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Snyder, Benjamin M.SEVEN-DOF CABLE-SUSPENDED ROBOT WITH INDEPENDENT SIX-DOF METROLOGY
Master of Science (MS), Ohio University, 2006, Mechanical Engineering (Engineering)

Traditional automated machining and material deposition systems are not easily scalable and can be expensive. This thesis presents a less expensive, scalable alternative – a seven degree-of-freedom (DOF) cable-suspended robot (CSR) for use in 3D sculpting, with further applications in automated machining, rapid prototyping, and construction. Two important novelties are a passive pose metrology system independent of the active drive system, and a simple yet non-traditional method of cable tensioning utilizing a spring mounted inline on the seventh active cable. This thesis presented the final design, construction, and controller implementation using a classical joint-level PID real-time control architecture, and the novel implementation of a 3D digitizer, called MicroScribe, as a master input device. The control system was applied to a full-scale robot at NIST where a scaled 3D duplication was performed using a MicroScribe to trace a maquette while the CSR cut an enlarged duplicate out of polystyrene in real-time.

Committee:

Robert Williams (Advisor)

Keywords:

robot; robotics; cable-suspended robots; cable-driven robots; cable-robots; cable robots; metrology; robot control; 3D duplication; 3D sculpting; maquette-enlarging; automated machining; automated sculpting

Alsaedi, Rusul JabbarON THE MUTUAL VISIBILITY OF FAT MOBILE ROBOTS
MS, Kent State University, 2016, College of Arts and Sciences / Department of Computer Science
Given a set of n >= 1 autonomous, anonymous, history-oblivious, silent, and possibly disoriented mobile robots operating following Look-Compute-Move cycles in the Euclidean plane, we consider the fundamental problem of providing mutual visibility for them, i.e., the robots must reposition themselves to reach a configuration in finite time without collisions where they all see each other. This problem arises under obstructed visibility where a robot can not see another robot if there lies a third robot on the line segment connecting their positions. This problem is important since it provides a basis to solve many other problems under obstructed visibility, and it has applications in many scenarios including coverage, intruder detection, etc. The literature on this problem assumed that the robots are dimensionless points, i.e., they occupy no space. However, this assumption can be easily refuted. For example, in reality, robots are not dimensionless, but they have a physical extent. Therefore, in this thesis, we initiate the study of the mutual visibility problem for the robots with extents. We address this problem in the recently proposed robots with lights model, where each robot is equipped with an externally visible persistent light that can assume colors from a fixed set of colors. This model corresponds to the classical oblivious robots model when the number of colors in the set is 1. In particular, we first develop a deterministic algorithm that provides mutual visibility for robots with extents of unit disc size avoiding collisions using only 4 colors in the color set. Note that this algorithm works for fat robots under the fully synchronous and semi-synchronous settings. We then present a faster algorithm that solves this problem in O(n) rounds in the fully synchronous setting.

Committee:

Gokarna Sharma (Advisor); Feodor Dragan (Committee Member); Hassan Peyravi (Committee Member)

Subjects:

Computer Science

Keywords:

Distributed Algorithms, Autonomous Mobile Robots, Fat Robots, Obstructed Visibility, Robots with Lights Model, Run-time, Configuration, Convex Hull, Mutual Visibility, Collisions

Vadia, JigarPlanar Cable Direct Driven Robot: Hardware Implementation
Master of Science (MS), Ohio University, 2003, Mechanical Engineering (Engineering)

The planar cable-direct-driven-robot was designed, constructed, simulated and controlled in this thesis. A new design of cross cable configuration was implemented. The kinematics, statics and dynamics modeling of the proposed design were derived. The static workspace was determined for the new design. Only the translational CDDR whose end-effector may be fitted with a traditional serial wrist mechanism to provide rotational freedom was considered in this thesis. The robot was simulated using Simulink and Matlab software. The hardware of the cable-direct-driven-robot was designed and constructed. The hardware was interfaced with the computer. Wincon software and Quanser control boards were used for real time implementation. The inverse kinematics of the robot was implemented for generating linear and circular trajectory in real time control. The independent cable length PD controller was implemented for the Cartesian coordinated control. The repeatability of the CDDR was evaluated.

