JP3744219B2 - Electronically controlled throttle valve control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for an electronically controlled throttle valve, and more particularly to a control device that increases the responsiveness of a throttle valve in an electronically controlled throttle valve in which an accelerator pedal and a throttle valve are not mechanically coupled.
[0002]
[Prior art]
Conventionally, the number of revolutions of an internal combustion engine mounted on a vehicle is controlled by the amount of depression of an accelerator pedal installed at the foot of the driver's seat. That is, the conventional internal combustion engine has a throttle valve connected to the accelerator pedal by a wire in the intake passage, and when the accelerator pedal is depressed, the opening degree of the throttle valve increases through the wire. Since the amount of intake air increases and the amount of fuel increases accordingly, the engine speed increases.
[0003]
On the other hand, in recent years, with the development of computers, electronically controlled internal combustion engines that attempt to optimally control the rotational speed of the internal combustion engine have been put into practical use. Such electronic control of the internal combustion engine is preceded by, for example, fuel injection amount control, ignition timing control, intake / exhaust valve opening timing control, etc. It is in the stage.
[0004]
The configuration of an electronically controlled throttle valve device 20 that is currently in practical use is shown in FIG. The electronically controlled throttle valve device 20 includes a throttle lever 16 connected to an accelerator pedal (not shown) with a wire, and an accelerator opening sensor that is built in the throttle lever 16 and detects an accelerator opening corresponding to the amount of depression of the accelerator pedal. 15, an engine control unit (hereinafter referred to as ECU) 10 to which the detected value of the accelerator opening of the accelerator opening sensor 15 is input, and a throttle provided in the intake passage 2 of the internal combustion engine according to the output of the ECU 10 A throttle motor 4 that opens and closes the valve 3, a throttle opening sensor 5 that detects the opening of the throttle valve 3, a retreat travel lever 17, a return spring 18 of the throttle valve 3, and a retreat travel lever 17 There is a relief spring 19. The throttle motor 4 has a built-in electromagnetic clutch.
[0005]
In the electronically controlled throttle valve device 20 configured as described above, when the accelerator pedal is depressed according to the driver's intention, the depression amount of the accelerator pedal is transmitted to the throttle lever 16 through the wire, and the throttle lever 16 rotates. An accelerator opening sensor 15 is built in the throttle lever 16, and the amount of depression of the accelerator pedal is detected by the rotation angle of the throttle lever 16. The depression amount of the accelerator pedal detected by the accelerator opening sensor 15 is transmitted to the ECU 10, which determines the opening of the throttle valve 3 according to the detected value of the depression amount of the accelerator pedal and drives the throttle motor 4. The opening of the throttle valve 3 is detected by a throttle opening sensor 5 and fed back to the ECU 10. The throttle motor 4 is a DC motor that has good response and low power consumption.
[0006]
The control at this time is proportional to the throttle motor 4 so that there is no deviation between the signal from the throttle opening sensor 5 that detects the opening of the throttle valve 3 and the signal from the accelerator opening sensor 15 ( Feedback control by P), integral (I), and differential (D) control (hereinafter simply referred to as PID control) is performed.
Further, in recent years, an electronic throttle device configured to eliminate the wire between the accelerator pedal and the throttle valve 3 has also been proposed. In the proposed electronic throttle device, a rotation angle sensor is provided on the support shaft of the accelerator pedal, or a stroke sensor of the accelerator pedal is provided, and a detection value of this sensor is directly input to the ECU 10. ing.
[0007]
By the way, the control constants of the P term, the I term, and the D term in the above-mentioned PID control are fixed values by intermediate tuning so as to satisfy the specifications in all operating states of the system. For this reason, in the conventional control device for the electronically controlled throttle valve by PID control, the responsiveness, stability, etc. of the throttle valve 3 are lowered because it cannot be an optimum value for each operating state of the engine. There was a problem.
[0008]
Some attempts have been made to increase the gain value of PID control in order to improve the responsiveness of the operation of the throttle valve to the accelerator pedal. However, this causes a problem that overshoot occurs during acceleration and undershoot occurs during deceleration. A new point is generated. In addition, in order to improve the reactivity of the throttle valve operation with respect to the accelerator pedal, the sampling cycle for detecting the throttle valve opening is shortened so that the target value (command value) in PID control can be quickly followed. However, if the sampling cycle is shortened and the control interval of the throttle motor 4 is shortened, overshoot and undershoot are likely to occur.
[0009]
Therefore, in JP-A-8-326561, in order to solve the problem of occurrence of overshoot and undershoot with respect to the target value of the throttle valve opening, the operating state of the throttle valve is determined in the PID control of the throttle valve, If it is determined that the throttle valve is operating even when the target opening set in accordance with the accelerator pedal depression amount is exceeded, it is determined that the throttle valve is overshooting, and the gain value of PID control (derivative term D) It has been proposed to change.
