In recent years, we have seen the applications of distributed autonomous mobile robots (DAMRs) in a broad spectrum of areas like search and rescue, disaster management, warehouse, and delivery systems. Although each type of systems employing DAMRs has its specific challenges, they are all limited by energy since the robots are powered by batteries which have not advanced in decades. This motivates the development of energy efficiency for such systems. Although there has been research on optimizing energy for robotic systems, their approaches are from low-level (e.g., mechanic, system control, or avionic) perspectives. They, therefore, are limited to a specific type of robots and not easily adjusted to apply for different types of robots. Moreover, there is a lack of work studying the problem from a software perspective and abstraction. In this thesis, we tackle the problem from a software perspective and are particularly interested in DAMR systems in which a team of networked robots navigating in a physical environment and acting in concert to accomplish a common goal. Also, the primary focus of our work is to design schedules (or plans) for the robots so that they can achieve their goal while spending as little energy as possible. To this end, we study the problem in three different contexts: - Managing reliability and energy consumption tradeoff. That is, we propose that robots verify computational results of one another to increase the corroboration of outputs of our DAMR systems. However, this new feature requires robots to do additional tasks and consume more energy. Thus, we propose approaches to reach a balance between energy consumption and the reliability of results obtained by our DAMR systems. - Extending the operational time of robots. We first propose that our DAMR systems should employ charging stations where robots can come to recharge their batteries. Then, we aim to design schedules for the robots so that they can finish all their tasks while consuming as little energy and time (including the time spent for recharging) as possible. Moreover, we model the working space by a connected (possibly incomplete) graph to make the problem more practical. - Coping with environmental changes. This path planning problem takes into account not only energy limits but also changes in the physical environment, which may result in overheads (i.e., additional time and energy) that robots incur while doing their tasks. To tackle the problem from a software perspective, we first utilize Gaussian Process and Polynomial Regression to model disturbances and energy consumption, respectively, then proposed techniques to generate plans and adjust them when robots detect environmental changes. For each problem, we give a formal description, a transformation to integer (linear) programming, online algorithms, and an online algorithm. Moreover, we also rigorously analyze the proposed techniques by conducting simulations and experiments in a real network of unmanned aerial vehicles (UAVs). / Thesis / Candidate in Philosophy

Bats have a unique flying style that allows them to be highly dexterous in capturing prey and have great freedom of movement in flight. Bats' wings have a wing membrane that is tensioned by their fingers and arms, allowing them to retract their wings laterally in flight. This distinct motion has allowed bats to be the only mammals capable of sustained flight, adding to their evolutionary uniqueness. This thesis presents the creation of the VALKRIE (Versatile Aerial Lifesize Kinetic Robot Inspired by bat Evolution) project: a to-scale simplified bat-inspired ornithopter that can be remotely controlled, sustain flight, and passively retract and extend its wings laterally. VALKRIE mimics the dimensions and size of its biological counterpart, Hipposideros diadema, a medium-sized bat; setting its aerodynamical constraints to the dimensions of Hipposideros diadema. Bats' maneuverability is derived from their unique wing motion while in flight, retracting and extending their wings. VALKRIE mimics this motion by simplifying the joint structure of a bat's wing and passively retracting and extending the wings. By simplifying the complex anatomy of bat wing motion, VALKRIE can maintain flight and generate sufficient lift for increasing altitude. With a simplified design, VALKRIE only has two motors that actuate wing flapping, wing retraction, and rotation of the hind legs. With this simplified design, the operator can remotely control VALKRIE by increasing and decreasing the wingbeat frequency and steering to the right and left with the hind legs. / Master of Science / Bats have a unique flying style that allows them to be highly dexterous in capturing prey and have great freedom of movement in flight. Bats' wings have a wing membrane that is tensioned by their fingers and arms, allowing them to retract their wings laterally in flight. This distinct motion has allowed bats to be the only mammals capable of sustained flight, adding to their evolutionary uniqueness. This thesis presents the creation of the VALKRIE (Versatile Aerial Lifesize Kinetic Robot Inspired by bat Evolution) project: a to-scale simplified bat-inspired ornithopter that can be remotely controlled, sustain flight, and passively retract and extend its wings laterally. VALKRIE mimics the dimensions and size of its biological counterpart, Hipposideros diadema, a medium-sized bat; setting its aerodynamical constraints to the dimensions of Hipposideros diadema. Bats' maneuverability is derived from their unique wing motion while in flight, retracting and extending their wings. VALKRIE mimics this motion by simplifying the joint structure of a bat's wing and passively retracting and extending the wings. By simplifying the complex anatomy of bat wing motion, VALKRIE can maintain flight and generate sufficient lift for increasing altitude. With a simplified design, VALKRIE only has two motors that actuate wing flapping, wing retraction, and rotation of the hind legs. With this simplified design, the operator can remotely control VALKRIE by increasing and decreasing the wingbeat frequency and steering to the right and left with the hind legs.

