JPH11324774A - Current detection failure determination method for throttle valve driving device - Google Patents

Abstract

(57) Abstract: A failure of a current detection device in current feedback control of a throttle valve actuator can be detected. A throttle valve of an automobile engine is opened / closed by supplying a current controlled by a PWM to an actuator, wherein a means for calculating a target current from a target opening and an actual opening is provided. In a throttle valve driving device provided with means for calculating a drive duty based on a detected current value, it is determined by calculation whether the throttle valve is in a transient state or a steady state, and when the throttle valve is in a steady state (TE = 0) If the difference between the number of times that the drive duty becomes equal to or more than the predetermined value B and the number of times that the drive duty becomes less than the predetermined value B becomes a predetermined number C, it is determined that the current detection is defective.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for judging a current detection defect of an actuator used in an engine throttle valve driving device, and more particularly to a method for judging a current detection defect in current feedback control.

[0002]

2. Description of the Related Art Conventionally, there has been known a method of controlling the opening and closing of an engine throttle valve by an electronic control unit using an actuator. A rotary solenoid proposed in JP-A-8-228466 as an actuator for this purpose has a rotor in which a magnet is added to a main air gap of a magnetic circuit having a main air gap and a sub air gap, and to which a magnetomotive force is applied by a coil. Be placed.
FIG. 1 shows an example of a throttle body of an automobile using such a rotary solenoid. The throttle body 1 shown in the figure has an intake path opened and closed by a throttle valve 2, and rotatably supports a throttle shaft 3 to which the throttle valve 2 is fixed.

A movable part of a throttle position sensor 4 for detecting a rotation angle of the throttle valve 2 and a rotor 5 of a rotary solenoid are fixed to the throttle shaft 3. A magnet 6 is adhered to the rotor 5, and the rotor 5 and the magnet 6 are disposed in a main air gap 9a between the yokes 9, 9. Sub air gaps 9b, 9b are formed on both sides of the main air gap 9a, and the core 7, the yoke 9, and the main air gap 9 are formed.
a, the sub air gaps 9b, 9b, and the yoke 9 form a magnetic circuit.

A coil 8 is wound around the core 7, and a current flowing through the coil 8 generates a magnetic field in the main air gap 9a and the sub air gaps 9b, 9b. The rotor 5 and the magnet 6 receive a driving torque directed to a position where the magnetic energy stored as a magnetic field is minimized. The hot water inlet / outlet nipples 10 and 10 are hot water inlet / outlet ports for preventing the throttle valve 2 from freezing.

FIG. 2 shows an example of a driving device for supplying a current modulated by PWM (pulse width modulation) to the coil of such a rotary solenoid. The microcomputer 11 shown in the figure includes a ROM, a RAM, an input / output interface, and an A / D converter. The microcomputer 11 has an actual opening signal from the throttle position sensor 4 and a target opening of a throttle valve calculated by an engine control unit (not shown). The target signal supplied to the throttle valve coil 8 is calculated such that the actual opening degree matches the target opening degree.

The drive circuit 12 includes a microcomputer 11
PW is applied to the coil 8 by the drive duty commanded by
Provides a current modulated by M. The current detection circuit 13 reads the current (average value) supplied from the drive circuit 12 and inputs a current value signal to the microcomputer 11. The microcomputer 11 calculates a drive duty from the current value signal and the target current and outputs the calculated drive duty to the drive circuit 12. When the current controlled by the PWM is supplied to the coil 8, the throttle valve of the throttle body 1 has an opening corresponding to the current, the opening is detected by the throttle position sensor 4, and the actual opening signal is transmitted to the microcomputer 11.
Is entered. Thus, the current feedback control is performed so that the current supplied to the coil 8 of the throttle valve matches the target current.

In such a drive device, when the current detection circuit 13 breaks down and the current read value is fixed to an arbitrary value within a normal range, for example, when a short circuit occurs via a resistor, the throttle valve is opened. Hunts. That is, in the current feedback control, the drive duty is changed because the current read value does not match the target current value.

When the drive duty changes, the actual current value changes, so that the opening of the throttle valve changes, and the actual opening does not match the target opening. Therefore, the target current value is changed. Since the target current value has changed in this way, the drive duty changes in the direction opposite to the previous one. Hunting of the throttle valve occurs due to repetition of this phenomenon, and control becomes impossible. FIG. 6 shows a change in the opening degree of the throttle valve when the hunting occurs as described above, and FIG. 7 shows a change in the target current at this time. FIG. 8 shows the change in the drive duty at this time.

