Testing an injection forging process for the production of automotive fasteners

Competition in the automotive fasteners production has been fierce and there are needs for higher quality, lower manufacturing-cost and fast delivery. To meet such needs, injection forging of automotive fasteners for possible industrial production has been investigated, considering its potential of forming complex-shaped components with shorter process chains. Initially, a comparison study on existing multi-stage forming and injection forging was conducted, supported by FE simulations, through which the feasibility of using injection forging for producing one type of fasteners was established preliminarily. The process was then tested through forming experiments based on which component accuracy, formed-material hardness and grain-flow lines were examined to evaluate the quality of the fasteners formed. Further, a manufacturing trial was carried out in the industry to examine the process feasibility in the industrial environment. Besides the parts with good quality having been achieved, the requirement for higher forming-force and the consequence as larger die-deflections were also identified through these studies. Based on the results obtained, improvements on the process and tool-design were proposed, focusing on the forming-force reduction and higher part-dimension accuracy

Evaluating the Augmented Reality Human-Robot Collaboration System

This paper discusses an experimental comparison of three user interface techniques for interaction with a mobile robot located remotely from the user. A typical means of operating a robot in such a situation is to teleoperate the robot using visual cues from a camera that displays the robot’s view of its work environment. However, the operator often has a difficult time maintaining awareness of the robot in its surroundings due to this single ego-centric view. Hence, a multi-modal system has been developed that allows the remote human operator to view the robot in its work environment through an Augmented Reality (AR) interface. The operator is able to use spoken dialog, reach into the 3D graphic representation of the work environment and discuss the intended actions of the robot to create a true collaboration. This study compares the typical ego-centric driven view to two versions of an AR interaction system for an experiment remotely operating a simulated mobile robot. One interface provides an immediate response from the remotely located robot. In contrast, the Augmented Reality Human-Robot Collaboration (AR-HRC) System interface enables the user to discuss and review a plan with the robot prior to execution. The AR-HRC interface was most effective, increasing accuracy by 30% with tighter variation, while reducing the number of close calls in operating the robot by factors of ~3x. It thus provides the means to maintain spatial awareness and give the users the feeling they were working in a true collaborative environment

Collaborating with a Mobile Robot: An Augmented Reality Multimodal Interface

Invited paperWe have created an infrastructure that allows a human to collaborate in a natural manner with a robotic system. In this paper we describe our system and its implementation with a mobile robot. In our prototype the human communicates with the mobile robot using natural speech and gestures, for example, by selecting a point in 3D space and saying “go here” or “go behind that”. The robot responds using speech so the human is able to understand its intentions and beliefs. Augmented Reality (AR) technology is used to facilitate natural use of gestures and provide a common 3D spatial reference for both the robot and human, thus providing a means for grounding of communication and maintaining spatial awareness. This paper first discusses related work then gives a brief overview of AR and its capabilities. The architectural design we have developed is outlined and then a case study is discussed

Cost Effective Computer Vision Based Structural Health Monitoring using Adaptive LMS Filters

Structural health monitoring (SHM) algorithms based on Adaptive Least Mean Squares (LMS) filtering theory can directly identify time-varying changes in structural stiffness in real time in a computationally efficient fashion. However, the best metrics of seismic structural damage are related to permanent and plastic deformations. The recent work done by the authors uses LMS-based SHM methods with a baseline non-linear Bouc-Wen structural model to directly identify changes in stiffness (modelling or construction error), as well as plastic or permanent deflections, in real-time. The algorithm validated, in silico, on a non-linear sheartype concrete structure using noise-free simulation-derived structural responses. In this paper, efficiency of the proposed SHM algorithm in identifying stiffness changes and plastic/permanent deflections under different ground motions is assessed using a suite of 20 different ground acceleration records. The results show that even with a fixed filter tuning parameters, the proposed LMS SHM algorithm identifies stiffness changes to within 10% of true value in 2.0 seconds. Permanent deflection is identified to within 14% of the actual as-modelled value using noisefree simulation-derived structural responses. Accuracy of the proposed SHM algorithm mainly relies on providing high-speed structural responses. However, due to a variety of practical constraints, direct high frequency measurement of displacement and velocity is not typically possible. This study explores the idea that emerging high speed line scan cameras can offer a robust and high speed displacement measure required for the modified LMS-based SHM algorithm proposed for non-linear yielding structures undergoing seismic excitation, and can be used for more precise estimation of the velocity using measured acceleration and displacement data. The displacement measurement method is tested to capture displacements of a computer-controlled cart under 20 different displacement records. The method is capable of capturing displacements of the cart with less than 2.2% error

