JP4980457B2 - Electronic throttle valve control device - Google Patents

Description

  The present invention relates to an electronic throttle valve control device, and more particularly to an electronic throttle valve control device for reducing power consumption for the purpose of improving fuel consumption.

  In recent years, efforts have been made to improve the fuel efficiency of automobiles from the viewpoint of preventing global warming. As one of them, a technology has been developed to reduce the power consumption of the electrically driven auxiliary machines, thereby reducing the amount of power generated by the engine and consequently improving the fuel consumption.

  There are various types of auxiliary equipment, but one of them is an electronic throttle system that controls the intake air of the engine by adjusting the angle of the butterfly with a motor.

  The electronic throttle system includes an electronic throttle valve, a control device that controls the electronic throttle valve, an accelerator opening sensor that converts an amount by which the driver steps on the accelerator into an electric signal and transmits the electric signal to the control device. The electronic throttle valve has a structure in which a reaction force is applied to a spring by a motor, and the balance position of both forces is a butterfly angle. The control device reads the butterfly angle with a throttle opening sensor, and performs feedback control so that the actual opening coincides with the target opening calculated by the accelerator opening sensor or the like. The calculation result is input to the motor drive circuit as a duty, and the motor is driven so that the actual opening of the electronic throttle valve becomes the target opening. There is a microcomputer in the control device, and these are repeatedly executed in a predetermined cycle.

  By the way, even when the control device breaks down, it is necessary to secure a predetermined intake air amount. Therefore, when the drive current is 0 A, that is, the duty is 0%, the electronic throttle valve is called the intermediate opening by the force of the spring. The opening will be reduced. When driving from the intermediate opening to the fully closed side and the fully opened side, the motor is driven so as to push in the spring by giving a duty so as to rotate backward and forward, respectively. As described above, since the drive stops where the motor and spring force balance, the relationship between the duty and the opening is as shown in FIG.

  At this time, there are two drive directions: a direction in which the spring is pushed, that is, a direction away from the intermediate opening, and a direction in which the spring is pushed back, that is, a direction approaching the intermediate opening. The duty value varies depending on the degree. That is, the relationship between the duty and the opening is a characteristic having hysteresis. This will be described with reference to FIG. When the opening A in FIG. 1 is the target opening and the actual opening is stable at the opening A, the duty is a value in the section B.

  Now, if the target opening is the opening A and the actual opening is also maintaining the opening A, the actual opening can be set to the opening A if the duty somewhere in the section B can be set to C%. It is possible to minimize the duty while keeping it at the same level. Since duty and power consumption are in a proportional relationship, that is, power consumption can be minimized. In Patent Document 1 (Japanese Patent Laid-Open No. 2009-62899), in order to make the duty close to C%, the target opening is once set to the opening side from the opening A, and then slowly returned to the opening A. , The duty is reduced toward C%.

  FIG. 2 shows the operation of Patent Document 1. In Patent Document 1, when the opening degree A is in a steady state at a certain duty D% in the section B, the target opening degree is once set to the opening side and slowly returned to the opening degree A, whereby the duty is finally obtained. It can be reduced to E% lower than D%. Then, by repeating this control (fluctuation control), the vicinity of the duty C% is approached.

JP 2009-62899 A

  In Patent Document 1, the actual opening is an opening different from the opening A during the period of Tup + Tdown of fluctuation control. The amount of deviation from the opening A is set within the allowable fluctuation range of the system. However, in the case of an electronic throttle system, the change in opening is sensitively reflected in the rotational speed of the internal combustion engine. Is narrow. In particular, in the idle region, a slight change in the opening degree also affects the rotation speed. For example, the opening of the electronic throttle valve is generally controlled with a resolution of 5V / 4096 by the signal of the throttle opening sensor, but only one portion of this resolution changes. The rotational speed of the internal combustion engine changes by about 10 rpm. The allowable fluctuation range of the rotational speed in the idle region is, for example, ± 25 rpm, and the rotational speed fluctuates within a range close to the allowable fluctuation range, for example, ± 20 rpm even during normal time when fluctuation control is not applied. For this reason, the allowable variation range of the opening that can be assigned for fluctuation control is zero. That is, the fluctuation control of Patent Document 1 cannot be applied.

