6th World Congresses of Structural and Multidisciplinary Optimization

1. Abstract Work has been carried out to investigate some of the important design parameters and performance criteria that should be addressed when designing servo mechanisms and, subsequently, to put forward a computationally efficient design procedure. Emphasis is put on the handling of the discrete design variables. A two-stage approach is presented that uses dimensionless parameters that maps data bases of commercially available components. At the first stage the dimensionless parameter are allowed to assume any value. At the second stage the dimensionless parameters are pushed towards integer values by means of penalization techniques. A three-degree of freedom open chain spatial mechanism is used as the fixed mechanism topology of the study. Each drive consists of an inverter driven servo motor attached to a planetary gear. In the optimization the designs are evaluated based on a typical working cycle involving the positioning of a certain payload. The design criteria include costs of drives and structural components, tool point precision, fatigue in welded details, over heating and stalling of the motors and gears as well time of operation.