JPH0768924B2 - Slot valve control device - Google Patents

Description

The present invention relates to a throttle valve control device for controlling the opening of a throttle valve provided in an engine for vehicles, for example.

[Conventional technology]

Conventionally, a throttle valve provided in a vehicle engine is directly connected to an accelerator pedal via a link mechanism, and is mechanically driven via the link mechanism according to the amount of depression of the accelerator pedal by a driver.

In addition, recently, there is a device that electrically detects the operation amount of the accelerator using a potentiometer, an optical encoder, or the like, and controls the opening of the throttle valve by an electric actuator such as a motor according to the detected operation amount. Many have been proposed.

By the way, although the accelerator operation amount is a macroscopic indication of the driver's will, it is not so microscopically. For example, the force with which the driver steps on the accelerator is not constant, and
Due to the influence of vibration of the vehicle and the like, the manipulated variable is detected as a scattered value with a small range and is input to the control unit. Since this variation becomes noise that deteriorates accuracy in control, it needs to be removed.

Here, JP-A-59-122743 and JP-A-60-164629.
In the publication, the detection signal indicating the accelerator operation amount is filtered and then processed by the control unit.

[Problems to be solved by the invention]

However, if the detection signal indicating the accelerator operation amount is filtered as shown in the above publication, there is a problem that the responsiveness deteriorates. Therefore, we try to improve the responsiveness by performing the filtering only at a predetermined timing or by limiting the frequency range to be filtered. However, the noise component included in the detection signal is removed only in the frequency domain, and it cannot be said that a fundamental solution has been made.

For example, when the vehicle picks up bumps on the road surface while driving, vibrations are transmitted to the driver's toes and the bumps are detected as the pedal moves, so no matter how much the accelerator is manipulated, the actual throttle The valve moves in response to the unevenness of the road surface, and the engine output cannot be controlled well, especially when the accelerator output should be finely adjusted near zero when the accelerator operation amount is near zero, such as during low speed traffic. There was a problem that it was hunting and was uncomfortable to ride.

As a practical problem, especially when the accelerator operation amount is near a low opening state, the vehicle receives the bounce of the unevenness of the seam on the road surface, and even if the driver tries to control the accelerator pedal to a constant opening degree, the pedal is realistic. Since there is a problem that the position of has been moved by the reaction from the road surface, it is inevitable that the throttle valve operates in response to the actual accelerator pedal movement, that is, the so-called “play” part. It can be said that the dead zone is most convenient.

Conventionally, if the throttle valve is mechanically connected to the accelerator pedal, there is play even if it is not actively provided. However, the size of mechanical play is basically constant for all accelerator operation amounts, so that it is absolutely necessary in the extremely small accelerator operation amount region such as during the above-described traffic jam driving. On the other hand, in the high accelerator opening range such as during normal driving, if acceleration response is taken into consideration, a large one is not necessary, but naturally, considering the magnitude of the accelerator operation amount, It was not set appropriately. Further, even if the play is positively provided, it has not been considered to change the play according to the accelerator operation amount.

Therefore, an object of the present invention is to eliminate the variation of the accelerator operation amount unrelated to the driver's intention with respect to the entire accelerator operation area, that is, at least the accelerator pedal is operated in the acceleration direction, That is, when the accelerator operation amount is zero while the engine output is output, play is provided in the accelerator operation amount, and this play is increased when the accelerator operation amount is small so that the throttle does not move even if the road surface unevenness is received. When the accelerator operation amount is large, it is set small so that the throttle valve follows the accelerator operation amount relatively sensitively.

In the present invention, this "play" is defined by the term "hysteresis" below. The hysteresis width as referred to in the present invention means that when the accelerator operation amount crosses a certain specific boundary value as in JP-A-58-214630, the boundary value is made different in the increasing direction and the decreasing direction. This is a so-called “play size” that is set for each operation amount as described above, which is different from a general property such as a difference in boundary value when the operation is performed.

[Means for solving problems]

In order to solve the above problems, the ninth aspect of the present invention is provided.
As shown in the figure, a throttle valve that adjusts the amount of air taken into the engine, an actuator that drives the throttle valve, a detection unit that detects the operation amount of the accelerator, and an accelerator operation amount that is detected by the detection unit. Based on the control means for controlling the actuator so that the opening of the throttle valve becomes a predetermined opening, and the accelerator operation amount detected by the detection means includes a state in which the accelerator operation amount is zero. And a hysteresis means for transmitting a hysteresis characteristic to the control means when operated to the acceleration side, and the hysteresis means is such that the hysteresis width is smaller when the accelerator operation amount is large than when it is small. The throttle valve control device is characterized in that the hysteresis characteristic is set.

