JPS58185393A - Vibration damper of ship - Google Patents

Abstract

PURPOSE:To reduce vibration of a ship body, by providing a pressure sensor, vibromotive force estimator, vibromotive frequency estimator and vibration evaluator. CONSTITUTION:A signal from a pressure sensor 1 is convertibly shaped to a voltage signal by a pressure interface device 5 and applied to a pressure signal input terminal 16, and a pressure signal input to the terminal 16 is converted to a digital signal by an A/D converter 22 further converted to estimated vibromotive force by a vibromotive force estimator 23 and input to a vibration evaluator 26. Simultaneously a time signal from a clock generator 25 and the pressure signal are used, and a vibromotive frequency is obtained by a frequency estimator 24 and input to the evaluator 26. In this way, a more effective vibration reducer of a ship body can be obtained.

Description

[Detailed description of the invention] The present invention relates to a vibration reduction device for a ship.

Conventional methods for reducing ship vibrations involve adjusting trim, changing propeller rotation speed, etc. based on experience during actual operation. At present, a device that quantitatively captures vibration and systematically executes or estimates vibration reduction has not yet been developed.

The present invention was proposed in view of these circumstances, and it quantitatively estimates the vibration situation of a ship, calculates the optimal swamp and trim, propeller rotation, propeller pitch angle, etc. according to the loading condition, The purpose of this device is to provide a vibration reduction device for ships that can effectively damp vibrations even on ships that are prone to vibration by avoiding vibration areas, etc., and is attached to the stern hull above the propeller. an excitation force estimator and an excitation frequency estimator that input the output of the pressure sensor and output an excitation force and an excitation frequency, respectively; and an excitation force, an excitation frequency, and a propeller rotation speed. , a vibration evaluator that inputs pitch angle and hiccup information and outputs the amount of vibration, and a display device that displays the amount of vibration in real time.

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view thereof, FIG. 2 is a rear view of FIG. 1, and FIG. 3 is a block diagram showing the circuit configuration of the present invention.

In the above figure, 1 is a pressure sensor attached to the stern hull above the propeller 3, 2 is a rudder, 4 is a main engine, and 5 is a pressure interface.

6 is a data processing device, 7 is a display device, 8 is an operation panel, 9 is a control innoturface, 10 is a propeller rotation speed control device, 11 is a propeller pitch angle control device, 12 is a ballast pump control device, 13 is a propeller rotation A number of pitch angle signal interface devices, 14 a stuttering signal interface device, 16 an output A of the pressure interface 5;
A pressure signal input terminal to the /D converter 22, 17 an input terminal for the output of the propeller rotation speed pitch angle signal interface 13 to the vibration evaluator 26, and 18 an input terminal for the output of the hiccup signal interface 14 to the vibration evaluator 26. Terminal 19 is an input terminal for the output of the operation panel 8 to the human power data converter 27, 2
0 is an input terminal for the output of the vibration evaluator 26 to the display device 7, 21 is an input terminal for the output of the reduction controller 28 to the control interface 9, 23 is an excitation force estimator, 24 is a frequency estimator, and 25 is an input terminal for the display device 7. A clock generator 29 is a control condition setter.

In such a device, the data processing device 6 processes the signal input from the pressure sensor 1 and sends it to control devices such as the propeller rotation speed control device 1O, the propeller pitch angle control device 11, and the ballast pump control device 12 as a vibration reduction operation. Outputs a control signal.

The main cause of vibration on a ship is the excitation force caused by the rotation of the propeller. Therefore, the pressure sensor 1 installed at the stern detects the excitation force, determines a vibration reduction method that corresponds to the situation, and applies various controls. Issue a command signal to the device.

The relationship between excitation force and pressure is determined in advance through sea trials, etc.
The control method is determined based on the relationship between the excitation force and the hull resonance frequency (hull unique frequency) stored in advance as data.

In other words, in the case of a fixed pitch propeller, the rotation speed is changed to the non-resonant side, and in the case of a variable pitch propeller, the pinch angle and the rotation speed are changed to the non-resonant side. At this time, the operation amount is commanded from the operation panel 8 using preset allowable rotation speed, pitch angle, trim, and stuttering as limiting conditions.

Trim and stutter settings shall be determined through predictive calculations during loading, but instructions to change trim and stutter will be given if necessary.

The signal 1'- from the pressure sensor 1 is converted into a voltage signal by the pressure interface device 5, and then sent to the pressure signal input terminal 1.
6 and input to the pressure signal input terminal 16 is converted into a digital signal by an A/I converter 22, and further converted into an estimated excitation force by an excitation force estimator 23, and then is used for vibration evaluation. input into the device 26. At the same time clock generator 2
Frequency estimator 24 using the time and pressure signals from 5
The excitation frequency is obtained and input to the vibration evaluator 26.

