<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-23T17:37:51.750792810Z</responseDate><request verb="GetRecord" identifier="oai:repository.nwu.ac.za:10394/36221" metadataPrefix="dim">https://repository.nwu.ac.za/server/oai/request</request><GetRecord><record><header><identifier>oai:repository.nwu.ac.za:10394/36221</identifier><datestamp>2020-11-06T09:02:44Z</datestamp><setSpec>com_10394_26463</setSpec><setSpec>col_10394_26475</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Van Schoor, G.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="advisor" lang="en_US">Uren, K.R.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author" lang="en_US">Otto, G.</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="researchID" lang="en_US">12134457 - Van Schoor, George (Supervisor)</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="researchID" lang="en_US">12064203 - Uren, Kenneth Richard (Supervisor)</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="accessioned">2020-11-05T07:10:28Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="available">2020-11-05T07:10:28Z</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued" lang="en_US">2020</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri" lang="en_US">https://orcid.org/0000-0003-2279-5871</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/10394/36221</dim:field>
   <dim:field mdschema="dc" element="description">PhD (Computer and Electronic Engineering), North-West University, Potchefstroom Campus</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract">A strategy is presented for the real-time generation of tactical, dynamically feasible 4D&#xd;
trajectories. The current framework for automatic flight control is analysed, along with&#xd;
current research into autonomous unmanned systems, to develop a technique for trajectory&#xd;
generation that not only works efficiently in the current architecture but also enhances&#xd;
the capabilities. The algorithm is based on a segmented trajectory constructed using quartic, i.e. 4ᵗʰ&#xd;
order, Pythagorean Hodograph (PH) curves based on Bézier splines. This yields nonic&#xd;
spatial curves, joined so as to ensure second order geometric (G²) continuity. The spatial&#xd;
trajectory is speci fied using way-points, tangents, and a geometric acceleration vector&#xd;
that controls the curvature. A velocity pro le is constructed to add the time component,&#xd;
which can be speci fied as a time of arrival or velocity at each way-point. Additionally&#xd;
the tangent, consisting of a heading and climb angle, can be specifi ed or calculated&#xd;
automatically. The primary contribution of this study is extending the algorithm to include all the&#xd;
orientational information, thus including the roll angle of the craft in the Pythagorean&#xd;
Hodograph (PH) curve construction. The demonstration of a basic aircraft performance&#xd;
model (APM) serves to illustrate the used of dynamic non-linear constraints, allowing for&#xd;
improved utilisation of the flight envelope. The computational advantages of using splines is shown by presenting an extensive collection of performance metrics to analyse the trajectory's efficiency and mission&#xd;
performance. The inclusion of the orientational dynamics allows for a more detailed&#xd;
analysis of the aircraft's aerodynamic performance. Using the results of the trajectory&#xd;
evaluation it is possible to apply kinodynamic constraints to ensure that the trajectory is&#xd;
within the aircraft's &#xd;
flight envelope.</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="thesistype" lang="en_US">Masters</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso" lang="en_US">en</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en_US">North-West University (South Africa)</dim:field>
   <dim:field mdschema="dc" element="subject">UAV</dim:field>
   <dim:field mdschema="dc" element="subject">Navigation</dim:field>
   <dim:field mdschema="dc" element="subject">Bézier Spline</dim:field>
   <dim:field mdschema="dc" element="subject">Kinodynamic</dim:field>
   <dim:field mdschema="dc" element="subject">Trajectory Generation</dim:field>
   <dim:field mdschema="dc" element="subject">Motion Planning</dim:field>
   <dim:field mdschema="dc" element="subject">Pythagorean Hodograph (PH) curve</dim:field>
   <dim:field mdschema="dc" element="title" lang="en_US">Advanced four-dimensional trajectory generation for tactical guidance of unmanned aerial vehicles</dim:field>
   <dim:field mdschema="dc" element="type" lang="en_US">Thesis</dim:field>
   <dim:field mdschema="others" element="access-status">open.access</dim:field>
</dim:dim></metadata></record></GetRecord></OAI-PMH>