DE3448045A1 - Rate-of-rotation measuring device with measuring element damping - Google Patents

Abstract

This device provides the use of a dry torqueless gyroscope with additional damping (15, 16) which can be implemented as gas friction damping, viscous friction or also material damping. In principle, the device acts like a dry rate gyro. Compared with a dry gyro of the conventional type, however, considerable structural simplifications and cost savings are obtained so that the rate-of-rotation measuring device is suitable for fields of application in which the use of a gyroscopic control is desirable but has hitherto not been contemplated because of the technical and financial expenditure being too high. <IMAGE>

Description

TER MEER · MÜLLER · STEINMEISTER- TTTEF - TTF-GOS-DIV

Yaw rate measuring device with measuring element damping

DESCRIPTION

The invention relates to a device for measuring rotation rates according to the preamble of claim 1.

The principle of the so-called dry gyro is known: The sensitive element, the rotor, is through an axle is driven and is attached to this axle in such a way that it acts like a free gyroscope. That The principle of most known constructions of dry gyroscopes is based on the fact that the rotor is driven by dynamic Tuning is decoupled from the drive axle. Decoupling by magnetic fields is also known or mechanical counter springs. The rotor then stops at the rate of rotation and an angle of inclination is built up between the rotor and the gyro housing, the signal of which is detected via a tap. With the so-called This tap signal is used for platform applications to stabilize a mechanical frame system. The torquer of the dry top, consisting of at least one torque magnet on the rotor and fixed to the housing In this application, the coil serves as a guide system for the platform to be stabilized, for example for leveling.

In the so-called strapdown applications, the tap signal is Switched to the torque via a controller in such a way that the rotor deflection is as small as possible. The torque cross current is then proportional to the rate of rotation and forms the measurement signal.

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TER MEER · MÜLLER ■ STEINMEISTER LITEF - LTF-0G5-DIV.

In both cases mentioned, the disturbing torques must be kept as small as possible, depending on the accuracy requirements will. Interfering torques occur, for example, due to friction (e.g. due to gas) and due to the unavoidable damping (e.g. by the spring material or by electromagnetic damping) of the rotor, which in the event of detuning of the zero point of the rotor tap leads to a drift D over a time constant:

D = i <* (1)

l /

(D: drift of the gyro; «? ': Time constant of the gyro; oc : deflection angle of the rotor)

Typical time constants for dry gyroscopes are between 5 and 50 seconds.

Dry gyroscopes with inertial accuracy require a relatively high level of manufacturing accuracy and a

* < 20 high expenditure on mechanics and electronics in the area of readjustment and control. However, there is a relatively high demand for gyroscopic applications in which reduced accuracy is sufficient. In many of these areas of application, the explained type of gyroscope could not or only partially prevail for reasons of cost.

The invention is therefore based on the object of providing a device for measuring the rotation rate by means of a gyroscope create that is suitable for a wide range of applications, but with significantly less mechanical effort and electronics can be produced much cheaper.

The invention is in a device of the type mentioned for rotation rate measurement by the in the characteristic of claim 1 specified features characterized.

TER SEA ■ MÖLLER ■ STEINMEISTER UI ^ Ef- LTF-ÜQ5- DIV

- "3Ü8045 \

Advantageous further developments of the inventive concept are specified in the subclaims and also explained in the following description of exemplary embodiments.

The basic idea of the invention is a known dry gyro to a biaxial rate gyro, which are also referred to as "dry rate gyro" could, to redesign and thereby simplify the mechanics and electronics of the gyro so that a to The result is an instrument comparable to conventional rate gyros in function and measurement accuracy, but with all the advantages of a dry top, especially the biaxiality. The core idea of the invention is In contrast to the previously known dry gyroscopes, not to reduce the damping, but to increase it, that a rate gyro is created.

With this principle, the rotor will make an angle with respect to its reference plane that is different from the Rotational speed of the housing (vehicle, missile) · depends. The output signal of the angle tap on the rotor is read out as a measure for the rotational speed, i.e. the above equation (1) for the damping disturbance torque, is used to read out the measurement signal.

