RU2846429C1 - Image stabilization system on a movable base - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to precision instrument making and specifically to gyroscopic equipment, and can be used in navigation systems. Essence of the proposed invention consists in the following. Image stabilization system on a movable base contains a comparator, a correction device, an amplifier, an adder, a correction link, power amplifier, which output is connected to the motor, angle sensor rigidly fixed together with the stabilized load, wherein one of motor outputs is connected with stabilized load while another output is connected with angle transducer input. Image stabilization system additionally includes negative feedback from the engine first output to the correction link input through the focusing link, and a gyro tachometer is also introduced, the output of which is connected through the threshold element with the ambiguity zone to the input of the adder, wherein the input of the gyro tachometer is connected to the third output of the engine.

EFFECT: higher accuracy of stabilization.

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Description

The invention relates to precision instrument making, namely to gyroscopic technology, and can be used in orientation, stabilization and navigation systems.

Known are two-axis gyroscopic optical image stabilizers, comprising a frame mounted on the same base as the photodetector, a platform mounted in the frame with gyroscopic sensors of angular velocity of the azimuth and altitude channels, and a mirror connected to the platform by a kinematic transmission with a gear ratio of 1:2, actuator motors of the azimuth and altitude channels mounted on the axes of rotation of the frame and mirror, correcting devices and amplifiers for stabilizing the azimuth and altitude channels, through which signals from the gyroscopic sensors of angular velocity are fed to the actuator motors [Babayev A.A. Stabilization of optical devices - L.: "Mashinostroenie", 1975, pp. 40-41].

The disadvantage of these devices is the need to install gyroscopic angular velocity sensors on the platform to ensure the required ratio between the rotation angle of the mirror and the gyroscopes, which increases the dimensions and weight of the structure. The kinematic transmission between the platform and the mirror increases the friction moments in the system, and errors in the kinematic transmission lead to a decrease in the accuracy of stabilization of the line of sight.

A device for stabilizing the line of sight is known [RU Patent No. 2260773 C1, IPC G01C 21/18, published 20.09.2005, Bulletin No. 26], comprising a frame, a mirror, actuator motors of the azimuth and altitude channels mounted on the axes of rotation of the frame and mirror, amplifying and correcting devices of the azimuth and altitude channels, the output of each of which is connected to the input of the actuator motor of the corresponding channel, an angle sensor mounted on the axis of rotation of the mirror, gyroscopic angular velocity sensors, a differentiating device, a computing device, a multiplier, an adder, and a subtracting device. The disadvantage of this device is the low accuracy of stabilization and the presence of a large drift of the gyroscopes.

The closest to the proposed device is the image stabilization system on a moving base [RU Patent No. 2753162 C2, IPC G01C 21/18, published 12.08.2021, Bulletin. No. 23], comprising an indicator gyroscopic platform with a stabilized load mounted thereon, a gimbal suspension, a gyroscope with angle sensors, an amplifying and correcting device representing a stabilization circuit containing a series-connected correcting device and an amplifier, the input of which receives a signal from a comparison device calculating the difference between the current reading of the gyroscope angle sensor and the guidance signal, a summer, the input of which receives a signal from the amplifier and a signal from the DC component removal link of the DUS, and the output is connected to the correction link, the output of which is connected to the summer, the input of which receives a signal from the current sensor and an output signal from the correction link, the output of which is connected to a power amplifier, the output of the power amplifier is connected to the engine, in addition, the system comprises DUS measuring the angular velocity of the stabilized load via pitch, azimuth, and roll channels, wherein the output of the DUS is connected to the DC component removal link, wherein the engine is connected with its first output to the input of the DUS, and with its second output it is connected to stabilized load, the third output is connected to the input of the angle sensor and the fourth output is connected to the current sensor.

The basis of the device for image stabilization on a moving base is a gyroscopic angle sensor rigidly fixed together with the stabilized load in a gimbal suspension on the vertical guidance drive frame. The gyroscopic angle sensor ensures modeling in the inertial space of two orthogonal axes with the ability to rotate the modeled axes in the inertial space at the required speed. The measuring axes coincide with the axes of rotation of the load, on the axes of which the vertical and horizontal guidance torque sensors are rigidly fixed, which are connected through the amplifying and correcting devices of the drive to the outputs of the corresponding gyroscope angle sensors. The gyroscope together with the vertical and horizontal channel torque sensors form a tracking system. Angular disturbances of the load are transmitted to the gyroscope housing. When the gyroscope housing is rotated relative to the rotor stationary in the inertial space, an electrical error signal appears proportional to the angle of rotation of the load. Under the influence of the amplified error signal, the torque sensor rotates the load so as to ensure that the gyroscope output signal is equal to zero. This ensures that the load is stabilized in two planes.

