Influence of aerodynamic load on aerocraft actuator and research on Special Loading with Hydraulic Load Simulator

This paper focuses on influence of aerodynamic load on aerocraft actuator, then proposes a new concept of Special Load to evaluate the ultimate performance of actuator, and explores how to process the Special Load simulation with Hydraulic Load Simulator (HLS). To test actuator stability and load stiffness, conventional methods generally use several specific loads for simulation and test considering both cases with no load and elasticity load. In general, if the system is stable without load, it will remain stable after loading. The elasticity load test is taken to measure the load stiffness of the system. Furthermore, theoretical and practical methods are insufficient to proceed the research of how authentic aerodynamic load influences actuator. Practical test experiences indicate that although the actuator passes the loading test with spring, some aerodynamic load profile will still make the actuator controller unstable in the real case. Based on the analysis of aerodynamic load, particularity of inertia, viscosity and elasticity load, a correlation model can be built aerodynamic load and state variables of actuator control system. In this paper, we attempt to replace aerodynamic load with a combination of some special loads as the Equivalent Special Load. In order to reproduce the influence on actuator of aerodynamic load with Equivalent Special Load, potential methods applying HLS are explored. Moreover, conducting the analysis of dissimilarities of special and conventional loading, as well as stability analysis, help put forward the requirements of controller for special loading.