JP4849224B2 - Control device for pump drive motor - Google Patents

Description

  The present invention controls the rotational speed of a motor that drives a hydraulic pump used to pump up brake fluid discharged to a reservoir during pressure reduction control in anti-skid control and return it to the hydraulic circuit of the anti-skid control device. The present invention relates to a pump drive motor control device.

  Conventionally, for example, a device disclosed in Patent Document 1 below is known as a control device for this type of pump driving motor. In this apparatus, a voltage generated by the motor when the power supply to the motor is in an off state (that is, a voltage generated by the induced electromotive force of the motor as a generator (hereinafter, simply referred to as “generated voltage”). )) And a drive pattern of the motor, which is composed of a voltage threshold value and a duration time during which the power supply is maintained in the ON state, is determined.

  When the power supply to the motor is in the off state, the power supply is switched from the off state to the on state when the generated voltage generated by the motor falls below the voltage threshold, and the power supply is on for the duration. The power supply is controlled to be turned on / off by the motor driving pattern so that the power supply is switched from the on state to the off state after being maintained in the state. As a result, the greater the voltage threshold and the longer the duration, the greater the (average) rotational speed of the motor (and hence the (average) discharge flow rate of the hydraulic pump) during anti-skid control. It has come to be. The “discharge flow rate” is a discharge amount per unit time.

  If the rotational speed of the motor is low during anti-skid control, the discharge flow rate of the hydraulic pump tends to be small and the reservoir tends to be filled with brake fluid. In this case, problems such as an increase in the stroke of the brake pedal and a problem that the wheel cylinder pressure cannot be sufficiently reduced in the pressure reduction control of the anti-skid control may occur. On the other hand, when the rotational speed of the motor is high, there may arise a problem that the operation noise of the motor and the hydraulic pump becomes large. That is, during anti-skid control, the motor rotation speed is preferably set to a small value when the amount of brake fluid in the reservoir (reservoir fluid amount) is small and set to a large value when the reservoir fluid amount is large. it is conceivable that.

  In addition, since the master cylinder pressure (and hence the discharge pressure of the hydraulic pump) acts as a load of the hydraulic pump, when the motor drive pattern is constant, the rotation speed of the motor decreases as the master cylinder pressure increases.

  From the above, the reservoir fluid amount and the master cylinder pressure are estimated, and the motor drive pattern (average supply power to the motor is larger as the reservoir fluid amount estimated value is larger or the master cylinder pressure estimated value is larger. Specifically, a technique for selecting a pattern having a larger voltage threshold or a longer duration and driving the motor with the selected motor drive pattern is known (for example, Patent Documents 2 to 2 below). 4).

Thereby, the rotational speed of the motor (and hence the discharge flow rate of the hydraulic pump) can be set to an appropriate value regardless of the reservoir fluid amount and the master cylinder pressure. Hereinafter, the motor drive pattern determined based on the estimated reservoir fluid amount and the master cylinder pressure estimated value as described above is referred to as a “motor reference drive pattern”.
Japanese translation of PCT publication No. 2002-506406 Japanese Patent Laid-Open No. 9-267636 Special table 2001-505505 gazette JP 2005-59627 A

  By the way, even if the motor drive pattern is constant, the rotation speed of the motor decreases as the motor progresses (thus, the discharge flow rate of the hydraulic pump decreases). Even if the rotation speed of the motor is constant, the discharge flow rate of the hydraulic pump becomes smaller as the deterioration of the hydraulic pump progresses. In addition, even when the estimated reservoir fluid amount or the estimated master cylinder pressure is calculated to be smaller than the actual value, the motor reference drive pattern is selected as a pattern with a smaller average supply power to the motor. The rotational speed of the motor is reduced (thus, the discharge flow rate of the hydraulic pump is reduced).

  That is, when the motor or the hydraulic pump is deteriorated, or when the reservoir fluid amount estimated value or the master cylinder pressure estimated value is calculated to be smaller than the actual value, if the motor is driven with the motor reference drive pattern, The discharge flow rate of the pump can be insufficient. As a result, problems such as an increase in the stroke of the brake pedal described above and a problem that the wheel cylinder pressure cannot be sufficiently reduced in the anti-skid control pressure reduction control may still occur.

  On the other hand, if the estimated reservoir fluid amount is calculated to be larger than the actual value, the motor reference drive pattern is selected to be a pattern with a larger average supply power to the motor. When is driven, the rotational speed of the motor increases. As a result, the problem that the operation noise of the motor and the hydraulic pump mentioned above becomes loud may still arise.

  Accordingly, an object of the present invention is to stably select an appropriate motor drive pattern in a pump drive motor control apparatus that controls the rotation speed of a motor that drives a hydraulic pump, and to stabilize the rotation speed of the motor. It is to provide something that can be maintained at an appropriate value.

  A pump drive motor control device according to the present invention includes an anti-skid control device that performs anti-skid control including the pressure reduction control, and pumps brake fluid discharged to a reservoir during the pressure reduction control. The present invention is applied to a brake hydraulic pressure control device for a vehicle including a hydraulic pump that returns the hydraulic pressure circuit and a motor that drives the hydraulic pump.

  A control device for a pump driving motor according to the present invention acquires a master cylinder pressure estimated value acquisition unit that acquires an estimated value of a master cylinder pressure, and an estimated value of a reservoir fluid amount that is an amount of brake fluid in the reservoir. When power supply to the motor is in an off state based on the reservoir fluid amount estimated value acquisition means, the acquired master cylinder pressure estimated value, and a value corresponding to the acquired reservoir fluid amount estimated value The reference drive of the motor comprising a reference value of a voltage threshold value to be compared with a voltage generated by the motor (the generated voltage) and a reference value of a duration time during which the power supply is kept on A motor reference drive pattern determining means for determining a pattern; a final value of the voltage threshold; and a final value of the duration. Motor final drive pattern determining means for determining a pattern equal to the drive pattern; and when the power supply is off, the power supply is turned off when the voltage generated by the motor falls below the voltage threshold final value. The power supply is controlled with the motor final drive pattern so that the power supply is switched from the on state to the off state after being switched to the on state and the power supply is kept on for the duration last value. Control means for controlling the rotational speed of the motor.

  With the above configuration, as described in the background section above, the pump drive motor control device according to the present invention is based on the master cylinder pressure estimated value and the reservoir fluid amount estimated value in principle. The motor is driven in a pattern equal to the motor reference drive pattern (voltage threshold reference value + duration reference value) determined in this manner.

  The pump drive motor control device according to the present invention is characterized in that the motor final drive pattern determining means is configured to replace the motor final drive pattern with the motor reference drive pattern instead of the motor reference drive pattern under a predetermined condition. Is provided with changing means for determining different patterns.

  According to this, when the motor is driven with a pattern equal to the motor reference drive pattern, the motor is driven with a pattern different from the motor reference drive pattern when the rotation speed of the motor is controlled to a value different from an appropriate value. can do. Accordingly, it is possible to stably select an appropriate motor driving pattern, and to stably maintain the motor rotation speed at an appropriate value.

  In the pump drive motor control device according to the present invention, the motor reference drive pattern determination means uses the motor reference drive pattern as a reference discharge for design based on the discharge flow rate of the hydraulic pump driven by the motor. A pattern corresponding to the case where the first discharge flow rate is smaller than the flow rate is set, and the changing means is configured so that the actual discharge flow rate of the hydraulic pump driven by the motor is the first discharge flow rate. When a state indicating that the flow rate is greater than the flow rate is detected, the motor final drive pattern is preferably determined to be a pattern in which the rotation speed is smaller than the motor reference drive pattern.

  In general, the discharge flow rate of the hydraulic pump when the motor is driven with a certain motor drive pattern (hereinafter referred to as “discharge flow rate of the hydraulic pump with respect to the motor drive pattern”) is a design median value ( Reference discharge flow rate) exists. On the other hand, as described above, the “discharge flow rate of the hydraulic pump with respect to the motor driving pattern” may change depending on the degree of deterioration of the motor and the hydraulic pump.

  The smaller the “discharge flow rate of the hydraulic pump relative to the motor drive pattern” assumed when creating the motor reference drive pattern, the greater the average reference power supplied to the motor. The voltage threshold value is larger or the duration time is longer).

  Accordingly, when the motor reference drive pattern is driven when the motor reference drive pattern is assumed and the hydraulic pump discharge flow rate with respect to the motor drive pattern is smaller than the actual value, the hydraulic pump The actual discharge flow rate becomes excessive. On the other hand, when the motor reference drive pattern is driven when the motor reference drive pattern is assumed and the hydraulic pump discharge flow rate relative to the motor drive pattern is larger than the actual value, the hydraulic pump The actual discharge flow rate is insufficient.

  From the above, when the “discharge flow rate of the hydraulic pump with respect to the motor drive pattern” is a value smaller than the reference discharge flow rate (preferably a value that should be guaranteed as a minimum in design (minimum guaranteed discharge flow rate)) If the motor is driven with the above motor reference drive pattern that is prepared assuming that, the shortage of the discharge flow rate of the hydraulic pump can be suppressed.

  That is, in this case, for example, when the degree of deterioration of the motor or the hydraulic pump is large and the actual value of “the discharge flow rate of the hydraulic pump with respect to the motor drive pattern” has decreased to the above-mentioned minimum guaranteed discharge flow rate, The actual discharge flow rate can be set to an appropriate value. On the other hand, if the motor or the hydraulic pump is not deteriorated or the degree of deterioration is small and the actual value of the “discharge flow rate of the hydraulic pump with respect to the motor drive pattern” is larger than the above-mentioned minimum guaranteed discharge flow rate, The actual discharge flow rate of the pump becomes excessive.

  Here, when the actual value of “the discharge flow rate of the hydraulic pump with respect to the motor drive pattern” is larger than the above-mentioned minimum guaranteed discharge flow rate, the motor drive pattern is determined to be a pattern whose rotational speed is smaller than the motor reference drive pattern. The extent to which the actual discharge flow rate of the hydraulic pump becomes excessive can be suppressed.

  The above configuration is based on such knowledge. According to this, even when the motor or the hydraulic pump is deteriorated, it is possible to suppress the shortage of the discharge flow rate of the hydraulic pump. It is possible to suppress a situation in which the wheel cylinder pressure cannot be sufficiently reduced in the pressure reduction control. In addition, when the motor and the hydraulic pump are not deteriorated, it is possible to suppress the extent to which the actual discharge flow rate of the hydraulic pump becomes excessive. The situation of becoming can be suppressed. That is, the rotational speed of the motor can be set to an appropriate value regardless of the degree of deterioration of the motor or the hydraulic pump. The first discharge flow rate is preferably set to the minimum guaranteed discharge flow rate.

  As described above, in order to detect a state indicating that the actual discharge flow rate of the hydraulic pump is larger than the first discharge flow rate, the control device according to the present invention described above, the reservoir fluid amount estimated value and the Timing estimation means for estimating when the reservoir fluid amount becomes zero based on the first discharge flow rate, and first detection means for detecting that the actual value of the reservoir fluid amount is zero, The changing means detects that the actual value of the reservoir fluid amount has become zero before the estimated time when the reservoir fluid amount becomes zero, so that the actual discharge flow rate of the hydraulic pump is changed to the first value. It is preferable to be configured to detect a state indicating that it is greater than one discharge flow rate.

  The reservoir fluid volume increases during the pressure reduction control, and decreases according to the discharge flow rate of the hydraulic pressure pump from the end of the pressure reduction control. That is, the time when the reservoir fluid amount becomes zero is estimated from, for example, the estimated reservoir fluid amount at the end of the pressure reduction control and the assumed discharge flow rate of the hydraulic pump (that is, the first discharge flow rate). can do. In this case, the estimated time at which the reservoir fluid amount becomes zero as the assumed first discharge flow rate is smaller is calculated at a later time.

  That is, when the actual discharge flow rate of the hydraulic pump is larger than the first discharge flow rate, the actual value of the reservoir fluid amount becomes zero before the estimated time when the reservoir fluid amount becomes zero. The above configuration is based on such knowledge. According to this, it can be detected easily and accurately that the actual discharge flow rate of the hydraulic pump is larger than the first discharge flow rate.

  When the actual value of the reservoir fluid amount becomes zero, the load on the hydraulic pump becomes very small. Therefore, when the power supply to the motor is off, the motor speed decreases (that is, the generated voltage decreases). Speed) is very small. This greatly delays the time when the power supply is switched from the off state to the on state. In other words, the time during which the power supply to the motor is maintained in the off state becomes very long. If such a principle is used, it can be detected that the actual value of the reservoir fluid amount has become zero.

