Unmanned Aerial Vehicle, Cooperative Transportation System, Moving Pendulum Dynamics, Loop Transfer Recovery, Parameter-Robust Linear Quadratic Gaussian This paper presents the design process of cooperative transportation system with multiple unmanned aerial vehicles connected with strings. Moving pendulum dynamics is modeled with Newtonian approach via combination of 3- dimensional Cartesian coordinates and spherical coordinates. The modeled system is controlled linear quadratic Gaussian / loop transfer recovery method. Furthermore, system parameter variations are compensated with parameter-robust linear quadratic Gaussian method. The numerical result of the both controls is compared to show improvements in parameter robustness.