Mapping grasps from human to anthropomorphic robotic hands is an open issue in research,because the master hand and the slave hand have dissimilar *** paper proposes a hybrid mapping method to solve this *** the propo...
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Mapping grasps from human to anthropomorphic robotic hands is an open issue in research,because the master hand and the slave hand have dissimilar *** paper proposes a hybrid mapping method to solve this *** the proposed method,fingers in the master and the slave hands are divided into vital and synergic fingers according to their contribution to the grasping *** tip of the vital finger of the master hand is first mapped to that of the slave hand while ensuring that both are in simultaneous contact with the object to be *** postural synergy theory,joints of the other synergic fingers of the slave hand are then used to generate an anthropomorphic grasping configuration according to the shape of the object to be *** this,a human-guided impedance controller is used to reduce the pre-grasping error and realize compliant interaction with the *** proposed hybrid mapping method can not only generate the posture of the humanoid envelope but can also carry out impedance-adaptive *** was evaluated using simulations and an experiment involving an anthropomorphic robotic slave hand.
High-precision turning(HPT)is a main processing method for manufacturing rotary high-precision components,especially for metallic ***,the generated vibration between tool tip and workpiece during turning may seriously...
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High-precision turning(HPT)is a main processing method for manufacturing rotary high-precision components,especially for metallic ***,the generated vibration between tool tip and workpiece during turning may seriously deteriorate the surface ***,exploring the effect of vibration on turning surface morphology and quality of copper parts using 3D surface topography regeneration model is crucial for predicting HPT *** developed model can update the machined surface topology in real *** this study,the effects of tool arc radius,feed rate,radial vibration,axial vibration and tangential vibration on the surface topography and surface roughness were *** results show that the effect of radial vibration on surface topography is greater than that of axial vibration and tangential *** radial vibration frequency is also *** vibration frequency changes,the surface topography profile presents three different types:the standard sinusoidal curve,the sinusoidal curve whose lowfrequency signal envelopes high-frequency signal,and the oscillation curve whose low-frequency signal superimposes high-frequency *** addition,HPT experiment was carried out to validate the developed *** surface roughness obtained in the experiment was Ra=53 nm,while the roughness obtained by the simulation was Ra=46 nm,achieving a prediction accuracy of 86.7%.Received 4 September 2022;revised 3 October 2022;accepted 17 October 2022.
Hemispherical shell resonator(HSR)is the core component of hemispherical resonator *** is aφ-shaped small-bore complex component with minimum curvature radius less than 3 ***,traditional polishing methods are difficu...
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Hemispherical shell resonator(HSR)is the core component of hemispherical resonator *** is aφ-shaped small-bore complex component with minimum curvature radius less than 3 ***,traditional polishing methods are difficult to polish *** ball-end magnetorheological polishing method can polish the small components with complicated three-dimensional surface and obtain non-destructive ***,this method is suitable for polishing ***,the material removal rate of the ordinary small ball-end magnetorheological polishing is low,leading to long polishing time and low output of *** solve this problem,a water bath heating assisted small ball-end magnetorheological polishing method is proposed in this *** influence rule of processing parameters on the material removal rate is studied experimentally.A set of optimal processing parameters is obtained to maximize the material removal *** with the ordinary method,the material removal rate of the new method can be improved by 143%.Subsequently,an HSR is polished by the new *** results show that the polishing time can be reduced by 55%,and the polished surface roughness can reach 7.7 *** new method has the great potential to be used in actual production to improve the polishing efficiency of HSR.
Background: In the manufacturing setup process of weapons, aviation, and aerospace, docking assembly is a key component in determining manufacturing efficiency and quality. The traditional docking method uses manual a...
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Bio-inspired magnetic helical microrobots have great potential for biomedical and micromanipulation applications. Precise interaction with objects in liquid environments is an important prerequisite and challenge for ...
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Bio-inspired magnetic helical microrobots have great potential for biomedical and micromanipulation applications. Precise interaction with objects in liquid environments is an important prerequisite and challenge for helical microrobots to perform various tasks. In this study, an automatic control method is proposed to realize the axial docking of helical microrobots with arbitrarily placed cylindrical objects in liquid environments. The docking process is divided into ascent, approach, alignment, and insertion stages. First, a 3D docking path is planned according to the positions and orientations of the microrobot and the target object. Second, a steering-based 3D path-following controller guides the helical microrobot to rise away from the container bottom and approach the target along the path. Third, based on path design with gravity compensation and steering output limits, alignment of position and orientation can be accomplished simultaneously. Finally, the helical microrobot completes the docking under the rotating magnetic field along the target orientation. Experiments verified the automatic docking of the helical microrobot with static targets, including connecting with micro-shafts and inserting into micro-tubes. The object grasping of a reconfigurable helical microrobot aided by 3D automatic docking was also demonstrated. This method enables precise docking of helical microrobots with objects, which might be used for capture and sampling, in vivo navigation control, and functional assembly of microrobots.
