JPS61234329A - Method and apparatus for restraining motion - Google Patents

Abstract

PURPOSE:To enable the implementing of a test for the motion of a ship or the like with no errors, by restraining the motion of a fluid of a model of a ship or the like with a multi-component detector and a servomotor driven depending on the difference between the output signal thereof and an external signal. CONSTITUTION:A frame 21 is provided with surge carriage 23 movable in the direction X and a sway carriage 22 movable in the direction Y and these carriages are respectively connected to servo motors 24 and 25 through a transmission gear. A rod 37 piercing the sway carriage 22 is made movable in the direction Z with another servo motor, to a drive end of which a model of a ship is connected through a loadcell 388 as a multi-component detector to construct a motion restraining apparatus. Then, the driving of each servo motor is controlled depending on the difference between the output of the load-cell 38 and a set load value to be automatically balanced. This can eliminate effect of inertial force or the like thereby enabling an accurate restraint without any error.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of restraining the motion of a model such as a ship in a fluid, and a motion restraint device thereof.

(Industrial Application Field) Waves are constantly acting on ships, offshore structures, and other objects operating or moored at sea. It is necessary to restrain the movement of such vessels so as to maintain them in the anchored state or to change these conditions. The present invention relates to a motion restraint method and a motion restraint device for a model of a ship, etc., which is used to test the motion of a ship, etc. in such a case.

(Prior Art) In the technical fields mentioned at the beginning, models of ships, etc. are used to conduct motion restraint tests of ships, etc.

The simulated mrtc in the fluid is the force I'z in the X, Y, and Z 5-axis directions.
, l'y.

Rotational moment M#X*'#Y* of yz and rotation υ of each axis
M#z can work. Considering the motion of the hull, etc., the motions in the surge direction X, sway direction Y1, and yaw direction θz are particularly important objects to be controlled. In order to control and restrain these movements, it is necessary to detect the force (hereinafter referred to as "fluid force") exerted by the fluid on the model, and a load cell is used for this purpose.

However, the drawbacks of the prior art are that errors occur in the force detection and servo systems due to the support structure of the model carriage and the servo mechanism for restraining movement, and that the mode of restraint of movement is limited and noisy.

One known method is to connect the model shaft in the fluid with a spring, and use the tension of the spring to detect the force and drive the robot system.

Another known method is to connect the model in the fluid with a carriage rope, guide the rope through a pulley, and apply a load to the end of the rope by applying a steel splitter.

The drawbacks of both of the above-mentioned known methods are that the weight of the carriage moving together with the ship model becomes an inertial force, which causes errors in force detection, and in the former case, the carriage is always restrained only in a force equilibrium state by the spring. In the latter case, it takes time to unfasten the steel splitter, and it is difficult to restrain the ever-changing movement. Although it is not possible to properly restrain movement in one direction, for example, in the sway direction, if movement in another direction, such as rotation in the yaw direction, is added to this, restraining the model's movement becomes impossible.

(Problems to be Solved) An object of the present invention is to create a motion restraint method and a motion restraint device for a model such as a ship, and to prevent errors from occurring in the servo system for motion restraint. and to be able to diversify motion constraints.

(Ninth Means to Solve the Problem) According to the present invention, the problems of the present invention are solved by the configurations described in claims 1 and 2.

The present invention will be explained in detail based on illustrated embodiments.

Prior to the detailed description of the present invention shown in FIGS. 1a, 11) and 2, a brief description of the prior art will be given.

FIG. 3 shows a ninth prior art device for restraining the movement of a model of a ship or the like. Model 1 has five directions Y, Z, and θX in the fluid, excluding the surge direction X.

θ! , θz are allowed. Each movement is independently measured using a potentiometer or the like.

A rod 2 is installed upright on the model 1, and the rod 2 is oriented in the sway direction Y.
The rod 2 is restricted in the rotational direction θz by the movable carriage 5lit, and can only move in two directions.

