| Summary: | 碩士 === 國立中央大學 === 機械工程研究所 === 97 === The main purpose of the thesis is to design a reentry capsule for the Taiwan sounding racket mission 8. The reentry capsule is improved in this project based on the result of then sounding racket mission 6. The 2.4GHz channel communication module is attached to the reentry capsule,for example,which can increase the probability of rescue. In addition, a new payload module, the rocket combustion system, is included in the reentry capsule for attitude control test in the space. Because of the increased weight of the capsule in the project,a balloon device is developed so that the capsule can float on the sea as waiting for rescuing. This thesis also develops the quality control methods for design of reentry capsule. The possible faiures can be controlled and improved before manufacturing and the environment tests. The reliability of the designed capsule can be therefore increased.
Based on the concept of modular design, the reentry capsule is divided into different capsule modules according to the specified functions and mission. In order to enable the communication of the electric and electronic control modules in each capsule module, a special design for mechanical and also electrical connection between two adjacent capsule modules was also developed. Considering the requirements of each module,the different functional units such as suspension mechanisms for electronic devices and the shell-opening mechanism for the ballon-capsule were also integrated with the corresponding capsule module. By using wedge-cushions the suspension mechanism enables not only to reduce the vibrstions and impacts in axial, radial and rotational direction, but also to realize a compact design for the capsule. The shield-shell of the balloon capsule is opened by a separation mechanism using a non-explosive actuator. The design can prevent the impacts on the electronic control modules when the shield-shells are opening.
The design quality of the developed reentry capsule is also controlled by using “Fault Tree Analysis” and “Failure Mode & Effect Analysis”. The possible design defects of the last mission were at first analyzed by using “failure tree analysis”. The defects are redesigned and corrected to avoid the potential failures. Based on the methods of failure mode & effect analysis, the sheets for design review were also established, which are able to decrease the failure probability during manufacture and fly mission.
Up to now the design and prototype of the reentry capsule has been completed. The functions of the design must be validated by the further environment tests. However the quality control methods developed in the thesis was verified that they can improve the design quality and also increase the reliability.
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