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酸液滤失性评价及控滤对策 被引量:10
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作者 卫玮 颜晋川 +2 位作者 刘斌 唐灵 杨琳 《钻井液与完井液》 CAS 2011年第3期66-68,96,共3页
酸液滤失机理和控滤方法是酸化压裂改造中面临的重要课题。通过开展酸液滤失性评价实验,在实验结果的基础上进一步认识酸液滤失特征,分析总结出影响酸液滤失的主要因素是天然缝洞的存在及酸蚀蚓孔的生成,酸液性质、酸浓度以及注酸速度... 酸液滤失机理和控滤方法是酸化压裂改造中面临的重要课题。通过开展酸液滤失性评价实验,在实验结果的基础上进一步认识酸液滤失特征,分析总结出影响酸液滤失的主要因素是天然缝洞的存在及酸蚀蚓孔的生成,酸液性质、酸浓度以及注酸速度对滤失均有明显影响。根据上述影响因素提出了选择降滤失能力的酸液体系、适当降低酸浓度、优化阶段施工排量、采用交替注入、暂堵降滤工艺等针对性的控滤对策。 展开更多
关键词 酸化压裂 碳酸盐岩 酸液 实验评价 控滤
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程序控滤失堵漏技术在JYX6-8HF井的应用
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作者 胡小奎 李阳 《江汉石油科技》 2020年第2期29-36,共8页
传统的技术手段在处理焦石坝工区钻井三开井漏时的成功率低,堵漏成功后复漏几率大,常规的井漏处理技术已经不能适应当下发展的需要,寻找一套快速、高效且一次性堵漏成功率高的新技术是当前亟待解决的新问题。以JYX6-8HF井为例,详细介绍... 传统的技术手段在处理焦石坝工区钻井三开井漏时的成功率低,堵漏成功后复漏几率大,常规的井漏处理技术已经不能适应当下发展的需要,寻找一套快速、高效且一次性堵漏成功率高的新技术是当前亟待解决的新问题。以JYX6-8HF井为例,详细介绍了该丼三开钻进中在五峰组发生失返性漏失时,采用程序控滤失堵漏技术进行墙漏的处理过程,对今后类似油基钻井液井段堵漏起到一定的借鉴作用。 展开更多
关键词 失返控滤 失堵漏 油基钻井液 页岩气
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大型相控阵量化瓣实时抑制及其波控实现 被引量:2
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作者 牛宝君 《微波学报》 CSCD 北大核心 1998年第4期330-334,共5页
本文研究了一种新的大型相控阵扫描量化瓣实时抑制技术,并分析波控实现机制。用数理统计方法对该技术进行了阐述,同时给出模拟仿真结果。该技术能明显抑制扫描量化瓣,为工程实现提供一种有效途径。
关键词 扫描量化瓣 数字移相器 实时抑制
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一种耐高温低伤害纳米复合清洁压裂液性能评价 被引量:8
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作者 乐雷 秦文龙 杨江 《石油与天然气化工》 CAS 北大核心 2016年第6期65-69,共5页
针对清洁压裂液的耐温性较差、滤失量过大等问题,研制了一种新型的耐高温低伤害纳米复合清洁压裂液。实验结果发现,一定浓度的MWNT,能够与蠕虫状胶束形成更为紧密的拟交联三维网状结构且能明显增黏;采用流变性实验优化MWNT质量分数为0.... 针对清洁压裂液的耐温性较差、滤失量过大等问题,研制了一种新型的耐高温低伤害纳米复合清洁压裂液。实验结果发现,一定浓度的MWNT,能够与蠕虫状胶束形成更为紧密的拟交联三维网状结构且能明显增黏;采用流变性实验优化MWNT质量分数为0.3%,得出纳米复合清洁压裂液配方为3%(w)BET-12两性表面活性剂+0.3%(w)MWNT。性能评价结果表明,在170s-1、150℃下,该压裂液黏度仍能保持在20mPa·s以上;70℃时滤失量相比传统清洁压裂液大大降低;剪切恢复性能良好,体系悬砂性能好,遇地层水或原油中烃类物质能自动破胶,高效且彻底,符合施工要求;对储层伤害较小,裂缝导流能力伤害率仅有8.9%。研究表明,该纳米复合清洁压裂液适合在中高温油气田推广应用。 展开更多
关键词 MWNT 两性表面活性剂 清洁压裂液 高温 控滤
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水平井平衡采油工艺技术 被引量:7
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作者 陈伟 冯小红 +3 位作者 张雪梅 李常友 郑金中 李德忠 《断块油气田》 CAS 2008年第2期107-109,共3页
针对水平井,尤其是长井段水平井开发过程中出现的各井段不能均衡采油,而导致底水或气顶锥进,极大影响水平井采收率的难题,结合目前现状,较为详细地阐述了水平井平衡采油的3种工艺技术:新型控液滤砂管技术、选择性采油技术和选择性射孔技... 针对水平井,尤其是长井段水平井开发过程中出现的各井段不能均衡采油,而导致底水或气顶锥进,极大影响水平井采收率的难题,结合目前现状,较为详细地阐述了水平井平衡采油的3种工艺技术:新型控液滤砂管技术、选择性采油技术和选择性射孔技术,并对这3种技术的适用范围及国内外应用情况都做了分析。水平井平衡采油工艺技术在应用上要做到因地制宜。 展开更多
关键词 水平井 平衡采油 选择射孔 选择采油 砂管
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腰英台油田特低渗透油藏压裂技术研究及应用 被引量:18
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作者 黄波 马收 +1 位作者 刘言亭 熊伟 《油气地质与采收率》 CAS CSCD 北大核心 2007年第4期101-102,共2页
腰英台油田不仅具有低孔、低渗透、层多而薄、微裂缝发育以及应力敏感性强的特点,还表现出明显的双重介质储层特征。由于天然裂缝开启导致的压裂液过量滤失和压裂早期砂堵,制约了该区油藏的有效开发。结合腰英台油田勘探开发过程中的压... 腰英台油田不仅具有低孔、低渗透、层多而薄、微裂缝发育以及应力敏感性强的特点,还表现出明显的双重介质储层特征。由于天然裂缝开启导致的压裂液过量滤失和压裂早期砂堵,制约了该区油藏的有效开发。结合腰英台油田勘探开发过程中的压裂改造实践,利用储层裂缝开启机理和压力降分析成果,通过分层地应力剖面研究及全三维压裂模拟、配套射孔优化、限流压裂、暂堵、双转向控缝和前置段塞等工艺的施实,较好地解决了该类储层压裂易早期砂堵的矛盾。现场应用60井次,有效率达80%,累积增产原油5×104t。 展开更多
关键词 特低渗透油藏 薄层 微裂缝 限流 前置段塞 缝降
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Robust adaptive dynamic surface control for nonlinear uncertain systems 被引量:5
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作者 朱永红 姜长生 费树岷 《Journal of Southeast University(English Edition)》 EI CAS 2003年第2期126-131,共6页