The sway carriage 3 is guided on the surge carriage 4 so as to be movable in the Y direction laterally with respect to the surge carriage 4. A pulley unit 5.5' is attached to both sides of the surge carriage 4; Optical wires 6, 6' are guided through the sway carriage 3, each end of which is fixed to the sway carriage 3.

Correction weights 7, 7' can be detached from the ends of the wires 6, 6'.

Also, both ends of the surge carriage 40 and the sway carriage 3
A spring 8.8' is hung between each of them. Further, a globe 9 is attached to the joint between the rod 2 and the model 1. The glove is used to measure rolling θX and pitching θY. Model 1 of rod 2
A spring 10, 10' is attached in the area between the yaw motion JZ and the surge carriage 4 to restrain the yaw movement JZ.

Also between the sway carriage 5 and the rod 2, a device for measuring heap movement and restraining the movement is provided.

In the above device, it is assumed that the model 1 is towed in the X direction and waves are acting from the direction of the arrow A. In this case, the motion of model 1 is in five directions FY, pz.

MIX, MIX, and MIz are measured independently, and their movements are constrained. When the wave A acts on the model 1, the spring 8.8' expands and contracts due to the movement of the model 1 in the sway direction Y, and the midpoint of the movement, ie, the sway carriage 5, shifts downstream of the wave A. As a result, the amount of displacement is measured using a potentiometer or the like, and the fluid force is determined by multiplying this by the spring constant of the springs 8, 8'. At this time, the sway carriage 3 is restrained from moving by a spring 8.8'.

Remove spring 8.8' and apply a correction amount of 87.7'. Therefore, the midpoint of the movement immediately sway carriage 3
If the weight is balanced against a frame (not shown), the force directly related to the movement can be found from the weight of the weight.

The known devices suffer from the drawbacks mentioned above.

A motion restraint device according to the invention is illustrated in FIGS. 1a, 1b and 2. FIG. The device shown in the figure can measure the forces 'Pi and FY in the surge direction be able to. Frame 21Vc sway carriage 22 and surge carriage 2
3 are arranged. Sway Carriage 22! Move in the Y direction on the surge carriage 23 that can be moved in the direction 1
! J Noh is being guided onto the frame 21.

A servo motor 24 is disposed on the frame 21 for driving e4 of the sway carriage 22, and a servo motor 25 is disposed for driving Mllb of the surge carriage 23. A servo motor may be attached to the rod 37, which will be described later, to restrict movement in the yaw direction θz. A pulley 25a Ic of the servo motor 25 is wrapped around the endless wires 26 and 26', and the wires 26 and 26' are wrapped around two boobies IJ 27 and 27' on the frame 21. Another endless wire 29 is wound between the goo 1J27 and the pulley 28 at the other end of the frame 21, and a part of the endless wire 29 is fixed to the surge carriage 23. Boo 927' fixed on frame 21
Another endless wire 29 is wound between the goo 928' and the goo 928'. A portion of this wire 29' is also fixed to the surge carriage 26. Thereby the servo motor 2
Accordingly, the surge carriage 23 can move forward and backward in the X direction on the frame 21 from the motor pulley 25a via the endless wires 29 and 29'. The wire 29' is also in transmission engagement with a surge potentiometer 30 on the frame 21. Therefore wire 29'
When the surge carriage 23 travels in the X direction, the surge potentiometer 50 is rotated, and the amount of movement of the surge carriage 23 in the X direction is measured according to the rotation angle of the surge carriage 29'.

Pulley 2 of another servo motor 24 on part frame 21
Another wire 31 is wound around 4aK. A sway potentiometer 32 disposed on the frame 21 is transmission engaged with this wire 31. This wire 31
In the upper part of the figure, the pulley 33 on the frame 21 and the
It is wound around a pulley 34 on the sway carriage 23 and a pulley 35 on the sway carriage 22, and is then fixed to the frame 21 at the left end of the figure via the pulley 34 again. In the lower region of the diagram, the same wire 310 passes through the pulley 53' on the frame 2tKBffl, the pulley 34' on the surge carriage 25, and the pulley 35' on the sway carriage 22, and then again on the pulley 34.
' and is fixed to the frame 21 at the left end of the figure.

