Abstract
We investigate swarms of autonomous mobile robots in the Euclidean plane. Each robot has a target function to determine a destination point from the robots’ positions. All robots in a swarm conventionally take the same target function. We allow the robots in a swarm to take different target functions, and investigate the effects of the number of distinct target functions on the problem-solving ability. Specifically, we are interested in how many distinct target functions are necessary and sufficient to solve some well-known problems which are not solvable when all robots take the same target function, regarding target function as a resource, like time and message, to solve a problem. The number of distinct target functions necessary and sufficient to solve a problem \(\varPi \) is called the minimum algorithm size (MAS) for \(\varPi \). (The MAS is \(\infty \), if \(\varPi \) is not solvable even for the robots with unique target functions.) We establish the MASs for solving the gathering and related problems from any initial configuration, i.e., in a self-stabilizing manner. Our results include: There is a family of the scattering problems cSCT \((1 \le c \le n)\) such that the MAS for the cSCAT is c, where n is the size of the swarm. The MAS for the gathering problem is 2. It is 3, for the problem of gathering all non-faulty robots at a single point, regardless of the number \((< n)\) of crash failures. It is however \(\infty \), for the problem of gathering all robots at a single point, in the presence of at most one crash failure.
Due to space limitation, some proofs and contributions are deferred to full version [7].
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Notes
- 1.
Here, we abuse a term “algorithm.” Despite that an algorithm must have a finite description conventionally, a target function (and hence a set of target functions) may not, as defined in Sect. 2. To compensate the abuse, when we will show the existence of an algorithm, we insist on giving a finite procedure to compute it.
- 2.
We say that one object is similar to another, if the latter is obtained from the former by a combination of scaling, translation, and rotation (but not by a reflection).
- 3.
Since \(Z_i\) is self-centric, \((0,0) \not \in P\) means an error of eye sensor, which we assume will not occur.
- 4.
We use the same notation < to denote the lexicographic order on \(R^2\) and the order on R to save the number of notations.
- 5.
We assume \(\boldsymbol{p}_0 = \boldsymbol{q}_0\).
- 6.
Since \(dist(\boldsymbol{o}_P, \boldsymbol{o}_P) = 0\), \(V_P({\boldsymbol{q}})\) is not compared with \(V_P(\boldsymbol{o}_P)\) with respect to \(\sqsupset \).
- 7.
Note that Z is uniquely determined, and the unit distance of Z is \(dist(\boldsymbol{p}_1,\boldsymbol{p}_3)/31\).
References
Agmon, N., Peleg, D.: Fault-tolerant gathering algorithms for autonomous mobile robots. In: 15th Annual ACM-SIAM Symposium on Discrete Algorithms, pp. 1063–1071(2004)
Altisen, K., Datta, A.K., Devismes, S., Durand, A., Larmore, L.L.: Election in unidirectional rings with homonyms. J. Parallel Distrib. Comput. 146, 79–95 (2010)
Ando, H., Oasa, Y., Suzuki, I., Yamashita, M.: A distributed memoryless point convergence algorithm for mobile robots with limited visibility. IEEE Trans. Robot. Autom. 15, 818–828 (1999)
Angluin, D.: Local and global properties in networks of processors. In: 12th ACM Symposium on Theory of Computing, pp. 82–93 (1980)
Arévalo, S., Anta, A.F., Imbs, D., Jiménez, E., Raynal, M.: Failure detectors in homonymous distributed systems (with an application to consensus). J. Parallel Distrib. Comput. 83, 83–95 (2015)
Asahiro, Y., Yamashita, M.: Compatibility of convergence algorithms for autonomous mobile robots. In: Rajsbaum, S., Balliu, A., Daymude, J.J., Olivetti, D. (eds.) Structural Information and Communication Complexity. SIROCCO 2023. LNCS, vol. 13892, pp. 149–164. Springer, Cham (2023). https://doi.org/10.1007/978-3-031-32733-9_8
Asahiro, Y., Yamashita, M.: Minimum algorithm sizes for self-stabilizing gathering and related problems of autonomous mobile robots. arXiv: 2304.02212
