JPH08114140A - Throttle control device - Google Patents

Abstract

PURPOSE: To improve output precision at low and high opening areas by using a plurality of sensor outputs and to improve drivability by smoothing switching of an output. CONSTITUTION: A sensor output Va for controlling a low opening from a throttle opening sensor 7 is inputted to a DC motor drive circuit 29 and an ECU 25 and a sensor output Vb for controlling a high opening to the ECU 25. A throttle command voltage before correction is calculated by the ECU 25 based on a throttle opening command value by an accelerator operation amount Ap of an accelerator position sensor 22 and the number Ne of revolutions of an engine of a number of revolutions sensor 35. The throttle command voltage is corrected based on a correction amount responding to an output difference between sensor outputs Va and Vb to calculate a throttle command voltage Vcmd. This constitution improves precision of region from the low opening area of a throttle opening to the high opening area thereof and eliminates a relative error during switching of the sensor outputs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle control device for an internal combustion engine, and more particularly to a throttle control device for electrically controlling the opening of a throttle valve with a motor or the like.

[0002]

2. Description of the Related Art Conventionally, in an electronic throttle system in which a throttle valve is electrically controlled by a DC motor according to the amount of depression of an accelerator pedal, the valve position is detected by a throttle opening sensor and the position F / B (feedback) is detected.
It is carried out. Therefore, if there is an error in the output of the throttle opening sensor, the controlled valve position will shift by that amount. Especially, ISC control (Idle Speed Con
(trol: idle speed control) In the low opening range of the throttle valve such as when the throttle valve is open, the output of the throttle opening sensor needs to be highly accurate because the air amount changes greatly with respect to the opening error.

As a prior art document related to a throttle control device which attempts to meet such a demand, there is known one disclosed in Japanese Patent Laid-Open No. 63-247609.

In this case, a throttle valve opening detecting device having two outputs for detecting a low opening and detecting a high opening is proposed, and a technique for improving the accuracy of detecting the opening of the throttle valve is shown. Has been done.

[0005]

Here, in the electronic throttle system, in order to improve the accuracy of the low opening range and the high opening range by a plurality of sensor outputs, it is necessary to switch the sensor output according to the opening. . However, in the electronic throttle system which performs the position F / B by the analog circuit, it is necessary to add a circuit for selecting and switching a plurality of sensor outputs. Also, when switching, the throttle valve changes stepwise in the opening or closing direction due to the relative error of the outputs of multiple sensors, and the opening does not switch smoothly. However, there was a problem that drivability deteriorated.

Therefore, the present invention has been made in order to solve such a problem, and in order to improve the accuracy of the low opening range and the high opening range of the throttle opening by using a plurality of sensor outputs, it is special. An object of the present invention is to provide a throttle control device that smoothly switches the sensor outputs without adding a switching circuit and has good drivability.

[0007]

A throttle control device according to a first aspect of the present invention comprises a plurality of magnetoelectric conversion elements and a magnet, and the plurality of magnetoelectric conversion elements are arranged such that the direction of a magnetic field received from the magnets is different for each magnetoelectric conversion element. Placed in different positions,
The magnetoelectric conversion element includes a throttle opening sensor that outputs a detection signal corresponding to the throttle opening when the direction or strength of the magnetic field received from the magnet changes with a change in the throttle opening, and the plurality of magnetoelectric conversion elements. Throttle opening detection means for detecting the throttle opening based on the output of one of the conversion elements, target throttle opening setting means for setting the target throttle opening according to the operating state, and the throttle Target throttle opening correction means for correcting the target throttle opening based on a correction amount corresponding to an output difference between a detection signal of the magnetoelectric conversion element and a detection signal of another magnetoelectric conversion element used for detecting the opening A throttle opening control means for feedback controlling the throttle opening so that the target throttle opening is achieved.

A throttle control device according to claim 2 is
In addition to the means provided in claim 1, the target throttle opening correction means continuously changes the correction amount for correcting the target throttle opening.

A throttle control device according to claim 3 is
In addition to the means provided in claim 1 or claim 2, the target throttle opening degree correction means increases the output accuracy in a low opening range of the throttle opening and the magnetoelectric conversion element and the throttle opening. The target throttle opening degree is corrected on the basis of a correction amount corresponding to an output difference of each detection signal from the magnetoelectric conversion element having high output accuracy in a high opening range.

According to a fourth aspect of the throttle control device,
A plurality of throttle opening sensors having different output characteristics; a throttle opening detecting means for detecting the throttle opening based on the output of one of the plurality of throttle opening sensors; Target throttle opening setting means for setting a target throttle opening, and the target throttle opening based on a correction amount according to an output difference between the output of the one throttle opening sensor and the output of the other throttle opening sensor. A target throttle opening correction means for correcting and a throttle opening control means for feedback-controlling the throttle opening so that the target throttle opening is achieved are provided.

