JPH0630714U - Fiber optic gyro table platform - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a highly accurate inertial reference device with long life, low maintenance cost. [Structure] A stable platform that uses a gyro and accelerometer to measure the attitude and azimuth of a moving body by creating a stable platform that is insulated from the angular motion of the moving body,
The gyro includes an optical fiber gyro that detects changes in attitude and azimuth, and an integrator that integrates the output to obtain an angle signal.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an inertial reference device mounted on a moving body, and more particularly to a stable platform type using an optical fiber gyro.

[0002]

[Prior art]

 Generally, the stable platform type inertial reference device is used for applications requiring high-precision inertial reference information (attitude, azimuth, speed, position). For example, a gimbal frame 41, 42 shown in FIG. ) The stable base 43, which is insulated from the motion of the angle, is detected from the signals detected by the gyros 44, 45, 46 and accelerometers 47, 48, 49 mounted on the stable base 43, and the posture and direction of the moving body are detected. It is used as a means for obtaining the speed and position of the moving body by integrating the signals of total 47, 48, 49.

FIG. 5 is a diagram showing a control system for one axis. The output signal corresponding to the tilt angle δθ detected by the accelerometer 47 mounted on the stable base 43 and measuring the acceleration in the one-axis direction is connected to the integrator 410. The output of the integrator 410 is applied to the torquer 44T of the gyro 44 via the calculator 411 that performs the calculation according to the characteristics of the system. By the action of the torquer 44T, the reference axis of the gyro 44 is corrected so that the stable base 43 becomes horizontal. The deviation of the reference axis of the gyro 44 is applied to the platform control system 412, drives the motor 413, and rotates the stable base 43 in a direction in which the accelerometer 47 does not detect the gravitational acceleration, and finally the stable base 43 is in a horizontal state. Becomes stable.

FIG. 6 is a conventional functional block diagram. In FIG. 6, 601 is an adder, 602 is an accelerometer, 603 is an adder, 604 is an integrator, 605 is an amplifier, 606 is a coefficient element, 607 is an integrator, 608 is an adder, 609 is a gyro, and 610 is the above-mentioned. A stable element including the platform control system 412, the motor 413, and the stabilizing base 43 in FIG. 4, 611 is an angle sensor, 612 is an adder, 613 is a gravitational acceleration, and 614 is an angle sensor. By providing a series of control loops for two axes as shown in FIG. 5 and matching the cycle to the Schurer cycle ωo (ωo ² = g / R, RΩ = V) as shown in FIG. In the same manner as in step 5, the stable platform 43 is controlled so that it is always horizontal at that point, so that the acceleration of the moving body with respect to the ground surface is separated from the gravitational acceleration, and the posture of the moving body with respect to the ground surface is always obtained. There is. Also, at the starting point, the azimuth of the moving body can be known by pointing the reference axis 4 (see FIG. 4) of the stabilizing base 43 stabilized by the gyro 609 also about the azimuth axis to, for example, true north. When moving near the surface of the earth, the correction of the angular velocity corresponding to the earth's rotation angular velocity and the moving velocity is added to the gyro, and the correction of the Coriolis acceleration is added to the output of the accelerometer to prevent the deterioration of navigation accuracy with respect to geographical coordinates. .

[0005]

[Problems to be solved by the device]

 The conventional stable platform type inertial device only uses a gyro that uses mechanical bearings, and since it has a limited lifespan, it requires replacement and overhaul of the gyro, which is very expensive. However, when replacing the inertial reference device, there was a problem that the mission of the mobile unit to be mounted was limited.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain an inertial reference device having a long life, low maintenance cost, and high accuracy.

[0007]

[Means for Solving the Problems]

 The optical fiber gyro table platform according to the present invention uses a gyro and an accelerometer to form a stable base that is insulated from the angular motion of the moving body, and measures the posture angle of the moving body. An optical fiber gyro that detects changes in attitude and azimuth and an integrator that integrates this output to obtain an angle signal are provided.

