微冲量测量的建模误差分析

Modeling error analysis of micro-impulse measurements

关键词:  微冲量测量  无阻尼振动  冲量瞬间耦合  建模误差

Key words:  Micro-impulse measurement  Undamped vibration  Impulse instantaneous coupling  Modeling error

摘要:

微冲量测量是脉冲微推力器推进性能研究的关键问题之一。利用摆等动力学结构,将冲量测量转化为摆角(位移)测量是微冲量测量的主要研究方法。基于二阶系统模型,在摆无阻尼振动及冲量瞬间耦合的条件下,定量研究了冲量测量的建模误差。研究结果表明,不管作用力的脉冲波形如何,只要作用力时间与摆的振动周期之比足够小且阻尼比足够小,建模误差完全可以忽略。

Abstract:

Micro-impulse measurement is one of the key problems for studies of propulsion performance of pulsed micro-thruster.The pendulum is usually used to measure micro-impulse,and impulse can be obtained by measuring rotation-angle.Based on second order system model,this paper quantitatively analyzes modeling error on the assumption that the vibration of pendulum is undamped and impulse is instantaneous coupling.The results show that if the radio of action time and vibration period is enough small and damping radio is also small,the modeling error can be ignored regardless of the pulse waveforms.