Inertial stabilized platforms consisting of a two-axis gimbal assembly are often modelled as two independent SISO systems, describing the dynamics of the elevation axis and the azimuth axis respectively. In reality the state of the elevation channel and the state of the azimuth channel affect each other. Hence, the system is better modelled as a MIMO system with coupled dynamics, which means that the system has multiple inputs and outputs, where each input can affect multiple outputs. Since the couplings between the elevation channel and the azimuth channel have a deteriorating effect on control it is of interest to analyse what gives rise to the coupled dynamics and if control performance can be improved by considering the coupled dynamics. For this purpose, this thesis attempts to derive a dynamic model of the system of interest, both with the aid of physical modeling and system identification. Both modeling methods result in models with similar dynamics which seem to capture the coupled dynamics in the relevant frequency range. From the physical modeling it can be inferred that the degree of coupled dynamics depends on the mass distribution of the two-axis gimbal assembly. For the specific configuration of the system used in this investigation, the degree of coupled dynamics proved to be relatively small with relatively small impact on control. Based on the derived models, three types of controllers were implemented, decentralized control, decentralized control with a decoupler and decentralized control with an inner loop for rejection of mutual disturbances acting between the elevation axis and azimuth axis. Compared to standard decentralized control, the decoupler resulted in a somewhat better reference tracking and in a somewhat worsened disturbance rejection. Compared to standard decentralized control, the inner loop disturbance compensator resulted in a somewhat better performance for reference and disturbance rejection. / Inertialstabiliserade plattformar bestående av en tvåaxlig gimbal modelleras ofta som två oberoende SISO system som beskriver dynamiken för rörelse kring elevationsaxeln respektive azimutaxeln. I verkligheten påverkar tillstånden i elevationskanalen samt azimutkanalen varandra. Därmed kan systemet bättre modelleras som ett kopplat MIMO system, vilket innebär ett system med multipla in och utsignaler, där varje insignal kan påverka flera utsignaler. Eftersom den kopplade dynamiken har en försämrande effekt på systemets reglerprestanda är det av intresse att undersöka varför den kopplade dynamiken uppkommer, samt om reglerprestanda kan förbättras genom att beakta den kopplade dynamiken. För att undersöka detta söker denna rapport att med fysikalisk modellering samt systemidentifiering bygga en modell av systemet som innehåller den kopplade dynamiken. Båda metoderna resulterar i modeller med liknande dynamik, som verkar fånga den kopplade dynamiken i det relevanta frekvensspannet. Från den fysikaliska modelleringen kan det härledas att graden av kopplad dynamik beror på massfördelningen av systemet. För den specifika konfigurationen av systemet som var föremål för denna undersökning visar det sig att den kopplade dynamiken är relativt svag med relativt liten inverkan på reglerprestanda. Baserat på de framtagna modellerna implementerades och undersöktes tre typer av controllers, decentralized control, decentralized control med en decoupler, samt decentralized control med en inre loop för kompensering av störningar mellan elevations- och azimutaxeln. Jämfört med endast decentralized control gav decouplern något bättre reglerprestanda med avseende på reference tracking, men något sämre reglerprestanda med avseende på disturbance rejection. Jämfört med endast decentralized control gav en inre loop för kompensering av störningar mellan elevations- och azimutaxeln något bättre reglerprestanda med avseende på reference tracking samt disturbance rejection.

For elderly Canadians, the prevalence of vision impairment caused by degenerative retinal pathologies, such as age-related macular degeneration and retinitis pigmentosa, is at an occurrence rate of 14 percent, and on the rise. It has been shown that visual function can be restored by electrically stimulating intact retinal tissue with an array of micro-electrodes with suitable signals. Commercial retinal implants carrying such a micro-electrode array achieve this, but to date must receive power and data over copper wire cable passing through a permanent surgical incision in the eye wall (sclera). This project is defined by a collaboration with iBIONICS, who are developing retinal implants for treatment of such conditions. iBIONICS has developed the Diamond Eye retinal implant, along with several technology sub-systems to form a comprehensive and viable medical solution. Notably, the Diamond Eye system can be powered wirelessly, with no need for a permanent surgical incision. The thesis work is focused on the formulation, simulation and hardware demonstration of a powering system, mounted on glasses frame, for a retinal implant. The system includes a Micro-Electro-Mechanical System (MEMS) mirror that directs a laser beam to the implant through the pupil opening. The work presented here is built on two main components: an iterative predictor-corrector algorithm (Kalman filter) that estimates pupil coordinates from measurements provided by an image-based eye tracking algorithm; and an misalignment compensation algorithm that maps eye pupil coordinates into mirror coordinates, and compensates for misalignment caused by rigid body motions of the glasses lens mirror and the MEMS mirror with respect to the eye. Pupil tracker and misalignment compensation control performance are illustrated through simulated scenarios. The project also involves the development of a hardware prototype that is used to test algorithms and related software.

In this study, a parametric model for a main battle tank electric gun turret drive system stabilization controller has been developed. Main scope was the study of the muzzle deviation due to barrel flexibility. Traverse and elevation dynamics has been modeled to include the drive-line and barrel flexibilities. Order of the models has been kept large enough to cover the frequencies dominant in the interest scope but at the same time low enough to create a parametric model which can be used in real-time fire control computers. Therefore a 5-dof elevation and a 7-dof traverse models have been implemented. These models have been used to design a classical feedback and feedforward controllers which performed good enough to meet 0.5mrad stabilization accuracies. After satisfactory results have been obtained from the stabilization controller, a special coincidence algorithm has been implemented by time-series analysis of the disturbance signal which is constantly being measured by the feedforward gyro. Necessity of predicting the future muzzle angular orientation due to the latency in fire is discussed and by using autoregressive modeling of the disturbance signal, future values of the disturbance signal has been entered into the observer model. The prediction horizon has been set to the time delay value between the trigger is pulled by the gunner and the ammunition exit from the muzzle. By checking the future coincidence within a very narrow windowing (0.05mrad) a 100% first round hit probability in theory has been achieved. This is assured since the coincidence inhibited the fire signals which were to miss the aiming point with a large error.

Cable-actuated manipulators (or 'cable robots') constitute a relatively new classification of robots which use motors, located at fixed remote locations, to manipulate an end-effector by extending or retracting cables. These manipulators possess a number of unique properties which make them proficient with tasks involving high payloads, large workspaces, and dangerous or contaminated environments. However, a number of challenges exist which have limited the mainstream emergence of cable robots. This thesis addresses two of the most important of these issues-- workspace analysis and disturbance compensation. Workspace issues are particularly important, as many large-scale applications require the end-effector to operate in regions of a particular shape, and to exert certain minimum forces throughout those regions. The 'Force-Feasible Workspace' represents the set of end-effector positions, for a given robot design, for which the robot can exert a set of required forces on its environment. This can be considered as the robot's 'usable' workspace, and an analysis of this workspace shape for point-mass cable robots is therefore presented to facilitate optimal cable robot design. Numerical simulation results are also presented to validate the analytical results, and to aid visualization of certain complex workspace shapes. Some cable robot applications may require mounting motors to moving bases (i.e. mobile robots) or other surfaces which are subject to disturbances (i.e. helicopters or crane arms). Such disturbances can propagate to the end-effector and cause undesired motion, so the rejection of motor mount disturbances is also of interest. This thesis presents a strategy for measuring these disturbances and compensating for them. General approaches and implementation issues are explored qualitatively with a simple one-degree-of-freedom prototype (including a strategy for mitigating accelerometer drift), and quantitative simulation results are presented as a proof of concept.