[0011]

In the throttle control device of the present invention, the throttle opening detection means detects the throttle opening based on the output of one of the plurality of magnetoelectric conversion elements, and the target throttle opening setting means detects the throttle opening. The target throttle opening is set according to the operating state. In addition, the target throttle opening degree is corrected based on the correction amount according to the output difference between the detection signal of the magnetoelectric conversion element used for detecting the throttle opening degree by the target throttle opening degree correction means and the detection signal of another magnetoelectric conversion element. To be done. Then, the throttle opening control means feedback-controls the throttle opening so that the target throttle opening is achieved.

According to the target throttle opening correction means of the throttle control device of the second aspect, in addition to the operation of the first aspect, the correction amount for correcting the target throttle opening is the output difference of the detection signals from the plurality of magnetoelectric conversion elements. Is continuously changed according to.

According to the target throttle opening correction means of the throttle control device of the third aspect, in addition to the operation of the first or second aspect, the output accuracy is high in the low opening range or the high opening range of the throttle opening. The target throttle opening is corrected based on the correction amount calculated according to the output difference of each detection signal from the magnetoelectric conversion element.

According to another aspect of the throttle control device of the present invention, the throttle opening detecting means detects the throttle opening based on the output of one of the plurality of throttle opening sensors having different output characteristics and the target value. The target throttle opening is set by the throttle opening setting means according to the operating condition. Further, the target throttle opening correction means corrects the target throttle opening based on the correction amount according to the output difference between the output of one throttle opening sensor and the output of the other throttle opening sensor. Then, the throttle opening control means feedback-controls the throttle opening so that the target throttle opening is achieved.

[0015]

EXAMPLES The present invention will be described below based on specific examples.

FIG. 2 is a perspective view showing the vicinity of a throttle valve to which the throttle control device according to one embodiment of the present invention is applied.

In FIG. 2, an intake pipe 1 for introducing intake air into an internal combustion engine has a throttle shaft 2 penetrating therethrough, and the throttle shaft 2 in the intake pipe 1 has a circular valve plate type throttle valve. 3 is fixed. A pair of L-shaped rotating members 4 and 5 are fixed to the throttle shaft 2. A valve spring 6 is attached to the bent piece 4 a of the rotating member 4 located to the right of the intake pipe 1. The valve spring 6 applies a force to the rotating member 4 in the direction of opening the throttle valve 3.
In this embodiment, the direction in which the valve spring 6 is contracted and the direction in which the throttle valve 3 is opened is the open direction, and conversely, the direction in which the valve spring 6 is extended and the direction in which the throttle valve 3 is closed are Is the closing direction.

A throttle opening sensor 7 for detecting the opening of the throttle valve 3 is provided at the left end of the throttle shaft 2. On the throttle shaft 2, a drive transmission gear 10 is rotatably supported between a throttle valve 3 and a rotating member 5 via a ball bearing 11. A projecting piece 10a is provided on the upper portion of the drive transmission gear 10 in the figure, and the projecting piece 10a faces the bending piece 5a of the rotating member 5. Here, since the rotating member 5 is biased in the opening direction by the valve spring 6, the protruding piece 10a of the drive transmission gear 10 and the bent piece 5a of the rotating member 5 are held in contact with each other. A motor spring 12 is attached to the protruding piece 10a.
Applies a force for rotating the drive transmission gear 10 in the opening direction.

On the other hand, the reduction gear 9 is meshed with the gear portion 10b provided in the arc portion of the drive transmission gear 10.
Further, a DC motor 8 is meshed with the reduction gear 9. The DC motor 8 is driven against the opening force of the valve spring 6 and the motor spring 12,
The drive transmission gear 10 is rotated in the closing direction. When the drive transmission gear 10 is rotated in the closing direction, the bending piece 5a of the rotating member 5 is pressed by the protruding piece 10a of the drive transmission gear 10, and the throttle valve 3 is rotated in the closing direction.

A fully closed stopper piece 13 is provided at a position where the rotating member 4 is being rotated in the closing direction. Then, when the throttle valve 3 is rotated in the closing direction according to the drive of the DC motor 8 and the bent piece 4a of the rotating member 4 contacts the fully closed stopper piece 13, the throttle valve 3 is further rotated in the closing direction. It cannot move and the contact position becomes the fully closed position of the throttle valve 3.

Further, a guard shaft 15 is rotatably supported coaxially with the throttle shaft 2. A guard plate 16 having a bent piece 16a is fixed to the end of the guard shaft 15, and the bent piece 16a of the guard plate 16 faces the bent piece 4a of the rotating member 4. When the throttle valve 3 is rotated in the opening direction, the bent piece 4a of the rotating member 4 contacts the bent piece 16a of the guard plate 16, so that the throttle valve 3 cannot be rotated further in the opening direction. . That is, the maximum allowable opening of the throttle valve 3 is determined by the position of the bent piece 16a of the guard plate 16. A guard spring 17 is attached to the guard plate 16, and the guard spring 17 biases the guard plate 16 in the closing direction.

An accelerator lever 21 fixed to the guard shaft 15 is connected to the accelerator pedal 20. Then, in response to the depression operation of the accelerator pedal 20, the accelerator lever 21 is rotated in the opening direction to increase the maximum allowable opening degree of the throttle valve 3. The accelerator position sensor 22 detects the accelerator operation amount corresponding to the depression of the accelerator pedal 20.

