JP2005035387A - Braking force controlling device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent unnecessary power consumption caused by excessively supplying a current to a braking force controlling means by erroneous determination, in a braking force controlling device supplying the current to the braking force controlling means to control braking force when an ignition switch is in an off state and a braking request of a driver is generated. <P>SOLUTION: Even if a brake pedal 12 is determined to be depressed while the ignition switch 84 is in the off state (S10, 20), and if an electronic controlling device 78 is started (S70), when a state in which depressing stroke St of the brake pedal does not change continues for not less than predetermined starting reference time T1 (S30) and a top lamp switch 86 is in the off state (S40), each valve is returned to a non-controlling position, and the supply of the current to each sensor is stopped to stop operation of the electronic controlling device 78 (S90). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle braking force control device, and more particularly to a so-called electronically controlled braking force control device.

  As one of braking force control devices for vehicles such as automobiles, for example, as described in Patent Document 1 below, electronic control for controlling the braking force of a wheel by braking force control means in accordance with the amount of braking operation by a driver Type braking force control device that supplies a current to the braking force control means to control the braking force when the driver requests braking with the ignition switch turned off. Is conventionally known.

According to such a braking force control device, even when the ignition switch is off, when the driver requests braking, current is supplied to the braking force control means. The braking force of the wheel can be controlled according to the amount of braking operation to satisfy the driver's braking request.
JP 2002-154414 A

  However, in the conventional braking force control device as described above, when a driver requests braking with the ignition switch turned off, a current is supplied to the braking force control means so that the braking force can be controlled. Therefore, when it is erroneously determined that there is a braking request by the driver due to erroneous detection of the braking operation amount by the driver even though there is actually no braking request by the driver, it is unnecessary based on the erroneous determination. In addition, there is a problem that current is supplied to the braking force control means, so that power from the power source is wasted.

  The present invention relates to a conventional braking force control device configured to supply a current to the braking force control means to control the braking force when a driver requests braking while the ignition switch is off. The main problem of the present invention is to reduce the possibility that the erroneous determination that there is a braking request by the driver is continuously made. It is to prevent the electric power of the power source from being unnecessarily consumed by unnecessary supply of electric current to the braking force control means based on the determination.

  According to the present invention, the main problem described above is the configuration of claim 1, that is, the control means for controlling the braking force of the wheel in accordance with the amount of braking operation by the driver, and the driver with the ignition switch turned off. In the vehicle braking force control device having means for supplying electric power to the control means, it is determined that the driver's braking operation has been performed with the ignition switch turned off. It has means for stopping the supply of power to the control means when a situation in which the amount of change per unit time of the driver's braking operation amount is below a reference value continues for a predetermined time or longer. This is achieved by a vehicle braking force control device.

  According to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 1, the means for supplying electric power to the control means is such that the master cylinder pressure is equal to or higher than the start determination reference value. Or when the operation displacement amount of the brake operator by the driver is equal to or greater than the start determination reference value, it is determined that the driver has performed a braking operation (configuration of claim 2).

  According to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 1 or 2, the means for stopping the supply of power is a change in master cylinder pressure per unit time. When the situation in which the magnitude of the quantity is less than or equal to the reference value or the situation in which the magnitude of the amount of change per unit time of the operation displacement amount of the braking operator by the driver is less than the reference value continues for a predetermined time or more, It is comprised so that supply of the electric power to may be stopped (structure of Claim 3).

  According to the present invention, in order to effectively achieve the main problems described above, the means for stopping the supply of electric power is the unit time of the braking operation amount of the driver. The power supply to the control means is stopped when the situation in which the magnitude of the amount of change per unit is less than or equal to a reference value continues for a predetermined time and the stop lamp switch is off. 4 configuration).

  According to the present invention, in order to effectively achieve the above-mentioned main problems, in the configuration of the above-described claims 1 to 3, the control means sets the target braking amount of the wheel based on the braking operation amount of the driver. The means for controlling the braking force of the wheel based on the target braking amount and stopping the power supply is such that the amount of change per unit time of the braking operation amount of the driver is below a reference value When the situation continues for a predetermined time or more, the braking operation amount of the driver used for the calculation of the target braking amount is gradually decreased, and the braking operation amount of the driver used for the calculation of the target braking amount is an end reference value. It is comprised so that supply of the electric power to the said control means may be stopped when it becomes the following (structure of Claim 5).

  According to the above configuration, the magnitude of the amount of change per unit time of the driver's braking operation amount after it is determined that the driver's braking operation has been performed with the ignition switch turned off is the reference value. If the following condition continues for a predetermined time or longer, the power supply to the control means is stopped, so the driver's braking operation amount is erroneously detected due to an abnormality in the means for detecting the driver's braking operation amount, etc. Even if it is determined that the driver's braking operation has been performed, the amount of braking operation detected by the driver does not change when the driver does not actually perform the braking operation. The situation where the amount of change per hit is below the reference value continues for a predetermined time or longer, and therefore, the supply of power to the control means is stopped to reliably reduce the possibility that the power of the power source is wasted. be able to.

