JP2551788B2 - Gyro compass - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a gyro compass used for ships and the like, and particularly to a short-term static stabilizing device thereof.

[Conventional technology]

With reference to FIG. 3, as an example of a gyro compass to which the short-term static control device according to the present invention can be applied, Japanese Patent No. 42 is used.
Explain the 8317 gyro compass.

In the figure, reference numeral (A) represents an entire gyro compass, (1) is a gyro case, and this gyro case (1) has a built-in gyro rotor that is rotated at a high speed and a constant rotation speed by an induction motor. , The rotation vector is southward (clockwise when viewed from the north side). The gyro case (1) has a pair of vertical shafts (2) and (2 ') arranged vertically.
Projecting, and these vertical shafts (2), (2 ') are mounted on the ball bearings (4), which are mounted at corresponding positions of the vertical ring (3) arranged on the outside of the gyro case (1),
Fit into the inner rings of (4 ') respectively. The lower end of the suspension line (5) is fixed to the upper vertical shaft (2), and the upper end thereof is attached to the vertical ring (3) via the suspension line mount (5 ').

Due to the above structure, the weight of the gyro case (1) is equal to that of the vertical shafts (2) and (2 ′) ball bearings (4)
The thrust load of (4 ') does not occur, and all suspension lines (5)
The ball bearing (4),
The friction torque of (4 ') can be greatly reduced. A pair of liquid stabilizers (6) for applying a finger north torque to the gyro are attached to the east and west of the vertical ring (3).

As shown in FIG. 4, each liquid stabilizer (6) is a kind of communicating pipe, and is a pot (6-
1 '), (6-1), a liquid having a high specific gravity (6-2) that fills the inside of these, and an air pipe (6) that connects the north and south urns (6-1), (6-1') above. -3), and a liquid pipe (6-4) communicating with them below.

As shown in FIG. 5, a damping weight (7) for damping the finger north movement is attached to the west side of the gyro case (1). On the east side of the gyro case (1), the primary coil (8-1) of the differential transformer for detecting the deflection angle around the vertical axes (2) and (2 ') of the gyro case (1) and the vertical ring (3). ), And the secondary coil (8-2) of the working transformer is attached to the position of the vertical ring (3) opposite to this, and constitutes a follow-up pickup (8). The vertical ring (3) further has vertical axes (2) and (2 ').
And a pair of horizontal axes (9) and (9 ') projecting outward from one of the east and west, which is orthogonal to both the gyro spin axis,
These horizontal axes (9), (9 ') are inside the ball bearings (11), (11') mounted at corresponding positions of the horizontal ring (10) arranged outside the vertical ring (3). Fit on each shaft. The horizontal ring (10) further has a pair of gimbal axes (12) and (12 ') in a horizontal plane and at a position orthogonal to the horizontal axes (9) and (9'). These gimbal axes (12),
(12 ') is a follower ring (1
The gimbal shaft ball bearings (14) and (14 ') attached to 3) are fitted respectively.

As shown in FIG. 3, the follower ring (13) has follower shafts (15) and (15 ') on the upper and lower sides, and these follower shafts (15) and (1
5 ') is fitted to the follower shaft ball bearings (17), (17') at corresponding positions of the board (16), respectively.

At the end of the upper follower shaft (15), attach the compass card (1
8) is attached, and the azimuth angle of the bow is read by this and the base line (18B) fixed to the position of the corresponding bow side of the board (16). An azimuth servomotor (19) is attached to the lower part of the board device (16), and its rotation shaft (19A) is located below the follower ring (13) via the azimuth pinion (20). Combine with. An azimuth transmitter (22) is attached to the lower part of the board device (16), and its rotating shaft (22A) is meshed with the azimuth gear (21) through a gear system to convert the azimuth signal into an electric signal. Call outside.

The part within the horizontal ring (10), that is, the part including the horizontal ring (10), the vertical ring (3), the gyro case (1), etc., is usually called a sharp area. The sharp part is the gimbal axis (12),
A lower heavy physical pendulum is constructed around (12 '), so that the horizontal axes (9) and (9') are independent of the hull inclination.
Always kept in a horizontal plane.

If there is a difference between the azimuth of the gyro case (1) and the azimuth of the vertical ring (3), the tracking pickup (8) provided between the two detects this difference and converts it into an electric signal. This electric signal is amplified by the external servo amplifier (23) and applied to the azimuth servo motor (19) (azimuth servo system).
The rotation of the azimuth servomotor (19) is transmitted to the follower ring (13) through the rotary shaft (19A), the gear train, and the azimuth gear (21), and further the horizontal ring (10), the horizontal shafts (9), (9 '). ) And the like, and is transmitted to the vertical ring (3) so that the azimuth deviation between the vertical ring (3) and the gyro case (1) is always kept at zero.

