DE1100102B - Device for eliminating the quadrant error in radio compasses - Google Patents

Description

The aim of the invention is to correct the quadrant error of the form tgq) = K tgq>', as is the case with radio compasses that are placed on moving bodies with a plane of symmetry, e.g. B. an aircraft, are installed, occurs and is transmitted as a location error to the display device.

In order to compensate for the quadrant error, various devices have been developed which into the mechanical transmission between the axis of rotation of the compass frame antenna and that of the latter Axis driven display means are switched on. These known devices have im generally a cam that has to be customized or ground for each case. An adjustable cam has also become known, which can be set according to the individual case got to.

The invention enables a simple and complete solution to the problem and has a device on radio compasses on the subject, which prevents the transmission of the quadrant error from the receiving frame to the display organ, that between the axis of rotation of the loop antenna and the display device driven by this axis arranged mechanical transmission means for the rotation is such a universal joint, in which the waves form an angle with one another which corresponds to the elimination of the quadrant error form.

The invention is based on the fact that the simple universal joint follows the law of motion tg.t '= cosa tgy , where χ and y mean the angle of rotation described by one and the other shaft of the universal joint and α the mutual inclination angle of these two waves. The agreement in the structure of this law of motion and the above formula for the quadrant error leads to the fact that with the aid of the device according to the invention a complete compensation of the quadrant error is possible, provided that the angle of inclination α between the shafts of the universal joint is chosen so that the value of cos α equals the value of the constant K in the formula for the quadrant error.

In application to a radio compass, in which the remote control of the display member by means of a to the There is an axis of rotation of the loop antenna connected encoder, the device according to the invention is preferably designed so that the two shafts of the universal joint with the correspondingly inclined towards each other The axes of rotation of the frame and the encoder are aligned and firmly connected, or these axes educate yourself.

According to a further feature of the invention

Facility for disposal

of the quadrant error

with radio compasses

Applicant:

Air equipment,

Asnieres, Seine (France)

Representative: H. Meissner sen.

and Dipl.-Ing. H. Meissner jun., Patent attorneys,

Bremen, Bahnhofstr. 28/31

Claimed priority:
France 8 June 1955

Georges Garnier, Asnieres, Seine (France),
has been named as the inventor

Means are provided that adjust the angle between the Shafts of the cardan joint to the value required to compensate for the quadrant error in the appropriate reference plane and allow it to be established. This reference plane is for airplanes generally the plane of symmetry.

Further details and features of the invention emerge from the following description of the radio compass according to the invention, which is illustrated schematically and by way of example in the drawing. In the drawing, A denotes the rotating frame of the radio compass. The axis 1 of the rotating frame is rotatable in a fixed bearing B.

The winding of the frame is connected to the two slip rings α and b . The current collecting brushes, which are connected to a high-frequency receiver C known from radio compasses, drag against these rings.

An antenna D _3, which is used to eliminate the ambiguity of the bearing (error of 180 °), is also connected to the receiver C.

A screw gear E , which meshes with a worm F , is keyed onto the shaft 1. The worm F is driven by the reversible two-phase motor G. The stator winding g ^{1 of} this motor is continuously supplied with alternating current from a local source (e.g. a current source of 400 p / s), while the stator winding g ^{2 is}

"■■ '·" - "109527/399

Catcher C is supplied with alternating current which, with respect to the current flowing through the winding g ¹ , either leads in phase by 90 ° each time the frame A is not in the position in which there is no voltage at its terminals or lagging.

In such an apparatus, the frame is rotated by the motor G so that it remains continuously in the above-mentioned direction (apparent direction of the transmitter). ίο

H denotes the transmitter of the remote transmitter, which is connected to the display receiver / located at a certain distance.

As a result of the weight of the aircraft carrying the radio compass, the frame yi, as is known, does not always indicate the exact direction of the transmitter. The indicated direction has the so-called quadrant or quarter circle error tg <p = K tg9 /, which only disappears in four frame positions, namely in two positions that correspond to the case in which the longitudinal center line of the aircraft runs in the direction of the transmitter, and with two positions which are offset by 90 ° with respect to the former. So if the moving part of the transmitter of the teletransmitter H is wedged directly onto the axis 1 of the frame A , then the display device delivers / information that is affected by the quadrant error.

For this reason, a correction device is switched between the axis 1 and the remote transmitter H in order to eliminate the quarter circle error concerned.

According to the invention, the correction system in question consists of a simple universal joint 2, the drive shaft of which is the axis 1 of the bearing frame A and which actuates the movable part of the remote transmitter H via the shaft 3.

With such a universal joint, as is well known, there is the law of motion

tgx = cosatgy

where χ is the angle of rotation of shaft 1, y is the angle of rotation of shaft 3 and α that of the two shafts 1

40 and 3 formed angles. It is sufficient to change the angle α so that cos α assumes the value of K in tgq> = Ktgcp '.

The quadrant error then disappears. In the case of a movable body that has a plane of symmetry has, such as B. in an aircraft, the angle σ lies in the plane of symmetry of the aircraft.

Locking means, not shown, make it possible, after the angle α has been determined, to block the remote display transmitter H in the required angular position, and the radio compass is then finally set (with regard to the elimination of the quadrant error) to the aircraft provided with it.

Claims (3)

PATENT CLAIMS: 1. Device for eliminating the Ouadrant error in radio compasses by means of an between the axis of rotation of the loop antenna and the display device driven by this axis arranged mechanical transmission means for the rotation, characterized in that the Transmission is such a universal joint, in which the shafts one of the elimination of the Form an angle corresponding to the quadrant error. 2. Device according to claim 1, characterized in that when remote control of the display member the two cardan shafts by means of an encoder connected to the axis of rotation of the frame antenna align with the correspondingly inclined axes of rotation of the frame and the encoder and are firmly connected or form these axes themselves. 3. Device according to claim 1 or 2, characterized in that means for setting and locking the quadrant error canceling angle between the shafts of the universal joint in a suitable reference plane, e.g. B. the plane of symmetry of an aircraft are provided. Considered publications:
French patent specification No. 934 738. 1 sheet of drawings © 109 527/399 2.61