52 research outputs found
An Amphibious Fully-Soft Miniature Crawling Robot Powered by Electrohydraulic Fluid Kinetic Energy
Miniature locomotion robots with the ability to navigate confined
environments show great promise for a wide range of tasks, including search and
rescue operations. Soft miniature locomotion robots, as a burgeoning field,
have attracted significant research interest due to their exceptional terrain
adaptability and safety features. In this paper, we introduce a fully-soft
miniature crawling robot directly powered by fluid kinetic energy generated by
an electrohydraulic actuator. Through optimization of the operating voltage and
design parameters, the crawling velocity of the robot is dramatically enhanced,
reaching 16 mm/s. The optimized robot weighs 6.3 g and measures 5 cm in length,
5 cm in width, and 6 mm in height. By combining two robots in parallel, the
robot can achieve a turning rate of approximately 3 degrees/s. Additionally, by
reconfiguring the distribution of electrodes in the electrohydraulic actuator,
the robot can achieve 2 degrees-of-freedom translational motion, improving its
maneuverability in narrow spaces. Finally, we demonstrate the use of a soft
water-proof skin for underwater locomotion and actuation. In comparison with
other soft miniature crawling robots, our robot with full softness can achieve
relatively high crawling velocity as well as increased robustness and recovery
Sora Generates Videos with Stunning Geometrical Consistency
The recently developed Sora model [1] has exhibited remarkable capabilities
in video generation, sparking intense discussions regarding its ability to
simulate real-world phenomena. Despite its growing popularity, there is a lack
of established metrics to evaluate its fidelity to real-world physics
quantitatively. In this paper, we introduce a new benchmark that assesses the
quality of the generated videos based on their adherence to real-world physics
principles. We employ a method that transforms the generated videos into 3D
models, leveraging the premise that the accuracy of 3D reconstruction is
heavily contingent on the video quality. From the perspective of 3D
reconstruction, we use the fidelity of the geometric constraints satisfied by
the constructed 3D models as a proxy to gauge the extent to which the generated
videos conform to real-world physics rules. Project page:
https://sora-geometrical-consistency.github.io/Comment: 5 pages, 3 figure
OpenGSL: A Comprehensive Benchmark for Graph Structure Learning
Graph Neural Networks (GNNs) have emerged as the de facto standard for
representation learning on graphs, owing to their ability to effectively
integrate graph topology and node attributes. However, the inherent suboptimal
nature of node connections, resulting from the complex and contingent formation
process of graphs, presents significant challenges in modeling them
effectively. To tackle this issue, Graph Structure Learning (GSL), a family of
data-centric learning approaches, has garnered substantial attention in recent
years. The core concept behind GSL is to jointly optimize the graph structure
and the corresponding GNN models. Despite the proposal of numerous GSL methods,
the progress in this field remains unclear due to inconsistent experimental
protocols, including variations in datasets, data processing techniques, and
splitting strategies. In this paper, we introduce OpenGSL, the first
comprehensive benchmark for GSL, aimed at addressing this gap. OpenGSL enables
a fair comparison among state-of-the-art GSL methods by evaluating them across
various popular datasets using uniform data processing and splitting
strategies. Through extensive experiments, we observe that existing GSL methods
do not consistently outperform vanilla GNN counterparts. However, we do observe
that the learned graph structure demonstrates a strong generalization ability
across different GNN backbones, despite its high computational and space
requirements. We hope that our open-sourced library will facilitate rapid and
equitable evaluation and inspire further innovative research in the field of
GSL. The code of the benchmark can be found in
https://github.com/OpenGSL/OpenGSL.Comment: 9 pages, 4 figure
Motion Kinematics Analysis of a Horse Inspired Terrain-Adaptive Unmanned Vehicle With Four Hydraulic Swing Arms
All terrain vehicles (ATV) perform tasks in unstructured environments where the advanced adaptive ability of rigid terrain has become a key factor. In this article, we propose a novel horse inspired all terrain eight-wheeled vehicle with four swing arms for transportation in the mountain battlefield. The mechanism structure and system configuration of the ATV are designed based on the horse leg kinematics analysis. In order to analyze the obstacle surmounting strategy of the ATV, the kinematics model and the center of gravity of the ATV are represented. A model reference adaptive control method is proposed for the hydraulic attitude control system. Then the model for obstacle surmounting is proposed for dynamics performance and geometric kinematics. Additionally, the simulation is executed in Adams to verify the analysis and strategy. Finally, the experiment is demonstrated for climbing a vertical wall, which is a challenging and typical terrain of the mountain battlefield