  Further, even if the fluctuation in the normal rotation speed without applying the fluctuation control is extremely small, about ± 15 rpm, or even if the allowable fluctuation range of the rotation speed in the idling range is as large as about ± 30 rpm, the fluctuation control is performed. The allowable variation range of the opening that can be allocated for use is limited to one resolution. This is because if the allowable variation range is two of the opening resolution, that is, about 20 rpm, is added to the fluctuation amount of the normal rotational speed, the driver will be recognized as a beep sound of the internal combustion engine, resulting in a problem of commerciality. Therefore, the resolution is limited to one.

  However, if the allowable variation range of the opening is one of the resolutions, the duty cannot be reduced even if the fluctuation control of Patent Document 1 is applied. Because, in Patent Document 1, it is necessary to lengthen the operation time Tdown for returning to the opening A again than the operation time Tup for once opening from the opening A, but if only one resolution is acceptable, As shown in FIG. 3, Tup and Tdown are equal to one calculation cycle, and it is not possible to make a difference between the operation time on the opening side and the closing side.

  As described above, in the electronic throttle system in which the change in the opening degree is sensitively reflected on the rotation speed of the internal combustion engine, the technique of Patent Document 1 cannot be applied to the idle region that is most frequently used as the operating state. Problems arise.

  The present invention has been made to solve such a problem, and can reduce the duty in the entire opening including the idling range without changing the opening of the electronic throttle valve, thereby improving the fuel consumption. An object of the present invention is to provide a control device for an electronic throttle valve.

The present invention relates to an electronic throttle valve control device for controlling the electronic throttle valve, which is connected to an electronic throttle valve for adjusting the intake air amount of the internal combustion engine, and includes values from various sensors for detecting the state of the internal combustion engine. Based on the target opening calculation means for determining the target opening of the electronic throttle valve, the actual opening that is the actual opening of the electronic throttle valve and the target opening are input, and the actual opening Feedback calculation means for performing feedback control so as to match the target opening, and a motor drive circuit for driving the electronic throttle valve according to the duty output by the feedback calculation means, the feedback calculation means comprising the electronic When it is determined that the opening of the throttle valve is steady, the duty by the feedback control is Stop tee updates, including the duty reduction processing section to be output to the motor driving circuit a value obtained by subtracting the small predetermined amount than the width of the drive hysteresis duty value immediately before updating stop as the duty, the feedback arithmetic unit When the opening of the electronic throttle valve is determined not to be steady, the duty is updated by the normal feedback control, and when the opening of the electronic throttle valve is determined to be steady, An electronic throttle valve control device that performs processing by a duty reduction processing unit.

The present invention relates to an electronic throttle valve control device for controlling the electronic throttle valve, which is connected to an electronic throttle valve for adjusting the intake air amount of the internal combustion engine, and includes values from various sensors for detecting the state of the internal combustion engine. Based on the target opening calculation means for determining the target opening of the electronic throttle valve, the actual opening that is the actual opening of the electronic throttle valve and the target opening are input, and the actual opening Feedback calculation means for performing feedback control so as to match the target opening, and a motor drive circuit for driving the electronic throttle valve according to the duty output by the feedback calculation means, the feedback calculation means comprising the electronic When it is determined that the opening of the throttle valve is steady, the duty by the feedback control is Stop tee updates, including the duty reduction processing section to be output to the motor driving circuit a value obtained by subtracting the small predetermined amount than the width of the drive hysteresis duty value immediately before updating stop as the duty, the feedback arithmetic unit When the opening of the electronic throttle valve is determined not to be steady, the duty is updated by the normal feedback control, and when the opening of the electronic throttle valve is determined to be steady, Since the electronic throttle valve control device performs processing by the duty reduction processing unit, the duty is reduced over the entire opening including the idle region without changing the opening of the electronic throttle valve, and the fuel consumption is reduced. Improvements can be made.

