CAD-based co-optimizations for geometry and motion profile towards energy-optimal point-to-point mechanisms

Energy consumption is receiving increasing attention due to environmental concerns. There is a high optimization potential concerning the energy consumption of industrial machines. Extensive research has been performed concerning geometry optimizations and motion profile optimizations towards energy-optimal point-to-point mechanisms. A co-optimization approach that integrates geometry and motion profile optimization in one architecture, outperforms methods that optimize motion profiles with suboptimal geometries, or vice versa. However, limited research focuses on co-optimizing geometry and motion profiles in one architecture. Therefore, a simultaneous, sequential, and nested co-optimization architecture is set up and compared. The most optimal motion profile and link lengths are determined for an industrial mechanism, resulting in a root mean square (rms) torque saving of 49.2%. To improve computational speed, a method that uses the derivation of a torque equation from three CAD simulations has been utilized. This method facilitates rapid convergence of the nested co-optimization. As a result, the major difference between the three co-optimization methods lies in the ability to converge rapidly to the minimum. This study demonstrates the nested co-optimization’s capacity to identify an enhanced optimum, reducing the computational time by 74.4% compared to the simultaneous co-optimization and by 78.3% compared to three sequential iterations.