JPH0697009B2 - Engine controller - Google Patents

Description

The present invention relates to a control device for an engine (internal combustion engine).

Conventionally, by detecting the opening of the throttle valve (throttle opening) with a throttle sensor consisting of a potentiometer, the fuel supply state to the engine and the engine idle state are controlled based on this throttle opening information and engine speed information. It is suggested to do so.

By the way, the engine control based on the throttle opening information has an advantage that the response is good, but on the other hand, there is a problem that it is difficult to achieve accurate control due to an error generated when the throttle sensor is attached.

The present invention is intended to solve such a problem, and while taking advantage of the advantage of the engine control based on the throttle opening information that the response is good, the control reliability is deteriorated due to the setting (installation) error of the throttle sensor. In order to prevent the above, that is, to ensure the accuracy of the throttle opening sensor, an attempt is made to calibrate the throttle opening sensor output by using the air flow sensor output that is correlated with the throttle opening. The relationship between the quantity and the throttle opening is relatively one-to-one without being influenced by the engine speed.
It is an object of the present invention to provide an engine control device capable of enhancing at least one of calibration accuracy and easiness of calibration by performing the calibration in a low load operation range of the engine corresponding to the above.

For this reason, the engine control device of the present invention includes an air flow sensor for detecting the amount of intake air in the intake passage of the engine, a throttle sensor for detecting the opening degree of the throttle valve interposed in the intake passage, and an engine controlled part. In comparison, the calibrating throttle valve opening estimated from the intake air amount detected by the air flow sensor and the actual throttle opening detected by the throttle sensor when the engine is in a low load operation state are compared. However, correction means for correcting the value of the opening degree of the throttle valve according to the comparison result is provided, and an engine control signal based on the opening degree information of the throttle valve corrected by the correction means is sent to the engine controlled. It is characterized in that a control means for outputting to the unit is provided.

An engine control device as an embodiment of the present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a schematic diagram showing an example of the indicator, and FIGS. 3 and 4 are flow charts for explaining the operation.

As shown in FIG. 1, an internal combustion engine E (hereinafter simply referred to as “engine E”) such as a gasoline engine mounted on a vehicle according to the present embodiment includes a turbocharger 3. The turbocharger 3 includes a turbine 4 installed in the exhaust passage 2 of the engine E and a compressor 5 installed in the intake passage 1 of the engine E and rotationally driven by the turbine 4.

A bypass passage that bypasses the turbine portion of the exhaust passage 2 is connected to the exhaust passage 2, and a waste gate valve 6 that opens and closes the bypass passage is provided.
The waste gate valve 6 is designed to be opened and closed by a two-diaphragm pressure response device 7, but pressure is applied by an electromagnetic switching valve 15 (this valve 15 has a return spring (not shown) for the valve body). By selectively supplying the atmospheric pressure and the supercharging pressure to one pressure chamber of the response device 7, the opening timing of the wastegate valve 6 and the like can be adjusted and at least two kinds of supercharging pressure characteristics can be realized. There is.

Further, in the intake passage 1 of the engine E, in order from the upstream side (air cleaner side), the air flow sensor 16, the compressor 5 of the turbocharger 3, the intercooler 8, and the electromagnetic fuel injection valves 9 and 10 (engine controlled parts) These valves 9,10
Has a different injection capacity) and a throttle valve 11, and the exhaust passage 2 of the engine E is provided with a turbine of the turbocharger 3 in order from the upstream side (engine combustion chamber side) thereof.
4, a catalytic converter 31 and a muffler (not shown) are provided.

The air flow sensor 16 detects the number of Karman vortices generated by the columnar body arranged in the intake passage 1 by the ultrasonic modulator or the change in the resistance value, thereby inhaling the intake passage 1. The amount of air is detected, and the digital output from the air flow sensor 16 is input to the controller 14. The digital output from the air flow sensor 16 is the controller 14
After being subjected to, for example, a 1/2 frequency divider, it is subjected to a process of correcting the opening degree (throttle opening degree) of the throttle valve 11 described later.

Further, it is generally said that the air flow sensor 16 malfunctions due to intake pulsation or the like in a low speed and high load state of the engine E, but in this embodiment, an intercooler 8 is provided on the downstream side of the air flow sensor 16 to appropriately adjust the dimensions of the air cleaner portion and the like. By doing so, since the above-mentioned intake pulsation hardly occurs, it is considered that the measurement reliability or accuracy of the air flow sensor 16 is sufficiently high.

Further, a rotation speed sensor 17 is provided, and this rotation speed sensor 17 detects the engine rotation speed by detecting engine rotation speed information from the primary minus terminal of the ignition coil 28, for example.

Furthermore, a throttle sensor 20 that detects the throttle opening
Is provided, and a potentiometer is used as the throttle sensor 20.