Multi-robot systems (MRS) offer many performance benefits over single robots for tasks that can be completed by one robot. They offer potential redundancies to the system to improve robustness and allow tasks to be completed in parallel. These benefits, however, can be quickly offset by losses in productivity from diminishing returns caused by interference between robots and communication problems. This dissertation developed and evaluated MRS control architectures to solve the dynamic multi-robot autonomous routing problem. Dynamic multi-robot autonomous routing requires robots to complete a trip from their initial location at the time of task allocation to an assigned destination. The primary concern for the control architectures was how well the communication requirements and overall system performance scaled as the number of robots in the MRS got larger. The primary metrics for evaluation of the controller were the effective robot usage rate and the bandwidth usage. This dissertation evaluated several different approaches to solving dynamic multi-robot autonomous routing. The first three methods were based off of common MRS coordination approaches from previous research. These three control architectures with distributed control without communication (a swarm-like method), distributed control with communication, and centralized control. An additional architecture was developed to solve the problem in a way that scales better as the number of robots increase. This architecture, mixed mode autonomy, combines the strengths of distributed control with communication and centralized control. Like distributed control with communication, mixed mode autonomy's performance degrades gracefully with communication failures and is not dependent on a single controller. Like centralized control, there is oversight from a central controller to ensure repeatable high performance of the system. Each of the controllers other than distributed control without communication is based on building world models to facilitate coordination of the routes. A second variant of mixed mode autonomy was developed to allow robots to share parts of their world models with their peers when their models were incomplete or outdated. The system performance was evaluated for three example applications that represent different cases of dynamic multi-robot autonomous routing. These example applications were the automation of open pit mines, container terminals, and warehouses. The effective robot usage rates for mixed mode autonomy were generally significantly higher than the other controllers with a higher numbers of robots. The bandwidth usage was also much lower. These performance trends were also observed across a wide range of operating conditions for dynamic multi-robot autonomous routing. The original contributions from this work were the development of a new MRS control architecture, development of system model for the dynamic multi-robot autonomous routing problem, and identification of the tradeoffs for MRS design for the dynamic multi-robot autonomous routing problem. / Ph. D.

Rugged terrains, including much of the earth's surface, other planets, and many man-made structures, are inaccessible to wheeled and tracked vehicles. This has inspired research into legged vehicles. Prior to the research described here, virtually all legged vehicle designs relied on the concept of mounting actuated leg-type mechanisms onto a single rigid frame or chassis. This dissertation research explores and advances a novel vehicle concept that uses passive legs attached to an actuated multibody structure. This new vehicle moves only its actuated body trunk to achieve locomotion; thus moving in a manner similar to that used by insect larvae known as caterpillars. The passive-legged design is termed a "crawling" vehicle, to differentiate it from "walking" vehicles, which have powered legs. A conceptual design for the proposed vehicle was developed using insights from observations of caterpillar specimen geometry, gaits, leg trajectories, and ranges of motion. The flexible, segmented body of the robot is realized using a series of actuated truss-like mechanisms, resulting in a configuration similar to the body structure of caterpillars. A computer simulation was developed to verify the concept and to assist in creating future designs. This simulation includes a parametric model of the robot structure, an efficient kinematics model, a motion programming method based on six-dimensional parametric cubic trajectories, static stability analysis, actuator velocity and acceleration analysis, wire-frame animations, and rendering, thus providing synthesis and analysis tools for this new class of vehicle. Results of this work show that by using properly designed Stewart-Gough platform mechanisms for the vehicle multibody structure, a range of motion very similar to that of caterpillars is achievable. Simulation tests showed that imitating the caterpillars" primary gait (or stepping sequence) yields superior speed and efficiency, with little reduction of stability, when compared to a simpler, more obvious gait. With proper controls, this crawling vehicle will, like its biological counterpart, be intrinsically stable and have excellent maneuverability over rough terrain. The crawling vehicle is shown to be a viable legged locomotion system that may prove to have superior rough terrain mobility to all previous types of man-made land vehicles. / Ph. D.

