DE2361277A1 - NORTH LOOKING PENDULUM - Google Patents

Description

PATENT LAWYERS Dipl.-Phys. JÜRGEN WEISSE. Dipl.-Chem. Dr. RUDOLF WOLGAST

D 5602 LANGENBERG BÖKENBUSCH 41 ' Postfadi86 Telephone: (02127) 4019 Telex: 8516895

Patent application

Bodenseewerk G-erätetechnik G-mbH, 7770 Überlingen

Roundabout pendulum looking north

The invention relates to a north-looking pendulum with a gyro unit suspended from a band with a Housing, on which a north-looking gyro directional moment acts, a tap for generating a signal in accordance with the Azimuth deflection of the gyro unit from a band zero position and a torque generator counteracting the gyro directional torque, which is acted upon by the tap signal via an amplifier.

In a known north-looking rotary pendulum (DT-OS 1 941 808) of this type, the gyro unit contains a single gyro. The gyro is roughly aligned with its spin axis in the north direction. The gyro straightening torque tries to turn the spin axis exactly in the north direction. This gyro straightening moment , which so

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to cause the gyro to move out of the band zero position is practically compensated for by the counter-torque of the torque generator via the tap and amplifier. The current in the torque generator is then proportional to the gyro directional torque and thus the deviation, the gyro axis from the lord direction.

With known circular pendulums looking north, the display is disturbed by unrest at the measuring station. Especially those through the Periodic shocks caused by a running engine in a motor vehicle can adversely affect the determination of the murder. Sine deterioration of the display occurs when the disturbing vibrations in resonance with the pendulum vibrations in the plane perpendicular to the iCreiseldrallach.se. Occur intercardinal components of the disturbing vibrations on, this leads to a "rectifier effect" which is intolerable Can assume values. This rectifier effect arises from the different moments of inertia of the gyro unit around the centrifugal spin axis and around an axis perpendicular to the centrifugal spin axis and the belt axis.

Such rectification effects are known in gyro compasses, in which a gyroscope unit, e.g. floating in a liquid, is movable on all sides and is under the influence of the gyro straightening torque turns in the direction of rotation. at In order to avoid the rectifying effects of such gyrocompasses, it has already been provided that the gyro unit has a Has pair of gyroscopes of the same twist in operation. The spin axes of these gyroscopes enclose an angle. The tops are each in a km is stored housing and this gyro housing are in turn mounted pivotably about vertical axes in a housing of the gyro unit. The gyro housing

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are coupled to one another by a link assembly, and in such a way that they always have the same swiveling movements in opposite directions relative to a fixed central plane, which contains the bisector of the gyroscope & allaohsen. The gyro housings are also by a Eeder elastically coupled to one another. The oscillation periods of the oscillations of the gyro unit around one to the -ßbene of The axis vertical to the centrifugal swirl axis is equal to the period of oscillation of the oscillations of the gyro unit around the bisector of the gyro-twist axes (J.W. Geckeier, INGENIEUR AROHIY, 1935, 229-253 and R. TJnterberger »magazine for Instrumentology "1961, 1-10).

en
The well-known gyrocompasses take a relatively long time to adjust to the north. In the case of a gyro pendulum, in which the gyro directional torque is compensated for by a counter-torque, the north direction is obtained in a considerably shorter time. With the known gyro pendulum (DT-OS 1 941 808), however, disturbances can occur due to vibrations at the measuring station and the "rectifier effect". It is not readily apparent whether the dual-gyro arrangement known from the gyrocompass that can be freely adjusted to the north can be used with a gyro pendulum and leads to a similar success. The invention is based on the knowledge found through theoretical considerations and calculations that with a two-gyro arrangement similar to the type known for gyrocompasses that can be freely adjusted to the north, a corresponding coordination of the oscillation periods is possible and a rectifier effect can thus be avoided even with a band-hung gyro with compensation of the gyro directional torque.

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The invention is therefore based on the problem of disturbances in a centrifugal pendulum of the type mentioned at the outset Measurement by unrest at the measuring station, as it is due to the "rectifier effect" of the gyro to avoid.

According to the invention, this is achieved in a rotary pendulum of the type defined at the outset in that the rotary unit has a pair of gyroscopes with the same swirl in operation, the swirl axes of which form an angle and those with gyroscopic housings Mounted pivotably about vertical axes in the housing of the gyro unit, by means of a link arrangement for execution oppositely identical pivoting movements are coupled to one another and elastically tied to a rest position, and that the period of oscillation of the azimuth oscillations of the gyro unit The period of oscillation of the oscillations of the gyro unit around the bisector of the gyroscopic spin axes is the same.

The invention is based on an exemplary embodiment below explained in more detail with reference to the accompanying drawings:

1 shows a schematic side view of a centrifugal pendulum according to the invention looking north.

Fig. 2 shows a plan view of the Kreisele ± unit with removed top.

