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1.
《Mechatronics》2021
The hybridization of automotive powertrains increases due to legislative regulations in order to reduce emissions. Hybrid Dual-Clutch Transmissions, where an electric machine is included in the transmission, play a key role in this topic because of their significantly lower losses in contrast to other transmission concepts. On the one hand the hybridization results in new functionalities such as boosting, electric drive and many more. But on the other hand it also increases complexity and the necessity of improved control algorithms because of the advanced interaction of the engine, the electric machine, the clutches and the vehicle. For a good drivability a fast and precise control of all actuators is mandatory. The key elements here are the clutches as they connect or decouple the propulsion sources from the wheels. In order to meet these requirements, two model-based control approaches are elaborated in this contribution. Beginning with a detailed nonlinear parametric model, it is reduced with two different approaches and the singular perturbation theory. With the reduced models a position-based and a pressure-based controller are designed, both with a Two-Degree-of-Freedom structure that contains a flatness-based feedforward component, a linear–quadratic regulator with integrator as feedback component, an observer for the stiff system, and a trajectory generation module. Both controllers show a fast control response and only small tracking errors in experiments performed on a transmission test bench, where the filling of the clutch and the tracking of several specific torque profiles, such as a fast engagement process are validated. 相似文献
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Lijun Gao Shengyi Liu Dougal R.A. 《Components and Packaging Technologies, IEEE Transactions on》2002,25(3):495-505
Presents here a complete dynamic model of a lithium ion battery that is suitable for virtual-prototyping of portable battery-powered systems. The model accounts for nonlinear equilibrium potentials, rate- and temperature-dependencies, thermal effects and response to transient power demand. The model is based on publicly available data such as the manufacturers' data sheets. The Sony US18650 is used as an example. The model output agrees both with manufacturer's data and with experimental results. The model can be easily modified to fit data from different batteries and can be extended for wide dynamic ranges of different temperatures and current rates. 相似文献
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OA系统中的动态工作流模型分析 总被引:1,自引:0,他引:1
针对办公业务流程的多变性,研究了工作流技术在OA系统中的应用,对WFMC定义元模型作了适当的扩展,使之能够实现OA系统中工作流的动态管理。提出并建立了该工作流系统的数学模型。 相似文献
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网页过滤系统旨在帮助用户屏蔽不健康的网页。提出了基于混合模式的网页过滤模型,将传统的基于网址过滤和敏感词过滤的方法与基于文本分类的过滤方法结合起来。重点讨论了特征量选取、网页结构化信息利用等方面的改进措施。实验表明这种模型在保持易于实现的特点的同时,在速度和准确度方面都有不同程度的提高。 相似文献
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Arthurs E. Goodman M.S. Kobrinski H. Vecchi M.P. 《Selected Areas in Communications, IEEE Journal on》1988,6(9):1500-1510
An architecture is presented for an optoelectronic hybrid packet switching system (HYPASS) for the distribution of multiple-bit-rate broadband services. HYPASS is based on an input-buffered/output-controlled arbitration protocol. The internal routing and interconnection utilizes a passive optical transport network with wavelength-tunable laser transmitters and fixed wavelength receivers. The single-stage multiwavelength optical interconnect provides an internally nonblocking network for large throughput routing of the bit-serial optical signals. An internal optical control network, with fixed-wavelength trouble receivers, sends output port information to the input nodes for arbitration and control. Packet buffer storage and control processing is performed by word-parallel electronic circuitry. The characteristics and device requirements for this design are presented along with results of a performance analysis of the arbitration and control protocol 相似文献
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汽车新型液压离合器液压操纵系统几乎100%使用先进的工程塑料,克服了金属离合器总、分泵的缺点,产品可靠性高,耐久性寿命试验达150万次以上。为了能更好地对这种新产品进行研制和性能测试,需要自主开发一种适 相似文献
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《Digital Communications & Networks》2020,6(1):108-114
This paper proposes a dynamic load balancing with learning model for a Sudoku problem solving system that has multiple workers and multiple solvers. The objective is to minimise the total processing time of problem solving. Our load balancing with learning model distributes each Sudoku problem to an appropriate pair of worker and solver when it is received by the system. The information of the estimated solution time for a specific number of given input values, the estimated finishing time of each worker, and the idle status of each worker is used to determine the worker-solver pairs. In addition, the proposed system can estimate the waiting period for each problem. Test results show that the system has shorter processing time than conventional alternatives. 相似文献
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P. Varzakas 《International Journal of Communication Systems》2008,21(5):549-557
A hybrid direct‐sequence/slow frequency hopping code‐division multiple‐access (DS/SFH CDMA) system operating in a Rayleigh fading environment is described and its spectral efficiency is estimated in terms of the theoretically achievable average channel capacity (in the sense of information theory) per user. The analysis covers the operation over a broadcast cellular time‐varying link and leads to a simple novel closed‐form expression for the optimal average spread signal‐to‐interference power ratio (SIR) received by each user based on the maximization of the achieved spectral efficiency. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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针对某飞机起动机部件中的离合器组件在手动模拟调试、人工观察信号判断其高转速与发动机脱开,和低转速与发动机再接通的测试过程中存在测试效率低、可靠性不高等问题,提出了一种采用了西门子变频器、交流电机、研华采集卡和工控机组成的自动测试系统。该系统可自动控制转速按设定的升降斜率运行,同时能自动捕捉离合器脱开、再接转速点的信号。经实际使用表明,系统运行性能良好,自动化程度高,提高了测试效率和可靠性。 相似文献
13.
