Squeeze-in Functionality for a Soft Parallel Robot Gripper

Grasping parts of inconsistent shapes, sizes and weights securely requires accurate part models and custom gripper fingers. Compliant grippers are a potential solution; however, each design approach requires the solution of unique problems. In this case, the durability and reliability of half lips (at least 1400 cycles) to perform consistently as springs of a specified stiffness (0.5N/mm) and displacement (5mm). Moreover, the challenge of low and small (3mm, 0.01kg bolt or Allen key) objects is addressed through vertical squeeze-in, implemented using an incline, lip and flex limiter as part of a 3D printed TPC spring. The squeeze-in phenomena are verified on large objects through a 30mm, 1.66kg common rail. Experimental results demonstrate the reliability when given a human-specified location for gripping, without the need for jigs or fixtures. Finally, the tested design is assessed for potential fulfillment of 7 of the United Nations sustainable development goals

Reshoring of Electric Bicycle Frame Manufacturing Through Postponement

Bicycle manufacturers struggle to meet the seasonal demand of their products due to frame manufacturing lead times of upwards of 6 months. As such, design and testing through FEA is assessed in terms of labour hours for a proposed product development strategy. The current method of manufacturing bicycle frames within the custom geometry class is through brazing lugs and tubes. This manufacturing method requires 115 tools and 30 labour hours. By contrast, 3D printing the lugs and gluing them to carbon fibres tubes can bring the tools used to 31 and the labour hours to 9. Overhead engineering costs have not been added to the investigation which is likely to greatly increase the price but also to add a quality component. The conclusion of the thesis points towards the technology being a promising candidate for domestic manufacturing within the European Union with the capability to reduce lead times to 3 or 4 months for 100 frames if finishing such as painting is not included. Further analysis and verification to this empirical study is needed before it can be implemented, particularly due to the novelty of the machines and materials used. The overhead engineering costs also needs further validation

Reshoring of Electric Bicycle Frame Manufacturing Through Postponement

Bicycle manufacturers struggle to meet the seasonal demand of their products due to frame manufacturing lead times of upwards of 6 months. As such, design and testing through FEA is assessed in terms of labour hours for a proposed product development strategy. The current method of manufacturing bicycle frames within the custom geometry class is through brazing lugs and tubes. This manufacturing method requires 115 tools and 30 labour hours. By contrast, 3D printing the lugs and gluing them to carbon fibres tubes can bring the tools used to 31 and the labour hours to 9. Overhead engineering costs have not been added to the investigation which is likely to greatly increase the price but also to add a quality component. The conclusion of the thesis points towards the technology being a promising candidate for domestic manufacturing within the European Union with the capability to reduce lead times to 3 or 4 months for 100 frames if finishing such as painting is not included. Further analysis and verification to this empirical study is needed before it can be implemented, particularly due to the novelty of the machines and materials used. The overhead engineering costs also needs further validation

Soft robotic gripper with compliant cell stacks for industrial part handling

Robot object grasping and handling requires accurate grasp pose estimation and gripper/end-effector design, tailored to individual objects. When object shape is unknown, cannot be estimated, or is highly complex, parallel grippers can provide insufficient grip. Compliant grippers can circumvent these issues through the use of soft or flexible materials that adapt to the shape of the object. This letter proposes a 3D printable soft gripper design for handling complex shapes. The compliant properties of the gripper enable contour conformation, yet offer tunable mechanical properties (i.e., directional stiffness). Objects that have complex shape, such as non-constant curvature, convex and/or concave shape can be grasped blind (i.e., without grasp pose estimation). The motivation behind the gripper design is handling of industrial parts, such as jet and Diesel engine components. (Dis)assembly, cleaning and inspection of such engines is a complex, manual task that can benefit from (semi-)automated robotic handling. The complex shape of each component, however, limits where and how it can be grasped. The proposed soft gripper design is tunable by compliant cell stacks that deform to the shape of the handled object. Individual compliant cells and cell stacks are characterized and a detailed experimental analysis of more than 600 grasps with seven different industrial parts evaluates the approach.publishedVersionPeer reviewe

Coordinating Shared Tasks in Human-Robot Collaboration by Commands

Human-robot collaboration is gaining more and more interest in industrial settings, as collaborative robots are considered safe and robot actions can be programmed easily by, for example, physical interaction. Despite this, robot programming mostly focuses on automated robot motions and interactive tasks or coordination between human and robot still requires additional developments. For example, the selection of which tasks or actions a robot should do next might not be known beforehand or might change at the last moment. Within a human-robot collaborative setting, the coordination of complex shared tasks, is therefore more suited to a human, where a robot would act upon requested commands.In this work we explore the utilization of commands to coordinate a shared task between a human and a robot, in a shared work space. Based on a known set of higher-level actions (e.g., pick-and-placement, hand-over, kitting) and the commands that trigger them, both a speech-based and graphical command-based interface are developed to investigate its use. While speech-based interaction might be more intuitive for coordination, in industrial settings background sounds and noise might hinder its capabilities. The graphical command-based interface circumvents this, while still demonstrating the capabilities of coordination. The developed architecture follows a knowledge-based approach, where the actions available to the robot are checked at runtime whether they suit the task and the current state of the world. Experimental results on industrially relevant assembly, kitting and hand-over tasks in a laboratory setting demonstrate that graphical command-based and speech-based coordination with high-level commands is effective for collaboration between a human and a robot.publishedVersionPeer reviewe

Cognitive semantics for dynamic planning in human-robot teams

Robots are making their way into our society and are foreseen to become an important part in our everyday life, at work or at home. Industrial factory layouts are moving robots out of enclosures bringing them side by side with human workers. As for service robots they are by definition meant to perform tasks in our immediate proximity. To be performed successfully, these tasks, also referred to as joint actions, require coordination and trust. Coordination implies that the robot needs to account for his actions and their effects on the environment but also for changes that the user introduces. Therefore, flexible planning capacities allowing on-the-fly adaptation to what a human is requesting or doing, together with a shared mental representation of the task, are needed. In this paper we present (i) a symbolic knowledge system and the way it translates into simple temporal networks (STN) to generate actions plans, and (ii) interaction models based on natural language. First results indicate the robot can build plans for a joint action according to several parameters given its conceptual semantic description. Furthermore, a human can interactively either modify the plan or ask for explanations about it. By several experiments we demonstrate the generation and adaptation of these dynamic human-robot collaboration plans.acceptedVersionPeer reviewe

Virtual Teaching for Assembly Tasks Planning

Small and Medium-size Enterprises require increasingly versatile robots that are capable of learning new skills during their operating life span, in addition to the ability to integrate themselves into human teams as a new and effective partner. Teaching information and skills to a robot can quickly become very complex, especially when considering that the human partner of the robot is inexperienced in the field and does not have access to intuitive interaction channels to train such robots. In this work, a system is proposed that can virtually define an assembly task, based on CAD modelling that describe constraints between assembly parts. These constraints are then extracted in an ontology which is automatically translated into Simple Temporal Networks (STNs) leading to joint action plans.Results show the automatic translation between virtual teaching and knowledge acquired by the robot on a peg-in-hole problem before illustrating the connection to planning for human-robot collaborative tasks. As a proof of concept, these developments demonstrate that a CAD guided assembly planner can circumvent the need for skilled robot programming.acceptedVersionPeer reviewe