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火星安全着陆轨迹快速生成的能控集法 被引量:5
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作者 葛丹桐 崔平远 高艾 《宇航学报》 EI CAS CSCD 北大核心 2017年第5期497-505,共9页
针对火星着陆器在动力下降过程可能存在的着陆轨迹实时修正和着陆点再选择等问题,本文通过离线计算着陆器在动力下降段开始时的能控集范围,并在实际着陆过程中判断着陆器当前状态与能控集间的关系,实时确定最终着陆点并快速搜索相应着... 针对火星着陆器在动力下降过程可能存在的着陆轨迹实时修正和着陆点再选择等问题,本文通过离线计算着陆器在动力下降段开始时的能控集范围,并在实际着陆过程中判断着陆器当前状态与能控集间的关系,实时确定最终着陆点并快速搜索相应着陆轨迹。若着陆器无法到达预定着陆点,则在视野范围内根据安全因子重新选择着陆点规划运动轨迹。仿真表明,基于能控集的快速轨迹规划法可根据着陆器的实际初始状态快速确定最终着陆点并获得相应着陆轨迹,以有限的燃耗实现火星安全软着陆的目标。 展开更多
关键词 火星动力下降 安全着陆 能控集 轨迹生成 安全因子
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非线性系统的能控集与近似能控集的估计
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作者 朱其吉 《数学物理学报(A辑)》 CSCD 北大核心 1989年第2期215-222,共8页
本文讨论用李雅普诺夫函数方法对非线性系统的能控集与近似能控集进行估计。
关键词 非线性系统 制系统 能控集
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一类混杂动态系统的能控性(Ⅲ)——含多时滞的情形 被引量:2
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作者 谢广明 王龙 叶庆凯 《应用数学和力学》 CSCD 北大核心 2003年第9期940-950,共11页
首次将时滞现象引入到线性切换系统的模型中,研究含有时滞线性切换系统的能控性及其判定条件.全部工作由三部分组成.第Ⅲ部分,主要研究含多时滞的线性切换系统的能控性及其判定规则.首先给出周期型系统的单周能控性和多周期能控性的定... 首次将时滞现象引入到线性切换系统的模型中,研究含有时滞线性切换系统的能控性及其判定条件.全部工作由三部分组成.第Ⅲ部分,主要研究含多时滞的线性切换系统的能控性及其判定规则.首先给出周期型系统的单周能控性和多周期能控性的定义和充要条件,其次给出非周期系统的能控性的定义和充要条件.最后,研究时滞大小不一致的情形,指出能控性与时滞大小无关. 展开更多
关键词 混杂动态系统 线性切换系统 时滞 能控 能控集 切换序列 切换路径
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一类混杂动态系统的能控性(Ⅱ)——含单时滞的情形 被引量:1
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作者 谢广明 王龙 叶庆凯 《应用数学和力学》 CSCD 北大核心 2003年第9期929-939,共11页
首次将时滞现象引入到线性切换系统的模型中,研究含时滞的线性切换系统的能控性及其判定条件.全部工作由三部分组成.第Ⅱ部分,主要研究含单时滞的线性切换系统的能控性及其判定准则.首先给出周期型系统的单周期能控性和多周期能控性的... 首次将时滞现象引入到线性切换系统的模型中,研究含时滞的线性切换系统的能控性及其判定条件.全部工作由三部分组成.第Ⅱ部分,主要研究含单时滞的线性切换系统的能控性及其判定准则.首先给出周期型系统的单周期能控性和多周期能控性的定义和充要条件,其次给出非周期系统的能控性的定义和充要条件. 展开更多
关键词 混杂动态系统 线性切换系统 时滞 能控 能控集 切换序列 切换路径
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输入矩阵定常型切换线性系统的能控性 被引量:1
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作者 徐志宇 许维胜 吴启迪 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2010年第4期586-588,共3页
重新考察一类切换线性系统的能控性,这类系统具有不同的系统矩阵和相同的输入矩阵.研究发现文献导出的必要充分条件为假命题,该判据只适用于2阶系统,对于3阶及以上系统其必要性不一定成立.并证明第一不变子空间只是能控状态集的真子集,... 重新考察一类切换线性系统的能控性,这类系统具有不同的系统矩阵和相同的输入矩阵.研究发现文献导出的必要充分条件为假命题,该判据只适用于2阶系统,对于3阶及以上系统其必要性不一定成立.并证明第一不变子空间只是能控状态集的真子集,而非其全体.最后通过1个反例对结论予以验证. 展开更多
关键词 切换线性系统 输入矩阵定常 能控 能控状态 必要充分条件
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The Application and Design of the Economical Nonlinear Controller
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作者 陈杰 龚至豪 +1 位作者 陈绿深 周宁 《Journal of Beijing Institute of Technology》 EI CAS 1995年第1期47+42-47,共7页
This anticle gives a design method of the economical nonlinear controller. The controller is composed of an expert intelligent coordination controller, a fuzzy prediction controller, a fuzzy feedforward controller, a ... This anticle gives a design method of the economical nonlinear controller. The controller is composed of an expert intelligent coordination controller, a fuzzy prediction controller, a fuzzy feedforward controller, a nonlinear controller and so on. The consistence of a distributed control system based on this controller is also shown briefly. 展开更多
关键词 fuzzy control theory nonlinear control system predictions distributed control system/intelligent control
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H∞ control of novel active steering integrated with electric power steering function 被引量:8
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作者 ZHAO Wan-zhong LI Yi-jun +2 位作者 WANG Chun-yan ZHAO Ting GU Xiao-yue 《Journal of Central South University》 SCIE EI CAS 2013年第8期2151-2157,共7页
Based on the traditional active steering system, a novel active steering system integrated with electric power steering function was introduced, which can achieve the functions of both active steering and electric pow... Based on the traditional active steering system, a novel active steering system integrated with electric power steering function was introduced, which can achieve the functions of both active steering and electric power steering. In view of the interference from road random signal and sensor noise in the novel active steering system, the H∞ control model of the novel active steering system was built. With satisfying steering feel, good robust performance and steering stability being the control objectives, the H∞ controller for the novel active front steering (AFS) system was designed. The simulation results show that the novel AFS system with H∞ control strategy can attenuate the road interference quickly, and there is no resonance peak in the bode diagram. It can make the driver obtain more useful information in the low frequency range, and attenuate the road interference better in the high frequency range, thus the driver can get more satisfying road feeling. Therefore, the designed H∞ controller can synthesize the advantages of both robust performance and robust stability, and has certain contribution to the design of novel AFS system. 展开更多
关键词 vehicle engineering active steering electric power steering H∞ control