Bats are famous for their capability of navigating in dense forests for hundreds of kilometers within one night by using their sonar system. Airborne sonar hasn't been heavily used in the industrial world compared to other sensors such as lidar, radar, and cameras. In this study, we applied a biosonar robot to navigate in a dense forest with bat-like FM-CF ultrasonic signals with deep learning. The results presented show that airborne biosonar can classify different areas' plants, in addition to achieving a similar level of navigation granularity compared to GPS, which is about 6 meters of radius resolution. The time- frequency representations of echoes from the forest are used as input data to explore the biosonar navigation ability, and the state-of-the-art CNN deep network (Resnet 152) is used as the brain to do the echolocation in the dense forest. The navigation ability can be improved significantly by combining multiple 10 ms long echoes, however, the data size of the reflected waves is much smaller than the other popularly used sensors, as echo can be collected at a rate of 40 echoes per second. The results can prove that airborne sonar can be used to navigate in GPS-denied environments, and can be an important sensor used in a scenario when other sensors meet constraints, like in the sensor fusion applications. / Doctor of Philosophy / The ability to identify natural landmarks could contribute to the navigation skills of echolo- cating bats and also advance the quest for autonomy in natural environments with man- made systems. The critical sensors used in autonomous robot navigation are camera array, radar, and lidar, airborne sonar hasn't been verified for its navigation efficiency. However, recognizing natural landmarks based on biosonar echoes has to deal with the unpredictable nature of echoes that are typically superpositions of contributions from many different reflec- tors with unknown properties. This dissertation intends to explore the bioinspired airborne sonar navigation ability in dense natural forests. The first part of this project is to use reflected echoes to navigate on a large scale, data was collected from different mountains which are dozens of kilometers away from each other, and we achieved the use of one single navigator in those locations. The second part is to explore the navigation granularity of airborne sonar sensors, data were collected from a small dense forest area, we try to classify which part of the foliage was based on the echo, and in the end, we achieved GPS accuracy for navigation. The finding in this work proves that the sonar sensor can play an important role in the sensing system, with the help of a deep neural network, with a 10 ms long echo, it can have a similar navigation ability to GPS.

Traditionally, underwater vehicles have been using propellers for locomotion but they are not only inefficient but generate large acoustic signature. Researchers have taken inspiration from efficient swimmers like fish to address the issue with alternate propulsion mechanism. Mostly, research on fish locomotion involved studying a foil tethered to a fixed point inside uniform flow. A major drawback of such study is that neither it resembles a freely swimming fish nor it takes into consideration the dynamics of moving fish on propulsive forces. Hence, in our current study, we focus on comparing the performance of a free swimming fin over tethered fin both experimentally and numerically. Experimentally, we focus on the oscillatory form of locomotion where the caudal fin pitches to generate necessary thrust as seen in boxfish. We intend to investigate the Caudal fin kinematics and its physical properties on locomotion performance. To better understand, we build an automated robo-physical model that swims in a circular path so as to carry extensive experiments. We focus on understanding the effect of flexibility, shape and thickness of caudal fin on performance. Currently, we have studied three different flexibility and for each flexibility, we studied three different shape. We found there must be an optimal flexibility for minimising the Cost of Transport (COT). We also propose that the steady forward speed linearly varies with tail tip velocity. Furthermore, we investigated the effect of thickness of fin and considered uniform and tapered fin with equal area moment of inertia. Numerically, we investigated