RU2591287C1 - Method of determining moment of pitch of floatation tank of two-degree floating gyroscope - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: invention can be used in production and operation of two-degree floating gyroscopes with contactless supports of suspension of gyroscopic chamber. Method consists in that operating gyroscope with contactless supports of suspension of gyroscopic chamber, heated to working temperature, is oriented in a position where its longitudinal axis is horizontal, and pair of radial axes of supports, parallel to measurement axis of gyroscope, is directed vertically, gyroscope temperature change is carried out successively in one and other side of its operating value and simultaneous measurement of control signals in channels of contactless supports is carried out, temperature where measured values of control signals are equal to zero are determined, pitch moment is calculated.

EFFECT: high accuracy of determining moment of pitch of gyroscopic chamber, possibility of controlling moment in assembled gyroscope with contactless supports of suspension of gyroscopic chamber, avoiding need to use special equipment.

1 cl, 1 dwg

Description

The invention relates to the field of precision instrumentation and can be used in the manufacture and operation of two-stage float gyroscopes with non-contact support gyrocamera, for example electrostatic, magnetic [U. Wrigley, W. Hollister, W. Denhard. Theory, design and testing of gyroscopes // M .: "Mir", 1972, p. 289].

A known method for determining the moment of trim of a float gyro camera of a two-stage float gyro with stone supports [USSR patent No. 1840722]. When implementing the method, the working gyroscope is oriented by the measuring axis perpendicular to the plane of the meridian. Then the gyroscope rotates around this axis by 180 °, after which its output signal is measured. Then the gyroscope rotates 180 ° in the opposite direction and its output signal is measured again. The moment of the trim of the gyrocamera is calculated by the values of the lengths of time between the end of the turn and the jump-like change in the output signal of the gyroscope occurring during mechanical contact in the supports.

The disadvantage of this method is the low accuracy. This drawback is due to the fact that the method does not allow to measure the trim of the float gyrocamera in a two-stage float gyro with non-contact supports. Due to the lack of mechanical contact in contactless bearings, jump-like changes in the output signal do not occur during gyroscope turns.

The closest in technical essence and the achieved positive effect to the claimed invention is a method for determining the trim moment of a float gyrocamera, implemented in a process bath filled with a supporting liquid [Kovalev MP, Morzhakov SP, Terekhov KS Dynamic and static balancing of gyroscopic devices // M .: "Mechanical Engineering", 1974, p. 233], which is taken as a prototype. The method is implemented when performing the following technological operations:

1. The process bath is filled with maintenance fluid.

2. The gyrocamera and the measuring device are lowered into the bath in the form of two gramometers, made, for example, in the form of floats.

3. The trunnions of the centering supports of the gyro camera are installed in the holes of the rods of the gramometers.

4. The liquid is heated to a temperature equal to the operating temperature of the gyroscope. After heating, under steady-state thermal conditions, one of the gramometers acts on a force F1 equal to the sum of the residual weight (residual weight - the difference between the weight and the buoyancy force) of the gyro camera and the force due to the presence of the trim moment; on another gramometer - the force F2, equal to the difference of these forces. The forces F1 and F2, acting in the supports of the gyro camera, are balanced by the buoyancy forces of the gramometers, which are pre-calibrated.

5. Reads from the scales of gram meters. By the semi-difference of their testimony, they judge the magnitude of the moment of the trim of the gyro camera.

The disadvantages of the method are:

- Low accuracy. This drawback is due to the fact that the creation in the process bath of temperature fields similar to the fields of a working gyroscope is impossible. As a result, the measured moment of the trim is different from the real moment acting in the assembled device.

- The inability to control the magnitude of the moment of the trim in the assembled gyroscope. Control is carried out only when balancing the gyrocamera in the bath.

- The need to use special technological equipment (for example, special bathtubs).

The objective of the present invention is to improve the manufacturing process of manufacturing two-stage float gyroscopes.

Technical result achieved:

- improving the accuracy of determining the moment of trim;

- creating the ability to control the moment of the trim of the gyro camera with non-contact supports in the assembled gyroscope;

- no need to use special technological equipment.

