Dissertation (PhD)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Thesis (MScIng)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 2008. / Title from PDF title screen. "March 2008." "ADA 479957." Includes bibliographical references (p. 39-40). Also available online.

Thesis (M.E.)--University of New South Wales, 1999. / Also availalbe online.

Thesis (PhD (Civil Engineering))--University of Stellenbosch, 2007. / The current codes of practice for the design of structures which were studied during this investigation do not explicitly account for the flexibilities and interactions of the Electric Overhead Travelling Crane (EOHTC) and the crane support structure. This leads to analysing the EOHTC and the gantry structure as a decoupled system for ease of computation. Thus, the interaction of the various components of the EOHTC and gantry structure is ignored, which may result in an incorrect assessment of the forces computed in the gantry structure’s members. This led to a study to determine the effects of a EOHTC on the gantry structure. The research was conducted through a series of limited experimental tests and extensive advanced Finite Element Analysis (FEA) simulations. This resulted in developing a computationally efficient FEA model of the full scale experimental EOHTC testing facility in the structural engineering laboratory at Stellenbosch University. The FEA model was developed to conduct simulations for the various load models, namely, vertical wheel load, horizontal longitudinal load and the horizontal lateral load models, as prescribed by the various codes. The research was then focussed at determining the maximum end buffer impact force responses when the crane runs into the end stops. The other load models were investigated by another researcher using the same FEA model. The results from the experimental tests were used to calibrate the FEA simulations. This proved exceptionally challenging due to the various structural response phenomena which occur during the impact of the crane against the end stops. A good correlation between the experimental values and the values predicted by the FEA simulations was achieved for the first impact. Modal analysis and modal superposition methods of analysis were used to determine the effect of the modes of vibration on the structural response to the end buffer impact. A FEA sensitivity analysis was conducted on a set of identified parameters which have a significant effect on the structural response to the end buffer impact. The maximum end buffer impact force was determined for a chosen level of reliability based on the responses from the sensitivity analysis using the Lagrange Multiplier method. These maximum end buffer impact forces are then compared with the forces prescribed by the codes. SABS 0160 slightly underestimates, while SANS 10160 severely overestimates the end buffer impact force obtained from the constraint optimization technique for a target level of reliability of β =3.

Baigiamojo darbo tema yra suprojektuoti 20 t. kieliamosios galios ožinį kraną. Variantų analizė buvo padaryta, važiuoklės pavarai, kravinių kėlimo mechanizmui ir krano tiltui. Technologinė analizė parodė, kokios įrangos reikia, pagaminti du velenus ir pirštą. Ožinio krano ekonominiai rodikliai, krano kaina ir jos galima pardavimo kaina buvo apskaičiuojama. / The final paper’s theme is to design the gantry crane which load’s capacity is 20 tones. The variant analysis was done. It revealed that chassis gear, telpher, and beam were the most suitable parts for the gantry crane. The technological analysis showed what kind of equipment was needed in order to product two shafts and the girder. The gantry crane’s economical indicators, the crane’s cost price and its possible sale-price were calculated.

Norrköpings Hamn och Stuveri AB står inför en stor utmaning då verksamheterna i Norrköping delvis ska konsolideras till Pampusterminalen på Händelö på grund av det nya stadsdelsprojektet i Inre hamnen. Tillkommande verksamhet kommer göra anspråk på terminalyta, något som idag inte finns tillgängligt i Pampusterminalen. Dessutom är visionen för containerterminalen att den årligen hanterade volymen ska öka till 154 000 TEU år 2025 från dagens årligen 70 000 TEU. Det har i det här examensarbetet undersökts för de fysiska möjligheterna att ersätta dagens hanteringssystem där Reachstackers används, med ett modernare och mer hållbart elektriskt RTG-system, samt hur RTG-systemet skulle påverka containerhanteringen. Dessutom har en investeringskalkyl upprättats för att reda ut de ekonomiska effekterna av ett byte. Med hjälp av ett antal kapacitetsberäkningsmodeller har det visat sig att NHS i ett NHS i ett framtida skede bör ha möjlighet att hantera 154 000 containrar med cirka 1 400 TGS och fyra RTG-kranar. De totala inköps- och installationskostnaderna för fyra RTG-kranar skulle uppgå till cirka 60 000 000 kronor. Investeringskalkylen resulterade i ett nettonuvärde på 20 905 550 kr vilket är att betrakta som lönsamt. Baserat på insamlat underlag till den här undersökningen är det därför rekommenderat att NHS går vidare med planerna på att byta hanteringssystem för containerdepån.