We propose a new method for robust adaptive backstepping control of nonlinear systems with parametric uncertainties and disturbances in the strict feedback form. The method is called dynamic surface control. Traditio... We propose a new method for robust adaptive backstepping control of nonlinear systems with parametric uncertainties and disturbances in the strict feedback form. The method is called dynamic surface control. Traditional backstepping algorithms require repeated differentiations of the modelled nonlinearities. The addition of n first order low pass filters allows the algorithm to be implemented without differentiating any model nonlinearities, thus ending the complexity arising due to the 'explosion of terms' that makes other methods difficult to implement in practice. The combined robust adaptive backstepping/first order filter system is proved to be semiglobally asymptotically stable for sufficiently fast filters by a singular perturbation approach. The simulation results demonstrate the feasibility and effectiveness of the controller designed by the method. 展开更多
关键词 nonlinear systems robust control adaptive control dynamic surface control UNCERTAINTIES
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Design of voltage-controlled dynamic band-pass filter based on VCA810 被引量:1
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作者 张艳花 杨录 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第2期147-152,共6页
In order to filter signal effectively according to selective center frequency, a voltage-controlled dynamic band-pass filter with gain compensation was designed based on voltage-controlled gain wideband amplifier VCA8... In order to filter signal effectively according to selective center frequency, a voltage-controlled dynamic band-pass filter with gain compensation was designed based on voltage-controlled gain wideband amplifier VCA810. The transfer function of the filter was analyzed and gain compensation voltages were given through tests; besides, a system was designed, including the gain compensation circuit and the control voltage circuit, etc. Center frequency will change from 1 kHz to 20 kHz according to control voltage on condition that bandwidth of the filter remains constant. The designed system has the advantages of simple structure, low noise, stable performance and convenient adjustment. 展开更多
关键词 VCA810 dynamic band-pass filter voltage-controlled gain compensation
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FREQUENCY-DOMAIN IMPLEMENTATION OF FILTERED-X ALGORITHMS WITH ON-LINE SYSTEM IDENTIFICATION FOR VIBRATION CONTROL
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作者 陈卫东 顾仲权 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1995年第1期99-103,共5页
This paper describes the implementation of frequency-domain least mean squares (LMS) and Filtered-X algorithms and compares the performance of the frequencydomain adaptive control algorithm to a comparable timedomain ... This paper describes the implementation of frequency-domain least mean squares (LMS) and Filtered-X algorithms and compares the performance of the frequencydomain adaptive control algorithm to a comparable timedomain controller. When the frequency-domain LMS step size is allowed to vary as a function of frequency,the frequency-domain algorithm exhibits a better vibration reduction than the time-domain algorithm for the weaker frequencies in the energy spectrum. 展开更多
关键词 vibration reduction feedforward control adaptive filters vibration control adaptive algorithms
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The Algorithms of Adaptive Active Noise Control Systems in a Duct
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作者 韩秀苓 程凡 +1 位作者 高建林 李传光 《Journal of Beijing Institute of Technology》 EI CAS 1995年第1期85+80-85,共7页
On the basis of the theory of adaptive active noise control(AANC) in a duct, this article discusses the algorithms of the adaptive control, compares the algorithm characteristics using LMS, RLS and LSL algorithms in t... On the basis of the theory of adaptive active noise control(AANC) in a duct, this article discusses the algorithms of the adaptive control, compares the algorithm characteristics using LMS, RLS and LSL algorithms in the adaptive filter in the AANC system, derives the recursive formulas of LMS algorithm. and obtains the LMS algorithm in computer simulation using FIR and IIR filters in AANC system. By means of simulation, we compare the attenuation levels with various input signals in AANC system and discuss the effects of step factor, order of filters and sound delay on the algorithm's convergence rate and attenuation level.We also discuss the attenuation levels with sound feedback using are and IIR filters in AANC system. 展开更多
