Projects:2021s1-13008 Design of Integrated Motor and Wheel for a Small Satellite Reaction Wheel

Project team

Project students

• Matthew Vianello (EEE)
• Matthew Tansell (EEE)
• Jamila Sabazova (ME)
• Jemma Andie Rose Twelftree (ME)

Supervisors

• Dr. Wen Soong
• Dr. Will Robertson
• Dr. Zebb Prime (Inovor Technologies)
• Dr. Amin Mahmoudi (Flinders University)

Abstract

Attitude Determination and Control System (ADCS) is the integrated closed loop system which allows a orbiting satellite to achieve real-time Satellite attitude determination and pointing control. There is a requirement for Satellites to have high accuracy Attitude determination and control for many of the payloads which are currently being deployed in these Satellites [2].

Cube Satellites are a miniaturized standard of satellite which was developed primarily for educational purposes. In recent years, the trend has shifted in the use of CubeSats from educational to more scientific and commercial type payloads. These payloads are demanding a higher degree of attitude accuracy than was previously required [2].

Commercial off the Shelf (COTS) components are commonly used in Cube Satellite systems [2]. Inovor technologies currently uses a Commercially available Brushless DC Motor (BLDC) for their Reaction Wheels. While the BLDC motor currently being used is high performing, it is a general purpose motor which ha\s not been optimized for Satellite Reaction Wheel applications. Additionally, the standard geometry of the motor stator places a restriction on the remaining Reaction Wheel design. There is currently a significant amount of retrofitting of the Reaction Wheel assembly required. This results in a less than optimized design.

There currently exists an opportunity to perform a ground-up design of a Reaction Wheel assembly and integrated motor for a Cube Satellite application. This design will have more design freedom and be able to be better integrated into Inovor Technologies ADCS module. Additionally, the design of integrated motor will be for the specific purpose of Satellite Reaction Wheel. A review of the existing research which relates to Cube Satellite Reaction Wheels and suitable motor types; the design of the integrated motor completed as part of this project will shift from using a BLDC motor to a Permanent Magnet Synchronous Motors (PMSM). The stator and rotor design of the motor will be performed concurrently with By researching optimal motor topologies, which will result in the required performance which is suitable for Satellite Attitude Control being defined, and collaborating with the Mechanical design to determine the suitable motor geometry; a Reaction Wheel design which improves not only on overall performance and reliability, but also better integrates into the Satellites ADCS is expected to be achieved.

Introduction

Reaction Wheels are a the preferred actuator of the ADCS as they, when compared to other types of ADCS actuators, can achieve higher pointing accuracy [2]. Reaction Wheels are integrated into a Satellite where they exploit the principal of momentum conservation to change a satellites pointing direction. The torque required to achieve this change in direction is obtained by accelerating or decelerating the speed of an electric motor [6]. The rotor shaft of the electric motor is fitted with a flywheel which increases the moment of inertia of the Reaction Wheel, and thus, increases the stored momentum.

Objectives

The objectives of the project are to design an integrated Reaction Wheel and electric motor. The performance needs to be optimized for the application of Cube Satellite Attitude Determination and Control System.

This is a multi-disciplined project, with both Mechanical Engineering and Electrical / Electronic Engineering students working collaboratively. The mechanical objectives for the project are to design an optimized Reaction Wheel given geometric constraints which will improve the performance and reliability of the existing Reaction Wheel currently being used. The electrical objectives are to research the optimal electric motor type and topology which is suitable for Satellite Reaction Wheel applications, and apply this topology into the design of a bespoke integrated motor for the Reaction Wheel.

Motor design and performance simulation and testing are all stated objectives of this project.

References

[1] R. V. Zuliana Ismail*, “A Study of Reaction Wheel Configurations for a 3-axis Satellite Attitude Control,” Advances in Space Research, vol. 45, pp. 750-759, 2009.

[2] D. K. Daniel Selva, “A survey and Assessment of the capabilities of Cubesats for Earth observation,” Acta Astronautica, vol. 74, pp. 50-68, 2012.

[3] R. S. Espen Oland, “Reaction Wheel Design for Cubesats,” in 4th International Conference on Recent Advances in Space Technologies, 2009.

[4] J. B. M. Pastena, “ADCS Subsystem for CubeSat: 3-axis high precision control in less than 0.5U,” in 1st IAA COngerence onUniversity Satellite MIssions, 2011.

[5] R. S. Espen Oland, “Reaction Wheel Design for CubeSats,” in 4th International Conference on Recent Advances in Space Technologies, Istanbul, Turkey, 2009.

[6] M. G. Sumitra. K, “Torque Ripple Minimization in Reaction Wheels Used in Satellites - A Comparison between Field Oriented Contol of BLDCM and PMCM Using SVPWM,” Internation Journal of Science and Research, vol. 4, no. 11, 2015.

[7] M. L. F. P. A. T. Andrea Cavagnino, “A Comparion Between the Axial Flux and the Radial Flux Structures for PM Synchronous Motors,” IEEE Transactions on aerospace and electronic systems, vol. 50(2), pp. 1359-1373, 2014.