34 research outputs found
Model-based Robotic Dynamic Motion Control for the Robonaut 2 Humanoid Robot
Robonaut 2 (R2), an upper-body dexterous humanoid robot, has been undergoing experimental trials on board the International Space Station (ISS) for more than a year. R2 will soon be upgraded with two climbing appendages, or legs, as well as a new integrated model-based control system. This control system satisfies two important requirements; first, that the robot can allow humans to enter its workspace during operation and second, that the robot can move its large inertia with enough precision to attach to handrails and seat track while climbing around the ISS. This is achieved by a novel control architecture that features an embedded impedance control law on the motor drivers called Multi-Loop control which is tightly interfaced with a kinematic and dynamic coordinated control system nicknamed RoboDyn that resides on centralized processors. This paper presents the integrated control algorithm as well as several test results that illustrate R2's safety features and performance
FAIMS operation for realistic gas flow profile and asymmetric waveforms including electronic noise and ripple
Monitoring Northern Bobwhite Populations Reduces Uncertainty About Management Effectiveness: A Paradigm of Empiricism and Hope
Northern bobwhite (Colinus virginianus) populations have been declining across their range for decades because of habitat loss, degradation, and fragmentation. Habitat restoration and management—sometimes coupled with other cultural practices—has long been the paradigm for bobwhite conservation. However, the lack of peer-reviewed empirical evidence supporting the success of active management to increase bobwhite density and growth rates has created skepticism and uncertainty among some conservationists and user groups. Thus, our objectives were to test the basic prediction that active management can increase bobwhite populations across a large spatial extent and highlight the importance of population monitoring to refine management through adaptive feedback. We developed a Bayesian N-mixture model to estimate bobwhite densities and population growth rates at 17 Wildlife Management Areas (WMAs) in four Southeastern US states. Based on expert opinion, we classified WMAs into two groups—actively managed (e.g., bobwhite specific management) and passively managed (land management in a non-specific species fashion)—to test our prediction. Populations significantly increased across the survey periods at 4 WMAs and significantly decreased at 1 WMA. Populations on actively managed WMAs grew at an average of 13% per year, while populations on passively managed WMAs had stable trends. Mean bobwhite densities ranged from 0.145 (95% CrI: 0.025, 0.435) to 2.853 (95% CrI: 2.131, 3.914) birds/ha—typical of estimates in the literature. On WMAs where bobwhites are a management objective, continued population monitoring is vital to reduce uncertainty and make optimal management decisions to maintain recreationally viable populations. We provide a robust approach to estimate bobwhite densities and population trends in response to management so managers can make well-informed decisions and adapt in the future. We offer the conservation community some of the first empirical evidence of positive growth rates in bobwhite populations that should stimulate hope in bobwhite restoration