JPS6218399B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a constant speed control method for a ship equipped with a fixed pitch propeller, and more particularly to a ship speed control method that can maintain the ship speed set based on the operation schedule against any changes in operating conditions. It is something. As a method of keeping the ship speed constant, a method using a variable pitch propeller has been disclosed in Japanese Patent Application Laid-Open No. 52-22298, etc., but an automated method for ships equipped with a fixed pitch propeller is not yet known. In the operation of a normal ship, there are often considerable restrictions on the schedule, and therefore the set speed must be maintained constant for a certain period of time, but ships equipped with fixed pitch propellers have to maintain this speed. Conventionally, this control has been performed by the crew manually operating the main engine, and it is necessary to secure personnel for constant speed operation. This invention was made in view of recent demands for labor saving, and aims to achieve automation of constant speed operation in ships equipped with fixed pitch propellers. In other words, the method for controlling the constant speed of a ship equipped with a fixed pitch propeller according to the present invention is to obtain a set horsepower corresponding to a set speed of the ship from the current horsepower and the detected ship speed, and calculate the current detected horse power and the current rotational speed. The main engine rotation speed is controlled by determining the constant rotation speed corresponding to the set horsepower from the value, or the set easy scale is determined from the set rotation speed and the set horsepower, and the main engine is controlled by the set easy scale. This system is characterized by being able to automatically match the current ship speed to the set ship speed and maintaining the ship speed constant. The invention will now be described in detail with reference to the block diagram of FIG. In the figure, 1 is a boat speed setting dial that sets the desired boat speed at that time, 2 is a rotation speed detector that measures the rotation speed of the propeller shaft at that time, and 3 is a rotation speed transmitter. It transmits the rotational speed measured by the detector 2. 4 is a rack scale transmitter that transmits the actual rack scale at that time, and 5 is a horsepower that calculates the horsepower at that time from the rotation speed and easy scale sent from the rotation speed transmitter 3 and the rack scale transmitter 4. It is a computing device. 6 is a ship speed detector such as an electromagnetic log that measures the actual ship speed at that time, 7 is a ship speed detector 6
A ship speed transmitter 8 transmits the measured ship speed from the horsepower and ship speed sent from the horsepower calculator 5 and ship speed transmitter 7, respectively, and the set ship speed sent from the ship speed setting dial 1. This is a setting horsepower calculation unit that calculates the horsepower to be set as described below. Reference numeral 9 denotes a setting rack scale calculator that calculates a rack scale from the set horsepower from the set horsepower calculator 8 and the set rotation speed from the set rotation speed transmitter 11, which will be described later; and 10, the set horsepower from the set horsepower calculator 8. and a set rotation speed calculation unit that calculates the rotation speed to be set from the current horsepower value from the horsepower calculation unit 5 and the current rotation speed from the rotation speed transmitter 3 as described later. Reference numeral 11 denotes a set rotation speed transmitter that transmits the set rotation speed determined by the set rotation speed calculator 10. Reference numeral 12 denotes a rack scale control device for adjusting the set rack scale from the set rack scale calculation unit 9. Reference numeral 13 denotes a rotation speed control device for controlling the set rotation speed sent from the set rotation speed transmitter 11. In addition, when controlling by the rotation speed control device 13 in FIG. 1, the setting rack scale calculator 9 and the rack scale control device 12, which are surrounded by broken lines, are unnecessary. The case where control is performed by the rotation speed control device 13 (first invention) will be described below. The set horsepower calculator 8 will be explained in more detail with reference to FIG. In FIG. 2, curve A is the relationship between ship speed and required horsepower under standard loading conditions of the ship and standard sea and meteorological conditions. This curve A is stored in the set horsepower calculator 8. Next, the horsepower and ship speed in actual sailing conditions are obtained from the horsepower calculator 5 and the ship speed transmitter 7. This horsepower is Pb,
Let the ship speed be Vb. This navigational state is point b in the diagram.
It is. From this point b, curve B is the relationship between horsepower and ship speed under the current sailing conditions. This determination method is, for example, as follows. First, the relationship between ship speed and horsepower is approximated by the following equation. P=q・V ^r ………(1) That is, for curve A, calculate the horsepower Pab, Pao for the ship speed Vb, Vo from the memorized relationship between the horsepower and ship speed, and substitute this into equation (1). Then, solve the simultaneous equations to find q and r. Let these values be qa and ra. Next, curve B is approximated, for example, as shown in the following equation. P=q ^b・V ^ra (2) Substitute point b (Pb, Vd) into equation (2) to find qb. By such a method, the curve B in the range of ship speeds Vb to Vo can be sufficiently approximated. Furthermore, the above formula
(1) and (2) can be replaced with other formulas, and this application is not intended to limit this. Therefore, under the current sailing conditions, the ship's speed
The horsepower Pbo required for sailing at Vo can be calculated using equation (2). Referring to FIG. 3, the setting rotation speed calculator 10 is as follows:
This will be explained in more detail. In FIG. 3, curve A is the relationship between the rotational speed and the required horsepower under the standard loading state of the ship and the standard sea and meteorological conditions. This curve A
is stored in the set rotation speed calculator 10. Next, the horsepower and rotational speed in the actual sailing state are obtained from the horsepower calculator 5 and the rotational speed transmitter 3.
Let this horsepower be Pb and the rotation speed Nb. This sailing state is point b in the figure. From this point b, curve b is the relationship between horsepower and rotational speed under the current sailing conditions. This determination is performed using the following method. First, the relationship between rotational speed and horsepower is approximated to, for example, the following relationship. P=x・N ^y ......(3) That is, in curve A, from the relationship between the stored horsepower and the rotation speed, the rotation speed Nab, Nao for the horsepower Pb, the set horsepower Po obtained by the set horsepower calculation unit 8, seek,
Substituting this into equation (3) and solving the simultaneous equations, x, y
seek. Let these values be xa and ya. Next, curve B is approximated as shown in the following equation. P=xb・^Nya ......(4) Substitute point b (Pb, Nb) into equation (4) to find xb. By such a method, the curve B in the range of horsepower Pb to Po can be sufficiently approximated. Therefore, under the current sailing conditions, the horsepower
The rotational speed Nbo corresponding to Po can be determined using equation (4).

