KR20120127678A - Device and method for controlling ship engine - Google Patents

Abstract

The actual rotational speed Ne of the main engine 11 is detected and input to the time delay logic 13 and the period calculating unit 15. The cycle calculating unit 15 detects a fluctuating period of the actual rotation speed Ne, and in the time delay logic 13, the actual rotation speed Ne is delayed for one quarter of a cycle and negative feedback is performed. . The deviation between the target rotational speed No and the feedback signal is input to the proportional control unit 14, and the gain corresponding to the change angular velocity omega of the actual rotational speed Ne calculated from the period obtained by the period calculating unit 15 is obtained. Proportionate operation is performed. In the N / FI conversion unit 12, the fuel index FIo corresponding to the target rotational speed No is calculated and added to the output from the proportional control unit 14.

Description

Marine engine control device and method {DEVICE AND METHOD FOR CONTROLLING SHIP ENGINE}

The present invention relates to a ship engine control device for controlling the operation of the ship's main machine.

In ships, a constant rotation speed control is generally employed to maintain the propeller rotation speed at a constant value. That is, in governor control of a ship cycle, the actual rotation speed is maintained by target PID speed by patent control (patent document 1). However, in the constant rotation speed control, the fuel supply amount (fuel index) is changed in accordance with the load variation, so the fuel economy may deteriorate. From this, depending on the sea, governor control may be performed in which the fuel supply amount (fuel index) is fixed to a fixed value.

Japanese Patent Application Laid-Open No. 8-200131

However, even if the fuel index is made constant and the periodic torque is kept substantially constant, if the propeller load fluctuates, the propeller torque is not kept constant, causing variations in thrust and lowering propulsion efficiency.

An object of the present invention is to perform cycle control in which propeller torque is constant, to suppress thrust fluctuations and to improve propulsion efficiency.

The marine engine control apparatus of the present invention is a marine engine control apparatus which outputs a fuel index by giving a target rotational speed, and returns a feedback signal delayed by 10% to 30% with respect to the period of change of the actual rotational speed of the main engine, The fuel index is varied in proportion to the angular velocity of the rotational speed.

The feedback signal is, for example, a signal obtained by delaying the actual rotation speed with a time delay logic, and the deviation between the target rotation speed and the feedback signal is output through, for example, a proportional calculation unit in which a gain corresponding to the variable angular velocity is set.

Further, the apparatus further includes a target rotational speed / fuel index converting means for calculating a fuel index corresponding to the target rotational speed, and the output from the proportional calculation unit is added to the fuel index corresponding to the target rotational speed.

Or the engine control apparatus for ships is equipped with a PI control part, the deviation of a target rotational speed and a feedback signal is input into a P1 control part, and the fuel index corresponding to a target rotational speed is produced and maintained by the I calculating part of a PI control part.

In addition, the feedback signal may be a structure generated by a derivative operation of the actual rotation speed.

The ship of this invention was provided with the said engine control apparatus for ships.

In addition, the ship engine control method of the present invention is a ship engine control method for outputting a fuel index by giving a target rotational speed, while returning a feedback signal delayed by 10% to 30% with respect to the period of change of the actual rotational speed of the main engine The fuel index is varied in proportion to the angular velocity of the actual rotational speed.

According to the present invention, it is possible to perform cycle control in which propeller torque is constant, to suppress thrust fluctuations and to improve propulsion efficiency.

1 is a control block diagram showing a configuration of an engine control device of a first embodiment.
2 is a graph for explaining the principle, action and effect of the invention.
3 is a control block diagram showing the configuration of the engine control apparatus of the second embodiment.
4 is a control block diagram showing the configuration of the engine control apparatus according to the third embodiment.
Fig. 5 is a control block diagram showing the configuration of the engine control device of the fourth embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to an accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS It is a control block diagram which shows the structure of the control apparatus of the marine engine which is 1st Embodiment of this invention.

