Joint Workspace Research Articles

Teleoperation Robot Control of a Hybrid EEG-Based BCI Arm Manipulator Using ROS

The development of assistive robots is gaining momentum in the robotic and biomedical fields. An assistive robotic system is presented in this research paper for object manipulation to aid people with physical disabilities. The robotic arm design is imported to a simulated environment and tested in a virtual world. This research includes the development of a versatile design and testing platform for robotic applications with joint torque requirements, workspace restrictions, and control tuning parameters. Live user inputs and camera feeds are used to test the movement of the robot in the virtual environment. To create the environment and user interface, a robot operating system (ROS) is used. Live brain computer interface (BCI) commands from a trained user are successfully harvested and used as an input signal to pick a goal point from 3D point cloud data and calculate the goal position of the robots’ mobile base, placing the goal point in the robot arms workspace. The platform created allows for quick design iterations to meet different application criteria and tuning of controllers for desired motion.

EviSIP: using evidence to change practice through mentorship – an innovative experience for reproductive health in the Latin American and Caribbean regions

ABSTRACT Maternal mortality is unacceptably high in our region. In 2015, the Latin American Center for Perinatology and Women´s Reproductive Health (CLAP) created a regional network of institutions including 16 countries, committed to improving epidemiological surveillance and healthcare of women in a situation of abortion or near miss event, using a common platform, the Perinatal Information System (SIP). The objective of the current pilot project was to test a new method of study called EviSIP (Evidence from SIP), a method of generating information on maternal near miss and abortion for the region. We describe the implementation of this initiative in reproductive healthcare facilities using SIP. Junior researchers/clinicians from these countries were included, along with expert researchers in reproductive health from across the world. Articles were produced with data on maternal near miss and abortion gathered from the SIP of each participating sentinel center; and recommendations from experts. EviSIP was the first joint workspace to discuss patient outcomes after treatment of abortion or near miss cases, with data analysis of each Sentinel Center; discuss and analyze data among centers, at a country and regional level; discuss the main outcomes and their impact on changing procedures and policies; strengthen the operational research capacity of the centers; develop and encourage the publication of scientific articles. The EviSIP initiative also promoted training of healthcare professionals in research. EviSIP provided a unique opportunity to train for research and mentorship and was pivotal to the production of scientific knowledge of reproductive health in the region.

Collaboration on large interactive displays: a systematic review

Large Interactive Displays (LIDs), such as tabletops or interactive walls, are promising innovations, which are increasingly used to support co-located collaboration. Yet the current evidence base on the impact of LID use on collaborative processes and outcomes, and associated influencing factors, is fragmented, particularly in comparison with other media. To address this gap, a systematic review was carried out in the databases Web of Science, Psych.Info, ACM, Elsevier, JSTOR and Springer and in the ACM CHI conference database. A corpus of 38 articles with experimental study designs met the eligibility criteria and was analyzed in-depth. With regard to collaboration processes, the findings suggest a relatively clear advantage of the use of LIDs over classic forms of collaboration, in particular over single-user environments (e.g. laptops). With attention to collaborative outcomes, positive effects of LIDs were identified for knowledge gains and social encounters, and mixed effects for task-related outcomes. The analysis further shows relevant influencing factors of LID, such as the separation of personal and joint work spaces and the deployment of horizontal instead of vertical displays. Conceptual and practice implications are discussed.

An Online Trajectory Generator on SE(3) for Human–Robot Collaboration

SummaryWith the increasing demand for humans and robots to collaborate in a joint workspace, it is essential that robots react and adapt instantaneously to unforeseen events to ensure safety. Constraining robot dynamics directly on SE(3), that is, the group of 3D translation and rotation, is essential to comply with the emerging Human–Robot Collaboration (HRC) safety standard ISO/TS 15066. We argue that limiting coordinate-independent magnitudes of physical dynamic quantities at the same time allows more intuitive constraint definitions. We present the first real-time capable online trajectory generator that constrains translational and rotational magnitude values of 3D translation and 3D rotation dynamics in a singularity-free formulation. Simulations as well as experiments on a hardware platform show the utility in HRC contexts.

Self-adaptive grasp process and equilibrium configuration analysis of a 3-DOF UACT robotic finger

Self-adaptation is a typical and widespread characteristic in underactuated finger grasp. This paper presents the self-adaptive grasp process and equilibrium configuration of a 3-DOF underactuated finger comprising cable-truss units, which uses a tendon-pulley transmission and parallel four-linkage mechanism to realise grasps. The structure and the self-adaptation at the grasp closing stage are illustrated. On the basis of a situation where one or two phalanges are in contact with the object, fixed-point grasp models and the joint workspaces are discussed, respectively. The corresponding workspace that is formed when the distal phalange contacts the object at a fixed point is assessed through numerical analysis. The expression of general static contact force is established by using the virtual work principle, and expressions reveal that the phalanges’ static statuses are obtained. According to the middle phalange contacting or not contacting with the object, the distributions of every phalange condition are assessed, and the self-adaptive grasp process in complex distribution regions and four equilibrium grasp configurations are analysed from two grasp situations. Valid and adequate self-adaptive grasp experiments are conducted to verify the accuracy of the self-adaptive grasping analysis.

