JP5779532B2 - Engine electronic governor - Google Patents

Description

  The present invention relates to an engine electronic governor, and more particularly, to an engine electronic governor capable of avoiding a narrow peak of periodic rotational speed fluctuation that may occur after the rotational speed deviation falls within a minute range. .

2. Description of the Related Art Conventionally, as an electronic governor of an engine, a control means includes a rotation speed deviation calculation means, a control value calculation means for PID control or PI control, a current control unit, and an actuator drive circuit. A rotational speed deviation between the rotational speed and the actual rotational speed is calculated, and based on this rotational speed deviation, a control value calculating means calculates a control value for PID control or PI control, and based on this control value, a current control unit Controls the actuator current of the actuator drive circuit, drives the actuator with this actuator drive current, and controls the fuel metering part of the fuel injection pump with this actuator, thereby converging the rotational speed deviation within a predetermined range (For example, refer to Patent Document 1).
Further, there is a control means that includes a dither current superimposing means, and the dither current superimposing means superimposes the dither current on the actuator drive current (see Patent Document 2).
The latter has an advantage that the output of the actuator is minutely vibrated by the dither current, and the response of the fuel metering unit can be enhanced by the minute vibration of the fuel metering unit following the dither current.

JP 2011-74771 A (see FIG. 2) JP 2009-85062 A (see FIG. 1)

<< Problem >> After the rotational speed deviation falls within a very small range, a narrow peak of periodic rotational speed fluctuation may occur.
When the control value calculating means for PID control or PI control and the dither current superimposing means are combined, as shown in FIG. 5, after the absolute value | ΔR | of the rotational speed deviation ΔR falls within the minute range LR, A narrow peak (P) with a number variation may occur.
The occurrence of such a narrow peak (P) is directly linked to frequency fluctuations. For example, when it is used for an engine generator, performance such as stability of voltage and frequency is lowered, and there is a problem such as flickering of an electric lamp. Arise.

  An object of the present invention is to provide an electronic governor for an engine that can avoid a narrow peak of periodic rotational speed fluctuations that may occur after the rotational speed deviation falls within a very small range.

(Invention-specific matters on which the invention of claim 1 is based )
As illustrated in FIG. 3 , the control means (1) includes a rotation speed deviation calculation means (2), a control value calculation means (3) for PID control or PI control, a current control section (4), and an actuator drive. A circuit (5), and a rotational speed deviation calculating means (2) calculates a rotational speed deviation between the target rotational speed and the actual rotational speed, and based on the rotational speed deviation, the control value calculating means (3) The control value of control or PI control is calculated, and based on this control value, the current control unit (4) controls the actuator drive current of the actuator drive circuit (5), and the actuator (6) is driven by this actuator drive current. By adjusting the fuel metering section (8) of the fuel injection pump (7) with this actuator (6), the rotational speed deviation ΔR is converged within a predetermined range,
An electronic governor for an engine, wherein the control means (1) includes dither current superimposing means (9), and the dither current superimposing means (9) superimposes the dither current on the actuator drive current.

(Cause of narrow peaks of periodic rotational speed fluctuations)
When the control value calculation means for PID control or PI control and the dither current superposition means are combined, the cause of the occurrence of a narrow peak of periodic rotational speed fluctuation after the rotational speed deviation is within a very small range is described in the present invention. As a result of the research, the inventors have obtained the following knowledge.
That is, referring to FIG. 1, when the target rotational speed is set to a certain value, the fuel pumping cycle of the fuel injection pump (7) and the vibration cycle of the fuel metering unit (8) by the dither current are synchronized. Sometimes. In this case, the fuel metering unit (8) whose operation is restricted for fuel pumping does not follow the vibration of the output unit (13) of the actuator (6), and the metering position of the fuel metering unit (8) is Deviation from an appropriate position may cause a minute rotational speed deviation (for example, rotational speed deviation of 1 rpm or less) to remain constantly. If this minute rotational speed deviation is left unattended, as shown in FIG. 5, the integral value I is accumulated, and as a result of control for canceling out this integral value I, a narrow peak (P) of periodic rotational speed fluctuations is obtained. Occur.
The inventors of the present invention have arrived at the present invention based on this finding.

(Invention-specific matters that characterize the invention according to claim 1 )
As illustrated in FIGS. 3 and 4, the control means (1) includes an integral value fluctuation rate determination means (3a) and an integration cancellation means (10), and the integration calculated by the control value calculation means (3). While the absolute value | ΔI / ΔT | of the integral value fluctuation rate ΔI / ΔT of the value I is below the predetermined reference fluctuation rate value SI, it is based on the fact that the integral value fluctuation rate judging means (3a) has judged this. An electronic governor for an engine, wherein the integration canceling means (10) cancels the integration of the integral value I by the control value calculating means (3).

