Robotic Manipulation of Environmentally Constrained Objects Using Underactuated Hands

Robotics for agriculture represents the ultimate application of one of our society\u27s latest and most advanced innovations to its most ancient and vital industry. Over the course of history, mechanization and automation have increased crop output several orders of magnitude, enabling a geometric growth in population and an increase in quality of life across the globe. As a challenging step, manipulating objects in harvesting automation is still under investigation in literature. Harvesting or the process of gathering ripe crops can be described as breaking environmentally constrained objects into two or more pieces at the desired locations. In this thesis, the problem of purposefully failing (breaking) or yielding objects by a robotic gripper is investigated. A failure task is first formulated using mechanical failure theories. Next, a grasp quality measure is presented to characterize a suitable grasp configuration and systematically control the failure behavior of the object. This approach combines the failure task and the capability of the gripper for wrench insertion. The friction between the object and the gripper is used to formulate the capability of the gripper for wrench insertion. A new method inspired by the human pre-manipulation process is introduced to utilize the gripper itself as the measurement tool and obtain a friction model. The developed friction model is capable of capturing the anisotropic behavior of materials which is the case for most fruits and vegetables.The limited operating space for harvesting process, the vulnerability of agricultural products and clusters of crops demand strict conditions for the manipulation process. This thesis presents a new sensorized underactuated self-adaptive finger to address the stringent conditions in the agricultural environment. This design incorporates link-driven underactuated mechanism with an embedded load cell for contact force measurement and a trimmer potentiometer for acquiring joint variables. The integration of these sensors results in tactile-like sensations in the finger without compromising the size and complexity of the proposed design. To obtain an optimum finger design, the placement of the load cell is analyzed using Finite Element Method (FEM). The design of the finger features a particular round shape of the distal phalanx and specific size ratio between the phalanxes to enable both precision and power grasps. A quantitative evaluation of the grasp efficiency by constructing a grasp wrench space is also provided. The effectiveness of the proposed designs and theories are verified through real-time experiments. For conducting the experiments in real-time, a software/hardware platform capable of dataset management is crucial. In this thesis, a new comprehensive software interface for integration of industrial robots with peripheral tools and sensors is designed and developed. This software provides a real-time low-level access to the manipulator controller. Furthermore, Data Acquisition boards are integrated into the software which enables Rapid Prototyping methods. Additionally, Hardware-in-the-loop techniques can be implemented by adding the complexity of the plant under control to the test platform. The software is a collection of features developed and distributed under GPL V3.0

Robotic cell project progress report

Treball desenvolupat dins el marc del programa 'European Project Semester'.The Robotic Cell Project belongs to the field of robotics within the electrical engineering industry. It is elaborated by four students from different engineering disciplines and different nationalities within the European Project Semester. The task is developed in cooperation with the robotics company KUKA from Vilanova I la Geltrú and coordinated by the UPC. The main goal of the project is to analyze and evaluate the advantages and disadvantages of the new Safe Teaching technology. This technology can be used in manual teaching aid for robotic trajectories to simplify the programming of complex operations as painting or polishing movements. The cell consists of a KUKA KR 16 robot with a force / torque sensor and the software needed for safety monitoring. It is already mounted and ready to be used

Theoretical and Experimental Investigation on the Multiple Shape Memory Ionic Polymer-Metal Composite Actuator

