JP4169764B2 - Throttle control device for internal combustion engine - Google Patents

Description

  The present invention relates to a throttle control device for an internal combustion engine that drives a motor and controls the opening of a throttle valve, for example, according to the amount of depression of an accelerator pedal.

2. Description of the Related Art Conventionally, a throttle control device for an internal combustion engine called an “electronic throttle system” that drives a motor in accordance with the amount of depression of an accelerator pedal and controls the opening of a throttle valve is known.
In this throttle control device for an internal combustion engine, it matches the signal from the accelerator opening sensor that detects the accelerator opening corresponding to the amount of depression of the accelerator pedal, or the target opening of the throttle valve obtained by the internal calculation of the microcomputer. As described above, when the motor is driven and the motor is driven, the throttle valve is opened and closed to control the intake air amount.

FIG. 10 is a configuration diagram illustrating an example of a conventional throttle control device disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-11564.
In FIG. 10, a throttle valve 2 provided in the intake pipe 1 is a butterfly valve and is driven by a motor 4 through a reduction gear 3. The throttle valve 2 appropriately adjusts the air flowing from an air cleaner (not shown) and supplies it to an engine (not shown).
The spring 5 attached to the rotating shaft of the throttle valve 2 is set so that the throttle valve 2 returns to a certain opening (hereinafter referred to as default opening) unless the motor 4 generates torque. As a result, even when the engine control unit (hereinafter referred to as ECU) 6 detects an abnormality and turns off the motor drive circuit 7, a predetermined amount of air is secured and the engine stops or the rotational speed becomes abnormal. A fail-safe function that can drive to the nearest repair shop, etc. is realized without increasing the price.
A position sensor 8 for detecting the opening degree is attached to the rotation shaft of the throttle valve 2 and is connected to the ECU 6. The ECU 6 can detect the current opening of the throttle valve 2 by A / D converting the signal of the position sensor 8. The ECU 6 performs A / D conversion on the signal from the position sensor 9 of the connected accelerator pedal, and uses it for calculating the target opening.

Subsequently, a process in the ECU 6 is shown in a block diagram as shown in FIG.
The microcomputer in the ECU 6 first performs A / D conversion on signals from the accelerator pedal position sensor 9 and the throttle valve position sensor 8 at a predetermined processing timing.
Next, the target opening is obtained according to the signal of the A / D converted accelerator pedal position sensor 9 and the engine operating state, and this is set as the target opening 10. Assuming that the signal of the throttle valve position sensor 8 previously A / D converted is the actual opening 11, the deviation calculating means 12 obtains a value obtained by subtracting the actual opening 11 from the target opening 10, and this is the deviation. And
The next throttle valve driving means 13 performs various calculations of the proportional term (P term) 14, the integral term (I term) 15, and the differential term (D term) 16 according to PID control so as to reduce the deviation. The operation amount 17 is obtained by adding the above results, and the PWM converter 18 generates a PWM signal to be supplied to the drive circuit 7. The PWM signal is transmitted from the ECU 6 to the drive circuit 7, and the drive circuit 7 amplifies the PWM signal and drives the motor 4.

An example of the PID control is shown in FIG.
Deviations obtained by subtracting the actual opening 11 from the target opening 10 are input to the proportional term 14, the integral term 15, and the differential term 16, respectively. Each term has a P term gain KP, an I term gain KI, and a D term gain KD, which are control constants. In the proportional term 14, the deviation and the P term gain are integrated, and in the integral term 15, the deviation is I. The value multiplied by the term gain is integrated, and in the differential term 16, the D term gain is applied to the result obtained by subtracting the deviation at the previous time from the deviation, and each is used as the output of each term. The outputs of the proportional term 14, the integral term 15, and the derivative term 16 are added to obtain an operation amount 17.

The response of the throttle valve 2 is determined by each gain of the PID control.
These values are determined so that the driver will not feel uncomfortable acceleration / deceleration when driving, and as fast as the mechanical throttle valve will be realized. It is determined so that the accuracy of adjusting the air amount can be obtained with the same accuracy as the conventional bypass valve for idle speed control. Therefore, in the PID control, it is necessary to control even a slight difference between the target opening and the actual opening with feedback so that these requirements are satisfied, and the control gain is set to a large value and agile. The operation amount is changed.

