JP6083328B2 - Solenoid valve control device, brake fluid pressure control device, reference point acquisition device, circuit characteristic acquisition method - Google Patents

Description

  The present invention relates to acquisition of characteristics of a control circuit that controls a solenoid valve.

Patent Document 1 describes a hydraulic control device that controls the hydraulic pressure of a clutch or the like of a hydraulically operated transmission for a vehicle. In the hydraulic control device, the hydraulic pressure of the clutch or the like is controlled by an electromagnetic valve, but a control circuit including a coil of the electromagnetic valve is provided, and the supply current to the coil is controlled by controlling the voltage.
On the other hand, the relationship between voltage and current in the control circuit (hereinafter referred to as characteristics or circuit characteristics) is expressed by the following equation.
Vc = Vs + R · Ic
Vc is an applied voltage, Ic is a current flowing through the coil, Vs is a bias voltage (intercept), and R is a resistance. Since the resistance R changes when the temperature changes, in the hydraulic control device described in Patent Document 1, the actual voltage V and current I (measurement points) are detected, and the detected measurement points (V *, I *) are detected. ), The actual resistance R is obtained {R = (V * −Vs) / I *}, and the actual characteristics are obtained.
Further, in the hydraulic control device described in Patent Document 1, the actual measurement point is acquired when the solenoid valve is not operating, such as when the shift position is N or P, and in a high current energized state. This is because the influence of the temperature change on the characteristics is large in a high current energized state.

JP-A-7-77271

  An object of the present invention is to ensure that the characteristics of a control circuit are obtained satisfactorily. For example, the characteristics of the control circuit can be acquired efficiently or can be acquired accurately.

Means and effects for solving the problem

In the electromagnetic valve control device according to the present invention, the control circuit for controlling the electromagnetic valve has a non-linear characteristic and a linear characteristic. Of these, the linear characteristic is acquired, and the acquired linear characteristic is converted into the acquired linear characteristic. Based on this, the supply current to the coil of the solenoid valve is controlled.
The control circuit has nonlinear characteristics (referred to as characteristics in the nonlinear region of the characteristics of the control circuit; hereinafter the same) and linear characteristics (referred to as characteristics in the linear region of the characteristics of the control circuit; hereinafter the same). It is equipped with.
In this control circuit, when the linear characteristic is used for controlling the current supplied to the coil of the solenoid valve and the nonlinear characteristic is not used, the necessity for acquiring the nonlinear characteristic is low. Therefore, if the nonlinear characteristic is not acquired and the linear characteristic is acquired, it can be acquired efficiently.
Further, if the nonlinear characteristic is ignored and the linear characteristic is acquired (for example, it is acquired based on only the actual measurement point in the linear region without acquiring the actual measurement point in the nonlinear region), the nonlinear characteristic is reduced. Compared to the case where the linear characteristic is acquired in consideration (for example, the characteristic is acquired so as to approximate both the actual measurement point in the linear region and the actual measurement point in the nonlinear region), the linear characteristic is accurate. Can be obtained.
The control circuit is usually configured to include an IC including a transistor, a coil, and the like, and the resistance of the entire control circuit includes the resistance of the IC, the resistance of the coil, and the like. In a circuit including a coil, the relationship between voltage and current is steadily linear, but in a circuit including an IC, there is a non-linear region (range). This non-linearity due to the IC is particularly noticeable when duty control is performed on the voltage. In the region where the non-linearity due to the IC is dominant, the relationship between the current and the voltage in the circuit including the coil and the IC becomes non-linear and becomes linear in the other region. As described above, the region where the relationship between the current and the voltage is nonlinear (nonlinear region) and the region where the relationship between the current and voltage is linear (linear region) can be separated, and the linear region is acquired without considering the nonlinear characteristics.
On the other hand, the resistance of the coil changes as the temperature changes, and becomes higher when the temperature is high than when the temperature is low. For example, even if the voltage is controlled so as to obtain the target current based on the linear characteristics, when the coil temperature is high, only a current smaller than the target current can be supplied, and the solenoid valve can be controlled well. There are cases where it is not possible. Therefore, it is desirable to obtain the actual linear characteristic, that is, the linear characteristic when the coil temperature is the actual temperature (the actual linear characteristic, hereinafter referred to as the real linear characteristic).

Patentable invention

  Hereinafter, the invention recognized as being capable of being claimed in the present application, or features of the invention will be described.

(1) (i) a control circuit including a coil of a solenoid valve; and (ii) a coil current for controlling a current supplied to the coil by controlling a voltage of the control circuit based on at least the characteristics of the control circuit. A solenoid valve control device including a control unit,
The characteristics of the control circuit are defined by the relationship between the voltage and the current, and include a nonlinear property in which the relationship between the voltage and the current is nonlinear, and a linear property in which the relationship is linear,
The electromagnetic valve control device includes a circuit characteristic acquisition device that acquires the linear characteristic without acquiring the nonlinear characteristic of the control circuit.
The linear characteristic is represented by a line segment, and the line segment may be defined by a point on an extension line of the line segment. For example, a line segment can be defined by a slope and an intercept (voltage value when the current is 0), but the intercept may be a point deviating from the line segment (a point deviating from the linear region). . In this case, a point (intercept) deviating from the line segment is also considered as one element that defines the linear characteristic. Therefore, the acquisition of the line segment that defines the linear characteristic includes not only the acquisition of the slope but also the acquisition of the intercept. The same applies to a reference point (a point used to determine a line segment, which is convenient for obtaining a line segment, hereinafter the same).
The linear characteristics of the control circuit can be obtained based on (a) a plurality of (at least two) measurement points (actually applied voltage, actual current supplied to the coil) in the linear region, or (b) Reference points that define linear characteristics can be stored in advance, and can be acquired based on the stored reference points and one or more (at least one) measured points in the linear region.
The line segment can be determined by statistically processing a plurality of actually measured points (which may include a reference point) in the linear region. For example, many points such as those based on the least-square method can be approximated, the line can be as large as possible, or the line can be larger than all actual measurement points.
Note that “voltage” and “current” described in this section include themselves and physical quantities corresponding to them one-to-one. For example, when the voltage of the control circuit is determined by the duty control of the switching element, the duty ratio is a physical quantity corresponding to the voltage on a one-to-one basis, and the circuit characteristics are acquired as a relationship between the current and the duty ratio.
(2) The electromagnetic valve control device according to (1), wherein the control circuit has the linear characteristic in a range where either one of the current and the voltage is larger than a region separation value.
The characteristics of the control circuit can be easily separated into a linear region and a nonlinear region depending on the magnitude of either one of current and voltage and the region separation value. The size of this region separation value (value greater than 0) is known.
Note that it is not necessary to strictly separate the linear region and the non-linear region, and the region separation value may be determined so that the range used for controlling the solenoid valve and the operation start current of the solenoid valve are included in the linear region.
(3) The control circuit has the linear characteristic in a range where the current is larger than a region separation value.
The circuit characteristic acquisition device includes (i) an actual measurement point acquisition unit that acquires at least one actual measurement point in a range where the current is larger than the region separation value and smaller than the operation start current of the solenoid valve, A real linear characteristic acquisition unit that acquires a real linear characteristic that is an actual linear characteristic of the control circuit based on the at least one actual measurement point acquired by the actual measurement point acquisition unit;
In the item (1) or (2), the coil current control unit includes a real linear characteristic dependence control unit that controls a supply current to the coil based on the real linear characteristic acquired by the real linear characteristic acquisition unit. The electromagnetic valve control device described.
When the operation start current Istart (described as Ista in FIG. 11 and the like) of the solenoid valve belongs to a linear region having a linear characteristic, the current is greater than the region separation value Io and smaller than the operation start current Istart (Io < Even if I <Istart) is supplied, the solenoid valve is inactive. Therefore, based on the actual measurement point of the current larger than the region separation value Io and smaller than the operation start current Istart, the real linear characteristic can be acquired in the non-operating state of the solenoid valve. The real linear characteristic can be acquired before the operation of the solenoid valve is started, and the real linear characteristic can be used from the start of the control of the solenoid valve. As a result, the operation start delay of the electromagnetic valve can be reduced, and the responsiveness at the start of control can be improved.
Further, when the electromagnetic valve control device is applied to a brake hydraulic pressure control device that controls the hydraulic pressure of the brake cylinder of the vehicle, a case where the actual measurement point is acquired in a range where the current is larger than the operation start current Istart is considered. Even if there is no request from the driver, the brake is operated, and there is a case where the user feels uncomfortable. On the other hand, if the measurement points are acquired in a range where the current is smaller than the operation start current Istart, the driver can hardly feel uncomfortable.
(4) The solenoid valve control according to (3), wherein the circuit characteristic acquisition device includes a learning condition real time linear characteristic acquisition unit that acquires the real linear characteristic when a predetermined learning condition is satisfied. apparatus.
For example, (a) the set time has elapsed since the last actual linear characteristic was acquired, (b) the solenoid valve is in an uncontrolled state, (c) there is no operation request for the device to be controlled by the solenoid valve, (d) There is a request for operation of the controlled device, but one or more of the following: (e) the possibility that the controlled device is likely to operate in the near future is satisfied. It can be considered that the learning condition is satisfied when the condition (a) and one or more of the conditions (b) to (e) are satisfied. If the solenoid valve control device is installed in a place where the temperature rises even if no current is supplied to the coil, the actual characteristics may be acquired periodically (every time the set time elapses). desirable.
(5) The circuit characteristic acquisition device includes: (i) a reference point storage unit that stores at least one reference point on a straight line including a line segment that defines the linear characteristic; and (ii) storage in the reference point storage unit A reference point-based real linear characteristic acquisition unit that acquires a real linear characteristic that is an actual linear characteristic of the control circuit based on the at least one reference point and the at least one actual measurement point. Thru | or a solenoid valve control device given in any 1 paragraph (4).
The straight line includes a line segment and an extension line of the line segment, but the reference point may be a point on the line segment or a point on the extension line of the line segment. Even if the reference point is acquired and stored in the electromagnetic valve control device, the reference point is acquired in an external device different from the electromagnetic valve control device, supplied from the external device, and stored in the electromagnetic valve control device. You may do it.
(6) The control circuit has a linear characteristic in a range where the current is larger than a region separation value,
The circuit characteristic acquisition device includes: (i) a reference point storage unit that stores at least one reference point in which the current is in a range equal to or less than the region separation value; and (ii) the at least the reference point storage unit that stores the at least one reference point. A reference point-based real linear characteristic acquisition unit that acquires a real linear characteristic that is an actual linear characteristic of the control circuit based on one reference point and at least one actual measurement point in a range where the current is larger than the region separation value. The electromagnetic valve control device according to any one of items (1) to (5).
The reference point is set in a range out of the linear region.
(7) The reference point storage unit includes a rotation center point storage unit that stores, as the reference point, a rotation center point that is a point through which a straight line including a line segment that defines the linear characteristic passes even if the temperature differs.
The reference point-based real linear characteristic acquisition unit acquires the real linear characteristic based on the at least one actual measurement point and the rotation center point stored in the rotation center point storage unit. The electromagnetic valve control device according to (5) or (6), including a section.
The rotation center point can be determined based on, for example, the intersection of a plurality of straight lines having different temperatures.
Although the voltage value (intercept) when the current is 0 can be set as the rotation center point, strictly speaking, a point other than the intercept (a point where the current is not 0 and the current is smaller than 0) May be the center point of rotation. Therefore, if the real linear characteristic is acquired based on the rotation center point, it can be acquired with higher accuracy than when the intercept is acquired as the rotation center point.
(8) The reference point storage unit includes an intercept storage unit that stores an intercept that is a value of the voltage when the current is 0 as the reference point,
The reference point-based real linear characteristic acquisition unit includes an intercept-based real linear characteristic acquisition unit that acquires the real linear characteristic based on the intercept stored in the intercept storage unit and the at least one measured point (5 The electromagnetic valve control device according to any one of items) to (7).
Note that both the intercept as the reference point and the rotation center point are stored in the storage unit, and the actual characteristic is selectively acquired based on one of these and at least one actual measurement point. You can also.