Attiya, H., Snir, M., Warmuth, M.K.: Computing on the anonymous ring. J. ACM 35(4), 845–875 (1988)
Bouzid, Z., Das, S., Tixeuil, S.: Gathering of mobile robots tolerating multiple crash faults. In: IEEE 33rd International Conference on Distributed Computing Systems, pp. 337–346 (2013)
Cieliebak, M., Flocchini, P., Prencipe, G., Santoro, N.: Distributed computing by mobile robots: gathering. SIAM J. Comput. 41, 829–879 (2012)
Cord-Landwehr, A., et al.: A new approach for analyzing convergence algorithms for mobile robots. In: Aceto, L., Henzinger, M., Sgall, J. (eds.) ICALP 2011. LNCS, vol. 6756, pp. 650–661. Springer, Heidelberg (2011). https://doi.org/10.1007/978-3-642-22012-8_52
Das, S., Flocchini, P., Santoro, N., Yamashita, M.: Forming sequences of geometric patterns with oblivious mobile robots. Distrib. Comput. 28, 131–145 (2015)
Delporte-Gallet, C., Fauconnier, H., Guerraoui, R., Kermarrec, A., Ruppert, E., Tran-The, H.: Byzantine agreement with homonyms. Distrib. Comput. 26, 321–340 (2013)
Delporte-Gallet, C., Fauconnier, H., Tran-The, H.: Leader election in rings with homonyms. In: Noubir, G., Raynal, M. (eds.) NETYS 2014. LNCS, vol. 8593, pp. 9–24. Springer, Cham (2014). https://doi.org/10.1007/978-3-319-09581-3_2
Dieudonné, Y., Petit, F.: Scatter of weak mobile robots. Parallel Process. Lett. 19(1), 175–184 (2009)
Dieudonné, Y., Petit, F.: Self-stabilizing gathering with strong multiplicity detection. Theor. Comput. Sci. 428, 47–57 (2012)
Dobrev, S., Pelc, A.: Leader election in rings with nonunique labels. Fund. Inform. 59(4), 333–347 (2004)
Flocchini, P.: Gathering. In: Flocchini, P., Prencipe, G., Santoro, N. (eds.) Distributed Computing by Mobile Entities. Lecture Notes in Computer Science, vol. 11340, pp. 63–82. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-11072-7_4
Liu, Z., Yamauchi, Y., Kijima, S., Yamashita, M.: Team assembling problem for asynchronous heterogeneous mobile robots. Theor. Comput. Sci. 721, 27–41 (2018)
Matias, Y., Afek, Y.: Simple and efficient election algorithms for anonymous networks. In: Bermond, J.-C., Raynal, M. (eds.) WDAG 1989. LNCS, vol. 392, pp. 183–194. Springer, Heidelberg (1989). https://doi.org/10.1007/3-540-51687-5_42
Prencipe, G.: Pattern formation. In: Flocchini, P., Prencipe, G., Santoro, N. (eds.) Distributed Computing by Mobile Entities. LNCS, vol. 11340, pp. 37–62. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-11072-7_3
Suzuki, I., Yamashita, M.: Distributed anonymous mobile robots - formation and agreement problems. SIAM J. Comput. 28, 1347–1363 (1999)
Yamashita, M., Kameda, T.: Computing on an anonymous network. In: 7th ACM Symposium on Principles of Distributed Computing, pp. 117–130(1988)
Yamashita, M., Kameda, T.: Electing a leader when processor identity numbers are not distinct (extended abstract). In: Bermond, J.-C., Raynal, M. (eds.) WDAG 1989. LNCS, vol. 392, pp. 303–314. Springer, Heidelberg (1989). https://doi.org/10.1007/3-540-51687-5_52
Yamashita, M., Kameda, T.: Leader election problem on networks in which processor identity numbers are not distinct. IEEE Trans. Parallel Distrib. Syst. 10(9), 878–887 (1999)
Yamashita, M., Suzuki, I.: Characterizing geometric patterns formable by oblivious anonymous mobile robots. Theor. Comput. Sci. 411, 2433–2453 (2010)
Yamauchi, Y., Uehara, T., Kijima, S., Yamashita, M.: Plane formation by synchronous mobile robots in the three-dimensional Euclidean space. J. ACM 64, 1–43 (2017)
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This work is supported in part by JSPS KAKENHI Grant Numbers JP17K00024 and JP22K11915.
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Asahiro, Y., Yamashita, M. (2023). Minimum Algorithm Sizes for Self-stabilizing Gathering and Related Problems of Autonomous Mobile Robots (Extended Abstract). In: Dolev, S., Schieber, B. (eds) Stabilization, Safety, and Security of Distributed Systems. SSS 2023. Lecture Notes in Computer Science, vol 14310. Springer, Cham. https://doi.org/10.1007/978-3-031-44274-2_23
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