  According to the second aspect of the present invention, when the master cylinder pressure is equal to or higher than the start determination reference value, or when the amount of displacement of the braking operator by the driver is equal to or higher than the start determination reference value, the driver's braking is performed. Since it is determined that the operation has been performed, it is determined that the driver's braking operation has been performed when both the master cylinder pressure and the operation displacement amount of the brake operator by the driver are equal to or greater than the start determination reference value, respectively. As compared with this, when the driver performs a braking operation, it is possible to reliably determine that.

  According to the third aspect of the present invention, the amount of change per unit time of the operation displacement amount of the brake operating element by the driver or the situation where the magnitude of change amount per unit time of the master cylinder pressure is less than the reference value. If the situation where the magnitude is below the reference value continues for a predetermined time or longer, the supply of power to the control means is stopped, so the means for detecting the master cylinder pressure and the amount of operation displacement of the brake operator by the driver are detected. Even if an abnormality occurs in any of the means to perform, it is possible to reliably determine the situation in which the magnitude of the amount of change in the braking operation amount per unit time is below the reference value, and thus the situation has continued for a predetermined time or more Sometimes the power supply to the control means can be reliably stopped.

  According to the fourth aspect of the present invention, when the amount of change in the amount of braking operation performed by the driver per unit time is not more than a reference value continues for a predetermined time or more and the stop lamp switch is off. In addition, since the supply of power to the control means is stopped, it is determined that the braking operation is not actually performed by the driver more accurately than when it is not determined that the stop lamp switch is off. be able to.

  According to the fifth aspect of the present invention, the target braking amount of the wheel is calculated based on the braking operation amount of the driver and the braking force of the wheel is controlled based on the target braking amount. When the situation in which the amount of change per unit time is less than or equal to the reference value continues for a predetermined time or longer, the driver's braking operation amount used for calculating the target braking amount is gradually reduced, and the target braking amount is calculated. Since the supply of power to the control means is stopped when the amount of braking operation of the driver provided to the vehicle becomes equal to or less than the end reference value, the power of the wheels when the supply of power to the control means is stopped is stopped. By gradually reducing the braking force, it is possible to prevent the braking force of the wheels from suddenly becoming zero.

[Preferred embodiment of problem solving means]
According to one preferred aspect of the present invention, in the configuration of the above first to fourth aspects, the control means controls the braking force of each wheel based on the master cylinder pressure and the amount of displacement of the brake operator by the driver. (Preferred embodiment 1).

  According to another preferred aspect of the present invention, in the configuration according to claim 1 or 2, the means for stopping the supply of electric power is a change amount per unit time of an operation displacement amount of the brake operator by the driver. When the situation where the magnitude of the power is below the reference value continues for a predetermined time or longer, the power supply to the control means is stopped (Preferred aspect 2).

  According to another preferred embodiment of the present invention, in the configuration of claim 5, the means for stopping the supply of electric power is based on the magnitude of the amount of change per unit time in the amount of braking operation by the driver. When the following situation continues for a predetermined time or more and the stop lamp switch is OFF, the amount of braking operation of the driver used for calculating the target braking amount is gradually reduced and used for calculating the target braking amount. The power supply to the control means is stopped when the amount of braking operation by the driver becomes equal to or less than the end reference value (preferred aspect 3).

  According to another preferred aspect of the present invention, in the configuration of the above-mentioned claim 5 or the preferred aspect 3, the control means is configured to set the target of each wheel based on the master cylinder pressure and the operation displacement amount of the brake operator by the driver. The braking amount is calculated, and the braking force of each wheel is controlled based on the target braking amount (preferred aspect 4).

  According to another preferred embodiment of the present invention, in the configuration of the above-mentioned claim 5 or preferred embodiment 3 or preferred embodiment 4, the means for stopping the supply of power is the amount of change per unit time of the master cylinder pressure. When the magnitude is less than the reference value or when the amount of change per unit time in the amount of operation displacement of the brake operator by the driver is less than the reference value, the driver's braking operation quantity per unit time It is comprised so that it may determine with the magnitude | size of variation | change_quantity being below a reference value (Preferable aspect 5).

  According to another preferred embodiment of the present invention, in the configuration of the above-mentioned claim 5 or preferred embodiment 3 or preferred embodiment 4, the means for stopping the supply of electric power is the amount of operation displacement of the brake operator by the driver. When the amount of change per unit time is less than or equal to a reference value, it is configured to determine that the amount of change per unit time of the driver's braking operation amount is less than or equal to a reference value (preferred aspect) 6).

