JP2605693B2 - Vehicle throttle valve control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling an intake air amount to an internal combustion engine by a throttle valve driven by a motor.

[Prior art and problems] Conventionally, as this type of apparatus, for example, Japanese Patent Application Laid-Open No. 61-843
There is also what is described in No. 4 gazette. That is, a device for controlling the opening degree of a throttle valve provided in an intake passage by controlling a motor, and inputs a depression amount of an accelerator pedal and signals from various sensors to a microcomputer, and based on a predetermined table map, a throttle valve. This is a device that calculates and controls the opening of the device.

However, in such an apparatus, since it is necessary to set a table map corresponding to various states in advance, a great deal of labor is required for designing.

As means for solving this, there is known a means for setting a throttle valve command value by so-called PID control in which a proportional, integral, and differential element is added to a deviation between a throttle request value and a throttle position detection value.

However, in the PID control, as shown in FIG. 9, when the deviation is small (control from time t0), fairly appropriate control is performed, but when the deviation is large (time t1). Control), the overshoot and the undershoot increase, and there is a practical problem.

In order to solve such a problem, a method using an additional integral type optimal regulator based on modern control theory has recently been proposed. According to this method, excellent control characteristics are exhibited with respect to overshoot and undershoot. However, when the control range is widened, in order to improve the characteristics, a large number of states must be obtained in advance or an observer must be inserted. There is a problem that a method of switching according to the output state must be adopted, and the configuration becomes complicated.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described conventional problems, and has as its object to provide a control device for a vehicle throttle valve having a simple configuration and no overshoot or undershoot.

[Means for Solving the Problems] To solve the above problems and achieve the above object, the present invention provides a throttle valve E for adjusting an intake air amount of an internal combustion engine as shown in FIG.
Driving means D for driving the throttle valve E in response to a control signal; throttle request value setting means A for outputting a throttle request value indicating a target position of the throttle valve E; and controlling the throttle valve E based on the throttle request value. A command value generating means B for outputting a throttle command value representing a target position; a position detecting means G for detecting the position of the throttle valve E; a throttle command value from the command value generating means B and the position detecting means G Based on the throttle position detection value of
Control means H for outputting a control signal to the drive means D such that the position of the throttle valve E is the position represented by the throttle command value; and the command value generation means B further comprises: A deviation between a throttle position detection value from G and a throttle request value set by the throttle request value setting means A is obtained, and when the deviation is equal to or less than a predetermined value, the throttle request value is output as the throttle command value. When the deviation is equal to or greater than a predetermined value, a request value obtained by correcting the change state of the throttle request value to a gradual change state by a predetermined delay characteristic set in advance is output as the throttle command value. A gist of the invention is a control device for a throttle valve for a vehicle.

In one embodiment of the present invention, the control means H
Is a state observer H1 for estimating or detecting a state quantity based on a dynamic model of the driving means D, and a cumulative value for integrating a deviation between a detected value from the position detecting means G and a command value from the command value generating means B. The unit H2, the state quantity from the state observer H1 and the accumulated value from the accumulating unit H2 are input, and the optimum feedback gain based on a predetermined dynamic model is integrated and output to the driving unit D. And an optimal feedback gain setting unit H3.

Here, the control means H is configured as an additional integral type optimal regulator. That is, the state model representing the dynamic behavior of the driving means D to be controlled is expressed by the following general expression.

It can be obtained by simulation.

In addition, the state observation unit H1 calculates the state variable Input a state estimator that can be treated equivalently to Here, the opening / closing speed of the throttle valve E and the like are calculated from the control signal to the driving means D and the position detection value of the position detecting means G.

The optimum feedback gain setting unit H3 is a unit that sets a feedback gain output to the driving unit D,
Weight parameter in the evaluation function J of the following equation (5) Repeat the simulation until the appropriate control characteristics are obtained. And the parameter Positive definite symmetric solution of Riccati equation (7) based on By seeking Optimal control input Is obtained by the following equation (11).

