Modern combat aircraft can fly at unusual orientations. The spatial disorientation trainer (SDT) examines a pilot's ability to recognise these orientations, to adapt to unusual positions and to persuade the pilot ...
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Modern combat aircraft can fly at unusual orientations. The spatial disorientation trainer (SDT) examines a pilot's ability to recognise these orientations, to adapt to unusual positions and to persuade the pilot to believe in the aircraft instruments for orientation and not in his own senses. The SDT is designed as a four-degree-of-freedom (4DoF) manipulator with rotational axes. Through rotations about these axes, different orientations can be achieved;different acceleration forces acting on the pilot can also be simulated. In this paper, a control algorithm of an SDT that improves the quality and safety of the SDT motion while improving position accuracy and reducing servo errors is proposed. This control algorithm uses approximate inverse dynamics based on the recursive Newton-Euler algorithm, which accounts for the motors present in the system;it calculates motor torques, as well as the forces and moments acting on the SDT links based on the achievable velocities and accelerations of the robot links. This algorithm enables accurate dimensioning of the axes bearings and links as well. The maximum possible accelerations of the SDT links are calculated in each interpolation period based on the total moments of inertia for the axes of rotation of these links, mutual influences of the link accelerations on each other, and motor capabilities. The forces, moments and torques that act on the SDT links obtained with the suggested algorithm have lower magnitude and smoother profile. In this study, the forces and angular velocities that act on the simulator pilot in the SDT are calculated along with the roll and pitch angles of the gondola for these forces. (C) 2015 Elsevier Ltd. All rights reserved.
This paper proposed a novel HEV driving system and related control algorithm based on multi-legs converters, which combines the power generation and the motor driving converter together. Compared with traditional HEV ...
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ISBN:
(纸本)9784886860989
This paper proposed a novel HEV driving system and related control algorithm based on multi-legs converters, which combines the power generation and the motor driving converter together. Compared with traditional HEV system, the proposed system is able to save one power leg meanwhile improve the system efficiency. In order to optimize the system performance, a control algorithm is discussed in the paper, which could further improve the system efficiency and simplify the system thermal design by controlling the generator working conditions. At last, some simulation results are given to validate the control algorithm and topology working principles.
Thermal management (TM) is one of the key factors required to ensure good performance of fuel cell stacks. In this study, thermal management strategies for a fuel cell system are presented to evaluate the parasitic po...
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Thermal management (TM) is one of the key factors required to ensure good performance of fuel cell stacks. In this study, thermal management strategies for a fuel cell system are presented to evaluate the parasitic power of the cooling system with changes of operating temperature of a PEMFC system. The fuel cell system model is composed of a dynamic fuel cell stack model to express heat generation and a detailed dynamic cooling module. The stack model uses an analytic approach;the cooling system model is composed of a radiator, fan, reservoir, water pump and three way valve. The fuel cell model is applied for specific control strategies;the performances of the controllers are evaluated in terms of the parasitic energy. Four control algorithms were compared to minimize parasitic energy, TM strategies 1, 2, 3, and 4. The MATLAB/SIMULINK platform was used in the development and implementation of the models and controllers. As a consequence, the TM strategy 1 algorithm was found to be more effective for low load condition. On the other hand, the TM strategy 4 algorithm was found to be more effective for high load condition. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
In the future smart grid,both sides of the generation and the demand participate in the real-time electricity market,and their activities are responsive to the electricity *** it is proposed the concept of "prici...
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In the future smart grid,both sides of the generation and the demand participate in the real-time electricity market,and their activities are responsive to the electricity *** it is proposed the concept of "pricing control." Considering the numerous algorithms of pricing control which are reported in literature,this paper performs a comparative study and evaluates their effectiveness and *** pricing control scheme of electricity market is *** control algorithms are presented,i.e.,info-fusion-based control,multiperiod optimal control,adaptive estimation,proportional-integral,and moving average *** differences are clarified;from the model description to the solving *** quality of the solution is computationally compared and analyzed.
This paper presents a time-varying control methodology for a variable-sized circular parachute to reach a target landing location. A trajectory is calculated for the immediate control horizon using wind forecast data....
