The Structural Synthesis Of Hybrid Manipulators With Two-layer Parallel Mechanism With Terminal 2R2T

The serial-parallel hybrid mechanism has the advantages of large working space of serial mechanism and strong bearing capacity of parallel mechanism,so it has a good application prospect in practice.Mechanism innovation is the original innovation of machinery and equipment,and the structural synthesis is effective means of mechanism innovation.At present,there are few researches on the structural synthesis of serial-parallel hybrid mechanisms at home and abroad,so the research on the structural synthesis of serial-parallel hybrid mechanism has important significance.In this paper,the hybrid manipulator with a two-layer parallel mechanism with terminal 2R2 T is taken as the research object.Based on the degree of freedom analysis principle of hybrid manipulators with two-layer parallel mechanism,and combined with the structural synthesis of atlas method,the structural synthesis of hybrid mechanisms is carried out.The main research work of this paper is as follows:According to the principle of degree of freedom analysis of hybrid manipulators with two-layer parallel mechanism and the method of structural synthesis by atlas method,combined with the 2R2 T freedom-space atlas,the degree of freedom combination mode of the lower and upper sub-parallel mechanisms and the constraint-space atlas of the lower and upper sub-parallel mechanisms are introduced.Based on the structural synthesis steps and flow charts of hybrid manipulators with two-layer of parallel mechanism,firstly the freedom-space atlas corresponding to 2R2 T is decomposed by combining the combination mode of freedom among 2+2/3/4sub-mechanisms,and combining with constrain-space atlas of sub-parallel mechanisms,the relationship between constraint-space atlas of the lower and upper sub-parallel mechanisms is obtained.Then the lower and upper sub-parallel mechanisms are constructed respectively according to constraint-space atlas of the sub-parallel mechanisms.Finally,according to the relationship between constraint-space atlas of the lower and upper sub-parallel mechanisms,the lower and upper sub-parallel mechanisms are combined together to construct the 2+2/3/4 type hybrid mechanism with terminal2R2 T.Based on the structural synthesis steps and flow charts of hybrid manipulators with two-layer of parallel mechanism,firstly the freedom-space atlas corresponding to 2R2 T is decomposed by combining the combination mode of freedom among 3+3/4sub-mechanisms,and combining with constrain-space atlas of sub-parallel mechanisms,the relationship between constraint-space atlas of the lower and upper sub-parallel mechanisms is obtained.Then the lower and upper sub-parallel mechanisms are constructed respectively according to constraint-space atlas of the sub-parallel mechanisms.Finally,according to the relationship between constraint-space atlas of the lower and upper sub-parallel mechanisms,the lower and upper sub-parallel mechanisms are combined together to construct the 3+3/4 type hybrid mechanism with terminal 2R2 T.