Further, the diaphragm actuator 18
During the cruise control traveling, the rod 18a contracts, and the guard plate 16 is rotated in the opening direction in the direction of increasing the maximum allowable opening of the throttle valve 3. Further, the rod 19a of the thermowax 19 contracts due to the cooling water temperature of the internal combustion engine. For example, when the cooling water temperature is low such as during cold start, the thermowax 19 contracts to open the guard plate 16 in the opening direction of the throttle valve 3. Rotate in a direction to increase the maximum allowable opening of. A guard sensor 23 for detecting the position of the guard plate 16 is arranged at the right end of the guard shaft 15 in the figure.

Next, the operation will be described with reference to FIG. 3 which schematically shows the configuration around the throttle valve of the throttle control device of FIG. The vertical direction in FIG. 3 is the opening / closing direction of the throttle valve 3, the upper side in the figure indicates the opening direction, and the lower side in the figure indicates the closing direction.

In FIG. 3, the maximum allowable opening amount in the opening direction of the throttle valve 3 which is the guard position of the guard plate 16 is determined by the accelerator operation amount of the accelerator pedal 20, the displacement amount of the diaphragm actuator 18 or the displacement amount of the thermowax 19. It is determined. Then, for example, when the accelerator pedal 20 is stepped on, the guard plate 16 is pulled upward in the drawing, and the maximum allowable opening degree of the throttle valve 3 increases.

The throttle valve 3 is pulled in the opening direction by a valve spring 6. The opening of the throttle valve 3 is determined by the balance between the driving force of the DC motor 8 in the closing direction and the urging force of the valve spring 6 and the motor spring 12 in the opening direction. That is, when the throttle valve 3 is maintained at a predetermined opening degree, the DC motor 8 generates a driving force in the closing direction against the opening force of the valve spring 6 and the motor spring 12. When the DC motor 8 is driven in the closing direction and the throttle valve 3 reaches the fully closed position, the rotating member 4
The bent piece 4a is brought into contact with the fully closed stopper piece 13.

Next, a description will be given with reference to FIG. 1 showing an electrical configuration of a throttle control device according to an embodiment of the present invention.

In FIG. 1, an ECU (Electronic Contr
ol Unit: electronic control unit) 25 mainly includes the CPU 2
6, a D / A converter 27, an A / D converter 28, a backup memory 34, and the like. And CP
Signals from the throttle opening sensor 7 and the accelerator position sensor 22 are input to the U26 via the A / D converter 28, and the CPU 26 outputs a sensor output Va (low opening control) described later based on these input signals. Sensor output), sensor output Vb (sensor output for high opening control), and accelerator operation amount Ap are detected. A signal from the rotation speed sensor 35 is input to the CPU 26, and the CPU 2
Reference numeral 6 detects the engine speed Ne based on this input signal.

Further, the DC motor drive circuit 29 has a PID
It is composed of a control circuit 30, a PWM (pulse width modulation) circuit 31, and a driver 32. Of these, in the PID control circuit 30, based on the throttle command voltage Vcmd calculated by the CPU 26 and the sensor output Va detected by the throttle opening sensor 7, proportional / integral / derivative operation is performed to reduce the deviation. Is implemented, throttle valve 3
Is calculated. Then, in the PWM circuit 31,
The control value signal output from the PID control circuit 30 is converted into the duty ratio signal Duty, and the duty ratio signal D
The DC motor 8 is driven by the driver 32 based on the uty.

The duty ratio signal Duty of the PWM circuit 31 is also sent to the CPU 26.
Based on the duty ratio signal Duty, the CPU 26 detects the lock current generated when the throttle valve 3 reaches the fully closed position. That is, lock current and DC
The duty ratio signal Duty as a drive signal of the motor 8 has a correlation, and the same change appears in the duty ratio signal Duty when the lock current is generated. Therefore,
In the device of this embodiment, the lock current is detected when the duty ratio signal Duty is equal to or greater than a predetermined value (85%).

The throttle opening sensor 7 is a non-contact sensor using a hall element, and its configuration is shown in FIG. The throttle opening sensor 7 of this embodiment is mainly composed of two Hall elements 41a and 41b and permanent magnets 42a and 42b. FIG. 4 shows two Hall elements 41.
It is explanatory drawing which shows the positional relationship of a, 41b and permanent magnet 42a, 42b, FIG.4 (a) is a front view, FIG.4 (b) is a right view of FIG.4 (a).

The permanent magnet (N pole) 42a and the permanent magnet (S
The poles 42b are arranged on the rotor 45 so as to be symmetrical with respect to the rotation center 2a of the throttle valve 3. The rotor 45 is fixed to the tip of the throttle shaft 2 of the throttle valve 3 and is rotated with the rotation of the throttle valve 3. Two Hall elements 41a, 41b
Is the axis 2b of the throttle shaft 2 of the throttle valve 3.
It is located above and is fixed to the bearing (not shown) side of the throttle shaft 2. Throttle valve 3 is in the fully closed position (Fig. 4
(A) and FIG. 4 (b)), the magnetically sensitive surface of one Hall element 41a is in the rotational direction of the throttle valve 3 with respect to the magnetic field formed by the permanent magnets 42a, 42b (FIG. 4 (b)).
Is fixed at an offset angle α in the direction of the arrow).

