智能桁架卫星的振动抑制与姿态控制方法研究

发布时间：2018-03-24 18:35

  本文选题：智能桁架卫星　切入点：振动抑制　出处：《哈尔滨工业大学》2016年硕士论文

【摘要】：卫星结构的大型化和复杂化已经成为当今这个航天任务多样化的时代不可避免的发展趋势。为了尽量延长卫星在轨时间并且高效完成任务需求,各类功能附件的安装十分必要,大型挠性桁架结构的应用也愈加广泛。对于在轨运行的桁架卫星而言,桁架结构受到环境干扰产生的振动响应以及桁架与卫星本体之间的动力学强耦合效应一直以来都是亟需解决的问题。由于目前较少有文献专门针对带有智能桁架结构的挠性卫星的姿态控制开展研究,因此本文针对智能桁架卫星的振动抑制和姿态稳定控制问题展开了如下几个方面的研究工作:首先介绍了卫星姿态模型建立过程中需要用到的几种坐标系,然后分别建立了忽略刚柔耦合效应的智能桁架结构的有限元模型、智能桁架卫星的运动学模型、桁架相对卫星本体固定的多智能桁架挠性卫星动力学模型。针对智能桁架卫星的挠性振动抑制问题,考虑到振动响应的根源在于智能桁架结构的挠性振动,将其等效为桁架减振问题,设计了两种基于独立模态空间控制理论的有限时间振动抑制控制器。首先,在忽略卫星本体与桁架间刚柔耦合效应的条件下,通过模态滤波器对系统状态的坐标变换和扩张状态观测器对系统总干扰的实时估计,基于“动态补偿线性化”思想简化模型并设计了基于齐次方法的有限时间控制器。进一步的,为增强系统对参数摄动及扰动具有的强鲁棒性,针对带有未知上界干扰情况,设计了双幂次趋近律形式的终端滑模自适应有限时间控制器。仿真结果表明,所设计的两种控制器都能够在有限时间内有效抑制智能桁架卫星的振动响应,终端滑模控制方法具有控制精度高、挠性振荡收敛快、鲁棒性强等特点。针对智能桁架卫星在存在外干扰的空间运行时的姿控问题,考虑智能桁架结构相对卫星本体固定情况,设计了两种不同的姿态稳定控制器。首先,通过非线性干扰观测器给出了未知干扰的估计信息,并对控制器设计时需要使用的桁架模态加速度信息及卫星角加速度信息设计了超螺旋观测器。接下来,通过加入刚柔耦合项对上一章中设计的终端滑模有限时间控制器进行了改造。最后,为了实现智能桁架卫星的姿态稳定控制,分别设计了不依赖精确模型的非线性预测控制器和具有有限时间收敛特性的终端滑模控制器。仿真结果表明,在上述两种控制律的作用下,智能桁架卫星的姿态最终都趋于稳定,模态振动响应得到了有效抑制。
[Abstract]:The large-scale and complicated structure of satellites has become an inevitable trend of development in the era of diversification of space missions. In order to prolong the time of satellites in orbit as far as possible and to fulfill the requirements of missions efficiently, it is necessary to install various functional accessories. Large flexible truss structures are also widely used. For truss satellites in orbit, The vibration response of truss structure caused by environmental disturbance and the dynamic strong coupling effect between truss and satellite body have always been the problems that need to be solved. Research on attitude control of flexible satellite with structure, Therefore, in this paper, the vibration suppression and attitude stability control of intelligent truss satellites are studied as follows: firstly, several kinds of coordinate systems are introduced in the process of satellite attitude model establishment. Then the finite element model of intelligent truss structure and the kinematics model of intelligent truss satellite are established respectively. Dynamic model of flexible multi-intelligent truss satellite with fixed truss relative to satellite body. In view of the problem of flexible vibration suppression of intelligent truss satellite, it is considered that the root of vibration response lies in the flexible vibration of intelligent truss structure. Two kinds of finite time vibration suppression controllers based on the independent modal space control theory are designed. Firstly, the rigid-flexible coupling effect between the satellite body and the truss is neglected. Through the coordinate transformation of the system state and the real-time estimation of the total disturbance of the system by the extended state observer, the modal filter is used to estimate the total disturbance of the system. Based on the idea of "dynamic compensation linearization", this paper simplifies the model and designs a finite time controller based on homogeneous method. Furthermore, in order to enhance the strong robustness of the system to parameter perturbation and perturbation, the system with unknown upper bound disturbance is proposed. A terminal sliding mode adaptive finite time controller in the form of double power approach law is designed. The simulation results show that the two controllers can effectively suppress the vibration response of intelligent truss satellite in finite time. The terminal sliding mode control method has the characteristics of high control precision, fast convergence of flexible oscillation and strong robustness. Aiming at the attitude control problem of intelligent truss satellite in space with external interference, the fixed case of intelligent truss structure relative to satellite body is considered. Two different attitude stabilization controllers are designed. Firstly, the unknown disturbance estimation information is given by nonlinear disturbance observer. The superhelix observer is designed for the truss modal acceleration information and the satellite angular acceleration information which need to be used in the controller design. The terminal sliding mode finite time controller designed in the previous chapter is modified by adding rigid-flexible coupling term. Finally, in order to realize the attitude stability control of intelligent truss satellite, The nonlinear predictive controller independent of the exact model and the terminal sliding mode controller with finite time convergence are designed, respectively. The simulation results show that under the above two control laws, Finally, the attitude of intelligent truss satellite tends to be stable, and the modal vibration response is effectively suppressed.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V448.2
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本文编号：1659525