Multi-Objective Parametric Optimization of an Equilibrator Mechanism

Abstract

In order to eliminate the moment unbalance of rotary systems, a certain type of equilibrator mechanism which is able to perfectly balance is utilized. It includes helical spring(s), a pulley and a cable attached to a certain hinge point on the rotary body. Actual implementations of the mechanism may not allow realization of the conditions for perfect balancing. Then, the problem is transformed into a multi objective constrained optimization, which includes multiple parameters and multiple objectives like minimizing the residual moment unbalance, minimizing the diameter and the length of the spring(s), maximizing the spring fatigue life as well necessity to satisfy some geometrical layout constraints and operational constraints on the springs. The system has been modeled in a quasi-static manner and optimized parametrically around the regions of operation. Pareto optimal fronts have been determined and the optimized parameters have been used as design parameters for realization of the actual system. The design of the mechanism has been algorithmically automated based on the requirements and constraints.