Figure 3 illustrates the angle and axis relationships.

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A gyro unit 12 is attached to a carrier tape 10 by means of a vertical mast 14 suspended «The so suspended gyro unit 12 on mast 14 and belt 10 forms a pendulum, which in can oscillate in two directions »In addition, the gyro unit 12 is under torsion of the belt 10 about a vertical axis rotatable »On the mast 14 sits a mirror 16 over which A light beam 20 is directed from a light transmitter 18 to a photoelectric receiver arrangement 22 22 is designed in a known and therefore not shown manner so that when the Gyro unit 12 around the belt axis out of a belt zero position an output signal that increases monotonically with this rotation delivers ο this output signal is transmitted via an amplifier 24 as well as a phase-correcting network 26 connected to the stator 28 of a torque generator 30, the rotor 32 of which is connected with the gyro unit 12 is connected »The torque generator 30 thus exerts a torque about the belt axis on the gyro unit which the gyro unit seeks to hold in the said band zero position.,

The gyro unit contains two gyros with swirl axes 34 »36, which are stored in rotor housings 38 or "40" The swirl axes form an angle with each other "The rotor housings 38, 40 are in turn, about vertical axes 42 and 44 in a housing 46 of the gyro unit pivotably mounted «The gyro housing 38, 40 are these coupled to one another by a linkage 48 Linkage consists of an arm 50 that is rigidly attached to the gyro housing 38 is attached and extends from its pivot axis 42 downward in Fig. 2, an arm 52 which is rigidly attached to daa Gyro housing 40 is attached and extends from its pivot axis 44 upward in Fig. 2, and a handlebar 54> the

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is hinged to the free ends of the two arms 50, 52. Sin Such a linkage 48 has the effect that when one of the gyro housing is pivoted, the other by the same angle is pivoted in the opposite direction in a form-fitting manner. If, for example, the gyro housing 38 is pivoted clockwise, the handlebar 54 is pulled to the left in FIG. 2 and pivots the gyro housing 40 against the arm 52 clockwise. The gyroscopic twist axes are therefore always symmetrical to a fixed one, the bisector of the gyroscopic twist axes containing level. With an extension 56 of the arm 52 a pair of springs 58 are connected, through which the gyro housing assembly is resiliently tied to a rest position.

Fig. 3 shows the angle and axis relationships in the described Gyro arrangement. The axis χ is the essentially horizontal bisector of the centrifugal axes and is referred to as the "major axis". The transverse axis y runs perpendicular to this and to the belt axis and through the pivot axes 42, 44. The angle of position of the gyro arrangement in relation to the vertical band axis is the angle »between the main axis χ and the north direction includes. The position angle of the gyro assembly around the main axis χ is denoted by γ and is the angle that the Forms transverse axis y with the horizontal. The position angle of the gyro assembly around the transverse axis is the angle ß that the Main axis χ forms with the horizontal. With e the angle is designated, which the twist axes 34> 36 form the top with the transverse axis y.

It further denotes:

H spin

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_ 7 -

ω angular velocity of the earth's rotation

φ latitude

C + c electrical and tape restraint constants

β _K angle between the main axis χ and the zero position of the tape

_a Storage of the tape zero position τοη Eord

⁸ T-, angle between the gyro axis ("gyroscopic swirl axis")

Xt

and transverse axis with stationary gyroscopes (gyro resting position)

e additional rotation of the centrifugal axes

compared to the resting position of the gyroscope when the gyroscope is running under the influence of the rotation of the earth

. small angular oscillations around the equilibrium

angle (ε _R + ε).

K Directional moment of the centrifugal pendulum around the transverse axis y s independent variable of the Laplace transform f Spring torque on the rotor housing

The components of the Gyroscopic drums generate a north-facing gyroscopic moment

H sine ω cos γ sin _a

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The mutually directed swirl components H cos s do not generate any resulting northing gyroscopic moment. These components respond to rotations around the main axis x, ie to changes in γ, and thus cause an increase in the oscillation period of the " γ oscillations" around the main axis x.

The system described has two pairs of oscillations: An α oscillation around the vertical band axis, which is always with an oscillation of the same frequency around the outer axis, and a γ oscillation around the main axis x, which is always is accompanied by an s oscillation of the same frequency of the gyroscopic twist axes 34j 36 about the pivot axes 42, 44.

The complete theory of the system described becomes very extensive. The equations of the complete system will be non-linear, and a closed solution cannot be achieved. The strict treatment is therefore with the help of an analog computer or through gradual integration in the digital computer. The two vibration groups are therefore initially decoupled below, each considered for itself, with conclusions on the overall behavior can be drawn from the results obtained in this way.

