Flight Mechanics, Flight Control and Aeroelasticity

Written-out Theses

Creation of trajectory optimization algorithms for energy consumption reduction (Master thesis).

Based on a given kinematic model of aircraft motion and a simplified consumption model, approaches to trajectory planning and optimization will be considered. These may include:

  • Collocation methods: Example "An Introduction to Trajectory Optimization: How to Do Your Own Direct Collocation" (Matthew Kelly).
  • Model Predictive Approaches (MPC).
  • Field-based methods: For example, A*
  • Graph-based methods: RRT

The paper includes a literature review and selection of an approach. A demonstration of feasibility (Matlab/Simulink/C) would be desirable.

If interested, please contact Henrik Spark.

 

Development of a method to determine the maximum accelerations of a UAV as a function of the flight condition (Bachelor or Master thesis, Flight Mechanics 2 required).
Based on the equations of motion of a multicopter, the maximum accelerations are to be determined (theoretically) as a function of the flight speed. The determined accelerations are to be subsequently verified using an appropriate method.

The steps include:

  • Research on the modeling and testing of multicopters.
  • Theoretical analysis of the maximum accelerations based on the equations of motion (simplified) of a multicopter.
  • Development of a method to experimentally determine the maximum accelerations.
  • Testing of the method in a nonlinear simulation (and in a flight test).

If interested, please contact Christopher Ruwisch.


Tracking Performance Analysis and Evaluation of UAVs with and without wind disturbances (Bachelor or Master Thesis, Flight Mechanics 2)   
Based on a nonlinear simulation model of a multicopter, the tracking performance of the position control system will be analyzed and evaluated.

Work in this area may include the following:

  • Research on analysis and evaluation of tracking performance of UAVs.
  • Modeling of wind disturbances (especially with respect to urban areas) in Matlab/Simulink or C++.
  • Analysis of tracking performance under different wind disturbances for a specified controller in a nonlinear simulation using appropriate methods.
  • Evaluation of tracking performance using a suitable metric.

If interested, please contact Christopher Ruwisch.

Creation of a basic flight controller for parametric aeroelastic model design of complete aircraft (Bachelor or Master thesis).

In the design of aircraft, the dimensioning of the structure depends on the flight loads. These in turn are significantly influenced by the flight control, which is primarily designed for the orbit and attitude control of an aircraft, taking into account the flight behavior. In the thesis, a generic flight controller is to be designed in such a way that its parameters are based on those of the respective designed aircraft configuration. Furthermore, this controller shall be integrated into an existing tool for aeroelastic model design.

If interested, please contact Wolf Krüger.

Development and assessment of a new, distributed load alleviation system based on integrated load- and actuator control (Master thesis)

The scope of the thesis comprises development and implementation of a decentralized load control system for the inboard and outboard ailerons, which is based on the new control concept. The controller shall be validated and compared to a classical control approach using a closed-loop simulation environment comprising of an aero-servo elastic model of a generic long-range aircraft, flight control systems and actuation models.

The steps include:

  • Defining a control structure based on the new approach, which is suitable to control the roll- and plunge dynamics as well as selected aeroelastic modes
  • Implementation of the control structure using MATLAB/SIMULINK
  • Derivation of linear models from the non-linear simulation for representative reference flight states
  • Linear design of the control parameters for the selected envelope points using structured state feedback and modal control techniques
  • Assessment of the control behaviour in the non-linear simulation for selected reference flight states (using the corresponding parameter set) 
  • Analysis of the control effort and sensitivity of stability and control quality with respect to actuator performance constraints
  • Comparison of the developed controller with a centralised load alleviation approach (relying on classical, position controller actuators) based on suitable benchmark criteria

If interested, please contact Dr.-Ing. Wolfram Meyer-Brügel

LPV/LFR Control for Active Flutter Suppression of a Typical Section (Master Thesis)

The FMRA has developed a novel gain-scheduling state-feedback control strategy to cope with the active flutter suppression of a smart airfoil model. Unlike other gainscheduled control approaches in the literature, this one allows combining the polytopic and linear fractional representations into a particular framework to increase the degrees of freedom of a control design. The synthesis conditions have been derived using parameter-dependent Lyapunov functions associated with a static full-block multipliers concept to obtain a less conservative condition such that all time-varying parameters of the linear system may be incorporated. The distinctive gain-scheduled controller is es-tablished from the existence of linear matrix inequalities (LMIs) conditions, where the main steps to obtain such a parameter-dependent controller are given.

The research task includes:

  • Literature review on Flutter, Active Flutter Suppression, LPV/LFR Control and typical section modelling.
  • Select and characterise a new set of torsional springs for the typical section.
  • Update and validate the typical section model via wind tunnel experiments.
  • Design the LPV/LFR Control for AFS of the typical section.
  • Implement and test the control for AFS of the typical section in the wind tunnel.
  • Discussion and critical evaluation of results.
  • Documentation of all work steps

If interested, please contact Dr. Pedro Jose Gonzalez Ramirez.