Development of biomimetic actuators has been an essential motivation in the study of smart materials. However, few materials are capable of controlling complex twisting and bending deformations simultaneously or separately using a dynamic control system. The ionic polymer-metal composite (IPMC) is an emerging smart material in actuation and sensing applications, such as biomimetic robotics, advanced medical devices and human affinity applications. Here, we report a Multiple Shape Memory Ionic Polymer-Metal Composite (MSM-IPMC) actuator having multiple-shape memory effect, and is able to perform complex motion by two external inputs, electrical and thermal. Prior to the development of this type of actuator, this capability only could be realized with existing actuator technologies by using multiple actuators or another robotic system. Theoretical and experimental investigation on the MSM-IPMC actuator were performed. To date, the effect of the surface electrode properties change on the actuating of IPMC have not been well studied. To address this problem, we theoretically predict and experimentally investigate the dynamic electro-mechanical response of the IPMC thin-strip actuator. A model of the IPMC actuator is proposed based on the Poisson-Nernst-Planck equations for ion transport and charge dynamics in the polymer membrane, while a physical model for the change of surface resistance of the electrodes of the IPMC due to deformation is also incorporated. By incorporating these two models, a complete, dynamic, physics-based model for IPMC actuators is presented. To verify the model, IPMC samples were prepared and experiments were conducted. The results show that the theoretical model can accurately predict the actuating performance of IPMC actuators over a range of dynamic conditions. Additionally, the charge dynamics inside the polymer during the oscillation of the IPMC are presented. It is also shown that the charge at the boundary mainly affects the induced stress of the IPMC. This study is beneficial for the comprehensive understanding of the surface electrode effect on the performance of IPMC actuators. In our study, we introduce a soft MSM-IPMC actuator having multiple degrees-of-freedom that demonstrates high maneuverability when controlled by two external inputs, electrical and thermal. These multiple inputs allow for complex motions that are routine in nature, but that would be otherwise difficult to obtain with a single actuator. To the best of our knowledge, this MSM-IPMC actuator is the first solitary actuator capable of multiple-input control and the resulting deformability and maneuverability. The shape memory properties of MSM-IPMC were theoretically and experimentally studied. We presented the multiple shape memory properties of Nafion cylinder. A physics based model of the IPMC was proposed. The free energy density theory was utilized to analyze the shape properties of the IPMC. To verify the model, IPMC samples with the Nafion as the base membrane was prepared and experiments were conducted. Simulation of the model was performed and the results were compared with the experimental data. It was successfully demonstrated that the theoretical model can well explain the shape memory properties of the IPMC. The results showed that the reheat glass transition temperature of the IPMC is lower than the programming temperature. It was also found that the back-relaxation of the IPMC decreases as the programming temperature increases. This study may be useful for the better understanding of the shape memory effect of IPMC. Furthermore, we theoretically modeled and experimentally investigated the multiple shape memory effect of MSM-IPMC. We proposed a new physical principle to explain the shape memory behavior. A theoretical model of the multiple shape memory effect of MSM-IPMC was developed. Based on our previous study on the electro-mechanical actuation effect of IPMC, we proposed a comprehensive physics-based model of MSM-IPMC which couples the actuation effect and the multiple shape memory effect. It is the first model that includes these two actuation effects and multiple shape memory effect. Simulation of the model was performed using finite element method. To verify the model, an MSM-IPMC sample was prepared. Experimental tests of MSM-IPMC were conducted. By comparing the simulation results and the experimental results, both results have a good agreement. The multiple shape memory effect and reversibility of three different polymers, namely the Nafion, Aquivion and GEFC with three different ions, which are the hydrogen, lithium and sodium, were also quantitatively tested respectively. Based on the results, it is shown that all the polymers have good multiple shape memory effect and reversibility. The ions have an influence on the broad glass transition range of the polymers. The current study is beneficial for the better understanding of the underlying physics of MSM-IPMC. A biomimetic underwater robot, that was actuated by the MSM-IPMC, was developed. The design of the robot was inspired by the pectoral fish swimming modes, such as stingrays, knifefish and cuttefish. The robot was actuated by two soft fins which were consisted of multiple IPMC samples. Through actuating the IPMCs separately, traveling wave was generated on the soft fin. Experiments were performed for the test of the robot. The deformation and the blocking force of the IPMCs on the fin were measured. A force measurement system in a flow channel was implemented. The thrust force of the robot under different frequencies and traveling wave numbers were recorded. Multiple shape memory effect was performed on the robot. The robot was capable of changing its swimming modes from Gymnotiform to Mobuliform, which has high deformability, maneuverability and agility

A Robotic Neuro-Musculoskeletal Simulator for Spine Research

An influential conceptual framework advanced by Panjabi represents the living spine as a complex neuromusculoskeletal system whose biomechanical functioning is rather finely dependent upon the interactions among and between three principal subsystems: the passive musculoskeletal subsystem (osteoligamentous spine plus passive mechanical contributions of the muscles), the active musculoskeletal subsystem (muscles and tendons), and the neural and feedback subsystem (neural control centers and feedback elements such as mechanoreceptors located in the soft tissues) [1]. The interplay between subsystems readily encourages thought experiments of how pathologic changes in one subsystem might influence another--for example, prompting one to speculate how painful arthritic changes in the facet joints might affect the neuromuscular control of spinal movement. To answer clinical questions regarding the interplay between these subsystems the proper experimental tools and techniques are required. Traditional spine biomechanical experiments are able to provide comprehensive characterization of the structural properties of the osteoligamentous spine. However, these technologies do not incorporate a simulated neural feedback from neural elements, such as mechanoreceptors and nociceptors, into the control loop. Doing so enables the study of how this feedback--including pain-related--alters spinal loading and motion patterns. The first such development of this technology was successfully completed in this study and constitutes a Neuro-Musculoskeletal Simulator. A Neuro-Musculoskeletal Simulator has the potential to reduce the gap between bench and bedside by creating a new paradigm in estimating the outcome of spine pathologies or surgeries. The traditional paradigm is unable to estimate pain and is also unable to determine how the treatment, combined with the natural pain avoidance of the patient, would transfer the load to other structures and potentially increase the risk for other problems. The novel Neuro-Musculo

