JP2001287630A - Brake controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly learn a dead zone width in a solenoid valve even when increase and decrease of pressure are repeated to compensate a shifted amount by feedback control when the dead zone width is shifted from an initial learnt value. SOLUTION: In this brake controller provided with a dead zone width learning means e for learning the dead zone width of the solenoid valve based on a current command value when a current for electrifying the solenoid valve is gradually increased and when a prescribed change is generated in a measured pressure value of a braking fluid, an initialization means f is provided to initialize an internal variable of a hydraulic feedback control operation means c when a brake fluid pressure command value changes first by a prescribed degree after the command value is kept within a prescribed range during a prescribed time, and the dead zone width learning means e is synchronized with the initialization by the initialization means f to serve as the means for learning the dead zone of the solenoid valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake control device for a vehicle applied to a regenerative cooperative brake control system for efficiently recovering regenerative energy by controlling a brake oil pressure while controlling a regenerative brake torque. .

[0002]

2. Description of the Related Art A conventional vehicle brake control device is disclosed in Japanese Patent Application Laid-Open No. 9-254758.

In this method, a driver's deceleration request amount is calculated from an operation amount of a brake operation member, a brake oil pressure command value is determined so that an actual vehicle deceleration coincides with the deceleration request amount. The current of the electromagnetic solenoid valve is feedback-controlled so that the oil pressure matches the command value. This solenoid valve is
It is connected to an accumulator (a high pressure is secured by a pump) and a reservoir tank (a low pressure). The hydraulic pressure is adjusted to a level necessary to suppress wheel rotation, and is supplied to a wheel cylinder. The electromagnetic solenoid valve includes a case where the pressure increasing valve and the pressure reducing valve are composed of two, and a case where a pressure increasing / decreasing valve that integrates their functions into one is used.

However, in such a conventional apparatus, the dead zone of the flow rate characteristic with respect to the current value, which the electromagnetic solenoid valve has, greatly affects the transient characteristic of the hydraulic control. Generally, an electromagnetic solenoid valve has a dead zone characteristic that, unless a certain amount of current flows, the valve does not open and oil does not actually flow due to a relationship between a spring force, an electromagnetic force, and a fluid force. In particular, the inexpensive and compact solenoid valve tends to have a larger dead zone (see FIG. 8).

[0005] Even if a hydraulic feedback control system that measures the actual wheel cylinder pressure with a pressure sensor, compares it with a hydraulic command value, and controls the current value of the solenoid valve, there is a dead zone as described above. When the control is reversed from pressure increase to pressure decrease and pressure decrease to pressure increase, the oil actually flows until the current command value of the solenoid valve is integrated to a value exceeding the dead zone due to the integral characteristics of the feedback controller. And the oil pressure does not follow the command value at all. That is, in the hydraulic feedback control system, an unnecessary dead time occurs when the hydraulic pressure command value is inverted.

[0006] This is because an electromagnetic solenoid valve is an O solenoid valve.
Problems commonly occurring when an N / OFF-type solenoid valve (current / flow characteristics are steep) or when a proportional solenoid valve (current / flow characteristics are relatively gentle) is used. It is.

In order to solve the above problems, the present applicant has proposed a vehicle brake control device described in Japanese Patent Application Laid-Open No. 2000-071959.

This prior art publication discloses a vehicle brake control device that performs feedback control of a wheel cylinder pressure by using an electromagnetic solenoid valve that opens in proportion to the current and changes the amount of brake oil. The dead zone width at which the solenoid valve opens for the first time is learned from the current command value of the solenoid valve and the wheel cylinder pressure, and after learning, the offset is corrected so that the wheel cylinder command pressure and the actual wheel cylinder It has the feature that the pressures are quickly matched.