(9) The electromagnetic valve control device includes a standard linear characteristic storage unit that stores at least a standard linear characteristic that is the linear characteristic when the temperature of the control circuit is a standard temperature,
The reference point-based real linear characteristic acquisition unit includes the standard linear characteristic stored in the standard linear characteristic storage unit, the at least one reference point stored in the reference point storage unit, and at least one actual measurement point. A gradient ratio acquisition unit that acquires a gradient ratio that is a ratio of the gradient when the coil temperature is an actual temperature with respect to a gradient of the voltage with respect to the current when the coil temperature is a standard temperature based on The electromagnetic valve control device according to any one of (5) to (8).
If the reference point is provided at a point where the extended line of the line defining the linear characteristic passes even if the temperature is different, it is a point on the extended line of the line defining the standard linear characteristic and It is also a point on the extension of the line segment that defines the linear characteristics. Therefore, the reference point can be considered as one element of the standard linear characteristic or can be considered as one element of the real linear characteristic.
(10) The coil current control unit controls a supply current to the coil based on the standard linear characteristic stored in the standard linear characteristic storage unit and the gradient ratio acquired by the gradient ratio acquisition unit. The solenoid valve control device according to item (9), including a gradient ratio dependence control unit.
A real linear characteristic can be acquired based on the gradient ratio and the standard linear characteristic stored in advance. Based on the gradient ratio and the standard linear characteristic, the same control as that based on the real linear characteristic can be performed, and there is an advantage that it is not necessary to store the real linear characteristic. Note that the gradient ratio can be considered to be a real linear characteristic.
In addition, if the gradient ratio is acquired immediately before the start of operation of the solenoid valve and the control based on the standard linear characteristic and the gradient ratio is started, it is compared with the case where the control based on the standard linear characteristic is started. Thus, the responsiveness at the start of control can be improved. For example, the time until the actual current reaches 90% of the target current can be shortened.
For this reason, it is desirable to use the gradient ratio for feedforward control.
(11) The electromagnetic valve control device includes a standard linear characteristic storage unit that stores at least a standard linear characteristic that is the linear characteristic when the temperature of the coil is a standard temperature,
The circuit characteristic acquisition device acquires a gradient ratio that is a ratio between a gradient of the voltage with respect to the current when the temperature of the coil is a standard temperature and the gradient when the temperature of the coil is an actual temperature. Including a slope ratio acquisition unit,
The coil current control unit corrects a control command value determined based on the standard linear characteristic stored in the standard linear characteristic storage unit based on the gradient ratio acquired by the gradient ratio acquisition unit. A correction unit is provided, and the current supplied to the coil is controlled based on the control command value after temperature correction obtained by correction by the control command value correction unit. The electromagnetic valve control device according to claim 1.
The gradient ratio can be referred to as a temperature correction factor.
(12) The reference point storage unit includes an intercept storage unit that stores, as the reference point, an intercept that is a value of the voltage when the current is 0,
The standard linear characteristic storage unit includes a standard linear characteristic that is the linear characteristic when the control circuit is at a standard temperature,
The gradient ratio acquisition unit includes (a) an actual intercept acquisition unit that acquires an actual intercept that is an actual intercept based on at least two actual measurement points when the coil temperature is an actual temperature, and (b) Corresponds to the actual intercept acquired by the intercept acquisition unit and one of the at least two actual measurement points, the intercept stored in the reference point storage unit, and the actual measurement points of the line segment defining the standard linear characteristic The electromagnetic valve control device according to any one of (9) to (11), further including an intercept-corresponding gradient ratio acquisition unit that acquires the gradient ratio based on a point to be performed.
The gradient ratio can be acquired based on the actual intercept, the intercept as the reference point, the actual measurement point, and the point on the line segment that defines the standard linear characteristic corresponding to the actual measurement point.
The intercept as a reference point can also be obtained at a standard temperature.

(13) The circuit characteristic acquisition device includes a reference point acquisition unit that acquires at least one reference point out of a region where the relationship between the voltage and the current is linear. The electromagnetic valve control device according to any one of the above.
Since the solenoid valve control device described in this section includes the reference point acquisition unit, for example, the reference point can be acquired using an external device that does not include the reference point acquisition unit.
Although the reference points can be acquired based on a plurality of actual measurement points, it is desirable to acquire a large number of actual measurement points at equal intervals in order to acquire the reference points accurately.
(14) The reference point acquisition unit acquires at least two straight lines including line segments that define the linear characteristics at different temperatures, and acquires the reference point based on an intersection of the at least two straight lines. The electromagnetic valve control device according to item (13) including a section.
The center of rotation, which is a point that passes even at different temperatures, can theoretically be obtained as an intersection of straight lines including two line segments acquired at arbitrary different temperatures. On the other hand, in consideration of variations and the like, it is also possible to obtain three or more straight lines having different temperatures and obtain one reference point (rotation center point) based on the intersection of two straight lines. it can. In addition, the temperatures at which the straight lines are acquired need only be different from each other, and the need for detecting the temperature is low.
(15) The reference point acquisition unit (i) a straight line acquisition unit that acquires a straight line including a line segment that defines the linear characteristic; and (ii) a temperature of the coil by supplying a heating current to the coil. And (iii) an intersection point for acquiring the reference point based on the intersection of at least two straight lines acquired by the straight line acquisition unit before and after the coil heating by the coil heating unit, respectively. The electromagnetic valve control device according to item (13) or (14), including an acquisition unit.
The temperature is changed by heating the coil. Since it is not necessary to change the temperature of the atmosphere in which the control circuit exists, it is possible to shorten the time required to acquire the reference point while reducing energy consumption.
(16) The reference point acquisition unit includes an intercept acquisition unit that acquires an intercept that is a voltage value when the current on the extension line of the line that defines the linear characteristic is 0. 15. The solenoid valve control device according to any one of items 15).
When the temperature changes, the slope of the line segment changes, but the intercept can be considered to be almost the same value. For example, when the nonlinear region has a narrow characteristic, the intercept can be regarded as the rotation center point.
In theory, the intercept can be acquired based on one straight line including a line segment that defines a linear characteristic. Therefore, the reference point can be acquired in a shorter time than when the rotation center point is used as the reference point.
(17) The solenoid valve includes the coil and a plunger, a solenoid that applies an electromagnetic driving force to the plunger according to a supply current to the coil, a valve member provided in the plunger, and the plunger The electromagnetic valve control device according to any one of items (1) to (16), further including a spring that applies an elastic force in a direction opposite to the electromagnetic driving force.
The solenoid valve may be a poppet valve or a spool valve.

(18) The electromagnetic valve control device according to any one of items (1) to (17) is provided, and the fluid pressure of the control target device connected to the electromagnetic valve is controlled by controlling the supply current to the coil. Fluid pressure control device to control.
The device to be controlled can be a brake cylinder of a fluid pressure brake, a clutch of a hydraulically operated transmission, a fluid pressure cylinder of a vehicle height adjusting device, or the like. In addition, a fluid pressure control mechanism provided on the upstream side of the fluid pressure brake can be used as a control target device. In any case, the present invention can be applied when acquiring the characteristics of a control circuit that controls the current supplied to the coils of various solenoid valves provided in the vehicle. Or atmospheric pressure.
(19) The fluid pressure control device includes a regulator connected to a back chamber provided behind the pressurizing piston of a master cylinder in which the brake cylinder is connected to a pressurizing chamber provided in front of the pressurizing piston. Including
The back chamber is connected to a servo chamber in front of a small diameter portion of a control piston included in the regulator;
The fluid pressure control device according to item (18), wherein the electromagnetic valve is connected to a control pressure chamber behind a large diameter portion of the control piston.
A regulator can be a control target device, a master cylinder or a brake cylinder can be a control target device, and the like.
When hydraulic pressure as fluid pressure is supplied to the control pressure chamber by the control of the electromagnetic valve, the control piston is operated in the regulator, and hydraulic pressure is supplied from the servo chamber to the back chamber of the master cylinder. The pressurizing piston is advanced in the master cylinder, and hydraulic pressure is supplied from the pressurizing chamber to the brake cylinder. Thus, the hydraulic pressure controlled by the electromagnetic valve is transmitted to the brake cylinder by the advance of the control piston and the advance of the pressurizing piston. Therefore, if the operation delay of the solenoid valve is large, the operation delay of the brake cylinder increases, which is not desirable. Therefore, it is desirable to acquire real linear characteristics with high accuracy and suppress the operation delay of the solenoid valve.
In the regulator, the hydraulic pressure in the control pressure chamber and the hydraulic pressure in the servo chamber may be the same.

(20) A circuit characteristic acquisition device that acquires a characteristic that is a relationship between a voltage and a current of a control circuit including a coil of a solenoid valve,
The characteristics of the control circuit include a non-linear characteristic in which a relationship between the current and the voltage is non-linear, and a linear characteristic that is linear.
The circuit characteristic acquisition apparatus includes a linear characteristic acquisition unit that acquires the linear characteristic without acquiring the nonlinear characteristic.
The circuit characteristic acquisition device described in this section can employ the technical features described in any one of the items (1) to (19).
(21) A circuit characteristic acquisition device that acquires a real linear characteristic that is an actual linear relationship between a voltage and a current of a control circuit including a coil of a solenoid valve,
(a) a plurality of sets of actual measurement points acquiring unit that acquires a plurality of sets of a plurality of sets of actual measurement points in which the voltage and the current are different from each other; A line segment determining unit that statistically processes points to determine one line segment, and the plurality of sets of actual measurement point acquiring units change (a-1) one of the voltage and the current And (a-2) a coil heating suppression unit that suppresses heating of the coil by reducing the current supplied to the coil each time the set of a plurality of measurement points is acquired. A circuit characteristic acquisition apparatus comprising:
A plurality of sets of actual measurement points that are different from each other while either one of the voltage and the current is changed are acquired. Next, the supply current to the coil is reduced, and heating of the coil is suppressed. Thereafter, a plurality of sets of actual measurement points are acquired while either one of the voltage and the current is changed. In this way, if the measurement points are acquired while suppressing the heating of the coil, it is possible to acquire a plurality of sets of measurement points at substantially the same temperature, and it is possible to acquire real linear characteristics with high accuracy. it can.
When suppressing the heating of the coil, it is desirable to maintain a state where the supply current to the coil is reduced for a set time or longer. In this case, the value of the current supplied to the coil and the set time can be determined as appropriate so that the heating of the coil can be suppressed. For example, the supply current value can be made smaller than the region separation value.
The circuit characteristics acquisition device described in this section can employ the technical features described in any one of the items (1) to (20).

(22) A reference point acquisition device for acquiring a reference point used for acquiring a real linear characteristic that is an actual linear relationship between a voltage and a current of a control circuit including a coil of a solenoid valve,
The reference point is a point deviating from a linear region in which the current and the voltage are in a linear relationship;
The reference point acquisition device, wherein the reference point acquisition device includes an actual measurement point-based reference point acquisition unit that acquires the reference point based on a plurality of actual measurement points in the linear region.
In Patent Document 1, there is no description that the intercept is a point deviated from the line segment representing the circuit characteristics.
The technical feature described in any one of the items (1) to (21) can be employed in the reference point acquisition device described in this item.
The reference point acquisition device may be provided in an in-vehicle device such as an electromagnetic valve control device or a fluid pressure control device, or may be provided in an external device different from the vehicle.
When the reference point is acquired, it is desirable that the number of actually measured points is large and acquired in a wide range. When the reference point acquisition device is provided in an external device different from the electromagnetic valve control device, it is possible to acquire a large number of actual measurement points in a wide range regardless of whether the electromagnetic valve is activated or not. .

