Cooperative control of autonomous multi-agent systems is a research areawhich is getting significant attention in recent years. Multi-agent systemsallow for a broad spectrum of applications and cooperation can increasetheir flexibility, efficiency and robustness to changes in external constraintsand disturbances. Focusing on autonomous vehicles, examples of possibleapplications of cooperative multi-agent systems include search and rescuemissions, autonomous delivery and performing of emergency landings.The purpose of the thesis is to develop and implement a cooperativerendezvous algorithm based on model predictive control and apply it to theproblem of autonomous landing in an indoor setting. The agents involved in themaneuver are a quadcopter and a ground carrier. The two agents cooperativelynegotiate on the optimal location for the touchdown taking also into accountrelevant spatial constraints and, if necessary, update that location, also referredto as rendezvous point, in real-time throughout the maneuver.The algorithm is first tested and validated in a simulated environment andfinally on the physical system during real-time operations.Additional scenarios are tested in the simulated environment in order tofurther inspect the potential capabilities of the developed algorithm. Thoseadditional simulations analyse how the algorithm behaves when a constantlateral wind influences the quadcopter; when the controllers operate at areduced frequency; and when the quadcopter is affected by an external Gaussiandisturbance.The developed algorithm proved to be suitable for the purpose, allowingthe agents to perform the desired maneuver in a relatively short time and witha high degree of precision. / Kooperativ reglering av autonoma fleragentsystem är ett forskningsområdesom har fått stor uppmärksamhet de senaste åren. Fleragentsystem möjliggörett brett spektrum av applikationer samtidigt som kooperation kan öka derasflexibilitet, effektivitet och robusthet mot förändringar i yttre begränsningar ochstörningar. Med fokus på autonoma fordon, exempel på möjliga tillämpningarav kooperativa fleragentsystem inkluderar sök- och räddningsuppdrag, autonomleverans och utförande av nödlandningar.Syftet med rapporten är att utveckla och implementera en kooperativrendezvous -algoritm baserad på modellprediktiv reglerteknik samt att tillämpaden för att utföra en inomhus autonom landning. I vår uppställning beståragenterna i manövern av en quadcopter och en markbärare. De två agenternaförhandlar samarbetsvilligt om den optimala platsen för landning samtidigtsom de beaktar relevanta rumsliga begränsningar och uppdaterar vid behovden platsen i realtid under hela manövern.Algoritmen testas och valideras först i en simulerad miljö och slutligen pådet fysiska systemet under en realtidsmiljö.Ytterligare scenarier testas i den simulerade miljön för att bortre inspekterapotentialen hos den utvecklade algoritmen. Dessa extra simuleringar illustrerarhur algoritmen beter sig när en konstant sidovind påverkar quadcoptern; närstyrenheterna arbetar med reducerad frekvens; och när quadcoptern påverkasav en yttre Gaussisk störning.Den utvecklade algoritmen visade sig vara lämplig för ändamålet, vilketgjorde att agenterna kunde utföra önskad manöver på relativt kort tid och medhög precision.

Vision-based conventional landing of a fixed wing UAV is addressed in this thesis. The work includes mathematical modeling, interface to a software for rendering the outside scenery, image processing techniques, control law development and outdoor experimentation. This research focuses on detecting the lines or the edges that flank the landing site, use them as visual cues to extract the geometrical parameters such as the line co-ordinates and the line slopes, that are mapped to the control law, to align and conventionally land the fixed wing UAV. Pre-processing and image processing techniques such as Canny Edge detection and Hough Transforms have been used to detect the runway lines or the edges of a landing strip. A Vision-in-the-Loop Simulation (VILS) set up on a personal computer or laptop, has been developed, without any external camera/equipment or networking cables that enables visual serving toper form vision-based studies and simulation. UAV mass, inertia, engine and aero data from literature has been used along withUAV6DOF equations to represent the UAV mathematical model. The UAV model is interfaced to a software using UDP data packets via ports, for rendering the outside scenery in accordance with the UAV’s translation and orientation. The snapshots of the outside scenery, that is passed through an internet URL by including the ‘http’ protocol, is image processed to detect the lines and the line parameters for the control. VILS set has been used to simulate UAV alignment to the runway and landing. Vision-based alignment is achieved by rolling the UAV such that the landing strip that is off center is brought to the center of the image plane. A two stage proportional aileron control input using the line co-ordinates, bringing the midpoints of the top ends of the runway lines to the center of the image, followed by bringing the mid points of the bottom ends of the runway lines to the center of the image has been demonstrated through simulation. A vision-based control for landing has been developed, that consists of an elevator command that is commiserate with the acceptable range of glide slope followed by a flare command till touch down, which is a function of the flare height and estimated height from the 3rd order polynomial of the runway slope obtained by characterization. The feasibility of using the algorithms for a semi-prepared or unprepared landing strip with no visible runway lines have also been demonstrated. Landing on an empty tract of land and in poor visibility condition, by synthetically drawing the runway lines based on a single 3rd order slope. vs height polynomial solution are also presented. A fixed area, and a dynamic area search for the Hough peaks in the Hough accumulator array for the correct detection of lines are addressed. A novel technique for crosswind landing, quite different from conventional techniques, has been introduced, using only the aileron control input for correcting the drift. Three different strategies using the line co-ordinates and the line slopes, with varying levels of accuracy have been presented and compared. About 125 landing data of a manned instrumented prototype aircraft have been analysed to corroborate the findings of this research. Outdoor experiments are also conducted to verify the feasibility of using the line detection algorithm in a realistic scenario and to generate experimental evidence for the findings of this research. Computation time estimates are presented to establish the feasibility of using vision for the problem of conventional landing. The thesis concludes with the findings and direction for future work.