This paper addresses an iterative learning control(ILC) design problem for discrete-time linear systems with randomly varying trial lengths. Due to the variation of the trial lengths, a stochastic matrix and an iterat...This paper addresses an iterative learning control(ILC) design problem for discrete-time linear systems with randomly varying trial lengths. Due to the variation of the trial lengths, a stochastic matrix and an iteration-average operator are introduced to present a unified expression of ILC scheme. By using the framework of lifted system, the learning convergence condition of ILC in mathematical expectation is derived without using λ-norm. It is shown that the requirement on classic ILC that all trial lengths must be identical is mitigated and the identical initialization condition can be also removed. In the end, two illustrative examples are presented to demonstrate the performance and the effectiveness of the proposed ILC scheme for both time-invariant and time-varying linear systems.展开更多
Abstract This paper conducts a simulation study of a novel aircraft environmental control system based on membrane dehumidification （MD-ECS）, and compares the system with the up-to-date four-wheel high pressure de-w...Abstract This paper conducts a simulation study of a novel aircraft environmental control system based on membrane dehumidification （MD-ECS）, and compares the system with the up-to-date four-wheel high pressure de-water system （4WHPDW-ECS）. Mathematical models for the two sys- tems are established, and a system simulation using a numerical technique is performed to analyze and compare the cooling performance of the two systems. Simulation results show that the cooling capacity of MD-ECS is much higher than that of 4WHPDW-ECS under the same working conditions, indicating that the novel system is theoretically feasible and promising. The effects of the sweep ratio of the membrane dehumidifier on the dehumidification and cooling performance of the system is also investigated.展开更多
This paper develops an approach to control unstable nonlinear multi-inputs multi-output(MIMO) square plants using MIMO fractional order(FO) controllers. The controller design uses the linear time invariant(LTI) state ...This paper develops an approach to control unstable nonlinear multi-inputs multi-output(MIMO) square plants using MIMO fractional order(FO) controllers. The controller design uses the linear time invariant(LTI) state space representation of the nonlinear model of the plant and the diagonal closedloop transfer matrix(TM) function to ensure decoupling between inputs. Each element of the obtained MIMO controller could be either a transfer function(TF) or a gain. A TF is associated in turn with its corresponding FO TF. For example, a D(Derivative) TF is related to a FO TF of the form Dδ, δ =[0, 1]. Two applications were performed to validate the developed approach via experimentation: control of the angular positions of a manipulator, and control of the car and arm positions of a translational manipulator.展开更多
A 1500 mA,10 MHz self-adaptive on-time （SOT） controlled buck DC-DC converter is presented. Both a low-cost ripple compensation scheme （RCS） and a self-adaptive on-time generator （SAOTG） are proposed to solve the...A 1500 mA,10 MHz self-adaptive on-time （SOT） controlled buck DC-DC converter is presented. Both a low-cost ripple compensation scheme （RCS） and a self-adaptive on-time generator （SAOTG） are proposed to solve the system stability and frequency variation problem. Meanwhile a self-adaptive power transistor sizing （SAPTS） technique is used to optimize the efficiency especially with a heavy load. The circuit is implemented in a 2P4M 0.35μm CMOS process. A small external inductor of 0.47 μH and a capacitor of 4.7 μF are used to lower the cost of the converter and keep the output ripple to less than 10 mV. The measurement results show that the overshoot of the load transient response is 8 mV @ 200 mA step and the dynamic voltage scaling （DVS） performance is a rise of 16/zs/V and a fall of 20 μs/V. With a SAPTS technique and PFM control, the efficiency is maintained at more than 81% for a load range of 20 to 1500 mA and the peak efficiency reaches 88.43%.展开更多