The problem is solved in that in the known method for determining the moment of the differential gyrocamera of a two-stage float gyro by balancing the forces acting in its supports:

- a working gyroscope with non-contact supports of the gyrocamera, heated to operating temperature, is oriented to a position in which its longitudinal axis is horizontal, and a pair of radial axes of supports parallel to the measuring axis of the gyroscope is directed vertically,

- the temperature T _{g of the} gyroscope is changed sequentially to one and the other side from its working value and the control signals are simultaneously measured in the channels of contactless supports,

- the temperatures are determined at which the values of the measured control signals are equal to zero, the moment of trim M _{d is} calculated by the formula:

M _d = F _d * L = 0.5 * ΔP * L = 0.5 * γ _jo * (T ₂ - T ₁ ) * α * V * L, g · cm, (1)

where Fd is the component of the reaction force of the supports, due to the moment of the trim trim of the gyrocamera, r;

L is the distance between the centers of application of forces in the supports, cm;

T ₂ , T ₁ - temperatures at which the components of the reaction forces of the supports, due to the moment of the trim, are balanced by the components of the reaction forces of the bearings, due to the residual weight of the float gyro camera, ° C (the fact of balancing is determined by the fact that the control signals in the channels of the supports of the non-contact suspension are equal to zero);

α is the temperature coefficient of change in the specific gravity of the liquid, 1 / ° C;

V is the volume of the float gyrocamera, cm ³ ;

γ _W0 is the specific gravity of the liquid at a temperature T ₀ , g / cm ³ ;

- изменение выталкивающей силы жидкости при изменении температуры прибора с T₁ на T₂, г. $$\Delta P={\gamma }_{\mathrm{well}\mathrm{about}}^{\ast }{(T_2-T_{\mathrm{one}})}^{\ast }{\alpha }^{\ast }V$$

- changing buoyancy fluid changing device temperature T ₁ to T _2, g

To implement the proposed method:

1. The gyroscope is mounted on a fixed base in a position in which its longitudinal axis is horizontal, and the axis of the non-contact supports of the gyrocamera parallel to the measuring axis of the device are directed vertically. This orientation excludes the appearance in the measurement results of an error due to the effect on the support of the gyroscopic moment.

2. The gyroscope is operational. To do this, the gyro motor is started, the float gyro camera is weighed in non-contact supports, the gyroscope (supporting fluid) is heated to a working temperature close to the temperature at which the residual weight of the float gyro camera is (close) to zero. The residual weight is the difference between the weight P and the ejection girokamery (Archimedean) _γzh force F = (T) ^{* V,} where γ _w (T) - specific weight of the liquid support which is a function of the temperature T [E. Nikitin, S.A. Shestov, V.A. Matveev. “Gyroscopic systems”, part III, Moscow, Vysshaya Shkola, 1988, p. 210, 211], V is the volume of the fluid displaced by the gyro chamber. In this case, in a real gyroscope, in one of the supports of the float gyro camera, a force equal to the sum of the components of the reaction forces of the support due to the residual weight of the gyro camera and its trim moment will act, in another support - a force equal to the difference of these forces. The forces acting in the supports are balanced by the forces formed by the contactless suspension. The magnitude of the forces is judged by the measurement of the control signals Uk1 and Uk2 in the channels of the contactless bearings, proportional to the forces acting in the bearings.

3. The temperature T _{g of the} gyro decreases with respect to its operating value, for example, in a discrete manner. At each fixed temperature, the control signals Uk1 and Uk2 are measured in the channels of the supports. With decreasing temperature, an increase in the specific gravity of the support fluid occurs, which results in an increase in the buoyancy force acting on the float gyrocamera. The temperature T _{1 is} determined at which the value of the control signal in the channel of one of the supports is zero. In this support, the component of the reaction force of the supports, determined by the residual weight of the gyro camera, will balance the component of the reaction force of the supports, determined by its moment of trim. Heavy organic liquids are used in float gyroscopes, the specific gravity of which varies linearly with temperature [E.A. Nikitin, S.A. Shestov, V.A. Matveev. “Gyroscopic systems”, part III, Moscow, Higher school, 1988, p. 210, 211]. At temperature T _{1, the} specific gravity of the liquid will be determined by the ratio

γ _W1 = γ _W0 [1-α (T ₁ -T ₀ )], g / cm ³ ,

where γ _W0 is the specific gravity of the liquid at a temperature T ₀ , g / cm ³ ;

α is the temperature coefficient of change in the specific gravity of the liquid, 1 / ° C;

γ _Ж0 , α and T ₀ - reference data, their values are determined by the manufacturer of the liquid used in the gyroscope.