It is a characteristic figure of a duty and an opening in an electronic throttle system. 10 is a timing chart for explaining fluctuation control in Patent Document 1; 9 is a timing chart in the case where the allowable variation range of fluctuation control is 1 in resolution in Patent Document 1. It is a block diagram which showed the structure of the electronic throttle system in Embodiment 1 of this invention. It is a control block diagram of the whole electronic throttle system in Embodiment 1 of this invention. It is a control block diagram of the feedback calculation means in Embodiment 1 of this invention. It is a flowchart which shows the process performed in a predetermined period in the duty reduction process part in Embodiment 1 of this invention. 6 is a flowchart illustrating counter initialization processing in the duty reduction processing unit according to the first embodiment of the present invention. It is a timing chart which shows operation | movement of the duty reduction process part in Embodiment 1 of this invention.

Embodiment 1 FIG.
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 4 is a diagram showing a configuration of the entire electronic throttle system provided with the control device for the electronic throttle valve according to the first embodiment of the present invention. An electronic throttle valve 1 is provided in an intake pipe of an engine which is an internal combustion engine, and adjusts an intake air amount to the engine. Further, the engine is provided with various engine control sensors 2, and using these pieces of information, the engine control unit 3 (hereinafter referred to as ECU 3) appropriately controls the operating state of the engine. Examples of the various engine control sensors 2 include an air flow meter, a crank angle sensor, a cooling water temperature sensor, an intake air temperature sensor, and an O ₂ sensor. The battery 4 is connected to the ECU 3 and supplies electric power to the ECU 3. The accelerator opening sensor 5 is connected to the ECU 3 and transmits the accelerator depression amount of the driver to the ECU 3. The ECU 3 includes a microcomputer (not shown), which reads signals from various engine control sensors 2 and a signal from the accelerator opening sensor 5 and reads the target opening of the electronic throttle valve 1 (hereinafter referred to as target opening). )). The ECU 3 constitutes the electronic throttle valve control device according to the first embodiment of the present invention.

  The electronic throttle valve 1 includes a DC motor 6, a gear 7, a butterfly 8, a spring 9, and a throttle opening sensor 10. The DC motor 6 is supplied with electric power from the ECU 3 and performs forward rotation and reverse rotation. The rotational torque is transmitted via the gear 7 to a shaft to which the butterfly 8, the spring 9, and the throttle opening sensor 10 are coaxially connected. The butterfly 8 stops moving when the rotational torques of the spring 9 and the DC motor 6 are balanced, and the angle of the butterfly 8 is detected by the throttle opening sensor 10 and read into the microcomputer in the ECU 3. From this value, the actual opening of the electronic throttle valve 1 (hereinafter referred to as the actual opening) is calculated, and feedback control is performed so that the value matches the target opening. 1 DC motor 6 is driven.

  FIG. 5 is a diagram showing a control block of the entire electronic throttle system according to the present invention. As shown in FIG. 5, the ECU 3 includes a target opening degree calculation unit 11, a feedback calculation unit 12, a failure determination unit 14, and a motor drive circuit 15. Further, a duty reduction processing unit 13 to be described later is provided in the feedback calculation means 12.

  In this configuration, first, the target opening 16 of the electronic throttle valve 1 is calculated by the target opening calculation means 11 in the ECU 3 from the signals of the various engine control sensors 2 and the accelerator opening sensor 5. For example, the sum of the opening determined from the temperature of the engine coolant and the opening proportional to the accelerator opening is determined as the target opening 16. The target opening 16 and the actual opening 17 read through the throttle opening sensor 10 are compared by the feedback calculation means 12 to calculate the duty and the motor driving direction. A method for calculating the duty will be described later. The determination method of the motor drive direction is determined by the magnitude relationship between the target opening 16 and the actual opening 17. That is, if the target opening 16 is larger than the actual opening 17, the driving direction is determined on the opening side, that is, the direction in which the motor is rotated forward, and conversely, the target opening 16 is more than the actual opening 17. If smaller, the driving direction is determined on the closing side, that is, in the direction in which the motor is rotated in the reverse direction. A duty reduction processing unit 13 that is a feature of the present invention is incorporated in the feedback calculation means 12 and performs an additional process on the duty calculated by the conventional method. Further, a failure determination means 14 is provided in the ECU 3. The failure determination unit 14 determines whether the electronic slot system is normal or failed, and when a failure occurs, the failure flag is set to 1 and output to the feedback calculation unit 12, and in response to this, the feedback calculation unit 12 performs a duty reduction process. The processing of unit 13 is not executed.

