About half a billion years ago, life on earth experienced a short period of very rapid diversification called the "Cambrian Explosion." Many theories have been proposed for the cause of the Cambrian ...Explosion, one of the most provocative being the evolution of vision, allowing animals to dramatically increase their ability to hunt and find mates. Today, technological developments on several fronts are fomenting a similar explosion in the diversification and applicability of robotics. Many of the base hardware technologies on which robots depend--particularly computing, data storage, and communications--have been improving at exponential growth rates. Two newly blossoming technologies--"Cloud Robotics" and "Deep Learning"--could leverage these base technologies in a virtuous cycle of explosive growth. I examine some key technologies contributing to the present excitement in the robotics field. As with other technological developments, there has been a significant uptick in concerns about the societal implication of robotics and artificial intelligence. Thus, I offer some thoughts about how robotics may affect the economy and some ways to address potential difficulties.
Background Children with allergic asthma have more frequent and severe human rhinovirus (HRV)–induced wheezing and asthma exacerbations through unclear mechanisms. Objective We sought to determine ...whether increased high-affinity IgE receptor (FcϵRI) expression and cross-linking impairs innate immune responses to HRV, particularly in allergic asthmatic children. Methods PBMCs were obtained from 44 children, and surface expression of FcϵRI on plasmacytoid dendritic cells (pDCs), myeloid dendritic cells, monocytes, and basophils was assessed by using flow cytometry. Cells were also incubated with rabbit anti-human IgE to cross-link FcϵRI, followed by stimulation with HRV-16, and IFN-α and IFN-λ1 production was measured by Luminex. The relationships among FcϵRI expression and cross-linking, HRV-induced IFN-α and IFN-λ1 production, and childhood allergy and asthma were subsequently analyzed. Results FcϵRIα expression on pDCs was inversely associated with HRV-induced IFN-α and IFN-λ1 production. Cross-linking FcϵRI before HRV stimulation further reduced PBMC IFN-α (47% relative reduction; 95% CI, 32% to 62%; P < .0001) and IFN-λ1 (81% relative reduction; 95% CI, 69% to 93%; P < .0001) secretion. Allergic asthmatic children had higher surface expression of FcϵRIα on pDCs and myeloid dendritic cells when compared with that seen in nonallergic nonasthmatic children. Furthermore, after FcϵRI cross-linking, allergic asthmatic children had significantly lower HRV-induced IFN responses than allergic nonasthmatic children (IFN-α, P = .004; IFN-λ1, P = .02) and nonallergic nonasthmatic children (IFN-α, P = .002; IFN-λ1, P = .01). Conclusions Allergic asthmatic children have impaired innate immune responses to HRV that correlate with increased FcϵRI expression on pDCs and are reduced by FcϵRI cross-linking. These effects likely increase susceptibility to HRV-induced wheezing and asthma exacerbations.
Series elastic actuators have beneficial properties for some robot applications. Several recent implementations contain alternative placements of the compliant element to improve instrumentation ...design. We use a class 1 versus class 2 lever model and energy-port methods to demonstrate in this paper that these alternative placements should still be classified as series elastic actuators. We also note that the compliance of proximal series elastic actuators is reflected by an augmented gear ratio dependent on the nominal gear ratio, which is significant for small gear ratios and approaches unity for large gear ratios. This reflected compliance is shown to differ depending on the sign of the gear ratio. We demonstrate that although the reflected compliance is only marginally influenced by the magnitude of the gear ratio, there are several notable differences, particularly for small gear ratios.
•DARPA's programs foster multi-disciplinary collaborations.•DARPA's BCI programs span four major challenges: detect, emulate, restore, & improve.•Aims: restore function after injury; improve ...performance of healthy individuals.
The Defense Advanced Research Projects Agency (DARPA) has funded innovative scientific research and technology developments in the field of brain–computer interfaces (BCI) since the 1970s. This review highlights some of DARPA's major advances in the field of BCI, particularly those made in recent years. Two broad categories of DARPA programs are presented with respect to the ultimate goals of supporting the nation's warfighters: (1) BCI efforts aimed at restoring neural and/or behavioral function, and (2) BCI efforts aimed at improving human training and performance. The programs discussed are synergistic and complementary to one another, and, moreover, promote interdisciplinary collaborations among researchers, engineers, and clinicians. Finally, this review includes a summary of some of the remaining challenges for the field of BCI, as well as the goals of new DARPA efforts in this domain.
Robot to the rescue Pratt, Gill A.
