Scissor lift with real-time self-adjustment ability based on variable gravity compensation mechanism

Most robots involved in vertical movement against gravitation require actuators large enough to support their own weight. To improve the inherent safety of such robots against the large actuators and reduce their energy consumption, numerous gravity compensation mechanisms (GCMs) have been proposed. Our previous study proposed a variable GCM (VGCM) that uses two types of springs and can adjust the compensation force. In this paper, a VGCM-based scissor lift (pantograph lift) that uses three springs and a smaller actuator is proposed. A prototype is designed and fabricated, and the performance of the prototype is evaluated experimentally. The results demonstrate that the developed scissor lift meets the design specifications. In addition, a load estimator is established based on the dynamic model of the scissor lift. A real-time self-adjustment method that automatically changes the compensation force is proposed, and its effectiveness is verified

Automobile Seat Comfort

Johnson Controlshttp://deepblue.lib.umich.edu/bitstream/2027.42/96204/1/me450f12project11_report.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96204/2/me450f12project11_photo.jp

Optimized Endpoint Delivery Via Unmanned Aerial Vehicles

Unmanned Aerial Vehicles (UAVs) are remotely piloted aircraft with a range of varying applications. Though early adoption of UAVs focused on military applications, surveillance, photography, and agricultural applications are presently on the rise. This work aims to ascertain how UAVs may be employed to elicit deceased transportation times, increased power efficiency, and improved safety. Resulting in optimized end point delivery. A combination of tools and techniques, involving a mathematical model, UAV simulations, redundant control systems, and custom designed electrical and mechanical components were used towards reaching the goal of a 10-kilogram maximum payload delivered 10 miles under 30 minutes. Two UAV prototypes were developed, the second of which (V2) showed promising results. Velocities achieved in V2, in combination with a versatile payload connector and proper networking, allowed for 5-10 mile deliveries of goods less than 8-kilograms to be achieved within a metropolis faster than the 30-minute benchmark

Towards Energy-Efficient Electrified Mobile Hydraulics : Considering Varying Application Conditions

In the face of global warming, companies in all kinds of industries need to take measures to reduce the use of fossil fuels, which is explicitly enforced by more and more upcoming emission legislation in many countries. In the case of heavy-duty mobile machines (HDMMs), a currently high-emitting sector, the most feasible method of reducing harmful emissions during operation is battery-based electrification. However, the relatively low capacities and high costs of available battery packs are restricting the operation times as well as upper power limits of battery-electric HD-MMs—at least under economically feasible conditions. In this scenario, the typically low energy-efficiencies of conventional hydraulic systems, which are essential for realizing linear actuation on HDMMs, are becoming more critical than ever before, and more efficient alternative concepts are required. As an answer to this demand, this thesis and the six publications on which it is based analyze how alternative hydraulic concepts for electrified HDMMs should look like, and two specific concepts are proposed as well as evaluated. In this scope, the focus is not only on improving the efficiency but also on other aspects that can prevent or accelerate the success of alternative hydraulic concepts on the market, such as costs and feasibility. Since those aspects cannot be analyzed in isolation from the application conditions, the essential characteristics of HDMMs and the differences of those characteristics between HDMM types are elaborated systematically. Furthermore, the implications of the transition from internal combustion engines (ICEs) to electric machines (EMs) as the prime movers for hydraulic pumps are identified by means of a literature review. Considering the insights from the analyses of those aspects, already existing hydraulic concepts—i.e., conventional as well as proposed alternatives for improved efficiency—are reevaluated, and beneficial elements of those concepts are filtered out for constructing two new concepts. Those two proposed concepts are characterized by a modular approach in which actuators can be valve-controlled, which might be less efficient but more cost-effective, or pump-controlled, as an alternative for more efficient yet costly actuation of selected functions on the HDMM. Simulation studies are used to demonstrate the efficiency of both concepts under varying configurations that are enabled through the modular nature of the concepts, and the differences in applying them on a telehandler, wheel loader, or excavator are analyzed. For the second concept, which is based on displacement-control and performed best in the simulations, a cost analysis is used to prove additionally that reasonably short payback times of the increased investment costs can be reached in different scenarios. Furthermore, the efficiency performance as well as feasibility—in terms of using commercially available components only and achieving good controllability—are experimentally validated on a telehandler

NOIRS 2011

"The National Institute for Occupational Safety and Health (NIOSH), in partnership with the Liberty Mutual Research Institute for Safety (LMRIS) and the National Safety Council (NSC), hosted the fifth National Occupational Injury Research Symposium (NOIRS) on October 18-20, 2011 at the Waterfront Place Hotel in Morgantown, West Virginia. NOIRS is the only national forum focused on the presentation of occupational injury research findings, data, and methods. This symposium served numerous objectives aimed at preventing traumatic occupational injury through research and prevention. They included: presenting current research findings; fostering collaboration among researchers from a broad range of disciplines, perspectives, and topic areas; identifying 'best practices' for the prevention of work-related injuries; exploring the cost-effectiveness of injury prevention strategies and interventions; showcasing innovative and high technology approaches to research and prevention; and continuing to promote the implementation of the National Occupational Research Agenda (NORA). Questions addressed included: What are the latest traumatic occupational injury research findings? What are emerging problems and research areas in workplace trauma? How is prevention through design being applied to occupational injury research and prevention? What activities are being done to implement research to practice in the area of traumatic occupational injury? What are the best practice intervention and prevention strategies? What are the economic costs of traumatic occupational injuries and are the prevention strategies cost-effective? What are the trends in traumatic occupational injury and fatality incidence? In research tools, techniques, and methods? In prevention? What specific workplace risks are faced by adolescents, older adults, foreign-born workers, non-English-speaking workers, low-literacy workers, and other special populations? How can researchers and practitioners in different sectors and disciplines better collaborate and coordinate their activities to reduce traumatic occupational injuries? What methods are available to assess, quantify, and compare traumatic occupational injury risks? Occupational injury researchers from all disciplines attended and shared their research. We encouraged participation by all interested individuals, including: safety researchers; safety practitioners; health care professionals; administrators; epidemiologists; engineers; manufacturers; communication researchers; regulators; employers; policy makers; insurers; students; advocates; workers; educators and trainers; and others interested in attending. The symposium consistd of contributed oral presentations in concurrent sessions and a poster session." - NIOSHTIC-2Welcome -- Symposium information -- Agenda at a glance -- Meeting facilities-main floor -- Acknowledgements -- Full agenda -- List of opening and closing plenary speakers -- List of pre-registered participants -- Abstracts -- Poster abstracts -- Abstract reviewers"October 2011.""This year's symposium theme, Future directions in occupational injury prevention research. NOIRS would not be possible without the support of our co-sponsors: the National Safety Council and the Liberty Mutual Research Institute for Safety." - p. [1]Available via the World Wide Web as an Acrobat .pdf file (1.64 MB, 190 p.)

Aeronautical engineering: A continuing bibliography with indexes (supplement 227)

This bibliography lists 418 reports, articles, and other documents introduced into the NASA scientific and technical information system in May, 1988

The 15th Aerospace Mechanisms Symposium

Technological areas covered include: aerospace propulsion; aerodynamic devices; crew safety; space vehicle control; spacecraft deployment, positioning, and pointing; deployable antennas/reflectors; and large space structures. Devices for payload deployment, payload retention, and crew extravehicular activities on the space shuttle orbiter are also described