JP4241419B2 - Brake control device for vehicle - Google Patents

Description

  The present invention relates to a vehicle braking control device, and more particularly to a braking control device that controls a braking force based on a braking operation amount of a driver with respect to a braking operation member.

  As one of the braking control devices for vehicles such as automobiles, for example, as described in the following Patent Document 1 relating to the application of the present applicant, the braking force control means based on the braking operation amount of the driver with respect to the braking operation member. The target braking control amount is calculated, and the braking control mode for controlling the braking force generating means provided on each wheel based on the target braking control amount, and the operating force of the driver for the braking operation member are transmitted to the braking force generating means. A braking control device for a vehicle having a driver braking mode for generating a braking force, and an abnormal state prediction means for predicting an abnormal state in which the control of the braking force in the braking control mode cannot be continued; Mode switching means for switching from the braking control mode to the driver braking mode when the braking control mode is switched from the braking control mode to the driver braking mode. 2. Description of the Related Art Conventionally, a vehicle brake control device is known in which a ratio of a braking force generated by a braking force generation unit to a driver's braking operation amount before switching is close to a ratio in a driver braking mode. .

According to such a braking control device, when an abnormal state is predicted in which braking force control in the braking control mode cannot be continued, the mode switching means switches from the braking control mode to the driver braking mode. The ratio of the braking force generated by the braking force generating means to the amount of braking operation of the driver by the braking force control means before the switching to the braking mode is made closer to the ratio in the driver braking mode. When switching to the braking mode, it is possible to reliably prevent the ratio of the braking force generated by the braking force generating means to the amount of braking operation performed by the driver from rapidly decreasing.
JP 2002-178900 A

  Generally, in a braking control device that is switched from the braking control mode to the driver braking mode when an abnormal state is predicted, it is necessary to restart the braking control in the braking control mode when the abnormal state is canceled.

  However, when the operation mode is switched from the driver braking mode to the braking control mode in a situation where the vehicle is traveling and the driver is performing a braking operation, the braking force generating means for the braking operation amount of the driver is controlled. Since the power ratio increases rapidly, the braking force of each wheel increases rapidly, and switching of the braking control mode cannot be performed smoothly and without a sense of incongruity. In the conventional braking control apparatus as described above, this problem is not taken into consideration, and there is room for improvement in this respect.

  The present invention relates to braking of a vehicle equipped with a braking device capable of switching between a first mode in which the boost ratio is the first ratio and a second mode in which the boost ratio is a second ratio that is greater than the first ratio. The main problem of the present invention is to increase the braking force when the operation mode of the braking device is switched from the first mode to the second mode. By making the change gentle, switching from the first mode to the second mode is performed smoothly and without a sense of incongruity.

According to the present invention, the main problem described above is the configuration according to claim 1, that is, the ratio of the braking force of the wheel to the amount of braking operation by the driver is the boost ratio, and the boost ratio is the first ratio. And a braking device that switches to a second mode that is a second ratio in which the boost ratio is greater than the first ratio, and the operating mode of the braking device is the first mode and the second mode. Mode determining means for determining which mode should be set, and control means for setting the operating mode to the operating mode determined by the mode determining means and controlling the braking force of each wheel based on the braking operation amount of the driver When the control means determines that the operation mode should be switched from the first mode to the second mode, the control means sets the operation mode to the vehicle braking control device. First While switch setting to the second mode than the mode of the second mode such that the energizing ratio gradually changes into the first ratio than the second ratio with time from the time of the switching setting has elapsed This is achieved by a vehicle braking control device characterized by controlling the braking force of each wheel.
Further, according to the present invention, the main problem described above is that the braking force of the wheel when the amount of braking operation by the driver is the same as that of the first mode is the first mode. A braking device that switches to a second mode that is greater than the value of mode, mode determining means that determines whether the operating mode of the braking device should be set to the first mode or the second mode, and the operation A braking control device for a vehicle, comprising: a control unit that sets a mode to an operation mode determined by the mode determination unit and controls a braking force of each wheel based on a braking operation amount of a driver; After the determination means determines that the operation mode should be switched from the first mode to the second mode, the time from the time when the operation mode is switched from the first mode to the second mode. There is achieved by a vehicle braking control device and controls the braking force of each wheel in the second mode such that the wheel braking force is increased gradually as it passes.

  According to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 1, the braking device includes braking force generating means provided on each wheel, and the control The means is configured to generate a braking force at the first ratio by transmitting a driver's operating force on the braking operation member to the braking force generating means in the first mode. 2 configuration).

  Further, according to the present invention, in order to effectively achieve the above-mentioned main problems, in the configuration of the above-described claim 1 or 2, the control means has the boost ratio in the second mode. The target braking force of each wheel is calculated based on the driver's operation force or operation driving amount with respect to the braking operation member so as to become the second ratio, and the braking force of each wheel is controlled to the target braking force. (Configuration of claim 3).

According to the present invention, in order to effectively achieve the main problem described above, in the configuration according to any one of claims 1 to 3, the boost ratio is higher than the first ratio. The time until the ratio becomes is longer as the vehicle speed is higher.

According to the present invention, in order to effectively achieve the main problem described above, in the configuration according to any one of claims 1 to 4, the boost ratio is higher than the first ratio. The time until the ratio becomes the rear wheel is longer than the front wheel (structure of claim 5).