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram showing a hydraulic circuit of a first embodiment of a vehicle braking force control apparatus according to the present invention, and FIG. 2 is a block diagram showing a control system of the embodiment shown in FIG. In FIG. 1, the solenoid of each valve is not shown for the sake of simplicity.

  In FIG. 1, reference numeral 10 denotes an electrically controlled hydraulic brake device. The brake device 10 includes a master cylinder 14 that pumps brake oil in response to a driver's depressing operation of the brake pedal 12. Have. A dry stroke simulator 16 is provided between the brake pedal 12 and the master cylinder 14.

  The master cylinder 14 has a first master cylinder chamber 14A and a second master cylinder chamber 14B, and these master cylinder chambers have a brake hydraulic pressure supply conduit 18 for the left front wheel and a brake hydraulic pressure control conduit for the right front wheel, respectively. One end of 20 is connected. Wheel cylinders 22FL and 22FR for controlling the braking force of the left front wheel and the right front wheel are connected to the other ends of the brake hydraulic pressure control conduits 18 and 20, respectively.

  In the middle of the brake hydraulic pressure supply pipes 18 and 20, normally open type electromagnetic on / off valves (master cut valves) 24L and 24R are provided, respectively. The electromagnetic on / off valves 24L and 24R are respectively connected to the first master cylinder chamber 14A and the second master cylinder chamber 14A. It functions as a shut-off valve that controls communication between the master cylinder chamber 14B and the corresponding wheel cylinders 22FL and 22FR. A wet stroke simulator 28 is connected to the brake hydraulic pressure supply conduit 18 between the master cylinder 14 and the electromagnetic open / close valve 24FL via a normally closed electromagnetic open / close valve (normally closed valve) 26.

  A reservoir 30 is connected to the master cylinder 14, and one end of a hydraulic pressure supply conduit 32 is connected to the reservoir 30. An oil pump 36 driven by an electric motor 34 is provided in the middle of the hydraulic supply conduit 32, and an accumulator 38 that accumulates high-pressure hydraulic pressure is connected to the hydraulic supply conduit 32 on the discharge side of the oil pump 36. One end of a hydraulic discharge conduit 40 is connected to the hydraulic supply conduit 32 between the reservoir 30 and the oil pump 36.

  Although not shown in FIG. 1, a conduit is provided for connecting the suction-side hydraulic supply conduit 32 and the discharge-side hydraulic supply conduit 32 of the oil pump 36, and an accumulator 38 is provided in the middle of the conduit. A relief valve is provided that opens when the pressure exceeds a reference value and returns oil from the discharge-side hydraulic supply conduit 32 to the suction-side hydraulic supply conduit 32.

  The hydraulic pressure supply conduit 32 on the discharge side of the oil pump 36 is connected to the brake hydraulic pressure supply conduit 18 between the electromagnetic on-off valve 24L and the wheel cylinder 22FL by a hydraulic control conduit 42, and the electromagnetic on-off valve 24R and the wheel by a hydraulic control conduit 44. It is connected to a brake hydraulic pressure supply conduit 20 between the cylinder 22FR, a hydraulic control conduit 46 to a left rear wheel wheel cylinder 22RL, and a hydraulic control conduit 48 to a right rear wheel wheel cylinder 22RR. .

  Normally closed electromagnetic linear valves 50FL, 50FR, 50RL, and 50RR are provided in the middle of the hydraulic control conduits 42, 44, 46, and 48, respectively. The hydraulic control conduits 42, 44, 46, 48 on the side of the wheel cylinders 22FL, 22FR, 22RL, 22RR with respect to the linear valves 50FL, 50FR, 50RL, 50RR are connected to the hydraulic discharge conduit 40 by the hydraulic control conduits 52, 54, 56, 58, respectively. And normally closed electromagnetic linear valves 60FL and 60FR are provided in the middle of the hydraulic control conduits 52 and 54, respectively, and normally closed electromagnetic solenoids are provided in the middle of the hydraulic control conduits 56 and 58, respectively. There are provided normally-open electromagnetic linear valves 60RL and 60RR that are cheaper than the conventional linear valves.

  The linear valves 50FL, 50FR, 50RL, and 50RR function as pressure increase valves (holding valves) for the wheel cylinders 22FL, 22FR, 22RL, and 22RR, respectively. The linear valves 60FL, 60FR, 60RL, and 60RR are wheel cylinders 22FL, 22FR, 22RL, and The linear valves function as pressure reducing valves for 22RR, so that these linear valves form a pressure increasing / decreasing control valve for controlling supply / discharge of high pressure oil to / from each wheel cylinder from the accumulator 38 in cooperation with each other.