[0010]
[Problems to be solved by the invention]
However, as described in JP-A-8-326561, if the gain value is changed after determining the overshoot of the throttle valve, the throttle valve is already in the overshoot region, and the throttle valve is brought into a normal operating state. There was a problem that the reactivity was not enough to return.
[0011]
Accordingly, the present invention provides a control device for an electronically controlled throttle valve that performs PID control. The throttle valve opening / closing speed is increased based on a command value of the throttle valve opening, and the throttle valve opening / closing speed is monitored. Control that can realize both high-speed response of the electronically controlled throttle valve and prevention of overshoot by reducing the subsequent opening and closing speed of the throttle valve when the opening of the valve approaches the opening based on the command value The object is to provide a device.
[0012]
[Means for Solving the Problems]
The features of the present invention that achieve the above object will be described below as first to fourth inventions.
The structural features of the first invention are as follows:A motor that opens and closes the throttle valve so that there is no deviation between the accelerator opening signal corresponding to the accelerator pedal depression amount detected by the accelerator opening sensor and the throttle valve opening signal from the throttle valve opening sensor Feedback control by proportional, integral and derivative controlsIn the control device for electronically controlled throttle valve, the accelerator openingsignalIs read every first cycleInA command value setting means for setting a command value for the throttle valve opening; a first opening / closing speed setting means for the throttle valve for setting a first opening / closing speed of the throttle valve based on the command value; and a throttle valveofOpeningsignalUntil the current throttle valve opening reaches a predetermined opening smaller than the command value, and means for reading the throttle valve opening as the current throttle valve opening every second cycle shorter than the first cycle A first throttle valve opening predicting means for calculating a first predicted throttle valve opening after the second period in accordance with the first opening / closing speed of the throttle valve; and a first predicted throttle valve openingThe driving force of the motor is determined according toWhen the first throttle valve opening / closing drive means and the current throttle valve opening become equal to or greater than the predetermined opening for the first time, a second opening / closing speed slower than this is set according to the first opening / closing speed of the throttle valve. A second prediction after the second cycle according to the second opening / closing speed of the throttle valve and the second opening / closing speed setting means of the throttle valve to be set, and when the current throttle valve opening is equal to or greater than the predetermined opening Second throttle valve opening prediction means for calculating the throttle valve opening, and second predicted throttle valve openingThe driving force of the motor is determined according to the throttle valve, and the throttle valve is driven to open and close to the command value.The second throttle valve opening / closing drive means is provided.
[0013]
The structural feature of the second invention is that, in the first invention, the first and second throttle valve opening / closing drive means supplies power to the motor in accordance with the first and second predicted throttle valve opening degrees. The motor is driven by the calculated duty ratio of the supplied power.
The structural features of the third invention are:A motor that opens and closes the throttle valve so that there is no deviation between the accelerator opening signal corresponding to the accelerator pedal depression amount detected by the accelerator opening sensor and the throttle valve opening signal from the throttle valve opening sensor Feedback control by proportional, integral and derivative controlsIn the control device for electronically controlled throttle valve, the accelerator openingsignalIs read every first cycleInA command value setting means for setting a command value for the throttle valve opening; a first opening / closing speed setting means for the throttle valve for setting a first opening / closing speed of the throttle valve based on the command value; and a throttle valveofOpeningsignalMeans for reading the throttle valve opening as the current throttle valve opening every second cycle shorter than the first cycle, and the first after the second cycle according to the first opening / closing speed of the throttle valve First throttle valve opening prediction means for calculating the predicted throttle valve opening, and the first predicted throttle valve openingThe driving force of the motor is determined according toWhen the throttle valve opening / closing drive means and the current throttle valve opening become equal to or greater than a predetermined opening smaller than the command value for the first time, the second slower than this, depending on the first opening / closing speed of the throttle valve. The second opening / closing speed setting means for setting the opening / closing speed and the second opening / closing speed after the second period according to the second opening / closing speed of the throttle valve when the current throttle valve opening is equal to or greater than the predetermined opening. Second throttle valve opening prediction means for calculating the second predicted throttle valve opening, and calculating a difference between the first predicted throttle valve opening and the second predicted throttle valve opening, and opening and closing the throttle valve Motor by drive meansDriving forceIs corrected by this difference, and the throttle valve is driven to open and close to the command value.DoThrottle valve opening / closing drive correction meansProvidedIt is characterized by that.
[0014]
The fourth aspect of the present invention is characterized in that, in the third aspect, the throttle valve opening / closing drive means calculates the duty ratio of the power supplied to the motor in accordance with the first predicted throttle valve opening, and the current throttle The motor is driven by a value obtained by correcting the calculated duty ratio of the supplied power with a difference when the valve opening degree is equal to or greater than the predetermined opening degree. .
