JP2000104605A - Elecrtronic governor of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the necessity of a map of correction coefficients for an actuator. SOLUTION: A current error deviation means computing means 11 receives an actual current signal 1e corresponding to an actual current for driving a control rack 1 and a current control signal S2 and delivers a correction current control signal S3 for maintaining an error between the actual current signal and the current control signal, and the actuator 4 is driven in accordance with the correction control signal S3 so as to control the actual rotational speed of an engine 3 to an instruction value. With this arrangement, irrespective of a decreased in the voltage of a power source battery and an increase in the temperature of the actuator, the control can be carried out while suppressing disturbance caused thereby, thereby it is possible to eliminate the necessity of preparation of a correction coefficient map. Further, since the current as the control object of the actuator is directly feed-back-controlled, it is possible to enhance the responsiveness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic governor for an engine, and more particularly to an electronic governor for an engine capable of performing stable speed control without being affected by disturbance.

[0002]

2. Description of the Related Art Conventionally, an actual engine speed and a fuel rack position are detected based on a map stored in a storage device so as to eliminate a difference between a given speed command value and an actually measured speed. Electronic governors that move a rack position control actuator are known.

[0003] In such an electronic governor, when the voltage of the power supply battery drops or the temperature of the actuator increases and the coil resistance increases, the current flowing through the actuator decreases, and the actuator cannot be driven sufficiently. is there. As a solution to this problem, for example, Japanese Unexamined Patent Publication No. 2-112644 discloses a method of providing a control means for calculating a control signal amount for an actuator. The control signal amount calculated by the calculation means is adapted to the voltage fluctuation of the power supply battery. An electronic governor that performs correction based on a correction coefficient map f (V) and a correction coefficient map f (T) corresponding to temperature fluctuation is disclosed.

In this electronic governor, a correction coefficient map f (V) when the battery voltage is changed and a correction coefficient map f (T) when the actuator temperature is changed are obtained in advance by experiments or the like. Accordingly, it is possible to correct for fluctuations in power supply battery voltage and fluctuations in temperature.

[0005]

However, the above-mentioned conventional electronic governor has the following problems. (A) With the conventional electronic governor, it takes time and effort to prepare a correction coefficient map f (V) corresponding to voltage fluctuation and a correction coefficient f (T) corresponding to temperature fluctuation in advance. In particular, the correction of the actuator due to the temperature fluctuation has not been sufficiently elucidated, and considering the various operating conditions of the engine and the surrounding environment, a correction coefficient map f (T) capable of sufficiently correcting the temperature fluctuation in each engine is obtained. It is not easy to make cheaply. (B) When the temperature fluctuation and the voltage fluctuation fluctuate relatively slowly, the above-described conventional technique using each correction coefficient map can cope with the fluctuation. However, when the temperature fluctuation and the battery voltage fluctuation are fast, the correction is performed. There is a possibility that sufficient responsiveness cannot be ensured by the method using the coefficient map.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic governor for an engine which can solve the above problems. An example of a specific purpose is as follows. (a) It is not necessary to create a correction coefficient map as in the related art. (b) The responsiveness is increased, and it is possible to cope with the case where the temperature fluctuation and the voltage fluctuation are fast. It should be noted that the problems of the invention other than those described above and the means for solving the problems will be described in detail in the description in the following specification.

[0007]

An electronic governor for an engine according to the present invention will be described below with reference to, for example, FIG. 1 showing a basic configuration of the present invention. First
The invention is applied to an engine 3 having a fuel injection pump 2 whose fuel injection amount is adjusted by a rack 1.
, An engine speed commanding means 5 for outputting a commanded speed signal Na, and a speed detecting means 6 for detecting the actual speed of the engine 3 and outputting an actual speed signal Ne corresponding to the actual speed. And a rack position detecting means 7 for detecting an actual position of the rack 1 and outputting an actual position detection signal De corresponding to the position, and detecting a current value flowing through the actuator 4 to correspond to the current value. A current detecting means 8 for outputting an actual current signal Ie;
e and a command speed signal Na as inputs, a speed deviation calculating means 9 for outputting a rack position control signal S1 for controlling a deviation between the actual speed and the command speed within an allowable range; Position detection signal De and rack position control signal S
1 as an input, and outputs a current control signal S2 for driving the actuator 4 so as to maintain the deviation between the actual position of the rack 1 and the target position within an allowable range; A correction current control signal S for controlling the deviation between the actual current value and the current control signal S2 to be maintained within an allowable range by using the signal Ie and the current control signal S2 as inputs.
And a current deviation calculating means 11 for outputting the engine speed 3 to drive the actuator 4 based on the corrected current control signal S3 so as to control the actual speed of the engine 3 to the command speed. . The second invention is characterized in that a calculating means 12 for calculating a target feedforward value to be given to the current deviation calculating means 11 at the time of outputting the rack position control signal S1 from the rotation speed deviation calculating means 9 is provided.

