JPS61175518A - Optical fiber sensor - Google Patents

Abstract

PURPOSE:To facilitate the miniaturization of a sensor along with a higher detection sensitivity, by integrating a sensor section comprising optical fibers and an optical signal analyzing section on the shell plate of the construction unit. CONSTITUTION:Lights from a light emitting source provided at an optical signal analyzing section 5 are made incident into both optical fibers 3a and 3b respectively for detection and environmental compensation at the sensor section 4 by each one end thereof. The incident lights are modulated depending on an angular velocity and temperature or the like due to other environmental factors. The lights thus modulated return to the optical signal analysis section 5 to be converted into an electrical signal. The optical signal is fed to a signal processing circuit, where the signal component based on the light propagated through the optical fiber 3b for environmental compensation is subtracted from those based on the light propagated through the optical fiber 3a for detection. Thus, the true angular velocity can be detected cleared of effect of physical quantity caused by the environment such as temperature and vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical fiber sensor that is mounted on a moving body and detects physical quantities such as angular velocity.

[Conventional technology]

In general, this type of optical fiber sensor has a sensor section constructed using an optical fiber, and receives an optical signal that propagates within the optical fiber of this sensor section and is modulated by physical quantities such as angular velocity, temperature, vibration, etc. It consists of an optical signal analysis section that performs analysis.

FIG. 2 shows the configuration of a conventional optical fiber sensor, in which a sensor consisting of a coiled optical fiber is mounted on the inner wall of an outer panel 12 that is a part of the structure of a moving object 11 (for example, a flying object). A section 13 is provided and connected to an optical signal analysis section 15. That is, the optical fiber constituting the sensor section 13 is connected to the outer panel 12 at several locations by the clamper 14 as shown in the figure, for example.
is fixed on the inner wall of the

[Problem that the invention seeks to solve]

However, in the conventional optical fiber sensor mentioned above,
Since the sensor unit 13 made of an optical fiber is disposed on the inner wall of the structural outer plate 12 of the movable body 11, the mounting space becomes large, making it difficult to miniaturize the sensor unit 13. Furthermore, in order to increase the detection sensitivity of the optical fiber sensor, it is necessary to lengthen the optical fiber, which poses a problem in that the mounting space becomes even larger.

The present invention has been made in view of the problems of the prior art, and requires a small mounting space and is easy to downsize.
Moreover, the purpose is to provide a highly sensitive optical fiber sensor.

[Means for solving problems]

In order to achieve the above object, the present invention includes a sensor section which is made of an optical fiber and detects physical quantities such as angular velocity, temperature, vibration, etc., and an optical signal that propagates within the optical fiber of this sensor section and is modulated by the physical quantity. The optical fiber sensor is comprised of a receiving optical signal analyzing section and is mounted on a moving body, characterized in that the sensor section is integrated with a structural outer plate of the moving body.

[Effect]

In the optical fiber sensor according to the present invention, an optical signal is input from the optical signal analysis section to the optical fiber of the sensor section integrated into the outer panel of the structure of the moving object, and this optical signal is modulated by various physical quantities. Thereafter, the optical signal returns to the optical signal analysis section and predetermined physical quantities, such as angular velocities, are accumulated quantitatively. The sensor section is composed of two optical fiber sensors, and the temperature,
Only the angular velocity component may be detected with high precision by canceling the modulation component of the optical signal due to a physical quantity based on an environmental factor such as vibration.

〔Effect of the invention〕

According to the present invention, taking advantage of the fact that the optical fiber has a shape and material that can be integrated with the structural members of the moving body made of composite materials, etc., the sensor section made of the optical fiber is connected to the moving body. By being integrated into the structural outer panel, a large detection space can be secured without increasing the actual mounting space occupied within the moving body, and the optical fiber sensor is small but has high detection sensitivity. can get.

(Example) FIG. 1 is a diagram for explaining the configuration of an optical fiber gyro as an optical fiber sensor according to an example of the present invention, and (a) is an external view of a moving object 1 (flying object); (b) is an enlarged view of a part of the moving body 1, (C) is a view of the entire optical fiber sensor, and (d) is a cross-sectional view showing the arrangement structure of the sensor section.

