RU2073208C1 - Gyrotheodolite with vertical orientation of gyrowheel rotary axis - Google Patents

Abstract

FIELD: geodetic and mining surveying equipment, gyrotheodolites of various types. SUBSTANCE: gyrotheodolite with vertical orientation of gyrowheel rotary axis has sensitive member, compensation device. Sensitive member is made in form of ferromagnetic rotor with spherical bearing surface, rotor center of gravity coincides with the center of the sphere. Located on the rotor symmetrically to its vertical axis is stator with cores of electromagnets having spherical surfaces in zone of interaction with rotor. Stator electromagnets are connected with source of alternating voltage via capacitors and damping units. Sensitive member in form of rotor with one blind cylindrical hole in the lower part and absence of such hole in the upper part near working zone of load-bearing magnetoresonance suspension reduce the tangents to rotor spherical surface, forces of interaction of suspension stator with rotor caused by magnetic fields leakage of stator that increases accuracy of operation of gyrotheodolite. Rotor of such shape also makes it possible to reduce angle at the cone vertex forming outside surfaces of cores of suspension stator that promotes reduction of resistance moment of rotor rotation. EFFECT: high efficiency. 5 cl, 3 dwg

Description

 The invention relates to technical physics and can be used in geodetic and surveying equipment to create gyrotheodolites of various types. Gyrotheodolites are designed to determine the deviation of the horizontal direction relative to the geographical meridian.

 Known gyrotheodolites with a vertical orientation of the axis of rotation of the gyroscope. The potential advantages of this type of devices are their less susceptibility to vibrational accelerations and linear translational movements of the objects on which they are installed, but the requirements for the accuracy of the gyroscope for this method of its application are quite high.

 In the aforementioned gyrotheodolite adopted as a prototype, a gyroscope with aerostatic suspension of a spherical rotor and a rather sophisticated photo-optical rotor orientation observation device are used. The rotor is maintained in suspension by aerostatic suspension forces directed upward by forcing pressurized compressed air into the gap between the rotor and the bottom cup with a spherical surface. The bowl is rotated around a vertical axis by an electric motor. The rotor is carried away by the aerodynamic forces arising between it and the rotating bowl. Due to the rotation of the Earth, the axis of rotation of the rotor occupies an equilibrium position other than vertical. The magnitude and direction of the indicated deviation is recorded by the photo-optical sensor.

 To actuate the described sufficient energy-intensive design, a relatively powerful engine was used, equipped with a radiator for heat removal. Since the parameters of the aerostatic suspension and rotational drive significantly depend on temperature, obtaining satisfactory accuracy characteristics is possible only after the completion of transient thermal processes, which, apparently, is possible not earlier than an hour. Naturally, the readings of such a gyrotheodolite are highly dependent on ambient temperature. In addition, the impact of a strong connection of the rotor through the air with surrounding parts to the manufacturing accuracy of the main parts of the device are quite stringent requirements. The low instrumental accuracy of such a gyroscope and the bulkiness of the structures, apparently, did not allow the gyrotheodolite of this type to find wide practical application.

 The problem to which the invention is directed is to create a modern, accurate, technological, small-sized and economical gyrotheodolite in nutrition. Small size and power consumption are especially important for portable field surveying tools.

 The problem is solved in that in a gyrotheodolite with a vertical orientation of the gyroscope rotor axis containing a sensing element and a writing-off device, the sensing element is made in the form of a ferromagnetic rotor with a spherical outer surface with a symmetrical relative axis of the stator with cores of electromagnets having in the interaction zone with the rotor of the surface of a spherical shape, and the stator electromagnets are connected through capacitors and damping units to the source alternating voltage or current. The magnetic resonance suspension thus formed keeps the gap between the rotor and the cores of the electromagnets unchanged. Since the rotor is suspended by the forces of an electromagnetic field, and not due to gas pressure, as in the prototype, the sensitive element is made with a sealed housing and a vacuum inside, which significantly reduces the necessary energy to bring the rotor into rotation and thereby improves accuracy and reduces the availability time , and also reduces the temperature susceptibility of gyrotheodolite in comparison with the prototype.

 Inside the sealed housing there is also a stator of an electric motor that drives the rotor, as well as a two-coordinate differential induction sensor that acts as a meter of angular deviations of the rotor relative to the axis of symmetry of the housing and the function of the torque sensor.

 Unlike the prototype, as well as the known gyroscopes with magnetic suspension, the rotor of the proposed device has one blind cylindrical hole in the lower part. The absence of such a hole in the upper part near the working zone of the power magnetic resonance suspension reduces the forces of interaction between the suspension stator and the rotor tangential to the spherical surface of the rotor due to the stator scattering fields, which increases the accuracy of the gyrotheodolite. A rotor of this shape also makes it possible to bring the cores of the suspension stator electromagnets closer to the vertical axis of symmetry of the housing, which helps to reduce the moments of resistance to rotor rotation.