  When the duty reduction processing unit 13 determines that the opening degree of the electronic throttle valve 1 is steady, the duty reduction processing unit 13 stops the feedback control to stop the update of the duty, and subtracts a predetermined reduction amount from the duty immediately before the stop of the update. Output the duty. On the other hand, when the duty reduction processing unit 13 determines that the opening degree of the electronic throttle valve 1 is not steady, the duty reduction processing unit 13 continues to update the duty by the normal feedback control, and sets the duty of the currently calculated value (which dynamically changes). Output.

  The duty and the motor driving direction calculated by the feedback calculation means 12 are converted into a PWM waveform by the motor driving circuit 15, and the DC motor 6 of the electronic throttle valve 1 is driven based on the converted PWM waveform. Thereafter, as already described, this driving force becomes the angle of the butterfly 8, and this angle is read by the ECU 3 by the throttle opening sensor 10, and the next feedback calculation is performed.

  FIG. 6 is a control block diagram of the feedback calculation means 12. Whether the system is normal by the target opening 16 calculated by the target opening calculating means 11 of FIG. 5, the actual opening 17 read from the throttle opening sensor 10 of the electronic throttle valve 1, and the failure determination means 14. A failure flag 18 that is a result of determining whether or not a failure is an input to the feedback calculation means 12.

  The portion other than the duty reduction processing unit 13 in the feedback calculation unit 12 has a configuration generally provided conventionally (hereinafter referred to as a conventional portion). First, the conventional part of the feedback calculation means 12 will be described. In the conventional part, a P-term arithmetic unit 20, an I-term arithmetic unit 21, a D-term arithmetic unit 22, and a duty converter 24 are provided. In this configuration, first, the target opening 16 and the actual opening 17 are input, the difference between them (= (target opening 16) − (actual opening 17)) is calculated, and this is set as the deviation 19. Deviation 19 is used as an input to each term of PID control, which is one of feedback control, that is, deviation 19 is input to P term computing unit 20, I term computing unit 21, and D term computing unit 22, respectively. An operation is performed on each of these terms, and the sum of their outputs is taken as an operation amount 23. Specifically, for example, a predetermined value is determined by using Kp, Ki, and Kd as gain constants, the P-term calculation unit 20 calculates Kp × deviation, and the I-term calculation unit 21 calculates Σ (Ki × Deviation) is calculated, and the D term calculation unit 22 calculates Kd × (deviation at the current time minus 1 deviation before the calculation cycle), and Kp × deviation + Σ (Ki ×), which is the sum of the calculation results. Deviation) + Kd × (deviation at current time-1deviation before calculation cycle) is obtained and substituted into the manipulated variable 23. Next, the operation amount 23 is converted into a duty 25 by a calculation such as multiplying the operation amount 23 by a predetermined coefficient in the duty conversion unit 24 and transmitted to the motor drive circuit 15 where it is output as a PWM waveform. become.

  Next, the duty reduction processing unit 13 of the present invention will be described. The duty reduction processing unit 13 is provided with a steady state determination unit 26 and a stability determination unit 27. The steady state determination unit 26 is input with the deviation 19, the target opening 16, the actual opening 17, and the failure flag 18, and based on these, it is determined whether or not it is steady. If the steady state determination unit 26 determines that the state is steady, the duty of the current calculated value calculated by the duty conversion unit 24 is not substituted into the duty storage area of the RAM (hereinafter referred to as duty 25), and The previous value is retained. On the other hand, when it is determined that the steady state determination unit 26 is not steady, normal feedback control is performed, that is, the duty 25 is updated with the current calculation value calculated this time by the duty conversion unit 24.

