Dynamics and Control of manipulating robots currently is a major field of research in robotics. Various methods of efficiently formulating the non-linear dynamics have been proposed with an emphasis on reducing the computations necessary to solve the dynamics. Several control concepts and algorithms have been suggested. / Master of Science

Collision-detection is a critical task for off-line robot path planning. A general robot path verification simulation system, GRPVSS, applicable for all industrial robots with open-looped links, is created to verify the intended robot path. The manipulator and obstacles are modeled by convex polyhedra to reduce the computation burden required by the collision detection algorithm. As a kinematic simulator, GRPVSS employs motion-time profiles or ideal trapezoid profiles which describe the position-vs-time relation of an individual joint, to generate the robot working trajectory. This approach makes the to-be-verified working path closer to the real one. Both point-to-point(PTP) and continuous path(CP) operations can be simulated by GRPVSS. Collision detection is conducted by performing geometric interference detection between the static configurations of the expanded moving robot and the static obstacles at each simulation step. Inn this case, the resolution of a simulation is critical to path verification. Simulations with low resolution take the risk of undetected collisions, while simulations with high resolution consume too much computing time. GRPVSS computes and employs the lowest resolution level that yields 100% path verification for the specified tolerances of manipulator dimensions. The tolerance value is specified by the user but should not be specified smaller than the positioning accuracy of the simulated industrial robot. The links of the manipulator are expanded by the amount of tolerance. GRPVSS is a graphic simulator. A systematic control supervisor is constructed for the simulator to request input and to proceed all functions interactively with users. The robot motion of a simulated path is animated on a 3-D graphical screen. A11 collision configurations and related information of the simulated path are stored in a file and shown on the screen. The graphical display works on graPHIGS, one of the 3-D graphical software packages published by IBM. / Master of Science

This thesis presents a unification of kinematic and force-based methods for the design and analysis of planetary gear trains along with a discussion of potential applications in tandem biking. Specifically, this thesis will provide a simple solution technique for the general case of a two-degree of freedom (2DOF) planetary gear train along with new graphical design aids. It will also address the use of epicyclic gear trains as a power coupling in a tandem bike. In the current literature, planetary gear trains are given a clear treatment with regard to the pure kinematics of the system, but little or no literature exists that includes the torques present in the system. By treating both the kinematics and torque balance of the most general case, this thesis attempts to fill a void in the current literature. After developing the solution to the general two-degree of freedom case using the Willis formula, a force analysis will be performed using the conservation of energy principle assuming zero losses. Once the total solution is known, nomographs will be presented as a simple design tool. These graphical aids enable the designer to simultaneously approximate both speeds and torques for the mechanism. After fully developing a satisfactory solution technique and design tools, these will be applied to the problem of coupling the power provided by the riders of a tandem bicycle. / Master of Science

Each year, falls from elevated structures, like scaffolding, kill or seriously injure over a thousand construction workers (Bureau of Labor Statistics, 2007). To prevent such falls, the development of a robotic system is proposed that can climb and navigate on the complex structures, performing hazardous inspection and maintenance in place of humans. In this work, a serpentine robotic system is developed that will be able to climb pole-like structures, such as scaffolding and trusses, commonly found on work sites. Serpentine robots have been proven to be effective at traversing unstructured terrains and manipulating complex objects. The work presented in this thesis adds a new method of mobility for serpentine robots, specifically those with actuated universal joint structures. Movement is produced by inducing a wobbling motion between adjacent modules through oscillatory motions in the actuated axis of the universal joint. Through the frictional interactions between the modules of the serpentine and the surface of the pole, the wobbling motion lets the serpentine effectively roll up the pole's surface. This work investigates theoretical and experimental results for a serpentine robot climbing a pole structure. It discusses the structure and design parameters of the robot and develops relationships between them. These geometric and performance-based relationships are then used to create a design space that provides a guide for choosing a combination of module dimensions for a desired set of performance parameters. From this, case studies are shown which give examples of how the design space can be used for several different applications. Based on the design space procedure, a serpentine robot, HyDRAS (Hyper-Redundant Discrete Robotic Articulated Serpentine) was designed and built. The robot was used to prove the validity of the design space procedure and to validate the climbing motion algorithms. Several tests were performed with HyDRAS that showed the practicality of the helical rolling motion, as well as the feasibility of serpentine pole climbing. Observations and discussion based on the experiments are given, along with the plans for future work involving pole-climbing serpentine robots. / Master of Science