(23) A reference point acquisition method for acquiring a reference point used for acquiring a real linear characteristic that is an actual linear relationship between a voltage and a current of a control circuit including a coil of a solenoid valve,
An actual point acquisition step for acquiring a plurality of actual points in a linear region in which the relationship between the voltage and the current is linear;
A reference point acquisition method, comprising: a reference point acquisition step of acquiring one reference point in a region outside the linear region based on a plurality of actual measurement points acquired in the actual measurement point acquisition step.
The technical feature described in any one of the items (1) to (22) can be adopted for the reference point acquisition method described in this item.
(24) A circuit characteristic acquisition method for acquiring a real linear characteristic which is a linear relationship between an actual voltage and a current of a control circuit including a coil of a solenoid valve,
An actual measurement point acquisition step of acquiring at least one actual measurement point in a range in which the voltage and the current have a linear relationship;
A circuit characteristic acquisition method comprising a real linear characteristic acquisition step of acquiring the real linear characteristic based on at least one actual measurement point acquired in the actual measurement point acquisition step and a reference point stored in advance .
The technical characteristics described in any one of items (1) to (23) can be employed in the circuit characteristic acquisition method described in this item.
(25) A circuit characteristic acquisition method for acquiring a real linear characteristic which is a linear relationship between an actual voltage and a current of a control circuit including a coil of a solenoid valve,
A plurality of actual measurement point acquisition steps for acquiring a plurality of actual measurement points in which the voltage and the current are different from each other in a range in which the voltage and the current have a linear relationship;
A coil heating suppression step of reducing the current flowing in the coil and suppressing heating of the coil after a plurality of actual measurement points are acquired in the multiple actual measurement point acquisition step;
By alternately repeating the plurality of actual measurement point acquisition steps and the coil heating suppression step, a plurality of sets consisting of a plurality of actual measurement points having different voltages and currents are acquired, and a plurality of sets included in the plurality of sets are included. A circuit characteristic acquisition method comprising: a real linear characteristic acquisition step of statistically processing the actual measurement points to acquire the real linear characteristic.
The technical characteristics described in any one of the items (1) to (24) can be employed in the circuit characteristic acquisition method described in this item.
(26) An actual characteristic acquisition device that acquires an actual characteristic that is an actual relationship between a voltage applied to a coil of a solenoid valve and a current flowing through the coil.
The technical characteristics described in any one of the items (1) to (25) can be employed in the actual characteristic acquisition device.

1 is a circuit diagram of a hydraulic brake system including an electromagnetic valve control device according to Embodiment 1 of the present invention. The hydraulic brake system includes a brake hydraulic pressure control device according to Embodiment 1 of the present invention, and the brake hydraulic pressure control device includes a reference point acquisition device according to Embodiment 1 of the present invention. Moreover, in this hydraulic brake system, the circuit characteristic acquisition method which concerns on Example 1 of this invention is implemented. (a) It is sectional drawing of the pressure increase linear valve contained in the said hydraulic brake system. (b) It is a figure which shows the relationship between the differential pressure | voltage of the said pressure increase linear valve, and an operation start electric current. (a) It is sectional drawing of the pressure-reduction linear valve contained in the said hydraulic brake system. (b) It is a figure which shows the relationship between the differential pressure | voltage of the said pressure reduction linear valve, and an operation start electric current. It is a figure which shows the periphery of brake ECU of the said hydraulic brake system. (a) It is a circuit diagram of a control circuit included in the brake ECU. It is a figure which shows the change of the electric current in the control circuit of (b) and (a). (a) It is a figure which shows the relationship between the electric current in the said control circuit, and a voltage. (b) It is a figure which shows notionally the linear characteristic of the said control circuit. It is a block diagram which shows typically the action | operation of the said brake ECU. It is a figure which shows the rotation center point of the linear characteristic of the said control circuit. (a) It is a figure which shows the state by which the said brake ECU and the external device were connected when a reference point is acquired. (b) It is a flowchart which shows the reference point acquisition program memorize | stored in the memory | storage part of the said brake ECU. (c) It is a figure which shows the change state of the electric current supplied to a coil, when acquiring a some straight line. (a) It is a flowchart which shows a part of said reference point acquisition program (actual point acquisition). (b) It is a figure which shows the change of the duty ratio at the time of acquiring an actual measurement point. (c) It is a figure which shows the change of the electric current value at the time of acquiring a measurement point. (d) It is a figure which shows the linear characteristic acquired based on the some measurement point. (a) It is a flowchart showing the temperature correction coefficient learning program memorize | stored in the memory | storage part of the said brake ECU. (b) It is a figure which shows the electric current change in the case of acquiring a measurement point. (c) It is a figure which shows the acquired real linear characteristic. It is a figure which shows notionally the linear characteristic memorize | stored in the memory | storage part of brake ECU of the hydraulic brake system containing the solenoid valve control apparatus which concerns on Example 2 of this invention, and the intercept as a rotation center point. The hydraulic brake system includes a brake hydraulic pressure control device according to Embodiment 2 of the present invention, and the brake hydraulic pressure control device includes a reference point acquisition device according to Embodiment 2 of the present invention. Moreover, in this hydraulic brake system, the circuit characteristic acquisition method which concerns on Example 2 of this invention is implemented. It is a flowchart which shows the reference point acquisition program memorize | stored in the memory | storage part of the said brake ECU. (a) It is a figure which shows the electric current change in the case of acquiring a measurement point. (b) It is a figure which shows the real linear characteristic acquired based on several measurement points. (a) It is a flowchart which shows the temperature correction coefficient learning program memorize | stored in the memory | storage part of the said brake ECU. (b) It is a figure which shows the electric current change in the case of acquiring a measurement point. It is a figure which shows another real linear characteristic and standard linear characteristic which are acquired in brake ECU of the said solenoid valve control apparatus. (a) It is a flowchart which shows the temperature correction coefficient learning program memorize | stored in the memory | storage part of the said brake ECU. (b) It is a figure which shows the electric current change in the case of acquiring a measurement point. It is a figure for demonstrating acquisition of the real linear characteristic in brake ECU of the hydraulic brake system containing the solenoid valve control apparatus which concerns on Example 3 of this invention. (b) It is a figure which shows the electric current change in the case of acquiring several measurement points. The hydraulic brake system includes a brake hydraulic pressure control device according to Embodiment 3 of the present invention, and the brake hydraulic pressure control device includes a reference point acquisition device according to Embodiment 3 of the present invention. Moreover, in this hydraulic brake system, the circuit characteristic acquisition method which concerns on Example 3 of this invention is implemented. It is a flowchart which shows the real linear characteristic acquisition program memorize | stored in the memory | storage part of the said brake ECU. It is a figure which shows the external device containing the reference point acquisition apparatus which concerns on Example 4 of this invention.

Embodiment of the Invention

Hereinafter, a hydraulic brake system including an electromagnetic valve control device according to an embodiment of the present invention will be described in detail based on the drawings. The hydraulic brake system includes a hydraulic control device as a fluid pressure control device. The electromagnetic valve control device includes a circuit characteristic acquisition device, and the circuit characteristic acquisition device includes a reference point acquisition device. Further, a reference point acquisition program is stored and executed in the circuit characteristic acquisition device. Thereby, the reference point acquisition method is executed. In the circuit characteristic acquisition device, a circuit characteristic acquisition method is executed.
The hydraulic brake system can be mounted on a hybrid vehicle, mounted on an electric vehicle or a fuel cell vehicle, or mounted on an internal combustion drive vehicle. When mounted on a hybrid vehicle, an electric vehicle, a fuel cell vehicle, etc., regenerative braking force is applied to the drive wheels, so regenerative cooperative control is performed, but in an internal combustion drive vehicle, regenerative cooperative control is performed. There is no. In any case, in the present hydraulic brake system, the brake force of the hydraulic brake is electrically controlled so as to have a desired magnitude.

<Configuration of hydraulic brake system>
As shown in FIG. 1, the hydraulic brake system includes (i) hydraulic pressures provided on the brake cylinders 6FL and 6FR of the hydraulic brakes 4FL and 4FR provided on the left and right front wheels 2FL and 2FR and on the left and right rear wheels 8RL and 8RR. Brake cylinders 12RL, 12RR of the brakes 10RL, 10RR, (ii) a hydraulic pressure generator 14 capable of supplying hydraulic pressure to the brake cylinders 6FL, 6FR, 12RL, 12RR, (iii) the brake cylinders 6FL, 6FR, 12RL, 12RR And a slip control valve device 16 provided between the hydraulic pressure generator 14 and the hydraulic pressure generator 14. The hydraulic pressure generator 14, the slip control valve device 16, and the like are controlled by a brake ECU 20 (see FIG. 4) mainly composed of a computer.
[Slip control valve device]
The slip control valve device 16 includes a plurality of electromagnetic on-off valves 16a and 16r. The plurality of electromagnetic on-off valves 16a and 16r are individually opened and closed by controlling the current supplied to the coils 18a and 18r, and the hydraulic pressures of the brake cylinders 6FL, 6FR, 12RL, and 12RR are individually controlled. The electromagnetic on-off valves 16a and 16r can be referred to as slip control valves.

[Hydraulic pressure generator]
The hydraulic pressure generator 14 includes (i) a brake pedal 24 as a brake operation member, (ii) a master cylinder 26, (iii) a rear hydraulic pressure controller 28 that controls the hydraulic pressure in the rear chamber of the master cylinder 26, and the like. .
{Master cylinder}
The master cylinder 26 includes (a) a housing 30, (b) pressure pistons 32 and 34 and an input piston 36 and the like which are fitted in a cylinder bore formed in the housing 30 in series with each other in a liquid-tight and slidable manner. Including.
The fronts of the pressurizing pistons 32 and 34 are front pressurizing chambers 40 and 42, respectively. The front pressurizing chamber 40 is connected to the left and right front wheels 2FL, 2FR via the fluid passage 44, and the brake cylinders 6FL, 6FR of the 4FR are connected to the front pressurizing chamber 42 via the fluid passage 46. The brake cylinders 12RL and 12RR of the hydraulic brakes 10RL and 10RR of the wheels 8RL and 8RR are connected. These hydraulic brakes 4FL, 4FR, 10RL, and 10RR are operated by supplying hydraulic pressure to the brake cylinders 6FL, 6FR, 12RL, and 12RR, respectively, and suppress the rotation of the wheels 2FL, 2FR, 8RL, and 8RR. .
Hereinafter, in the present specification, when it is not necessary to distinguish wheel positions for hydraulic brakes, FL, FR, RL, and RR indicating wheel positions may be omitted.
Further, return springs are disposed between the pressure piston 32 and the housing 30 and between the two pressure pistons 32 and 34, respectively, and urge the pressure pistons 32 and 34 in the backward direction. When the pressurizing pistons 32 and 34 are in the retracted end position, the front pressurizing chambers 40 and 42 are communicated with the reservoir 52, respectively.

