JP2008126719A - Controller of motor for anti-skid control - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control a rotation speed (delivery flow rate of hydraulic pump) of a motor for driving the hydraulic pump for pumping a brake liquid in a reservoir so as to avoid that the reservoir is filled with the brake liquid and is evacuated during ABS control. <P>SOLUTION: During ABS control, the (average) rotation speed of the motor is controlled so as to become a target rotation speed NEt. An initial value NEini of the value NEt (value at ABS control starting time (time t1)) is determined based on vehicle body deceleration at the ABS control starting time such that it is changed within a range that the reservoir liquid amount is larger than "0" and is smaller than the maximum reservoir liquid amount Qfull during the ABS control. Changing trend of the reservoir liquid amount presumption value Q is determined every time when renewal timing (times t2, t3, t4) of the value NEt arrives. In the case of increasing trend (times t2, t4), the value NEt is renewed to a larger value, and in the case of reducing trend (time t3), the value NEt is renewed to a smaller value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotational speed of a motor that drives a hydraulic pump used to pump up brake fluid discharged to a reservoir and discharge it to a hydraulic circuit of an anti-skid control device during pressure reduction control in anti-skid control. The present invention relates to a control device for an anti-skid control motor to be controlled. Hereinafter, the anti-skid control may be referred to as “ABS control”.

Conventionally, a control device for this type of ABS control motor has been widely known (for example, see Patent Document 1 below). In the device described in this document, the (average) rotation speed of the motor (and hence the (average) discharge flow rate of the hydraulic pump) is controlled as follows so that the operating noise of the motor driving the hydraulic pump does not increase. Is done. The “discharge flow rate” is a discharge amount per unit time.
Japanese translation of PCT publication No. 2002-506406

  That is, the voltage threshold value compared with the voltage generated by the motor when the power supply to the motor is in the off state (that is, the voltage generated by the induced electromotive force of the motor as a generator (generated voltage)), and the power supply The driving pattern of the motor is determined from the time during which the motor is maintained in the ON state (ON time). The power supply is switched from the off state to the on state when the power generation voltage becomes equal to or less than the voltage threshold, and the power supply is maintained from the on state to the off state for the on time. The power supply is controlled to be turned on / off by the motor driving pattern. As a result, the larger the voltage threshold is, and the longer the on-time is, the larger the (average) rotational speed of the motor is controlled during ABS control.

  By the way, when the rotational speed of the motor is low during ABS control, the discharge flow rate (intake flow rate from the reservoir) of the hydraulic pump tends to be small and the reservoir tends to be filled with the brake fluid. When the reservoir is filled with the brake fluid, there may arise a problem that the wheel cylinder pressure cannot be sufficiently reduced in the ABS control pressure reduction control in which the stroke of the brake pedal becomes large.

  In order to avoid the reservoir being filled with the brake fluid, for example, as shown in FIG. 12, pressure reduction control (corresponding to times t11 to t11 ′, t12 to t12 ′, t13 to t13 ′, t14 to t14 ′) The amount of brake fluid in the reservoir (reservoir fluid amount), which increases due to the above, becomes a relatively large value so that the rotational speed of the motor becomes zero before the next pressure reduction control start time (corresponding to times t12, t13, t14). It is thought that it is effective to control to.

  However, in this case, a state where the reservoir liquid amount is not zero and a state where the reservoir liquid amount is zero occur alternately. When the reservoir fluid amount is zero (ie, the pump suction flow rate is zero), the hydraulic pump load is higher than when the reservoir fluid amount is not zero (ie, the pump suction flow rate is not zero). Is significantly smaller, the rotational speed of the hydraulic pump (and therefore the motor) is significantly increased.

  For example, in the example shown in FIG. 12, assuming that the motor drive pattern (and hence the target rotational speed of the motor) is kept constant after time t11, the timing at which the reservoir fluid amount becomes zero from other than zero (for example, Each time (see time t110) arrives, the load of the hydraulic pump decreases rapidly, and the actual rotational speed of the motor increases significantly. On the other hand, every time when the reservoir fluid amount changes from zero to other than zero (see, for example, times t12, t13, t14, etc.), the load of the hydraulic pump increases rapidly and the actual rotational speed of the motor increases. Significantly smaller.

  As described above, when the rotational speed of the motor is controlled to a relatively large value so that the reservoir fluid amount becomes zero before the next decompression control start time, the rotational speed of the motor varies. As a result, the operation sound of the motor also fluctuates, and there is a problem that the vehicle occupant is uncomfortable.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a motor control device for an ABS control in which the motor rotation speed (hydraulic pump's rotational speed) is avoided so as to avoid the reservoir being filled with brake fluid and the reservoir fluid amount becoming zero. An object of the present invention is to provide an anti-skid control motor control apparatus capable of controlling the discharge flow rate.

  A control device for an ABS control motor according to the present invention is applied to an ABS control device that performs ABS control for performing pressure reduction control for reducing the wheel cylinder pressure of a vehicle wheel when the vehicle wheel tends to be locked. The rotational speed of the motor that drives the pump that discharges the brake fluid discharged to the reservoir by the control into the hydraulic circuit of the ABS control device is controlled.

