STUDY ON DIMENSION SYNTHESIS OF PLANAR 4-BAR LINKAGES FOR RIGID-BODY GUIDANCE WITH PRESCRIBED TIMING

摘要

A computer method is firstly proposed, which is used to do the dimension synthesis of planar 4-bar linkages for rigid-body guidance with Prescribed Timing (in short PT) by harmonic component's database of the coupler's rotation-angle function. The relationship between position function of rigid-body guidance with PT and coupler's rotation-angle function of 4-bar linkage is analyzed. The key of the method is to solve the real dimension of linkage, coupler's point position and installing dimensions of the linkage. Considering solving the problem, a harmonic component's database of the coupler's rotation-angle function including 20350 dimensional types, taking the crank-rocker linkage as an example, is established. So, it is possible to choose some linkages from the database to realize rigid-body guidance with PT by using fuzzy identification method quickly, and to approximately achieve infinite positions* of dimensional synthesis for rigid-body guidance. An example is given to illustrate the efficiency and advantage of this method.