[0008]

According to the first aspect of the invention, the current control signal obtained by the rotational speed deviation calculating means and the position deviation calculating means is compared with the actual current value flowing through the actuator by the current deviation calculating means, and the deviation is calculated. It is controlled so as to be maintained within an allowable range. This control operation is performed so as to maintain the deviation resulting from the cause within an allowable range regardless of the cause of the deviation of the current, for example, the decrease in the voltage of the power supply battery or the increase in the temperature of the actuator. Unlike the prior art, it is not necessary to analyze the effects of voltage fluctuation and temperature fluctuation and provide a correction coefficient map caused by voltage fluctuation and a correction coefficient map caused by temperature fluctuation. Further, since the current itself, which is the final control target of the actuator, is feedback-controlled, the value corrected by the correction coefficient maps f (T) and f (V) is feedback-controlled as a whole, as compared with the related art.
Responsiveness can be made faster.

According to the second aspect of the present invention, the control amount is provided by providing a calculating means for calculating a target feedforward value to be given to the current deviation calculating means at the time of outputting the rack position control signal from the rotational speed deviation calculating means. , The control operation can be performed assuming a change of the governor in advance, and the governor responsiveness can be further increased. Since the rack position control has a simple relationship determined by, for example, the balance of the spring with the electromagnetic force of a solenoid as an actuator, the target feed-fed value of such feed-fade control is calculated. Is relatively easy to do.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram in the case where the engine electronic governor of the present invention is applied to a diesel engine.
As shown in FIG. 2, the diesel engine 3 includes an engine main body 3a and a fuel injection pump 2 attached to the engine main body 3a. The electronic governor includes an actuator 4 for driving the control rack 1 of the fuel injection pump 2, a rack position detecting unit 7 for detecting the control rack position, a rotational speed detecting unit 6 for detecting the actual rotational speed of the engine, and the actuator 4. A current detector 8 for detecting an actual flowing current value; a controller 14; and a rotation speed commander 5 for commanding a rotation speed at which the engine 3 operates according to an instruction of an operator.
And an abnormality detection unit 15 for detecting at least one abnormality of the rotation speed detection unit 6, the rack position detection unit 7, and the current detection unit 8.

The rotation speed command unit 5 includes, for example, a speed control lever,
A position of an accelerator or the like is detected by a position sensor (not shown), and a command speed signal Na corresponding to the operation position is output. The control unit 14 includes an actual position detection signal De output from the rack position detection unit 7, an actual rotation number signal Ne output from the rotation number detection unit 6, and an actual current signal output from the current detection unit 8. Ie and the command rotation speed signal Na from the rotation speed command unit 5 are input, and the control unit 14 outputs a correction current control signal S3 to the actuator 4. The control unit 14 includes a rotational speed deviation calculation unit 9, a position deviation calculation unit 10, and a current deviation calculation unit 11, and calculates a target feedforward value to be given to the current deviation calculation unit 11 as necessary. A changeover switch 16 provided between the position deviation calculator 10 and the current deviation calculator 11;
An abnormal-time command value generation unit 13 that generates a command value when at least one of the rotation speed detection unit 6 and the rack position detection unit 7 is abnormal is provided. FIG. 2 shows an embodiment in which all the components described above are provided.

The abnormal-time command value generator 13 detects the position of the speed control lever or the like, and supplies a current command value to the superposition circuit 23 of the current deviation calculator 11 according to the detected position. The rotation speed deviation calculation unit 9 includes a superimposition circuit 18 on which the command rotation speed signal Na and the actual rotation speed signal Ne are superimposed, and a rotation speed PI compensation circuit 19, and the command rotation speed signal Na and the real rotation speed signal N
e is calculated by the superimposing circuit 18 and the rotational speed P
The rack position control signal S1 is obtained while maintaining the response and stability of the control by the I compensation circuit 19. The position deviation calculating unit 10 includes a superposition circuit 20 on which the rack position control signal S1 and the actual position detection signal De are superimposed, a position PI compensation circuit 21, and a position D (differential) compensation circuit 22. Deviation ΔD between signal S1 and actual position detection signal De
Is calculated by the superposition circuit 20, and the position PI compensation circuit 21,
The current control signal S2 for compensating the actual rack position is obtained by the position D compensation circuit 22. This current control signal S
2 is a control signal for driving the actuator 4.

The current deviation calculating section 11 includes a superimposing circuit 23 on which the actual current signal Ie and the current control signal S2 are superimposed, a current PI compensating circuit 24, a current converting section 25 for converting a voltage to a current, A voltage converter 26 for converting the voltage into a voltage, calculating a deviation ΔI between the actual current signal Ie and the current control signal S2 by the superposition circuit 23, and maintaining the response and stability of the control by the current PI compensation circuit 24. , And a correction current control signal S3. The process of changing the current value in accordance with the obtained deviation is performed by changing the PWM pulse width.

The changeover switch 16 cuts off the flow of signals between the position deviation calculator 10 and the current deviation calculator 11 in response to a signal F indicating that the abnormality detector 15 is abnormal. The abnormality detection unit 15 determines whether or not the output signals of the detection units 6, 7, and 8 are appropriate values in consideration of the operation state in the operation state. It is also possible to configure by software means that outputs the signal F to the changeover switch 15.