[0009]

However, in the above-described conventional vehicle brake control device, the current supplied to the electromagnetic solenoid valve is gradually increased, and the wheel cylinder pressure changes by a predetermined amount. The dead zone width is learned from the current command value at that time, and after learning, the offset is corrected.By continuing to energize the electromagnetic solenoid valve, the solenoid characteristics change over time, and the dead zone is changed. If the width deviates from the first learning value, the deviation is compensated by feedback control (time t3 to t in FIG. 9).
4) Therefore, the wheel cylinder pressure does not become uncontrollable.
However, during this time, while the pressure increase / decrease is repeated, the dead band width of the pressure increase / decrease valve is continuously corrected by the feedback control. Therefore, in the next learning of the dead band width, the one-side valve (the pressure increase valve at time t4 in FIG. 9) When the valve is not completely closed, the current command value of the learned valve (the pressure reducing valve at time t4 in FIG. 9) is erroneously learned as the dead zone width (time t4 in FIG. 9).

The present invention has been made in view of such a conventional problem. When the dead zone width of the electromagnetic solenoid valve deviates from the initial learning value, the feedback control compensates for the deviation and increases / decreases the pressure. It is an object of the present invention to provide a vehicle brake control device capable of correctly learning a dead zone width even when repeated.

[0011]

In order to achieve the above object, according to the present invention, the hydraulic pressure acting on the brake for suppressing the rotation of the wheel is determined based on the amount of operation of the brake operating member by the driver. A brake oil pressure command value calculating means for calculating a command value, a brake oil pressure measuring means for measuring an actual oil pressure value acting on a brake for suppressing the rotation of the wheel, and a brake oil pressure measured value being made coincident with the brake oil pressure command value. In order to calculate the current command value to the electromagnetic solenoid valve by inputting both values, an electromagnetic solenoid valve current for performing current control on the electromagnetic solenoid valve based on the calculated current command value The control means gradually increases the current flowing through the electromagnetic solenoid valve, and changes the brake oil pressure measured value by a predetermined amount. A dead zone width learning means for learning a dead zone width of the electromagnetic solenoid valve based on the current command value at the time of occurrence, and using the learned dead zone width as an offset correction value of the current command value for current control of the electromagnetic solenoid valve. In the vehicle brake control device, when the brake oil pressure command value stays within a predetermined range for a predetermined time and then changes by a predetermined amount for the first time, initialization means for initializing an internal variable of the hydraulic feedback control calculation means is provided. The dead band width learning means is characterized in that it is means for learning a dead band width of the electromagnetic solenoid valve in synchronization with the initialization by the initialization means.

According to a second aspect of the present invention, in the vehicle brake control device according to the first aspect, the dead zone width learning means is configured to perform initialization by the initialization means at the first learning immediately after the start of brake control. Is a means for learning the dead zone width of the electromagnetic solenoid valve independently.

[0013]

According to the first aspect of the present invention, in the brake oil pressure command value calculating means, the hydraulic pressure acting on the brake for suppressing the rotation of the wheel is determined based on the operation amount of the brake operating member by the driver. Is calculated, the actual value of the hydraulic pressure acting on the brake for suppressing the rotation of the wheel is measured by the brake hydraulic pressure measuring means, and the brake hydraulic pressure command value is matched with the brake hydraulic pressure command value by the hydraulic feedback control calculating means. Therefore, by inputting both values, the current command value to the electromagnetic solenoid valve is calculated, and the current control for the electromagnetic solenoid valve is performed by the electromagnetic solenoid valve current control means based on the calculated current command value. In this feedback control, the dead zone width learning means gradually increases the current supplied to the electromagnetic solenoid valve, and based on the current command value when the brake oil pressure measurement value changes by a predetermined amount, the dead zone of the electromagnetic solenoid valve is determined. The width is learned, and the learned and stored dead band width is used for the current control of the electromagnetic solenoid valve as the offset correction value of the current command value. On the other hand, when the initializing means changes by a predetermined amount for the first time after the brake oil pressure command value stays within the predetermined range for a predetermined time, the internal variable of the hydraulic feedback control calculating means is initialized. Therefore, the dead zone width learning means learns the dead zone width of the electromagnetic solenoid valve in synchronization with the initialization by the initialization means. Therefore, by continuing to energize the electromagnetic solenoid valve, the solenoid characteristics change over time, and when the dead zone width deviates from the first learning, even if feedback control compensates for the deviation and repeats increasing and decreasing pressure, feedback Since the learning is performed in synchronization with the control initialization, there is an effect that the dead zone width can be correctly learned.