  The steady state determination unit 26 determines that (a) the absolute difference between the previous value and the current value of the target opening 16 (Δ target opening) is smaller than a preset first constant K1, and (b) the actual opening. The absolute difference (Δactual opening) between the previous value of 17 and the current value is smaller than a preset second constant K2, and (c) the absolute value of the deviation 19 is smaller than a preset third constant K3. (D) When the failure flag 18 is reset, that is, when all of the four conditions (a) to (d) satisfying that the electronic throttle system is not broken are determined as steady, otherwise Judged not to exist.

  The result of the steady state determination unit 26 is input to the stability determination unit 27. Here, if the state is constant for a predetermined time, it is determined that the state is stable, and the switch is switched so that the predetermined reduction amount 28 is subtracted from the duty 25. Otherwise, it is determined that the operation is not stable, and the duty 25 is output to the motor drive circuit 15 as it is.

  The operation of the duty reduction processing unit 13 will be described with reference to the flowchart of FIG. These programs and constants are stored in the ROM in the microcomputer, as with the feedback calculation means 12 to which the present invention is applied, and are executed at the same cycle as the feedback calculation means 12.

  In step S1, the duty reduction processing unit 13 first calculates a Δ target opening (= | (the previous calculation) that is an absolute difference between the target opening 16 ′ at the previous calculation and the target opening 16 at the current calculation. Target opening 16 ′) − (Target opening 16 at the time of current calculation) |) is calculated and compared with the first constant K1. If the Δ target opening is smaller than the first constant K1, a Yes determination is made and the process proceeds to step S2. On the other hand, if the Δ target opening is equal to or greater than the first constant K1, the determination is No and the process proceeds to step S6. The first constant K1 is set to, for example, control resolution (5V / 4096) × 2.

  Next, in step S2, Δ actual opening (= | (actual opening 17 ′ at the previous calculation)), which is an absolute difference between the actual opening 17 ′ at the previous calculation and the actual opening 17 at the current calculation. -(Actual opening 17 at the time of the current calculation) |) is calculated and compared with the second constant K2. If the Δ actual opening is smaller than the second constant K2, a Yes determination is made and the process proceeds to step S3. On the other hand, if the Δ actual opening is equal to or greater than the second constant K2, the determination is No and the process proceeds to step S6. The second constant K2 is set to, for example, control resolution (5V / 4096) × 2.

  Next, in step S3, the absolute value of the deviation (= | (target opening 16 at the current calculation) − (−) is the absolute difference between the target opening 16 at the current calculation and the actual opening 17 at the current calculation. The actual opening 17) |) at the time of calculation this time is calculated and compared with the third constant K3. If the absolute value of the deviation is smaller than the third constant K3, a Yes determination is made and the process proceeds to step S4. On the other hand, if the absolute value of the deviation is greater than or equal to the third constant K3, the determination is No and the process proceeds to step S6. The third constant K3 is set to, for example, control resolution (5V / 4096) × 1.

  Further, in step S4, the failure flag 18 is read, and if the system is normal, a Yes determination is made and the process proceeds to step S5. If the system is abnormal, the determination is No and the process proceeds to step S6.

  In step S5, a counter c1 that counts the time during which the pre-processing is determined to be steady, that is, the time during which all the determinations in steps S1 to S4 are Yes, is subtracted. The subtraction of the counter c1 indicates that 1 is subtracted if the value of the counter c1 stored in the RAM is 1 or more, and no processing is performed otherwise. Thereafter, the process proceeds to step S7.

  In step S6, a fifth constant K5 set in advance as an initial value is substituted into the counter c1. The fifth constant K5 is set to a value corresponding to 100 ms, for example. Next, the process proceeds to step S7.

  Next, in step S7, it is determined whether or not the counter c1 is zero. If it is 0, it becomes Yes determination (determined that it is steady), and progresses to step S8. On the other hand, if the counter c1 is 1 or more, it is No determination (determination is not steady), and the process proceeds to step S10.

  In step S8, the feedback control is stopped as a routine process. That is, the duty at the time of the current calculation is not substituted for the duty 25, the value of the duty 25 remains the previous value, and the integration of the I term calculation unit 21 is stopped. Next, in step S9, the counter c2 is decremented by 1, and the process proceeds to step S12.

