JP4994505B1 - Marine engine control apparatus and method - Google Patents

Abstract

The present invention performs main engine control in which propeller torque is constant, suppresses thrust fluctuation, and improves propulsion efficiency.
An actual rotational speed Ne of a main engine 11 is detected and input to a time delay logic 13 and a period calculation unit 15. The period calculation unit 15 detects the fluctuation cycle of the actual rotational speed Ne, and the time delay logic 13 delays the actual rotational speed Ne by a quarter period and performs negative feedback. The deviation between the target rotational speed No and the feedback signal is input to the proportional control unit 14 and proportional calculation is performed with a gain corresponding to the fluctuation angular speed ω of the actual rotational speed Ne calculated from the period obtained by the period calculating unit 15. The fuel index FIo corresponding to the target rotational speed No is calculated in the N / FI conversion unit 12 and added to the output from the proportional control unit 14.
[Selection] Figure 1

Description

  The present invention relates to a marine engine control apparatus that controls the operation of a main engine of a marine vessel.

  In ships, constant rotation speed control for maintaining the propeller rotation speed at a constant value is generally employed. That is, in the governor control of the ship main engine, the actual rotational speed is maintained at the target rotational speed by PID control (Patent Document 1). However, in the constant rotation speed control, the fuel supply amount (fuel index) varies depending on the load variation, and thus the fuel efficiency may deteriorate. Therefore, depending on the sea condition, governor control for fixing the fuel supply amount (fuel index) to a constant value may be performed.

Japanese Patent Laid-Open No. 8-200231

  However, even if the fuel index is kept constant and the main engine torque is kept substantially constant, if the propeller load fluctuates, the propeller torque is not kept constant, so that the thrust fluctuates and propulsion efficiency decreases.

  An object of the present invention is to perform main engine control with a constant propeller torque, suppress thrust fluctuation, and improve propulsion efficiency.

  The marine engine control device according to the present invention is a marine engine control device that provides a target rotational speed and outputs a fuel index, and feeds back a feedback signal delayed by 10% to 30% with respect to the fluctuation cycle of the actual rotational speed of the main engine. In addition, the fuel index is varied in proportion to the fluctuation angular velocity of the actual 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 via a proportional calculation unit in which a gain corresponding to the variable angular speed is set, for example. .

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

  Alternatively, the marine engine control device includes a PI control unit, and a deviation between the target rotation speed and the feedback signal is input to the PI control unit, and a fuel index corresponding to the target rotation speed is generated and generated in the I calculation unit of the PI control unit. Maintained.

  Further, the feedback signal may be generated by differential calculation of the actual rotational speed.

  A ship according to the present invention includes the marine engine control device.

  Further, the marine engine control method of the present invention is a marine engine control method for providing a target rotational speed and outputting a fuel index, and providing a feedback signal delayed by 10% to 30% with respect to the fluctuation cycle of the actual rotational speed of the main engine. While returning, the fuel index is varied in proportion to the angular velocity of the actual rotational speed.

  According to the present invention, main engine control in which the propeller torque is constant can be performed, thrust fluctuation can be suppressed, and propulsion efficiency can be improved.

It is a control block diagram which shows the structure of the engine control apparatus of 1st Embodiment. It is a graph for demonstrating the principle of this invention, and an effect | action and effect. It is a control block diagram which shows the structure of the engine control apparatus of 2nd Embodiment. It is a control block diagram which shows the structure of the engine control apparatus of 3rd Embodiment. It is a control block diagram which shows the structure of the engine control apparatus of 4th Embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a control block diagram showing the configuration of a marine engine control apparatus according to the first embodiment of the present invention.

  The marine engine control device 10 of this embodiment is a governor system that controls fuel supply to the main engine 11, and a crankshaft (not shown) of the main engine 11 is connected to a propeller (not shown) for propulsion. Is done. In the marine engine control device 10, the target rotational speed No is set as the target value, and the actual rotational speed Ne that is the output of the main engine 11 is detected by a known method using a turning gear or the like.

