With the increasing size of space facilities,on-orbit assembly requires robots to move on different heights of *** paper proposes a bio-inspired attachment mechanism for robot feet to enable climbing on different heig...
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With the increasing size of space facilities,on-orbit assembly requires robots to move on different heights of *** paper proposes a bio-inspired attachment mechanism for robot feet to enable climbing on different heights of *** by the attachment and grasping abilities of Dynastes Hercules,we utilize its foot microstructures,such as microhooks and setae,to achieve efficient contact and firm grip with the *** morphology and arrangement of these structures can inspire the design of robot feet to improve their grasping and stability *** study the biological structure of Dynastes Hercules,design and optimize the bio-inspired structure,analyze the influence of various factors from theoretical and experimental perspectives,and verify the feasibility of the scheme through *** propose an ideal climbing strategy that provides useful reference for robot applications in ***,the influence laws of various factors in this paper can be applied to robot foot design to improve their operation ability and stability performance in the space *** bio-inspired mechanism can improve robot working range and efficiency,which is critical for on-orbit assemblyin space.
Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate ***,existing inertial piezoelectric actuators still face the challenges of rollback motion and bulky power **...
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Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate ***,existing inertial piezoelectric actuators still face the challenges of rollback motion and bulky power *** this work,an alternate excitation strategy and a customized small power supply for a bimorph rotary piezoelectric actuator(BRPA)are proposed to solve the *** BRPA prototype is designed with a bipedal symmetrical structure,measuring 35 mm in height and 32 mm in diameter,which has a maximum rotation velocity of 0.247 rad/s and a resolution of 0.66μ*** to the bipedal symmetrical structure,the friction directions between the driving feet and the rotor can be coordinated to suppress the *** rollback ratio is almost zero when the phase difference of the exciting signal is set as 180°.The customized power supply is designed and manufactured,whose size is 58 mm×56 mm×46 *** can output signals for the single step mode and the continuous mode,and they are adopted to excite BRPA to achieve a small stroke with one single step and a large stroke with continuous step,***,an experimental system for optical fiber alignment is developed based on the BRPA and the customized small power supply,the experiment has verified the practicability of this work in the precision fields,especially in the miniaturized precision systems.
The utilization of high-resolution haptic feedback devices in a virtual reality(VR)environment can increase the precision of controlling remotely operated vehicles and reduce training costs for subsea construction ***...
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The utilization of high-resolution haptic feedback devices in a virtual reality(VR)environment can increase the precision of controlling remotely operated vehicles and reduce training costs for subsea construction *** paper introduces a novel flexible-driven wearable pin-array *** spatial separation of the control box and actuator allows the device to attain natural and seamless interactive movements while delivering high-density haptic feedback in *** pin array consists of 25 haptic pin modules that run on a linear servo motor via a flexible shaft for force *** analysis and calculation of the flexible transmission resistance effect using the haptic pin module's shaft length and bending radius were conducted.A series of experiments was performed to gather comprehensive data on the pin module's output,transmission resistance and error,and response delay to optimize its structural design and transmission *** device's effectiveness in rendering shape and coarse texture was evaluated via two user *** results affirm that the introduced device enables users to precisely discern seven shapes and four distinct coarse surfaces.
This manuscript introduces a non-resonant, wide-band, tri-axial vibration-based electromagnetic energy harvester (VEMEH) with a cylindrical permanent magnet that freely moves over silicone micro beads in a Teflon casi...
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This manuscript introduces a non-resonant, wide-band, tri-axial vibration-based electromagnetic energy harvester (VEMEH) with a cylindrical permanent magnet that freely moves over silicone micro beads in a Teflon casing. The micro beads operate as anti-friction micro bearings between the magnet's bottom surface and the double-sided planar coil, smoothing in-plan motion and moreover, also act as micro-springs during out-of-plan vibration. Besides two double-sided planar coils, the harvester has a wound coil to boost energy conversion. The harvester's tri-axial ability, lower frequency response, and larger frequency bandwidth are due to the freely moving magnet without the suspension spring. Furthermore, the harvester's simple architecture allows the harvester to seamlessly integrate with vibration source equipment, thus easily converting the real tri-axial excitation into electrical power. Additionally, experimental results show that the developed harvester can generate much more power than single-coil energy harvesters. The developed harvester is also integrated with a low-power wireless monitoring system for remote equipment condition monitoring in order to demonstrate its practical utility. The VEMEH exhibits remarkable performance, featuring an open-circuit RMS voltage of 367.3 mV at 40 Hz and 3 g acceleration during in plan vibrations. Under these excitation conditions, at an optimal load resistance of 149.8, the harvester attains an RMS load voltage of 174.9 mV and a peak output power of 204.2 W. The device produces an increased open-circuit voltage of 547.5 mV at 20 Hz and 3 g when exposed to vertical vibrations, yielding a load voltage of 272.3 mV and a power output of 495 W. The harvester functions well throughout an extensive frequency spectrum, ranging from 10 Hz to 120 Hz horizontally and from 10 Hz to 200 Hz vertically, offering versatility for diverse applications. The devised VEMEH prototype, rectification circuitry, and rechargeable system are integra
In this study,the efects of diferent heat treatment process parameters on the microstructure and mechanical properties of Al-12Si-5Cu-1.1Mg-2.3Ni-0.3La alloy were *** showed that eutectic Si underwent three stages dur...