A Muscle Teleoperation System of a Robotic Rollator Based on Bilateral Shared Control
The approach that achieves the teleoperation between human muscle signals and the mobile robot is increasingly applied to transfer human muscle stiffness to enhance robotic performance. In this paper, we develop a mobile rollator control system applying a muscle teleoperation interface and a shared control method to enhance the obstacle avoidance in an effective way. In order to control intuitively, haptic feedback is utilized in the teleoperation interface and is integrated with EMG stiffness to provide a large composition force. Then the composition force is implemented with an artificial potential field method to keep the robotic rollator away from the obstacle in advance. This algorithm is superior to the traditional APF algorithm regardless of the required time and trajectory length. The experimental results demonstrate the effectiveness of the proposed muscle teleoperation system
Common dc-link capacitor harmonic current minimization for cascaded converters by optimized phase-shift modulation
This paper investigates the influence of a constant carrier phase shift on the DC-link
capacitor harmonic current of cascaded converters used in fuel-cell and mild-hybrid electric vehicles.
In these applications, a DC-DC converter can be adopted between the battery and the motor drive
inverter in a cascaded structure, where the two converters share the same DC-link. Since the DClink
capacitor of such a system represents a critical component, the optimization of the converter
operation to limit the current stress and extend the lifetime of the capacitor is an primary objective.
This paper proposes the use of a carrier phase shift between the modulations of the two converters in
order to minimize the harmonic current of the DC-link capacitor. By harmonic analysis, an optimal
carrier phase shift can be derived depending on the converter configuration. Analytical results are
presented and validated by hardware-in-the-loop experiments. The findings show that the pulse
width modulation carrier phase shift between the interleaved boost converter and the voltage source
motor drive inverter has a significant influence on the DC-link capacitor current and thus on its
lifetime. A case study with two-cell and three-cell interleaved boost converters shows a possible
DC-link capacitor lifetime extension of up to 390%.peer-reviewe
Application of Angiotensin Receptor–Neprilysin Inhibitor in Chronic Kidney Disease Patients: Chinese Expert Consensus
Chronic kidney disease (CKD) is a global public health problem, and cardiovascular disease is the most common cause of death in patients with CKD. The incidence and prevalence of cardiovascular events during the early stages of CKD increases significantly with a decline in renal function. More than 50% of dialysis patients die from cardiovascular disease, including coronary heart disease, heart failure, arrhythmia, and sudden cardiac death. Therefore, developing effective methods to control risk factors and improve prognosis is the primary focus during the diagnosis and treatment of CKD. For example, the SPRINT study demonstrated that CKD drugs are effective in reducing cardiovascular and cerebrovascular events by controlling blood pressure. Uncontrolled blood pressure not only increases the risk of these events but also accelerates the progression of CKD. A co-crystal complex of sacubitril, which is a neprilysin inhibitor, and valsartan, which is an angiotensin receptor blockade, has the potential to be widely used against CKD. Sacubitril inhibits neprilysin, which further reduces the degradation of natriuretic peptides and enhances the beneficial effects of the natriuretic peptide system. In contrast, valsartan alone can block the angiotensin II-1 (AT1) receptor and therefore inhibit the renin–angiotensin–aldosterone system. These two components can act synergistically to relax blood vessels, prevent and reverse cardiovascular remodeling, and promote natriuresis. Recent studies have repeatedly confirmed that the first and so far the only angiotensin receptor–neprilysin inhibitor (ARNI) sacubitril/valsartan can reduce blood pressure more effectively than renin–angiotensin system inhibitors and improve the prognosis of heart failure in patients with CKD. Here, we propose clinical recommendations based on an expert consensus to guide ARNI-based therapeutics and reduce the occurrence of cardiovascular events in patients with CKD
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