JP3017635B2 - Control device for current control type solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a current control type solenoid valve.

[0002]

2. Description of the Related Art In a vehicle, a machine tool, or the like, a current control type solenoid valve is used for various purposes such as hydraulic control.
For example, a solenoid valve for controlling the intake air amount of an internal combustion engine, a solenoid valve for generating a lock-up clutch slip control pressure for an automatic transmission, a solenoid valve for generating an accumulate back pressure control pressure for an automatic transmission, and a throttle valve for generating a throttle pressure for an automatic transmission Such is a solenoid valve. In order to drive such a current control type solenoid valve, a battery of a vehicle is used as a power source.

In order to control the above-described current control type solenoid valve, a current control type solenoid valve which is operated in response to a change in drive current is provided between a battery and the current control type solenoid valve. Current control means for changing the drive current flowing from the battery to the current control type solenoid valve, wherein the actual drive current of the current control type solenoid valve or the actual output pressure of the solenoid valve is a command current or the solenoid valve. There has been proposed a feedback control device for a current control type solenoid valve that controls the above current adjusting means so as to coincide with the target output pressure. JP 6
The control device described in Japanese Patent Application Laid-Open No. 2-241013 is one example.

[0004]

When the power supply voltage fluctuates, for example, when the output current of the battery is rapidly increased, such as when the headlights of the vehicle are turned on or the heater is energized. However, the output voltage of the power supply is changed due to the influence, but the response characteristic of the conventional feedback control device of the current-controlled solenoid valve as described above usually cannot follow the rapid change of the output voltage of the battery. Therefore, there is a disadvantage that the drive current of the current control type solenoid valve is affected and the output of the current control type solenoid valve fluctuates due to the fluctuation of the output voltage of the battery of the vehicle.

If the conventional feedback control device for a current control type solenoid valve controls the current adjusting means so that the actual drive current of the current control type solenoid valve coincides with the command current, The actual drive current value of the current control type solenoid valve detected by the detection means may include an offset by an amplifier circuit included in the current detection means, and accurate feedback control of the current control type solenoid valve may be performed. In some cases it could not be done.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a control device for a current control type solenoid valve which is not affected by fluctuations in the output voltage of a battery. Is to do. A second object of the present invention is to provide a current control device capable of performing accurate feedback control so that an offset is not included in the actual drive current value of the current control type solenoid valve detected by the current detection means. An object of the present invention is to provide a control device for a control type solenoid valve.

[0007]

A first object of the present invention to achieve the first object is to provide a current control type solenoid valve which is operated in response to a change in drive current.
A current adjusting means provided between the battery and the current control type solenoid valve for changing a drive current flowing from the battery to the current control type solenoid valve; and detecting an actual drive current of the current control type solenoid valve. A control device for a current control type solenoid valve, comprising: a current detection unit; and a feedback control unit that controls the current adjustment unit so that an actual drive current detected by the current detection unit matches a command current. , (A)
Output voltage change detection means for detecting a change in the output voltage of the battery; and (b) the current control type based on a change in the voltage of the battery.
A predetermined value is set to cancel the change in the drive current of the solenoid valve.
And a feedback gain changing means for changing a feedback gain of the feedback control means based on a change in the output voltage detected by the output voltage change detecting means.

[0008]

In this way, the current caused by the battery voltage change
Predetermined so as to cancel the change in the drive current of the control type solenoid valve.
From the obtained relationship , the feedback gain of the feedback control means is changed by the feedback gain changing means based on the change in the output voltage of the battery detected by the output voltage change detecting means.

[0009]

Therefore, according to the first aspect of the present invention,
Change in drive current of current-controlled solenoid valve due to battery voltage change
Since the feedback gain of the feedback control means is changed based on the change in the output voltage of the battery from a predetermined relationship so as to cancel the change of the vehicle, such as when turning on the headlights of the vehicle or energizing the heater, etc. Even if the output current of the battery is suddenly increased, the output of the feedback system is changed in response to the decrease in the output voltage of the battery, so that the output of the feedback system is changed due to the fluctuation of the output voltage of the power source such as the battery of the vehicle. Thus, the influence of the drive current of the current control type solenoid valve or the change of the output of the current control type solenoid valve is eliminated.

Here, the current detecting means is preferably
An amplifier for amplifying a voltage generated between both ends of a current detection resistor connected in series with the current control type solenoid valve, and a filter for smoothing an output signal of the amplifier are included. In this way, even if noise is mixed in the value detected by the current detecting means, the noise is advantageously removed by the filter means.