The structural feature of the fifth invention is that in any of the first to fourth inventions, the first and second opening / closing speeds are corrected by the state of the throttle motor, the battery voltage, or the ambient temperature. It is characterized by further providing means.
[0015]
According to the present invention, in a control device for an electronically controlled throttle valve that performs PID control, the detected value of the accelerator opening sensor is read at a predetermined time interval and set as a command value for the accelerator opening, and the throttle value is determined based on the command value. The first opening / closing speed of the valve is set and the detected value of the throttle valve opening sensor is read in a short cycle until the current throttle valve opening reaches a predetermined opening smaller than the command value. The throttle valve is driven to open and close by a motor so as to follow the first reference throttle valve opening determined by the opening / closing speed, and when the opening reaches a predetermined opening, the second opening / closing speed determined by the second opening / closing speed is lower than the first opening / closing speed. Since the throttle valve is driven to open and close up to the command value by following the reference throttle valve opening of 2, the response of the electronically controlled throttle valve becomes faster and overshoot and Undershoot is prevented.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail based on specific examples with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected and demonstrated about the structural member same as the structural member of the electronic control throttle valve apparatus 20 demonstrated in FIG.
FIG. 2 schematically shows an electronically controlled fuel injection type multi-cylinder internal combustion engine 1 equipped with a control device for a throttle valve according to an embodiment of the present invention. In FIG. 2, a throttle valve 3 is provided in the intake passage 2 of the internal combustion engine 1 on the downstream side of an air cleaner (not shown), and a throttle which is an actuator for driving the throttle valve 3 is provided at one end of a shaft of the throttle valve 3. A motor 4 is provided, and a throttle opening sensor 5 that detects the opening of the throttle valve 3 is provided at the other end. That is, the throttle valve 3 of this embodiment is an electronically controlled throttle that is opened and closed by a throttle motor 4.
[0017]
A surge tank 6 is provided in the intake passage 2 on the downstream side of the throttle valve 3, and a pressure sensor 7 for detecting the pressure of intake air is provided in the surge tank 6. Further, on the downstream side of the surge tank 6, a fuel injection valve 8 is provided for supplying pressurized fuel from the fuel supply system to the intake port for each cylinder. The output of the throttle opening sensor 5 and the output of the pressure sensor 7 are input to an ECU (Engine Control Unit) 10 incorporating a microcomputer.
[0018]
A coolant temperature sensor 11 for detecting the coolant temperature is provided in the coolant passage 9 of the cylinder block of the internal combustion engine 1. The water temperature sensor 11 generates an analog voltage electrical signal corresponding to the temperature of the cooling water. The exhaust passage 12 is provided with a three-way catalytic converter (not shown) that simultaneously purifies three harmful components HC, CO, and NOx in the exhaust gas. O is a kind of air-fuel ratio sensor₂A sensor 13 is provided. O₂The sensor 13 generates an electrical signal according to the oxygen component concentration in the exhaust gas. These water temperature sensors 11 and O₂The output of the sensor 13 is input to the ECU 10.
[0019]
Further, the ECU 10 includes an accelerator pedal depression amount signal (accelerator opening signal) from an accelerator opening sensor 15 that is attached to the accelerator pedal 14 and detects an accelerator depression amount, and a crank angle attached to a distributor (not shown). The engine speed Ne from the sensor is input.
In the configuration as described above, when a key switch (not shown) is turned on, the ECU 10 is energized to start the program, take in the output from each sensor, open and close the throttle valve 3 and the fuel injection valve 8, Alternatively, other actuators are controlled. The ECU 10 includes an A / D converter that converts analog signals from various sensors into digital signals, an input / output interface 101 through which input digital signals from various sensors and signals for driving the actuators enter and exit, and arithmetic processing. A CPU 102, a memory such as a ROM 103 and a RAM 104, a clock 105, and the like are provided, and these are connected to each other via a bus 106. Since the configuration of the ECU 10 is publicly known, further explanation is omitted.
[0020]
When the accelerator pedal depression amount signal from the accelerator opening sensor 15 is input to the ECU 10, the ECU 10 outputs the accelerator pedal depression amount signal at a predetermined cycle T, for example, a 10 ms cycle, as shown in FIG. Sampling. Then, the ECU 10 outputs the sampling value α at the time ta as a command value θCM of the throttle valve opening at the time ta as shown in FIG. Similarly, the ECU 10 thereafter outputs the accelerator pedal depression amount signal sampled every predetermined period T so that the command value θCM = β at the time tb and the command value θCM = γ at the time tc.