  The ABS control motor control device according to the present invention is characterized in that an acquisition means for acquiring an estimated value of the brake fluid amount (reservoir fluid amount) in the reservoir during the ABS control, and the reservoir fluid amount estimated value Then, a value corresponding to the target rotational speed of the motor is determined so that the amount of the reservoir fluid is larger than zero and the range is smaller than the maximum amount of brake fluid that can be stored in the reservoir (maximum reservoir fluid amount). And a control means for controlling the rotational speed of the motor during the ABS control based on the target rotational speed equivalent value. Here, the “target rotational speed equivalent value” refers to the target rotational speed of the motor itself, the target required discharge flow rate of the hydraulic pump, and the like.

  According to this, during the ABS control, it can be avoided that the reservoir is filled with the brake fluid (the reservoir fluid amount becomes the maximum reservoir fluid amount) and that the reservoir fluid amount becomes zero. Therefore, the occurrence of the problems such as “the brake pedal stroke becomes large and the wheel cylinder pressure cannot be sufficiently reduced in the pressure reduction control of the ABS control” can be suppressed, and the reservoir fluid amount is not zero. It is also possible to suppress the above-described “variation in the rotational speed of the motor” that accompanies occurrence of the zero state alternately.

  In this case, the determining means is configured to set the target rotational speed equivalent value (initial value thereof) at the same point based on the vehicle body deceleration of the vehicle at the start of the anti-skid control. Is preferred.

  In general, the greater the friction coefficient of the road surface on which the vehicle is traveling during ABS control (and thus the greater the vehicle body deceleration during ABS control), the greater the flow rate of brake fluid discharged to the reservoir during decompression control. Tend. In other words, there is a very strong correlation between the flow rate of the brake fluid discharged to the reservoir and the vehicle body deceleration during the pressure reduction control. Therefore, according to the above configuration, when controlling the rotational speed of the motor so that the reservoir fluid amount is within a range larger than zero and smaller than the maximum reservoir fluid amount, the initial value of the target rotational speed of the motor is accurately determined. It can be set well.

  Further, it is preferable that the determining means is configured to update the target rotational speed equivalent value based on a change tendency of the reservoir fluid amount estimated value. Consider a case where an estimated error is included in the estimated reservoir fluid amount. In this case, even if the rotational speed of the motor is controlled based on the estimated reservoir fluid amount itself so that the estimated reservoir fluid amount itself is within a range larger than zero and smaller than the maximum reservoir fluid amount, The reservoir fluid amount may be zero or the maximum reservoir fluid amount due to the influence of the estimation error.

  On the other hand, even when the estimation error is included in the reservoir fluid amount estimation value, the change tendency (increase / decrease direction) of the reservoir fluid amount estimation value is not easily affected by the estimation error, and the change in the reservoir fluid amount estimation value The tendency (increase / decrease direction) tends to coincide with the actual change tendency (increase / decrease direction) of the reservoir fluid amount.

  The above configuration is based on such knowledge. According to this, compared with the case where the target rotational speed of the motor is updated based on the estimated reservoir fluid amount itself, the actual reservoir fluid amount is larger than zero and larger than the maximum reservoir fluid amount. The rotational speed of the motor can be controlled so as to shift within a small range.

  For example, the determining means is configured to update the target rotational speed equivalent value to a larger value (smaller value) when the estimated reservoir fluid amount is in an increasing tendency (decreasing tendency). In this case, more specifically, when the current value of the estimated brake fluid amount obtained each time a predetermined timing arrives is larger (smaller) than the previous value, the target rotational speed equivalent value is larger. Updated to a value (smaller value). In this case, it is preferable that the increase amount due to the update of the target rotation speed equivalent value is set to a larger value as the degree of the increase tendency of the reservoir fluid amount estimation value is larger. The “predetermined timing” is, for example, a pressure reduction control in the ABS control when a predetermined time (a certain time) elapses (at least one control cycle including at least the pressure reduction control and the pressure increase control is continuously executed). The end point, the end point of the pressure increase control in the ABS control, and the like.

  The tendency that the estimated amount of brake fluid is increasing (decreasing) means that the discharge flow rate of the hydraulic pump (and hence the rotational speed of the motor) is insufficient (excessive). Therefore, according to the above configuration, the target rotational speed of the motor can be appropriately updated so that the actual reservoir fluid amount changes within a range larger than zero and smaller than the maximum reservoir fluid amount.

  Further, the determination means may be configured to update the target rotational speed equivalent value based on an increasing gradient of the reservoir fluid amount estimated value during the pressure reduction control. More specifically, when the increasing gradient of the reservoir fluid amount estimated value during the pressure reduction control is larger (smaller) than a reference value, the target rotational speed equivalent value is updated to a larger value (smaller value). . The “reference value” may be constant or may be set to a larger value as the vehicle body deceleration increases.

  During the ABS control, there is an optimum value of the increasing gradient of the reservoir fluid amount during the decompression control, which is necessary for the reservoir fluid amount to change within a range larger than zero and smaller than the maximum reservoir fluid amount. Therefore, assuming that the reference value is set to this optimum value, the increase gradient of the reservoir fluid amount during the pressure reduction control is larger (smaller) than the reference value. This means that the rotation speed) is insufficient (excessive). Therefore, even with the above configuration, the target rotational speed of the motor can be appropriately updated so that the actual reservoir fluid amount changes within a range larger than zero and smaller than the maximum reservoir fluid amount.

  Embodiments of an ABS control 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 an ABS control device 10 including a control device for an ABS control motor according to an embodiment of the present invention. The ABS control device 10 includes a brake fluid pressure control unit 30 that generates a braking force based on the brake fluid pressure on each wheel.