According to the present invention, in order to effectively achieve the main problem described above, in the configuration according to any one of claims 1 to 5, the control means is configured to perform a situation or operation in which the vehicle is stopped. When the mode determination means determines that the operation mode should be switched from the first mode to the second mode in a situation where the braking operation amount of the person is below a reference value, the boost ratio is immediately the so that configured to control the braking force of each wheel in the second mode so that from the first ratio varies to the second ratio (configuration of claim 6).

According to the first aspect of the present invention, when the operation mode of the braking device is determined by the mode determination means to be switched from the first mode to the second mode, the operation mode is switched and set. Since the braking force of each wheel is controlled in the second mode so that the increase ratio gradually changes from the first ratio to the second ratio as time elapses from the point of time, the operation mode is more than the first mode. The increase in braking force when switching to the second mode can be moderated, whereby the switching from the first mode to the second mode can be performed smoothly and without a sense of incongruity.

  Further, according to the configuration of the second aspect, each wheel is provided with a braking force generating means, and in the first mode, the operating force of the driver with respect to the braking operation member is transmitted to the braking force generating means. Since the braking force is generated at the first ratio, when the operation mode of the braking device is the second mode, the braking force of each wheel can be surely made higher than the operation force of the driver with respect to the braking operation member. it can.

  According to the third aspect of the present invention, in the second mode, the target control of each wheel is based on the driver's operating force or driving amount with respect to the brake operating member so that the boost ratio becomes the second ratio. Since the power is calculated and the braking force of each wheel is controlled to the target braking force, when the operation mode of the braking device is the second mode, the braking force of each wheel is set to be greater than the driver's operating force on the braking operation member. The braking force can be reliably controlled to be high and corresponding to the braking operation amount of the driver with respect to the braking operation member.

  Further, according to the configuration of claim 4, the time until the boost ratio becomes the second ratio from the first ratio is longer as the vehicle speed is higher. Therefore, the higher the vehicle speed is, the more the operation mode of the braking device is the first mode. The increase in braking force when switching to the second mode is moderated, so that the braking force is insufficient when the operating mode of the braking device is switched from the first mode to the second mode at low vehicle speeds. It is effective to prevent sudden increase in braking force when the operating mode of the braking device is switched from the first mode to the second mode at high vehicle speeds, and to deteriorate the running stability of the vehicle due to this. Can be prevented.

  According to the fifth aspect of the present invention, since the rear wheel is longer than the front wheel until the boosting ratio becomes the second ratio from the first ratio, the operation mode of the braking device is higher than that of the first mode. The increase rate of the rear wheel braking force when switching to the second mode is made smaller than the increase rate of the front wheel braking force, thereby causing the rear wheel braking force to be excessive compared to the front wheel and the result. It is possible to effectively prevent a decrease in the stability of the vehicle that performs the operation.

According to the configuration of the sixth aspect, the operation mode is changed from the first mode to the second mode by the mode determination means in a situation where the vehicle is in a stopped state or a situation where the amount of braking operation by the driver is below a reference value. When it is determined that the vehicle should be switched to, the boost ratio is immediately changed from the first ratio to the second ratio, so that the situation where the vehicle is stopped or the driver's braking operation amount is below the reference value In the situation, it is possible to reliably prevent the change of the boost ratio from the first ratio to the second ratio from being unnecessarily slowed.
According to the seventh aspect of the present invention, the operation mode is switched from the first mode to the second mode after the mode determination means determines that the operation mode should be switched from the first mode to the second mode. Since the braking force of each wheel is controlled in the second mode so that the braking force of the wheel gradually increases as time elapses from the given time point, the first mode is the same as in the case of the configuration of claim 1 above. Further, the increase in the braking force during the switching to the second mode can be moderated, whereby the switching from the first mode to the second mode can be smoothly performed without a sense of incongruity.

[Preferred embodiment of problem solving means]
According to one preferable aspect of the present invention, in the configuration according to any one of the first to seventh aspects, the mode determination means cannot perform normal braking force control in the second mode. Then, it is determined that the operation mode should be switched to the first mode, and when the operation mode is in the first mode, when the normal braking force control can be performed in the second mode, the operation mode is changed. It is configured to determine that the setting should be switched from the first mode to the second mode (preferred aspect 1).

  According to another preferred aspect of the present invention, in the configuration of the preferred aspect 1 described above, the mode determination means switches the operation mode to the first mode when the voltage of the power source for driving the braking device is not normal. When the operation mode is in the first mode and the voltage of the power source driving the braking device becomes normal, it is determined that the operation mode should be switched from the first mode to the second mode. (Preferred aspect 2)

  According to another preferred embodiment of the present invention, in the configuration of the preferred embodiment 2, the power source includes a main power source and a sub power source, and the braking device is driven by the main power source when the voltage of the main power source is normal. When the main power supply voltage is not normal, it is driven by the sub power supply. When the main power supply voltage is not normal, the mode determination means determines that the operation mode should be switched to the first mode and set the operation mode. When the voltage of the main power supply becomes normal when the power supply is in the first mode, the operation mode is determined to be switched from the first mode to the second mode (preferred aspect 3).