A heap potentiometer 36 is fixed to the sway carriage 22, and this is connected to a rod 37 which will be explained later.
It is used to measure displacement in two directions.

In FIG. 1b, the rod 37 is connected to the sway carriage 22.
penetrates through. The rod 57 is the sway carriage 22
It is guided so as to be rotatable relative to the main body and movable in two directions. A servo motor can be attached to the sway carriage 22 to restrain the yaw movement Moz of the rod 57. A load cell 38 as a multi-force detector is attached to the lower part of the rod 37. The load cell is a three-component force. It is also possible to use a load cell with a three-component force to a six-component force. The torsion bar 40 passes through the load cell 38 and the screw 3
9 is fixed to the rod cell 381C. A model of a ship or the like is fixed to the drive end of the load cell 38. When using the servo motor for restraining the rotational movement M#z of the rod 57 described above, this torsion bar 4° for measuring the movement MIIZ in the yaw direction becomes unnecessary. In this case, the yaw movement of the model can be restrained by a servo motor. In the range below the load cell 38, a yaw angle θz potentiometer 41, a pitching θτ potentiometer 42, and a rolling Ox potentiometer 43 are attached to the rod 37 for measuring the rotation angle, respectively.

Load cell 38t - 3 component force and 9 cases, inferior force IFx.

h and MHz can be measured and the model restraints can be applied to balance each load to the set load. This K realizes a servo function in three directions. The error in the servo system is divided by 't#.

In FIGS. 1a and 1b, a wire pulley is used as a transmission device for transmitting the servo drive force of the servo motor 24.25 to each carriage.

However, other known transmission means such as belts, chains, gears, screws, hydraulic motors, cylinders may also be used.

The servo system according to the present invention is represented by a block diagram as shown in FIG. A preamplifier 51 is connected to the load cell 38, and a main amplifier is connected to this. The main amplifier 52 is connected to a digital display 53 and at the same time to a subtracter 54. The output side of the subtracter 541CFi load setter 55 is connected. The output side of the subtracter 54 goes through the servo amplifier 56 in three directions! , Y, and θz servo motors. The load cell 38 can have three or more components, and a corresponding number of servo motors can be provided to restrict the movement. When controlled driving by the servo motor is performed, the force indicated by the load cell 38 gradually converges to the load setting value.

The motion restraint method and motion restraint device according to the present invention operate as follows.

The load setting device 55 is located at the ninth position of the model (not shown in FIG. 2).
Set the required load to . A fluid force acts on the load cell 38 and this force is displayed on the digital display 53. A subtractor 54 performs subtraction between the fluid force as an actual value and a set value, and the difference is input to each servo motor.

(Therefore, the carriages 22, 25 and rod 37 are servo driven or servo rotated, and as a result, the servo drive or servo rotation is performed until the force detected by the load cell becomes equal to the value set on the load setting device 55. It will be done.

In this way, the force indicated by the load cell 38 is always displayed on the digital display 5SIIC, and the robot system is driven until the force indicated by the load cell becomes equal to the set value.

The operation of such a servo system with the device according to FIGS. 1a and 1b goes through the following operating sequence. The rotary motor 25 rotates according to the setting value of the load setting device 55, and the surge carriage 23 is moved through the wires 26, 26, 9, 29' wound around the pulleys 27, 22', 28, 28'.
A motion in the X direction is applied to. Meanwhile the other wire! +Fi
Pulley s3. ss', sa, 3c.