[Action]

According to the above configuration, when the accelerator operation amount is operated to the acceleration side including the state of zero, it is transmitted to the control device with the hysteresis characteristic by the hysteresis device, and when the accelerator operation amount is large, it is small. Since the hysteresis characteristic is set so that the hysteresis width is smaller than that at the time, it effectively removes the fluctuation amount of the accelerator operation amount that is irrelevant to the driver's intention and tends to occur especially when the accelerator is not operated. Then, it is transmitted to the control means, and when the accelerator operation amount is large, the throttle valve follows the accelerator operation amount relatively sensitively.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of the present embodiment. An engine 1 is a spark ignition type four cylinder engine, and an intake pipe 2 and an exhaust pipe 3 are connected to the engine 1. An air cleaner 4 is provided upstream of the intake pipe 2, and a throttle valve 5 for adjusting the amount of air taken into the engine 1 is provided downstream thereof. An electromagnetic fuel injection valve 6 for injecting fuel into an intake port (not shown) of the engine 1 is provided at each branch portion (4 places) of the intake pipe 2.

An intake air temperature sensor for detecting the intake air temperature is provided in the intake pipe 2.
10. Opening sensor for detecting the opening of throttle valve 5.
11, an intake pressure sensor 12 for detecting intake pressure is provided.

Further, the engine 1 is provided with a water temperature sensor 13 for detecting the water temperature of the cooling water of the engine 1 and a rotation sensor 14 for detecting the engine speed.

Further, the exhaust pipe 3 is provided with an air-fuel ratio sensor 15 for detecting the air-fuel ratio based on the residual oxygen concentration in the exhaust gas.

Further, 20 is an accelerator pedal operated by the driver, and 21 is a return spring. The operation amount of the accelerator pedal 20 is detected by an accelerator sensor 16 provided on the rotary shaft of the accelerator pedal 20.

Reference numeral 25 denotes a motor that constitutes a throttle valve driving actuator equipped with a rotor (not shown) connected to the shaft of the throttle valve 5 and rotationally drives the throttle valve 5. In addition,
The motor 25 is composed of, for example, a step motor or a DC motor.

The detection signals from the above sensors are sent to the electronic control unit (ECU) 3
Entered in 0. The ECU 30 is mainly composed of a microcomputer, executes various calculations according to the detection signals from the above-mentioned sensors, and outputs drive signals to the injection valve 6 and the motor 25.

The main structure of the ECU 30 is shown in FIG. Reference numeral 31 is a calculation unit that executes the calculation of the valve opening time of the injection valve 6, the drive amount of the motor, and the like based on the detection signals from the above-mentioned sensors. Reference numeral 32 denotes a storage unit that constantly stores map data and coefficients used in the calculation by the calculation unit 31, and temporarily stores the calculation result calculated by the calculation unit 31 and the detection signal from each sensor. I remember. An input unit 33 receives a detection signal from each sensor and performs processing such as A / D conversion and waveform shaping on the detection signal. An output unit 34 outputs a drive signal to the injection valve 6 and the motor 25 according to the calculation result obtained by the calculation unit 31. A common bus 35 connects the arithmetic unit 31, the storage unit 32, the input unit 33, and the output unit 34, and is used for mutual transmission of data.

FIG. 3 shows a flow chart of a program executed as a main routine in the arithmetic unit 31, and in particular, only an example of a control program portion for the throttle valve 5 is omitted.

In FIG. 3, a voltage from a power supply (not shown) is applied to the ECU 30 to start the processing of this main routine. First, in step 301, the data stored in the storage unit 32, the input unit 33, and the output are stored. The part 34 is initialized.
Next, at step 302, the intake air temperature signal T _A ,
Throttle opening signal θ _s , intake pressure signal P _m , water temperature signal T _w ,
The rotation speed signal N _e , the air-fuel ratio signal S _{A / F} , and the signal from the accelerator sensor 16 are fetched. In step 303, the basic target opening θ _SO of the throttle valve 5 is read from the basic target opening map stored in the storage unit 32 based on the signal of the accelerator sensor 16, and the correction value is obtained based on each of the other signals. The basic target opening θ _SO is corrected by this correction value to calculate the current target opening θ _SS . In step 304, the above target opening θ
Based on _SS , the current control amount D _S is read from the control amount map stored in the storage unit 33, and the control amount D _S obtained in step 305 is output to the output unit 34. After that, after processing other control programs, the process returns to step 302 again.

