Incremental Modeling and Simulation of Mechanical Power Transmission for More Electric Aircraft Flight Control Electromechanical Actuation System Application
In the field of more electric aircraft, electromechanical actuators (EMAs) are becoming more and more attractive because of their outstanding benefits of aircraft fuel reduction, maintenance costs saving, and system flexibility improvement. For aerospace electromechanical actuator applications, mechanical power transmission is critical for safety, in which reflected inertia to load, heat generated by energy losses and faults due to jamming, free play and free run are specific issues. According to the system engineering process and simulation aided design, this communication proposes an incremental approach for the virtual prototyping of EMA mechanical power transmission. Resorting to the Bond graph formalism, the parasitic effects are progressively introduced and realism of models is increased step by step. Finally, the numerical implementations are presented and compared with basic, advanced and full models of mechanical power transmission in AMESim environment. Multi level submodels are available and can be re used for preliminary sizing, thermal balance verification and response to fault analysis. NOMENCLATURE Cb Cm Cj Cs Bearing translation support, motor electromagnetic, nut screw inertial, rod output to surface torque [N/m] F0 Preload force [N] Fb Fc Fd Fe Bearing support translation, compliance contact, damping, elastic force [N] Fex, External aerodynamic force [N] Ff f F f F Initial normal, faults injections and temperature sensitivity friction force [N] FL Load force [N] Fm Fs Motor shaft output, rod output to surface force [N] jam F Jamming stiction force [N] fv Viscous friction coefficient [N/(m/s) Im Is Motor windings, DC supplied current [A] Pd Pf Damping, friction loss [W] S Heat power [J/sK] Um Us Motor wingdings, DC supplied voltage [V] vb ve vr vs vsr Bearing support, elastic, relative, rod output to surface, relative rod/support translational velocity [m/s] x0 0 x 0 x Initial normal, faults injections, temperature sensitivity backlash/preload parameter [m] xc Position command [m] xw Wear parameter of nut screw [m] xr Relative elastic deformation [m] f f Initial, temperature sensitivity friction factor[ x Temperature dependency backlash/preload parameter d i Efficiency direct, indirect Temperature [degC] b mn sr Support rotational, motor rotor, relative nut/support, relative rod/support angular velocity [rad/s] i Current/torque loop angular frequency [rad/s] EHA Electro hydrostatic actuator EMA Electro mechanical actuator EM Electric motor HSA Hydraulic servo actuator MPT Mechanical power transmission PDE Power drive electronics INTRODUCTION Safer, cheaper and greener technologies are important initiatives for the next generation air transport in upcoming decades. In response to these needs, the aerospace industry is looking for an innovation (incremental or disruptive) in safetycritical actuation systems. In recent years, a significant interest is towards "more electric aircraft" The trend is to increase the usage of power by Wire (PbW) electrical actuators: electrohydrostatic actuator (EHA) and electro mechanical actuator (EMA) These are envisioned to take the place of conventional hydraulic servo actuators (HSA) Compared to EHAs, EMAs totally remove the central and local hydraulic circuits, resulting in increased economic, competitive and environmental Proceedings of the ASME 2016 International Mechanical Engineering Congress and Exposition IMECE2016 November 11 17, 2016, Phoenix, Arizona, USA