In the thus configured throttle opening sensor 7, the permanent magnets 42a and 42b are connected to the hall elements 41a and 41a as the throttle shaft 2 of the throttle valve 3 rotates.
Since it rotates around 41b, the Hall elements 41a, 41
The magnetic field direction with respect to the magnetic sensitive surface of b changes. At this time, 2
The strength of the parallel magnetic field formed by the two permanent magnets 42a and 42b is always constant. As a result, the Hall elements 41a, 4
If the angle of incidence of the magnetic field on the magnetic sensitive surface of 1b is the rotation angle θ, the sensor output V from each Hall element 41a, 41b
a and Vb change as in the following equations (1) and (2).

[0034]

[Equation 1] Va = VHA · sin θ (1)

[0035]

## EQU00002 ## Vb = VHA.sin (.theta .-. Alpha.) (2) where VHA is the maximum output value depending on the magnetic flux, the device current, the Hall coefficient, and the like.

As described above, the angles of the magnetic fields applied to the two Hall elements 41a and 41b change independently with the rotation of the permanent magnets 42a and 42b, and the two Hall elements 41a and 41b are shown in FIG. Output a sine wave as shown. Therefore, the two Hall elements 41a and 41b have higher output accuracy at the midpoint (small error) with respect to the upper and lower limits of the sensor output, and low output accuracy at the upper and lower limit ends (large error). Therefore, the output errors ΔVa and ΔVb of the two Hall elements 41a and 41b are ΔVa <ΔVb in the low opening range of the throttle valve 3 and ΔVa> ΔVb in the high opening range of the throttle valve 3. Therefore, the sensor output Va is used as a low opening control sensor output, and the sensor output Vb is used as a high opening control sensor output.

Next, the throttle control by the low opening control sensor output Va and the high opening control sensor output Vb will be described based on the flowchart of FIG. 6 and with reference to the block diagram of FIG. 7. The portion surrounded by the broken line in FIG. 7 corresponds to the arithmetic processing of FIG. 6 by the CPU.

In step S101, the accelerator operation amount Ap and the engine speed Ne at that time are read. Next, the process proceeds to step S102, and as shown in FIG. 8, the accelerator operation amount Ap at that time is calculated using the relationship between the accelerator operation amount Ap, the engine speed Ne and the throttle opening command value θcmd.
Also, the throttle opening command value θcmd is calculated from the engine speed Ne (see block 100 of the target opening calculation in FIG. 7). Then, the process proceeds to step S103, and step S1
Based on the throttle opening command value θcmd calculated in 02, the low opening control sensor output Va input to the DC motor drive circuit 29 as an analog F / B circuit shown in FIG.
Throttle command voltage Vcmd ′ before correction according to the characteristic diagram of
Is calculated (block 4 of target opening → voltage conversion in FIG. 7)
00). At this time, the low opening control sensor output Va is the fully closed learning value Vao as the offset output at the fully closed position.
Is corrected by. The fully closed learning value Vao of the low opening control sensor output Va at the fully closed position is obtained in the fully closed position learning La block 200 of FIG. 7 and also at the fully closed position of the high opening control sensor output Vb at the fully closed position. The learning value Vbo is obtained by the fully closed position learning routine described later in the fully closed position learning Lb block 300 of FIG.

The processing up to this point corresponds to the conventional control, and the portion indicated by the chain double-dashed line in FIG. 7 is the correction section in the apparatus of this embodiment. At the time of opening control, the sensor output Vb 'for high opening control in which the offsets are pseudo-aligned at the fully closed position is used to
It is possible to obtain the same controllability as that obtained with / B.

Next, the routine proceeds to step S104, where the obtained sensor outputs Va, Vb and fully closed learning values Vao, Vb.
Va '= Va-Vao and Vb' = Vb-Vbo are calculated from o, and the offsets of the two sensor outputs are aligned.
Two sensor outputs Va ′ with the same offset,
Vb ′ is a characteristic diagram as shown in FIG. 10 from FIG. 5, and in the present embodiment, there is a characteristic deviation of Δv because it is a sine wave whose phase is shifted by 25 ° (= 30 ° −5 °). When the error between the two sensor outputs Va ′ and Vb ′ whose offsets are aligned is 0, Va′−Vb ′ is Δv. Therefore, Δv for the throttle opening command value θcmd is calculated in block 500 of FIG. 7 based on the characteristic diagram shown in FIG.
V = Va'-Vb'-Δv is calculated.

Next, in step S105, the switching coefficient Ko is calculated based on the high opening control sensor output Vb 'in block 600 of FIG. A block 600 in FIG. 7 is a block for calculating a switching coefficient Ko between the throttle control by the low opening control sensor output Va ′ and the throttle control by the high opening control sensor output Vb ′, and when Ko = 0. The throttle control is performed only by the low opening control sensor output Va '(no correction), and the throttle control is performed by the high opening control sensor output Vb' when Ko = 1. Here, in order to smoothly switch between the two sensor outputs Va 'and Vb', the value of the switching coefficient Ko gradually approaches 1 as the throttle opening command value θcmd increases.

