The application scope of the forward scatter radar(FSR)based on the Global Navigation Satellite system(GNSS)can be expanded by improving the detection ***,the forward-scatter signal model when the target crosses the b...
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The application scope of the forward scatter radar(FSR)based on the Global Navigation Satellite system(GNSS)can be expanded by improving the detection ***,the forward-scatter signal model when the target crosses the baseline is ***,the detection method of the for-ward-scatter signal based on the Rényi entropy of time-fre-quency distribution is proposed and the detection performance with different time-frequency distributions is ***-tion results show that the method based on the smooth pseudo Wigner-Ville distribution(SPWVD)can achieve the best ***,combined with the geometry of FSR,the influence on detection performance of the relative distance between the target and the baseline is ***,the proposed method is validated by the anechoic chamber measurements and the results show that the detection ability has a 10 dB improvement compared with the common constant false alarm rate(CFAR)detection.
This study aims to design and optimize a motor-driven frog-like jumping robot leg for efficient vertical jumps and multiple consecutive horizontal jumps. We have conducted bionic research on frog legs' structure a...
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Solar arrays are the primary energy source for *** traditional rigid solar arrays improve power supply,the quality increases ***,it is difficult to satisfy the requirements of high-power and low-cost space *** this st...
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Solar arrays are the primary energy source for *** traditional rigid solar arrays improve power supply,the quality increases ***,it is difficult to satisfy the requirements of high-power and low-cost space *** this study,a shape-memory polymer composite(SMPC)boom was designed,fabricated,and characterized for flexible reel-type solar *** SMPC boom was fabricated from a smart material,a shape-memory polymer composite,whose mechanical properties were ***,a mathematical model of the bending stiffness of the SMPC boom was developed,and the bending and buckling behaviors of the boom were further analyzed using the ABAQUS *** SMPC boom was fabricated to demonstrate its shape memory characteristics,and the driving force of the booms with varying geometric parameters was *** also designed and manufactured a reel-type solar array based on an SMPC boom and verified its self-deployment *** results indicated that the SMPC boom can be used as a deployable unit to roll out flexible solar arrays.
This paper analyzed the impact of phase back electromotive force (back EMF) harmonics on torque of dual three phase permanent magnet synchronous motor (DTPPMSM) from the view of electromagnetic power, and proposed a t...
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With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy ***,in a market-oriented operation ...
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With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy ***,in a market-oriented operation mode,the power dispatching control center aims to reduce the overall power purchase cost while ensuring the security of the power ***,a security-constrained transmission maintenance optimization model considering generation and operational risk costs is proposed *** model is built on double-layer optimization framework,where the upper-layer model is used for maintenance and generation planning,and the lowerlayer model is primarily used to address the operational security risk arising from the random prediction error and N-1 transmission ***,a generation-maintenance iterative algorithm based on a defined cost feedback is included to increase solution *** cost is determined using long-term security-constrained unit commitment,and the operational risk cost is obtained using a double-layer N-1 risk assessment *** electrical correlation coupling coefficient is proposed for the solution process to avoid maintenance of associated equipment simultaneously,thereby improving model convergence *** IEEE 118-bus system is used as a test case for illustration,and test results suggest that the proposed model and algorithm can reduce the total cost of transmission maintenance and system operation while effectively improving the solution efficiency of the joint optimization model.
The Mars quadrotor is a vertical take-off and landing aerial platform developed to enhance the efficiency of Mars exploration. The four-blade rotor has a high thrust coefficient due to its high solidity, which enables...
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Tens of crawling bio-robots with cockroaches as the mobile platform have been developed with various *** with artificial crawling robots of the same size,they revealed better flexibility,larger payload,and stronger **...
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Tens of crawling bio-robots with cockroaches as the mobile platform have been developed with various *** with artificial crawling robots of the same size,they revealed better flexibility,larger payload,and stronger *** features made bio-robots ideal for pipeline inspection scenarios because the advancements in locomotion mechanisms and efficient power systems are still hurdles for current artificial *** this study,we controlled the bio-robot to crawl in the confined dark pipeline and achieved autonomous motion control with the help of an onboard sensing ***,a micro-camera was mounted on the electronic backpack of the cockroach for image collection,and an IMU sensor was used to compute its body *** electronic backpack transmitted images to the host computer for junction recognition and distance ***,the insect's habituation to electrical stimulation has long been an uncertain factor in the control of ***,a synergistic stimulation strategy was proposed to markedly reduce the habituation and increase the number of effective turning controls to over 100 *** is also found that both the increase of payload and the application of stimulations could promote the metabolic rate by monitoring carbon dioxide *** the integration of synergistic stimulation and autonomous control,we demonstrated the fully autonomous pipeline navigation with our cockroach bio-robot,which realized the cycle number of approximately 10 in a *** research provides a novel technology that has the potential for practical applications in the future.
Passive jamming is believed to have very good potential in countermeasure *** this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is *** amplitude of the incident ...
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Passive jamming is believed to have very good potential in countermeasure *** this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is *** amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying *** of the decoying effect on corner reflectors’radar cross section and positions are analyzed and *** show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.
Landing mechanism tends to rebound and turn over,and the stability time is long when landing on the small celestial *** landing performance in different conditions is necessary to be evaluated to guide the ***,landing...
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Landing mechanism tends to rebound and turn over,and the stability time is long when landing on the small celestial *** landing performance in different conditions is necessary to be evaluated to guide the ***,landing performance evaluation is realized by *** factors affecting the landing performance including cardan element damping,foot anchors,retro-rocket thrust,landing slope angle,and landing attitude are analyzed.A microgravity platform is built to test the landing mechanism,and the consistency between the simulation and the experiment is *** the basis of simulation and experiment,some landing suggestions are proposed to improve the landing performance.
When humanoid robots attempt to walk on terrain such as shaking platforms,time-varying disturbances are introduced to the support *** abrupt changes of inclination angle can cause the robot to lose balance upon landin...
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When humanoid robots attempt to walk on terrain such as shaking platforms,time-varying disturbances are introduced to the support *** abrupt changes of inclination angle can cause the robot to lose balance upon landing,presenting significant challenges for balance control *** address this issue,we propose a novel divergent component of motion(DCM)-based time-varying disturbance walking(DCM-TVDW)*** method allows the robot to walk on rugged surfaces and helps to maintain dynamic balance when subjected to large time-varying *** the DCM-TVDW control method,we first adjust the robot's center of mass and stride height to adapt to transitions between different terrain types via a variable height stabilization method,and hold these quantities constant as base *** then combine DCM with the N-step capturability *** combination allows for dynamic balance through multi-step adjustments from the initially unstable region,thereby extending the robots stability *** and experimental results demonstrate that the DCM-TVDW method enables the SJ-Bruce robot to traverse a dynamically shaking platform with an inclination angle of approximately 22°.
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