  In step S10, the feedback control is continued as a normal process other than the steady state. That is, the duty at the time of the current calculation is substituted into the duty 25 as in the conventional manner, and the integration of the I term calculation unit 21 is performed as in the conventional manner. Next, in step S11, a sixth constant K6 set in advance as an initial value is substituted into the counter c2, and the process proceeds to step S12. The sixth constant K6 is set to a value corresponding to 20 ms, for example.

  In step S12, it is determined whether the counter c2 is zero. If it is 0, it becomes Yes determination (determined that it is stable), and it progresses to step S13. If it is 1 or more, it will be No determination (determination is not stable) and it will progress to step S18.

  In step S13, it is determined whether the counter c3 is 0 or not. If it is 0, it becomes Yes determination (predetermined repetition time passes), and it progresses to step S14. If it is 1 or more, the determination is No (the predetermined repetition time has not elapsed), and the process proceeds to step S20.

  In step S14, it is determined whether or not the counter c4 is greater than zero. If it is greater than 0 (1 or more), a Yes determination is made (reach a predetermined number of repetitions), and the process proceeds to step S15. If it is 0, No determination is made (the predetermined number of repetitions has not been reached), the process proceeds to END, and all the processes are completed.

  In step S15, a value obtained by subtracting a preset seventh constant K7 as the reduction amount 28 from the value stored in the duty 25 is substituted into the duty 25 as a new duty.

  The seventh constant K7 is set in consideration of the following conditions. First, the minimum value of the hysteresis width in consideration of variations such as temperature and individual differences of the electronic throttle valve 1 to be controlled is determined in advance from the electronic throttle valve design values and characteristic values. The total reduction amount, which is the product of the number of repetitions K9 and the seventh constant K7 described in step S19, is not only smaller than the minimum value of the hysteresis width, but also indicates that the duty after subtraction goes out of the hysteresis width. In order to prevent this, it is recommended to set the hysteresis width to about 1/5 to 1/10 of the minimum value. For example, if a value of about 1/6 of the minimum value of the hysteresis width is a duty of 1%, 1% / K9 is set to K7.

  In the next step S16, the initial value K8 is substituted for the counter c3. In the next step S17, 1 is subtracted from the counter c4, and the process proceeds to END, and all the processes are completed. This constant K8 corresponds to the predetermined repetition time in step S13, and is set to a value corresponding to 50 ms, for example.

  On the other hand, if the determination is No in step S12, 0 is substituted for the counter c3 in step S18, and the initial value K9 is substituted for the counter c4 in the next step S19, and the process proceeds to END, and all the processes are completed. This constant K9 corresponds to the predetermined number of repetitions in step S14, and is set to 2 times, for example.

  If the determination is No in step S13, the counter c3 is decremented by 1 in step S20, the process proceeds to END, and all the processes are completed.

  Further, when the microcomputer in the ECU 3 is turned on, it is necessary to initialize the counter RAM related to the duty reduction processing unit 13 of the present invention. In this case, step S21 shown in FIG. 8 is executed. That is, the initial value K5 is assigned to the counter c1, the initial value K6 is assigned to the counter c2, 0 is assigned to the counter c3, and the initial value K9 is assigned to the counter c4, and the process ends. The program of FIG. 8 is also stored and executed in the ROM in the microcomputer as in FIG.

  The operation of FIG. 7 will be described with reference to the timing chart of FIG. Here, the duty C% is used in the meaning of FIG. 1, and the constant K9 is set to 2 as in the above example.

  When the target opening is constant at the opening A and the actual opening is approaching the opening A (Δtarget opening <K1), the duty is dynamically changed by feedback control and is higher than C% Value. At this time, the counter c1 is K5, the counter c2 is K6, the counter c3 is 0, and the counter c4 is K9.

  At time T1, it is assumed that all the conditions that Δactual opening degree <K2, | deviation | <K3, and the system is normal based on the failure flag are satisfied. Then, the counter c1 starts subtraction and eventually becomes 0, and then the counter c2 starts subtraction and eventually becomes 0. This time when it becomes 0 is assumed to be T2.

