碩士 / 國立交通大學 / 機械工程系所 / 105 / In general, satellite launcher takes off vertically from launch pad, flies through the atmosphere so that it can perform orbit insertion where rocket shall propel itself up to the designated inertia velocity required for its payload to orbit the Earth. During the course of flight, several disturbances, such as aerodynamic force, wind gust, imperfection of sensor/actuator between real and measurement/command, guidance law, autopilot law and timing of flight sequences will ultimately impact the accuracy of final orbit insertion. As a result, there is a need to build a simulation tool to evaluate the impact toward the accuracy of orbit insertion owing to those disturbances, laws and timing of actions during the flight.
In this thesis, a highly modularized simulation tool with high fidelity capable of simulating the flight of a rocket based on its physical properties is modified based on publicly available GNC (guidance navigation and control). The newly developed code has gone through numerous validation simulations against the original code. The simulator considers these aforementioned disturbances, navigation, guidance and control laws and sequence of ignition/separation actions along with designated timing. The sequence of actions during flight are summarized as follows. First, thruster vector control (TVC) vector tilts at an angle immediately after rocket taking off. After the jettison of first stage, the second stage starts a gravity turn in a near zero angle of attack manner to minimize the aerodynamic loss during flight. After the second stage engine cuts off, the rocket coasts for a certain period of time until its attitude reaches a appropriate flight path angle. Later, the third stage engine ignites and the activates a close loop control using reaction control system (RCS) or TVC with guidance using Powered Explicit Guidance (PEG) will be enabled for accurate orbit insertion.
For the proposed flight sequence, the simulation suggests that the timing or the proper flight path angle to enable the close-loop PEG on the third stage will impact the accuracy of the final orbit insertion. Further investigation of this particular factor is performed by the comparison of orbit insertion accuracy for different flight path angles. Completion of this simulation tool shall benefit our future development in Processor-In-the-Loop (PIL) and Hardware-In-the-Loop (HIL).
| Identifer | oai:union.ndltd.org:TW/105NCTU5489002 |
| Date | January 2016 |
| Creators | Lai, Jun-Xu, 賴俊旭 |
| Contributors | Wu, Jong-Shinn, 吳宗信 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 43 |
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