This paper presents a continuum manipulator inspired by the anatomical characteristics of the elephant ***,the manipulator mimics the conoid profile of the elephant trunk,which helps to enhance its *** design features...
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This paper presents a continuum manipulator inspired by the anatomical characteristics of the elephant ***,the manipulator mimics the conoid profile of the elephant trunk,which helps to enhance its *** design features two concentric parts:inner pneumatically actuated bellows and an outer tendon-driven helical *** tendons control the omnidirectional bending of the manipulator,while the fusion of the pneumatic bellows with the tendon-driven spring results in an antagonistic actuation mechanism that provides the manipulator with variable stiffness and *** paper presents a new design for extensible manipulator and analyzes its stiffness and motion *** results are consistent with theoretical analysis,thereby demonstrating the validity of the theoretical approach and the versatile practical mechanical properties of the continuum *** impressive extensibility and variable stiffness of the manipulator were further demonstrated by performing a pin-hole assembly task.
In this paper,a visual servoing approach is developed to capture the docking rings of tumbling non-cooperative satellites with a space *** primary challenge addressed is the potential for the docking ring to leave the...
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In this paper,a visual servoing approach is developed to capture the docking rings of tumbling non-cooperative satellites with a space *** primary challenge addressed is the potential for the docking ring to leave the monocular camera’s field-of-view as the manipulator approaches the target,due to the ring’s large *** solve this issue,a two-phase visual servoing scheme combining a monocular camera and a three-line structured light vision system is *** an effort to augment the success rate and safety of capture operations,several constraints are formulated,encompassing manipulator’s kinematics,monocular camera’s field-of-view,obstacle avoidance,structured light’s breakpoints and smooth ***,a nonlinear model predictive controller is proposed to manage these constraints in real-time and regulate the *** models are established based on image moments and pose for each phase,selecting these features as visual feedback to simplify the formulation of servo constraints and avoid the complex circle-based pose ***,to ensure unbiased predictions,the model disturbances arising from the imprecise estimation of target motion parameter are observed using an extended Kalman filter,which are then incorporated into the predictive control *** simulation results demonstrate the effectiveness of this scheme.
This study focuses on addressing kinematic singularity analysis and avoidance issues for a space station remote manipulator system(SSRMS)-type reconfigurable space *** manipulator is equipped with a non-spherical wris...
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This study focuses on addressing kinematic singularity analysis and avoidance issues for a space station remote manipulator system(SSRMS)-type reconfigurable space *** manipulator is equipped with a non-spherical wrist and two lockable passive telescopic links(LPTLs),which enable it to have both active revolute and passive prismatic joints and operate in two distinct *** begin with the kinematic singularity analysis,the study derives the differential kinematic equations for the manipulator and identifies the dominant Jacobian matrix that causes ***,an in-depth analysis of singularities from multiple perspectives is ***,a kinematic singularity map method is proposed to capture the distribution of singularities within the reachable ***,the influence of the two LPTLs on singularities is thoroughly ***,a new method based on the matrix rank equivalence principle is introduced to determine singularity conditions,enabling the identification of all the singular configurations for the SSRMS-type reconfigurable ***,this method significantly reduces computational complexity,and the singularity conditions obtained have more concise *** the singularity avoidance problem,a novel method is developed,which simultaneously addresses the requirements of real-time performance,high precision,and the avoidance of both kinematic singularities and joint limit *** from these excellent properties,the proposed method can effectively resolve the singularity issues encountered separately by the SSRMS-type reconfigurable manipulator in its two operational *** typical simulations validate the utility of all the proposed methods.
Humanoid robots have attracted much attention by virtue of their compatibility with human ***,biped humanoids with immense promise still cannot function steadily and reliably in real-world settings in the current ***,...
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Humanoid robots have attracted much attention by virtue of their compatibility with human ***,biped humanoids with immense promise still cannot function steadily and reliably in real-world settings in the current ***,rationally combining a humanoid robot with different stable mobile platforms is a favoured solution for diverse ***,a new versatile humanoid robot platform,aiming to provide a generic solution that can be flexibly deployed in diverse scenarios,for example,indoors and fields is *** humanoid robot platform incorporates multimodal perception,and extensible interfaces on hardware and software,allowing it to be rapidly integrated with different mobile platforms and end-effectors,only through easyto-assemble ***,the platform has achieved impressive integration,lightness,dexterity,and strength in its class,with human-like size and rich perception,targeted to have human-intelligent manipulation skills for human-engineered ***,this article elaborates on the reasoning behind the design choices,and outlines each ***,the essential performance of the platform is successfully demonstrated in a set of experiments with precise and dexterous manipulation,and human–robot collaboration requirements.
Intelligent robots play a crucial role in space exploration,representing a significant trend in space automation *** robots,which can regenerate configurations and functions through self-reconfiguration[1],offer disti...
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Intelligent robots play a crucial role in space exploration,representing a significant trend in space automation *** robots,which can regenerate configurations and functions through self-reconfiguration[1],offer distinct adaptability and versatility[2,3]over traditional robots with fixed structures and single-purpose ***,self-reconfiguration is regarded as a highly promising capability for space exploration and remains a primary motivation for research in this field[4].
A small resonant inchworm piezoelectric robot with six driving feet which are set evenly along the circumference is proposed and tested.A bonded-type structure is adopted to realize a small *** radial bending vibratio...
