Eight-DOF Dynamic Modeling of EMA Mechanical Transmission and Spalling Fault Characteristic Analysis

Abstract

Electromechanical actuators (EMAs), as the critical actuator system of next-generation aircraft, have attracted the attention of many institutions and enterprises around the world. However, due to harsh working conditions, their reliability cannot satisfy the requirements of widespread application in aircraft. Therefore, in order to conduct fault diagnosis on EMAs, in this paper, we establish a comprehensive dynamic model under numerous assumptions to study the fault characteristics that may occur in the displacement and acceleration responses of EMA systems. First, an eight-DOF dynamic model containing typical mechanical components of an EMA is established. Then, by obtaining the impact forces between balls and the spalling fault and the nonlinear relationship between the total elastic restoring forces and the change of ball deformation when the fault occurs, a faulty dynamic model is established. Comparison of the simulation results between the normal and faulty model reveals that the acceleration amplitude at the third harmonic of the ball passage frequency increases when fault occurs. Based on this phenomenon, a numerical calculation method of fault characteristics is proposed. Finally, the effectiveness of the established models and the identified phenomenon are verified by experiments conducted on an EMA test rig in a laboratory environment.

Performance and Challenges of Planetary Roller Screw Mechanism in Complex Conditions: A Comprehensive Review of Recent Progress

“…These contributions not only enhance our understanding of specific fault mechanisms but also pave the way for more resilient and fault-tolerant mechanical designs. The eight-DOF dynamic modeling of EMAs by Yin et al [165] and the spall fault quantification method for flight control EMAs by Ismail et al [166] reflect the ongoing efforts to refine diagnostic models and methodologies. These studies contribute to a granular understanding of mechanical failures, facilitating targeted interventions and prolonging the service life of critical components.…”