  According to another preferred aspect of the present invention, in the configuration of the preferred aspect 2 described above, the power source includes a plurality of power source units that drive the braking device for the corresponding wheel, and the mode determination means is any power source. When the unit voltage is not normal, it is determined that the operation mode should be switched to the first mode, and the operation mode is set to the first when all the power supply unit voltages are normal when the operation mode is the first mode. It is configured to determine that the mode should be switched from the second mode to the second mode (preferred aspect 4).

  According to another preferred embodiment of the present invention, in the configuration of claim 2, the braking device controls the braking force by controlling the braking pressure of each wheel, and the braking operation member includes a master cylinder. The braking device sets the braking pressure of each wheel to the pressure in the master cylinder when the operation mode is in the first mode, and uses the pressure from the high pressure source when the operation mode is in the second mode. The pressure is configured to be controlled to be higher than the pressure in the master cylinder (preferred aspect 5).

  According to another preferred aspect of the present invention, in the configuration of claim 3, the control means calculates the target braking pressure of each wheel based on the driver's operating force or driving amount with respect to the braking operation member. And it is comprised so that the braking pressure of each wheel may turn into target braking pressure (Preferable aspect 6).

  According to another preferred aspect of the present invention, in the configuration of the preferred aspect 6 described above, the control means should switch the operation mode of the braking device from the first mode to the second mode by the mode determination means. Is determined, the target braking pressure is corrected to be reduced, and the target braking pressure reduction correction amount is gradually decreased as time elapses from the switching setting time point, so that the boost ratio is changed from the first ratio to the second ratio. It is comprised so that it may change gradually (the preferable aspect 7).

  According to another preferable aspect of the present invention, in the configuration of the preferable aspect 7, the control means is configured to end the target brake pressure reduction correction when the boost ratio becomes the second ratio (preferably. Aspect 8).

  According to another preferred embodiment of the present invention, in the configuration of the preferred embodiment 7, the control means has a target braking pressure and a boost ratio of the second ratio when the boost ratio is the first ratio. The target braking pressure is reduced and corrected so as to be the sum of the weights with the target braking pressure at the time, and the weight for the target braking pressure when the boost ratio is the second ratio is gradually increased as time elapses from the time of switching setting. (Preferred embodiment 9)

  The present invention will now be described in detail 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 control device according to the present invention applied to a vehicle equipped with a braking device including a front wheel system and a rear wheel system, and FIG. It is a block diagram which shows an electronic controller. In FIG. 1, the solenoids of the electromagnetic on-off valves are omitted for the purpose of simplification.

  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 one ends of brake hydraulic pressure supply conduits 18 and 20 are connected to these master cylinder chambers, respectively. Wheel cylinders 22FL and 22FL 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 control conduits 18 and 20, respectively.

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

  The hydraulic pressure supply conduit 32 on the discharge side of the oil pump 36 is connected to the brake hydraulic pressure supply conduit 20 between the electromagnetic on-off valve 24B and the wheel cylinder 22FL by a hydraulic control conduit 42, and the electromagnetic on-off valve 24A and the wheel by a hydraulic control conduit 44. It is connected to a brake hydraulic pressure supply conduit 18 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 solenoid 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, and 48 on the side of the wheel cylinders 22FL, 22FR, 22RL, and 22RR with respect to the electromagnetic on-off valves 50FL, 50FR, 50RL, and 50RR are connected to the hydraulic discharge conduits by hydraulic control conduits 52, 54, 56, and 58, respectively. 40, electromagnetic on-off valves 60FL, 60FR, 60RL, and 60RR are provided in the middle of the hydraulic control conduits 52, 54, 56, and 58, respectively.

  The electromagnetic opening / closing valves 50FL, 50FR, 50RL, 50RR function as pressure-increasing control valves for the wheel cylinders 22FL, 22FR, 22RL, 22RR, respectively. The electromagnetic opening / closing valves 60FL, 60FR, 60RL, 60RR are wheel cylinders 22FL, 22FR, 22RL, Therefore, these solenoid on-off valves cooperate with each other to control the supply and discharge of high-pressure oil to and from each wheel cylinder from within the accumulator 38, thereby increasing or decreasing the corresponding wheel cylinder pressure. It constitutes a pressure regulator.

  As shown in FIG. 1, the brake hydraulic pressure control conduit 18 between the first master cylinder chamber 14A and the electromagnetic on-off valve 24A has a pressure for detecting the pressure in the control conduit as the first master cylinder pressure Pm1. A sensor 66 is provided. Similarly, a pressure sensor 68 for detecting the pressure in the control conduit as the second master cylinder pressure Pm2 is provided in the brake hydraulic control conduit 20 between the second master cylinder chamber 14B and the electromagnetic on-off valve 24B. .

  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 Pfr and Pfl in the wheel cylinders 22FR and 22FL are provided in the brake hydraulic pressure supply conduits 18 and 20 between the electromagnetic on-off valves 24A and 24B and the wheel cylinders 22FR and 22FL, respectively. 74FR and 74FL 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 24A and 24B, the electromagnetic on-off valve 26, the motor 34, the electromagnetic on-off valves 50FL, 50FR, 50RL, 50RR, the electromagnetic on-off valves 60FL, 60FR, 60RL, 60RR, and the electromagnetic on-off valves 64F and 64R will be described in detail later. It is controlled by the electronic control unit 76. The electronic control unit 76 includes a microcomputer 78, a drive circuit 80, and a power source 82.

