Two-handed assembly with immersive task planning in virtual reality

Assembly modelling is the process of capturing entities and activity information related to assembling and assembly. Currently, most CAD systems have been developed to ease the design of individual components, but are limited in their support for assembly designs and planning capability, which are crucial for reducing the cost and processing time in complex design, constraint analysis and assembly task planning. This paper presents a framework of a two-handed virtual assembly (VA) planner for assembly tasks, which coordinates two hands jointly for feature-based manipulation, assembly analysis and constraint-based task planning. Feature-based manipulation highlights the important assembling features (e.g. dynamic reference frames, moving arrow, mating features) to guide users for the ease of assembly and in an efficient and fluid manner. The users can freely navigate and move the mating pair along the collision-free path. The free motion of two-handed input in assembly is further restricted to the allowable motion guided by the constraints recognised on-line. The allowable motion in assembly is planned by the logic steps derived from the analysis of constraints and their translation in the progress of assembly. No preprocessing or predefined assembly sequence is necessary since the planning is produced in real-time upon the two-handed interactions. Mating features and constraints in databases are automatically updated after each assembly to simplify the planning process. The two-handed task planner has been developed and experimented for several assembly examples including a drill (12-parts) and a robot (17-parts). The system can be generally applied for the interactive task planning of assembly-type applications.     

Collaborative virtual reality platform for visualizing space data and mission planning

This paper presents the system architecture of a collaborative virtual environment in which distributed multidisciplinary teams involved in space exploration activities come together and explore areas of scientific interest of a planet for future missions. The aim is to reduce the current challenges of distributed scientific and engineering meetings that prevent the exploitation of their collaborative potential, as, at present, expertise, tools and datasets are fragmented. This paper investigates the functional characteristics of a software framework that addresses these challenges following the design science research methodology in the context of the space industry and research. An implementation of the proposed architecture and a validation process with end users, based on the execution of different use cases, are described. These use cases cover relevant aspects of real science analysis and operation, including planetary data visualization, as the system aims at being used in future European missions. This validation suggests that the system has the potential to enhance the way space scientists will conduct space science research in the future.

     

Using virtual reality techniques in maxillofacial surgery planning

The primary goal of our research has been to implement an entirely computer-based maxillofacial surgery planning system [1]. An important step toward this goal is to make virtual tools available to the surgeon in order to carry out a three-dimensional (3D) cephalometrical analysis and to interactively define bone segments from skull and jaw bones. An easy-to-handle user interface employs visual and force-feedback devices to define subvolumes of a patient's volume dataset [2]. The defined subvolumes, together with their spatial arrangements based on the cephalometrical results, eventually lead to an operation plan. We have evaluated modern low-cost, force-feedback devices with regard to their ability to emulate the surgeon's working procedure. Once the planning of the procedure is complete, the planning results are transferred to the operating room. In our intra-operative concept the visualisation of planning data is speech controlled by the surgeon and correlated with the patient's position by an electromagnetic 3D sensor system.     

Cognitive and affective processes for learning science in immersive virtual reality

As immersive virtual reality (IVR) systems proliferate in classrooms, it is important to understand how they affect learning outcomes and the underlying affective and cognitive processes that may cause these outcomes. Proponents argue that IVR could improve learning by increasing positive affective and cognitive processing, thereby supporting improved performance on tests of learning outcome, whereas opponents of IVR contend that it could hurt learning by increasing distraction, thereby disrupting cognitive learning processes and leading to poorer learning outcomes. In a media comparison study, students viewed a biology lesson either as an interactive animated journey in IVR or as a slideshow on a desktop monitor. Those who viewed the IVR lesson performed significantly worse on transfer tests, reported higher emotional arousal, reported more extraneous cognitive load and showed less engagement based on EEG measures than those who viewed the slideshow lesson, with or without practice questions added to the lessons. Mediational analyses showed that the lower retention scores for the IVR lesson were related to an increase in self-reported extraneous cognitive load and emotional arousal. These results support the notion that immersive environments create high affective and cognitive distraction, which leads to poorer learning outcomes than desktop environments.     

Effects of virtual presence and learning outcome using low-end virtual reality systems

Low-cost technology is essential to integrate Virtual Reality (VR) into educative institutions around the world. However, low-cost technology usually refers to low-end technology, which may compromise the level of immersion of the VR system. This study evaluates whether low-end and high-end VR systems achieve a comparable learning outcome regardless their immersion level. We also analyze the relationship between virtual presence and the learning outcome arising from a VR educational experience. An evaluation with 42 participants was conducted. We measured learning outcome and virtual presence under three different configurations, namely: a desktop computer, a low-end VR system, and a high-end VR system. The impact of simulator sickness was also analyzed. Results revealed a lower learning outcome in the less immersive configuration (i.e. desktop) and a similar learning outcome in both low-end and high-end VR systems. Even though low-end VR systems are less immersive and produce a lower level of virtual presence than high-end VR systems, the results support the use of low-end VR systems for educative applications.     