Preferably, the feedback control means calculates a deviation between the command current and an actual current value detected by the current detection means, and multiplies the deviation by an integration constant. An integral control value calculating means for calculating an integral control value, a difference calculating means for calculating a difference value of the deviation, a proportional control value calculating means for multiplying the difference value by a proportional constant to calculate a proportional control value; Operation change value calculation means for calculating an operation change value by adding the integral control value and the proportional control value; and integration means for calculating a new operation output value by adding the operation change value to the previous operation output value. including.

Preferably, the output voltage change detecting means includes a battery output voltage detecting means for detecting an actual output voltage of the battery, a filter means for discriminating a low frequency component of the output voltage of the battery, Output voltage change value calculating means for calculating a change value of the output voltage of the battery by calculating a difference between the output voltage of the battery and a low frequency component of the output voltage.

[0013] Preferably, the feedback gain changing means is configured to determine the actual output voltage of the battery from a predetermined relationship so as to cancel the change in the drive current of the current control type solenoid valve due to the change in the battery voltage. And determining means for determining the integral constant and the derivative constant based on

[0014]

According to a second aspect of the present invention, there is provided a current control type solenoid valve which is operated in response to a change in drive current. A current adjusting means provided between the battery and the current control type solenoid valve for changing a drive current flowing from the battery to the current control type solenoid valve; and detecting an actual drive current of the current control type solenoid valve. A control device for a current control type solenoid valve, comprising: a current detection unit; and a feedback control unit that controls the current adjustment unit so that an actual drive current detected by the current detection unit matches a command current. ,
(a) a drive current cutoff unit that cuts off a drive current of the current control type solenoid valve by the current adjustment unit; and (b) a drive current cutoff of the current control type solenoid valve by the drive current cutoff unit. (C) an offset value determining means for determining a value detected by the current detecting means as an offset value in advance, and (c) subtracting the offset value determined by the offset value determining means from a value detected by the current detecting means. Actual driving current calculating means for calculating the driving current.

[0015]

With this configuration, the value detected by the current detecting means when the driving current of the current control type solenoid valve is interrupted by the driving current interrupting means is determined in advance as the offset value by the offset value determining means. You. Then, the actual drive current is calculated by subtracting the offset value determined by the offset value determination means from the value detected by the current detection means by the actual drive current calculation means.

[0016]

Therefore, according to the second aspect of the present invention,
Since the actual drive current is calculated by removing the offset from the actual drive current value of the current control type solenoid valve detected by the current detection means, the current control type solenoid valve of the current control type solenoid valve is calculated based on the actual drive current. Accurate feedback control is performed.

Here, preferably, the current detecting means comprises:
An amplifier for amplifying a voltage generated between both ends of a current detection resistor connected in series with the current control type solenoid valve, and a filter for smoothing an output signal of the amplifier are included. In this way, even if noise is mixed in the value detected by the current detecting means, the noise is suitably removed by the filter means, and there is an advantage that the offset value as a DC component can be accurately obtained.

Preferably, the offset value determining means determines whether or not a predetermined time has elapsed since the drive current of the current control type solenoid valve was interrupted by the drive current interrupting means. A time determining means for determining an offset value based on a value detected by the current detecting means when the elapsed time determining means determines that the predetermined time has elapsed. Due to the inductance of the coil of the current control type solenoid valve or the capacitance included in the filter means, even if the drive current after being cut off by the drive current cut off means drops transiently, the stable state after the predetermined time has passed Since the value is determined as the offset value, there is an advantage that the offset value can be obtained accurately.

Preferably, the offset value determining means smoothes the detection value of the current detecting means after the driving current of the current control type solenoid valve is interrupted by the driving current interrupting means. And the detected value smoothed by the smoothing means is determined as an offset value. In this way, even if noise is mixed in the value detected by the current detecting means, the influence of the noise can be suppressed as much as possible.

Preferably, the feedback control means is a deviation calculating means for calculating a deviation between the command current and an actual current value detected by the current detecting means, and the deviation is multiplied by an integration constant. An integral control value calculating means for calculating an integral control value, a difference calculating means for calculating a difference value of the deviation, a proportional control value calculating means for multiplying the difference value by a proportional constant to calculate a proportional control value; Operation change value calculation means for calculating an operation change value by adding the integral control value and the proportional control value; and integration means for calculating a new operation output value by adding the operation change value to the previous operation output value. including.

