3-HSS型并聯(lián)機床靜剛度預估及動力學建模方法研究.pdf

1、天津大學博士學位論文3HSS型并聯(lián)機床靜剛度預估及動力學建模方法研究姓名：趙興玉申請學位級別：博士專業(yè)：機械制造及其自動化指導教師：黃田2001.1.1AbstractWiththeaidofthefiniteelementmethodmodalsynthesisandmultirigidbodydynamicsthisdissertationdealswiththekeyissuesrelevanttothestaticstifnes

2、spredictiondynamicmodelingandanalysisanddimensionalsynthesisandthedeterminationofservomotorparametersofatripodbasedparallelkinematicmachine.Thefollowingcreativeworkhasbeencompleted口^ccordingtotheconceptofGIE(GeneralInert

3、ialEllipse)thedynamicconditionnumberisdefinedandadynamicdimensionalsynthesismethodisproposed.Itisprovedthatthedimensionalparametersachievedbydynamicdimensionalsynthesisisidenticaltothosebythekinematicsynthesisforthesameo

4、bjectivefunction.口Acomprehensivemethodologyispresentedthatenablestheservomotorparametersofparallelkinematicmachinestobedeterminedaccordingtothedesignspecificationsintermsofthecuttingloadfastfeedingandacceleratingcapabili

5、ties.Duetothecharacteristicsoftheparallelformatthesingularvaluedecompositiontechniqueisemployedtodeterminethelowerandupperboundsoftheservomotorparameterssuchastheratedspeedandtorque.Anapproachisalsodevelopedtodetermineth

6、emaximumequivalentmomentofinertiaoftheplatformandstrutsonaservoaxiswhichthereforeallowstheacceleratingcapabilityoftheservosystemtobeexaminedintermsofthemaximumtorquerequired.口Asimpleyetcomprehensiveapproachispresentedtha

7、tenablesthestiffnessofatripodbasedparallelkinematicmachinetobequicklyestimated.Theapproachcanbeimplementedbytwosteps.Inthefirststepthemachinestructureisdecomposedintotwosubstructuresassociatedwiththemachineframeandthepar

8、allelmechanism.Thestifnessmodelofeachsubstructureisformulatedbyassumingthatthecomponentsintheotherarerigid.Thisisfollowedbythesecondstepthatenablesthestifnessmodelofthemachinestructuretobeachievedbylinearsuperposition.3D

9、representationsofthemachinestifnesswithintheusableworkspacearepredicted.Thestifnessmodelformulatedissosimplethatitcanbeeasilyintegratedintotheoptimizationcycleintheconceptualdesignorusedtoaccessanexistingstructure.口Themo

10、dalsynthesis(CMS)techniqueisusedforthedynamicmodelingofthefeedtransmissionsystem.Thesystemasawholeisdividedintoseveralsubstructuresandtheequationofthemotionisderivedaccordingtotheboundaryconstraints.Themethodenjoystheadv

11、antagesofsimplicityandhighefficiencywhichtherebycanbeusedtoinvestigatetheinfluencesofthegeometricalparametersonthelowordermodes.口Consideringthedynamiccharacteristicsofthemachineframethefreeinterfacemodesynthesismethodisu

12、sedforthedynamicmodelingoftheprototypemachine.Themachinetoolisdividedintoseveralsubstructuressuchasframestrutsandplatform.Thefiniteelementmethodisusedtomodelthesubstructuresandtheequationsofmotionareformulatedusingthefre