In such a hunting, when the actual current value fluctuates within the normal range, a failure cannot be detected by a general failure determination method for detecting that the current is outside the normal range. I couldn't tell you something wrong.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a current feedback control for an engine throttle valve driving device for supplying a PWM-controlled current to an actuator. To provide a method for judging a current detection failure.

[0011]

According to the present invention, there is provided a method of judging a current detection failure of a throttle valve driving device, wherein opening and closing control of a throttle valve of an automobile engine is performed by supplying a PWM-controlled current to an actuator. Means for calculating a target current from the target opening and the actual opening,
In a throttle valve driving device comprising means for calculating a drive duty based on the target current and the detected current value, it is determined by calculation whether the throttle valve is in a transient state or a steady state. When the state in which the drive duty is equal to or more than a predetermined value continues for more than a predetermined number of times, it is determined that the current detection is defective.

The present invention also provides a method for judging a current detection failure of a throttle valve driving device, which controls opening and closing of a throttle valve of an automobile engine by supplying a current controlled by PWM to an actuator. In a throttle valve driving device including a means for calculating a target current from an actual opening and a means for calculating a drive duty based on the target current and a detected current value, whether the throttle valve is in a transient state or a steady state. Is determined by calculation, and when the difference between the number of times that the drive duty is equal to or more than the predetermined value and the number of times that the drive duty is less than the predetermined value becomes a predetermined number in the steady state, it is determined that the current detection is defective. It is characterized by the following.

In the method for determining a current detection failure of each of the throttle valve driving devices, an opening of the throttle valve which follows the target opening with a first-order delay is calculated, and the target opening and the calculated throttle valve are calculated. The throttle valve is determined to be in a steady state when the difference from the opening of the throttle valve is equal to or less than a certain value.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A current detection failure judging method according to an embodiment of the present invention is carried out by a drive device for a throttle valve actuator shown in FIG. Each component in FIG. 2 is as described in the conventional example, and a detailed description thereof will be omitted. As described above, current is supplied to the coil of the throttle valve by the drive duty by the circuit shown in FIG. 2. In addition to the current supply processing, the microcomputer 11 performs steady state determination processing shown in FIG. 3 and current detection shown in FIG. The defect determination processing is periodically and sequentially executed.

In the steady state determination process shown in FIG. 3, first, in step S1, a calculated opening Y (n) that follows the target opening with a first-order delay is calculated. Formula Y (n) = (1-K)
K in × Y (n−1) + K × target opening... Is a constant of a first-order delay. When Y (n) is calculated periodically by the following equation, Y (n) changes following the target opening as shown in FIG. 5 with respect to the change in the target opening.

Next, in step S2, it is determined whether or not the absolute value of the difference between Y (n) and the target opening is greater than a predetermined value B. If it is, the steady state flag TE is set to 1 in step S3. If not, the routine sets the steady state flag TE to 0 in step S4, and then terminates this routine in step S5 with Y (n-1) = Y (n). As shown in FIG. 5, Y (n) is calculated by the steady state determination process, and the value of the steady state flag TE is set to 1 or 0 based on the difference between the target opening and Y (n).

In the current detection failure determination processing shown in FIG. 4, a current detection failure is determined only in a steady state, that is, when TE = 0. In the current detection failure determination processing, first, in step S10
In, it is determined whether or not the drive duty is equal to or greater than a predetermined value B that cannot be realized in a steady state. If the drive duty is equal to or greater than the predetermined value B, the process proceeds to step S11.

In step S11, a large duty flag du is set.
The process proceeds to step 13 with tyL set to 1. Step S1
In step 2, the large duty flag dutyL is set to 0 and step 1 is performed.
Move to 3. In step S13, the steady state flag TE
Is determined to be 1 or not, and if it is 1, step S1
The process proceeds to step S4, and if not 1, the process proceeds to step S16.
In step S14, the steady state flag TE is set to 0. Next, in step S15, the large duty flag duty
The process proceeds to step 16 with L set to 0.

In step S16, a large duty flag du
It is determined whether or not tyL is 1, and if it is 1, the process proceeds to step S17. If not, the process proceeds to step S21. In step S17, the current detection failure counter IFBC
Is determined to be less than the upper limit, and if less than the upper limit, the process proceeds to step S18, and if not, the process proceeds to step S19. In step S18, the current detection failure counter IFBC is incremented, and in step S1
Move to 9.

In step S19, it is determined whether or not the current detection failure counter IFBC is equal to or greater than the upper limit value C. If the current detection failure counter IFBC is equal to or greater than the upper limit value C, the process proceeds to step S20. . In step S20, it is determined that the current detection is defective, and this routine ends. When it is determined that the current detection is defective, it is displayed on the display device, the current feedback control is stopped, and only the position feedback for supplying the current value calculated from the target opening and the actual opening is performed.

