JP2017072057A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device capable of improving control accuracy of a throttle valve.SOLUTION: A control device 30: is applied to an internal combustion engine 10 which comprises an actuator 15 to open and close a throttle valve 13 and a sensor 14 to detect an actual opening of the throttle valve 13; and controls the actuator 15 so that the actual opening becomes equal to a target opening. The control device also has: a control amount acquisition section which acquires a control amount of the actuator 15 on the basis of a difference between the actual opening and the target opening; a learning section which acquires a value, for correcting the control amount on the basis of responsiveness of the throttle valve 13 when the same is opened and closed, as a learning value; and a control section which corrects the control amount with the learning value and controls the actuator 15 with the corrected control amount.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device that controls the opening of a throttle valve.

  Conventionally, a throttle valve control device using a DC motor as a drive source has been considered, and a proportional term (P control component), an integral term (I control component) of a deviation between the target opening and the actual opening of the throttle valve, The opening degree of the throttle valve is controlled by feedback control based on PID control using a differential term (D control). However, when the opening degree of the throttle valve is controlled only by the PID control, the torque characteristics due to the friction of the sliding portion (around the shaft) of the throttle valve affects the open / close response, leading to a decrease in control accuracy.

  As a means for solving the decrease in the control accuracy of the throttle valve, there is a control device described in Patent Document 1. In the control device described in Patent Document 1, control accuracy is improved by generating a motor torque obtained by adding a correction amount corresponding to a torque characteristic to a control amount by PID control.

Japanese Patent Laid-Open No. 2-125937

  The frictional force generated in the sliding portion of the throttle valve changes due to individual differences, aging, and the like. Therefore, there is a divergence between the friction force assumed at the time of manufacture and the actual friction force, and if the control amount is corrected using a predetermined correction amount, the throttle valve opening / closing control is delayed. As a result, the control accuracy decreases.

  The present invention has been made to solve the above-described problems, and a main object thereof is to provide a control device capable of improving the control accuracy of a throttle valve.

  The present invention is applied to an internal combustion engine including an actuator that opens and closes a throttle valve and a throttle opening sensor that detects an actual opening of the throttle valve, and the actuator is used to match the actual opening with a target opening. A control amount obtaining unit for obtaining a control amount of the actuator based on a difference between the actual opening and the target opening, and opening and closing the throttle valve, and responsiveness at the time of opening and closing The throttle valve is opened and closed, a learning unit that acquires a value for correcting the control amount based on responsiveness at the time of opening and closing as a learning value, and the control amount is corrected by the learning value and corrected A control unit that controls the actuator according to a control amount.

  If the responsiveness at the time of opening and closing the throttle valve is acquired, a learning value corresponding to the torque characteristic at the time of acquisition can be obtained. Then, if the control value of the throttle valve is corrected using the learned value, and the throttle valve opening / closing control is performed using the corrected control amount, control according to the frictional force or the like at the time of acquisition of the learned value can be performed. it can. Therefore, even if there is an individual difference in the throttle valve or aging deterioration or the like occurs, it is possible to perform control according to them, and to improve the control accuracy of the throttle valve.

It is a schematic block diagram of an engine control system. It is a control block diagram which shows control of a throttle valve. It is a flowchart which shows a series of processes which ECU performs.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. In this embodiment, an engine control system is constructed for an in-vehicle gasoline engine. In the control system, control of fuel injection amount, control of ignition timing, and the like are performed with an electronic control unit (ECU) as a center.

  FIG. 1 is an overall schematic configuration diagram of an engine control system in the present embodiment. An intake pipe 11 of the engine 10 is provided with an air flow meter 12 for detecting an intake air amount, and a throttle valve 13 is provided on the downstream side of the air flow meter 12. The opening degree (actual opening degree) of the throttle valve 13 is detected by a throttle sensor 14, and the opening degree of the throttle valve 13 is adjusted by a motor 15 that is an actuator.

  An intake valve 16 and an exhaust valve 17 are provided at an intake port and an exhaust port of the engine 10, respectively. Then, air is introduced into the combustion chamber 18 by the opening operation of the intake valve 16. The engine 10 is provided with an injector 19 that supplies fuel to the combustion chamber 18. The fuel supplied from the injector 19 is mixed with air in the combustion chamber 18 to become an air-fuel mixture.