Preferably, the control device for the current control type solenoid valve includes a battery output voltage detecting means for detecting an actual output voltage of the battery, and an operation output value of the feedback control means. And a battery output voltage fluctuation correcting means for correcting by a correction value based on the actual voltage value so that the operation of the current control type solenoid valve is not affected by the fluctuation of the output voltage of the battery. In this way, even if the output voltage value of the battery changes low due to the lighting of the headlights or the energization of the heater, the operation output value of the feedback control means is corrected by the change, and the drive current is increased. There is an advantage that the operation of the current control type solenoid valve is not affected.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing a vehicle current control type solenoid valve 10 to be controlled by a control device according to the present invention. The solenoid valve 10 is used as a lock-up clutch slip control pressure generating solenoid valve, an accumulate back pressure control pressure generating solenoid valve, a throttle pressure generating solenoid valve, etc. provided in a hydraulic control circuit of an automatic transmission for a vehicle. And is also referred to as a linear solenoid valve.

As shown in FIG. 1, the solenoid valve 10 has an input port 12 for supplying a constant modulator pressure or a source pressure P _IN which is a line pressure, an output port 14 for outputting an output pressure P _OUT , A valve body 18 formed with a drain port 16 from which oil is discharged, a first land 20, a valve 26 formed with a second land 22 and a third land 24 having a larger diameter than the first land 20, and a second land The feedback oil chamber 30 communicated with the output port 14 via the communication passage 28 formed obliquely to the valve 22 and the valve element 26 in the valve opening direction in which the communication between the input port 12 and the output port 14 is established. The biasing spring 32 and the core 3 contacting the valve 26
4 and a coil 3 for generating a magnetic force for attracting the core 34
6 and a socket 40 into which a plug (not shown) is inserted for electrically connecting the coil 36.

The electromagnetic actuator 38 of the solenoid valve 10
Generates a thrust corresponding to the drive current I _SOL of the coil 36 to connect the valve 26 to the input port 12 and the output port 14.
And the valve is urged in a valve closing direction to shut off the valve. Assuming that the thrust of the electromagnetic actuator 38 is F (I), the urging force of the spring 32 is W, and the cross-sectional areas of the first land 20 and the second land 22 are A ₁ and A ₂ , the output pressure P _OUT becomes Control is performed according to the equation shown in Equation 1. That is, a hydraulic signal having a magnitude corresponding to the drive current I _SOL of the coil 36, that is, the output pressure P _OUT is output.
Note that C ₁ and C ₂ in Equation 1 are constants,
_{1 = 1 / (A 2 -A} 1), a _{C 2 = W / (A 2} -A 1).

[0026]

## EQU1 ## P _OUT = C ₁ · F (I) -C ₂

FIG. 2 shows a control device mounted on a vehicle for controlling the operation of the solenoid valve 10. In FIG. 2, an ignition switch 56, a current control element 58 such as a transistor, and a coil 3 are provided between a positive terminal 52 of a battery 50 of the vehicle and a ground, that is, a metal body 54.
6. The current detecting resistors 60 are connected in series.

A voltage detecting circuit 62 functioning as an output voltage detecting means detects an output voltage v _B at the + terminal 52 of the battery 50 and outputs a digitized voltage signal VB indicating the output voltage v _B to the arithmetic and control unit 64. To supply. In addition, coil 3
6, a current detection circuit 66 functioning as current detection means for detecting the drive current _ISOL includes an amplifier 68 for amplifying a voltage signal generated across the current detection resistor 60, a filter 7
0, an A / D converter 72, and a driving current I of the coil 36.
A voltage signal VIO representing _SOL is supplied to the arithmetic and control unit 64. The filter 70 is, for example, an L-type low-pass filter including a parallel capacitor 74 and a series resistor 76.
An averaged waveform is output by removing a ripple of about 300 Hz or more.

The arithmetic and control unit 64 is usually constituted by a microcomputer or the like for controlling the gear position of the automatic transmission and the engagement state of the lock-up clutch. The arithmetic and control unit 64 processes the input signal in accordance with a program stored in advance to determine the duty ratio D of the solenoid valve 10 and converts the duty signal into a drive signal D _SOL having a pulse width corresponding to the duty ratio D. The signal D _SOL is output to the current control element 58 via the drive circuit 78. Thereby, the drive current I _SOL of the coil 36 is adjusted. In the present embodiment, the drive circuit 78 and the current control element 58 correspond to current adjusting means for changing the drive current _ISOL of the coil 36.