  In this case, whenever the change means detects a state indicating that the actual discharge flow rate of the hydraulic pump driven by the motor is larger than the first discharge flow rate, the motor final drive pattern is It is preferable that the rotation speed is determined to be a smaller pattern.

  According to this, until the actual discharge flow rate of the hydraulic pump matches or approaches the first discharge flow rate, the motor final drive pattern is gradually changed from the motor reference drive pattern in a direction in which the rotation speed decreases. It can be changed. Therefore, the actual discharge flow rate of the hydraulic pump can be brought close to the first discharge flow rate with high accuracy. In other words, the rotational speed of the motor can be accurately set to an appropriate value regardless of the degree of deterioration of the motor or the hydraulic pump.

  Further, the changing means is configured such that the rotation speed of the motor final drive pattern is smaller than the pattern corresponding to the case where the discharge flow rate of the hydraulic pump driven by the motor becomes the designed reference discharge flow rate. It is preferable to be configured to prohibit the pattern from being determined.

  According to this, for example, there is an erroneous detection that the actual discharge flow rate of the hydraulic pump is larger than the first discharge flow rate even though the actual discharge flow rate of the hydraulic pump is not larger than the first discharge flow rate. Even if the situation to be repeated is generated, it can be suppressed that the rotational speed of the motor is controlled to be excessively small.

  Further, in the pump drive motor control device according to the present invention, when the change means detects that the master cylinder pressure estimated value is calculated to be smaller than the actual value, It is preferable that the motor final drive pattern is determined to be a pattern in which the rotation speed is larger than the motor reference drive pattern.

  As described above, when the master cylinder pressure estimated value is calculated to be smaller than the actual value, the motor reference drive pattern is selected to be a pattern with a smaller average supply power to the motor. Accordingly, when the motor is driven with a motor final drive pattern equal to the motor reference drive pattern, the rotational speed of the motor may be smaller than an appropriate value.

  According to the above configuration, in such a case, the rotational speed of the motor can be increased. Therefore, even when the estimated master cylinder pressure is calculated to be smaller than the actual value, the rotational speed of the motor can be controlled to an appropriate value.

  In this case, the changing unit detects that the time during which the power supply is maintained in the off state (hereinafter sometimes simply referred to as “off time”) is shorter than the first time, It is preferably configured to detect a condition indicating that the estimated master cylinder pressure value is calculated to be smaller than the actual value.

  Since the master cylinder pressure acts as a load of the hydraulic pump, the higher the master cylinder pressure, the higher the motor rotation speed decrease speed (that is, the power generation voltage decrease speed) during the off time. In other words, the off time is shortened. Therefore, the off time can be estimated by using the master cylinder pressure estimated value (and the voltage threshold).

  Here, the fact that the actual off-time is shorter than the estimated off-time means that the master cylinder pressure estimated value is calculated to be smaller than the actual value. The above configuration is based on such knowledge. According to this, by setting the first time to a time shorter than the estimated off time, for example, the master cylinder pressure estimated value is calculated to be smaller than the actual value easily and accurately. It can be detected.

  In this case, the change means detects that the master cylinder pressure estimated value is smaller than the actual value by continuously detecting that the off time is shorter than the first time by the first number of times. More preferably, it is configured to detect a condition indicative of According to this, it can be detected with higher accuracy that the estimated value of the master cylinder pressure is calculated to be smaller than the actual value.

  Each time the change means detects a state indicating that the estimated value of the master cylinder pressure is calculated to be smaller than an actual value, the motor final drive pattern is determined to be a pattern in which the rotation speed becomes larger. It is preferable to be configured to follow. According to this, in the case where the estimated master cylinder pressure value is calculated to be smaller than the actual value, the rotational speed of the motor can be more reliably increased to an appropriate value.

  In this case, in the state where the motor final drive pattern is determined to be a pattern in which the rotation speed is larger than the motor reference drive pattern, the changing unit has determined that the off time has become the first time or more. If detected, the motor final drive pattern is preferably configured to return toward the motor reference drive pattern.

  The off time tends to become longer as the rotation speed of the motor increases. Therefore, when the off time is equal to or longer than the first time, it means that the rotational speed of the motor is sufficiently large. According to the above configuration, for example, erroneous detection that the master cylinder pressure estimated value is calculated to be smaller than the actual value even though the master cylinder pressure estimated value is not calculated to be smaller than the actual value is repeated. Even if the situation to be done occurs, it can be suppressed that the rotational speed of the motor is controlled to be excessively large.

  In the pump drive motor control apparatus according to the present invention, when the change means detects a state indicating that the estimated reservoir fluid amount is calculated to be smaller than an actual value, It is preferable that the motor final drive pattern is determined to be a pattern in which the rotation speed is larger than the motor reference drive pattern.

  As described above, also when the estimated reservoir fluid amount is calculated to be smaller than the actual value, the motor reference drive pattern is selected as a pattern with a smaller average supply power to the motor. Accordingly, when the motor is driven with a motor final drive pattern equal to the motor reference drive pattern, the rotational speed of the motor may be smaller than an appropriate value.

  According to the above configuration, in such a case, the rotational speed of the motor can be increased. Therefore, even when the estimated reservoir fluid amount is calculated to be smaller than the actual value, the rotational speed of the motor can be controlled to an appropriate value.

  In this case, the change means detects that the state in which the off time is shorter than the second time continues for the third time, so that the estimated reservoir fluid amount is calculated to be smaller than the actual value. It is preferable to be configured to detect a state indicating the above. Here, it is preferable that the second time is set to be longer than the first time.

  As described above, if the estimated reservoir fluid amount is calculated to be smaller than the actual value, the motor rotation speed tends to be smaller than an appropriate value. If the state where the rotational speed of the motor is smaller than an appropriate value continues, the state where the actual value of the reservoir fluid amount does not become zero may continue for a relatively long time from the end of the pressure reduction control. Here, as described above, when the actual value of the reservoir fluid amount becomes zero, the load of the hydraulic pump becomes very small, so that the off time becomes sufficiently longer than the estimated off time.

  From the above, the fact that the actual off-time is shorter (repeated) for a relatively long time than the estimated off-time vicinity means that the actual amount of the reservoir fluid is maintained for a relatively long time. This means that the state where the value does not become zero continues, that is, the estimated reservoir fluid amount is calculated to be smaller than the actual value. The above configuration is based on such knowledge. According to this, by setting the second time to, for example, a time in the vicinity of the estimated off time, the estimated reservoir fluid amount is calculated to be smaller than the actual value easily and accurately. It can be detected.

  In this case, each time the change means detects a state indicating that the estimated reservoir fluid amount is calculated to be smaller than the actual value, the motor final drive pattern is changed to a pattern in which the rotational speed is increased. It is preferable to be configured so as to be determined. According to this, in the case where the estimated reservoir fluid amount is calculated to be smaller than the actual value, the rotational speed of the motor can be more reliably increased to an appropriate value.

  In this case, in the state where the motor final drive pattern is determined to be a pattern in which the rotation speed is larger than the motor reference drive pattern, the changing unit has determined that the off-time has become the second time or more. If detected, the motor final drive pattern is preferably configured to return toward the motor reference drive pattern.

  As described above, the off time tends to become longer as the rotational speed of the motor increases. Therefore, when the off time is equal to or longer than the second time, it means that the rotational speed of the motor is sufficiently large. According to the above configuration, for example, erroneous detection that the estimated reservoir fluid amount is calculated to be smaller than the actual value even though the estimated reservoir fluid amount is not calculated to be smaller than the actual value is repeated. Even if the situation to be done occurs, it can be suppressed that the rotational speed of the motor is controlled to be excessively large.

  In the pump drive motor control device according to the present invention, the actual value of the reservoir fluid amount has become zero even after the fourth time has elapsed since the change unit detected the stop of the vehicle. If the motor is not detected, it is preferable that the motor final drive pattern is determined to be a pattern in which the rotation speed becomes higher.

  According to this, when the state where the actual value of the reservoir fluid amount does not become zero is continued for a relatively long time after the vehicle is stopped, the rotational speed of the motor can be increased. As a result, the time when the actual value of the reservoir fluid amount becomes zero can be advanced.

  In addition, in the pump drive motor control device according to the present invention, the reservoir fluid amount estimated value acquisition means detects the reservoir fluid amount when it is detected that the actual value of the reservoir fluid amount has become zero. It is preferred to be configured to reset the quantity estimate to zero.

  According to this, the estimated reservoir fluid amount can be brought close to the actual value. In addition, it can be suppressed that the rotational speed of the motor is controlled to be larger than an appropriate value due to the reservoir fluid amount estimated value being calculated to be larger than the actual value. In addition, when calculating the reservoir fluid amount estimation value, the “discharge flow rate of the hydraulic pump with respect to the motor drive pattern” is a value smaller than the reference discharge flow rate (for example, the above-mentioned minimum guaranteed discharge flow rate) The estimated reservoir fluid amount tends to be calculated larger than the actual value. Therefore, the above configuration is effective in such a case.

  In the pump drive motor control device according to the present invention, the reservoir fluid amount estimated value acquisition unit may not detect that the actual value of the reservoir fluid amount has become zero over a fifth time period. It is also preferable that the reservoir fluid amount estimation value is corrected to a larger value.

  As described above, the state where the actual value of the reservoir fluid amount does not become zero over a relatively long time means that the estimated value of the reservoir fluid amount is calculated to be smaller than the actual value. According to the above configuration, when it is detected that the estimated reservoir fluid amount is calculated to be smaller than the actual value, the estimated reservoir fluid amount can be corrected to a larger value.

  As a result, the estimated reservoir fluid amount can be brought close to the actual value. In addition, it can be suppressed that the rotational speed of the motor is controlled to be smaller than an appropriate value due to the estimated reservoir fluid amount being smaller than the actual value. In addition, when the “discharge flow rate of the hydraulic pump with respect to the motor drive pattern” assumed when calculating the estimated reservoir fluid amount is the reference discharge flow rate, if the motor or the hydraulic pump is deteriorated, the reservoir The estimated liquid amount tends to be calculated smaller than the actual value. Therefore, the above configuration is effective in such a case.

  Embodiments of a pump drive motor control apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a vehicle equipped with a vehicle brake fluid pressure control device 10 including a pump drive motor control device according to an embodiment of the present invention.

  The brake fluid pressure control device 10 includes a brake fluid pressure control unit 30 for generating braking force by brake fluid pressure on each wheel. The brake fluid pressure control unit 30 is shown in FIG. As shown, a brake fluid pressure generator 32 that generates a brake fluid pressure according to the operating force of the brake pedal BP, and wheel cylinders Wfr, Wfl, Wrr, Wrl respectively disposed on the wheels FR, FL, RR, RL. The brake fluid pressure adjusting unit 33, the FL brake fluid pressure adjusting unit 34, the RR brake fluid pressure adjusting unit 35, the RL brake fluid pressure adjusting unit 36, and the reflux brake fluid supplying unit 37 that can adjust the brake fluid pressure supplied to the engine, respectively. It is comprised including.

  The brake fluid pressure generating unit 32 includes a vacuum booster VB that responds when the brake pedal BP is operated, and a master cylinder MC that is connected to the vacuum booster VB. The vacuum booster VB uses an air pressure (negative pressure) in an intake pipe of an engine (not shown) to assist the operation force of the brake pedal BP at a predetermined ratio and transmit the assisted operation force to the master cylinder MC. It has become.

  The master cylinder MC has two output ports including a first port and a second port. The master cylinder MC receives the supply of brake fluid from the reservoir RS and responds to the assisted operating force by the first master. A cylinder hydraulic pressure is generated from the first port, and a second master cylinder pressure corresponding to the assisted operating force, which is substantially the same hydraulic pressure as the first master cylinder pressure, is generated from the second port. It is supposed to occur. Since the configurations and operations of the master cylinder MC and the vacuum booster VB are well known, a detailed description thereof will be omitted here. In this way, the master cylinder MC and the vacuum booster VB (brake hydraulic pressure generating means) generate the first master cylinder pressure and the second master cylinder pressure according to the operating force of the brake pedal BP, respectively. .