  Note that the electromagnetic on / off valves 24L and 24R are kept open during non-control when no drive current is supplied to the electromagnetic on / off valves, linear valves and motor 34, and the electromagnetic on / off valves 26, linear valves 50FL to 50RR, linear valves 60FL and 60FR is maintained in a closed state, and linear valves 60RL and 60RR are maintained in an open state (non-control mode). In addition, when any one of the linear valves 50FL to 50RR and the linear valves 60FL to 60RR is lost and the pressure in the corresponding wheel cylinder cannot be normally controlled, each electromagnetic on-off valve is set to the non-control mode. As a result, the pressure in the wheel cylinders of the left and right front wheels is directly controlled by the master cylinder 14.

  As shown in FIG. 1, a brake hydraulic pressure control conduit 18 between the first master cylinder chamber 14A and the electromagnetic on-off valve 24L detects a pressure in the control conduit as a first master cylinder pressure Pm1. One pressure sensor 66 is provided. Similarly, the brake pressure control conduit 20 between the second master cylinder chamber 14B and the electromagnetic on-off valve 24R is provided with a second pressure sensor 68 for detecting the pressure in the control conduit as the second master cylinder pressure Pm2. It has been. The brake pedal 12 is provided with a stroke sensor 70 for detecting a brake pedal depression stroke St by a driver, and a pressure for detecting the pressure in the conduit as an accumulator pressure Pa is provided in a hydraulic supply conduit 32 on the discharge side of the oil pump 34. A sensor 72 is provided.

  Pressure sensors for detecting the pressure in the corresponding conduits as the pressures Pfl and Pfr in the wheel cylinders 22FL and 22FR are provided in the brake hydraulic pressure supply conduits 18 and 20 between the electromagnetic on-off valves 24L and 24R and the wheel cylinders 22FL and 22FR, respectively. 74FL and 74FR are provided. Further, in the hydraulic control conduits 46 and 48 between the electromagnetic on-off valves 50RL and 50RR and the wheel cylinders 22RL and 22RR, respectively, pressure sensors for detecting the pressure in the corresponding conduits as the pressures Prl and Prr in the wheel cylinders 22RL and 22RR. 74RL and 74RR are provided.

  The electromagnetic on / off valves 24L and 24R, the electromagnetic on / off valve 26, the motor 34, the linear valves 50FL to 50RR, and the linear valves 60FL to 60RR are controlled by an electronic control unit 78 shown in FIG. 2 as will be described in detail later. The electronic control unit 78 includes a microcomputer 80 and a drive circuit 82. Although not shown in detail in FIG. 1, the microcomputer 80 has, for example, a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other via a bidirectional common bus. It may be.

  In the microcomputer 80, a signal indicating the first master cylinder pressure Pm1 and the second master cylinder pressure Pm2 from the pressure sensors 66 and 68, a signal indicating the depression stroke St of the brake pedal 12 from the stroke sensor 70, and a pressure sensor 72, respectively. A signal indicating the accumulator pressure Pa and a signal indicating the pressure Pi (i = fl, fr, rl, rr) in the wheel cylinders 22FL to 22RR are input from the pressure sensors 74FL to 74RR, respectively, and an ignition switch (IGSW) 84 and A stop lamp switch (STPSW) 86 receives a signal indicating whether or not the ignition switch 84 is in an ON state and a signal indicating whether or not the brake pedal 12 is depressed.

  The electronic control unit 78 includes a standby control circuit 88. When the door not shown is opened and closed when the ignition switch 84 is OFF, the power supply circuit 90 causes the microcomputer 80, pressure Electric power is supplied to the sensors 66 and 68 and the stroke sensor 70, thereby making the microcomputer 80 and these sensors operable to bring the electronic controller 78 into a standby state. When the ignition switch 84 is turned on while the electronic control unit 78 is in the standby state, power is supplied from the power supply circuit 90 to the other sensors and drive circuit 82, and the other sensors and drive circuit 82 also operate. As a result, the electronic control device 78 is activated.

  The power supply circuit 90 is always connected to the stop lamp switch 86. When the stop lamp switch 86 is turned on when the brake pedal 12 is depressed, the stop lamp 92 is turned on and the top lamp switch 86 is turned on. A signal indicating the state is supplied to the microcomputer 80. The microcomputer 80 stores a power supply control and braking force control routine according to the flowchart shown in FIG. 3 as will be described later, and when the electronic control device 78 is activated by switching the ignition switch 84 on, When the brake pedal 12 is depressed, the electromagnetic on-off valve 26 is opened and the electromagnetic on-off valves 24L and 24R are closed. In this state, the master cylinder pressures Pm1, Pm2 and stroke sensors detected by the pressure sensors 66, 68 are opened. Based on the depression stroke St detected from 70, the target wheel cylinder pressure Pti (i = fl, fr, rl, rr) of each wheel is calculated to be higher than the master cylinder pressures Pm1, Pm2, and the braking pressure Pi of each wheel is calculated. Each linear valve 50FL-50RR and 60FL-60RR is controlled so that becomes the target wheel cylinder pressure Pti. To (normal control mode).