The invention according to claim 1 has the following effects.
<Effect> It is possible to avoid a narrow peak of periodic rotational speed fluctuations that may occur after the rotational speed deviation falls within a very small range.
As illustrated in FIGS. 3 and 4, the control means (1) includes an integral value fluctuation rate determination means (3a) and an integration cancellation means (10), and the integration calculated by the control value calculation means (3). While the absolute value | ΔI / ΔT | of the integral value fluctuation rate ΔI / ΔT of the value I is below the predetermined reference fluctuation rate value SI, it is based on the fact that the integral value fluctuation rate judging means (3a) has judged this. Thus, since the integration canceling means (10) cancels the integration of the integral value I by the control value calculating means (3), the integral value I based on the minute rotation speed deviation is not accumulated, and the integral value I is canceled. As a result, the occurrence of a narrow peak of periodic rotational speed fluctuation does not occur. For this reason, it is possible to avoid a narrow peak of periodic rotational speed fluctuation that may occur after the rotational speed deviation falls within the minute range LR.

It is a block diagram of the electronic governor of the engine which concerns on the reference form of this invention. It is a graph of the engine speed by control of the electronic governor of FIG. It is a block diagram of the electronic governor of the engine which concerns on embodiment of this invention. It is a graph of the engine speed by control of the electronic governor of FIG. It is a graph of the engine speed and integral value by control of the electronic governor of the engine which concerns on a prior art.

1 and 2 illustrate an electronic governor for an engine according to the reference embodiment of the present invention, FIG. 3, FIG. 4 is a diagram illustrating an electronic governor for an engine according to an embodiment of the present invention, and this reference embodiment In the embodiment , an electronic governor of a diesel engine will be described.

First, a reference form will be described.
This diesel engine electronic governor is used for an engine generator.
As shown in FIGS. 1 and 2, the control means (1) includes a rotation speed deviation calculating means (2), a PID control type control value calculating means (3), a current control section (4), and an actuator drive. A circuit (5), and a rotational speed deviation calculating means (2) calculates a rotational speed deviation between the target rotational speed and the actual rotational speed, and based on the rotational speed deviation, the control value calculating means (3) The control value of the control is calculated, and based on this control value, the current controller (4) controls the actuator drive current of the actuator drive circuit (5), and drives the actuator (6) with this actuator drive current. By adjusting the fuel metering section (8) of the fuel injection pump (7) with the actuator (6), the rotational speed deviation ΔR is converged within a predetermined range, and the control means (1) is a dither current superimposing means ( 9), and this dither current superimposing means (9) The dither current is superimposed.

  As shown in FIG. 1, a target rotational speed detecting means (19) and an actual rotational speed detecting means (20) are connected to the rotational speed deviation calculating means (2). The target engine speed detecting means (19) is a potentiometer that detects the target engine speed by detecting the position of the accelerator pedal. The actual rotational speed detection means (20) is a pickup coil that detects the actual rotational speed of the engine.

As shown in FIG. 1, the control value computing means (3) includes a proportional term computing unit (14), an integral term computing unit (11), and a differential term computing unit (15).
The control value calculation means (3) calculates the PID calculation formula of the control value based on the rotational speed deviation.
The PID arithmetic expression is as follows.
Control value = Kp × (rotational speed deviation) + Ki × (cumulative deviation value) + Kd × (difference from previous deviation)
Here, Kp × (rotational speed deviation) is a proportional term, Ki × (cumulative deviation) is an integral term, Kd × (difference from previous deviation) is a differential term, Kp is a proportional gain, Ki is an integral gain, Kd Is the differential gain.
The control value calculation means (3) may be a PI control calculation means without the differential term calculation unit (15).

As shown in FIG. 1, the actuator (6) is a linear solenoid.
The fuel injection pump (7) is a Bosch type row fuel injection pump.
The fuel metering unit (8) is a fuel metering rack (16).
The fuel metering rack (16) is urged toward the fuel increase side by the urging spring (17) and is received by the output portion (13) of the actuator (6).
When the output portion (13) of the actuator (6) is pulled toward the main body by the electromagnetic force of the solenoid, the fuel metering rack (16) is driven to the fuel increase side by the biasing force of the biasing spring (17). When the output portion (13) of the actuator (6) is pushed out from the main body side by the urging force of the return spring (18), the fuel metering rack (16) is driven to the fuel reduction side.
When the actuator (6) is not energized, the output section (13) is pushed out from the main body side by the urging force of the return spring (18), and the fuel metering rack (16) is held at the no fuel injection position.

As shown in FIG. 1 and FIG. 2, the control means (1) includes a rotation speed deviation determination means (2a) and an integration cancellation means (10), and the absolute value of the average value ΔRav of the rotation speed deviation ΔR over a predetermined time Δt. While the value | ΔRav | is below the predetermined reference deviation value SR, the integration canceling means (10) controls the control value calculating means (3) based on the fact that the rotation speed deviation judging means (2a) has determined this value. Cancel the integration of the integral value I. In this embodiment, the reference deviation value SR is a value smaller than the minute range LR and less than 1 rpm. As this reference deviation value SR, an appropriate value may be selected according to the system to be applied. When the rotational speed deviation ΔR is in the minute range LR, the reference deviation value SR is set such that the absolute value | ΔRav | of the average value ΔRav of the rotational speed deviation ΔR for the predetermined time Δt is less than the predetermined reference deviation value SR. Is set in advance.
As illustrated in FIGS. 1 and 2, in this reference form, the control means (1) includes a rotation speed deviation determination means (2a) and an integration cancellation means (10), and the rotation speed deviation ΔR for a predetermined time Δt. While the absolute value | ΔRav | of the average value ΔRav is below the predetermined reference deviation value SR, the integration canceling means (10) controls based on the determination by the rotational speed deviation determining means (2a). Since the integration of the integral value I by the value calculation means (3) is canceled, the integral value I based on the minute rotation speed deviation does not accumulate, and the periodic rotation speed that has occurred as a result of the control that cancels out this integral value I has occurred. Narrow peaks of fluctuation do not occur. For this reason, it is possible to avoid a narrow peak of periodic rotational speed fluctuation that may occur after the rotational speed deviation falls within the minute range LR.

