On–off and proportional–integral controller for a morphing wing. Part 1: Actuation mechanism and control design

Abstract

The main objective of this research work is the development of an actuation control concept for a new morphing actuation mechanism made of smart materials, which is built from a shape memory alloy (SMA). Two lines of smart actuators were incorporated to a rectangular wing to modify the upper wing surface, made of a flexible skin, with the intention to move the laminar-to-turbulent transition point closer to the wing trailing edge. After a brief introduction of the morphing wing system architecture and requirements, the actuation lines' design and instrumentation are presented. The integrated controller controls the SMA actuators via an electrical current supply, so that the transducer position can be used to eliminate the deviation between the required values for vertical displacements (corresponding to the optimized airfoils) and their physical values. The final configuration of the integrated controller is a combination of a bi-positional (on–off) controller and a PI (proportional–integral) controller, due to the two heating and cooling phases of the SMA wires' interconnection. This controller must behave like a switch between the cooling and the heating phases, situations where the output current is 0 A, or is controlled by a PI type law. The PI controller for the heating phase is optimally tuned using integral and surface minimum error criteria (Ziegler–Nichols). The controller is numerically tested on the linear identified system in terms of time response, Bode diagram, amplitude and phase stability margins, and root-locus.

New Methodology for Optimal Flight Control Using Differential Evolution Algorithms Applied on the Cessna Citation X Business Aircraft – Part 1. Design and Optimization

“…In the same way a PID controller was tuned in [7], and in [8], for a linear model of a morphing wing relying on the engineer's experience, and validated on its nonlinear model. In order to overtake the time wasting during the trial and error method, many algorithms were developed in the last decades to optimize the controller performances.…”

Numerical simulation and wind tunnel tests investigation and validation of a morphing wing-tip demonstrator aerodynamic performance

“…In the closed-loop configuration, the displacements were automatically determined as a function of the pressure readings from the wing upper surface [27,28]. In addition, two new controllers were developed; the first one was based on an optimal combination of the bi-positional and Proportional-Integral (PI) laws [29,30], while the second one was a hybrid fuzzy logic-PID controller [31,32]. The wind tunnel tests were performed in the 2 m × 3 ma t m o s p h e r i c closed circuit subsonic wind tunnel at NRC.…”

Morphed Vertical Tailplane Assessment for Certification Requirements

“…The aerodynamic pressure distribution for morphed rudder is smoother than the resulting for a conventional one. Similar use of aerodynamic profile morphing to delay the boundary layer transition from laminar to turbulent has been previously analyzed with SMA actuators [18,19].…”