The ship engine control apparatus 10 of this embodiment is a governor system which controls the fuel supply to the main engine 11, The crankshaft (not shown) of the main engine 11 is attached to the propeller for propulsion (not shown). Connected. In the ship engine control apparatus 10, the target rotational speed No is set as a target value, and the actual rotational speed Ne which is the output of the main engine 11 is detected by a well-known method using a turning gear or the like.

The target rotation speed No is converted into the fuel index FIo by the N / FI converter 12. In addition, in parallel with this, in this embodiment, the deviation from the actual rotation speed Ne of the main engine 11 fed back via the time delay logic 13 is calculated | required, and the proportional control 14 performs a proportional calculation. .

In this embodiment, the proportional control part 14 performs a proportional calculation with the gain which is proportional to the fluctuation angular velocity o of the real rotation speed Ne, and the time delay logic 13 adjusts the phase of the real rotation speed Ne. Delay by approximately 90 ° or about 10-30% of the variation period. Further, the gain of the proportional control unit 14 and the delay time of the time delay logic 13 are the period T of the actual rotation speed Ne calculated by the period calculation unit 15 based on the change of the actual rotation speed Ne. Is determined based on

In addition, the signals from the N / FI converter 12 and the proportional controller 14 are added to the actuator 16, and the actuator 16 supplies fuel of an amount corresponding to the fuel index FI in the main engine ( To 11).

Next, with reference to FIG. 2, the principle of the propeller torque constant control of this invention is demonstrated compared with fuel index constant control.

In addition, in FIG. 2, periodic rotation speed N (FIG. 2A), fuel index FI, or periodic torque Qe (FIG. 2B), propeller torque Qp, in fuel index constant control and propeller torque constant control are shown. The time variation of thrust (FIG. 2C) and torque coefficient Kq (FIG. 2D) is shown with the average value as 100%. In addition, in FIG. 2, the variation of each physical quantity in fuel index constant control is shown in the section of 0 to 25 second, and the variation of each physical quantity in propeller torque constant control is shown in the section of 30 to 55 second.

When dimensioning each physical quantity by fluid density (ρ), propeller diameter (D), and target rotational speed (No), the propeller torque (Qp) uses torque coefficient (Kq) and periodic rotational speed (N).

.

Here, the propeller torque Qp, the torque coefficient Kq, and the cycle rotational speed N are used using the respective average values Qpa, Kqa, Na, and the fluctuation components ΔQp, ΔKq, and ΔN.

Qp = Qpa + ΔQp

Kq = Kqa + ΔKq

N = Na + ΔN

And linear approximation around the mean,

Can be approximated with

Here, when the average value Kqa of the torque coefficient is 1 (100%), that is, the average propeller torque Qpa is 1 (100%), the average rotational speed Na around the average value is substantially the target rotational speed ( No) (= 1), the propeller torque fluctuation component ΔQp is represented by

.

In addition, when the inertia moment of the rotating part including the engine and the propeller is I and the periodic torque is Qe, Euler's equation of motion is

. Here, when the periodic torque Qe is separated into its average value Qea and the fluctuation component ΔQe, and expressed as Qe = Qea + ΔQe, since Qea is substantially the same as Qpa (Qea = Qpa), Equation 4 Is

.

Fuel Index Schedule Control

Since the periodic torque Qe is approximately directly proportional to the fuel index FI and can be substantially equal to the fuel index FI except for the coefficient, it can be considered that ΔQe = 0 in the fuel index constant control (FIG. 2B). Left). In this case, Equation 5 is

.

Here, load fluctuation due to disturbance such as waves is represented as fluctuation ΔKq of torque coefficient Kq, and sine wave of fluctuating angular velocity ω is shown in ΔKq (Fig. 2D left).

(T is time),

. Substituting this in Equation 6 Euler's equation of motion

.

Here, the normal solution of Equation 9 is

(Left of FIG. 2A).