The virtual playground: an educational virtual reality environment for evaluating interactivity and conceptual learning

The research presented in this paper aims at investigating user interaction in immersive virtual learning environments, focusing on the role and the effect of interactivity on conceptual learning. The goal has been to examine if the learning of young users improves through interacting in (i.e. exploring, reacting to, and acting upon) an immersive virtual environment (VE) compared to non-interactive or non-immersive environments. Empirical work was carried out with more than 55 primary school students between the ages of 8 and 12, in different between-group experiments: an exploratory study, a pilot study, and a large-scale experiment. The latter was conducted in a virtual environment designed to simulate a playground. In this “Virtual Playground,” each participant was asked to complete a set of tasks designed to address arithmetical “fractions” problems. Three different conditions, two experimental virtual reality (VR) conditions and a non-VR condition, that varied the levels of activity and interactivity, were designed to evaluate how children accomplish the various tasks. Pre-tests, post-tests, interviews, video, audio, and log files were collected for each participant, and analysed both quantitatively and qualitatively. This paper presents a selection of case studies extracted from the qualitative analysis, which illustrate the variety of approaches taken by children in the VEs in response to visual cues and system feedback. Results suggest that the fully interactive VE aided children in problem solving but did not provide a strong evidence of conceptual change as expected; rather, it was the passive VR environment, where activity was guided by a virtual robot, that seemed to support student reflection and recall, leading to indications of conceptual change.     

Perception-based learning for motion in contact in task planning

This paper presents a new approach to error detection during motion in contact under uncertainty for robotic manufacturing tasks. In this approach, artificial neural networks are used for perception-based learning. The six force-and-torque signals from the wrist sensor of a robot arm are fed into the network. A self-organizing map is what learns the different contact states in an unsupervised way. The method is intended to work properly in complex real-world manufacturing environments, for which existent approaches based on geometric analytical models may not be feasible, or may be too difficult. It is used for different tasks involving motion in contact, particularly the peg-in-hole insertion task, and complex insertion or extraction operations in a flexible manufacturing system. Several real examples for these cases are presented.Category: (8) AI in Robotics and Manufacturing/FMS.     

Comparison of intelligent control planning algorithms for robot's part micro-assembly task

Two intelligent control (path or motion) planning algorithms, based on a neural network and a fuzzy set theory, related to a robotic quasi-static part micro-assembly task are introduced. The part micro-assembly considered in this paper consists in a mating a part with an assembly hole or a receptacle (target) without a jamming. These algorithms are then compared through the utilization of experimentally measured data as well as simulations and a set of criteria. An entropy function, which is a useful measure of the variability and the information in terms of uncertainty, is introduced to measure its overall performance of a task execution related to the part micro-assembly task. Fuzzy set theory is introduced to address the uncertainty associated with the part micro-assembly procedure. The degree of uncertainty associated with the part micro-assembly is used as an optimality criterion, e.g. minimum fuzzy entropy, for a specific task execution. It is shown that the machine organizer using a sensor system can intelligently determine an optimal control value, based on explicit performance criteria. The algorithms utilize knowledge processing functions such as machine reasoning, planning, inferencing, learning, and decision-making. The results show the effectiveness of the proposed approaches. The proposed techniques are applicable to a wide range of robotic tasks including motion planning, pick and place operations, and part mating with various shaped parts.     

Human-robot collaboration disassembly planning for end-of-life product disassembly process

The disassembly process is the main step of dealing with End-Of-Life (EOL) products. This process is carried out mostly manually so far. Manual disassembly is not efficient economically and the robotic systems are not reliable in dealing with complex disassembly operations as they have high-level uncertainty. In this research, a disassembly planning method based on human-robot collaboration is proposed. This method employs the flexibility and ability of humans to deal with complex tasks, alongside the repeatability and accuracy of the robot. Besides, to increase the efficiency of the process the components are targeted based on the remanufacturability parameters. First, human-robot collaboration tasks are classified, and using evaluation of components remanufacturability parameters, human-robot collaboration definition and characteristics are defined. To target the right components based on their remanufacturability factors, the PROMETHEE II method is employed to select the components based on Cleanability, Reparability, and Economy. Then, the disassembly process is represented using AND/OR representation and the mathematical model of the process is defined. New optimization parameters for human-robot collaboration are defined and the genetic algorithm was modified to find a near-optimal solution based on the defined parameters. To validate the task classification and allocation, a 6-DOF TECHMAN robot arm is used to test the peg-out-hole disassembly operation as a common disassembly task. The experiments confirm the task classification and allocation method. Finally, an automotive component was selected as a case study to validate the efficiency of the proposed method. The results in comparison with the Particle Swarm algorithm prove the efficiency and reliability of the method. This method produces a higher quality solution for the human-robot collaborative disassembly process.     

