Doctor of Philosophy, The Ohio State University, 2014, Electrical and Computer Engineering

This work presents the development of an integrated flight controller for a generic model of a hypersonic air-breathing vehicle. The flight control architecture comprises a guidance and trajectory planning module and a nonlinear inner-loop adaptive controller. The emphasis of the controller design is on achieving stable tracking of suitable reference trajectories in the presence of a specific engine fault (inlet unstart), in which sudden and drastic changes in the vehicle aerodynamics and engine performance occur. First, the equations of motion of the vehicle for a rigid body model, taking the rotation of the Earth into account, is provided. Aerodynamic forces and moments and engine data are provided in lookup-table format. This comprehensive model is used for simulations and verification of the control strategies. Then, a simplified control-oriented model is developed for the purpose of control design and stability analysis. The design of the guidance and nonlinear adaptive control algorithms is first carried out on a longitudinal version of the vehicle dynamics. The design is verified in a simulation study aiming at testing the robustness of the inner-loop controller under significant model uncertainty and engine failures. At the same time, the guidance system provides reference trajectories to maximize the vehicle's endurance, which is cast as an optimal control problem. The design is then extended to tackle the significantly more challenging case of the 6-degree-of-freedom (6-DOF) vehicle dynamics. For the full 6-DOF case, the adaptive nonlinear flight controller is tested on more challenging maneuvers, where values of the flight path and bank angles exceed the nominal range defined for the vehicle. Simulation studies show stable operation of the closed-loop system in nominal operating conditions, unstart conditions, and during transition from sustained scramjet propulsion to engine failure mode.

Committee: Andrea Serrani Prof. (Advisor); Umit Ozguner Prof. (Committee Member); Zhang Wei Prof. (Committee Member) Subjects: Aerospace Engineering; Computer Engineering; Electrical Engineering; Engineering

Doctor of Philosophy in Engineering, Cleveland State University, 2023, Washkewicz College of Engineering

Joint mechanics research relies on joint kinematics and kinetics measurements, represented from relative relationships of local coordinate systems (CS) belonging to bones of the joint. It's common to define these CSs from anatomical landmarks, which are sensitive to observer variability and often don't result in CS that best represent the functional motion of the joint. This work is presented in three articles addressing the following aims: 1) to develop a method to objectively define coordinate systems through optimization of unique passive movement paths, 2) to develop an alternative method to objectively define coordinates systems for joints with non-unique passive movement paths, and 3) to validate the methods in vitro. Article 1 introduces an objective method for calculating functional CS definitions for bones in joints that observe three-cylindrical-joint kinematic chain decomposition methods and applies the method on tibiofemoral joint specimens. This method is driven by low resistance joint motion during loading profiles and not from anatomical landmark selection. Significant improvements in CS reproducibility were observed with functional CS, compared to anatomical. Significant decreases in off-axis motion during passive flexion profiles were also observed with functional CS. Article 2 establishes benefits in using Functional CS in vitro with human cadaveric tibiofemoral joints and rat stifle joints. Functional CS, compared to anatomical, significantly 1) reduced variation in intra-knee kinematic response, 2) reduced kinematic cross-talk, 3) reduced variation in inter-knee kinematic response, and 4) improved force/torque control performance. Scalability was demonstrated, as benefits extended to rat stifle testing. Article 3 presents a method for establishing Functional-Aggregate vertebral CS in the spine. Functional motion is only used to optimize CS origins, because passive movement paths are non-unique in the spine. An aggregate of anatomical landmar (open full item for complete abstract)

Committee: Robb Colbrunn (Advisor); Antonie van den Bogert (Committee Member); Ahmet Erdemir (Committee Member); Jason Halloran (Committee Member); Deborah Epsy (Committee Member) Subjects: Biomechanics; Biomedical Engineering; Biomedical Research; Robotics

Master of Science, The Ohio State University, 2020, Mechanical Engineering

Four motion cueing algorithms are evaluated for a low cost, driver-in-loop (DiL) simulator with limited platform motion: roll, pitch, and heave. The DiL is augmented with additional non-vestibular cueing. Double lane change and slalom maneuvers are chosen for evaluating the algorithms because they incorporate lateral dynamics. The primary aim of the simulator is for vehicle assessment purposes. The population for conducting the experimental runs is restricted to be drivers with no prior professional or competitive driving background. For this reason, the experiment is designed to have the maneuvers driven under sub-limit conditions. The experiments are conducted in a virtual driving environment designed for conducting isolated experiments. The virtual world was designed to increase the ease of repeatability of the experimental runs. The simulated vehicle run data is gathered and analyzed based on vehicle lateral dynamics, driver input, and driver's performance. Statistical analysis is conducted to identify the presence of significant differences resulting from the variation of motion cueing algorithms over 24 drivers. Within subjects analysis, paired hypothesis testing, and effect size are computed for analyzing the driving data. The drivers are also monitored for simulator sickness using a subjective questionnaire for each of their experimental driving runs. The results from this study can be used to identify the effect of change of motion cueing on the regular drivers. Furthermore, it can also assist in quantitatively ranking the algorithms evaluated. If any of the algorithms are observed to cause drastic degradation in driver's performance, it will be eliminated in the continual of the research. Statistical analysis showed that double lane change was better at differentiating the cueing algorithms. For both the maneuvers, driver input changed significantly with similar vehicle performance and driver's performance. The vehicle motion-based cueing alg (open full item for complete abstract)

