Hydrodynamic exciter control for durability analysis

The durability tests are most important for mechanical system development in term of their correct functionalities during life-cycle period. The mechanical vibration tests are mandatory for crucial mechanisms like brakes, chassis and direction control parts etc. Transportation producers have to fulfil durability standards which are defined as power spectral density spectrum of mechanical excitation in three axes. The spectrum of mechanical vibration is prescribed as the input to the system and has to be observed during whole tests. The hydrodynamic valves as exciters are more suitable than electromechanical system cause of higher capacity load. The disadvantage might be the controlling of the prescribed spectrum cause of their natural frequencies and the friction between the piston and cylinder. Those two deficiencies are possible to solve by using iteration control method and no gasket system with suction of the hydraulic oil.