[0021]
FIG. 4 is a block diagram showing functions in the ECU 10 of FIG. 2 for realizing the present invention. When the accelerator pedal depression amount signal is input to the ECU 10, the command value is set by the command value setting function 110 every predetermined time T as described above. This command value is input to a PID control function 111 including a differential action function 111D, a proportional action function 111P, and an integral action function 111I. The PID control function 111 calculates the opening / closing speed of the throttle valve based on this command value, and outputs a target value of the throttle valve opening determined by the opening / closing speed of the throttle valve. The target value of the throttle valve opening is output to the duty output calculation function 112, where the duty ratio of the throttle motor drive signal corresponding to the target value of the throttle valve opening is calculated. The duty ratio of the throttle motor drive signal is output to the throttle motor 4, and the throttle motor 4 is driven to change the opening of the throttle valve. The opening degree of the throttle valve is detected by the throttle opening degree sensor 5, and this detected value is fed back to the PID control function 111.
[0022]
The above function is a normal throttle valve control system. In the present invention, an acceleration / deceleration prediction calculation function 113 is added to this control system. The acceleration / deceleration prediction calculation function 113 takes in the output of the duty output calculation function 112 and feeds back a predetermined signal to the input side of the duty output calculation function 112 in order to control the output of the duty output calculation function 112. is there. The detected value of the throttle valve opening detected by the throttle opening sensor 5 is also input to the acceleration / deceleration prediction calculation function 113.
[0023]
Here, an example of the control of the present invention in the control device for the electronically controlled throttle valve configured as shown in FIG. 4 will be described with reference to the flowchart shown in FIG. The procedure shown in this flowchart is executed in another sampling period Ts shorter than the above-described sampling period T. In this case, T = mTs, where m is a natural number.
[0024]
In step 501, it is first determined whether or not the current time is the sampling period T. If it is the sampling period T, the process proceeds to step 502, and as described in FIGS. 3 (a) and 3 (b), the current detected opening of the accelerator opening sensor 15 (the amount of depression of the accelerator pedal) is read. This is the current throttle valve opening command value θCM. In the following step 503, the first opening / closing speed V1 of the throttle valve is calculated according to the magnitude of the command value θCM, and the process proceeds to step 504.
[0025]
The first opening / closing speed V1 of the throttle valve indicates the upper limit value of the follow-up speed of the throttle valve opening with respect to the command value θCM, and the follow-up speed of the throttle valve opening with respect to the command value θCM is the first opening / closing speed V1. Guarded. The magnitude of the first opening / closing speed V1 may be stored in advance in the ROM 103 in the form of a map so as to be determined according to the magnitude of the command value θCM at the time of calculating the first opening / closing speed V1. The first opening / closing speed V1 of the throttle valve can also be obtained by modern control. That is, the first opening / closing speed V1 of the throttle valve can be obtained by creating a state equation using parameters such as the command value θCM, the accelerator pedal depression amount, the battery voltage, and the temperature at the time of calculating the throttle valve, and solving this. Can be sought.
[0026]
On the other hand, when it is determined in step 501 that the current time t1 is not the sampling period T, the process proceeds to step 504 without executing steps 502 and 503.
In step 504, the current opening degree θth of the throttle valve 3 is read from the detection output of the current throttle opening degree sensor 5. In the following step 505, the first opening / closing speed V1 of the throttle valve calculated in step 503 and the current opening θth of the throttle valve 3 read in step 504 are used after a predetermined time Ts (after the next sampling cycle Ts). ) To calculate the predicted opening θe1 of the throttle valve. The throttle valve opening predicted value θe1 is an amount represented by a difference from the current throttle valve opening θth.
[0027]
In the subsequent step 506, the drive amount of the throttle motor 4 that drives the throttle valve 3 is calculated as the drive duty ratio DD1 in correspondence with the throttle valve opening predicted value θe1 calculated in step 505. This drive duty ratio DD1 can be calculated from a map corresponding to the predicted opening value θe1 of the throttle valve.
Examples of this map are shown in FIGS. FIG. 6 is an example of a map in which the X axis is the predicted opening value (speed) and the Y axis is the drive duty ratio DD1. A drive duty ratio DD1 corresponding to the predicted opening value θe1 can be obtained from this map. FIG. 7 is an example of a map in which the X-axis indicates the throttle valve position, the Y-axis indicates the estimated opening of the throttle valve, and the Z-axis indicates the drive duty ratio DD1. In the map of FIG. 7, the value of the drive duty ratio DD1 according to the predicted opening degree θe1 can be obtained by taking into account the throttle valve position (throttle valve opening degree) at that time, so that a more accurate drive duty ratio DD1 can be obtained. Can be sought.
[0028]
In this embodiment, the above control is performed until the opening degree θth of the throttle valve 3 reaches a predetermined opening degree close to the command value θCM of the throttle valve opening degree. For example, the predetermined opening may be about 85% of the command value θCM of the throttle valve opening, although it varies depending on engine performance. Here, the predetermined opening is described as 85% of the command value θCM of the throttle valve opening.