The pressurizing piston 34 includes (a) a front piston portion 56 provided at the front portion, (b) an intermediate piston portion 58 provided at the intermediate portion and projecting in the radial direction, and (c) provided at the rear portion. A rear small diameter portion 60 having a smaller diameter than the piston portion 58 is included. The front piston portion 56 and the intermediate piston portion 58 are fitted in the housing 30 so as to be liquid-tight and slidable, respectively. This is a chamber 62.
On the other hand, the housing 30 is provided with an annular inner peripheral projection 64, and the rear piston portion 58, that is, the rear small-diameter portion 60 is fitted in a liquid-tight and slidable manner. As a result, a back chamber 66 is formed between the intermediate piston portion 58 and the inner peripheral projection 64 behind the intermediate piston portion 58.
It may be considered that the front piston portion 56 and the intermediate piston portion 58 constitute a pressurizing piston, or the front piston portion 56 and the intermediate piston portion 58 constitute a pressurizing piston portion. it can.
The input piston 36 is positioned behind the pressure piston 34, and the space between the rear small diameter portion 60 and the input piston 36 is an input chamber 70. The brake pedal 24 is linked to the rear portion of the input piston 36 via an operating rod 72 or the like.

The annular chamber 62 and the input chamber 70 are connected by a connecting passage 80, and a communication control valve 82 is provided in the connecting passage 80. The communication control valve 82 is an electromagnetic on-off valve that is opened / closed by turning on / off the current supplied to the coil 82s, and is a normally closed valve that is closed when the current is off. A portion of the connection passage 80 closer to the annular chamber 62 than the communication control valve 82 is connected to the reservoir 52 by a reservoir passage 84, and a reservoir cutoff valve 86 is provided in the reservoir passage 84. The reservoir shut-off valve 86 is an electromagnetic on-off valve that is opened and closed by turning on and off the supply current to the coil 86s, and is a normally open valve that is open when it is off.
A stroke simulator 90 is connected to the portion of the connection passage 80 closer to the annular chamber 62 than the communication control valve 82 via the simulator passage 88. Since the stroke simulator 90 is connected to the input chamber 70 via the simulator passage 88 and the connection passage 80, the stroke simulator 90 is allowed to operate when the communication control valve 82 is open and is blocked when the communication control valve 82 is closed. Thus, the communication control valve 82 has a function as a simulator control valve.
Furthermore, a hydraulic pressure sensor 92 is provided in a portion closer to the annular chamber than a portion where the reservoir passage 84 of the connection passage 80 is connected. The hydraulic pressure sensor 92 detects the hydraulic pressure in the annular chamber 62 and the input chamber 70 in a state where the annular chamber 62 and the input chamber 70 are communicated with each other and are disconnected from the reservoir 52. Since the hydraulic pressure detected by the hydraulic pressure sensor 92 has a magnitude corresponding to the operating force of the brake pedal 24, it can be referred to as an operating force sensor or an operating hydraulic pressure sensor.

{Back hydraulic pressure control device}
A back hydraulic pressure control device 28 is connected to the back chamber 66.
The back hydraulic pressure control device 28 includes (a) a high pressure source 100, (b) a regulator 102, (c) a linear valve device 104, and the like.
The high-pressure source 100 includes a pump device including a pump 105 and a pump motor 106, and an accumulator 108 that stores hydraulic fluid discharged from the pump device in a pressurized state. The accumulator pressure, which is the hydraulic pressure of the hydraulic fluid stored in the accumulator 108, is detected by the accumulator pressure sensor 109, but the pump motor 106 is controlled so that the accumulator pressure is maintained within a predetermined setting range. The
The regulator 102 includes (d) a housing 110, and (e) a pilot piston 112 and a control piston 114 provided in the housing 110 in a direction parallel to the axis L and arranged in series with each other. A cylinder bore having a stepped shape is formed in the housing 110, and a pilot piston 112 and a control piston 114 are fitted in a liquid-tight and slidable manner on the large diameter portion, and connected to the high pressure source 100 on the small diameter portion. A high pressure chamber 116 is formed. A pilot pressure chamber 120 is provided between the pilot piston 112 and the housing 110, and a control pressure chamber 122 is provided behind the control piston 114. Between the control piston 114 and a step portion between the large diameter portion and the small diameter portion of the cylinder bore. Is the servo chamber 124. A high pressure supply valve 126 is provided between the servo chamber 124 and the high pressure chamber 116.

The high-pressure supply valve 126 is a normally closed valve. (F) The valve seat 130, (g) The valve element 132 provided so as to be seated and separated from the valve seat 130, and (h) The valve element 132 is attached to the valve seat 130. It includes a spring 136 and the like that applies an elastic force in the seating direction (retracting direction).
On the other hand, a fitting hole extending in parallel with the axis L is formed at the center of the main body of the control piston 114, and a portion extending in a direction (radial direction) orthogonal to the axis L is provided. A liquid passage 140 communicated with the liquid is formed. The liquid passage 140 is always in communication with a low pressure port connected to the reservoir 52.
A valve opening member 144 extending in parallel with the axis L is fitted into the fitting hole. An axial passage 146 is formed in the central portion of the valve opening member 144 in parallel with the axis L, the rear end opens to the liquid passage 140, and the front end faces the valve element 132. As a result, the front end portion of the valve opening member 144 facing the valve element 132 and the low pressure port are connected via the axial passage 146 and the liquid passage 140.
A spring 150 is provided between the valve opening member 144 and the housing 110 to urge the control piston 114 (having the valve opening member 144) in the backward direction.
As described above, the control piston 114 generally has a stepped shape, the rear of the large diameter portion is the control pressure chamber 122, and the front of the large diameter portion and the small diameter portion is the servo chamber 124. The hydraulic pressure in the servo chamber 124 is increased with respect to the hydraulic pressure in the control pressure chamber 122.
Depending on the structure of the regulator 102 and the like, the hydraulic pressure in the servo chamber 124 and the hydraulic pressure in the control pressure chamber 122 may be the same.

The pilot pressure chamber 120 is connected to the liquid passage 46 through the pilot passage 152. Therefore, the hydraulic pressure of the front pressurizing chamber 42 of the master cylinder 26 acts on the pilot piston 112.
A back chamber 66 of the master cylinder 26 is connected to the servo chamber 124 via a servo passage 154. Since the servo chamber 124 and the back chamber 66 are directly connected, the hydraulic pressure in the servo chamber 124 and the hydraulic pressure in the back chamber 66 are basically the same height. A servo fluid pressure sensor 156 is provided in the servo passage 154 to detect the servo fluid pressure that is the fluid pressure in the servo chamber 124.

A linear valve device 104 including a pressure increasing linear valve 160 and a pressure reducing linear valve 162 is connected to the control pressure chamber 122, and the hydraulic pressure in the control pressure chamber 122 controls the pressure increasing linear valve 160 and the pressure reducing linear valve 162. Controlled by The pressure increasing linear valve 160 is a normally closed valve provided between the control pressure chamber 122 and the high pressure source 100, and the pressure reducing linear valve 162 is a normally open valve provided between the control pressure chamber 122 and the reservoir 52. It is a valve.
As shown in FIG. 2A, the pressure-increasing linear valve 160 includes a poppet valve portion 170 and a solenoid 172. The poppet valve portion 170 includes a valve seat 174 and a valve element 176, and the valve element 176 as a valve seat 174. The solenoid 172 includes a coil 180 and a plunger 182 that applies an electromagnetic driving force Fd generated when electric current is supplied to the coil 180 to the valve element 176. Prepare. Further, the pressure-increasing linear valve 160 is provided in such a posture that a differential pressure acting force Fp corresponding to a hydraulic pressure difference between the high pressure source 100 and the control pressure chamber 122 acts in a direction in which the valve element 176 is separated from the valve seat 174.
Fp + Fd: Fs
When the sum of the differential pressure acting force Fp and the electromagnetic driving force Fd becomes larger than the elastic force Fs of the spring 178, the pressure-increasing linear valve 160 is switched from the closed state to the open state. FIG. 2B shows the relationship between the valve current Ista and the differential pressure. In the present embodiment, the operation start current (minimum value of the operation start current) Istamin when the differential pressure is maximum is larger than the region separation value Io described later (Istamin> Io).

As shown in FIG. 3A, the pressure-reducing linear valve 162 includes a poppet valve portion 186 and a solenoid 188. The poppet valve portion 186 includes a valve seat 190, a valve element 191, and a valve element 191 from the valve seat 190. A spring 192 that applies an elastic force Fs in the direction of separation, and a solenoid 188 includes a coil 194 and a plunger 195. When a current is supplied to the coil 194, an electromagnetic driving force Fd in a direction for seating the valve element 191 on the valve seat 190 is applied.
Further, a differential pressure acting force Fp corresponding to the differential pressure between the control pressure chamber 122 and the reservoir 52 acts in a direction to separate the valve element 191 from the valve seat 190.
Fs + Fp: Fd
When the electromagnetic driving force Fd becomes larger than the sum of the differential pressure acting force Fp and the spring elastic force Fs, the pressure reducing linear valve 162 is switched from the open state to the closed state. The relationship is shown in FIG. In this embodiment, the operation start current (minimum value of the operation start current) Istamin when the differential pressure is minimum (0) is larger than the region separation value Io.

[Brake ECU]
As shown in FIG. 4, the brake ECU 20 is connected to the operation hydraulic pressure sensor 92, the accumulator pressure sensor 109, and the servo hydraulic pressure sensor 156 described above, and the stroke of the brake pedal 24 (hereinafter sometimes referred to as an operation stroke). A stroke sensor 200 for detecting a current), a current monitor 202 for detecting a current flowing through the coil, and the like, and a pump motor 106, a coil 180 of the pressure-increasing linear valve 160, a coil 194 of the pressure-reducing linear valve 162, and the like are connected. The
The brake ECU 20 is mainly composed of a computer, and includes an execution unit 210, a storage unit 212, a control circuit 214, and the like. The storage unit 212 includes a circuit characteristic storage unit 220, a reference point acquisition program storage unit 222, and the like, and stores a plurality of programs, tables, and the like. The control circuit 214 controls the supply current to the coil 180 or the like of the electromagnetic valve 160. In this embodiment, a case will be described in which the supply current to the coil 180 of the pressure-increasing linear valve 160 is controlled.
In addition, the hydraulic brake system is operated by electric energy supplied from the power source 250.

As shown in FIG. 5A, the control circuit 214 is configured by connecting a power source 250, a switching element 252, and a coil 180 in series. The resistor 254 equivalently describes the entire resistance of the control circuit 214, such as the resistance of an IC having the coil 180 and the switching element 252. The switching element 252 can be a transistor, for example, and by controlling the duty, the voltage applied to the coil 180 is controlled, and the current flowing through the coil 180 is controlled. Since the voltage applied to the coil 180 is larger when the duty ratio is large than when it is small, in this embodiment, the voltage is represented by the duty ratio.
In the control circuit of FIG.
u (t) = R · i (t) + L · di (t) / dt
Is established. u (t) is a voltage applied to the coil 180 by duty control of the switching element 252, and i (t) is a current flowing through the coil 180. L is the inductance of the coil 180, and R is the resistance value of the entire control circuit 214.
When the above equation is Laplace transformed (d / dt = s), the following equation is obtained.
I (s) = {1 / (L · s + R)} · U (s)
As shown in the above equation, the transfer function between the voltage (duty ratio) and the current is expressed by a first-order lag response equation. As shown in FIG. 5 (b), the current value increases with a delay with respect to the change of the duty ratio (transiently), and thereafter (steadily) with a constant magnitude determined by the duty ratio and the resistance value. Become.