  In particular, in the illustrated embodiment, the power supply 82 includes a main power supply 84, a sub power supply 86, and a relay circuit 88, which are not shown in detail in FIG. The main power source 84 has a charging capacity larger than that of the sub power source 86. The relay circuit 88 supplies drive current from the main power supply 84 to the electromagnetic on-off valve 24A and the like (normal mode) when the voltage Vem of the main power supply 84 is equal to or higher than a reference value Vemh (positive constant). When it is less than the reference value Vemh, a drive current is supplied from the sub power source 86 to the electromagnetic on-off valve 24A or the like (backup mode).

  In addition, the electromagnetic on / off valves 24A and 24B are maintained in the open state during non-control when no drive current is supplied to the electromagnetic on / off valves and the motor 34, and the electromagnetic on / off valve 26, the electromagnetic on / off valves 50FL, 50FR, 50RL, 50RR, and the electromagnetic on / off valve 60FL, 60FR, 60RL, and 60RR are maintained in a closed state, whereby the brake device 10 causes the driver braking mode (the first brake mode in which the pressure in the wheel cylinders 22FL and 22FR of the left and right front wheels is controlled by the pressure in the master cylinder 14. Mode).

  Although not shown in detail in FIG. 2, the microcomputer 78 has, for example, a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output port device. These may have a general configuration in which they are connected to each other by a bidirectional common bus.

  The input / output port device of the microcomputer 78 indicates a signal indicating the first master cylinder pressure Pm1 and the second master cylinder pressure Pm2 from the pressure sensors 66 and 68, respectively, and indicates the depression stroke St of the brake pedal 12 from the stroke sensor 70. A signal indicating the accumulator pressure Pa from the pressure sensor 72, a signal indicating the pressure Pi (i = fl, fr, rl, rr) in the wheel cylinders 22FL to 22RR from the pressure sensors 74FL to 74RR, and a power source 82 from the relay circuit 88, respectively. Signals indicating whether the drive current is supplied in the normal mode or the backup mode are respectively input.

  The ROM of the microcomputer 78 stores the control flow shown in FIGS. 3 to 6 as will be described later. When the drive current is supplied by the power source 82 in the normal mode, the CPU uses the pressure sensors 66 and 68 described above. The final target deceleration Gt of the vehicle is calculated based on the detected master cylinder pressures Pm1 and Pm2 and the stepping stroke St detected by the stroke sensor 70, and the target braking pressure Pti (i = i = i) of each wheel is calculated based on the final target deceleration Gt. fl, fr, rl, rr) are calculated and controlled so that the wheel cylinder pressure of each wheel becomes the target braking pressure Pti (braking control mode, that is, the second mode).

  The target braking pressure Pti is higher than the pressure in the master cylinder 14, and therefore the ratio of the wheel cylinder pressure to the pressure in the master cylinder 14 when the operation mode is the braking control mode is the operation mode is the driver braking mode. Greater than the ratio of the wheel cylinder pressure to the pressure in the master cylinder 14 (which is 1). When the driver's braking operation amount is equal to or greater than the reference value, the target braking pressures Ptrl and Ptrr for the left and right rear wheels are calculated to be lower than the target braking pressures Ptfl and Ptfr for the left and right front wheels.

  Particularly in the illustrated embodiment 1, the left and right front wheel wheel cylinders 22FL and 22FR, the electromagnetic on-off valves 50FL and 50FR, the electromagnetic on-off valves 60FL and 60FR, the electromagnetic on-off valve 24B, and the like control the braking force of the left and right front wheels. The front wheel system is configured as a system, and the operation of the left and right front wheels depends on whether or not the braking force of at least one of the left and right front wheels cannot be normally controlled in the braking control mode. The mode is simultaneously switched between the driver braking mode and the braking control mode. When the operation mode of the front wheel system is the driver braking mode, the pressure in the left and right rear wheel wheel cylinders 22RL and 22RR is controlled to the same pressure as the pressure in the left and right front wheel wheel cylinders 22FL and 22FR. When the pressure in the wheel cylinders 22RL and 22RR cannot be controlled to the same pressure as the pressure in the wheel cylinders 22FL and 22FR for the left and right front wheels, the electromagnetic on-off valves 50RL and 50RR are maintained in the closed state. 60RL and 60RR are kept open.

  Similarly, the left and right rear wheel wheel cylinders 22RL and 22RR, the electromagnetic on-off valves 50RL and 50RR, the electromagnetic on-off valves 60RL and 60RR, the electromagnetic on-off valve 24A, etc. are rear wheel systems as a second system for controlling the braking force of the left and right rear wheels. Depending on whether or not the braking force of at least one of the left and right rear wheels cannot be normally controlled in the braking control mode, the operation modes of the left and right rear wheels are simultaneously controlled. The mode is switched between the driver braking mode and the braking control mode. Even when the operation mode of the rear wheel system is the driver braking mode, if the front wheel system is normal, the operation mode of the front wheel system is maintained in the braking control mode.