[0029]
Step 507 determines whether or not the opening θth of the throttle valve 3 has reached a predetermined opening close to the command value θCM of the throttle valve opening, for example, the opening θth of the throttle valve 3 has reached 85% of the command value θCM. Whether or not. If θth <θCM × 0.85 in step 507, the throttle motor 4 is driven using the drive duty ratio DD1 obtained by the procedure from step 502 to step 506 as it is. Accordingly, when θth <θCM × 0.85 in step 507, the process proceeds to step 508 to set a flag n to be described later to 0, and then the drive duty ratio DD1 calculated in step 506 is set in step 516 to the throttle motor 4 The output is made as the drive duty ratio, and this routine is terminated.
[0030]
On the other hand, when θth ≧ θCM × 0.85 in step 507, the process proceeds to step 509. In step 509, whether or not θth ≧ θCM × 0.85 is satisfied for the first time in step 507 is determined based on the value of the flag. That is, when θth ≧ θCM × 0.85 for the first time in step 507, the value of the flag n is 0, so that the processing of step 510 and step 511 is performed. When the value of the flag n is 0, the routine proceeds to step 510, where the second opening / closing speed V2 of the throttle valve is calculated from the first opening / closing speed V1 of the throttle valve. Here, the second opening / closing speed V2 of the throttle valve is a value smaller than the first opening / closing speed V1 of the throttle valve, and is set in advance according to the value of the first opening / closing speed V1 of the throttle valve. It can be calculated using a map as shown in FIG. The map shown in FIG. 8 may be used after being corrected according to the state of the throttle motor, the voltage of the battery mounted on the engine, or the ambient temperature.
[0031]
In this way, after calculating the second opening / closing speed V2 of the throttle valve in step 510, the process proceeds to step 511, the value of the flag n is set to 1, and the process proceeds to step 512. Accordingly, when the process proceeds to step 509 thereafter, the value of the flag n is 1, so that the process proceeds to step 512 without executing the processes of steps 510 and 511. Thus, the flag n is for calculating the second opening / closing speed V2 of the throttle valve only at step 510 only when θth ≧ θCM × 0.85 for the first time at step 507.
[0032]
In step 512, the throttle valve opening predicted value θe2 after a predetermined time Ts, according to the second opening / closing speed V2 of the throttle valve calculated in step 510 and the current opening θth of the throttle valve 3 read in step 504. Is calculated.
In the subsequent step 513, a difference θthdf between the predicted throttle valve opening θe1 calculated in step 505 and the predicted throttle valve opening θe2 calculated in step 512 is calculated. In the next step 514, an increase / decrease amount DDΔ of the drive duty ratio DD1 of the throttle motor 4 that drives the throttle valve 3 is calculated in correspondence with the difference θthdf. The increase / decrease amount DDΔ of the drive duty ratio can be calculated using the map corresponding to the throttle valve opening predicted value θe1 described above as it is.
[0033]
In the following step 515, the drive duty ratio DD1 of the throttle valve calculated in step 506 is corrected by the increase / decrease amount DDΔ of the drive duty ratio calculated in step 514. When step 515 ends, the routine proceeds to step 516, where the corrected drive duty ratio DD1 of the throttle valve is output as the drive duty ratio of the throttle motor 4, and this routine ends.
[0034]
Therefore, after θth ≧ θCM × 0.85 in step 507, the drive duty ratio DD1 output in step 516 is corrected in step 515 by the drive duty ratio DD1 of the throttle motor 4 calculated in step 506. The throttle motor is driven with this corrected drive duty ratio DD1.
[0035]
FIG. 9 shows changes in the command value θCM, the throttle valve opening (opening predicted values θe1, θe2), and the throttle motor drive duty ratio DD1 with time when the time t1 corresponds to the calculation cycle of the command value θCM. It is a time chart which shows. Here, it is assumed that the current throttle valve opening degree θth is n °, and the calculated value of the command value θCM in step 502 is 5 °.
[0036]
Under this condition, the first opening / closing speed V1 of the throttle valve is calculated in accordance with the command value θCM of 5 ° (step 503), and then the current value of the throttle valve opening θth is read as 5 °. After (step 504), the predicted opening value θe1 of the throttle valve after the sampling period Ts is calculated (step 505). Here, the predicted opening value of the throttle valve after the sampling period Ts is F.
[0037]
Thus, when the predicted throttle opening after the sampling period Ts is calculated as F, the throttle motor duty ratio DD1 corresponding to the calculated value is calculated (step S1).506), The throttle motor is duty-driven at the duty ratio DD1 (step 516).
Such duty driving of the throttle motor is continued during a period T1 from time t1 to time t2. During the period T1, if the throttle valve opening predicted value θe1 changes as F, A, B, C, E as shown in the figure, the drive duty ratio DD1 of the throttle motor accordingly changes to F ′, A ′. , B ′, C ′, E ′. Period T1 is control by normal PID control.