As described above, the resistor 254 includes the resistance of the IC having the switching element 252 and the resistance of the coil 180. In the circuit including the coil 180, the relationship between the voltage and the current (hereinafter, the relationship between the voltage and the current may be referred to as a characteristic or a circuit characteristic) is constantly linear. In a circuit including an IC, it is known that the relationship between voltage and current becomes nonlinear in a region where the voltage is small. This non-linearity is particularly noticeable when voltage control is performed by duty control. Therefore, as indicated by the solid line in FIG. 6A, the characteristics of the control circuit 214 (a circuit including the IC and the coil 180) are nonlinear in the low voltage region and linear in the high voltage region. Is larger than the region separation value Io (Io> 0), the relationship between voltage and current is linear.
On the other hand, the resistance value R of the coil 180 increases as the temperature increases, as shown in the following equation.
R (T) = R (T0) + γ (T−T0)
T is an actual temperature, T0 is a standard temperature (for example, 25 ° C.), and γ is a positive coefficient. Therefore, as shown in FIG. 6 (a), the relationship between the current and the duty ratio in the linear region is a relationship indicated by a solid line when the temperature is a standard temperature, and a relationship indicated by a two-dot chain line when the temperature is high. When becomes lower, the relationship shown by the alternate long and short dash line is obtained.

<Operation in hydraulic brake system>
[Outline]
When this hydraulic brake system is mounted on an electric vehicle, a hybrid vehicle or the like, regenerative cooperative control is performed in principle.
For example, when the brake pedal 24 is depressed by the driver, a braking request is issued. When the braking force corresponding to the braking request is satisfied by the regenerative braking force, the hydraulic brakes 4 and 10 are not operated.
The linear valve device 104 is not controlled and the regulator 102 is inactive. The control piston 114 is in the retracted end position, and the reservoir 52 is communicated with the servo chamber 124. No hydraulic pressure is supplied to the back chamber 66 of the master cylinder 26.
In the master cylinder 26, the communication control valve 82 is opened and the reservoir shut-off valve 86 is closed, so that the input chamber 70 and the annular chamber 62 are communicated with each other, and these are shut off from the reservoir 52, and the stroke simulator 90. As the brake pedal 24 advances, the input piston 36 is advanced relative to the pressurizing piston 34 and the stroke simulator 90 is activated.
Further, since the area of the pressure receiving surface facing the annular chamber 62 of the intermediate piston portion 58 and the area of the pressure receiving surface facing the input chamber 70 of the rear small diameter portion 60 are the same, in the pressurizing piston 34, The forward force caused by the hydraulic pressure and the backward force caused by the hydraulic pressure in the annular chamber 62 are balanced.
In this state, in principle, the pressurizing piston 34 is not moved forward, and no hydraulic pressure is generated in the front pressurizing chambers 40 and 42. No hydraulic pressure is supplied to the brake cylinders 6 and 12, and the hydraulic brakes 4 and 10 are in an inoperative state.

On the other hand, when the braking force required by the driver is insufficient with the regenerative braking force, the hydraulic brakes 4 and 10 are operated.
In the regulator 102, when the control hydraulic pressure Psi that is the actual hydraulic pressure in the control pressure chamber 122 is increased by the control of the linear valve device 104, the control piston 114 is advanced. The valve opening member 144 contacts the valve element 132, the servo chamber 124 is shut off from the reservoir 52, and the servo hydraulic pressure Psb increases. When the control piston 114 is further advanced, the valve opening member 144 separates the valve element 132 from the valve seat 130, and the high pressure supply valve 126 is opened. The servo chamber 124 and the high pressure chamber 116 are communicated, and the servo hydraulic pressure Psb is supplied to the back chamber 66.
In the master cylinder 26, the pressurizing piston 34 is advanced by the hydraulic pressure in the back chamber 66, the hydraulic pressure is generated in the front pressurizing chambers 40, 42, supplied to the brake cylinders 6, 12, and the hydraulic brake 4 , 10 are activated.
Thus, the hydraulic pressure of the brake cylinders 6 and 12 is controlled by the control of the linear valve device 104, and the hydraulic braking force and the regenerative braking force are controlled to satisfy the braking force required by the driver. .

When the hydraulic brake system is mounted on an internal combustion drive vehicle or when regenerative cooperative control is not performed, the linear valve device 104 is arranged so that the braking force requested by the driver is satisfied by the hydraulic braking force. Be controlled.
Hereinafter, control of the linear valve device 104 will be described with reference to FIG. In this embodiment, the control of the current supplied to the coil 180 of the pressure-increasing linear valve 160 will be described.
[Control of linear valve]
In the target current calculation unit 300, a target current Iref that is a target value of the supply current to the coil 180 of the pressure-increasing linear valve 160 is determined according to the braking request.
A requested total braking force Fref, which is a braking force requested by the driver, is obtained based on at least one of the detection value of the operation hydraulic pressure sensor 92 and the detection value of the operation stroke sensor 200. When the required total braking force Fref is satisfied by the regenerative braking force Feref, the required hydraulic braking force Fpref is set to zero. In this case, the linear valve device 104 is not controlled.
On the other hand, when the required total braking force Fref is not satisfied by the regenerative braking force Feref, the required hydraulic braking force Fpref is set to a value larger than zero. The target hydraulic pressure of the brake cylinders 6, 12, that is, the target hydraulic pressure Pref of the front pressurizing chambers 40, 42 is determined and the target hydraulic pressure of the rear chamber 66 is determined so that the required hydraulic braking force Fpref is satisfied. . Due to the structure of the master cylinder 26 and the like, a certain relationship is established between the hydraulic pressure in the front pressurizing chambers 40 and 42 and the hydraulic pressure in the rear chamber 66.
In the regulator 102, the target hydraulic pressure in the back chamber 66 is set to the target servo hydraulic pressure Psbref that is the target hydraulic pressure in the servo chamber 124. Further, a certain relationship is established between the servo fluid pressure Psb and the control fluid pressure Psi due to the structure of the regulator 102 and the like. Based on the relationship between the servo fluid pressure and the control fluid pressure and the target servo fluid pressure Psbref, the target control fluid pressure Psiref, which is the target fluid pressure in the control pressure chamber 122, is obtained. The control hydraulic pressure Psi is estimated based on the actual servo hydraulic pressure Psb detected by 156.
Then, the target value Iref of the supply current to the coil 180 of the pressure-increasing linear valve 160 is determined and output so that the estimated control fluid pressure Psi approaches the target control fluid pressure Psiref.

The duty ratio determining unit 302 determines and outputs a duty ratio Dn for controlling the switching unit 252 based on the circuit characteristics of the control circuit 214 stored in the circuit characteristic storage unit 220 and the target current Iref. The In this embodiment, the circuit characteristic storage unit 220 has a relationship between the current and the duty ratio at the standard temperature (hereinafter, the circuit characteristic at the standard temperature is referred to as the standard characteristic), as indicated by the bold line in FIG. It is remembered. Even if only the linear region portion of the standard characteristic defined by the thick solid line (hereinafter referred to as the standard linear characteristic) is stored in the circuit characteristic storage unit 220, the standard defined by the thick solid line and the thick broken line is stored. Characteristics (including standard linear characteristics and standard nonlinear characteristics that are part of the nonlinear region) may be stored.
In the temperature correspondence correction unit 304, the duty ratio Dn determined by the duty ratio determination unit 302 is corrected using the temperature correction coefficient KT and output (duty ratio Dout). The correction of the duty ratio Dn will be described later.

The power supply voltage correction unit 306 corrects and outputs the input duty ratio Dout based on the voltage level of the power supply 250 (Dout1). When the power supply voltage is low, the input duty ratio Dout is corrected to be larger than when the power supply voltage is high. The relationship between the power supply voltage and the correction value of the duty ratio is acquired in advance, and is mapped and stored, for example.
In the noise removal unit 308, if the input duty ratio Dout1 is not between the lower limit value (for example, 0) and the upper limit value (for example, 100%), the lower limit The value or the upper limit value is determined and output (Dout2).
The switching element control unit 310 controls the switching element 252 with the input duty ratio Dout2. By controlling the switching element 252 with the duty ratio Dout2, a current corresponding to the coil 180 is supplied.

The actual current (actual current) flowing through the coil 180 is detected by the current monitor 202 and fed back.
In the A / D converter 320, the actual current Ia (analog value) detected by the current monitor 202 is converted into a digital value and output.
In the current monitor correction unit 321, temperature correction of the current monitor 202 is performed, or a digital value is converted into a current value.
In the digital filter 322, noise and the like are removed and smoothed. In this embodiment, the moving average value is acquired and output (Iaf).
In the duty ratio acquisition unit 324, the duty ratio Daf corresponding to the actual current Iaf is acquired based on the input actual current Iaf and the standard characteristic (or standard linear characteristic) stored in the circuit characteristic storage unit 220. .
Then, a deviation (Dn−Daf) that is a difference between the duty ratio Daf corresponding to the actual current Iaf and the duty ratio Dn corresponding to the target current Iref is acquired and supplied to the PID control unit 326. In the PID control unit 326, the feedback control value DFB is acquired so that the duty ratio deviation (Dn−Daf) becomes small. Then, it is added to the duty ratio Dout output from the temperature correspondence correction unit 304.
On the other hand, since the output value Dout of the temperature corresponding correction unit 304 is the feedforward control value DFF (Dout = DFF), the duty ratio input to the switching element control unit 310 is the feedforward control value and the feedback control value. The combined size (DFB + DFF) is set, and the switching element 252 is controlled by combining feedforward control and feedback control.
It should be noted that interrupt processing may be performed when the duty ratio deviation (Dn−Daf) is greater than a set value.

{Temperature correction}
In the duty ratio determination unit 302, the duty ratio Dn is determined based on the target current Iref and the standard characteristics. However, as described above, the resistance value R of the control circuit 214 changes as the temperature changes. . Therefore, as shown in FIG. 6 (a), when the switching element 252 is controlled with the duty ratio Dn, if the actual temperature, which is the actual temperature of the coil 180, is lower than the standard temperature, the current larger than the target current Iref. (Ia1> Iref) flows when the actual temperature is higher than the standard temperature, the current flowing from the target current Iref becomes smaller (Ia2 <Iref). For example, the operation start current of the pressure increasing linear valve 160 may not be satisfied. is there.
Further, as described above, the hydraulic brakes 4 and 10 are actuated by generating hydraulic pressure in the control pressure chamber 122 of the regulator 102 as a trigger. However, the hydraulic pressure in the control pressure chamber 122 is transmitted to the front pressurization chambers 40 and 42 by the advancement of the control piston 114 and the pressurization pistons 32 and 34, and is transmitted through a plurality of members. Therefore, if the supply current at the start of control of the pressure increasing linear valve 160 to the coil 180 is insufficient and the opening of the pressure increasing linear valve 160 is delayed, the operation delay of the hydraulic brakes 4 and 10 increases.
Therefore, in this embodiment, the temperature correspondence correction unit 304 corrects and outputs the duty ratio Dn determined by the standard characteristics based on the actual temperature.

On the other hand, as described above, the relationship between the voltage (corresponding to the duty ratio) applied to the coil 180 in the control circuit 214 and the current flowing through the coil 180 includes a non-linear region and a linear region {FIG. 6 (a). }. The valve opening current as the operation start current of the pressure-increasing linear valve 160 is included in the linear region, and the characteristics in the linear region are used for controlling the supply current to the coil 180.
Therefore, in this embodiment, as indicated by the solid line, the alternate long and short dash line, and the alternate long and two short dashes line in FIG. Is done. This is because the characteristics of the non-linear region are not used for controlling the current supplied to the coil 180, and thus it is less necessary to acquire the characteristics of the non-linear region. Also, if the characteristics of the nonlinear region are not acquired, but only the characteristics of the linear region are acquired, it takes less time than when the characteristics including both the characteristics of the linear region and the nonlinear region are acquired. Real linear characteristics can be easily obtained. Furthermore, if the characteristic of the linear region is acquired without considering the characteristic of the nonlinear region, the real linear characteristic can be acquired accurately.

