气浮台垂向自动调节系统设计及姿态稳定控制

发布时间：2018-10-15 15:15

【摘要】：为了更好地探索和利用太空资源,各种航天器相继被制造出来执行相应的任务。然而,空间环境与地面环境孑然不同,真空、辐射和微重力等条件对航天器提出了严格的要求。太空任务的复杂性和高运行成本使得人们不得已需要在地面对航天器进行测试试验,因此全物理仿真器应运而生。全物理仿真器可在地面完整模拟航天器在轨运行状态,极大地降低了航天器执行任务前的测试成本,也能提高复杂任务的执行效果。为了缩短使用六自由度气浮台进行试验时的准备时间,优化初始状态及提高控制效果,将针对六自由度气浮台的垂向位置控制和姿态稳定控制进行深入研究。首先,研究垂向气浮轴承工作过程,分析了气浮轴承气隙对运动的阻力因素,同时分析气源输入不稳定因素。选择具体执行机构并建模。将气浮轴承抽象为变质量气腔并建模,并以此为基础建立垂向位置自动调节系统总模型。通过仿真,对模型进行可行性验证及特征分析。其次,采用双阀分段控制方案。根据控制要求,分析了分段控制的参数,并设计了分段开关逻辑及程序。然后,按照提出的双阀控制方案,在细调阶段采用数字增量式PID控制器;在粗调阶段采用模糊PID控制器。在粗调控制中,放弃经验整定的模糊规则,设计了适应度函数,并对遗传优化算法中的各个主要算子进行改进,对规则进行优化处理。而后对控制方案进行综合仿真。再次,研究了六自由度气浮台试验准备阶段及停靠阶段上台体的姿态稳定控制。应用误差四元数建立气浮台上台体的姿态模型。针对抑制外部干扰和迅速稳定的需求,设计新型非奇异快速终端滑模切换函数,并使用反步法推得趋近控制律。采用数值仿真验证此控制算法。最后,进行硬件选型、软硬件系统搭建。设计人机交互界面,编写控制程序并对提出的控制方案进行工程实验测试。
[Abstract]:In order to better explore and utilize space resources, various spacecraft have been created to carry out corresponding missions. However, the space environment is different from the ground environment, vacuum, radiation and microgravity conditions put forward strict requirements for spacecraft. Because of the complexity of space mission and the high cost of operation, people have to test the spacecraft in the ground, so the all-physical simulator emerges as the times require. The full physical simulator can simulate the state of spacecraft in orbit completely on the ground, which greatly reduces the test cost before the spacecraft carries out the mission, and can also improve the performance of complex tasks. In order to shorten the preparation time, optimize the initial state and improve the control effect, the vertical position control and attitude stability control of the six-degree-of-freedom air flotation platform are studied. Firstly, the working process of the vertical air bearing is studied, and the resistance factors of the air gap to the movement of the air bearing are analyzed, and the unstable factors of the air source input are also analyzed. Select specific implementing mechanism and model. The air bearing is abstracted as a variable mass air chamber and modeled, and the general model of the vertical position automatic control system is established based on the model. Through simulation, the feasibility of the model is verified and the characteristics are analyzed. Secondly, two-valve subsection control scheme is adopted. According to the control requirements, the parameters of the piecewise control are analyzed, and the logic and program of the piecewise switch are designed. Then, according to the proposed double valve control scheme, the digital incremental PID controller is used in the fine tuning stage, and the fuzzy PID controller is used in the coarse tuning stage. In rough tuning control, the fuzzy rule of empirical tuning is abandoned, the fitness function is designed, the main operators in genetic optimization algorithm are improved, and the rules are optimized. Then the control scheme is simulated synthetically. Thirdly, the attitude stability control of the onstage in six degrees of freedom test preparation stage and docking stage is studied. The error quaternion is used to establish the attitude model of the air floatation platform. A novel sliding mode switching function of a nonsingular fast terminal is designed for the demand of suppressing external interference and fast stability and the approach control law is obtained by using the backstepping method. The control algorithm is verified by numerical simulation. Finally, hardware selection, hardware and software system construction. The man-machine interface is designed, the control program is written and the proposed control scheme is tested by engineering experiments.
【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】：2017
【分类号】：V416.8;TP273

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