JPH0371013A - Optical fiber gyro device - Google Patents

Abstract

PURPOSE:To eliminate the influence of equipment which is connected to a controller by insulating a sensor main body which handles a fine analog signal from the side of an external controller. CONSTITUTION:An optical fiber gyro sensor main body 6 and external controller 9 are connected by a transmission line 8 through a photocoupler, the controller 9 is provided with a converter 41 for electric feeding, and the converter 41 and optical fiber gyro sensor are connected by a power line insulated from the ground of the input power source of the controller 9. Then the main body 6 and controller 9 while insulated by the photocoupler are connected by the transmission line 8 and the power line 7 which connects the converter 41 and main body 6 is insulated from the input power source ground of the controller 9. consequently, the electromagnetic resistance characteristic and the easiness of use of the main body 6 are improved greatly as well as the miniaturization of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical fiber gyro device, and particularly to a gyro device in which a sensor body and an external control device are separated.

[Prior Art] Generally, a gyro is a sensor that measures the rotational angular velocity of an object, and can also measure an angle by integrating it over time. FIG. 5 is a conceptual diagram of the input and output of a conventional weaving type (spinning type) gyro 1. By supplying the power source 2, an analog signal output 3 is obtained. Figure 6 similarly shows a conventional optical fiber gyro 4.
FIG. 2 is a conceptual diagram of input and output. By supplying power supply 2,
An analog signal output 3 and a digital signal output 5 are obtained. The digital signal output 5 can be serially transmitted to, for example, an external combination or computer by defining an interface.

[Problems to be Solved by the Invention] When mounting an optical fiber gyro (OFG) on a moving object, the following items are practically required.

(1) Miniaturization of the OFG sensor body (2) Prevention of OFG malfunction due to power supply noise on the mounted equipment side (3) Prevention of induction from the OFG to the mounted equipment (4) O
Monitoring function of the operation of the FG main unit (5) Interfacing with a computer or measuring instrument and preventing OFG malfunction when external equipment # is connected Q51 Setting the signal output mode to the computer or measuring instrument (7) Measurement from the computer to the OFG Mode setting (8) Remote measurement between OFG sensor and external controller.

However, currently, OFG output modes and externally connected devices are limited, and large devices are required to meet the various needs mentioned above.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide an optical fiber gyro device that is compact, electromagnetically stable, and has a multifunctional external controller.

[Means for Solving the Problems] The gist of the present invention is to provide an optical fiber that connects an optical fiber gyro sensor body consisting of an optical interferometer and a signal processing circuit and an external controller connected thereto by a cable having a multi-core transmission line. In a gyro device, an optical fiber gyro sensor body and an external controller are connected by a transmission line via a photocoupler, and the external controller is provided with a power supply converter, and the converter and the optical fiber gyro sensor are connected to the external controller. It is connected to the input power supply ground using an insulated power line.

[Function] According to the above configuration, the optical fiber gyro sensor body and the external controller are connected by an insulated wide feed line using a photocoupler,
Additionally, since the power line connecting the power converter and the sensor body is insulated from the input power supply ground of the external controller, ease of use can be greatly improved, including electromagnetic resistance and miniaturization of the sensor body.

[Example] Preferred embodiments of the present invention will be described below.

First, the optical fiber gyro (OFG) sensor according to the present invention will be explained with reference to FIGS. 3 and 4.

FIG. 3 shows the configuration of an optical system of an all-optical fiber phase modulation type OFG. Light Source Moji: 1. - The optical fiber 17 is coupled to a highly birefringent (highly birefringent) critical wavefront preserving (PM) fiber, and the incident light is split into two by a directional coupler 18a, one polarizer, and a directional coupler 18b, each connected to a connection point 20. Therefore, one enters the PM fiber loop 21 and circulates counterclockwise, and the other passes through the optical phase modulator 22 and becomes the PM fiber loop 2.
1 and rotate clockwise. PM fiber loop 2
1, each incident light is received by the light receiver 23 from the other through the directional coupler 18b, the fi photon 19, and the directional coupler 18a, and is processed by the signal processing circuit 24 to determine the angular velocity and angle. is detected, and the modulation degree of the optical phase modulator 6 is controlled. This phase modulator 6 is I)
Wrap the PM fiber around the Z T cylinder for 2 to 3 m,
The degree of modulation is controlled by applying AC power to the PZT.

FIG. 4 shows details of the signal processing circuit 24, and in the figure, 2
5 is the OFG optical system shown in FIG. 2, and 27 is an APC circuit for driving the light source 17.

