Theoritical Study Of Two Six-dof Parallel Manipulators With Planner Limbs

6-DOF parallel manipulator is an excellent candidate for advanced roboticapplications by virtue of their low moving inertia, highstiffness, high dexterity, and highpower to weight ratio.6-DOF parallel manipulator has broad application prospects and isalways the hot spot of research within the field of parallel manipulator. The closed-loopmechanism is widely used in parallel mechanism type synthesis, which can effectivelysimplify parallel mechanism, compact structure, improve the mechanism performance,such as stiffness, dexterity, stationarity, etc.Based on a six bar closed loop structure, two six-DOF parallel mechanisms (GS1,GS2) with panar limbs are proposed in this paper. The position analysis of GS1and GS2are obtained by using the vector method, respectively. Utilizing the affected coefficientmethod, unified kinematic model of planner limb has been modified.Based on the principle of virtual work and Newton Euler Equation, the unified staticand dynamic models of planner limb with six bar closed loop structure are established.Taking parallel mechanism GS1and GS2as examples, the courses of establishing thekinematic and dynamic models of parallel mechanism with the planar limbs are elaboratedand verified based on Adams virtual prototyping technology and Matlab software.The parameter effects on the fixed orientation workspace of GS1and GS2areanalysed through the simple variable method. Based on the kinematic Jacobian matrix, thesingular characteristics of parallel mechanism GS1and GS2are modified. The results withreference value are obtained, which provide a reference for prototype design, dimensionsynthesis and structure optimization of GS1and GS2. Under the same specification, theparallel mechanism GS1and GS2show wide application prospects by comparing withworkspace of6-6stewart mechanism.