2,726 research outputs found
Virtual reality for assembly methods prototyping: a review
Assembly planning and evaluation is an important component of the product design process in which details about how parts of a new product will be put together are formalized. A well designed assembly process should take into account various factors such as optimum assembly time and sequence, tooling and fixture requirements, ergonomics, operator safety, and accessibility, among others. Existing computer-based tools to support virtual assembly either concentrate solely on representation of the geometry of parts and fixtures and evaluation of clearances and tolerances or use simulated human mannequins to approximate human interaction in the assembly process. Virtual reality technology has the potential to support integration of natural human motions into the computer aided assembly planning environment (Ritchie et al. in Proc I MECH E Part B J Eng 213(5):461–474, 1999). This would allow evaluations of an assembler’s ability to manipulate and assemble parts and result in reduced time and cost for product design. This paper provides a review of the research in virtual assembly and categorizes the different approaches. Finally, critical requirements and directions for future research are presented
End to End Satellite Servicing and Space Debris Management
There is growing demand for satellite swarms and constellations for global
positioning, remote sensing and relay communication in higher LEO orbits. This
will result in many obsolete, damaged and abandoned satellites that will remain
on-orbit beyond 25 years. These abandoned satellites and space debris maybe
economically valuable orbital real-estate and resources that can be reused,
repaired or upgraded for future use. Space traffic management is critical to
repair damaged satellites, divert satellites into warehouse orbits and
effectively de-orbit satellites and space debris that are beyond repair and
salvage. Current methods for on-orbit capture, servicing and repair require a
large service satellite. However, by accessing abandoned satellites and space
debris, there is an inherent heightened risk of damage to a servicing
spacecraft. Sending multiple small-robots with each robot specialized in a
specific task is a credible alternative, as the system is simple and
cost-effective and where loss of one or more robots does not end the mission.
In this work, we outline an end to end multirobot system to capture damaged and
abandoned spacecraft for salvaging, repair and for de-orbiting. We analyze the
feasibility of sending multiple, decentralized robots that can work
cooperatively to perform capture of the target satellite as a first step,
followed by crawling onto damage satellites to perform detailed mapping. After
obtaining a detailed map of the satellite, the robots will proceed to either
repair and replace or dismantle components for salvage operations. Finally, the
remaining components will be packaged with a de-orbit device for accelerated
de-orbit.Comment: 13 pages, 10 figures, Space Traffic Management Conference. arXiv
admin note: text overlap with arXiv:1809.02028, arXiv:1809.04459,
arXiv:1901.0971
Combining Dynamic Modeling With Geometric Constraint Management to Support Low Clearance Virtual Manual Assembly
This research presents a novel approach to virtual assembly that combines dynamic modeling with geometric constraint-based modeling to support low clearance manual assembly of CAD models. This is made possible by utilizing the boundary representation solid model data available in most contemporary CAD representations, which enables (a) accurate collision/physics calculations on exact model definitions, and (b) access to geometric features. Application of geometric constraints during run-time, aid the designer during assembly of the virtual models. The feasibility of the approach is demonstrated using a pin and hole assembly example. Results that demonstrate the method give the user the ability to assemble parts without requiring extensive CAD preprocessing and without over constraining the user to arrive at predetermined final part orientations. Assembly is successful with diametral clearance as low as 0.0001 mm, as measured between a 26 mm diameter hole and pin
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