无人机捷联惯组隔振系统动力学分析与优化设计

Dynamical analysis and optimization of the damping system of strap-down inertial measurement unit used in UAV

针对捷联惯组在无人机中的特殊安装环境,提出了一种在偏移安装环境中实现三轴向等刚度与准解耦隔振系统的设计方法。首先建立了隔振系统的六自由度动力学模型及其动力学方程,对隔振系统进行动力学分析。分析结果表明:当隔振器的轴径刚度比为0.8左右且阻尼比大于0.125时系统可以实现设计要求。最后,设计并制造隔振系统,分别在振动台上以及无人机飞行环境中对其进行试验验证。试验结果与理论计算相吻合:隔振系统有效地削弱了偏移安装环境带来的捷联惯组振动问题,可以实现三轴向等刚度设计与准解耦状态。

Aiming at the special installation requirements of the UAV strap-down inertial measurement unit,a design method for the damping system that could reach the tri directive equal rigid design and quasi-decoupled state for the offset installation environment is proposed.A six-degree-of-freedom mechanical dynamic model and its equations of the damping system are established at first.The dynamic analysis of damping system is carried out.The results show that the damping system could meet the design requirements when the shaft-to-radius stiffness of the isolator is about 0.8 and the damping ratio is above 0.125.Finally,the vibration isolator of the UAV strap-down inertial measurement unit is designed and manufactured.The damping system was tested and verified on the shaking table and in the flight environment of the UAV.And the experiments also prove that the damping system effectively weakens the vibration problem of the strap-down inertial measurement unit caused by offset installation environment,which could implement the tri directive equal rigid design and quasi-decoupled state.