These gains are set according to the overall torque characteristics of the throttle valve.
A major factor that determines this torque characteristic is the characteristic of the spring 5 attached to the rotary shaft of the throttle valve. An example is shown in FIG.
A preload is set for the spring 5, and the sign of the torque applied to the throttle valve is reversed at the default opening. The torque increases as the distance from the default opening increases, but basically the preload torque accounts for most of the torque generated by the spring.

Therefore, overall, the throttle can be driven so as to satisfy the above requirements, while the throttle valve has a nonlinear torque change such as friction, hysteresis, or torque ripple. In particular, at the default opening, since the rotation direction of the motor is reversed as described above, the change in torque is large.
For this reason, even when trying to keep the throttle valve at a constant throttle opening by such a nonlinear change in torque, it opens and closes at a low frequency (1 Hz to several Hz) and a minute angle (about 0.1 °). In other words, a so-called hunting phenomenon may occur.
In particular, at the default opening, since the amount of torque change is large, hunting is likely to occur.

Here, the mechanism of occurrence of hunting will be described.
Since the control gain is set to match the overall torque characteristics of the throttle valve, the actual opening almost converges to the target opening, but there is a slight deviation due to a nonlinear torque change that varies depending on the opening. The actual opening may stop with the remaining.
At this time, since the deviation is small, the proportional term is a slight constant value, and since the actual opening is stopped, the differential term is zero. For this reason, in order to correct this deviation, the integral term increases monotonously (decreases if the target opening is smaller than the actual opening), and the manipulated variable also increases or decreases monotonically.
Since the butterfly is stopped, in order to move the deviation to zero, in addition to the nonlinear torque change amount, the manipulated variable must change until the torque component due to static friction is overcome. If the manipulated variable exceeds this value, the throttle valve moves, but the torque due to static friction becomes excessive, and there is also a nonlinear torque change at the changed opening, so when the target opening is exceeded, the throttle valve Will stop. Then, this time, in the opposite direction, the integral term changes monotonously in the opposite direction, and eventually, when the manipulated variable exceeds the static friction, it moves to return the throttle valve, but until the target opening is exceeded again. It will work. This repetition appears as low frequency hunting.

In order to prevent hunting from occurring due to such nonlinearly changing torque, there have been inventions for solving this problem.
These inventions can be broadly divided into active and passive types.
In the active type, a situation in which hunting is likely to occur is determined in advance, and in that situation, the occurrence of hunting is prevented by a technique such as suppressing an integral term calculation that causes hunting.
For example, in Japanese Patent Laid-Open No. 2004-11564, the integral term calculation is stopped when the deviation between the target opening and the actual opening becomes small. Japanese Patent Laid-Open No. 9-72231 proposes to limit detection to a default opening, and to lower the gain or prohibit feedback control at the default opening.

  On the other hand, the passive type is to prevent hunting from continuing further by a method such as suppressing the integral term calculation that causes hunting after actually detecting the occurrence of hunting. For example, in Japanese Patent Laid-Open No. 9-151766, the offset control amount added to the PID control by detecting the occurrence of hunting from the integral of the deviation between the target opening and the actual opening, the number of inversions of the actual opening, and the like. It has been proposed to reduce.

JP 2004-11564 A Japanese Patent Laid-Open No. 9-72231 JP-A-9-151766

The active type described above is intended only for situations where there is a possibility of occurrence of hunting designed in advance, and therefore hunting under conditions that were not assumed at the time of design cannot be prevented. In Patent Document 2, since it does not cope with non-linear changes in torque other than the intermediate opening, hunting that can occur at these openings cannot be prevented. On the other hand, if all possibilities are targeted, suppression is applied even when hunting is not performed, and convergence is adversely affected.
In Patent Document 1, even when hunting may not be performed, if the deviation between the target opening and the actual opening is small, the integral term calculation stops unconditionally, and as a result, the convergence to the target opening deteriorates. .
In addition, since any of the examples can cope only with a change designed in advance, it cannot cope with a change in torque caused by a secular change.
Further, in the passive type, there is a problem that the time until detection becomes long. In Patent Document 3, it cannot be detected unless hunting occurs at least several times, and influences such as fluctuations in engine speed are inevitable until then.