 The differences in the currents of the suspension electromagnets are used to determine the initial orientation of the gyrotheodolite relative to the vertical of the place.

 In FIG. 1 shows a functional diagram of the proposed gyrotheodolite; in FIG. 2 and 3 diagrams of the components of the measuring unit and the damping unit, as well as generating signals proportional to the deviation of the housing of the measuring unit from the vertical direction.

 The housing of the gyroscopic measuring unit 1 with the associated orthogonal axes X, Y, Z is mounted in the gyrotheodolite body and oriented so that the mentioned axes coincide with the corresponding gyrotheodolite axes, the axis of symmetry Z being oriented vertically and the direction of one of the horizontal axes , for example, the Y axis, approximately coincided with the direction N of the geographic meridian. The angle ψ between the aforementioned horizontal direction should be determined by the gyrotheodolite. Block 2 damping and generating signals proportional to the deviation of the Z axis from the direction of the local vertical, together with the power converter 3 provides the functioning of the spatial magnetic suspension of the rotor of the gyroscope installed in the housing 1. Signals 4 and 5, proportional to the deviation of the Z axis from the direction of the local vertical, come through low-pass filters 6 and 7 to visual indicators 8 and 9, according to the readings of which the operator combines the directions of the Z axis and the local vertical. Together with indicators or instead of them, blocks 8 and 9 may include drives for automatic gyrotheodolite leveling or computing devices that produce an amendment to gyrotheodolite readings, taking into account the mismatch between the directions of the Z axis and the vertical.

 The two-coordinate angle sensor 10 of the angular deviations of the gyroscope rotor axis from the direction of the Z axis of the housing 1 is connected through amplifiers - converters 11 and 12 to the two-coordinate moment sensor 13. All these elements form a two-coordinate tracking system, which seeks to reduce the mentioned angular deviations.

The specified tracking system performs various functions depending on whether the center of gravity of the rotor and the center of its outer spherical surface coincide or do not coincide. For the case of an astatic gyroscope, that is, the case of the mentioned centers coinciding, and with sufficiently large amplification of the converter amplifiers, electrical signals proportional to the absolute angular velocities w _x and ω _{y of the} rotation of the housing 1 about the X and Y axes will appear on their outputs. In this case, the blocks 1, 10, 11, 12, 13 perform the functions of a two-coordinate gyrotachometer. The values of ω _x and ω _{y are} determined from the following obvious relations
ω _x = ΩcosΦsinψ ω _y = ΩcosΦcosψ
where Ω is the angular velocity of the Earth;
v geophysical latitude.

 When the center of gravity of the rotor is located below the center of its outer surface, the rotor behaves like a gyro-pendulum with a vertical axis of rotation. In this case, the gains of blocks 11 and 12, as well as the transfer function of the sensor 13 are selected from the conditions for the necessary damping of free precession oscillations of the gyro-pendulum, i.e., the two-coordinate tracking system considered earlier performs the functions of a damping device.

It should be noted that the modification of the claimed device with an automatic gyroscope provides a faster completion of transient processes, i.e., a faster solution of the task, while the modification of the device with a gyro-pendulum is potentially capable of working with greater accuracy. In fact, even in the case of a deliberate construction of a gyrotheodolite with an astatic gyroscope due to imperfect technology, there is always a residual rotor imbalance, which must be taken into account when operating the device. The outputs of the converters 11 and 12 are also connected to a device 14 generating a value and sign of the angle j, based on the previously mentioned information on the values of w _x and ω _y . The development of the angle ψ can be carried out, for example, by constructing a horizontal projection of the absolute angular velocity vector from its two components, i.e., from w _x and ω _y .

For small values of the angle ψ, i.e., for the initial rough orientation of the gyrotheodolite along the meridian, the value of this angle is defined as the ratio w _x / ω _y . The device 14 may also include a drive for automatically aligning the Y axis of block 1 with the N direction, that is, a drive turning the block 1 around the Z axis. In this case, the input signal of the drive is the value -ω _x , which is reset during block 1 rotation , since with rotation the angle ψ will decrease to zero. The angle of rotation of the drive relative to its initial position will be equal to the angle j.

 The outputs of block 2, on which signals are generated proportional to the forces developed by the suspension electromagnets, are connected to block 15. This block contains high-pass filters and amplifiers that isolate the variable components of these signals proportional to the variable components of linear accelerations along the symmetry axes of the gyro rotor suspension electromagnets. The output of block 15 is connected to a computing device 16 that generates a correction Dj to the readings of the gyrotheodolite, compensating for its errors due to vibration of the base.

