Design of an Energy-Aware Cartesian Impedance Controller for Collaborative Disassembly

Human-robot collaborative disassembly is an emerging trend in the sustainable recycling process of electronic and mechanical products. It requires the use of advanced technologies to assist workers in repetitive physical tasks and deal with creaky and potentially damaged components. Nevertheless, when disassembling worn-out or damaged components, unexpected robot behaviors may emerge, so harmless and symbiotic physical interaction with humans and the environment becomes paramount. This work addresses this challenge at the control level by ensuring safe and passive behaviors in unplanned interactions and contact losses. The proposed algorithm capitalizes on an energy-aware Cartesian impedance controller, which features energy scaling and damping injection, and an augmented energy tank, which limits the power flow from the controller to the robot. The controller is evaluated in a real-world flawed unscrewing task with a Franka Emika Panda and is compared to a standard impedance controller and a hybrid force-impedance controller. The results demonstrate the high potential of the algorithm in human-robot collaborative disassembly tasks.Comment: 7 pages, 6 figures, presented at the 2023 IEEE International Conference on Robotics and Automation (ICRA). Video available at https://www.youtube-nocookie.com/embed/SgYFHMlEl0

A Formal Model of Corruption, Dishonesty and Selection into Public Service

Recent empirical studies have found that in high corruption countries, inherently more dishonest individuals are more likely to want to enter into public service, while the reverse is true in low corruption countries. In this note, we provide a simple formal model that rationalizes this empirical pattern as the result of countries being stuck in different self-sustaining equilibria where high levels of corruption and negative selection into public service are mutually reinforcing. Experiences with corruption vary widely across countries. In some places, high levels of corruption have seemingly always been a fixture of the public sector. In other places, corruption has been practically nonexistent for many decades. A set of recent empirical studies, Hanna and Wang (2013), Banerjee, Baul, and Rosenblat (2015) and Barfort et al. (2015), have suggested that these differences may be related to cross-country differences in the propensity for dishonesty among public sector employees, as more dishonest individuals are more likely to want to enter into public service in high-corruption countries, while the converse holds in low-corruption countries. In this note, we provide a simple formal model that rationalizes this empirical pattern. The model shows how the endogenous self-selection of more or less dishonest individuals into the public sector creates multiple, self-sustaining equilibria. When the level of corruptio

Evaluation of Subjective Appetite Assessment under Free-Living vs. Controlled Conditions: A Randomized Crossover Trial Comparing Whole-Grain Rye and Refined Wheat Diets (VASA-Home)

Background: Accurate assessment of self-reported appetite under free-living conditions is warranted to conduct large-scale intervention studies measuring appetite at a feasible cost. However, the performance of visual analogue scales (VASs) for this purpose has not been widely examined. Method: This randomized crossover trial was conducted to evaluate VASs in free-living vs. clinic-based settings and to assess appetite response following hypocaloric whole-grain rye and refined wheat diets. Twenty-nine healthy adults with overweight or obesity continuously answered VAS questions about their perceived appetite from morning to evening. Results: No differences in whole-day VAS scores (primary outcome) between clinic-based and free-living settings were observed, whereas measures of total area under the curve (tAUC) showed increased fullness in clinic-based interventions of 7% (p < 0.008) for whole-day responses and 13% (p < 0.03) following a snack. Appetite responses for a whole day did not differ between diets whereas rye-based dinners induced 12% (p < 0.016) higher fullness and reduced hunger by 17% (p < 0.02) irrespective of setting. A reduction in hunger of 15% (p < 0.05) was also observed following rye-based vs. wheat-based lunches. Conclusion: The results suggest that the VAS is valid for evaluation of appetite responses between diets under free-living conditions. No difference in self-reported appetite over the whole day was found after whole-grain rye vs. refined wheat-based diets, but there were some suggested differences at certain postprandial periods, in individuals with overweight or obesity

Distribution of genuine high-dimensional entanglement over 10.2 km of noisy metropolitan atmosphere

In a recent quantum key distribution experiment, high-dimensional protocols were used to show an improved noise resistance over a 10.2 km free-space channel. One of the unresolved questions in this context is whether the communicating parties actually shared genuine high-dimensional entanglement. In this letter we introduce an improved discretisation and entanglement certification scheme for high-dimensional time-bin setups and apply it to the data obtained during the experiment. Our analysis answers the aforementioned question affirmatively and thus the experiment constitutes the first transmission of genuine high-dimensional entanglement in a single degree of freedom over a long-range free-space channel.Comment: 6 pages, 3 figure

Ten-year comparison of two different techniques for femoral bone cavity preparation-broaching versus compaction in patients with cementless total hip arthroplasty:a randomized radiostereometric study of 30 total hip arthroplasties in 15 patients operated bilaterally

AIMS: Femoral bone preparation using compaction technique has been shown to preserve bone and improve implant fixation in animal models. No long-term clinical outcomes are available. There are no significant long-term differences between compaction and broaching techniques for primary total hip arthroplasty (THA) in terms of migration, clinical, and radiological outcomes. METHODS: A total of 28 patients received one-stage bilateral primary THA with cementless femoral stems (56 hips). They were randomized to compaction on one femur and broaching on the contralateral femur. Overall, 13 patients were lost to the ten-year follow-up leaving 30 hips to be evaluated in terms of stem migration (using radiostereometry), radiological changes, Harris Hip Score, Oxford Hip Score, and complications. RESULTS: Over a mean follow-up period of 10.6 years, the mean stem subsidence was similar between groups, with a mean of -1.20 mm (95% confidence interval (CI) -2.28 to -0.12) in the broaching group and a mean of -0.73 mm (95% CI -1.65 to 0.20) in the compaction group (p = 0.07). The long-term migration patterns of all stems were similar. The clinical and radiological outcomes were similar between groups. There were two intraoperative fractures in the compaction group that were fixed with cable wire and healed without complications. No stems were revised. CONCLUSION: Similar stem subsidence and radiological and clinical outcomes were identified after the use of compaction and broaching techniques of the femur at long-term follow-up. Only the compaction group had intraoperative periprosthetic femur fractures, but there were no long-term consequences of these. Cite this article: Bone Jt Open 2021;2(12):1035–1042