  The first port of the master cylinder MC is connected to each of the upstream side of the FR brake fluid pressure adjusting unit 33 and the upstream side of the FL brake fluid pressure adjusting unit 34. Similarly, the second port of the master cylinder MC is connected to each of the upstream side of the RR brake hydraulic pressure adjusting unit 35 and the upstream side of the RL brake hydraulic pressure adjusting unit 36. Thus, the first master cylinder pressure is supplied to the upstream portion of the FR brake fluid pressure adjusting unit 33 and the upstream portion of the FL brake fluid pressure adjusting unit 34, and the upstream portion of the RR brake fluid pressure adjusting unit 35. The second master cylinder pressure is supplied to each of the upstream portions of the RL brake fluid pressure adjusting unit 36.

  The FR brake fluid pressure adjusting unit 33 includes a pressure increasing valve PUfr that is a normally open linear electromagnetic valve and a pressure reducing valve PDfr that is a 2-port 2-position switching type normally closed electromagnetic on-off valve. When the pressure reducing valve PDfr is in the closed state shown in FIG. 2 (a state corresponding to non-excitation (OFF)), the communication between the wheel cylinder Wfr and the reservoir RSf is cut off and the open state (a state corresponding to excitation (ON)). ), The wheel cylinder Wfr communicates with the reservoir RSf.

  A force in the opening direction based on an urging force from a coil spring (not shown) is constantly acting on the valve body of the pressure increasing valve PUfr, and a differential pressure between the master cylinder pressure and the wheel cylinder pressure (hereinafter simply referred to as “actual difference”). The force in the opening direction based on the pressure direction) and the force in the closing direction based on the suction force that increases in proportion to the energizing current value (command current value Id) of the pressure increasing valve PUfr is applied. It has become.

  As a result, as shown in FIG. 3, the command differential pressure ΔPd corresponding to the suction force is determined so as to increase in proportion to the command current value Id. Here, I0 is a current value corresponding to the urging force of the coil spring. The pressure increasing valve PUfr is closed when the command differential pressure ΔPd is larger than the actual differential pressure (that is, when the command current value Id is larger than the actual differential pressure equivalent current value), and the FR brake hydraulic pressure is closed. The communication between the upstream part of the adjusting part 33 and the wheel cylinder Wfr is cut off. On the other hand, the pressure increasing valve PUfr opens when the command differential pressure ΔPd is smaller than the actual differential pressure (that is, when the command current value Id is smaller than the actual differential pressure equivalent current value), and the FR brake fluid pressure adjusting unit The upstream portion of 33 communicates with the wheel cylinder Wfr. As a result, the brake fluid upstream of the FR brake fluid pressure adjusting unit 33 flows into the wheel cylinder Wfr, so that the actual differential pressure can be adjusted to coincide with the command differential pressure ΔPd.

  In other words, the actual differential pressure (allowable maximum value) can be controlled according to the command current value Id of the pressure increasing valve PUfr. Further, when the pressure increasing valve PUfr is in a non-excited state (that is, when the command current value Id is set to “0”), the pressure increasing valve PUfr is kept open by the biasing force of the coil spring. Further, the command current value Id is set to a value corresponding to the command differential pressure ΔPd that is sufficiently larger than the differential pressure that can be generated as the actual differential pressure (for example, the valve closing maintaining current value Ihold (see FIG. 3)). Thus, the pressure increasing valve PUfr is maintained in a closed state.

  As a result, when the pressure reducing valve PDfr is closed and the command current value Id to the pressure increasing valve PUfr is gradually decreased from the current differential pressure equivalent current value, the actual differential pressure gradually decreases. As a result, the brake fluid pressure (wheel cylinder pressure) in the wheel cylinder Wfr increases smoothly. The operation in this case is referred to as operation in the linear pressure increasing mode.

  When the pressure increasing valve PUfr is kept closed and the pressure reducing valve PDfr is closed, the wheel cylinder pressure is maintained at the current hydraulic pressure regardless of the hydraulic pressure upstream of the FR brake hydraulic pressure adjusting unit 33. . The operation in this case is referred to as the operation in the holding mode. Furthermore, when the pressure increasing valve PUfr is kept closed and the pressure reducing valve PDfr is opened, the brake fluid in the wheel cylinder Wfr is returned to the reservoir RSf, whereby the wheel cylinder pressure is reduced. The operation in this case is referred to as the operation in the decompression mode.

  As described above, the brake fluid pressure (wheel cylinder pressure Pwfr) in the wheel cylinder Wfr is controlled by the linear pressure increasing mode, holding control, and pressure reducing control according to the three control modes of the linear pressure increasing mode, the holding mode, and the pressure reducing mode. It has come to be.

  In addition, a check valve CV1 that allows only one-way flow of brake fluid from the wheel cylinder Wfr side to the upstream portion of the FR brake fluid pressure adjusting unit 33 is disposed in parallel with the pressure increasing valve PUfr. When the operated brake pedal BP is released, the brake fluid pressure in the wheel cylinder Wfr is quickly reduced.

  Similarly, the FL brake hydraulic pressure adjusting unit 34, the RR brake hydraulic pressure adjusting unit 35, and the RL brake hydraulic pressure adjusting unit 36 are respectively a pressure increasing valve PUfl and a pressure reducing valve PDfl, a pressure increasing valve PUrr and a pressure reducing valve PDrr, and a pressure increasing valve PUrl and The pressure reducing valve PDrl is constituted by the wheel cylinder Wfl, the wheel cylinder Wrr, and the wheel cylinder Wrl by controlling each pressure increasing valve (normally open linear electromagnetic valve) and each pressure reducing valve (normally closed electromagnetic on-off valve). The brake fluid pressure (wheel cylinder pressures Pwfl, Pwrr, Pwrl) can be controlled by linear pressure-increasing control, holding control, and pressure-reducing control, respectively. In addition, check valves CV2, CV3, and CV4 that can achieve the same function as the check valve CV1 are arranged in parallel on the pressure increasing valves PUfl, PUrr, and PUrl, respectively.

  The reflux brake fluid supply unit 37 includes a DC motor MT and two hydraulic pumps HPf and HPr that are simultaneously driven by the motor MT. The hydraulic pump HPf pumps the brake fluid in the reservoir RSf returned from the pressure reducing valves PDfr and PDfl through the check valve CV7, and adjusts the brake fluid pressure through the check valves CV8 and CV9. It supplies to the upstream part of the part 33 and FL brake hydraulic pressure adjustment part 34. FIG.

  Similarly, the hydraulic pump HPr pumps up the brake fluid in the reservoir RSr that has been recirculated from the pressure reducing valves PDrr and PDrl through the check valve CV10, and the pumped brake fluid through the check valves CV11 and CV12. The hydraulic pressure adjusting unit 35 and the RL brake hydraulic pressure adjusting unit 36 are supplied upstream of the hydraulic pressure adjusting unit 35 and the RL brake hydraulic pressure adjusting unit 36. In order to reduce the pulsation of the discharge pressures of the hydraulic pumps HPf and HPr, a hydraulic circuit between the check valves CV8 and CV9 and a hydraulic circuit between the check valves CV11 and CV12 are provided with dampers DMf, DMr is disposed.

  With the configuration described above, the brake hydraulic pressure control unit 30 applies the brake hydraulic pressure (that is, the master cylinder pressure) to each wheel cylinder according to the operating force of the brake pedal BP when all the solenoid valves are in the non-excited state. Each can be supplied. In this state, for example, by controlling the pressure increasing valve PUrr and the pressure reducing valve PDrr, only the wheel cylinder pressure Pwrr can be adjusted to a pressure smaller than the (second) master cylinder pressure. That is, the brake hydraulic pressure control unit 30 can reduce the wheel cylinder pressure of each wheel independently from the master cylinder pressure.

  Referring to FIG. 1 again, the vehicle brake hydraulic pressure control device 10 includes a wheel speed sensor 41fl, 41fr, 41rl, 41rr that outputs a signal having a pulse each time the corresponding wheel rotates by a predetermined angle, and a brake pedal. A brake switch 42 that outputs a signal that is turned on (High signal) or turned off (Low signal) depending on whether or not the BP is operated is provided, and an electronic control unit 50 is provided.

  The electronic control unit 50 includes a CPU 51, a routine (program) executed by the CPU 51, a table (lookup table, map), a ROM 52 in which constants and the like are stored in advance, and the CPU 51 temporarily store data as necessary. The microcomputer includes a RAM 53 for storing data, a backup RAM 54 for storing data while the power is on, and holding the stored data while the power is shut off, an interface 55 including an AD converter, and the like. .

  The interface 55 is connected to the wheel speed sensor 41 ** and the brake switch 42, and supplies signals from the wheel speed sensor 41 ** and the brake switch 42 to the CPU 51, and in accordance with instructions from the CPU 51, the brake 55 Drive signals are sent to the electromagnetic valves (pressure increase valve PU ** and pressure reduction valve PD **) of the hydraulic pressure control unit 30 and the motor MT.

  In addition, “**” appended to the end of various variables etc. “fl” added to the end of the various variables etc. to indicate which of the various wheels FR, etc. , “Fr”, etc., for example, the pressure increasing valve PU ** includes a left front wheel pressure increasing valve PUfl, a right front wheel pressure increasing valve PUfr, a left rear wheel pressure increasing valve PUrl, and a right rear wheel pressure increasing valve PUrr. Is comprehensively shown.

  Thereby, the command current value Id ** (energization current value) of the above-described pressure increasing valve PU ** is controlled by the CPU 51. Specifically, as shown in FIG. 4, the CPU 51 determines the ratio of the energization time Ton ** to the pressure increasing valve PU ** with respect to the one cycle time Tcycle ** (that is, the duty ratio Ratioduty ** = (Ton ** / By adjusting (Tcycle **)), the average (effective) current (= command current value Id **) is adjusted. As a result, the command current value Id ** can be variably controlled linearly for each wheel by individually adjusting the duty ratio Ratioduty ** for each wheel (ie, duty control).

  The brake hydraulic pressure control unit 30 (CPU 51) described above executes one of the well-known ABS controls so that the wheel slip generated by the operation of the brake pedal BP by the driver does not become excessive. Yes. In this example, when a predetermined ABS control start condition is satisfied, until the predetermined ABS control end condition is satisfied, the ABS control including the above-described decompression control / holding control / linear pressure increase control is continuously performed. It is designed to be executed multiple times.

(Outline of rotational speed control of motor MT)
Next, the rotation of the motor MT by the brake fluid pressure control device (hereinafter also referred to as “this device”) including the pump drive motor control device according to the embodiment of the present invention configured as described above. An outline of speed control will be described. This apparatus uses a power transistor Tr as a switching element shown in FIG. 5 built in the electronic control unit 50 until a motor control start condition described later is satisfied when a motor control start condition described later is satisfied. The rotational speed of the motor MT is controlled.

  More specifically, as shown in FIG. 5, the power transistor Tr has a collector terminal connected to a vehicle power supply (voltage Vcc (12 (V) in this example)) and an emitter terminal connected to the power source of the vehicle. It is connected to one terminal of the motor MT. The other terminal of the motor MT is grounded (voltage GND). Further, a motor control signal Vcont generated by an instruction from the present device (CPU 51) is applied to the base terminal of the power transistor Tr.

  As shown in FIG. 5, the motor control signal Vcont is generated so as to be either high level or low level, and the power transistor Tr is turned on when the motor control signal Vcont is high level. On the other hand, when the motor control signal Vcont is at a low level, it is turned off. In other words, the motor MT is in a state in which the voltage Vcc is applied and the hydraulic pumps HPf and HPr are driven when the motor control signal Vcont is at a high level (power supply to the motor MT is on, hereinafter simply referred to as “power supply to the motor MT”). When the motor control signal Vcont is at a low level, the voltage Vcc is not applied (the power supply to the motor MT is off, hereinafter simply referred to as the “off state”). It becomes.

  As a result, the motor terminal voltage VMT (see FIG. 5), which is the voltage between the two terminals of the motor MT, is constant when the motor MT is on. On the other hand, when the motor MT is in an off state, the motor terminal voltage VMT is a voltage generated by the motor MT. This “voltage generated by the motor MT” is the above-mentioned generated voltage generated by the induced electromotive force of the motor MT as a generator, and decreases as the rotational speed of the motor MT that rotates due to inertia decreases. When the rotation speed is “0”, it becomes “0”.

  As shown in FIG. 6, in this apparatus, the motor terminal voltage VMT (and thus the generated voltage) is described later in accordance with a decrease in the rotational speed of the motor MT that rotates due to inertia when the motor MT is in an off state. The motor MT is switched from the off state to the on state when the voltage threshold value Von (the final value of the voltage threshold value) is set or less, and the on time Ton (the duration time) is set as described later. After driving the hydraulic pumps HPf and HPr while maintaining the motor MT in the ON state over the final value), the motor MT is switched from the ON state to the OFF state to stop the driving of the hydraulic pumps HPf and HPr.