  At time T2, the duty is a value obtained by subtracting K7 from the previous value, K8 is substituted for the counter c3, and one is subtracted from the counter c4. The counter c3 starts subtraction after the next calculation cycle and eventually becomes 0. This time when it becomes 0 is set as T3.

  At time T3, the duty is a value obtained by further subtracting K7 from the previous value, K8 is substituted for the counter c3, and one more counter c4 is subtracted to 0. The counter c3 starts subtraction after the next calculation cycle and eventually becomes 0. However, since the counter c4 is 0, the duty is not subtracted any more.

  In this way, the duty is reduced, and on the other hand, since it is C% or more, the actual opening does not change from the opening A. That is, only the duty is reduced, and the problem of Patent Document 1 can be solved.

  In such a case, for example, when the throttle opening changes due to the vibration of the electronic throttle valve, or when noise is added to the signal of the throttle opening sensor, the actual opening changes and Δ actual opening occurs. Consider a case where the degree ≧ K2 or | deviation | ≧ K3. This time is T4.

  At time T4, since it is determined not to be steady, the counter c1 is set to K5, the counter c2 is set to K6, the counter c3 is set to 0, and the counter c4 is set to K9, and the feedback control is resumed. For this reason, the duty changes dynamically, and the actual opening degree is converged to the opening degree A. This time is T5. At this time, the converged duty converges to one of the sections B in FIG. 1, but does not necessarily coincide with the duty at time T1.

  At time T5, Δ actual opening degree <K2, | deviation | <K3, and the counter c1 starts subtraction again and eventually becomes 0, and then the counter c2 starts subtraction and eventually becomes 0. This time is T6.

  At time T6, as with time T2, the duty is subtracted from the previous value by K7, K8 is substituted for the counter c3, and one counter c4 is subtracted. The counter c3 starts subtraction after the next calculation cycle and eventually becomes 0. This time is T7.

  At time T7, similarly to time T3, the duty is a value obtained by further subtracting K7 from the previous value, K8 is substituted for the counter c3, and one more counter c4 is subtracted to 0. The counter c3 starts subtraction after the next calculation cycle and eventually becomes 0. However, since the counter c4 is 0, the duty is not subtracted any more. The duty at this time does not necessarily coincide with the duty at time T3, and as shown in FIG. 9, the duty may be larger than the duty at time T3. However, compared with the case where the present invention is not applied, the duty of K7 × K9 minutes (for example, 1%) can be reduced, and the actual opening degree is not changed. That is, the problem of Patent Document 1 can be solved.

  For example, if the ON resistance of the motor drive circuit is 0.3Ω, the harness resistance between the ECU and the motor is 0.17Ω, and the coil resistance of the motor is 1.2Ω, the total resistance is 1.67Ω ( = 0.3 (Ω) +0.17 (Ω) +1.2 (Ω)), and assuming that the battery voltage is 14 V, the current value corresponding to 100% duty is about 8.38 A (≈14 (V) ÷ 1 .67 (Ω)). If the total duty reduction amount (K9 × K7) is 1%, it corresponds to 0.0838A, and if the minimum value of the hysteresis width is 0.5A, this corresponds to about 1/6 reduction. The amount of reduction is appropriate. The amount of power consumption reduction due to this duty reduction amount of 1% is about 1.17 W of 14 (V) × 0.0838 (A). The technique of Patent Document 1 cannot be applied to control of an electronic throttle valve having a very narrow allowable fluctuation range of the opening, and cannot reduce power consumption. However, the present invention does not affect the opening, It is possible to reduce the power consumption of about 1 W including the idle region where the frequency is high.

  In addition to when the failure flag indicating the failure of the electronic throttle system is set, for example, when the process for learning the fully closed opening or fully opened opening of the electronic throttle valve is executed, the present invention This process is not performed.

