Good trajectory tracking and fast convergence are critical characteristics on medical and industrial applications. This behavior must be ensured despite the presence of disturbances to successfully complete the task. This work presents the design and robustness comparison of two control approaches computationally implemented on UR5 robot for trajectory tracking. The control methods that will be compared are proportional-derivative control with gravity compensation and sliding mode control. Both control methods will be designed to ensure stability and good tracking of circular helicoidal trajectory on the operational space. In order to evaluate the robustness of both control methods, a controlled white-noise signal will be added to robot model. The obtained results indicate that sliding mode control deals better with external disturbances than proportional-derivative control with gravity compensation.