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Object Position and Orientation Determination and Verification in Mixed Reality Using Computer Vision
Get PDFWhen assembling anything, using the correct part at each step is crucial; however, so is providing sufficient guidance for the correct placement of each item. Current mixed reality technology makes it possible to determine the orientation and position of an ���ideal��� object. Identifying and calculating the position and orientation of an object is far easier when the object has more features or a larger size, but this project was created to fill the gap that is created when smaller, simpler objects are used. The proposed system will be implemented on the HoloLens 2, a mixed and augmented reality headset, and will focus on determining the orientation of an object after it has been placed. Once the orientation of the object has been obtained, the system will be able to display holograms in the mixed reality environment to point to specific features on the object or to instruct the user to move it in a certain way. This is one of the fundamental pieces that will allow for complete assembly guidance from a system hence reducing the knowledge barrier required for complex assembly processes. The system discussed herein is being designed as a proof of concept since commercial technology is not advanced enough to allow for this system to function at its maximum potential. As the technology advances, this system can be expanded upon or updated accordingly
An Analysis of Bone Artifacts from Hall's Cave, Texas
Get PDFHall���s Cave, Texas (41KR474) is an archaeological site that has had an episodic history of human occupation for over 10,500 years. Archaeological excavations conducted in 2017 and 2018 resulted in the recovery of numerous lithic artifacts and some bone artifacts. While the lithic tools have been studied, the bone tools found during the excavation were not previously described or analyzed. My project intends to glean as much information from the tools as possible using non-destructive analysis. Through quantitative and qualitative analyses, the use and origin of the bone tools found at Hall���s Cave will provide archaeologists with a deeper understanding of the activities Native Peoples engaged in at this site. Five awl fragments, five beads and bead fragments, and 2 bead blanks were identified. The artifacts range in age from the Early Archaic to Early Historic and reflect a variety of cultural changes as well as technological and material choices
Path Planning and Human-Robot Interaction Control for Upper Limb Rehabilitation Exoskeleton
Get PDFRobot-assist rehabilitation constitutes a burgeoning field, supported by a corpus of empirical research positing the inherent efficacy of robotic systems. In general, the process for robot-assisted rehabilitation is to provide appropriate support to patients to assist them with regaining the performance of motor tasks. In comparison to end-effector type devices, exoskeleton-type apparatuses offer the advantage of exerting direct control over individual joints while concurrently mitigating deviant postures and motions. This affords a more precise and targeted regimen for the rehabilitation of each specific joint. In our laboratory, we conceived and fabricated the CLEVERarm���a six-degree-of-freedom exoskeleton. This innovative robot exhibits the capability to achieve precise alignment at the shoulder joint by orchestrating its joint movements in synchronization with the the human body. The development of this well-crafted device now positions us on the cusp
of achieving a comprehensive and optimally functioning exoskeleton system. The ensuing focus of our research centers on the refinement and establishment of sophisticated control algorithms, constituting the principal subject of investigation in this study.
In the realm of robot-assisted rehabilitation, a frequently encountered undertaking pertains to the pursuit of trajectory following. This task encompasses the formulation of a predetermined trajectory, the conception of a control algorithm, and the evaluation of performance. To tackle these three distinct domains, this study has introduced dedicated solutions for each of them. First, with regards to trajectory tracking, the study introduces a novel trajectory planning methodology, yielding
more anthropomorphic reaching motions. The presented work specifically focuses on solving the resolution of redundancy in reaching motions. This method is based on the notion of maximum manipulability as defined in Kim et al, 2012 with two additional refinements by the current authors: (1) Swivel angle primitive and (2) Combined straight line primitive. A human-robot configuration transformation model is also designed for mapping the coordinates from the human upper-limb
configuration space to the exoskeleton joint space. In the context of designing control algorithms, this investigation formulates two controllers. The first controller serves as a real-time control algorithm, responsible for furnishing appropriate torque inputs to individual robot joints. It relies on a human-robot interaction index denoted as J. The second controller functions as an iterative trajectory refinement approach during each training iteration. It incorporates a power transform function meticulously designed to modify conventional symmetric bell-shaped velocity profiles. The realtime assessment of performance, as quantified by the index J, is attained through the utilization of fuzzy logic techniques. Furthermore, the evaluation of performance across successive training iterations is accomplished through the introduction of a criterion embedded within the velocity profiles. Surface electromyography (sEMG) signals, owing to their considerable predictive capacity with regard to upper limb motion, hold promise for prospective applications in robot-assisted rehabilitation. In this context, our study introduces a deep learning model tailored to forecast upper limb motions by leveraging the information encoded in the sEMG signals. Within the scope of this investigation, two distinct models are formulated. The first model pertains to real-time intention prediction within the upper limb���s configuration space, while the second model addresses the prediction of entire trajectories for upper limb reaching motions. To enhance data pre-processing, a personalized standardization (PSD) technique is introduced, which yields notably superior accuracy compared to conventional data pre-processing methodologies. Experimental verification results are presented for the aforementioned algorithms, demonstrating their efficacy and suitability for application in the field of robot-assisted rehabilitation
Leaving Lenin Behind: Constitutional Change and Democracy Under Stalin
Get PDFEarly Soviet leaders held out the new 1936 Constitution of the USSR as an emblem of political reform and a new era of Soviet politics. These declarations were accompanied by changes to the ideological rhetoric concerning democracy from Stalin and the party elites, departing from previous conceptions of the Soviet state and placing democracy at the forefront. Rather than aligning with commonly held Western ideals about a democratic state, however, Stalin set out to delineate the boundaries of a new conception of democracy grounded in Soviet legal and political thought. The philosophical theory underpinning this approach differed from other democratic states in key ways that contributed to the practical functioning of Soviet elections and the Soviet state. Previous research has investigated the international propaganda value of democracy to the USSR and the failure of the USSR to institute free, liberal democracy, but comparatively little research has sought to examine Soviet democracy on its own merits in terms of the state���s own political foundations and philosophy. Through critical analysis of Lenin���s and Stalin's political theory and the events surrounding the enactment of the 1936 Constitution, I can develop a Soviet model of democracy based on the foundational principles outlined therein. Examining alternative conceptions of democracy is critical to understanding the limitations of our own institutions and preventing totalitarian backsliding