[0038]
On the other hand, when the throttle valve opening θth reaches 85% of the command value θCM at time t2, the second opening / closing speed V2 of the throttle valve is set at time t2 in accordance with the first opening / closing speed V1 of the throttle valve. Calculated (step 510), a throttle valve opening predicted value θe2 after the sampling period Ts is calculated (step 512). Here, the value of the predicted throttle valve opening θe1 after the sampling period Ts is D ″, and the predicted throttle valve opening θe2 is D.
[0039]
Thus, when the throttle valve opening θth reaches 85% of the command value θCM, the value D ″ of the predicted opening value θe1 corresponding to the first opening / closing speed V1 of the throttle valve and the throttle valve opening 2 is calculated, and a difference θthdf is calculated (step 513), and a duty ratio increase / decrease amount DDΔ corresponding to the difference θthdf is calculated. (Step 514), the drive duty ratio DD1 of the throttle motor is corrected by the increase / decrease amount DDΔ of this duty ratio (step 515), and thereafter, until the time t3 when the throttle valve opening θth coincides with the command value θCM. During the period T2, the throttle motor is driven with the corrected drive duty ratio DD 1. The period T2 is a period during which acceleration / deceleration prediction calculation is performed in the PID control of the present invention.
[0040]
The above description is the control when the throttle valve is driven in the valve opening direction, but the control when the throttle valve is driven in the valve closing direction is the command value θCM, the throttle valve opening (opening predicted value θe1 , θe2), and the drive duty ratio DD1 of the throttle motor is exactly the same except for the negative magnitude, and the description thereof is omitted.
In the example described above, when the throttle valve opening degree θth reaches 85% of the command value θCM, the throttle valve opening / closing speed is changed from the first opening / closing speed V1 to the second opening / closing speed V2 smaller than this. However, switching from the first opening / closing speed V1 to the second opening / closing speed V2 is not limited to when the throttle valve opening degree θth reaches 85% of the command value θCM, and depends on the performance of the engine. You can choose appropriately.
[0041]
As described with reference to FIG. 9, according to the present invention, the throttle valve drive duty ratio is such that the predicted throttle valve opening values θe1 and θe2 are indicated by the solid line RT with respect to the throttle valve opening command value θCM. Since DD1 is appropriately determined as indicated by the solid line RD, the throttle valve is driven smoothly without causing overshoot or undershoot. On the other hand, according to the conventional control, the throttle valve opening predicted value θe2 increases as indicated by a two-dot chain line UT after time t2 with respect to the throttle valve opening command value θCM. The drive duty ratio DD1 also increases as indicated by a two-dot chain line UD, and the throttle valve causes overshoot or undershoot.
[0042]
In the example described with reference to FIG. 9, the PID control gain is set appropriately. However, when the PID control gain is set to a large value, the predicted opening θe1 of the throttle valve is the first value of the throttle valve. FIG. 10 shows an example in which guarding is always performed at the opening / closing speed V1. Even in this case, according to the present invention, the throttle valve drive duty ratio DD1 is indicated by the solid line RD so that the throttle valve opening predicted values θe1 and θe2 are indicated by the solid line RT with respect to the command value θCM of the throttle valve opening. As shown by, the throttle valve is appropriately determined, so that the throttle valve is smoothly driven without causing overshoot or undershoot.
[0043]
Further, the first and second opening / closing speeds V1 and V2 may have an allowable width as shown by broken lines V1a and V1b and V2a and V2b in FIG.
In the embodiment described above, the throttle valve opening predicted value θe1 corresponding to the first opening / closing speed V1 of the throttle valve is also calculated after the throttle valve opening reaches 85% or more of the command value θCM. The difference θthdf between the predicted opening value θe2 of the throttle valve corresponding to the second opening / closing speed V2 of the throttle valve and the predicted opening value θe1 was calculated. Then, a duty ratio increase / decrease amount DDΔ corresponding to the difference θthdf is calculated, and a throttle motor drive duty ratio DD1 obtained from the throttle valve opening predicted value θe1 corresponding to the first opening / closing speed V1 of the throttle valve is calculated. The throttle motor was driven by correcting with the increase / decrease amount DDΔ.
[0044]
However, after the throttle valve opening reaches 85% or more of the command value θCM, the throttle motor drive duty ratio DD1 is directly calculated from the throttle valve opening predicted value θe2 corresponding to the second opening / closing speed V2 of the throttle valve. Can be calculated to drive the throttle motor. FIG. 11 is a flowchart showing this control procedure as a second embodiment of the present invention.
[0045]
The control procedure shown in FIG. 11 is the same as the control procedure described in FIG. Therefore, the same step numbers as in FIG.