Next, the routine proceeds to step S106, where the uncorrected throttle command voltage Vcmd 'and the switching coefficient Ko and the error .DELTA.
Throttle command voltage Vcm by correcting based on V
d is calculated, and this routine ends. That is, Va'-
If F / B correction is performed so that Vb ′ becomes Δv, it means that the sensor output Vb ′ is pseudo F / B. Here, if the sensor outputs Va 'and Vb' have linear characteristics and the slope and gain are the same, the block 500 of FIG. 7 can be omitted.

Next, the operation of the apparatus of this embodiment will be described with reference to FIG.
Will be described with reference to. Two sensor outputs Va ′ and V whose offsets are made uniform after the learning of the fully closed position for easy understanding.
Assuming that b'has a linear characteristic (slope is also the same), the operation when the block 500 of FIG. 7 is omitted will be described.

In FIG. 11, the error Δ when not corrected
θ ′ is calculated by the following equation (3).

[0045]

## EQU00003 ## .DELTA..theta. '= (Vcmd'-Va'). Kth (3) where Kth is the inclination [deg / V] of the sensor output for low opening control.
Is.

Then, the error Δθ when correcting with the high opening control sensor output Vb ′ is calculated by the following equation (4).

[0047]

[Mathematical formula-see original document] .DELTA..theta. = [Vcmd '-{(Vcmd'-Va')-(Vcmd'-Vb ')}-Va']. Kth = [Vcmd '-{-Va' + Vb '}-Va']. Kth = [Vcmd′−Vb ′] · Kth (4) That is, the sensor output for high opening control Vb ′ is an analog F / B.
The error will be the same as if you did.

Next, the processing procedure of the fully closed position learning La200 and the fully closed position learning Lb300 of the CPU 26 used in the throttle control device according to the embodiment of the present invention will be described with reference to the flowchart of FIG. This will be described with reference to the chart.

The flowchart of FIG. 12 shows a routine for learning the fully closed reference voltage V0 of the throttle valve 3. This routine is started by the CPU 26 at predetermined time intervals. The timing chart of FIG. 13 shows the throttle opening (throttle command voltage Vcmd and sensor output Vth), accelerator operation amount A at each timing.
p, motor load current, duty ratio signal Duty, counter value ti, and learning execution flag XLRN. In addition, in FIG. 12, the throttle is operated to a desired throttle opening until the timing T1 in FIG.
It is assumed that the depression of the accelerator pedal 20 is stopped at timing T1 and thereafter the throttle valve 3 is rotated in the closing direction by driving the DC motor 8.

First, in step S201, it is determined whether the fail flag XFAIL is 1. Note that this fail flag XFAIL is set by a fail detection routine (not shown).
When FAIL is 1, it means at the time of fail. When the determination condition of step S201 is not satisfied and the engine is not in the fail state, the process proceeds to step S202, and it is determined whether the accelerator operation amount Ap detected by the accelerator position sensor 22 exceeds 0. Here, when the determination condition of step S201 is satisfied or when the determination condition of step S202 is satisfied, step S2
03, the learning execution flag XLRN is reset to 0, and this routine is ended.

On the other hand, if the determination condition of step S202 is not satisfied, the process proceeds to step S204. In this way, after the routine is started, step S204
In the process up to, the throttle opening is held at the predetermined opening before the timing T1 in FIG. 13, so the motor load current and the duty ratio signal Duty are held at the predetermined values for the closing side. That is, as shown in FIG. 8, the throttle opening command value θcmd is calculated from the accelerator operation amount Ap and the engine speed Ne, and further, as shown in FIG. Command voltage V
cmd ′ is calculated. This uncorrected throttle command voltage Vcmd 'is corrected based on the switching coefficient Ko and the error ΔV, and the throttle command voltage Vcmd is calculated. The DC motor drive circuit 29 drives the DC motor 8 by the throttle command voltage Vcmd to adjust the throttle valve 3 to a predetermined opening.

When the depression of the accelerator pedal 20 is stopped at the timing T1 in FIG. 13, the motor load current and the duty ratio signal Duty rapidly increase to the closing side.
After that, when the accelerator operation amount Ap becomes 0 at timing T2, the throttle command voltage Vcmd decreases to a predetermined value KVth, and the motor load current and the duty ratio signal D
The uty is once changed from the closed side to the open side.

In step S204, it is determined whether the sensor output value Vth from the throttle opening sensor 7 is less than or equal to a predetermined value KVth. Here, when the sensor output value Vth becomes equal to or less than the predetermined value KVth at the timing T3 in FIG. 13, the process proceeds to step S205. In step S205, it is determined whether the engine speed Ne is, for example, 1500 rpm or more as the predetermined speed. When the determination condition of step S205 is satisfied, the process proceeds to step S206. In step S206, it is determined whether the learning execution flag XLRN is 0. When the determination condition of step S206 is satisfied, the process proceeds to step S207. On the other hand, when the determination conditions of steps S204 to S206 are not satisfied, this routine ends.

