DE3016500C2 - Compass - Google Patents

Description

The invention relates to a gyro compass of the type specified in the preamble of claim 1.

In a known gyro compass of this type (DE-OS 26 27 037) the plumb line consists of an am Centrifugal frame pivoted pendulum, on which magnets are arranged, which are on the rotary rotor exercise the guiding moments by means of their attractive force. This well-known gyro compass stands out characterized in that the plumb line sensor generates the guide torque through direct action on the rotor, instead, as is also known (DE-PS 23 05 663), to generate electrical signals, which in turn drive motors steer.

The known gyro compass according to DE-OS 26 27 037 still has three major disadvantages:

(1) The deflection of the pivoted pendulum changes the gas flows in the area of the centrifugal rotor and can thereby generate undesirable drift moments;

(2) to maintain the compass function even when tilted against the vertical around the spinning axis, must z. B. the pendulum suspension can also be designed to pivot about the spin axis, what means increased effort;

(3) in order to suppress the roll error, the pendulum must be dampened very strongly, for which purpose likewise Effort and a relatively large installation space are required.

The invention is based on the object of providing a gyro compass as described in the preamble of claim 1 specified design while maintaining its advantages so that the disadvantages mentioned are avoided will.

According to the invention, this object is provided by what is stated in the characterizing part of claim 1 Design solved.

This configuration is also characterized by great simplicity and high operational reliability.

Expedient embodiments of the invention are specified in the subclaims.

The invention can be applied with particular advantage to a gyro compass in which, as in DE-OS 26 27 03? described, the rotor with its shaft mounted in the rotor frame to common Circulation is connected by a cardan joint, which is dynamically tuned and therefore no restoring torque exerts on the rotary rotor when the axis of rotation of the rotary rotor from its coaxial position to Drive shaft temporarily drifts

In the drawings, in which preferred embodiments of the invention are illustrated, FIG

F i g. 1 schematically the gyro frame and its suspension,

F i g. 2 shows a vertical longitudinal section through the in F i g. 1 gyro frame shown, in welctiem the Slidably guided bodies that form plumb lines are symmetrical when the centrifugal axis is in a horizontal position to the plane IH-III, which is the cardan axes of the cardan joint,

F i g. 3 the section through the hub of the rotary rotor in the plane HI-III.

4 shows a horizontal longitudinal section through the Gyro frame of a modified embodiment of the gyro compass, in which the forming the plumb sensor displaceable body is arranged at a considerable distance from the plane receiving the cardan axes and with the magnets exert additional torque,

F i g. 5 shows the right part of FIG. 4 corresponding longitudinal section of an embodiment that differs from of those of FIG. 4 differs by a different design of the magnets and

F i g. 6 shows a diagram for the course of the period of oscillation and the degree of damping as a function of the geographical latitude ψ.

In a ship-mounted housing 10 is a cardan frame 12 by means of two pins 14 and 16 around a Azimuth axis 18 rotatably mounted, which runs parallel to the vertical axis of the ship. The pin 14 carries a tap 20, which taps the azimuth angle between the frame 12 and the ship and as an electrical Signal passes. The azimuth angle can be determined by a compass rose arranged parallel to the tap are displayed.

About an axis 22 running at right angles to the azimuth axis 18 is pivotable by two coaxial axes Pin 24 and 26 in frame 12 the gyro gesture !! 28 stored, which in F i g. 1 not shown Rotary rotor 30 carries.

In the case of the FIG. 1 embodiment of the invention shown has the rotary rotor in relation to the Angle of rotation of the ship in rough seas only a small amount of freedom of movement in the gyro frame 28. Therefore, it must Gyro frame 28 can be decoupled from the ship by rotatable mounting and the centrifugal rotor di> rch frame tracking controller be tracked. For this purpose, two tracking controllers are provided with the control electronics 21 and the servomotor 23 for the tilt axis 22 and the control electronics 25 and the servomotor 29 for the Azimuth axis 18 is provided. Using the signals of the in FIG. 1 lead not shown gyro taps the two tracking regulators follow the gyro frame 28 and ensure that the deflection of the rotary rotor remains limited to small values compared to the rotary frame 28. The deflections are in the order of magnitude of arc seconds for dynamically tuned gyroscopes

The gyro taps are shown in Fig.2 Es are inductive angle pickups, one of which is perpendicular to the plane of the drawing Axis effective in the form of pick-off coils 19 is shown, while the other measuring axis belonging pick-up coils are arranged in front of and above the plane of the drawing.

