复合式磁流变缓冲装置抗连续冲击特性及控制方法研究

A new type of hybrid pounding-MR buffer system is proposed according to the complicated conditions under continuous impact loadings, such as the continuous artillery firing, down-the-hole(DTH) drilling and other damping systems, etc. This proposal aims to investigate the essential mechanism and response characteristics of this novel buffering manner and develop an optimal flexible control strategy based on floating technology for the soft landing of protected structures. First of all, by considering the composition relationship of different configurations, the effects of hysteresis characteristics, eddy current and mechanical structure on time delay phenomenon are analyzed by numerical simulation and a physical model of electromagnetic driving circuit with current controller is established, followed by the development of some relevant compensation measures for time delay. Secondly, based on the pounding force model combined with the multi-physical model of MR shock absorber, a parametric dynamic model of the hybrid buffer system is established. The influence of the factors such as the mass of the collision unit and the spring stiffness on the performance of hybrid buffering system and matching relations of relative parameters, etc are obtained by repeated tests. After that, taking the uncertainty, floatability and hysteresis of the effective stroke under continues impacts into account, an optimal control strategy is determined by the floating technology and state equations. Finally, four different combination patterns of prototypes are fabricated and continuous impact tests are therefore carried out and the effectiveness of proposed control strategy is validated by simulation and experiments. The contributions of this proposal will provide theoretical and practical guidance for the application of magnetorheological technology in the field of anti-continuous impacts.

针对火炮连发、潜孔凿岩等连续冲击复杂工况，提出一种碰撞-磁流变复合式缓冲装置，研究该新型缓冲方式的作用机理与响应特性，建立一种基于浮动技术的最优柔性控制策略，用于实现每次冲击的“软着陆”。研究内容：①统筹考虑不同构型组合关系，通过模拟仿真分析引起时延现象的磁滞特性、涡流效应和机械结构等因素，建立电磁驱动回路响应模型，并提出相应时延补偿措施；②利用碰撞力模型结合缓冲器多场耦合模型，建立碰撞-磁流变复合式缓冲系统的参数化动力学模型，并通过反复试验获得碰撞单元质量、弹簧刚度等要素对复合式缓冲装置性能的影响规律和参数匹配关系；③针对连续冲击作用下缓冲装置有效行程的不确定性、浮动性和迟滞性，根据浮动技术及状态方程确定最优柔性控制策略；④进行4种不同组合方式的样机制作与连续冲击试验，并利用仿真与实验验证所提出控制策略的有效性。研究成果对磁流变技术在抗连续冲击领域的工程应用提供理论和实践指导。

本项目以连续冲击载荷条件下碰撞-磁流变复合式缓冲装置的工作机理与动态响应为研究对象，目的是通过将部分冲击能量以碰撞形式耗散结合磁流变材料的黏度/刚度可调性及控制策略来实现缓冲装置的"软着陆"，设计了基于多级线圈独立可加载电流的新型剪切/挤压复合磁流变缓冲器和并联式复合缓冲装置；分别建立了复合式缓冲装置应用于1）火炮发射反后坐和2）电梯突发坠落两种复杂工况下的动力学模型，研究了磁-流-温多场耦合作用下磁流变胶流变特性及屈服应力动态响应特性；建立了复合缓冲装置电磁驱动回路响应模型，提出了多目标优化设计方式及时延补偿机制；搭建了适用于不同冲击工况条件缓冲装置性能测试的试验平台，进行了单次冲击（模拟火炮反后坐）和多次冲击（模拟电梯突发坠落）工况下受控结构的动态特性测试；研究得到了结构参数、流变性能、响应特性及柔性控制策略（统一加载电流模式、组合控制模式、PID控制策略）等因素对复合式缓冲装置输出性能，如受力、加速度、屈服应力与冲击速度、位移及时间等动态响应规律。本项目研究所得复合缓冲装置具备结构简单、能耗低、可调范围宽、响应迅速等优点，可作为极端工况下减振缓冲领域的一种新型有效缓冲方式，不仅能针对不同冲击载荷作用工况提供最优缓冲阻尼力，而且减小了系统的体积、质量和复杂程度，将极大地促进磁流变缓冲技术在车辆主动悬架系统、军用防护装置、火炮反后坐、直升机起落架和引信延期保险机构等军民两用场合的推广应用。三年来，本项目研究成果已经在国内外公开发表学术论文13篇，其中SCI检索期刊9篇，EI检索期刊3篇，获得国家发明专利5项，间接培养硕士研究生3名，项目负责人也由讲师晋升为副教授，并获聘本校学术型硕士指导教师资格。