  As shown in FIG. 2 showing the schematic configuration, the brake hydraulic pressure control unit 30 is composed of two systems, a system related to the wheels RR and FL and a system related to the wheels FR and RL, and constitutes a so-called X pipe. ing.

  The brake fluid pressure control unit 30 is disposed in each of the brake fluid pressure generating unit 32 that generates the brake fluid pressure (master cylinder pressure Pm) corresponding to the operation force of the brake pedal BP, and the wheels FR, FL, RR, and RL. RR brake hydraulic pressure adjusting unit 33, FL brake hydraulic pressure adjusting unit 34, FR brake hydraulic pressure adjusting unit 35, RL brake hydraulic pressure adjusting unit capable of adjusting the brake hydraulic pressure supplied to the wheel cylinders Wfr, Wfl, Wrr, Wrl, respectively. 36 and a reflux brake fluid supply unit 37.

  The brake fluid pressure generating unit 32 includes a vacuum booster VB and a master cylinder MC connected to the vacuum booster VB. 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.

  The RR brake fluid pressure adjusting unit 33 includes a pressure increasing valve PUrr which is a normally open linear electromagnetic valve capable of adjusting a differential pressure steplessly (linearly), and a pressure reducing valve which is a two-port two-position switching type normally closed electromagnetic on-off valve. PDrr. Similarly, the FL brake hydraulic pressure adjusting unit 34, the FR 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 PUfr and a pressure reducing valve PDfr, a pressure increasing valve PUrl, and It consists of a pressure reducing valve PDrl.

  The reflux brake fluid supply unit 37 includes a DC motor MT and hydraulic pumps HPf and HPr that are simultaneously driven by the DC motor MT. The hydraulic pump HPf pumps up the brake fluid in the reservoir RSf returned from the pressure reducing valves PDrr and PDfl, and supplies it to the upstream portion of the RR brake fluid pressure adjusting unit 33 and the FL brake fluid pressure adjusting unit 34. Yes.

  Similarly, the hydraulic pump HPr pumps up the brake fluid in the reservoir RSr returned from the pressure reducing valves PDfr and PDrl and supplies it to the upstream portion of the FR brake fluid pressure adjusting unit 35 and the RL brake fluid pressure adjusting unit 36. It has become.

  Referring to FIG. 1 again, the ABS control device 10 includes wheel speed sensors 41fl, 41fr, 41rl, and 41rr, a brake switch 42, and an electronic control device 50. The electronic control unit 50 is a microcomputer that includes a CPU 51, a ROM 52, a RAM 53, a backup RAM 54, an interface 55, and the like that are connected to each other via a bus.

  The interface 55 is connected to the sensor 41 ** and the brake switch 42, and supplies a signal to the CPU 51. In accordance with an instruction from the CPU 51, the electromagnetic valve (pressure increase valve PU **, And a pressure reducing valve PD **) and a drive signal to 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 shown.

  The ABS control device 10 according to the embodiment of the present invention configured as described above executes one of well-known ABS controls in order to suppress the wheel lock. In this example, as the ABS control, one control cycle including a set of pressure reduction control, holding control, and linear pressure increase control is continuously and repeatedly executed with respect to the wheel cylinder pressure Pw **.

(Outline of rotational speed control of motor MT)
Next, the rotational speed control of the motor MT by the ABS control device (hereinafter also referred to as “this device”) including the control device for the ABS control motor according to the embodiment of the present invention configured as described above. The outline of will be described. In this apparatus, the rotational speed of the motor MT is controlled using a power transistor Tr as a switching element shown in FIG.

  More specifically, as shown in FIG. 3, the power transistor Tr has its collector terminal connected to the vehicle power supply (voltage Vcc) and its emitter terminal connected to one terminal of the motor MT. ing. 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. 3, the motor control signal Vcont is generated so as to be either high level or low level. When the motor control signal Vcont is at a high level, the power transistor Tr is turned on and the voltage Vcc is applied to the motor MT. As a result, as shown in FIG. 4, the motor terminal voltage VMT (see FIG. 3), which is the voltage between the two terminals of the motor MT, is constant at the voltage Vcc, and the hydraulic pumps HPf and HPr are driven. (The power supply to the motor MT is turned on, hereinafter simply referred to as “on state”).

  On the other hand, when the motor control signal Vcont is at a low level, the power transistor Tr is turned off and the voltage Vcc is not applied to the motor MT (power supply to the motor MT is turned off, hereinafter simply referred to as “off state”). .) In this 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. 4, this apparatus has a motor terminal voltage VMT that decreases 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 (therefore, the generated voltage). When the voltage becomes less than or equal to a voltage threshold Von that can be determined and changed based on a target rotational speed NEt (corresponding to the target rotational speed equivalent value) described later, the motor MT is switched from the off state to the on state. After driving the hydraulic pumps HPf and HPr while maintaining the motor MT on for a time Ton (constant in this example), the motor MT is switched from the on state to the off state, and the hydraulic pumps HPf and HPr are switched. Stop driving.

  The present apparatus repeats a motor drive pattern consisting of the voltage threshold Von and the on-time Ton to turn on / off the power supply to the motor MT so that the actual rotational speed NE of the motor MT is the target rotational speed NEt. The rotational speed of the motor MT (accordingly, the rotational speed of the hydraulic pumps HPf and HPr, the discharge flow rate) is controlled so as to match the above.

