Robot Swarms for Planetary Exploration

The exciting possibility of water, raw materials, and even life on other planets and satellites in our solar system will require the development of mechanisms for low-cost, fault-tolerant exploration of these bodies. One approach to the development of these mechanisms is the use of a large number of small, inexpensive robots acting cooperatively as a swarm of insects might in foraging for food. This paper examines some of the issues involved in using "swarms" of small, inexpensive, insect-like robots for planetary exploration. Specifically, this paper discusses ongoing work with robots like Jonathan Mills' Stiquito or Lego platforms used to investigate swarm behaviors for the purpose of planetary exploration. This paper addresses investigations into methods of locomotion, comparing the advantages of legs, wheels, and tracks for robots operating in a variety of hostile environments. Next, the advantages and disadvantages of two types of swarm control are discussed: centralized control using a "queen" to control the swarm and decentralized control using identical, completely autonomous robots acting in concert. Some possible methods of collecting data and returning it to investigators on Earth are also discussed. Simulation results for the various control strategies are presented, as are experimental results, where they have been completed. Since this is ongoing research, this paper concludes with a discussion of topics requiring further research.