1. The following differential equations result for pure _a and β vibrations:

Moments around the vertical belt axis:
(1) 2 H sin s ei cos φ α + (C + c) « _F + 2 H sins β = 0

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Moments about the transverse axis j%

(2) K β - 2 H ₀ sine "" = 2 H _Q sine _{ω Q} sin _φ The geometrical relationship applies

In these equations,

2 H sins = north-facing swirl component, which in

the equilibrium position β _R + s

becomes 2 H sin (e + s)

^ω cos φ = horizontal component of the earth's angular velocity for the geographical latitude φ

The artificial damping of the device is not included in the present consideration, since only the oscillation time is to be calculated.From the same period, ^a = 0 is assumed, which is permissible because of the pre-alignment of the device to the north and for the purpose of determining the oscillation time, so that a "=" becomes. The solution of the system of equations results in a differential equation of the second order

(4) (2 H _Q sin «) s + C + c + 2H _Q sin« ω cos φ i K = 0 with the oscillation time

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(5)

- ίο -

(2 H ₀ sin a) ²

· (O + c + 2 H sin's © cos ») K. ^v β a 0 e ^

Since (2 H sin β ω cos «) is small compared to (G + c), can to write in a simplified way:

(2 H sin _e ) ² (6) Tp * 2 «If ° '

^p I (G _a + c) K

2. The system of equations for the γ and e oscillations results as follows: %

Moments about the üdiwenkachsen 42, 44s Spring moment + gyro counter moment + precession moment =

(7) 2 fi «+ 2 H _Q w _e COS ₉ sin« _Q A »+ 2 H ₀ cos s _Q \ =

Moments around the main axis:

Pendulum moment - precession moment =

(8) K γ 2 h _Q cos c. β = 0 When resolved, this system of equations gives:

(9) (2 H ₀ cos,) ² 's + 2 K (f + H ₀ w _e cos ,, sin,) _{A e} =

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This gives the oscillation duration of the γ and c oscillations to

(10) T = 2 _π

(2 H cos β) ²

'I 2 K (f + H _Q ω _β cos φ sin _e )

-For the numerical values assumed below, H ω cos φ sin · small compared to f. Therefore, the

Expression for T.

(11) T.

γ, s

(2 H cos O ²

2Kf

A numerical example with realizable values is given below:

H ₀ = 2000 pcm see. ■

k '= 15,000 pcm

ω cos φ = 4.9 * 10 ~ ⁵ see "(for Überlingen)

c = 30 ° sin β = 0.5 cos β = 0.866 »^ (evj +

(C + c) = 99 (2 H sineoj cos φ) ■ λ α ο e

This becomes the denominator under the square root sign in equation (5) increased by a suitable choice of the restraint compared to the unbound oscillation one hundred times. It results:

(C ₁ + c _a ) = 99 (2 .2000. 0.5. 4.9 .10 " ⁵ ) = 9.7 pcm / rad.

It will

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α , β

(2. 2000. 0.5)

(9.7 + 2. 2000th. 0.5. 4.9 10 ~ ^5). 15th

= έπ

4th 10

1.47.

= 32.8 sec

If T = T is to be made, then f must be as follows to get voted

f = (2 «)

(2 H cos «) ²

2 lc T

α, β

(2 π) ² (2. 2000. 0.866) ² 2. 15,000. 32.8 ^

= 14.8

pcm

wheel

pcm

That is quite a realizable value. With f = 14.8

wheel

becomes! «, cos φ sin e = 2000. 4.9. 10 ~ ⁵ .0.5 = 0.047

negligible against f, "as assumed in equation (11) became.

The calculation carried out shows that "with an arrangement of the type described, the period of oscillation T _e gMch the

Period of oscillation T ^ β can be made and thus the rectifier effect becomes less important. Since both vibrations remain coupled via the pulsating twist, an artificial damping of the a and β vibrations will also dampen the γ and e vibrations. It is also an immediate one

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viscous damping of the β-oscillations, possible. The inventive Construction allows the construction of a gyroscope, which even with a restless surface, especially in; Vehicles with the engine running, quickly and without errors It is possible to determine the north direction. , "_ ·

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Claims (1)

Patent entitlement North-looking rotary pendulum with a gyro unit with a housing suspended from a band, onto which a north-looking pendulum Gyro directional torque acts, a tap to Generation of a signal according to the measure of the azimuth deflection the gyro unit from a band zero position and a torque generator counteracting the gyro directional torque, which is acted upon by the tap signal via an amplifier is, characterized in that the gyro unit (12) has a pair of gyros with the same twist (H) during operation, whose twist axes (34> 36) enclose an angle and the with gyro housings (38, 40) mounted in the housing (46) of the gyro unit (12) so as to be pivotable about vertical axes (42, 44), by means of a link arrangement (48) for execution in opposite directions the same pivoting movements are coupled together and elastically tied to a rest position, and that the period of oscillation (T ο) equal to the azimuth oscillations of the gyro unit (12) is the period of oscillation (T _Y β) of the oscillations of the • j Gyro unit (12) around the bisector (x) of the centrifugal axes (34, 36). 509824/0168