JPH03172557A - Control method for actuator synchronizing with engine speed - Google Patents

Abstract

PURPOSE:To enable it to do synchronous control between a crankshaft and an actuator so accurately by installing two rotary encoders of specific structure each, detecting each phase of both these elements, and controlling the actuator according to a deviation in their output signals. CONSTITUTION:In a device which controls air intake timing by installing a rotary valve 2 being driven by a motor 8, there are provided with two rotary encoders 13, 14 detecting each phase of a crankshaft and the rotary valve 2 separately. Both these rotary encoders 13, 14 are constituted so as to emit such an output as having a dead zone eliminated by installing two angle detecting sensors 25, 26 with light receiving parts 25b, 26b for detecting light run past a slit train installed in a slit disk 21 adjacently in an annular manner and composing respective output signals of these light receiving parts 25b, 26b. Then the motor 8 is controlled by an electronic control unit 9 on the basis of a deviation between both the output signals of these rotary encoders 13, 14.

Description

[Detailed Description of the Invention] <Industrial Use> The present invention relates to a control method for an actuator that is synchronized with engine rotation, and uses a rotary encoder that can detect the phases of a crankshaft and an actuator without creating a dead zone. The design was devised so that good control could be achieved.

<Prior art> As shown in Fig. 6, the intake system of an automobile engine has
The rotary valve 2 driven by the motor 8 is
: There is something inserted in the middle of 1. The rotary valve 2 is controlled via a motor 8 so that its rotation is synchronized with the rotation of the engine 3, and its phase is appropriately controlled to control the timing of air intake into the engine 3. . In other words, while the opening/closing timing of the intake valve 4 of the engine 3 and the opening/closing timing of the exhaust valve 5 are fixedly selected based on the vertical dead center in each intake/exhaust mode, in order to improve fuel efficiency, the engine 3
There is a desire to stop the intake of air into the combustion chamber 7 relatively early in the low rotation range, and to stop it relatively late in the high rotation range. The rotary valve 2 above meets this demand.
This is an intake system with

As described above, the reason why it is possible to improve fuel efficiency by making the timing of air intake variable between the low speed range and the high speed range of the engine 3 is as follows. That is, in the intake stroke, when the intake valve 4 is in the open state, the piston 6
By descending, air is sucked into the combustion chamber 7. At this time, since the descending speed of the piston 6 is slow in the low rotation range of the engine 3, air proportional to the amount of descending of the piston 6 is drawn into and filled into the combustion chamber 7. Even if the combustion chamber 7 is closed, the combustion chamber 7 can be moved to the compression process with substantially the maximum amount of air being filled in the combustion chamber 7. On the other hand, in the high rotation range of the engine 3, the descending speed of the piston 6 is fast, so even if the piston 6 descends, the inside of the combustion chamber 7 only becomes negative pressure, and the air cannot follow the descent of the piston 6. As a result of the time delay occurring in the flow of air into the combustion chamber 7, if the intake valve 4 is closed at the bottom dead center of the piston 6, the pressure within the combustion chamber 7 will be lower than atmospheric pressure. That is, the combustion chamber 7
The amount of air filled in the engine is less than in the low rotation range. Therefore, in this case, it is more desirable to delay the timing of stopping the intake of air until the inside of the combustion chamber 7 reaches atmospheric pressure, and to move to the compression process with a sufficiently large amount of air charged.

In this way, the timing at which the intake valve 4 is closed is made later than when using a normal intake system that does not have the quaternary pulp 2, and sufficient air is filled into the combustion chamber 7 even in the high speed range of the engine 3. At the same time, in the low speed range, the rotary valve 2 is closed relatively early, and the opening/closing timing of the intake valve 4 is fixed while the air is being The inhalation timing is variable.

Therefore, in the intake system shown in FIG. 6, the rotation of the motor 8 that drives the rotary valve 2 is controlled by the electronic control device 9 to synchronize the rotation of the rotary valve 2 with the rotation of the engine 3 and correspond to the rotation speed of the engine 3. It is designed to control the phase accordingly. For this purpose, information representing the phase of the crankshaft and the phase of the rotary valve 2 is supplied to the electronic control unit 9 via the four-way encoder 10.11. At this time, the rotary encoder 10 detects the rotational phase of the camshaft 12 connected to the crankshaft, and the rotary encoder 11 detects the rotational phase of the shaft of the motor 8.