  In particular, in the illustrated first embodiment, the electronic control unit 76 returns to the normal mode from the backup mode when the driving current is supplied from the power source 82 when the operating mode of the braking device 10 is the driver braking mode. Sometimes, the operation mode of the braking device 10 is switched from the driver braking mode to the braking control mode, and the target braking pressure Pti of each wheel is reduced and corrected, and the reduction correction amount of the target braking pressure Pti is gradually reduced. When the operation mode of the braking device 10 is switched from the driver braking mode to the braking control mode, a sudden increase in braking pressure is prevented, so that the switching from the driver braking mode to the braking control mode can be smoothly performed. Do.

  Next, the braking force control in the illustrated embodiment 1 will be described with reference to the flowcharts shown in FIGS. The control according to the flowcharts shown in FIGS. 3 and 4 is started in the braking control mode when an ignition switch (not shown) is turned on, and is repeatedly executed every predetermined time. In FIG. 3, the flag Ft relates to whether or not the pressure increase ratio is in the process of being gradually increased, and 1 means that the pressure increase ratio is in the process of being gradually increased.

  First, in step 10, a signal indicating the first master cylinder pressure Pm1 detected by the pressure sensor 66 is read, and in step 20, it is determined whether or not the flag Ft is 1. It is determined whether or not the pressure increasing ratio is being gradually increased. If a negative determination is made, the process proceeds to step 30. If an affirmative determination is made, the brake device 10 is set to the driver braking mode in step 40. Further, the elapsed time Tc from the time when the switching to the braking control mode is set is incremented by a predetermined time ΔTc corresponding to the cycle time of the flowchart shown in FIG.

  In step 30, it is determined whether or not the operation mode of the braking device 10 is the braking control mode, that is, the braking pressure of each wheel is controlled to a pressure higher than the master cylinder pressure Pm at a pressure increase ratio larger than 1. The process proceeds to step 150 when an affirmative determination is made, and to step 50 when a negative determination is made.

  In step 50, for example, whether or not it is necessary to shift the operation mode of the braking device 10 from the driver braking mode to the braking control mode by determining whether or not the power source 82 has returned to the normal state from the backup state. When a determination is made and a negative determination is made, the process returns to step 10. When an affirmative determination is made, the operation mode of the braking device 10 is switched to the braking control mode and the flag Ft is set to 1 in step 60. Set to

  In step 70, the final target deceleration Gt of the vehicle is calculated according to the routine shown in FIG. 4, and the target braking pressure (target wheel cylinder pressure) Pti (i = i = i) of each wheel is calculated based on the final target deceleration Gt. fl, fr, rl, rr) are calculated.

  In step 90, based on the elapsed time Tc from the time when the operation mode of the braking device 10 is switched from the driver braking mode to the braking control mode, step 140, which will be described later, is obtained from a map corresponding to the graph shown in FIG. The weight Rt used for the correction calculation of the target braking pressure Pti is calculated.

  In step 100, it is determined whether or not the vehicle is in a stopped state or the driver is not performing a braking operation, and a negative determination is made, that is, whether the vehicle is in a traveling state or the driver. When it is determined that the braking operation is being performed, the process proceeds to step 120 as it is. When an affirmative determination is performed, the weight Rt is set to 1 in step 110 and then the process proceeds to step 120. The determination as to whether or not the vehicle is in a stopped state may be made, for example, by determining whether or not the vehicle speed V detected by a vehicle speed sensor (not shown in the figure) is below a reference value. The determination of whether or not the braking operation is not performed may be performed by determining whether or not the master cylinder pressures Pm1 and Pm2 and the stepping stroke St are less than or equal to a reference value, for example.

In step 120, it is determined whether or not Rt is 1, that is, whether or not further incrementing of Rt is required. If affirmative determination is made, step 130 is performed. When the flag Ft and the elapsed time Tc are reset to 0 and a negative determination is made, in step 140, the average value of the first master cylinder pressure Pm1 and the second master cylinder pressure Pm2 is set to Pma, and before correction. The target braking pressure Pti of each wheel is reduced and corrected according to the following formula 1 with the target braking pressure Pti of each wheel as Ptfi.
Pti = (1-Rt) Pma + RtPtfi (1)

  In step 150, for example, it is determined whether or not the power supply 82 is in a backup state, that is, the voltage Vem of the main power supply 84 is less than the reference value Vemc, and the drive current is supplied from the sub power supply 86 to the electromagnetic on-off valve 50FL. By determining whether or not the operation is performed through the relay circuit 88, it is determined whether or not it is necessary to shift the operation mode of the braking device 10 from the braking control mode to the driver braking mode, and a negative determination is performed. In step 160, the target braking pressure Pti of each wheel is calculated in the same manner as in step 70 described above. If an affirmative determination is made, in step 170, for example, in the case of the above-mentioned Patent Document 1. The operation mode of the braking device 10 is processed so as to shift to the driver braking mode in the same manner as described above.

  In step 180, the braking force of each wheel is controlled by controlling each valve of the braking device 10 so that the braking pressure Pi of each wheel becomes the corresponding target braking pressure Pti, and then the process returns to step 10. .

  In step 72 of the target deceleration Gt calculation routine of FIG. 4 executed in step 70, the map corresponding to the graph shown in FIG. 6 is based on the stepping stroke St detected by the stroke sensor 70. A target deceleration Gst based on the depression stroke is calculated, and in step 74, an average value Pma of the first master cylinder pressure Pm1 and the second master cylinder pressure Pm2 is calculated, and based on the average value Pma, The target deceleration Gpt based on the master cylinder pressure is calculated from the map corresponding to the graph shown in FIG.

