The construction industry needs an accurate real-time positioning system. Such a system, if successfully implemented, would lead to significant increases in the performance of many construction operations. This thesis presents the Automated Laser Position System (ALPS) for accurate real-time positioning. ALPS is a spin-off of the Automated Position And Control System (APAC) research, sponsored by the National Science Foundation under grant DMC-8717476. The ALPS concept has three primary components: a rotation laser, laser detectors and a central processing unit. ALPS generates both horizontal (X,Y) and vertical (Z) position information. It is mathematically predicted that ALPS could produce accuracies of ± 17 mm in the horizontal and ± 5,9 mm in the vertical, at a range of 400 m. Position measurements would be updated 50 times a second. / Master of Science

In designing devices to produce straight-line motion, the designer has a fundamental choice between selecting sliding devices or selecting pinned linkages. Although they are more complex to design and implement, linkages will often prove a less expensive, more efficient, and generally more satisfactory option than simple sliders. The objective of this thesis is to provide a tool to the designer that serves as an aid in making intelligent decisions in the selection of four-bar linkage type straight-line-mechanisms. This thesis provides research into the selection, evaluation, and implementation of existing straight-line mechanism designs. Twenty-two straight-line mechanisms are compared for both compactness and fidelity of the straight-line path. Also, figures showing position, velocity, and acceleration of each a included. The functional product of to this work is a software program called Straight-line. Straight-line gives the designer a graphical environment from which a wide variety of straight-line mechanisms can be quickly analyzed and evaluated. The software also provides a new type-synthesis technique that allows the designer to generate a straight-line-mechanism by graphically inputting a desired path. / Master of Science

A wrapping cam mechanism consists of a cam wrapped by a belt or flexible band. An analytical method for synthesizing wrapping cam mechanisms has recently been developed. This thesis extends the previous work and describes the development of an interactive wrapping cam synthesis package based on analytical methods. The software presented in this thesis generates cam profiles for eight configurations of wrapping cam-pulley or wrapping cam-sprocket mechanisms. This software package has a graphical user interface to give intuitive interactions. The modularity of the software package increases the flexibility for future program extension. This thesis also discusses the extended synthesis methods for a wrapping cam-link mechanism. / Master of Science

Nearly 27,000 vehicle occupants are killed annually in the United States, with passenger car and light truck occupants amassing 25,000 of these. Over 50% of passenger car and light truck occupant fatalities are due to frontal crashes. Although advancements in safety technology have reduced the number of fatalities and injuries, motor vehicle collisions are still a major issue in the United States. Continued development of computational models and biofidelic anthropomorphic test devices (ATDs) necessitates benchmarking of current surrogates and further analysis of an occupant's biomechanical response in automobile collisions. This thesis presents data from low-speed frontal sled tests performed with human volunteers, a Hybrid III 50th percentile male ATD, and post mortem human surrogates (PMHSs). The first study sought to investigate the effects of muscle bracing by human volunteers. The second study sought to compare the responses of the relaxed and braced volunteers in the first study to those of the Hybrid III and PMHS subjects. Overall, these two studies provide novel biomechanical data that can be used to refine and validate computational models and ATDs used to assess injury risk in automotive collisions. The third study was focused on quantifying the ability for children to swing a sword-like toy. Over 200,000 toy-related injuries occur every year in the United States. Currently, data is unavailable with regard to sword-like toys. Incorporating the knowledge gained by this study will allow manufacturers to reduce the inherent risks associated with their products as well as market them to the correct target age groups. / Master of Science

