JP2012016987A - Device and method for support of driving operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the operability of vehicle-speed control when starting a vehicle by releasing a brake force for maintaining a vehicle stop state according to the acceleration operation of a driver.SOLUTION: When an acceleration operation amount Sa is not larger than a first threshold th1, a final brake force command value FB is set as a holding brake force command value B, and when the acceleration operation amount Sa exceeds the first threshold th1, the final brake force command value FB is decreased within a range in which the final brake force command value is smaller than the holding brake force command value FBas the acceleration operation amount Sa becomes large (step S109). Alternatively, when the acceleration operation amount Sa is not larger than a second threshold th2, a drive force command value FA is set as creep torque Tc, and when the acceleration operation amount Sa exceeds the second threshold th2, the drive force command value FA is increased in a range in which the drive force command value is larger than the creep torque Tc as the acceleration operation amount Sa becomes large (S112).

Description

  The present invention relates to a driving operation support device and a driving operation support method.

  Stop holding braking force is generated in order to maintain the stop state of the vehicle, and when the accelerator opening becomes equal to or greater than the threshold value Aref, the stop holding braking force is released, and thereafter, the accelerator opening degree is less than the threshold value Aref. When the threshold value is greater than or equal to the large threshold A2, there is one that generates a driving force according to the accelerator opening (see Patent Document 1).

JP 2008-265616 A

  However, when the stop holding braking force is released by an accelerator operation exceeding the threshold value Aref in a state where the shift position is in the driving range such as the D range or the R range, the vehicle starts to move with a driving force corresponding to at least the creep torque from that point. become. Therefore, when it is desired to start slowly with a driving force smaller than the creep torque, it is necessary to switch from the accelerator pedal to the brake pedal, which may give a driver a sense of complexity.

  The subject of this invention is improving the operativity of vehicle speed control, when releasing the braking force for maintaining a stop state according to a driver | operator's accelerator operation, and starting a vehicle.

  The driving operation support device according to the present invention sets a holding braking force command value for holding the stopped state when the vehicle is stopped, and depends on the holding braking force command value and the accelerator operation amount of the driver. A final braking force command value is set, and the braking force of the vehicle is controlled according to the final braking force command value. When the accelerator operation amount is equal to or less than a predetermined first threshold value, the final braking force command value is set to the holding braking force command value, and when the accelerator operation amount exceeds the first threshold value, the accelerator operation amount is set. The larger the amount is, the smaller the final braking force command value is set within the range less than the holding braking force command value.

  According to the driving operation support device according to the present invention, the final braking force command value can be set according to the accelerator operation amount. Therefore, when the driver increases the accelerator operation amount from the state where the vehicle is stopped, the holding braking force is increased. The final braking force command value set as the command value can be reduced. That is, when releasing the braking force for maintaining the stop state and starting the vehicle, the braking force of the vehicle can be controlled only by the accelerator operation, so that the operability of the vehicle speed control can be improved.

It is a schematic block diagram of a driving operation support device. It is a schematic block diagram of a brake actuator. It is a flowchart which shows a driving operation assistance control process. It is a graph which shows the braking / driving force according to the accelerator operation amount Sa. It is a graph which shows transition of braking force until holding braking force is canceled. It is a graph which shows transition of the driving force until an accelerator return operation is complete | finished. It is a graph which shows transition of the driving force after an accelerator return operation is complete | finished. It is a time chart which shows operation | movement of 1st embodiment. It is a map at the time of changing driving force cancellation accelerator operation amount Sar. It is a graph which shows the braking / driving force according to the accelerator operation amount Sa. It is a time chart which shows operation | movement of 2nd embodiment. It is a graph which shows the braking / driving force according to the accelerator operation amount Sa. It is a time chart which shows operation | movement of 3rd embodiment. It is a flowchart which shows a driving operation assistance control process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<< first embodiment >>
"Constitution"
FIG. 1 is a schematic configuration diagram of a driving operation support device.
Electromagnetic induction type wheel speed sensor 1 for detecting wheel speeds Vw _{FL to} Vw _RR of each wheel, accelerator sensor 2 for detecting accelerator pedal operation amount (accelerator opening) Sa, and brake pedal operation amount ( The brake sensor 3 for detecting the brake opening degree Sb is connected to the controller 5.

The controller 5 is composed of, for example, a microcomputer, and executes driving operation support control processing, which will be described later, based on detection signals from the sensors, and drives and controls the engine output control device 6 and the brake actuator 8.
Here, the engine output control device 6 is configured to control the engine output (the number of revolutions and the engine torque) by adjusting the throttle valve opening, the fuel injection amount, the ignition timing, and the like in the engine 7. .

FIG. 2 is a schematic configuration diagram of the brake actuator.
The brake actuator 8 is interposed between the master cylinder 10 and the wheel cylinders 11FL to 11RR.

  The master cylinder 10 is a tandem type that produces two systems of hydraulic pressure according to the driver's pedaling force. The master cylinder 10 transmits the primary side to the front left and rear right wheel cylinders 11FL and 11RR, and the secondary side transmits the right front wheel and A diagonal split system is used for transmission to the left rear wheel cylinders 11FR and 11RL.

Each of the wheel cylinders 11FL to 11RR is incorporated in a disc brake that presses a disc rotor with a brake pad to generate a braking force, or a drum brake that generates a braking force by pressing a brake shoe against the inner peripheral surface of the brake drum. Yes.
The brake actuator 8 uses a brake fluid pressure control circuit used for anti-skid control (ABS), traction control (TCS), stability control (VDC: Vehicle Dynamics Control), etc. Regardless, the hydraulic pressures of the wheel cylinders 11FL to 11RR can be increased, held and reduced.