  The present invention has been made to solve such a conventional problem. The present invention is made passive so that any hunting can be detected, and the hunting is performed once by detecting the behavior of feedback control at the initial stage of hunting. It is an object of the present invention to provide a throttle control device for an internal combustion engine that can be detected by the time it occurs and can solve the problem of detection time.

The present invention controls the drive of the motor based on the deviation between the target opening of the throttle valve and the actual opening given according to the amount of depression of the accelerator pedal, and feedback controls the actual opening of the throttle valve to the target opening. In the internal combustion engine throttle control device,
A deviation calculation means for calculating a deviation that is a difference between the target opening and the actual opening, and a feedback control including at least a function for integrating the deviation is obtained, and the motor is driven in accordance with the operation quantity. The throttle valve driving means for controlling the opening of the throttle valve and the actual opening of the throttle valve are constant without change, and the output value of the function to be integrated or the operation amount is only increased or decreased. And a valve behavior determining means for determining that the hunting state is continued for a predetermined time. The throttle valve driving means integrates the function when the valve behavior determining means determines the hunting state. The output value or the operation amount is reduced or the output correction means for stopping the update is provided.

Further, the present invention controls the drive of the motor based on the deviation between the target opening of the throttle valve and the actual opening given according to the amount of depression of the accelerator pedal, etc., so that the actual opening of the throttle valve is changed to the target opening. In a throttle control device for an internal combustion engine that performs feedback control,
A deviation calculating means for calculating a deviation the a difference between the target opening and the actual opening, determine the manipulated variable by the feedback control including a function of integrating at least the deviation, driving the motor in accordance with the operation amount The throttle valve driving means for controlling the opening of the throttle valve and the output value of the function to be integrated or the value of the manipulated variable, where the actual opening is the same as the value one hour before. A valve behavior determination that holds a time value, and determines that the difference between the held value and the current value exceeds a predetermined value, and the actual opening does not change and continues for a predetermined predetermined time, as a hunting state and means, in the throttle valve driving means, if it is determined that hunting state by said valve behavior determination unit, the output value of the function of the integration, or the operation amount, to reduce or stop the update Those configured to have a force correction means.

  According to the throttle control device for an internal combustion engine of the present invention, the hunting state can be determined in the process of monotonically increasing or decreasing the output value of the function to be integrated or the operation amount before reaching hunting. As with conventional devices, not only the conditions assumed at the time of design but also any hunting can be detected in a short time, and the output value of the function to be integrated or the operation amount can be corrected to quickly Hunting can be suppressed.

  Further, according to the throttle control device for an internal combustion engine of the present invention, the hunting state can be determined even when the output value of the function to be integrated or the operation amount increases or decreases while fluctuating.

Embodiment 1 FIG.
The internal combustion engine throttle control apparatus according to Embodiment 1 of the present invention will be described below with reference to FIGS. In the figure, the same reference numerals as those in FIG. 11 showing the prior art denote the same or corresponding parts, and duplicate explanations are omitted.
FIG. 1 is a block diagram showing a main configuration of a throttle control device for an internal combustion engine according to Embodiment 1 of the present invention. 1 differs from FIG. 11 showing the prior art in that a valve behavior determining means 19 and an output correcting means 20 are added.

In the valve behavior determining means 19 of the first embodiment, the manipulated variable can be increased monotonously (decrease if the target opening is smaller than the actual opening) even though the actual opening of the throttle valve has not changed. In this case, the hunting state is determined. This is because, as described above in the section “Background Art”, when hunting occurs due to the mechanism of hunting, an integral term, that is, a monotonous increase or decrease in the manipulated variable occurs.
Further, the output correction means 20 corrects the operation amount when the valve behavior determination means 19 determines that the hunting state is present. Specifically, the operation amount is corrected to decrease toward 0, that is, the absolute value is decreased. Alternatively, the operation amount is not updated and the previous value stored in advance is restored.
Hereinafter, the arithmetic processing according to the first embodiment will be described with reference to the flowcharts of FIGS.