In step S207, the minute opening value Δθcmd (for example, 0.1 °) is subtracted from the throttle opening command value θcmd i−1 calculated in the previous routine to obtain the throttle opening command value θcmd i for this time. Is required. And
The throttle command voltage Vcmd i is calculated from the throttle opening command value θcmd i using FIG. 9, and this throttle command voltage Vcmd i is output to the DC motor drive circuit 29. The DC motor drive circuit 29 controls the throttle command voltage V
pulse width modulation of cmd i to duty ratio signal Duty,
The C motor 8 is driven. That is, by the processing of step S207, the throttle valve 3 is rotated in the closing direction by the minute opening value Δθcmd, as shown between the timing T3 and the timing T4 in FIG.

Next, in step S208, the duty ratio signal Dut output from the DC motor drive circuit 29 is output.
It is determined whether y is equal to or greater than 85% as a predetermined value set in advance. If it is determined in step S208 that the throttle valve 3 has not reached the fully closed position (the period between the T3 timing and the T4 timing in FIG. 13) and the duty ratio signal Duty is less than 85%, step S209.
, The counter value ti is reset to 0, and this routine ends.

On the other hand, when the throttle valve 3 reaches the fully closed position at the timing T4 and the bent piece 4a of the rotating member 4 contacts the fully closed stopper piece 13, the motor load current increases to the closed side. As a result, the lock current is generated and the duty ratio signal Duty is rapidly increased to the closing side. In this way, the duty ratio signal Duty is 85 in step S208.
When it becomes equal to or more than%, the process proceeds to step S210 and the counter value ti is incremented by "1".

Next, in step S211, it is determined whether the counter value ti is greater than or equal to the predetermined time Kt. If the counter value ti is less than the predetermined time Kt in step S211, the process proceeds to step S212, and the fully closed reference voltage V0 is calculated by the following equation (5) using the sensor output value Vth from the throttle opening sensor 7. That is, the arithmetic mean value of the sensor output value Vth i of the throttle opening sensor 7 this time and the sensor output value Vth i-1 of the previous throttle opening sensor 7 is calculated and set as the fully closed reference voltage V 0.

[0058]

## EQU5 ## V0 = (Vth i-1 + Vth i) / 2 (5) The calculated fully closed reference voltage V0 is updated as the fully closed reference voltage V0 of the backup memory 34.

On the other hand, when the counter value ti becomes equal to or larger than the predetermined value Kt at the timing T5 in FIG. 13, the process proceeds from step S211 to step S213, and the learning execution flag XLRN.
Is set to "1", and this routine ends. in this way,
Full-closed position learning is executed simultaneously with sensor outputs Va and Vb,
Vao and Vbo are required.

Next, a routine for countermeasures against erroneous learning due to noise will be described with reference to FIG.

First, in step S301, it is determined whether the fail flag XFAIL is 0. Step S3
When the determination condition of 01 is satisfied, step S302
Then, it is determined whether the throttle opening command value θcmd is 0 °. When the determination condition of step S302 is satisfied, the process proceeds to step S303, and it is determined whether the sensor output value Vth by the throttle opening sensor 7 is equal to or less than a predetermined value KVth. When the determination condition of step S303 is satisfied, the process proceeds to step S304 and it is determined whether the duty ratio signal Duty is 85% or more. Here, the duty ratio signal Duty being 85% or more means that the bent piece 4a of the rotating member 4 is in contact with the fully closed stopper piece 13 when the throttle valve 3 is at the fully closed position. Nevertheless, it means that the DC motor 8 is going to be driven further in the closing direction, and the fully closed reference voltage V0 of the backup memory 34 is too small. For this reason,
When the determination condition of step S304 is satisfied, it is necessary to correct the fully closed reference voltage V0, so step S305.
Then, a value obtained by adding a minute voltage value ΔV (for example, 1 mV) to the fully closed reference voltage V0 is used as the fully closed reference voltage V0 (= V0
+ ΔV), and thereafter, until the duty ratio signal Duty falls below 85%, steps S304 to S305.
The process of is repeated. Here, when the determination conditions of steps S301 to S304 are not satisfied, this routine is ended.

By executing such processing,
Even when noise is superimposed on the output line of the throttle opening sensor 7 and the fully closed reference voltage V0 is erroneously learned to be a small value, the value is corrected to an appropriate value.

As described above, in the throttle fully closed position learning of the present embodiment, when the throttle valve 3 reaches the fully closed position, the DC motor 8 is driven in the closing direction by the command value to cause the throttle valve 3 to move. Interlocking rotating member 4
The bent piece 4a and the fully closed stopper piece 13 are brought into contact with each other. Then, the lock current generated at the time of this contact is detected as an increase in the duty ratio signal Duty, and the fully closed position is detected. Further, the fully closed reference voltage V0 at the fully closed position can be updated, and the opening degree of the throttle valve 3 is adjusted based on the updated value.