A compact 3-DOF shoulder mechanism constructed with scissors linkages for exoskeleton applications

A novel 3-degrees-of-freedom (DOF) spherical mechanism, singularity-free in the anatomical shoulder joint workspace, is described. The use of curved scissors linkages interconnected by revolute joints, whose axes share the same remote centre-of-motion, achieves the most compact design of its kind. The kinematics of this scissors shoulder mechanism (SSM) are derived and presented. A design equation restricting the linkage's curvature by the central/pitch angle of the fully stretched scissors is obtained. Motion-captured data are used for validating the reachable 3-d workspace while a test-subject is wearing a null protraction/retraction constrained exoskeleton. The embodiment of the SSM as a shoulder joint for an exoskeleton device does not compromise the upper extremity function within the anatomical reachable 3-d workspace. It operates within a volume of 0.236 m3, corresponding to 68.09% and 94.97% of the volumes of the full active (0.350 m3) and null protraction/retraction constrained active (0.223 m3) reachable workspaces of the test-subject, respectively. Thus, the SSM represents a simplification of a spatial spherical mechanism design and overcomes the need for the use of redundant links and optimization routines.

Workspace Analysis of a Hybrid Kinematic Machine Tool with High Rotational Applications

This paper presents a novel parallel manipulator with one translational and two rotational (1T2R) degrees of freedom that can be employed to form a five-degree-of-freedom hybrid kinematic machine tool for large heterogeneous complex structural component machining in aerospace field. Compared with serial or parallel machine, hybrid machine has the merits of high stiffness, high speed, large workspace, and complicated surface processing ability. To increase stiffness, three-degree-of-freedom redundantly actuated and overconstrained 2PRU-PRPS parallel manipulator (P denotes the active prismatic joint) is proposed, which is utilized as the main body of hybrid machine. By resorting to the screw theory, the degree of freedom of the proposed mechanism is briefly addressed including the initial configuration and general configuration and validated by Grübler-Kutzbach (G-K) equation. Next, kinematic inverse solution and parasitic motion of the parallel manipulator are deduced and the transformational relations between the Euler angle and Tilt-Torsion (T-T) angle are identified. Thirdly, the performance evaluation index of orientation workspace is introduced, and the reachable workspace and joint workspace are formulated. Through specific examples, the reachable workspace, task workspace, and joint workspace of the redundant actuation parallel manipulator are depicted. Compared with overstrained 2PRU-PRS parallel manipulator, corresponding analyses illustrate that the proposed parallel manipulator owns much better orientation capability and is very meaningful to the development of the five-axis hybrid machine tool.

Doing time and motion diffractively: academic life everywhere and all the time

This article offers a diffractive methodological intervention into workplace studies of academic life. In its engagement of a playful, performative research and writing practice, the article speaks back to technocratic organisational and sociological workplace ‘time and motion’ studies which centre on the human and rational, and presume a linear teleology of cause and effect. As a counterpoint, we deploy posthumanist new materialist research practices which refuse human-centric approaches and aim to give matter its due. As a means to analyse what comes out of our joint workspaces photo project we produce two ‘passes’ through data – two diffractive experiments which destabilise what normally counts as ‘findings’ and their academic presentation. The article deploys the motif of ‘starting somewhere else’ to signal both our intention to keep data animated, alive and interactive, and to utilise visual and written modes of seriality as enabling constraints which produce a more generative focus on the mundane, emergent, unforeseen, and happenstance in studies of daily working life.

A New Informatics Geography.

Anyone with knowledge of information systems has experienced frustration when it comes to system implementation or use. Unanticipated challenges arise frequently and unanticipated consequences may follow. Working from first principles, to understand why information technology (IT) is often challenging, identify which IT endeavors are more likely to succeed, and predict the best role that technology can play in different tasks and settings. The fundamental purpose of IT is to enhance our ability to undertake tasks, supplying new information that changes what we decide and ultimately what occurs in the world. The value of this information (VOI) can be calculated at different stages of the decision-making process and will vary depending on how technology is used. We can imagine a task space that describes the relative benefits of task completion by humans or computers and that contains specific areas where humans or computers are superior. There is a third area where neither is strong and a final joint workspace where humans and computers working in partnership produce the best results. By understanding that information has value and that VOI can be quantified, we can make decisions about how best to support the work we do. Evaluation of the expected utility of task completion by humans or computers should allow us to decide whether solutions should depend on technology, humans, or a partnership between the two.