According to the second aspect of the present invention, in the dead zone width learning means, at the first learning immediately after the start of the brake control, the dead zone width of the electromagnetic solenoid valve is learned independently of the initialization by the initialization means. Is done. In other words, if the initialization of the dead zone width always includes the initialization by the initialization means, the dead zone width of the electromagnetic solenoid valve cannot be learned at the first opportunity immediately after the start of the brake control. On the other hand, at the time of the first learning immediately after the start of the brake control, by making it unrelated to the initialization, there is an effect that the dead zone width of the electromagnetic solenoid valve can be learned at the first opportunity immediately after the start of the brake control.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual diagram showing a vehicle brake control device according to the present invention.
b is a brake oil pressure measuring means, c is a hydraulic feedback control calculating means, d is an electromagnetic solenoid valve current controlling means,
e is a dead zone width learning means, and f is an initialization means. In the dead zone width learning means e, the dead zone of the electromagnetic solenoid valve is synchronized with the initialization by the initialization means except for the first learning immediately after the start of the brake control. By learning the width, when the dead zone width deviates from the initial learning, the dead zone width can be correctly learned even if feedback control compensates for the deviation and repeats increasing and decreasing.

FIG. 2 is an overall system diagram showing a vehicle brake control device according to an embodiment of the present invention. This is the application of the vehicle brake control device of the present invention to a "regenerative cooperative brake control system" that efficiently recovers regenerative energy by controlling the brake oil pressure under pressure during regenerative brake torque control by an AC synchronous motor. Things.

To explain the structure, reference numeral 1 denotes a brake pedal operated by a driver, which is connected to a hydraulic booster 2, a master cylinder 3 and a master cylinder (hereinafter, the master cylinder is referred to as M / CYL). The hydraulic booster 2 uses the high pressure (sequence controlled by the pressure switch 21) accumulated in the accumulator 19 by the pump 18,
The brake pressure is boosted and supplied to M / CYL3. Also,
This high pressure is also used as a source pressure for hydraulic feedback control. Numerals 4 and 5 are oil path switching valves, and both valves are controlled in synchronization. The figure shows the state when power is not supplied.
The oil of CYL3 is supplied to the wheel cylinder 7 as it is (normal mode).

At the time of energization, M / CYL3 has 6 stroke simulators (oil load equivalent to wheel cylinder 7).
To ensure the same brake pedal feeling as in the normal mode. At the same time, the wheel cylinder 7 (hereinafter, the wheel cylinder is referred to as W / CYL) is connected to the solenoid valves 10 and 11 for hydraulic control, and is disconnected from the M / CYL3.

Reference numeral 10 denotes a pressure increasing valve which is located between the high pressure line and the W / CYL 7 and adjusts an amount of oil flowing into the W / CYL 7. 11 is a pressure reducing valve, W / C
W / CY located between YL7 and reservoir (low pressure)
Adjust the amount of oil flowing out of L7. The hydraulic pressure of W / CYL 7 is controlled using one set of solenoid valves 10 and 11.

Reference numeral 8 denotes an M / CYL pressure sensor for measuring an M / CYL pressure (a required amount of braking by a driver). 9 is W /
W / C to measure CYL pressure (for feedback control)
YL pressure sensor. Reference numeral 20 denotes a source pressure sensor that measures an accumulator pressure (source pressure).

Reference numeral 12 denotes a brake control controller, which includes a CPU, a ROM, a RAM, a digital port, an A / D
It is composed of a one-chip microcomputer (or a plurality of chips realizing the same function) with built-in ports and various timer functions, a circuit for high-speed communication, and a circuit for driving each actuator. The respective functions of the means shown are performed by the brake control controller 12. FIG. 2 shows the W / C for one wheel.
Although the configuration relating to YL7 is shown, the other three wheels have the same configuration and are not shown.

