Calibration Research On The Measurement Of Twin-engine Thrust Vector

Aerospace technology is a deep integration of information technology and manufacturing, consisting many new achievements of science and technology. The development of the aerospace industry has an important influence on world policy, military, economic, technology and life style. In recent decades, with the continuous development of space exploration and aerospace technologies, rocket engine, as the core of spacecraft dynamics, plays a vital role. It needs a series of tests on the thrust vector performance before the engine is finalized. The accuracy evaluation of the test system is the calibration process of the test system, so it is obviously important to study the calibration of test system.Based on the twin-engine thrust vector system as research object, this paper describes the development status and measuring principle of thrust vector calibration. Combining the research results of the piezoelectric sensor in the rocket thrust measurement, aiming at the difficulties in calibration test of twin-engine system, the paper researches on structure design and parameter selection of the calibration system, through theoretical comparison, analysis and calculation, finite element simulation analysis and experimental verification.In order to realize the calibration of resultant forces in twin-engine system vector, representation method and definition of the vector force are defined, and measurement requirements and the design difficulties of calibration system are analyzed. For twin-engine system, there are two kinds of force situation, the vector force acting on the dynamometer supporting plane or outside. The decoupling calculation of the sensor output under the two conditions is carried out, providing theoretical basis for calibration experiment design. The mechanical model of calibration test system is built, and the influence of the dynamometer and the adapter on the calibration system is analyzed. The parameter range of length of side is defined though theory analysis and calculation when the four sensors are arranged in a square. The dimension parameters of the dynamometer upper plate are improved using the finite element method. In order to realize the adapter function of a pair of two between the dynamometer and the engine, three integral design schemes are proposed. The speaker type for the actual implementation of the program is determined. In order to get the static performance index of the sensor in different directions, three-dimensional orthogonal calibration test is designed. The normalized sensitivity of the sensor and the interference compensation coefficient of the test system are obtained by the calibration fitting curve. Finally, to verify the accuracy of the twin-engine thrust measuring system, calibration tests of deflection loading and engine simulation are designed.Three-dimensional orthogonal calibration results show that the measuring system has good static characteristics. Due to the interference between the tri-axial forces sensor, the interference coefficients is calculated and compensated. The calibration results show that it proves high accuracy, meeting the design requirements, and realizing the precise thrust vector measurement of twin-engine system.