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A small resonant inchworm piezoelectric robot with six driving feet which are set evenly along the circumference is proposed and tested.A bonded-type structure is adopted to realize a small *** radial bending vibration mode and longitudinal vibration mode are excited at the same *** superposition of these two vibration modes makes the driving feet produce elliptical *** the driving force can be generated by friction coupling between the driving foot and the operating *** structure of the robot is designed by finite element *** geometric parameters are adjusted to make the resonant frequencies of the vibration modes as close as *** elliptical trajectories generated at the driving feet are discussed in *** vibration and motion characteristics of the prototype are tested,and the resonant frequencies of the radial bending mode and the longitudinal vibration mode are degenerated *** optimal working frequency of the prototype is 21.5 *** maximum speed of the prototype is 200 mm/s,and the displacement resolution is 0.71μ*** measured results show that the resonant inchworm piezoelectric robot can be used for fast and high-precision transportation in narrow space.
Venipuncture robots have superior perception and stability to humans and are expected to replace manual ***, their use is greatly restricted because they cannot make decisions regarding the puncture sites. Thus, this ...
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Venipuncture robots have superior perception and stability to humans and are expected to replace manual ***, their use is greatly restricted because they cannot make decisions regarding the puncture sites. Thus, this study presents a multi-information fusion method for determining puncture sites for venipuncture robots to improve their autonomy in the case of limited resources. Here, numerous images have been gathered and processed to establish an image dataset of human forearms for training the U-Net with the soft attention mechanism(SAU-Net) for vein segmentation. Then, the veins are segmented from the images, feature information is extracted based on near-infrared vision, and a multiobjective optimization model for puncture site decision is provided by considering the depth, diameter, curvature, and length of the vein to determine the optimal puncture site. Experiments demonstrate that the method achieves a segmentation accuracy of 91.2% and a vein extraction rate of 86.7%while achieving the Pareto solution set(average time: 1.458 s) and optimal results for each vessel. Finally, a near-infrared camera is applied to the venipuncture robot to segment veins and determine puncture sites in real time, with the results transmitted back to the robot for an attitude adjustment. Consequently, this method can enhance the autonomy of venipuncture robots if implemented dramatically.
Neural interfaces based on surface Electromyography(EMG)decomposition have been widely used in upper limb prosthetic *** the current EMG decomposition framework,most Blind Source Separation(BSS)algorithms require EMG ...
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Neural interfaces based on surface Electromyography(EMG)decomposition have been widely used in upper limb prosthetic *** the current EMG decomposition framework,most Blind Source Separation(BSS)algorithms require EMG with a large number of channels(generally larger than 64)as input,while users of prosthetic limbs can generally only provide less skin surface for electrode placement than healthy *** performed decomposition tests to demonstrate the performance of the new framework with the simulated EMG *** results show that the new framework identified more Motor Units(MUs)compared to the control group and it is suitable for decomposing EMG signals with low channel *** order to verify the application value of the new framework in the upper limb prosthesis system,we tested its performance in decomposing experimental EMG signals in force fitting experiments as well as pattern recognition *** average Pearson coefficient between the fitted finger forces and the ground truth forces is 0.9079 and the average accuracy of gesture classification is 95.11%.The results show that the decomposition results obtained by the new framework can be used in the control of the upper limb prosthesis while only requiring EMG signals with fewer channels.
Asteroid exploration is significant for studying the origin of the solar system,establishing planetary defenses,and alleviating the resource crisis of the *** anchoring is the basis of in-situ exploration and resource...
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Asteroid exploration is significant for studying the origin of the solar system,establishing planetary defenses,and alleviating the resource crisis of the *** anchoring is the basis of in-situ exploration and resource development and ***,the performance of asteroid force-closure anchoring is investigated using the discrete element *** micro parameters of the simulated materials are calibrated with angle of repose and uniaxial compression experiments,based on which the regional modeling method is adopted to establish the anchoring discrete element *** anchoring experiments are conducted on a self-developed microgravity simulation platform to verify the accuracy of the simulation *** asteroid anchoring simulations are performed to investigate the influence of external force on the anchoring *** analysis of anchoring force varying with time and the interaction between the anchor and regolith particles reveals the influence mechanism of external force direction on the anchoring *** external force direction affects the critical anchoring force by influencing the failure of the force-closure *** comprehensive analysis of simulation results clarifies the variation of the critical anchoring force with the external ***,a stable anchoring region is established,beneficial for asteroid anchoring device design.
Bolt assembly by robots is a vital and difficult task for replacing astronauts in extravehicular activities(EVA),but the trajectory efficiency still needs to be improved during the wrench insertion into hex hole of **...
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Bolt assembly by robots is a vital and difficult task for replacing astronauts in extravehicular activities(EVA),but the trajectory efficiency still needs to be improved during the wrench insertion into hex hole of *** this paper,a policy iteration method based on reinforcement learning(RL)is proposed,by which the problem of trajectory efficiency improvement is constructed as an issue of RL-based objective ***,the projection relation between raw data and state-action space is established,and then a policy iteration initialization method is designed based on the projection to provide the initialization policy for *** iteration based on the protective policy is applied to continuously evaluating and optimizing the action-value function of all state-action pairs till the convergence is *** verify the feasibility and effectiveness of the proposed method,a noncontact demonstration experiment with human supervision is *** results show that the initialization policy and the generated policy can be obtained by the policy iteration method in a limited number of demonstrations.A comparison between the experiments with two different assembly tolerances shows that the convergent generated policy possesses higher trajectory efficiency than the conservative *** addition,this method can ensure safety during the training process and improve utilization efficiency of demonstration data.
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