Objective: To evaluate the relative position of the femur and tibia in cranial cruciate ligament (CCL) intact stifles, CCL deficient stifles, and stifles following a novel extracapsular procedure (lateral extracapsular suture system or LESSa) under load at specific joint angles. Study Design: In vitro biomechanical study. Methods: Twenty pelvic limbs from 11 dogs were used to evaluate the relative position of the femur and tibia between 3 stifle conditions (CCL intact, CCL deficient, and LESSa treated) at a load of 30 % and stifle angles of 125", 135", and 145" using electromagnetic tracking sensors. Results: Cranial cruciate ligament deficient stifles had significantly greater (p <0.0001) cranial displacement and internal rotation of the tibia relative to the femur than CCL intact stifles or LESSa treated stifles at all stifle angles. Cranial displacement of the tibia relative to the femur for CCL intact and LESSa treated were not significantly different from one another at stifle angles of 125", but were significantly different at stifle angles of 135" (p = 0.0182) and 145" (p = 0.0012). There was no significant difference in internal rotation of the tibia relative to the femur between CCL intact and LESSa treated stifles at any of the stifle angles. Conclusion: LESSa effectively decreases cranial tibial displacement and eliminates internal rotation of the tibia relative / Master of Science

"Quasar-mode feedback" occurs when momentum and energy from the environment of accreting supermassive black hole couple to the host galaxy. One mechanism for such a coupling is by high-velocity (up to ~0.2c) quasar-driven ionized outflows, appearing as blue-shifted absorption and emission lines in quasar spectra. Given enough energy and momentum, these outflows are capable of affecting the evolution of their host galaxies. This dissertation presents the studies of emission and absorption quasar outflows from different perspectives. (1). By conducting large broad absorption line (BAL) quasar surveys in both Sloan Digital Sky Survey and Very Large Telescopes (VLT), we determined various physics properties of quasar absorption outflows, e.g., the electron number density ((n_e), the distance of outflows to the central quasar (𝑅), and the kinetic energy carried by the outflow (𝐸̇_k). We demonstrated that half of the typical BAL outflows are situated at 𝑅 > 100 pc, i.e., having the potential to affect the host galaxies. (2). Our group carried out a Hubble Space Telescope program (PI: Arav) for studying the outflows in the Extreme-UV, collaborating with Dr. Gerard Kriss from Space Telescope Science Institute (STScI). We developed a novel method to fit the multitude of quasar absorption troughs efficiently and accurately. We have identified the most energetic quasar-driven outflows on record and discovered the largest acceleration and velocity-shift for a quasar absorption outflow. (3). By using the VLT data, Xu led the project to study the relationships between BAL outflows and emission line outflows. We found possible connections between these two types of quasar outflows, e.g., the luminosity of the [𝑂_III λ5007 emission profile decreases with increasing n_e derived from the BAL outflow in the same quasar. These findings are consistent with BAL and emission outflows being different manifestations of the same wind, and the observed relationships are likely a reflection of the outflow density distribution. / Doctor of Philosophy / Super massive black holes (SMBHs) are believed to exist in the center of almost all massive galaxies, where the brightest accreting ones are named "quasars". "Quasar-mode feedback" occurs when momentum and energy from the environment of accreting SMBHs couple to the host galaxy. One mechanism for such a coupling is by high-velocity (up to ~0.2c) quasar-driven ionized outflows, appearing as blue-shifted absorption and emission lines in quasar spectra. Given enough energy and momentum, these outflows are capable of affecting the evolution of their host galaxies. Such quasar outflows are invoked to explain a variety of observations, e.g., the chemical enrichment of the intergalactic medium (IGM), the shape of the observed quasar luminosity function, and the self-regulation of the growth of the SMBHs. In this dissertation, I focus on studying the emission and absorption outflows observed in quasars spectra, collected with the largest telescopes and most powerful instruments in the world. (1). By conducting large broad absorption line (BAL) quasar surveys in both Sloan Digital Sky Survey and Very Large Telescopes (VLT), we determined various physics properties of quasar absorption outflows, e.g., the electron number density (n_e), the distance of outflows to the central quasar (𝑅), and the kinetic energy carried by the outflow (𝐸̇_k). We demonstrated that half of the typical BAL outflows are situated at 𝑅 > 100 pc, i.e., having the potential to affect the host galaxies. (2). Our group carried out a Hubble Space Telescope program (PI: Arav) for studying the outflows in the Extreme-UV, collaborating with Dr. Gerard Kriss from Space Telescope Science Institute (STScI). We developed a novel method to fit the multitude of quasar absorption troughs efficiently and accurately. We have identified the most energetic quasar-driven outflows on record and discovered the largest acceleration and velocity-shift for a quasar absorption outflow. (3). By using the VLT data, Xu led the project to study the relationships between BAL outflows and emission line outflows. We found possible connections between these two types of quasar outflows, e.g., the luminosity of the [𝑂_III] λ5007 emission profile decreases with increasing n_e derived from the BAL outflow in the same quasar. These findings are consistent with BAL and emission outflows being different manifestations of the same wind, and the observed relationships are likely a reflection of the outflow density distribution.