As described above, the throttle control device according to the present embodiment comprises the magnetoelectric conversion element composed of the two Hall elements 41a and 41b and the magnets composed of the permanent magnets 42a and 42b, and the plurality of magnetoelectric conversion elements are composed of the magnets. The direction of the magnetic field received from is arranged at a different position for each of the magnetoelectric conversion elements,
The magnetoelectric conversion element outputs a detection signal Va or Vb corresponding to the throttle opening by changing the direction or strength of the magnetic field received from the magnet with the change of the throttle opening, and a throttle opening sensor 7. A throttle opening detection means that is achieved by the CPU 26 that detects the throttle opening based on the output of one of the plurality of magnetoelectric conversion elements, and a target throttle opening is set according to the operating state. A correction amount ΔV corresponding to the output difference between the target throttle opening degree setting means achieved by the CPU 26 and the detection signal of the magnetoelectric conversion element used for detecting the throttle opening and the detection signal of another magnetoelectric conversion element. Throttle command voltage Vcmd corresponding to the target throttle opening based on
Target throttle opening correction means achieved by the CPU 26 that corrects', and a CPU that feedback-controls the throttle opening so that the target throttle opening is achieved.
And a throttle opening control means achieved at 26, which can be the embodiment of claim 1.

Therefore, the two throttle elements 41a, 41 of the throttle opening sensor 7 are detected by the throttle opening detecting means.
The throttle opening is detected based on the detection signal of one Hall element in b, and the target throttle opening setting means sets the target throttle opening according to the operating state. Further, the target throttle opening degree is corrected based on the correction amount ΔV corresponding to the output difference between the detection signal of the hall element used for detecting the throttle opening degree by the target throttle opening degree correction means and the detection signal of another hall element. Throttle command voltage Vcm
d'is corrected. Then, the throttle opening control means feedback-controls the throttle opening so that the target throttle opening is achieved.

Therefore, in the region where the detection accuracy of the sensor output is inferior, the output is corrected by the other sensor outputs, so that the feedback control is accurately performed from the low opening range to the high opening range of the throttle opening, and at the time of switching. There is no relative error between the outputs of the two sensors at 1, and the drivability becomes good.

Further, the throttle control device of this embodiment is
The target throttle opening degree correction means achieved by the CPU 26 continuously changes the correction amount ΔV according to the target throttle opening degree, and this can be the embodiment of claim 2.

Therefore, the correction amount ΔV for correcting the throttle command voltage Vcmd ′ corresponding to the target throttle opening is continuous in accordance with the output difference of the detection signals Va and Vb from the magnetoelectric conversion element composed of the two Hall elements 41a and 41b. Be changed. Therefore, there is no relative error between the outputs of the two sensors when switching from the low opening range to the high opening range, and the drivability becomes extremely good.

Further, in the throttle control device of this embodiment, the target throttle opening degree correction means achieved by the CPU 26 is a magneto-electric device composed of a hall element 41a having a high output accuracy in the low opening range of the throttle opening. The target throttle opening based on the correction amount ΔV corresponding to the output difference between the detection signals Va and Vb from the magnetoelectric conversion element including the conversion element and the Hall element 41b with high output accuracy in the high opening range of the throttle opening. To correct the throttle command voltage Vcmd 'corresponding to the above. This can be the embodiment of claim 3.

Therefore, the two Hall elements 41a, 4a
With the detection signals Va and Vb from the magnetoelectric transducer 1b, the output accuracy from the low opening range to the high opening range of the throttle opening is maintained high. Therefore, the reliability of the correction amount ΔV calculated according to the output difference of the detection signals from the two magnetoelectric conversion elements can be improved.

Further, the throttle opening sensor 7 in the embodiment of claim 1 can be constituted by a plurality of throttle opening sensors having different output characteristics as the embodiment of claim 4. Also in this case, it is possible to obtain the same operation and effect as the embodiment of claim 1.

By the way, in the above-described embodiment, the throttle opening sensor 7 including the two Hall elements 41a and 41b.
The throttle command voltage Vcmd is corrected by using the two detection signals from, but the Hall element is further added, and the throttle command voltage Vcm is corrected by using three or more detection signals.
It is also possible to get d.

Further, although the throttle opening sensor of the above embodiment is composed of the Hall element as the magnetoelectric conversion element,
When the present invention is implemented, the present invention is not limited to this, and the detection signal corresponding to the throttle opening is changed by changing the direction or strength of the magnetic field received from the magnet with the change of the throttle opening. Anything that outputs can be used.

[0074]

As described above, according to the throttle control device of the first aspect, the target throttle opening set by the target throttle opening setting means is set by the target throttle opening correction means. It is corrected based on the correction amount according to the output difference between the detection signal of the magnetoelectric conversion element used for detection and the detection signal of another magnetoelectric conversion element. That is, even in the region where the detection accuracy of the magnetoelectric conversion element used to detect the throttle opening is poor, it is corrected by the detection signals of other magnetoelectric conversion elements. The throttle opening can be accurately feedback-controlled up to the range.

According to the throttle control device of claim 2,
In addition to the effect of the first aspect, the correction amount for correcting the target throttle opening by the target throttle opening correction means is continuously changed according to the output difference of the detection signals from the plurality of magnetoelectric conversion elements. As a result, it is possible to eliminate a relative error between the outputs of the plurality of sensors when switching from the low opening range to the high opening range.