  The primary side has a normally open type first gate valve 12A capable of closing a flow path between the master cylinder 10 and the wheel cylinder 11FL (11RR), and a flow path between the first gate valve 12A and the wheel cylinder 11FL (11RR). A normally open type inlet valve 13FL (13RR) that can be closed, an accumulator 14 communicating between the wheel cylinder 11FL (11RR) and the inlet valve 13FL (13RR), and a flow path between the wheel cylinder 11FL (11RR) and the accumulator 14 are provided. A normally closed outlet valve 15FL (15RR) that can be opened and a flow path that communicates between the master cylinder 10 and the first gate valve 12A and between the accumulator 14 and the outlet valve 15FL (15RR) are opened. The normally closed type second gate valve 16A, the accumulator 14 and the outlet valve 15FL (15RR) are connected to the suction side, and the first gate valve 12A and the inlet valve 13FL (13RR) are connected to the discharge side. And a pump 17. A damper chamber 18 is disposed on the discharge side of the pump 17 to suppress pulsation of discharged brake fluid and weaken pedal vibration.

  Similarly to the primary side, the secondary side also has a first gate valve 12B, an inlet valve 13FR (13RL), an accumulator 14, an outlet valve 15FR (15RL), a second gate valve 16B, a pump 17, A damper chamber 18.

  The first gate valves 12A and 12B, the inlet valves 13FL to 13RR, the outlet valves 15FL to 15RR, and the second gate valves 16A and 16B are two-port, two-position switching, single solenoid, and spring offset type electromagnetic operations, respectively. The first gate valves 12A and 12B and the inlet valves 13FL to 13RR open the flow path at a non-excited normal position, and the outlet valves 15FL to 15RR and the second gate valves 16A and 16B are non-excited. The flow path is closed at the normal position.

The accumulator 14 is a spring-type accumulator in which a compression spring is opposed to a cylinder piston.
The pump 17 is a positive displacement pump such as a gear pump or a piston pump that can ensure a substantially constant discharge amount regardless of the load pressure.

  With the above configuration, the primary side will be described as an example. When the first gate valve 12A, the inlet valve 13FL (13RR), the outlet valve 15FL (15RR), and the second gate valve 16A are all in the non-excited normal position. Then, the hydraulic pressure from the master cylinder 2 is transmitted as it is to the wheel cylinder 11FL (11RR) and becomes a normal brake.

  Even when the brake pedal is not operated, the first gate valve 12A is energized and closed while the inlet valve 13FL (13RR) and the outlet valve 15FL (15RR) are kept in the non-excited normal position. The second gate valve 16A is excited and opened, and the pump 17 is further driven to suck the hydraulic pressure of the master cylinder 2 through the second gate valve 16A and discharge the hydraulic pressure to the inlet valve 13FL (13RR). ) To the wheel cylinder 11FL (11RR) to increase the pressure.

  If the inlet valve 13FL (13RR) is excited and closed when the first gate valve 12A, the outlet valve 15FL (15RR), and the second gate valve 16A are in the non-excited normal position, the wheel cylinder 11FL (11RR) is closed. ) To the master cylinder 2 and the accumulator 14 are blocked, and the hydraulic pressure of the wheel cylinder 11FL (11RR) is maintained.

  Further, when the first gate valve 12A and the second gate valve 16A are in the non-excited normal position, the inlet valve 13FL (13RR) is excited and closed, and the outlet valve 15FL (15RR) is excited and opened. The hydraulic pressure in the wheel cylinder 11FL (11RR) flows into the accumulator 14 and is reduced. The hydraulic pressure flowing into the accumulator 14 is sucked by the pump 17 and returned to the master cylinder 2.

Also on the secondary side, the normal braking, pressure increasing, holding, and pressure reducing operations are the same as the operations on the primary side, and detailed description thereof will be omitted.
Therefore, the controller 5 controls each wheel by drivingly controlling the first gate valves 12A and 12B, the inlet valves 13FL to 13RR, the outlet valves 15FL to 15RR, the second gate valves 16A and 16B, and the pump 17. The fluid pressure in the cylinders 11FL to 11RR is increased / held / reduced.

In the present embodiment, a diagonal split method is used in which the brake system is divided into front left / rear right and front right / rear left, but the present invention is not limited thereto. The front / rear split method may be adopted.
Further, in the present embodiment, the spring-shaped accumulator 14 is adopted, but the present invention is not limited to this, and brake fluid extracted from each wheel cylinder 11FL to 11RR is temporarily stored to efficiently reduce pressure. Therefore, any type such as a weight type, a gas compression direct pressure type, a piston type, a metal bellows type, a diaphragm type, a bladder type, and an in-line type may be used.

  In the present embodiment, the first gate valves 12A and 12B and the inlet valves 13FL to 13RR open the flow path at the non-excited normal position, and the outlet valves 15FL to 15RR and the second gate valves 16A and 16B are non-excited. Although the flow path is closed at the normal excitation position, the present invention is not limited to this. In short, since it is only necessary to open and close each valve, the first gate valves 12A and 12B and the inlet valves 13FL to 13RR open the flow path at the excited offset position, and the outlet valves 15FL to 15RR and the second gate are opened. The valves 16A and 16B may close the flow path at the excited offset position.

Next, a driving operation support control process executed by the controller 5 every predetermined time (for example, 10 msec) will be described.
FIG. 3 is a flowchart showing the driving operation support control process.
In step S101, it is determined whether or not the start operation support flag is set to “fs = 1”. If this determination result is “fs = 0”, it is determined that the start operation support is unnecessary, and the process proceeds to step S102. On the other hand, if the determination result is “fs = 1”, it is determined that the start operation support is necessary, and the process proceeds to step S108 described later. It is assumed that the start operation support flag is reset to “fs = 0” in the initial setting.