(Actual operation)
Next, the actual operation of this apparatus will be described with reference to FIGS. 5 to 7 showing a routine executed by the CPU 51 of the electronic control unit 50 in a flowchart and the time chart shown in FIG. In FIG. 10, the vehicle body speed Vso, the wheel speed Vw of the wheel on which the ABS control is executed (ABS control execution wheel), and the master cylinder pressure when the ABS control is started / executed for only one wheel from time t1. Pm, wheel cylinder pressure Pw of the ABS control execution wheel, and reservoirs RSf, RSr (hereinafter also simply referred to as “reservoir”) of the brake fluid amount (reservoir fluid amount) of the one corresponding to the ABS control execution wheel ) And an example of a change in the target rotational speed NTt of the motor MT.

  The CPU 51 repeatedly executes the motor control start / end determination routine shown in FIG. 5 every elapse of a predetermined time (program execution cycle Δt). Accordingly, when the predetermined timing is reached, the CPU 51 starts processing from step 500, proceeds to step 505, and calculates the wheel speed Vw ** (speed of the outer circumference of the wheel) based on the output of the wheel speed sensor 41 **. . Subsequently, the CPU 51 proceeds to step 510 and sets the vehicle body speed Vso to the maximum value of the wheel speed Vw **.

  Next, the CPU 51 proceeds to step 515 and determines 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 the motor control is not being executed and the motor control start condition is not satisfied, the value of the flag DRIVE is “0”. Accordingly, the CPU 51 determines “Yes” in step 515 and proceeds to step 520 to determine whether or not the 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 520 and immediately proceeds to step 595 to end the present routine tentatively. Such an operation is repeatedly executed until the motor control start condition is satisfied. The example shown in FIG. 10 corresponds to the time before time t1.

  Next, a case where ABS control is started in this state (that is, a case where a motor control start condition is satisfied) will be described. In the example shown in FIG. 10, it corresponds to time t1. In this case, when the CPU 51 proceeds to step 520, it determines “Yes”, proceeds to step 525, and changes the value of the flag DRIVE from “0” to “1”.

  Next, the CPU 51 proceeds to step 530 to obtain the vehicle body deceleration DVso by differentiating the vehicle body speed Vso with respect to time (and reversing the sign). Thereby, the vehicle body deceleration DVso becomes a value at the ABS control start time (time t1 in FIG. 10).

  Next, the CPU 51 proceeds to step 535 and obtains an initial value NEini of a target rotational speed of the motor MT based on the vehicle body deceleration DVso and a table MapNEini (not shown). Thereby, the value NEini is set to a larger value as the vehicle body deceleration DVso is larger.

  This value NEini changes within a range in which the reservoir fluid amount is larger than “0” and smaller than the maximum reservoir fluid amount Qfull (the maximum value of the brake fluid amount that can be stored in the reservoir RSf or the reservoir RSr) during the ABS control. As described above, this value is determined according to the vehicle body deceleration at the start of ABS control.

  The table MapNEini used for determining the value NEini is, for example, the motor MT necessary for the reservoir fluid amount to change within a range larger than “0” and smaller than the maximum reservoir fluid amount Qfull during ABS control. The optimum value of the rotational speed can be created through experiments, simulations, and the like that search for various values of the vehicle body deceleration at the start of ABS control.

  Next, the CPU 51 proceeds to step 540, and sets the target rotational speed NEt at the present time (that is, the ABS control start time, time t1 in FIG. 10) to the value NEini. Thus, the target rotational speed NEt (= NEini) at the start of ABS control is determined based on the vehicle body deceleration DVso at the start of ABS control. Then, the CPU 51 proceeds to step 545, and sets an estimated value Q of the reservoir fluid amount that is calculated and updated in a routine described later to an initial value “0” that is a value at the start of ABS control.

  Then, the CPU 51 proceeds to step 550 to obtain a value Qc (the time t2 in FIG. 10) which is the reservoir fluid amount estimated value Q obtained every time the pressure increase control end time (corresponding to the “predetermined timing”) arrives. , T3, t4, corresponding to the reservoir fluid amount estimated value Q) is set to the initial value Q0, and the routine proceeds to step 595 to end the present routine tentatively.

  Here, the value Qc is used for updating the target rotational speed NEt of the motor MT, as will be described later. In this example, the initial value Q0 of the previous value Qcb of the value Qc is a pressure increase corresponding to the case where the vehicle body deceleration at the start of ABS control is the value DVso and the rotational speed NE of the motor MT is controlled to the value NEini. It is set to the reservoir fluid amount at the end of control. This initial value Q0 can also be obtained through experiments, simulations, etc. while variously changing the vehicle body deceleration (and the rotational speed of the motor MT) at the start of ABS control.

  Thereafter, since the value of the flag DRIVE is “1”, the CPU 51 makes a “No” determination when proceeding to step 515 and proceeds to step 555, where the motor control end condition is satisfied. It is determined whether or not. In this example, the motor control end condition is satisfied when the ABS control ends and the duration TIMoff of the OFF state exceeds a predetermined time T2 (constant).

  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 555 to proceed to step 560, where the (average) rotational speed NE of the motor MT is equal to the target rotational speed NEt (currently equal to the value NEini by the processing of step 540). The voltage threshold Von is set / changed so as to match, and the motor drive pattern consisting of the voltage threshold Von and the on-time Ton (constant) is repeated to control on / off the power supply to the motor MT. Then, the CPU 71 immediately proceeds to step 595 and once ends this routine. Such processing is repeatedly executed until the motor control end condition is satisfied.