Since the dynamic model, the coefficient of the minimum dimension observer, and the coefficient of the optimum feedback gain for the driving means D are obtained in advance and the actual control is performed only in the electronic control device of the control means H using the results. is there.

[Operation] In the control device for a vehicle throttle valve of the present invention, the driving means D drives the throttle valve E according to the control signal, and the position detecting means G detects the actual position of the throttle valve E; Throttle request value setting means A
A throttle request value indicating a target position of the throttle valve E is output based on an accelerator pedal depression amount and various input conditions.

Then, the command value generating means B outputs a throttle command value indicating the control target position of the throttle valve E based on the throttle request value. A deviation between the position detection value (actual position) and the throttle request value set by the throttle request value setting means A is obtained, and when the deviation is equal to or less than a predetermined value, the throttle request value from the throttle request value setting means A is used as a throttle. When the deviation is equal to or greater than a predetermined value, a request value obtained by correcting a change state of the throttle request value to a gradual change state by a predetermined delay characteristic set in advance is output as a throttle command value.

Then, based on the throttle command value from the command value generation means B and the throttle position detection value from the position detection means G, the control means H controls the drive means so that the position of the throttle valve E becomes the position represented by the throttle command value. A control signal is output to D.

That is, in the vehicle throttle valve control device of the present invention, the deviation ER between the throttle request value from the throttle request value setting means A and the actual position of the throttle valve E is determined.
Is smaller than or equal to a predetermined value, the throttle request value is directly input to the control means H as a control target position (throttle command value), and feedback control of the throttle valve E is performed. In some cases, feedback control is performed by inputting the required value obtained by correcting the changed state of the throttle request value to a gradual change state with a predetermined delay characteristic as a control target position to the control means H. I have.

According to such a control device for a vehicle throttle valve of the present invention, when the required throttle value changes suddenly and the deviation ER becomes equal to or greater than a predetermined value, the control means H sends the actual value of the throttle valve E to the control means H. Since a control target position (throttle command value) having a small deviation from the position is input, it is possible to prevent the control amount from the control means H to the drive means D from becoming excessively large. Overshoot and undershoot can be suppressed.

Further, when the deviation ER is equal to or less than a predetermined value without a large change in the throttle request value, the throttle request value is directly input to the control means H as the control target position.
In an operating state in which the throttle request value is slightly changed, control responsiveness does not deteriorate.

In addition, in the control device for a vehicle throttle valve according to the present invention, when the deviation ER becomes equal to or more than a predetermined value, the control amount to the driving means D is not simply suppressed, but the throttle required value is not limited. Is corrected to a gradual change state by a predetermined delay characteristic set in advance, and the corrected throttle request value is used as a control target position (throttle command value).

Therefore, even if the deviation ER is equal to or greater than a predetermined value,
The difference between the actual position of the throttle valve E and the control target position changes in accordance with the degree of change in the required throttle value. As a result, the amount of control from the control means H to the driving means D also varies with the change in the required throttle value. Since it increases or decreases in accordance with the degree, control of overshoot and undershoot in the case where the throttle request value changes suddenly and control responsiveness can be achieved at a high level.

As described above, according to the control device for a throttle valve for a vehicle of the present invention, overshoot and undershoot in control can be suppressed without impairing control responsiveness. The throttle valve E can be quickly and accurately controlled over a wide range without complicating.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a view showing the configuration of the engine. Reference numeral 20 denotes an engine main body. A throttle valve 24 is provided in an intake passage 21 to the engine main body 20. Is sent. The opening of the throttle valve 24 is adjusted by a motor 30 that operates in response to a control signal from an electronic control device 40 described later. Various sensors are attached to the engine, that is, an air flowchart meter 32 that outputs an intake air amount signal according to an intake air amount, a throttle position sensor 34 that detects an opening degree of a throttle valve 24, and a cylinder 28 are provided. Water temperature sensor 36, oxygen sensor 39 provided in exhaust passage 38, etc.
There is.