  In step S102, it is determined whether or not a holding operation support (hereinafter referred to as PKB support) for generating a holding braking force for holding the stopped state when the vehicle is stopped is required. For example, when an obstacle or other vehicle existing in the traveling direction of the host vehicle is detected and the vehicle is stopped by automatic braking according to the separation distance, it is determined that PKB support is necessary. Further, when the vehicle is stopped on a slope road, it is determined that PKB support is necessary as hill start assist. Even when the vehicle is stopped by the driver's braking operation, when a predetermined time has elapsed since the driver generated a braking force exceeding the holding braking force, or when the driver turned on the PKB switch Also, it is determined that PKB support is necessary. If it is determined that PKB support is not necessary, the process proceeds to step S103. On the other hand, if it is determined that PKB support is necessary, the process proceeds to step S106 described later.

  In step S103, the final braking force command value FB is set according to the brake operation amount Sb with reference to the map in the drawing. This map is set so that the final braking force command value FB increases as the brake operation amount Sb increases.

  In the subsequent step S104, the driving force command value FA is set according to the accelerator operation amount Sa with reference to the map in the drawing. In this map, when the accelerator operation amount Sa is equal to or less than a predetermined third threshold th3, the driving force command value FA is set to the creep torque Tc, and the accelerator operation amount Sa exceeds the threshold th3 (for example, about 3 deg). Sometimes, the larger the accelerator operation amount Sa is, the larger the driving force command value FA is set in a range larger than the creep torque Tc. The creep torque Tc corresponds to the driving force when the vehicle moves while the engine is idling in a normal AT vehicle without stepping on the accelerator pedal. Note that the driving force generated without stepping on the accelerator pedal in a normal AT vehicle as described above is generally referred to as creep torque. For example, in an electric vehicle, the creep torque of an AT vehicle is simulated when the accelerator pedal is not operated. It is known that torque is output from a motor, and the creep torque includes torque output by imitating the creep torque of an AT vehicle when the accelerator pedal is not operated.

  In the subsequent step S105, the brake actuator 8 is driven and controlled to achieve the final braking force command value FB, and the engine output control device 6 is driven and controlled to achieve the driving force command value FA, and then a predetermined main program is executed. Return to.

On the other hand, in step S106, a holding braking force command value FB _PKB for generating the holding braking force is set. The holding braking force command value FB _PKB may be a predetermined value that can hold the host vehicle in a stopped state even if the number of occupants, the loaded load, the road surface gradient, or the like changes. It may be variable according to the number of occupants, the loaded load, the road surface gradient, etc. so that it can be held.

  In subsequent step S107, the start operation support flag is set to “fs = 1”, and then the process proceeds to step S105.

  On the other hand, in step S108, it is determined whether or not the holding braking force release flag is reset to “fr = 0”. If the determination result is “fr = 0”, it is determined that the holding braking force has not been released, and the process proceeds to step S109. On the other hand, if the determination result is “fr = 1”, it is determined that the holding braking force has been released, and the process proceeds to step S113 described later. The holding braking force release flag is reset to “fr = 0” in the initial setting.

In step S109, the final braking force command value FB is set according to the holding braking force command value FB _PKB and the accelerator operation amount Sa with reference to the map in the drawing. In this map, when the accelerator operation amount Sa is equal to or less than a predetermined first threshold th1 (for example, about 3 deg), the final braking force command value FB is set to the holding braking force command value FB _PKB , and the accelerator operation amount Sa is set to the first value. When the threshold value th1 is exceeded, the final braking force command value FB is set to be smaller within the range less than the holding braking force command value FB _PKB as the accelerator operation amount Sa is larger. Here, the accelerator operation amount Sa when the final braking force command value FB becomes 0 due to the increase in the accelerator operation amount Sa is defined as a braking force release accelerator operation amount Sbr.

In subsequent step S110, it is determined whether or not the accelerator operation amount Sa is equal to or greater than the braking force release accelerator operation amount Sbr. If the determination result is “Sa ≧ Sbr”, it is determined that the holding braking force has been released, and the process proceeds to step S111. On the other hand, if the determination result is “Sa <Sbr”, it is determined that the holding braking force has not been released, and the process proceeds to step S112.
In step S111, the holding braking force release flag is set to “fr = 1”.

  In subsequent step S112, the map in the figure is referred to, and after setting the driving force command value FA according to the accelerator operation amount Sa, the process proceeds to step S105. In this map, when the accelerator operation amount Sa is equal to or smaller than a predetermined second threshold th2 (for example, about 10 deg) larger than the first threshold th1, the driving force command value FA is set as the creep torque Tc, and the accelerator operation amount is set. When Sa exceeds the second threshold th2, the driving force command value FA is set to be larger in a range larger than the creep torque Tc as the accelerator operation amount Sa is larger. Here, the second threshold th2 is the same as the braking force release accelerator operation amount Sbr.

On the other hand, in step S113, the final braking force command value FB is set to zero.
In a succeeding step S114, it is determined whether or not the accelerator operation amount Sa is equal to or smaller than a predetermined third threshold th3 smaller than the second threshold th2. If the determination result is “Sa> th3”, it is determined that the accelerator return operation has not ended, and the process proceeds to step S112. On the other hand, if the determination result is “Sa ≦ th3”, it is determined that the accelerator return operation has ended, and the process proceeds to step S115.

In step S115, the start operation support flag is reset to “fs = 0”.
In the subsequent step S116, the holding braking force release flag is reset to “fr = 0”, and then the process proceeds to step S105.

<Action>
FIG. 4 is a graph showing the braking / driving force according to the accelerator operation amount Sa.
FIG. 5 is a graph showing the transition of the braking force until the holding braking force is released.
FIG. 6 is a graph showing changes in driving force until the accelerator return operation is completed.
FIG. 7 is a graph showing the transition of the driving force after the accelerator return operation is completed.
FIG. 8 is a time chart showing the operation of the first embodiment.