FIG. 3 shows the relationship between the pulse waveform of the drive signal D _SOL and the drive current I _SOL of the coil 36. FIG.
The solid line on the upper side of FIG. 7 shows a drive signal D _SOL50 with a duty ratio D of about 50%.
_By opening and closing the current control element 58 with _SOL50 ,
The driving current I _SOL5 shown in the lower solid line in FIG.
₀ is flushed. As shown by the upper broken line in FIG. 3, when the duty ratio D becomes a drive signal D _{SOL30 of} about 30%, the current control element 58 is opened and closed by such a drive signal D _SOL30, so that the coil 36 drive current I _{SO L30} shown by the broken line in the lower of FIG. 3 is flowed. As described above, in the present embodiment, the drive current I _SOL of the coil 36 is adjusted according to the duty ratio D of the drive signal D _SOL .

FIG. 4 is a functional block diagram for explaining the control function of the arithmetic and control unit 64. In the figure, an input signal conversion means 90 outputs, for example, a command duty ratio DOUT corresponding to a command current commanded from a control means (not shown) to drive the solenoid valve 10 so as to generate a hydraulic signal of a predetermined magnitude. It is converted to a target value (voltage value) VR. The magnitude of the target value VR indicates the target drive current of the coil 36. The deviation calculating means 92 calculates a deviation EV between the target value VR and the actual driving current value (voltage value) VIO detected by the current detection circuit 66. The integral control value calculating means 94 calculates the integral control value K _I · EV by multiplying the deviation EV by an integration constant K _I. Difference calculation means 96
Calculates the difference value DEV [= EV (k) -EV (k-1)] between the previous and current sampling values of the deviation EV. The proportional control value calculating means 98 multiplies the difference value DEV by a proportional constant K _P to obtain a proportional control value K _P · DE
Calculate V. The operation change value calculating means 100 calculates the operation change value DDO by adding the integral control value K _I · EV and the proportional control value K _P · DEV. The integrating means 102 calculates the operation change value DDO by using the previous operation output value DO (k-1).
To the new current operation output value DO
(K) is calculated.

The current operation output value DO (k) calculated by the integrating means 102 is updated as a drive duty ratio D, and the output signal converting means 104 is provided with the drive duty ratio D at a predetermined frequency of, for example, about 300 Hz. It is converted into a drive signal _DSOL which is a pulse signal. Here, the deviation calculating means 92, the integral control value calculating means 9
4. The difference calculating means 96, the proportional control value calculating means 98, the operation change value calculating means 100, and the integrating means 102
Feedback control means 105 that eliminates V and matches target value VR with actual drive current value VIO of solenoid valve 10.
Is composed.

On the other hand, the filter means 106 discriminates the low frequency component v _BO of the output voltage v _B of the battery 50, and
08 is a low frequency component v from the output voltage v _B of the battery 50.
The change value Δv _B of the output voltage is calculated by subtracting _BO . The low frequency component v _BO may be, for example, a moving average value of the output voltage v _B of the battery 50. Filter means 10
6 and the subtracting means 108 constitute an output voltage change detecting means 110 for calculating a change value Δv _B of the output voltage v _B of the battery 50.

The feedback gain changing means 112
From the relationship stored in advance, the output voltage change detecting means 11
0 based on the output voltage change value Δv _B detected by
Determining means for newly determined the integration constant feedback gains K _I and the proportional constant K _P of said feedback control means 105, integral constant K _I and the proportional use in the integral control value calculating means 94 and the proportional control value calculating means 98 Updating means for updating the constant K _P. The above relationship is obtained in advance so as to cancel the change in the drive current I _SOL of the solenoid valve 10 due to the voltage change value Δv _B of the battery 50. For example, in the block showing the feedback gain changing means 112 in FIG. The data is stored in a memory in the arithmetic and control unit 64 in the form of a data map as described.

Hereinafter, the control operation of the arithmetic and control unit 64 will be described in detail with reference to flowcharts shown in FIGS. FIG. 5 shows several milliseconds for updating the integration constant K _I and the proportionality constant K _{P according} to the voltage change value Δv _B of the battery 50.
FIG. 6 shows a routine that is repeatedly executed at a predetermined cycle of 10 to several tens of ms.
3 shows a routine for executing feedback control for making the actual drive current value VIO of the solenoid valve 10 equal to the actual drive current value VIO.

At step SA1 in FIG. 5, the actual output voltage v _B of the battery 50 is read. Relatively long predetermined interval moving average value v _BO of is calculated as the low-frequency component of step SA2 output voltage v _B. In step SA3, the change value Δv _B is calculated by subtracting the moving average value v _BO from the actual output voltage v _B. In step SA4, for example, the feedback gain changing means 11 shown in FIG.
2, the integral constant K _I and the proportional constant K _P are newly determined based on the actual change value Δv _B. Then, in step SA5, the newly determined integral constant K _I and proportional constant K _P are updated so as to be used as the feedback gain in the feedback control. The above step SA2 is performed by the filter 106
Step SA3 corresponds to the subtraction means 108, and steps SA4 and SA5 correspond to the determination means and the update means of the feedback gain changing means 112.