In step S21, it is determined whether or not the current detection failure counter IFBC exceeds a lower limit value D. If the current limit value exceeds the lower limit value D, the process proceeds to step S22, and if not, the routine ends. . Step S2
In step 2, the current detection failure counter IFBC is decremented, and this routine ends.

By performing the steady state determination processing shown in FIG. 3 and the current detection failure determination processing shown in FIG. 4 periodically and sequentially, it is possible to determine the current detection failure regardless of the fluctuation of the target opening. As shown in FIG. 5, when the target opening degree changes stepwise, it becomes a transient state, and the drive duty becomes a large value that is not realized in the steady state. However, steps S14, S15, S21, and S22 in FIG. Is executed, and the current detection failure counter IFBC is not incremented, and the current detection failure is not determined. Also,
As described in the conventional example, when the current detection circuit breaks down and the current read value is fixed to an arbitrary value within the normal range, the throttle valve hunts and is determined to be in a steady state by the steady state determination process. Also, the drive duty becomes a large value that cannot be realized in the steady state, and steps S17 and S18 in FIG. 4 are repeated, and it can be determined that the current detection is defective.

The embodiment is configured as described above.
The present invention is not limited to this. For example, when the difference between the number of times that the drive duty becomes equal to or more than the predetermined value and the number of times that the drive duty becomes less than the predetermined value becomes a predetermined number in the steady state, the current detection failure is determined. Instead, the current detection failure may be determined when the state in which the drive duty is equal to or more than the predetermined value has continued for a predetermined number of times or more when the drive duty has continued for a predetermined time or more in the steady state.

[0024]

As described above, according to the method for determining the current detection failure of the throttle valve driving device, the failure of the current detection device in the current feedback control of the throttle valve actuator can be detected. Avoid the situation. Moreover, danger can be avoided beforehand by displaying the failure of the current detection device.

[Brief description of the drawings]

FIG. 1A is a sectional view showing a throttle body used in an embodiment of the present invention, FIG. 1B is a left side view of the throttle body excluding a cover, and FIG.
FIG. 2 is a right side view of the throttle body.

FIG. 2 is a block diagram showing a drive device of a throttle valve actuator used in the embodiment of the present invention.

FIG. 3 is a flowchart showing the operation of the embodiment.

FIG. 4 is a flowchart showing the operation of the embodiment.

FIG. 5 is a time chart showing the operation of the embodiment.

FIG. 6 is a graph showing a change in throttle valve opening when a current detection failure occurs in a conventional throttle valve driving device.

FIG. 7 is a graph showing a change in a target current value when a current detection failure occurs in a conventional throttle valve driving device.

FIG. 7 is a graph showing a change in drive duty when a current detection failure occurs in a conventional throttle valve driving device.

[Explanation of symbols]

Reference Signs List 1 throttle body 2 throttle valve 3 throttle shaft 4 throttle position sensor 5 rotor 6 magnet 7 core 8 coil 9 yoke, 9a main air gap, 9b auxiliary air gap 10 hot water inlet / outlet nipple 11 microcomputer 12 drive circuit 13 current detection circuit

Claims (3)

[Claims] 1. A control device for controlling the opening and closing of a throttle valve of an automobile engine by supplying a PWM-controlled current to an actuator, comprising: means for calculating a target current from a target opening and an actual opening; And a means for calculating a drive duty based on the detected current value and a detected current value.In the throttle valve drive device, it is determined by calculation whether the throttle valve is in a transient state or a steady state,
A method for determining a current detection failure in a throttle valve driving device, comprising determining a current detection failure when a state in which the drive duty is equal to or greater than a predetermined value continues for a predetermined number of times or more in a steady state. 2. A means for controlling the opening and closing of a throttle valve of an automobile engine by supplying a current controlled by PWM to an actuator, wherein a means for calculating a target current from a target opening and an actual opening is provided; And a means for calculating a drive duty based on the detected current value and a detected current value.In the throttle valve drive device, it is determined by calculation whether the throttle valve is in a transient state or a steady state,
A current detection failure when the difference between the number of times the drive duty is equal to or more than a predetermined value and the number of times the drive duty is less than a predetermined value is a predetermined number in a steady state; A method for determining a current detection failure of a valve driving device. 3. A throttle valve opening which follows the target opening with a first-order delay is calculated, and a difference between the target opening and the calculated opening of the throttle valve is equal to or less than a predetermined value. 3. The method according to claim 1, wherein the throttle valve is determined to be in a steady state.