A helicopter rotor in a descent flight encounters its own wake, resulting in a doughnut-shaped ring around the rotor disk, known as the Vortex Ring State (VRS). In this paper, a new inflow model is proposed to calcula...
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A helicopter rotor in a descent flight encounters its own wake, resulting in a doughnut-shaped ring around the rotor disk, known as the Vortex Ring State (VRS). In this paper, a new inflow model is proposed to calculate induced flow in the vertical descent regime. The proposed model addresses the issues typical in descent flight, including excessive unsteady blade loads, thrust and torque fluctuations, vibration, and loss of control. The proposed inflow model avoids detailed flow calculations that require expensive computation and thus makes it amenable to real-time simulation applications. It can also account for the influence of rotor parameters in the analysis, such as blade twist, solidity, and disk loading, and thus make it more viable than simple parametric extension of the momentum theory model considered in the literature. Simulation results using the proposed VRS inflow model in conjunction with a generic helicopter model are included to illustrate certain aspects typical of a helicopter rotor in a descent flight.
A systems re-engineering technique to integrated control and supervision for applications to industrial multi-zone furnaces has been elaborated by using known theories on generalized predictive control and nonlinear p...
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In the present study, we employed stereoscopic particle image velocimetry (SPIV) to investigate the characteristics of turbulence structures in a drag-reduced turbulent channel flow with addition of surfactant. The te...
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The popular and several restricted forms of task allocation issue are NP problems. It searches a feasible matching scheme to realize corresponding object models. This paper adopted Hungarian algorithm to realize task ...
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ISBN:
(纸本)0780384032
The popular and several restricted forms of task allocation issue are NP problems. It searches a feasible matching scheme to realize corresponding object models. This paper adopted Hungarian algorithm to realize task allocation of the robots based on two-dimensional assignment problem aiming at multimobile robot system. It resolves the problem for the robot how to get the tasks and realize them at minimal cost And we designed an emulational test bed based on the multi-robot material flow system of the storages and docks which made distributed programming using LAN. Then we made some emulational experiments on Hungarian algorithm and compared it with the other algorithms.
The research of artificial immune systems (AIS), which, inspired by the vertebrate immune mechanism, has become one of the hot issues in the artificial intelligence fields. A new algorithm is proposed in this paper ba...
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ISBN:
(纸本)0780382730
The research of artificial immune systems (AIS), which, inspired by the vertebrate immune mechanism, has become one of the hot issues in the artificial intelligence fields. A new algorithm is proposed in this paper based on the immunological vaccination mechanism, which includes three parts: 1) checking of gene loss, 2) vaccinating, and 3) producing memory. Integrated with evolutionary computation, the proposed algorithm can solve the problem of prematurity and speed up to approach the global optimal fitness values. Finally, the algorithm is used to optimize two different complex functions for testing. The simulation results show that the algorithm is more effective and valid compared with other algorithms.
This paper considers the problem of control of networked systems via output feedback. The controller consists of two parts: a state observer that estimates plant state from the output when it is available via the comm...
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This paper considers the problem of control of networked systems via output feedback. The controller consists of two parts: a state observer that estimates plant state from the output when it is available via the communication network, and a model of the plant that is used to generate a control signal when the plant output is not available from the network. Necessary and sufficient conditions for the exponential stability of the closed loop system are derived in terms of the networked dwell time and the system parameters. The results suggest simple procedures for designing the output feedback controller proposed. Numerical simulations show the feasibility and efficiency of the proposed methods.
The characteristics of vortex structures and turbulent events of drag-reducing surfactant (CTAC) solution flows in a two-dimensional channel have been studied using particle image velocimetry (PIV) to measure the inst...
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The computational aspects of the output regulation problem are considered. The standard solution of the output regulation problem uses the explicit solution of the so-called regulator equation being a highly complex P...
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In this paper, we propose a control architecture for meandering locomotion of snake-like robots based on neural oscillator network (NON). The proposed architecture is composed of a network of central pattern generator...
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In this paper, we propose a control architecture for meandering locomotion of snake-like robots based on neural oscillator network (NON). The proposed architecture is composed of a network of central pattern generators (CPGs) to realize propagation of purposive oscillation with specific phase shift. By implementing this architecture to a simulator with consideration of mechanical dynamics of a real snake-like robot, we present realization of meandering motion and preliminary policies about parameter settings of the NON. Moreover, we present that real robot can successfully exhibit meandering movement by using controller output of the proposed architecture.
We designed a global optimization algorithm and a local optimization algorithm based on immune optimization, and then proposed an effective self-tuning scheme of fuzzy controller for time-variable plant. For a time-va...
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ISBN:
(纸本)0780382730
We designed a global optimization algorithm and a local optimization algorithm based on immune optimization, and then proposed an effective self-tuning scheme of fuzzy controller for time-variable plant. For a time-variable plant, the global optimization algorithm was adopted to optimize nominal controller offline. When the plant changed, new optimal controller could be rapidly obtained by local optimization, then it was switched into control to implement self-tuning control and improve the control performance. Simulations show that the system has strong robustness and can implement high accuracy control for some industrial plants, which strongly support its practical value.
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