Autonomous system clock frequency controller for pico- and nano- satellites

• Main Author: Ian Kamajaya
• Other Authors: Low Kay Soon
• Format: Theses and Dissertations
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Computer hardware, software and systems
• Online Access: https://hdl.handle.net/10356/62573
• Institution: Nanyang Technological University

Abstract Nano-satellites and Pico-satellites – also called miniaturized satellites – are satellites weighing less than 20kg and 1.33 kg respectively. Over the last decade, there has been growing trend to build miniaturized satellites for research and technology demonstration. One of the major concerns in any satellite system is the power. The problem is more apparent in the miniaturized satellites classes as their extremely limited physical size restricts the area available for the solar panels. There have been various works in the miniaturized satellites research area to tackle this power limitation issue. One sub-area which is yet to be more extensively researched is the optimization of micro-controller’s power use. Some miniaturized satellite projects have been known for having issues in the later phase of their development for overlooking micro-controller’s power use in their early stage of the development. In the computer science field, there have been various researches aimed to reduce power consumption of Central Processing Unit (CPU). One popularly known technique which aims to reduce CPU power consumption through the optimization of the micro-processor’s power use is Dynamic Voltage Scaling/Dynamic Voltage and Frequency Scaling (DVS/DVFS). Though this technique has been widely researched in the computer science field, it has some shortcomings which put this technique off from miniaturized satellite applications. DVS/DVFS relies on special hardware components, namely, a programmable DC-DC switching voltage regulator and a high performance (≥ 400 MHz) processor with wide operating frequency ranges. While those components are available in most of the modern computers, they are hardly present in the miniaturized satellite applications, which are often controlled by low-speed (≤ 100 MHz) micro-controllers and having only a programmable clock generator to generate its system clock frequency. This research work aims to fill the gap between the research in the computer science field and the actual implementation in the miniaturized satellites. By introducing a simple and autonomous system clock frequency controller which only depend on a programmable system clock generator, this research work aims to extend the research on optimization of the high speed micro-processor’s power use to the low-speed micro-controllers, making it suitable for miniaturized satellite applications.