Specification design of planar feature based on the new generation geometrical product specification and verification

In accordance with the new generation geometrical product specification and verification (GPS), the specification design process and the measurement and verification process must satisfy with duality principle so as to avoid the ambiguous problems during the verification process. To solve the problems how to generate the specification surface model of planar feature and design and apply the corresponding specification operators. This paper firstly presents a method to generate the specification surface model of planar feature. The tolerance mathematic model of the planar factors should be established in first step. Then the influences of processing technology on the specification surface model need to be considered. The simulation points under the normal distribution are generated in the tolerance zone. By using the fitting approach of the least-squares B spline, the specification surface model is generated. Secondly, this paper makes a corresponding analysis and design on specification operators of plane feature with flatness requirement. Lastly takes the worktable of M7140 grinding machine as an example, builds its specification surface model and the specification design results by operations on specification surface model are given.