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Method for Incorporation of Controllability in Heat Exchanger Network Synthesis by Integrating Mathematical Programming and Knowledge Engineering 被引量:3
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作者 李志红 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2002年第6期711-716,共6页
A method for incorporation of controlling the heat exchanger networks with or without splits is proposed by integrating mathemati-cal programming and knowledge engineering. The simultaneous optimal mathematical model ... A method for incorporation of controlling the heat exchanger networks with or without splits is proposed by integrating mathemati-cal programming and knowledge engineering. The simultaneous optimal mathematical model is established. This method can be practically used in the integration of large-scale heat exchanger networks, not only to synthesize automatically but also to satisfy the requirement of struc-tural controllability with more objective human intervention. 展开更多
关键词 heat exchanger network CONTROL INTEGRATION SYNTHESIS
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Sensing Time Optimization in Energy-Harvesting Cognitive Radio with Interference Rate Control 被引量:3
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作者 DENG Zhian LIU Xin +1 位作者 JIA Min LU Weidang 《China Communications》 SCIE CSCD 2016年第1期47-56,共10页
In this paper,an energy-harvesting cognitive radio(CR) is considered,which allows the transmitter of the secondary user(SU) to harvest the primary signal energy from the transmitter of the primary user(PU) when the pr... In this paper,an energy-harvesting cognitive radio(CR) is considered,which allows the transmitter of the secondary user(SU) to harvest the primary signal energy from the transmitter of the primary user(PU) when the presence of the PU is detected.Then the harvested energy is converted into the electrical power to supply the transmission of the SU at the detected absence of the PU.By adopting the periodic spectrum sensing,the average total transmission rate of the SU is maximized through optimizing the sensing time,subject to the constraints of the probabilities of false alarm and detection,the harvested energy and the interference rate control.The simulation results show that there deed exists an optimal sensing time that maximizes the transmission rate,and the maximum transmission rate of the energy-harvesting CR can better approach to that of the traditional CR with the increasing of the detection probability. 展开更多
关键词 cognitive radio spectrum sensing energy detection energy harvest transmission rate
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The safety parameters monitoring system for the coal mine based on CAN bus communication and intelligent data acquisition 被引量:4
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作者 Bin Guangfu Chu Wangwen +1 位作者 Balbir S. Dhillon He Wenbiao 《Engineering Sciences》 EI 2008年第4期92-96,共5页
In this paper,a monitoring and controlling system for the safety in production and environmental parameters of a small and medium-sized coal mine has been developed after analyzing the current domestic coal production... In this paper,a monitoring and controlling system for the safety in production and environmental parameters of a small and medium-sized coal mine has been developed after analyzing the current domestic coal production and security conditions. The client computer can convert the analog signal about the safety in production and environmental parameters detected from the monitoring terminal into digital signal,and then,send the signal to the coal mine safety monitoring centre. This information can be analyzed,judged,and diagnosed by the monitoring-management-controlling software for helping the manager and technical workers to control the actual underground production and security situations. The system has many advantages including high reliability,better performance of real-time monitoring,faster data communicating and good practicability,and it can effectively prevent the occurrence of safety incidents in coal mines. 展开更多
关键词 small and mediumsized coal mine safety CAN bus communication intelligent data acquisition production parameters monitoring environmental parameters monitoring
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Effect of Distance between Double Glazing on the Performance of a Solar Thermal Collector Control
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作者 Nabila Ihaddadene Azzeddine Mahdi Razika Ihaddadene 《Journal of Mechanics Engineering and Automation》 2015年第3期161-166,共6页