This thesis presents a technique for designing planar four-bar linkages by coupling optimization, dynamics and kinematics. This synthesis technique gives the designer the ability to design linkages having a desired resistance profiles under an assumed motion profile. The design approach presented in this thesis calculates the resistance forces by using both the static and the anticipated dynamic effects of the resistance loading. Almost all research to date has assumed that the static forces in the linkage dominate the dynamic forces; hence, the dynamic effects have been neglected. This thesis shows that this assumption is often invalid. The traditional approach for designing resistance-generating mechanisms has been based on closed-form methods that attempt to exactly match the resistance at a small number of discrete positions. This work uses a numerical optimization method that allows for the matching of the entire resistance curve by approximately matching a set of positions that define the shape of the curve. This work furthers the discipline of mechanism design by combining dynamics into existing linkage synthesis methods, resulting in an improved synthesis method that includes both static and dynamic effects. While this approach can be used in many applications, this work focuses on the design of exercise equipment. This focus is because exercise equipment designed to optimally stress a specific muscle group usually have a specific " strength curve " used to design the resistance load. The "strength curve" is the locus of all maximum loads moveable by the exerciser in all body part positions over the full range of motion. This application ideally suits the specification of the problem addressed in this thesis. / Master of Science

This study investigated the effects of delayed auditory feedback (DAF) on speech kinematics during tongue twisters and monologues. Participants were 20 adults (10 men, 10 women) aged 18-29 with typical speech and hearing abilities. A smartphone app provided DAF latencies of 50 ms, 100 ms, and 150 ms. Kinematic measures were made of peak speed, stroke distance, and hull area for the tongue front, jaw, and lower lip under typical and the three DAF conditions. Results indicated that DAF significantly reduced peak speed and stroke distance for all articulators during tongue twisters (p < .01), with the effect magnitude increasing with longer delays. No significant DAF effects were observed in monologues (p > .05). Sex differences were noted, with women showing higher speeds and longer stroke distances across both tasks (p < .05). These findings suggest that DAF disrupts motor performance, particularly in structured tasks, and that sex differences are present in speech kinematics. Future research could explore the perceptual impacts of DAF and the cognitive load associated with speech under altered feedback conditions.

Physics education research found that graphs in kinematics have been a problem to students, even at university level. The study hence investigates what deficiencies first-year Physics students at the Central University of Technology, Bloemfontein, South Africa have in terms of transferring mathematics knowledge and understanding when solving kinematics problems. According to the National Department of Education (DoE, 2003), mathematics enables learners to have creative and logical reasoning about problems in the physical and social worlds. Graphs in kinematics are one of the domains that need that skill in mathematics. DoE (2011) further emphasises that learners should be able to collect, analyze, organize and critically evaluate information at the end of their FET sector and that include graphing in kinematics. The study started by exploring graph sense and comprehension from literature. The study further explored from a literature review students‘ problems and possible solutions in transferring their mathematics understanding and knowledge to solve physics problems. The literature study served as conceptual framework for the empirical study, i.e. the design and interpretation of questionnaires, and interview questions. The mathematics and kinematics questions of the questionnaire were divided into four constructs, namely area, gradient, reading coordinates and form/expression of graphs. The participants undertook the questionnaire and interviews voluntarily according to the research ethics. Hundred and fifty two (152) out of 234 students registered for first-year physics from the faculties of humanities (natural science), health and environmental science and engineering and information technology undertook the questionnaire. The researcher interviewed 14 students of these participants as a follow up to the responses of the questionnaire. The responses of the participants were analysed statistically to conclude this study. The average percentages of the questionnaire showed that the majority (62.7% participants) have the mathematics knowledge compared to the low percentage of 34.7 % on physics knowledge. With regard to the constructs the participants generally performed similarly on gradient, reading coordinates and form/expression, i.e. they could either answer both the corresponding mathematics and physics questions and neither of them. In the area construct, most participants with the mathematics knowledge did not transfer it to the physics context. The study further revealed that the majority of interviewees do not have an understanding of the basic physics concepts such as average velocity and acceleration. The researcher therefore recommends that physical science teachers in the FET schools should also undergo constant training in data handling and graphs by subject specialists and academic professionals from Higher Education Institutions. Other remedial actions are also proposed in the dissertation. / MSc (Natural Science Education), North-West University, Potchefstroom Campus, 2015