  When the motor control start condition is satisfied, the apparatus repeats the motor drive pattern (the motor final drive pattern) including the voltage threshold Von and the on time Ton as described above until the motor control end condition is satisfied. Thus, the power supply to the motor MT is turned on / off to control the rotation speed of the motor MT (accordingly, the rotation speed of the hydraulic pumps HPf and HPr). Hereinafter, the time during which the motor MT is maintained in the off state is referred to as “off time Toff” (see FIG. 6).

  The motor drive pattern (voltage threshold Von and on-time Ton) is determined in accordance with the table Map (X, Y) shown in FIG. Hereinafter, a pattern determined based on the table shown in FIG. 7 is referred to as a “motor reference drive pattern”. The value X (= 1, 2, 3) is selected based on the required discharge flow rate qre, and the value Y (= 1, 2, 3, 4) is selected based on the master cylinder pressure estimated value Pm described later. For example, in the case of X = 2, Y = 2 (refer to the area shown by hatching in FIG. 7), the voltage threshold Von = 4 (V) and the on time Ton = 40 msec are set.

The required discharge flow rate qre (cm ³ / sec) is the decompression control of the estimated value Q (cm ³ ) of the reservoir fluid amount (the sum of the brake fluid amounts in the reservoirs RSf and RSr) calculated and updated as will be described later. The value obtained by dividing the value Q1 at the end time by the target time Ttrg1 (sec) (constant) (qre = Q1 / Ttrg1). The target time Ttrg1 is a control target for the time from when the decompression control ends to when the reservoir fluid amount becomes zero. That is, the required discharge flow rate qre is the total of the hydraulic pumps HPf and HPr required to make the reservoir fluid amount that takes a maximum value at the end of the pressure reduction control zero after the target time Ttrg1 has elapsed from the end of the pressure reduction control. This is the discharge flow rate (discharge amount per unit time). The necessary discharge flow rate qre is updated step by step every time the end of the pressure reduction control comes, and is set to a larger value as the value Q1 is larger.

  As can be understood from FIG. 7, the motor reference drive pattern indicates that the average supply to the motor MT increases as the required discharge flow rate qre (accordingly, the reservoir fluid amount estimated value Q) increases or the master cylinder pressure estimated value Pm increases. The pattern is set such that the power is larger (specifically, the voltage threshold Von is larger or the on-time Ton is longer). This is because, as described in the background section, it is preferable that the rotational speed of the motor MT is set to a larger value as the reservoir fluid amount is larger, and that the master cylinder pressure is constant when the motor drive pattern is constant. This is based on the fact that the larger the is, the smaller the rotational speed of the motor MT is.

  In addition, the motor reference drive pattern is a discharge flow rate of the hydraulic pumps HPf and HPr when the motor MT is driven by a certain motor drive pattern (hereinafter, simply referred to as “drive discharge flow rate”). Is assumed to be equal to a value (minimum guaranteed discharge flow rate, the first discharge flow rate) that should be guaranteed at least in design, which is determined in consideration of deterioration of the motor MT and the hydraulic pumps HPf and HPr. Have been made. Note that the time in parentheses in the table shown in FIG. 7 corresponds to a motor reference drive pattern that is produced assuming that the drive discharge flow rate is equal to the design median value (nominal flow rate, the reference discharge flow rate). The on-time Ton, hereinafter referred to as “nominal on-time Tonnom”.

  Thus, the on-time Ton corresponding to the minimum guaranteed discharge flow rate (for example, 40 msec in the shaded region in FIG. 7) is the nominal on-time Tonnom corresponding to the nominal flow rate (for example, 20 msec in the shaded region in FIG. 7). Longer than. This is based on the fact that the average supply power to the motor MT necessary to secure a certain discharge flow rate of the hydraulic pumps HPf, HPr increases as the drive discharge flow rate decreases.

  In this apparatus, the motor drive pattern (voltage threshold Von and on-time Ton) is determined in principle to be equal to the motor reference drive pattern determined according to the table Map (X, Y) shown in FIG. On the other hand, the present apparatus determines the motor drive pattern (voltage threshold Von and on time Ton) to be a pattern different from the motor reference drive pattern under a predetermined condition. Hereinafter, this will be described with reference to flowcharts and the like.

(Actual operation)
Next, the actual operation of the apparatus will be described with reference to FIGS. 8 to 15, which are flowcharts showing routines executed by the CPU 51 of the electronic control unit 50, and the time charts shown in FIGS. 16 and 17. .

  The CPU 51 repeatedly executes the motor control start / end determination routine shown in FIG. 8 every elapse of a predetermined time. Accordingly, when the predetermined timing is reached, the CPU 51 starts processing from step 800 and proceeds to step 805 to determine whether or not the value of the flag DRIVE is “0”. Here, the flag DRIVE indicates that the motor control is being executed when the value is “1”, and indicates that the motor control is not being executed when the value is “0”.

  If it is assumed that the motor control is not being executed and the motor control start condition is not satisfied (see before time t1 in FIG. 16), the value of the flag DRIVE is “0”. Accordingly, the CPU 51 makes a “Yes” determination at step 805 to proceed to step 810 to determine whether or not a motor control start condition is satisfied. In this example, the motor control start condition is satisfied when the ABS control is started.

  At this stage, since the motor control start condition is not satisfied as described above, the CPU 51 makes a “No” determination at step 810 to immediately proceed to step 895 to end the present routine tentatively. Such an operation is repeatedly executed until the motor control start condition is satisfied.

  Next, the case where ABS control is started in this state (that is, the case where the motor control start condition is satisfied) will be described (see time t1 in FIG. 16). In this case, when the CPU 51 proceeds to step 810, it determines “Yes”, proceeds to step 815, and changes the value of the flag DRIVE from “0” to “1”.

  Next, the CPU 51 proceeds to step 820, and sets the voltage threshold value Von and the on time Ton to the initial values determined using the function Vonini and the function Tonini that use the master cylinder pressure estimated value Pm as an argument, respectively. The master cylinder pressure estimated value Pm is sequentially updated using one of well-known methods by repeatedly executing a routine (not shown) during the ABS control. For example, the master cylinder pressure estimated value Pm is calculated from the open / close state of the pressure increasing valve PU ** and the pressure reducing valve PD ** and the command current value Id of the pressure increasing valve PU **, the wheel cylinder pressure, and the “master cylinder pressure and It can be calculated by estimating the differential pressure from the wheel cylinder pressure and adding the estimated differential pressure value to the estimated wheel cylinder pressure value Pw **. Details of this method are described in, for example, Japanese Patent Laid-Open No. 9-267636. The means for acquiring the master cylinder pressure estimated value Pm in this way corresponds to the master cylinder pressure estimated value acquiring means.

  Subsequently, the CPU 51 proceeds to step 825 to set the on-time shortening time DTo to the initial value “0”, and in step 830 to set the reservoir fluid amount estimated value Q to the initial value “0”, and then to step 835. Then, the flags F1 and F2 are set to the initial value “0”, and in the subsequent step 840, the X reduction amount DX and the Y reduction amount DY are set to “0”. Here, DTon, F1, F2, DX, and DY are values used to determine the motor drive pattern (voltage threshold Von and on-time Ton) to a pattern different from the motor reference drive pattern. Detailed description.

  Then, the CPU 51 proceeds to step 845, sets the flag ON to the initial value “1”, clears the ON duration TIMon in the subsequent step 850, and then proceeds to step 895 to end this routine once. Here, the flag ON indicates that the motor MT is in an on state when the value is “1”, and indicates that the motor MT is in an off state when the value is “0”. The ON duration time TIMon is measured by a timer (not shown) built in the electronic control unit 50 and represents the duration time of the motor MT in the ON state.

  Thereafter, since the value of DRIVE is “1”, the CPU 51 determines “No” when it proceeds to step 805 and proceeds to step 855, and the motor control end condition is satisfied at step 855. It is determined whether or not. In this example, the motor control end condition is satisfied when the ABS control ends and the OFF duration TIMoff exceeds a time T3 described later. The off duration TIMoff is measured by a timer (not shown) built in the electronic control unit 50 and represents the duration of the motor MT in the off state.

  At this stage, since the motor control is started immediately, the motor control end condition is not satisfied. Therefore, the CPU 51 makes a “No” determination at step 855 to immediately proceed to step 895 to end the present routine tentatively. Such processing is repeatedly executed until the motor control end condition is satisfied.

  On the other hand, if the motor control end condition is satisfied in this state, the CPU 51 determines “Yes” when it proceeds to step 855 and proceeds to step 860 to change the value of the flag DRIVE from “1” to “0”. . As a result, the value of the flag DRIVE becomes “0”. Therefore, when the CPU 51 proceeds to step 805, it determines “Yes”, proceeds to step 810, and again monitors whether or not the motor control start condition is satisfied. To come.

  As described above, by repeatedly executing the routine of FIG. 8, immediately after the motor control start condition is satisfied, various values are set to the initial values and the ON duration time TIMon is cleared. Further, the value of the flag DRIVE is maintained at “1” while the motor control is being executed, and is maintained at “0” when the motor control is not being executed.

  Further, the CPU 51 repeatedly executes the motor control execution routine shown in FIG. 9 every elapse of a predetermined time. Accordingly, when the predetermined timing is reached, the CPU 51 starts processing from step 900 and proceeds to step 905 to determine whether or not the value of the flag DRIVE is “1”.

  If it is immediately after the start of motor control (see time t1 in FIG. 16), as described above, the flag DRIVE = 1 (step 815) and the flag ON = 1 (step 845). The on duration TIMon is cleared (step 850). Therefore, the CPU 51 determines “Yes” in Step 905 and proceeds to Step 910 to determine whether or not the value of the flag ON is “1”. In Step 910, the CPU 51 determines “Yes” and proceeds to Step 910. Proceed to 915.

  When the CPU 51 proceeds to step 915, it determines whether or not the ON duration TIMon is equal to or longer than the ON time Ton (currently set to the initial value by the processing of step 820). The present time is immediately after the ON duration TIMon is cleared, and TIMon <Ton. Therefore, the CPU 51 makes a “No” determination at step 915 to proceed to step 920.

  When the CPU 51 proceeds to step 920, it determines whether or not the flag ON is “1”, determines “Yes”, proceeds to step 925, and turns on the motor MT (specifically, the motor MT). Set control signal Vcont to High level). Such processing is repeatedly executed until the condition of step 915 is satisfied. As a result, the voltage VMT between the motor terminals is kept constant at the voltage Vcc, and the driving of the hydraulic pumps HPf and HPr is continued (see after time t1 in FIG. 16).

  On the other hand, when the ON duration TIMon reaches the ON time Ton in this state (see time t3 in FIG. 16), the CPU 51 determines “Yes” when it proceeds to step 915, proceeds to step 930, and sets the flag ON Is changed from “1” to “0”, and in step 935, the OFF duration TIMoff is cleared. Then, the CPU 51 makes a “No” determination at step 920 and proceeds to step 940 to turn off the motor MT (specifically, the motor control signal Vcont is set to a low level). Thereby, the driving of the hydraulic pumps HPf and HPr is finished.

  Thereafter, since the value of the flag ON is “0”, the CPU 51 makes a “No” determination when proceeding to Step 910 and proceeds to Step 945 where the motor terminal voltage VMT is the voltage threshold Von (currently, the step It is determined whether or not it is equal to or less than the initial value set by the process of 820.

  Since the current time is immediately after the motor MT is changed from the on state to the off state, VMT> Von. Accordingly, the CPU 51 makes a “No” determination at step 945 to proceed to steps 920 and 940 to maintain the motor MT in the off state. Such processing is continued until the motor terminal voltage VMT, which decreases as the rotational speed of the motor MT decreases while the motor MT is in the OFF state, reaches the voltage threshold value Von.

  When the motor terminal voltage VMT reaches the voltage threshold value Von (see time t4 in FIG. 16), the CPU 51 determines “Yes” when it proceeds to step 945, proceeds to step 950, and sets the flag ON to “0”. Is changed from “1” to “1”, and the duration TIMon is cleared in the subsequent step 955. Then, the process proceeds to steps 920 and 925, and the motor MT is turned on again. As a result, the driving of the hydraulic pumps HPf and HPr is started again.

  Thereafter, since the value of the flag ON is “1”, the CPU 51 determines “Yes” when proceeding to Step 910 and monitors again whether or not the condition of Step 915 is satisfied. As a result, the hydraulic pumps HPf and HPr continue to be driven again until the condition of step 915 is satisfied (see time t4 and thereafter in FIG. 16).