  A spark plug 20 is attached to the cylinder head of the engine 10. A high voltage is applied to the spark plug 20 at a desired ignition timing through an ignition device (not shown) including an ignition coil. By applying this high voltage, a spark discharge is generated between the opposing electrodes of the spark plug 20, and the air-fuel mixture in the combustion chamber 18 is ignited and used for combustion. The exhaust gas after combustion is discharged to the exhaust pipe by opening the exhaust valve 17. Further, a water temperature sensor 21 for detecting the temperature of the cooling water is provided in the cooling water passage of the cylinder block of the engine 10.

  The ECU 30, which is a control device, is configured mainly with a microcomputer including a CPU, a ROM, a RAM, and the like, and executes various control programs stored in the ROM, so that the engine 10 can be operated according to the engine operating state each time. Implement various controls. The ECU 30 calculates the fuel injection amount, ignition timing, and the like based on various detection signals that are input as needed, and controls the drive of the injector 19 and the ignition device. Moreover, ECU30 acquires the temperature of the cooling water from the water temperature sensor 21, and acquires the voltage of the battery 31 which supplies electric power to various apparatuses.

  In addition, the ECU 30 acquires an accelerator operation amount by the driver from an accelerator sensor 22 provided on the accelerator pedal. Then, an opening degree (target opening degree) of the throttle valve 13 is obtained based on the accelerator operation amount, and a control signal is transmitted to the motor 15 so that the actual opening degree of the throttle valve 13 becomes the target opening degree. The opening degree of 13 is controlled.

  The control of the throttle valve 13 will be described with reference to FIG. In performing the control shown in FIG. 2, the ECU 30 functions as a control amount acquisition unit. First, the phase advance correction unit 40 adds a value (phase advance correction amount) obtained by Z-converting the actual opening to the actual opening of the throttle valve 13. Then, the target deviation is calculated by subtracting the opening obtained by adding the past change to the actual opening of the throttle valve 13 from the target opening. By this calculation, a control parameter corresponding to general differential control is included in the target deviation. That is, the phase advance correction unit 40 performs differential control.

  The proportional correction unit 41 multiplies the deviation between the actual opening and the target opening by the P term gain to obtain the P term control amount. The integral correction unit 42 calculates a control amount so as to fill a steady deviation between the actual opening and the target opening of the throttle valve 13. Specifically, the deviation between the actual opening and the target opening is multiplied by the I term gain, and the integral term is added to the value obtained by Z-converting the value. Then, the added value is fed back to a value obtained by multiplying the target deviation by the I term gain to obtain an I term control amount. Therefore, the I term control amount is calculated according to the cumulative value of the target deviation.

  The P term control amount obtained by the proportional correction unit 41 and the I term control amount obtained by the integral correction unit 42 are added to obtain a PID control amount. When the PID control amount is obtained in this way, the PID control amount is converted into a duty ratio indicating the energization period of the motor 15 that drives the throttle valve 13, and the ECU 30 functions as a control unit to energize the motor 15. .

  By the way, when the opening degree of the throttle valve 13 (throttle opening degree) is controlled, torque that inhibits the opening / closing operation of the throttle valve 13 is generated due to the frictional resistance of the sliding portion of the throttle valve 13 or the like. Therefore, in the present embodiment, an offset amount of the duty ratio that corrects the delay in the opening / closing control due to the torque is provided. Then, the offset amount of the duty ratio is added to the PID control amount. At this time, since this torque changes due to individual differences of the throttle, changes over time, etc., the ECU 30 functions as a learning unit, and performs learning (torque characteristic learning) for updating the response when the throttle is opened and closed. It is said.

  This torque characteristic learning is performed by step response, and is performed by transmitting a drive signal to the motor 15 and measuring the time until the throttle opening reaches the target opening. In this torque characteristic learning, the duty ratio offset amount, which is the learning value acquired and stored in the previous torque characteristic learning, is added to the PID control amount as the previous value. Then, the measured response time is compared with a predetermined value, and it is determined whether or not the response time is larger than the predetermined value.