A 10 MHz ripple-based on-time controlled buck converter is presented. A novel low-cost dual ripple compensation, which consists of coupling capacitor compensation and passive equivalent series resistance compensation,...A 10 MHz ripple-based on-time controlled buck converter is presented. A novel low-cost dual ripple compensation, which consists of coupling capacitor compensation and passive equivalent series resistance compensation, is proposed to achieve a fast load transient response and robust stability simultaneously. Implemented in a 2P4M 0.35 um CMOS process, the converter achieves fix-frequency output with a ripple of below 10 mV and an overshoot of 10 mV at 400 mA step load transient response. With width optimization of the power transistors in an ultra-heavy load and PFM control in a light load, the efficiency stays at over 83% for a load range from 20 mA to 1.5 A and the peak efficiency reaches 90.16%.展开更多
For the electrical control system of XA6132 milling machine circuit complexity, reliability and flexibility, high failure rate. Mitsubishi FX2N-40MR programmable controller is used to improve the performance and effic...For the electrical control system of XA6132 milling machine circuit complexity, reliability and flexibility, high failure rate. Mitsubishi FX2N-40MR programmable controller is used to improve the performance and efficiency of the entire electrical control system by technological transformation. Mitsubishi FX2N-d0MRPLC on electrical control system transformation can expand link to the technological transformation of the similar equipments.展开更多
目的系统评价红景天治疗慢性稳定性心绞痛的疗效及安全性。方法网络检索Cochrane图书馆、PubMed、中国生物医学文献数据库(CBM)、维普数据库(VIP)、中文期刊全文数据库(CNKI)数据库截止2013年4月已发表的中、英文临床研究文献。纳入红...目的系统评价红景天治疗慢性稳定性心绞痛的疗效及安全性。方法网络检索Cochrane图书馆、PubMed、中国生物医学文献数据库(CBM)、维普数据库(VIP)、中文期刊全文数据库(CNKI)数据库截止2013年4月已发表的中、英文临床研究文献。纳入红景天或联合西药与西药常规比较治疗慢性稳定性心绞痛的随机对照试验,按照数据提取表提取数据,采用Cochrane手册临床试验质量评价标准评价文献质量,应用Rev Man 5.2软件对资料进行荟萃分析。结局的效应指标以比值比(OR)及其95%可信区间(CI)表示。结果 7篇随机对照试验共662例慢性稳定性心绞痛患者符合纳入标准,全部为中文文献,无1篇设计科学,评价质量高的文献。与单纯西药常规治疗比较,联用口服红景天对心绞痛的症状临床疗效有效率优于常规治疗(OR=2.49,95%CI:1.02~6.09),加用静脉滴注红景天其症状疗效亦优于常规治疗(OR=4.86,95%CI:2.4~9.82);口服红景天不能提高心电图疗效[OR=1.25,95%CI:0.67~2.34),静脉用药则可提高临床疗效(OR=2.94,95%CI:1.61~5.35)。在常规治疗的基础上,静脉加用红景天可改善患者高低切变率全血黏度,逆方差(IV)分别为-1.36、-0.99,95%CI分别为-1.65^-1.07、-1.26^-0.71,而不能降低患者纤维蛋白原和D-二聚体水平;单纯常规治疗不良反应发生率高于加用红景天组(OR=0.1,95%CI:0.02~0.51)。结论在常规治疗基础上,红景天可进一步改善患者的心绞痛症状,加用静脉用药可以提高心电图改善率,降低不良反应。但由于纳入研究的方法学质量较低、样本数目偏少,干预周期偏短等因素影响,该结论需要设计科学合理,样本数更大,且实施严格的多中心临床试验加以验证。展开更多
文摘This paper addresses an iterative learning control(ILC) design problem for discrete-time linear systems with randomly varying trial lengths. Due to the variation of the trial lengths, a stochastic matrix and an iteration-average operator are introduced to present a unified expression of ILC scheme. By using the framework of lifted system, the learning convergence condition of ILC in mathematical expectation is derived without using λ-norm. It is shown that the requirement on classic ILC that all trial lengths must be identical is mitigated and the identical initialization condition can be also removed. In the end, two illustrative examples are presented to demonstrate the performance and the effectiveness of the proposed ILC scheme for both time-invariant and time-varying linear systems.
基金support from Aeronautical Science Foundation of China(No.2011ZC09006)
文摘Abstract This paper conducts a simulation study of a novel aircraft environmental control system based on membrane dehumidification （MD-ECS）, and compares the system with the up-to-date four-wheel high pressure de-water system （4WHPDW-ECS）. Mathematical models for the two sys- tems are established, and a system simulation using a numerical technique is performed to analyze and compare the cooling performance of the two systems. Simulation results show that the cooling capacity of MD-ECS is much higher than that of 4WHPDW-ECS under the same working conditions, indicating that the novel system is theoretically feasible and promising. The effects of the sweep ratio of the membrane dehumidifier on the dehumidification and cooling performance of the system is also investigated.