Further, an intake air temperature sensor 18 for detecting the intake air temperature, an atmospheric pressure sensor 19 for detecting the atmospheric pressure are provided, a water temperature sensor 21 for detecting the engine cooling water temperature, and an O ₂ sensor for detecting the oxygen concentration in the exhaust gas. 22, a knock sensor 23 for detecting an engine knock state, a vehicle speed sensor 24 for detecting a vehicle speed, an idle switch 25 for detecting an engine idle state, a cranking switch 26 for detecting an engine cranking time, a crank by a photoelectric conversion means with a distributor 29. A crank angle sensor 27 for detecting an angle is provided, and signals from these sensors and switches are input to the controller 14.

The intake air temperature sensor 18, atmospheric pressure sensor 19, water temperature sensor 21,
Since the detection signals of the throttle sensor 20, the O ₂ sensor 22, the knock sensor 23 and the like are analog signals, they are input to the controller 14 via the A / D converter.

Further, the atmospheric pressure sensor 19 may be incorporated in the controller 14.

Further, an actuator 12 such as a DC motor is provided as an engine controlled part for rotating the throttle valve 11 via a rod or the like to control the engine speed during idling.

Further, an ignition coil 28 is provided, and the ignition coil 28 is configured such that a primary current is interrupted by a power transistor 30 as a switching transistor.

Further, a display meter 13 is provided in the vehicle compartment.

The display 13 includes, for example, a needle 13 as shown in FIG.
1d drive unit controls signal (current) from controller 14
In response to this, the needle 131d is rotated, whereby the negative pressure region 131
a, supercharging area 131b, supercharging area 131c (this supercharging area 131c
Has a needle-type display section 13a for indicating either of the red zones) or a segment-type display section 13b in which light-emitting diodes (LEDs) are arranged in rows and these LEDs blink as appropriate. Things can be considered.

When the display meter 13 has the needle type display unit 13a, a control signal is supplied from the controller 14 to the display meter 13 via the fV converter and the current drive circuit.

By the way, the controller 14 is configured to include a CPU, a memory (including a map), and an appropriate input / output interface. Specifically, the controller 14 is specifically provided when the engine E is under the following operating conditions. Air flow sensor
The throttle opening θs for calibration estimated from the intake air amount detected by 16 (actually, this intake air amount is corrected by the intake air temperature and atmospheric pressure. The same applies hereinafter) (this θs is the same as the intake air amount. Relationship stored in the map) and the actual throttle opening θr detected by the throttle sensor 20 and corrects the value of the throttle opening according to the comparison result. The control means M2 outputs the engine control signal based on the throttle opening information corrected by the correction means M1 to the engine controlled portion such as the electromagnetic fuel injection valve 9 or the actuator 12 when the vehicle is in the state. ing.

The data corrected by the correcting means M1 is used specifically for the case where surging occurs in the intake system during deceleration of the engine E or the air flow sensor.
Engine is calculated from the estimated intake air amount (simulated intake air amount; this can be estimated only from the throttle opening) by estimating the intake air amount from the throttle opening and engine speed when 16 is disconnected. A fuel supply control means for outputting a fuel supply control signal (this corresponds to an "engine control signal") to the electromagnetic fuel injection valve 9 in accordance with the operating state of E is conceivable, and the engine speed during idling is set to the engine speed. The control signal (this corresponds to the engine control signal) to the actuator 12 in order to control based on the number (this control is referred to as rotation speed feedback control) as well as to control based on the throttle opening (this control is referred to as position feedback control). An output feedback control means (idle speed control means) for output can be considered. The operating condition for the correction by the correcting means M1 is, for example, when the throttle opening is stable for estimating the throttle opening from the intake air amount, when the throttle opening is in an extremely low opening range (near idle). Is selected, specifically when the following conditions are satisfied.

(1) The rotation speed feedback control is continued for a predetermined time. (2) The intake air amount is within a preset predetermined range. In addition to the above-mentioned surging and failure of the airflow sensor, the airflow sensor Normal time to output a fuel supply control signal to the electromagnetic fuel injection valves 9 and 10 according to the operating state of the engine E obtained from the actual intake air amount detected by 16 and the engine speed detected by the rotation speed sensor 17. Although the fuel supply control means is provided, the controller 14 also has the function of such control means.

Further, the controller 14 outputs a signal corresponding to the intake passage pressure to the indicator 13 on the basis of the information on the intake air amount corrected by the intake air temperature and the atmospheric pressure and the information on the engine speed, and an intake passage pressure display control means. , An ignition timing control means for outputting an ignition timing control signal to the power transistor 30 according to the operating state of the engine E, the pressure responsive device for adjusting the opening timing of the waste gate valve 6 to obtain different boost pressure characteristics It also has the function of wastegate valve control means for outputting a signal to the electromagnetic switching valve 20 for controlling the valve 7.

With the above configuration, the throttle opening is calibrated as follows. That is, as shown in FIG. 3, various data are input in step A1, but then step A1.
At 2, A3, it is determined whether the throttle opening can be corrected by the correction means M1. First, in step A2, it is determined whether the rotation speed feedback control has continued for a predetermined time, and if YES in step A2, step A3
Then, it is determined whether the intake air amount detected by the air flow sensor 16 is within a predetermined range. If this step A3
However, if YES, it is determined that the throttle opening can be corrected, and the process proceeds to step A4. In this step A4, the correcting throttle opening θs and the actual throttle opening θr are compared by the correcting means M1, and θs−θr as a result of this comparison is regarded as a set error (installation error) of the throttle sensor 20. The value of the throttle opening is corrected by the error.

