A general two-phase coordinated planning and control algorithm is developed to determine optimal motions among obstacles and dynamic objects in a shared environment. The algorithm consists of a two-phase approach: pla...
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ISBN:
(纸本)0818685484
A general two-phase coordinated planning and control algorithm is developed to determine optimal motions among obstacles and dynamic objects in a shared environment. The algorithm consists of a two-phase approach: planning a global path for each object subject to the constraints of the workspace and then locally optimizing along each global path to minimize some process dependent cost function. The order in which objects are planned will also affect the overall performance of the system. The algorithm is applied to a simulated surface-mount assembly system. The results show an improvement over other planning and control methods.
Reactive power compensation is used by utilities to ensure customer voltages are within pre-defined tolerances and reduce system resistive losses. While much attention has been paid to model-based control algorithms f...
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ISBN:
(纸本)9781467380409
Reactive power compensation is used by utilities to ensure customer voltages are within pre-defined tolerances and reduce system resistive losses. While much attention has been paid to model-based control algorithms for reactive power support and Volt Var Optimization (VVO), these strategies typically require relatively large communications capabilities and accurate models. In this work, a non-model-based control strategy for smart inverters is considered for VAR compensation. An Extremum Seeking control algorithm is applied to modulate the reactive power output of inverters based on real power information from the feeder substation, without an explicit feeder model. Simulation results using utility demand information confirm the ability of the control algorithm to inject VARs to minimize feeder head real power consumption. In addition, we show that the algorithm is capable of improving feeder voltage profiles and reducing reactive power supplied by the distribution substation.
This paper presents a model predictive control for the quantum series-parallel LCC-type resonant converter. A hybrid model for the converter including the autonomous change of the systems structure by the output recti...
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ISBN:
(纸本)9781479921478
This paper presents a model predictive control for the quantum series-parallel LCC-type resonant converter. A hybrid model for the converter including the autonomous change of the systems structure by the output rectifier of the converter is derived. By solving the piecewise linear state equations for the possible input voltages, generated by an II-bridge, the change of the output voltage can be calculated. The maximum resonant current and the voltage across the series-resonant capacitor at the next zero crossing of the resonant current can be estimated, too. Simulation results and measurements show the effectiveness of the control algorithm with constrained resonant current and multistep prediction.
The bit-rate control algorithm for video sequence encoding with Region Of Interest (ROI) is presented in this paper The algorithm distributes available bit budget among image layers taking into consideration both the ...
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ISBN:
(纸本)0780393856
The bit-rate control algorithm for video sequence encoding with Region Of Interest (ROI) is presented in this paper The algorithm distributes available bit budget among image layers taking into consideration both the distance from ROI and the local complexity. It improves the image quality, in ROI by lowering the image quality, outside ROI with the preservation of the global constraint of the encoded stream bit-rate. The algorithm also ensures the gradual image quality degradation outside ROI.
State-of-art powered prosthetic legs are often controlled using a collection of joint impedance controllers designed for different phases of a walking cycle. Consequently, finite state machines are used to control tra...
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ISBN:
(纸本)9781509021826
State-of-art powered prosthetic legs are often controlled using a collection of joint impedance controllers designed for different phases of a walking cycle. Consequently, finite state machines are used to control transitions between different phases. This approach requires a large number of impedance parameters and switching rules to be tuned. Since one set of control parameters cannot be used across different amputees, clinicians spend enormous time tuning these gains for each patient. This paper proposes a virtual constraint-based control scheme with a smaller set of control parameters, which are automatically tuned in real-time using an extremum seeking controller (ESC). ESC, being a model-free control method, assumes no prior knowledge of either the prosthesis or human. Using a singular perturbation analysis, we prove that the virtual constraint tracking errors are small and the PD gains remain bounded. Simulations demonstrate that our ESC-based method is capable of adapting the virtual-constraint based control parameters for amputees with different masses.