35.55', these pulleys rotate or the respective lengths of wire 31 from the fixed ends of the upper and lower ranges do not change so that the sway carriage 22
no movement occurs. At this time, the fluid force FT is applied in the sway direction Y.
2, the sway carriage 22 is moved by the servo motor 24 in the direction in which the fluid force is equal to the set value based on the servo system shown in FIG. At this time, the fluid force is displayed on the digital display 53.

The displacement θz in the yaw direction is also measured by the potentiometer 41, and the rod 57 is servo-rotated by the servo motor until the movement of the rod 57 is balanced with the set value indicated by the load setting device 55. Since the constraint is in equilibrium with the set value, it is not limited to a motion constraint mode that is limited to a force equilibrium state due to a spring.

Of course, if the set value is set to zero, the moment M in the yaw direction
oz will also be zero. This restraint corresponds to a force balance mode by a spring.

As described above, the fluid force is displayed on the digital display 53, and at this time, the load cell 38 is automatically balanced to a state where a force equal to the set value is applied. As a result, the effects of inertial forces are eliminated, and the correct fluid force can be measured and motion restrained (unlike those using springs or weights). Since each carriage is servo-driven by each servo motor, the movement of the model is different from that using conventional springs and steel parts.
When the difference in the measured force IIC'A is included, the disadvantages of being difficult to operate and not being able to measure or constrain movement are completely eliminated.

In the case of restraint by springs, motion is restrained only under a force equilibrium state, and even if the force equilibrium state collapses from the motion restraint state and the model moves in either direction, that motion is restricted by the tension of the spring. The disadvantage is that it is

The method according to the present invention using a servo motor does not have such drawbacks, and furthermore, it is possible to restrain the motion not only to keep the model stationary in the fluid, but also to keep it in a constant running state. This is a big advantage. This makes it possible to constrain different motion states of the model in the fluid, and correspondingly different motion test results to be obtained. The model is always in an equilibrium state with a fluid force equal to the set value acting on it, so the motion waveform is accurate.

The set load can be adjusted only with a dial or external voltage, which greatly improves operability.

[Brief explanation of the drawing]

Fig. 1a is a plan view of a preliminary device for implementing the method of restraining the motion of a model of a ship or the like in a fluid according to the present invention, Fig. 1b is a side view thereof, Fig. 2 is a block diagram of the servo system, and The figure shows a motion restraint device f for a model in a fluid according to the prior art. Reference numeral 21 in the figure... Frame 22... Sway carriage 23... Surge carriage 2425... Servo motor 57... Rod 3rd... Multi-force detector 55... Load setting device

Claims (4)

[Claims] (1) Using a multi-force detector to detect the motion of a model of a ship, etc. in a fluid,
A motion restraint method characterized in that the motion is restrained by a servo motor driven by the difference between the output signal and an external signal. (2) Using a multi-force detector to detect the motion of a model of a ship, etc. in a fluid;
In a device for carrying out a motion restraint method of restraining by a servo motor driven by the difference between the output signal and an external signal, a surge carriage (23) is movable in one direction (X) in a frame (21). A sway carriage (22) is guided on the surge carriage (23) so as to be movable in a direction (Y) perpendicular to the direction (X), and each carriage is driven by a transmission device by each servo motor (24, 25). Servo-driven through the sway carriage (22)
A rod (37) passes through the rod perpendicularly to the rod, and another servo motor is attached to the rod, which enables the model to be servo-driven in the yaw direction (θz), and a multi-force detector ( 38), and the fluid force acting on the model is automatically balanced by the servo system so that it is always equal to the set value set in the load setting device (55). A motion restraint device for a model of a ship, etc., characterized by: (3) A motion restraint device for a model such as a ship according to claim 2, which uses a torsion bar (Δ0) instead of a servo system in the yaw direction (θz). (4) Force in 6 directions (FX, FY, FZ, M_θ_X, M
_θ_Y, M_θ_Z) is detected, and the movement of the model is restrained so as to be automatically balanced by a servo system to a value set by a load setting device (55). A motion restraint device for a model of a ship, etc., as described in item 3 or 4.