Overview of our laboratory

Space systet can be achieved only by small satellites.

To take advantage of small sized space systems, these systems should acquire unique abilities by focusing on phenomena which are more effective for smaller satellites. Additional advantages can be gained by the additional use of various resources and other things found in its orbital environment. Our research group recognizes that a smaller sized satellite is more affected by its environment. Additionally, it considers the use of these environments, to achieve higher performance with smaller system resources to be useful. Furthermore, space applications with these high performance bus systems are studied, by taking advantage of the unique abilities of these small spacecraft.

Attitude control maneuver using interplanetary magnetic field

Attitude orbit and control system by the use of space environment.
In our research, we continue to expand the abilities and applications of small spacecraft, while considering the space environments that more easily affect smaller sized spacecraft, specifically environmental outer magnetic fields and space plasma. We focus on attitude and orbit determination and control for small spacecraft to expand the abilities and applications. Except for attitude orbit control systems, our interest lies on C&DH, thermal, communication, space system designs, and their applications. We also try to find chances for in-orbit demonstrations for the benefit of proposing space systems.

1. Research topics

Space systems

Magnetic docking system

Making application of multiple small sized satellite easier　

In recent year, docking of satellite has been pointed out as an important technology in using multiple small satellite as one system. In order to allow small sized satellite which heavy weight and space restriction to perform docking, we are study the use of simple magnets or magnetized objects to see whether if guiding, keeping combination and separation can be perform using only one component. We hope to make mission with multiple spacecraft easier to accomplished.

Efficient remote sensing through autonomous image recognition　

Satellite remote sensing is widely used for various purposes such as land management, forest management, water resource management, and food security. In such a situation, efficient remote sensing for obtaining information over large areas while avoiding obstacles like clouds are necessary. This research aims to achieve efficient remote sensing through autonomous image recognition, recognizing the clouds. For cloud detection, this research utilizes a Convolutional Neural Network (CNN) to detect clouds that hinder observation, instead of directly detecting the observation targets. This approach helps reduce the algorithm's complexity, making it feasible to implement on satellite onboard computers with limited processing capabilities. The information of the cloud detection results are used for attitude control by applying the magnetic moment generated by a magnetic actuator in the geomagnetic field. The algorithm was implemented on a small satellite, and preparations for in-orbit demonstration. This research was supported by the Japan Keirin Autorace foundation (JKA) in the fiscal year 2022.

A novel attitude control method for space membrane using space environmental force

Space membrane deployment/attitude control using electromagnetic force　

We are researching for a novel method to deploy/attitude control space membrane using electromagnetic force. In our proposed method, first, copper film is placed on membrane. Then, using hoop stress and Lorentz force generated from interaction with magnetic field in space environment, deployment and attitude control of membrane is performed. By changing the current flow in copper film, deployment force and control force strength can be changed. Currently, we are researching to see whether if this method allow easier control of the vibration during deployment or restoring of membrane as well as whether if it can be used as fuel free attitude changing method.

Attitude control of Spacecraft

Attitude control maneuver using interplanetary magnetic field

In recent year, the use of smaller space probe has been proposed and researched on. In our research, we study methods to perform attitude and/or angular momentum control using interplanetary magnetic field and its interaction with magnetic moment of space probe.

Magnetic torque born from shape anisotropy

To make clear the magnetic forces acting on small-sized satellite　

In the case of small-sized satellite, which has small moment of inertial, magnetic torques and various other environmental torques can have heavy effect on its attitude dynamics. In this research, we focus on the magnetic torque born from the shape anisotropy of magnetic moment of components within small-sized satellite. This torque is generated from the interaction of geomagnetic field and magnetic moment which get larger the more asymmetric these components are. Just like magnetic torque generated by remnant magnetic moment, which has been deeply researched, we found that magnetic torque generated from shape anisotropy of magnetic moment of component is also large and can heavily effect the accuracy of attitude control. By making clear how magnetic torque generated from shape anisotropy, we hope to increase the accuracy of attitude determination and control.

Orbit control of Spacecraft

Deorbit using magnetic plasma

Applying magnetic torquer of attitude control system into orbit control　

In order to reduce the increasing amount of space debris, an international rule where every satellite must deorbit (return to earth’s atmosphere) within 25 years after the end of the missions has been made. Even small-sized satellites, which has been increasing in demand in the recent years, are also not exempted from this rule. However, due to their heavy restriction in size, weight and power consumption, small-sized satellites is incapable of performing orbit control, making it a problem for them to obey the 25 years deorbit rule. In order to overcome this problem, a method that make used of the components that are already loaded within the satellite, “Magnetic plasma deorbit by using magnetic torquer of attitude control system” was proposed. In this method, drag force is generated by using the interaction between magnetic torquer, which is commonly used in small-sized satellites attitude control, and space plasma, which exists at low earth orbit. In this research, we study on how much this magnetic plasma deorbit method can change the small-sized satellite orbit and whether if we can reduce the deorbiting time if the output of magnetic torquer is controlled. Furthermore, research is also being done to see if this method is applicable to perform and maintain formation fly of small-sized satellite.

2. CanSat

As a preliminary practice for actual satellite development, we develop a can-size imitation (Cansat) that contains basic functions of actual satellite. In 2018, in relation to one of our research topics “attitude control of space membrane using electromagnetic force”, we developed and launched a Cansat that has membrane’s deployment structure as well as a circuit that allows large electric current flow on top of the satellite’s membrane. The developed Cansat was launched at ARLISS, an annual event at Black Rock desert in Nevada State, America where many teams around the world gather together and launch their Cansat.

3. Publications

2022

International conferences

2021

Journal papers

International conferences

2020

Journal papers

International conferences

2019

Journal papers

International conferences

2018

Journal papers

International conferences

2017

Journal papers

International conferences

2016

Journal papers

International conferences