  On the other hand, when the electronic control unit 78 is activated by depressing the brake pedal 12 when the microcomputer 80 and each sensor are in the standby state, the microcomputer 80 opens the electromagnetic on-off valve 26 and opens the electromagnetic on-off. The valves 24L and 24R are closed, and the master cylinder pressures Pm1 and Pm2 detected by the pressure sensors 66 and 68 in that state and the depression stroke St detected by the stroke sensor 70 are used to set the target wheel cylinder pressure Pti ( i = fl, fr, rl, rr) is calculated to be higher than the master cylinder pressures Pm1, Pm2, and the linear valves 50FL-50RR and 60FL-60RR are set so that the braking pressure Pi of each wheel becomes the target wheel cylinder pressure Pti. (Control mode when the brake pedal is depressed)

  As can be understood from the above description, the electromagnetic on-off valves 24L and 24R, the electromagnetic on-off valve 26, the motor 34, the linear valves 50FL to 50RR, the linear valves 60FL to 60RR, the electronic control device 78, the pressure sensor 66 and the like cooperate with each other. Thus, the control means is configured to control the braking force of the wheel according to the braking operation amount of the driver.

  In the illustrated first embodiment, in the normal control mode, when the ignition switch 84 is turned off, the power supply to the microcomputer 80, the pressure sensors 66 and 68, and the stroke sensor 70 is maintained. However, the supply of power to the other sensors and drive circuit 82 is stopped, thereby bringing the electronic control unit 78 into a standby state.

  On the other hand, in the case of the brake pedal depression start-up control mode, as described in detail later, the situation where the amount of change per unit time in the amount of braking operation by the driver is equal to or less than a reference value is greater than or equal to a predetermined time. If the operation is continued, that is, when the driver is not actually performing the braking operation, the supply of electric power to the microcomputer 80, each sensor, and the drive circuit 82 is stopped. It is prevented that electric power is wastefully supplied to the microcomputer 80, each sensor, and the drive circuit 82 and wasteful braking force control is performed due to the determination that the power is broken.

  Although not shown in the drawing, after the supply of power to the microcomputer 80, each sensor, and the drive circuit 82 is stopped, in other words, when the electronic control unit 78 is not activated and is not in a standby state. When the driver depresses the brake pedal 12 and the top lamp switch 86 is turned on, the signal is supplied to the power supply circuit 90, whereby the electronic control device 78 is activated, and the microcomputer 80, each sensor, drive Supply of power to the circuit 82 is resumed.

  Next, the power supply control and the braking force control in the first embodiment will be described with reference to the flowchart shown in FIG. The control according to the flowchart shown in FIG. 3 is started when the microcomputer 80 is started, and is repeatedly executed at predetermined time intervals.

  First, in step 10, it is determined whether or not the ignition switch 84 is in an on state, that is, whether or not the electronic control device 78 is activated and the braking force is controlled in the normal control mode. If the determination is affirmative, the process proceeds to step 70 as it is. If the determination is negative, the process proceeds to step 20.

  In step 20, it is determined whether or not there is a braking request by the driver. If a negative determination is made, the process proceeds to step 80. If an affirmative determination is made, the process proceeds to step 30. Whether or not there is a braking request by the driver is determined by, for example, whether the average value Pma of the master cylinder pressures Pm1 and Pm2 detected by the pressure sensors 66 and 68 is equal to or greater than the start reference value Pms (positive constant) or It may be performed by determining whether or not the stepping stroke St detected by the stroke sensor 70 is greater than or equal to the start reference value Sts (positive constant).

  In step 30, it is determined whether or not the state in which the stepping stroke St detected by the stroke sensor 70 does not change continues for a predetermined start reference time T1 (positive constant), and a negative determination is made. If YES, the process proceeds to step 70. If an affirmative determination is made, the process proceeds to step 40. Whether the stepping stroke St does not change is determined based on whether the change amount ΔSt of the stepping stroke St per unit time, for example, the cycle time of the flowchart shown in FIG. It may be performed by determining whether or not it is equal to or less than a constant).

  In step 40, it is determined whether or not the top lamp switch 86 is in an OFF state. If an affirmative determination is made, the process proceeds to step 90. If a negative determination is made, the process proceeds to step 70.

  In step 70, power is supplied to the pressure sensor 72, the pressure sensors 74FL to 74RR, the drive circuit 82, or power is supplied to the pressure sensor 72 and the like, and the electromagnetic on-off valve 26 is opened or opened. The valve state is maintained, and the electromagnetic open / close valves 24L and 24R are closed or the valve closed state is maintained.

