Abstract: The electro-hydraulic load simulator is a key equipment for hardware-in-loop simulation of aircraft. The simulation creditability is directly related to the load trace precise. There is no identified estimation standard for it now, which causes some misunderstand for the design and implementation. Some estimation methods are summarized, which problems are disclosed. Furthermore, it is illustrated from two sides. First, presents the evaluation methods for the performance of load simulator; On the other hand, to require the performance of the load simulator by evaluating the actuator, mainly discuss the influence of the dynamic stiffness of the actuator.

Key words: Trace of load spectrum Load simulator, Actuator, Dynamic stiffness Extraneous force, Estimation criteria