Fiber-optic system for measuring large inclination angles of large-sized test benches for rocket, space and aviation technology

Abstract

Background. Nowadays during modernization of domestic rocket-space and aviation equipment (RS and AT) special attention is paid to the accuracy of measurement of spatial position of large-size test stands. Design and technological parameters of RS and AE products depend on the accuracy of measuring the stand inclination angle. The used measuring instruments, including the tilt angle, should not create additional electromagnetic interference during testing of RS and AT products; therefore, the use of fiber-optic measuring instruments is considered more preferable. The object of the research is fiber-optic information- measuring systems (FIMS) of large-size RS and AT test benches. The subject of the research are scientific and technical solutions of fiber-optic tilt angle sensors (FOTAS) of attenuator type, which are a part of FOTAS of large-size test benches. The purpose of the study is to extend the functionality of FIMS in measuring the tilt angles of large-size test benches in the range of ±20 degrees. Materials and methods. The main approach to achieve the set goal is adaptation of known technical solutions of fiber-optic sensors (FOS) of linear and angular displacements to the conditions of tilt angle measurement by modernization of optical-mechanical system (MOMS) of FOTAS. The provisions of the theory of measurements, methods of geometrical optics, mathematical processing of the obtained results, modeling and graphical constructions in Microsoft Office, MathCAD programs were used in the research. Results. The structural scheme of FIMS on the basis of attenuator-type FOTAS has been developed, which is characterized by the possibility of simultaneous measurement of inclination angle, angular velocity and angular acceleration with the help of one inclination angle sensor, since the change of stand position in space is an inertial process. A schematic representation of the mutual spatial position of the light rays and elements of the FOTAS when the pendulum is deflected when the stand is tilted is presented, on the basis of which the possibility of measuring the angle in the range of ±20 degrees is proved. The structure of a two-channel pendulum-type attenuator-type FOTAS is determined. Conclusions. Implementation of FIMS on large-size RS and AT test benches provides their absolute spark-explosion-fire safety. Improvement of the MOMS, in which the attenuator is formed in the body of the pendulum, allowed to extend the range of measurement of the FIMS angle up to ±20 degrees. The new structure of FIMS will allow to significantly reduce hardware costs for measurement of such parameters as tilt angle, angular velocity and angular acceleration of a large-size test stand.

Keywords

• information-measuring system
• tilt angle
• angular velocity
• angular acceleration
• fiber-optic sensor
• large-size test bench
• attenuator
• pendulum
• structural scheme