  In step 80, it is determined whether or not the situation where the driver has not requested braking continues for a predetermined end reference time T2 (positive constant) or more. If a negative determination is made, the process proceeds to step 70. When a positive determination is made, the routine proceeds to step 90. Whether or not there is a braking request by the driver is determined by, for example, whether the average value Pma of the master cylinder pressures Pm1 and Pm2 detected by the pressure sensors 66 and 68 is equal to or less than the end reference value Pme (positive constant) or This may be performed by determining whether or not the stepping stroke St detected by the stroke sensor 70 is equal to or less than the end reference value Ste (positive constant).

  In step 90, the electromagnetic on-off valve 26 is closed, the electromagnetic on-off valves 24L and 24R are opened, and then the supply of electric power to each sensor and the drive circuit 82 is stopped. The supply of power to the computer 80 is stopped, whereby the operation of the electronic control unit 78 is stopped.

  In step 100, a signal indicating the master cylinder pressure Pm1 detected by the pressure sensor 66 is read, and a map corresponding to the graph shown in FIG. 5 based on the average value Pma of the master cylinder pressures Pm1 and Pm2. Thus, the target deceleration Gpt based on the master cylinder pressure is calculated.

  In step 110, based on the depression stroke St detected by the stroke sensor 70, a target deceleration Gst based on the depression stroke is calculated from a map corresponding to the graph shown in FIG.

In step 120, the weight α (0 ≦ α ≦ 1) for the target deceleration Gpt is calculated from the map corresponding to the graph shown in FIG. 7 based on the previous final target deceleration Gtf, and the following equation is used: According to 1, the final target deceleration Gt is calculated as a weighted sum of the target deceleration Gpt and the target deceleration Gst. In the illustrated embodiment, the weight α is calculated based on the previous final target deceleration Gtf, but may be modified to be calculated based on the target deceleration Gpt or Gst.
Gt = α · Gpt + (1−α) Gst (1)

In step 130, Ki (i = fl, fr, rl, rr) is defined as a coefficient of the target wheel cylinder pressure of each wheel with respect to the final target deceleration Gt (a positive coefficient considering the braking effectiveness coefficient of each wheel). The target wheel cylinder pressure Pti (i = fl, fr, rl, rr) of each wheel is calculated according to the following equation 2, and in step 140, hydraulic feedback is performed so that the wheel cylinder pressure of each wheel becomes the target braking pressure Pti. Controlled by
Pti = Ki ・ Gt (2)

  Thus, according to the illustrated first embodiment, at the time of normal braking force control, it is determined in step 10 that the ignition switch 84 is in the on state, and in step 70, the electromagnetic on-off valve 26 is opened or opened. The electromagnetic on-off valves 24L and 24R are closed or maintained in the closed state, and the average value Pma of the master cylinder pressures Pm1 and Pm2 and the depression stroke St of the brake pedal 12 are set in steps 100 to 140. Based on the final target deceleration Gt, the final target deceleration Gt is calculated, and the braking force of each wheel is controlled in a brake-by-wire manner in the normal control mode.

  When the brake pedal 12 is depressed with the ignition switch 84 turned off, a negative determination is made in step 10, an affirmative determination is made in step 20, and a negative determination is made in step 30. Thus, in the brake pedal depression start-up control mode, the braking force of each wheel is controlled in a brake-by-wire manner according to the amount of braking operation by the driver, as in the normal control mode.

  On the other hand, even if it is determined that the brake pedal 12 is depressed with the ignition switch 84 turned off, that is, a negative determination is made in step 10 and an affirmative determination is made in step 20, If the determination is caused by erroneous detection due to abnormality of the pressure sensors 66 and 68 or the stroke sensor 70, and the driver does not actually perform the braking operation, the depression stroke St detected by the stroke sensor 70 is Since there is no change and the stop lamp switch 86 is in the OFF state, an affirmative determination is made in steps 30 and 40, the electromagnetic on-off valve 26 is closed in step 90, and the electromagnetic on-off valves 24L and 24R. After that, the power supply to each sensor, drive circuit 82, and microcomputer 80 is stopped. .

  Therefore, according to the first embodiment shown in the drawing, even if it is determined that there is a driver's braking request with the ignition switch 84 turned off, each sensor is not used when the driver is not actually performing a braking operation. Then, the supply of power to the drive circuit 82 and the microcomputer 80 is stopped, thereby ensuring that power is wastedly supplied to the drive circuit 82 and the like, and that wasteful power is consumed by wasteful braking force control. Can be prevented.