The detection signal of each sensor and a signal corresponding to the amount of depression of the accelerator pedal 37 are input to the electronic control unit 40.
The electronic control unit 40 has a CPU 42 for performing arithmetic processing, an input port 44 for converting each sensor signal into a signal that can be processed by the CPU 42, and a ROM 4 in which various control programs are stored in advance.
6, a RAM 48 as a primary storage means, and an output port 49 for converting a control signal from the CPU 42 into a drive signal to the drive motor 30 of the throttle valve 24.

Next, according to the control system diagram of FIG.
The control system in the above will be described. In particular, the vector equation in the above state equation (1), output equation (2), etc. The following describes how to find the above, how to find an observer based on this, and how to find the feedback gain.

FIG. 3 is a diagram showing a control system diagram, and does not show a hardware configuration.

In FIG. 3, as a configuration for driving the throttle valve 24, first, a required value setting unit 50 for outputting a required throttle value y ^* (k) according to the depression amount of the accelerator pedal 37 is provided. The request value y ^* (k) is input to the throttle command value generator 52. Then, a throttle command value yd (k) is output from the throttle command value generating section 52 in a process according to a flowchart shown in FIG. 8 described later, and the command value yd (k) is calculated by the additional integral type optimal regulator 60 to be used for driving. The control value u (k) to the motor 30 is output.

The additional integral type optimal regulator 60 includes an integrator 62,
It comprises an observer 64 and a feedback amount determining unit 66.

That is, the integrator 62 accumulates the deviation between the throttle command value yd (k) and the throttle position detection value y (k) and accumulates the difference.
iER is required.

The observer 64 (state observation unit) uses a control value u (k) to the drive motor 30 and a throttle position detection value y (k) to represent a state variable amount representing the internal state of the drive motor 30. And the state estimator Is what you want.

The feedback amount determining unit 66 (optimum feedback gain setting unit) adds the optimum feedback gain to the state estimation amount VS (k), y (k) and the cumulative value iER. Is integrated and added to control value u to drive motor 30.
(K) is output.

So, next, build the actual dynamic model, design the observer, and the optimal feedback gain. Will be described.

 First, a dynamic model of the driving motor 30 is constructed.

In the control characteristics of the motor, the input U (s) and the output Y
When the transfer function G (s) is obtained from (s) by Laplace transform, The above equation (20) is subjected to Laplace inversion, and 0.9d ² y (t) / dt ² + dy (t) / dt−76u (t) = 0 d ² y (t) / dt ² + 1.1dy (T) / dt-84u (t) = 0 (22) is obtained.

When this is transformed into the states and output equations shown by the above equations (1) and (2), it is expressed as the following equation.

That is, the state equation of the driving motor 30 is Then, the coefficients of the above equations (1) and (2) are expressed as follows.

A minimum-dimensional observer is constructed using the state equations (24) and (26). Prior to this description, a general observer construction is based on the following principle.

That is, a general observer is represented by a signal flow diagram as shown in FIG. It is.

Here, the condition that the observer is satisfied in the above equations (28) and (30) is that the following equation is satisfied.

Ie further, If you take E (t) → 0 (t → ∞), and It is known that That is, the state variables Is the state variable estimated by the observer Will be equal to In addition, That is, Are of order n and l.

Now, corresponding to the above equations (24) and (26) Is defined as follows: The minimum dimension observer is Is known to be given by And (n-1)
^* L-order, that is, here, n = 2 and l = 1, so to obtain an observer using the first-order design parameter meter matrix L, May be determined. Here, the above equation (4
0) In (42), L is a first-order and scalar, and all other elements are known, so that the above-described coefficient values can be substituted into the following equation.

Here, since y (t) is a detected value of the position of the throttle valve, (d / dt) y (t) obtained by differentiating the y (t) means the opening / closing speed VS (t) of the throttle valve 24. Become.

Therefore, the above equations (44) and (46) are expressed as the following equation (48) when the sampling frequency is minute and a discrete system is used and expressed as the opening / closing speed VS (t).