  As described above, the ECU 3 that is the electronic throttle valve control device of the present invention is the target opening degree calculation means 11 that determines the target opening degree 16 of the electronic throttle valve 1 and the actual opening degree of the electronic throttle valve 1. The actual throttle opening 17 and the target opening 16 are input, the feedback calculation means 12 that performs feedback control so that the actual opening 17 coincides with the target opening 16, and the electronic throttle according to the duty 25 output by the feedback calculation means 12 And a motor drive circuit 15 for driving the valve 1, and when the feedback calculation means 12 determines that the opening degree of the electronic throttle valve 1 is steady, it stops updating the duty 25, and starts from the duty immediately before the stop of the update. A duty reduction processing unit 13 for outputting the duty obtained by reducing the reduction amount 28 to the motor drive circuit 15; Therefore, when the opening degree is steady, the drive current can be reduced by subtracting, as the reduction amount 28, a predetermined value that falls within the drive hysteresis range, that is, a predetermined value smaller than the hysteresis width, from the duty. Therefore, the duty can be reduced over the entire opening including the idling range without changing the opening, and the power consumption can be reduced, that is, the fuel consumption can be improved without affecting the engine speed. There is an effect that can be.

  In the above description, an example in which the constant K6 is set to a predetermined value is described. However, the present invention is not limited to this case, and the constant K6 may be set to 0. Step S7) in FIG. 7 and the establishment of the stability determination (step S12 in FIG. 7) are simultaneous.

  In the above description, an example in which the constant K9 is set to 2 has been described. However, the present invention is not limited to this, and the constant K9 is set to 1 to reduce the duty by the constant K7 (step S15 in FIG. 7). It may be only once.

  The constants K1 to K3 and K5 to K9 described with reference to FIGS. 7 and 8 were fixed values, but the values changed according to various engine control sensors 2, for example, water temperature, battery voltage, and opening position. As described above, the values of the constants K1 to K3, K5 to K9 can be used as map data.

  The feedback control can be similarly applied to other feedback control such as differential preceding PID control and PI control in addition to the above PID control.

  Further, the present invention is not limited to the electronic throttle system of the internal combustion engine, but is to be controlled such as other devices used for controlling the internal combustion engine (for example, variable valve device, EGR device, etc.) and various devices used other than the internal combustion engine. This is a system that controls the operation amount and duty so that the control amount matches the target value, and can be widely applied to systems having hysteresis with respect to the operation amount and duty.

  1 electronic throttle valve, 2 sensors for engine control, 3 engine control unit (ECU), 4 battery, 5 accelerator opening sensor, 6 DC motor, 7 gear, 8 butterfly, 9 spring, 10 throttle opening sensor, 12 feedback Calculation means, 13 Duty reduction processing section, 14 Failure determination means, 15 Motor drive circuit, 16 Target opening, 17 Actual opening, 18 Failure flag, 19 Deviation, 20 P term calculation section, 21 I term calculation section, 22 D Term calculation unit, 23 operation amount, 24 duty conversion unit, 25 duty, 26 steady state determination unit, 27 stability determination unit, 28 reduction amount.

Claims (1)

An electronic throttle valve controller for controlling the electronic throttle valve, connected to an electronic throttle valve for adjusting an intake air amount of an internal combustion engine,
Target opening degree calculation means for determining a target opening degree of the electronic throttle valve based on values from various sensors for detecting the state of the internal combustion engine;
A feedback calculation means for inputting an actual opening that is an actual opening of the electronic throttle valve and the target opening, and performing feedback control so that the actual opening matches the target opening;
A motor drive circuit for driving the electronic throttle valve according to the duty output by the feedback calculation means,
The feedback calculation means includes
When it is determined that the opening of the electronic throttle valve is steady, the duty update by the feedback control is stopped, and a value obtained by subtracting a predetermined amount smaller than the drive hysteresis width from the duty value immediately before the stop of the update is obtained. A duty reduction processing unit that outputs to the motor drive circuit as the duty;
When the feedback calculation means determines that the opening of the electronic throttle valve is not steady, updates the duty by the normal feedback control, and determines that the opening of the electronic throttle valve is steady In the electronic throttle valve control apparatus, the duty reduction processing unit performs processing.

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