Reference numeral 15 denotes an AC synchronous motor connected to the drive wheels 16 of the vehicle via a speed reduction mechanism. The AC synchronous motor performs drive torque control and recovery of vehicle kinetic energy to the battery 17 by regenerative brake control. Reference numeral 14 denotes a DC / AC conversion current control circuit, which is located between the DC battery and the AC synchronous motor 15 and is configured to generate an AC / DC current based on a three-phase PWM signal from the motor controller 13. Perform the conversion. The motor control controller 13
The regenerative brake torque is controlled based on the regenerative brake torque command value received by communication from the second brake controller. At the time of driving, drive torque control by the AC synchronous motor 15 is performed. In addition, battery 1
Calculates the maximum allowable regenerative torque value that can be determined by the state of charge, temperature, etc. of the control unit 7, and communicates with the brake controller 1 via communication.
Send to 2.

FIGS. 3, 4 and 5 are flowcharts showing the control operation performed by the microcomputer of the brake control controller 12. The routine shown in FIG.
ec). (K) is the current calculation, (kn)
Means the operation n times before.

In S10, the signals of the M / CYL pressure sensor 8, the W / CYL pressure sensor 9, and the original pressure sensor 20 are measured using an A / D converter built in the microcomputer, and converted into predetermined physical units. M / CYL pressure Pmc (k) and W / CYL pressure Pwc
(k) and the original pressure Pline (k) are calculated.

In S20, the motor control controller 13
The maximum permissible regenerative motor torque Tmmax (k) is read from the high-speed communication reception buffer.

In S30, a driver braking torque request value Tbdem (k) is calculated from the following equation using the M / CYL pressure Pmc (k) and the vehicle specification constant K1 stored in the ROM in advance. Tbdem (k) = Pmc (k) × Constant K1 Constant K1 = W / CYL area × Brake pad area × Brake rotor effective radius × Brake friction coefficient

In S40, it is determined whether or not the regenerative cooperative brake control is to be performed. If the following equation is satisfied, the process proceeds to S50; otherwise, the process proceeds to S310. M / CYL pressure Pmc (k) ≧ constant K2 and maximum allowable regenerative motor torque Tmmax (k) ≧ constant K3

First, the case where the regenerative cooperative brake control is not performed will be described. S310 is an output process performed when the regenerative cooperative brake control is stopped (that is, when the hydraulic feedback control is stopped). A port output is performed so that the oil path switching valves 4 and 5 are set to the normal mode, and a D / A output for outputting each current command value (= 0) of the pressure increasing valve 10 and the pressure reducing valve 11 to each current control circuit. And a transmission process for transmitting the regenerative motor torque command value (= 0) to the motor control controller 13 using high-speed communication. One control routine ends.

The following is an explanation of the case where regenerative cooperative brake control is performed. In S50, the driver braking torque request value T
bdem (k) is distributed to the hydraulic brake torque command value Tbcom (k) and the regenerative brake torque command value Tmcom (k). When Tbdem (k) ≧ Tmmax (k) Tbcom (k) = Tbdem (k) −Tmmax (k), Tmcom (k) = Tmmax
(k) When Tbdem (k) <Tmmax (k) Tbcom (k) = 0, Tmcom (k) = Tbdem (k) Further, the hydraulic brake torque command value Tbcom (k) and the vehicle specification constant K1 are used. Then, the brake hydraulic pressure command value Pcom (k) is calculated. Pcom (k) = Tbcom (k) ÷ Constant K1 Constant K1 = W / CYL area × Brake pad area × Brake rotor effective radius × Brake friction coefficient

At S60, the difference ブ レ ー キ of the brake oil pressure command value
Pcom (k) is calculated, and the process proceeds to S70. △ Pcom (k) = Pcom (k) -Pcom (k-1)

In S70, it is determined whether or not a predetermined change has occurred in the brake oil pressure command value. ΔPcom (k) ≦ predetermined value K1
If it is 0, the process proceeds to S80. Otherwise, proceed to S90.