  As described above, by repeatedly executing the routine of FIG. 9, the motor MT is controlled to be turned on / off by the motor drive pattern having the voltage threshold Von and the on-time Ton, so that the rotational speed of the motor MT (accordingly, the hydraulic pumps HPf, HPr) Rotational speed) is controlled. In this example, the motor drive pattern (voltage threshold Von and on-time Ton) is referred to as a time when the motor MT is changed from the off state to the on state (hereinafter referred to as “motor ON”), as will be described later. ) Is updated every time. The value of the flag ON is maintained at “1” while the motor MT is in the on state, and is maintained at “0” while the motor MT is in the off state. The routine in FIG. 9 corresponds to the control means.

  If the flag DRIVE = 0 (motor control is not being executed), the CPU 51 makes a “No” determination at step 905 to proceed to step 960, sets the value of the flag ON to “0”, and then proceeds to step 920. , 940, and the motor MT is maintained in the off state.

  Further, the CPU 51 repeatedly executes the routine for calculating the reservoir fluid amount shown in FIG. 10 every elapse of a predetermined time (program execution cycle Δt). Hereinafter, the reservoirs RSf and RSr may be simply referred to as “reservoirs”. Accordingly, when the predetermined timing is reached, the CPU 51 starts processing from step 1000 and proceeds to step 1005 to determine whether or not the value of the flag DRIVE is “1”. Proceed to 1095 to end the present routine tentatively.

  Assuming that motor control is being executed (see time t1 and after in FIG. 16), as described above, the flag DRIVE = 1 (step 815). Therefore, the CPU 51 determines “Yes” in step 1005 and proceeds to step 1010 to determine whether or not the pressure reduction control is being performed.

  If the current time is under pressure reduction control (see times t1 to t2, t8 to t9, etc. in FIG. 16), the CPU 51 determines “Yes” in step 1010 and proceeds to step 1015 to set the discharge flow rate qdrain to It is determined based on the estimated wheel cylinder pressure value Pw ** and the function funcqdrain with Pw ** as an argument. The discharge flow rate qdrain is the flow rate of the brake fluid that is discharged from the pressure reducing valve PD ** and flows into the reservoir during pressure reduction control (pressure reducing valve PD **: open state). Since the discharge flow rate qdrain can be calculated from the wheel cylinder pressure and the opening area (constant) of the pressure reducing valve PD ** in the open state, it can be obtained as a function of the wheel cylinder pressure Pw **. Note that when the pressure reduction control is simultaneously executed for two or more wheels, the discharge flow rate qdrain is the sum of the discharge flow rates for the respective wheels.

  On the other hand, when the present time is not under pressure reduction control (that is, during holding control or linear pressure increase control, refer to times t2 to t8, t9 to t14, etc. in FIG. 16), the CPU 51 proceeds to step 1010. It determines with "No", progresses to step 1020, and sets the discharge flow volume qdrain to "0". This is based on the fact that the pressure reducing valve PD ** is maintained in the closed state during the holding control or the linear pressure increasing control.

  Subsequently, the CPU 51 proceeds to step 1025 to set the discharge flow rate qpump1 of the hydraulic pumps HPf, HPr, the current motor drive pattern (Von, Ton), the master cylinder pressure estimated value Pm, and Von, Ton, Pm. Obtained based on the table Mapqpump as an argument. The discharge flow rate qpump1 depends on the rotation speed of the hydraulic pumps HPf and HPr and the master cylinder pressure, and increases as the rotation speed increases and decreases as the master cylinder pressure increases. Accordingly, the discharge flow rate qpump1 can be obtained based on the motor drive pattern and the master cylinder pressure estimated value Pm as described above.

  In this example, the table Mapqpump is created assuming that the drive discharge flow rate is equal to the minimum guaranteed discharge flow rate. That is, the discharge flow rate qpump1 is calculated to a value (the first discharge flow rate) corresponding to the minimum guaranteed discharge flow rate.

  Next, the CPU 51 proceeds to step 1030 and obtains a change amount ΔQ per program execution cycle Δt of the reservoir fluid amount estimated value Q according to the following equation (1). Here, “qdrain · Δt” corresponds to the amount of brake fluid flowing into the reservoir per program execution cycle Δt, and “qpump1 · Δt” is sucked from the reservoir into the hydraulic pumps HPf and HPr per program execution cycle Δt. This corresponds to the amount of brake fluid applied.

ΔQ = qdrain ・ Δt−qpump1 ・ Δt (1)

  Next, the CPU 51 proceeds to step 1035 to set the reservoir fluid amount estimated value Q to the initial value “0” in step 830 immediately after the value at that time (at the start of ABS control (ie, at the start of motor control)). Is updated by adding the obtained change amount ΔQ.

  Subsequently, the CPU 51 proceeds to Step 1040 to determine whether or not the updated reservoir fluid amount estimated value Q is negative. If “No” is determined, the CPU 51 immediately proceeds to Step 1095, while “Yes”. In step 1045, the reservoir fluid amount estimated value Q is set to "0", the process proceeds to step 1095, and this routine is temporarily ended.

  As described above, by repeatedly executing the routine of FIG. 10, the estimated reservoir fluid amount Q is obtained from the flow rate of the brake fluid discharged from the pressure reducing valve PD ** and the flow rate of the brake fluid sucked by the hydraulic pumps HPf and HPr. Is updated every time the program execution cycle Δt elapses. As a result, as shown in FIG. 16, the estimated reservoir fluid amount Q (≧ 0) increases during the pressure reduction control (time t1 to t2, time t8 to t9, etc.) due to the relationship of qdrain> qpump1. During the holding control or the linear pressure increasing control (time t2 to t8, t9 to t14, etc.), since qdrain = 0 is maintained, it decreases according to the discharge flow rate qpump1. In this way, the means for acquiring the reservoir fluid amount estimated value Q corresponds to the reservoir fluid amount estimated value acquiring means.

  Since the actual drive discharge flow rate is larger than the minimum guaranteed discharge flow rate, the actual discharge flow rates of the hydraulic pumps HPf and HPr are larger than the discharge flow rate qpump1. Accordingly, as shown in FIG. 16, during the holding control or the linear pressure increasing control (time t2 to t8, t9 to t14, etc.), the decreasing gradient (slope) of the actual value Qact (see the broken line) of the reservoir fluid amount ) Is larger than the decreasing gradient (slope) of the reservoir fluid amount estimation value Q. That is, in this example, the reservoir fluid amount estimated value Q tends to be calculated larger than the actual value Qact.

  Further, the CPU 51 repeatedly executes a routine for performing the process at the end of the decompression control shown in FIG. 11 every elapse of a predetermined time (program execution cycle Δt). Therefore, when the predetermined timing comes, the CPU 51 starts processing from step 1100 and proceeds to step 1105 to determine whether or not the value of the flag DRIVE is “1”. Proceed to 1195 to end the present routine tentatively.

  If it is immediately after the pressure reduction control is finished (see times t2, t9, etc. in FIG. 16), the flag DRIVE = 1, so the CPU 51 makes a “Yes” determination at step 1105 to determine the step. Proceeding to 1110, it is determined whether or not it is immediately after the end of pressure reduction control. If “No” is determined, the process immediately proceeds to step 1195 to end the present routine tentatively.

  Since the current time is immediately after the end of the pressure reduction control, the CPU 51 makes a “Yes” determination at step 1110 and proceeds to step 1115 to set the value Q1 to the current time, that is, the estimated reservoir fluid amount Q at the time when the pressure reduction control ends. In step 1120, the required discharge flow rate qre is set to a value obtained by dividing the value Q1 by the target time Ttrg1.

  Subsequently, the CPU 51 proceeds to step 1125, and obtains the estimated sky time Tempest by dividing the value Q1 by the current discharge flow rate qpump1 calculated in the previous step 1025. As shown in FIG. 16, this empty estimated time Tempest is the time from the time when pressure reduction control ends (for example, time t2) to the time when the reservoir fluid amount is estimated to be zero (for example, time t10). This step 1125 corresponds to the time estimation means.

  Then, the CPU 51 clears the continuation time TIM1 in step 1130, proceeds to step 1195, and once ends this routine. Here, the duration time TIM1 is measured by a timer (not shown) built in the electronic control unit 50, and represents the elapsed time from the end of the latest decompression control. The estimated sky time Tempest and the duration TIM1 are values used to determine the motor drive pattern (voltage threshold Von and on-time Ton) to a pattern different from the motor reference drive pattern. It will be described later.

  In this manner, by repeatedly executing the routine of FIG. 11, every time the pressure reduction control end time comes, the value Q1, the required discharge flow rate qre, and the estimated empty time Tempest are updated stepwise, and the duration TIM1 is cleared. The

  Further, the CPU 51 repeatedly executes a routine for performing processing at the time of motor OFF shown in FIG. 12 (when the motor MT is changed from the on state to the off state) every elapse of a predetermined time. Accordingly, when the predetermined timing is reached, the CPU 51 starts processing from step 1200 and proceeds to step 1205 to determine whether or not the value of the flag DRIVE is “1”. Proceeding to 1295, the present routine is ended once.

  If it is immediately after the motor-off time has arrived (see times t3, t6, t12, etc. in FIG. 16), the flag DRIVE = 1, so the CPU 51 determines “Yes” in step 1205. Then, the process proceeds to step 1210, where it is determined whether or not the flag ON has changed from “1” to “0”. If the determination is “No”, the process immediately proceeds to step 1295 and the present routine is temporarily terminated.

  Since the current time is immediately after the flag ON is changed from “1” to “0” by the processing in the previous step 930, the CPU 51 determines “Yes” in step 1210 and proceeds to step 1215, starting from the current time. The estimated off time Toffest, which is the estimated value of the off time Toff, is converted into the current master cylinder pressure estimated value Pm, the motor drive pattern (Von, Ton), and the table MapToffest with Pm, Von, Ton as arguments. Ask based. The estimated off time Toffest is an estimated value of the off time Toff when the reservoir fluid actual value Qact does not become “0” during the off time Toff.

  When the reservoir fluid actual value Qact does not become “0” during the off time Toff, the off time Toff depends on the master cylinder pressure and the voltage threshold value Von. The larger is, the shorter. The larger the master cylinder pressure is, the shorter the off time Toff is. The larger the master cylinder pressure is, the larger the load of the motor MT becomes. Is based on the increase in the slope of decrease. Accordingly, the estimated OFF time Toffest can be obtained based on the master cylinder pressure estimated value Pm and the voltage threshold value Von in this way.

  Subsequently, the CPU 51 proceeds to step 1220 to set the time T1 (corresponding to the first time) to a value obtained by multiplying the estimated OFF time Toffest by the coefficient α1, and then in step 1225, the time T2 (the second time). (Corresponding to time) is set to a value obtained by multiplying the off-estimated time Toffest by a coefficient α2. The coefficient α1 is a positive value less than “1”, and is, for example, 0.5 in this example. The coefficient α2 is a positive value close to “1” equal to or greater than “1”, and is 1.1, for example, in this example.

  Next, the CPU 51 proceeds to step 1230 and obtains the reservoir empty time OFF time Toffemp based on the current voltage threshold Von and a table MapToffemp using Von as an argument. The reservoir empty time OFF time Toffemp is an estimated value of the OFF time Toff when the reservoir fluid actual value Qact is maintained at “0” during the OFF time Toff.

  When the reservoir fluid actual value Qact is maintained at “0” during the off time Toff, the load of the motor MT becomes very small regardless of the master cylinder pressure. Therefore, the rotation of the motor MT during the off time Toff. The speed decreasing gradient is constant at a small value regardless of the master cylinder pressure. Accordingly, the off time Toff in this case depends only on the voltage threshold Von. Therefore, the reservoir empty time OFF time Toffemp can be obtained based on the voltage threshold value Von in this way. Note that the reservoir empty time OFF time Toffemp is longer than the estimated OFF time Toffest.

  Then, the CPU 51 proceeds to step 1235, sets the time T3 to a value obtained by multiplying the reservoir empty time OFF time Toffemp by a coefficient α3, proceeds to step 1295, and once ends this routine. The coefficient α3 is a positive value close to “1” less than “1”, and is, for example, 0.95 in this example.

  As described above, the time T1, T2, T3, the estimated OFF time Toffest, and the reservoir empty time OFF time Toffemp are updated stepwise each time the motor OFF time is reached by repeatedly executing the routine of FIG. These values are values used to determine the motor drive pattern (voltage threshold Von and on time Ton) to a pattern different from the motor reference drive pattern, which will be described later.