FIG. 2 is a flowchart showing the calculation process of the valve behavior determining means 19.
In FIG. 2, it is the same as that of the prior art until the calculation of PID control is performed and the results are added to obtain the manipulated variable.
Next, after determining the operation amount, the valve behavior determining means 19 determines hunting.
In step S106, the change amount of the operation amount calculated last time is stored, and the change amount of the current operation amount is obtained.
In the next step S107, it is determined whether the change amount of the manipulated variable is the same as the sign of the change amount of the previous calculation, that is, whether the manipulated variable is changing in the same direction.
From the hunting mechanism, zero or direction reversal indicates that the actual opening of the throttle is the same as the target opening or straddled the target opening, that is, a predetermined value set by a time counter described later. Since the throttle is driven by time K5, it is determined that it is not in the hunting state. In this case, the determination is N, the process proceeds to step S113, hunting = none, the time counter is set to 0 in step S114, the process goes to the end, and the calculation process of the valve behavior determination unit is terminated.

On the other hand, if the operation amount is changing in the same direction in step S107, the determination is Y, and the process proceeds to step S109.
If the actual opening does not change in step S109, the elapse of the predetermined time K5 is determined in step S110, and if it continues for K5 or more, it is determined in step S111 that hunting = is present, and the valve exits to the end. The calculation process of the behavior determination unit is terminated.
If the actual opening has changed in step S109, the determination is N. In step S113, hunting = none, and in step S114, the time counter is set to 0, and the process goes to the end.
If the predetermined time K5 has not elapsed in step S110, the time counter is advanced in step S112, the process proceeds to the end, and the calculation process of the valve behavior determination means is terminated.

Next, the calculation processing of the output correction means 20 is shown in the flowchart of FIG.
In FIG. 3, in step S200, the operation amount 17 calculated by the PID control is stored in the buffer bef.
Next, in step S201, the result of the valve behavior determination means 19 is referred to. If it is not in the hunting state, the determination is N, the process is ended, and the calculation process of the output correction means 20 is terminated.
In this case, the manipulated variable 17 is not corrected, and the value calculated by the PID control is directly converted into DUTY by the PWM converter 18.
If hunting is present in step S201, the determination is Y, and the process proceeds to step S202, where a buffer aft for correcting the operation amount 17 is calculated .

  Three examples of step S210, step S220, and step S230 are illustrated as methods for correcting the operation amount. These are appropriately selected depending on the type of PID control.

When step S210 is selected as step S202, the process proceeds from step S201 to step S211 to determine whether the operation amount stored in the buffer bef is positive or negative.
When the manipulated variable is positive, it indicates that the throttle opening is on the open side with respect to the default opening in FIG. 13. In this case, the process proceeds to step S212, and the predetermined value K6 is subtracted from the buffer bef, and a negative value not shown in the figure. After performing a guard process that does not result in an error, the buffer aft is calculated and stored as the operation amount corrected in step S203.
When the manipulated variable is negative, it is a case where there is an actual opening on the closing side from the default opening, so in step S213, a predetermined value K6 is added to the buffer bef, and a guard process that does not become positive (not shown) is performed, The data is stored in the buffer aft, and is stored as an operation amount in step S203 .

  When step S220 is selected as step S202, a predetermined value K7 smaller than 1 is multiplied by the buffer bef and stored as the operation amount corrected in step S203.

  Furthermore, when step S230 is selected as step S202, the previous operation amount stored in advance is substituted into the buffer aft, and is stored as the operation amount corrected in step S203. That is, the current operation amount calculation is invalidated.

After performing correction for such an operation amount, the process goes to the end, and the calculation process of the output correction means is terminated.
Thereafter, the process proceeds to the PWM converter 18 as in the prior art.