  The target rotational speed No is converted into a fuel index FIo in the N / FI conversion unit 12. In parallel with this, in the present embodiment, a deviation from the actual rotational speed Ne of the main engine 11 fed back via the time delay logic 13 is obtained, and a proportional calculation is performed in the proportional control unit 14.

  In this embodiment, the proportional control unit 14 performs a proportional calculation with a gain proportional to the fluctuation angular velocity ω of the actual rotational speed Ne, and the time delay logic 13 sets the phase of the actual rotational speed Ne to approximately 90 ° or about the fluctuation period. Delay 10-30%. The gain of the proportional control unit 14 and the delay time of the time delay logic 13 are determined based on the cycle T of the actual rotation speed Ne calculated by the cycle calculation unit 15 based on the fluctuation of the actual rotation speed Ne.

  The signals from the N / FI conversion unit 12 and the proportional control unit 14 are added and input to the actuator 16, and the actuator 16 supplies the main engine 11 with an amount of fuel corresponding to the fuel index FI.

  Next, the principle of the constant propeller torque control of the present invention will be described with reference to FIG. 2 in contrast to the constant fuel index control.

  FIG. 2 shows main engine rotation speed N (FIG. 2 (a)), fuel index FI or main engine torque Qe (FIG. 2 (b)), propeller torque Qp or thrust ( FIG. 2 (c)) shows the time variation of the torque coefficient Kq (FIG. 2 (d)) with the average value being 100%. Further, in FIG. 2, the fluctuation of each physical quantity in the fuel index constant control is shown in the section of 0 to 25 seconds, and the fluctuation of each physical quantity in the constant propeller torque control is shown in the section of 30 to 55 seconds.

When each physical quantity is made dimensionless with the fluid density ρ, the propeller diameter D, and the target rotational speed No, the propeller torque Qp is calculated using the torque coefficient Kq and the main engine rotational speed N. Qp = Kq · N ² (1)
It is expressed.

Here, the propeller torque Qp, the torque coefficient Kq, and the main engine rotation speed N are calculated using the average values Qpa, Kqa, Na and the fluctuation components ΔQp, ΔKq, ΔN, respectively. Qp = Qpa + ΔQp
Kq = Kqa + ΔKq
N = Na + △ N
When the equation (1) is linearly approximated around the average value, ΔQp = (∂Qp / ∂Kq) · ΔKq + (∂Qp / ∂N) · ΔN
= Na ² · ΔKq + 2Kqa · Na · ΔN (2)
Can be approximated.

Here, when the average value Kqa of the torque coefficient is 1 (100%), that is, when the average propeller torque Qpa is 1 (100%), the average rotational speed Na around the average value is substantially equal to the target rotational speed No (= 1). ), The propeller torque fluctuation component ΔQp is obtained from the equation (2) as follows: ΔQp = ΔKq + 2 · ΔN (3)
It is expressed as

Also, assuming that the inertia moment of the rotating part including the engine and propeller is I and the main engine torque is Qe, Euler's equation of motion is dN / dt = (Qe−Qp) / I (4)
It becomes. Here, when the main engine torque Qe is separated into its average value Qea and fluctuation component ΔQe and expressed by Qe = Qea + ΔQe, Qea is substantially equal to Qpa (Qea = Qpa), and the equation (4) is expressed by dΔ N / dt = (ΔQe−ΔQp) / I (5)
It is expressed.

(Fuel index constant control)
Since the main engine torque Qe is substantially directly proportional to the fuel index FI and is 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). At this time, the equation (5) is expressed as dΔN / dt = −ΔQp / I (6)
It is expressed.

Here, load fluctuation due to disturbance such as waves is expressed as fluctuation ΔKq of torque coefficient Kq, and ΔKq is a sine wave of fluctuation angular velocity ω (left in FIG. 2 (d)).
ΔKq = A · sin (ωt) (7)
(T is time), from equation (3): ΔQp = A · sin (ωt) + 2 · ΔN (8)
It becomes. Substituting this into equation (6), Euler's equation of motion is
dΔN / dt = − (A · sin (ωt) + 2 · ΔN) / I (9)
It becomes.

