PRE2024 3 Group13

Ideas

1. we can also use swarm behavior of ants, krill, termite, locusts, bees.
2. maybe we can distinguish between a few mother robots that controls the other robots, like in a ant nest: Queen, worker, male (to fertilize the queen), Warriors .etc

Users: Space Agencies (ESA, NASA, etc.)

Group members

Name	Student ID	Email address
Bas Coppus	1706160	b.coppus@student.tue.nl
Mikolaj Pujanek	1732595	m.p.pujanek@student.tue.nl
Maksim Fisekovic	1889524	m.fisekovic@student.tue.nl
Ingmar Verweij	1629433	i.verweij@student.tue.nl
Thomas Passon	1890190	t.passon@student.tue.nl

Introduction

Type an introduction

Who does what

Bas: transporting Helium back to Earth

Mikolaj: bringing Helium to refinery/mass driver

Maksim: control of the swarm

Ingmar: locating Helium

Thomas: mining Helium

Literature review

Massdrivers

The paper: "Lunar based massdriver applications" describes that there are two types of mass drivers a Gauss or a coilgun and a Lorentz Rail Accelerator (LRA). Due to the simplistic design of the components and the developed railgun technology, the work in this paper will be considered with the LRA.

The LRA needs to be powered and the best way to do do this is by making PV-panels out of the minerals of the moon, which has an efficiency of 16%. These solar-panels do not track the sun, because they are robust and low in maintenance. This means that only 40% of the lunar revolution (27.3 Earth days) the massdriver can not operate.

A small vehicle is used to load the massdriver. This reduces the retention time within the first acceleration modules. A vehicle with a load is sliding down a ramp in which the barrel of the LRA is at equal height of the payload such that the vehicle and load can detach with each other. In this case a velocity of 1 m/s is used. This way of loading or injecting is needed, otherwise the heat load and friction would damage the modules of the payload. To monitor the launch, a control center is needed with a sufficient height to oversee the launching and if needed breakoff the launch. This breakoff can be done by extending the barrel and do the reverse of the injection process.

The best way to build the massdriver is to use the minerals of the moon. The rails will be made by aluminum due to the higher conductivity per kilogram ratio as copper for example. Oxygen is a by product from a lot of refining metals.

The velocity of the payload increases the barrel quadratically but the acceleration decreases the barrel linearly. So the launch velocity has to be minimized to keep the total acceleration short. A maximum acceleration of 20g is permitted for comparable payload launches at Earth. The payload can directly shoot to Earth via elliptic trajectories. These shots are called Earthshots. The most efficient launch opportunity is at the lunar apogee, but only once shot per lunar orbit can be achieved. So, for frequent launches, an optimized sit is chosen between the perigee and mean lunar distance for balancing energy efficiency and launch frequency. This is feasible when the launch velocity is between 2.1-2.5 km/s and the barrel is between 15-16km long. The best position is at Oceanus Procellarum; Encke and kapler craters and Reiner-Gamma lunar swirl.

For large scale projects, a mass of 10 metric tons of payload is needed. This can not be launched in one shot due to technical limitations(the rails would melt due to the high currents). So a stacking concept of multiple LRA's are used. The simplest way is stacking in the width. The gap width between the rails is 200mm, with this geometry, the highest force density can be achieved. To shot the a payload of 10 ton with 20g a current of 560kA is needed and a launch time of 12.5 s can be achieved. The acceleration modules have a length of 1 m, so only the first module has a heating load of 1 s, which will be designed to cope with this. If the massdriver operates continuously, a power of 8.63 GW is needed.

It is also possible to shot these payloads into the lunar orbit for constructing space stations or space crafts. With precise calculation, ships can gather these payloads. These payloads can also be gathered by guiding systems inside the payload.

Mikolaj:

Maksim: [1] https://arxiv.org/pdf/2011.07759, [2] https://cris.vtt.fi/ws/portalfiles/portal/52430289/2021.Saffre.HCII2021_submitted.pdf, [3] https://www.researchgate.net/publication/262935843_Robot_Swarms_Dynamics_and_Control, [4] https://sylvesterkaczmarek.com/blog/robotic-swarm-intelligence-for-lunar-exploration/, [5] https://link.springer.com/article/10.1007/s10569-009-9183-8