Steps 501 to 505 are the same as the procedure described with reference to FIG. 5. In step 501, it is determined whether or not the current time is the sampling period T. In step 502, the throttle valve opening is determined from the current accelerator pedal depression amount. The command value θCM is calculated, the first opening / closing speed V1 of the throttle valve is calculated at step 503, the current opening θth of the throttle valve 3 is read at step 504, and after a predetermined time (sampling period) Ts at step 505. A throttle valve opening predicted value θe1 is calculated.
[0046]
In the control of FIG. 5, the drive duty ratio DD1 of the throttle motor 4 corresponding to the throttle valve opening predicted value θe1 is calculated in step 506. In this embodiment, after the step 505 is completed, the throttle valve 3 Step 507 is executed to determine whether the opening θth is about 85% of the command value θCM of the throttle valve opening.
If θth <θCM × 0.85 in step 507, the flag n is set to 0 in step 508, and then step 601 corresponding to step 506 of the control in FIG. 5 is performed. That is, in step 601, the drive duty ratio DD1 of the throttle motor corresponding to the predicted opening value θe1 is calculated. In step 516, the drive duty ratio DD1 calculated in step 601 is output as the drive duty ratio of the throttle motor 4, and this routine is terminated.
[0047]
On the other hand, the procedure from step 509 to step 512 performed when θth ≧ θCM × 0.85 in step 507 is the same as the procedure described in FIG. 5. In step 509, θth ≧ θCM × 0.85 is the first time in step 507. In step 510, the second opening / closing speed V2 of the throttle valve is calculated from the first opening / closing speed V1 of the throttle valve, the value of the flag n is set to 1 in step 511, and predetermined in step 512. A predicted opening value θe2 of the throttle valve after time (sampling period) Ts is calculated.
[0048]
In the next step 602, the throttle motor drive duty ratio DD1 corresponding to the predicted opening degree θe2 is calculated, and the routine proceeds to step 516, where the throttle valve drive duty ratio DD1 is output as the throttle motor 4 drive duty ratio. End the routine.
In this embodiment, after θth ≧ θCM × 0.85 in Step 507, the drive duty ratio DD1 output in Step 516 is the value of the throttle motor 4 corresponding to the predicted opening value θe2 calculated in Step 602. This is the drive duty ratio DD1, which is the same value as the drive duty ratio DD1 corrected in step 515 in the control of FIG. Therefore, also in this embodiment, the throttle motor is driven similarly to the control of FIG.
[0049]
As described above, in the present invention, the throttle valve is driven and controlled while predicting the drive duty ratio of the throttle motor, so that it is predicted how much time the throttle valve reaches the command value after the command value changes. Therefore, accurate air-fuel ratio control becomes possible, and engine emissions can be reduced. In other words, until now, when controlling the air-fuel ratio on the engine side, the behavior of the throttle valve could not be grasped, but in the present invention, the behavior of the throttle valve can be grasped to some extent. Therefore, the amount of intake air can be determined and fuel injection can be executed accordingly, which improves engine emissions.
[0050]
【The invention's effect】
As described above, according to the present invention, in the control device for an electronically controlled throttle valve that performs PID control, the opening / closing speed of the throttle valve can be increased based on the command value of the throttle valve opening, and the throttle valve The opening / closing speed of the throttle valve is monitored, and when the opening degree of the throttle valve approaches the opening degree based on the command value, the subsequent opening / closing speed of the throttle valve is reduced, thereby improving the response of the electronically controlled throttle valve and overshooting. There is an effect that both prevention can be realized.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a configuration of a conventional electronically controlled throttle.
FIG. 2 is a configuration diagram showing a configuration of an electronically controlled multi-cylinder internal combustion engine equipped with a control device for an electronically controlled throttle valve according to an embodiment of the present invention.
3A is a diagram illustrating an example of a depression amount characteristic of an accelerator pedal, and FIG. 3B is a diagram illustrating a characteristic of a command value obtained from the depression amount characteristic of an accelerator pedal of FIG.
FIG. 4 is a control block diagram of the present invention.
FIG. 5 is a flowchart showing an example of a throttle valve control procedure in the electronically controlled throttle valve control apparatus of the present invention.
FIG. 6 is a characteristic diagram showing a relationship between a predicted opening value of a throttle valve and a drive duty ratio.
FIG. 7 is a characteristic diagram showing the relationship between the throttle valve position, the predicted opening of the throttle valve, and the drive duty ratio in three dimensions.
FIG. 8 is a characteristic diagram showing a relationship between a first opening / closing speed and a second opening / closing speed of the throttle valve of the present invention.
9 is a time chart showing changes in command values, throttle valve first and second opening / closing speeds, throttle valve opening predicted values, and drive duty ratios based on the control procedure of FIG. 5;
10 shows a command value based on the control procedure of FIG. 5, the first and second opening / closing speeds of the throttle valve, the predicted opening value of the throttle valve, and the drive duty when the gain in the PID control of FIG. 4 is increased. It is a time chart which shows the mode of a change of ratio.