In step 76, the weight α (0 ≦ α ≦ 0.6) for the target deceleration Gst is calculated from the map corresponding to the graph shown in FIG. 8 based on the target deceleration Gpt. The final target deceleration Gt is calculated as a weighted sum of the target deceleration Gpt and the target deceleration Gst according to the following equation 2. In the illustrated embodiment, the weight α is set in a range satisfying 0 ≦ α ≦ 0.6, but the maximum value is not limited to 0.6, and is 0 or more and 1 or less. It can be any value.
Gt = αGst + (1-α) Gpt (2)

In step 80, the coefficient of the target braking pressure (target wheel cylinder pressure) of each wheel with respect to the final target deceleration Gt is Ki (i = fl, fr, rl, rr), and the following is based on the final target deceleration Gt. The target braking pressure Pti (i = fl, fr, rl, rr) of each wheel is calculated according to Equation 3.
Pti = KiGt (3)

  Thus, according to the illustrated first embodiment, it is determined in step 20 that the pressure increasing ratio is not in the process of gradually increasing, and in step 30, it is determined that the operating mode of the braking device 10 is the driver braking mode. In step 50, it is determined whether or not the operation mode of the braking device 10 needs to be shifted from the driver braking mode to the braking control mode, and it is necessary to shift from the driver braking mode to the braking control mode. In step 60, the operation mode of the braking device 10 is switched to the braking control mode.

  In steps 20 and 40, an elapsed time Tc from the time when the operation mode of the braking device 10 is switched to the braking control mode is calculated. In step 70, each wheel is operated based on the braking operation amount of the driver. The target braking pressure Pti is calculated, the weight Rt is calculated based on the elapsed time Tc so that the weight Rt gradually increases as the elapsed time Tc increases in step 90, and based on the weight Rt in steps 100-140. As the elapsed time Tc increases, the target braking pressure Pti is reduced and corrected so that the reduction correction amount of the target braking pressure Pti gradually decreases, and in step 180, the braking pressure Pi of each wheel becomes the corresponding target braking pressure Pti. Be controlled.

  Therefore, according to the illustrated first embodiment, the power source 82 returns to a normal state, and the operation mode of the braking device 10 is switched from the driver braking mode as the first mode to the braking control mode as the second mode. The increase change of the braking force at the time can be moderated, whereby the switching from the driver braking mode to the braking control mode can be performed smoothly and without a sense of incongruity.

  In particular, according to the illustrated first embodiment, as shown in FIG. 5, the gradual increase rate of the weight Rt is variably set according to the vehicle speed V so as to decrease as the vehicle speed V increases. Compared to the case where the rate of increase of Rt is constant, the higher the vehicle speed, the milder the increase in braking force when the operation mode of the braking device is switched from the driver braking mode to the braking control mode. The braking device operation mode is controlled from the driver braking mode in the high vehicle speed range while preventing the braking force from being insufficient when the operation mode of the braking device is switched from the driver braking mode to the braking control mode. It is possible to effectively prevent a sudden increase in braking force when switching to the mode and a deterioration in the running stability of the vehicle due to this.

  Further, according to the first embodiment shown in the figure, when it is determined in step 100 that the vehicle is in a stopped state or the driver does not perform a braking operation, the weight Rt is gradually increased in step 110. Therefore, when the operation mode of the braking device is switched from the driver braking mode to the braking control mode in a situation where the vehicle is in a stopped state or a situation where the driver does not perform a braking operation, The boost ratio Pti / Pma can be immediately changed from the first ratio to the second ratio, so that the boost ratio can be changed in a situation where the vehicle is stopped or the driver is not braking. It is possible to reliably prevent the change from being slowed unnecessarily.

  FIG. 9 is a flowchart showing a main part of a braking control routine in the second embodiment of the vehicle braking control apparatus according to the present invention. In FIG. 9, the same steps as those shown in FIG. 3 are assigned the same step numbers as those shown in FIG.

  In the second embodiment, based on the elapsed time Tc from the time point when the operation mode of the braking device 10 is switched from the driver braking mode to the braking control mode in step 90 executed next to step 70, A front wheel weight Rtf and a rear wheel weight Rtr are calculated from a map corresponding to the graph shown in FIG. If an affirmative determination is made in step 100, the front wheel weight Rtf and the rear wheel weight Rtr are set to 1 in step 110, respectively.

In step 120, it is determined whether or not the weight Rtr for the rear wheel is 1, that is, whether or not the further increasing process of Rtr is necessary, and an affirmative determination is made. Sometimes, at step 130, the flag Ft and the elapsed time Tc are reset to 0, respectively, and when a negative determination is made, at step 140, the target braking pressure Pti of each wheel is reduced and corrected according to the following equations 4 to 7. .
Ptfl = (1-Rtf) Pma + RtfPtffl (4)
Ptfr = (1-Rtf) Pma + RtfPtffr (5)
Ptrl = (1-Rtr) Pma + RtrPtfrl (6)
Ptrr = (1-Rtf) Pma + RtfPtfrr (7)

  Thus, according to the illustrated second embodiment, as in the first embodiment described above, the power source 82 returns to a normal state, and the operation mode of the braking device 10 is the second mode compared to the driver braking mode as the first mode. The increase in braking force when switching to the braking control mode as a mode can be moderated, thereby enabling smooth switching from the driver braking mode to the braking control mode without a sense of incongruity, In addition, it is possible to reliably prevent the change in the boost ratio from being unnecessarily delayed in a situation where the vehicle is in a stopped state or a situation where the driver does not perform a braking operation.

