1. A method for controlling a trajectory of an effector from a current state to a target state, the method comprising the steps of: increasing degrees of freedom in Null space by representing the effector trajectory in a task description disregarding rotation of the effector about a symmetry axis of a target object; applying, by a processor, additional control criteria to control the trajectory based on the increased degrees of freedom in Null space; and controlling the effector trajectory on the basis of the task description and the additional control criteria to reach the target state.