Here, the steady solution of equation (9) is
ΔN = B · sin (ωt + θ) (10)
B = −A / √ ((ωI) ² +4)
θ = −tan ⁻¹ (ωI / 2)
(Left side of FIG. 2A).

That is, in the constant fuel index control, when a periodic load fluctuation expressed by the equation (7) is applied to the propeller, the main engine rotation speed N has a phase θ delay corresponding to the moment of inertia I as shown in the equation (10). fluctuate. At this time, the propeller torque Qp and the thrust Th (= Kt · N ² , Kt: thrust coefficient) fluctuate as in the equation (8) (left in FIG. 2C), and the propulsion efficiency decreases. Here, it is assumed that the thrust coefficient Kt fluctuates in substantially the same manner (in the same phase) as the torque coefficient Kq except for the difference in offset.

(Propeller torque constant control)
On the other hand, if the propeller torque Qp is constant, ΔQp = 0 (FIG. 2 (c) right), and if this is substituted into the equation (3), ΔN = −ΔKq / 2 (11)
Is obtained. That is, when the linear approximation is established around the average value, in order to make the propeller torque Qp constant, the main engine rotational speed N is adjusted to the variation ΔKq of the torque coefficient Kq and the target rotational speed No is centered according to the equation (11). What is necessary is just to make it fluctuate (FIG. 2 (a) right).

When the propeller torque Qp is constant (when ΔQp = 0), the equation (5) is expressed as dΔN / dt = ΔQe / I.
And the fluctuation component ΔQe of the main engine torque Qe is ΔQe = I · (dΔN / dt) (12)
It becomes.

Here, as in the case of the constant fuel index control, when the periodic variation of the equation (7) is assumed for the torque coefficient Kq (FIG. 2 (d) right), the condition for making the propeller torque Qp constant is (11 ) From the equation: ΔN = −A · sin (ωt) / 2
Thus, it can be seen that the main engine rotational speed N may be varied with an amplitude of ½ in phase opposite to the variation ΔKq of the torque coefficient (FIG. 2 (a) right). In addition, from the equation (12), the main engine torque Qe is set around the average value Qea. ΔQe = −ω · I · A · cos (ωt) / 2 (13)
(Fig. 2 (b) right).

  As described above, the fuel index FI can be regarded as the main engine 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 (FIG. 2 (c) )right). That is, in the first embodiment, as shown in FIG. 1, in the time delay logic 13, the phase obtained by delaying the phase of the actual rotational speed Ne by 90 ° (one quarter cycle) is negatively fed back, and the proportional control unit 14. Then, amplification is performed with a gain corresponding to the fluctuation angular velocity ω.

  As described above, according to the first embodiment, the propeller torque can be kept constant and the thrust can be kept constant, and the reduction in propulsion efficiency due to load fluctuation can be prevented.

  Next, a marine engine control apparatus according to a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a control block diagram showing the configuration of the marine engine control device of the second embodiment.

  In the marine engine control apparatus 10 of the first embodiment, the fuel index FIo corresponding to the target rotational speed No is generated through the N / FI conversion unit 12 using only P control. However, in the marine engine control device 20 of the second embodiment, PI control is used and the N / FI conversion unit 12 is not used. Other configurations are the same as those of the first embodiment, and the same reference numerals are used for the same configurations and the description thereof is omitted.

  In the marine engine control device 20, the deviation between the target rotational speed No and the feedback signal of the actual rotational speed Ne via the time delay logic 13 is input to the proportional + integral control unit (PI control unit) 17. The input deviation is subjected to various calculations in the proportional + integral control unit (PI control unit) 17 and is output to the actuator 16. 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 integration time constant is set to a longer time that is not affected by the fluctuation period.