Meaning making through use of interactive whiteboards during physics group work. A case study from engineering education

This paper presents a case study of how the interactive whiteboard (IWB) may facilitate collective meaning-making processes in group work in engineering education. In the case, first-year students attended group-work sessions as an organised part of a basic physics course at a Norwegian university college. Each student group was equipped with an IWB, which the groups used to write down and hand in their solutions to the physics problems. Based on a Vygotskian, dialectical stance, this study investigates how the students used the IWB in the group-work situation. From qualitative analysis of video data, we identified four group-work processes where the IWB played a key role: exploratory, explanatory, clarifying and insertion. The results show that the IWB may facilitate a 'joint workspace', a social realm in which the students' dialogues are situated.

The Stewart Platform Dynamic Model Coupling Characteristic Analysis

The method for Stewart platform decentralized control in joint workspace, need to find and use the model for decentralized control. Therefore, according to the symmetry of structure characteristics of the platform reveal the inertia matrix block diagonal dominant characteristics of joint space. Analyze the inertia matrix block diagonally dominant characteristics of the platform site, and then come to the platform parameters which can meet the block diagonally dominant index.

Students’ use of the interactive whiteboard during physics group work

This paper presents a case study of how the interactive whiteboard (IWB) may facilitate collective meaning-making processes in group work in engineering education. In the case, first-year students attended group-work sessions as an organised part of a basic physics course at a Norwegian university college. Each student group was equipped with an IWB, which the groups used to write down and hand in their solutions to the physics problems. Based on a Vygotskian, dialectical stance, this study investigates how the students used the IWB in the group-work situation. From qualitative analysis of video data, we identified four group-work processes where the IWB played a key role: exploratory, explanatory, clarifying and insertion. The results show that the IWB may facilitate a ‘joint workspace’, a social realm in which the students’ dialogues are situated.

TelePresence in Rural Medical Education: A Mixed Methods Evaluation

In response to rural health workforce shortages, universities and training providers offer rural and remote clinical placements. This has led to development of educational methods to counter the barriers of distance. In this emerging field, recent improvements in technology have provided solutions including the use of sophisticated videoconferencing systems such as the Cisco TelePresence model CTS-500. This paper evaluates the use of TelePresence in diverse medical education activities using a mixed methods design—questionnaires n=60, individual interviews n=33, and observed practice of activities n=22. TelePresence was found to be beneficial to learning and teaching and superior to other systems participants had used. In particular, the audiovisual quality, resulting intimacy, convenience, and ease of use facilitated teaching and learning, while the fixed camera and poorly arranged physical environment were found to be limitations. The system is best suited for small group activities. Clinical skills-based activities are viable. It is recommended that technical support be available during setup and use and a picture-in-picture mode be included and improved integration of office suite software to provide a joint workspace for display of presentations, images, editing or annotation of documents, and file sharing.

A parallel mechanism and a control strategy based on interactive force using on hip joint power assist

In this paper, hip joint power assist (HJPA) system is given to offer assistive power to human hip joint. This paper introduces a parallel assisting mechanism and a control strategy based on interactive force between human thigh and the HJPA exoskeleton, and pseudo-compliance control. Different from conventional assisting systems, the assisting mechanism is a 3UPS parallel mechanism which can give its assist to all degrees of freedom (DOFs) of hip joint within its joint workspace. To verify the effectiveness of the parallel mechanism and the control strategy, an experimental platform is constructed, and some correlative experiments have been made. The experimental results show that the proposed HJPA system can work effectively to offer assistive effect to wearers.

Engineering students’ experiences from physics group work in learning labs

Background: This paper presents a case study from a physics course at a Norwegian university college, investigating key aspects of a group-work project, so-called learning labs, from the participating students’ perspective.Purpose: In order to develop these learning labs further, the students’ perspective is important. Which aspects are essential for how the students experience the learning labs, and how do these aspects relate to the emergence of occurrences termed joint workspace, i.e. the maintenance of content-related dialogues within the group?Programme description: First year mechanical engineering students attended the learning labs as a compulsory part of the physics course. The student groups were instructed to solve physics problems using the interactive whiteboard and then submit their work as whiteboard files.Sample: One group of five male students was followed during their work in these learning labs through one term.Design and methods: Data were collected as video recordings and fieldwork observation. In this paper, a focus group interview with the students was the main source of analysis. The interpretations of the interview data were compared with the video material and the fieldwork observations.Results: The results show that the students’ overall experience with the learning labs was positive. They did, however, point to internal aspects of conflicting common and personal goals, which led to a group-work dynamics that seemed to inhibit elaborate discussions and collaboration. The students also pointed to external aspects, such as a close temporal proximity between lectures and exercises, which also seemed to inhibit occurrences termed joint workspace.Conclusions: In order to increase the likelihood of a joint workspace throughout the term in the learning labs, careful considerations have to be made with regard to timing between lectures and exercises, but also with regard to raising the students’ awareness about shared and personal goals.