At S80, assuming that there is no predetermined change in the brake oil pressure command value, the time measurement counter CNT1 is incremented (CNT1 (k)) to measure the elapsed time.
= CNT1 (k-1) +1), and the process proceeds to S120.

At S90, assuming that there is a predetermined change in the brake oil pressure command value, the elapsed time is checked. CNT1
If (k)> predetermined time K11, the process proceeds to S100. Otherwise, proceed to S110.

In S100, it is determined that the brake oil pressure command value has started for the first time after a state in which the brake oil pressure command value has not been changed for a predetermined time, and initialization of internal variables of the feedback compensator and dead zone of the proportional valve are performed. Need learning. CNT1 (k) = 0, FRESET = 1, F
STUDY = 1. Proceed to S120.

In step S110, it is determined that the state in which the brake oil pressure command value has not been changed for a predetermined time does not continue for a predetermined time, and the brake oil pressure command value has started to move, so that the internal variables of the feedback compensator are initialized and the dead zone of the proportional valve is learned. Do not need. CNT1 (k) = 0. Proceed to S120.

In S120, an initialization flag is determined.
When FRESET = 1, the process proceeds to S130. FREESE
If T = 0, proceed to S140.

In step S130, the internal variables of the feedback compensator and the initialization flag are initialized. Xr (k) = 0,
Xf (k) = 0, Xμ (k) = 0, FRESET = 0. S14
Go to 0.

In S140 to S170, as shown in FIG. 6, the operation of the hydraulic control compensator using the known “two-degree-of-freedom control structure” and “μ synthesis” is performed. Note that the internal variable X
The initial values of r (0), Xf (0), and Xμ (0) are all set to zero.

In S140, the reference model W / C pressure Pref (k) is calculated using the target W / C pressure Pcom (k) as an input.
Equation (1) is a discrete-time state equation, and (k + 1) indicates a value after one sample period. Xr (k) is a variable vector, Ar,
Br, Cr, and Dr indicate constant matrices stored in the ROM in advance. Proceed to S150. Xr (k + 1) = Ar.Xr (k) + Br.Pcom (k) (1) Pref (k) = Cr.Xr (k) + Dr.Pcom (k)

In S150, the feed-forward compensator (= reference model / plant model) is calculated by using the target W / C pressure Pcom (k) as an input. Proceed to S160. Xf (k + 1) = Af.Xf (k) + Bf.Pcom (k) (2) Icom_ff (k) = Cf.Xf (k) + Df.Pcom (k)

In S160, the reference model W / C pressure Pref
Feedback compensator (designed in advance using μ-synthesis) using the deviation ΔPwc (k) of (k) and the W / C pressure Pwc (k) as an input
Is calculated. Proceed to S170. ΔPwc (k) = Pref (k) −Pwc (k) (3) Xμ (k + 1) = Aμ × Xμ (k) + Bμ ・ Pwc (k) Icom_fb (k) = Cμ × Xμ (k) + Dμ・ Pwc (k)

At S170, the output Icom_ff (k) of the feedforward compensator and the output Icom_com
After adding _fb (k), the electromagnetic valve current command value Icom (k) is calculated by limiting the upper and lower limits (± Imax). S18
Go to 0. Icom (k) = Icom_ff (k) + Icom_fb (k)

In step S180, in order to eliminate the influence of the difference in the flow rate characteristic of the electromagnetic valve due to the differential pressure, a correction coefficient corresponding to the differential pressure is tabulated from the table data for each of the pressure-increasing and decreasing electromagnetic valves 10, 11. calculate. Note that the constant Pcom_
atm corresponds to atmospheric pressure. Proceed to S190. K_in (k) = TABLE_in (Pline (k) −Pwc (k)) K_out (k) = TABLE_out (Pwc (k) −Pcom_atm)

In S190, a learning flag is determined. F
If STUDY = 1, proceed to S200. FSTUD
If Y = 0, proceed to S210. At the learning opportunity after the start of the control, the initial value of the learning flag is set to FST so that the learning can be performed without synchronization with the initialization of the feedback control.
UDY (0) = 1 is set.