The rotary encoders 10 and 11 include a slit disk attached to a rotating body and an angle detection sensor that detects the absolute angle of the slit disk by detecting light passing through a slit provided in the slit disk. Prepared.

A plurality of slits (180 slits) of the slit disk are arranged on the same circle of the slit disk, for example, at intervals of 1° of the center angle. All but one of these, 179 (this is defined as a slit every 1°), are set to the same size, and the remaining one (this is defined as a slit every 360") is set to a different size. It is set.

The angle detection sensor includes a light emitting section (light source) and a light receiving section, which are disposed to face each other on both sides of the slit disk where slits every 1° and slits every 360° are provided.

When the slit of the slit disk comes to the angle detection sensor, the light from the light emitting section passes through the slit, so the light receiving section receives the light and detects that the slit has passed.

The angle detection sensor outputs a 1° signal when it detects passing through a slit every 1°, and outputs a 360'' signal when it detects passing through a slit every 360°.

Then, when a 360° signal is received, the count is reset, and the next 1° signal is counted in order.
The absolute angle of the slit disk (therefore, the absolute angle of the rotating body) is detected in units of 1°.

<Problems to be solved by the invention> Rotary encoders 10, 1 according to the prior art as described above
1, if the passage of the slit every 360" is incorrectly detected due to disturbances such as ignition noise or other switch noise, the system rotates once (rotated 360 degrees) and then detects the passage of the slit every 36 degrees. Not only is there a problem in that the absolute angle cannot be detected until the motor 8 is stopped, but also the absolute angle (phase) cannot be detected when the rotating body such as the motor 8 is stopped. For example, when starting the engine 3, the intake valve 4 and rotary valve 2 may be out of phase, and even if the intake valve 4 opens during the intake stroke, the rotary valve 2 may remain closed. Until the passage of the slit is detected every 360 degrees and the phase of the rotary valve 2 is corrected, the relationship with the rotational phase of the engine 3 will not be as specified, resulting in a situation where smooth starting is not possible. Incidentally, engines 3 and 7 - motor 8 are not mechanically connected and rotate independently of each other, so even if they rotate synchronously during rotation, the amount of inertia rotation after the stop operation is generally different. Therefore, their phases often do not maintain a predetermined relationship.

The above problem is a common problem when the actuator is driven in synchronization with the rotation of the engine 3 based on the information detected by the rotary encoder 10°11.

In view of the above-mentioned prior art, the present invention provides an actuator that synchronizes with engine rotation, which can control the synchronous movement of both the crankshaft and the actuator using a rotary encoder that can always detect the phases of the crankshaft and the actuator, even when they are stopped. The purpose is to provide a control method for

Means for Solving the Problems> The configuration of the present invention that achieves the above object processes information representing the phase of the engine crankshaft and information representing the phase of the actuator in synchronization with the rotation of the engine. A control system for the actuator that is synchronized with the engine rotation to drive the actuator.The rotary encoder that detects the phase of the crankshaft and the phase of the actuator is drilled at a constant center angle with different slit widths. a slit disk which has a slit row consisting of a plurality of slits arranged in an annular shape and is rotatable by being attached to a rotating body; a light emitting part that emits light; and a light emitting part that receives light. It has a light receiving part that sends out a signal indicating this, and these light emitting part and light receiving part are arranged on opposite sides of the slit disk to form a pair, and the light passing through the slit is alternately arranged. and two angle detection sensors arranged adjacently on a ring so as to detect the angle, respectively, calculate the difference between the output signals of the two angle detection sensors, and generate a signal representing this difference. The present invention is characterized in that the phase of the crankshaft and the phase of the actuator are controlled to match each other by comparing the signals obtained by detecting the absolute values of .