  In particular, according to the first embodiment shown in the figure, as shown in FIG. 10, the weight Rtr for the front wheel and the weight Rtr for the rear wheel are slower than the weight Rtf for the rear wheel. Since the calculation is performed according to the elapsed time Tc so as to increase, the rate of increase of the braking pressures Prl and Prr of the rear wheels when the operation mode of the braking device 10 is switched from the driver braking mode to the braking control mode is determined as the braking pressure of the front wheels. By making the rate smaller than the increase rate of Pfl and Pfr, it is possible to effectively prevent the braking force of the rear wheels from becoming excessive compared to the front wheels and the resulting decrease in vehicle stability.

  FIG. 11 is a block diagram showing an electronic control unit of Embodiment 3 of the vehicle braking control device according to the present invention. In FIG. 11, the same members as those shown in FIG. 2 are denoted by the same reference numerals as those shown in FIG.

In the third embodiment, the power supply 82 includes a power supply unit 90 for driving the first system electromagnetic on-off valve 24B and the like of the braking device 10, and a power supply unit 92 for driving the second system electromagnetic on-off valve 24A and the like. ing. The voltages Ve1 and Ve2 of the power supply units 90 and 92 are detected by SOC meters 94 and 96, respectively, and signals indicating the voltages Ve1 and Ve2 are input to the microcomputer 78 of the electronic control unit 76.

  Although not shown in the flowchart, in the third embodiment, in the step corresponding to step 50 in the first or second embodiment, the voltages Ve1 and Ve2 of at least one of the power supply units 90 and 92 are set. By determining whether or not both of the voltages Ve1 and Ve2 of the power supply units 90 and 92 have become equal to or higher than the normal determination reference value from a state below the abnormality determination reference value, the operation mode of the braking device 10 is braked from the driver braking mode. It is determined whether or not it is necessary to shift to the control mode.

  Similarly, in the step corresponding to step 150 in the first or second embodiment, the voltages Ve1 and Ve2 of the power supply units 90 and 92 are both higher than the normal determination reference value, so that at least one of the power supply units 90 and 92 is at least one. Whether or not it is necessary to shift the operation mode of the braking device 10 from the braking control mode to the driver braking mode from the driver control mode by determining whether or not the voltages Ve1 and Ve2 are below the abnormality determination reference value. Is determined. The other steps are executed in the same manner as in the first or second embodiment.

  Therefore, according to the third embodiment, when the power source 82 returns to the normal state and the operation mode of the braking device 10 is switched from the driver braking mode to the braking control mode, as in the first and second embodiments described above. Thus, the change in the braking force of the vehicle can be moderated, whereby the switching from the driver braking mode to the braking control mode can be performed smoothly and without a sense of incongruity. Similar exceptional effects can be obtained.

  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 final target deceleration Gt of the vehicle is calculated based on the amount of braking operation by the driver, and the target braking pressure Pti of each wheel is calculated based on the final target deceleration Gt. When the ten operation modes are switched from the driver braking mode to the braking control mode, the target braking pressure Pti is corrected for reduction, and the reduction correction amount of the target braking pressure Pti is the elapsed time Tc from the time when the switching setting of the operation mode is set. The vehicle target deceleration Gto corresponding to the average value Pma of the master cylinder pressures Pm1 and Pm2 is calculated, and the vehicle target deceleration Gto and the final target deceleration Gt are calculated. The corrected final target deceleration Gt may be calculated as the sum of the weights, and the target braking pressure Pti of each wheel may be calculated based on the corrected final target deceleration Gt.

  In the first embodiment, the rate of increase of the weight Rt is variably set according to the vehicle speed V so as to decrease as the vehicle speed V increases. In the second embodiment, the weight Rtf for the front wheels and The rear wheel weight Rtr is calculated so that the rear wheel weight Rtr increases more slowly than the front wheel weight Rtf. In the second embodiment, the vehicle speed V is The higher the value, the smaller the front wheel weight Rtf and the rear wheel weight Rtr, so that the above-described first and second embodiments may be combined.

  Further, in each of the above-described embodiments, the braking pressure of each wheel is controlled to the target braking pressure calculated based on the average value Pma of the first and second master cylinder pressures and the brake pedal depression stroke St. However, as long as the target braking pressure of each wheel is controlled based on the amount of braking operation performed by the driver during normal braking, the target braking pressure of each wheel is in an arbitrary manner known in the art. May be calculated.

  In each of the above-described embodiments, the braking device 10 includes a front wheel system as the first system and a rear wheel system as the second system, but the braking device 10 controls the left front wheel and the right rear wheel. A first system for controlling power and a second system for controlling the braking force of the right front wheel and the left rear wheel may be used.