FIG. 7 shows the relationship between the output voltage v _{B of} the battery 50, the moving average value v _BO , and the change value Δv _B. If the output voltage v _B as shown in A of FIG abruptly drop, the moving average value v _BO is hardly changed, change value Delta] v _B is the value shown in the lower part of FIG.

In the feedback control routine of FIG. 6, step SM corresponding to the input signal converting means 90 is performed.
At 1, the command duty ratio DOUT is converted to a target value VR representing a corresponding target current value. Subsequent step S
At M2, the drive current value VIO indicating the magnitude of the actual drive current of the coil 36 of the solenoid valve 10 detected by the current detection circuit 66 is read. Next, in step SM3 corresponding to the deviation calculating means 92, the target value V
The deviation EV between R and the drive current value VIO is calculated. In step SM4 corresponding to the integral control value calculating means 94, the integral control value K _I · EV is calculated by integrating the constant K _I is multiplied by the deviation EV.

In step SM5 corresponding to the difference calculation means 96, a difference value DEV [= EV (k) -EV (k-1)] between the previous and current sampling values of the above-mentioned deviation EV is calculated. In step SM6 corresponding to the proportional control value calculating means 98, a proportional control value K _P · DEV is calculated by multiplying the difference value DEV by a proportional constant K _P. Next, in step SM7 corresponding to the operation change value calculating means 100, the integral control value K _I · E
The operation change value DDO is calculated by adding V and the proportional control value K _P · DEV. Further, in step SM8 corresponding to the integrating means 102, a new current operation output value DO (k) is calculated by adding the operation change value DDO to the previous operation output value DO (k-1). You. In step SM9, the current operation output value DO
(K) is updated as the drive duty ratio D, and is converted into a drive signal D _SOL having the drive duty ratio D, which is a pulse signal of a predetermined frequency of, for example, about 300 Hz, and output in step SM10. In this embodiment, the steps SM9 and SM10 are performed by the output signal converting means 1
04.

As described above, in this embodiment, based on the change Δv _B of the output voltage v _B of the battery 50 detected by the output voltage change detecting means 110, the feedback of the feedback control means 105 is performed by the feedback gain changing means 112. The integral constant K _I and the proportional constant K _P which are gains are changed. Therefore, even when the output current of the battery 50, such as during energization of the lighting and the heater of headlights of the vehicle has been abruptly increased, the output of the feedback system in response to a decrease in the output voltage v _B of the battery 50 Therefore, the drive current of the current control type solenoid valve 10 is affected or the output pressure P _{OUT of the} current control type solenoid valve 10 changes due to the fluctuation of the output voltage of the battery 50 of the vehicle. Is eliminated.

The current detecting circuit 66 of the present embodiment includes an amplifier 68 for amplifying a voltage generated at both ends of a current detecting resistor 60 connected in series with the solenoid valve 10 and an output signal of the amplifier 68. Since the filter 70 for smoothing is included, even if noise is mixed in the value detected by the current detection circuit 66, the noise is advantageously removed by the filter 70.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 8 is a diagram for explaining the control function of the arithmetic and control unit 64 in another embodiment. In the present embodiment, the filter means 106, the subtraction means 108, and the feedback gain changing means 112 are removed as compared with the embodiment of FIG. 4 described above, but the offset learning means 120 and the battery output voltage fluctuation correction means 122 Has been added.

In FIG. 8, the offset learning means 120
Is a drive current interrupting means 116 for interrupting the drive current of the solenoid valve 10 by the drive circuit 78 and the current control element 58
And an offset value determining means 118 for determining in advance the value VIO detected by the current detecting circuit 66 as an offset value KVIOFF when the drive current of the solenoid valve 10 is interrupted by the drive current interrupting means.
The actual drive current calculation means 124 calculates the signal VI representing the actual drive current by subtracting the offset value KVIOFF determined by the offset value determination means 118 from the value VIO detected by the current detection circuit 66.

The battery output voltage fluctuation correction means 122
Determines the correction value f (v _BB / v _B ) based on the actual output voltage v _B of the battery 50 detected by the voltage detection circuit 62, and determines the operation output value DO of the feedback control unit 105.
Is corrected by the correction value f (v _BB / v _B ) to determine the drive duty ratio D, so that the operation of the solenoid valve 10 is not affected by the fluctuation of the output voltage of the battery 50. V _BB of the correction value f (v _BB / v _B) is the output voltage of the battery 50 in design.

