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1	Control of Unmanned Aerial Vehicles using Non-linear Dynamic Inversion / Design av styrlagar för obemannade farkoster med hjälp av exakt linjärisering Karlsson, Mia January 2002 (has links) This master's thesis deals with the control design method called Non-linear Dynamic Inversion (NDI) and how it can be applied to Unmanned Aerial Vehicles (UAVs). In this thesis, simulations are conducted using a model for the unmanned aerial vehicle SHARC (Swedish Highly Advanced Research Configuration), which Saab AB is developing. The idea with NDI is to cancel the non-linear dynamics and then the system can be controlled as a linear system. This design method needs much information about the system, or the output will not be as desired. Since it is impossible to know the exact mathematical model of a system, some kind of robust control theory is needed. In this thesis integral action is used. A problem with NDI is that the mathematical model of a system is often very complex, which means that the controller also will be complex. Therefore, a controller that uses pure NDI is only discussed, and the simulations are instead based on approximations that use a cascaded NDI. Two such methods are investigated. One that uses much information from aerodata tables, and one that uses the derivatives of some measured outputs. Both methods generate satisfying results. The outputs from the second method are more oscillatory but the method is found to be more robust. If the signals are noisy, indications are that method one will be better. Reglerteknik Non-linear Dynamic Inversion exact linearization cascaded structure integral action flight control Unmanned Aerial Vehicles Reglerteknik Automatic control Reglerteknik
2	Control of Unmanned Aerial Vehicles using Non-linear Dynamic Inversion / Design av styrlagar för obemannade farkoster med hjälp av exakt linjärisering Karlsson, Mia January 2002 (has links) <p>This master's thesis deals with the control design method called Non-linear Dynamic Inversion (NDI) and how it can be applied to Unmanned Aerial Vehicles (UAVs). In this thesis, simulations are conducted using a model for the unmanned aerial vehicle SHARC (Swedish Highly Advanced Research Configuration), which Saab AB is developing. </p><p>The idea with NDI is to cancel the non-linear dynamics and then the system can be controlled as a linear system. This design method needs much information about the system, or the output will not be as desired. Since it is impossible to know the exact mathematical model of a system, some kind of robust control theory is needed. In this thesis integral action is used. </p><p>A problem with NDI is that the mathematical model of a system is often very complex, which means that the controller also will be complex. Therefore, a controller that uses pure NDI is only discussed, and the simulations are instead based on approximations that use a cascaded NDI. Two such methods are investigated. One that uses much information from aerodata tables, and one that uses the derivatives of some measured outputs. Both methods generate satisfying results. The outputs from the second method are more oscillatory but the method is found to be more robust. If the signals are noisy, indications are that method one will be better.</p> Reglerteknik Non-linear Dynamic Inversion exact linearization cascaded structure integral action flight control Unmanned Aerial Vehicles Reglerteknik Automatic control Reglerteknik
3	Implementation and comparison of the Aircraft Intent Description Language and point-mass Non-Linear Dynamic Inversion approach to aircraft modelling in Modelica Shreepal, Arcot Manjunath, Vijaya Kumar, Shree Harsha January 2021 (has links) The study is conducted to determine practical modelling and simulation techniques to perform dynamic stability and performance analysis on a 3 Degrees of freedom aircraft model using a Modelica-based commercial tool called Modelon Impact. This study is based on a conceptual aircraft model where in-depth details about the aircraft configuration are unknown and the aim is to determine a suitable model that can capture the longitudinal dynamics and aerodynamic constraints of the aircraft during the conceptual design phase. Requirements include short execution time, easy model development, and minimal data requirements. Therefore, this thesis aims at developing plant and control architectures in Modelon Impact which can be utilized for the rapid development of aircraft concepts with adequate fidelity in a longitudinal mission-based tracking environment. In a conceptual aircraft design environment, to identify a suitable methodology that mitigates the limitations of a traditional feedback controller, two methodologies are considered for comparison: Sequential DAE resolution (SDR) and Dynamic inversion (DI) control which is discussed from an object-oriented aircraft model. The advantages and shortcomings of each of the models discussed above are compared by conducting several experiments in increasing order of longitudinal mission complexity, and the most appropriate model among the two for a conceptual stage of aircraft design development is ascertained. The two methodologies discussed are compared for their level of complexity, code structure, readability, and ease of usability. aircraft Modelling Modelling and Simulation Aircraft Intent model-based systems engineering Flight dynamics Longitudinal stability Aircraft Modelling Non-linear Dynamic Inversion Conceptual aircraft design Dynamic Inversion control methods aircraft plant model Object-oriented aircraft model Air traffic management Modelica Modelon Impact Modelica tool 3DoF AIDL point-mass model Aerospace Engineering Rymd- och flygteknik

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