Float integrating gyroscopes

2016-01-01

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Increasingly widespread is the stabilization of the platform with accelerometers with the help of a block of float integrating gyroscopes. Being very sensitive to the angular movements of the platform, integrating gyroscopes, in contrast to power stabilization, precessing, do not create any unloading moment themselves, but only feed signals from their sensors to the unloading engines. Since these signals do not occur simultaneously with the application of an external moment, but only after some deviation of the platform, something like a small jitter (vibration) of the platform near the middle position is observed. The axes of the rotors of the integrating gyroscopes are parallel to the three axes of stabilization of the platform - in three mutually perpendicular planes.

Integrating Gyro - gyroscope with two degrees of freedom - can be obtained by eliminating the outer frame of the free gyro and linking the inner frame with liquid damper. The name "integrating" stems from the problem solved gyroscope: the rotation of the platform to maintain the angle of rotation proportional to the angle of rotation of the frame platform, t. E. The time integral of the angular velocity of rotation of the platform.

Float integrating gyroscope capable of integrating the angular velocities of the order of • 5 10-5 rad / sec (0,172 rev / min), m. E. It is sensitive to an angular velocity approximately equal to one revolution per day 1,5. At the same time, he is able to integrate the angular speed of more than 4,5 rad / s, t. E. More 42 / min. Thus, the ratio of maximum to minimum speed measurement is 9 * 104.

Since integrating gyroscope in its pure form it can measure only a small rotation angles of the platform for the measurement of large angles of rotation of the base he should turn himself continuously using the tracking servo.

The tracking servo. In the inertial tracking servo is used to provide a given geometric stabilization platform f for any changes in the estimated position of the aircraft in the air.

Since the gyros are able to perceive the slightest input turns around their axes, and accelerometers - catching negligible acceleration, servo drives must be very sensitive to weak signals emitted by these devices, and in response to them necessarily turning platform. Fast action tracking systems must be extremely large, and dynamic error - small.

Components actuators, such as electromagnetic amplifiers, electric servo motors and gearboxes used in the past, comply with the required accuracy, linearity, small time constants and good dynamic characteristics. New device used in servo is mikrosin.

Mikrosin - Resolver high, able to be both a sensor and setting unit, the design mikrosinov both cases use is unchanged. However mikrosin sensor can only operate on alternating current and mikrosin-dial - on alternating and direct current.

Microsensors in front of potentiometric sensors have the great advantage that they do not have sliding contacts. In addition, the sensitivity threshold of the wire potentiometer depends on the diameter of the wire, and in the microsin it is practically zero (1 / 600 °), which, with a rotor diameter of about 18 mm, corresponds to a linear displacement of the rotor pole relative to the stator pole at 0,26 μ. Therefore, when the measured angle is small, the microsine has a significant advantage over the potentiometer, despite the fact that the rotor weight greatly exceeds the weight of the potentiometer brush.

To float integrating gyroscopes, which are mounted inside mikrosiny-setting devices and sensors, this fact does not matter.

The integrators convert the input signal into a signal of another form, as described integral (often over time). For example, if the input voltage of the integrator is supplied, the output voltage is removed from the terminals.

For inertial navigation, where it is necessary to integrate the signals of acceleration in a very large range (up to a thousandth of a dozen), it requires not only high accuracy but also performance in a wide range of measurement of the input quantities. This problem is solved using multistage integrators.

Adders - devices algebraically summing information from two or more sources. Any inertial system should summarize the multiple signals. For example, the signal from the program unit and the feedback signal is algebraically summed with the error signal coordinate measuring instrument or a signal of the first integrator.

Adders consist either of electrical circuits, including potentiometers, inductive resistances and capacitances, or of several cascades of electronic tubes. Most commonly used adders built on the basis of potentiometers, voltage dividers, magnetic amplifier control windings and bridge circuits.

Trigonometric device. In inertial systems used in navigation, often multiplies the measured value, for example the speed (in the form of voltage) for a trigonometric function of the angle of, say, the track.

For trigonometric functions sine and cosine of the angle applied sine-cosine potentiometers and ac - rotary transformers.

More complicated trigonometric dependence obtained with the function of the potentiometers.

Multipliers are used to multiply and divide two or more quantities. They are created on potentiometers using bridge circuits and a magnetoelectric ratiometer. Bridge circuits allow you to multiply and divide quantities with much greater accuracy than potentiometric ones, since the measurement result does not depend on the load resistance.

Thus, thanks to a stabilized platform inertial system continuously and automatically, in addition to its main task, simultaneously determine the rate of roll and pitch angles, t. E. The angles characterizing the position of the aircraft relative to the horizon and meridian planes.

Knowing these values under certain flight speed, distance and direction to the desired destination (KPM, MRP) is necessary for the automatic control of the aircraft using the autopilot and automation of power plants.

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