Physics education research found that graphs in kinematics have been a problem to students, even at university level. The study hence investigates what deficiencies first-year Physics students at the Central University of Technology, Bloemfontein, South Africa have in terms of transferring mathematics knowledge and understanding when solving kinematics problems. According to the National Department of Education (DoE, 2003), mathematics enables learners to have creative and logical reasoning about problems in the physical and social worlds. Graphs in kinematics are one of the domains that need that skill in mathematics. DoE (2011) further emphasises that learners should be able to collect, analyze, organize and critically evaluate information at the end of their FET sector and that include graphing in kinematics. The study started by exploring graph sense and comprehension from literature. The study further explored from a literature review students‘ problems and possible solutions in transferring their mathematics understanding and knowledge to solve physics problems. The literature study served as conceptual framework for the empirical study, i.e. the design and interpretation of questionnaires, and interview questions. The mathematics and kinematics questions of the questionnaire were divided into four constructs, namely area, gradient, reading coordinates and form/expression of graphs. The participants undertook the questionnaire and interviews voluntarily according to the research ethics. Hundred and fifty two (152) out of 234 students registered for first-year physics from the faculties of humanities (natural science), health and environmental science and engineering and information technology undertook the questionnaire. The researcher interviewed 14 students of these participants as a follow up to the responses of the questionnaire. The responses of the participants were analysed statistically to conclude this study. The average percentages of the questionnaire showed that the majority (62.7% participants) have the mathematics knowledge compared to the low percentage of 34.7 % on physics knowledge. With regard to the constructs the participants generally performed similarly on gradient, reading coordinates and form/expression, i.e. they could either answer both the corresponding mathematics and physics questions and neither of them. In the area construct, most participants with the mathematics knowledge did not transfer it to the physics context. The study further revealed that the majority of interviewees do not have an understanding of the basic physics concepts such as average velocity and acceleration. The researcher therefore recommends that physical science teachers in the FET schools should also undergo constant training in data handling and graphs by subject specialists and academic professionals from Higher Education Institutions. Other remedial actions are also proposed in the dissertation. / MSc (Natural Science Education), North-West University, Potchefstroom Campus, 2015

Upper limb deficits post stroke affect up to 60% of stroke survivors. The assessment of motor deficits post stroke is important for identifying rehabilitation goals and assessing treatment efficacy. Current clinical tools used to assess motor impairment utilize clinical observation to describe the performance of diagnostic motor tasks. However there are some concerns regarding the ability of these scales to fully describe the quality of performance, and detect small but important changes which reflect motor recovery. Kinematic analysis has been increasingly suggested to augment clinical assessment; however, current kinematic tools are not well suited to the time and financial constraints of a clinical environment. The objective of this thesis was to investigate the feasibility of utilizing low-cost, depth sensing technology (Kinect sensor) to augment the current upper limb stroke assessment. Study one characterizes the accuracy of the Kinect sensor, and defines optimal markers and conditions for data collection. Results revealed sufficient ability to quantify metrics for the hand, and the trunk. Study two explored the feasibility of clinical use for the Kinect sensor, specifically its ability to distinguish kinematic performance between the affected and less-affected limbs within an individual, and differences in the affected limb between individuals. Results from study 2 indicated that the Kinect is able to identify interlimb differences and correlations with upper limb impairment scores for some kinematic metrics. Findings from this thesis suggest a potential use for the Kinect in a clinical environment for the purposes of upper limb stroke assessment; however, there are many factors and limitations which need to be considered prior to its use.

Denna studie har undersökt huruvida Inverse Kinematics kan användas tillsammans med spelets miljö för att förbättra en karaktärs animationer och rörelse. Artiklarna som diskuteras i arbetet har använts som inspiration för att skapa artefakterna som använts i undersökningen. En kvantitativ undersökning genomfördes där deltagarna fick spela igenom två demoversioner, en med Inverse Kinematics kombinerat med animationer och en utan. Sedan fick deltagarna svara på en enkät om hur de upplevde spelkaraktärens rörelser. Utifrån svaren i undersökningen kunde slutsatsen dras att skillnaderna i animationerna knappt var märkbara då spelarna fokuserade på andra saker i spelet. Med hjälp av en större mer utförlig undersökning skulle arbetet i framtiden kunna användas inom spelbranschen för att förbättra animationer.