operation by the occupant has been performed, the process proceeds to step S107, and the release speed for releasing the holding of the braking force is the same as that during normal accelerator operation. The release speed (normal release speed) is set, and then this routine is temporarily terminated.

  On the other hand, if the obstacle avoidance operation by the occupant has not been detected yet, and a negative determination is made in step S202, the process proceeds to step S108, where the brake fluid pressure is reduced, that is, the braking force for a predetermined time. Is stopped or the amount of decrease in braking force is reduced, and the brake fluid pressure reduction speed, that is, the release speed when releasing the holding of the braking force is slower than the normal pressure reduction speed (release speed). It is controlled to become. In other words, if it is determined that the accelerator pedal depressing operation is a rapid and strong depressing operation, the amount of decrease in the braking force when releasing the holding of the braking force is reduced, and the normal decompression time (release time) It is controlled to be longer. Thereafter, the control after step S109 is executed as in the first control example shown in FIG.

  As described above, by executing the control by the control device of the present invention, the accelerator operation by the depression of the accelerator pedal of the occupant is detected in the state where the braking force of the vehicle Ve is maintained, and the brake hydraulic pressure is detected. When the braking force is released when the pressure is reduced, an accelerator sudden operation in which the accelerator operation speed at that time is faster than a predetermined speed is detected, and the accelerator pedal depression amount, depression angle, depression pressure, etc. When the accelerator operation amount is larger than a predetermined amount, the brake fluid pressure reduction amount, that is, the braking force decrease amount is reduced. For this reason, it is possible to reliably detect a sudden and strong accelerator operation due to, for example, an occupant's erroneous operation, and when the driving force rapidly increases due to such a sudden and strong accelerator operation, The holding of the braking force can be released while reducing the amount of decompression and gradually decreasing the braking force. As a result, even when a sudden and strong accelerator operation is performed, it is possible to avoid starting with unstable acceleration or starting with an unintended acceleration by the occupant. Improvements can be made.

  For example, after a sudden and strong accelerator operation is performed, the accelerator pedal is temporarily released, or the accelerator pedal depression amount is reduced to a predetermined amount or less, or the accelerator pedal operation direction is changed from the depression direction to the release direction. When the accelerator pedal is depressed again at the normal depression speed, that is, when the accelerator pedal is depressed again, that is, a sudden and strong accelerator operation is detected, and the accelerator operation amount at that time is once reduced, then again When accelerator operation at normal accelerator operation speed is detected, control to release the holding of the braking force while decreasing the braking force gently and decreasing the braking fluid pressure is not performed. . In other words, even when an abrupt and strong accelerator operation is detected, for example, when the accelerator pedal is depressed again at a normal depression speed, the brake fluid pressure at which the holding of the braking force is released is released. The reduced pressure amount is not reduced, and the holding state of the braking force is released at the normal pressure reduction speed or the normal pressure reduction time, that is, at the normal release speed or the normal release time. Therefore, the holding of the braking force can be released in an appropriate state according to the operation state of the accelerator operation of the occupant, and the vehicle Ve can be started smoothly.

  When the accelerator operation is detected and the holding of the braking force of the vehicle Ve is released, for example, when an obstacle in the forward direction of the vehicle Ve such as another stopped vehicle is detected, the holding of the braking force is released. The pressure reduction amount of the brake fluid pressure is reduced. For this reason, when the vehicle Ve starts when the holding of the braking force is released and there is an obstacle ahead in the traveling direction of the vehicle Ve, the holding state of the braking force is gradually released, and thus the abrupt An increase in driving force can be suppressed, and a collision with an obstacle can be avoided.

  Here, the relationship between the above-described specific example and the present invention will be briefly described. The above-described functional means of steps S101 to S104 correspond to the braking force holding means of the present invention, and the functions of steps S105, S106, and S109. The functional means corresponds to the accelerator operation state detecting means of the present invention, and the functional means of steps S105 and S107 correspond to the braking force releasing means of the present invention. The functional means of steps S106 to S110 and S202 correspond to the release speed changing means of the present invention, and the functional means of step S201 corresponds to the obstacle detecting means of the present invention.

  The present invention is not limited to the above specific example. In the specific example, the vehicle to which the present invention is applied is an FR type two-wheel drive vehicle, but the vehicle is not a FR type vehicle. It may be a four-wheel drive vehicle.