  Further, the CPU 51 repeatedly executes a routine for performing the process 1 (reservoir empty determination) when the motor is ON shown in FIG. 13 every elapse of a predetermined time. Accordingly, when the predetermined timing is reached, the CPU 51 starts the process from step 1300 and proceeds to step 1305 to determine whether or not the value of the flag DRIVE is “1”. Proceed to 1395 to end the present routine tentatively.

  Assuming that it is immediately after the motor-ON time has arrived (see times t4, t7, t13, etc. in FIG. 16), since the flag DRIVE = 1, the CPU 51 determines “Yes” in step 1305. Then, the process proceeds to step 1310, where it is determined whether or not the flag ON has changed from “0” to “1”. If the determination is “No”, the process immediately proceeds to step 1395 to end the present routine tentatively.

  Since the current time is immediately after the flag ON is changed from “0” to “1” by the processing in the previous step 950, the CPU 51 determines “Yes” in step 1310, proceeds to step 1315, and the off time Toffc. Is set to a time equal to the duration TIMoff. That is, the off time Toffc is the actual off time Toff that has been continued up to the present time.

  Subsequently, the CPU 51 proceeds to step 1320 to determine whether or not the off time Toffc is longer than the time T3 set in the previous step 1235. Here, as described above, the time T3 is set to a time approximately equal to the reservoir empty time off-time Toffemp, so that the off-time Toffc is longer than the time T3 is the off-time that has been continued up to the present time. It means that the reservoir fluid actual value Qact was maintained at “0” over Toff. That is, when the condition of step 1320 is satisfied, it can be determined that the reservoir is “empty”. Hereinafter, the determination in step 1320 is referred to as “reservoir empty determination”. This step 1320 corresponds to the first detecting means.

  If “No” is determined in step 1320, the CPU 51 immediately proceeds to step 1395 to end the present routine tentatively. On the other hand, the case where “Yes” is determined in step 1320 (see times t7 and t13 in FIG. 16) will be described later. As described above, the “reservoir empty determination” is executed every time the motor is turned on by repeatedly executing the routine of FIG.

  Further, the CPU 51 repeatedly executes a routine for performing the process 2 (determination of the motor drive pattern) when the motor is ON shown in FIG. 14 every elapse of a predetermined time. Accordingly, when the predetermined timing is reached, the CPU 51 starts processing from step 1400 and proceeds to step 1402 to determine whether or not the value of the flag DRIVE is “1”. Proceed to 1495 to end the present routine tentatively.

  If it is immediately after the motor-ON time has arrived (see times t4, t7, t13, etc. in FIG. 16), the flag DRIVE = 1, so the CPU 51 determines “Yes” in step 1402. Then, the process proceeds to step 1404, where it is determined whether or not the flag ON has changed from “0” to “1”. If the determination is “No”, the process immediately proceeds to step 1495 and the present routine is temporarily terminated.

  Since the current time is immediately after the flag ON is changed from “0” to “1” by the processing in the previous step 950, the CPU 51 determines “Yes” in step 1404 and proceeds to step 1406. The reference value Xb of the value X in FIG. 7 is selected from the current required discharge flow rate qre determined in 1120, and the reference value Yb of the value Y in FIG. 7 is selected from the current master cylinder pressure estimated value Pm. . This step 1406 corresponds to the motor reference drive pattern determining means.

  Subsequently, the CPU 51 proceeds to step 1408, where the off time Toffc set in the previous step 1315 (that is, the off time Toff continued until the present time) is set in the previous step 1220. It is determined whether a state shorter than T1 is continued N1 times (constant). Here, the case where the determination is “Yes” will be described later.

  If “No” is determined in step 1408, the CPU 51 proceeds immediately to step 1414, and the value of the flag F1 (the initial value is set to “0” in the previous step 835) is “1”. Is determined. Here, the case where the determination is “Yes” will be described later.

  If “No” is determined in step 1414, the CPU 51 immediately proceeds to step 1424, and the off time Toffc is equal to or longer than the time T 1 and from the time T 2 set in the previous step 1225. It is determined whether or not the short state “T1 ≦ Toffc <T2” is continued (repeated) for a time T4 (corresponding to the third time). The time T4 is set to, for example, twice the control cycle time of ABS control (for example, 500 msec). Here, the case where the determination is “Yes” will be described later.

  If “No” is determined in step 1424, the CPU 51 proceeds immediately to step 1430, and the value of the flag F2 (the initial value is set to “0” in the previous step 835) is “1”. Is determined. Here, the case where the determination is “Yes” will be described later.

  When it is determined “No” in step 1430, the CPU 51 immediately proceeds to step 1440, and sets the value X to the value Xb selected in the previous step 1406 plus the X reduction amount DX, The value Y is set to a value obtained by adding the Y reduction amount DY to the value Yb selected in the previous step 1406. Here, the X reduction amount DX and the Y reduction amount DY are set to the initial value “0” in the previous step 840. Accordingly, if the X reduction amount DX and the Y reduction amount DY are not changed from the initial value “0”, the value X is set to a value equal to the value Xb, and the value Y is set to a value equal to the value Yb.

  Next, when the CPU 51 proceeds to step 1442, based on the table Map (X, Y) shown in FIG. 7 and the set values X, Y, the voltage threshold Von, the on time Ton (the minimum guaranteed discharge). Time corresponding to the flow rate) and nominal on-time Tonnom (time corresponding to the nominal flow rate) are selected.

  Subsequently, the CPU 51 proceeds to step 1444 to change the on time Ton to a time obtained by subtracting the on time shortening time DTo from the selected time. Here, the on-time reduction time DTo is set to the initial value “0” in the previous step 825. Accordingly, if the on-time shortening time DTo is not changed from the initial value “0”, the on-time Ton is not changed from the time selected in Step 1442.

  Next, the CPU 51 proceeds to Step 1446 to determine whether or not the on-time Ton changed in Step 1444 is shorter than the nominal on-time Tonnom. If it is determined “No”, the CPU 51 immediately proceeds to Step 1495. On the other hand, if “Yes” is determined, the CPU 51 proceeds to step 1448 to set the on-time Ton to a time equal to the nominal on-time Tonnom. That is, the lower limit value of the on-time Ton is set to the nominal on-time Tonnom. This process is effective when the on-time reduction time DTo is not “0” as will be described later.

  As described above, the motor drive pattern (the motor final drive pattern) (the voltage threshold Von, the on time Ton) is determined and updated every time when the motor is turned on by repeatedly executing the routine of FIG. The motor drive pattern (voltage threshold Von, on-time Ton) updated in this way is used in the determination in step 915 and the determination in step 945 of the routine of FIG.

  Further, as described above, when the on-time shortening time DTo, the X reduction amount DX, and the Y reduction amount DY are all set to “0”, the motor drive pattern (voltage threshold Von, on-time Ton) The pattern is set equal to the pattern determined in 1406 (that is, the motor reference drive pattern). The routine of FIG. 14 corresponds to the motor final drive pattern determining means.

  Further, the CPU 51 repeatedly executes the routine for performing the processing after the vehicle stop shown in FIG. 15 every elapse of a predetermined time. Accordingly, when the predetermined timing is reached, the CPU 51 starts processing from step 1500 and proceeds to step 1505 to determine whether or not the value of the flag DRIVE is “1”. Proceeding to 1595, the present routine is ended once.

  Assuming that motor control is being executed, the CPU 51 determines “Yes” in step 1505 and proceeds to step 1510 to determine whether or not the vehicle is stopped. This determination is performed by determining whether or not the vehicle body speed Vso obtained by one of the known methods is “0” from the output signal of the wheel speed sensor 41 **. This step 1510 corresponds to the second detection means.

  When determining “No” in step 1510, the CPU 51 immediately proceeds to step 1595 to end the present routine tentatively. On the other hand, the case where “Yes” is determined in step 1510 will be described later.

  The case where the motor drive pattern (voltage threshold Von, on-time Ton) is set to be equal to the pattern determined in step 1406 (that is, the motor reference drive pattern) has been described above. Next, a case where the motor drive pattern (voltage threshold Von, on time Ton) is determined to be different from the motor reference drive pattern will be described.

  First, the case where it is determined that the reservoir is “empty” in the “reservoir empty determination” described above (that is, the case where “Yes” is determined in step 1320 of FIG. 13) will be described. That is, as in the time t7, t13, etc. in FIG. 16, the stage (see the time t5, t11, etc.) before the start time (see the time t6, t12) of the off time Toff continued until that time. Let us consider a case where the reservoir fluid actual value Qact has already reached “0” and the reservoir fluid actual value Qact is maintained at “0” during the off time Toff.

  In this case, the CPU 51 proceeds from step 1320 to step 1325, resets the reservoir fluid amount estimated value Q to “0”, and resets the required discharge flow rate qre to “0” in subsequent step 1330. Hereinafter, the effect of this will be described.

  First, since the reservoir fluid amount estimated value Q at the time when it is determined that the reservoir is “empty” can be made to coincide with the actual value Qact (= 0), the reservoir fluid amount estimated value Q after this time is estimated. The accuracy can be increased.

  In addition, for example, as shown at times t7 and t13 in FIG. 16, the reservoir fluid amount estimated value Q when the reservoir is determined to be “empty” is a value larger than “0”. In this case, consider a case where the reservoir fluid amount estimation value Q is not reset to “0”. In this case, as indicated by a broken line or a two-dot chain line in FIG. 16, the reservoir fluid amount estimated value Q (calculated larger than the reservoir fluid amount actual value Qact as described above) gradually increases from the actual value Qact. It tends to diverge. Therefore, when the reservoir fluid amount estimation value Q is calculated to be considerably large, the required discharge flow rate qre is calculated to be considerably large (step 1120), and the value Xb is set to a large value in step 1406. Can be considered. As a result, a situation may occur in which the rotational speed of the motor MT is controlled to be excessively large.

  On the other hand, in this example, since the reservoir fluid amount estimated value Q is reset to “0” every time it is determined that the reservoir is “empty”, occurrence of such a situation can be suppressed.

  Referring again to FIG. 13, when the CPU 51 proceeds from step 1330 to step 1335, it is determined whether or not the duration TIM <b> 1 is shorter than the estimated sky time Tempest. Proceed immediately. On the other hand, if the determination is “Yes”, the CPU 51 proceeds to step 1340 to set the ON time reduction time DTo by adding the value DT (for example, 5 msec) to the value at that time (initial value is “0”). Update to Hereinafter, the effect of this will be described.

  For example, as shown in FIG. 16, the time from the end of the pressure reduction control (see time t2) to the time when the reservoir is determined to be “empty” (see time t7) (that is, the duration TIM1). ) Is shorter than the estimated empty time Tempest (time t2 to t10), the actual driving discharge flow rate is based on the discharge flow rate qpump1 (= the minimum guaranteed discharge flow rate, see steps 1025 and 1125). Also means big. That is, it means that the actual drive discharge flow rate is larger than the drive discharge flow rate (= the minimum guaranteed discharge flow rate) assumed when the table of FIG. 7 is produced. Accordingly, in this case, the actual discharge flow rate of the hydraulic pumps HPf and HPr may be excessive.

  In such a case (ie, when “Yes” is determined in step 1335), as described above, the on-time shortening time DTo (initial value is “0”) is increased by the value DT. As a result, the ON time Ton is set to a time shorter by the value DT from the time determined from the table of FIG. 7 in step 1444 of FIG. For example, in the example shown in FIG. 16, “Yes” is determined at step 1335 at time t7, and as a result, the on-time Ton is set shorter by the value DT from time t7 to t12.

  Thus, the motor drive pattern (Von, Ton) is determined to be a pattern having a lower rotational speed than the motor reference drive pattern. Thereby, since the rotational speed of the motor MT is controlled to be small, the extent to which the actual discharge flow rate of the hydraulic pumps HPf and HPr described above becomes excessive can be suppressed.

  Such processing is executed every time “Yes” is determined in step 1335. That is, for example, in the example shown in FIG. 16, “Yes” is determined at step 1335 also at time t13, and as a result, after time t13, the on-time Ton is set shorter by a value (2 · DT). The Thereby, the extent to which the actual discharge flow rate of the hydraulic pumps HPf and HPr becomes excessive can be gradually suppressed. In other words, the rotational speed of the motor MT can be gradually approached to an appropriate value. Note that the on-time Ton is not set to be shorter than the nominal-time on-time Tonnom by the processing of Steps 1446 and 1448 described above.