In order to optimize the flight characteristics of aircraft, wings must be designed for the specific mission an aircraft will see. An airplane rarely has one specific mission, and therefore is usually designed as a compromise to meet many flight objectives with a single wing surface. Large-scale shape change of a wing would enable a wing design to be optimized for multiple missions. Engineers at the National Aeronautics and Space Administration (NASA) Langley Research Center are investigating a new Hyper-Elliptic Cambered Span (HECS) wing configuration that may lead to increased stability and control, and to improved aerodynamic efficiency, during flight. However, during take-off and landing, a conventional wing design (not curved down) may be preferred. Thus a need has been developed for a wing whose contour can be changed during flight. The so-called "morphing" that is required has been limited by a lack of feasible design solutions. One design concept is to use an adaptive structure, with an airfoil skin applied, as the shape-changing driver. Most designs of this kind require multiple actuators to control the changing shape. This thesis introduces a novel design for a morphing wing mechanism using a single degree-of-freedom kinematic chain. In this work, the concept is introduced with sufficient background to aid in understanding. The design tools developed include a synthesis procedure and a sensitivity analysis to determine the effects of manufacturing errors. / Master of Science

Objective: To determine the ability of the Tibial Plateau Leveling Osteotomy (TPLO) to restore normal joint kinematics in a cranial cruciate ligament (CrCL)-deficient stifle through a loaded range of motion. Methods: Paired pelvic limbs from 12 dogs were compared in an in vitro biomechanical study. Each limb was placed in a custom designed jig at 120° of stifle extension under an axial load of 20% body weight. Electromagnetic motion tracking sensors were placed on the distal femur and proximal tibia. A force was applied at approximately 10 N/sec to mimic the action of the quadriceps muscle. Force application allowed the limb to move from 120° to maximal extension. Positional data was acquired at 60 points/second. Each limb was tested under normal, CrCL-deficient, and TPLO-treated conditions. Results: The TPLO failed to normalize CTT within the CrCL-deficient stifle; however, values trended towards intact values throughout the range of motion. No significant differences were noted in internal rotation in any of the three conditions from 120° – 137°. Hyperextension values did not differ significantly between conditions. Conclusion: Data from this biomechanical model suggests that the TPLO fails to neutralize CTT throughout a loaded range of motion. Internal rotation and hyperextension values were not found to differ significantly between intact, CrCL-deficient and TPLO repaired stifles. The effectiveness of the TPLO in restoring normal biomechanics is more significant at greater angles of flexion. / Master of Science

