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This paper looks at all aspects of developing a robotic arm and hand that consists of five fingers which is able to imitate human movements. The imitation ability, accuracy and factors affecting both points are studied. A project like this requires the interplay of various electrical components to achieve the desired results.The prototype constructed measured the controller’s movements of the fingers with the help of flex sensors. The movements in the elbow and wrist however were measured with the help of potentiometers. The flex sensors and potentiometers were connected to an Arduino Mega which then sent the values with the help of a transmitter. The robotic arm consists of an Arduino Uno, seven servomotors and a receiver that reads the messages sent from the transmitter. All values were converted into degrees that rotated the motor axles accordingly. The prototype produced positive results, showing that it was able to copy all movements done by the controller. Tests were conducted to study the accuracy and imitationability. The conclusion was that the factors affecting imitation and accuracy were mostly connected to the weight of the robot and the design of the hand. / Denna uppsats behandlar olika aspekter i utvecklingen av en robotarm vars gripdon är en hand med fem fingrar, med syfte att kunna imitera mänskliga rörelser. Imitationsförmågan, noggrannheten samt vilka faktorer som påverkar dessa studeras. För att uppnå ett önskvärt resultat har det krävts styrning och samverkan mellan olika elektroniska komponenter. I prototypen som presenteras mättes fingrarnas rörelsemed hjälp av flexsensorer samt rörelsen i armbåge och handleden med hjälp av vridpotentiometrar. Flexsensorerna och potentiometrarna var anslutna till en Arduino Mega vars värden skickades med hjälp av en sändare. Elektronikkomponenterna som användes i robotarmen var en ArduinoUno, sju servomotorer och en mottagare, vars funktion var att läsa av meddelanden som skickades från sändaren. Alla värden omvandlades till grader och motoraxlarna roterade i enlighet med dessa. Prototypen uppnådde ett önskvärt betteende då roboten hade förmågan att imitera alla rörelser som utfördes av styrenheten. Noggrannheten och imitationsförmågan undersöktes med olika tester. De mest betydelsefulla faktorer som påverkade imitationen och noggrannheten av prototypen var kopplade till vikten av roboten och designen av handen, enligt slutsatserna som har dragits.

Hand impairments have a significant impact on quality of life and career performance. This effect is specially bold in the agricultural community, since farming activities involve continuously carrying and lifting heavy objects. Assistive robotic technologies hold considerable promise in alleviating such impairment issues. However, no portable assistive device is developed for farming applications, which requires additional considerations to ensure functionality of the device and its practicality in agricultural settings. In this work, a bi-layered structure for a robotic glove is presented, which consists of a passive extension and an active flexion layers. The former is responsible for extending the fingers, using a set of elastic bands. The flexion layer, which helps with flexing the fingers and grasping of objects, is a lightweight, self-contained, portable, cable-driven, and single-actuated robotic glove. The cable configuration is inspired from the human hand flexor tendons. Due to uncertainties associated with the fabric's flexibility and potential slippage between the cable and the glove, the designed mechanisms and sensory and control systems are initially implemented on a robotic hand. The rigid structure of the robotic hand provides a suitable proving ground for the design and control ideas. The novel power transmission system design enables the active layer to perform adaptive grasp of objects with unknown shapes, sizes, and material textures. The sensory system includes a bend sensor to detect the wearer's intention to perform grasp or release actions. Additionally, a PVDF-based sensor is developed for slip-detection, which is used as feedback to prevent further slipping of the grasped objects. Overall, the active flexion layer weighs 265 gr and can provide the maximum grasping force of 122 N, which is a noticeable improvement in comparison to the literature. / Doctor of Philosophy / Hand impairments have a significant impact on quality of life and career performance. This effect is specially bold in the agricultural community, since farming activities involve continuously carrying and lifting heavy objects. Assistive robotic technologies hold considerable promise in alleviating such impairment issues. However, no portable assistive device is developed for farming applications, which requires additional considerations to ensure functionality of the device and its practicality in agricultural settings. In this work, a bi-layered structure for a robotic glove is presented, which helps with grasping objects. The first layer is responsible for extending the fingers, using a set of elastic bands. The second layer, which helps with flexing the fingers, is a lightweight, self-contained, and portable robotic glove. A novel cable-driven power transmission system is designed to perform reliable grasps using only one actuator. The power transmission system design enables the robotic glove to grasp objects with unknown shapes, sizes, and material textures. The intention of the wearer for performing a grasp or releasing an object is detected using a bend sensor. Additionally, a vibration sensor is utilized for detecting the slip of the grasped object and preventing further slipping and dropping the object. The functionality of the developed robotic gloved is evaluated through experiments, where different geometry and weight of objects are grasped.

