含运动副间隙的舵机用空间4R执行机构动态特性研究

Research on Dynamic Characteristics of 4R Actuator in Space for Rudder Gear with Kinematic Pair Clearance

为探究运动副间隙对舵机用空间4R执行机构动态特性的影响,以一种舵机用空间4R执行机构为例,考虑运动副间隙的作用,利用L-N接触力碰撞模型和修正的Coulomb摩擦模型,研究间隙大小对机构运动精度和运动副受力的影响,确定当机构考虑单间隙和双间隙时的最佳间隙量范围。建立空间4R机构的刚柔耦合模型,分析了在空间4R机构中考虑一个或两个间隙、含或不含柔性体时间隙和柔性体对机构动态特性的影响,证明柔性体的存在会明显增强间隙碰撞对机构的影响。该研究成果可为舵机用空间4R机构的设计提供参考依据,有利于执行机构的实际应用。

To explore the influence of the movement pair clearance on the dynamic characteristics of the space 4R actuator for the steering gear,with a space 4R actuator for the steering gear as the example and in consideration of the effect of the movement pair clearance,the L-N contact force collision model and the modified Coulomb friction were applied to explore the effect of the gap size on the mechanism's motion accuracy to the force of the kinematic pair and determine the optimal gap amount range when the mechanism was concered with single and double gaps.The rigid-flexible coupling model of the spatial 4R mechanism was established,and the influence of the gap and the flexible body on the dynamic characteristics of the mechanism was analyzed as one or two gaps were taken into account in the spatial 4R mechanism,with or without a flexible body.Existence of the flexible body is proven to have marked impact of clearance collisions on the mechanism.The reseach results can provide reference basis for the design of the space 4R mechanism for steering gear,which is conducive to practical engineering applications.