  At this time, since it is desirable that the response time is constant regardless of individual differences, aging deterioration, and the like, the predetermined value is set in advance and stored in the memory. If the measured response time is larger than the predetermined value, it means that it takes time to reach the target opening if the throttle control is performed with the previous value, so that the throttle opening reaches the target value earlier. Therefore, the duty offset amount is increased from the previous value and stored. On the other hand, if the measured time is smaller than the predetermined value, it means that if the throttle control is performed with the previous value, the target opening will be reached early, so the throttle opening will reach the target value later. In order to do this, the duty offset amount is reduced from the previous value and stored.

  When the throttle opening is changed from fully closed (0 °) to fully open (90 °) in performing torque characteristic learning in this way, the response time of the step response becomes long and it takes time to learn the torque characteristic. Become. In addition, since the frictional force and the like may change depending on the opening range, for example, when responsiveness is obtained when changing from 0 ° to 90 °, the throttle opening is slightly changed. Control accuracy may not be guaranteed.

  Therefore, in the present embodiment, when performing the torque characteristic learning, the throttle opening range (opening range) is selected prior to performing the step response, and the step response is performed within the selected opening range. This opening range is set at intervals of 10 °, for example. That is, if 20 ° to 30 ° is selected as the opening range, the throttle opening is set to 20 ° before performing the step response, and the motor 15 is further driven from this state until the throttle opening reaches 30 °. Measure the time. At this time, as described above, since it is desirable that the response time is constant regardless of individual differences, aging deterioration, etc., a predetermined value to be compared with the response time is set in advance for each opening range, and the selected opening time is It is read from the memory according to the degree range and used.

  Further, the frictional force generated in the sliding portion may differ between the opening operation and the closing operation of the throttle valve 13. Therefore, when selecting the opening range, it is also selected whether the response of the opening operation is obtained or the response of the closing operation is obtained. After performing the opening operation, the closing operation may be performed in the same opening range.

  In addition, in performing torque characteristic learning, the responsiveness of each opening range may be obtained in order, or the torque for an opening range having a high use frequency, for example, an opening range of about 0 ° to 40 °. It is good also as what increases the frequency | count of performing characteristic learning.

  Next, a series of processes executed by the ECU 30 according to the present embodiment will be described with reference to the flowchart of FIG. The flowchart shown in FIG. 3 is repeatedly executed every predetermined control cycle.

  First, it is determined whether the engine 10 has already been warmed up (S101). This process is a process performed to perform torque characteristic learning when the temperature in the vicinity of the throttle valve is the same as that during normal use of the engine 10, and whether or not the water temperature acquired from the water temperature sensor 21 is greater than a predetermined value. This is done by determining whether or not. If the engine 10 has already been warmed up (S101: YES), it is determined whether or not the ignition switch is OFF (S102). This is because if the ignition switch is not OFF and the engine 10 is being driven, if torque characteristic learning is performed, control of the engine 10 will be hindered. If the ignition switch is OFF (S102: YES), it is determined whether or not the voltage of the battery 31 is equal to or higher than a predetermined value (S103). This is because when the voltage of the battery 31 is smaller than a predetermined value, the torque of the motor 15 is small, and it takes more time in the step response, and correct torque characteristics cannot be obtained.

  On the other hand, at least one of the case where the engine 10 is not warmed up (S101: NO), the case where the ignition switch is not OFF (S102: NO), and the case where the voltage is smaller than a predetermined value (S103: NO). If the condition is satisfied, it is determined that the torque characteristic learning condition is not satisfied, and the series of processing ends.

  If the torque characteristic learning start condition is satisfied in this way, the opening range of the throttle valve 13 for executing the torque characteristic learning is selected (S104). Subsequently, a step response is performed in the selected throttle opening range, and the response time of the throttle opening when the step response is executed is measured (S105). If the response time of the step response is obtained, it is determined whether the response time is a predetermined value or more (S106). At this time, the predetermined value to be compared with the response time is set according to the selected opening range as described above. If the response time is equal to or greater than a predetermined value (S106: YES), it means that the friction of the sliding portion of the throttle valve 13 is large and a response delay occurs when the throttle valve 13 is driven. For this reason, the learning value is increased (S107), and the series of processing ends. On the other hand, if the response time is smaller than the predetermined value (S106: NO), it means that the friction of the sliding portion of the throttle valve 13 is small and the response is quick when the throttle valve 13 is driven. Therefore, the learning value is decreased (S108), and a series of processing is terminated.

  With the above configuration, the control device according to the present embodiment has the following effects.