Through the above processing, the output unit 34 forms a drive signal corresponding to the control amount D _S , and then outputs this drive signal to the motor 25. Then, the motor 25 is driven to rotate the throttle valve 5 based on the drive signal, so that the opening degree is adjusted according to the throttle valve 5 and the accelerator operation amount signal θ _A.

Further, the injection time for the injection valve 6 is obtained by the calculation unit 31 by a conventionally known means, and the injection valve 6 is driven according to a pulsed drive signal corresponding to the injection time from the output unit 34,
A predetermined amount of fuel is injected into the intake pipe 2.

By the way, the accelerator sensor used in this embodiment
16 generates a detection signal proportional to the operation amount of the accelerator pedal 20, and basically has a hysteresis characteristic when it is operated to the acceleration side including the state where the accelerator operation amount is zero as shown in FIG. The processing to have is done in ECU30. In FIG. 6, the detection signal from the accelerator sensor 16 is the input data x, and the processed signal is the output data y.
Is shown as. Therefore, the relationship between the accelerator operation amount (output signal of the accelerator sensor 16) θAO and the accelerator operation amount signal θA has a hysteresis as shown in FIG.

That is, the accelerator operation amount signal θ _A begins to rise after the driver operates the accelerator pedal 20 by a predetermined amount from the state where the accelerator pedal 20 is not operated (point A in FIG. 4).
After returning from the maximum manipulated variable state (point B) by a predetermined amount, the accelerator manipulated variable signal θ _A begins to drop (point C).

By the way, even if the driver intends to keep the accelerator operation amount θ _AO constant, the operation amount θ _AO is delicate as shown by 0 to T ₁ in Fig. 5 (a) due to the influence of vibration from the road surface. Fluctuates. Therefore, if the accelerator operation amount θ _AO is directly transmitted to the ECU 30 without the above-mentioned configuration,
Depending on the relationship between the accelerator operation amount set in the storage unit 32 in the CU 30 and the basic target opening degree θ _SO of the throttle valve 5, only the dynamic component is amplified and the opening degree of the throttle valve 5 is shown in FIG. varies as shown in the 0 to T ₁₎ of, it can exacerbate the movement feeling giving unnecessary fluctuations in the air flow.

However, according to the above configuration, 0 to T _{1 in} FIG.
The subtle fluctuation of the accelerator operation amount θ _AO shown in Fig. 4 is due to the hysteresis characteristic having a width between points D to E in Fig. 4 provided in the ECU 30, as shown in Fig. 5 (c). According to the intention, the opening of the throttle valve 5 is controlled to a substantially constant opening. That is, it is possible to improve the accuracy in controlling the opening of the throttle valve 5.

By the way, in the signal processing by the filter as shown in the above publication, the same effect as that of the above embodiment can be obtained in a state where the driver is operating so that the accelerator operation amount is constant. However, in a transient state such as when the driver suddenly depresses the accelerator pedal 20, the detection signal from the accelerator sensor 16 is largely smoothed by the filter, so that FIG.
As shown by the broken line from T ₁ onward, there is a time delay in the change in the opening of the throttle valve 5, and the responsiveness during a transition such as the acceleration feeling is greatly deteriorated.

However, according to the above configuration, although a slight delay is caused by the width of the hysteresis characteristic, the accelerator operation amount θ _AO can be directly transmitted to the ECU 30 as the accelerator operation amount signal θ _A after that, so T in FIG. _As shown by the solid line from ₁ onward, the response during transient can be kept high compared to the signal processed using a filter.

That is, in the present invention, whether or not the change in the accelerator operation amount is due to the driver's intention is determined not by the frequency component but by the fluctuation range, and by doing so, the response is hardly deteriorated. Under any driving condition, fluctuations in the accelerator operation amount that are unrelated to the driver's intention can be eliminated, and sufficiently accurate throttle valve opening control can be realized.

