스플라인 경로계획 방법에 따른 수중 로봇팔의 유체항력 특성 분석

Abstract

In this paper, we analyze how spline trajectory planning methods of articulated robotic arms in an underwater environment affects on the optimized result of hydrodynamic drag force term. The drag force included in dynamic equation of cylindrical underwater arms is mathematically modeled by joint angles and joint velocities. Genetic algorithm(GA) and Sequential Quadratic Programming(SQP) techniques are used to optimize hydrodynamic drag force in the situation where robotic arms move along the trajectory composed of spline. In order to increase optimality, we propose 2-level optimization scheme, which adopts the GA as first level optimization to locate approximal global solution and SQP as second level optimization to locate exact global solution. To verify the validity of the proposed method, we will show examples of modeling of dynamic equation for robot arm of simple three links and analysis characteristic of optimized drag force with different spline trajectory planning methods adopting quintic polynomial equation and 4-3-4.