Committee: Rebecca Dupaix (Advisor); Stephanie Stockar (Committee Member); Jeffrey Chrstos (Other) Subjects: Automotive Engineering; Engineering; Mechanical Engineering

Master of Science (M.S.), University of Dayton, 2013, Electrical Engineering

Hyper-redundant robotics is a branch of advanced robotic technology recognized as a method to improve manipulator performance in complex and unstructured environments. Research in both kinematic and dynamic control of hyper-redundant manipulator plays an import role in high-tech field like modern industry, military and space applications. The kinematic redundancy considered in this thesis means the total degrees of freedom (DOF) of robot is more than the degrees of freedom required for the task to be executed. The redundancy provides infinite solutions to achieve the same position and orientation of the end-effector. Therefore, the efficacy of kinematic algorithm affects the accuracy and stability of both motion control and path tracking. In this thesis, we mainly focus on constructing an application robotic platform based on kinematic modeling of a 9-DOF hyper-redundant manipulator. We firstly take a brief introduction of the background, related work, significance and objective of this thesis. Then the kinematic model of 9-DOF manipulator is established along with its home position configuration. The next work is divided into two parts: first is the construction of hardware platform, and the second one is to design an application software with user interface (UI). In addition, the result of proposed thesis design is demonstrated in a number of experiments. In the end, conclusion and future work are presented.

Committee: Raul Ordonez (Committee Chair); Vijayan Asari (Committee Member); Malcolm Daniels (Committee Member) Subjects: Electrical Engineering

Master of Science (MS), Ohio University, 2011, Mechanical Engineering (Engineering and Technology)

The purpose of this thesis is to study a 7-DOF humanoid cable-driven robotic arm, implement kinematics and dynamics analysis, present different cable-driven designs and evaluate their merits and drawbacks. Since this is a redundant mechanism, kinematics optimization is used to avoid joint limits, singularities and obstacles. Cable kinematics analysis studies the relations between lengths of cables and pose of the end-effector. This is a design modified from the literature. Several new designs are compared in statics analysis of the whole arm and the most favorable design is suggested in terms of motion range and the consumption of cable tensions. Linear programming is used to optimize cable tensions. The energy consumption of the cable-driven arm is much less than that of the traditional motor-driven arm in dynamics analysis. Cable-driven robots have potential benefits but also some limitations.

Committee: Robert Williams PhD (Advisor) Subjects: Mechanical Engineering; Robotics; Robots

Master of Science (MS), Ohio University, 2008, Electrical Engineering (Engineering and Technology)

The MARK II is a biologically inspired walking robot utilizing modern hardware. The purpose of the project is to create a robotic platform that is capable of mimicking the motion of various biological organisms such as insects, lizards, and other biologics. With a quadruped platform (4 degrees of freedom per leg) detailed experiments can be run regarding motion behavior of biological systems in a controlled environment without the use of biological organisms. Advances in biorobotic walkers will provide insight into biological animal behavior, fluid robotic motion and system wide control design and implementation.

Committee: Maarten Uijt de Haag Dr. (Advisor); Robert Williams II Dr. (Committee Member); Zhu Zhen Dr. (Committee Member); Scott Hooper Dr. (Committee Member) Subjects: Biology; Computer Science; Electrical Engineering; Mechanical Engineering; Robots

Master of Science (MS), Ohio University, 2003, Mechanical Engineering (Engineering)

This thesis has presented kinematics, hardware construction, and control architecture for the planar parallel 3-RPR manipulator built at Ohio University. This three-dof manipulator is actuated by three active pneumatic cylinder prismatic joints. The revolute joints are all passive. The workspace computation and analysis have also been presented in chapter 2. In a limited workspace the robot can reach general planar poses (translation and rotation). Applications for this type of robot include manufacturing and assembly where high speed and accuracy are required in a relatively small workspace. Other applications are planar motion simulators and haptic interfaces. The 3-RPR hardware is controlled in real-time via a PC with a Simulink model reading LVDT feedback and commanding solenoid valves via the Quanser Multi-Q boards and Wincon software. The control architecture controls the three pneumatic cylinder lengths independently but simultaneously in this environment. The coordinated Cartesian control of the 3-RPR planar parallel robot via linearized independent prismatic link length control has been implemented. The Simulink block diagram is built, based on this control architecture. The control routine for the Cartesian control modes (inverse pose control or resolved rate control) has been proposed and can be implemented as suggested in the concluding chapter. Future work suggests hardware improvements should be made to improve accuracy. Also, workspace optimization can be done for future work.

Committee: Robert Williams, II. (Advisor) Subjects: Engineering, Mechanical

Master of Science (MS), Ohio University, 2006, Electrical Engineering & Computer Science (Engineering and Technology)

Developing a six degree-of-freedom (6-DOF) aircraft model has many practical purposes, especially in these times of rapidly growing Uninhabited Air Vehicle (UAV) technologies. This thesis covers some of the various topics involved in the development of such a model. The research performed was conducted at the Avionics Engineering Center, utilizing the Brumby R/C aircraft. Topics include a brief overview of the instrumentation system, techniques for inertia estimation, and system identification using the Ordinary Least Squares (OLS) method. Finally, the design and development of a Matlab/SIMULINK model will be covered, which will illustrate the accuracy and validity of the 6-DOF model.

Committee: Douglas Lawrence (Advisor) Subjects: Engineering, Aerospace