Committee:

Robert II Williams (Advisor)

Keywords:

Cable Robots; Wire Robots; 3-degree of Freedom Robots; End Effector

Petitt, Cody R.Hardware Application for Rapid Prototyping, Modeling and Validation of Cable- Suspended Robot Systems
Master of Science (MS), Ohio University, 2016, Mechanical Engineering (Engineering and Technology)
The need for additional research tools that allow for more extensive analysis exists in the field of Cable Suspended Robots (CSR) research. This system addresses that need by providing a hardware model as a type synthesis system that can be used to determine the possible designs, given a vast range of design specifications. This two part system was configured to be adaptable, transferable, and modular, allowing a workspace and trajectory validation and singularity analysis to be completed on an easy to use hand operated Subsystem #1. Offering visual and haptic feedback and potential control validation on Subsystem #2, which allows for a desired trajectory to be automated with easy to use microcontrollers and software program. The system was validated using two real-world CSR models, proving it can adequately represent a CSR. A prototype configuration was deployed onto the system, validation and trajectory results were positive; leading to the conclusion that this system is useful for type synthesis and prototyping of CSR configurations.

Committee:

Robert Williams II, Ph.D. (Advisor)

Subjects:

Engineering; Robotics

Keywords:

Type Synthesis; Prototyping; Cable-Suspended Robots; Cable Robots

Carter, Brian EdwardOmni-directional locomotion for mobile robots
Master of Science (MS), Ohio University, 2001, Mechanical Engineering (Engineering)
In this Thesis, a brief overview of mobile robots and omni-directional robots is presented, as well as a detailed history of the RoboCup competition. The player robot design process undertaken by the Ohio University Mechanical Engineering department led by the author) is discussed in detail, and the inverse kinematic equations and dynamic equations of motion are derived. These dynamic equations were then used to create two Simulink simulations, the simple and complex dynamic models. A third simulation was created to compensate for the slipping disturbances in the wheel motivated by initial experimental work. The most accurate of the simulations (the third, dubbed the Slip Simulation) was then compared with the experimental data.

Committee:

Robert Williams, II (Advisor)

Subjects:

Engineering, Mechanical

Keywords:

Mobile Robots; Omni-Directional Robots; RoboCup Competition; Dynamic Equations; inverse kinematic equations; Simulink simulations; slipping disturbances

Mirletz, Brian TietzAdaptive Central Pattern Generators for Control of Tensegrity Spines with Many Degrees of Freedom
Doctor of Philosophy, Case Western Reserve University, 2016, EMC - Mechanical Engineering
This work seeks to advance understanding of how to construct and control tensegrity spines: highly compliant robots with many degrees of freedom inspired by biological spines. Tensegrity describes systems of rigid bodies stabilized by cables, where on a simulated twelve segment robot up to 72 degrees of freedom require constraints or control. To coordinate the high number of actuators, central pattern generator (CPG) based controllers provide goal directed, adaptive trajectories for movement on rough terrain. As a result, this work details, to the author's knowledge, the first CPG based robotic control capable of goal directed locomotion on rough terrain. This control scheme is implemented on four different tensegrity spine designs. Prior to this work, tensegrity spines were passive, hand constructed models; the open source NASA Tensegrity Robotics Toolkit (NTRT) was created to develop robots inspired by these and other tensegrity models using physics based simulation. This work also discusses the development and implementation within NTRT of a cable model with contact dynamics and realistic forces. Finally, the simulations are validated against the forces measured in the hardware implementation of a three segment tensegrity spine robot.