ι ο The rotary rotor 30 is closed with its drive shaft 32 common rotation by a spring cardan joint 34 coupled so that it is about each of two cardan axes that can oscillate in the plane ΙΠ-ΙΙΙ the axis of the Cut rotor shaft 32, one of these two cardan axes at right angles to the other and to the Axis of the rotor shaft 32 extends

The gyro frame 28, which is designed as a cylindrical pot in the present embodiment, carries on its edge 36 an annular body 38 attached to it, which receives the stator 40 of the rotor motor. The rotor 42 is rigidly attached to the end of the rotor drive shaft 32 38 on the roller bearings 44 with which the shaft 32 is mounted in the gyro frame 28

In this respect, the design described corresponds to the known state of the art.

In contrast to this, however, the plumb line sensor consists of one carried by the rotor 30

jo and in its axial direction slidably guided body 46, which is resiliently tied in the position in which he has the common center of gravity of himself and the rotor 30 with the center can coincide in which the axis of the rotor 30 penetrates the plane III-III. At a If this centrifugal axis is inclined, this body 46 is displaced along the centrifugal axis. That has then the effect that this body 46 exerts the guiding moment on the rotor through its weight, which causes the precession into the meridian plane.

In the illustrated embodiment, the flexible restraint of the displaceable body 46 takes place in that helical compression springs 48 act on the ends thereof and are supported on the rotary rotor 30.

A cup-shaped intermediate piece 50, the edge of which is on the inside, belongs to the ring-shaped rotary rotor 30 is attached to a flange 52 of the rotary rotor and the bottom of which carries a guide tube 54. The leaf springs of the cardan joint 34 are formed through slots in the wall of a pot-shaped body 56 worked out, the bottom of which sits rigidly on the drive shaft 32 and its cylindrical wall in the space between the circuits; ' 30 and the intermediate body 50 protrudes and with its edge the flange of the rotor 30 is rigidly attached.

The torque exerted by the displaceable weight 46 on the rotary rotor acts around the horizontal guide axis at right angles to the rotor axis and is the elevation ε of the rotor axis in proportion to

M ₁₁ =

ΗωΙ

ω _F cos Φ
In this formula is

H = gyroscopic swirl

ωό = natural angular frequency of the compass oscillation

(D £ = earth rate

Φ = latitude
ε = elevation of the rotor axis opposite
the horizon plane

The axis of this guide torque must to avoid an impermissible change in the damping of the Compass oscillations are held horizontally on average over time with an accuracy of ± 1 °. This is especially true when the compass is tilted around the rotor axis, as occurs as a result a heeling of the ship occurs Trim influences can be considerably greater than 1 ° and in special cases, e.g. B. by shifting the load, Can exceed values of 20 - 30 °, there is the sub-task, the sufficiently precise horizontal To ensure the position of the guide torque axis in the mean over time.

The displaceable weight 46 both solves the task of the guide torque according to the formula (1) as well as the sub-task of keeping the axis horizontal around which this guide torque acts.

This results from the following:

An elevation angle ε of the rotor axis produces an axial displacement of the body 46 of approximately

= in ι gc / c

(5)

m, = mass of the body 46

c = combined axial stiffness of the two springs 48

and a proportional moment of gravity
Mκ « mjg ² ε / c.

(6)

which acts as a guide torque GR in the sense of equation (1).

It will now be explained by which configuration of the described arrangement the "intercardinal loop error" the gyrocompass is suppressed. This error arises as a cross-coupling effect at Effect of horizontal alternating accelerations - due to swell - the same frequency in the directions parallel and perpendicular to the rotor axis. This means accelerations when the compass is steady simultaneously in north-south and east-west direction. Since the largest horizontal acceleration amplitudes usually caused by the roll oscillation of the ship due to the compass being in a distance above or, more rarely, below the roll axis is installed, this error reaches its limit largest values on intercardinal courses - 45 ", 135" etc. - which explains its name.