That is, in the fuel index constant control, when a periodic load fluctuation represented by Equation 7 is applied to the propeller, the periodic rotational speed N fluctuates as shown in Equation 10 due to the delay of the phase θ according to the moment of inertia I. do. At this time, the propeller torque Qp and thrust Th (= Kt · N ² , Kt: thrust coefficient) fluctuate as in Equation 8 (left of FIG. 2C), and the propulsion efficiency is lowered. In addition, it is assumed here that the thrust coefficient Kt fluctuates approximately (in phase) with the torque coefficient Kq except for the difference of the offset amount.

(Propeller torque constant control)

On the other hand, if propeller torque Qp is constant, (DELTA) Qp = 0 (FIG. 2C right), and substituting this into Formula (3)

. That is, when the linear approximation is established around the average value, in order to make the propeller torque Qp constant, the target rotational speed No is centered by adjusting the periodic rotational speed N to the variation ΔKq of the torque coefficient Kq. It is good to change according to Formula (11) (FIG. 2A right).

Further, when propeller torque Qp is constant (ΔQp = 0), Equation 5

dΔN / dt = ΔQe / I

Denotes the variation component ΔQe of the periodic torque Qe

.

Here, as in the fuel index constant control, when a periodic variation of the equation (7) is assumed in the torque coefficient Kq (Fig. 2D), the condition for making the propeller torque Qp constant is expressed from the equation (11).

ΔN = -Asin (ωt) / 2

It can be seen that the periodic rotation speed N may be changed in an amplitude of 1/2 in the opposite phase to the variation ΔKq of the torque coefficient (Fig. 2A right). In addition, this is based on the equation 12, and the periodic torque Qe is set around the average value Qea.

It corresponds to the fluctuation | variation in (FIG. 2B right).

As described above, the fuel index FI may be regarded as the periodic torque Qe. Therefore, when the load variation is given by the equation (7), the propeller torque Qp is kept constant by adding the variation of the equation (13) to the fuel index (FIo) corresponding to the target rotational speed (No). ). That is, in the first embodiment, as shown in FIG. 1, the delay of the phase of the actual rotational speed Ne by 90 ° (a quarter cycle) in the time delay logic 13 is negatively returned. In the proportional control unit 14, amplification is performed at a gain corresponding to the variable angular velocity?.

As mentioned above, according to 1st Embodiment, propeller torque is kept constant, thrust is kept constant, and the fall of propulsion efficiency by load fluctuation can be prevented.

Next, with reference to FIG. 3, the control apparatus of the marine engine which is 2nd Embodiment of this invention is demonstrated. 3 is a control block diagram which shows the structure of the control apparatus of the marine engine of 2nd Embodiment.

In the marine engine control apparatus 10 of the first embodiment, only the P control is used, and the fuel index FIo corresponding to the target rotational speed No is generated through the N / FI converter 12. However, in the ship engine control apparatus 20 of 2nd Embodiment, PI control is used and the N / FI conversion part 12 is not used. In addition, the other structure is the same as that of 1st Embodiment, and the same code | symbol is used about the same structure, and the description is abbreviate | omitted.

In the ship engine control apparatus 20, the deviation of the feedback signal of the actual rotation speed Ne via the target rotation speed No and the time delay logic 13 is input to the proportional + integral control unit (PI control unit) 17. . The input deviation is outputted to the actuator 16 by performing each calculation in the proportional + integral control unit (PI control unit) 17. Further, the fuel index FIo corresponding to the target rotational speed No is generated and maintained in the I calculation unit of the proportional + integral control unit (PI control unit) 17. At this time, the integral time constant is set to a slightly longer time which is not affected by the fluctuation period.

As described above, also in the second embodiment, as in the first embodiment, the propeller torque can be kept constant, and the same effect can be obtained.

In the first and second embodiments, the time delay logic is used to delay the actual rotation speed to provide feedback, and the gain of the proportional calculation unit is set corresponding to the fluctuating angular speed of the actual rotation speed. It can also be configured to feed back by implementing.