First, for example, when the vehicle is stopped by automatic braking (determination in S102 is “No”), PKB support is performed (S106). That is, the holding braking force command value FB _PKB for generating the holding braking force is set, and the brake actuator 8 is driven and controlled according to this (S105). As a result, the driver can maintain the stopped state of the vehicle without depressing the brake pedal.

It is desirable to release the holding braking force command value FB _PKB and start the vehicle when the driver depresses the accelerator pedal from the state where the PKB support is performed. However, if the holding braking force command value FB _PKB is released all at once in a state where the shift position is in the driving range such as the D range or the R range, the vehicle starts to move with a driving force corresponding to at least the creep torque Tc from that point. . Therefore, when it is desired to start slowly with a driving force smaller than the creep torque Tc, it is necessary to immediately switch from the accelerator pedal to the brake pedal, which may give a driver a sense of complexity.

Therefore, as shown in FIG. 4, when the accelerator operation amount Sa is equal to or smaller than the first threshold th1, the final braking force command value FB is set to the holding braking force command value FB _PKB , and the accelerator operation amount Sa is set to the first threshold th1. When exceeding, the final braking force command value FB is decreased within the range less than the holding braking force command value FB _PKB as the accelerator operation amount Sa is increased (step S109).

As a result, the final braking force command value FB can be set according to the accelerator operation amount Sa. Therefore, when the driver increases the accelerator operation amount from the state where the vehicle is stopped, the holding braking force command value FB _PKB is set. Further, the final braking force command value FB can be reduced. Therefore, the creep torque Tc can be resisted by the braking force according to the accelerator operation, and the vehicle can be started at a speed equal to or lower than the creep vehicle speed. That is, it is possible to suppress the feeling of jumping out of the vehicle by slowly starting with a driving force smaller than the creep torque Tc only by the accelerator operation. As described above, when the vehicle is started by releasing the holding braking force command value FB _PKB for holding the stopped state, the braking force of the vehicle can be controlled only by the accelerator operation, so that the operability of the vehicle speed control is improved. be able to.

  Until the accelerator operation amount Sa becomes equal to or greater than the braking force release accelerator operation amount Sbr (determination in S110 is “No”), the holding braking force release flag is maintained in the state of “fr = 0”, as shown in FIG. Moreover, if the accelerator pedal is returned, the braking force can be increased again. Therefore, the driver's braking request can be met. Further, if the accelerator pedal is returned to the first threshold th1 or less, the stop state can be held by the holding braking force. Therefore, it is possible to respond to the driver's request for stop holding.

  On the other hand, as shown in FIG. 4, when the accelerator operation amount Sa is equal to or smaller than the second threshold th2, the driving force command value FA is set to the creep torque Tc, and when the accelerator operation amount Sa exceeds the second threshold th2, As the accelerator operation amount Sa is larger, the driving force command value FA is increased within a range larger than the creep torque Tc (S112).

  As a result, while the accelerator pedal is below the second threshold th2, the creep torque Tc is maintained. However, when the accelerator pedal is depressed beyond the second threshold th2, the vehicle is driven with a driving force exceeding the creep torque Tc. Can be started immediately. Therefore, the driver's acceleration request can be met.

  When the accelerator operation amount Sa becomes equal to or greater than the second threshold th2 (= Sbr) (the determination in S110 is “Yes”), the holding braking force release flag is set to “fr = 1” (S111), and thereafter Sets the final braking force command value FB to 0 even if the accelerator operation amount Sa is less than the braking force release accelerator operation amount Sbr (S113).

  In this way, once the holding braking force is released, the braking force control according to the accelerator operation is stopped, so that the feeling of deceleration when the accelerator pedal is returned is returned to the normal feeling and the driver's uncomfortable feeling is reduced. Can do.

  Further, since the second threshold th2 is set to be the same as the braking force release accelerator operation amount Sbr, it is possible to continuously shift from the braking force control according to the accelerator operation to the driving force control according to the accelerator operation. it can. That is, when the accelerator pedal is depressed and the holding braking force decreases and disappears, the driving force continuously increases, so that the operability of the vehicle speed control can be improved.

  Further, until the accelerator operation amount Sa becomes equal to or less than the third threshold th3 (determination in S114 is “No”), the start operation support flag is maintained in the state of “fs = 1”, so as shown in FIG. If the accelerator pedal is stepped over the second threshold th2, the vehicle can be driven with a driving force exceeding the creep torque Tc, and if the accelerator pedal is returned to the second threshold th2 or less, the vehicle is driven with the creep torque Tc. Can be run.

  When the accelerator operation amount Sa becomes equal to or less than the third threshold th3 (determination of S114 is “Yes”), the start operation support flag is reset to “fs = 0” (S115), and thereafter, FIG. As shown, the driving force command value FA corresponding to the accelerator operation is returned to the normal state. That is, when the accelerator operation amount Sa is equal to or less than the third threshold th3, the driving force command value FA is set to the creep torque Tc. When the accelerator operation amount Sa exceeds the third threshold th3, the accelerator operation amount Sa increases as the accelerator operation amount Sa increases. The driving force command value FA is increased within a range larger than the creep torque Tc (S104).

  As described above, once the accelerator return operation is completed, the control of the driving force by the start operation support is stopped, so that the acceleration feeling when the accelerator pedal is depressed is returned to the normal feeling and the driver's uncomfortable feeling is reduced. be able to.

《Application example》
First, in the first embodiment, when the accelerator operation amount Sa is equal to or greater than the braking force release accelerator operation amount Sbr, the holding braking force release flag is set to “fr = 1”, but the accelerator operation amount Sa is When it is equal to or greater than the second threshold th2, the holding braking force release flag may be set to “fr = 1”. In the first embodiment, since the second threshold th2 is set to be the same as the braking force release accelerator operation amount Sbr, the operation is substantially the same.