VS (k) = - Lw2 ( k-1) + (- L 2 -1.1) y (k) +
84u (k) + Ly (k) (48) In addition to rearranging this equation, w2 (k-1) = VS (k-1)
VS (k) = − LVS (k−1) − (L ² −L + 1.1) y (k)
+ 84u (k) (50)

L = 10 is obtained by repeating various simulations,
Substituting this into equation (50) gives: VS (k) = − 10VS (k−1) −91.1y (k) + 84u (k) (52)

Therefore, the output of the observer is VS (k) obtained by equation (52).

Next, the optimal feedback gain The following describes how to obtain the value.

First, the weight parameters Q and R in the evaluation function J of the above equation (5) are obtained by repeating the simulation until an appropriate control characteristic is obtained. And the parameter
Solving the Riccati equation (7) based on Q and R, and using the above equation (11), the throttle position detection value y (k), the VS (k) designed by the observer and the accumulated value iER
(K) shows the optimal feedback gain obtained by solving the Riccati equation. Are integrated and added to obtain a control value for the drive motor 30.

As mentioned above, the construction of the dynamic model, the design of the minimum dimension observer, and the optimal feedback gain Has been described, but these are obtained in advance,
In the electronic control circuit, actual control is performed using only the result.

Next, control actually performed by the electronic control unit 40 will be described with reference to the flowchart of FIG. In the following description, values handled in actual processing are denoted by a suffix (k), and values handled last time are denoted by a suffix (k-1).

First, after reading the throttle position detection value y (k) from the throttle position sensor 34 (step 100),
Read throttle request value y ^* (k) (step 11)
0). The throttle request value y ^* (k) is a value calculated by the electronic control unit 40 from the accelerator pedal depression amount and the like.

 In the next step 120, the throttle command value yd (k) is
calculate. This throttle command value yd (k) will be described later.
Selectively calculated based on the flowchart of FIG.
Specifically, the throttle request value y^*(K), also
Is the smoothed throttle command value y Selected from (k)
Things.

Thereafter, a deviation ER (k) between the throttle command value yd (k) and the throttle position detection value y (k) (= yd (k) -y
(K)) is calculated (step 130).

Next, the state estimator Is calculated (step 140). That is, the opening / closing speed VS (k) of the throttle valve 24 depends on the observer gain due to the above-described observer design. Is [P0 Q0 Q1], it is obtained by the following equation (60).

VS (k) = P0.VS (k-1) + Q0y (k) + Q1U (k-
1) ... (60) Next, the deviation ER (k) obtained in step 130 is integrated to obtain an integrated cumulative value iER (k) from the following equation (62) (step 150).

iER (k) = iER (k−1) + FAD1 · ER (k) (62) Then, the throttle position detection value y (k), the opening / closing speed VS (k) obtained in step 140, the integrated cumulative value iER, Furthermore, the optimal feedback gain previously stored in the ROM 46 Is used to determine the control voltage U (k) to the drive motor 30 (step 160).

U (k) = FAD0.y (k) + FAC0.VS (k) + iER
(K) (64) The control voltage U (k) is output to the drive motor 30 to control the opening of the throttle valve 24 (step 170). After this process, the subscript indicating the number of times of sampling, calculation and control is incremented by 1 (step 180), and the process returns to the first step 100 to repeat the process.

Next, the throttle command value yd (k) used in step 120 of the flowchart of FIG. 5 will be schematically described with reference to time charts for the opening degree of the throttle valve shown in FIGS. 6 and 7.

 Referring to FIG.^*Is the throttle request value, y Hanama
Throttle command value, and y is the throttle position detection value.
You. Now, at time t0, the throttle request value y^*Is stepwise^*
a, and the deviation ER from the throttle position detection value y
When it is larger than the constant value ERo1, the throttle command value yd is used.
And the smoothed throttle command value y Is output.

 Annealing throttle command value y Is the throttle command value
Output by the raw part (hereinafter also referred to as command value generator) 52
(Fig. 3), throttle request value y^*A temporary delay
This is a value output as a number.