According to the throttle control device of claim 3,
In addition to the effect of claim 1 or claim 2, the target throttle opening degree correction means has a high output accuracy from a low opening area to a high opening area of the throttle opening based on detection signals from a plurality of magnetoelectric conversion elements. Will be maintained. As a result, the reliability of the correction amount calculated according to the output difference of the detection signals from the plurality of magnetoelectric conversion elements can be improved.

According to the throttle control device of claim 4,
The target throttle opening set by the target throttle opening setting means is a detection signal of a throttle opening sensor used for detecting the throttle opening by the target throttle opening correction means and a detection signal of another throttle opening sensor. It is corrected based on the correction amount according to the output difference between That is, even in a region where the detection accuracy of the throttle opening sensor used to detect the throttle opening is inferior, it is corrected by the detection signals of the other throttle opening sensors, so that the throttle opening is increased from the low opening area to the high opening area. The throttle opening can be accurately feedback-controlled up to the opening range.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an electrical configuration of a throttle control device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the vicinity of a throttle valve to which a throttle control device according to an embodiment of the present invention is applied.

FIG. 3 is a schematic diagram showing a configuration around a throttle valve of a throttle control device according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a configuration of a throttle opening sensor used in the throttle control device according to the embodiment of the present invention.

FIG. 5 is a characteristic diagram showing an output of a throttle opening sensor used in the throttle control device according to the embodiment of the present invention.

FIG. 6 is a flowchart showing a processing procedure of throttle control of a CPU used in a throttle control device according to an embodiment of the present invention.

FIG. 7 is a block diagram showing throttle control of a throttle control device according to an embodiment of the present invention.

FIG. 8 is a characteristic diagram showing a relationship among an accelerator operation amount, an engine speed and a throttle opening command value used in a throttle control device according to an embodiment of the present invention.

FIG. 9 is a characteristic diagram showing a relationship between a throttle opening command value and a throttle command voltage used in the throttle control device according to the embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a characteristic deviation between two sensor outputs with respect to a throttle opening command value used in the throttle control device according to the embodiment of the present invention.

FIG. 11 is an explanatory diagram showing a relationship between a throttle command voltage before correction and a throttle command voltage after correction in the throttle control of the throttle control device according to the embodiment of the present invention.

FIG. 12 is a flowchart showing a processing procedure for learning a fully closed position of a CPU used in a throttle control device according to an embodiment of the present invention.

FIG. 13 is a timing chart of FIG.

FIG. 14 is a flowchart showing a processing procedure of an erroneous learning countermeasure due to noise or the like in throttle control of a CPU used in a throttle control device according to an embodiment of the present invention.

[Explanation of symbols]

 1 Intake Pipe 2 Throttle Shaft 3 Throttle Valve 4, 5 Rotating Member 7 Throttle Opening Sensor 8 DC Motor 13 Fully Closed Stopper Piece 22 Accelerator Position Sensor 25 ECU (Electronic Control Unit) 26 CPU 29 DC Motor Drive Circuit 35 Rotation Speed Sensor

Claims (4)

[Claims] 1. A plurality of magnetoelectric conversion elements and a magnet,
The plurality of magnetoelectric conversion elements are arranged at positions where the directions of the magnetic fields received from the magnets are different for each of the magnetoelectric conversion elements, and the magnetoelectric conversion elements have a direction or strength of a magnetic field received from the magnets in accordance with a change in throttle opening. Changes, the throttle opening sensor that outputs a detection signal according to the throttle opening, and the throttle opening sensor that detects the throttle opening based on the output of one of the plurality of magnetoelectric conversion elements Degree detecting means, a target throttle opening degree setting means for setting a target throttle opening degree according to an operating state, a detection signal of the magnetoelectric conversion element used for detecting the throttle opening, and a detection of another magnetoelectric conversion element. Target throttle opening correction means for correcting the target throttle opening based on a correction amount corresponding to an output difference from a signal, and the target throttle opening And a throttle opening control means that feedback-controls the throttle opening so that 2. The throttle control device according to claim 1, wherein the target throttle opening correction means continuously changes the correction amount for correcting the target throttle opening. 3. The target throttle opening correction means enhances the output accuracy in the low opening range of the throttle opening and the magnetoelectric conversion element in which the output accuracy in the high opening range of the throttle opening is high. 3. The target throttle opening is corrected based on a correction amount according to an output difference of each detection signal from the magnetoelectric conversion element.
Throttle control device described in. 4. A plurality of throttle opening sensors having different output characteristics, and throttle opening detecting means for detecting the throttle opening based on the output of one of the plurality of throttle opening sensors. Target throttle opening setting means for setting a target throttle opening according to the operating state, and the correction amount according to the output difference between the output of the one throttle opening sensor and the output of the other throttle opening sensor A throttle control device comprising: a target throttle opening correction unit that corrects a target throttle opening; and a throttle opening control unit that feedback-controls the throttle opening so that the target throttle opening is reached.