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This paper presents a time-varying control methodology for a variable-sized circular parachute to reach a target landing location. A trajectory is calculated for the immediate control horizon using wind forecast data. To create a parachute-payload trajectory, a three-degree-of-freedom kinematic model is developed. Using this, the performance envelope is determined, revealing the potential target range of the system during a descent. Next, this model is further developed into a control methodology to determine the necessary descent rate, to reach the desired landing target, to be controlled via parachute size manipulation. Finally, simulation results are presented to validate the control scheme. Various release locations were simulated with paired uncontrolled/controlled parachute descents from within the performance envelope. Results demonstrate the feasibility of the system, with controlled parachute descents actively navigating toward the target. With accurate wind data, the vehicle can overcome release location errors as well as vehicle uncertainties and perform significantly better than an uncontrolled parachute in reaching targeted landing locations.
Dynamic external shading is considered an effective measure for improving energy performance and decreasing cooling loads. Optimal control principle is needed to minimize energy use and maximize occupants' satisfa...
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Dynamic external shading is considered an effective measure for improving energy performance and decreasing cooling loads. Optimal control principle is needed to minimize energy use and maximize occupants' satisfaction. We developed and described in detail optimal control macros in software IDA ICE 4.5 and simulated office building energy performances with varying facade solutions and climates over Europe. Primary energy savings between 1 and 32 kWh/m(2) were reached. Shading control to avoid glare during office hours and overheating outside work time was recommended in Tallinn and Paris. In addition shading adjustment according to room temperature during work time was necessary in Athens to minimize energy use. Also suntracking could be used in Tallinn and Paris, but PI-controllers for slat angle control were needed in Athens. Cooling load comparison of internal and external shading showed significant reduction in space cooling capacities ranging between 40% and 70%, whereas design date selection influenced cooling system design considerably besides facade solutions and orientations. Developed control macros are proposed for testing in other studies in order to find optimal control principles satisfying office workers which then could be generally implemented in design guidelines and manuals.
A mathematical model on fuzzy sets that describes the dependence of the shape deviations of curved automobile glass on the tempering regime is developed. An adaptive control algorithm for the tempering regime using si...
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A mathematical model on fuzzy sets that describes the dependence of the shape deviations of curved automobile glass on the tempering regime is developed. An adaptive control algorithm for the tempering regime using simplex planning is proposed. Simulation modeling is used to show that the quality of tempered glass produced on operating equipment can be improved by automating the control of the technological tempering process.
Actuators are often assumed to be perfectly aligned when designing for a stable closed-loop system. In practice, small actuator misalignments can cause the system to perform poorly, or worse, become unstable. Conseque...
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Actuators are often assumed to be perfectly aligned when designing for a stable closed-loop system. In practice, small actuator misalignments can cause the system to perform poorly, or worse, become unstable. Consequently, adaptive observers can be introduced that build online estimates for the unknown misalignments and recover closed-loop stability. In this paper, the problem where the control axes are independently misaligned in three dimensions is considered. A study of the problem indicates a fundamental geometric difference between in-plane and out-of-plane misalignments. Accordingly, special attention is paid to the case where two axes are independently misaligned. New nonlinear adaptive observers are introduced for both the in-plane and out-of-plane problems that guarantee that the misalignment axis estimates remain unit vectors. Furthermore, a Lyapunov-like stability analysis is performed to show convergence of the misalignment estimates to their true values for a wide range of misalignment angles. In addition, a novel control system is developed for a representative dynamic system containing the aforementioned actuator misalignments that ensures perfect asymptotic tracking of prescribed reference trajectories. Also, an axis decoupling method is described that helps alleviate some of the inherent issues in the estimation problem. Detailed proofs and numerical simulations are presented to help illustrate the technical aspects of the work.
As a means to improve the efficiency and flexibility of transportation systems, platooning technology suggests as a way of reducing carbon dioxide emissions and safe driving at a high speed velocity. This paper descri...
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ISBN:
(纸本)9784907764388
As a means to improve the efficiency and flexibility of transportation systems, platooning technology suggests as a way of reducing carbon dioxide emissions and safe driving at a high speed velocity. This paper describes a control algorithm for platooning and remaining the safety distance between vehicles. We also propose a control algorithm that enables when the vehicles to travel on the road in the intersection, to allow to the group formation the new platoon and control the separation distance. Simulation results and experiments by RoboCar show the feasibility of proposed algorithm.
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