  In the first embodiment, the driving force command value FA is set by referring to a predetermined map in step S112 until the accelerator operation amount Sa becomes equal to or smaller than the third threshold th3. May be changed. For example, when the accelerator operation amount Sa is in a range from th3 to th2 (th3 <Sa ≦ th2), the driving force command value FA maintains the creep torque Tc, and becomes a dead zone with respect to a change in the accelerator operation amount Sa.

  Therefore, when the accelerator operation amount Sa decreases from the state where the accelerator operation amount Sa exceeds the second threshold th2, the accelerator operation at the time when the driving force command value FA is set to the creep torque Tc due to the decrease in the accelerator operation amount Sa. The decrease rate of the accelerator operation amount Sa is set such that the amount Sa is the driving force release accelerator operation amount Sar, and the driving force release accelerator operation amount Sar is in a range not less than the third threshold th3 and less than the second threshold th2. A reduction rate of the driving force command value FA may be set.

FIG. 9 is a map when the driving force release accelerator operation amount Sar is changed.
For example, if the driving force release accelerator operation amount Sar is set to the third threshold th3, the decreasing gradient of the driving force command value FA with respect to the decrease in the accelerator operation amount Sa becomes gentle, and the driving force command value FA with respect to the accelerator operation amount Sa. The dead zone can be reduced to zero. Accordingly, it is possible to suppress a feeling of missing operation when the accelerator operation amount Sa exceeds the second threshold th2 and then becomes the second threshold th2 or less again.

In the first embodiment, the engine vehicle has been described. However, the engine vehicle may be applied to an electric vehicle (EV). In this case, the inverter output may be controlled according to the driving force command value FA, or the holding braking force command value FB _PKB may be generated by a three-phase short circuit.

"effect"
As described above, the processing in step S106 corresponds to “holding braking force command value setting means”, the accelerator sensor 2 corresponds to “accelerator operation amount detection means”, and the processing in steps S109 and S113 corresponds to “final braking force command value setting means”. The processing in step S105 and the brake actuator 8 correspond to “brake control means”. Further, the processes of steps S112 and S104 correspond to “driving force command value setting means”, and the process of step S105 and the engine output control device 6 correspond to “accelerator control means”.

(1) Holding braking force command value setting means for setting a holding braking force command value for holding the stopped state when the vehicle is stopped, and accelerator operation amount detecting means for detecting the driver's accelerator operation amount A final braking force command value setting means for setting a final braking force command value according to the holding braking force command value set by the holding braking force command value setting means and the accelerator operation amount detected by the accelerator operation amount detection means. And brake control means for controlling the braking force of the vehicle in accordance with the final braking force command value set by the final braking force command value setting means, wherein the final braking force command value setting means includes the accelerator operation amount. Is equal to or less than a predetermined first threshold value, the final braking force command value is set to the holding braking force command value, and when the accelerator operation amount exceeds the first threshold value, Higher operation amount is large is set smaller the final braking force command value in a range of less than the retaining braking force command value.

  Thus, since the final braking force command value can be set according to the accelerator operation amount, when the driver increases the accelerator operation amount from the state where the vehicle is stopped, the final braking force set as the holding braking force command value is set. The command value can be reduced. That is, when releasing the braking force for maintaining the stop state and starting the vehicle, the braking force of the vehicle can be controlled only by the accelerator operation, so that the operability of the vehicle speed control can be improved.

(2) Driving force command value setting means for setting a driving force command value according to the accelerator operation amount, and an accelerator for controlling the driving force of the vehicle according to the driving force command value set by the driving force command value setting means Control means, wherein the driving force command value setting means converts the driving force command value to a creep torque when the accelerator operation amount is equal to or less than a predetermined second threshold value greater than the first threshold value. When the accelerator operation amount exceeds the second threshold value, the driving force command value is set larger in a range larger than the creep torque as the accelerator operation amount is larger.

  As a result, the creep torque is maintained while the accelerator operation amount is less than or equal to the second threshold value, but when the accelerator operation amount exceeds the second threshold value, the vehicle is promptly started with the driving force exceeding the creep torque. be able to.

(3) The accelerator operation amount at the time when the final braking force command value setting means sets the final braking force command value to 0 as the accelerator operation amount increases is defined as a braking force release accelerator operation amount, and the second The threshold value is set to be the same as the braking force release accelerator operation amount.

  Thereby, it is possible to continuously shift from the braking force control according to the accelerator operation to the driving force control according to the accelerator operation. That is, when the accelerator operation amount is increased and the holding braking force command value decreases and disappears, the driving force command value continuously increases, so that the operability of the vehicle speed control can be improved.

(4) The final braking force command value setting means determines the final braking force command value when the accelerator operation amount becomes less than the second threshold again after the accelerator operation amount becomes equal to or greater than the second threshold. Is set to 0.

  As described above, once the accelerator operation amount becomes equal to or greater than the second threshold value and the holding braking force command value is canceled, the control of the braking force command value according to the accelerator operation amount is stopped. The feeling of deceleration can be returned to the normal feeling, and the driver's uncomfortable feeling can be reduced.

(5) The final braking force command value setting means determines that the final braking force command value setting means determines that the final braking force command value setting means determines that the final braking force command value setting means returns the final braking force command value when the accelerator operating amount is less than the braking force releasing accelerator operating amount after Set the braking force command value to 0.

  In this way, the accelerator operation amount becomes equal to or greater than the braking force release accelerator operation amount, and once the holding braking force command value is canceled, the control of the braking force command value according to the accelerator operation amount is stopped, so the accelerator operation amount is returned. The feeling of deceleration at the time can be returned to the normal feeling, and the driver's uncomfortable feeling can be reduced.