  The determination time K5 of the valve behavior determination means 19 needs to be set shorter than the hunting cycle, for example, 200 ms. Further, when it is not hunting, the time to converge to the target opening is about 100 ms. Therefore, for example, if the determination time K5 is set to 150 ms, hunting can be detected without erroneous determination in normal operation. .

As described above, according to the throttle control apparatus for an internal combustion engine of the first embodiment of the present invention, operation amount is monotonously increased or decreased, and the actual opening constant, but if continued for a predetermined time period, hunting It determines that the state, since the corrected operation amount, not only the specific conditions assumed in the design stage as in the conventional apparatus, it is possible to detect any hunting. In addition, since the hunting state can be determined in the process of monotonous increase or decrease before hunting, hunting can be detected in a short time and hunting can be suppressed quickly.

Embodiment 2. FIG.
4 and 5 are block diagrams showing the configuration of the main part of the throttle control device for an internal combustion engine according to the second embodiment of the present invention.
In the first embodiment, the operation processing of the valve behavior determination means 19 and the output correction means 20 is performed on the manipulated variable 17, but as explained in the above-mentioned [Background Art] section , hunting occurs. When the deviation between the target opening and the actual opening is small, the change amount of the manipulated variable is equal to the change amount of the integral term.
Therefore, as shown in FIG. 4, a similar device can be configured by using the output value of the integral term instead of the operation amount used in the first embodiment (FIG. 1).
In FIG. 4, the details of the valve behavior determination means 19 and the output correction means 20 are the same as those of the first embodiment, only by replacing the manipulated variable with the output value of the integral term.

Further, when an integral term is used in the calculation process of the valve behavior determining means 19, not only the integral term but also the manipulated variable is corrected for the target of the output correcting means 20, and the change amount of the manipulated variable is the change of the integral term. Yes, because it is equal to the amount. In this case, the configuration is as shown in FIG.
In this case as well, the details of the valve behavior determination means 19 are the same as those of the first embodiment only by replacing the manipulated variable with the output value of the integral term.

  In the above, the feedback control is shown in the most basic form of PID control. However, in practice, there are various forms of feedback control, and therefore the deviation between the target opening and the actual opening is small. However, there is a form in which the change amount of the integral term does not coincide with the change amount of the operation amount. In this case, a correct hunting state may not be detected if the valve behavior determining means 19 determines only the direction of change in the manipulated variable or integral term. Therefore, in this case, the characteristics of the feedback control before the application of the present invention is analyzed, and the input of the valve behavior determining means 19 and the insertion position of the output correcting means 20 are operated like an integral term in the feedback control. It is necessary to change the control term to This will be described again in the sixth embodiment described later.

  As described above, the second embodiment can achieve the same effects as those of the first embodiment.

Embodiment 3 FIG.
In the first embodiment, the valve behavior determination means 19 uses the hunting state determination condition that the operation amount increases (or decreases) in the same direction and the actual opening degree is constant. However, some throttle valve controls have a mechanism (dither control) that improves the control resolution of the valve by minutely changing the target opening constantly in a short period of time, for example, 10 ms.
In such a case, even if the actual opening does not change and is constant , the deviation of the target opening-actual opening changes, for example, when the target opening changes, and therefore, the PID control method and gain setting Depending on the value, the sign of the manipulated variable may change in a short time . For example, as shown in FIG. In this case, in the first embodiment, since the determination time K5> the dither control cycle, it is always determined that the hunting state is not established.

The third embodiment of the present invention deals with such a case, and the valve behavior determining means 19 continues the hunting determination for a predetermined time.
FIG. 7 shows a flowchart of the calculation process of the valve behavior determination means 19.
In FIG. 7, the process up to step S107 is the same as in FIG. If the operation amount has changed in the same direction in step S107, the holding counter is incremented in step S121, and otherwise, the holding counter is reset in step S122.
Next, in step S109, it is determined whether or not the actual opening has changed. If it has changed, both the UP counter and the DOWN counter are reset to 0 in step S133, and N determination is made in step S126. It is determined that hunting = none and exits to the end.
If the actual opening does not change in step S109, the process proceeds to step S123, and the holding counter is compared with a predetermined value K8. If it is equal to or greater than K8, that is, the time for holding the hunting determination is reached, the process proceeds to step S129, and if the gradient of the current operation amount is the UP direction, the UP counter is incremented in step S130, and the DOWN counter is Reset. Thereafter, in step S126, the hunting determination is performed by comparison with the predetermined value K5.