  The graph of FIG. 2 shows a process in which the vertical axis represents the engine speed and the horizontal axis represents time, and the process returns to the target speed after the actual speed decreases from the target speed by applying a load. While the absolute value | ΔRav | of the average value ΔRav of the rotation speed deviation ΔR of Δt is below a predetermined reference deviation value SR, the integration canceling means (10) integrates the integral value I by the control value calculating means (3). In the meantime, in the control value calculation means (3), the control value is calculated with the integral value I at the time of starting to fall below the absolute value | ΔRav | below the predetermined reference deviation value SR.

Next, an embodiment will be described.
As shown in FIGS. 3 and 4, the control means (1) includes an integral value fluctuation rate determination means (3a) and an integration cancellation means (10), and the integral value calculated by the control value calculation means (3). While the absolute value | ΔI / ΔT | of the integral value fluctuation rate ΔI / ΔT of I is below a predetermined reference fluctuation rate value SI, it is based on the fact that the integral value fluctuation rate judgment means (3a) has judged this. The integration canceling means (10) cancels the integration of the integral value I by the control value calculating means (3). When the absolute value | R | of the rotational speed deviation ΔR is within the minute range LR, the absolute value | ΔI / ΔT of the integrated value fluctuation rate ΔI / ΔT of the integrated value I calculated by the control value calculating means (3). The reference fluctuation rate value SI is set so that | is less than a predetermined reference fluctuation rate value SI. ΔT is a predetermined time, and ΔI is a fluctuation value of the integral value I at the predetermined time ΔT.

The graph of FIG. 4 shows a process in which the vertical axis represents the engine speed and the horizontal axis represents time, and the process returns to the target speed after the actual speed decreases from the target speed by applying a load. While the absolute value | ΔI / ΔT | of the fluctuation rate ΔI / ΔT is below the predetermined reference fluctuation rate value SI, the integration canceling means (10) cancels the integration of the integral value I by the control value calculating means (3). Therefore, in the meantime, in the control value calculation means (3), the control value is calculated with the integral value I at the time of starting to fall below the absolute value | ΔI / ΔT | being lower than the predetermined reference fluctuation rate value SI.
Other configurations are the same as those of the reference embodiment , and in FIGS. 3 and 4, the same reference numerals as those of FIGS.

(1) Control means
(2) Speed deviation calculation means
(2a) Speed deviation judging means
(3) Control value calculation means
(3a) Integral value fluctuation rate determination means
(4) Current controller
(5) Actuator drive circuit
(6) Actuator
(7) Fuel injection pump
(8) Fuel metering section
(9) Dither current superposition means
(10) Integration cancellation means
(11) Integral term calculation unit Δt Predetermined time ΔR Rotational speed deviation | ΔRav | Absolute value SR of standard deviation of rotational speed SR Standard deviation value I Integral value ΔI / ΔT Integral value fluctuation rate | ΔI / ΔT | Integral value fluctuation rate Absolute value SI standard fluctuation rate value

Claims (1)

The control means (1) includes a rotation speed deviation calculation means (2), a control value calculation means (3) for PID control or PI control, a current control section (4), and an actuator drive circuit (5). The rotation speed deviation calculating means (2) calculates the rotation speed deviation between the target rotation speed and the actual rotation speed, and based on this rotation speed deviation, the control value calculation means (3) calculates the control value for PID control or PI control. Based on this control value, the current control section (4) controls the actuator drive current of the actuator drive circuit (5), drives the actuator (6) with this actuator drive current, and this actuator (6) By metering the fuel metering section (8) of the fuel injection pump (7), the rotational speed deviation ΔR is converged within a predetermined range,
In the electronic governor of the engine, the control means (1) includes a dither current superimposing means (9), and the dither current superimposing means (9) superimposes the dither current on the actuator drive current.
The control means (1) includes an integral value fluctuation rate determination means (3a) and an integration cancellation means (10), and the integral value fluctuation rate ΔI / ΔT of the integral value I calculated by the control value calculation means (3). While the absolute value | ΔI / ΔT | is below the predetermined reference fluctuation rate value SI, the integration canceling means (10) controls the control value based on the fact that the integral value fluctuation rate judging means (3a) has judged this. An electronic governor for an engine, wherein the integration of the integral value I by the computing means (3) is canceled.

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