Committee:

Roger Quinn (Advisor); Kiju Lee (Committee Member); Joeseph Prahl (Committee Member); M. Cenk Çavusoglu (Committee Member)

Subjects:

Mechanical Engineering; Robotics; Robots

Keywords:

Tensegrity; Central Pattern Generators; Robotics; Robots; Compliance; Impedance Control; Biologically Inspired Robots; Spines; Distributed Control; Machine Learning; Monte Carlo

Pabbu, Akhil SaiIncorporating Passive Compliance for Reduced Motor Loading During Legged Walking
Master of Science in Electrical Engineering (MSEE), Wright State University, 2017, Electrical Engineering
For purposes of travelling on all-terrains surfaces that are both uneven and discontinuous, legged robots have upper-hand over wheeled and tracked vehicles. The robot used in this thesis is a simulated hexapod with 3 degrees of freedom per leg. The main aim is to reduce the energy consumption of the system during walking by attaching a passive linear spring to each leg which will aid the motors and reduce the torque required while walking. Firstly, the ideal stiffness and location or the coordinates for mounting the spring is found out using gradient based algorithm called `Simultaneous Perturbation and Stochastic Approximation Algorithm’ (SPSA) on a flat terrain using data from a single walking step. Motor load is approximated by computing the torque impulse, which is the summation of the absolute value of the torque output for each joint during walking. Once the ideal spring and mount is found, the motor loading of the robot with the spring attached is observed and compared on three different terrains with the original loading without the spring. The analysis is made on a single middle leg of the robot, which is known to support the highest load when the alternating tripod gait is used. The obtained spring and mounting locations are applied to other legs to compute the overall energy savings of the system. Through this work, the torque impulse was decreased by 14 % on uneven terrain.

Committee:

Luther Palmer, III., Ph.D. (Advisor); Zach Fuchs, Ph.D. (Committee Member); Xiaodong Zhang, Ph.D. (Committee Member)

Subjects:

Electrical Engineering; Robotics

Keywords:

Legged robots; Energy optimization in legged robots; Optimization using SPSA; Gradient based optimization; Spring placement on a hexapod; Energy cost; Torque distribution

Henning, Timothy PaulDynamics and controls for an omnidirectional robot
Master of Science (MS), Ohio University, 2003, Mechanical Engineering (Engineering)
This thesis presents a brief overview of mobile robots and omni-directional motion. The design process of the Ohio University RoboCup robots is also explained in detail, along with recommended design changes for future robots. The forward and inverse kinematic equations are derived along with the dynamic equations of motion. These equations were then used to perform computer simulations and hardware experiments to evaluate and improve on the current performance of the robot. Hardware experiments were also done using a vision-based system. These results were then compared to the results of the hardware simulations completed with a tethered robot. Experiments were also run to show the effects of slippage as the speed of the robot is increased. The results show that the dynamic model used in Simulink properly represents the actual robot. They also show that some type of higher order path planning is needed in order for the robot to make smooth movements. In comparing the hardware experiments, the tethered robot shows a definite improvement in the speed and accuracy of the robot while completing predetermined patterns.

Committee:

Robert Williams, II. (Advisor)

Subjects:

Engineering, Mechanical

Keywords:

Mobile Robots; Omni-Directional Motion; RoboCup Robots; Inverse Kinematic Equations; Computer Simulations; Hardware Experiments; Vision-Based System; Tethered Robot; Predetermined Patterns