关键词 adaptive control system adaptive filters noise control /adaptive algorithm LMS algorithm
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阿尔泰高山区金矿带的确定和意义 被引量:1
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作者 朱韶华 《新疆地质》 CAS CSCD 1993年第3期215-221,共7页
根据地质、地球化学和资源总量预测等方法的综合研究表明,在阿尔泰高山区红山咀断裂以北宽20~30km,东西长约150km地带为一重要金成矿带。金矿赋存于晚古生代陆相酸—中酸性火山岩地层中,空间上受冰长石-黄铁绢英岩化蚀变带严格控制,是... 根据地质、地球化学和资源总量预测等方法的综合研究表明,在阿尔泰高山区红山咀断裂以北宽20~30km,东西长约150km地带为一重要金成矿带。金矿赋存于晚古生代陆相酸—中酸性火山岩地层中,空间上受冰长石-黄铁绢英岩化蚀变带严格控制,是以毒砂、辉锑矿等金属硫化物为主要载体的层控浅成低温热液溶滤型金矿,也是一种新的重要的金矿工业类型。 展开更多
关键词 阿尔泰山 金矿带 浅成低温热液溶型矿床
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PRINCIPLE AND EXPERIMENTAL DEMONSTRATION OF ADAPTIVE CANCELLATION OF STRUCTURAL VIBRATION IN TIME DOMAIN
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作者 彭福军 马扣根 顾仲权 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1995年第2期109-113,共5页
This paper presents the principle and critical factors of adaptive cancellation of structural vibration in time domain(ACSV-TD).Digital-analog simulations and model tests are conducted on cancelling forced vibration o... This paper presents the principle and critical factors of adaptive cancellation of structural vibration in time domain(ACSV-TD).Digital-analog simulations and model tests are conducted on cancelling forced vibration of a cantilever beam.Filtered-X RLS algorithm is used to get faster convergence speed and stronger adaptability (in comparison with LMS algorithm). The results demonstrate the efficiency and adaptability of the ACSV-TD. 展开更多
关键词 adaptive control structural vibration vibration control adaptive filtering vibration cancellation
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A CMOS Low Power Fully Differential Sigma-Delta Frequency Synthesizer for 2Mb/s GMSK Modulation 被引量:1
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作者 张利 池保勇 +2 位作者 姚金科 王志华 陈弘毅 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第12期2106-2111,共6页
A CMOS fully-differential 2.4GHz ∑-△ frequency synthesizer for Gaussian minimum shift keying (GMSK)modulation is presented. A pre-compensation fractional-N phase-locked loop(PLL)is adopted in the modulator.The t... A CMOS fully-differential 2.4GHz ∑-△ frequency synthesizer for Gaussian minimum shift keying (GMSK)modulation is presented. A pre-compensation fractional-N phase-locked loop(PLL)is adopted in the modulator.The transfer function of the type- Ⅱ third-order phase-locked loop is deduced,and the important parameters that affect the loop transfer function are pointed out. Methods to calibrate the important loop parameters arc introduced. A differential tuned LC-VCO and a fully-differential charge pump are adopted in the PLL design. The designed circuits are simulated in a 0.18gm 1P6M CMOS process. The power consumption of the PLL is only about llmW with the low power consideration in building blocks design, and the data rate of the modulator can reach 2Mb/s. 展开更多
关键词 CMOS FRACTIONAL-N Gaussian minimum shift keying phase-locked loop~ sigma-delta
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Proactive traffic responsive control based on state-space neural network and extended Kalman filter 被引量:3
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作者 过秀成 李岩 杨洁 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期466-470,共5页