the effect of phase offset between heave and pitch motion on the performance of a freely swimming fin and compared that to a tethered fin. A freely-swimming fin self propels and moves with steady speed while a tethered fin remains stationary and actuates under uniform flow. We model the fin as a rigid body undergoing prescribed motion in an inviscid fluid and solved for coupled interaction using panel method. We show the effect of phase offset for optimum performance and found a significant difference between tethered and freely swimming fin. / M.S. / Underwater vehicles use propeller based mechanism but they are inefficient and generate noise. Researchers have taken inspiration from nature to replace propellers with efficient propulsion mechanism. In the current study, we design a robotic model to understand the effect of various kinematic and physical properties of tail fin on performance. Our research is unique from past study in the aspect that most research involved studying performance using a robotic model fixed at its position which does not resemble a freely-swimming fish. Hence, in our current study, we focus on comparing the performance of our freely swimming model with tethered fin. The robot has one degree of freedom and can pitch its tail to generate thrust. We intend to investigate the tail fin kinematics and its physical properties on locomotion performance. We focus on understanding the effect of flexibility, shape and thickness of fin on performance. Currently, we have studied three different flexibility and for each flexibility, we studied three different shape. We showed there exists an optimal flexibility for maximising efficiency. For any fin undergoing combined pitch and heave motion, there exists a phase offset between them which will maximise the performance. Researchers have tried to understand its impact using both experiment and numerical simulation. In the current study, we study the impact of phase offset between pitch and heave for a freely-swimming fin and compare that to a fixed fin. A freely-swimming fin self propels and moves with steady speed while a tethered fin remains stationary and actuates under uniform flow. We show the effect of phase offset for optimum performance and found a significant difference between tethered and freely swimming fin.

Painting still plays a fundamental role in communication nowadays. For example, the paint on the road, called road surface marking, guides the traffic in order and maintains the high efficiency of the entire modern traffic system. With the development of the Autonomous Ground Vehicle (AGV), the idea of a line Painting Robot emerged. In this thesis, a Painting Robot was designed as a standalone system based on the AGV platform. In this study, the mechanical and electronic design of a Painting Robot was discussed. The overall design was to fulfill the requirements of the line painting. Computer vision techniques were applied to this thesis since the camera was selected as the major sensor of the robot. Advanced control theory was introduced to this thesis as well. Three different controllers were developed. The Proportional-Integral (PI) controller with an anti-windup feature was designed to overcome the drawbacks of the traditional PI controller. Model Reference Adaptive Control (MRAC) was introduced into this thesis to deal with the uncertainties of the system. At last, the hybrid PI-MRAC controller was implemented to maintain the advantages of both PI and MRAC approaches. Experiments were conducted to evaluate the performance of the entire system, which indicated the successful design of the Painting Robot. / Master of Science / Painting still plays a fundamental role in communication nowadays. With the development of the Autonomous Ground Vehicle (AGV), the idea of a line Painting Robot emerged. In this thesis, a Painting Robot was designed as a standalone system based on the AGV platform. In this study, a Painting Robot with a two-camera system was designed. Computer vision techniques and advanced control theory were introduced into this thesis. Three different controllers were developed, including Proportional-Integral (PI) with an anti-windup feature, Model Reference Adaptive Control (MRAC) and the hybrid PI-MRAC. Experiments were conducted to evaluate the performance of the entire system, which indicated the successful design of the Painting Robot.