Sending a man in space is extremely dangerous. In order to continue the space exploration, robots have to be used. Designed properly, robots can handle any kind of operations in deep space. But in space there is no support such as an after-sale service. That is why their conception must be as perfect as possible to satisfy many tests. This is also the case of the ERA (European Robotic Arm). Its operations must be tested on the ground. But since forces acting at ground level are different than in space (e.g. gravity), the ERA must be in such position (the Iron Bird project) so that the target that it wants to reach must be brought by another robot. This other robot is called ERICA (Era Iron-bird CLU hArdware simulation). The goal of this project is to make the mechanical conception of the ERICA. The project was carried out in four parts. The first consisted in gathering information about the ERA in order to establish the requirements. The second was a pre-conception part. The third consists in explaining the research that had been made to choose the proper design of the ERICA. In the fourth part, the mechanical and electrical conception is presented. The ERICA is a gantry system where the payload is a gimbal holding a target. That way, the 6 degrees of freedoms of the ERA are achieved. The gantry system is provided by LinMotion and the motors by Maxon. The electronic parts are attached to the gantry at different places. A frame surrounds the working envelope so that the CLU (Camera and Lightning Units) can be fixed on it as well as protective plates against the CLU’s laser.

Rotary Cranes (Tower Cranes) are common industrial structures that are used in building construction, factories, and harbors. These cranes are usually operated manually. With the size of these cranes becoming larger and the motion expected to be faster, the process of controlling them became dicult without using automatic control methods. In general, the movement of cranes has no prescribed path. Cranes have to be run under dierent operating conditions, which makes closed-loop control preferable. In this work, two types of controllers are studied: fuzzy logic and time-delayed position feedback controllers. The fuzzy logic controller is introduced first with the idea of split-horizon; that is, to use some fuzzy engines for tracking position and others for damping load oscillations. Then the time-delayed position feedback method is applied. Finally, an attempt to combine these two controllers into a hybrid controller is introduced. Computer simulations are used to verify the performance of these controllers. An experimental setup was built on which the time-delayed position feedback controller was tested. The results showed good performance. / Master of Science

Cranes are increasingly used in transportation and construction. increasing demand and faster requirements necessitate better and more efficient controllers to guarantee fast turn-around time and to meet safety requirements. Container cranes are used extensively in ship-to-port and port-to-ship transfer operations. In this work, we will extend the recently developed delayed position feedback controller to container cranes. In contrast with traditional work, which models a crane as a simple pendulum consisting of a hoisting cable and a lumped mass at its end, we have modeled the crane as a four-bar mechanism. The actual configuration of the hoisting mechanism is significantly different from a simple pendulum. It consists typically of a set of four hoisting cables attached to four different points on the trolley and to four points on a spreader bar. The spreader bar is used to lift the containers. Therefore, the dynamics of hoisting assemblies of large container cranes are different from that of a simple pendulum. We found that a controller which treats the system as a four-bar mechanism has an improved response. We developed a controller to meet the following requirements: traverse an 80-ton payload 50 m in 21.5 s, including raising the payload 15 m at the beginning and lowering the payload 15 m at the end of motion, while reducing the sway to 50 mm within 5.0 s at the end of the transfer maneuver. The performance of the controller has been demonstrated theoretically using numerical simulation. Moreover, the performance of the controller has been demonstrated experimentally using a 1/10th scale model. For the 1/10th scale model, the requirements translate into: traverse an 80 kg payload 5 m in 6.8 s, including raising 1.5 m at the beginning and lowering 1.5 m at the end of motion, while reducing the sway to 5 mm in under 1.6 s. The experiments validated the controller. / Master of Science