Hereinafter, the arithmetic and control unit 64 in this embodiment will be described.
Will be described with reference to the flowcharts of FIGS. FIG. 9 illustrates an operation of calculating the actual drive current value VI by obtaining the offset value KVIOFF.
FIG. 10 illustrates a different part of the feedback control routine of FIG.

FIG. 9 shows an offset learning and an actual drive current calculation learning routine. Step SB1 in FIG.
Then, it is determined whether or not the ignition key 56 has been operated to the ON state. If the determination in step SB1 is denied, step SB1 is repeatedly executed.
The contents of _D are cleared and the offset value VIOF at the transition
The content of F is cleared, and the content of offset value KVIOFF is cleared.

In the following step SB3, the duty ratio D input to the output signal converting means 104 is set to a predetermined value, for example, 80 to 100% preferentially.
The drive current I _SOL flowing through 6 is a maximum value for a predetermined period. Next, at step SB4, the duty ratio D
Is preferentially set to 0%, and the drive current I _SOL flowing through the coil 36 is cut off. The state at time t _{0 in} FIG. 11 indicates this state. Therefore, the current detection value VIO is determined by the inductance of the coil 36 and the influence of the parallel capacitor 74 included in the filter 70, as shown in the lower part of FIG.
It decreases exponentially from time ₀ . Step SB3 above
Corresponds to the energizing means for energizing the coil 36 prior to the current interruption, and the above step SB4 corresponds to the drive current interruption means 116 in the offset learning means 120.

[0049] Then, the start time of the counting operation of the timer T _D In step SB5, whether counting contents of step SB6 in timer T _D exceeds a preset determination reference value T _D1 is determined. This criterion value T _D1 is a transient offset value VIOFF according to Equation 2 described below.
Is calculated, for example, a value of about 50 ms is adopted. If the determination in step SB6 is negative, step SB5 and subsequent steps are repeatedly executed.
If the result is affirmative, in step SB7, the transient offset value VIOFF is calculated based on the voltage signal VIO representing the actual drive current value detected by the current detection circuit 66 from the relationship shown in Expression 2. The above equation (2) suppresses a change in the offset value VIOFF at the transient time by adding the current sampling value to the offset value VIOFF at the transient time calculated in the previous control cycle and dividing the result by 2 to thereby reduce the external noise. Since the influence is reduced, step SB7 in this embodiment corresponds to a smoothing unit.

[0050]

## EQU2 ## VIOFF (k) = [VIOFF (k-1) +
VIO (k)] / 2

[0051] In step SB8, whether counting of timer T _D exceeds a preset determination reference value T _VI is determined. The criterion value T _VI is the time to calculate the offset value KVIOFF stable state, for example a value of about 100ms is employed. Step SB8 above
If the determination in step SB5 is negative, step SB5 and subsequent steps are repeatedly executed. If the determination is positive, step SB9 is performed.
In the above, the offset value VIOFF at the time of the final transition calculated by Expression 2 is the offset value KVIOFF in the stable state.
Will be updated as In the present embodiment, the above step SB8
Corresponds to elapsed time determination means for determining whether or not a predetermined time has elapsed from the time when the drive current of the solenoid valve 10 was cut off to the time when the transient change ended and the state became stable. And SB9 correspond to the offset value determining means 118 in the offset learning means 120.

Next, steps SB10 and SB11
Is repeatedly executed. That is, the voltage signal VIO output from the current detection circuit 66 in step SB10
Are successively read, in step SB11, equation 3
From the voltage signal VIO, the offset value KVIO
By subtracting the FF, a value VI representing the actual drive current is sequentially calculated. In this embodiment, this step S
B11 corresponds to the actual drive current calculation means 124.

[0053]

## EQU3 ## VI = VIO-KVIOFF

In this embodiment, in the state where the value VI representing the actual drive current is sequentially calculated as described above, the same feedback control routine as that of FIG. 6 is executed. The difference is that SM21 is executed instead of step SM9 in FIG. That is, in step SM20 in FIG. 10, the correction coefficient k _D for correcting the variation of the output voltage v _B of the battery 50 is determined on the basis of the actual output voltage v _B from Equation 4. In Equation 4, v _BB is the designed output voltage value of the battery 50, and the correction coefficient k _D is the drive current flowing when the output voltage v _B of the battery 50 is the designed output voltage value v _BB. Is determined to be obtained. In step SM21, the duty ratio D (k) is calculated from Equation 5 based on the correction coefficient k _D and the operation output value DO (k). In the present embodiment, the step SM20 is performed by the battery output voltage fluctuation correction unit 122.
It corresponds to.