A processing program for giving a hysteresis characteristic to the signal from the accelerator sensor 16 executed by the arithmetic unit 31 in the ECU 30 in the present embodiment shown in FIG. 6 is as shown in the flowchart in FIG. 7, for example. Then, this program is inserted between steps 302 and 303 of the flowchart of FIG. 3 and executed in the main routine.

First, in step 801, the amount of accelerator operation time taken in step 302 of FIG. 3, i.e. obtains a difference between the input data x _n and the input data x _n-1 the current that has been stored and held in the storage unit 32 , X. That is, X corresponds to the fluctuation range of the accelerator pedal 20. The initial value of x _n-1 is 0. Next, at step 802, the difference (Δx _max −x _n-1 ) between the hysteresis width Δx _max and the Δx _n-1 that was previously stored in the storage unit 32 and stored in the storage unit 32 and the variation obtained at step 701. Compare with width X. Note that Δx _n-1 is the previous input data
Input / output difference between x _n-1 and the previous output data y _n-1 (X _n-1 −
y _n-1 ).

If it is determined in step 802 that X ≧ Δx _max −Δx _n−1 , the process proceeds to step 803, and if it is determined that X <Δx _max −Δx _n−1 , the process proceeds to step 804.

That is, in step 802, it is determined whether the change from the previous input data x _n-1 to the current input data x _n has changed further beyond the range of the hysteresis width Δx _max , and if “YES”. The process proceeds to step 803, and if “NO”, the process proceeds to step 804.

In step 803, the current input / output difference Δx _n is set to the maximum value,
That is, the hysteresis width Δx _max is given to the current input / output difference Δx _n , and the process proceeds to step 809. Input data in step 809
Pull the current input and output difference Δx _n from x _n, to calculate the time of the data y _n. In step 810, the current input data x _n and the current input / output difference Δx _n are stored in the storage unit 32 as the current input data x _n x _n-1 and Δx _n-1 for the present routine processing. Go to step 303.

Also if the process proceeds to step 804, the fluctuation width X at step 804 it is determined that whether the X ≧ 0, the if X ≧ 0 from the previous input data x _n-1 to the current input data x _n Although the change is in the increasing direction, it is determined that the change is within the range of the hysteresis width Δx _max , and the process proceeds to step 805. In step 805, the current input / output difference Δx _n-1 plus the fluctuation width X is set as the current input / output difference Δx _n, and then step 809
Then, the process is performed in the same manner as described above to calculate the output data y _{n of} this time. In this case, the current output data y _n is the same as the previous output data y _n-1 . Then, after step 810, the process proceeds to step 303 in FIG.

If it is determined in step 804 that X <0, that is, the change in the input data x is in the decreasing direction, the process proceeds to step 806. In step 806, it is determined whether or not the fluctuation width X in the decreasing direction, that is, -X is larger than or equal to the previous input / output difference Δx _n-1 . That is, it is judged whether the change of the input data x is such that the change exceeds the range of the hysteresis width Δx _{max in} the decreasing direction. If “YES”, step 8
If "NO" in 07, the process proceeds to step 808. Step 807
Then, the current input / output difference Δx _{n is set} to 0, the process proceeds to step 809, and the following processing is performed in the same manner as described above to calculate the current output data y _n , and then, via step 810, step 303 in FIG.
Go to.

If the process proceeds to step 808, it is determined that the change in the input data x in the decreasing direction is within the range of the hysteresis width Δx _max , and similar to step 805, the previous input / output difference Δx.
The input / output difference Δx _n is obtained by adding the fluctuation width X to _n−1 , and then the process proceeds to step 809. Step 809 thereafter be the same as described above, determine the current output data y _n, step 81
After 0, the process proceeds to step 303 in FIG. Also in this case, the output data y _n
Is the same as the previous output data y _n-1 .

Therefore, according to the processing of the above-mentioned flowchart of FIG. 7, while the change of the input data x, that is, the change of the accelerator operation amount does not exceed the range of the hysteresis width Δx _max , the output data y,
That is, the accelerator operation amount signal θ _A used in step 303 of FIG. 3 does not change, and therefore, like the above-described embodiment,
Subtle fluctuations unrelated to the driver's will are eliminated. Also although the change in the input data x if beyond the range of the hysteresis width [Delta] x _max slight delay due amount that exceeds the range of the hysteresis width [Delta] x _max is, the output data y is the same changing characteristics clogging Figure 8 and the input data x Since the relationship between x and y is the relationship with the slope of 1, the responsiveness is the same as that of the above-described embodiment, and the responsiveness during the transition can be sufficiently secured. The opening of the throttle valve 5 can be controlled as shown by the solid line in FIG. 5C in response to the movement of the accelerator operation amount in FIG.