 The cares of gyroscopes with a spherical rotor under conditions of vibration of the base have a rather complicated dependence on technological defects of their manufacture and suspension properties. The resulting values of the departures depend on the amplitude of vibrational accelerations, the square of this amplitude, as well as on the direction of the vector of these accelerations with respect to the axis of rotation of the rotor and the direction of gravity. In this case, departures occur both in the plane of vibrational accelerations and in the perpendicular direction.

 Since block 15 receives four signals proportional to the projections of the linear acceleration vector into four directions lying in two orthogonal planes intersecting along the Z axis, it is possible to construct at each given moment the magnitude and direction of the linear vibrational acceleration vector relative to the coordinate system X, Y , Z and calculate the gyro drift values around the X and Y axes.

за время измерения;
определяется поправка Δψ согласно выражения

а для случая малого угла ψ поправка вычисляется по формуле

Значения конкретных коэффициентов в модели уходов гироскопа определяется экспериментально для каждого данного образца гиротеодолита путем измерения Δψ и сигналов, вырабатываемых блоком 15, в процессе калибровки на вибрирующем основании при различных амплитудах и направлениях вибрации.Thus, in block 16, the following operations are performed:
the magnitude and position of the vector of linear vibrational accelerations is determined;
the value of the square of the magnitude of the specified vector is obtained;
the magnitude and direction of the resulting care is calculated;
the components of the gyroscope departure, Dw _x and Δω _y around the X and Y axes, are determined;
mean values are determined

during the measurement;
the correction Δψ is determined according to the expression

and for the case of a small angle ψ, the correction is calculated by the formula

The values of specific coefficients in the gyroscope drift model are determined experimentally for each given sample of the gyrotheodolite by measuring Δψ and signals generated by block 15 during calibration on a vibrating base with different amplitudes and directions of vibration.

 If the gyrotheodolite is not designed to work on a vibrating base, blocks 15 and 16 may not be included in its composition.

 As shown in FIG. 2, the measuring unit 1 contains a gyroscope with a spherical rotor 17. Inside the rotor there is an axisymmetric cavity providing the necessary ratio of its moments of inertia around the orthogonal axes. At the bottom of the rotor there is a cylindrical hole associated with the internal cavity. A stator 18 of a magnetic resonance suspension symmetrical with respect to the vertical Z axis is located over a rotor at a certain distance and has cores of electromagnets having spherical surfaces in the area of interaction with the rotor. The stator is the main element of the magnetic resonance suspension. Terminals 19 and 20 of the coils of the electromagnets of the stator 18 are connected through damping units 21 and 22 to a power converter 3 generating alternating voltage or current. Each of these blocks contains a capacitor, forming a series resonant circuit with an electromagnet, and two bipolar uni-half-wave rectifiers connected between in parallel. The load of each rectifier is a parallel-connected resistance and a capacitor.

 The rotor is suspended due to the corresponding changes in the currents of the electromagnet of the stator 18 when the rotor is moved relative to it, which is ensured by the application of tuning of serial resonant circuits. In blocks 21 and 22, derivatives of the envelope of alternating currents flowing through electromagnets are also generated.

 Bipolar outputs 23 and 24 of blocks 21 and 22 through an adder 25, for example resistive, are connected to output 4. When the Z axis deviates from the vertical voltage, the equality of the currents of the left and right electromagnets of the stator 18 is violated, as a result of which a direct current voltage proportional to the aforementioned appears on the output 4 deviation and corresponding polarity.

 The outputs 23 and 24 of the blocks 21 and 22 are also connected with the block 15.

 The measuring unit 1 also includes a stator 26, which rotates the rotor 17, and a two-axis differential induction sensor 27 with its electronic converter 28.

 The stator 26 performs the initial forced acceleration of the rotor 17, and then turns off. If it is necessary to maintain a constant rotor speed over long time intervals, the stator 26 is transferred from the forced to the nominal operating mode.

 The two-coordinate sensor 27 is simultaneously a sensor 10 of the angular deviations and the sensor 13 of the moment. The operation of the sensor 27 is provided by the converter 28 in one of the known ways, for example, by dividing the signals in time.

 If it is necessary to obtain a higher level of stresses 4 and 5 in the gyrotheodolite composition, in addition to the elements shown in FIG. 2, bipolar rectifiers 29, 30 are introduced, the connections of which with the blocks 1, 21, 22 and 25 are shown in FIG. 3. The increase in the steepness of signals 4 and 5 in this case is due to the resonant properties of the rotor suspension circuits. Since the rectifiers 29, 30 are connected directly to the coils of electromagnets that make up the resonant circuits of the suspensions, due to the high quality factor of the circuits, the voltages supplied to the rectifiers significantly exceed the corresponding voltages appearing on the terminals 23, 24 of blocks 21, 22.