The error is given by

(2)

α, = permanent azimuth misalignment due to the horizontal accelerations O _x , a,

O _x ^ Oy _n = amplitudes of the horizontal accelerations of the same frequency in north-south and east-west directions

⁼ Phase angle dilatation of the oscillations a "" and a ""

= Acceleration due to gravity

and achieved under normal sea and installation conditions depending on the compass design and geographical location Latitude values between 100 and 1000 °. The effect of alternating horizontal accelerations is used to suppress it to filter sufficiently in the direction of the rotor axis to the target torque.

For this purpose, the tube 54 is hermetically sealed and partially filled with a liquid, which, when the rotor rotates, as shown at 58, rests on the outer wall of the pipe. As a result of the rapid rotation of the rotary rotor around its axis, the displaceable body 46 floats, without touching the inner wall of the tube 54 in the process. The prerequisite for this is that the density of the displaceable body related to its outer contours no more than l '/ 2 times the density of the Liquid is. The springs 48 are preferably made of such a material that they also swim in the liquid without touching the walls. This is a very easy and Defined displaceability of the body 46 within the tube 54 is given. The body 46 shifts because of its spring restraint under the action of axial forces by a force-proportional path.

jo The body 46 has an axial bore 60, the one Equalization of gas volumes permitted on both sides. Preferably this hole is from its center the ends widened conically This has the consequence that parts of the liquid, for example at

j5 can catch a standstill of the gyro in the bore, can be quickly thrown off by the centrifugal effect of the rotation after switching on.

The dimensions of the tube 54 and the displaceable body 46 are chosen so that the displacement the body in the tube becomes more viscous due to the fluid friction in the gap between the body and the tube Resistance is opposed, the filtering of the alternating accelerations parallel to the rotor axis in its effect on the displacement of the body 46 causes this filtering is sufficient if for the Displacement of the body 46 a time constant between 25 and 50 seconds takes effect. It is takes into account that this arrangement approximates a system of the first order, in which besides the

so amplitude suppression sets a phase angle between acceleration oscillation and body displacement of almost 90 ° which is favorable for suppression of roll errors
The compass oscillation, which is unicr the action of the Fühnnoniciits, must be sufficiently damped by additional measures in order to ensure a rapid oscillation in the meridian direction. This is important both after switching on the compass and after malfunctions, e.g. due to ship maneuvers. This damping can be achieved by exerting a much smaller damping torque Md proportional to the guide torque, which acts on the rotor around the vertical axis. This type of damping is known as "vertical damping"

For the limitation of the compass errors it is of decisive importance that the zero points of the guiding torque Mr and the damping torque Md remain stable to a high degree in their mutual position.

The zero points are those elevation angles ε at which the directional moment about the horizontal axis and the damping moment about the vertical axis pass through zero. A change in the distance between the two zero positions relative to one another by a value An generates an azimuth error

\ ^{Α Δε} \ = 2D

ω /.- cos φ

\ Δε \

which is 12 to 10O times the relative zero point change in the usual design, depending on the geographical latitude.

In order to ensure the stability of the zero point difference Δε, a mechanism is provided for generating the damping torque which makes use of the same displacement of the body 46 as the directing torque generation.

The verticality of the damping moment axis is not as critical as the horizontality of the Directional torque axis, since the damping torque is only a fraction of the directional torque and its coupling to the horizontal axis only results in a relatively small change in the compass natural frequency causes no further adverse effects

Because of this, the generation of the damping torque with the help of an arrangement that is fixed to the gyroscope frame if the compass is tilted around the rotor axis by heeling angles of up to 30 °, for example corresponding change in direction of the damping torque axis generated, permissible. An exception are Schuler-tuned compasses, in which the period of oscillation must be adhered to relatively precisely. but the requirements that are relatively simple for compasses such as those in question here are not those in any case represent the most appropriate interpretation.

The mechanism for generating the damping torque is illustrated in FIG. 2 embodiment shown carried by a tubular holder 62 flanged to the bottom of the cup-shaped frame 28, which is shown in FIG the gap protrudes, which is delimited on the outside by the intermediate piece 50 and on the inside by the pipe 54 This tubular holder carries a rod-shaped permanent magnet 64 on its inner wall, the extends parallel to the axis of the tube 54 and at the same height as this axis and such Length has that it sufficiently covers the inherent length and the displacement range of the body 46 In This magnet 64 generates a magnetic field over its entire axial length in this entire area is to a high degree homogeneous. In this embodiment, the displaceable body 46 consists of one ferromagnetic substance and is therefore attracted by the permanent magnet 64 in the horizontal direction. To keep the magnetic field as even as possible shape, the permanent magnet 64 on the pipe 54 facing side carry a pole piece 66 made of a soft magnetic material. The tubular Carrier 62 shields the magnetic field from the other gyro components. To avoid eddy current effects in the To avoid tubular support 62 enclosed components, these consist of an electrically poor conductive building material, for example the tube 54 made of glass and the sliding body 46 made of ferrite