In this research paper, an attempt has been made to come across the effect of distance between double glazing on the efficiency of a solar thermal collector. Experiments were carded out on an active solar energy demon... In this research paper, an attempt has been made to come across the effect of distance between double glazing on the efficiency of a solar thermal collector. Experiments were carded out on an active solar energy demonstration system (ET 200). Commercial glass pane of 3 mm thick having the same dimensions as that of the apparatus was placed above the collector at a distance of 2 cm, 4 cm and 6 cm. Tests were done with and without the added glass. Experiments were performed for double glazing with two positions of the light meter. In one position, it was placed in the middle of the collector surface. While, in the other one, the light meter was placed in the middle of the added glass. To study the effect of double glazing on the performance of the solar collector ET 200, the correct position of the light meter was to place it exactly in the middle of the additional pane under the lamp. Double glazing does not enhance the performance of the solar collector because of the high resistance of the system glass air glass. The efficiency of double glazing solar collector decreases with the increasing the distance of the two separated glasses. 展开更多
关键词 Solar energy solar collector double glazing distance between double glazing.
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Intelligent Control and Maintenance Man-agement Integrated System Based on Multi-Agents for Coal-Preparation Plant 被引量:3
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作者 MENG Fan-qin WANG Yao-cai 《Journal of China University of Mining and Technology》 EI 2006年第2期206-210,共5页
This paper discusses the progress of computer integrated processing (CIPS) of coal-preparation and then preserits an intelligence controlled production-process, device-maintenance and production-management system of... This paper discusses the progress of computer integrated processing (CIPS) of coal-preparation and then preserits an intelligence controlled production-process, device-maintenance and production-management system of coal- preparation based on multi-agents (IICMMS-CP). The construction of the IICMMS-CP, the distributed network control system based on live intelligence control stations and the strategy of implementing distributed intelligence control system are studied in order to overcome the disadvantages brought about by the wide use of the PLC system by coaipreparation plants. The software frame, based on a Multi-Agent Intelligence Control and Maintenance Management integrated system, is studied and the implemention methods of IICMMS-CP are discussed. The characteristics of distributed architecture, cooperation and parallel computing meet the needs of integrated control of coal-preparation plants with large-scale spatial production distribution, densely-related processes and complex systems. Its application further improves the reliability and precision of process control, accuracy of fault identification and intelligence of production adjustment, establishes a technical basis for system integration and flexible production. The main function of the system has been tested in a coal-preparation plant to good effect in stabilizing product quality, improving efficiency and reducing consumption. 展开更多
关键词 intelligence controlled process multi-agent system computer integrated processing system coal preparation plant
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Finite Set-Model Predictive Current Control of Three-Phase Voltage Source Inverter for RES (Renewable Energy Systems) Applications
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作者 Ali Almaktoof Atanda Raji Tariq Kahn 《Journal of Energy and Power Engineering》 2014年第4期749-756,共8页
This paper focuses on a combination of three-phase VSI (voltage source inverter) with a predictive current control to provide an optimized system for three-phase inverters that control the load current. A FS-MPC (f... This paper focuses on a combination of three-phase VSI (voltage source inverter) with a predictive current control to provide an optimized system for three-phase inverters that control the load current. A FS-MPC (finite set-model predictive control) strategy for a three-phase VSI for RES (renewable energy systems) applications is implemented. The renewable energy systems model is used in this paper to investigate the system performance when power is supplied to resistive-inductive load. With three different cases, the evaluation of the system is done. Firstly, the robustness of control strategy under variable DC-Link is done in terms of the THD (total harmonic distortion). Secondly, with one prediction step, the system performance is tested using different sampling time, and lastly, the dynamic response of the system with step change in the amplitude of the reference is investigated. The simulations and result analyses are carried out using Matlab/Simulink to test the effectiveness and robustness of FS-MPC for two-level VSI with AC filter for resistive-inductive load supplied by a renewable energy system. 展开更多
关键词 Finite set-model predictive control three-phase voltage source inverter renewable energy system application AC filter Matlab/Simulink.