[0055]

## EQU4 ## k _D = f (v _BB / v _B )

[0056]

D (k) = k _D · DO (k)

As described above, according to the present embodiment, the value V detected by the current detection circuit 66 when the drive current of the solenoid valve 10 is cut off by the drive current cut-off means 116.
IO is determined in advance as an offset value KVIOFF by the offset value determining means 118. Then, the actual drive current calculation unit 124 subtracts the offset value KVIOFF determined by the offset value determination unit 118 from the detection value VIO detected by the current detection circuit 66 to calculate a signal value VI representing the actual drive current. You. Therefore, according to the present embodiment, the current detection circuit 6
6, the offset value KVIO is subtracted from the value VIO detected by
The value V representing the actual drive current by removing the FF
Since I is calculated, accurate feedback control of the current control type solenoid valve 10 is performed based on the value VI.

Further, according to the present embodiment, the offset value determining means 118 determines the predetermined time T from the time when the drive current of the solenoid valve 10 is interrupted by the drive current interrupting means 116.
An elapsed time determining means for determining whether or not _VI has elapsed, and when the elapsed time determining means determines that the predetermined time T _VI has elapsed, an offset value based on a detection value VIO detected by the current detecting circuit 66. Determine KVIOFF. For this reason, even if the drive current after being cut off by the drive current cut-off means 116 is transiently reduced due to the inductance of the coil 36 of the solenoid valve 10 or the capacitance included in the filter 70, the stable state is reached. Is determined as the offset value, so that there is an advantage that the offset value KVIOFF can be accurately obtained.

Further, according to the present embodiment, the offset value determining means 118 controls the current detection circuit 66 after the drive current of the solenoid valve 10 is cut off by the drive current cutoff means 116.
And a detection value smoothed by the smoothing means is determined as an offset value KVIOFF. Therefore, even if noise is mixed in the detection value VIO, Even so, there is an advantage that the influence of the noise is suppressed as much as possible.

Further, according to the present embodiment, step SB1
Offset learning means 12 corresponding to steps SB9 to SB9
0 is the ignition key 5 corresponding to step SB1
6; and an energizing means for immediately energizing the solenoid valve 10 when the on operation of the ignition key 56 is detected by the on-operation detecting means. Drive current interruption means 1
Since the offset value determining means 118 determines the offset value KVIOFF when the drive current is interrupted by the drive unit 16, the offset value KVIOFF is advantageously determined before the vehicle starts moving.

Further, according to the present embodiment, the battery output voltage change
Dynamic correction means 122 is provided by battery output voltage detection circuit 62
The actual output voltage v of the detected battery 50_BAnd design
Pressure v _BBAnd the correction value f (v_BB/ V_B)
To calculate the corrected duty ratio D.
Output voltage of the battery by lighting
Even if the value changes low, the feedback system only
The operation output value of the control means is corrected and the drive current is increased.
Advantageously, the operation of the current control type solenoid valve 10 is not affected.
There is.

While the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, some or all of the means shown in FIG. 4 or FIG. 8 are constituted by the arithmetic functions of the arithmetic and control unit 64 operating according to a program stored in advance, but are constituted by hard logic elements. It may be configured by a digital circuit or an analog circuit that performs arithmetic processing using an analog signal.

The above-mentioned feedback gain changing means 112 shown in FIG. 4 is provided with a hydraulic oil temperature means for detecting the temperature T _{OIL of the} hydraulic oil supplied to the solenoid valve 10, for example, as shown in FIG.
May comprise a gain correction means for correcting a feedback gain i.e. the integration constant K _I and the proportional constant K _P, based on the temperature T _OIL of the actual hydraulic oil from the relationship shown in.
In this way, it is possible to reduce a change in the responsiveness of the solenoid valve 10 due to a change in the viscosity of the hydraulic oil.

Further, instead of step SB1 in FIG. 9, a step may be provided in which step SB2 and subsequent steps are repeatedly executed at predetermined time intervals of several minutes to tens of minutes. In such a case, step SB3 for energizing before the drive current of the electromagnetic valve 10 is cut off may be omitted.

The above-mentioned feedback control means 10
The control method in 5 can be changed to another method, and the feedback gains K _I and K _P changed by the feedback gain changing means 112 differ according to the control method.

In the above-described embodiment, the proportional constant K _P and the integration constant K _I as the feedback gains are both changed by the feedback gain changing means 112, but only one of them may be changed.

