基于扩展分形理论的导引头伺服机构动态特性控制研究

Servo mechanism is a key component of the seeker to catch a target. Its assembly links will directly affect the accuracy of precision guided weapons. Advanced assembly process is an important part to ensure the seeker to capture the target accurately and reliably. The project is aimed at the situation that the assembly performance of the seeker is poor and cannot promise the dynamic characteristics. It is proposed to make the joint surface contact as the starting point of the assembly process theory. Through the expansion of the fractal theory, the dynamic model of the asperity is established with the consideration of friction, staggered contact, elastic-plastic phase and base deformation. The deformation mechanism between the assembly process and the contact surface is explored. The relationship between the assembly process parameters and the stiffness-damping of the microstructure of the surface is researched. The microscopic joint surface model is mapped to the key assembly links by means of the macroscopic method to control the dynamic performance of the seeker in the assembly process. Through the implementation of the project, it can form a method which can guide the seeker servo mechanism assembly process. It can also lay certain technical foundations for the future development of new seekers, which has important theoretical significance and practical value.

伺服机构作为导引头捕捉目标的关键部件，其装配环节将会直接影响到精确制导武器的精准性。先进的装配工艺方法可以保证导引头可靠精确地捕捉目标。项目针对导引头伺服机构装配性能一致性差、动态特性难以保证的情况，提出以结合面接触作为装配工艺理论研究的切入点，通过对分形理论进行扩展，建立考虑摩擦、交错、弹塑性变形、基底变形的微凸体动力学模型，探索伺服机构装配工艺造成接触表面变形的机制，研究装配工艺参数与零部件表面微观结构刚度阻尼之间的关系，将微观结合面模型通过宏观化方法映射到关键装配环节中，实现在装配过程中对导引头动态性能的控制。通过项目的实施可形成指导导引头伺服机构装配工艺的辅助方法，还可以为将来新型导引头的研制奠定一定的技术基础，具有较大的理论意义和实用价值。

导引头是精确制导装备的关键设备，随着航天科技的不断发展和军事装备的迫切需求，导引头不断向高精度、高动态响应、高可靠性、小型化方向发展，对导引头的设计、制造、装配等都提出了更高的要求，先进的装配工艺方法是约束导引头性能的关键环节。本项目针对导引头伺服机构装配工艺机理研究匮乏，装配调整一致性差的问题，以结合面物理接触层面作为理论研究的切入点，提出了一种基于斜微凸体接触的改进分形模型，分析了接触半径和临界接触面积，探索伺服机构装配工艺造成接触表面轮廓变形的机制，研究装配工艺参数对零部件表面微观层面的刚度阻尼映射关系，揭示利用零部件表面粗糙度等属性控制表面形貌参数的方法，研究可靠的微观结合面宏观化理论方法，将装配工艺对微观层面的刚度阻尼的作用联系到宏观的关键装配环节中，建立装配工艺参数和动力学参数映射模型，从而在理论上搭建从装配结合面到装配体、从微观到宏观的装配工艺设计和优化体系方法。利用试件表面观察和载荷变形测量等实验，获得了加工表面的接触刚度。从结果来看，修正后的分形刚度模型在一定程度上更为合理和准确。可为装配工艺设计和装配仿真提供可靠的科学依据，在工程中提高装配调整的可靠性和一次成功率，提升装配质量控制水平，改善对导引头伺服机构性能调控方法，具有较大的理论和实用价值。