Research On The Thrust Vector Measuring System For Rocket Motor Dynamic Characteristics

The trajectory/attitude controlled engine is an important part of a guided missile power system whose major working pattern is impulse. The inclination and offset of the actual engine thrust will directly affect the precision of the flying control and the hitting target in the flying test. Accordingly it is very significant to investigate the engine's dynamic and static characteristics.In this paper, the thrust and thrust vector measuring platform system for trajectory/attitude controlled rocket engine is introduced. Aiming at the request of the thrust vector measuring system, the collectivity scheme is validated, and the equipments for dynamic and static calibration are designed. Moreover, the mechanism modeling and the experiment modeling are used for researching the dynamic characteristic of the measuring system. The thrust vector measuring platform system is made up of 4 three-direction piezoelectric quartz force transducers. Through using the output of each force transducer, the thrust vector eccentricity parameters can be calculated by some deduced expressions. The transfer function of the measuring platform system is set up by using mechanism modeling method, and the parameter is got by both academic analysis and experiment. The transfer function of the entire system is set up by mode analysis. The finite-element analysis is used to evaluate the natural frequency. By using the mode-testing method, a more precise test of the entire measuring system is done, and the natural frequency, damping ratio, principal modes of vibration and residual in 4KHz of the entire measuring system in the actual installation estate have been got. The dynamic force generator is based on the vibration exciter which is used as the actuator to get the needed dynamic force with the corresponding signal generator and power amplifier.The experiments and the simulating calculations show that the measuring platform can attain the using standard which was stipulated by the CIRP-STCC. The measuring platform system can satisfy the actual working requirement and has attained the anticipant goals, and the transfer function being established is accurate and reliable. What is more, it built the foundation for the further study on optimizing the structure parameters of the vector measuring system.