Messay-Kebede, TemesguenComputationally Efficient and Robust Kinematic Calibration Methodologies and their Application to Industrial Robots
Doctor of Philosophy (Ph.D.), University of Dayton, 2014, Electrical Engineering
Robot kinematic calibration is the process of enhancing the positioning accuracy of a given manipulator and must be performed after robot manufacture and assembly or during periodical maintenance. This dissertation presents new computationally efficient and robust kinematic calibration algorithms for industrial robots that make use of partial measurements. These include a calibration method that requires the supply of Cartesian coordinates of the calibration points (3DCAL) and another calibration technique that only requires the radial measurements from the calibration points to some reference (1DCAL). Neither method requires orientation measurements nor the explicit knowledge of the where-about of a reference frame. Contrary to most other similar works, both methods make use of a simplified version of the original Denavit-Hartenberg (DH) kinematic model. The simplified DH(-) model has not only proven to be robust and effective in calibrating industrial manipulators but it is also favored from a computational efficiency viewpoint since it consists of comparatively fewer error parameters. We present a conceptual approach to develop a set of guidelines that need to be considered in order to properly construct the DH(-) model such that it is parameterically continuous and non-redundant. We also propose an automated method to provide a characterization of the parameters that can be insightful in identifying redundant/irrelevant parameters and deducing the DH(-) error model of a manipulator. The method is a hybrid scheme comprised of the Simulated Annealing (SA) algorithm and a local solver/optimizer and it conducts a statistical analysis on the estimates of a given error parameter that is indicative of its relevance. For the type of industrial robots used in this dissertation, we made note that calibrating the home position only is sufficient to attain adequate results for most robotics applications. Hence, we put forward for consideration of a yet simpler calibration model; the DH(-)(-) model. We employ the Trust Region (TR) method to minimize the objective functions (solve for the error parameters of the simplified error models) of both frameworks (3DCAL and 1DCAL). We also compare the performance of the proposed methods to that of a state-of-the-art commercial system (Motocal) using the same materials, data and internationally recognized performance standards. Our experimental results suggest that our methods are more robust and yield better results compared to that of MotoCal.

Committee:

Raul Ordonez, Ph.D. (Committee Chair); Russell Hardie, Ph.D. (Committee Member); John Loomis, Ph.D. (Committee Member); Ruihua Liu, Ph.D. (Committee Member)

Subjects:

Engineering; Robotics

Keywords:

Kinematic Calibration; Optimization; Simulated Annealing; Trust Region; CompuGauge; MotoCal; Industrial Robots; Yaskawa Motoman Robotics Inc

Chung, Tae-SangForce and compliance control for rough-terrain locomotion by multi-legged robot vehicles /
Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Robots;Locomotion

Ghayoumi, MehdiFACIAL EXPRESSION ANALYSIS USING DEEP LEARNING WITH PARTIAL INTEGRATION TO OTHER MODALITIES TO DETECT EMOTION
PHD, Kent State University, 2017, College of Arts and Sciences / Department of Computer Science
Analysis of human emotion is very important as the field of social robotics where a new generation of humanoids and other smart devices will interact with humans. Emotional expression is a universal language for interaction with humans. Understanding human emotions is a necessary and important step for human-computer interaction. Human emotion is expressed as a complex combination of facial expressions, speech (including silence) and gestures postures, various limb-motions, gaze, and blinking. Multiple research models have been developed for limited facial expression analysis, speech based emotion analysis, limited models for gesture analysis and their limited integration. However, such analysis is limited to single frame analysis time-efficiency, limited handling of occlusion, notion of colors in facial expression analysis, lack of exploitation of symmetry, lack of dynamic change in assigning weight between the modalities based upon environmental requirement and six basic emotions. This research develops a convolutional neural network based deep learning model that recognizes human facial expressions exploiting a combination of symmetrical representation to handle occlusion; a unified model based upon transforming facial muscle motion to geometric feature points; fusion of multiple modalities and fast hashing techniques for real-time emotion recognition. It also proposes a new model for recognition of mixed-emotion in real-time.

Committee:

Arvind K. Bansal (Advisor); Javed I. Khan (Committee Member); Cheng Chang Lu (Committee Member); Stephen B. Fountain (Committee Member); William E. Merriman (Committee Member)

Subjects:

Artificial Intelligence; Computer Science; Robotics; Robots

Keywords:

Human Computer Interaction, Emotion, Facial Expression, Deep Learning, Convolutional Neural Networks, Social Robots

Diller, Eric DavidDesign of a Biologically-Inspired Climbing Hexapod Robot for Complex Maneuvers
Master of Sciences, Case Western Reserve University, 2010, EMC - Mechanical Engineering
Some insects are able to climb on nearly any surface and in many orientations using a variety of attachment mechanisms. In addition, these insects are capable of performing complex maneuvers such as transitioning between orthogonal surfaces, behaviors which are desirable in a climbing robot. A hexapod robot which climbs using biologically-inspired strategies was built for this purpose. DIGbot, a 2.8 kg robot, uses distributed inward gripping (DIG) to actively engage its spines with the surface. This enables the robot to climb vertical and inverted surfaces of high roughness, such as wire mesh, carpet or tree bark. DIGbot is the first robot able to perform tight turns on vertical as well as inverted surfaces.This thesis presents the design, construction and operation of DIGbot. The performance of the hexapod is quantified by analyzing its motion during these maneuvers.