The State-of-Art of Underwater Vehicles - Theories and Applications

An autonomous underwater vehicle (AUV) is an underwater system that contains its own power and is controlled by an onboard computer. Although many names are given to these vehicles, such as remotely operated vehicles (ROVs), unmanned underwater vehicles (UUVs), submersible devices, or remote controlled submarines, to name just a few, the fundamental task for these devices is fairly well defined: The vehicle is able to follow a predefined trajectory. AUVs offer many advantages for performing difficult tasks submerged in water. The main advantage of an AUV is that is does not need a human operator. Therefore it is less expensive than a human operated vehicle and is capable of doing operations that are too dangerous for a person. They operate in conditions and perform task that humans are not able to do efficiently, or at all (Smallwood & Whitcomb, 2004; Horgan & Toal, 2006; Caccia, 2006)

Broccoli sprout beverage is safe for thyroid hormonal and autoimmune status: Results of a 12-week randomized trial.

Sulforaphane is a redox-active natural product present in cruciferous vegetables like broccoli. Broccoli sprout-derived products are promising agents for the prevention of oxidative stress-related diseases, but some have long been suspected of thyroidal toxicity. Recent findings also raise the possibility that long-term exposure to sulforaphane, or to other natural substances or drugs that modulate the activity of the transcription factor Nrf2 (NFE2-related factor 2) may lead to thyroid dysfunction or thyroid autoimmune disease, questioning the safety of trials with sulforaphane-containing products. Previous studies addressing possible effects of sulforaphane-related compounds from natural product extracts on the thyroid were quite short and/or inconsistent. To investigate whether long-term exposure to a beverage enriched with sulforaphane and its precursor glucoraphanin may affect thyroid function, we analyzed biochemical measures of thyroid function and thyroid autoimmunity in 45 female participants in a randomized clinical trial at baseline and after 84 days of beverage administration. Serum levels of thyroid-stimulating hormone, free thyroxine and thyroglobulin were not affected by the treatment, and neither was the thyroid autoimmunity status of participants. These results provide evidence in favor of the safety of chemoprevention strategies that target the activation of Nrf2 to protect against environmental exposures and other oxidative stress-related pathologies

Observation of Two New N* Peaks in J/psi -> ppi−nˉp pi^- \bar n and pˉπ+n\bar p\pi^+n Decays

The $\pi N$ system in decays of $J/\psi\to\bar NN\pi$ is limited to be isospin 1/2 by isospin conservation. This provides a big advantage in studying $N^*\to \pi N$ compared with $\pi N$ and $\gamma N$ experiments which mix isospin 1/2 and 3/2 for the $\pi N$ system. Using 58 million $J/\psi$ decays collected with the Beijing Electron Positron Collider, more than 100 thousand $J/\psi \to p \pi^- \bar n + c.c.$ events are obtained. Besides two well known $N^*$ peaks at 1500 MeV and 1670 MeV, there are two new, clear $N^*$ peaks in the $p\pi$ invariant mass spectrum around 1360 MeV and 2030 MeV. They are the first direct observation of the $N^*(1440)$ peak and a long-sought "missing" $N^*$ peak above 2 GeV in the $\pi N$ invariant mass spectrum. A simple Breit-Wigner fit gives the mass and width for the $N^*(1440)$ peak as $1358\pm 6 \pm 16$ MeV and $179\pm 26\pm 50$ MeV, and for the new $N^*$ peak above 2 GeV as $2068\pm 3^{+15}_{-40}$ MeV and $165\pm 14\pm 40$ MeV, respectively