The linear characteristic is a relationship between the current in a range where the current is larger than the region separation value Io and the duty ratio, but it is less necessary to strictly define the size of the region separation value Io. In addition, it is difficult to strictly determine the boundary line between the linear region and the nonlinear region. Further, what is actually required is an area used for control. Therefore, the region separation value Io only needs to be determined so as to include the region used for control, and is not necessarily a strict boundary line between the linear region and the nonlinear region.
Linear characteristics are defined by line segments. In other words, the linear characteristic is defined by the portion (line segment) in which the current is larger than the region separation value Io in the straight line. The maximum current value at the other end of the line segment is determined by the standard of the coil 180 of the pressure-increasing linear valve 160, the standard of the control circuit 214, and the like.
On the other hand, a straight line including a line segment defining this linear characteristic is
D = α · I + β
And is a straight line having an intercept β (β> 0). The intercept β is a duty ratio when the current I is 0, and is a point on the extension line of the line segment (a point deviating from the linear region). However, when a point deviating from the linear region such as the intercept is used to define the linear characteristic, the intercept or the like is considered to be one element representing the linear characteristic and is stored in the circuit characteristic storage unit 220.

The temperature correction coefficient KT is a ratio of the gradient α (= ΔD / ΔI) in the case of the actual temperature to the gradient αn (= ΔDn / ΔIn) of the duty ratio with respect to the current in the case where the coil 180 temperature is the standard temperature (= α / αn).
The temperature correction coefficient KT is acquired based on the standard temperature characteristic, the actual measurement point, and the reference point. The reference point is a value used to obtain the temperature correction coefficient KT. In this embodiment, the rotation center point that is a point through which an extended line of a line segment that defines linear characteristics passes even if the temperature changes. Is done. Theoretically, it is the resistance of the coil 180 that changes with changes in temperature, and changes in other elements are small compared to changes in the resistance of the coil 180, so it is considered that there is a center point of rotation. The rotation center point Qc (Ic, Dc) shown in FIG. 8 is acquired before the vehicle is allowed to travel and is stored in the circuit characteristic storage unit 220. Although the reference point is in a range outside the linear region, it can be considered as an element of the linear characteristic because it is on the extension of the line segment that defines the real linear characteristic or the standard linear characteristic.

The actual duty ratio Da, which is the actual duty ratio, and the actual current value, which is the current that actually flows through the coil 180, before the control of the pressure-increasing linear valve 160 is started after the vehicle is allowed to travel. One actual measurement point Qa (Ia, Da) represented by Ia is acquired. The actual measurement point is a point where the current Ia is larger than the region separation value Io and smaller than the valve opening current Ista of the pressure increasing linear valve 160.
The duty ratio Dn is a duty ratio determined by standard characteristics and a target current Iref (for example, Ia), and is a duty ratio necessary for obtaining a current value Iref (Ia) when the temperature is a standard temperature. is there.
KT = (Da-Dc) / (Dn-Dc)
If the above equation is modified so that Da is Dout, the following equation is obtained.
Dout = KT · (Dn−Dc) + Dc
As shown in the above equation, a real linear characteristic is acquired based on the standard property, temperature correction coefficient, and rotation center point. If the standard property (relationship between Dn and Iref) is substituted into the above equation, the relationship between Dout and Iref The real linear characteristic that is the relationship can be obtained}, and based on the real linear characteristic, when the temperature of the coil 180 is the actual temperature, the duty ratio Dout required to bring the actual current closer to the target current Iref is To be acquired.
Further, when the rotation center point is considered as an element of the standard characteristic, it can be considered that the real linear characteristic can be obtained based on the standard characteristic and the temperature correction coefficient. Furthermore, since the standard characteristic is stored in advance, it can be considered that the temperature correction coefficient is a real linear characteristic.

"Obtaining Reference Point"
The rotation center point Qc as the reference point is acquired by the reference point acquisition program represented by the flowchart of FIG. 9B before the vehicle is allowed to travel.
For example, when the vehicle is ready to run, the vehicle manufacturing process (for example, the assembly process, the manufacturing process of the control circuit 214, etc.), the repair or replacement of the hydraulic brake system, etc. are performed. This is the case when inspection is performed. Even if the control circuit 214 is mounted on the vehicle body, the control circuit 214 may be in a state before being assembled to the vehicle body (or removed from the vehicle body).
For example, as shown in FIG. 9 (a), the brake ECU 20 and an external device 300 included in equipment such as a factory are connected, and a reference point acquisition program stored in the brake ECU 20 by a trigger signal output from the external device 300 And the rotation center point Qc is acquired.
As shown in FIG. 8, the rotation center point Qc is obtained by obtaining a straight line including a line segment defining two linear characteristics having different temperatures from each other, and is an intersection of them. Theoretically, the intersection of two straight lines with different temperatures can be used as the rotation center point Qc. However, when the variation is taken into account, two intersections of three or more straight lines are obtained. Thus, the rotation center point Qc can be determined.
Further, although the temperature of the coil 180 can be changed by changing the temperature of the atmosphere in which the control circuit 214 exists, changing the temperature of the entire equipment requires a lot of energy and takes time. Therefore, in this embodiment, as shown in FIG. 9 (c), after a plurality of actual measurement points for acquiring a straight line are acquired, a current equal to or greater than a set value is passed through the coil 180 for a set time. The temperature of 180 is increased (changed). The current and set time that are equal to or greater than the set value are times during which the temperature can be changed by heating the coil 180. Moreover, the temperature at the time of acquiring the straight line containing the line segment which prescribes | regulates two linear characteristics does not matter, and what is necessary is just to differ. It suffices if the temperatures for acquiring the line segments that define the two linear characteristics are different, and it is not necessary to detect the temperatures for acquiring the actual measurement points.
It should be noted that the acquisition of the actual measurement point and the subsequent coil heating can be performed continuously (without the coil current being set to 0).

In step 1 (hereinafter simply referred to as S1. The same applies to other steps), it is determined whether or not the count value n of the counter is equal to or greater than the set value ne. The counter counts the number of straight lines including a line segment that defines the acquired linear characteristics, and determines whether or not a predetermined number ne of straight lines have been acquired. Since the initial value of the counter value is 0, the determination is NO when S1 is executed first. In S2, a plurality of actual measurement points Qa are acquired, and in S3, one straight line (gradient αk, intercept βk) including a line segment that defines linear characteristics based on the plurality of actual measurement points Qa is acquired (k = 0, 1, 2, ...). In S4, the coil 180 is heated, and in S5, the count value n of the counter is incremented by one.
Next, the process returns to S1. Thereafter, S2 to S5 are repeatedly executed until the count value reaches the set value ne, and the straight line is acquired while the coil 180 is heated. When the count value reaches the set value ne (which is 2 in the present embodiment), the determination is YES, and in S6, the rotation center point Qc is acquired based on the two (ne) straight lines. . The rotation center point Qc (Ic, Dc) is used as a reference point, and is stored in the circuit characteristic storage unit 220 in S7 (Dc may be stored), and the count value is returned to 0 in S8.

The actual measurement point Qa is acquired according to the flowchart shown in FIG. 10A (S2).
Since it is before the vehicle is allowed to travel, a plurality of (for example, three or more) actual measurement points Qa can be acquired in a wide linear region. Regardless of the operating state of the hydraulic brakes 4, 10, the magnitude of the current supplied to the coil 180 can be controlled. In order to define a line segment, it is only necessary to determine at least two actual measurement points. However, a line segment can be more accurately defined based on many actual measurement points. A large number of acquired actual measurement points are statistically processed, and one line segment is identified.
In this embodiment, the duty ratio is increased by a set value as shown in FIG. 10B (Da1, Da2,...), And the current value at that time is changed as shown in FIG. The actual current values (Ia1, Ia2,...) Are acquired by measurement by the current monitor 202. The duty ratio is increased stepwise and the actual current is increased stepwise.
In other words, the target current Iref is increased by a set value, and the duty ratio Dn is obtained based on the target current Iref and the standard characteristics. The duty ratio Dn increases linearly as the target current Iref increases. Therefore, the setting value is increased.

In S21, the switching element 252 is controlled with the duty ratio Da1, and in S22, the current flowing through the coil 180 is measured by the current monitor 202 (Ia1). Since the current is increased with a delay, it is measured after reaching a steady state. In S23, the actual measurement point Qa1 (Ia1, Da1) is stored. Next, the duty ratio is increased (Da2> Da1), and in S24, the switching element 252 is controlled with the duty ratio Da2, the current is measured (Ia2), and the measured point Qa2 is stored. Hereinafter, a predetermined number (range) of actual measurement points Qaj (j = 1, 2,...) Are acquired and stored (S29).
Based on the plurality of actual measurement points Qaj thus obtained, as shown in FIG. 10 (d), a line segment (straight line including the line segment) defining the linear characteristic at a certain temperature is acquired (inclination αk , Intercept βk).

"Temperature correction coefficient learning"
Then, after the vehicle is brought into a state where it can travel (in a state where the vehicle can travel), the temperature correction coefficient KT is acquired when the learning condition is satisfied. The travelable state can be a state after the vehicle is completed and shipped, a state after the ignition switch is turned on, or the like. In the present embodiment, it is determined that the learning condition is satisfied when the learning timing is reached and the hydraulic brakes 4 and 10 are in the non-operating state.
Since the rear hydraulic pressure control device 28 is provided near the engine (when this hydraulic brake system is mounted on a hybrid vehicle or a gasoline vehicle), it is heated by the operation of the engine and the temperature changes. It is also susceptible to outside temperature. Therefore, it is determined that the learning timing has been reached regularly, that is, every time the set time has elapsed since the temperature correction coefficient KT was acquired last time.
The non-operating state of the hydraulic brakes 4 and 10 includes (i) a state where the required hydraulic braking force Fpref is 0, (ii) a state where no current is supplied to the coil 180 of the pressure-increasing linear valve 160, iii) When the brake pedal 24 is not depressed (when the required total braking force Fref is 0), (iv) When the regenerative cooperative control is performed, the required total braking force Fref and the actual regenerative braking force Fe are less than 0. It can be set to one or more states, such as the state where the required hydraulic braking force Fpref is large. If learning is performed in a state where the brake pedal 24 is depressed and the required hydraulic braking force Fpref is 0, the temperature correction coefficient KT is acquired at the actual temperature immediately before the start of the pressure increasing linear valve 160. can do.
In addition, it can be added to the learning condition that the engine is in an operating state or the ignition switch is ON.

A flowchart of the KT learning program is shown in FIG.
In S41, it is determined whether or not the learning timing has been reached, and in S42, it is determined whether or not the hydraulic brakes 4 and 10 are in a non-operating state. When the learning timing has been reached and the hydraulic brakes 4 and 10 are not in the applied state, the current flowing through the coil 180 is larger than the region separation value Io in S43, as shown in FIG. The switch element 252 is controlled with a duty ratio Da (duty ratio determined by the target current Iref and the standard characteristics shown by the solid line in FIG. 6A) that is smaller than the current Ista. In other words, a voltage corresponding to the duty ratio Da is applied, and in S44, the actual current Ia in that case is measured after reaching a steady state. In S45, the temperature correction coefficient KT is acquired {KT = (Da−Dc) / (Dn−Dc)} and stored in S46. The temperature correction coefficient KT is updated as appropriate.
As shown in FIG. 11 (c), the temperature at that time is usually higher than the standard temperature. Therefore, when controlled by the duty ratio Da, the temperature is less than the current Iref that flows when the temperature is the standard temperature. A current Ia flows.