The horizontal force that the permanent magnet 64 exerts on exercises the displaceable body 46, is thus directed horizontally when the gyro frame is not tilted. So this is done by this force on the gyroscope Acting guide torque Mo solely due to the axial position of the sliding body 46 is determined, as well as this applies to the guiding moment Mr. Because that

Gyro frame 28 with which the permanent magnet 64 is rigid

is connected, very precisely to the rotor 30 and the tracked with this rigidly connected pipe 54 the horizontal pull remains high

Dimensions constant. The symmetrical position of the body 46 to the plane

III-III with the rotary axis in a horizontal position necessarily leads to a large diameter of the cardan spring joint 34 and requires the arrangement of the intermediate piece 50 Circumstances disadvantages for the stability of the gyroscope fers. In Figure 4 is now an embodiment shown, in which the intermediate piece 50 is omitted and therefore the cardan spring joint is essential gets smaller diameter.

In this embodiment that is namely the

displaceable body 46 leading tube 54 at an axial distance from the spring cardan joint 34 on Rotary rotor 30 attached on one side. For this purpose the tube 54 has a flange at its inner end 70, which is attached to the flange 52 of the rotary rotor 30 is screwed on.

If the displaceable body 46 is in its illustrated central position, then the common center of gravity of the rotary rotor 30 is inclusive the parts attached to this and the sliding one Weight 46 at the point at which the rotor axis penetrates the transverse center plane of the universal joint 34. Then the guide torque Mr is equal to zero. In order to generate a zero point for the damping torque Md as well, the tubular holder 62 carries opposite the Permanent rod magnet 64 on its inner wall Magnet 72 with a pole piece 74 made of soft iron. Opposite this magnet 72 there is an off Ferrite existing armature 76, which at the end of the tube 54 facing away from the rotor 30 The magnet 72, which is magnetized in the radial direction, exercises through its acting on the armature 76 Attractive force exerts a torque on the rotary rotor 30 which is just as large as that of the radial magnetized magnet 64 on the rotor the central position of the displaceable body 46 exerted lead torque Md. This torque is therefore to NuIL when the displaceable body 46 its

Takes center position The structural and stability advantages

with this arrangement there are functional disadvantages in the form of a lower long-term stability of the damping moment, e.g. due to different aging of the two magnets 64 and 72, some influence of deflection and something higher calibration effort to produce the Initial correspondence of the zero points of the directional and damping torque Different aging of the magnets can be eliminated by moving them in the radial direction magnetized permanent magnets 64 and 72 are replaced by electromagnets or by the one described later Variant according to FIG. 5.

Compasses of the type described typically have oscillations that are dependent on the geographical latitude φ duration 7ο = 2Λτ / ωο and with permanent magnetic damping arrangement also equally dependent on the width of the damping. Both the oscillation value Tj and the damping factor D are proportional to l / j / cös <f> -

They change between Φ - 0 and Φ = 75 ° by almost a factor of 2. The curve is shown in the diagram in FIG. 6.

In spite of the latitude dependency, such a compass is useful in a large latitude range Properties. The table shows a design example:

Geographical 45 ° broad Φ 80 ° 0 ° 1.19 60 ° 75 ° 2.40 1 / i / cos Φ 1 95 1.41 1.97 192 Natural vibration 80 113 158 duration 7 ^ ₁ min 0.83 1.68 Attenuation 0.7 0.99 1.38

A latitude-dependent azimuth error occurs
αΦ = sin Φ (ο)

where R means the radius of the earth. The width error in the design according to the table with permanent magnetic damping torque generator is 4.88 ° · ύτιΦ and can easily be corrected using a table or by adjusting the rose. For a fixed latitude, it is to be made zero by earth rate compensation via a fixed axial unbalance of the centrifugal rotor.

In the case of electrical damping magnet excitation of the type shown in FIG. 4, an additional winding can be used > the electromagnet taking the place of the magnet 30 exerts a width-dependent moment that compensates for the width error.

