耳介を持つバイノーラル聴覚ロボットの音源方向推定の検討 - 奥乃研究室

On sound direction estimation by binaural auditory robots with pinnae, Makoto KUMON and Daisuke KIMOTOKumamoto Universitykumon@gpo.kumamoto-u.ac.jpAbstractBinaural auditory systems which use two microphonesto percieve auditory signals are consideredas the minimal configuration for practicalsound localization since animals are ableto achieve this ability only with their two ears.Interaural Time Difference(ITD) of two signalsmeasured by two ears can be used to estimatethe direction of the sound source in the planewhere two ears locate. However, the deviationperpendicular to the plane does not make anydifference in ITD, which implies additional featuresbut ITD are necessary to estimate thedirection of the sound source. It is knownthat human and animals with two ears utilizetheir pinnae, or external ears, to localize soundsources since irregular shapes of pinnae encodethe direction of the sound source as frequencydomain cues.Because the relationship between the angle andthe cue is complicated, this paper considers themethod to extract such frequecy cues preciselyby introducing a linear transformation of thecue space. In order to validate the proposedapproach, experiments with a real binaural auditoryrobot with a pinna were conducted, andresults show the improvement of the obtainedestimates.1 , , [,2001]. , , . , 2, , . 2 , , . , 2 ., MUSIC[Shimidt, 1986][, 2010]. , , , (). , () , 2 , , ., . ,. , [Shaw, 1968]., . , ,Shimoda [Shimoda, 2006], . , Hörnstein [Hornstein, 2006], . Finger [Finger,2010], , .

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3.2 , , .3.2.1 θ, φ , X d (θ, φ) . θ 1 , · · · , θ Nθ , φ 1 , · · · , φ Nφ ,N θ × N φ , ., , X . , , X . , .S(X, X d ) = < X, X d > M|X||X d |(1), S X θ, φ , S(X) = S(X, θ, φ) .3.2.2 S , . , (N F ) S ( S 1 · · · S N F) , ∏{¯S(θ, φ) = α S k ((θ, φ) − min S k (ξ, η) )}ξ,ηk=1,···N F, . , α ∑¯S(θ, φ) = 1θ,φ. , S , . , N F S ., ¯S , . , . , , . , , . , E µ Σ .E =∑∣ ∣ ¯S(X, θ, φ) − ρp(θ, φ, µ, Σ) 2θ 1 , · · · , θ Nθφ 1 , · · · , φ Nφ(2), p(θ, φ, µ, Σ) µ, Σ , ρ ¯S .3.2.3 [, 2008] , , , S () ., x 1 , · · · x m , M . ( n m ) A ,A = [x 1 , x 2 , · · · , x m ]x i = A [0, 0, · · · , 1, · · · , 0] T. A A † ≡ A † = A T (AA T ) −1 A † x i = [0, 0, · · · , 1, · · · , 0] T, M A † , j 1 y j,< x i , y j > M = δ ij, ., , , . , . , , , , ([, 2008]) .4 4.1 , 2 . θ, φ 180 10 , 90 10 ,

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, (d) (e) ., , . , , , . (a) 0(deg) -30(deg) (c) 0(deg) 30(deg) (b) 0(deg) 0(deg) (d) 0(deg) -30(deg) (e) 0(deg) (f) 0(deg) 0(deg)30(deg)Figure 4: () 5 . , , . , , . (2) , S 1, 2 . , E ¯S φ, θ , Mathworks MATLAB (fminsearch) . ¯S N F 10 20 , S . 1 , N F = 20 , (a) 0(deg) -45(deg) (c) 0(deg) 45(deg) (e) 45(deg) 0(deg) (b) 45(deg) 0(deg) (d) 0(deg) -45(deg) (f) 0(deg) 45(deg)Figure 5: (), 5 . , , . 2 , () , , ., , .5 , ,, [, 2008]. , ,