  Thus, the rotational speed NE of the motor MT is controlled to coincide with the target rotational speed NEt (the value NEt can be appropriately updated / changed by a routine described later) (therefore, the rotational speeds of the hydraulic pumps HPf, HPr, The discharge flow rate is controlled). As a result, during the ABS control, the reservoir fluid amount is adjusted (should be) so as to change within a range larger than “0” and smaller than the maximum reservoir fluid amount Qfull. This step 560 corresponds to the control means.

  On the other hand, when the motor control end condition is satisfied in this state, the CPU 51 determines “Yes” when the process proceeds to step 555 and proceeds to step 565 to change the value of the flag DRIVE from “1” to “0”. .

  Thereafter, since the value of the flag DRIVE is “0”, the CPU 51 determines “Yes” when it proceeds to step 515, proceeds to step 520, and again determines whether or not the motor control start condition is satisfied. To monitor.

  Thus, by repeatedly executing the routine of FIG. 5, 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. While the value of the flag DRIVE is maintained at “1”, the rotational speed NE of the motor MT is controlled so as to coincide with the target rotational speed NEt that can be appropriately updated and changed.

  Further, the CPU 51 repeatedly executes the routine for calculating the reservoir fluid amount shown in FIG. 6 every elapse of a predetermined time following the routine of FIG. Therefore, when the predetermined timing is reached, the CPU 51 starts processing from step 600 and proceeds to step 605 to determine whether or not the value of the flag DRIVE is “1”. Proceeding to 695, the present routine is temporarily ended.

  Assuming that motor control is being executed (see time t1 and thereafter in FIG. 10), as described above, the flag DRIVE = 1 (step 525). Accordingly, the CPU 51 determines “Yes” in step 605 and proceeds to step 610 to determine whether or not the pressure reduction control is being performed.

  When the present time is under pressure reduction control (refer to times t1 to t1 ′, t2 to t2 ′, t3 to t3 ′, and t4 to t4 ′ in FIG. 10), the CPU 51 determines “Yes” in step 610. Proceeding to step 615, the discharge flow rate qdrain is determined based on the wheel cylinder pressure Pw acquired by one of the well-known methods 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 open pressure reducing valve PD, it can be obtained as a function of the wheel cylinder pressure Pw in this way. 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 during linear pressure increase control, refer to times t1 ′ to t2, t2 ′ to t3, t3 ′ to t4, etc. in FIG. 10) The CPU 51 makes a “No” determination at step 610 to proceed to step 620, and sets the discharge flow rate 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 625 to set the discharge flow rate qpump of the hydraulic pumps HPf, HPr, the current target rotational speed NEt, the master cylinder pressure estimated value Pm, and the table Mapqpump using NEt, Pm as arguments. , Based on. The discharge flow rate qpump 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. Therefore, the discharge flow rate qpump can be obtained based on the target rotational speed NEt and the master cylinder pressure estimated value Pm in this way.

  Next, the CPU 51 proceeds to step 630 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 “qpump · Δt” is sucked from the reservoir to the hydraulic pumps HPf and HPr per program execution cycle Δt. This corresponds to the amount of brake fluid applied.

ΔQ = qdrain · Δt−qpump · Δt (1)

  Next, the CPU 51 proceeds to step 635 to set the reservoir fluid amount estimated value Q to the initial value “0” in step 545 immediately after the value at that time (at the start of ABS control (that is, at the start of motor control)). Is updated by adding the obtained change amount ΔQ.

  Subsequently, the CPU 51 proceeds to step 640 to determine whether or not the updated reservoir fluid amount estimated value Q is negative. When determining “Yes”, the CPU 51 determines the reservoir fluid amount estimated value Q in step 645. Reset to “0”. On the other hand, if the CPU 51 makes a “No” determination at step 640, it proceeds to step 650, determines whether or not the reservoir fluid amount estimated value Q is larger than the maximum reservoir fluid amount Qfull, and determines “Yes”. In step 655, the estimated reservoir fluid amount Q is reset to the maximum reservoir fluid amount Qfull. By these processes, the guard liquid amount estimated value Q is guarded to a value not less than “0” and not more than the value Qfull. Then, the CPU 71 proceeds to step 695 to end the present routine tentatively.

  On the other hand, if the CPU 51 determines “No” in step 650 (ie, 0 <Q <Qfull), the CPU 51 immediately proceeds to step 695 without resetting the reservoir fluid amount estimated value Q.

  Thus, by repeatedly executing the routine of FIG. 6, the reservoir fluid amount estimated value Q (0 <Q <Qfull) is sucked by the flow rate of the brake fluid discharged from the pressure reducing valve PD and the hydraulic pumps HPf and HPr. It is updated every time the program execution cycle Δt elapses based on the flow rate of the brake fluid. As a result, as shown in FIG. 10, the estimated reservoir fluid amount Q increases during the pressure reduction control (time t1 to t1 ′, time t2 to t2 ′, etc.) due to the relationship of qdrain> qpump. During the holding control or the linear pressure increasing control (time t1 ′ to t2, t2 ′ to t3, etc.), since qdrain = 0 is maintained, it decreases according to the discharge flow rate qpump. Thus, the means for acquiring the reservoir fluid amount estimated value Q corresponds to the acquisition means.

  Further, the CPU 51 repeatedly executes the routine for updating the motor rotation speed shown in FIG. 7 every elapse of a predetermined time following the routine of FIG. Therefore, when the predetermined timing comes, the CPU 51 starts processing from step 700 and proceeds to step 705 to determine whether or not the value of the flag DRIVE is “1”. Proceed to 795 to end the present routine tentatively.