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A NOVEL CALL ADMISSION CONTROL SCHEME IN CELLULAR/WLAN INTEGRATION AND PERFORMANCE ANALYSIS 被引量:1
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作者 Xia Weiwei Shen Lianfeng 《Journal of Electronics(China)》 2009年第2期168-178,共11页
In order to achieve the Quality of Service(QoS) provisioning and efficient resource utili-zation in cellular network and Wireless Local Area Network(WLAN) integration,an Integrated Ser-vice-Based Call Admission Contro... In order to achieve the Quality of Service(QoS) provisioning and efficient resource utili-zation in cellular network and Wireless Local Area Network(WLAN) integration,an Integrated Ser-vice-Based Call Admission Control(ISB-CAC) scheme is proposed in this paper.The integrated network is modeled by using multi-dimensional Markov chains.The numerical analysis is presented to evaluate the important performance measures such as the blocking probability of originating calls,the dropping probability,and the average transfer time,etc.The steady-state probabilities of the multi-dimensional Markov chains are obtained by using an iterative approach,and the CAC pa-rameters are optimally designed.The analytical model is validated by the computer simulation.It is shown that compared with the conventional WLAN-First Call Admission Control(WF-CAC) scheme,the proposed ISB-CAC scheme not only provides better QoS for mobile users but also utilizes the bandwidth resources more efficiently. 展开更多
关键词 Cellular/WLAN integration Call Admission Control(CAC) Quality of Service(QoS) Vertical handoff Markov process
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A novel experimental system for performance evaluation of water powered percussive rock drill
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作者 李夕兵 李志国 +1 位作者 周梓荣 刘希灵 《Journal of Central South University》 SCIE EI CAS 2011年第6期1902-1909,共8页
A set of water powered excavation test system was developed for the comprehensive performance testing and evaluation of water powered percussive rock drill indoors. The whole system contains hydraulic power section, e... A set of water powered excavation test system was developed for the comprehensive performance testing and evaluation of water powered percussive rock drill indoors. The whole system contains hydraulic power section, electronic control system, test and data acquisition system, and assistant devices, such as guideway and drilling bench. Parameters of the water powered percussive rock drill can be obtained by analyzing testing data, which contain impact energy, front and back cavity pressure, pressure and flow in each working part, drilling velocity, frequency and energy efficiency etc. The system is applied to test the self-designed water powered percussive rock drill SYYG65. The parameters of water powered percussive rock drill with impact pressure of about 8.9 MPa are 58.93 J for impact energy, and 8.97% for energy efficiency, which prove the effectiveness of system. 展开更多
关键词 water powered percussive rock drill performance test water powered excavation comprehensive evaluation
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Control strategy of a novel electric power steering system integrated with active front steering function 被引量:25
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作者 ZHAO WanZhong LIN Yi +1 位作者 WEI JianWei SHI GuoBiao 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第6期1515-1520,共6页
A novel electric power steering system(EPS) integrated with active front steering(AFS) is developed.It has functions of both AFS system and EPS system with two actuator units:the AFS actuator unit and the EPS actuator... A novel electric power steering system(EPS) integrated with active front steering(AFS) is developed.It has functions of both AFS system and EPS system with two actuator units:the AFS actuator unit and the EPS actuator unit.The AFS actuator unit controls the displacement transfer behavior of the steering system,and improves the handling stability under adverse road conditions by varying the steering ratio directly related to the speed and road conditions.The EPS actuator unit controls the force transfer behavior of the steering system,and improves the steering portability and road feel of the vehicle.Based on a dynamic model,the mixed H2/H∞ control strategy of the EPS actuator and the active steering intervention control strategy of the AFS actuator are designed.The simulation indicates that the novel EPS system with the designed control strategies has obvious advantages in vehicle handling stability and the driver's road feel over the traditional EPS system,and extends the vehicle's steering performance. 展开更多
关键词 vehicle engineering electric power steering active steering control strategy
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Acquisition algorithm assisted by AGC control voltage for DSSS signals 被引量:4
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作者 SHEN YuYao WANG YongQing +1 位作者 LIU MinLi WU SiLiang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第12期2195-2206,共12页
An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AG... An appropriate acquisition configuration in terms of signal quality can optimize the acquisition performance. In view of this, a new approach of acquisition assisted by the control voltage of automatic gain control(AGC) is proposed. This approach judges the signal power according to the AGC control voltage and switches the working modes correspondingly and adaptively. Non-coherent accumulation times and the detection threshold are reconfigured according to the working mode. Theoretical derivation and verification by simulation in typical situations are provided, and the algorithm is shown to be superior in terms of the mean acquisition time, especially in strong signal scenarios compared with the conventional algorithm. 展开更多
关键词 direct sequence spread spectrum ACQUISITION AGC control voltage carrier-to-noise density ratio estimation adaptive working mode switch
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