(6) The driving force command value setting means determines that the accelerator operation amount becomes equal to or less than the second threshold again after the accelerator operation amount exceeds the second threshold value, and the accelerator operation amount is the second threshold value. When the accelerator operation amount exceeds the third threshold again after becoming below a predetermined third threshold value that is smaller than a threshold value, the greater the accelerator operation amount, the greater the driving force within the range of the creep torque. Set a larger command value.

  As described above, once the accelerator operation amount becomes equal to or less than the third threshold value and the accelerator return operation is completed, the control of the driving force for supporting the start operation is stopped, so that the acceleration feeling when the accelerator operation amount is increased is stopped. Can be restored to the normal feeling and the driver's uncomfortable feeling can be reduced.

(7) When the accelerator operation amount decreases from a state in which the accelerator operation amount exceeds the second threshold value, the driving force command value setting means sets the driving force command value by reducing the accelerator operation amount. The accelerator operation amount at the time of setting the creep torque is set as a driving force release accelerator operation amount, and the driving force release accelerator operation amount is in a range not less than the third threshold and less than the second threshold. In addition, a decrease rate of the driving force command value with respect to a decrease rate of the accelerator operation amount is set.

  Thereby, the dead zone of the driving force command value with respect to the accelerator operation amount when the accelerator operation amount is in the range from the third threshold value to the second threshold value can be reduced. In addition, it is possible to suppress a feeling of operation loss when the accelerator operation amount exceeds the second threshold value and then becomes the second threshold value or less again.

(8) A holding braking force command value for holding the stopped state is set when the vehicle is stopped, and a final braking force command value is set according to the holding braking force command value and the accelerator operation amount of the driver. And controlling the braking force of the vehicle according to the final braking force command value, and when the accelerator operation amount is equal to or less than a predetermined first threshold, the final braking force command value is When the holding braking force command value is set and the accelerator operation amount exceeds the first threshold value, the final braking force command value is set within a range less than the holding braking force command value as the accelerator operation amount increases. Set smaller.

  Thus, since the final braking force command value can be set according to the accelerator operation amount, when the driver increases the accelerator operation amount from the state where the vehicle is stopped, the final braking force set as the holding braking force command value is set. The command value can be reduced. That is, when releasing the braking force for maintaining the stop state and starting the vehicle, the braking force of the vehicle can be controlled only by the accelerator operation, so that the operability of the vehicle speed control can be improved.

<< Second Embodiment >>
"Constitution"
In the second embodiment, the second threshold th2 is set larger than the braking force release accelerator operation amount Sbr.
For example, the braking force release accelerator operation amount Sbr is set to about 7 deg, and the second threshold th2 is set to about 10 deg.

<Action>
FIG. 10 is a graph showing the braking / driving force according to the accelerator operation amount Sa.
FIG. 11 is a time chart showing the operation of the second embodiment.

  Since the second threshold th2 is set to be larger than the braking force release accelerator operation amount Sbr, the accelerator operation is performed during the period from the braking force control corresponding to the accelerator operation to the driving force control corresponding to the accelerator operation. Accordingly, a region where neither the final braking force command value FB nor the driving force command value FA changes is provided. In the region from the braking force release accelerator operation amount Sbr to the second threshold th2, the creep torque Tc is maintained, and the vehicle starts at the creep vehicle speed. Thus, it becomes easy to maintain the creep state by actively providing a region in which neither the final braking force command value FB nor the driving force command value FA changes according to the accelerator operation. Therefore, it is suitable for a driver who desires creep running.

《Application example》
In the first embodiment, when the accelerator operation amount Sa is equal to or greater than the braking force release accelerator operation amount Sbr, the holding braking force release flag is set to “fr = 1”, but the accelerator operation amount Sa is the second value. The holding braking force release flag may be set to “fr = 1” when it is equal to or greater than the threshold th2. In the second embodiment, since the second threshold th2 is set larger than the braking force release accelerator operation amount Sbr, even after the holding braking force is released, the accelerator operation amount Sa is equal to the second threshold th2. If the accelerator pedal is returned before the above is reached, the braking force can be increased again. Further, if the accelerator pedal is returned to the first threshold th1 or less, the stop state can be held by the holding braking force. Therefore, it is possible to respond to the driver's request for stop holding.

"effect"
(1) The accelerator operation amount at the time when the final braking force command value setting means sets the final braking force command value to 0 by the increase in the accelerator operation amount is set as a braking force release accelerator operation amount, and the second The threshold value is set larger than the braking force release accelerator operation amount.
As a result, a region is provided in which neither the final braking force command value nor the driving force command value changes according to the accelerator operation during the period from the transition from the braking force control according to the accelerator operation to the driving force control according to the accelerator operation. It is done. Thus, it becomes easy to maintain the creep state by actively providing a region in which neither the final braking force command value nor the driving force command value changes according to the accelerator operation.

<< Third embodiment >>
"Constitution"
In the third embodiment, the second threshold th2 is set to be smaller than the braking force release accelerator operation amount Sbr.
For example, the braking force release accelerator operation amount Sbr is set to about 10 deg, and the second threshold th2 is set to about 7 deg.

<Action>
FIG. 12 is a graph showing the braking / driving force according to the accelerator operation amount Sa.
FIG. 13 is a time chart showing the operation of the third embodiment.

  Since the second threshold th2 is set smaller than the braking force release accelerator operation amount Sbr, the driving force control corresponding to the accelerator operation is started before the braking force control corresponding to the accelerator operation is completed. That is, the driving force command value FA is increased before the holding braking force command value FB becomes zero. In general, it is difficult to finely adjust the driving force as the engine output characteristics. Therefore, smooth transition can be realized by starting the driving force control according to the accelerator operation before the braking power control according to the accelerator operation is completed. Further, depending on the setting of the second threshold th2 and the braking force release accelerator operation amount Sbr, it is possible to arbitrarily design the vehicle behavior when shifting from the braking force control to the driving force control.

