基于压电纤维复合材料的航天柔性结构半主动振动控制研究

With the rapid development of China's aerospace industry, the antenna structures evolve in the direction larger size,lower stiffness and higher flexibility, which leads to very low fundamental vibration frequency and damping factor, so that their vibration excited by attitude control and other disturbances takes very long time to decay. Therefore, vibration reduction is a critical issue related to maneuvering of flexible antenna structure and improvement of positioning precision. Many studies have been carried out on vibration control of antenna structures and many breakthrough results have been achieved. However, most of studies are focused on active vibration control methods, which usually require high-performance digital signal processing system in implementation and bulky power supply system during control. Due to these requirements by active control systems, they are not very suitable for application in space structure, in which weight and power supply are important issues. To overcome the drawbacks in the active control systems, a low-powered semi-active approach based on synchronized switching technique using MFC piezoelectric materials is proposed in the study. The project aims at meeting the demands by the control systems in aerospace field, such as compactness, light-weight, high-performance, and good robustness, and focuses on solving the following key issues: (1) theoretical foundation of wide-band semi-active control for flexible structures; (2) asymmetric switching method for MFC actuators; (3) theory of energy conversion in wide band vibration control of flexible structures and optimization of switching algorithm under asymmetric switching condition; (4) implementation of the semi-active control system with high efficiency and low power consumption. The research achievements will provide theoretical and technological foundation for application of semi-active control methods in aerospace engineering.

随着我国航天事业的迅猛发展，天线结构向着大型化、低刚度与柔性化方向发展，由此带来的振动问题受到更多的重视，降低振动水平对提高天线的定位精度等至关重要。在当前的振动控制研究中，主要有主动、被动和半主动，而目前天线结构振动控制研究中主要采用主动控制方法。本项目瞄准航天领域对控制系统提出的苛刻要求（控制系统紧凑、重量轻，控制效果鲁棒性高、效果好等），针对目前主动控制方法通常需要复杂的信号处理系统和庞大的能量供给系统的缺点，和被动控制方法对环境变化适应能力差的不足，提出基于压电纤维复合材料MFC的半主动振动控制新方法，实现天线结构的振动控制。着重解决以下关键问题（1）建立柔性结构的宽频带半主动控制理论；（2）结合MFC驱动器特性，建立非对称切换方法；（3）建立非对称切换条件下的能量转换理论和开关切换的优化方法；（4）实现高效低功耗的半主动控制系统。为压电材料在航空航天等领域得到更好的应用奠定基础。

随着我国航天事业的迅猛发展，天线结构向着大型化、低刚度与柔性化方向发展，由此带来的振动问题受到越来越多的重视，降低振动水平对提高天线的定位精度等至关重要。国内外对天线结构的振动控制已经开展了较多的研究，取得了很多突破性的成果。在当前的振动控制研究中，主要的振动控制方法有主动、被动和半主动三种。本项目瞄准航天领域对控制系统提出的苛刻要求（控制系统紧凑、重量轻，控制效果鲁棒性高，控制效果好等），针对目前主动控制方法通常需要复杂的信号处理系统和庞大的能量供给系统的缺点，和被动控制方法对环境变化适应能力差的不足，提出了基于压电纤维MFC的半主动振动控制新方法，实现了天线结构的振动控制。着重解决了以下关键问题：（1）建立了柔性结构的宽频带半主动控制理论；（2）结合MFC驱动器特性，建立了非对称切换方法；（3）建立了能量转换的分析方法和开关切换的优化方法；（4）实现了高效低功耗的半主动控制系统。对某型天线展开臂的在展开以及受到扰动后引起的振动进行半主动抑制。试验结果表明，整个控制系统总重量控制在2kg以内，控制后阻尼比提高到5%以上。为压电材料在航空航天等领域得到更好的应用奠定基础。