Committee:

Roger Quinn, PhD (Advisor); Joseph Mansour, PhD (Committee Member); Roy Ritzmann, PhD (Committee Member)

Subjects:

Mechanical Engineering

Keywords:

climbing robots biologically-inspired

Puehn, Christian GDevelopment of a Low-Cost Social Robot for Personalized Human-Robot Interaction
Master of Sciences, Case Western Reserve University, 2015, EMC - Mechanical Engineering
This thesis presents two social robotic platforms, Philos V.1 and Philos V.2, which are designed for personalized human-robot interaction (HRI). Personalized HRI is realized through programmable expressive (i.e. gestures and sound/speech generation) and perceptive functions (i.e. human face tracking and recognition, touch detection, and speech recognition) of the robots. In addition, a wearable sensor device was developed for integration with these social robots to further improve the health monitoring and assessment functions of the robots as well as personalizing the robots social behavior based on the user's biobehavioral data. Among the many potential applications of a social robot, this thesis focuses on elderly healthcare where positive health outcomes are expected by providing companionship, assisting with daily activities, and monitoring health status.

Committee:

Kiju Lee (Advisor); Roger Quinn (Committee Member); Francis Merat (Committee Member)

Subjects:

Mechanical Engineering; Robotics; Robots

Keywords:

Social robots; human-robot interaction; wearable sensor

Rude, Howard NathanIntelligent Caching to Mitigate the Impact of Web Robots on Web Servers
Master of Science (MS), Wright State University, 2016, Computer Science
With an ever increasing amount of data that is shared and posted on the Web, the desire and necessity to automatically glean this information has led to an increase in the sophistication and volume of software agents called web robots or crawlers. Recent measurements, including our own across the entire logs of Wright State University Web servers over the past two years, suggest that at least 60\% of all requests originate from robots rather than humans. Web robots display different statistical and behavioral patterns in their traffic compared to humans, yet present Web server optimizations presume that traffic exhibits predominantly human-like characteristics. Robots may thus be silently degrading the performance and scalability of our web systems. This thesis investigates a new take on a classic performance tool, namely web caches, to mitigate the impact of robot traffic on web server operations. It proposes a cache system architecture that:~(i) services robot and human traffic in separate physical memory stores, with separate polices;~(ii) uses an adaptable policy for admitting robot related resources;~(iii) combines a deep neural network with Bayesian models to improve request prediction. Experiments with real data demonstrate (i) significant reduction in bandwidth usage for prefetching and (ii) improvements in hit rate for human driven traffic compared to a number of baselines, especially in configurations where web caches have limited size.

Committee:

Derek Doran, Ph.D. (Committee Chair); Tanvi Banerjee, Ph.D. (Committee Member); John Gallagher, Ph.D. (Committee Member)

Subjects:

Computer Science

Keywords:

web cache; web robots; crawlers; prefetching; prediction; LSTM

Song, Shin-MinKinematic optimal design of a six-legged walking machine /
Doctor of Philosophy, The Ohio State University, 1984, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Robots;Locomotion;All terrain vehicles

Buchner, Helmut JosefControl of robot manipulators on task oriented surfaces by nonlinear decoupling feedback and compensation of certain classes of disturbances /
Doctor of Philosophy, The Ohio State University, 1986, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Robots;Manipulators ;Feedback control systems;Robotics

Pech, Thomas JoelA Deep-Learning Approach to Evaluating the Navigability of Off-Road Terrain from 3-D Imaging
Master of Sciences (Engineering), Case Western Reserve University, 2017, EECS - Computer and Information Sciences
This work investigates a strategy for evaluating the navigability of terrain from 3-D imaging. Labeled training data was automatically generated by running a simulation of a mobile robot nai¨vely exploring a virtual world. During this exploration, sections of terrain were perceived through simulated depth imaging and saved with labels of safe or unsafe, depending on the outcome of the robot's experience driving through the perceived regions. This labeled data was used to train a deep convolutional neural network. Once trained, the network was able to evaluate the safety of perceived regions. The trained network was shown to be effective in achieving safe, autonomous driving through novel, challenging, unmapped terrain.

