Research And Development Of Calibration Devices For Rocket Motor Thrust Vector Measuring System

Due to the rapid development of modern aviation and aerospace industry, accurate measurement of rocket motor thrust rector is of vital importance to control aircraft's flying position and increase percentage of hits. The thrust of trajectory-controlled rocket motor is a space vector, whose size and direction are unceasingly changing. And its practical thrust functionary line always has a deviation from theory axis of motor nozzle, which is called motor thrust bias. If practical thrust bias of trajectory-controlled rocket motor is beyond the limit, it will cause some negative effects on accuracy of control and hits, and even lead to failure of the test. Thus, it's urgent and necessary to develop rocket motor thrust vector measuring system as quickly as possible in order to evaluate the performance of rocket motor correctly.Firstly, rocket motor thrust vector measuring system is introduced, which is composed of 4 three-component piezoelectric force transducers. Using the output of each force transducer, the thrust vector eccentricity parameters can be calculated by some deduced expressions.Secondly, static calibration and dynamic calibration devices are designed in order to test static and dynamic performance of rocket motor thrust vector measuring system. Static calibration device will affect the accuracy of static measurement directly. Through lots of tests and analyses, hydraulic loading equipment for tension is selected to calibrate the main thrust, while hydraulic loading equipment is selected for lateral thrust. Dynamic calibration device is based on vibration exciter, which principal is that an electrified inductor will be affected by induced force in a magnetic field. The output of the signal generator is imported to vibration exciter through power amplifier, and then vibration exciter could generate corresponding dynamic force. Signal generating circuit is made up of single chip MSP430F149 and other related circuits, such as D/A converting circuit.The experiments show that rocket motor thrust vector measuring system owns good static performance, its linearity, repeatability and sensitiveness of measurement all can meet the required technical targets. It's also proved by experiments that the principle for the standard dynamic force generator is correct, and the actually acquired trapezoidal dynamic force in the experiment has attained the anticipant goals. Using the device, dynamic calibration on thrust vector measuring system is made, and the results show that dynamic performance of the system is excellent and meets the technical targets fully.