Abstract: Currently Least Square Method (LSM) is commonly applied in the error evaluation,but it is adaptive to the condition of low accuracy requirement.Besides,the error value obtained by LSM is not the minimum.In order to accurately evaluate perpendicularity error,a minimum zone mathematical model for the perpendicularity error evaluation was given based on the new generation Geometrical Product Specification and verification(GPS) standards.According to the characteristics of perpendicularity error evaluation,a new adaptive particle swarm optimization algorithm with dynamically changing inertia weight is proposed to implement optimization in the error evaluation.Finally,an example was given to illustrate the proposed method.

Key words: the new generation GPS, the minimum zone method, perpendicularity, inertia weight, adaptability particle swarm optimization