For example, the control block diagram of the control apparatus 22, 25 of the marine engine of 3rd and 4th embodiment which uses a differential calculation is shown to FIG. 4,5. In addition, in the following description, about the structure similar to 1st, 2nd embodiment, the same referential mark is used and the description is abbreviate | omitted.

The third embodiment of FIG. 4 corresponds to the first embodiment of FIG. 1, and the fourth embodiment of FIG. 5 corresponds to the second embodiment of FIG. 3. That is, in the third embodiment, the fuel index FIo corresponding to the target rotational speed No is generated through the N / FI converter 12, and the actual rotational speed Ne is the derivative calculation logic 21, It returns to the fuel index FIo from the N / FI conversion part 12 via the proportional control part 14 positively. In the differential calculation logic 21, a differential calculation is performed at the actual rotation speed Ne, and in the proportional control unit 14, the differential signal is amplified to a predetermined gain.

On the other hand, in the fourth embodiment, the actual rotation speed Ne is positively returned via the differential calculation logic 21 and the proportional control unit 14 as in the third embodiment, and negative feedback to the input side of the target rotation speed No. The deviation is input to the integration control unit 24. In other words, the integral time constant of the integration controller 24 is set to a slightly longer time unaffected by the fluctuation period, and the fuel index FIo corresponding to the target rotational speed No is determined in the I calculation of the integration controller 24. It is created and maintained. The feedback signal output from the proportional control unit 14 is fed back to the signal FIo from the integration control unit 24, and the sum thereof is input to the actuator 16.

As mentioned above, also in the structure of 3rd, 4th embodiment, propeller torque constant control can be implement | achieved like 1st, 2nd embodiment.

In addition, propeller torque constant control of 1st-4th embodiment is used together with rotation speed constant control, fuel index constant control, output constant control, etc., for example, and is selectively switched automatically or manually according to the resolution, for example. do. Propeller torque constant control is suitable when the load fluctuation due to waves or the like is a substantially constant period of about 20 seconds or less (more preferably 10 seconds or less), and is selected under such conditions, for example. In the first and second embodiments, propeller torque constant control can be switched to output constant control by setting the delay time of the time delay logic to 0 and the proportional gain of the control unit to 1.

10, 20, 22, 25 Marine Engine Control
11 main engine
12 N / FI converter
13 time delay logic
14 proportional control
15 cycle output unit
16 actuator
17 Proportional + Integral Control Unit (PI Control Unit)
21 Differential Arithmetic Logic
24 integral control unit

Claims (7)

A ship engine control device for outputting a fuel index by giving a target rotational speed, the feedback signal being delayed by 10% to 30% with respect to the period of change of the actual rotational speed of the main engine, and at the same time And the fuel index is changed in proportion to the fluctuating angular velocity. The method of claim 1, wherein the feedback signal is a signal obtained by delaying the actual rotation speed by a time delay logic, and a proportional calculation unit configured to set a gain whose deviation between the target rotation speed and the feedback signal corresponds to the variable angular velocity. Marine engine control apparatus characterized in that the output. 3. The apparatus according to claim 2, further comprising target rotational speed / fuel index converting means for calculating a fuel index corresponding to the target rotational speed, wherein output from the proportional calculation unit is added to the fuel index corresponding to the target rotational speed. A ship engine control device characterized in that. A PI control unit is provided, wherein the deviation between the target rotational speed and the feedback signal is input to the PI control unit, and a fuel index corresponding to the target rotational speed is generated and maintained by the I calculation unit of the PI control unit. Marine engine control device characterized in that the. The marine engine control apparatus according to claim 1, wherein the feedback signal is generated by a derivative operation of the actual rotation speed. The ship provided with the ship engine control apparatus in any one of Claims 1-5. A ship engine control method for outputting a fuel index by giving a target rotational speed, the feedback signal being delayed by 10% to 30% with respect to the period of change in the actual rotational speed of the main engine, and at the same time proportional to the fluctuation angular velocity of the actual rotational speed. By varying the fuel index.

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