In order to achieve a sufficiently large rotation rate range for small deflections of the rotor that occur in practice achieve, the damping must be chosen so large that the time constant only a few. Milliseconds.

In principle, different options for damping the rotor around the measuring axes can be considered will.

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TER SEA ■ MÜLLER ■ STEiNME-ISTER LTF-005-DIV.

(a) In the case of damping with drive load , the damping vector will point in the direction of the rotor axis without an external rate of rotation. At a rate of rotation, the rotor deflects until the component of the damping that falls in the input axis corresponds to the rate of rotation. With this solution, however, the motor has to overcome the basic damping. For this reason, electromagnetic brakes, for example, are suitable for this type, in which the magnet system is fixed to the housing and has alternating polarity along the circumference of the rotor.

(b) In the case of damping without noticeable drive load according to the invention, gas damping consisting of a chamber and a damping part (paddle) is provided, whereby both the chamber and the paddle can each be connected to the rotor or the housing or the shaft . There are four possible solutions. It is particularly advantageous to choose a rotationally symmetrical arrangement in order to keep the load on the drive low.

The invention and advantageous details are described below with reference to the drawing in an exemplary manner Embodiment explained in more detail.

The single figure shows an example of a construction for a dry rate gyro with gas damping.

The sectional view shows an embodiment of a dynamically tuned dry rate gyro Gas damping according to the invention. In a rotationally symmetrical housing 3 is a motor rotor 8 (external rotor) with a shaft 6 through two unspecified

TER MEER · MÖLLER · STEIN M EJ STHR. LTF-OO5-DIV.

Bearings in bearings. The motor stator 7 is through one at a time serving as a magnetic yoke cover 11 held. At the end remote from the stator 7 is a support 9 for a spring joint placed on the shaft 6, which is held by a stop screw TO. The spring joint 5 is of known construction and does not require any further explanation for the person skilled in the art. With the spring joint 5, a further rotor 4 is connected, which via the spring joint 5 is pivotable relative to the shaft 6 about two axes by a small angular amount.

The shaft 6 is via the spring joint 5 with the approximately spherical rotor 4 as a measuring element in the example shown tied together. The rotor 4 has a flange-like protruding ring extension on the outside in a plane vertical alignment to the shaft 6 on, which rotates in a damping groove formed by two annular circumferential lugs 16. At a rate of rotation will be when tilting the measuring element 4, the gap between the ring-flange approach 15 and a wall of the groove formed by the annular lugs 16 narrow, so that a significant reduction of the air flow cross-section occurs with a corresponding increase in damping. To adjust the damping, however For other reasons (e.g. corrosion protection) it can be useful to fill the space inside the hood 1 with a to fill another gas.

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Claims (3)

TER MEER-MÜLLER-STEINMEISTER ¹ PATENT LAWYERS - EUROPEAN PATENT ATTORNEYS Dipl.-Chem. Dr. N. ter Meer Dipl. Ing. H. Steinmeister Dipl.lng.RE Müller Artur-Ladebeck-Strasse 51 Mauerkircherstrasse 45 D-8OOO MUNICH 80 D-4800 BIELEFELD 1 LTF-005-DIV. November 25, 1985 Mü / vL LITEF
(Litton Technical Works) of HELLIGE GmbH Lörracher Strasse 18 D-7800 Freiburg i.Br. Yaw rate measuring device with measuring element damping PATENT CLAIMS 1, device for rate measurement with a dry Torquerless gyroscope with increased damping. The one connected to the rotor axis (6) and movable about two measuring axes Has rotor (4), the inclination of which can be read out as a direct measure of the rate of rotation, characterized in that the damping is a fluid damping in which the one with the rotor axis (6) connected rotor (4) as a damping element during rotation due to the narrowing of a fluid flow path (Gas or liquid) can be acted upon with additional damping. TER MEER · MÜLLER · STEINMEISTER LTF-005-DIV 2. Device according to claim 1, characterized in that the damping as a flange-like on the outer circumference of the rotor (4) protruding ring extension (15) is formed, which is formed in a by two annular circumferential extensions (16) - Damping groove runs around. 3. Device according to claim 2, characterized in that the interior of the rotation rate measuring device with a different gas than air is filled.