Six-DOF parallel manipulators with maximal singularity-free joint space or workspace

SUMMARYSingularity-free workspace is a very important criterion for the design of manipulators, especially for parallel manipulators which are well known for their limited workspace and complex singularities. This paper studies geometric parameters and dexterity measures that affect the size of a singularity-free joint space and proposes methods for the development of 6-DOF Stewart–Gough parallel manipulators that have better singularity-free joint space. With a local dexterity measure as the objective function, a systematic method is employed to search for the design with a maximal singularity-free joint space. The related workspaces are also investigated. It is shown that the workspace is not proportional to the size of the joint space and that manipulators with a larger singularity-free workspace usually have relatively poor dexterity.

Simulation tool for teaching and learning 3D kinematics workspaces of serial robotic arms with up to 5‐DOF

AbstractThis work develops a new educational simulation tool whose objective is to make attractive and practical teaching and learning in kinematics of serial robotic arms. At engineering laboratories in which practices with robotic arms are necessary for understanding fundamental concepts of theory, students need to accomplish a complete study attending to different aspects related with kinematics. Its graphic user interface (GUI) is a straight‐forward and easy‐to‐follow Denavit–Hartenberg (DH)‐based method which helps at engineering practices without requiring a programming knowledge. We develop, in a theoretical way, both forward (FK) and inverse kinematics (IK), which are necessary to demonstrate the study of an educational robotic arm as a practical case. The interactive simulation tool allows defining DH parameters and geometry in serial arms with up to 5 degrees of freedom (DOF). Thus, the interest of this work lies in an innovative graphic environment which teaching professionals can use to study DH convention, observe the movement of serial robotic manipulators and map both forward and joint workspaces in a visual manner. This process is much simpler that interpreting the results in an analytic way. Furthermore, the generic capabilities of this simulation tool allow comparing different robot arm configurations (considering its physical parameters and mechanical characteristics previously known), both if robotic arms are physically available or not in lab. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 750–761, 2012

Workspace Based Controller Design and Performance Evaluation of MDOF Force Sensorless Bilateral System

SUMMARY Redundant multi-degree-of-freedom (MDOF) bilateral system in workspace is expected to be a key technology for the development of next-generation robots because of the variety of feasible tasks. Nowadays, four-channel bilateral structures based on acceleration control have been introduced to realize both position and force tracking in a bilateral control system. Additionally, torque observers have been implemented to facilitate force feedback without the use of torque/force sensors. However, differences in controller composition between the joint space and workspace are still unclear. In particular, observer designs in both spaces are important for a realization of torque/force sensorless bilateral control. This paper presents a performance evaluation of an MDOF force sensorless bilateral system performed by considering the design space of observers by numerical and experimental analyses. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(4): 70–80, 2014; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22481

Non-linear adaptive synchronisation control of multi-agent robotic systems

In this article, an internal and an external synchronisation have been investigated, in the presence of uncertain parameters. The proposed controller is designed to synchronise the movement of robot group tracking the same desired trajectory. To this effect, using a consensus algorithm, we provide an adaptive control under two different schemes. In the mutual synchronisation topology, robot network requires only local neighbour-to-neighbour information exchange between robots. The interaction topology of agents network is represented using an undirected graph. However the objective of the external synchronisation coordinated scheme is to design interconnections and feedback controllers for slaves, such that their positions and velocities synchronise to those of the leader robot. It is assumed that robots in cooperation have the same joints number and equivalent joint work spaces. The proposed adaptive law based on combination of Lyapunov direct method and concepts from cross-coupling control has been developed to guarantee asymptotic convergence to zero of both position and synchronisation errors.

Nonlinear Control and Synchronization with Time Delays of Multiagent Robotic Systems

We investigate the cooperative control and global asymptotic synchronization Lagrangian system groups, such as industrial robots. The proposed control approach works to accomplish multirobot systems synchronization under an undirected connected communication topology. The control strategy is to synchronize each robot in position and velocity to others robots in the network with respect to the common desired trajectory. The cooperative robot network only requires local neighbor‐to‐neighbor information exchange between manipulators and does not assume the existence of an explicit leader in the team. It is assumed that network robots have the same number of joints and equivalent joint work spaces. A combination of the lyapunov‐based technique and the cross‐coupling method has been used to establish the multirobot system asymptotic stability. The developed control combines trajectory tracking and coordination algorithms. To address the time‐delay problem in the cooperative network communication, the suggested synchronization control law is shown to synchronize multiple robots as well as to track given trajectory, taking into account the presence of the time delay. To this end, Krasovskii functional method has been used to deal with the delay‐dependent stability problem.