First, the processing at the time of non-learning will be described. S21
0, the dead zones of the pressure increasing and reducing valves 10 and 11 (FIG. 8)
Offset value OFFSET_in (k), O
Using FFSET_out (k), the current command values I_in (k) and I_out (k) for the pressure increasing and pressure reducing valves are offset-corrected.
In addition, in order to respond before learning the dead zone width,
In SET_in (0) and OFFSET_out (0), representative values of the dead zones of the pressure increasing and reducing valves 10 and 11 are set to initial values. Proceed to S240, I_in (k) = OFFSET_in (k) + Icom (k) · K_in (k) where 0 ≦ I_in ≦ constant K4 I_out (k) = OFFSET_out (k) + Icom (k) · K_out
(k) where 0 ≦ I_out ≦ constant K5 The constant K4 is a current value for obtaining the maximum flow rate of the pressure-intensifying valve 10, and the constant K5 is a current value for obtaining the maximum flow rate of the lower summer valve 11.

S240 is an output process performed during the regenerative cooperative brake control. In order to output the ports so that the oil path switching valves 4 and 5 are set to the control mode, and to output the respective current command values I_in (k) and I_out (k) of the pressure increasing valve 10 and the pressure reducing valve 11 to the respective current control circuits. Then, a transmission process for transmitting a regenerative motor torque command value to the motor control controller 13 using high-speed communication is performed.
One control routine ends.

Next, learning will be described. In S200,
Determine whether the pressure is increasing or decreasing. If Icom (k) ≧ 0, the process proceeds to S220 as pressure increase. If Icom (k) <0, the process proceeds to S230 as decompression.

In S220, the pressure increasing valve 10 is energized,
Since the pressure reducing valve 11 is closed, the electromagnetic valve current command value after the differential pressure correction is used as the current value of the pressure increasing valve 10. S2
Go to 50. I_in (k) = Icom (k) · K_in (k) I_out (k) = 0

In S230, the pressure reducing valve 11 is energized,
Since the pressure increasing valve 10 is closed, the electromagnetic valve current command value after the differential pressure correction is set as the current value of the pressure reducing valve 11. S2
Go to 50. I_out (k) = | Icom (k) · K_in (k) | I_in (k) = 0

S250 is an output process performed during regenerative cooperative braking control. In order to output the ports so that the oil path switching valves 4 and 5 are set to the control mode, and to output the respective current command values I_in (k) and I_out (k) of the pressure increasing valve 10 and the pressure reducing valve 11 to the respective current control circuits. Then, a transmission process for transmitting a regenerative motor torque command value to the motor control controller 13 using high-speed communication is performed.
Proceed to S260.

At S260, the difference of the W / C pressure ΔPwc (k)
Is calculated. Proceed to S270. ΔPwc (k) = Pwc (k) −Pwc (k-1)

In S270, it is determined whether or not a predetermined change in the W / C pressure has occurred in order to learn the dead zone width of the proportional valve. If ΔPwc (k)> predetermined value K12, the process proceeds to S280. Otherwise, one control routine ends.

In S280, it is determined whether the pressure is increasing or decreasing.
If Icom (k) ≧ 0, the process proceeds to S290 as pressure increase. Ico
If m (k) <0, the process proceeds to S300 as pressure reduction.

In S290, the current command value of the pressure increasing valve 10 is learned as the dead zone width of the pressure increasing valve 10. In addition,
From the next control routine, the offset correction of the dead band width is performed in S210, so that the offset correction overlaps with Icom (k) including the dead band width calculated so far.
To prevent this, the initialization flag FRE is set so that feedback control can be initialized in the next control routine.
SET = 1. Therefore, learning is not performed in synchronization with this initialization. One control routine ends. OFFSE
T_in (k) = I_in (k), FSTUDY = 0, FRESET
= 1