  If the inclination of the current operation amount is in the DOWN direction, N determination is made in step S129, Y determination is made in step S131, the DOWN counter is incremented in step S132, and the UP counter is reset. Thereafter, in step S126, the hunting determination is performed by comparison with the predetermined value K5. If the inclination of the current operation amount is 0, N determination is made in step S131, both the UP counter and DOWN counter are reset to 0 in step S133, and N determination is made in step S126. Therefore, hunting is performed in step S113. = It is determined that there is none and exits to the end. That is, when the time to be held has elapsed, the UP counter and the DOWN counter have the same function as the time counter of FIG. 2 and perform hunting determination.

On the other hand, if the holding counter is less than the predetermined value K8 in step S123, that is, if the hunting determination is held, the process proceeds to step S124, and the inclination of the current operation amount is examined.
If the gradient of the current operation amount is the UP direction, the UP counter is incremented in step S125, and the DOWN counter is held as it is.
If the inclination of the current operation amount is in the DOWN direction, N determination is made in step S124, Y determination is made in step S127, the DOWN counter is incremented in step S128, and the UP counter is held as it is. If the gradient of the current operation amount is 0, N is determined in step S127, and both the UP counter and the DOWN counter are held.
In either case, in comparison with the predetermined value K5 in step S126, if Y determination is made, hunting is detected in step S111, and if N determination is made, hunting is determined in step S113, and the process proceeds to the end.
That is, when the time to be held has not elapsed, the UP counter and the DOWN counter that are originally operated in reverse are set to be held without being reset.

To assist the above understanding, a timing chart of the counter operation is shown in FIG.
Although the operation of the UP counter and the DOWN counter is illustrated from the operation amount, the condition of the actual opening is ignored for simplicity.

The predetermined time K8 needs to be set to about the cycle of the target opening of dither control / 2 + α, and to be shorter than the cycle of the low frequency hunting. In this flowchart, the time counter in FIG. 2 is set separately from the UP counter and the DOWN counter, and the determination time K5 and the holding time K8 can be set independently. For example, the UP counter, the DOWN counter, If the current operation amount slope is UP direction, +1, and if the current operation amount inclination is DOWN direction, -1 is set, and K5 or more, or hunting = 1 or more when -K5 or more. This is also feasible.

  As described above, according to the third embodiment of the present invention, even when the actual opening does not change and is constant, the target opening changes across the actual opening. Even in such a case, hunting can be detected with high accuracy.

Embodiment 4 FIG.
In the fourth embodiment of the present invention, the manipulated variable is subjected to filter processing so that it is not affected by the reversal of the manipulated variable in a short time. In the dither control, since the period of the target opening is about 10 ms, a filter that does not affect the determination time K5 can be set.
In this case, as shown in step S105 of FIG. 8, a step of filtering the operation amount may be inserted before step S106. Of course, if there is a process using the operation amount before step S106, the filter processing step may be inserted before the process, and the filtering process may be determined according to the situation.

Embodiment 5 FIG.
The actual opening of the throttle valve sometimes changes due to noise or A / D conversion error. The fifth embodiment of the present invention prevents the erroneous determination that the valve behavior is not in the hunting state, and applies a filter process to the actual opening. In this case, as shown in step S108 of FIG. 8, a step of performing filter processing on the actual opening may be inserted, for example, before step S109. Of course, if there is a process using the actual opening before step S109, a filter processing step may be inserted before the process, and it is only necessary to determine where to perform the filter process depending on the situation.