"effect"
(1) The accelerator operation amount at the time when the final braking force command value setting means sets the final braking force command value to 0 by the increase in the accelerator operation amount is set as a braking force release accelerator operation amount, and the second The threshold value is set smaller than the braking force release accelerator operation amount.
In general, fine adjustment when starting up the driving force as an engine output characteristic is difficult, but smooth transition is achieved by starting the driving force control according to the accelerator operation before the braking power control according to the accelerator operation is completed. Can be realized. Further, depending on the setting of the second threshold value and the braking force release accelerator operation amount, it is possible to arbitrarily design the vehicle behavior when shifting from the braking force control to the driving force control.

<< 4th embodiment >>
"Constitution"
In the fourth embodiment, the first threshold th1 at which the final braking force command value FB starts to decrease from the holding braking force command value FB _PKB , the decreasing gradient when the final braking force command value FB is decreased, and the driving force command value FA. The second threshold th2 that starts increasing from the creep torque Tc is changed according to the accelerator operation speed of the driver.

FIG. 14 is a flowchart showing the driving operation support control process.
Here, since a new step S121 is added and adjustments are made to the processing of steps S109 and S112, it is the same as the first embodiment described above, and thus detailed description of the same parts is omitted. To do.
When the determination result in step S101 is “fs = 1”, it is determined that the start operation support is necessary, and the process proceeds to step S121.

In step S121, the accelerator operation amount Ss [deg / sec] is calculated according to the accelerator operation amount Sa [deg], and then the process proceeds to step S108. Note that the speed in the depression direction of the accelerator pedal is a positive value, and the speed in the return direction is a negative value.
In step S109, the first threshold th1 is decreased as the accelerator operation speed Ss increases. For example, the first threshold th1 is set as shown in the following formula (1).

th1 = max [1, {3-0.4 × min (5, Ss-5)}]
………… (1)
However, the maximum value of the first threshold th1 is 3 [deg].

  Therefore, when the accelerator operation speed Ss is smaller than 5 [deg / sec], the first threshold th1 is 3 [deg], and when the accelerator operation speed Ss is greater than 5 [deg / sec], the first threshold th1. When th1 becomes smaller than 3 [deg] and the accelerator operation speed Ss becomes 10 [deg / sec] or more, the first threshold th1 becomes 1 [deg].

  Further, as the accelerator operation speed Ss increases, the decrease rate of the final braking force command value FB with respect to the increase rate of the accelerator operation amount Sa is increased, that is, the final braking force command value FB decreasing gradient is increased. For example, as shown in the following equation (2), the final braking force command value FB is set.

FB = {FB _PKB / (Sbr−th1)} × (Sa−th1)
………… (2)
Here, the braking force release accelerator operation amount Sbr is calculated by the following equation (3).

Sbr = max [4, {10-1.2 × min (5, Ss-5)}]
………… (3)

However, when the final braking force command value FB becomes a negative value, FB = 0. The maximum value of the final braking force command value FB is the holding braking force command value FB _PKB .

Therefore, when the accelerator operation amount Sa is equal to or less than the first threshold th1, the final braking force command value FB becomes the holding braking force command value FB _PKB , the accelerator operation amount Sa is larger than the first threshold th1, and the braking force release accelerator When the accelerator operation amount Sa is smaller than the operation amount Sbr, the final braking force command value FB decreases as the accelerator operation amount Sa increases. When the accelerator operation amount Sa exceeds the braking force release accelerator operation amount Sbr, the final braking force command value FB becomes zero. Become.

  When the accelerator operation speed Ss is smaller than 5 [deg / sec], the braking force release accelerator operation amount Sbr is 10 [deg], and when the accelerator operation speed Ss is larger than 5 [deg / sec], the braking force is released. When the release accelerator operation amount Sbr becomes smaller than 10 [deg] and the accelerator operation speed Ss becomes 10 [deg / sec] or more, the braking force release accelerator operation amount Sbr becomes 4 [deg].

  In step S112, the second threshold th2 is decreased as the accelerator operation speed Ss increases. For example, the second threshold th2 is set as shown in the following equation (4).

th2 = max [Sbr + 1, {12-1.2 × min (5, Ss-5)}]
………… (4)
However, the maximum value of the second threshold th2 is 12 [deg].

  Therefore, when the accelerator operation speed Ss is smaller than 5 [deg / sec], the second threshold th2 is 12 [deg], and when the accelerator operation speed Ss is larger than 5 [deg / sec], the second threshold th2 When th2 is smaller than 12 [deg] and the accelerator operation speed Ss is 10 [deg / sec] or more, the second threshold th2 is 6 [deg].

<Action>
When the driver depresses the accelerator pedal at a high speed, it is clear that the driver wants a quick start.

Therefore, first, the accelerator operation speed Ss is calculated (S121), and the first threshold th1 is decreased as the accelerator operation speed Ss increases. Thereby, the final braking force command value FB can be started to decrease from the holding braking force command value FB _PKB at an earlier timing. Therefore, it is possible to meet the demand of a driver who wants to start quickly.

Further, the faster the accelerator operation speed Ss, the larger the decreasing gradient when decreasing the final braking force command value FB. As a result, the holding braking force command value FB _PKB can be quickly released. Therefore, it is possible to meet the demand of a driver who wants to start quickly.

  Further, the second threshold th2 is decreased as the accelerator operation speed Ss is increased. Thereby, it is possible to start increasing the driving force command value FA at an earlier timing. Therefore, it is possible to meet the demand of a driver who wants to start quickly.

"effect"
(1) The final braking force command value setting means increases the rate of change of the final braking force command value with respect to the rate of change of the accelerator operation amount as the driver's accelerator operation speed increases.
As a result, the holding braking force can be quickly released, and the driver's request for a quick start can be met.

