Engineering topics

Gan, Quan

Publications and source records attributed to Gan, Quan.

5 records

DOE OSTI2021

Internet of Samples

Abstract Material samples are indispensable data sources in many natural science, social science, and humanity disciplines. More and more researchers recognize that samples collected in one discipline can be of great value for another. This has motivated organizations that manage a large number of samples to make their holdings accessible to the world. Currently, multiple projects are working to connect natural history and other samples managed by individual institutions or individuals into a universe of samples that follow FAIR principles. This poster reports the progress of the US NSF‐funded iSamples project, in the context of other efforts initiated by US DOE, DiSCCo, BCoN, and GBIF. By October 2021, we will also be able to present an iSamples prototype. We encourage individual organizations that hold material samples to get to know these projects and help shape these projects to realize the goal of a global linked sample cloud that connects all material samples and is accessible to all.

Richard, Stephen M.↗

NASA NTRS2006

Humanoids for Lunar and Planetary Surface Operations

Human-like shape makes humanoids well suited for being fostered/taught by humans, and for learning from humans, which we consider the best means to develop cognitive and perceptual/motor skills for truly intelligent, cognitive robots.

autonomous behavior↗

NASA NTRS2005

Humanoids for lunar and planetary surface operations

This paper presents a vision of humanoid robots as human's key partners in future space exploration, in particular for construction, maintenance/repair and operation of lunar/planetary habitats, bases and settlements. It integrates this vision with the recent plans, for human and robotic exploration, aligning a set of milestones for operational capability of humanoids with the schedule for the next decades and development spirals in the Project Constellation. These milestones relate to a set of incremental challenges, for the solving of which new humanoid technologies are needed. A system of systems integrative approach that would lead to readiness of cooperating humanoid crews is sketched. Robot fostering, training/education techniques, and improved cognitive/sensory/motor development techniques are considered essential elements for achieving intelligent humanoids. A pilot project in this direction is outlined.

information fusion↗

NASA NTRS2005

Humanoid Locomotion: An Experimental Study on Signal Processing and Dynamic Approaches to Humanoid Walk Generation

It is hoped that one day robots will assist in lunar and Martian surface exploration by constructing facilities before their human counterparts arrive; robots with a human form-factor may be desirable since they can potentially use the same set of tools designed for humans. With the goal in mind, locomotion may be one of the biggest challenges for a humanoid sine the terrain is most likely uneven and varying. An adjustable walk has been developed for the HOAP-2 robot by gathering motor data from a preprogrammed fixed walk and using signal processing techniques. The result is a basic walk pattern adjustable in the frequency domain that can be used as a central pattern generator (CPG) in which the robot can modify using sensor feedback. Ultimately, the feedback can be applied to have the humanoid walk on various terrains, slopes, and avoid obstacles.

Gan, Quan↗

NASA NTRS2002

Vibration Reduction of Helicopter Blade Using Variable Dampers: A Feasibility Study

In the report, the investigation of controlling helicopter-blade lead-lag vibration is described. Current practice of adding passive damping may be improved to handle large dynamic range of the blade with several peaks of vibration resonance. To minimize extra-large damping forces that may damage the control system of blade, passive dampers should have relatively small damping coefficients, which in turn limit the effectiveness. By providing variable damping, a much larger damping coefficient to suppress the vibration can be realized. If the damping force reaches the maximum allowed threshold, the damper will be automatically switched into the mode with smaller damping coefficient to maintain near-constant damping force. Furthermore, the proposed control system will also have a fail-safe feature to guarantee the basic performation of a typical passive damper. The proposed control strategy to avoid resonant regions in the frequency domain is to generate variable damping force in combination with the supporting stiffness to manipulate the restoring force and conservative energy of the controlled blade system. Two control algorithms are developed and verified by a prototype variable damper, a digital controller and corresponding algorithms. Primary experiments show good potentials for the proposed variable damper: about 66% and 82% reductions in displacement at 1/3 length and the root of the blade respectively.

Lee, George C.↗