An industrial vision system is a useful and often integral part of a computer integrated manufacturing system. Successful integration of vision capabilities into a manufacturing system involves extracting from image data the information which has meaning to the task at hand, and communicating that information to the larger system. The goal of this research was to integrate the activities of a stand-alone vision system into the operation of a manufacturing system; more specifically, the host controller and vision system were expected to work together to determine the status of pallets moving through the system. Pallet status was based on whether the objects on the pallet were correct in shape, location, and orientation, as compared to a pallet model generated using the microcomputer-based CADKEY CAD program. Cadd.c, a C language program developed for this research, extracts object area, perimeter, centroid, and principal angle from the CAD KE Y model for comparison to counterparts generated by the vision system. This off-line approach to supplying known parameters to the vision system was chosen over the traditional "teach by showing" method to take advantage of existing CAD data and to avoid disruption of the production system. The actual comparison of model and image data was performed by a program written in VPL, the resident language of the GE Optomation II Vision System. The comparison program relies on another short VPL program to obtain a pixel/inch ratio which equates the disparate units of the two systems. Model parameters are passed to the vision system via hardware and software links developed as part of this research. Three C language programs enable the host computer to communicate commands and parameters, and receive program results from the vision system. Preliminary testing of the system revealed that the object location and surface texture, lighting conditions, and pallet background all affected the image parameter calculations and hence the comparison process. / Master of Science

This paper discusses the design and implementation of a high performance, custom control solution for series elastic actuators (SEA) in a parallel or serial configuration. In many modern robotics applications, controlling actuator output force accurately and with high bandwidth is extremely important. The series elastic actuator has become popular in applications which require precise force control, however currently not many commercial options exist. Commonly, these actuators are custom designed and use electric motors, however most off-the-shelf electric motor drives are not designed for this specific application. In this paper, the hardware and software architecture of a control device designed specifically for force controlled series elastic actuators is described, along with test results on a novel SEA design. / Master of Science

The design of unmanned underwater vehicle (UUV) was inspired by the form and functionality of Jellyfish. These natural organisms were chosen as bio-inspiration for a multitude of reasons including: efficiency, good room for payload, and a wide range of sizes and morphology. Shape memory alloy (SMA) actuators were selected as the primary source of actuation for the propulsion of the artificial jellyfish node. These actuators offer high power density which enables a compact system size and silent operation which is preferred for surveillance.  SMA wires mimic the form and function of natural muscles; allowing for a wider range of applications than conventional actuators. Commercial SMA wires (100 um in diameter) can exhibit a 4% deformation of the initial actuator length with a blocking stress of over 200 MPa. The deformation of SMA wire is not enough to mimic the bell contraction of jellyfish. In order to resolve this problem, a beam-shape composite actuator using SMA wires as the active component, termed as BISMAC, was designed to provide large curvature. The BISMAC design was inspired by rowing jellyfish bell contraction. Characterization of maximum deformation in underwater conditions was performed for different actuator configurations to analyze the effect of design parameters that include silicone thickness, flexible steel thickness and distance between SMA and flexible steel. A constant cross-section (CC) BISMAC of 16 cm in length was found to achieve deformation with a radius of curvature of 3.5 cm. Under equilibrium conditions, the CC-BISMAC was found to achieve 80% of maximum deformation consuming 7.9 J per cycle driven at 16.2 V/0.98 A and frequency of 0.25 Hz. Using the a developed analytical model, an actuator design was fabricated mimicking the maximum deformation profile of the A. aurita. The optimized AA-BISMAC achieved a maximum curvature of 0.428 1/cm as compared to 0.438 1/cm for the A. aurita with an average squared root error of 0.043 (1/cm), 10.2% of maximum A. aurita curvature.   