4. The temperature T _{g of the} gyroscope (supporting fluid) increases in a discrete way and at the same time the control signals in the channels of the supports are measured. With increasing temperature, the specific gravity of the support fluid decreases, which results in a decrease in the buoyancy force acting on the float gyrocamera. Determined temperature T ₂ at which the pilot channel value in the other support (with respect to the analyzed support in step 3) is zero. In this case, the component of the reaction force of the supports, due to the moment of the trim, will be balanced by the component of the reaction force of the supports, due to the residual weight of the gyro camera. At temperature T _{2, the} specific gravity of the liquid will be determined by the ratio

γ _W2 = γ _W0 [1-α (T ₂ -T ₀ )].

5. When the temperature changes from T ₁ to T ₂ value of the specific weight of the fluid changes by

. $$\Delta {\gamma }_{\mathrm{well}}={\gamma }_{\mathrm{well}\mathrm{one}}-{\gamma }_{\mathrm{well}2}={\gamma }_{\mathrm{well}0}^{\ast }{(T_2-T_{\mathrm{one}})}^{\ast }\alpha ,g/\mathrm{from}{m}^3$$

.

The value of the residual weight of the gyro camera will change by

$$\Delta P=\Delta {\gamma }_{\mathrm{well}}^{\ast }V={\gamma }_{\mathrm{well}0}^{\ast }{(T_2-T_{\mathrm{one}})}^{\ast }{\alpha }^{\ast }V,g$$

Using the above ratios, the moment of trim M _{d of the} float gyrocamera is calculated by the formula (1).

Compared with the prototype method, the use of the proposed method provides the following advantages:

- provides a more accurate determination of the moment of the trim (by determining the moment directly in the conditions of a working gyroscope);

- allows you to control the magnitude of the moment of the trim in the assembled gyroscope;

- does not require additional processing equipment (for example, in the form of special bathtubs).

Additionally, when implementing the method, it is possible to determine (clarify) the operating temperature of the gyroscope directly in the conditions of a working gyroscope. The operating temperature determines the values of the forces acting in the suspension supports of the float gyro camera, affecting the accuracy of the gyroscope. The value of the operating temperature is determined by the half-sum of the temperatures T ₁ and T ₂ .

The above confirms the possibility of obtaining the claimed technical result.

At the enterprise, the proposed method was tested on a two-stage float gyro with non-contact electrostatic support for the gyro camera. Accepted parameters: γ _W0 = 1.83 gsm ³ , α = 0.001 1 / ° C, V = 100 cm ³ , L = 2 cm; T _g = 55 ° C.

As a result of the implementation of the proposed method

- The graphs of changes in the control signals in the channels of the gyro camera supports from the temperature Tg of the gyroscope are determined (Fig. 1).

In FIG. 1 adopted the following notation:

Uk1, Uk2 - control signals in the channels of the supports, the axes of which are directed vertically, mV;

T _g - temperature of the gyroscope, ° C;

T _1, T ₂ - temperature values at which the measured values of pilot signals in the channels are equal to zero, ° C.

- determine the temperature value T ₂ = 55,3 ° C, T ₁ = 54,8 ° C.

- The moment of trim M _d = 0.09 gsm was calculated.

Currently, the method is used in the manufacture of two-stage float gyroscopes with non-contact electrostatic supports of the float chamber.

Claims (1)

A method for determining the moment of the differential of a gyrocamera of a two-stage float gyro by balancing the forces acting in its supports, characterized in that the working gyro with non-contact supports of the gyro, heated to operating temperature, is oriented to a position in which its longitudinal axis is horizontal and the pair of radial axes of the supports, parallel to the measuring axis of the gyroscope, directed vertically, the gyroscope temperature is changed sequentially in one and the other side from its operating value and simultaneously th measurement of control signals in the channels of the contactless suspension supports, determine the temperature at which the values of the measured control signals are zero, calculate the moment of trim M _d according to the formula
M _d = F _d * L = 0.5 * ΔP * L = 0.5 * γ _w0 * (T ₂ - T ₁ ) * α * V * L, g · cm,
where F _d - component of the reaction force of the supports, due to the moment of trim of the float gyrocamera, g;
L is the distance between the centers of application of forces in the supports of a contactless suspension, cm;
ΔΡ is the change in the residual weight of the chamber when the temperature changes from T ₁ to T ₂ , g;
γ _W0 - the specific gravity of the liquid at a temperature T ₀ determined by the manufacturer of the liquid, g / cm ³ ;
T ₂ , T ₁ - temperatures at which the components of the reaction forces of the supports, due to the moment of the trim, are balanced by the components of the reaction forces of the bearings, due to the residual weight of the float gyro camera, ° C;
α is the temperature coefficient of change in the specific gravity of the liquid, 1 / ° C;
V is the volume of the float gyrocamera, cm ³ .

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