  Assuming that motor control is being executed (see time t1 and thereafter in FIG. 10), the flag DRIVE = 1 (step 525) as described above. Accordingly, the CPU 51 makes a “Yes” determination at step 705 to proceed to step 710, where the linear pressure increase control end point (ie, the start point of the next control cycle (decompression control)) based on the slip ratio of the wheel. ), Whether or not the update timing of the target rotational speed NEt of the motor MT has come, and if “No” is determined, the process immediately proceeds to step 795. That is, in this example, the update timing is set to the end point of the linear pressure increase control (that is, the start point of the next control cycle (decompression control)). FIG. 10 corresponds to times t2, t3, and t4.

  Assuming that the update timing of the target rotational speed NEt has arrived, the CPU 51 determines “Yes” in step 710 and proceeds to step 715 to set the value Qc to the current reservoir fluid amount estimated value Q. That is, as described above, the value Qc is the reservoir fluid amount estimated value Q that is obtained every time the pressure increase control end time comes (see times t2, t3, and t4 in FIG. 10).

  Subsequently, the CPU 51 proceeds to step 720 and sets the value R to a value (Qc / Qcb). Here, as described above, the value Qcb is the previous value of the value Qc (the value Qc at the previous update timing), and the initial value of the value Qcb is set to the value Q0 in the previous step 550. Thereafter, the value Qcb is updated to the value Qc at that time every time the update timing comes in step 740 described later. Therefore, the current value R is a value representing an increasing / decreasing tendency of the reservoir fluid amount estimated value Q between the previous update timing and the current update timing.

  Next, the CPU 51 proceeds to step 725 to determine whether or not R ≧ 1 (that is, whether or not the reservoir fluid amount estimated value Q tends to increase). Hereinafter, first, the case where it is determined as “Yes” in Step 725 (that is, the case where the reservoir fluid amount estimated value Q tends to increase) will be described. FIG. 10 corresponds to times t2 and t4.

  In this case, the CPU 51 proceeds to step 730, and determines an increase amount NEup (≧ 0) by updating the target rotational speed NEt based on the value R and the table MapNEup shown in FIG. Accordingly, the value NEup is set to “0” when the value R = 1, and is set to a larger value as the value R (≧ 1) is larger. In other words, the increase amount NEup is set to a larger value as the degree of the increasing tendency of the reservoir fluid amount estimation value Q is larger. Subsequently, the CPU 51 proceeds to step 735 and updates the target rotational speed NEt by adding the increase amount NEup to the current target rotational speed NEt.

  Next, a case where it is determined “No” in step 725 (that is, a case where the reservoir fluid amount estimated value Q tends to decrease) will be described. In FIG. 10, it corresponds to time t3. In this case, the CPU 51 proceeds to step 745 and determines a decrease amount NEdown (≧ 0) due to the update of the target rotational speed NEt based on the value R and the table MapNEdown shown in FIG.

  Thereby, the value NEdown is set to a larger value as the value R (0 ≦ R <1) is smaller. In other words, the greater the degree of the decreasing tendency of the reservoir fluid amount estimated value Q, the larger the decrease amount NEdown is set. Subsequently, the CPU 51 proceeds to step 750, and updates the target rotational speed NEt by subtracting the decrease NEdown from the current target rotational speed NEt.

  Then, the CPU 51 proceeds to step 740 to update the previous value Qcb of the value Qc to the value Qc at that time as described above, and proceeds to step 795 to end this routine once. The routine in FIG. 7 (and steps 535 and 540 in FIG. 5) corresponds to the determination unit.

  As described above, according to the ABS control motor control apparatus according to the embodiment of the present invention, during the ABS control, the (average) rotational speed NE of the motor MT is controlled to coincide with the target rotational speed NEt. Is done. The initial value NEini of the target rotational speed NEt (value at the start of ABS control, see time t1 in FIG. 10) is the reservoir fluid amount during ABS control based on the vehicle deceleration DVso at the start of ABS control. Is determined so as to shift within a range larger than “0” and smaller than the maximum reservoir fluid amount Qfull.

  During the ABS control, each time the update timing of the target rotational speed NEt arrives (when the linear pressure-increasing control ends), it is determined whether the reservoir fluid amount estimated value Q tends to increase or decrease. Then, when the reservoir fluid amount estimation value Q tends to increase (R ≧ 1) (see times t2 and t4 in FIG. 10), that is, the discharge flow rates of the hydraulic pumps HPf and HPr (accordingly, the rotation of the motor MT). If the (speed) is insufficient, the target rotational speed NEt is updated to a larger value. Therefore, the decreasing gradient of the reservoir fluid amount (reservoir fluid amount estimated value Q) after time t2 ′ to t3 and time t4 ′ is the reservoir fluid amount (reservoir amount at time t1 ′ to t2 and time t3 ′ to t4). Each is larger than the decreasing gradient of the estimated liquid amount Q). As a result, the occurrence of a situation in which the reservoir fluid amount reaches the maximum reservoir fluid amount Qfull during the ABS control due to the initial value NEini being estimated to be smaller can be suppressed.

