In the daily life and in using technologies people interact with continuous medium like air or water. In present article a motion of the vibrator with constant air or water flow excitation is observed. In the first part of the article a motion of the vibrator with constant air or water flow velocity excitation is investigated. The main idea is to find optimal control law for variation of additional area of vibrating object within certain limits. The criterion of optimization is the time required to move object from initial position to end position. For the solution of high-speed problem the maximum principle is used. It is shown that optimal control action is on boundaries of area limits. Examples of synthesis of real mechatronic systems are given.