 Similarly, the suspension elements of the gyrotheodolite gyro rotor are made, operating in a vertical plane passing through the Y axis, i.e., located in a plane perpendicular to the plane of FIG. 2 and 3. The dimensions of the measuring unit 1 with all its components can be quite small and not exceed 50 mm in diameter and the same length.

 The power consumption of the gyrotheodolite to provide the devices shown in FIG. 1 3, without automatic drives for leveling and turning in azimuth does not exceed 10 15 watts.

 Thus, the claimed gyrotheodolite contains a two-coordinate electronic level, a three-coordinate fast-acting accelerometer and a two-coordinate gyrotachometer with an astatic three-step gyroscope or gyro-pendulum with a vertical axis of rotation of the rotor, according to the readings of which the initial orientation of the gyrotheodolite and the angle correction unit are calculated, as well as the angle unit depending on leveling errors and base vibrations.

 The basis of the measuring unit of the claimed gyrotheodolite is a spherical ferromagnetic rotor, held in equilibrium by the forces of an electromagnetic field of alternating current, developed by a stator of a magnetic resonance suspension located above it. Suspended in this way, the rotor serves as an accelerometer, as well as a two-coordinate electronic level. Since the rotor is in a vacuum and can run on coast, the accuracy of this device is very high.

 In the proposed gyrotheodolite, in contrast to the known gyroscopes with a symmetrical magnetic suspension, a hemispherical rotor suspension is used. This solution not only simplifies the design of the gyrotheodolite and reduces its energy consumption, but also improves the accuracy of work. The latter circumstance is due to the fact that the gyro rotor is automatically centered relative to the hemisphere of one suspension stator located above it, while in the presence of two suspension stators, the gyro accuracy is very significantly affected by the relative positions of these stators.

 The rotor shape, which does not contain any holes or other surface disturbances in the area of its interaction with the suspension stator, also contributes to the accuracy of the gyrotheodolite.

 The main technical results, compared with the prototype, achieved in the claimed device, as follows from the foregoing, are a significant increase in accuracy, reduction in availability, overall dimensions, weight and power consumption.

 The composition of the proposed gyrotheodolite, as well as in other gyrotheodolites, can include an optical sight, a meter for measuring the angle of rotation of the sight, a base for mounting the device on the ground or on the chassis of a vehicle, as well as other devices whose nomenclature and design depend on the particular application of the gyrotheodolite.

Claims (4)

1. Gyrotheodolite with a sensitive element containing a gyroscope with a spherical rotor with a vertical orientation of its rotation axis, a charging device and an azimuthal direction generating unit, characterized in that the sensitive element is made in the form of a sealed evacuated housing containing a ferromagnetic rotor with a spherical outer surface and located above a stator symmetrical with respect to the vertical axis with electromagnet cores having spherical surfaces in the zone of their interaction action with a rotor, and each stator electromagnet is connected to an alternating voltage (current) source through a capacitor and a damping unit connected in series to it, as well as a two-coordinate sensor that interacts with the rotor and is connected to the azimuthal direction generating unit and the outputs of amplifier converters whose inputs connected to a writing device,
2. A gyrotheodolite according to claim 1, characterized in that the spherical rotor of the gyroscope has a cylindrical hole connected to the internal cavity, the axis of symmetry of which are parallel to the axis of rotation of the rotor, said hole being located in the lower part of the rotor.  3. Gyrotheodolite according to paragraphs. 1 and 2, characterized in that each damping unit contains two parallel-connected one-half-wave bipolar rectifiers, each of which is connected to a parallel-connected resistance and capacitor.  4. Gyrotheodolite according to paragraphs. 1 to 3, characterized in that it uses adders, for example, resistive, visual indicators of the deviation of the gyrotheodolite housing from the vertical direction and (or) the drive of automatic leveling of the housing, the inputs of each adder being connected to bipolar rectifiers of damping blocks connected in series with the electromagnets of the suspension stator , the axis of symmetry of which are located in one vertical plane passing through the center of the rotor, and the outputs of the adders are associated with the corresponding visual indicators and (or) drives the automatic leveling.  5. Gyrotheodolite according to paragraphs. 1 3, characterized in that it uses adders, for example, resistive, visual indicators of the deviation of the gyrotheodolite housing from the vertical direction and (or) the drive automatically leveling the housing, two pairs of different-voltage rectifiers, each pair of rectifiers connected in input to the stator electromagnet, and the second rectifier of a different polarity of the pair is connected to the stator electromagnet lying in the same vertical plane as the previously indicated electromagnet, and the rectifiers are connected to the inputs by the output ora, the output of which is connected with an indicator deviation and (or) driven automatic leveling.

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