Research On Structural And Kinematic Characteristics And Parameterized Solid Kinematic Simulation Of Linkages

Some theoretical problems on kinematic analysis of spatial linkage and circuit identification of linkages, the method of parameterized solid motion simulation of linkages are studied systematically and deeply in this dissertation.The circuit identification of planar single-input-dyads mechanism (SIDM) is studied. A planar SIDM with j loops (expressed in term of SMj) can be regarded as comprising of a SIDM with j -\ loops (expressed in term of SMj-1) and a dyad (expressed in term of dyadj). Then, the circuit condition of SM, is determined by the circuit condition of SMj-1 and the configuration of dyadj. Based on the above thought and combined with the automatic generation of structural decomposing of planar mechanism according to the type transformation theory, circuit automatic identification of planar SIDM are realized, two examples are given to demonstrate the use of this method.Mobility problem (including circuit defect, crank problem and the order of motion) of Stephenson six-bar linkage is studied. AS- SBC contains a basic four-bar loop (BFBC ) and a dyad. Base on the distance of two common joints shared by the BFBC .and the dyad, the model of circuit identification is established. Via this model, automatic identification of circuit and circuit defect of S - SBC are realized. The procedures to check for the existence of a crank in all types of S - SBM are found. The method of stationary configuration loop to solve the order of motion of S - SBM is presented. The results resolve three of the most complicated and troublesome problems encountered in the precision point synthesis and provide theoretical basis and technical method for dimensional scheme selection of S - SBM.The circuit of the first group spatial linkages is studied. Four parameters for determining the type of circuit of spherical four-bar linkage are defined. According to the relationship of these parameters, three types of circuit of spherical four-bar linkage are found, which is proved in view of geometry point. Base on the theory of sphere triangle, an approach of identifying the circuit and branch defect of spherical four-bar linkage is proposed. This method is also valid for identifying the circuit and branch defect of first group spatial linkages based on the equivalent of circuit properties of the first group spatial linkages and its equivalent sphere four-bar linkage Base on the property of the solutions of quartic equation, the conclusion that the number and order of branch between two adjacent stationary positions of the input link are derived. Then, the new method to identify circuits of spatial single-loop linkages with four closures is presented. All types of the manner on which the branches coalesce at the stationary positions of the input link are obtained and the procedures to determine the type automatically are developed. The automatic generation algorithm using all information of the coalesced branches is studied. The results are believed the first attempt that resolves the circuit identification problem of the spatial linkages with four closures.The theory of type transformation of planar linkages has been extended to the kinamatic analysis of spatial linkages. The structural decomposing criterion and its automatic generation algorithm for multi-loop spatial linkages are discussed. The kinematic algorithm of the basic unit is given based on the position analysis method of single-loop spatial linkages and he kinematic influence coefficient method. A computer program for automatic analysis of spatial mechanisms is developed.The method of parameterized solid kinametic simulation of the linkages on the SolidWorks platform is studied. Integrated kinematic analysis system of Object-Oriented with powerful function of parameterized feature model of SolidWorks, Using the various Application Programming Interface which the SolidWorks provided, The three-dimensional parameterized solid kinametic simulation system of the linkages are achieved with the tool of VC++6.0. This system provided exact reference data and varied...