General,high-precision theoretical modeling method is not well developed in the field of soft robotics,which holds back motion control and practical application of soft *** concept of modularization brings novel struc...
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General,high-precision theoretical modeling method is not well developed in the field of soft robotics,which holds back motion control and practical application of soft *** concept of modularization brings novel structure,novel locomotion patterns as well as novel control method for soft *** paper presents the concept of hierarchical control method for modular soft robot system and a H-configuration pneumatic modular soft robot is designed as the control *** H-configuration modular soft robot is composed of two basic motion units that take worm-like locomotion *** locomotion principle of the basic motion unit is analyzed and the actuation sequence is optimized by evolution strategy in VOXCAD simulation *** differential drive method is applied to the H-configuration modular soft robot with multi motion modes and vision sensor is used to control the motion mode of the *** H-configuration modular soft robot and the basic motion unit are assembled by a cubic soft module made of silicone ***,connection mechanism is designed to ensure that the soft modules can be assembled in any direction and *** are conducted to verify the effect of the hierarchical control method of the modular soft robots.
In this paper, our objective is to achieve stable walking for biped robots using a simple yet powerful control scheme. This control scheme consists of a planning and control framework. For the motion planner, we utili...
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Fiber Bragg Gratings (FBG) are used widely for that it is small and sensitive. It is suitable to insert a sensor based on FBGs to some narrow cavities. At the same time, a slender continuum structure requires tiny sen...
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Clarifying the relationship between stress sensitivities of permeability and porosity is of great significance in guiding underground resource *** and more studies focus on how to construct stress sensitivity models t...
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Clarifying the relationship between stress sensitivities of permeability and porosity is of great significance in guiding underground resource *** and more studies focus on how to construct stress sensitivity models to describe the relationship and obtain a comprehensive stress sensitivity of porous ***,the limitations of elastic deformation calculation and incompleteness of considered tortuosity sensitivity lead to the fact that the existing stress sensitivity models are still unsatisfactory in terms of accuracy and ***,a more accurate and generic stress sensitivity model considering elastic-structural deformation of capillary cross-section and tortuosity sensitivity is proposed in this *** elastic deformation is derived from the fractal scaling model and Hooke's *** the effects of elastic-structural deformation on tortuosity sensitivity,an empirical formula is proposed,and the conditions for its applicability are *** predictive performance of the proposed model for the permeability-porosity relationships is validated in several sets of publicly available experimental *** experimental data are from different rocks under different pressure *** mean and standard deviation of relative errors of predicted stress sensitivity with respect to experimental data are 2.63%and 1.91%.Compared with other models,the proposed model has higher accuracy and better predictive generalization *** is also found that the porosity sensitivity exponent a,which can describe permeability-porosity relationships,is 2 when only elastic deformation is considered.a decreases from 2 when structural deformation is also *** addition,a may be greater than 3 due to the increase in tortuosity sensitivity when tortuosity sensitivity is considered even if the rock is not fractured.
Fixed-wing aircraft cannot maintain optimal aerodynamic performance at different flight speeds. As a type of morphing aircraft, the shear variable-sweep wing(SVSW) can dramatically improve its aerodynamic performance ...
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Fixed-wing aircraft cannot maintain optimal aerodynamic performance at different flight speeds. As a type of morphing aircraft, the shear variable-sweep wing(SVSW) can dramatically improve its aerodynamic performance by altering its shape to adapt to various flight *** order to achieve smooth continuous shear deformation, SVSW's skin adopts a flexible composite skin design instead of traditional aluminum alloy materials. However, this also brings about the non-linear difficulty in stiffness modeling and calculation. In this research, a new SVSW design and efficient stiffness modeling method are proposed. Based on shear deformation theory, the flexible composite skin is equivalently modeled as diagonally arranged nonlinear springs, simulating the elastic force interaction between the skin and the mechanism. By shear loading tests of flexible composite skin, the accuracy of this flexible composite skin modeling method is verified. The SVSW stiffness model was established, and its accuracy was verified through static loading tests. The effects of root connection, sweep angles, and flexible composite skin on the SVSW stiffness are analyzed. Finally, considering three typical flight conditions of SVSW: low-speed flow(Ma = 0.3,Re = 5.82 × 10^(6)), transonic flow(Ma = 0.9, Re = 3.44 × 10^(6)), and supersonic flow(Ma = 3,Re = 7.51 × 10^(6)), the stiffness characteristics of SVSW under flight conditions were *** calculated results guide the application of SVSW.
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