The set error amount of the throttle sensor 20 obtained in step A4 is appropriately stored in the memory of the controller 14,
After that, when a predetermined time elapses and the engine E is again under the above-mentioned operating conditions, the set error amount of the throttle sensor 20 is obtained again, and the learning of correcting the throttle opening value with this new set error value. Control is performed.

If NO in steps A2 and A3, the throttle opening value is not corrected.

An example of engine control according to this embodiment is shown in FIG. That is, first, in step B1, it is determined whether or not the engine E is under a specific operating condition (such as when the intake system is surging during deceleration, or during an idle condition where position feedback control is desired). If YES in step B1, the control means M2 performs engine control based on the throttle opening information corrected by the correcting means M1 (including the throttle opening information already corrected) in step B2.

However, if NO in step B1, the normal-time fuel supply control means performs control based on the actual intake air amount information in step B3.

In this way, the engine control depending on the throttle opening that is performed under a specific operating condition of the engine E can be accurately executed, and thus the performance of, for example, idle speed control or fuel control during deceleration is improved. is there.

It should be noted that until the detection of the setting error of the throttle sensor 20 is completed, the engine control based on the throttle opening is not performed even when the engine E is under the specific operating condition as described above. This is because if the engine control is forced in such a case, the control accuracy will rather deteriorate.

Further, the intake air amount does not have to be corrected for the intake air temperature and the atmospheric pressure.

In addition, the device can be used on engines installed in non-turbo vehicles.

As described above in detail, according to the engine control device of the present invention, the air flow sensor for detecting the intake air amount in the intake passage of the engine and the throttle sensor for detecting the opening degree of the throttle valve interposed in the intake passage. And an engine controlled part, and a calibrating throttle valve opening estimated from the intake air amount detected by the air flow sensor when the engine is in a low load operating state and an actual throttle valve detected by the throttle sensor. Compensation means is provided for comparing the throttle opening degree and the value of the throttle valve opening degree according to the result of the comparison, and engine control based on the throttle valve opening degree information corrected by the compensation means. With a simple configuration in which control means for outputting a signal to the engine controlled section is provided,
The relationship between the intake air amount and the throttle opening is calibrated in a low-load operating range of the engine, which corresponds to a relatively one-to-one correspondence without being influenced by the engine speed. The operational effect typified by at least one of the above simple configurations is obtained, which has the advantage that the engine control performed under the specific operating condition of the engine can be realized with high accuracy.

[Brief description of drawings]

FIG. 1 shows an engine control device as an embodiment of the present invention. FIG. 1 is an overall configuration diagram thereof, FIG. 2 is a schematic diagram showing an example of its indicator, and FIGS. It is a flow chart for explaining an operation. 1 ... Intake passage, 2 ... Exhaust passage, 3 ... Turbocharger, 4 ... Turbine, 5 ... Compressor, 6 ... Wastegate valve, 7 ... Pressure response device, 8 ... Intercooler, 9,10 ...... Electromagnetic fuel injection valve, 11 ...... Throttle valve, 12 ...... Actuator, 13 ...... Indicator, 13a ......
Needle type display unit, 13b …… Segment type display unit, 14 …… Controller, 15 …… Electromagnetic switching valve, 16 …… Air flow sensor, 17 …… Revolution speed sensor, 18 …… Intake air temperature sensor, 19 ……
Atmospheric pressure sensor, 20 ... Throttle sensor, 21 ... Water temperature sensor, 22 ... O ₂ sensor, 23 ... Knock sensor, 24 ... Vehicle speed sensor, 25 ... Idle switch, 26 ... Cranking switch, 27 ... … Crank angle sensor, 28… Ignition coil, 29… Distributor, 30… Power transistor, 31… Catalytic converter, 131a… Negative pressure area, 131b… Supercharging area, 131c… Supercharging area, 131d
…… Needle, E …… Engine, M1 …… Correction means, M2 …… Control means.

 ─────────────────────────────────────────────────── --- Continued from the front page (56) References JP-A-55-142942 (JP, A) JP-A-58-211547 (JP, A) JP-A-55-148925 (JP, A) JP-A-57- 175916 (JP, A)

Claims (1)

[Claims] 1. An air flow sensor for detecting an intake air amount in an intake passage of an engine, and a throttle sensor for detecting an opening degree of a throttle valve provided in the intake passage.
A throttle valve opening for calibration estimated from the intake air amount detected by the air flow sensor when the engine is in a low load operation state and an actual throttle opening detected by the throttle sensor. And a correction means for correcting the value of the opening degree of the throttle valve according to the comparison result, and an engine control signal based on the opening degree information of the throttle valve corrected by the correction means is provided. An engine control device comprising control means for outputting to the engine controlled part.