Simulation tools for hybrid electric vehicles (HEVs) can be classified into steady-state and dynamic models, according to their purpose. Tools with steady-state models are useful for system-level analysis. The information gained is helpful for assessing long-term behavior of the vehicle. Tools that utilize dynamic models give in-depth information about the short-term behavior of sublevel components. In this paper, a dynamic model of a hybrid electric vehicle that includes fuel cells, batteries, ultracapacitors, and induction machine drives is presented. Simulation results of vehicle configurations with a battery, a fuel cell-battery combination and a fuel cell-ultracapacitor combination are discussed. The focus of the model is a detailed assessment of different subsystem components, particularly component losses. 相似文献
14.
Farre J. Bodtker E. Jacobsen G. Stubkjaer K.E. 《Photonics Technology Letters, IEEE》1992,4(12):1354-1357
The authors present detailed results concerning the dynamic range of an amplitude-shift keyed (ASK) heterodyne optical communication system where the transmitted signal is impaired by significant amounts of laser phase noise. Theoretical results are evaluated for a system with up to ten in-line optical amplifiers and a significant influence of the laser phase noise is found for the maximum allowable transmission span and the dynamic range. With ten amplifiers, a linewidth of 11% of the bit rate causes the span to be reduced by 12.2 dB and the dynamic range to be reduced by 5.7 dB. The results have been confirmed using two amplifiers in a field trial experiment at a bit rate of 636 Mb/s with an IF linewidth of 70 MHz 相似文献
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《Mechatronics》2016
The paper presents the design of a pin-on-disc type tribometer intended for experimental characterization of static and dynamic friction behaviors for various sliding sample pairs. The normal force, slip speed, and temperature, as the main influencing parameters, are precisely controlled during experiments, by applying vertical and rotational servo-axes and an electric heater built in the rotating disc. A compact three-axial piezoelectric force sensor, placed between the vertical-axis screw drive and the friction sample, provides direct measurement of normal and tangential forces used to calculate the sample coefficient of friction. The slip speed is measured directly using an incremental encoder mounted at the rotational table. The disc temperature is measured by a built-in Pt probe, whose wires, together with the heater wires, are connected to the temperature control unit by means of slip rings. The tribometer performances are demonstrated through a study of coefficient of friction, shudder sensitivity, and wear rate characterization for a dry clutch friction material. 相似文献
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Patrice Russo Firas Yengui Gael Pillonnet Sophie Taupin Nacer Abouchi 《Microelectronics Journal》2013
We present an optimization of the voltage scaling algorithm in low power audio class-G amplifier for headphones application to allow longer playback time. The optimization approach minimizes the voltage difference between the internal audio amplifier power supply and its output signal over a large range of operating conditions. The modeling is based on a behavioral model enabling accurate and rapid evaluation of efficiency and audio quality with realistic input stimuli. The model validated in practice is used to optimize the voltage scaling using only few power supply levels. Thanks to a global search algorithm followed by a local one, the optimization gives the better parameters for voltage scaling algorithm while keeping a good audio quality. The proposed configuration increases the efficiency up to 48% at nominal operation. 相似文献
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光电经纬仪伺服系统一般是位置、速度双闭的随动系统,其跟踪精度和动态响应能力是衡量系统性能的重要标志.动态高型方法在原有控制系统基础上增加一个或多个积分环节构成高型系统,从而减小跟踪误差.将动态高型方法应用于光电经纬仪伺服系统中,从理论、仿真到工程实现进行了比较全面的研究,获得了一些具有独创性的结论.最后进行了动态Ⅲ型系统的跟踪能力Matlab仿真.当目标为最大加速度60(°)/s2、最大速度60(°)/s的等效正弦时,稳态跟踪误差达1.3″,对于最大加速度120(°)/s2、最大速度120(°)/s的等效正弦,仿真稳态跟踪误差达24″. 相似文献
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Spin transport through the interface in a semiconductor/ferromagnetic insulator hybrid structure is studied by the nonequilibrium statistical operator method under conditions of the spin Seebeck effect. The effective parameter approach in which each examined subsystem (conduction electrons, magnons, phonons) is characterized by its specific effective temperature is considered. The effect of the resonant (electric dipole) excitation of the spin electronic subsystem of conduction electrons on spin-wave current excitation in a ferromagnetic insulator is considered. The macroscopic equations describing the spin-wave current caused by both resonant excitation of the spin system of conduction electrons and the presence of a nonuniform temperature field in the ferromagnetic insulator are derived taking into account both the resonance-diffusion propagation of magnons and their relaxation processes. It is shown that spin-wave current excitation is also of resonant nature under the given conditions. 相似文献
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《Mechatronics》2006,16(6):365-378
The paper describes the development of an electrically operated pneumatic fast-switching valve for pneumatic position control systems. The valve was designed and fabricated as an on–off valve with 2/2-way function and its characteristics were investigated. The detailed theoretical analysis and preliminary tests were carried out on the manufactured valve and showed that the switching time of the single stage valve is about 4.5 ms and provides a 460 l/min of flow rate at standard air conditions. Production and assembling of the valve is rather simple and does not need a manufacturing operation with tight tolerance and therefore, it is envisaged as a low cost valve. The four of 2/2-way function valves are applicable for the realization of pneumatic actuators driving with a well-known established technique of the pulse width modulation (PWM). 相似文献