 That is, the function of the temporary delay is the throttle request value y^*,
Annealing throttle command value y^*From the input / output relationship of, The smoothed throttle command value y Is y = E^-a^Ty^*k^-1+ (1-e^-a^T) Yk^-1 … (82)

 And the throttle request value y^*Torn throttle command
Value y Is smaller than the deviation ERo2 (at time t
1), the required value y^*As the throttle command value yd
Is output.

 Similarly, when the operation of closing the throttle valve 24 is performed.
As shown in FIG. 7, the throttle request value y^*And the slot
The deviation ER from the detected position y is larger than the deviation ERc1.
(Time t2), the first-order lag expressed by the above equation (82)
Annealing throttle command value y And then smoothed out
Throttle command value y And throttle request value y^*The difference between
When the value falls within the fixed value ERc2 (time t3), a throttle request is issued.
Value y^*Is output as is.

That is, the throttle command value yd is limited as an output within a predetermined range with respect to the throttle position detection value y.

Hereinafter, the flowchart of FIG. 8 for realizing the processing of the throttle command value outlined with reference to FIGS. 6 and 7 will be described.

First, a required throttle value y ^* (k) based on the accelerator pedal depression amount and the like and a detected throttle position value y (k) from the throttle position sensor 34 are read (step 200), and then the required value y ^* (k) is read. And the detected value y
A deviation ER from (k) is obtained (step 210).

Next, the flag F is determined (step 220).
This flag F is for determining whether or not the control based on the throttle command value in the present process is the first time. When this control is the first time, F = 0, and when the open control is started,
When F = 1 and the closing control is started, F = −1. Here, since this is the first process, step 230
Move to

In step 230, it is determined whether the operation in the closing direction, the operation in the opening direction, or the stop of the throttle valve 24 is requested based on the deviation ER, and the operation in the closing direction is requested. If it is determined that
Proceeding to 240, a determination is made as to whether the ER is greater than or equal to the predetermined value ERc1.On the other hand, if it is determined that an operation in the opening direction is required, the process proceeds to step 250, where the deviation ER Is determined to be equal to or greater than a predetermined value ERo1.

If it is determined in step 240 or 250 that the deviation ER is equal to or smaller than the predetermined value ERc1 or ERo1,
In step 260 or step 270, the required throttle value y ^*
(K) is set to the throttle command value yd (k) as it is,
The flowchart is once ended.

 On the other hand, in step 240 or step 250, the deviation ER
When it is determined that the value is equal to or more than the fixed value ERc1 or ERo1,
First, the flag F indicating the closing operation or the opening operation is set to 1 or-
It is set to 1 (steps 265 and 275). And the slot
Torr request value y^*(K) is passed through the command value generator 52 (step
280). In the next step 290, output from the command value generator 52
Annealed throttle command value y (K) throttle
Set as the command value yd (k). After this processing,
The flowchart ends, and repeats from step 200.

If it is determined in step 220 that the flag F is 1 or −1, the process proceeds to step 400, in which the process for canceling the smoothed throttle command value yd (k) is performed in the following steps.

 That is, first, the smoothed throttle command value y (K)
And throttle request value y^*Deviation ER from (k) And calculate
Step 400) Next, the control operation of the throttle valve 24
Whether the direction is the closing direction or the opening direction is determined by the flag F (step
410), in the case of the closing direction (F = -1), the deviation ER
It is determined whether (k) is equal to or greater than a predetermined value ERc2 (step
420). If the value is equal to or more than the predetermined value ERc2,
As the throttle command value yd (k), the smoothed throttle command value
y Continue (k) (Step 430, Step 440),
On the other hand, when the value is equal to or less than the predetermined value ERc2, the throttle request value y^*
(K) is set as the throttle command value yd (k)
(Step 450), and resets the flag F (step
460). As a result, the smoothed throttle command value yd
This means that the process according to (k) has been canceled.

 Similarly, in step 410, open the throttle valve 24.
When it is determined that the direction control is performed (F =
1), deviation ER at step 520 Is greater than or equal to a predetermined value ERo2
Is determined.