Horizontal axis (9), (9 ') by the action of azimuth servo system
And the gyro spin axis are always orthogonal to each other, and the torsion torque of the suspension wire (5) is not applied to the gyro at all. That is, the vertical axis (2) with the servo system,
The gyro case (1) is completely insulated by the angular motion of the hull by the action of the three axes (2 '), horizontal axes (9) and (9') and gimbal axes (12) and (12 '). That's right, and it constitutes a gyroscope.

It is the above-mentioned liquid ballast (6) that gives the pointing force, that is, the function as a compass to the above-mentioned gyroscope.
Is.

Next, the principle of the liquid stabilizer (6) will be described with reference to FIG. Note that FIG. 4 is a diagram in the case where the finger north end of the gyro is raised by an angle θ with respect to the horizontal plane. Considering the case where the ship is at rest, the liquid (6-
The liquid surface of 2) is orthogonal to the direction of gravity g. Therefore, compared with the case of zero inclination, the liquid in the shaded area in the figure decreases in the northern jar (6-1 ') and decreases in the southern jar (6-
It will increase in 1). Now, the distance from the horizontal axis (9), (9 ') to the center of both urns (6-1), (6-1') is r ₁ , both urns (6-1), (6-1 ') The cross-sectional area of S, liquid (6-
If the specific gravity of 2) is ρ, the weight of the liquid in the inclined portion is S × r ₁ sin θ × ρ × g.

The above weight imbalance is due to both the north and south urns (6-
1 '), (6-1), and the horizontal axis (9),
Since the moment arm from (9 ′) is r ₁ , the torque T _H around the horizontal axes (9) and (9 ′) made by the liquid ballast (6) when tilted by the angle θ is approximately Therefore, T _H = 2Sr ₁ ² g ρθ.

Here, K is called a ballast constant, where 2Sr ₁ ² gρ = K. That is, the liquid stabilizer (6) applies a torque proportional to the inclination of the gyro spin axis with respect to the horizontal plane to the gyro horizontal axis (9),
It exerts an action around (9 '), whereby the gyro has a finger north force and becomes a gyro compass.

On the other hand, as shown in FIG. 5, the damping weight (7) includes the vertical axes (2) and (2 '), and in the plane orthogonal to the gyro spin axis, the damping weight (7) is defined by the vertical axes (2) and (2'). Mounted on the gyro case (1) at a distance of r ₂ (perpendicular to the paper surface). FIG. 5 is a view of the gyro case (1) as viewed from the west side in a state in which the north side of the finger rises and is inclined by an angle θ with respect to the horizontal plane. The gravitational acceleration g acts on the damping weight (7) of mass m, and a force of m × g acts on this in the vertical direction. This force on the vertical axis (2),
It is considered by decomposing into a component mg cos θ parallel to (2 ′) and a component mg sin θ parallel to the spin axis. Of these, the components parallel to the vertical axes (2) and (2 ') only act as loads on the vertical axis ball bearings (4) and (4'), but the components parallel to the spin axis are Vertical axis (2), (2 ')
Is multiplied by a distance r ₂ from and acts on the gyro as a torque around the vertical axes (2) and (2 ′). If this torque is written as Tφ, Tφ is approximately given by the following equation.

Tφ = μ · θ where μ = mgr ₂ That is, the damping weight (7) is a device that applies a torque proportional to the inclination of the gyro spin axis with respect to the horizontal plane around the gyro vertical axes (2) and (2 ′). Yes, this can attenuate the compass fingering movement.

FIG. 6 shows the conventional gyro compass described above,
The azimuth error φ from the true north of the finger north end of the gyro spin axis and the inclination angle θ are variables, and the finger north motions with respect to these initial errors φ ₀ and θ ₀ are represented by a Laplace operator and a transfer function. It is shown in. In the figure,
g is gravitational acceleration, R is earth radius, Ω is earth rotation angular velocity,
H is the angular momentum of the gyro, λ is the latitude at that point, K is the finger north constant (ballast constant), μ is the damping constant, and S is the Laplace operator.