BISMAC actuators are unidirectional flexible actuators capable of exhibiting high curvature. To extend the application range of these actuators, they were modified to achieve bidirectional deformation. The new bidirectional actuators termed as "BiFlex" actuators had the capability to achieve large deformation in two directions. The FlexLegs consist of six segments which can be actuated individually. Two different sets of legs were constructed to determine the effect of size. The small legs measured 35.8 mm in height and 63.2 mm in width and the large legs were 97.4 mm in height and 165.4 mm in width. The small FlexLegs achieved a maximum deformation of 12 % and 4 % in the x- and y-direction respectively using a power of 0.7 W while producing a maximum force of 0.023 N. They were also able to withstand a load of 1.18 N. The large FlexLegs had a maximum deformation of 57 % and 39 % in the x- and y-direction respectively using a power of 3 W while producing a force of 0.045 N. They were able to withstand a load of 0.25 N. The legs were also able to perform several walking algorithms consisting of stepping, crabbing and yawing. In order to reduce the power consumption and contraction time of SMA wires, a feedback control scheme using wire resistance was developed. The controller required the knowledge of threshold resistance and safe current inputs which were determined experimentally. The overheating effect of SMA wires was analyzed for BioMetal Fiber (BMF) and Flexinol 100 "m diameter wires revealing an increase in resistance as the wires overheated. The controller was first characterized on a SMA wire with bias spring system for a BMF 100 using I_hi=0.5 A and I_low=0.2 A, where hi corresponds to peak current for fast actuation and low corresponds to the safe current which prevents overheating and maintains desired deformation. A contraction of 4.59% was achieved in 0.06 s using the controller and the deformation was maintained for 2 s at low current. The BISMAC actuator was operated using the controller with I_hi=1.1 A and I_low=0.65 A achieving a 67% decrease in contraction time compared to using a constant driving current of I_low=0.2 A and a 60% decrease in energy consumption compared to using constant I_hi=0.5 A while still exceeding the contraction requirements of the Aurelia aurita. Two fundamental parameters at the composition level were associated with the power consumption of SMA: i) martensite to austentite phase transition temperature and ii) thermal hysteresis. Ideally, one would like to reduce both these quantities and for this purpose an equiatomic Ni-Ti alloy was modified with Cu. Replacing nickel with 10 at% copper reduces the thermal hysteresis by 50% or more. For Ni-Ti alloys with nickel content greater than 50 at%, transition temperature decreases linearly at a rate of 100 "C/Ni at%. Given these two power reducing factors, an alloy with composition of Ni40+xTi50-xCu10 was synthesized with x = 0, ±1, ±2, ±3, ±4, ±5. Metal powders were melted in an argon atmosphere using an RF induction furnace to produce ingots. All the synthesized samples were characterized by differential scanning calorimetric (DSC) analysis to reveal martensite to austenite and austenite to martensite transition temperatures during heating and cooling cycles respectively. Scanning electron microscopy (SEM) was conducted to identify the density and microstructure of the fractured samples. The results show the possibility of achieving low power consuming high performance SMAs. Using the BISMAC actuator and feedback control system, a robotic jellyfish called Robojelly that mimics the morphology and kinematics of the Aurelia aurita species was created. A systematic fabrication technique was developed to replicate the essential structural features of A. aurita. Robojelly's body was fabricated from RTV silicone having a total mass of 242 g and bell diameter of 16.4 cm. Robojelly was able to generate enough thrust in static water conditions to propel itself and achieve a proficiency of 0.19 s-1 while the A. aurita achieves a proficiency of around 0.25 s-1. A thrust analysis based on empirical measurements for natural jellyfish was used to compare the performance of the different robotic configurations. The configuration with best performance was a Robojelly with segmented bell and a passive flap structure. Robojelly was found to consume an average power on the order of 17 W with the actuators not having fully reached thermal steady state. A comparative kinematics analysis was conducted between a natural Aurelia aurita and Robojelly. The resistance feedback controller was implemented to tailor the deformation profile of BISMAC actuators embedded in Robojelly. Robojelly's performance was quantified in terms of thrust production and power consumption during vertical swimming experiments. A maximum average instantaneous thrust production of 0.006 N was achieved at a driving current (Ihi) of 1.5 A with 35% duty cycle. Rapid heating of SMA wires was found to reduce power consumption and increase thrust. The bell kinematic analysis revealed resemblance and differences in bell deformation trajectories of the biomimetic and natural jellyfish. The inflexion point of the A. aurita was found to convert an inner bell trajectory into an outer one during contraction which assists the thrust production. A biomimetic robot inspired by Cyanea capillata, termed as "Cyro", was developed to meet the functional demands of underwater surveillance in defense and civilian applications. The design of Cyro required kinematics of large C. capillata which are elusive creatures. Obtaining accurate kinematic data of animals is essential for many biological studies and bio-inspired engineering applications. Many animals such as the C. capillata however, are either too large or too delicate to transport to controlled environments where accurate kinematic data can easily be obtained. Often, in situ recordings are the only means available but are often subject to multi-axis motion and relative magnification changes with time, which lead to large discrepancies