"Control of supply current"
In the temperature correspondence correction unit 304, the duty ratio Dn determined based on the target current Iref and the standard characteristics in the duty ratio determination unit 302 is expressed by the equation Dout = KT · (Dn−Dc) + Dc.
(Dn → Dout) and output (Dout).
As shown in FIG. 7, in the temperature correspondence correction unit 304, the duty ratio Dn determined based on the standard characteristics is corrected, and the feedback control value is added to the output duty ratio Dout, and the correction according to the power supply voltage is performed. As a result, the duty ratio output to the switching element 252 is determined.
When the required hydraulic braking force Fpref is greater than 0 and the current supply command to the coil 180 is output first, the feedback control value is not output from the PID control unit 326, and the duty ratio is set to a smaller value. Often. On the other hand, in the present embodiment, when the required hydraulic braking force Fpref is 0, that is, before the operation of the pressure increasing linear valve 160, the temperature correction coefficient KT is obtained. Temperature correction can be performed. Further, as shown in FIG. 11B, since the temperature correction is acquired based on the actual measurement points (Da, Ia), it is considered that the value is substantially the same as the value obtained by the feedback control. Can do. As a result, the initial response can be improved, and the time ts required for the actual current at the start of current supply to reach 90% of the target current Iref should be shorter than that in the conventional hydraulic brake system. Can do.

In this embodiment, the rear hydraulic pressure control device 28, the brake ECU 20, the current monitor 202, etc. constitute a brake hydraulic pressure control device, and the brake ECU 20, the current monitor 202, etc. constitute an electromagnetic valve control device, of which The circuit characteristics acquisition device is configured by the current monitor 202, the execution unit 210 of the brake ECU 20, the storage unit 212, the control circuit 214, and the like, and the coil current control unit is configured by the part that is executed according to the block diagram of FIG. The coil current control unit is also a real linear characteristic dependence control unit.
In addition, a real linear characteristic acquisition unit, a reference point-based real linear characteristic acquisition unit, and a rotation center point-based real linear characteristic acquisition unit are configured by a part that stores and executes a KT learning program in the circuit characteristic acquisition device. Of these, the measured point acquisition unit is configured by the part that stores S43 and 44, the part that executes S43, 44, and the like, and the gradient ratio acquisition unit is configured by the part that stores S45, the part that executes S45, and the like. Further, a reference point acquisition device, a reference point acquisition unit, and an actual measurement point-based reference point acquisition unit are configured by a part for storing a reference point acquisition program, a part for execution, and the like. Of these, the straight line acquisition unit is configured by the part that stores S2, 3 and the part to execute, the coil heating unit is configured by the part that stores S4, the part that executes, etc., and the part that stores S6 and the part that executes Etc. constitute an intersection-based reference point acquisition unit. Further, the circuit characteristic storage unit 220 and the like constitute a standard linear characteristic storage unit, a reference point storage unit, and a rotation center point storage unit.
Further, the gradient correspondence control unit and the control command value correction unit are configured by the temperature correspondence correction unit 304 of the coil current control unit.
The execution of S43 and S44 of the KT learning program corresponds to the actual measurement point acquisition process, and the execution of S45 corresponds to the real linear characteristic acquisition process.

In the present embodiment, as shown in FIG. 12, the rotation center point is the intercept βc. In other words, the gradient changes as the temperature changes, but the intercept (duty ratio when the current I = 0) can be considered to be a substantially constant value. In particular, the intercept βc can be regarded as the rotation center point for the control circuit having the characteristic that the nonlinear region is narrow.
As shown in FIGS. 14 (a) and 14 (b), a plurality of actually measured points (at least two) are acquired before the vehicle is allowed to travel, and a straight line including a line segment that defines linear characteristics. Is obtained, and the intercept βc is obtained. Then, the intercept βc is stored in the circuit characteristic storage unit 220.
The reference point acquisition program represented by the flowchart of FIG. 13 is executed. In this embodiment, the temperature of the coil 180 does not matter, but it may be a temperature near the standard temperature.
In S61, a plurality of actual measurement points Qaj are acquired in the same manner as described above. In S62, a straight line including a line segment that defines a linear characteristic is acquired based on a plurality of measured points Qaj (αc, βc), and in S63, an intercept βc that is a duty ratio when the current is 0 is obtained. Remembered.

And in the state which can drive | work a vehicle, the temperature correction coefficient KT is acquired according to the KT learning program represented by the flowchart of Fig.15 (a).
When the learning timing is reached and the hydraulic brakes 4 and 10 are in a non-actuated state, the determination in S81 is YES and the determination in S82 is NO. In S83 to 85, one actual measurement point Qa is acquired and stored. . In S86, the temperature correction coefficient KT is acquired and stored in S87. The temperature correction coefficient KT is expressed by the following equation: KT = (Da−βc) / (Dn−βc)
Get according to.
In the temperature correspondence correction unit 304, the duty ratio Dn determined by the duty ratio determination unit 302 is corrected based on the temperature correction coefficient KT and the intercept βc and output.
Dout = KT · (Dn1−βc) + βc
As in this embodiment, if the intercept βc is considered as the rotation center point, the reference point can be easily acquired accordingly.

Further, as in the case of the first embodiment, as shown in FIG. 15B, the actual measurement point is acquired before the operation of the pressure increasing linear valve 160 and the temperature correction coefficient KT is acquired. An appropriate current determined based on the real linear characteristic can be supplied. As a result, the valve opening delay of the pressure increasing linear valve 160 can be suppressed, and the time ts until the actual current reaches 90% or more of the target current Iref can be shortened satisfactorily.
In the present embodiment, the intercept storage unit is configured by the circuit characteristic storage unit 220 and the like, and the intercept-based actual characteristic acquisition unit is configured by the part that stores the KT learning program represented by the flowchart of FIG. Is configured.

As shown in FIG. 16, an actual intercept β * is acquired based on a plurality of actually measured points, and the temperature correction coefficient KT (real linear characteristics) is acquired based on the acquired intercept β *, the intercept βc as a reference point, and the like. ). This is because there is a possibility that the intercept may be shifted as the temperature changes.
In the present embodiment, the reference point acquisition program represented by the flowchart of FIG. 13 is similarly executed before the vehicle is allowed to travel, and the intercept βc as the reference point is acquired and stored. The intercept βc as a reference point may be acquired at a standard temperature.
When the learning condition is satisfied after the vehicle is allowed to travel, two measured points (Da1, Ia1) and (Da2, Ia2) are acquired, and an actual intercept β is obtained based on these two measured points. * Is acquired. Then, the temperature correction coefficient KT is acquired based on the actual intercept β * and one actual measurement point {for example, (Da1, Ia1)} and the standard characteristics and the reference point βc stored in advance.

The temperature correction coefficient KT is acquired according to the temperature correction coefficient KT learning program of FIG.
When the learning timing is reached and the hydraulic brakes 4 and 10 are in the non-actuated state, the determination at S91 is YES and the determination at S92 is NO, and two measurement points Qa1 and Qa2 are acquired at S93 to 98. The As shown in FIG. 17 (b), the switching elements 252 are respectively controlled with the duty ratios Da1 and Da2, and after reaching the steady state, the actual current values are measured and stored {(Ia1, Da1 ), (Ia2, Da2)}. Currents Ia1 and Ia2 that actually flow are in a linear region and are smaller than the operation start current Ista of the pressure-increasing linear valve 160.
Then, in S99, as shown in FIG. 16, a straight line intercept β * determined from these two actually measured points Qa1 and Qa2 is acquired, and in S100, the temperature correction coefficient KT is acquired and stored.
KT = (Da1-β *) / (Dn1-βc)
Then, the temperature corresponding correction unit 304 corrects the input duty ratio Dn according to the following equation, and outputs the duty ratio Dout.
Dout = KT · (Dn−βc) + β *
Dn is a duty ratio determined based on the target current Iref and the standard characteristics, as in the case of the above embodiment.
As described above, in the present embodiment, the real linear characteristic can be obtained well even if the intercept shifts with a change in temperature.

In the first and second embodiments, the temperature correction coefficient KT is acquired, and the real linear characteristic is acquired by the standard linear characteristic and the temperature correction coefficient KT. However, the straight line including the line segment defining the real linear characteristic is used. Can be actually obtained and stored.
In the present embodiment, in a state where the vehicle can run, when a predetermined learning timing is reached and the hydraulic brakes 4 and 10 are in a non-acting state, the current is larger than the region separation value Io, and A plurality of different actual measurement points in a range smaller than the operation start current are acquired, and a real linear characteristic is acquired based on the plurality of actual measurement points. In other words, a plurality of sets of a plurality of actual measurement points having different currents and duty ratios are acquired, and real linear characteristics are acquired based on all the actual measurement points included in the plurality of sets.
When the current supplied to the coil 180 of the pressure-increasing linear valve 160 is actually controlled, the duty ratio Dout can be obtained according to the obtained actual linear characteristic.

An example of a flowchart of the real linear characteristic learning program is shown in FIG.
In S101, it is determined whether or not the learning timing has been reached. In S102, it is determined whether or not the hydraulic brakes 4 and 10 are in an inoperative state. When the learning timing has been reached and the hydraulic brakes 4 and 10 are in the non-actuated state, it is determined in S103 whether or not a set of a plurality of actually measured points has reached the set number. When the number is smaller than the set number, as shown in FIG. 18B, in S104 to 106, the switching element 252 is controlled with the duty ratio Da1, and the current (Ia1) after reaching the steady state is measured. The actual measurement point Qa1 (Da1, Ia1) is stored. Next, in S107 to 109, the duty ratio is increased (Da2> Da1), and the current (Ia2) after reaching the steady state is measured by controlling with the increased duty ratio Da2, and the actual measurement point Qa2 (Da2, Ia2) is stored. As described above, after one set of the two actual measurement points Qa1 and Qa2 is acquired, in S110 and 111, the current is controlled to be smaller than the region separation value Io during the set time (I <Io ), Heating of the coil 180 is suppressed. The measurement point acquisition is suspended, and an interval is provided. Thereafter, in S112, the count value of the set counter is incremented by 1, and the process returns to S103. Hereinafter, similarly, in a non-operating state of the brake, S104 to S112 are repeatedly executed until the count value reaches the set number, and current values Ia1 and Ia2 when controlled by the duty ratios Da1 and Da2 are acquired. A set of two actually measured points Qa1 and Qa2 is acquired. When the count value of the set number counter reaches the set number, the determination in S103 is YES, and in S113, a straight line (α, β) including a line segment that defines the real linear characteristic is acquired and stored. In S114, the count value of the set counter is set to 0. The straight line including the line segment defining the actual linear characteristic is updated as appropriate.
Thus, it is not essential to acquire the temperature correction coefficient, and the real linear characteristic can be directly acquired.

In S113, line segments can be acquired and data can be mapped and stored.
Further, the number of actual measurement points included in one set may be three or more. In a range larger than the region separation value Io and smaller than the operation start current Ista of the pressure-increasing linear valve 160, the actual linear characteristic can be obtained more accurately when the number of actually measured points is larger.

  In the present embodiment, a circuit characteristic acquisition apparatus is configured by a part for storing and executing a real linear characteristic learning program represented by the flowchart of FIG. 19, and among them, execution of S103 to S109 is acquisition of a plurality of actual measurement points. Corresponding to the process, the execution of S110 and 111 corresponds to the coil heating suppression process, and the execution of S113 and 114 corresponds to the multiple-point-based real linear characteristic acquisition process.

In each of the above-described embodiments, the reference point acquisition program is stored in the vehicle brake ECU 20, but as shown in FIG. You can also keep it.
The external device 300 is mainly a computer and includes an execution unit 302, a storage unit 304, and the like. Is done. Then, the reference point acquisition program is executed in the execution unit 302 of the external device 300 to acquire the reference point, and the acquired reference point is supplied to the brake ECU 20 and stored in the circuit characteristic storage unit 220. It is done.
Between the external device 300 and the brake ECU 310, data such as a duty ratio and a current value is supplied by communication. In the present embodiment, the reference point acquisition program storage unit 222 is not provided in the storage unit 212 of the brake ECU 310.
In this embodiment, it can be considered that the reference point acquisition device is configured by the external device 300 or the like. Further, it can be considered that the external device 300 and the brake ECU 310 constitute an electromagnetic valve control device.