According to the present invention having the above configuration, each slit of each rotary encoder is set to a different slit width depending on the absolute angle of the slit disk, so that the angle detection sensor Based on this amount of light, the absolute angle of the slit disk is detected even when the engine and actuator are stopped. In case B, each light receiving part of the angle detection sensor detects the light passing through the slit alternately at adjacent positions on the annular ring, so the signal output from each light receiving part is between the two ends of the slit in the annular direction. They will have the same waveform with a different phase by the angle,
Absolute angles of the engine and actuator are detected without creating dead zones.

<Examples> Examples of the present invention will be described in detail below based on the drawings. In this embodiment, the actuator is the motor 8 shown in FIG.
Moreover, it is applied to the control method shown in the figure.

FIG. 1 is a block diagram showing an embodiment of the present invention. As shown in the figure, the rotary encoder 13, which is an engine crank angle sensor, and the rotary encoder 14, which is a rotary valve crank angle sensor, are able to connect the crankshaft and rotary valve without causing a dead zone, as will be described in detail later. These rotary encoders have the same configuration and can always detect two phases. Of the output signals of these rotary encoders 13 and 14, ■ is an ignition signal ◎ representing the open/closed state of the ignition switch 15, as well as electronic 1! It is supplied to the IJ control device 9. The electronic control device 9 performs predetermined signal processing and controls the rotation of the motor 8 using the control signal ◎, so that the valve 1 and the valve 2 rotate synchronously while maintaining a predetermined phase relationship with the crankshaft. .

FIG. 2 is a flowchart showing a processing algorithm in the electronic control unit 9. As shown in FIG.

FIG. 3(a) is a front view showing the rotary encoders 13 and 14, and FIG. 3 (bl is a side view thereof).

As shown in the figure, a quadri-tary encoder 13°14 (
Since both have the same configuration, detailed explanation will be given only for one.) A slit disk 21 attached to the crankshaft and the shaft of the motor 8, and three angle detection sensors that detect the absolute angle of this slit disk 21. 24°25.
It has 26.

Each slit disk 21 has slit rows 22 and 23 arranged on two concentric circles around its center.

Among these, the slit row 22 is a slit row every 16, and has a plurality of (here, 2-180) slits 22a every 1" arranged at intervals of 1° of the center angle of the slit disk 21. The 1° slits 22a are each set to have a size corresponding to 1° of the central angle in the circumferential direction, and are also set to have the same size in the radial direction.

Further, the slit row 33 is a slit row every 10°,
The slit disk 21 has a plurality of (in this case, 18) slits 33a arranged at intervals of 10 degrees on the central angle.
It consists of Each of the 106 slits 33a is set to a size corresponding to a central angle of 10° in the circumferential direction, but is set to a different size from each other in the radial direction. In this example, there are 18 slits 33a every 10°.
The size in the radial direction is set to gradually increase as the rotation progresses, as viewed from the angle detection sensors 25 and 26.

Here, the absolute angle of the slit disk 21 is 06 to 10
"20'~30', 40"~506. ...340
Slits 4 23a are provided at positions of 6 to 350°, and these slits 23a are arranged in this order as 1st, 2nd, 3rd, and 3rd slits. ... Name it the 18th slit. If the radial size of the first slit 23a is 1, then the 2nd, 3rd, 4th, and so on. ... 18
The radial size of each slit 23a is tt2, 3, 4. ... It is set to 18.

On the other hand, the angle detection sensors 24, 25, 26 are light emitting units (light sources such as LEDs or light bulbs) 24a, 25a that emit light.
, 26a, and light-receiving sections (light-receiving elements such as phototransistors or photodiodes) 24b, 25b, and 26b that receive light and send out signals representing the received light, and these light-emitting sections 24a and 25a.

26a and the light receiving sections 24b, 25b, 26b are arranged on opposite sides of the slit disk 21. Among these, the light emitting part 24a of the angle detection sensor 24
The light receiving portions 24b and 24b face each other at positions corresponding to the slit rows 22. Further, the light emitting parts 25a, 26a and the light receiving parts 25b, 26b of the angle detection sensors 25, 26 are arranged at 10°.
Of each slit 23a, one larger than the largest one in the radial direction is used. As a result, the light receiving section 25b,
The output signal of 26b reflects the area of slit 23a. Further, the angle detection sensors 25 and 26 are arranged adjacent to each other on a ring so that the respective light receiving sections 25b and 26b alternately detect the light passing through the slit 23a.