The state-space neural network and extended Kalman filter model is used to directly predict the optimal timing plan that corresponds to futuristic traffic conditions in real time with the purposes of avoiding the lagg... The state-space neural network and extended Kalman filter model is used to directly predict the optimal timing plan that corresponds to futuristic traffic conditions in real time with the purposes of avoiding the lagging of the signal timing plans to traffic conditions. Utilizing the traffic conditions in current and former intervals, the network topology of the state-space neural network (SSNN), which is derived from the geometry of urban arterial routes, is used to predict the optimal timing plan corresponding to the traffic conditions in the next time interval. In order to improve the effectiveness of the SSNN, the extended Kalman filter (EKF) is proposed to train the SSNN instead of conventional approaches. Raw traffic data of the Guangzhou Road, Nanjing and the optimal signal timing plan generated by a multi-objective optimization genetic algorithm are applied to test the performance of the proposed model. The results indicate that compared with the SSNN and the BP neural network, the proposed model can closely match the optimal timing plans in futuristic states with higher efficiency. 展开更多
关键词 state-space neural network extended Kalman filter traffic responsive control timing plan traffic state prediction
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A new detector in EBPSK communication system
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作者 靳一 吴乐南 +1 位作者 王继武 余静 《Journal of Southeast University(English Edition)》 EI CAS 2011年第3期244-247,共4页
In order to raise the detection precision of the extended binary phase shift keying (EBPSK) receiver, a detector based on the improved particle swarm optimization algorithm (IMPSO) and the BP neural network is des... In order to raise the detection precision of the extended binary phase shift keying (EBPSK) receiver, a detector based on the improved particle swarm optimization algorithm (IMPSO) and the BP neural network is designed. First, the characteristics of EBPSK modulated signals and the special filtering mechanism of the impacting filter are demonstrated. Secondly, an improved particle swarm optimization algorithm based on the logistic chaos disturbance operator and the Cauchy mutation operator is proposed, and the EBPSK detector is designed by utilizing the IMPSO-BP neural network. Finally, the simulation of the EBPSK detector based on the MPSO-BP neural network is conducted and the result is compared with that of the adaptive threshold-based decision, the BP neural network, and the PSO-BP detector, respectively. Simulation results show that the detection performance of the EBPSK detector based on the IMPSO-BP neural network is better than those of the other three detectors. 展开更多
关键词 extended binary phase shift keying DETECTOR impacting filter logistic chaos disturbance Cauchy mutation adaptive threshold-based decision
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Self-excited vibration problems of maglev vehicle-bridge interaction system 被引量:12
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作者 李金辉 李杰 +1 位作者 周丹峰 余佩倡 《Journal of Central South University》 SCIE EI CAS 2014年第11期4184-4192,共9页