  According to the illustrated embodiment 1, even when the supply of power to the sensors, the drive circuit 82, and the microcomputer 80 is stopped, the brake pedal 12 is depressed by the driver and the top lamp switch 86 is turned on. When the signal is supplied to the power supply circuit 90, the electronic control unit 78 is activated, and the supply of power to the microcomputer 80, each sensor, and the drive circuit 82 is resumed. It can be surely secured.

  When it is determined that there is a driver's braking request with the ignition switch 84 turned off, when the driver actually performs a braking operation, the depression stroke St of the brake pedal 12 is generally Therefore, a negative determination is made in step 30, and steps 70 and 100 to 140 are executed. Thus, each wheel according to the braking operation amount of the driver even when the ignition switch 84 is off. Can be reliably controlled to a pressure higher than the master cylinder pressure.

  FIG. 4 is a flowchart showing power supply control and braking force control in the second embodiment of the vehicle braking force control apparatus according to the present invention. In FIG. 4, the same step numbers as those shown in FIG. 3 are assigned to the same steps as those shown in FIG.

  In the second embodiment, if an affirmative determination is made in step 40, the depression stroke St of the brake pedal 12 used for the calculation of the target deceleration Gst in step 110 in step 50 is determined. The fixed amount Std (positive constant) is reduced. In step 60, it is determined whether or not the stepping stroke St is equal to or less than the end reference value Stc (positive constant). If a negative determination is made, the process proceeds to step 70. The process proceeds to step 90 when an affirmative determination is made. The other steps in this embodiment are executed in the same manner as in the first embodiment.

  Thus, according to the second embodiment shown in the figure, it is determined in step 30 that the state in which the stepping stroke St detected by the stroke sensor 70 does not change continues for a predetermined start reference time T1 or more. If it is determined that the lamp switch 86 is in the OFF state, the stepping stroke St of the brake pedal 12 used for the calculation of the target deceleration Gst in step 110 is gradually reduced in step 50. Since the operation of the electronic control device 78 is stopped when it is determined that the stepping stroke St is equal to or less than the end reference value Stc, the operational effects of the first embodiment can be obtained, and the electronic control device 78 When the operation is stopped, it is possible to reliably prevent the braking force of each wheel from rapidly decreasing to zero.

  In particular, according to the first and second embodiments shown in the drawing, even if it is determined in step 30 that the state in which the stepping stroke St detected by the stroke sensor 70 does not change continues for a predetermined start reference time T1 or more, step 40 In this case, the operation of the electronic control unit 78 is not stopped unless it is determined that the top lamp switch 86 is in the OFF state. Therefore, the operation of the electronic control unit 78 is required as compared with the case where the determination in step 40 is not performed. The possibility of the operation being stopped in the situation can be reduced.

  Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

  For example, in each of the above-described embodiments, the target braking pressure Pti of each wheel is set as a value indicating the amount of braking operation by the driver in both the normal control mode and the brake pedal depression start-up control mode. The driver's required deceleration Gt is calculated based on the average value Pma of the master cylinder pressures Pm1, Pm2 and the brake pedal depression amount St, and the target braking pressure Pti for each wheel is calculated based on the driver's required deceleration Gt. However, the control of the braking force itself does not form the gist of the present invention, and may be executed in any manner known in the art, and in particular, the brake pedal depression start-up control. In the mode, the target braking pressure Pti of each wheel is calculated based on an average value Pma of master cylinder pressures Pm1 and Pm2 as a value indicating the amount of braking operation of the driver, and the target deceleration of each wheel is calculated. The braking pressure Pti may be modified to be calculated based on the driver's requested deceleration Gt.

  Further, in each of the above-described embodiments, there is a situation in which there is no change in the braking operation amount of the driver by determining whether or not the situation in which the depression amount St of the brake pedal is not changed has continued for a predetermined start reference time T1. A determination is made as to whether or not it has continued for a predetermined time or more. However, when the state in which the rake pedal depression amount St does not change continues for a predetermined start reference time T1 or the master cylinder pressures Pm1 and Pm2 When the situation in which the average value Pma does not change continues for a predetermined start reference time T1 or more, it is corrected to determine whether or not the situation in which the driver's braking operation amount does not change continues for a predetermined time or more. May be.

  In the second embodiment described above, it is determined in step 30 that no change in the stepping stroke St detected by the stroke sensor 70 has continued for a predetermined start reference time T1. If it is determined that the top lamp switch 86 is in the OFF state, the stepping stroke St of the brake pedal 12 used for the calculation of the target deceleration Gst in step 110 is gradually reduced in step 50, and step 60 is started. In step 50, the operation of the electronic control unit 78 is stopped when it is determined that the stepping stroke St is equal to or less than the end reference value Stc. In step 50, the target deceleration Gpt in step 100 is stopped. The average value Pma of the master cylinder pressures Pm1 and Pm2 used for the calculation is gradually decreased and the target decrease in step 110 is performed. The depression stroke St of the brake pedal 12 used for the calculation of the speed Gst is gradually reduced, and it is determined in step 60 that the average value Pma is equal to or less than the termination reference value Pmc (positive constant) or the depression stroke St is the termination criterion. It may be modified so that the operation of the electronic control unit 78 is stopped when it is determined that the value is not more than the value Stc.