As shown in FIG. 1, the structural outer plate, which is a structural member constituting the body of the moving body 1, is divided into a plurality of parts in the circumferential direction, and each of the divided structural outer plates 2 has two sections each. A sensor section 4 made up of coiled (loop-shaped) optical fibers 3a and 3b is integrally provided. That is, the structural outer panel 2 is made of a composite material, and the optical fibers 3a and 3b are integrally molded and embedded within the structural outer panel 2.

Here, one optical fiber 3a in the sensor section 4 is used for detecting angular velocity, and the other optical fiber 3b is used for environmental compensation to compensate for angular velocity detection errors due to physical quantities based on environmental factors such as temperature and pressure. be.

Both ends of the detection optical fiber 3a and the environmental compensation optical fiber 3b are respectively connected to an optical signal analysis section 5 installed at an appropriate location within the moving body 1. This optical signal analysis section 5 includes an optical element including a light emitting source, a light receiving section, etc., and an IC.
It has a built-in signal processing circuit. Further, optical ICs, which have been rapidly progressing in recent years, can also be used in the optical signal analysis section 5.

The operation of the optical fiber sensor of this embodiment is as follows. Light from a light emitting source (for example, a laser diode) provided in the optical signal analysis section 5 enters both optical fibers 3a and 3b for detection and environmental compensation in the sensor section 4 from one end. The light incident on each optical fiber 3a, 3b is modulated by the angular velocity and physical quantities based on other environmental factors (for example, temperature, vibration, etc.). These modulated lights return to the optical signal analysis section 5 from the other end of each optical fiber 3a, 3b, and are converted into an electrical signal by a light receiving element (photodiode, phototransistor, etc.).

In the optical signal analysis section 5, the optical signal converted into an electric signal is supplied to a signal processing circuit, and environmental compensation is performed from the signal (mainly the component modulated by the angular velocity) component based on the light propagated through the detection optical fiber 3a. A signal component (mainly a component modulated by temperature, vibration, etc.) based on the light propagated through the optical fiber 3b is subtracted. As a result, the true angular velocity is detected, with the influence of physical quantities based on the environment, such as temperature and motion, removed.

According to the present invention, the sensor section is integrated with the structural outer panel of the moving body on which the optical fiber sensor is mounted, so that the mounting space for the optical fiber sensor is essentially limited to the optical signal analysis section. In general, it is possible to reduce the size of the sensor, and moreover, it is possible to secure a large detection space, so that high sensitivity can be achieved.

Furthermore, according to the above embodiment, the influence of the environment, which increases due to the integration of the sensor section into the structural outer panel of the moving body, is compensated for by using the optical fiber for environmental compensation in addition to the optical fiber for detection. As a result, more accurate and highly stable detection is possible.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the configuration of an optical fiber sensor according to an embodiment of the present invention, in which (a) is an external view of a moving object on which the optical fiber sensor is mounted, and (b) is an external view of the moving object. (C) is a configuration diagram of the optical fiber sensor, (d) is a sectional view showing the mounting structure of the optical fiber, and Figure 2 is the configuration of a conventional optical fiber sensor. (aρ ~ A diagram showing a state in which an optical fiber sensor is mounted on an outer panel that is a structural member of a moving object, (
b) is a configuration diagram of an optical fiber sensor, and (g) is a sectional view showing the mounting structure of the optical fiber. DESCRIPTION OF SYMBOLS 1... Moving body, 2... Structural part outer plate of moving body, 3a.
... optical fiber for detection, 3b... optical fiber for environmental compensation, 4... sensor section, 5... optical signal analysis section. Applicant Sub-Agent Patent Attorney Takehiko Suzue No. 1 (a) (c) (b) (d) Mu3゜

Claims (1)

[Claims] It consists of a sensor section that is made of an optical fiber and detects physical quantities such as angular velocity, temperature, and vibration, and an optical signal analysis section that receives an optical signal that propagates within the optical fiber of this sensor section and is modulated by the physical quantity. An optical fiber sensor mounted on a moving body, characterized in that the sensor section is integrated with a structural outer plate of the moving body.