Cogging Torque Minimization in PM Motors Using Robust Design Approach

Cogging torque minimization is necessary for low torque ripple applications such as precision tooling, robotics, etc. Various techniques are available but few techniques are proved to be effective in mass production under manufacturing tolerances/variations. The research provides a design approach to minimize cogging torque by making the motor robust to manufacturing variations and dimensional tolerances. Several control and noise factors are identified to apply the robust design technique. The quality of robustness is judged by the signal-to-noise ratio. A tradeoff is exercised to maximize output torque in selecting the control parameters. The research shows the effectiveness of such design techniques in designing motors for mass production without adding cost or complexity. Experimentation by modeling has been chosen using finite element analysis. Motors using the optimized parameters are built and tested thus verifying the design approach.