Quick summary of each article: [1]: This article describes a build idea for a robot swarm that would be operational on Mars. This robot swarm would consist of robots of constant speed, operated through an autonomous control principle. By making use of the CACER-II algorithm for pathfinding, as well as layered information maps for gathering data. [2] This article describes the difference between direct and indirect control, and looks at several possible control scheme implementations. [3] This chapter from a book goes into depth about the behaviour of swarms and how that can be translated into control schemes for swarm robotics. The book offers information about swarm robotics as a whole, instead of focusing only on space applications. [4] This blog is an extremely well-written summary on existing swarm robotics and goes into depth on exactly swarm robotics in space. A myriad of examples on swarm robotics in space are given, as well as shown in several YouTube videos. While not describing swarm control in great detail, this blog gives many practical examples and implementations of swarms in space, which could form the basis for our control system. [5] This article explains the rules necessary for controlling spacecraft swarms. This is slightly different than our desired project, as this article mainly mentions satellites and swarms travelling through space. However, the rules about swarm control should be applicable to most control systems.

What is the best way to design the swarm control? It is hard to tell, however, using autonomous or semi-autonomous control seems necessary. It is borderline impossible for humans to remotely control the swarm from earth. An information map could be implemented to avoid obstacles and perceive the environment. The robot design meant for Mars uses the CACER - II algorithm for pathfinding. Something perhaps more achievable is a semi-autonomous system for multiple robots as presented in [2]. In this system, the robots are hardcoded to act based on a set of rules, depending on the position of the so called leader robot. This leader robot is remotely controlled by humans. This implementation seems feasible, as article [4] claims that a study has been conducted on swarm navigation on planets, where researchers propose communication between units through time-division multiple access (TDMA), which would enable all units to constantly be aware of the position of the other units.

Ingmar: [1] http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2175.pdf [2] https://doi.org/10.1016%2Fj.icarus.2009.12.032 [3] https://doi.org/10.1007/s11434-010-4198-9 [4] https://doi.org/10.1007/s11433-011-4561-0 [5] https://doi.org/10.1006/icar.2000.6545 [6] https://doi.org/10.1016/j.icarus.2009.11.034 [7] https://doi.org/10.1006/icar.2000.6545

Summary: From [1] it was found that He-3 is implanted into the lunar surface by the solar wind. The problem is not the implantation, however, but the retention of the He-3 within the lunar surface. The retention of He-3 depends on the grain size of the lunar regolith [1] (<50 micron seems to hold the most helium-3), the electroconductivity of the lunar regolith (TiO2 was mentioned)[3] and it also seems to depend on the solar exposure [2], meaning less sunlight is better able to retain the He-3. This would mean that craters at the lunar poles seem to be the best option [2]. The Chang-E-1 mission was able to measure the thickness of the regolith layer by measuring the thermal radiation of the lunar regolith [4][5][6] (I don't fully understand this yet). Another method was found in [7] by using radar waves (at 70cm) and measuring the thickness by using scattering from the underlying substrate.

Thomas:

Individual effort

Week 1

Name	Total time	Progress and time
Bas Coppus	4h	Making small basic sections in the wiki page and trying to understand how to edit the page works (1h). Finding a subject to research and how to implement this research into a program, prototype or a literature research and finding some papers (2h) . Meeting at 12-02-2025 (1h), Summarizing paper [1] (2h), finding 5 papers (1h),
Mikolaj Pujanek
Maksim Fisekovic
Ingmar Verweij		Find a research subject (1h), Wednesday meeting (1hr), Literature review (4hrs)
Thomas Passon

Week 2

Name	Total time	Progress and time
Bas Coppus
Mikolaj Pujanek
Maksim Fisekovic
Ingmar Verweij
Thomas Passon

Week 3

Name	Total time	Progress and time
Bas Coppus
Mikolaj Pujanek
Maksim Fisekovic
Ingmar Verweij
Thomas Passon

Week 4

Name	Total time	Progress and time
Bas Coppus
Mikolaj Pujanek
Maksim Fisekovic
Ingmar Verweij
Thomas Passon

Week 5

Name	Total time	Progress and time
Bas Coppus
Mikolaj Pujanek
Maksim Fisekovic
Ingmar Verweij
Thomas Passon

Week 6

Name	Total time	Progress and time
Bas Coppus
Mikolaj Pujanek
Maksim Fisekovic
Ingmar Verweij
Thomas Passon

Week 7

Name	Total time	Progress and time
Bas Coppus
Mikolaj Pujanek
Maksim Fisekovic
Ingmar Verweij
Thomas Passon