in animal kinematics. In Chapter 5, techniques to compensate for magnification and body rotation of animal footage were developed. A background reference point and animal dimensions were used to account for magnification. A linear fit of body points were used to measure body rotation. These techniques help resolve animal kinematics from in situ video footage. The techniques were applied to a large jellyfish, Cyanea capillata, swimming in ocean waters. The bell kinematics were captured by digitizing exumbrella profiles for two full swimming cycles. Magnification was accounted for by tracking a reference point on the ocean floor and by tracking the C. capillata exumbrella arclength in order to have a constant scale through the swimming cycles. A linear fit of the top bell portion was used to find the body angle with respect to the camera coordinate system. Bell margin trajectories over two swimming cycles confirm the accuracy of the correction techniques. The corrected profiles were filtered and interpolated to provide a set of time-dependent points along the bell. The ability to use in situ footage with significant multi-axis motion provides an opportunity to analyze previously impractical footage for gaining a better understanding of large or delicate organisms. The swimming kinematics of the C. capillata were analyzed after extracting the required kinematics from the in situ video. A discrete model of the exumbrella was developed and used to analyze the kinematics. The exumbrella discretization was done using three different methods. The first method consists of analyzing the animal anatomy for structural and mechanical features. The second method consists of analyzing the bell kinematics for areas of highest deformation over time. The third method consists of optimizing node locations that can provide minimal error with comparison to the digitized profiles. Two kinematic models of the C. capillata swimming motion were developed by fitting Fourier series to the discretized segments and angles formed by each segment. The four-segment anatomical kinematic model was used to analyze the bell kinematics of the C. capillata. It was found that the bell does not deform uniformly over time with segments lagging behind others. Hysteresis between contraction and relaxation was also present through most of the exumbrella. The bell margin had the largest hysteresis with an outer path during contraction and inner path during relaxation. The subumbrella volume was approximated based on the exumbrella kinematics and was found to increase during contraction. Cyro was designed to mimic the morphology and swimming mechanism of the natural counterpart. The body of the vehicle consists of a rigid support structure with linear DC motors which actuate eight mechanical arms. The mechanical arms in conjunction with artificial mesoglea create the hydrodynamic force required for propulsion. The full vehicle measures 170 cm in diameter and has a total mass of 76 kg. An analytical model of the mechanical arm kinematics was developed. The analytical and experimental bell kinematics were analyzed and compared to the C. capillata. Cyro reached the water surface untethered and autonomously from a depth of 182 cm in five actuation cycles. It achieved an average velocity of 8.47 cm/s while consuming an average power of 70 W. A thrust stand was developed to calculate the thrust directly from a single bell segment yielding an average thrust of 27.9 N for the whole vehicle. Steady state velocity during Cyro's swimming test was not reached but the measured performance during its last swim cycle resulted in a cost of transport of 10.9 J/kg m and total efficiency of 3%. It was observed that a passive flexible margin or flap, drastically increases the performance of the Robojelly. The effects of flap length and geometry on Robojelly were analyzed using PIV. The flap was defined as the bell section which is located between the flexion point and bell margin. The flexion point was established as the location where the bell undergoes a significant change compliance and therefore in slope. The flap was analyzed in terms of its kinematics and hydrodynamic contribution. An outer trajectory is achieved by the flap margin during contraction while an inner trajectory is achieved during relaxation. The flap kinematics was found to be replicable using a passive flexible structure. Flaps of constant cross section and varying lengths were put on the robotic vehicle to conduct a systematic parametric study. Robojelly's swimming performance was tested with and without a flap. This revealed a thrust increase 1340% with the addition of a flap.  Velocity field measurements were performed using planar Time Resolved Digital Particle Image Velocimetry (TRDPIV) to analyze the change in vortex structures as a function of flap length.  The robot input parameters stayed constant over the different configurations tested thus maintaining a near constant power consumption. Non-dimensional circulation results show a dependence on flap kinematics and geometry. The robot was approximated as a series of pitching panels circularly oriented around its apex. The first circulation peak of the pitching panel approximation revealed a normalized standard deviation of 0.23. A piston apparatus was designed and built to test different flexible margin configurations. This apparatus allow the isolation of the flap parameters and remove the uncertainties coming from the robotic vehicle. / Ph. D.