Using virtual reality for industrial design learning: a methodological proposal

ABSTRACT

Nowadays, the different computer tools available enable designers to create complex industrial prototypes. The use of these tools is constrained by the limitations imposed by common devices, such as screens and displays. Recently emerged virtual and augmented reality techniques have started being used as supports in many learning and industrial environments. Beyond the new possibilities that these tools offer for designing industrial objects, the underlying question is whether these new technologies could improve the creativity of designers to enable them to get a better understanding of the designing process itself. This paper presents a methodological proposal for the deployment of an industrial design engineering course aimed not only at learning different design techniques, but also at assessing the creativity skills of students. The practical contents include the use of virtual reality devices, to help the designer overcome the limitations of prototype visualisation and make better designing decisions. Moreover, a creativity test will be performed at the beginning and at the end of the course to assess the changes in creativity skills taking place within the experiment group versus the changes in a traditional learning (control) group.     

Heuristics for demand-driven disassembly planning

Remanufacturing of used products has become accepted as an advantageous disposition option within the field of reverse logistics. Remanufacturing, where a firm takes returned products at the end of their life and disassembles them to obtain parts which are reassembled into “good as new” products, may require so-called demand-driven- disassembly, where a specific amount of returned products must be disassembled to yield parts which are either demanded externally, or used in the remanufacturing operation. While in its simplest form, the solution can be merely calculated, more realistically complex product structures require a more powerful solution method. The first choice, integer programming (IP) can be used to arrive at an optimal solution, with the disadvantage that the time required to solve the problem explodes with increasingly complex product structures and longer time horizons. Another possible method, heuristics which were presented in a previous work on this problem [Taleb and Gupta (Computers & Industrial Engineering 1997; 32(4): 949–61], offer a faster, easier solution with the disadvantage that it is not necessarily optimal, and under certain circumstances may deliver an infeasible result. In this work, this problem was corrected and the heuristic was extended in several important ways to deal with holding costs and external procurement of items. The methodology is illustrated by an example. Another advantage of the heuristic is that it can be programmed into code and executed via spreadsheet application, which will facilitate its application. A performance study reveals that the new heuristic performs quite well for a wide spectrum of randomly generated problem test instances.     

Integrating video-capture virtual reality technology into a physically interactive learning environment for English learning

The aim of this study is to design and develop a Physically Interactive Learning Environment, the PILE system, by integrating video-capture virtual reality technology into a classroom. The system is designed for elementary school level English classes where students can interact with the system through physical movements. The system is designed to be easily established with a minimal amount of equipments that includes a personal computer, a webcam, and a projector. The learning activities comprise six stages, holding specific tasks and learning objectives. Each stage is designed with a distinct device. These devices, including a conical cap, a pistol, a searchlight, a magnet, and a spray paint can, are designed to improve the accuracy of detection as well as to increase student enjoyment during the learning process. Furthermore, the system consists of five functional modules, such as providing an interface for teachers to incorporate appropriate learning materials according to their specific teaching requirements. An empirical study is conducted to examine the effects of the use of the PILE system by comparing two different types of English learning methods with 60 second-grade students from two classes at an elementary school in Taiwan. Four different tests are used to assess the different aspects of the system: an English learning achievement test, a questionnaire assessing students’ learning motivation, a Short Feedback Questionnaire (SFQ), and a teacher interview. The results of students’ English learning achievement tests show that there was a significant difference between the pretest and the posttest in the experimental group, as well as between the two groups in the delayed test. These results demonstrate that the system had a significantly beneficial effect on students’ long-term learning. The results from the questionnaires on students’ learning motivation and the SFQ reveal that the system enhanced the students’ learning motivation. The results gained from the teacher’s interview illustrate that the teacher believed this system was beneficial in assisting English learning. All findings collectively demonstrate that the proposed PILE system effectively assist English learning in a classroom environment.     

Construction of a computer-simulated mixed reality environment for virtual factory layout planning

To survive the cut-throat competition in the manufacturing industry, many companies have introduced digital manufacturing technology. Digital manufacturing technology not only shortens the product development cycle times but also improves the precision of engineering simulation. However, building the virtual objects needed for a digital manufacturing environment requires skilled human resources; it is also costly and time-consuming. A high precision environment with the similar resources is also needed for a high precision simulation. In this paper, we propose a method of constructing a mixed reality-based digital manufacturing environment. The method integrates real objects, such as real images, with the virtual objects of a virtual manufacturing system. This type of integration minimizes the cost of implementing virtual objects and enhances the user's sense of reality. We studied several methods and derived a general framework for the system. Finally, we developed our idea into a virtual factory layout planning system. To assign the pose and position of real objects in virtual space, we applied a circle-based tracking method which uses a safety sign instead of the planar-square-shaped marker generally used for registration. Furthermore, we developed the framework to encapsulate simulation data from legacy data and process data for visualization based on mixed reality.     

