Bioinspired flight serves to balance the advantages of fixed-wing flight as well as traditional rotary systems. A flapping wing aerial system exhibits high maneuverability at low speeds like a rotary system and the higher efficiency that fixed-wing systems exhibit in forward flight. A method to actuate a flapping wing structure is using piezoelectric elements. Using flapping wings to perform aerial maneuvers and facilitate stable flight will require precise control of the piezoelectric elements and control surfaces. The focus of the research is the construction of a feedback control platform for the flapping wing aerial system. For any type of feedback control architecture, an accurate way of estimating the current state of the system is required for precise tracking control. Since the control system will be implemented in an aerial vehicle, the system must be lightweight to allow for a larger payload capacity for the aircraft. Nonlinearities arising from uncertainties and unmodeled environmental effects lead to changes in the system model and a linear control scheme will exhibit suboptimal performance and instability. The desire of this aircraft to be able to perform under different flight conditions make determination of an accurate system model a time-consuming and vast undertaking. These flight conditions include take off, gliding, and landing under different wind, pressure, temperature, and payload specifications. Sliding Mode Control and Lyapunov-based methods have been explored extensively due to their capability of handling nonlinear systems directly while guaranteeing stable tracking control. However, determining an appropriate model to approximate the system dynamics is difficult and can lead to undesirable results. These variations can be accounted for by using a model-free control approach. In this work, a model-free controller based on the Sliding Mode Control method implemented for a flapping wing aerial system is considered. The model-free control algorithm only requires knowledge of the system parameters such as the order of the system and state measurements. The algorithm has been implemented successfully in traditional unmanned aerial systems achieving adequate control of system states. While the goal is for the Model-free algorithm to be implemented on a flapping-wing unmanned aerial system, at the time of this thesis, the construction is still in progress. Therefore, an analogous system was built to test the algorithms. A balancing system consisting of a DC motor and propeller mounted to a servo motor for thrust vectoring was constructed. A linear controller derived from the system model was compared in simulation and testing to the Model-Free Sliding Mode Control algorithm.
Library of Congress Subject Headings
Sliding mode control; Actuators; Airplanes--Wings--Design and construction; Piezoelectric devices
Mechanical Engineering (MS)
Department, Program, or Center
Mechanical Engineering (KGCOE)
Hare, Walker, "Implementation of Model-Free Sliding Mode Control on a Multi-Input Multi-Output System" (2023). Thesis. Rochester Institute of Technology. Accessed from
RIT – Main Campus