RU2150087C1 - Indicator of direction of geographic meridian - Google Patents

Abstract

FIELD: orientation of object with respect to plane of geographic meridian. SUBSTANCE: sensitive element is put on object with use of gimbal suspension composed of outer ring and inner cross piece. Sensitive element includes inert body tied by means of restoring members to oscillation exciter. It will oscillate about axes of its suspension as result of interaction of translation velocity of inert body with angular velocity of rotation of the Earth. Amplitudes of these oscillations depend on direction of geographic meridian. Angle transducers which inputs are connected to input of computer are set on axes of suspension of sensitive element. Computer calculates angle determining position of object relative to plane of geographic meridian. Time of determination of orientation of object with reference to geographic meridian amounts to some seconds or a few tens of seconds. EFFECT: reduced energy consumption and mass and size characteristics of indicator. 1 dwg

Description

 The invention relates to measuring technique and can be used to determine the orientation of the object relative to the direction of the plane of the geographical meridian.

 Known gyrocompass (GC) with indirect control [1], containing a gyrodrive mounted inside a vertical ring on bearings located along a horizontal axis perpendicular to the main axis of the gyroscope. The vertical ring is suspended in the follower ring on a torsion bar and guide bearings. The follower ring is installed in the housing on a biaxial gimbal. The center of gravity of the sensing element (SE), which includes a gyrodrive and a vertical ring, coincides with the suspension point. A flat pendulum-horizon indicator is installed on the gyrodrive chamber so that its sensitivity axis is parallel to the main axis of the gyroscope. On the internal and external axes of the suspension of the gyroscope installed torque sensors, which receive signals from the horizon indicator. After the transition time, the main axis of the gyrocompass shows the direction of the plane of the geographic meridian. Thus, the time to determine the direction of the meridian is within the period of the precession oscillations of the HA and amounts to tens of minutes. The gyrocompass has significant weight and size characteristics and power consumption.

 Known ground gyrocompass with stone supports [2]. Such a gyrocompass consists of a sensitive element (SE) and the instrument body. A gyrodrive with a horizontal axis of rotation is installed inside the SE. The FE is installed in the housing on stone supports, to reduce the contact pressure on the supports, the FE is immersed in a supporting fluid, which is simultaneously used as a conductor to transfer power to the gyrodrive from the electrodes of the housing to the corresponding electrodes of the CE. The SE of such a gyrocompass makes damped harmonic oscillations relative to the direction of the geographic meridian, the position of which is calculated according to a certain algorithm based on the readout of readings from the SE. Reducing the time to determine the direction of the geographic meridian with a gyrocompass can be achieved only by reducing the period of its undamped oscillations. For this, it is necessary to reduce the magnitude of the kinetic moment and increase the recovery moment of the gyrocompass. A decrease in the kinetic moment leads to a sharp decrease in the accuracy of the HA, an increase in the recovery moment is advisable only within certain limits and leads to an increase in the dimensions of the device. In addition, the time to determine the direction of the meridian by the gyrocompass also includes the acceleration time of the gyro motor to its nominal speed. All this limits the possibility of reducing the time to determine the direction of the meridian with a gyrocompass, which can be reached on the order of 10-15 minutes.

 Known pendulum gyroscopic compass on a torsion bar [3]. This device, selected as a prototype, is designed to determine the azimuth of an object in a fixed base relative to the Earth. The gyrocompass contains a sensitive element (SE), which is suspended on the torsion bar in the body as a two-coordinate physical pendulum. A gyrodrive is installed in the SE, the axis of rotation of which is horizontal. To eliminate the effect of the moment of elasticity forces of the torsion bar on the SE, a follow-up system is used that turns the upper end of the torsion bar following the rotation of the gyro motor, as a result of which the torsion bar remains untwisted. The position of the meridian plane is determined in the mode of weakly damped oscillations from the points of reversal, that is, the points of the limiting deviations of the SE in azimuth. The disadvantage of such a gyrocompass is that it takes at least one period of its precession oscillations to determine the direction of the meridian. The period of precessional fluctuations of the HA is usually about 8-12 minutes. In addition, before the start of the measurement process, it is necessary to ensure acceleration of the gyromotor, which is 0.5-2 minutes. The presence of a gyro motor necessitates a specialized power source (alternating current, frequency 400 or 500, or 1000 Hz) of sufficient power. The possibility of reducing the weight and size characteristics of the gyrocompass is also limited due to the presence of a gyro motor and the need to ensure a sufficient torsion bar length.

 The present invention is to provide a meter having a time to determine the direction of the meridian of a unit or tens of seconds.