A framework for virtual disassembly analysis

Product reuse or recyclability is enhanced by designing the product for inexpensive and efficient disassembly. However, accomplishing enhanced product design requires design for disassembly (DFD) tools. This paper presents a disassembly framework that consists of design modules; both of these are embodied in the geometric DFD tool. These modules consist of different tasks including: selection of the appropriate disassembly method; producing an optimized disassembly sequence; evaluating a disassembly sequence for cost; producing design change recommendations. These considerations make a product easier to disassemble and therefore have potential benefit to the environment.     

Urban underground space planning based on FPGA and virtual reality system

The underground plaza is a place of leisure activities for citizens, represents the quality of the city's underground space, experience, so the space is significant. The present study of the ten large-scale urban underground space of the study summarized the essential elements and the underground plaza of the corresponding numerical interval's interface form. It describes the interface format's spatial experience of influence an underground plaza; on this basis, the underground plaza virtual model is built in a different interface format. The isovist method and the SD method to comb the Immersive Virtual Reality System (IVRS) platform, the shape of the interface and spatial experience, and the correlation between the related compliance indicators proposed interface form are quantitative analysis. It is summarized. Experimental results, spatial experience have indicated better at 0.402 interface density and interface 2–3 aperture aspect ratio. This is, it can become a reference and basis for the future of urban underground space design.     

智能空间下基于分层任务网络的服务机器人任务规划

针对在复杂、动态的家庭环境下,如何让机器人获取足够多的环境信息并根据环境信息进行自主的任务规划,提出了智能空间技术支持下基于分层任务网络的服务机器人任务规划方案.利用智能空间技术为机器人提供充足的环境上下文信息,用基于分层任务网络设计的JSHOP2规划器执行机器人任务规划.为了提高机器人任务规划的自主性和智能性,在规划领域文件中加入不同的模板信息,使机器人具有根据环境的不同自动对任务进行调整的能力.仿真实验结果表明利用该方法能够有效地提高机器人任务规划的性能.     

A welding task data model for intelligent process planning of robotic welding

Nowadays, as an efficient and automatic welding machine that accepts and executes human instructions, welding robots are widely used in industry. However, the lack of intelligence in process planning makes welding preparation complex and time-consuming. In order to realize intelligent process planning of robotic welding, one of the key factors is designing a welding task data model that can support process planning. However, current welding task models have some drawbacks, such as inaccurate geometry information, lacking information on welding requirements, and lacking consideration of machine-readability and compatibility. They cannot provide sufficient information for intelligent process planning. In this paper, a welding task data model, which includes information on accurate geometry, dimension and welding requirement, is presented to solve these problems. Firstly, through requirement analysis, necessary information items of a welding task data model are analyzed and summarized. Then the welding task data model is designed in detail by using EXPRESS. The feasibility of proposed welding task data model is demonstrated through creating the welding task file of an automobile front door subassembly. Moreover, an application framework of the welding task file is presented. Results show that proposed welding task data model is feasible for supporting intelligent process planning and information integration of robotic welding.     

Using virtual reality for dynamic learning: an extended technology acceptance model

Virtual Reality - Virtual reality (VR) is being researched and incorporated into curricula and training programs to expand educational opportunities and enhance learning across many fields....     

Intelligent virtual environments for virtual reality art

The development of virtual reality (VR) art installations is faced with considerable difficulties, especially when one wishes to explore complex notions related to user interaction. We describe the development of a VR platform, which supports the development of such installations, from an art+science perspective. The system is based on a CAVE™-like immersive display using a game engine to support visualisation and interaction, which has been adapted for stereoscopic visualisation and real-time tracking. In addition, some architectural elements of game engines, such as their reliance on event-based systems have been used to support the principled definition of alternative laws of Physics. We illustrate this research through the development of a fully implemented artistic brief that explores the notion of causality in a virtual environment. After describing the hardware architecture supporting immersive visualisation we show how causality can be redefined using artificial intelligence technologies inspired from action representation in planning and how this symbolic definition of behaviour can support new forms of user experience in VR.     

A method for evaluating the learning concentration in head-mounted virtual reality interaction

Virtual Reality - In education, learning concentration is closely related to the quality of learning, and teachers can adjust their teaching methods accordingly to improve the learning outcomes of...