Now, if there is an azimuth error φ, this error φ multiplied by the horizontal component Ωcosλ (100) of the earth's rotation angular velocity Ω acts as an angular velocity input on the element (101) around the horizontal axis of the gyro, and the initial inclination The tilt angle θ of the gyro is generated together with the angle θ ₀ . The vertical ring (3) also has a similar inclination due to the inclination angle θ of the gyro spin axis, the liquid stabilizer (6) attached to the vertical ring (3) also inclines, and the liquid (6-2) inside is lower. By moving to the jar, a torque of Kθ is generated around the horizontal axis of the gyro. This torque Kθ divided by the angular momentum H of the gyro, plus the vertical component Ωsinλ of the Earth's rotation angular velocity, acts on the element (102) around the vertical axis of the gyro as an angular velocity input, and the initial bearing error The addition of φ ₀ results in an azimuth error φ and the loop closes. This loop is the gyro compass finger north loop. This loop is an oscillating solution because there are two poles represented by 1 / S in the loop. On the other hand, the gyro tilt angle θ is obtained by dividing the torque μθ by multiplying the damping constant μ by the angular momentum H, and is negatively fed back to the horizontal axis element (101) of the gyro as an angular velocity input so as to reduce the tilt angle θ, and the above-mentioned finger Attenuate the north loop finger north movement. This loop is a damping loop.

[Problems to be solved by the invention]

Generally, in a gyro compass for a ship, the finger north movement cycle is set to about 90 minutes in order to prevent an acceleration error occurring in the gyro compass due to horizontal acceleration such as acceleration / deceleration and turning of the ship. Condition) Design is being done. Therefore, after starting the gyro compass,
It takes a considerable amount of time for it to settle to the north and become usable (this is called the settling time).

In most ships, the above-mentioned settling time is not a problem in operation, but in some special purpose ships, this long settling time becomes a problem.

Therefore, the present invention is to provide a gyrocompass provided with a short-term settling device capable of shortening the settling time.

[Means for solving problems]

According to the present invention, a gyro case (1) having a gyro with a substantially horizontal spin axis, a supporting device for supporting the gyro case with three-axis degrees of freedom, and a spin axis for the gyro. In a gyro compass having a function of outputting a tilt angle with respect to a horizontal plane and a function of applying a torque around the vertical axis of the gyro case in proportion to an input signal, a control device which inputs a signal corresponding to the tilt angle (52 ) Is provided to differentiate the signal corresponding to the tilt angle for a predetermined time after activation of the gyro compass in the control device, and to shorten the settling time by using the resulting differentiated signal as the input signal. You can get the gyro compass you made.

[Action]

A signal (51A) obtained by differentiating the output signal (50A) of the accelerometer (50) is applied to the vertical torquer (51) for a predetermined time immediately after the activation of the gyro compass. That is, when the gyro spin axis is rising, it is controlled so that its ascending speed becomes faster, and when it is descending, the descending speed is controlled so as to become faster, and as a result, the gyro compass Since the finger north cycle becomes shorter and the attenuation becomes faster, the initial heading error can be eliminated in a short time, and the usage state of the gyro compass can be secured in a short time.

[Example] With reference to FIG. 1, a gyro compass (A) of the present invention
An example of the short-term static control device will be described. In the figure, the same members as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

The difference between the example of the present invention shown in FIG. 1 and the conventional example of FIG. 3 is that the vertical ring (3) in the example of the present invention of FIG. 1 has an input shaft parallel to the spin axis of the gyro rotor. An accelerometer or inclinometer (50) having a vertical axis (2), (2) of the gyro case (1) is applied to the vertical ring (3) and the gyro case (1). ′) A vertical torquer (51) attached around the accelerometer (5
0) output signal (50A) (proportional to the tilt angle of the gyro spin axis to the horizontal plane) is input, and the vertical torquer (51)
This is the point where a control device (52) for supplying an output signal (51A) to is provided.

As shown in FIG. 1, the control device (52) has an on / off switch (61), and the switch (61) is turned on / off by a mode switching signal from the timer device (62) to control the output signal. To be done. The timer device (62) starts operation by the gyro compass switch-on signal (SWA) or a signal equivalent to this, and turns off the switch (61) when a preset short-term settling time has elapsed. To output the signal. The period during which the timer device (62) is operating will be referred to as the short-term stationary mode (hereinafter, the navigation mode).

The control device (52) inputs the output signal (50A) of the accelerometer (50) to the vertical torquer (51) through the control amplifier (60) as the control signal (51A) in the short-term static control mode. . An example of the transfer function of the control amplifier (60) is expressed by the following equation.