 The solution of this problem is achieved by the fact that in the directional measuring device of the geographical meridian containing the sensing element, made in the form of a physical pendulum mounted in the housing using a two-coordinate suspension, according to the invention, the sensing element contains an inertial body coupled by an elastic connection with the vibration exciter. The two-coordinate suspension is made in the form of a biaxial cardan suspension, on the axes of which angle sensors are installed, the output signals of which are fed to the input of the calculator. The essence of the device lies in the fact that as a result of the interaction of the speed of translational movement of the inertial body with the angular velocity of rotation of the Earth, the SE will oscillate around its suspension axes. The amplitudes of these oscillations depend on the orientation of the object relative to the direction of the geographical meridian, which are calculated by the calculator.

 Signs that distinguish the proposed measuring instrument of the direction of the geographical meridian from the pendulum gyroscopic compass closest to it on the torsion suspension are the presence of an inertial body in the SE, to which the vibration exciter installed in the SE reports translational motion along the plumb line. As a result of the interaction of the angular velocity of the Earth’s rotation and the translational movement of the inertial body, the CE makes angular vibrations around its suspension axes, the amplitudes of these vibrations depend on the orientation of the object relative to the direction of the geographic meridian, which reduces the time to determine the direction of the geographic meridian, reduces energy consumption and weight and size characteristics of the device.

 The time to determine the direction of the geographical meridian of the proposed meter is the sum of the readiness of the pathogen, the time of the transition process in the system, the calculation time of the computer and is one or tens of seconds.

 The drawing shows a device for measuring the direction of the geographical meridian.

 The geographic meridian direction measuring instrument (see the drawing) contains a sensing element 1 mounted on the object using a cardan suspension consisting of an outer ring 2 and an internal cross 3. In CE 1, an inertial body 5 is mounted on the guides 4, which is connected with the vibration exciter 6 by elastic elements 7. The causative agent 6 is mounted on the housing of the CE, on the axes of the suspension of which angle sensors 8, 9 are installed. Signals from the angle sensors are supplied to the calculator 10.

, обусловленная периодическим поворотным ускорением

[4]. В общем случае оси подвеса ЧЭ не совпадают с направлением восток - запад (ось ξ), следовательно, вокруг этих осей действуют моменты

где m - масса ЧЭ, 1 - длина маятника, α - угол, определяющий ориентацию объекта относительно направления меридиана.The measuring direction of the geographical meridian works as follows. In the operating mode, the pathogen informs the inertial body 5 of the translational oscillatory motion along the plumb line according to the law z = z ₀ sinωt, where z is the deviation of the body center of mass along the OZ axis at time t, z ₀ is the amplitude of the center of mass of the body, ω is the angular frequency of oscillations of the center of mass of the body. Together with the Earth, body 5 participates in a portable motion with a speed of Ω _η = Ω _З cosφ, where Ω _З is the angular velocity of the Earth's daily rotation, φ is the latitude of the place. As a result of this, inertia force acts on body 5

due to periodic rotational acceleration

[4]. In the general case, the CE suspension axes do not coincide with the east – west direction (ξ axis); therefore, moments act around these axes

where m is the mass of the SE, 1 is the length of the pendulum, α is the angle that determines the orientation of the object relative to the direction of the meridian.

 These moments cause oscillations of the sensitive element 1 around its suspension axes, the amplitudes of these oscillations depend on the orientation of the object relative to the direction of the meridian (angle α). The angles of variation of the SE are measured by angle sensors 8, 9, the output signals of which are fed to the calculator 10. The calculator 10 calculates the angle α, which determines the position of the object relative to the direction of the geographic meridian.

As an example of the technical implementation of the inventive device, a meter can be used in which an electrodynamic type exciter is used, which contains a permanent magnet mounted on the SE housing and a coil connected with an inertial body. The coil is powered by voltage U = U _о sinωt. Non-contact angle sensors, for example, capacitive or optoelectronic, can be used as angle sensors. The signals from the angle sensors are fed to a computer, based on a digital single-chip microcomputer. The computer should also include analog-to-digital converters for converting voltages from angle sensors to a digital code proportional to them; an indication unit for displaying the received information about the azimuth angle.

Sources of information
1. Matveev S.S. Gyrocompasses and gyrohorizon compasses. - L .: Shipbuilding, 1974, p. 33-38.

 2. Sergeev M. A. Ground gyrocompasses. - L .: Engineering, 1969, p. 124-151.

 3. Odintsov A.A. Theory and calculation of gyroscopic devices. - Kiev: Vichy School, 1985, p. 161 - 165.

 4. Copyright certificate N 1675671, G 01 C / 00, 09/07/91.

Claims (1)

 A geographic meridian direction measuring instrument containing a sensing element in the form of a physical pendulum installed in the housing using a two-coordinate suspension, characterized in that the sensing element contains an inertial body coupled by an elastic coupling with an oscillation pathway, which communicates the inertial body along the pendulum plumb line, and the two-coordinate the suspension is made in the form of a gimbal suspension with angle sensors installed on its axes, the outputs of which are connected to the input of the calculator.