振动与冲击
振動與遲擊
진동여충격
JOURNAL OF VIBRATION AND SHOCK
2014年
10期
43-49
,共7页
间隙%减振平台%连续接触模型%动力学%达朗贝尔原理
間隙%減振平檯%連續接觸模型%動力學%達朗貝爾原理
간극%감진평태%련속접촉모형%동역학%체랑패이원리
clearance%vibration reduction platform%continuous contact model%dynamics%d'Alembert principle
基于连续接触模型研究空间球面副间隙对新型减振平台(4-SPS/CU并联机构)动力学性能影响。将4-SPS/CU并联机构中一条驱动支链与下平台相连球面副间隙视为一刚性无质量杆。建立球面副间隙数学模型及该并联机构含关节间隙的位置方程;利用达朗贝尔原理建立理想4-SPS/CU并联机构动态静力学平衡方程并导出该机构所有关节反力;将理想机构运动副反力位置角近似等于该机构球面副中无质量间隙杆方位角;通过对含关节间隙的驱动支链受力重新分析建立该机构含关节间隙的动力学模型。数值计算、对比分析该并联机构考虑关节间隙与理想关节条件下球面副关节反力随时间变化,分析关节间隙对该并联机构运动学特性及驱动力影响,为该并联机构间隙补偿与控制策略提供理论依据。
基于連續接觸模型研究空間毬麵副間隙對新型減振平檯(4-SPS/CU併聯機構)動力學性能影響。將4-SPS/CU併聯機構中一條驅動支鏈與下平檯相連毬麵副間隙視為一剛性無質量桿。建立毬麵副間隙數學模型及該併聯機構含關節間隙的位置方程;利用達朗貝爾原理建立理想4-SPS/CU併聯機構動態靜力學平衡方程併導齣該機構所有關節反力;將理想機構運動副反力位置角近似等于該機構毬麵副中無質量間隙桿方位角;通過對含關節間隙的驅動支鏈受力重新分析建立該機構含關節間隙的動力學模型。數值計算、對比分析該併聯機構攷慮關節間隙與理想關節條件下毬麵副關節反力隨時間變化,分析關節間隙對該併聯機構運動學特性及驅動力影響,為該併聯機構間隙補償與控製策略提供理論依據。
기우련속접촉모형연구공간구면부간극대신형감진평태(4-SPS/CU병련궤구)동역학성능영향。장4-SPS/CU병련궤구중일조구동지련여하평태상련구면부간극시위일강성무질량간。건립구면부간극수학모형급해병련궤구함관절간극적위치방정;이용체랑패이원리건립이상4-SPS/CU병련궤구동태정역학평형방정병도출해궤구소유관절반력;장이상궤구운동부반력위치각근사등우해궤구구면부중무질량간극간방위각;통과대함관절간극적구동지련수력중신분석건립해궤구함관절간극적동역학모형。수치계산、대비분석해병련궤구고필관절간극여이상관절조건하구면부관절반력수시간변화,분석관절간극대해병련궤구운동학특성급구동력영향,위해병련궤구간극보상여공제책략제공이론의거。
Joints with clearance are essential components of multi-body systems,and impact forces exist among joint elements,they induce vibrations and noise,reduce component life,and lead to a loss of precision.Joint clearance of a mechanical system is necessary to allow the relative motion of connected bodies.Here,a dynamic modeling for a novel vibration reduction platform (4-SPS/CU parallel mechanism)with spherical joint clearance was presented based on the continuous contact model.One of the driving chains was connected to the lower part of the platform with a spherical joint, and the clearance in this spherical joint was taken as a no-mass rigid link in the 4-SPS/CU parallel mechanism.Firstly, the mathematical model of the spherical joint clearance and the position equations for the parallel mechanism with clearance were built.Secondly,the kinetostatic equilibrium equations of an ideal parallel mechanism were successfully established via d'Alembert principle.All of the joint reactions were induced by solving the kinetostatic equilibrium equations.On the basis of the above results,the position angles of the ideal mechanism's joint reactions corresponding to kinematic pairs were assumed to be approximately equal to the orientation angles of the no-mass rigid link in the spherical joint.Lastly,the dynamic equations of the mechanism with clearance were built by doing again force analysis of the driving chain with joint clearance.The driving forces,kinematic characteristics and joint reactions of the parallel mechanism were analyzed with numerical calculation considering spherical joint dearance and ideal joint,respectively. The study results provided a theoretical basis for design of parallel mechanisms.