(2) The second threshold value is set smaller as the driver's accelerator operation speed is faster.
Thereby, it is possible to start increasing the driving force command value at an earlier timing, and it is possible to meet the demand of the driver who wants to start quickly.

(3) The first threshold value is set smaller as the driver's accelerator operation speed is faster.
As a result, the final braking force command value can be started to decrease from the holding braking force command value at an earlier timing, and the request of the driver who wants to start quickly can be met.

DESCRIPTION OF SYMBOLS 1 Wheel speed sensor 2 Acceleration sensor 3 Brake sensor 5 Controller 6 Engine output control apparatus 7 Engine 8 Brake actuator 10 Master cylinder 11FL-11RR Wheel cylinder 12A, 12B Gate valve 13FL-13RR Inlet valve 14 Accumulator 15FL-15RR Outlet valve 16A, 16B Gate valve 17 Pump FA Driving force command value FB Final braking force command value FB _PKB holding braking force command value Sa Accelerator operation amount Sar Driving force release accelerator operation amount Sb Brake operation amount Sbr Braking force release accelerator operation amount Ss Accelerator operation speed

Claims (13)

Holding braking force command value setting means for setting a holding braking force command value for holding the stopped state when the vehicle is stopped;
An accelerator operation amount detection means for detecting the driver's accelerator operation amount;
Final braking force command value setting means for setting a final braking force command value according to the holding braking force command value set by the holding braking force command value setting means and the accelerator operation amount detected by the accelerator operation amount detection means; ,
Brake control means for controlling the braking force of the vehicle according to the final braking force command value set by the final braking force command value setting means,
The final braking force command value setting means sets the final braking force command value to the holding braking force command value when the accelerator operation amount is equal to or less than a predetermined first threshold, and the accelerator operation amount is When the first threshold value is exceeded, as the accelerator operation amount is larger, the final braking force command value is set to be smaller within a range less than the holding braking force command value. Driving force command value setting means for setting a driving force command value according to the accelerator operation amount;
Accelerator control means for controlling the driving force of the vehicle according to the driving force command value set by the driving force command value setting means,
The driving force command value setting means sets the driving force command value to a creep torque when the accelerator operation amount is equal to or less than a predetermined second threshold value greater than the first threshold value, 2. The driving operation according to claim 1, wherein when the amount exceeds the second threshold, the driving force command value is set to be larger in a range larger than the creep torque as the accelerator operation amount is larger. Support device. The accelerator operation amount at the time when the final braking force command value setting means sets the final braking force command value to 0 as the accelerator operation amount increases is defined as a braking force release accelerator operation amount,
The driving operation support apparatus according to claim 2, wherein the second threshold value is set to be the same as the braking force release accelerator operation amount. The accelerator operation amount at the time when the final braking force command value setting means sets the final braking force command value to 0 as the accelerator operation amount increases is defined as a braking force release accelerator operation amount,
The driving operation support apparatus according to claim 2, wherein the second threshold value is set to be larger than the braking force release accelerator operation amount. The accelerator operation amount at the time when the final braking force command value setting means sets the final braking force command value to 0 as the accelerator operation amount increases is defined as a braking force release accelerator operation amount,
The driving operation support apparatus according to claim 2, wherein the second threshold value is set smaller than the braking force release accelerator operation amount.   The final braking force command value setting means sets the final braking force command value to 0 when the accelerator operation amount becomes less than the second threshold again after the accelerator operation amount becomes equal to or greater than the second threshold. The driving operation support device according to any one of claims 2 to 4, wherein the driving operation support device is set.   The final braking force command value setting means is configured to output the final braking force command when the accelerator operation amount becomes less than the braking force release accelerator operation amount after the accelerator operation amount becomes equal to or greater than the braking force release accelerator operation amount. A driving operation support device according to any one of claims 2 to 5, wherein a value is set to 0.   8. The final braking force command value setting means increases the rate of change of the final braking force command value with respect to the rate of change of the accelerator operation amount as the driver's accelerator operation speed increases. The driving operation support device according to any one of the above.   9. The driving operation support apparatus according to claim 2, wherein the second threshold value is set to be smaller as the driver's accelerator operation speed is faster.   10. The driving operation support apparatus according to claim 1, wherein the first threshold value is set to be smaller as the driver's accelerator operation speed is faster.   The driving force command value setting means is configured such that the accelerator operation amount becomes equal to or less than the second threshold again after the accelerator operation amount exceeds the second threshold, and the accelerator operation amount is lower than the second threshold. When the accelerator operation amount exceeds the third threshold again after becoming a small predetermined third threshold value or less, the larger the accelerator operation amount, the larger the range of the driving force command value within the range of the creep torque. The driving operation support device according to any one of claims 2 to 8, wherein the driving operation support device is set to be large.   When the accelerator operation amount decreases from a state where the accelerator operation amount exceeds the second threshold, the driving force command value setting means sets the driving force command value to the creep torque according to a decrease in the accelerator operation amount. The accelerator operation amount at the time of setting to the driving force release accelerator operation amount, and the driving force release accelerator operation amount is in the range of the third threshold or more and less than the second threshold The driving operation support apparatus according to claim 11, wherein a decreasing rate of the driving force command value with respect to a decreasing rate of the accelerator operation amount is set. Setting a holding braking force command value for holding the stopped state when the vehicle is stopped, setting a final braking force command value according to the holding braking force command value and the accelerator operation amount of the driver, Controlling the braking force of the vehicle according to the final braking force command value,
When the accelerator operation amount is equal to or less than a predetermined first threshold value, the final braking force command value is set to the holding braking force command value, and when the accelerator operation amount exceeds the first threshold value. The driving operation support method, wherein the final braking force command value is set to be smaller within a range less than the holding braking force command value as the accelerator operation amount is larger.

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