 Then, in step 520, it is determined that it is equal to or more than the predetermined value ERo2.
When the power is turned off,
Quotation y (K) is set as the throttle command value yd (k)
On the other hand, if the value falls below the predetermined value ERo2, the slot
Required value y^*(K) is set to the throttle command value yd (k)
To reset the flag F (step 530).
540).

Therefore, according to the above-described embodiment, when the feedback control is performed according to the flowchart of FIG. 5, the throttle command in which the deviation between the throttle request value y ^* (k) and the throttle position detection value y (k) does not increase beyond a predetermined range. Value yd
(K) is obtained by the flowchart of FIG. For this reason, from the characteristics of the control means configured by modern control,
Overshoot and undershoot can be reduced, and feedback control is performed with a command value that establishes linear approximation, eliminating the need to set a large number of state parameters in advance, and switching between observers and observers. Since it is not necessary, the configuration of the system can be simplified.

[Effects of the Invention] As described above, according to the present invention, only when the deviation between the throttle request value from the throttle request value setting means and the position detection value (actual position) of the throttle valve is equal to or more than a predetermined value. Since the request value obtained by correcting the change state of the throttle request value to a gradual change state by a predetermined delay characteristic is input to the control means as the control target position (throttle command value), the control response is not impaired. , Control overshoot and undershoot can be suppressed, and thus, without complicating the configuration of the control means,
The throttle valve can be quickly and accurately controlled over a wide range.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of the configuration of the present invention, FIG. 2 is a configuration diagram showing an engine system according to an embodiment of the present invention, FIG. 3 is a schematic diagram showing the configuration of the embodiment, FIG. FIG. 5 is a signal flow diagram of the embodiment, FIG. 5 is a flowchart for controlling the drive motor according to the embodiment, and FIGS. 6 and 7 are time charts for explaining the operation state of the throttle valve of the embodiment. FIG. 8 is a flowchart showing the processing of the throttle valve command value, and FIG. 9 is a time chart for explaining the problems of the prior art. A: required throttle value setting means B: command value generating means, D: driving means E: throttle valve, G: position detecting means H: control means H1: state observing section, H2: accumulating section H3: Optimum feedback gain setting unit 24: Throttle valve, 30: Drive motor 34: Throttle position sensor 40: Electronic control unit 40

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Katsuhiro Oba 1-1-1 Showa-cho, Kariya-shi Nippondenso Co., Ltd. (56) References JP-A-61-83469 (JP, A) (JP, A) Japanese Utility Model Showa 61-9333 (JP, U)

Claims (2)

(57) [Claims] 1. A drive means for driving a throttle valve for adjusting an intake air amount of an internal combustion engine according to a control signal; a throttle request value setting means for outputting a throttle request value indicating a target position of the throttle valve; Command value generating means for outputting a throttle command value representing a control target position of the throttle valve based on the throttle request value; position detecting means for detecting the position of the throttle valve; and a throttle command from the command value generating means. Control means for outputting a control signal to the drive means so that the position of the throttle valve becomes a position represented by the throttle command value, based on the value and the throttle position detection value from the position detection means. The command value generation means includes a throttle position detection value from the position detection means and the throttle request value. A deviation from a throttle request value set by the setting means is obtained, and when the deviation is equal to or smaller than a predetermined value, the throttle request value is output as the throttle command value. A throttle valve control device for a vehicle, wherein a request value obtained by correcting a change state of the request value to a gradual change state by a predetermined delay characteristic set in advance is output as the throttle command value. . 2. The control means comprises: a state observer for estimating or detecting a state quantity based on a dynamic model of the drive means; a throttle position detection value from the position detection means and a command value from the command value generation means. An accumulator that integrates a deviation from a throttle command value, a state quantity from the state observer and an accumulated value from the accumulator are input, and an optimal feedback gain based on a predetermined dynamic model is integrated. The control device for a vehicle throttle valve according to claim 1, further comprising: an optimal feedback gain setting unit that outputs the feedback feedback gain to the driving unit.