  On the other hand, when the reservoir fluid amount estimation value Q tends to decrease (R <1) (see time t3 in FIG. 10), that is, the discharge flow rates of the hydraulic pumps HPf and HPr (accordingly, the rotational speed of the motor MT). Is excessive, the target rotational speed NEt is updated to a smaller value. Therefore, the decreasing gradient of the reservoir fluid amount (reservoir fluid amount estimated value Q) at times t3 'to t4 is smaller than the decreasing gradient of the reservoir fluid amount (reservoir fluid amount estimated value Q) at times t2' to t3. As a result, the occurrence of a situation in which the reservoir fluid amount reaches “0” during the ABS control due to the initial value NEini being estimated to be large can be suppressed.

  In addition, even if the reservoir fluid amount estimate value Q includes an estimation error, the change tendency (increase / decrease direction) of the reservoir fluid amount estimate value Q is not easily affected by the estimation error, and the reservoir fluid amount estimate The change trend of the value Q (increase / decrease direction) tends to coincide with the actual change tendency (increase / decrease direction) of the reservoir fluid amount. As a result, the target rotational speed NEt is updated based on the reservoir fluid amount estimation value Q so that the reservoir fluid amount estimation value Q itself changes between “0” and the maximum reservoir fluid amount Qfull. Thus, by updating the target rotational speed NEt of the motor MT based on the changing tendency of the reservoir fluid amount estimated value Q as in this example, the actual reservoir fluid amount is made larger than “0” with higher accuracy. The rotational speed of the motor MT can be controlled so as to shift within a range smaller than the maximum reservoir fluid amount Qfull.

  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 embodiment described above, the target rotational speed NEt of the motor MT itself is used as the “value corresponding to the target rotational speed of the motor”, but the target discharge flow rates of the hydraulic pumps HPf and HPr are used. May be.

  In the above embodiment, the value R (= Qc / Qcb), that is, the ratio of the current value to the previous value of the value Qc is used to acquire the change tendency of the reservoir fluid amount estimated value Q. A value S (= Qc−Qcb) obtained by subtracting the previous value from the current value of the value Qc may be used. In this case, it can be determined that the reservoir fluid amount estimated value Q tends to increase when S ≧ 0, and the reservoir fluid amount estimated value Q tends to decrease when S <0.

  In the above embodiment, the end point of the linear pressure increase control is adopted as the “predetermined timing” for determining whether the reservoir fluid amount estimation value Q is increasing or decreasing. The end point of the pressure reduction control (that is, the start point of the holding control) or the end point of the holding control (that is, the starting point of the linear pressure increase control) may be used. Further, as the “predetermined timing”, a time point at which a predetermined time (a predetermined time) elapses after the start of the ABS control may be employed.

  In the above embodiment, the voltage threshold Von is controlled to control the rotational speed of the motor MT, but the on-time Ton may be controlled to control the rotational speed of the motor MT. Further, both the voltage threshold Von and the on time Ton may be controlled in order to control the rotation speed of the motor MT.

  In the above embodiment, the initial value NEini of the target rotational speed NEt is determined based on the vehicle body deceleration Vso. However, the initial value NEini of the target rotational speed NEt may be determined based on the road surface friction coefficient. .

  In addition, in the above embodiment, the target rotational speed NEt is updated based on whether the estimated reservoir fluid amount Q is increasing or decreasing. The target rotation speed NEt may be updated based on the increasing gradient of the quantity estimated value Q. In this case, the routine shown in the flowchart of FIG. 11 is executed instead of the routine of FIG. In the routine of FIG. 11, the same step number as the step number of FIG. 7 is assigned to the same step as the step of the routine of FIG.

  The routine shown in FIG. 11 differs from the routine shown in FIG. 7 only in that steps 715 and 720 in FIG. 7 are replaced with steps 1105 and 1110. Only differences from the routine of FIG. 7 will be described below. In the routine of FIG. 11, the “update timing” in step 710 is set at the end of the pressure reduction control.

  In step 1105, the increasing gradient grad of the reservoir fluid amount estimated value Q during the current decompression control is calculated. This increase gradient grad may be calculated from, for example, two reservoir fluid amount estimation values Q at the current decompression control start time and the decompression control end time, or a plurality of (three or more) times during the current decompression control. May be calculated based on the reservoir fluid amount estimation value Q.

  In step 1110, the value R is set to a value (grad / gradref). The value gradref (corresponding to the reference value) is, for example, a reservoir fluid during pressure reduction control that is necessary for the reservoir fluid amount to change within a range larger than “0” and smaller than the maximum reservoir fluid amount Qfull during ABS control. It is the optimum value (reference value) of the increase gradient of the quantity, and can be determined based on the vehicle body deceleration DVso.

  As a result, when the increasing gradient grad of the current decompression control is greater than or equal to the reference value gradref, R ≧ 1. In this case, steps 730 and 735 are executed and the target rotational speed NEt is updated to a larger value. These processes are based on the fact that the increasing gradient grad is larger than the reference value gradref means that the discharge flow rates of the hydraulic pumps HPf and HPr (and hence the rotational speed of the motor MT) are insufficient. .

  On the other hand, when the increasing gradient grad is less than the reference value gradref, R <1. In this case, steps 745 and 750 are executed, and the target rotational speed NEt is updated to a smaller value. These processes are based on the fact that the increasing gradient grad is smaller than the reference value gradref means that the discharge flow rates of the hydraulic pumps HPf and HPr (and hence the rotational speed of the motor MT) are excessive.

  Even with this configuration, the target rotational speed NEt of the motor can be appropriately updated so that the actual reservoir fluid amount changes within a range larger than “0” and smaller than the maximum reservoir fluid amount Qfull.

