Browsing by Author "Edwards, Christopher"

Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Flight evaluation of a sliding mode online control allocation scheme for fault tolerant control
    (Elsevier, 2020-01-21) Chen, Lejun; Edwards, Christopher; Alwi, Halim; Sato, Masayuki
    This paper develops a sliding mode fault tolerant control scheme based on a Linear Parameter Varying (LPV) system representation of the plant. The scheme includes a control allocation component, which is capable of utilizing the available healthy actuators in the face of actuator faults/failures, in an effort to retain close to nominal fault free performance. The proposed scheme is validated using the Japan Aerospace Exploration Agency’s Multi-Purpose Aviation Laboratory (MuPAL-α" role="presentation">) research aircraft. The flight test results demonstrate good lateral-directional state tracking performance with no visible performance degradation in the presence of rudder and aileron faults.
  • Thumbnail Image
    ItemOpen Access
    Simultaneous fault and input time delay estimation for an actuator system: theory and flight data validation
    (IEEE, 2021-06-18) Chen, Lejun; Edwards, Christopher; Alwi, Halim; Sato, Masayuki
    This paper proposes a first order sliding mode observer for the purpose of simultaneously estimating the unknown input time delay and reconstructing the loss of effectiveness in a model of an actuator. The adaptive algorithm is driven by the ‘equivalent output error injection’ signal associated with the sliding motion. Sufficient conditions are given to ensure finite time convergence of the state estimation error system, ensuring both the time delay estimation error and the estimation error associated with the actuator fault converge to a small region around zero. The efficacy of the approach has been evaluated via both a numerical simulation and flight data validation.