FIG. 11 is a flowchart showing another example of a throttle valve control procedure in the electronically controlled throttle valve control apparatus of the present invention.
[Explanation of symbols]
2 ... Intake passage
3 ... Throttle valve
4 ... Throttle motor
5 ... Throttle opening sensor
10 ... ECU
14 ... Accelerator pedal
15 ... Accelerator opening sensor
16 ... Throttle lever

Claims (5)

A motor that opens and closes the throttle valve so that there is no deviation between the accelerator opening signal corresponding to the accelerator pedal depression amount detected by the accelerator opening sensor and the throttle valve opening signal from the throttle valve opening sensor A control device for an electronically controlled throttle valve that performs feedback control by proportional, integral, and differential control with respect to
A command value setting means for setting a command value for the throttle valve opening Nde write read the accelerator opening signal to the first each period,
First opening / closing speed setting means for setting the first opening / closing speed of the throttle valve based on the command value;
The opening signal of the throttle valve, a reading means of the throttle valve opening to load the first every short second period than the period as the current throttle valve opening,
Until the current throttle valve opening reaches a predetermined opening smaller than the command value, the first predicted throttle valve opening after the second period is calculated according to the first opening / closing speed of the throttle valve. First throttle valve opening degree predicting means,
A first throttle valve opening / closing driving means for determining a driving force of the motor according to the first predicted throttle valve opening;
When the current throttle valve opening becomes equal to or greater than the predetermined opening for the first time, a second opening / closing speed of the throttle valve is set in accordance with the first opening / closing speed of the throttle valve. Opening and closing speed setting means;
When the current throttle valve opening is equal to or greater than the predetermined opening, a second predicted throttle valve opening after the second period is calculated according to a second opening / closing speed of the throttle valve. Throttle valve opening prediction means, and
And a second throttle valve opening / closing driving means for determining a driving force of the motor according to the second predicted throttle valve opening and driving the throttle valve to open / close to the command value. Electronically controlled throttle valve control device. 2. The electronically controlled throttle valve control device according to claim 1, wherein the first and second throttle valve opening / closing driving means are connected to the motor in accordance with the first and second predicted throttle valve opening degrees. A control device for an electronically controlled throttle valve, wherein a duty ratio of the supplied power is calculated and the motor is driven according to the calculated duty ratio of the supplied power. A motor that opens and closes the throttle valve so that there is no deviation between the accelerator opening signal corresponding to the accelerator pedal depression amount detected by the accelerator opening sensor and the throttle valve opening signal from the throttle valve opening sensor A control device for an electronically controlled throttle valve that performs feedback control by proportional, integral, and differential control with respect to
A command value setting means for setting a command value for the throttle valve opening Nde write read the accelerator opening signal to the first each period,
First opening / closing speed setting means for setting the first opening / closing speed of the throttle valve based on the command value;
The opening signal of the throttle valve, a reading means of the throttle valve opening to load the first every short second period than the period as the current throttle valve opening,
First throttle valve opening prediction means for calculating a first predicted throttle valve opening after the second period in accordance with a first opening / closing speed of the throttle valve;
A throttle valve opening / closing driving means for determining a driving force of the motor according to the first predicted throttle valve opening;
When the current throttle valve opening becomes equal to or greater than a predetermined opening smaller than the command value for the first time, a second opening / closing speed slower than this is set according to the first opening / closing speed of the throttle valve. Second opening / closing speed setting means for the throttle valve;
When the current throttle valve opening is equal to or greater than the predetermined opening, a second predicted throttle valve opening after the second period is calculated according to a second opening / closing speed of the throttle valve. Throttle valve opening prediction means, and
The difference between the first predicted throttle valve opening and the second predicted throttle valve opening is calculated, and the driving force of the motor by the opening / closing drive means of the throttle valve is corrected by this difference, and the throttle control device for electronically controlled throttle valve, characterized in that it comprises a closing drive means for correcting the throttle valve for opening and closing the valve to the command value. The electronic control throttle valve control device according to claim 3, wherein the throttle valve opening / closing drive means calculates a duty ratio of power supplied to the motor in accordance with the first predicted throttle valve opening, When the current throttle valve opening is equal to or greater than the predetermined opening, the calculated power supply duty ratio is used. When the current throttle valve opening is greater than or equal to the predetermined opening, the calculated supply power duty ratio is corrected using the difference. An electronically controlled throttle valve control device characterized by driving. 5. The electronically controlled throttle valve control device according to claim 1, wherein the first and second opening / closing speeds are corrected according to a state of a throttle motor, a battery voltage, or an ambient temperature. A control device for an electronically controlled throttle valve, further comprising speed correction means.

Images