1 is a schematic configuration diagram of a vehicle equipped with an ABS control device for a vehicle including a control device for an ABS control motor 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 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. 3 is a flowchart illustrating a routine for performing start / end determination of motor control executed by a CPU illustrated in FIG. 1. 3 is a flowchart showing a routine for calculating a reservoir fluid amount executed by a CPU shown in FIG. 1. 3 is a flowchart showing a routine for updating a motor rotation speed executed by a CPU shown in FIG. 1. 3 is a graph showing a table that defines a relationship between a value indicating a change tendency of an estimated reservoir fluid amount and an increase amount due to an update of a target rotation speed of a motor, which is referred to by a CPU shown in FIG. 1. 2 is a graph showing a table that defines a relationship between a value indicating a change tendency of an estimated reservoir fluid amount and a decrease amount due to an update of a target rotation speed of a motor, which is referred to by a CPU shown in FIG. 1. It is the time chart which showed an example in case the target rotational speed of a motor is updated according to the change tendency of a reservoir fluid amount estimated value by embodiment of this invention. It is the flowchart which showed the routine for updating the motor rotational speed which CPU of the control apparatus of the ABS control motor which concerns on the modification of embodiment of this invention performs. It is the time chart which showed an example in case the rotational speed of a motor is controlled so that the amount of reservoir fluid which increases by pressure reduction control may become zero in the stage before the next pressure reduction control start time.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... ABS control apparatus of a 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 (12)

This is applied to an anti-skid control device (51, 30) for performing anti-skid control for reducing pressure to reduce the wheel cylinder pressure of the vehicle wheel when there is a tendency to lock, and the reservoir (RSf, The control device for the motor for anti-skid control that controls the rotational speed of the motor (MT) that drives the pump (HPf, HPr) that discharges the brake fluid discharged to the RSr) into the hydraulic circuit of the anti-skid control device Because
Acquisition means (51, routine of FIG. 6) for acquiring an estimated value (Q) of a reservoir fluid amount that is a brake fluid amount in the reservoir during the anti-skid control;
Based on the estimated reservoir fluid amount acquired by the acquisition means, the brake fluid amount in the reservoir is changed within a range that is larger than zero and smaller than the maximum amount (Qfull) of brake fluid that can be stored in the reservoir. Determining means (51, 535, 540, routines in FIGS. 7 and 11) for determining a value (NEt) corresponding to the target rotational speed of the motor,
Control means (51, 560) for controlling the rotational speed of the motor during the anti-skid control based on the target rotational speed equivalent value (NEt) determined by the determining means;
A control device for a motor for anti-skid control comprising: In the control apparatus of the motor for anti-skid control of Claim 1,
The determining means includes
Control of an anti-skid control motor configured to set the value corresponding to the target rotational speed at the same point based on the vehicle body deceleration (DVso) of the vehicle at the start of the anti-skid control (535, 540) apparatus. In the control device for the anti-skid control motor according to claim 1 or 2,
The determining means includes
An anti-skid control motor control device configured to update the target rotational speed equivalent value based on a change tendency (R) of the reservoir fluid amount estimated value (routine of FIG. 7). In the control apparatus of the motor for anti-skid control of Claim 3,
The determining means includes
A control device for an anti-skid control motor configured to update the target rotation speed equivalent value to a larger value (730, 735) when the reservoir fluid amount estimated value tends to increase. In the anti-skid control motor control device according to claim 4,
The determining means includes
When the current value of the estimated reservoir fluid amount (Qc) obtained each time a predetermined timing arrives is greater than the previous value, the target rotational speed equivalent value is updated to a larger value. Control device for motor for anti-skid control. In the control device of the motor for anti-skid control according to claim 4 or 5,
The determining means includes
The anti-skid control motor configured to set the increase amount (NEup) due to the update of the target rotation speed equivalent value to a larger value (730) as the degree of the increase tendency of the estimated reservoir fluid amount increases. Control device. In the control apparatus of the motor for anti-skid control of Claim 3,
The determining means includes
The anti-skid control motor control device configured to update the target rotation speed equivalent value to a smaller value (745, 750) when the estimated reservoir fluid amount tends to decrease. The anti-skid control motor control device according to claim 7,
The determining means includes
When the current value of the estimated reservoir fluid amount (Qc) obtained each time a predetermined timing arrives is smaller than the previous value, the target rotational speed equivalent value is updated to a smaller value. Control device for motor for anti-skid control. In the control device for the motor for anti-skid control according to claim 7 or 8,
The determining means includes
The anti-skid control motor configured to set the amount of decrease (NEdown) due to the update of the target rotation speed equivalent value to a larger value (745) as the degree of the decrease tendency of the estimated reservoir fluid amount increases. Control device. In the control device for the anti-skid control motor according to claim 1 or 2,
The determining means includes
A control device for an anti-skid control motor configured to update the value corresponding to the target rotational speed based on an increasing gradient (grad) of the estimated reservoir fluid amount during the pressure reduction control (routine of FIG. 11) . The anti-skid control motor control device according to claim 10,
The determining means includes
When the increase gradient (grad) of the estimated reservoir fluid amount during the pressure reduction control is larger than the reference value (gradref), the target rotational speed equivalent value is updated to a larger value (730, 735). Anti-skid control motor control device. The anti-skid control motor control device according to claim 10,
The determining means includes
When the increase gradient (grad) of the estimated reservoir fluid amount during the pressure reduction control is smaller than the reference value (gradref), the target rotational speed equivalent value is updated to a smaller value (745, 750). Anti-skid control motor control device.

Images