τ _f is the time constant of the oscillation filter, η is the differential time, S
Indicates the Laplace operator, respectively.

In this example, the control device (52) is basically a differentiator, and produces a torque proportional to the time derivative of the tilt angle of the gyro spin axis (output signal (50A) of the accelerometer (50)). Positive feedback is given to the vertical ToruCa (51). That is, the gyro spin axis is (for example, the north end of the finger)
When rising, the rising speed is increased faster, and when it is falling, the falling speed is increased faster, thereby shortening (shortening) the cycle of the finger north movement and strengthening the damping action. It is possible to significantly reduce the settling time. A block diagram of this short-term static mode is shown in FIG. The difference between the example of the present invention shown in FIG. 2 and the conventional example shown in FIG. 6 is that a portion surrounded by a dotted line in FIG. 2 is added to the example of FIG. . For simplicity, the transfer function of the control amplifier (60) is represented by a differential element S, and the gain from the accelerometer (50) that detects the tilt angle θ of the gyro to the vertical torquer (51) is represented by η.

When the characteristic equation representing the motion of the orientation error φ in FIG. 2 is calculated, the following equation is obtained.

(H- [eta]) + [mu] + K [Omega] cos [lambda] [phi] = 0 Therefore, by adding the short-term static definite mode indicated by [eta], [eta] acts to reduce the angular momentum H of the gyro. From the above formula, the gyro finger north movement cycle T is Also, the half-circumferential damping factor F, which indicates the degree of damping, is Becomes

That is, in the short-term settling mode, by applying the torque η around the vertical axis of the gyro, the gyro cycle T can be shortened and the half-cycle damping rate F can be reduced, resulting in the conventional gyro compass. It is possible to significantly reduce the settling time.

As is clear from the above equation, η <H is required to keep the finger north movement stable.

In addition, before starting the gyro rotor, a voltage is applied to the azimuth servo motor (19) to rotate the follower ring (13), and the azimuth slew mode is added to match the correct heading. Can be shortened.

The above is the case where the present invention is applied to the accelerometer and the gyro compass without the vertical torquer shown in FIG. 3, but the present invention is not limited to the above, for example, the function of the accelerometer, That is, if a gyro compass capable of outputting a signal corresponding to the inclination angle of the sunpin shaft with respect to the horizontal plane and having a function of applying a torque corresponding to an input signal around the vertical axis of the gyro, those functions are utilized. That is, a gyro compass with a reduced settling time can be obtained only by adding the control device of the present invention without newly providing an accelerometer and a vertical torquer.

〔The invention's effect〕

According to the present invention, a gyro compass having a simple structure, a low cost, and a short settling time can be obtained by adding the short-term settling mode having the above-described structure. By giving a signal corresponding to the time derivative of the gyro spin axis as a torque around the vertical axis, a short settling time can be achieved by a simple calculation. Compared with the method of increasing the original finger north torque (around the horizontal axis) (shortening the finger north cycle) (this method has a torque around the vertical axis), the torque required for short-term settling is small, so it is small. ToruCa can be used, and an amplifier with low power consumption can be used.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a gyro compass according to the present invention, FIG. 2 is a block diagram of a transfer function used for explaining the principle of the gyro compass according to the present invention shown in FIG. 1, and FIG. FIG. 4 is a perspective view of a conventional gyro compass that can be used, FIG. 4 is a schematic diagram of a liquid ballast, FIG. 5 is an explanatory view of the principle of a damping weight, and FIG. 6 is a guide of the conventional gyro compass shown in FIG. Each block diagram regarding exercise is shown. In the figure, (1) is a gyro case, (3) is a vertical ring, (6) is a liquid stabilizer, (7) is a damping weight, (50) is an accelerometer, (51) is a vertical torquer, and (52) is The respective control devices are shown.

Claims (1)

(57) [Claims] 1. A gyro case containing a gyro having a spin axis substantially horizontal, a support device for supporting the gyro case with three degrees of freedom, and an inclination angle of the spin axis of the gyro with respect to a horizontal plane. In a gyro compass having a tilt angle output function and a torquer function that applies torque around the vertical axis of the gyro case in proportion to an input signal, a signal that receives the signal from the tilt angle output function and outputs it to the torquer function For generating a signal corresponding to the differentiation of the tilt angle for a predetermined time after the activation of the gyro compass, and the direction of the torque corresponding thereto further increases the tilt angle. A gyro compass characterized in that the magnitude η of its proportionality constant is smaller than the angular momentum H of the gyro.