CAJ | 학술논문

设计的微推力测试系统主要由扭摆机构构成，该扭摆机构置于真空仓内，具有经过特殊设计的悬挂结构以及扭秤结构，可实现对推进器单脉冲冲量的开环测量，同时还能够对平均推力在开环和闭环条件下进行测量。因在推力测试的过程中存在的大量干扰会导致测试结果受到影响甚至被淹没于噪声中，故首先根据扭摆的运动特性确定了测试装置的动力学模型以及阶跃响应模型，并验证了在系统的阶跃响应模型中，系统的第五阶自然频率与外界干扰项的频率一致。其次，通过确定测试系统中干扰噪声的频率来确定巴特沃兹滤波器的上限截止频率和下限截止频率。最后，设计巴特沃兹滤波器的电路，并仿真得到了系统的滤波特性图。通过特性图可看出，滤波器有效地衰减了相应频段内的干扰噪声，大大降低了测试信号的干扰。
설계적미추력측시계통주요유뉴파궤구구성，해뉴파궤구치우진공창내，구유경과특수설계적현괘결구이급뉴칭결구，가실현대추진기단맥충충량적개배측량，동시환능구대평균추력재개배화폐배조건하진행측량。인재추력측시적과정중존재적대량간우회도치측시결과수도영향심지피엄몰우조성중，고수선근거뉴파적운동특성학정료측시장치적동역학모형이급계약향응모형，병험증료재계통적계약향응모형중，계통적제오계자연빈솔여외계간우항적빈솔일치。기차，통과학정측시계통중간우조성적빈솔래학정파특옥자려파기적상한절지빈솔화하한절지빈솔。최후，설계파특옥자려파기적전로，병방진득도료계통적려파특성도。통과특성도가간출，려파기유효지쇠감료상응빈단내적간우조성，대대강저료측시신호적간우。
The micro thrust measuring system designed in this thesis was mainly composed of a torsion pendulum structure, which is arranged in the vacuum chamber. With the specially-designed suspension structure and the torsion balance structure, open loop measurement of the propeller single pulse impulse could be realized;the average thrust measurements could also be carried out in the open and closed loop conditions. However, in the process of thrust measurement existed a lot of interference, as a result, the test results were affected by noise even submerged in noise. So according to the motion characteristics of torsional pendulum we first determined the dynamics model of the test device and the step response model. We found that in the step response of the system model, the fifth order natural frequency of the system accorded with the external interference frequency. Secondly, we determined the upper and lower cutoff frequency in Butterworth filter by determining the noise in the frequency of testing system. Finally, through designing the circuit of the Butterworth filter and through simulation we got the waveform characteristics graph. It could be clearly seen that the designed filter could obviously attenuate interference noise, greatly reduce the interference to test signal.