  In the above specific example, the brake actuator for controlling the braking force applied to the wheel is illustrated as an actuator that operates the hole cylinder by the hydraulic pressure of the hydraulic fluid as shown in FIG. An actuator that operates to apply braking force to the wheel by an electric servo motor may be used. In short, the braking force applied to the wheel is controlled separately from the occupant's braking operation such as depressing the brake pedal. Any mechanism can be used.

  Further, as shown in FIG. 5, an example in which an inclination angle sensor is provided as a sensor for detecting a road surface inclination angle is shown. However, without providing an inclination angle sensor, a longitudinal acceleration sensor, a wheel speed sensor, etc. It is also possible to estimate the road gradient based on the detected value.

  In the above specific example, an example is shown in which the presence or absence of the steering operation of the occupant is determined based on the detected value of the rudder angle sensor, but instead of the detected value of the rudder angle sensor, a turn signal switch (turn signal switch) or the like It is also possible to determine the presence or absence of a steering operation using this control signal.

It is a flowchart for demonstrating the 1st control example by the control apparatus of this invention. It is a flowchart for demonstrating the 2nd control example by the control apparatus of this invention. It is a conceptual diagram which shows typically the power train and control system of a four-wheel drive vehicle which can apply the control apparatus of this invention. It is a conceptual diagram which shows typically the hydraulic system regarding the braking force control of one wheel among the structures of the brake actuator used for the control apparatus of this invention. It is a block diagram which shows roughly the control system used for the control apparatus of this invention. 6 is a time chart showing a change state of a throttle opening and a brake fluid pressure when the brake fluid pressure is reduced at a normal pressure reduction speed when control by the control device of the present invention is executed. It is a time chart which shows the change state of the throttle opening and the brake fluid pressure when the accelerator pedal is stepped on again when the control by the control device of the present invention is executed. FIG. 5 is a time chart showing changes in the throttle opening and the brake fluid pressure when the brake fluid pressure is reduced at a decompression speed when the accelerator pedal is suddenly and strongly depressed when the control device of the present invention is controlled. It is.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Power source (engine), 2 ... Transmission, 3, 4, 9, 10 ... Wheel, 12 ... Wheel cylinder, 13 ... Master cylinder, 14 ... Brake actuator, 36 ... Brake pedal, 100 ... Electronic control unit, 101 DESCRIPTION OF SYMBOLS ... Wheel speed sensor, 102 ... Shift position sensor, 103 ... Brake pedal sensor, 104 ... Accelerator pedal sensor, 105 ... Throttle valve sensor, 106 ... Drive torque sensor, 107 ... Longitudinal acceleration sensor, 108 ... Inclination angle sensor, 109 ... Rudder Angle sensor, 110: Radar data processing device, 111: CCD camera / image processing device, Ve: Vehicle.

Claims (5)

In addition to the braking operation of the occupant, the braking force holding means for holding the braking force applied to the wheel, the accelerator operation state detection means for detecting the occupant's accelerator operation state, and the accelerator operation state detection means detect the occupant's accelerator operation. A braking control device for a vehicle comprising braking force release means for reducing the braking force and releasing the holding state when
The release speed at which the amount of decrease in the braking force by the braking force release means decreases as the accelerator operation speed detected by the accelerator operation state detection means increases while the braking force is held by the braking force holding means. A braking control device for a vehicle, comprising a changing means.   The release speed changing means includes means for reducing the amount of decrease in the braking force when the accelerator operation state detecting means detects an accelerator sudden operation in which the accelerator operation speed is faster than a predetermined speed. The vehicle brake control device according to claim 1.   The release speed changing means is detected when the accelerator sudden operation is detected by the accelerator operation state detecting means, and the accelerator operation amount detected by the accelerator operation state detecting means is larger than a predetermined amount. The vehicle braking control device according to claim 1, further comprising means for reducing a reduction amount of the braking force.   The release speed changing means determines the amount of decrease in the braking force when the accelerator operation is detected by the accelerator operation state detecting means and then the accelerator operation amount is once reduced and the accelerator operation is detected again. The vehicle braking control apparatus according to any one of claims 1 to 3, further comprising means for performing no reduction. An obstacle detection means for detecting an obstacle ahead of the vehicle in the traveling direction;
4. The release speed changing means includes means for reducing a reduction amount of the braking force when the obstacle is detected by the obstacle detection means. Vehicle braking control device.

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