In this paper, a dual-beam photothermal self-mixing substance trace detection system is proposed. The crystal violet (CV) solution of the sample undergoes a thermal lens effect under the action of pump photoperiod exc...
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In this paper,the rigid spacecraft rendezvous problem is studied in the sense of fully-actuated *** to the attitude and orbit dynamics,the fully-actuated system model is *** the linear quadratic optimal controller of ...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
In this paper,the rigid spacecraft rendezvous problem is studied in the sense of fully-actuated *** to the attitude and orbit dynamics,the fully-actuated system model is *** the linear quadratic optimal controller of the fully-actuated system is designed for spacecraft rendezvous ***,numerical simulation and physical experiment are *** simulation and experiment results indicate the effectiveness and practicability of the optimal controller.
In the satellite capture task of space robot, when the target satellite is in the operational space, the manipulator needs to be adjusted to the capture configuration for successful capture. Based on the demand for co...
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This study is concerned with the output tracking of networked high-order fully actuated(NHOFA) systems subject to input saturation and prescribed performance.A predictive control based constrained control approach is ...
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ISBN:
(数字)9789887581536
ISBN:
(纸本)9781665482561
This study is concerned with the output tracking of networked high-order fully actuated(NHOFA) systems subject to input saturation and prescribed performance.A predictive control based constrained control approach is presented to cope with this *** this approach,an incremental HOFA prediction model is constructed via a Diophantine Equation,and then a cost function,considering input saturation and prescribed performance,is optimized by multi-step output prediction,so that an optimal constrained tracking controller is established to satisfy the tracking requirement and given *** analysis presents a simple condition of bounded stability and tracking performance of closed-loop NHOFA systems,which offers a reliable foundation for constrained coordinated control of NHOFA multiagent systems.A numerical simulation of flying-around for air-bearing simulator is shown to prove the feasibility of the proposed approach.
Road environments can include several local optimal solutions to be explored by a motion planning algorithm, which can be computationally complex. This work proposes a two-stage approach, where each stage solves the s...
Road environments can include several local optimal solutions to be explored by a motion planning algorithm, which can be computationally complex. This work proposes a two-stage approach, where each stage solves the same basis-spline parameterized optimal control problem. In the first step, a solution is selected from a discrete set of trajectory candidates. In the second one, the trajectory is refined by a nonlinear optimization algorithm in the continuous solution space. The non-uniform basis-spline parameterization guarantees the trajectory's time-continuous feasibility. Final costs are introduced to ensure convergence towards a final manifold. The approach is evaluated in a highway scenario where other vehicles must be circumnavigated to reach a specified velocity and lane center.
Sign language plays an important role in information transmission and emotional communication between deaf-mute people and the outside world. With the development of artificial intelligence technology, the recognition...
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Soft sensors experience an increasing interest in recent years, as they can replace expensive hardware meters and the required embedded computing hardware has become cheap and powerful. We report results for the imple...
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Soft sensors experience an increasing interest in recent years, as they can replace expensive hardware meters and the required embedded computing hardware has become cheap and powerful. We report results for the implementation of a soft sensor for the flow rate estimation in centrifugal pumps that achieves root mean square errors of about 5%. The proposed soft sensor is based on generic models for the drive and hydraulic part of the pump to ensure widespread applicability. We show the soft sensor and the models it is based on can be parametrized with simple measurements. All theoretical considerations are corroborated with measurements on a real industrial pump in a laboratory setup. The results show that the proposed soft sensor is capable of providing reliable flow rate estimates in spite of plant model mismatch and uncertain hardware components.
We demonstrate the broadband low-noise Kerr-Raman frequency comb source in an ultrahigh Q microrod resonator, and investigate the mechanisms leading to mode-locked frequency combs. By engineering the interaction betwe...
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In this paper,the fixed-time stability of spacecraft formation reconfiguration(position tracking)is ***,a novel nonsingular terminal sliding mode surface is designed and based on which a fixed-time coordinated control...
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In this paper,the fixed-time stability of spacecraft formation reconfiguration(position tracking)is ***,a novel nonsingular terminal sliding mode surface is designed and based on which a fixed-time coordinated controller is designed to keep the closed-loop system states have a finite settling time bounded by some predefined ***,another nonsingular terminal sliding mode surface is designed by combining the artificial potential function and the aforementioned sliding surface,which meets the mutual distance constraint during transition process among spacecraft when it is *** another coordinated controller with fixed-time observer considering mutual distance constraint is presented,which guarantees the closed-loop system states stable also in bounded settling ***,simulation results are shown to validate the correctness of the proposed *** is worth mentioning that the control schemes also work even though there is a properly limit on the control input.
Through a case analysis,this study examines the spatiotemporal evolution of microseismic(MS)events,energy characteristics,volumetric features,and fracture network development in surface well hydraulic fracturing.A tot...
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Through a case analysis,this study examines the spatiotemporal evolution of microseismic(MS)events,energy characteristics,volumetric features,and fracture network development in surface well hydraulic fracturing.A total of 349 MS events were analyzed across different fracturing sections,revealing significant heterogeneity in fracture *** scanning results showed that cumulative energy values ranged from 240 to 1060 J across the sections,indicating notable *** reservoir volume(SRV)analysis demonstrated well-developed fracture networks in certain sections,with a total SRV exceeding 1540000 m^(3).The hydraulic fracture network analysis revealed that during the midfracturing stage,the density and spatial extent of MS events significantly increased,indicating rapid fracture propagation and the formation of complex *** the later stage,the number of secondary fractures near fracture edges decreased,and the fracture network *** comparing the branching index,fracture length,width,height,and SRV values across different fracturing sections,Sections No.1 and No.8 showed the best performance,with high MS event densities,extensive fracture networks,and significant energy ***,Sections No.4 and No.5 exhibited sparse MS activity and poor fracture connectivity,indicating suboptimal stimulation effectiveness.
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