[Formula] becomes. As described above, the present invention calculates the current horsepower by the horsepower calculator 5 based on the current easy scale from the easy scale transmitter 4 and the current rotation speed from the rotation speed transmitter 3. This calculation result, the current ship speed from the ship speed transmitter 7, and the ship speed setting dial 1
The set horsepower corresponding to the set ship speed set in is calculated by the set horsepower calculator 8, and the set horsepower is calculated from the set horsepower, the current horsepower P, and the current rotation speed N.
0 to determine the set rotation speed corresponding to the set horsepower, this set rotation speed is transmitted by the set rotation speed transmitter 11, and the main engine rotation speed is controlled by the rotation speed control device 13 so that the set rotation speed is obtained. Control. In addition, when the rotation speed control device 13 is controlled by the easy scale control device 12 instead of the rotation speed control device 13 (second invention), the rotation speed control device 13 is not necessary, and the setting easy scale calculator 9 and the easy scale surrounded by the broken line are used. A control device 12 is employed. Then, from the set rotation speed from the set rotation speed transmitter 11 and the set horsepower from the set horsepower calculator 8, a setting rack scale calculator 9
The setting rack scale may be obtained by using the rack scale, and the main engine may be controlled by adjusting the fuel flow rate based on the rack scale. Since the present invention is as described above, it is possible to quickly match the current ship speed to the set ship speed, and the ship speed can be automatically maintained constant.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a characteristic diagram showing the relationship between ship speed and required horsepower, and FIG. 3 is a characteristic diagram showing the relationship between required horsepower and rotational speed. 1: Ship speed setting dial, 2: Rotation speed detector,
3: Rotation speed transmitter, 4: Easy scale transmitter, 5:
Horsepower calculator, 6: Ship speed detector, 7: Ship speed transmitter,
8: Set horsepower calculator, 9: Set rack scale calculator, 10: Set rotation speed calculator, 11: Set rotation speed transmitter, 12: Rat scale control device, 13: Rotation speed control device.

Claims (1)

[Scope of Claims] 1. Determine the set horsepower corresponding to the ship speed setting value from the current horsepower and ship speed detection value, and determine the set rotation speed corresponding to the set horsepower from the current horsepower detection value and the current rotation speed detection value. A method for controlling a constant ship speed in a ship equipped with a fixed pitch propeller, which is characterized by controlling the main engine rotation speed by determining the following. 2. Find the set horsepower corresponding to the ship speed setting value from the current horsepower and ship speed detection value, find the set rotation speed corresponding to the set horsepower from the current horse power detection value and the current rotation speed detection value, and then 1. A method for constant ship speed control in a ship equipped with a fixed pitch propeller, characterized in that a set easy scale is determined from the set rotational speed and the set horsepower, and the main engine is controlled based on the set easy scale.