  The frictional force generated at the sliding portion of the throttle valve 13 changes due to individual differences and aging deterioration. In the present embodiment, the torque characteristic learning is used to correct the PID control amount using the acquired learning value, and the throttle valve 13 is controlled using the corrected PID control amount. The corresponding control can be performed.

  The frictional force generated at the sliding portion of the throttle valve 13 is not constant because it has a correlation with the opening range, and it is difficult to give an appropriate correction amount in advance. In the present embodiment, since the opening range of the throttle valve 13 is selected when performing the torque characteristic learning, a correction amount corresponding to the throttle opening can be used when performing the throttle opening / closing control. Therefore, the control accuracy of the throttle control can be improved.

  The frictional force generated at the sliding portion of the throttle valve 13 gradually changes from the state at the time of manufacture due to deterioration over time. Therefore, when performing the torque characteristic learning, if the correction amount from the manufacturing state is to be obtained, in addition to whether the learning value is a positive value or a negative value, the correction amount is also There is a need to calculate. In this embodiment, when performing torque characteristic learning, the response time is obtained using the previous value of the learned value, and the increase / decrease from the previous value is performed depending on whether the response time is greater than a predetermined value. Therefore, it is not necessary to calculate the increase / decrease amount, and the processing can be reduced.

<Modification>
In the embodiment, the PID control is performed using the target opening and the actual opening of the throttle valve 13, but feedback control other than PID control may be performed. Even in this case, similarly to the embodiment, a process of adding the correction amount based on the learning value to the control amount obtained as a result of the feedback control is performed.

  In the embodiment, the duty ratio offset amount is used as a learning value, and the learning value is used to correct the duty ratio as a control amount. However, the learning value is not limited to the duty ratio offset amount.

  In the embodiment, when the torque characteristic learning is performed, the learning value is increased if the response time is equal to or greater than a predetermined value, and the learning value is decreased if the response time is less than the predetermined value. In this regard, a first predetermined value and a second predetermined value smaller than the first predetermined value are provided as predetermined values, and if the response time is equal to or greater than the first predetermined value, the learning value is increased, and the response time is less than the second predetermined value. If so, the learning value may be decreased. By doing so, it is possible to suppress a situation in which the learning value frequently changes when the difference between the response time and the predetermined value is small.

  In the embodiment, it is adopted that the ignition switch is OFF as a condition for performing torque characteristic learning. In this regard, if the vehicle has an idling stop function, it may be a condition that the idling stop is not being performed and the ignition switch is OFF. This is because it is necessary to wait for the restart of the internal combustion engine during idling stop, and if the throttle opening learning process is performed, the throttle opening learning process is not completed when the restart condition is satisfied. This is because there is a risk of delay in restart.

  In the embodiment, the offset amount of the duty ratio obtained as the learning value is added to the PID control amount. However, a coefficient that multiplies the PID control amount as the learning value may be obtained.

  DESCRIPTION OF SYMBOLS 13 ... Throttle valve, 14 ... Throttle sensor, 15 ... Motor, 30 ... ECU, 31 ... Battery.

Claims (5)

The present invention is applied to an internal combustion engine (10) that includes an actuator (15) that opens and closes a throttle valve (13) and a sensor (14) that detects the actual opening of the throttle valve. A control device (30) for controlling the actuator,
Based on the difference between the actual opening and the target opening, a control amount acquisition unit for obtaining a control amount of the actuator;
A learning unit that opens and closes the throttle valve, and acquires a value for correcting the control amount based on responsiveness at the time of opening and closing as a learning value;
And a control unit that corrects the control amount with the learned value and controls the actuator with the corrected control amount. The learning unit obtains the learning value, obtains a response time using the control amount corrected by the learning value acquired previously,
If the response time is less than a predetermined value, reduce the learning value,
The control device according to claim 1, wherein the learning value is increased when the response time is greater than a predetermined value.   The learning unit sets an opening range between the throttle fully opened and fully closed to obtain the learning value, and performs at least one of the throttle opening operation and the closing operation within the set range. The control device according to claim 1, wherein the learning value is obtained by performing.   The control device according to claim 1, wherein the learning unit acquires the learning value while the internal combustion engine is stopped.   The control device according to any one of claims 1 to 4, wherein the learning unit acquires the learning value when a voltage of a battery (31) that supplies electric power to the actuator is greater than a predetermined value.

Images