WebRTC is a promising standard for real- time communication in the browser. It supports transfer of delay sensitive real-time video and audio material using SRTP, as well as transfer of arbitrary data using SCTP. The ...
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ISBN:
(纸本)9780988304536
WebRTC is a promising standard for real- time communication in the browser. It supports transfer of delay sensitive real-time video and audio material using SRTP, as well as transfer of arbitrary data using SCTP. The congestion control algorithms of these two transport protocols are optimized for two different goals: While RTP tries to keep delays minimal, SCTP tries to maximize throughput. This contradiction leads to an excess in queuing delay and ultimately a deterioration of user experience when these protocols are used simultaneously. The work at hand introduces a novel algorithm for coupling the two transport protocols in order to achieve both goals at the same time. We have implemented our algorithm in the OMNeT++/INET simulation environment and present results to prove that the algorithm works as intended. We found that our approach keeps queuing delays in tolerable regions for all link configurations tested, enabling the concurrent use of WebRTC Media Channels and SCTP Data Channels independent of the queue length of the access router.
Mechanical vibrations have a deleterious effect on the performance of high accuracy astronomical instruments. In particular the future generation of astronomical instruments is designed to deliver images of unpreceden...
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ISBN:
(纸本)9783952426913
Mechanical vibrations have a deleterious effect on the performance of high accuracy astronomical instruments. In particular the future generation of astronomical instruments is designed to deliver images of unprecedent accuracy and are therefore expected to be even more sensitive to telescope vibrations. It is then necessary to implement mechanical and software counter actions to mitigate their effect and to guarantee the expected accuracy and resolution. In this paper we report on the implementation of an adaptive control algorithm for the vibration rejection in single conjugated and laser tomography adaptive optics systems. The proposed approach can be easily adapted to the two different AO control architectures delivering the expected performance. Experimental validations at the telescope are also reported.
Manufacturing systems belong to a class of discrete-event systems. Main research objectives here include development of suitable models for manufacturing systems and their analysis. Moreover, various control algorithm...
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ISBN:
(纸本)9781467345057
Manufacturing systems belong to a class of discrete-event systems. Main research objectives here include development of suitable models for manufacturing systems and their analysis. Moreover, various control algorithms are being developed to maximize utilization and throughput, while trying to achieve acceptable level of time and space complexity. In general, there is always a trade off between given objectives. In this paper we propose an exact mathematical procedure to relate matrix model of manufacturing systems and control policy based on Banker's algorithm. Matrix model allows straightforward application in industrial systems as well as structural analysis. On the other side, it gives a framework for application of various versions of Banker's algorithm.
With six-rotor aircraft attitude control as the research object, it's model is formulated, and the attitude control algorithm based on cascade PID controller is proposed. The effectiveness of the algorithm is veri...
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ISBN:
(纸本)9781509043644
With six-rotor aircraft attitude control as the research object, it's model is formulated, and the attitude control algorithm based on cascade PID controller is proposed. The effectiveness of the algorithm is verified by simulation with MATLAB. On this basis, by using the Mahony complementary filtering algorithm for posture estimation, the physical verification of cascade PID controller is carried out. The simulation and experimental results show that the cascade PID controller has good performance on the attitude control of the six-rotor aircraft, the position tracking response is fast, the steady error is little, and the performance of the aircraft is stable.
A real-time system has been successfully used since 2004 in the RFX-mod nuclear fusion experiment to control the position of the plasma and its Magneto Hydrodynamic (MHD) modes. However, its latency and the limited co...
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ISBN:
(纸本)9781467310826;9781467310833
A real-time system has been successfully used since 2004 in the RFX-mod nuclear fusion experiment to control the position of the plasma and its Magneto Hydrodynamic (MHD) modes. However, its latency and the limited computation power of the used processors prevented the usage of more aggressive control algorithms. Therefore a new hardware and software architecture have been designed to overcome such limitations and to provide a shorter latency and a much increased computation power. The new system is based on a Linux multi-core server and uses MARTe, a framework for real-time control which is gaining interest in the fusion community.
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