  In each of the above-described embodiments, the pressure increase / reduction control valve for controlling the wheel cylinder pressure Pi of each wheel is composed of linear valves 50FL-50RR as pressure increase control valves and linear valves 60FL-60RR as pressure reduction control valves. However, these valves may be replaced with control valves having functions of increasing and decreasing pressure and holding.

  In each of the above-described embodiments, the electromagnetic on-off valve 26 is opened or maintained in the control mode when the brake pedal is depressed and activated, as in the normal control mode. As described in Japanese Patent Application No. 2003-65996 and the drawings of the applicant's application, the electromagnetic on-off valve 26 is maintained in a closed state, and each wheel is controlled based on the master cylinder pressure Pm1 or Pm2. It may be modified so that the braking force is controlled. Further, in this case, when the driver depresses the brake pedal 12 and then depresses again, the control of the braking force may be shifted from the brake pedal depressing activation control mode to the normal control mode.

  Furthermore, although the master cylinder pressure is detected by the two pressure sensors 66 and 68, the master cylinder pressure may be corrected so as to be detected by one pressure sensor.

1 is a schematic configuration diagram illustrating a hydraulic circuit according to a first embodiment of a vehicle braking force control apparatus according to the present invention. Example 1 It is a block diagram which shows the control system of the braking force control apparatus in Example 1. FIG. Example 1 3 is a flowchart showing a power supply control and braking force control routine in the first embodiment. Example 1 7 is a flowchart showing a power supply control and braking force control routine in Embodiment 2. (Example 2) It is a graph which shows the relationship between the average value Pma of a master cylinder pressure, and target deceleration Gpt. (Examples 1 and 2) It is a graph which shows the relationship between the depression stroke St of a brake pedal, and the target deceleration Gst. (Examples 1 and 2) It is a graph which shows the relationship between the weight (alpha) with respect to the last final target deceleration Gtf and the target deceleration Gpt. (Examples 1 and 2)

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Brake device 12 Brake pedal 14 Master cylinder 22FL-22RR Wheel cylinder 24F, 24R, 26 Electromagnetic on-off valve 50FL-50RR Linear valve 60FL-60RR Linear valve 66, 68 Pressure sensor 70 Stroke sensor 72, 74FL-74RR Pressure sensor 78 Electronic control Device 84 Ignition switch 86 Stop lamp switch 88 Standby control circuit 90 Power supply circuit

Claims (5)

  Control means for controlling the braking force of the wheel according to the amount of braking operation by the driver, and means for supplying electric power to the control means when the driver performs a braking operation with the ignition switch turned off. In the vehicle braking force control device, the amount of change per unit time in the amount of braking operation performed by the driver after it is determined that the driver has performed braking operation with the ignition switch turned off is the reference value. A vehicle braking force control apparatus comprising: means for stopping supply of electric power to the control means when the following situation continues for a predetermined time or more.   The means for supplying power to the control means is a driver's braking operation when the master cylinder pressure is equal to or higher than its start determination reference value or when the amount of displacement of the brake operator by the driver is equal to or higher than its start determination reference value. The vehicle braking force control device according to claim 1, wherein the vehicle braking force control device is determined to have been performed.   The means for stopping the supply of power is a situation where the magnitude of the change amount per unit time of the master cylinder pressure is below a reference value, or the magnitude of the change amount per unit time of the operation displacement amount of the brake operator by the driver. 3. The vehicle braking force control device according to claim 1, wherein the supply of electric power to the control unit is stopped when a state where the value is equal to or less than a reference value continues for a predetermined time or more.   The means for stopping the supply of power is when a situation where the magnitude of the amount of change per unit time of the braking operation amount of the driver is not more than a reference value continues for a predetermined time or more and the stop lamp switch is off. 4. The vehicle braking force control device according to claim 1, wherein supply of electric power to the control means is stopped. The control means calculates the target braking amount of the wheel based on the braking operation amount of the driver, controls the braking force of the wheel based on the target braking amount, and the means for stopping the supply of power is the braking force of the driver. When the situation where the magnitude of the change amount per unit time of the operation amount is equal to or less than the reference value continues for a predetermined time or more, the driver's braking operation amount used for the calculation of the target braking amount is gradually reduced, and the target The vehicle according to any one of claims 1 to 3, wherein the supply of electric power to the control means is stopped when a braking operation amount of a driver used for calculating a braking amount is equal to or less than an end reference value. Braking force control device.

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