An optimal design technique is applied to the design of the machine unit of the industrial robot, KAISEM, made in the previous year. The structure is modeled as an assemblage of beam type elements, representing horizontal arm, vertical supports and rotary supports.
The mean diameter and the thickness of each element are considered as design variables. The optimal design formulation includes constraints on effective stress, nodal displacement and design variable bounds and is based on the static response. The objective function is taken as a combination of weight and moment of inertia about the rotation axis to compensate the lack of not considering dynamic response.
A program is developed based on a generalized steepest descent algorithm and is applied to the robot KAISEM, to obtain an improved design. The weight of the robot was reduced by more than 50% comparing with that of KAISEM without sacrifice in the stiffness.
A detail design drawing based on the result of optimal design is given along with the important factors which must be taken care of in the manufacturing stage.