The self-excited vibration problems of maglev vehicle-bridge interaction system were addressed, which greatly degrades the stability of the levitation control, decreases the ride comfort, and restricts the cost of the... The self-excited vibration problems of maglev vehicle-bridge interaction system were addressed, which greatly degrades the stability of the levitation control, decreases the ride comfort, and restricts the cost of the whole system. Firstly, the coupled model containing the quintessential parts was built, and the mechanism of self-excited vibration was explained in terms of energy transmission from levitation system to bridge. Then, the influences of the parameters of the widely used integral-type proportion and derivation(PD) controller and the delay of signals on the stability of the interaction system were analyzed. The result shows that the integral-type PD control is a nonoptimal approach to solve the self-excited vibration completely. Furthermore, the differential-type PD controller can guarantee the passivity of levitation system at full band. However, the differentiation of levitation gap should be filtered by a low-pass filter due to noise of gap differentiation. The analysis indicates that a well tuned low-pass filter can still keep the coupled system stable. 展开更多
关键词 maglev vehicle-bridge interaction system self-excited vibration energy
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Adaptive Controller for Vehicle Active Suspension Generated Through LMS Filter Algorithms 被引量:2
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作者 孙建民 舒歌群 《Transactions of Tianjin University》 EI CAS 2006年第3期163-168,共6页
The least means squares (LMS) adaptive filter algorithm was used in active suspension system. By adjusting the weight of adaptive filter, the minimum quadratic performance index was obtained. For two-degree-of-freed... The least means squares (LMS) adaptive filter algorithm was used in active suspension system. By adjusting the weight of adaptive filter, the minimum quadratic performance index was obtained. For two-degree-of-freedom vehicle suspension model, LMS adaptive controller was designed. The acceleration of the sprung mass,the dynamic tyre load between wheels and road,and the dynamic deflection between sprung mass and unsprung mass were determined as the evaluation targets of suspension performance. For LMS adaptive control suspension, compared with passive suspension, acceleration power spectral density of sprung mass acceleration under the road input model decreased 8-10 times in high frequency resonance band or low frequency resonance band. The simulation results show that LMS adaptive control is simple and remarkably effective. It further proves that the active control suspension system can improve both the riding comfort and handling safety in various operation conditions, and the method is fit for the active control of the suspension system. 展开更多
关键词 adaptive controller LMS filter algorithms riding comfort handling safety
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Design and analysis of dual-mode structure repetitive control based hybrid current regulation scheme for active power filters
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作者 邹志翔 王政 程明 《Journal of Southeast University(English Edition)》 EI CAS 2013年第4期407-413,共7页
An all-digital hybrid current regulation scheme for the single-phase shunt active power filter (APF) is presented. The proposed hybrid current control scheme integrates the deadbeat control and the dual-mode structu... An all-digital hybrid current regulation scheme for the single-phase shunt active power filter (APF) is presented. The proposed hybrid current control scheme integrates the deadbeat control and the dual-mode structure repetitive control (DMRC) so that it can offer superior steady-state performance and good transient features. Unlike the conventional schemes, the proposed scheme-based APF can compensate both the odd and the even order harmonics in grid. The detailed design criteria and the stability analysis of the proposed hybrid current controller are presented. Moreover, an improved structure which incorporates the proposed hybrid controller and the resonant controller for tracking specific order harmonics is given. The relationships between the resonant controller and different repetitive control schemes are discussed. Experimental results verify the effectiveness and advantages of the proposed hybrid control scheme. 展开更多