文摘This paper develops an approach to control unstable nonlinear multi-inputs multi-output(MIMO) square plants using MIMO fractional order(FO) controllers. The controller design uses the linear time invariant(LTI) state space representation of the nonlinear model of the plant and the diagonal closedloop transfer matrix(TM) function to ensure decoupling between inputs. Each element of the obtained MIMO controller could be either a transfer function(TF) or a gain. A TF is associated in turn with its corresponding FO TF. For example, a D(Derivative) TF is related to a FO TF of the form Dδ, δ =[0, 1]. Two applications were performed to validate the developed approach via experimentation: control of the angular positions of a manipulator, and control of the car and arm positions of a translational manipulator.
文摘A 1500 mA,10 MHz self-adaptive on-time （SOT） controlled buck DC-DC converter is presented. Both a low-cost ripple compensation scheme （RCS） and a self-adaptive on-time generator （SAOTG） are proposed to solve the system stability and frequency variation problem. Meanwhile a self-adaptive power transistor sizing （SAPTS） technique is used to optimize the efficiency especially with a heavy load. The circuit is implemented in a 2P4M 0.35μm CMOS process. A small external inductor of 0.47 μH and a capacitor of 4.7 μF are used to lower the cost of the converter and keep the output ripple to less than 10 mV. The measurement results show that the overshoot of the load transient response is 8 mV @ 200 mA step and the dynamic voltage scaling （DVS） performance is a rise of 16/zs/V and a fall of 20 μs/V. With a SAPTS technique and PFM control, the efficiency is maintained at more than 81% for a load range of 20 to 1500 mA and the peak efficiency reaches 88.43%.
文摘A 10 MHz ripple-based on-time controlled buck converter is presented. A novel low-cost dual ripple compensation, which consists of coupling capacitor compensation and passive equivalent series resistance compensation, is proposed to achieve a fast load transient response and robust stability simultaneously. Implemented in a 2P4M 0.35 um CMOS process, the converter achieves fix-frequency output with a ripple of below 10 mV and an overshoot of 10 mV at 400 mA step load transient response. With width optimization of the power transistors in an ultra-heavy load and PFM control in a light load, the efficiency stays at over 83% for a load range from 20 mA to 1.5 A and the peak efficiency reaches 90.16%.
基金supported by the Hubei Province Education Science "Twelfth Five Year Plan" 2013 annual research topic,No.2013B298
文摘For the electrical control system of XA6132 milling machine circuit complexity, reliability and flexibility, high failure rate. Mitsubishi FX2N-40MR programmable controller is used to improve the performance and efficiency of the entire electrical control system by technological transformation. Mitsubishi FX2N-d0MRPLC on electrical control system transformation can expand link to the technological transformation of the similar equipments.
文摘目的系统评价红景天治疗慢性稳定性心绞痛的疗效及安全性。方法网络检索Cochrane图书馆、PubMed、中国生物医学文献数据库(CBM)、维普数据库(VIP)、中文期刊全文数据库(CNKI)数据库截止2013年4月已发表的中、英文临床研究文献。纳入红景天或联合西药与西药常规比较治疗慢性稳定性心绞痛的随机对照试验,按照数据提取表提取数据,采用Cochrane手册临床试验质量评价标准评价文献质量,应用Rev Man 5.2软件对资料进行荟萃分析。结局的效应指标以比值比(OR)及其95%可信区间(CI)表示。结果 7篇随机对照试验共662例慢性稳定性心绞痛患者符合纳入标准,全部为中文文献,无1篇设计科学,评价质量高的文献。与单纯西药常规治疗比较,联用口服红景天对心绞痛的症状临床疗效有效率优于常规治疗(OR=2.49,95%CI:1.02~6.09),加用静脉滴注红景天其症状疗效亦优于常规治疗(OR=4.86,95%CI:2.4~9.82);口服红景天不能提高心电图疗效[OR=1.25,95%CI:0.67~2.34),静脉用药则可提高临床疗效(OR=2.94,95%CI:1.61~5.35)。在常规治疗的基础上,静脉加用红景天可改善患者高低切变率全血黏度,逆方差(IV)分别为-1.36、-0.99,95%CI分别为-1.65^-1.07、-1.26^-0.71,而不能降低患者纤维蛋白原和D-二聚体水平;单纯常规治疗不良反应发生率高于加用红景天组(OR=0.1,95%CI:0.02~0.51)。结论在常规治疗基础上,红景天可进一步改善患者的心绞痛症状,加用静脉用药可以提高心电图改善率,降低不良反应。但由于纳入研究的方法学质量较低、样本数目偏少,干预周期偏短等因素影响,该结论需要设计科学合理,样本数更大,且实施严格的多中心临床试验加以验证。