In S300, the current command value of the pressure reducing valve 11 is learned as the dead zone width of the pressure reducing valve 11. In addition,
From the next control routine, the offset correction of the dead band width is performed in S210, so that the offset correction overlaps with Icom (k) including the dead band width calculated so far.
To prevent this, the initialization flag FRE is set so that feedback control can be initialized in the next control routine.
SET = 1. Therefore, learning is not performed in synchronization with this initialization. One control routine ends. OFFSE
T_out (k) = I_out (k), FSTUDY = 0, FREESE
T = 1

Next, the function and effect will be described. First,
When the regenerative cooperative brake control is performed, the current control for the pressure increasing and reducing valves 10 and 11 is performed in S10 → S20 → S3 of FIG.
The process proceeds from 0 to S40, and from S40, the flow proceeds to S50 to S300.

Basically, in S10, W / CYL
The pressure Pwc (k) is calculated, and in S50, the brake oil pressure command value Pcom (k) is calculated using the hydraulic brake torque command value Tbcom (k) and the vehicle specification constant K1, and S140
In steps S170 to S170, the output Icom_ff (k) of the feedforward compensator and the output Icom_fb (k) of the feedback compensator
After summing, the electromagnetic valve current command value Icom (k) is calculated by limiting the upper and lower limits (± Imax), and the solenoid valve is operated based on the calculated electromagnetic valve current command value Icom (k). Current control is performed on the pressure increasing and reducing valves 10 and 11.

In the current control based on the feedforward compensation and the feedback compensation, the pressure increasing / decreasing valve 10 is controlled in synchronization with the initialization of the internal variable of the feedback control.
Eleven dead zones are learned. That is, when the brake hydraulic pressure command value Pcom (k) stays within the predetermined range for a predetermined time and then changes by a predetermined amount for the first time, in synchronization with the initialization of the internal variable of the feedback control, the pressure increase / decrease valve 10,
In order to learn the dead zone width of No. 11, S60 → S7 of FIG.
When the process proceeds from 0 → S90 → S100, in S100, the reset flag FRESET is set to FRESET = 1, and the learning flag FSTUDY is set to FSTUDY = 1.
Is set, and since FRESET = 1, the process proceeds from S120 to S130 to initialize the internal variables of the feedback control.

Then, in S190 of FIG. 5, FSTUDY
If = 1, the process proceeds to S200 and thereafter, and the pressure increasing valve 10 or the pressure reducing valve 11 to be learned is gradually energized, and the pressure reducing valve 11 or the pressure increasing valve 10 on one side is completely closed (S200, S220, S230),
When the brake oil pressure changes by a predetermined amount (S27
0), the dead zone width of the pressure increasing valve 10 or the pressure reducing valve 11 is learned (S280, S290, S300).

Therefore, the pressure increasing valve 10 and the pressure reducing valve 11
By continuing to energize the solenoid, the solenoid characteristics change over time, and when the dead zone width deviates from the initial learning, even if feedback control compensates for the deviation and repeats increasing and decreasing, feedback control initialization and Since learning is performed in synchronization, there is an effect that the dead zone width can be correctly learned.

That is, in the dead zone width learning of the pressure reducing valve 11 shown in FIG. 7, the dead band width of the pressure increasing / decreasing valves 10 and 11 is corrected by feedback control from time t3 to time t4 while increasing / decreasing the pressure repeatedly. However, since the dead zone width is learned in synchronization with the time t4 when the feedback control is initialized, the current command value Iout (of the pressure reducing valve 11 to be learned is learned in a state where the pressure increasing valve 10 on one side is completely closed. Since k) is learned, the dead zone width can be correctly learned at time t5 in FIG.

In S190 of FIG. 5, FSTUDY =
1 is determined, but the initial value of the learning flag FSTUDY is set to FSTUDY (0) = 1, so that
At the time of the first learning immediately after the start of the brake control, regardless of the initialization of the feedback control, the pressure increase / decrease valve 1
A dead zone width of 0, 11 is learned.

That is, if the condition for learning the dead zone width always includes the condition for initializing the feedback control, at the first opportunity immediately after the start of the brake control, the pressure increasing / decreasing valve 1
The dead zone width of 0, 11 cannot be learned.