In the above-described embodiment, the current control type solenoid valve 10 for a vehicle used in a hydraulically controlled automatic transmission or the like has been described. However, the current control type solenoid valve 10 used for controlling a machine tool or another machine is used. The solenoid valve 10 may be used.

The above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a vehicle current control type solenoid valve controlled by a control device of FIG. 2;

FIG. 2 is a diagram illustrating a circuit configuration of a control device for a vehicle current control type solenoid valve according to an embodiment of the present invention.

3 is a diagram showing a drive pulse signal for driving the vehicle current control type electromagnetic valve of FIG. 1 and a drive current flowing by the drive pulse signal.

FIG. 4 is a functional block diagram illustrating a control function of the arithmetic and control unit in FIG. 2;

5 is a flowchart illustrating a control operation of the arithmetic and control unit of FIG. 2 for realizing the function of FIG. 4, and is a diagram illustrating an operation of changing a feedback gain.

FIG. 6 is a flowchart illustrating a control operation of the arithmetic and control unit of FIG. 2 for realizing the function of FIG. 4;
FIG. 8 is a diagram for explaining a feedback control operation for causing an actual drive current of the solenoid valve to match a target value.

7 is a diagram illustrating the relationship between a change value Δv _B of the output voltage of the battery obtained in step SA3 of FIG. 5, and a moving average value v _BO for obtaining the change value and an actual output voltage v _B.

FIG. 8 is a diagram corresponding to FIG. 4 in another embodiment of the present invention.

9 is a flowchart illustrating a control operation of the arithmetic and control unit of FIG. 2 for realizing the function of FIG. 8, and is a diagram illustrating an offset learning / actual drive current calculation routine.

10 is a flowchart illustrating a control operation of the arithmetic and control unit of FIG. 2 for realizing the function of FIG. 8, and is a diagram illustrating a main part of a feedback control routine.

11 is a current detection value VIO generated by the operation of FIG. 9;
5 is a time chart for explaining a change state at the time of transient.

FIG. 12 is a diagram showing a relationship for correcting a feedback gain in another embodiment of the present invention.

[Explanation of symbols]

 10: current control type solenoid valve for vehicle (current control type solenoid valve) 58: current control element, 78: drive circuit (current adjustment means) 62: voltage detection circuit (output voltage detection means) 66: current detection circuit (current detection) Means: 105: feedback control means 110: output voltage change detection means 112: feedback gain change means 116: drive current cutoff means 118: offset value determination means 120: offset learning means 124: actual drive current calculation means

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yasuhiro Tsuzuki 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Corporation (72) Inventor Yukihide Niimi 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Japan Denso Stock In-house (56) References JP-A-62-188876 (JP, A) JP-A-62-241013 (JP, A) JP-A-56-53201 (JP, U) JP-A-56-45903 (JP, U) ) Hikaru Hei 2-87185 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16K 31/06 310

Claims (2)

(57) [Claims] 1. A current control type solenoid valve that is operated in response to a change in drive current, and is provided between a battery and the current control type solenoid valve and flows from the battery to the current control type solenoid valve. Current adjusting means for changing the drive current, current detection means for detecting the actual drive current of the current control type solenoid valve, and the current drive means detected by the current detection means so that the actual drive current coincides with the command current. What is claimed is: 1. A control device for a current control type solenoid valve, comprising: a feedback control unit for controlling a current adjusting unit; and an output voltage change detecting unit for detecting a change in an output voltage of the battery; Drive of control type solenoid valve
From a relationship predetermined to offset the change in current,
On the basis of the output voltage detected output voltage changes due to the change detection unit, a control unit of said feedback gain changing means for changing the feedback gain of the feedback control means, current-controlled electromagnetic valve, which comprises. 2. A current control type solenoid valve which is operated in response to a change in drive current, and is provided between a battery and the current control type solenoid valve and flows from the battery to the current control type solenoid valve. Current adjusting means for changing the drive current, current detection means for detecting the actual drive current of the current control type solenoid valve, and the current drive means detected by the current detection means so that the actual drive current coincides with the command current. What is claimed is: 1. A control device for a current control type solenoid valve, comprising: a feedback control unit for controlling a current adjustment unit; a drive current cutoff unit for interrupting a drive current of said current control type solenoid valve by said current adjustment unit; Offset value determining means for determining in advance a value detected by the current detecting means as an offset value when the drive current of the current control type solenoid valve is interrupted by current interrupting means; And a real drive current calculating means for calculating an actual drive current by subtracting the offset value determined by the current value determining means from the value detected by the current detecting means. .