The operation of the electronic governor configured as described above will be described. (Control during Normal Operation) In response to the command speed signal Na given from the speed command unit 5, the speed deviation calculation unit 9, the position deviation calculation unit 10, and the current deviation calculation unit 11
Actual rotation speed signal Ne, actual position detection signal De, actual current signal I
The deviation of e is taken, and the deviation is controlled to approach zero. Then, the final corrected current control signal S3 is converted from a voltage to a current, and the value of the current flowing through the actuator 4 is changed to change the position of the control rack 1 so that the actual engine speed approaches the commanded rotation value. Control. With this configuration, the current deviation calculation unit 11
In the above, even if some disturbance occurs in the current flowing through the actuator 4, the influence of the disturbance can be quickly canceled in the current control feedback loop existing inside the rotation speed control loop and the position control loop, and the electronic governor Overall responsiveness and reliability can be improved.

If the state in which the difference between the current control signal S2 output from the position deviation calculator 11 and the actual current actually flowing through the actuator is large continues for a long time, it is highly likely that an abnormality has occurred. There is an advantage that the control unit 14 can easily detect an abnormality. As another embodiment of the present invention, based on the difference between the actual current actually flowing through the actuator and the current control signal S2, a means for detecting an abnormality of the electronic governor or estimating an abnormal position is provided. A configuration is conceivable in which the occurrence of an abnormality is notified to an operator by lighting a warning lamp or the like.

In FIG. 1, when a calculation section 12 for providing a target feed-forward value is provided as shown by a dashed line, it is possible to give the current deviation calculation section 11 a value that can approach the target more quickly. And the calculation time can be reduced.

(Control at the time of abnormality) When the abnormality signal F of the abnormality detection unit 15 is output to the changeover switch 16, the changeover switch 16 is turned off, and the signal between the position deviation calculation unit 10 and the current deviation calculation unit 11 is transmitted. Block transmission. Then, based on the command speed signal Na of the speed command unit 5, the command value generator 13 at the time of abnormality supplies a current command value of a magnitude corresponding to the command speed signal Na to the superposition circuit 23. Then, the current deviation calculator 11 drives the actuator 4 based on the given current command value. In addition, when the load is set as needed, it is also possible to configure so that the worker can judge the load by himself and give the load value.

In another configuration, a broken line 27 in FIG.
As shown in the figure, the current conversion unit 25 in the current deviation calculation unit 11
Can be directly changed based on the command value. In this case, even if the current detection unit 8, the superimposition circuit 23, and the current PI compensation circuit 24 do not function, the operation of the engine can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a basic configuration of an electronic governor for an engine of the present invention.

FIG. 2 is a block diagram showing an embodiment of an electronic governor for an engine of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Control rack, 2 ... Fuel injection pump, 3 ... Engine, 4 ... Actuator, 5 ... Rotation speed command part, 6 ...
Rotational speed detector, 7 ... Position detector, 8 ... Current detector, 9 ...
Rotational speed deviation calculator, 10: position deviation calculator, 11: current deviation calculator, 12: calculator.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yamaichi 64 Ishizu-Kitacho, Sakai-shi, Osaka F-term in Kubota Sakai Works (reference) 3G060 AB01 AC08 BA03 BA17 BA19 CA01 CC00 DA00 DA06 FA07 GA00 GA02 GA03 3G301 HA02 JA00 JA03 JA10 JB09 LB14 LC01 LC10 MA11 NA05 NA06 NA08 NB02 NB06 ND01 ND42 PE01A PE01Z PF03Z PG02Z

Claims (2)

[Claims] 1. An actuator (4) for driving a rack (1), which is employed in an engine (3) having a fuel injection pump (2) whose fuel injection amount is adjusted by the rack (1), and a command rotation. Rotation speed command means (5) for outputting a number signal; rotation speed detection means (6) for detecting an actual rotation speed of the engine (3) and outputting an actual rotation speed signal corresponding to the actual rotation speed; Rack position detecting means (7) for detecting the actual position of 1) and outputting an actual position detection signal corresponding to the position.
Current detection means (8) for detecting a current value flowing through the actuator (4) and outputting an actual current signal corresponding to the current value
A rotation speed deviation calculating means that receives the actual rotation speed signal and the command rotation speed signal and outputs a rack position control signal for controlling the deviation between the actual rotation speed and the command rotation speed to be maintained within an allowable range ( 9) and driving the actuator (4) such that the deviation between the actual position of the rack (1) and the target position is maintained within an allowable range by using the actual position detection signal and the rack position control signal as inputs. A position deviation calculating means (10) for outputting a current control signal, and a correction current for controlling the deviation between the actual current value and the current control signal by inputting the actual current signal and the current control signal so as to maintain the deviation within an allowable range. Current deviation calculating means for outputting a control signal
(11) for driving the actuator (4) based on the corrected current control signal to control the actual rotation speed of the engine (3) to be the commanded rotation speed. Electronic governor. 2. The electronic governor for an engine according to claim 1, wherein a target feed feed signal to be supplied to said current deviation calculating means (11) at the time of output of a rack position control signal from said rotational speed deviation calculating means (9). Calculation means (1) for calculating the value
An electronic governor for an engine, wherein the electronic governor is provided with 2).