  As described above, assuming that the drive discharge flow rate is equal to the minimum guaranteed discharge flow rate, the actual drive discharge flow rate is assumed when the table of FIG. Therefore, the actual discharge flow rate of the hydraulic pumps HPf and HPr can be suppressed from being insufficient. In addition, the rotational speed of the motor MT can be gradually approximated to an appropriate value by increasing the on-time reduction time DTo by the value DT every time it is determined “Yes” in Step 1335. .

  Next, a case where the state of “the off time Toffc <time T1” continues N1 times (that is, a case where “Yes” is determined in step 1408 of FIG. 14) will be described. In this case, when the CPU 51 proceeds to step 1408, it determines “Yes”, proceeds to step 1410, and sets the Y reduction amount DY to a value obtained by adding the value Y1 to the value at that time (initial value is “0”). Update. Here, the value Y1 is a function of a value (Yb + DY) obtained by adding the current value DY to the reference value Yb of the value Y selected in step 1406. When Yb + DY = 1, Y1 When Y = 2, Yb + DY = 2 or 3, Y1 = 1, and when Yb + DY = 4, Y1 = 0 is set. Then, the CPU 51 proceeds to step 1412 and changes the flag F1 from “0” to “1”. That is, the flag F1 = 1 indicates that the Y reduction amount DY is larger than “0”. Hereinafter, the effect of this will be described.

  As described above, the time T1 is a time obtained by multiplying the estimated off time Toffest by a coefficient α1 (for example, 0.5). That is, the time T1 is shorter than the estimated OFF time Toffest. Therefore, the fact that the actual off time Toffc is shorter than the time T1 means that the off estimated time Toffest is calculated longer. Here, as described above, the estimated OFF time Toffest is calculated as a longer time as the estimated master cylinder pressure value Pm is smaller.

  From the above, the OFF time Toffc being shorter than the time T1 means that the master cylinder pressure estimated value Pm is calculated to be smaller than the actual value. Therefore, the motor reference drive pattern is selected as a pattern with a smaller average supply power to the motor MT (a pattern corresponding to the lower frame in FIG. 7), and the rotation speed of the motor MT becomes smaller than an appropriate value. Cases can occur. In other words, the actual discharge flow rate of the hydraulic pumps HPf and HPr may be insufficient.

  When such a tendency continues (that is, when “Yes” is determined in step 1408), as described above, the Y reduction amount DY (initial value is “0”) is increased by the value Y1. The Thus, thereafter, in step 1440 in FIG. 14, the value Y is set to a value larger than the value Yb by the Y reduction amount DY (= Y1). That is, in step 1442, a pattern with a larger average supply power to the motor MT than the motor reference drive pattern (a pattern corresponding to the upper frame in FIG. 7) is selected.

  In this way, the motor drive pattern (Von, Ton) is determined to be a pattern whose rotational speed is higher than the motor reference drive pattern. Thereby, since the rotational speed of the motor MT is controlled to be large, it is possible to suppress the extent to which the actual discharge flow rates of the hydraulic pumps HPf and HPr described above are insufficient.

  This Y reduction amount DY can be set to a larger value every time it is determined as “Yes” in step 1408. As a result, the rotational speed of the motor MT (accordingly, the actual discharge flow rate of the hydraulic pumps HPf and HPr) can be gradually brought close to an appropriate value.

  On the other hand, when the flag F1 = 1 (that is, when DY> 0 and the motor drive pattern is determined to be a pattern in which the rotational speed is larger than the motor reference drive pattern), the CPU 51 proceeds to step 1414 when “ The process proceeds to step 1416, where it is determined whether “T1 ≦ Toffc” continues N2 times (constant).

  The off time Toff tends to increase as the rotational speed of the motor MT increases. That is, when the off time Toffc is equal to or longer than the time T1, it means that the rotational speed of the motor MT is sufficiently large.

  Each time a case where such a tendency continues is detected (that is, every time “Yes” is determined in step 1416), the CPU 51 proceeds to step 1418 to set the Y reduction amount DY (> 0) to “1”. Just make it smaller. In step 1420, the CPU 51 determines whether or not the Y reduction amount DY has reached “0”. If the determination is “Yes”, in step 1422, the flag F1 is changed from “1” to “0”. change. Since flag F1 = 0 thereafter, it is determined as “No” in step 1414.

  By such processing, every time it is determined as “Yes” in step 1416, the motor drive pattern (Von, Ton) is gradually returned toward the motor reference drive pattern.

  Next, the case where the state of “time T1 ≦ the above-mentioned off time Toffc <time T2” continues for T4 time (constant) (that is, when “Yes” is determined in step 1424 in FIG. 14) will be described. To do. In this case, the CPU 51 makes a “Yes” determination when proceeding to step 1424, proceeds to step 1426, and sets the X reduction amount DX to a value obtained by adding the value X1 to the value at that time (initial value is “0”). Update. Here, the value X1 is a function of a value (Xb + DX) obtained by adding the current value DX to the reference value Xb of the value X selected in step 1406, and Xb + DX = 1 or 2 When X1 = 1 and Xb + DX = 3, X1 = 0 is set. Then, the CPU 51 proceeds to step 1428 to change the flag F2 from “0” to “1”. That is, the flag F2 = 1 indicates that the X reduction amount DX is larger than “0”. Hereinafter, the effect of this will be described.

  As described above, the time T2 is a time obtained by multiplying the estimated off time Toffest by a coefficient α2 (for example, 1.1). That is, the time T2 is a time in the vicinity of the estimated OFF time Toffest, and is sufficiently shorter than the reservoir empty time OFF time Toffemp. Therefore, the state where the actual OFF time Toffc is shorter than the time T2 continues (repeated) means that the state where the reservoir fluid actual value Qact does not become zero continues.

  On the other hand, if the state in which the reservoir fluid amount estimated value Q is calculated to be smaller than the actual value Qact continues, the motor reference drive pattern is a pattern in which the average power supplied to the motor MT is smaller (in FIG. The tendency that the rotational speed of the motor MT is smaller than an appropriate value may be continued. As a result, the actual discharge flow rates of the hydraulic pumps HPf and HPr are insufficient, and the state where the reservoir fluid actual value Qact does not become zero can be continued.

  From the above, the fact that the state in which the off time Toffc is shorter than the time T2 continues means that the state in which the reservoir fluid pressure estimated value Q is calculated to be smaller than the actual value Qact continues.

  When such a tendency continues (that is, when “Yes” is determined in step 1424), as described above, the X reduction amount DX (initial value is “0”) is increased by the value X1. The Thus, thereafter, in step 1440 of FIG. 14, the value X is set to a value larger than the value Xb by the X reduction amount DX (= X1). That is, in step 1442, a pattern having a larger average supply power to the motor MT than the motor reference drive pattern (a pattern corresponding to the right frame in FIG. 7) is selected.

  In this way, the motor drive pattern (Von, Ton) is determined to be a pattern whose rotational speed is higher than the motor reference drive pattern. Thereby, since the rotational speed of the motor MT is controlled to be large, it is possible to suppress the continuation of the state where the reservoir fluid actual value Qact does not become zero.

  This X reduction amount DX can be set to a larger value every time it is determined as “Yes” in step 1424. As a result, the rotational speed of the motor MT (accordingly, the actual discharge flow rate of the hydraulic pumps HPf and HPr) can be gradually brought close to an appropriate value.

  On the other hand, when flag F2 = 1 (that is, when DX> 0 and the motor drive pattern is determined to be a pattern in which the rotational speed is higher than the motor reference drive pattern), the CPU 51 proceeds to step 1430 when “ The process proceeds to step 1432, where it is determined whether or not the state of “T2 ≦ Toffc” has occurred N3 times (constant) within the time T5 (constant).

  As described above, the off time Toff tends to increase as the rotational speed of the motor MT increases. That is, that the off time Toffc is equal to or longer than the time T2 means that the rotational speed of the motor MT is sufficiently large.

  Each time a case where such a tendency continues is detected (that is, every time “Yes” is determined in step 1432), the CPU 51 proceeds to step 1434 and sets the X reduction amount DX (> 0) to “1”. Just make it smaller. In step 1436, the CPU 51 determines whether or not the X reduction amount DX has reached “0”. If it is determined to be “Yes”, the flag F2 is changed from “1” to “0” in step 1438. change. Thereafter, since flag F2 = 0, it is determined as “No” in step 1430.

  By such processing, every time it is determined as “Yes” in step 1432, the motor drive pattern (Von, Ton) is gradually returned toward the motor reference drive pattern.

  Next, processing after the vehicle stops (that is, a case where “Yes” is determined in step 1510 in FIG. 15) will be described with reference to FIG. FIG. 17 is a time chart showing an example when the ABS control is started / continued from time t1 (therefore, motor control is started / continued) and the vehicle stops at time t2.

  If it is assumed that the vehicle being traveled has stopped (see time t2 in FIG. 17), the CPU 51 determines “Yes” in step 1510, proceeds to step 1515, and determines whether or not the vehicle has just stopped. In step 1515, “Yes” is determined, and the process proceeds to step 1520. Based on the vehicle body deceleration Gx1 at the start of the latest decompression control and the table MapT6 using Gx1 as an argument, the time T6 is determined. get. Thereby, the time T6 is set to a longer time as the vehicle body deceleration Gx1 is larger.

  Subsequently, the CPU 51 proceeds to step 1525 to clear the elapsed time TIM2. Here, the continuation time TIM2 is measured by a timer (not shown) built in the electronic control unit 50, and represents an elapsed time from the vehicle stop point.

  Next, the CPU 51 proceeds to step 1530 to determine whether or not the elapsed time TIM2 has exceeded the time T6 (in FIG. 17, whether or not time t3 has arrived). Since the current time is immediately after the vehicle is stopped, the CPU 51 makes a “No” determination, proceeds immediately to step 1595, and once ends this routine. Thereafter, the CPU 51 repeats the processing of steps 1505, 1510, 1515, and 1530 until the elapsed time TIM2 exceeds the time T6 while the motor control is continuing (DRIVE = 1).

  If the elapsed time TIM2 exceeds the time T6 while the motor control is continuing (DRIVE = 1) (see time t3 in FIG. 17), the CPU 51 determines “Yes” when it proceeds to step 1530, and proceeds to step 1535. The required discharge flow rate qre is changed to a value obtained by dividing the latest value Q1 calculated in the previous step 1115 by the target time Ttrg2 (<target time Ttrg1). Since the process is completed, the value Q1 is kept constant at the latest value before the vehicle stops, so that the required discharge flow rate qre is changed from the value (Q1 / Ttrg1) to the value (Q1 / Trg2) increases stepwise, and the effect of such processing will be described below.

  The fact that the motor control end condition (step 855 in FIG. 8) is not satisfied even after the time T6 has elapsed after the vehicle has stopped is that the off time Toff has not been satisfied after the vehicle has stopped, as indicated by the broken line in FIG. This means that the state longer than the time T3 does not occur for a relatively long time, that is, the state where the reservoir fluid actual value Qact does not become zero for a relatively long time.

  In such a case, if the required discharge flow rate qre is increased, the motor drive pattern (Von, Ton) is rotated from the first time the motor is turned on after the time when the required discharge flow rate qre is increased (time t3 in FIG. 17). It can be determined to a pattern where the speed is greater. As a result, the rotational speed of the motor MT can be increased, and as a result, the time when the reservoir fluid actual value Qact becomes zero (time t4 in FIG. 17) can be advanced.

  Accordingly, in FIG. 17, the motor control end condition (step of FIG. 8) is reached at the time (time t6) when the off time Toff started from the time of the first motor OFF after time t4 (time t5) reaches the time T3. 855) is established and the motor control is finished. That is, the end time of the motor control can be advanced.

  As described above, according to the pump drive motor control device according to the embodiment of the present invention, the drive pattern (Von, Ton) of the motor MT is, in principle, the master cylinder pressure estimated value Pm, The required discharge flow rate qre (= a value proportional to the estimated reservoir fluid amount Q) and a pattern equal to the motor reference drive pattern determined by the table Map (X, Y) shown in FIG. 7 are determined (DTon = When DX = DY = 0, that is, when X = Xb and Y = Yb). On the other hand, at least one of DTon, DX, and DY becomes a value other than “0” under a predetermined condition, and the drive pattern (Von, Ton) of the motor MT is determined to be a pattern different from the motor reference drive pattern.