Committee:

Wyatt Newman (Advisor); Cenk Cavusoglu (Committee Member); Michael Lewicki (Committee Member)

Subjects:

Computer Science; Robotics; Robots

Keywords:

Mobile robots, Autonomous Navigation, Machine Learning, Artificial Neural Networks, Terrain, Simulation, Training Data, Data Generation, Labeling, Classifiers, Convolutional Neural Networks, Point Clouds, Perception, Prediction, Artificial Intelligence

Shakeel, AmlaanService robot for the visually impaired: Providing navigational assistance using Deep Learning
Master of Science, Miami University, 2017, Computational Science and Engineering
Assistive technology helps improve the day to day activities for people with disabilities. One of the methods utilized by assistive technologists employs the use of robots. These are called service robots. This thesis explores the idea of a service robot for the visually impaired to assist with navigation and is inspired by the use of guide dogs. The focus of this thesis is to develop a robot to achieve autonomous indoor navigation using computer vision to identify image based goals in an unfamiliar environment. The method presented in this thesis utilizes a deep learning framework, called Faster R-CNN, to train a computer to classify and localize exit signs in real time. A proof of concept is presented using NVIDIA Jetson, and TurtleBot, a robot kit, which runs a robot software development framework Robot Operating System (ROS). The model is trained successfully using Faster R-CNN and is validated. The model is used for real-time object classification on the prototype robot.

Committee:

Yamuna Rajasekhar (Advisor); John Femiani (Committee Member); Donald Ucci (Committee Member)

Subjects:

Computer Science; Electrical Engineering; Robotics

Keywords:

Assistive technology; Deep learning; Robotics; Indoor navigation; Computer vision; Robot Operating System; ROS; Caffe; Faster R-CNN; Convolutional Neural Networks; CNN; Microsoft Kinect; Service robots; visually impaired; mobility; depth perception

Suh, Suk-HwanDevelopment of an algorithm for a minimum-time trajectory planning problem under practical considerations /
Doctor of Philosophy, The Ohio State University, 1986, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Robots;Robotics;Algorithms

Vijaykumar, R.Motion planning for legged locomotion systems on uneven terrain /
Doctor of Philosophy, The Ohio State University, 1988, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Robots--Motion

Tsai, Chi-KengComputer control of an electro-hydraulic robot leg with proximity ranging system /
Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Robots;Automation

Maciejewski, Anthony AlexanderThe analysis and control of robotic manipulators operating at or near kinematically singular configurations /
Doctor of Philosophy, The Ohio State University, 1988, Graduate School

Committee:

Not Provided (Other)

Subjects:

Engineering

Keywords:

Manipulators;Robots

Taylor, Brian KyleImplementation and Benchmarking of a Whegs Robot in the USARSim Environment
Master of Sciences (Engineering), Case Western Reserve University, 2008, Mechanical Engineering
Simulating robots in a virtual domain has multiple benefits, including serving as a training tool for end-users and a tool for robot development/testing. USARSim (Unified System for Automation and Robot Simulation) is a tool that can accomplish these goals. It is based on the Unreal Tournament 2004 gaming engine, which approximates the physics of how robots interact with their environments. Whegs™ robots (mobile ground vehicles that derive robust locomotion from abstracted biological principles) can benefit from simulation in USARSim. This thesis describes a Whegs™ robot model that was constructed and benchmarked in USARSim. The simulation was given the same behavioral characteristics as real Whegs™ vehicles and then validated. Qualitative tests were performed for basic walking and climbing to understand the vehicle's behavior. Quantitative tests were performed for basic walking to: compare the simulated robot's rotational body movements to those of the real robot, and to improve the simulation's performance.