This dissertation presents the kinematics study on two cases of parallel locomotion mechanisms. A parallel locomotion mechanism can be defined as "a mechanism with parallel configuration and discrete contact with respect to the ground which renders a platform the ability to move". The first case is a tripedal robot and the second case is an actuated spoke wheel robot. The kinematics study on these two mobile robots mainly includes mobility, inverse and forward kinematics, instantaneous kinematics, singularity and so on. The tripedal robot STriDER (Self-excited Tripedal Dynamic Experimental Robot) is expected to walk utilizing its built-in passive dynamics, but in its triple stance phase, the kinematic configuration of the robot behaves like an in-parallel manipulator. The locomotion of this novel walking robot and its unique tripedal gait are discussed, followed by the definitions of its coordinate frames. Geometric methods are adopted for the forward and inverse displacement analysis in its triple stance phase. Simulations are presented to validate both the inverse and the forward displacement solutions. The instantaneous kinematics and singularity analysis are developed respectively. Based on the screw theory, the Jacobian matrices are assembled. Using Grassmann Line Geometry, each row of the Jacobian matrices is interpreted as a line in 3D space and the analytical conditions of the linear dependency cases are identified, which corresponds to the forward singular configurations of the robot. The actuated spoke wheel robot IMPASS (Intelligent Mobility Platform with Active Spoke System) is investigated as the second case. It is revealed that this robot has multiple modes of locomotion on the ground and it is able to change its topology by changing the contact scheme of its spokes with the ground. This robot is treated as a mechanism with variable topologies and Modified Grübler-Kutzbach criterion and Grassmann Line Geometry are adopted to identify the degrees of freedom (DOF) for each case of its topological structures. The characteristic DOF are then verified through the testing on the robot prototype. The forward and inverse kinematics is investigated for two cases of its topologies. In order to improve the computation efficiency of the inverse kinematics formulation, virtual serial manipulator models are constructed. The effectiveness of the virtual serial manipulator models has been validated with numerical simulations. In conclusion, kinematics analyses have been successfully performed on the two parallel locomotion mechanisms. The results are utilized to control the robots' motions in specific configurations. The foundation has been laid for the future development of the robot prototypes and the future research on dynamics, control, intelligence and so on. / Ph. D.

This thesis addresses two important issues when operating the novel three legged mobile robot STriDER (Self-excited Tripedal Dynamic Experimental Robot); how to stand up after falling down while minimizing the motor torques at the joints and considerations for gait planning. STriDER uses a unique tripedal gait to walk with high energy efficiency and has the ability to change directions. In the first version of STriDER, the concept of passive dynamic locomotion was emphasized; however, for the new version, all joints are actively controlled for robustness. The robot is inherently stable when all three feet are on the ground due to its tripod stance, but it can still fall down if it trips while taking a step or if unexpected external forces act on it. The unique structure of STriDER makes the simple task of standing up challenging for a number of reasons; the high height of the robot and long limbs require high torque at the actuators due to its large moment arms; the joint configuration and length of the limbs limit the workspace where the feet can be placed on the ground for support; the compact design of the joints allows limited joint actuation motor output torque; three limbs do not allow extra support and stability in the process of standing up. This creates a unique problem and requires novel strategies to make STriDER stand up. This thesis examines five standing up strategies unique to STriDER: three feet pushup, two feet pushup, one foot pushup, spiral pushup, and feet slipping pushup. Each strategy was analyzed and evaluated considering constraints such as static stability, friction at the feet, kinematic configuration and joint motor torque limits to determine optimal design and operation parameters. Using the findings from the analysis, experiments were conducted for all five standing up strategies to determine the most efficient standing up strategy for a given prototype using the same design and operation parameters for each method. Also, a literature review was conducted for human standing from a chair and human pushup exercises and the conclusions were compared to the analysis presented in this thesis. Many factors contribute to the development of STriDER's gait. Several considerations for gait planning as the robot takes a step are investigated, including: stability, dynamics, the body's maximum and minimum allowable heights, the swing legs foot clearance to the ground, and the range of the subsequent swing foot contact positions. A static stability margin was also developed to asses the stability of STriDER. This work will lay the foundation for future gait generation research for STriDER. Additionally, guidelines for future work on single step gait generation based on kinematics and dynamics are discussed. The findings presented will advance the capabilities and adaptability of the novel robot STriDER. By studying standing up strategies and gait planning issues, the most efficient control methods can be implement for standing up and preparing to take a step and lay out the foundations for future research and development on STriDER. / Master of Science