Browsing by Author "Enenakpogbe, Emmanuel"

Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    Control of an eVTOL using nonlinear dynamic inversion
    (IEEE, 2022-05-27) Enenakpogbe, Emmanuel; Whidborne, James F.; Lu, Linghai
    This paper presents a Nonlinear Dynamic Inversion (NDI) based flight controller using virtual controls, generalised forces and moments for the longitudinal motion control of a VTOL aircraft including transition manoeuvres. The control architecture is general for piloted, semi-automatic and fully-automated flight. It consists of a main inner-loop NDI controller that is used for forward cruise flight and an outer linear controller used for low speed and hover. Forward and backward transition manoeuvres are executed by switching between the NDI-based controller and position control loops. Simulation results show the control potential for both hover and cruise as well as over the vital transition flight phase.
  • Thumbnail Image
    ItemOpen Access
    Control of an over-actuated fixed-wing vectored thrust eVTOL
    (IEEE, 2024-05-22) Enenakpogbe, Emmanuel; Whidborne, James F.; Lu, Linghai
    A novel full-envelope controller for an over-actuated fixed-wing vectored thrust eVTOL aircraft is presented. It proposes a generic control architecture applicable to piloted, semi-automatic and fully-automated flight consisting of an aircraft-level controller (high-level controller) and a control allocation scheme. The aircraft-level controller consists of a main inner-loop non-linear dynamic inversion controller and an outer-loop proportional-integral linear controller. The inner-loop classical non-linear dynamic inversion controller is used for forward cruise flight while the outer-loop proportional-integral linear controller is used for hover/low speed control and position control. The control allocation scheme uses a novel architecture which transfers the non-linearity in the vectored thrust effector model formulation to the computation of the actuator limits by converting the effector model from polar to rectangular form thus allowing the use of a linear optimisation technique. The linear optimisation technique is an Active Set Linear Quadratic Programming constrained optimisation algorithm with a weighted least squares formulation. The control allocation allocates the overall control demand (virtual controls) to individual redundant effectors while performing control error minimisation, control channel prioritization and control effort minimization. Simulation results shows forward transition from hover to cruise and clearly demonstrates that the controller can handle saturation (position or rate). The proposed controller can also handle actuator failures.
  • Thumbnail Image
    ItemOpen Access
    Full envelope control of over-actuated fixed-wing vectored thrust eVTOL
    (MDPI, 2024-11-27) Enenakpogbe, Emmanuel; Whidborne, James F.; Lu, Linghai
    A novel full-envelope controller for an over-actuated fixed-wing vectored thrust eVTOL aircraft is presented. It proposes a generic control architecture, which is applicable to piloted, semi-automatic, and fully automated flight, consisting of an aircraft-level controller (high-level controller) and a control allocation scheme. The aircraft-level controller consists of a main inner loop classical nonlinear dynamic inversion controller and an outer loop proportional–integral linear controller. The inner loop nonlinear dynamic inversion controller is a velocity controller that cancels the nonlinear bare airframe dynamics, while the outer loop proportional–integral linear controller is an attitude and navigation position controller. Together, they are used for hover/low-speed control and forward flight. The control allocation scheme uses a novel architecture, which transfers the nonlinearity in the vectored thrust effector model formulation to the computation of the actuator limits by converting the effector model from polar to rectangular form, thus allowing the use of classical control allocation linear optimisation technique. The linear optimisation technique is an active set linear quadratic programming constrained optimisation algorithm with a weighted least squares formulation. The control allocation allocates the overall control demand (virtual controls) to individual redundant effectors while performing control error minimisation, control channel prioritisation and control effort minimisation. Simulation results show the transition from hover to cruise, climb and descent, and coordinated turn clearly demonstrate that the controller can handle actuator saturation (position or rate).