Tool Exchangeable Grasp/Assembly Planner

This paper proposes a novel assembly planner for a manipulator which can simultaneously plan assembly sequence, robot motion, grasping configuration, and exchange of grippers. Our assembly planner assumes multiple grippers and can automatically selects a feasible one to assemble a part. For a given AND/OR graph of an assembly task, we consider generating the assembly graph from which assembly motion of a robot can be planned. The edges of the assembly graph are composed of three kinds of paths, i.e., transfer/assembly paths, transit paths and tool exchange paths. In this paper, we first explain the proposed method for planning assembly motion sequence including the function of gripper exchange. Finally, the effectiveness of the proposed method is confirmed through some numerical examples and a physical experiment.Comment: This is to appear Int. Conf. on Intelligent Autonomous System

Human-based framework for the assembly of elastic objects by a dual-arm robot

Abstract This paper proposes a new framework for planning assembly tasks involving elastic parts. As an example of these kind of assembly tasks, we deal with the insertion of ring-shaped objects into a cylinder by a dual-arm robot. The proposed framework is a combination of human movements to determine the overall assembly strategy and an optimization-based motion planner to generate the robot trajectories. The motion of the human’s hands, more specifically, the motion of the fingers gripping the object is captured by a Leap Motion Controller. Then, key points in the recorded trajectory of the position and orientation of the human’s fingers are extracted. These points are used as partial goals in the optimization-based motion planner that generates the robot arms’ trajectories which minimize the object’s deformation. Through experimental results it was verified the validity of the extracted key points from the human’s movements that enable the robot to successfully assemble ring-shaped elastic objects. We compared these results with the assembly done by purely repeating all of the human’s hands movements

A Path to Industry 5.0 Digital Twins for Human–Robot Collaboration by Bridging NEP+ and ROS

The integration of heterogeneous hardware and software components to construct human-centered systems for Industry 5.0, particularly human digital twins, presents considerable complexity. Our research addresses this challenge by pioneering a novel approach that harmonizes the techno-centered focus of the Robot Operating System (ROS) with the cross-platform advantages inherent in NEP+ (a human-centered development framework intended to assist users and developers with diverse backgrounds and resources in constructing interactive human–machine systems). We introduce the nep2ros ROS package, aiming to bridge these frameworks and foster a more interconnected and adaptable approach. This initiative can be used to facilitate diverse development scenarios beyond conventional robotics, underpinning a transformative shift in Industry 5.0 applications. Our assessment of NEP+ capabilities includes an evaluation of communication performance utilizing serialization formats like JavaScript Object Notation (JSON) and MessagePack. Additionally, we present a comparative analysis between the nep2ros package and existing solutions, illustrating its efficacy in linking the simulation environment (Unity) and ROS. Moreover, our research demonstrates NEP+’s applicability through an immersive human-in-the-loop collaborative assembly. These findings offer promising prospects for innovative integration possibilities across a broad spectrum of applications, transcending specific platforms or disciplines

Graph-Based Framework on Bimanual Manipulation Planning from Cooking Recipe

It is difficult to effectively operate a dual-arm robot using only the information written in a cooking recipe. To cope with this problem, this paper proposes a graph-based approach on bimanual cooking motion planning from a cooking recipe. In our approach, we first decompose the cooking recipe into graph elements. Then, we try to connect the graph elements taking into account the attributes of the input/output nodes. If two graph elements cannot be connected to each other, we search for a graph element that can be inserted between them from a motion database. Since the constructed graph includes the whole sequence of the robot’s motions to perform the cooking task, we can generate a task sequence of a dual-arm manipulator simultaneously performing two different tasks by using two arms. Through experimental study, we show that it is possible to generate robot motions from a cooking recipe and perform the cooking motions while simultaneously moving the left and right arms

Difficulty and complexity definitions for assembly task allocation and assignment in human–robot collaborations: A review

This paper presents a literature review on the different aspects of task allocation and assignment problems in human–robot collaboration (HRC) tasks in industrial assembly environments. In future advanced industrial environments, robots and humans are expected to share the same workspace and collaborate to efficiently achieve shared goals. Difficulty- and complexity-aware HRC assembly is necessary for human-centric manufacturing, which is a goal of Industry 5.0. Therefore, the objective of this study is to clarify the definitions of difficulty and complexity used to encourage effective collaboration between humans and robots to leverage the adaptability of humans and the autonomy of robots. To achieve this goal, a systematic review of the following relevant databases for computer science was performed: IEEE Xplore, ScienceDirect, SpringerLink, ACM Digital Library, and ASME Digital Collection. The results extracted from 74 peer-reviewed research articles published until July 2022 were summarized and categorized into four taxonomies for 145 difficulty and complexity definitions from the perspectives of (1) definition-use objectives, (2) evaluation objectives, (3) evaluation factors, and (4) evaluation variables. Next, existing definitions were primarily classified according to the following two criteria to identify potential future studies on the formulation of new definitions for human-centric manufacturing: (1) agent specificity and (2) common aspects in manual and robotic assemblies.Kiyokawa T., Shirakura N., Wang Z., et al. Difficulty and complexity definitions for assembly task allocation and assignment in human–robot collaborations: A review. Robotics and Computer-Integrated Manufacturing 84, 102598 (2023); https://doi.org/10.1016/j.rcim.2023.102598