That is, the dead zones of the light receiving sections 25b and 26b appear alternately,
By combining the output signals of these light receiving sections 25b and 26b, the dead zone can be removed as a result.

FIG. 4 is a circuit diagram showing the signal processing system of the angle detection sensors 24, 25.degree. 26, and FIG. 5 is a waveform diagram of each part thereof.

As shown in both figures, the light receiving sections 24b and 2sb.

The light-receiving element 26b has an electrical resistance that decreases when it receives light, and is connected in series with the resistors R1, R2, and R3, respectively, as the light-receiving element 24b.

5 The voltage applied to both ends of 25b and 26b is output signal V,
, V2. It is now sent out as v3.

Among these, the output signal (■) of the light receiving section 24b that detects the light passing through the slit array 22 every 1° is the reference voltage (the voltage when no light is received) and the reduced voltage (the voltage when the light is received) at intervals of 16 degrees. ) is repeated.

In addition, output signals V2. v,
Let, as shown in Fig. 5(a) and Fig. 5(b), the same waveform is obtained in which the reference voltage and the reduced voltage with different levels are repeated every 10' intervals, but the output The signal v3 is delayed in phase by 10° from the output signal v2.

The differential amplifier 30 receives the output signal (2) supplied via the buffer amplifier 29. (2) The difference between 3 (V3-V2) is calculated. Therefore, the output signal v4 of the differential amplifier 30
As shown in FIG. 5 [C1], there are six voltages with the same absolute value and opposite sign every 10 degrees. The absolute value detection section 31 detects the absolute value of the output signal v4, and therefore, the output signal vs has a waveform in which the negative voltage is inverted and changes every 20 degrees, as shown in FIG. 5(d). Become.

The electronic control device 9 receives the output signal V4. ’vs based on the slit disk 21
It calculates the absolute angle of .

Since the rotary encoder applied to the embodiment of the present invention is configured as described above, when the slit disk 21 rotates together with the crankshaft and the motor 8, the slits 22a and 23a of each slit row 22 and 23 act as angle detection sensors. When passing through 24, 25, 26, the light receiving section 24b,
25b and 26b are light emitting parts 24a.

Receives the light from 25a and 26a and outputs each output signal v, .
v2. v, is changed.

At this time, the slit row 22 obtained by the light receiving section 24b
The detected digital value (1° signal) for the central angle of the slit disk 21 (that is, the angle of the crankshaft) is 1°.
0 (value when no light is received) and 1 (value when light is received) are repeated every other time.

On the other hand, the detected digital value (1
0° signal) every 20'' of the central angle of the slit disk 1 (the crankshaft angle) without forming a dead zone.
Continuously 1, 2, 3. ...It will be 18. That is, since the 18 slits 23a of the slit row 23 are set in 18 steps so that the size in the radial direction gradually increases, the amount of light passing through the slits 23a also gradually increases.

As shown in FIG. 5(d), the amount of change in the resultant output signal V is determined when the absolute angle of the slit disk 21 (absolute angle of the crankshaft) is 0''~20''20°~406...
It becomes larger as the angle increases from 3400 to 360°. Therefore, the digital output value also shows that the absolute angle of the slit disk 21 (absolute angle of the crankshaft) is 06
-206: 1.20' - 40°: 2. ...3
When the angle is from 40° to 360°, the angle increases continuously to 18 without forming a dead zone, and the slit disk 21 (therefore, the crankshaft) rotates 360° until it reaches 0° to 360°.
At position 206, the digital output value also returns to 1.

Therefore, based on the slit row 23, every 20@,
The absolute angle of the slit disk 21 (that is, the crankshaft) can be detected.

In this way, the absolute angle of the slit disk 21 (that is, the crankshaft) is set to 1" based on the detection data every 20 degrees based on the slit row 23 and the detection data every 1" based on the slit row 22. It can be detected in units.

In particular, due to the magnitude of the digital output value, the slit disk 21
Since the absolute angle of the (crankshaft) can be determined every 20", even if the slit 22g of the 9-lit row 22 is incorrectly detected every 1°,
The absolute angle of the slit disk 1 (crankshaft) can be detected at least in units of 20 degrees.

