Research Of Sphericity Error、Cylindricity Error Evaluation Algorithm Based On Datum Matching

Along with the development of science and technology, high precision cylindricaland spherical parts were used more widely in the precision machinery instrumentation,aviation aerospace equipment, machinery and other high-tech areas. The cylindricityerror and sphericity error is one of important index to evaluate the machining precisionof the cylindrical and spherical parts. The error size of it has great influence in thewhole of the height of the mechanical system of performance. Research the evaluationalgorithm of the cylindricity error and sphericity error which has the independentproperty right of high precision, high efficiency has an important role in research anddevelopment the precision test instrument of the cylindricity error and sphericity errorthat have independent property rights of our country.By analyzing and researching the definition and the geometric characteristics andthe evaluation principle and the evaluation algorithm of its related references of thecylindricity and sphericity error, this paper did some research on the evaluationalgorithm of the cylindricity error and sphericity error following several aspects:1. The definition of the evaluation datum of the cylindricity error and sphericityerror is put forward, and makes a thorough analysis research on the correspondingevaluation datum and the error function of unified problems.2. A new algorithm of evaluate the cylindricity error----the geometry optimizationsearch of cylindricity error evaluation algorithm based on datum matching has be putforward by analyzing and discussing the evaluation method and the evaluationprinciple and the evaluation algorithm of the cylindricity error.3. Two new algorithm of evaluate the sphericity----the mesh search of sphericityerror evaluation algorithm based on datum matching and the geometry optimizationsearch of sphericity error evaluation algorithm based on datum matching have be putforward by analyzing and discussing the evaluation method and the evaluationprinciple and the evaluation algorithm of the sphericity error. 4. The mathematical simulation, the test and the examples verification of thecylindricity error and sphericity error have been done. Based on the results of themathematical simulation and examples verification, analysis the relationship of themesh point number of the mesh search algorithm and the evaluation precision of thesphericity error, the determination principle of the initial reference point and the initialside length of the geometric optimization algorithm and the judge conditions adapt tothe termination matching search of the evaluation precision were given.The algorithm of this paper are with pure geometry relationship matching searchfor the evaluation datum of the cylindricity error and sphericity error, and to avoidconfirm the optimizing step length, the direction and the angle, the convergence speedfast, applied it to the evaluation of the cylindricity and sphericity error evaluation canquickly get the global optimal solution. Though the test and the examples verificationshows that the algorithm can matching search the corresponding ideal evaluationdatum primely, and then can be effectively, accurately and quickly realize to theaccurate evaluate of the cylindricity error and the sphericity error.