The precise Permanent Magnetic Couplings (PMC) is a core component of the vacuum robot. Accurate analysis and efficient optimal design are essential to improve transmission performance of vacuum robot and avoid costly trial. The state-of-art of the related research was firstly reviewed. Then a practical mathematical model with a novel criterion was set up. Furthermore

two typical analytical methods

the Equivalent Magnetic Charge (EMC) and the Current Sheet Model (CSM) were improved and compared with the 3D FEA method on efficiency and accuracy. Last but not the least

the Design of Experiments (DOE) was introduced and an effective and practical optimizing process was proposed. The results showed that the accuracy of the improved EMC was increased by about 6% and the efficiency was increased by 117% compared with the original EMC method. The error of the CSM method was 30% bigger than that of the 3D FEA

though the efficiency of CSM was much higher. It is very important to provide proper initial parameter guess to ensure a rapid convergence on optimizing process. The proper initial values can be obtained only by using nine simulation models with the DOE method. Multiple sets of optimizing cases were gained easily through standard optimization methods. The proposed optimizing method can satisfy the requirements of practicability

higher precision

as well as strong stabilization.