The output of the photoreceiver 23 of the OFG optical system 25 passes through an amplifier 27 and is synchronously detected by synchronous detectors 28a to 28c, and the detected component is converted into DC through a filter 29 and sent to a multiplexer 30 and an A/D. Converter 31, interface #I3
2 and is input to the microcomputer 33. On the other hand, 37 is an alternating current generator such as a sine wave, which passes through a frequency divider 38 and generates the fundamental wave, second harmonic wave, and fourth harmonic wave to synchronous detectors 28a to 28c.
is added as a reference signal, and a fundamental wave of a predetermined AC voltage is applied to the optical phase modulator 22. 34 is an external high-speed arithmetic processor that outputs angular velocity and angle 35, outputs the harmonic component ratio (4th harmonic wave and 72nd harmonic wave) as modulation degree output 36, and automatically adjusts the voltage control device 39 at high speed. .

The above is a general outline of the sensor body.

Now, in FIG. 1, the OFG sensor body 6 and the external controller 9 are connected by a cable 45 consisting of a power supply line 7 and a transmission line 8.As can be seen from the figure, the external controller 9 has an analog display 10. The display type (angle and angular velocity) and full scale can be set using a keyboard or a switch 12.

Next, the connection relationship between the OFG sensor main body 6 and the external controller 9 will be explained with reference to FIG.

Photocouplers 4.0a4 and 4.0Ob are provided at the input and output ends of the microcombi, filter 33 of the OFG sensor 6, respectively. On the other hand, the external controller 9 is provided with a microcomputer 33b, and the microcomputer 33
The input/output end of b is connected to the coupler 40 via the transmission line 8.
a, 4. Each is connected to Ob. The signal sent from the OFG sensor body 6 is a TTL level serial signal, and the microcomputer 33b of the external controller 9 outputs an analog display 10. Analog display 14. Digital output (serial)
15. Digital output (parallel) 16 etc. R8232
It is designed to be output via a C connector or the like.

The external controller 9 has AC/DC or D connected to the power supply 2.
A power supply converter 41 such as a C/DC converter is provided, and a secondary power source 43 of this converter 41 is electrically insulated from the input side and connected to the OFG sensor body 6 via a power line 8 . Further, from the converter 41, the internal elements of the external controller 9 are driven by a power source whose level has been appropriately converted.

As shown in the figure, the cable 45 consisting of the power supply line 7 and the transmission line 8 has a total of 7 cores, with the power supply line 7 having 3 cores and the transmission line 8 having 4 cores. Connectors (not shown) are provided on both sides to enable connector connection.

In the above, the microcomputer 3 of the external controller 9
3b and the micro combinator 33 of the OFG sensor body 6
The transmission line 8 for transmitting and receiving data is photocouplers 40a and 40b.
The power line 7 is also insulated from the ground (CGND) of the power supply of the external controller 7, and the ground (CGND) and the ground (SGND) of the sensor body 6 are electrically connected. Since it is completely insulated, it is not affected by power supply noise.

Note that it is also possible to connect a plurality of sensor sections to one external controller by making some changes to the external controller.

[Effects of the Invention] As described below, the present invention provides the following effects.

Width: The sensor headquarters, which handles minute analog signals, is insulated from the external controller side, so it is not affected by equipment connected to the controller. It is also advantageous in terms of safety.

(2) Since serial transmission is performed, the number of cables is small, the connector structure is simple, and the waterproof and drip-proof design of the gate is easy.

(3) By attaching a serial/parallel converter to the external controller side, parallel output or DA output can be obtained in an isolated state.

(4) When grounding the ground on the external controller side to the housing, by insulating the power supply of the sensor body from the housing,
Prevents guidance by ground loops.

(5) The sensor body can be made smaller.

Width) Since it does not include analog signals, the sensor and the outer cylinder are shown in the figure as a block diagram showing one embodiment of the present invention. FIGS. 3 and 4 show the OFG in the present invention.
The main body of the sensor is shown, and Figure 3 is a block diagram of its optical system.
Figure 4 is a block diagram of the signal processing circuit, Figure 5 is a conceptual diagram showing the input/output relationship of a conventional mechanical gyro, and Figure 6 is a conceptual diagram showing the input/output relationship of a conventional optical fiber type gyro. .

In the figure, 6 is the OFG sensor body, 7 is a power line, 08 is a transmission line, 9 is an external controller, 41 is a power supply converter, and 45 is a gable.

Claims (1)

[Claims] 1. In an optical fiber gyro device that connects an optical fiber gyro sensor body consisting of an optical interferometer and a signal processing circuit and an external controller connected thereto by a cable having a multi-core transmission line, the optical fiber The gyro sensor body and the external controller are connected via a photocoupler with a transmission line, and the external controller is provided with a power supply converter, and the converter and the optical fiber gyro sensor are isolated from the input power supply ground of the external controller. An optical fiber gyro device characterized in that it is connected with a power line. 2. The optical fiber gyro device according to claim 1, wherein the external controller includes a microcomputer, a display section, a keyboard or a switch, and an interface circuit with an external computer and a measuring instrument. 3. The optical fiber gyro device according to claim 1, wherein at least one of the cables consisting of the transmission section and the power line is connected to the optical fiber gyro sensor body or an external controller.