Furthermore, according to the rotary encoder 13.14, since the light passing through the slit 23a is always detected by one of the light receiving sections 25b and 26b, the slit 23a
A dead zone is not formed due to the portion through which light does not pass. Therefore, even when the slit disk 21 is stopped, the absolute angle can be detected with a resolution of 20 degrees.

Here, slit rows 3 with different sizes of slits 23a are provided at 10° intervals by dividing 360° into 18 equal parts. It is also possible to divide it into appropriate equal parts and provide them at appropriate angular intervals. As the number of slits 23a increases, the accuracy of detecting the absolute angle of the length of the slits 23a improves. Output signal v1. (2) It is better to adjust the positions of the light receiving parts 25b and 26b and the width of the slit 23a in the annular direction so as not to generate 20- noise at the switching point of 2. A similar effect can also be obtained by passing the output signals V, , v2 through an electrical filter circuit.

Further, the signal processing system sends the output signals V, , v2 to the husband A/D.
Of course, it may be converted and supplied to the electronic control unit 9, and an algorithm within the electronic control unit 9 may perform arithmetic processing similar to the processing of the differential amplifier I#30 and the absolute value detection unit 31 in the above embodiment. .

Also, regarding the slit row 2, one
It may be arranged at intervals other than degrees (for example, intervals of 2'' or intervals of 0.5 degrees).

<Effects of the Invention> As specifically explained above in conjunction with the embodiments, according to the present invention, the plurality of slits formed at each constant central angle are different from each other depending on the absolute angle of the slit disk. width is set, and the light receiving part of the angle detection sensor is =
22= Since the phase of the engine and actuator can be detected with a rotary encoder that detects the amount of light according to the slit width and can detect the absolute angle of the slit disk based on the amount of light, noise is reduced. The absolute angles of the engine and actuator can be reliably detected even when external disturbances such as the following occur. In addition, in the rotary encoder, the light receiving parts are arranged adjacent to each other on a ring so that the dead zones between the slits affect each other alternately, and the output signals of both are combined and processed, so the dead zone is removed. Since the absolute angle of the slit disk can always be detected even when the slit disk is stopped without waiting for the slit disk to rotate until it reaches a predetermined phase, it is possible to perform good synchronized control of the engine and actuator.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing a processing algorithm in the electronic control device, and FIG. 3(a) is a front view showing a rotary encoder used in the embodiment. Fig. 3 (bl is a vertical cross-sectional view thereof, Fig. 4 is a circuit diagram showing the signal processing system of the angle detection sensor, Fig. 5 (al to Fig. 5(d) is a waveform diagram of each part, Fig. 6 is a configuration diagram showing a control system of a rotary valve. In the drawing, 2 is a rotary valve, 3 is an engine, 8 is a motor, 9 is an electronic control device), 13. 14 is a four-tary encoder, 21 is a slit disk, 23 is a slit row, 23a is a slit, 25.26 is an angle detection sensor, 25a and 26a are light emitting parts, and 25b and 26b are light receiving parts.

Claims (1)

[Claims] An actuator synchronized with engine rotation, which processes information representing the phase of the engine crankshaft and information representing the phase of the actuator to drive the actuator in synchronization with the engine rotation. In the control method, the rotary encoder that detects the phase of the crankshaft and the phase of the actuator is composed of a plurality of slits arranged in an annular shape, each having a different slit width and bored at a constant center angle. A slit disk having a row of slits and rotatable by being attached to a rotating body, a light emitting section for emitting light, and a light receiving section for receiving the light and transmitting a signal representing the received light. The light-emitting part and the light-receiving part are arranged on opposite sides of the slit disk to form a pair, and are arranged adjacent to each other on the ring so as to alternately detect the light passing through the slit. By having two angle detection sensors, respectively calculating the difference between the output signals of the two angle detection sensors, and comparing the signals obtained by respectively detecting the absolute values of the signals representing this difference. An actuator control method that synchronizes with engine rotation, characterized by controlling the crankshaft phase and the actuator phase to match.