Annals of Scientific Society for Assembly, Handling and Industrial Robotics

This Open Access proceedings present a good overview of the current research landscape of industrial robots. The objective of MHI Colloquium is a successful networking at academic and management level. Thereby the colloquium is focussing on a high level academic exchange to distribute the obtained research results, determine synergetic effects and trends, connect the actors personally and in conclusion strengthen the research field as well as the MHI community. Additionally there is the possibility to become acquainted with the organizing institute. Primary audience are members of the scientific association for assembly, handling and industrial robots (WG MHI)

BIM modelling automation on reinforcement detailing of slabs

With the continuously undergoing development of new technologies, that lead to a gain of efficiency on daily processes, it is not surprising that, all around the world, one can face its increasing implementation even in an industry as old as Construction. The range of possibilities in this technological age was seized by civil engineers resulting in the development of the BIM methodology. Its implementation, although slow, has taken place since the beginning of this century, easing the communication and coordination processes between professionals, required in the development of any type of construction. Arduous and time-consuming tasks are being aided by new automatizing software, thus decreasing the chance of human error and increasing the project performance. One of the most difficult set of information to be transmitted between an engineering office and the construction site is the rebar detailing in reinforced concrete structures. Keeping in mind that the justification for extensive element detailing is the improvement of non-verbal communication between the structural engineer and the contractor, it is clear that this message must be passed as rigorously as possible. The development of a structural model with in depth representation of all reinforcement elements eases both the interpretation of the layout by the contractor as also the eventual detection of critical zones and optimization of the planning and construction processes by the engineer. The present thesis takes advantage of BIM technology with the development of a set of intertwined routines in different software that automatically reproduce three-dimensional reinforcement elements in two-way orthogonal slabs supported on all sides. Thus, the introduction of slab related data into a developed Excel Worksheet will support its reinforcement design through various methods. Accordingly, via the visual programming software Dynamo, different selected reinforcement zones are represented as three dimensional elements within the global model in Revit. To ascertain the application of the developed program routines compared to the traditional methods and representations, a case study is presented.Com o desenvolvimento contínuo de novas tecnologias que levam ao aumento da eficiência dos processos diários, não é de surpreender que, em todo o mundo, se verifique a sua crescente implementação, mesmo num sector tão antigo como o da Construção. A gama de possibilidades que acompanha a era tecnológica foi aproveitada por engenheiros civis, resultando no desenvolvimento da metodologia BIM. A sua implementação, embora lenta, tem ocorrido desde o início deste século, facilitando o processo de comunicação e coordenação entre todos os profissionais envolvidos no desenvolvimento de qualquer tipo de construção. Tarefas árduas e demoradas estão a ser apoiadas por novos software automáticos, diminuindo a ocorrência de erros humanos e aumentando o desempenho dos projetos. Uma das informações mais difíceis de transmitir entre um escritório de engenharia e o estaleiro é a pormenorização de armaduras em estruturas de betão armado. Tendo em mente que o que justifica a extensiva pormenorização de elementos é a melhoria da comunicação não verbal entre o engenheiro estrutural e o construtor, fica claro que essa mensagem deve ser transmitida com o maior rigor possível. O desenvolvimento de um modelo estrutural com representação detalhada de todos os elementos de reforço facilita a interpretação do layout não apenas pelo construtor, mas também a eventual deteção de zonas críticas e a otimização do processo de planeamento e construção por parte do engenheiro. A presente dissertação tira partido da tecnologia BIM com o desenvolvimento de um conjunto de rotinas interligadas em diferentes softwares que reproduzem automaticamente elementos de reforço tridimensionais em lajes retangulares armadas nas duas direções e com apoios em todos os bordos. Assim, a introdução dos dados relacionados com as lajes, diretamente numa folha de cálculo Excel, apoiará o dimensionamento das armaduras de reforço através de vários métodos. Consequentemente, através do software de programação visual Dynamo, as diferentes zonas de reforço selecionadas são representadas como elementos tridimensionais dentro do modelo global, no software Revit. Para averiguar a aplicação das rotinas desenvolvidas e comparar os seus resultados com os métodos tradicionais de dimensionamento e representação, será apresentado um caso de estudo