外界扰动是通过摆式陀螺寻北仪的悬带从基座传递到陀螺房,为了分析悬带对外力矩的传递规律,从摆式陀螺寻北仪结构出发,由拉格朗日方程建立悬带摆角模型,在瞬时冲击力、常外值力和简谐外力作用到基座时分别解算悬带摆角模型,在小角度时由悬带摆角反映陀螺房所受外力矩。通过实验验证,在一定条件下,悬带摆角频率近似单摆频率;在瞬时冲击力和常值力的作用下,悬带摆角从受力时刻开始简谐振动,摆幅由外力决定;在简谐外力作用下,悬带摆角为单摆频率与外力频率两者振动的线性叠加,当简谐外力频率与单摆的固有频率相近时,将发生共振。
External disturbance is transferred from the base to gyro room through the suspension tape of pendulous gyroscope. In order to analyze the transfer rule of the external moment of suspension tape, a model for the swing angle of suspension tape is established by Lagrange's equation based on the structure of pendulous gyro north finder, and is solved under the condition that instantaneous impact force,constant external force and simple harmonic external force are acted on the base. The swing angle of suspension tape reflects the moment of external force borne by gyro room when the angle is small. It is proved by experiment that: 1) under certain conditions, frequency of the swing angle of suspension tape approaches to that of a simple pendulum; 2) under the instantaneous impact force and constant force, the swing angel of suspension tape becomes to simple harmonic vibration from the moment of being stressed, of which, the swing amplitude depends on the external force;and 3) under a simple harmonic external force,the swing angle of suspension tape is a linear superposition of vibration by both the frequency of simple pendulum and external force, and resonance appears when the frequency of simple harmonic external force approaches to the inherent frequency of simple pendulum.