Embodiment 6 FIG.
As mentioned in Embodiment 1, various forms there because the feedback control, the valves behavior determination unit, is not determined only by the direction of change of the operation amount and the integral term, the correct hunting state It may not be detected.
The sixth embodiment of the present invention addresses such a case, and according to the characteristics of PID control before applying the present invention, by adding a determination condition to the valve behavior determination means, the manipulated variable and the integral term It is possible to make a determination based on a monotonic increase or decrease of A and a constant actual opening.
This additional condition is, for example, as shown in step S100, step S101, and step S102 in FIG. 8, where the change rate of the target opening is not more than a predetermined value K1 (step S100), or the absolute value of the deviation is a predetermined value K2. Below (step S101), or the deviation sign is the same as the sign of the previous time, or the deviation is 0 (step S102), or a combination of these, and the like may be inserted before step S106.

  According to the sixth embodiment, by restricting the output value of the function to be integrated or the operation amount to be the output value of the deviation integration function, erroneous determination and determination omission are prevented, and accuracy is improved. Can be improved.

Embodiment 7 FIG.
In the first embodiment, the valve behavior determination is performed in the entire throttle opening and the hunting state is detected. In the seventh embodiment of the present invention, the detection area is set near the default opening in the valve behavior determination. It is limited.
In this case, since the detection area becomes narrow, it is possible to set each predetermined value more strictly, and it is possible to improve performance such as determination reliability and determination time reduction.
For example, as shown in step S103 and step S104 in FIG. 8, the absolute difference between the target opening and the default opening is a predetermined value K3 or less (step S103), or the absolute difference between the default opening and the actual opening is A predetermined value K4 or less (step S104) or a combination of these may be inserted before step S106.

Embodiment 8 FIG.
In the first embodiment, hunting is detected by utilizing the presence or absence of the direction reversal of the operation amount, but it cannot be determined by dither control as shown in FIG . The eighth embodiment of the present invention enables detection of the hunting state even when the output value of the integrating function or the operation amount increases or decreases while fluctuating. If the change amount of the manipulated variable after the change of the value does not change is equal to or greater than a predetermined value, hunting is determined by setting the hunting state. The calculation process flowchart of the valve behavior determining means 19 of the eighth embodiment is as shown in FIG.

In FIG. 9, the valve behavior determination means 19 first counts up the time counter in step S112, and determines in step S109 whether the actual opening of the throttle valve is constant .
If the actual opening has changed, the determination is N, and the substitution flag for controlling the process of holding the operation amount in the operation amount record is set to 0 in step S119.
In step S114, the time counter is set to 0. In step S113, hunting = none is set and the process goes to the end.

If the actual opening has not changed, the determination in step S109 is Y, and the manipulated variable is substituted into the manipulated variable record (not shown) according to the substitution flag (not shown). Since there is a lot of accumulation, that is, there is a possibility of a hunting state, in step S110, the elapsed time from when the actual opening does not change is determined, and if the predetermined value K5 has elapsed, hunting = Yes, go to the end.
If the predetermined value K5 has not elapsed, hunting = none is set in step S113, and the process goes to the end.

According to the eighth embodiment, as compared with the first embodiment, since the overall change in the operation amount is captured and determined, it is less affected by the change in the operation amount, and can be applied to the dither control.
However, since the predetermined value K9 is the manipulated variable, that is, the torque value, the determination value setting depends on the nonlinear torque change characteristic of the throttle valve. For this reason, it is difficult to set the determination value as compared with the first embodiment.
The second to seventh embodiments can be similarly applied to the eighth embodiment.

