Simulation of aircraft multi-axis acceleration in a four-axis Human Centrifuge System

Abstract

High G-accelerations produced during Aircraft Combat Manoeuvres (ACMs) can adversely affect the physiological and psychological conditions of aircrew and deteriorate their performance. Human Centrifuge Systems (HCSs) provide an effective G-acceleration training tool to prepare and increase the G-tolerance of aircrew. Though highly capable HCSs are available, they are yet to be fully optimised to accurately and reliably recreate the G-vectors produced by ACMs. Optimisation steps to achieve this improvement involve the configurational structure, motion capability, and motion control of HCSs. To improve the motion capability and control of HCSs, the relationship between aircraft G-vectors and HCS G-vectors should be profoundly investigated. This work analyses the G-vectors of common ACMs and the corresponding G-vectors as well as kinematics of an active four Degree-of-Freedom (DoF) HCS. The mathematical models of an aircraft and HCS kinematics are developed using rigid body equations of motion through Newton-Euler method. The relationship between aircraft G-vectors and HCS G-vectors is established using inverse kinematics with an optimal solver. The outcomes of this study show that an active four-DoF HCS with gondola roll, pitch, and yaw rotation can replicate the G-vectors of common ACMs with small discrepancies. The largest error between the reference and achieved G-vectors occurred along the local z-axis of the HCS gondola during the transition of roll, pitch, and yaw motions of the gondola to the required angle replicating the G-vectors of the ACMs. The tracing errors are not significant; hence they can be mitigated with an optimal control technique. The presented outcomes will provide an essential step in identifying the optimal design and refined requirements for an HCS to efficiently replicate aircraft G-vectors. The applied methodology is easily adaptable to HCS with different structures and DoFs.