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

  In the first and second embodiments, feedback is performed by delaying the actual rotational speed using the time delay logic, and the gain of the proportional calculation unit is set corresponding to the fluctuation angular speed of the actual rotational speed. A configuration may also be adopted in which a differential operation is performed on the rotational speed to feed back.

  For example, FIGS. 4 and 5 show control block diagrams of the marine engine control devices 22 and 25 of the third and fourth embodiments using differential calculation. In the following description, the same reference numerals are used for the same configurations as those in the first and second embodiments, and the description thereof is 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. That is, in the third embodiment, the fuel index FIo corresponding to the target rotational speed No is generated through the N / FI conversion unit 12, and the actual rotational speed Ne is determined by the N / FI via the differential operation logic 21 and the proportional control unit 14. Positive feedback is provided to the fuel index FIo from the converter 12. In the differential operation logic 21, differential operation is performed on the actual rotational speed Ne, and in the proportional control unit 14, the differential signal is amplified with a predetermined gain.

  On the other hand, in the fourth embodiment, the actual rotational speed Ne is positively fed back via the differential operation logic 21 and the proportional control unit 14 as in the third embodiment, and negatively fed back to the input side of the target rotational speed No. The deviation is input to the integration control unit 24. That is, the integration time constant of the integration control unit 24 is set to a longer time that is not affected by the fluctuation period, and the fuel index FIo corresponding to the target rotational speed No is generated and maintained in the I operation of the integration control unit 24. . The feedback signal output from the proportional control unit 14 is positively fed back to the signal FIo from the integration control unit 24, and the sum thereof is input to the actuator 16.

  As described above, also in the configurations of the third and fourth embodiments, the propeller torque constant control can be realized as in the first and second embodiments.

  Further, the constant propeller torque control in the first to fourth embodiments is used in combination with constant rotation speed control, constant fuel index control, constant output control, and the like, and is selectively switched automatically or manually according to the sea condition, for example. . Propeller torque constant control is suitable when the load fluctuation due to waves or the like has a substantially constant cycle 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, the propeller torque constant control can be switched to the constant output control by setting the delay time of the time delay logic to 0 and setting the proportional gain of the control unit to 1.

10, 20, 22, 25 Marine Engine Control Device 11 Main Engine 12 N / FI Conversion Unit 13 Time Delay Logic 14 Proportional Control Unit 15 Period Calculation Unit 16 Actuator 17 Proportional + Integral Control Unit (PI Control Unit)
21 Differentiation logic 24 Integral controller

Claims (7)

  A marine engine control device that provides a target rotational speed and outputs a fuel index, which feeds back a feedback signal that is delayed by 10% to 30% with respect to a fluctuation cycle of the actual rotational speed of the main engine, and also changes the actual rotational speed. A marine engine control apparatus characterized by varying the fuel index in proportion to an angular velocity.   The feedback signal is a signal obtained by delaying the actual rotational speed with a time delay logic, and a deviation between the target rotational speed and the feedback signal is output via a proportional calculation unit in which a gain corresponding to the fluctuation angular speed is set. The marine engine control device according to claim 1.   A target rotational speed / fuel index conversion means for calculating a fuel index corresponding to the target rotational speed is provided, and an output from the proportional calculation unit is added to a fuel index corresponding to the target rotational speed. The marine engine control device according to claim 2.   A PI control unit is provided, and a deviation between the target rotation speed and the feedback signal is input to the PI control unit, and a fuel index corresponding to the target rotation speed is generated and maintained in the I calculation unit of the PI control unit. The marine engine control device according to claim 2.   The marine engine control device according to claim 1, wherein the feedback signal is generated by a differential operation of the actual rotational speed.   A ship comprising the marine engine control device according to any one of claims 1 to 5.   A marine engine control method for providing a target rotational speed and outputting a fuel index, which feeds back a feedback signal delayed by 10% to 30% with respect to a fluctuation cycle of an actual rotational speed of a main engine, and changes the actual rotational speed. A marine engine control method, wherein the fuel index is varied in proportion to an angular velocity.

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