Attitude and position control of a quadrotor using on board vision system

Download

index.pdf

Date

2019

Author

Tüzel, Şerafettin

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

311
views

311
downloads

In this thesis, localization and trajectory following of a quadrotor is obtained with attitude and position control along with the help of an onboard monocular camera. Two control strategies are adopted for this aim, which are well-known PID and nonlinear backstepping controllers. For the PID algorithm, a cascaded structure is preferred so that angular rates are regulated as the inner loop of the attitude controller. At the outer loop of this system, angles are stabilized by producing rate references to the inner loop. PID is a proven method to control nonlinear systems, giving satisfactory system performances. Linearised or simplified system models are generally used to design PID controllers, and implementation is usually straight forward. On the other side, backstepping controller is selected since it does not cancel nonlinearities of the system model. The aim of this method is to obtain the final inputs by creating virtual system inputs in a recursive manner. Since it directly uses system equations of motion, nonlinearities like coupling between axes and actuator frictions are comprised by the controller. This also enables better performance in disturbance rejection. If the strategy is followed properly, backstepping gives satisfactory results. To be able to design these controllers, quadrotor system is modelled within this study. Equations of motion are obtained and quadrotor behaviour is simulated by using Simulink. The responses of the controllers to given references are compared with the usage of this model representation. A real platform is formed for the verification of the proposed control methods. The quadrotor uses a Pixhawk board which includes the main control algorithms. These algorithms are formed in Simulink and Embedded Coder is used to trasfer the program to the Pixhawk. For the localization operation, RaspberryPi board is selected and also used with Simulink application. From the images obtained by the Raspberry, position errors are propagated so that attitude controllers on the Pixhawk can regulate the errors down to zero for stabilization. Serial communication is preferred as the connection interface and hardware and software schemes are explained along this study. As the main aim orients, designed localization and path tracking capabilities are shown on the target platform.

Subject Keywords

Vehicles, Remotely piloted., Quadrotor, PID, Backstepping Controller, Path Tracking, Image Processing.

URI

http://etd.lib.metu.edu.tr/upload/12624740/index.pdf
https://hdl.handle.net/11511/44817

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Landing autopilot design for an UAV Hanköylü, Merve; Çiloğlu, Tolga; Department of Electrical and Electronics Engineering (2011) In this thesis, a landing autopilot for an UAV (IAI Pioneer RQ-2) is designed based on a nonlinear MATLAB model implemented with MATLAB/Simulink. In order to control the movement of the UAV at lateral and longitudinal axes, a speed, an altitude, a heading angle (direction) and a yaw rate controllers are designed. Controller design procedure is started with determination of different trim points of the aircraft. Next, the corresponding initial states and initial inputs are obtained. The model is linearized a...
OPTICAL SYSTEM DESIGN, INTEGRATION AND TESTING OF A 2D SCANNING LIDAR Cerit, Kübra; Bek, Alpan; Department of Physics (2022-1-20) In this thesis, optical system design, integration and testing of a compact LIDAR system with 270 degree field-of-view that based on time of flight principle is developed by Rekrom Optoelectronics. This system can identify objects and measure distances up to 100 m away. LIDAR has become a much needed and used technology in various fields. The most important of these areas are robotic systems, autonomous vehicles and unmanned aerial, land and sea platforms navigation and environmental awareness. The main r...
Trajectory tracking of a quadrotor unmanned aerial vehicle (UAV) via attitude and position control Suiçmez, Emre Can; Kutay, Ali Türker; Department of Aerospace Engineering (2014) In this thesis, trajectory tracking of a quadrotor UAV is obtained by controlling attitude and position of the quadrotor simultaneously. Two independent control methods are used to track desired trajectories accurately. One of these methods is a nonlinear control approach called as "backstepping control". The other method is a more unique optimal control approach called as "Linear Quadratic Tracking(LQT)". In addition, fixed-gain LQR controller which is widely used in literature is also used for comparison ...
External geometry and flight performance optimization of turbojet propelled air to ground missiles Dede, Emre; Tekinalp, Ozan; Department of Aerospace Engineering (2011) The primary goal for the conceptual design phase of a generic air-to-ground missile is to reach an optimal external configuration which satisfies the flight performance requirements such as flight range and time, launch mass, stability, control effectiveness as well as geometric constraints imposed by the designer. This activity is quite laborious and requires the examination and selection among huge numbers of design alternatives. This thesis is mainly focused on multi objective optimization techniques for...
Object recognition and segmentation via shape models Altınoklu, Metin Burak; Ulusoy, İlkay; Tarı, Zehra Sibel; Department of Electrical and Electronics Engineering (2016) In this thesis, the problem of object detection, recognition and segmentation in computer vision is addressed with shape based methods. An efficient object detection method based on a sparse skeleton has been proposed. The proposed method is an improved chamfer template matching method for recognition of articulated objects. Using a probabilistic graphical model structure, shape variation is represented in a skeletal shape model, where nodes correspond to parts consisting of lines and edges correspond to pa...

Citation Formats

Ş. Tüzel, “Attitude and position control of a quadrotor using on board vision system,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Mechanical Engineering., Middle East Technical University, 2019.