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In this study,the efects of diferent heat treatment process parameters on the microstructure and mechanical properties of Al-12Si-5Cu-1.1Mg-2.3Ni-0.3La alloy were *** showed that eutectic Si underwent three stages during solution treatment:difusing,spheroidization and *** the solution temperature and time increased,the size of eutectic Si showed a trend of frst decreasing and then *** with the heat treatment time,the heat treatment temperature had a more signifcant efect on the mechanical *** coarsening of microstructure was the main reason for the deterioration of mechanical *** Al_(3)Ti and Al_(3)CuNiLa in the microstructure after aging can signifcantly improve the mechanical properties of the *** Al_(11)La_(3) with secondary precipitation occurred in the La-rich *** addition of La inhibited the growth of coherent/semi-coherentθandβphases,which was very benefcial for the improvement of high-temperature *** the optimal heat treatment process parameters of 500℃×4 h+190℃×4 h,the ultimate tensile strength(UTS)of the alloy reached 366.65 *** high-temperature strength and elongation of the alloy reached 101.98 MPa and 13.77%at 350℃,respectively.
This research article aims to predict the remaining usage time of roller bearings using machine learning algorithms. The specific classifiers employed in this study are Support Vector Machines, Random Forest Classifie...
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In this work,possible short-term thermal exposure oxidation in hot processing including semi-solid processing is *** aim to investigate the short-term oxidation behavior of a novel powder metallurgy Al_(0.8)Co_(0.5)Cr...
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In this work,possible short-term thermal exposure oxidation in hot processing including semi-solid processing is *** aim to investigate the short-term oxidation behavior of a novel powder metallurgy Al_(0.8)Co_(0.5)Cr_(1.5)CuFeNi high entropy alloy(HEA)in high-temperature solid(1000-1100℃)and semi-solid(1125-1225℃)*** 1000 to 1225℃,mass gain increases from 0.31 to 0.45 mg cm^(-2)after 60 min oxidation,presenting superior oxidation resistance in the semi-solid state compared with other semi-solid ***α-Al_(2)O_(3)grains are the predominant component of oxide scales and no obvious internal oxidation layer occurs in both solid and semi-solid ***_(2)O_(3)scale growth is predominantly determined by outward Al^(3+)*** solid oxidation,different scale formation kinetics occur on various phases and the BCC(B2)phase has faster scale formation *** is attributed to outward Al^(3+)diffusion rate differences in various component *** semi-solid oxidation,the increased degree of chaos and number of vacancies in the liquid phase provide a diffusion channel,leading to rapid Al_(2)O_(3)*** resistance in the semi-solid state is attributed to dense Al_(2)O_(3)scales formed through selective oxidation of Al.
The effect of the strain hardening exponent(n)of a material on the changes in shape,strain inhomogeneity,and contact pressure was investigated during wire flat rolling to understand its effect on the deformation behav...
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The effect of the strain hardening exponent(n)of a material on the changes in shape,strain inhomogeneity,and contact pressure was investigated during wire flat rolling to understand its effect on the deformation behavior of a flat-rolled wire and to determine the optimal working conditions with *** deformation behaviors of wires with various n values were systematically compared using finite element *** shape of the deformed wire was found to depend on the n value of the *** the contact width and lateral spreading of the wire decrease with increasing n,resulting in a large reduction in area with the n *** strain homogeneity of the wire increases with the n value of the *** improvement in the strain homogeneity with the n value is attributable to two factors:a lower strain concentration in the central region and a higher overall elongation as n *** addition,the average effective strain of the wire cross section decreases with the n value of a material during wire flat *** contact pressure distribution on the surface of the wire differs significantly depending on the n *** materials with a low n value,the contact pressure exhibits a higher value at the entry and edge zones of the contact *** contrast,materials with high n values exhibit a higher contact pressure at the exit *** behavior can be explained by the strain hardening behavior of the material during wire flat rolling.
In this study, the performance analysis of a refrigeration system operating with different refrigerants was conducted for three defrosting methods (air, electric heating, and hot gas) within an existing refrigeration ...
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Herein, we present a wheel-based robot that functions through a pole vault mechanism. When the robot encounters a curb, it climbs up by leveraging a pole in front and using the thrust from the rear wheel. In this situ...
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