The exemplary embodiments described can be modified in many ways.

ίο So in the variant of FIG. 4 the two magnets 64 and 72 can be replaced by a single electromagnet 164 , which acts equally on the displaceable body 46 and the armature 76, if this is excited by alternating current of a suitable frequency and the displaceable body 46 is made of a non-magnetic, electrically conductive material. In this case, the electromagnet 164 exerts a repulsive and repulsive effect on the body 46 as a result of the eddy currents generated therein

the armature 76 made of ferrite has an attractive force. Both forces act together in the same way as that provided by magnets 64 and 72 in FIG. 4 generated, but the zero point of the damping torque thus generated with a single electromagnet is less dependent on aging and deflection of the rotor 30 compared to the frame 28. When AC excitation of the electromagnet 164 , the tube 62 is to avoid undesirable eddy currents z. B. made of ferrite.

The spring 48 in FIG. 2 can be replaced by another equivalent arrangement, e.g. by a magnetic spring.

For this purpose 4 sheets of drawings

Claims (11)

Patent claims: 1. Compass with a gyro frame (28) pivoted relative to the compass housing, with a rotary rotor (30) mounted therein so that it can pivot on all sides about a center point, with one on Inclination of the rotor axis responding plumb sensor (46) as well as a cooperating with this, on the outer circumferential surface of the rotary rotor (30) fixedly arranged magnet system (64), in order to generate guide moments, v / calibrate the Let the rotor axis precess in the meridian plane and dampen this precession movement, characterized in that the plumb sensor consists of one carried by the rotor (30) and The body (46), which is displaceably stirred in its axial direction, is capable of yielding is tied up in which he has the common focus of himself and the gyroscope (30) but can coincide with the center point when the rotor axis is inclined and shifts therefore, through its weight, it exercises the guiding moment causing the precession into the meridian plane and that the magnet system (64) is arranged such that its field is in the path of the displaceable Body (46) extends and exerts on this the damping serving torque 2. Gyro compass according to claim 1, characterized in that the displaceable body (46) One of them can be displaced in a tube (54) connected coaxially to the rotary rotor (30) Contains viscous liquid. 3. Gyro compass according to claim 2, characterized by an axial bore (60) of the displaceable Body (46). 4. Gyro compass according to claim 3, characterized in that the axial bore (60) of their center widened conically towards the ends. 5. Gyro compass according to claim 1, 2 or 3, characterized in that the magnet system (64) with the pivotable axis relative to the compass housing (10) and the rotor axis tracked gyro frame (28) is firmly connected and on the displaceable body (46) one at not tilted gyroscope frame, horizontal damping force independent of the position of the body exercises. 6. Gyro compass according to claim 5, characterized in that the magnet system has a radial contains magnetized magnet (64) coaxial from the inner wall of a gyroscope frame (28) to the rotor drive shaft attached tube (62) is carried, which the sliding Body (46) containing tube (54) surrounds, wherein the magnet (62) extends over such a length extends that it covers the length and the displacement range of the body (45). 7. Gyro according to any one of claims 2 -6 with the gyro rotor (30) with its stored in w gyro frame (28) drive shaft (32) connected to a common circulation Federkardangelenk (34), characterized in that the leading the sliding body (46) Tube (54) is fastened on one side at an axial distance from the cardan joint (34) b5 on the rotary rotor (30). 8. Gyro compass according to claim 7, characterized in that the rotor (30) the opposite end of the tube (54) receiving the displaceable body (46) has one on it attached armature (76) carries., which is magnetized radially by a fixed on the gyro frame (28) Magnet (72) is attracted in a radial direction opposite to that which is im Claim 6 mentioned magnet (64) exercises 9. Gyro compass according to one of claims 3-8, characterized in that for the purpose of suppressing the intercardinal roll error Dimensions of the tube (54) and the displaceable body (46) such a high flow resistance cause the liquid that this the displacement of the body (46) up to one Time constant of typically between 25 and 50 seconds attenuates 10. Gyro compass according to one of claims 5 - 9, characterized in that the holder (62) surrounds the magnet system (64, 72) and consists of ferromagnetic material 11. Gyro compass according to claim 8, characterized characterized in that the armature (76) attracting electromagnet (164) an additional, width-dependent has excitable winding to compensate for the width error.