On the other hand, at the time of the first learning immediately after the start of the brake control, the initial value of the learning flag FSTUDY is set to FSTUDY (0) = 1, which is independent of the initialization, so that At the first opportunity, there is an effect that the dead zone widths of the pressure increasing and reducing valves 10 and 11 can be learned.

The embodiment of the present invention has been described above, but the specific configuration is not limited to this embodiment and is included in the present invention unless it changes the gist of the claims. It is.

For example, in the embodiment, an example of application to the regenerative cooperative brake control device has been described. However, the wheel cylinder pressure is controlled by using an electromagnetic solenoid valve that opens in proportion to the current and changes the brake oil amount. This can be applied to other systems as long as the brake control system feeds back the feedback.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a vehicle brake control device of the present invention.

FIG. 2 is an overall system diagram showing a vehicle brake control device according to the first embodiment.

FIG. 3 is an overall flowchart showing a control operation performed by a microcomputer of a brake control controller of the device according to the first embodiment.

FIG. 4 shows control operations S60 to S1 performed by the microcomputer of the brake control controller of the device according to the first embodiment.
FIG.

FIG. 5 is a flowchart showing control operations performed by the microcomputer of the brake control controller of the device according to the first embodiment;
It is a flowchart of 300.

FIG. 6 is a control block diagram illustrating a configuration of a two-degree-of-freedom control system.

FIG. 7 is a time chart illustrating learning of a dead zone width of the pressure reducing valve in the brake control according to the first embodiment.

FIG. 8 is a current-flow rate characteristic diagram showing a dead band width of the pressure increasing valve and the pressure reducing valve.

FIG. 9 is a time chart showing learning of the dead zone width of the pressure reducing valve in the conventional brake control.

[Explanation of symbols]

 a Brake oil pressure command value calculation means b Brake oil pressure measurement means c Hydraulic feedback control calculation means d Electromagnetic solenoid valve current control means e Dead zone width learning means f Initialization means 1 Brake pedal 2 Hydraulic booster 3 Master cylinder 4,5 Reference Signs List 6 Stroke simulator 7 Wheel cylinder 8 Master cylinder pressure sensor 9 Wheel cylinder pressure sensor 10 Pressure increasing valve (electromagnetic solenoid valve) 11 Pressure reducing valve (electromagnetic solenoid valve) 12 Brake control controller 13 Motor control controller 14 DC / AC conversion current control circuit 15 AC synchronous motor 16 Drive wheel 17 Battery 18 Pump 19 Accumulator 20 Source pressure sensor 21 Pressure switch

Claims (2)

[Claims] 1. A brake oil pressure command value calculating means for calculating a command value of a hydraulic pressure acting on a brake for suppressing rotation of a wheel based on an operation amount of a brake operation member by a driver, etc., and suppressing the rotation of the wheel. Brake oil pressure measurement means for measuring the actual value of the oil pressure acting on the brake; Hydraulic pressure feedback control calculating means for calculating; electromagnetic solenoid valve current control means for performing current control on the electromagnetic solenoid valve based on the calculated current command value; and brake for gradually increasing the current flowing to the electromagnetic solenoid valve Dead zone of the solenoid valve based on the current command value when the oil pressure measurement value changes by a predetermined amount A dead zone width learning means for learning the dead zone width which is learned and stored as an offset correction value of the current command value for the current control of the electromagnetic solenoid valve. In the meantime, if the predetermined amount changes for the first time after staying within the predetermined range, initialization means for initializing an internal variable of the hydraulic feedback control calculation means is provided, and the dead zone width learning means is initialized by the initialization means. And a means for learning a dead zone width of the electromagnetic solenoid valve in synchronization with the brake control device. 2. The brake control device for a vehicle according to claim 1, wherein said dead zone width learning means is provided with an electromagnetic solenoid valve at the first learning immediately after the start of brake control, irrespective of initialization by said initialization means. And a means for learning the dead zone width of the vehicle.