Fig 4 - uploaded by Umberto Saetti
Content may be subject to copyright.
Source publication
This paper describes the development, implementation, and validation of a generic tilt-rotor simulation model with coupled flight dynamics, state-variable aeromechanics, and aeroacoustic. A major novelty of this work lies in the integration of the flight dynamics with a state-space free-vortex wake code that adopts a near-wake vortex-lattice model....
Context in source publication
Context 1
... algorithm is stopped when ∥e k ∥ ∞ becomes less than an arbitrary tolerance. The high-order LTI system computed as part of the last iteration constitutes an approximation of the NLTP dynamics about the periodic solution thus found, and can readily be used for stability analysis or feedback control design. A flowchart of the algorithm is shown in Fig. ...
Citations
... As in similar works [6,4,14], to ensure the validity of the control system a robust mathematical model was developed. The resolution of the model affects the validity of the control system and thus we must ensure the model considers all parameters within the scope of the chosen configuration. ...
... Given the derived safe operating area, we can select several points, within the region, as design points for our control simulation [14]. At each point, we will tune the PID gains to achieve the best result and then use gain scheduling to tie the design points together, as the aircraft transitions. ...
Tiltrotors are an aircraft concept with the ability to rotate their rotors freely, achieving vertical take-off and fast forward flight. The combination of helicopter and fixed-wing flight into one aircraft provides versatility in mission selection, yet challenges persist in their construction and control. Tiltrotor aircraft can operate in three primary modes: helicopter, fixed-wing, and transition, with the transition mode facilitating the shift between helicopter and fixed-wing flight. However, control within this transition region is inherently challenging due to its non-linear nature, hence tiltrotors have been predominantly limited to military applications. Thus, this paper aims to explore transition mode control for a large-size tiltrotor aircraft, tailored to civil applications. A novel, large-sized, tiltrotor concept is presented, accompanied by a derived mathematical model describing the aircrafts behaviours. A PID control method has been used to control the height, pitch, and velocity variations within the transition mode with secondary control loop developed to control the tilt angle during transition. The derived model and control are then implemented within a MATLAB simulation, where the control method was iterated to improve performance. The results show a full transition was achieved in under 14 seconds, where altitude variations were kept below 10 metres. Though the transition mode control was successful, a collective look at the data showcases issues with assumptions as well as thrust discontinuities. The implications of these results are discussed, with suggested improvements proposed for future work.