In this thesis, we develop a new method for Additive Manufacturing of felt to make three dimensional objects. Felting is a method of intertwining fibers to make a piece of textile. In this work, a 6 DOF UR-5 robotic arm equipped with a 3 DOF tool head to test various approaches to using felting. Due to the novelty of this approach several different control architectures and methodologies are presented. We created felted test samples using a range of processing conditions, and tested them in an Instron machine. Samples were tested parallel to the roving fiber direction and perpendicular to the roving fiber direction. Additionally, two pieces of felt were attached to each other with needling, and these were tested with T-peel tests, pulling both in the direction of the roving fibers and perpendicular to the fibers. We present results for the Young's Modulus and Ultimate Strength of each of these samples. It is anticipated that given the appropriate combination of materials and robotic tooling, this method could be used to make parts for a multitude of applications ranging from custom footwear to advanced composites. / Master of Science / In this paper a new approach to Additive Manufacturing centered on mechanically binding fibers together into a cohesive part is presented. This is accomplished via a robotic system and a process called felting, whereby needles push fibers into each other, entangling them. To validate this approach each system and method was tested individually. We present the results of mechanical tests of a variety of felted samples. Given the results, it is believed that robotic needle felting may be a beneficial method of manufacture for several fields, and it has the potential to easily make customized products.

Robotic arms are essential in a variety of industrial processes. However, the dexterous workspace of a robotic arm is limited. This limitation can be overcome by making the robotic arm mobile. Such robots, which comprise a robotic manipulator installed on a wheeled mobile platform, are called mobile robots. A mobile manipulator can attain a position in space which a robotic arm with fixed base may not be able to reach otherwise. To be applicable to a variety of scenarios, these robots need to meet user-defined margins on their trajectory tracking error, irrespective of the payload transported, faults, and failures. In this thesis, we study the dynamics of mobile manipulator comprising both a differential-drive mobile robot (DDMR) and a robotic arm. Thus, we design a model reference adaptive controller (MRAC) for this mobile manipulator to regulate this vehicle and guarantee robustness to uncertainties in the robot's inertial properties such as the mass of the payload transported and friction coefficients. / Master of Science / Humans are able to perform tasks effectively owing to their extraordinary sense of perception and due to their ability to easily grasp things. Although humans are well-suited to perform any process, within an industrial context, a variety of tasks might pose danger to humans, like dealing with hazardous materials or working in extreme environments. Moreover, humans may suffer from fatigue while performing repetitive tasks. These considerations gave rise to the idea of robots which could do the work for humans and instead of humans. Mobile manipulators are a kind of robot that is well-suited for performing a variety of tasks such as collecting, manipulating, and deploying objects from multiple locations. In order to make robots perform a user-specified task, we need to study how the robot reacts to external forces. This knowledge helps us derive a mathematical model for the robotic system. This dynamical model would then be essential in controlling the motion of the robot. In this thesis, we study the dynamics of a mobile manipulator, which comprises a two-wheeled ground platform and a five degrees-of-freedom robotic arm. The dynamical model of this mobile robot is then employed to design a controller that guarantees user-defined margins of error despite uncertainties in some properties, such as the mass of the payload transported.

Yes / The full-text of this article will be released for public view at the end of the publisher embargo, 6 months from first publication.