双体卫星地面试验系统设计及隔振效能分析

发布时间：2019-04-13 16:09

【摘要】：随着当代航天技术的不断进步,太空望远镜等有效载荷对卫星平台提出了更高的指向精度要求。航天器上有效载荷的高精度定向一方面需要敏感器或指向设备具有更高的精度和灵敏度,而另一方面则需要搭载敏感器或指向设备的航天器平台具有更高的定姿定向精度和控制稳定度。现阶段,航天器上所应用的敏感器已经具备了很高的测量精度和灵敏度,而其所处的工作环境则成为影响其测量精度的主要因素,也就是说,其指向精度主要受搭载平台的控制稳定度的制约,因此,降低航天器所处环境的噪声干扰对其的影响,保证航天器的姿态稳定度已成为一个重要的研究课题。针对上述需求,人们将隔振技术应用到航天器中,降低噪声源的噪声干扰,保证敏感元件工作环境的稳定性,而其一般的工作原理是在航天器平台上加入隔振机构,降低环境噪声干扰,保证有效载荷的工作稳定性。本文正是基于航天器上有效载荷的高精度指向需求,并在国外所提出的双体卫星无扰载荷平台(Disturbance Free Payload,DFP)原理的基础上,设计出了一种双体卫星地面试验系统,并通过建立模型,模拟本模拟器正常运行的工作环境,并进行了隔振效率及指向精度改善效率的分析。本系统包含三个分系统,分别是载荷平台试验系统、服务平台试验系统和隔振机构。并针对三个分系统,采用数学方法分别建立三个分系统的动力学模型,并根据工程实际经验,确定了三个分系统控制策略,包括隔振机构的电流环控制、载荷平台模拟器的绝对位姿环控制和服务平台模拟器的相对位姿环控制。同时,分析了本试验系统在实际工作时所受到的外界干扰及其类型,在详细考虑其所受干扰以及所处试验环境的前提下进行了动力学仿真。并通过载荷平台与服务平台在指向精度和振动效率上的对比,得到本文所设计的试验系统的隔振效能及指向精度改善效率。仿真结果表明,通过在地面模拟器上对双体卫星概念的应用以及载荷平台与服务平台测量数据的对比,模拟器在指向精度和隔振效率上均取得很大的改善,从而验证了双体卫星概念对卫星姿态控制稳定度的改善效果,也证明了这一概念在未来航天中的可行性。
[Abstract]:With the development of modern space technology, space telescopes and other payloads put forward higher pointing accuracy requirements for satellite platforms. High-precision orientation of payloads on spacecraft requires, on the one hand, higher precision and sensitivity from sensors or pointing devices. On the other hand, spacecraft platform with sensor or pointing equipment is required to have higher orientation accuracy and stability. At present, the sensors used on spacecraft already have very high measurement precision and sensitivity, and the working environment of the sensor has become the main factor affecting its measurement accuracy, that is to say, Its pointing accuracy is mainly restricted by the control stability of the platform on board. Therefore, it has become an important research topic to reduce the influence of noise interference in the environment of the spacecraft and ensure the attitude stability of the spacecraft. In view of the above requirements, the vibration isolation technology is applied to spacecraft to reduce the noise interference of the noise source and ensure the stability of the working environment of the sensitive components. The general principle of the vibration isolation technology is to add the vibration isolation mechanism to the spacecraft platform. Reduce the disturbance of environmental noise and ensure the stability of the payload. In this paper, based on the requirement of high precision pointing of payload on spacecraft, and on the basis of the principle of two-body satellite load-free platform (Disturbance Free Payload,DFP), a ground test system of two-body satellite is designed, which is based on the principle of two-body satellite load-free platform (Disturbance Free Payload,DFP) proposed by foreign countries. Through the establishment of the model, the working environment of the simulator is simulated, and the efficiency of vibration isolation and the improvement of pointing accuracy are analyzed. The system consists of three subsystems: load platform test system, service platform test system and vibration isolation mechanism. According to the practical experience of engineering, the control strategies of three subsystems are determined, including the current loop control of vibration isolation mechanism, and the dynamic models of three subsystems are established by means of mathematical method, and the dynamic models of three subsystems are established by means of mathematical method. Absolute position attitude loop control of load platform simulator and relative position attitude loop control of service platform simulator. At the same time, the external interference and the types of the system are analyzed, and the dynamic simulation is carried out on the premise of considering the interference and the test environment in detail. Through the comparison of pointing accuracy and vibration efficiency between load platform and service platform, the vibration isolation efficiency and pointing accuracy improvement efficiency of the test system designed in this paper are obtained. The simulation results show that the pointing accuracy and vibration isolation efficiency of the simulator are greatly improved by the application of the concept of two-body satellite on the ground simulator and the comparison of the measured data between the load platform and the service platform. It is proved that the concept of two-body satellite can improve the stability of satellite attitude control, and the feasibility of this concept in future spaceflight is also proved.
【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】：V416.8

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