摘要
为了抑制惯性导航平台的角振动,基于隔振理论,建立了具有弹性支承的六自由度刚体在基座位移激励下的振动微分方程.分析了振动方程解耦的参数条件;依据惯导平台减振系统线振动固有频率尽可能低、角振动固有频率尽可能高的设计原则,利用抗扭软轴来增加系统的角刚度,并采用有限元模型进行了数值仿真.模态分析结果表明,设置抗扭软轴后,角振动模态频率提高至无抗扭软轴时的2.3倍左右,且对线振动模态频率不产生影响.频率响应分析结果表明,抗扭软轴能够提高平台角振动固有频率,表征角振动的位移频率响应共振频率由27 Hz提升至64Hz左右,并且角刚度的增大使角偏移降低了一个数量级.由此表明,采用抗扭软轴来增大惯导平台减振系统角刚度、抑制角振动是有效可行的.
To reduce the angular vibration of inertial navigation platform, an oscillatory differential equation for six degrees of freedom elastically-supported rigid body with base displacement excitation was established based on the theory of vibration isolation. The condition of equation decouple was analyzed. According to the principle that the translational vibration frequency should be as low as possible and the angular vibration frequency should be as high as possible, torsion-resistant flexible shaft was adopted to improve the angular stiffness of the inertial navigation platform system. Numeri- cal simulation was carried out by finite element model. The results of modal analysis show that the modal frequency of angular vibration with the fixed torsion-resistant flexible shaft is about 2.3 times that of the state without torsion-resistant flexible shaft. And the torsion-resistant flexible shaft has no effect on the modes of translational vibration. The frequency response analysis results show that the torsion-resistant flexible shaft can improve the angular resonant frequency. The resonant frequency of displacement frequency response which can mirror the angular vibration is improved from about 27 to 64 Hz. And the angular deviation is reduced by an order of magnitude with the increase of the angular stiffness. This indicates that torsion-resistant flexible shaft is effective in augmenting angular stiffness and restricting angular vibration.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第1期60-64,共5页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(10902024)
教育部新世纪优秀人才支持计划资助项目(NCET-11-0086)
江苏省自然科学基金资助项目(BK2010397)
航空科学基金资助项目(20090869009)
关键词
惯性导航平台
角振动
减振
抗扭软轴
角刚度
inertial navigation platform
angular vibration
vibration reduction
torsion-resistant flexible shaft
angular stiffness