Bulletin of the atomic scientists,
20/1/1/, Volume:
70, Issue:
1
Journal Article
Peer reviewed
The 2011 disaster at the Fukushima Daiichi Nuclear Power Plant highlighted the promise and shortcomings of robots. Had robots been able to quickly enter the plant and vent accumulated hydrogen, a ...meltdown could have been averted, but training requirements and technology limitations delayed their deployment. The US Defense Advanced Research Projects Agency launched the DARPA Robotics Challenge to catalyze development of semi-autonomous robots capable of operating in dangerous, degraded environments so society is prepared to respond to future disasters. The challenge brings together robotics systems and software experts from around the world in a series of competitions to overcome technological obstacles related to robotic mobility, manipulation, perception, human-robot interface, and actuation. Over a period of less than three years, DARPA expects the field of robotics to undergo a historic transformation that could drive innovation in robots for defense, health care, agriculture, and industry. DARPA outlines its objectives for the challenge, addresses the ethics and present realities of robotics, and charts the development path to capable, cost-effective systems.
This paper presents a general control architecture for bipedal walking which is based on a divide-and-conquer approach. Based on the architecture, the sagittal-plane motion-control algorithm is ...formulated using a control approach known as Virtual Model Control. A reinforcment learning algorithm is used to learn the key parameter of the swing leg control task so that speed control can be achieved. The control algorithm is applied to two simulated bipedal robots. The simulation analyses demonstrate that the local speed control mechanism based on the stance ankle is effective in reducing the learning time. The algorithm is also demonstrated to be general in that it is applicable across bipedal robots that have different length and mass parameters.
Distributed synchronous clocking Pratt, G.A.; Nguyen, J.
IEEE transactions on parallel and distributed systems,
03/1995, Volume:
6, Issue:
3
Journal Article
Peer reviewed
It has historically been difficult to distribute a well-aligned hardware clock throughout the physical extent of a synchronous processor. Traditionally, this task has been accomplished by ...distributing the output of a central oscillator over a tree-like network, with repeaters at necessary intervals. While straightforward in concept, this method suffers from poor reliability, poor scalability and high skew. In this paper, we present an alternative approach-Distributed Synchronous Clocking-that maintains the simplicity of synchronous operation without suffering the drawbacks of centralized clocking. A network of independent oscillators takes the place of the centralized clock source, providing separate clock signals to the physically distant parts of a computing system. A distributed error correction algorithm effects global phase alignment by utilizing Local comparisons of neighboring oscillator phase. In contrast to centralized clock distribution, distributed clocking has the inherent potential for complete scalability and graceful degradation. However, because oscillator phase is a modular quantity, a naive implementation of distributed synchronous clocking can suffer from mode-lock-the trapping of local oscillator phase in undesirable stable equilibria where global phase is not aligned. We present a simple method for eliminating this problem in k-ary Cartesian meshes and give a proof of its correctness for two-dimensional networks. An electronic implementation is also presented and several engineering issues relating to error tolerance are discussed.< >
This paper presents two frontal plane algorithms for 3D dynamic bipedal walking. One of which is based on the notion of symmetry and the other uses reinforcement learning algorithm to learn the ...lateral foot placement. The algorithms are combined with a sagittal plane algorithm and successfully applied to a simulated 3D bipedal robot to achieve level ground walking. The simulation results showed that the choice of the local control law for the stance-ankle roll joint could significantly affect the performance of the frontal plane algorithms.
We have been working on several control and actuation improvements applicable to the design of biomimetic robots and assistive (e.g. prosthetic or orthotic) devices. This paper focuses on the ...implementation of a joint-level impedance controller for series-elastic actuators that eliminates the use of joint angle sensor information, instead using information from co-located commutation sensors on the back of a brushless motor and a compression sensor on the series elasticity. This approach is both more robust than previous systems and less subject to instabilities due to stiction and backlash.
The MIT Leg Lab is best known for the seminal work of Marc Raibert, who showed in the 1980s that robotic running could be accomplished using a few simple, decoupled control laws. Raibert had shown ...how to calculate the control effort required for the next step of a run based on the results of the previous step, using simple physics-based rules. But smoothly controlling joints in a continuous-time fashion to effect walking seemed more difficult, particularly for non-stead state conditions. It was unclear how to combine passive dynamics with active control. Other researchers were beginning to address robot walking, and the rich diversity of their approaches was very exciting. It thus seemed that walking was the next important area. We embarked on a two-pronged approach: one focusing on making improvements to electromechanical actuators and robot design, the other on walking algorithms and control.
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