Committee:

Roger Quinn, PhD (Committee Chair); Christopher Hernandez, PhD (Committee Member); Joseph Mansour, PhD (Committee Member)

Subjects:

Mechanical Engineering

Keywords:

USARSim; Biologically Inspired Robots; Whegs; Urban Search and Rescue; Simulation; Benchmarking; Validation

Ambike, Satyajit S.Characteristics of Spatial Human Arm Motion and the Kinematic Trajectory Tracking of Similar Serial Chains
Doctor of Philosophy, The Ohio State University, 2011, Mechanical Engineering

This work studies spatial reaching motion in healthy humans. Research suggests that for individual instances of movement, the central nervous system (CNS) composes an explicit wrist path, which is transformed into joint motions in a time-invariant fashion. This is the time invariance hypothesis (TIH), and its validation for spatial motion is the first goal of this study. The human arm is typically modeled as a multi-link, serial chain. When one joint of a serial chain is actuated, it simultaneously causes movement at other joints because of interaction effects. Based on horizontal-plane reaching studies, the leading joint hypothesis (LJH) proposes that the interaction effects at (mostly) the proximal joint in the multi-link serial-chain model of the arm are low. Therefore, the CNS ignores this interaction effect to simplify the computation of joint torques and control of the joint trajectory. The second objective of this dissertation is to validate the LJH for spatial motion.

In a spatial reaching experiment, healthy subjects performed point-to-point reaching movements at three distinct speeds. Data analysis revealed time-invariant wrist paths only for some subjects in some reaching tasks, suggesting that the TIH is not a truly general organizing principle for spatial reaching motion. Therefore, this hypothesis needs refinement and further investigation. On the other hand, the interaction effects at the shoulder joint were small for a majority of the movements in this experiment so, the LJH was successfully extended to spatial motion.

The TIH identifies the inputs and outputs of the first stage in the process of composing the muscle activations for a given motor task. A computational algorithm that can potentially be used to execute this transformation was developed next. The algorithm, called speed-ratio control, also has beneficial applications in commercial robot control. It is demonstrated that the application of this algorithm to robotic serial chains provides greater navigational accuracy in the vicinity of certain kinds of singularities.

Speed ratio control applies to non-redundant serial chains. The simplest model of the human arm consists of three-degree-of-freedom spherical joints at the shoulder and the wrist and a revolute joint at the elbow. This yields seven degrees of freedom for the arm. For positioning and orienting the hand relative to the thorax, only six degrees of freedom are necessary. The human arm is, therefore, a redundant serial chain. The formal process of extending the algorithm to redundant serial chains is undertaken. Initial work in which three- and four-degree-of-freedom planar chains track point paths is presented. Speed ratio control allows the resolution of the redundancy in the mechanism by maximizing the output-space tracking accuracy. Examples show superior local tracking performance with this approach compared to path tracking using unweighted pseudoinverse solutions.

Committee:

James P. Schmiedeler, Dr (Advisor); Gary L. Kinzel, Dr (Advisor); Robert A. Siston, Dr (Committee Member); Richard J. Jagacinski, Dr (Committee Member)

Subjects:

Kinesiology; Mechanical Engineering; Robotics

Keywords:

Human Motor Control; Spatial Arm Motion; Time Invariance Hypothesis; Leading Joint Hypothesis; Serial Robots; Spatial Trajectory Tracking; Speed Ratio Control; Singularity Tracking; Redundant Serial Chains

Lee, How GiapAn economic model for evaluating robot applications
Master of Science (MS), Ohio University, 1984, Industrial and Manufacturing Systems Engineering (Engineering)

An economic model for evaluating robot applications

Committee:

Rwa Lee (Advisor)

Subjects:

Engineering, Industrial

Keywords:

Robot; Industrial Robots; ACRS Despreciation

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