Robotics

A,tomauca, Vol. ¡7, No. pr, 5569, ¡911 Prinled in Crea, Btiiain
¡X)O5-IIWI/8l/OlO4]55A 5 502.tiWO l’ergamon Prrss Ltd.
4 ¡991 Inianaiiottal rederntion of Automaiic Control
Non-ParametricMethods of
System Identification
PETER E WELLSTEADt


The non—parantetrit met/tods oJ specrral and impulse response es! ünat fon allow the nature of dato a~uI underlying systems te be exposed ¡ti agro phw ¿md ¡nformative man ner.

he, Word mdcx Idcntiflcatic,n freqtiency response: impulse responso; spectlaI anaíysis.


A~rcF—The non-parametric denlií’tcation of systems o tcnus ofunparametrized rcprescntations such as 11w impulso rtspotlse and freqttoncy resç~ot1sc is considered. H:is~c approache9 are ootlined o a retrospectivo setting as :1ro ¡he rdationships betweeti nr~n-part.metricand paruirtetric idetttirication modets. Thc ¡inicie concludes wil It
asCsstnelil of nrnrna ¡‘a mcl nc mcl lt*is wlr cli is condttcl ccl ii temis of typical industrial applic:ttions.INVRODtJCTION

lIJE MM of ¡bis paper is te takc a serni-nistorical look at ene particular aspect of system identification. and te assess its uses hy way of practical applications. ¡n this scnse the intcnuionis ¡o present a ttmtorial exposition coloured fol by theoretical ami algorithrnic resuIt btu by applied practical experience. For a complemetitary appraisal of llieorctical restilts sec Ljtrng andGlover has been paralleled ja other arcas, mes! notably scismtc exploradon and speech processing (Wakila, 1972; Kanasewich. 19751.
The possihle darnage inflicted by direct use of an impulsive testsignal on conirol system hardware and ¡lic presencc of otilput anise has lcd lo a decline in lis use. Tlie eontrary is truc in seismic, biological and biomcdical wnrk whcre impulse-like test sigrtals areoRen the most practicable forms. Thc currently acceptcd approach la cciii rol systems work is, of coursc. bbc implicit impulse response test method via 11w correlation equation (equation la). To be...