In each of the above-described embodiments, the case where the actual linear characteristic of the control circuit 214 including the coil 180 of the pressure increasing linear valve 160 is acquired has been described. The same can be applied to the case where the real linear characteristic of the control circuit including the coil 194 is acquired.
Further, not only the pressure-increasing linear valve 160 and the pressure-decreasing linear valve 162, but the actual linearity of the control circuit including the coil 82s of the communication control valve 82, the coil 86s of the reservoir shut-off valve 86, and the coils 18a and r of the electromagnetic on-off valves 16a and r. Properties can be obtained as well.

Further, the brake fluid pressure control device including the electromagnetic valve that is the target for obtaining the real linear characteristic is not limited to that in the present embodiment. The present invention is not limited to the electromagnetic valve included in the back surface hydraulic pressure control device 28, but may be a brake hydraulic pressure control device that controls the output hydraulic pressure of the pump device by the electromagnetic valve and supplies the hydraulic pressure to the brake cylinder.
In addition to solenoid valves used in brake fluid pressure control devices, solenoid valves used in fluid pressure control of transmissions, solenoid valves used in fluid pressure control of vehicle height adjustment devices, engine air, and fuel supply The present invention can be applied to electromagnetic valves and the like that are used, and can be widely applied to in-vehicle electromagnetic valves and the like.
Further, the reference point can be acquired during the operation of the hydraulic brakes 4 and 10. When the hydraulic brakes 4 and 10 are in operation and the required hydraulic braking force is changed and the target hydraulic pressure Psiref in the control pressure chamber 122 changes, the duty ratio and the current value can be acquired. A plurality of actual measurement points can be acquired.
Further, when the required total braking force Fref is 0 or the like, if the electromagnetic on-off valve 16r of the slip control device 16 is opened, the actual measurement point can be acquired in a wide range, and the reference point is acquired. be able to. In addition, since the actual measurement points can be acquired in a wide range even in the parking brake operating state, the reference points can be acquired accurately.

Further, when the actual measurement point is acquired, duty control is performed so that the actual current becomes the target current Iref so that the duty ratio Daref when the actual current reaches the target current Iref is acquired. You can also The actual measurement point Q in this case is determined by (Daref, Iref).
Further, it is not necessary to store both the standard linear characteristic and the standard nonlinear characteristic as the standard characteristic, and it is only necessary to store the standard linear characteristic. The embodiment can be implemented in various modifications and improvements based on knowledge.

  4, 10: Hydraulic brake 6, 12: Brake cylinder 14: Hydraulic pressure generator 20: Brake ECU 28: Back hydraulic pressure control device 82: Communication control valve 84: Reservoir shutoff valve 102: Regulator 122: Control pressure chamber 124: Servo chamber 160: Pressure increasing linear valve 162: Pressure reducing linear valve 180, 194: Coil 202: Current monitor 214: Control circuit 212: Storage unit 220: Circuit characteristic storage unit 222: Reference point acquisition program storage unit 252: Switching element 254: Resistance 300: External device 306: Reference point acquisition program storage unit

Claims (13)

(i) a control circuit including a coil of a solenoid valve; and (ii) a coil current control unit that controls a voltage supplied to the control circuit based on at least characteristics of the control circuit to control a supply current to the coil. A solenoid valve control device comprising:
The characteristics of the control circuit are defined by the relationship between the voltage and the current, and include a nonlinear property in which the relationship between the voltage and the current is nonlinear, and a linear property in which the relationship is linear,
The control circuit has the linear characteristic in a range where the current is larger than a region separation value;
The electromagnetic valve control device includes a circuit characteristic acquisition device that acquires the linear characteristic without acquiring the nonlinear characteristic of the control circuit, and the circuit characteristic acquisition device is configured such that the current is larger than the region separation value. And an actual measurement point acquisition unit that acquires at least one actual measurement point in a range smaller than the operation start current of the solenoid valve, and the control based on at least the at least one actual measurement point acquired by the actual measurement point acquisition unit A real linear characteristic acquisition unit that acquires a real linear characteristic that is an actual linear characteristic of the circuit;
The electromagnetic valve control device, wherein the coil current control unit includes a real linear characteristic based control unit that controls a supply current to the coil based on the real linear characteristic acquired by the real linear characteristic acquisition unit . The real linear characteristic dependence control unit includes: (i) a reference point storage unit that stores at least one reference point in which the current is in a range equal to or less than the region separation value; and (ii) stored in the reference point storage unit. said at least one reference point, according to claim 1 including a reference point rely actual linear characteristic acquisition unit for acquiring the actual linear characteristic based on said at least one measured point obtained by the actual measurement point acquiring section Solenoid valve control device. The reference point storage unit includes a rotation center point storage unit that stores, as the reference point, a rotation center point that is a point through which a straight line including a line segment defining the linear characteristic passes even if the temperature is different,
The reference point-based real linear characteristic acquisition unit acquires the real linear characteristic based on the rotation center point stored in the rotation center point storage unit and the at least one actual measurement point. The electromagnetic valve control device according to claim 2 , comprising an acquisition unit. The reference point storage unit includes an intercept storage unit that stores an intercept that is a value of the voltage when the current is 0 as the reference point;
The reference point rely actual linear characteristic acquisition unit, claims, including sections rely actual linear characteristic acquisition unit for acquiring the actual linear characteristic based on said at least one measured point and stored the sections to the section storage unit 2. The electromagnetic valve control device according to 2 or 3 . The solenoid valve control device includes a standard linear characteristic storage unit that stores at least a standard linear characteristic that is the linear characteristic when the temperature of the coil is a standard temperature,
The reference point-based real linear characteristic acquisition unit includes the standard linear characteristic stored in the standard linear characteristic storage unit, at least one reference point stored in the reference point storage unit, and the at least one actual measurement point. A gradient ratio acquisition unit that acquires a gradient ratio that is a ratio of the gradient when the coil temperature is an actual temperature with respect to a gradient of the voltage with respect to the current when the coil temperature is a standard temperature Including
The coil current control unit controls a supply current to the coil based on the standard linear characteristic stored in the standard linear characteristic storage unit and the gradient ratio acquired by the gradient ratio acquisition unit. The electromagnetic valve control device according to any one of claims 2 to 4 , comprising a control unit. (i) a control circuit including a coil of a solenoid valve, and (ii) based on at least the characteristics of the control circuit
A solenoid valve control device including a coil current control unit that controls a voltage supplied to the coil by controlling a voltage of the control circuit,
The characteristics of the control circuit are defined by the relationship between the voltage and the current, and include a nonlinear property in which the relationship between the voltage and the current is nonlinear, and a linear property in which the relationship is linear,
The solenoid valve control device acquires the linear characteristic without acquiring the nonlinear characteristic of the control circuit, and the standard linear characteristic that is the linear characteristic when the temperature of the coil is a standard temperature. A standard linear characteristic storage unit that stores at least
The circuit characteristic acquisition device acquires a gradient ratio that is a ratio between a gradient of the voltage with respect to the current when the temperature of the coil is a standard temperature and the gradient when the temperature of the coil is an actual temperature. Including a slope ratio acquisition unit,
The coil current control unit corrects a control command value determined based on the standard linear characteristic stored in the standard linear characteristic storage unit based on the gradient ratio acquired by the gradient ratio acquisition unit. An electromagnetic valve control device comprising a correction unit and controlling a supply current to the coil using the control command value corrected by the control command value correction unit. (i) a control circuit including a coil of a solenoid valve, and (ii) based on at least the characteristics of the control circuit
A solenoid valve control device including a coil current control unit that controls a voltage supplied to the coil by controlling a voltage of the control circuit,
The characteristics of the control circuit are defined by the relationship between the voltage and the current, and include a nonlinear property in which the relationship between the voltage and the current is nonlinear, and a linear property in which the relationship is linear,
The control circuit has the linear characteristic in a range where the current is larger than a region separation value;
The solenoid valve control device includes a circuit characteristic acquisition device that acquires the linear characteristic without acquiring the nonlinear characteristic of the control circuit, and the circuit characteristic acquisition device is an extension of a line segment that defines the linear characteristic. An electromagnetic valve control device comprising: a reference point acquisition unit that acquires at least one reference point that is a point on a line based on a plurality of actual measurement points in a range where the current is larger than the region separation value. The reference point acquisition unit acquires at least two straight lines each including a line segment that defines the linear characteristic based on the plurality of actual measurement points acquired at different temperatures, and an intersection of the at least two straight lines. The electromagnetic valve control device according to claim 7 , further comprising an intersection acquisition unit that acquires the reference point based on the reference point. The intersection acquisition unit is (i) a straight line acquisition unit that acquires a straight line including a line segment that defines the linear characteristic; and (ii) a coil that raises the temperature of the coil by supplying a heating current to the coil. and a heating unit, according to claim 8 and acquires the reference point based on at least two straight intersection acquired before and and after the respective said linear acquisition section of the coil heating by the coil heating unit The electromagnetic valve control device described in 1. A brake cylinder fluid of a hydraulic brake that includes the solenoid valve control device according to any one of claims 1 to 9 , and that suppresses rotation of a vehicle wheel by controlling a supply current to the coil by the solenoid valve control device. A brake fluid pressure control device for controlling pressure,
The hydraulic pressure control device includes a regulator connected to a back chamber provided behind the pressure piston of the master cylinder,
The brake cylinder is connected to a pressure chamber in front of the pressure piston;
The regulator comprises (i) a control piston having a small diameter portion and a large diameter portion, (ii) a control pressure chamber provided on the large diameter portion side of the control piston, and (iii) the small diameter portion of the control piston. And a servo chamber provided on the side, wherein the electromagnetic valve is connected to the control pressure chamber, and the back chamber is connected to the servo chamber. A reference point acquisition device that acquires a reference point used to acquire a real linear characteristic that is an actual linear relationship between a voltage and a current of a control circuit including a coil of a solenoid valve,
The reference point is a point deviating from a linear region in which the current and the voltage are in a linear relationship;
The reference point acquisition device, wherein the reference point acquisition device includes an actual measurement point-based reference point acquisition unit that acquires the reference point based on a plurality of actual measurement points in the linear region. A circuit characteristic acquisition method for acquiring a real linear characteristic that is an actual linear relationship between a voltage and a current of a control circuit including a coil of a solenoid valve,
A plurality of actual measurement point acquisition steps for acquiring a plurality of actual measurement points in which the voltage and the current are different from each other in a range in which the voltage and the current have a linear relationship;
A coil heating suppressing step of suppressing the heating of the coil by acquiring a plurality of measuring points having different voltages and currents in the plurality of actually measuring point acquisition step, and then reducing the current flowing in the coil to be smaller than the cooling current. ,
By alternately repeating the plurality of actual measurement point acquisition steps and the coil heating suppression step, a plurality of sets consisting of a plurality of actual measurement points having different voltages and currents are acquired, and a plurality of sets included in the plurality of sets are included. And a multi-point-based real linear characteristic acquisition step of statistically processing the actual measurement points to acquire the real linear characteristic. A circuit characteristic acquisition method for acquiring a real linear characteristic that is an actual linear relationship between a voltage and a current of a control circuit including a coil of a solenoid valve,
An actual measurement point acquisition step of acquiring at least one actual measurement point in a range in which the voltage and the current have a linear relationship;
A circuit characteristic acquisition method comprising a real linear characteristic acquisition step of acquiring the real linear characteristic based on at least one actual measurement point acquired in the actual measurement point acquisition step and a reference point stored in advance .

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