项目/论文提案样本

AE295A -硕士项目建议书
介绍给博士. Nikos Mourtos
作者:约书亚·本顿

2011年9月1日

Miniaturization, Integration, Analysis, and High-Altitude Flight Testing of a Scalable 用于目标载荷返回的自主gps制导伞

背景与背景

A parafoil is a special type of airfoil that is non-rigid and relies on dynamic pressure 在飞行中保持形状. 由于它们是非刚性的(因此可折叠/可包装)， parafoils lend themselves very well to applications where controlled descent is required, 但是对于任何一种传统的机翼结构来说，装载都是有限的. 同时, compared to a traditional round parachute, parafoils have much greater directional control, improved glide performance, and the ability to adjust rate of descent by 变形翼型的形状通过控制(或“切换”)线. 这些属性 of parafoils have made them very popular for human aerial descent, where the entire parafoil as well as a redundant backup can be stowed in a backpack and deployed rapidly 在必要的时候.

In addition to manned applications, parafoils provide an attractive means to deliver 各种有效载荷(如.g. 军事用品、应急设备、食品包) 以中等程度的准确度到达遥远或难以到达的地方. 这个精度 can be further improved by including an autonomous control system on the payload, which can effectively steer the parafoil in the same fashion as a human would, guiding 它对着陆点的精确度更高. 在过去的十年里，有几个 independent research efforts have focused on doing exactly this, providing complete, “intelligent” parafoil systems which autonomously steer themselves to a pre-defined 运送有效载荷(通常是军用物资)的着陆点. 最近的研究成果 have improved accuracy of these systems from a few kilometers landing error to orders 量级较小，取决于盛行风和初始落差高度.

In my work at NASA Ames 研究 Center, we have identified a need to return small payloads (such as biological samples and small science experiments) from the International Space Station when desired or necessary, independently of the larger manned or supply 到访监测站次数相对较少的车辆. 我们提出的解决方案 to this problem requires a means to guide the payload on the final leg of its journey to a selected landing point, with a high degree of precision, to aid in simple and 立即检索. 在建议的返回系统中可用的体积空间 eliminates rigid wing structures as a solution, and the gliding device for atmospheric 在再入大气层之前，必须保持下降状态. 由于这些原因，一个降落伞系统 看起来是个很有吸引力的解决方案.

In addition to ISS return applications, a well-developed autonomous parafoil system could be scaled larger and used for a number of other applications of interest to 我们，包括从亚轨道探测火箭飞行中返回的实验， which currently relies on slow, expensive, and frequently- unsuccessful water recovery 从租来的船上.

We have identified and worked with researchers at the Naval Postgraduate School in 他们正在开发一种gps制导的伞翼装置. 从我们的 collaboration, we have built our own version of their GPS-guided return device, and 在低空(~3000英尺)进行过几次跌落测试吗. AGL)从一个自治 无人机. 我们还与大学的同事和一个学生团队合作 of Idaho in 3 high-altitude balloon drops of the device, but two of these drops resulted in failures: the first, failure to separate from the balloon due to tangling; and 第二，伞翼不能完全充气.

问题定义和方法

Though we have already fabricated a prototype version of the autonomous parafoil return device we wish to use for the ISS, there are still many problems to solve to make 这是一个实际可行的解决方案:

  1. 自主控制系统的小型化: At present, the autonomous steering system that hangs below the parafoil is much too large volumetrically to fit within the confines of the ISS sample return system. A design of the physical structure and a more efficient packaging scheme are required to miniaturize the control system while still maintaining reliability and functionality. Smaller steering servos, more efficient line rigging and tensioning, and a smaller 电池(同时仍保持设计余量)是实现这一目标所必需的.
  2. 高空翼伞空气动力学特性: Due to the nature of the application we wish to use this device for, it is advantageous 在尽可能高的高度获得操舵权. 通过这样做， 提高了目标着陆的最大可达地面距离. 不幸的是, functioning of a parafoil relies on dynamic pressure to maintain its structural shape, and high-altitude use is problematic due to collapse and “nose-diving” of the parafoil 超过它的有效载荷. 为了了解我们能达到的最大滑翔能力 parafoil return device, the aerodynamics of the parafoil at high altitude/low pressure 需要通过分析和测试进行表征和验证. CFD、真空 chamber testing, and another high-altitude balloon test in April 2012 will be used 分析和验证降落伞在高空的性能.
  3. 伞翼结构的半刚性: To eliminate the problem of parafoil collapse in low dynamic pressure, a method of self-deployment while maintaining packable stowage capability will be developed. A system of lightweight spring-like material will be added to the parafoil to make the structure “semi-rigid” and capable of maintaining its shape in a low pressure 环境. 真空室测试将提供一种在气球之前进行验证的方法 综合系统的飞行测试.
  4. 先进的指导代码的软件移植到一个较新的控制板: At present, our version of the Naval Postgraduate School’s GPS-guided parafoil device 使用与他们的设备不同的微处理器板. 以前，我只编程 our board to steer the device to a specified heading, rather than to a specific set 着陆坐标. 高级代码的移植版本是存在的，但是是编写的 对于我们的控制板的旧版本，并且尚未经过测试/调试. As part of the development effort, the ported code requires modification for compatibility 用新版本的控制板进行调试，并进行地面测试.

As noted above, an opportunity exists to flight-test the entire system from a high-altitude balloon in April 2012 with the collaboration of the University of Idaho’s RISE balloon 团队. 这是我们过去合作过的同一个团队，并开发了一个 excellent working relationship and understanding of all necessary procedures and protocols 用于伞翼系统的安全飞行试验. 在飞行过程中，载荷和气球 are tracked via redundant GPS transponders on the APRS radio network (amateur HAM 波段)，能够精确地恢复有效载荷系统.

Data returned from the flight testing includes HD video (一个 camera up-looking to the parafoil and another looking 45 degrees to the ground); a GPS flight track including time and altitude via the APRS network as well as the data-logging control board of the parafoil device; and three-dimensional comp一个nt velocity and acceleration of 通过机载IMU控制翼伞有效载荷.