关键词 active power filter dual-mode structure repetitive control (DMRC) current control harmonic compensation resonant controller
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Improved control strategy for PMSM based on fuzzy sliding mode control and sliding-mode observer 被引量:2
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作者 ZHAO Feng LUO Wen +1 位作者 GAO Fengyang YU Jiale 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第4期433-441,共9页
Aimed at the problems of large torque ripple,obvious chattering and poor estimation accuracy of back-EMFs in traditional permanent magnet synchronous motor(PMSM)control system with sliding mode observer(SMO),an improv... Aimed at the problems of large torque ripple,obvious chattering and poor estimation accuracy of back-EMFs in traditional permanent magnet synchronous motor(PMSM)control system with sliding mode observer(SMO),an improved control strategy for PMSM based on a fuzzy sliding mode control(FSMC)and a two-stage filter sliding mode observer(TFSMO)is proposed.Firstly,a novel reaching law(NRL)used in the speed loop based on hyperbolic sine function is studied,and fuzzy control ideal is shown to achieve the self-turning of the parameter for the reaching law,thus a fuzzy integral sliding mode controller based on the novel reaching law is designed in speed loop.Then the suppression effect upon chattering caused by the novel reaching law is analyzed strictly by discrete equation.Secondly,in order to restrain the high frequency components and measurement noise in back-EMFs,a two-stage filter structure based on a variable cut-off frequency low-pass filter(VCF-LPF)and a modified back-EMF observer(MBO)is conceived,and the rotor position is compensated reasonably.As a result,a TFSMO is designed.The stability of the proposed control strategy is proved by Lyapunov Criterion.The simulation and experiment results show that,compared with traditional SMO,the controller suggested above can obtain very nice system respond when the motor starts and is subjected to external disturbances,and effectively improve the problems about torque ripple,chattering and the estimation accuracy of back-EMF. 展开更多
关键词 permanent magnet synchronous motor(PMSM) novel reaching law(NRL) fuzzy sliding mode control(FSMC) two-stage filter sliding mode observer(TFSMO)
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Motion cue based pedestrian detection with two-frame-filtering
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作者 吕敬钦 Zhang Miaohui Yang Jie 《High Technology Letters》 EI CAS 2015年第3期328-332,共5页
This study proposes a motion cue based pedestrian detection method with two-trame-filtering (Tff) for video surveillance. The novel motion cue is exploited by the gray value variation between two frames. Then Tff pr... This study proposes a motion cue based pedestrian detection method with two-trame-filtering (Tff) for video surveillance. The novel motion cue is exploited by the gray value variation between two frames. Then Tff processing filters the gradient magnitude image by the variation map. Summa- tions of the Tff gradient magnitudes in cells are applied to train a pre-deteetor to exclude most of the background regions. Histogram of Tff oriented gradient (HTffOG) feature is proposed for pedestrian detection. Experimental results show that this method is effective and suitable for real-time surveil- lance applications. 展开更多
关键词 pedestrian detection two-frame-filtering (TFF) Tff magnitude vector (TffMV) Histogram of Tff oriented gradient HTffOG) SVM video surveillance
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