It is a block diagram which shows the principal part structure of the throttle control apparatus of the internal combustion engine in Embodiment 1 of this invention. It is a flowchart which shows the arithmetic processing of the valve behavior determination means in Embodiment 1 of this invention. It is a flowchart which shows the arithmetic processing of the output correction means in Embodiment 1 of this invention. It is a block diagram which shows the principal part structure of the throttle control apparatus of the internal combustion engine in Embodiment 2 of this invention. It is a block diagram which shows the principal part structure of the throttle control apparatus of the internal combustion engine in Embodiment 2 of this invention. It is an example figure which shows the behavior of an actual opening degree, a target opening degree, and an operation amount when the dither control is performed on the throttle valve driving means in the throttle control device of the internal combustion engine. It is a flowchart which shows the arithmetic processing of the valve behavior determination means in Embodiment 3 of this invention. Embodiments 4 to 7 of the present invention are flowcharts showing the calculation processing of the valve behavior determination means. It is a flowchart which shows the arithmetic processing of the valve behavior determination means in Embodiment 8 of this invention. It is the schematic which shows the whole structure of the throttle control apparatus of an internal combustion engine. It is a block diagram which shows the principal part structure of the throttle control apparatus of the conventional internal combustion engine. It is a block diagram which shows the computing equation of PID control of the throttle control apparatus of an internal combustion engine. It is a graph which shows the relationship between the opening degree of the throttle valve of the throttle control apparatus of an internal combustion engine, and the torque of a spring. It is a timing chart which shows the counter operation | movement in Embodiment 3 of this invention.

Explanation of symbols

1 Intake pipe 2 Throttle valve
4 Motor
6 ECU
7 Driving circuit 8 Position sensor 10 Target opening 11 Actual opening 12 Deviation means 13 Throttle valve driving means 17 Operation amount 18 PWM converter 19 Valve behavior determination means 20 Output correction means

Claims (7)

In the throttle control device for an internal combustion engine that controls the drive of the motor based on the deviation between the target opening and the actual opening of the throttle valve, and feedback-controls the actual opening of the throttle valve to the target opening.
A deviation calculation means for calculating a deviation that is a difference between the target opening and the actual opening, and a feedback control including at least a function for integrating the deviation is obtained, and the motor is driven in accordance with the operation quantity. The throttle valve driving means for controlling the opening of the throttle valve and the actual opening of the throttle valve are constant without change, and the output value of the function to be integrated or the operation amount is only increased or decreased. And a valve behavior determining means for determining that the hunting state is continued for a predetermined time. The throttle valve driving means integrates the function when the valve behavior determining means determines the hunting state. output value, or, the operation amount is small, or throttle control for an internal combustion engine and having an output correction means for stopping updating Location. In the throttle control device for an internal combustion engine that controls the drive of the motor based on the deviation between the target opening and the actual opening of the throttle valve, and feedback-controls the actual opening of the throttle valve to the target opening.
A deviation calculating means for calculating a deviation the a difference between the target opening and the actual opening, determine the manipulated variable by the feedback control including a function of integrating at least the deviation, driving the motor in accordance with the operation amount The throttle valve driving means for controlling the opening of the throttle valve and the output value of the function to be integrated or the value of the manipulated variable, where the actual opening is the same as the value one hour before. A valve behavior determination that holds a time value, and determines that the difference between the held value and the current value exceeds a predetermined value, and the actual opening does not change and continues for a predetermined predetermined time, as a hunting state and means, in the throttle valve driving means, if it is determined that hunting state by said valve behavior determination unit, the output value of the function of the integration, or the operation amount, to reduce or stop the update Throttle control apparatus for an internal combustion engine and having a force correction means. When the output value of the function to be integrated or the manipulated variable is decreased from increasing or reversed from decreasing to increasing, the valve behavior determining means continues the previous determination for a predetermined time. The throttle control device for an internal combustion engine according to claim 1 or 2 . 4. The valve behavior determination means performs a filtering process on the output value of the function to be integrated or the manipulated variable, and determines it based on a value after the filtering process . 5. A throttle control device for an internal combustion engine according to claim 1. 5. The internal combustion engine according to claim 1, wherein the valve behavior determination unit determines the determination related to the actual opening based on a value obtained by filtering the actual opening. Engine throttle control device. In the valve behavior determining means, the amount of change in the target opening is less than or equal to a predetermined value, the deviation is less than or equal to a predetermined value, or the sign of the deviation does not change from one hour ago.
6. The throttle control device for an internal combustion engine according to claim 1, wherein a determination condition is added . The throttle control device for an internal combustion engine according to any one of claims 1 to 6 , wherein the valve behavior determination unit performs a hunting state detection region only in the vicinity of a default opening .

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