[0008]

[Function] As a gyro, an optical fiber gyro having no movable parts is combined with an integrator for converting the output of the optical fiber gyro that detects a change in attitude and azimuth angle into an angle signal, and functions as a stable platform.

[0009]

【Example】

 FIG. 1 is a block diagram of an embodiment of an optical fiber gyro table platform according to the present invention, in which 101 is an adder, 102 is an accelerometer, 103 is an adder, 104 is an integrator, 105 is an amplifier, and 106 is a coefficient. Elements, 107 is an integrator, 108 is an adder, 109 is an integrator, 110 is a stable element similar to FIG. 6, 111 is an angle sensor, 112 is an adder, 113 is gravitational acceleration, 114 is an angle sensor, Reference numeral 115 is an optical fiber gyro. In general, an optical fiber gyro is based on the principle that, when a closed optical path is rotating, a phase difference occurs between left-handed light and right-handed light that travel around the optical path, and the angular velocity can be detected from the phase difference. For example, as shown in FIG. 2, laser light exits the laser light source 21 and enters the circular orbit of the fiber loop 22. The light is bisected by the beam splitter 23 and becomes left-handed light and right-handed light. After propagating in the fiber loop 22, each light reaches the same beam splitter 23 and reaches the detector 24 again. Here, the intensity of the interfering light produced by superposition is measured.If the entire system is stationary at this time, both left and right lights pass through exactly the same optical path length, so at the combining point both lights The phases of light are the same. However, when this circular orbit rotates in one direction at a rotational angular velocity Ω, a phase shift occurs between the left and right lights. This phase difference Δθ appears as the intensity of the interference light, and the intensity of the interference light is measured to obtain the rotation angular velocity.

FIG. 3 is a diagram showing a state in which the ship has moved from position to position, and the operation will be described by taking this as an example. The acceleration detected by the accelerometer 102 is Coriolis-corrected by the adder 103, which is integrated by the integrator 104 to detect the speed, which is amplified by the amplifier 105 to obtain the output Ωc. Ωc is integrated by the integrator 107 via the coefficient element 106 and converted into the position signal D. Further, Ωc is input to the adder 108 as a correction component for an angular velocity due to the velocity of the moving body with respect to the ground surface. At this time, the earth rotation correction δERC is also input to the adder 108. An optical fiber gyro 115 attached to a stabilizing table which constitutes a part of the stable element 110 detects an angular velocity with respect to the inertial system of the stabilizing table as an angular velocity sensor, and this output is subtracted and input to an adder 108 to obtain the above-mentioned Ωc. Corrected by δERC. The output of the adder 108 is integrated by the integrator 109 to obtain the angle of the stable base with respect to the ground surface. The adder 112 obtains a difference δθ of θV (rotation angle of the horizontal plane) with respect to the tilt angle θc of the stabilizing table in consideration of the initial tilt −δθ o, and outputs it to the angle sensor 114. The angle sensor 114 detects the angle θM of the moving body with respect to the horizontal, and the angle sensor 114 obtains an angle output θM−δθ.

[0011]

[Effect of device]

 As described in detail above, according to the present invention, since the optical fiber gyro is used, it is possible to obtain a highly accurate inertial reference device having a long life, low maintenance cost.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of an optical fiber gyro table platform according to the present invention.

FIG. 2 is a principle diagram of an optical fiber gyro.

FIG. 3 is a diagram showing a state in which a ship has moved.

FIG. 4 is a configuration diagram of a general stable platform inertial reference device.

FIG. 5 is a diagram showing a control system for one axis.

FIG. 6 is a conventional functional block diagram.

[Explanation of symbols]

 115 optical fiber gyro 102 accelerometer 109 integrator 110 stable element (stabilizer)

Claims (1)

[Scope of utility model registration request] 1. A stable platform, which uses a gyro and an accelerometer to measure a posture azimuth of a moving body by forming a stable stand that is insulated from the angular motion of the moving body, and detects a change in the posture azimuth as a gyro. An optical fiber gyro table platform, comprising: an optical fiber gyro that operates and an integrator that integrates the output to obtain an angle signal.