In FIGS. 4 and 6, the hysteresis width Δx _max is set to a constant value for simplification of description, but in the present invention, it is shown in FIG. 8 as x (x _n ), that is, as a function of the accelerator operation amount. As shown, it is set to be large when the amount of operation is small and small when the amount of operation is large, and is stored as a map in the storage unit 32 so that it can be read and used when the process shown in FIG. 7 is executed. There is. In this way, the air amount is sensitively changed by the accelerator operation, so that the stability is guaranteed in the state where the operation amount is small, which easily leads to a jerk. Further, in a state in which the operation amount is large, that is, in a state in which the driver requests a large output from the engine, the hysteresis width Δx _max is reduced to secure the response-oriented characteristic. It should be noted that, since most of the states with a large amount of operation occur transiently such as acceleration, it is assumed that the stability can be relatively neglected.
Even if it is set as shown in the figure, the driving feeling is not deteriorated.

In the above embodiment, the rotation of the motor 25 is controlled by the throttle valve 5
The structure in which the opening of the throttle valve 5 is adjusted by transmitting it to the shaft of the motor has a rod for moving the motor 25 forward and backward by a drive signal from the ECU 30 as shown in JP-A-59-20539. The throttle valve 5 may be provided with a lever portion that comes into contact with the rod, and the opening of the throttle valve 5 may be adjusted by the movement of the rod.

〔The invention's effect〕

As described above, according to the present invention, when the accelerator operation amount is operated to the acceleration side including the state of zero, it is transmitted to the control device with a hysteresis characteristic by the hysteresis device, where the accelerator operation amount is Since the hysteresis characteristic is set so that the hysteresis width is smaller when it is large than when it is small, it is easy to occur especially when the accelerator is not operated, and the fluctuation amount of the accelerator operation amount that is unrelated to the driver's will Is transmitted to the control means after being effectively removed, and when the accelerator operation amount is large, the throttle valve follows the accelerator operation amount relatively sensitively, which is preferably unrelated to the driver's intention. A driver who can transmit only the fluctuation amount of the accelerator operation amount to the control means under any driving condition and is beyond the range of the hysteresis width. Since the accelerator operation amount according to the intention is transmitted to the control means with almost no deterioration, it has an excellent effect that a sufficiently accurate throttle valve opening control can be realized with almost no loss of responsiveness.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing the configuration of an embodiment of the present invention, and FIG.
FIG. 1 is a block diagram showing the configuration of the ECU shown in FIG. 1, FIG. 3 is a flow chart of a Mayroutine executed by the calculation unit of FIG. 2, and FIG. 4 shows the relationship between the accelerator operation amount and the accelerator operation amount signal. FIG. 5 is a characteristic chart showing a time chart showing changes in throttle valve opening with respect to changes in accelerator operation amount.
FIG. 6, FIG. 7 and FIG. 8 are characteristic diagrams, flow charts and maps for explaining another embodiment of the present invention, and FIG. 9 is a block diagram showing a schematic configuration of the present invention. 1 ... Engine, 2 ... Intake pipe, 5 ... Throttle valve, 16
…… Accelerator sensor, 25 …… Motor, 30 …… ECU, 31 …… Computing section, 32 …… Storage section, 33 …… Input section, 34 …… Output section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-54848 (JP, A) JP-A-60-164629 (JP, A) Practical application Sho-59-105041 (JP, U)

Claims (1)

[Claims] 1. A throttle valve for adjusting the amount of air taken into an engine, an actuator for driving the throttle valve, a detection unit for detecting an accelerator operation amount, and an accelerator operation amount detected by the detection unit. Based on the control means for controlling the actuator so that the opening of the throttle valve becomes a predetermined opening, and the accelerator operation amount detected by the detection means includes a state in which the accelerator operation amount is zero. And a hysteresis means for transmitting a hysteresis characteristic to the control means when it is operated toward the acceleration side, and the hysteresis means has a smaller hysteresis width when the accelerator operation amount is large than when it is small. A throttle valve control device having a hysteresis characteristic set.