(,)(0 ◦ , −30 ◦ )(0 ◦ , 0 ◦ )(0 ◦ , 30 ◦ )(0 ⋆ , −45 ⋆ )(45 ◦ , 0 ◦ )(0 ◦ , 45 ◦ )Table 1: ()N F = 10 N F = 20, , ( (-2.1,-30.9) ) ( (0.0,-30.0) )29.9 13.2 0.0189 0.0077⋆ 31.82⋆ 0.0128( (-0.5,0.0) ) ( (0.0,0.0) )14.2 0.0013 0.0243 0.000⋆ 0.319⋆ 0.000( (-2.0,30.3) ) ( (0.0,30.0) )35.3 −8.38 0.198 −0.0047⋆ 19.0⋆ 0.0067((-29.6,-90.8)) ( (0.0,-50.1) )340 46411.9 18.2⋆ 962⋆ 31.7( (49.5,-0.2) ) ( (50.0,0.0) )24.5 10.60.315 0.184⋆ 46.0⋆ 0.374( (-4.0,42.0) ) ( (0.0,40.0) )35.2 −17.9 0.0887 0.0309⋆ 54.9⋆ 0.0907(,)(0 ◦ , −30 ◦ )(0 ◦ , 0 ◦ )(0 ◦ , 30 ◦ )(0 ⋆ , −45 ⋆ )(45 ◦ , 0 ◦ )(0 ◦ , 45 ◦ )Table 2: ()N F = 10 N F = 20, , ( (-16.6,-32.7) ) ( (-28.6,-25.5) )816 −143 719 −152⋆ 418⋆ 241( (-41.1,29.7) ) ( (-10.1,8.7) )687 −521 104 −85.5⋆ 1060⋆ 161( (-23.9,27.5) ) ( (0.8,30.0) )722 70.1126 5.11⋆ 121⋆ 6.09( (30.3,-53.5) ) ( (3.6,-46.9) )799 −121 752 −108⋆ 416⋆ 283( (46.1,0.5) ) ( (47.0,0.0) )39.8 −2.13 24.2 −0.636⋆ 23.0⋆ 2.66( (-5.8,44.1) ) ( (-3.9,47.2) )797 33.9531 20.9⋆ 149⋆ 49.5. , , [, 2008], ., , . ,2 , , .[, 2001] , ,, pp.69–74,2001.[Shimidt, 1986] Schmidt, R.O.: Multiple Emitter Locationand Signal Parameter Estimation, in IEEETrans. Antennas Propagation, Vol. AP-34 pp.276-280, 1986.[, 2010] , , S. Thompson, , : 64ch , SIG-Challenge , pp.3-8, 2010[Shaw, 1968] Shaw, E. A., and Teranishi, R.: Soundpressure generated in an external-ear replica andreal human ears by a nearby point source, Journal ofthe Acoustical Society of America, Vol 44-1, pp.240-249, 1968[Shimoda, 2006] T. Shimoda, T. Nakashima, M. Kumon,R. Kohzawa, I. Mizumoto and Z. Iwai: SpectralCues for Robust Sound Localization with Pinnae,in Proceedings of the 2006 IEEE/RSJ InternationalConference on Intelligent Robots and Systems,pp.386–391, 2006[Hornstein, 2006] Hörnstein, J., Lopes, M., Santos-Victor, J. and Lacerda, F.: Sound Localizationfor Humanoid Robots - Building Audio-Motor Mapsbased on the HRTF, in Proceedings of the 2006IEEE/RSJ International Conference on IntelligentRobots and Systems, pp.1170–1176, 2006.[Finger, 2010] Finger, H., Ruvolo, P., Liu, S.C., Movellan,J.:Approaches and Databases for Online Calibrationof Binaural Sound Localization for RoboticHeads, Proceedings of 2010 IEEE/RSJ InternationalConference on Intelligent Robots and Systems,pp.4340-4345, 2010.[, 2008] :, C , Vol.74-739, pp.642–649, 2008