  Further, in each of the above-described embodiments, the electromagnetic on-off valves 24A and 24B control the communication between the master cylinder 14 and the right front wheel wheel cylinder 22FR and the left front wheel wheel cylinder 22FL, respectively. The on-off valve 24B is replaced with a three-way two-position switching valve that controls the communication between the master cylinder 14 and the left front wheel wheel cylinder 22FL and the right front wheel wheel cylinder 22FR, and the electromagnetic on-off valve 24A is connected to the master cylinder 14 and the left rear wheel. The three-way two-position switching valve that controls the communication between the wheel cylinder 22RL and the right rear wheel wheel cylinder 22RR may be replaced, and the electromagnetic on-off valve 24B is the master cylinder 14, the left front wheel wheel cylinder 22FL, and the right rear wheel. Replaced with a three-way two-position switching valve that controls the communication with the wheel cylinder 22RR, 24A may be replaced with a three-way two-position switching valve that controls communication between the master cylinder 14 and the wheel cylinder 22FR for the right front wheel and the wheel cylinder 22RL for the left rear wheel.

1 is a schematic configuration diagram showing an embodiment of a vehicle braking control device according to the present invention applied to a vehicle including a braking device including a front wheel system and a rear wheel system. 1 is a block diagram illustrating an electronic control device according to a first embodiment. 3 is a flowchart showing a braking force control routine in the first embodiment. It is a flowchart which shows the target deceleration calculating routine performed in step 70 of FIG. It is a graph which shows the relationship between elapsed time Tc and weight Rt from the time of the operation mode of a braking device being switched and set to the brake control mode. It is a graph which shows the relationship between the depression stroke St of a brake pedal, and the target deceleration Gst. It is a graph which shows the relationship between the average value Pma of a master cylinder pressure, and target deceleration Gpt. It is a graph which shows the relationship between the target deceleration Gpt and the weight (alpha) with respect to the target deceleration Gst. It is a flowchart which shows the principal part of the braking control routine in Example 2 of the braking control apparatus of the vehicle by this invention. It is a graph which shows the relationship between the elapsed time Tc from the time of switching the operation mode of the braking device from the driver braking mode to the braking control mode, the weight Rtf for the front wheels, and the weight Rtr for the rear wheels. It is a block diagram which shows the electronic controller of Example 3 of the braking control apparatus of the vehicle by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Brake device 12 Brake pedal 14 Master cylinder 22FL-22RR Wheel cylinder 66, 68 Pressure sensor 70 Stroke sensor 72, 74FL-74RR Pressure sensor 76 Electronic control device 82 Power supply 84 Main power supply 86 Sub power supply

Claims (7)

The ratio of the braking force of the wheel to the driver's braking operation amount is defined as a boost ratio, the first mode in which the boost ratio is the first ratio, and the second ratio in which the boost ratio is greater than the first ratio. A brake device that switches to the second mode, mode determination means for determining whether the operation mode of the brake device should be set to the first mode or the second mode, and the operation mode The vehicle braking control device includes a control unit that sets the operation mode determined by the mode determination unit and controls the braking force of each wheel based on the amount of braking operation performed by the driver. The control unit is the mode determination unit. together with the when the operation mode is determined to be switched from the first mode to the second mode, switch sets the operation mode to the first mode from the second mode by, And it characterized that you control the braking force of each wheel in the second mode so that the energizing ratio with time from the time of switching setting has elapsed gradually changes into the first ratio than said second ratio A vehicle braking control device.   The braking device has braking force generation means provided on each wheel, and the control means transmits the driver's operation force on the braking operation member to the braking force generation means in the first mode. The braking control device for a vehicle according to claim 1, wherein a braking force is generated at the first ratio.   In the second mode, the control means calculates a target braking force for each wheel on the basis of the driver's operating force or operating driving amount with respect to the braking operation member so that the increase ratio becomes the second ratio. The vehicle braking control device according to claim 1, wherein the braking force of each wheel is controlled to the target braking force. Vehicle brake control device according to any one of claims 1 to 3 wherein the energizing ratio is equal to or longer time the vehicle speed is high until the second ratio than said first ratio. The vehicle braking control according to any one of claims 1 to 4 , wherein the time until the boost ratio becomes the second ratio from the first ratio is longer for the rear wheels than for the front wheels. apparatus. The control means switches the operation mode from the first mode to the second mode by the mode determination means in a situation where the vehicle is in a stopped state or a situation where a driver's braking operation amount is below a reference value. when it is determined that should the claims, characterized that you control the braking force of each wheel in the second mode to change to the energizing ratio immediately the first said than the ratio of the second ratio Item 6. The vehicle brake control device according to any one of Items 1 to 5. A brake device that switches between the first mode and a second mode in which the braking force of the wheel when the amount of braking operation by the driver is the same is greater than the value of the first mode; and the operation of the brake device A mode determining means for determining whether the mode should be set to the first mode or the second mode; and the operating mode determined by the mode determining means to set the operating mode to the driver's braking operation amount. a in the brake control device in a vehicle and control means for controlling the braking force of each wheel on the basis of the to switch the operation mode to the first mode from the second mode by said mode determining means After the determination, the second mode is such that the braking force of the wheel gradually increases as time elapses from the time when the operation mode is switched from the first mode to the second mode. Brake control apparatus for a vehicle, characterized by controlling the braking force of each wheel by chromatography mode.

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