The stabilized load rotation is performed by rotating the gyroscope rotor in the inertial space due to the moment sensors built into the gyroscopic angle sensor. The load rotation is performed by the tracking system through the corresponding vertical and horizontal guidance moment sensors. To measure the guidance angles along the channels, the device includes vertical and horizontal guidance angle sensors. The angle sensors measure the angular position of the load relative to the stabilization device body.

The disadvantage of this device is the low accuracy of line of sight stabilization.

The technical objective of the present invention is to improve the accuracy of stabilization.

The stated problem is solved due to the fact that in the image stabilization system on a movable base, containing a comparison device, a correcting device, an amplifier, an adder, a correction link, a power amplifier, the output of which is connected to the engine, an angle sensor, rigidly fixed together with the stabilized load, wherein one of the engine outputs is connected to the stabilized load, and the other output is connected to the input of the angle sensor, a negative feedback is additionally introduced from the first engine output to the input of the correction link through a forcing link, and a gyrotachometer is introduced, the output of which is connected through a threshold element with an ambiguity zone to the input of the adder, wherein the input of the gyrotachometer is connected to the third engine output.

The figure shows a structural diagram of one channel of the image stabilization system on a movable base.

The image stabilization system on a movable base comprises a guidance device 1, the signal from which is fed to a comparison device 2 connected to a correction device 3, the output of which is connected to an input of an amplifier 4. The output of the amplifier 4 is connected to one of the inputs of the adder 5. The output of the adder 5 is connected to an input of the engine 8 via a correction link 6 and a power amplifier 7. The first output of the engine 8 is connected to one of the inputs of the correction link 6 via a forcing link 9 included in the negative feedback from the output of the engine 8 to the input of the correction link 6. The second output of the engine 8 is connected to the input of the comparison device 2 via an angle sensor 10. The third output of the engine 8 is connected to the input of the adder 5 via a gyrotachometer 11 and a threshold element with an ambiguity zone 12, connected in series along the information inputs. The fourth output of the engine 8 is connected to a load 13 (optical elements).

The internal contents of the comparison device, the correction element, the amplifiers, the adder, the correction element, the threshold element with an ambiguity zone are described in the books: P. Horowitz, W. Hill. The Art of Circuit Engineering. Moscow: Mir, vol. 1-3, 1993. The internal contents of the gyrotachometer are described in the patent for invention RU 2325659 C1, IPC G01P 9/02, published 27.05.2008, Bulletin No. 15.

The image stabilization using the proposed system is performed as follows. The signal from the guidance device 1 is fed to the comparison device 2, where the difference between it and the current value of the deviation from the angle sensor 10 is calculated. The difference in signals through the correction device 3 and the amplifier 4 is fed to the input of the adder 5, in which the signal from the output of the amplifier 4 is compared with the value of the signal received from the gyrotachometer 11 through the threshold element with the ambiguity zone 12. The resulting difference in signals is fed to the input of the correction link 6. The signal from the output of the correction link 6 is fed to the input of the power amplifier 7, in which the control signal for the engine 8 is formed. In this case, the angular movement of the load 13 (optical units) connected to the engine 8 occurs to deflect or stabilize the position of the line of sight. Power amplifier 7 and engine 8 are covered by flexible negative feedback, into which a forcing link 9 is introduced. Inclusion of forcing link 9 in the negative feedback ensures the quality of the transient process in the image stabilization system on a moving base.

The introduction of a gyro-tachometer and a threshold element with an ambiguity zone into the image stabilization system allows for a decrease in the value of the constant component in the output signal. In addition, the introduction of a forcing link allows for the quality of the transient process to be ensured and the accuracy of the image stabilization system on a moving base to be increased.

Claims (1)

An image stabilization system on a movable base, containing a series-connected comparison device, a correcting device, an amplifier, an adder, a correction link, a power amplifier, the output of which is connected to a motor, an angle sensor, rigidly fixed together with a stabilized load, wherein one of the motor outputs is connected to the stabilized load, and the other output is connected to the input of the angle sensor, characterized in that negative feedback is additionally introduced into it from the first motor output to the input of the correction link through a forcing link, and a gyrotachometer is introduced, the output of which is connected through a threshold element with an ambiguity zone to the input of the adder, wherein the input of the gyrotachometer is connected to the third motor output.