  As a result, the rotational speed of the motor MT can be brought close to an appropriate value, and the problem that arises because the rotational speed of the motor MT is controlled to be small, that is, the brake pedal stroke increases, ABS control. In this pressure reduction control, the occurrence of problems such as the wheel cylinder pressure being unable to be sufficiently reduced can be suppressed. In addition, it is possible to suppress the occurrence of problems that occur due to the fact that the rotational speed of the motor MT is controlled to be large, that is, problems such as increased operating noise of the motor and the hydraulic pump.

  Further, if it is not detected that the reservoir fluid amount actual value Qact becomes zero even after a predetermined time (T6) has elapsed since the vehicle stopped, the motor final drive pattern is changed to a pattern in which the rotational speed becomes larger. As a result, the time when the reservoir fluid actual value Qact becomes zero after the vehicle stops can be advanced.

  In addition, when it is detected that the reservoir fluid amount actual value Qact becomes zero, the reservoir fluid amount estimated value Q is reset to “0”. As a result, it is possible to suppress occurrence of a situation in which the rotational speed of the motor MT is controlled to be large by calculating the reservoir fluid amount estimated value Q (and hence the required discharge flow rate qre) to be large.

  The present invention is not limited to the above embodiment, and various modifications can be employed within the scope of the present invention. For example, in the above embodiment, it is detected that the actual drive discharge flow rate when the motor is ON is larger than the drive discharge flow rate (= the minimum guaranteed discharge flow rate) assumed when the table of FIG. 7 is produced. If it is determined (“Yes” in step 1335), the on-time Ton is set shorter (steps 1340 and 1444) in order to reduce the rotational speed of the motor MT. In order to reduce the rotational speed of MT, the voltage threshold Von may be set smaller.

  Further, in the above embodiment, it is configured to detect that the master cylinder pressure estimated value Pm is calculated to be smaller on the condition that the state of “Toffc <T1” continues N1 times (step 1408). However, it may be configured to detect that the master cylinder pressure estimated value Pm is calculated to be smaller when the state of “Toffc <T1” occurs only once.

  Further, in the above embodiment, the fact that the reservoir fluid amount estimated value Q is calculated to be smaller is detected on the condition that the state of “T1 ≦ Toffc <T2” has continued for T4 time (step 1424). Although it is configured, it may be configured to detect that the reservoir fluid amount estimated value Q is calculated smaller on condition that the state of “T1 ≦ Toffc <T2” continues for a predetermined number of times.

  In the above embodiment, “reservoir empty determination” is performed when the motor is ON (step 1320). However, the duration TIMoff of the OFF time Toff when the motor MT is in the OFF state is the time T3. It may be configured such that “reservoir empty determination” (TIMoff> T3) is performed when the time is reached.

  In the above embodiment, the required discharge flow rate qre is changed from the value (Q1 / Ttrg1) to the value (Q1 / Ttrg2) in order to increase the required discharge amount qre after the vehicle stops. It is configured to increase qre (step 1535), but by changing the required discharge flow rate qre to a value (Q1 / Ttrg1) multiplied by a predetermined coefficient (a value greater than “1”), The required discharge flow rate qre may be increased.

  In the above embodiment, the motor drive pattern (Von, Ton) is changed every time the motor is turned on, but the motor drive pattern (Von, Ton) is changed to a required discharge flow rate qre. You may update whenever it updates (that is, every time decompression control is completed).

  In addition, in the above embodiment, when the estimated reservoir fluid amount Q is calculated (see the above equation (1)), the hydraulic pump HPf is assumed assuming that the drive discharge flow rate is equal to the minimum guaranteed discharge flow rate. , HPr discharge flow rate qpump1 is calculated (steps 1025 and 1030), and the discharge flow rates of the hydraulic pumps HPf and HPr are calculated assuming that the drive discharge flow rate is equal to the design median value (nominal flow rate). You may calculate.

  In this case, when it is not detected over a predetermined time (the fifth time) that the reservoir fluid actual value Qact has become zero, it is preferable to correct the reservoir fluid amount estimated value Q to a larger value.

  Thus, when calculating the discharge flow rate of the hydraulic pumps HPf and HPr used for the calculation of the reservoir fluid amount estimated value Q on the assumption that the drive discharge flow rate is equal to the nominal flow rate, the motor MT and the hydraulic pressure When the pumps HPf and HPr are deteriorated, the reservoir fluid amount estimated value Q tends to be calculated to be smaller than the actual value Qact. That is, there is a tendency that the reservoir fluid actual value Qact does not become zero over a relatively long time.

  On the other hand, according to the above configuration, when it is detected that the reservoir fluid amount estimated value Q is calculated to be smaller than the actual value Qact, the reservoir fluid amount estimated value Q is corrected to a larger value ( For example, the reservoir fluid amount estimated value Q can be brought close to the actual value Qact by increasing in a stepwise manner. In addition, it can be suppressed that the rotational speed of the motor MT is controlled to be smaller than an appropriate value due to the reservoir fluid amount estimated value Q being calculated to be smaller than the actual value Qact.

1 is a schematic configuration diagram of a vehicle equipped with a vehicle brake fluid pressure control device including a pump drive motor control device according to an embodiment of the present invention. It is a schematic block diagram of the brake fluid pressure control part shown in FIG. It is the graph which showed the relationship between the command electric current and command differential pressure about the pressure increase valve shown in FIG. It is the figure which showed the electricity supply pattern at the time of controlling the command current shown in FIG. 3 by duty control. It is a schematic block diagram of the drive circuit for drive-controlling the motor shown in FIG. It is the graph which showed the example of the motor drive pattern. It is the figure which showed the table used in order to determine a motor reference drive pattern. 3 is a flowchart illustrating a routine for performing start / end determination of motor control executed by a CPU illustrated in FIG. 1. 2 is a flowchart showing a routine for performing motor control executed by a CPU shown in FIG. 1. 2 is a flowchart showing a routine for calculating an estimated reservoir fluid amount executed by a CPU shown in FIG. 1. 3 is a flowchart showing a routine for performing processing at the end of decompression control executed by a CPU shown in FIG. 1. 3 is a flowchart showing a routine for performing processing at the time of motor OFF executed by a CPU shown in FIG. 1. FIG. 3 is a flowchart showing a routine for performing a process 1 when the motor is ON, which is executed by the CPU shown in FIG. 1. FIG. FIG. 3 is a flowchart showing a routine for performing process 2 when the motor is ON, which is executed by the CPU shown in FIG. 1. FIG. FIG. 2 is a flowchart showing a routine for performing processing after a vehicle stop executed by a CPU shown in FIG. 1. FIG. It is a time chart for demonstrating the change at the time of ON time change, and resetting the reservoir fluid amount estimated value to zero. It is a time chart for demonstrating the action | operation at the time of changing a motor drive pattern after a vehicle stop.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Brake hydraulic pressure control apparatus of vehicle, 30 ... Brake hydraulic pressure control part, 41 ** ... Wheel speed sensor, 50 ... Electronic control unit, 51 ... CPU, MT ... Motor, HPf, HPr ... Hydraulic pump, RSf, RSr ... Reservoir

Claims (7)

  A combination of pressure reduction control for reducing the wheel cylinder pressure of the wheel when the wheel tends to lock during braking of the vehicle and pressure increase control for increasing the wheel cylinder pressure when the locking tendency is eliminated by the pressure reduction control. Applied to anti-skid control device that executes multiple times,
  A reservoir fluid amount estimated value acquisition means for acquiring an estimated value of the brake fluid amount at the end of the decompression control in the reservoir storing the brake fluid discharged in the decompression control;
  A hydraulic pump control means for setting a rotational speed of a motor that drives a hydraulic pump that pumps up the brake fluid in the reservoir based on the estimated value of the reservoir fluid amount, and that drives the hydraulic pump at the set motor rotational speed When,
  Empty detection means for detecting that the actual value of the amount of brake fluid in the reservoir has become zero;
  After the end of the pressure reduction control, the brake fluid amount in the reservoir is reduced from the reservoir fluid amount estimated value to zero based on the driving of the hydraulic pump by the motor rotational speed set by the hydraulic pump control means. If it is detected that the actual value of the amount of brake fluid in the reservoir has become zero before the estimated time is reached, the rotational speed of the motor that drives the hydraulic pump after the detection is determined, Change means for making the motor rotational speed set lower than the hydraulic pump control means;
  A pump drive motor control device comprising:   The pump drive motor control device according to claim 1,
  Vehicle stop detecting means for detecting that the vehicle has stopped,
  The changing means is
  If it is not detected that the actual value of the brake fluid amount in the reservoir has become zero after the stop of the vehicle is detected, the motor rotation speed set by the hydraulic pump control means is A pump drive motor control device configured to be larger than a motor rotation speed set based on the reservoir fluid amount estimation value.   The pump drive motor control device according to claim 1,
  A master cylinder pressure estimated value acquisition means for acquiring an estimated value of a master cylinder pressure according to a brake operation by a driver of the vehicle;
  The rotational speed of the motor is adjusted by controlling a ratio of an on time during which power supply to the motor is maintained in an on state and an off time during which power supply to the motor is maintained in an off state. Composed of
  The hydraulic pump control means includes
  The motor rotational speed is configured to be set based on the reservoir fluid amount estimated value and the master cylinder pressure estimated value,
  The changing means is
  Based on the master cylinder pressure estimated value in a state where the actual value of the brake fluid amount in the reservoir is maintained at a value greater than zero, the actual off time during which the power supply to the motor is actually maintained in the off state. The hydraulic pump control when it is detected that the estimated off time during which the power supply to the motor estimated in this way is maintained in the off state is shorter than a first time obtained by multiplying a positive coefficient smaller than 1 A pump drive motor control device configured to make a motor rotation speed set by the means larger than a motor rotation speed set based on the reservoir fluid amount estimation value and the master cylinder pressure estimation value.   In the control apparatus of the motor for a pump drive of Claim 3,
  The changing means is
  In a state where the motor rotation speed set by the hydraulic pump control means is larger than the motor rotation speed set based on the reservoir fluid amount estimation value and the master cylinder pressure estimation value, the actual off time is When it is detected that the first time has elapsed, a motor rotation speed set by the hydraulic pump control means is set based on the estimated reservoir fluid amount and the estimated master cylinder pressure. A pump drive motor control device configured to return toward a rotational speed.   The pump drive motor control device according to claim 1,
  A master cylinder pressure estimated value acquisition means for acquiring an estimated value of a master cylinder pressure according to a brake operation by a driver of the vehicle;
  The rotational speed of the motor is adjusted by controlling a ratio of an on time during which power supply to the motor is maintained in an on state and an off time during which power supply to the motor is maintained in an off state. Composed of
  The hydraulic pump control means includes
  The motor rotational speed is configured to be set based on the reservoir fluid amount estimated value and the master cylinder pressure estimated value,
  The changing means is
  Based on the master cylinder pressure estimated value in a state where the actual value of the brake fluid amount in the reservoir is maintained at a value greater than zero, the actual off time during which the power supply to the motor is actually maintained in the off state. A state shorter than a second time obtained by multiplying an estimated off time in which the power supply to the motor, which is estimated to be maintained in an off state, is multiplied by a coefficient larger than 1, is the next decompression from the start of the decompression control. When it is detected that the operation has continued for approximately twice the time until the start of control, the motor rotation speed set by the hydraulic pump control means is determined as the reservoir fluid amount estimated value and the master cylinder pressure estimated value. The pump drive motor control device is configured to be larger than the motor rotation speed set based on the above.   In the control apparatus of the motor for a pump drive of Claim 5,
  The changing means is
  In a state where the motor rotation speed set by the hydraulic pump control means is larger than the motor rotation speed set based on the reservoir fluid amount estimation value and the master cylinder pressure estimation value, the actual off time is When it is detected that the second time has elapsed, the motor rotational speed set by the hydraulic pump control means is set based on the reservoir fluid amount estimated value and the master cylinder pressure estimated value. A pump drive motor control device configured to return toward a rotational speed.   In the control apparatus of the motor for a pump drive of Claim 1,
  The rotational speed of the motor is adjusted by controlling a ratio of an on time during which power supply to the motor is maintained in an on state and an off time during which power supply to the motor is maintained in an off state. Composed of
  The sky detecting means includes
  The actual OFF time during which the power supply to the motor is actually maintained in the OFF state is estimated when the actual value of the brake fluid amount in the reservoir is maintained at zero. The power supply to the motor is OFF The system is configured to detect that the actual value of the brake fluid amount in the reservoir has become zero based on detecting that it is longer than the third time based on the estimated reservoir space-time off time maintained in the state. The pump drive motor controller.

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