The propeller rotation speed and pitch angle are applied to the input terminal 17 via the interface device 13, and the trim and stutter information are applied to the input terminal 18 via the stutter signal interface 14, respectively, to the vibration evaluator 2.
Enter 6. Reference numeral 19 is an input/output terminal with the operation panel 8, and the limiting conditions (allowable rotation speed, etc.) set on the operation panel 8 are sent to the control condition setter 29 via the input data converter 27. The output signal of 29 is input to a vibration evaluator 26 and a mitigation controller 28 . The vibration evaluator 26 determines the amount of vibration moment by moment from the vibration characteristics specific to the target ship based on the estimated excitation force, excitation frequency, etc., and outputs this to the display device 7 and the mitigation controller 28.

In this N, the amount of vibration is an amount that is temporarily set as shown in the following formula in order to understand the vibration of the ship's hull, and it is an amount that is temporarily set as shown in the following formula, and is a value that is calculated based on the vibration of the main ship, superstructure, mast, chimney, main engine, shaft system, etc. It expresses the response characteristics, and the unit is acceleration (other dimensions are also possible), which is the sum of the vibration acceleration of each part.

Amount of vibration - F (p, f-) -'4 F+ (at,
fI-)1-1 The dip is, for example, F+=kixatxf+, where ai=amplitude kI==: Coefficient fI of constant or variable - frequency amplitude a is determined, for example, by the following equation.

Here, g = Acceleration of gravity F* = Excitation force T1 - = Period of excitation force T = Natural vibration period of the ship Δ1 - Displacement volume including additional water = 2 damping coefficient = δ, /11 δn = Logarithmic damping Lead =
Coefficient (=0.4 to 0.6) In this way, each control device 10, 11 . The operating amount for 12 is calculated and input from the input terminal 21 to each control device 10, 11, and 12 via the control interface 9. At this time, the control condition setter 29 distributes the manipulated variables.

The distribution of the amount of operation is the propeller that causes vibration.

As a vibration reduction measure, by dividing the operation amount of equipment that affects each vibration force, such as the main engine, waves, and auxiliary equipment, into preset ratios or ratios determined by the magnitude of vibration, etc.
Decide which of several methods to focus on, such as changing the main engine rotational speed (propeller rotational speed), changing the propeller pitch angle, changing the trim by ballast injection, and changing the draught. 50% effect due to rotation speed range,
Assuming that the operation amount is distributed to 50% of the effect of changing the pitch angle, the rotation speed is reduced by 5 rpm and the pinch angle is reduced by 1°.

According to such a device, the following effects can be achieved.

(1) According to the actual loading condition, stagnant condition, and navigation condition,
Fine-grained vibration mitigation measures can be taken, improving the safety of passengers and onboard equipment.

(2) Even ships that generate vibrations can be used satisfactorily in operation, and costly modifications are not necessary, so the cost of vibration countermeasures can be reduced.

(3) Even if the vibration is within the permissible range, this device can create the best navigational conditions, reducing operational losses due to vibration, resulting in fuel savings.

In the above example, you can freely select a device other than the pressure sensor as long as it has the same function, and any side pressure method for the pressure sensor is fine, but the structure must be able to withstand water pressure that can be considered at the mounting location. There is.

Further, the present invention is useful as a device that does not implement measures to reduce vibration, but only quantitatively indicates the degree of vibration.
When controlling, it shall be carried out according to each propulsion device, such as a fixed pinch propeller, a variable pitch propeller, or a single-shaft or two-shaft propeller.

In short, according to the present invention, a pressure sensor attached to a position above the propeller of the stern hull and an excitation force estimator and an excitation frequency estimation device input the outputs of the pressure sensor and output an excitation force and an excitation frequency, respectively. vessel and the above excitation force.

Excitation frequency, propeller rotation speed, and pitch angle.

By providing a vibration evaluator that inputs stanchion information and outputs the amount of vibration, and a display device that displays the amount of vibration in real time, an effective vibration reduction device for a ship body is obtained. Above all, it is extremely useful.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the present invention, FIG. 2 is a rear view of FIG. 1, and FIG. 3 is a block diagram showing the circuit configuration of the present invention. 1... Pressure sensor, 2... Rudder, 3... Propeller 4... Main engine, End... Pressure interface, 6...
Data processing device, 7...Display device 8...Operation panel, 9...Control interface, 10...Propeller rotation speed control device, 11...Propeller pitch angle control device, 12...Ballast pump control Device, 13... Propeller rotation speed pitch angle signal interface device, 14
...Staffing signal interface, 16...Pressure signal input terminal, 17...Input terminal, 18...Input terminal, 1
9...Input/output terminal, -120...Input terminal, 211...
- Input terminal 22... A/D converter, 23... Excitation force estimator, 24... Frequency estimator, 25... Clock generator 26... Vibration-evaluator, 27... - Input data converter 28...reduction controller, 29...control condition setter. Sub-Agent Patent Attorney Masafumi Tsukamoto Figure 11 P) Figure 2

Claims (1)

[Claims] A pressure sensor attached to a position above the propeller of the stern hull; an excitation force estimator and an excitation frequency estimator that input the output of the pressure sensor and output an excitation force and an excitation frequency, respectively; It is characterized by being equipped with a vibration evaluator that outputs the amount of vibration by inputting the vibration force, the excitation frequency, the propagating rotation speed, the pitch angle, and the hiccup information, and a display device that displays the amount of vibration in real time. Vibration reduction device for ships.