Magnetic Actuator Workshop 6 Robust Design

Workshop Supplement January 30, 2001 Inventory # W Robust Design Magnetic Actuator Description A magnetic actuator consists of a coil, an iron path for the flux to travel and the movable part called the armature. The force applied on the armature is closely related to the amount of magnetic flux in the circuit. Like a fluid, the flux will be greater when the resistance is decreased by either increasing the dimensions of the iron path or increasing the material “conductivity.” Determine the interaction between the control parameter, Inner Leg Thickness, and the noise parameter, BH curve variation. Objective Determine if a useful interaction exists between the thickness of the Inner Leg of the iron path (controlled by dimension R1) and the possible variation in the material property (controlled by a factor, MatFact.)

Workshop Supplement January 30, 2001 Inventory # W Robust Design...Magnetic Actuator Instructions 1.Using the system editor, review the file pm.dat in the specified directory. The geometry input should be a function of R1, and the material property curve should be modified by MatFact. The response function, force on the armature, should be retrieved as parameter Fval. 2.Enter ANSYS (or clear the database) and read input from pm.dat. The material property is nonlinear, so the solution is iterative. At the end of the solution, check the value of Fval retrieved (Newtons) in the output window. 3.Enter the optimizer and identify pm.dat as the analysis file.

Workshop Supplement January 30, 2001 Inventory # W Robust Design...Magnetic Actuator 4.Identify optimization variables. Design variables are R1 and MATFACT: 9 < R1 < < MATFACT < 1.1 There are no state variables in this example. Objective function is FVAL, with default tolerance. 5.Run the Factorial Tool. Choose a full factorial run (which will create 4 solutions). 6.List the resulting design sets. 7.Review two-factor interaction results. Note that the interaction is positive, indicating that variation in force due to the noise parameter MatFact is greater when R1 is greater.