基于独立运动分流标记法的多环耦合机构自由度分析方法

基于运动分流法,提出一种改进的多环耦合机构的自由度分析方法,可将复杂的多环耦合机构拆分成多个运动独立的链.应用螺旋理论分析独立运动链所含耦合节点相对于机架的独立运动,并用广义运动副等效代替,整个机构就可以等效为一个并联机构.通过分析等效并联机构的运动和约束螺旋系,即可确定多环耦合机构动平台的自由度数目和性质.将提出的方法应用于一种Hoberman Switch-Pitch魔球机构的自由度分析,验证了该方法的有效性及简单性.

Method of Mobility Calculation for a Coupled Mechanism Based on Independent Motion Shunting Measurement

An improved method based on screw theory for constraint and mobility analysis of complex coupled multi-loop mechanisms is proposed. The innovation is the proposition of motion shunting measure, by which the complex multi-loop coupled mechanisms can be split into several independent elements. The relative motion of the coupled-nod link in each element was analyzed and replaced by a generalized kinematic chain. The coupled mechanism was ultimately regarded as a common parallel mechanism. Limb twist systems and limb constraint systems of the equivalent parallel mechanism were analyzed and the characteristic of the output mobility was identified. With the proposed method, a typical Hoberman Switch-Pitch ball was analyzed, which shows the validity and simplification of the new method.