在嵌入式平台下,高像素摄像头驱动的开发受到嵌入式处理器速度有限和系统资源有限的限制.为了更好地解决这一问题,本文基于PXA270嵌入式平台,使用Q u ick Capture接口技术,采用DMA描述符链的数据传送方式和双RAM池策略,并采用内存共享...在嵌入式平台下,高像素摄像头驱动的开发受到嵌入式处理器速度有限和系统资源有限的限制.为了更好地解决这一问题,本文基于PXA270嵌入式平台,使用Q u ick Capture接口技术,采用DMA描述符链的数据传送方式和双RAM池策略,并采用内存共享设计思想,降低了数据行走路径,在提高了数据传送速率的同时充分利用嵌入式系统的有限内存资源,降低了内存占用率,保证了获取高分辨率图像的要求.最终在YL-E270开发板上实现了分辨率为400万的CMO S摄像头驱动,通过实际测试,结果表明本文设计的高像素摄像头驱动程序具有良好的稳定性和性能,与低像素摄像头采集的文字图像相比,文字识别的正确率可提高17.5%,采用内存共享机制可减少21.5%内存占用率.展开更多
Solid oxide fuel cells (SOFCs) are considered to be one of the most important clean,distributed resources. However,SOFCs present a challenging control problem owing to their slow dynamics,nonlinearity and tight operat...Solid oxide fuel cells (SOFCs) are considered to be one of the most important clean,distributed resources. However,SOFCs present a challenging control problem owing to their slow dynamics,nonlinearity and tight operating constraints. A novel data-driven nonlinear control strategy was proposed to solve the SOFC control problem by combining a virtual reference feedback tuning (VRFT) method and support vector machine. In order to fulfill the requirement for fuel utilization and control constraints,a dynamic constraints unit and an anti-windup scheme were adopted. In addition,a feedforward loop was designed to deal with the current disturbance. Detailed simulations demonstrate that the fast response of fuel flow for the current demand disturbance and zero steady error of the output voltage are both achieved. Meanwhile,fuel utilization is kept almost within the safe region.展开更多
This work presents a novel coordinated control strategy of a hybrid photovoltaic/battery energy storage(PV/BES) system. Different controller operation modes are simulated considering normal, high fluctuation and emerg...This work presents a novel coordinated control strategy of a hybrid photovoltaic/battery energy storage(PV/BES) system. Different controller operation modes are simulated considering normal, high fluctuation and emergency conditions. When the system is grid-connected, BES regulates the fluctuated power output which ensures smooth net injected power from the PV/BES system. In islanded operation, BES system is transferred to single master operation during which the frequency and voltage of the islanded microgrid are regulated at the desired level. PSCAD/EMTDC simulation validates the proposed method and obtained favorable results on power set-point tracking strategies with very small deviations of net output power compared to the power set-point. The state-of-charge regulation scheme also very effective with SOC has been regulated between 32% and 79% range.展开更多
Control of clarifier in the activated sludge process is critical for ensuring effective wastewater treatment. This paper is to study appropriate control strategies for a clarifier in an industrial wastewater treatment...Control of clarifier in the activated sludge process is critical for ensuring effective wastewater treatment. This paper is to study appropriate control strategies for a clarifier in an industrial wastewater treatment plant. Five control strategies are proposed, implemented and evaluated in a simulation software （West ＋＋）. The sludge blanket height and the effluent suspended solids concentration were proposed as the measured variable. The manipulated variable was the quantity of polymer added to the system. The strategies were evaluated in terms of their ability to maintain the sludge blanket height below 1.5m, their polymer requirements, their sensitivity to poor tuning and the required control action.展开更多
A hybrid automaton modeling approach that incorporates state space partitioning, phase dynamic modeling and control law synthesis by control strategy is utilized to develop a hybrid automaton model of molten carbonate...A hybrid automaton modeling approach that incorporates state space partitioning, phase dynamic modeling and control law synthesis by control strategy is utilized to develop a hybrid automaton model of molten carbonate fuel cell (MCFC) stack shutdown. The shutdown operation is divided into several phases and their boundaries are decided according to a control strategy, which is a set of specifications about the dynamics of MCFC stack during shutdown. According to the control strategy, the specification of increasing stack temperature is satisfied in a phase that can be modeled accurately. The model for phase that has complex dynamic is approximated. The duration of this kind of phase is decreased to minimize the error caused by model approximation.展开更多
Controlling the nucleation and growth of organic-inorganic hybrids perovskite is of key importance to improve the morphology and crystallinity of perovskite films. However, the growth mechanism of perovskite films bas...Controlling the nucleation and growth of organic-inorganic hybrids perovskite is of key importance to improve the morphology and crystallinity of perovskite films. However, the growth mechanism of perovskite films based on classical crystallization theory is not fully understood. Here, we develop a supersaturation controlled strategy(SCS) to balance the nucleation and crystal growth speeds. By this strategy, we are able to find an ideal supersaturation region to realize a balance of nucleation and crystal growth, which yields highly crystallized perovskite films with micrometer-scale grains. Besides, we provide a thoughtful analysis of nucleation and growth based on the fabrication of the perovskite films. As a result, the highest photovoltaic power conversion efficiencies(PCE) of 19.70% and 20.31% are obtained for the planar and the meso-superstructured devices, respectively. This strategy sheds some light for understanding the film growth mechanism of high quality perovskite film, and it provides a facile strategy to fabricate high efficiency perovskite solar cells.展开更多
Perovskite is rising as the most promising material for the next generation of solar cells,due to its high efficiency,low cost,and convenient fabrication.However,the stability of perovskite solar cells remains to be a...Perovskite is rising as the most promising material for the next generation of solar cells,due to its high efficiency,low cost,and convenient fabrication.However,the stability of perovskite solar cells remains to be a challenge towards large-scale application.Perovskite materials play a key role in improving the stability of PSCs,and tremendous efforts have been committed to stabilizing the perovskite materials,including composition regulation,crystallization control,and interface optimization.Herein we review the state-of-the-art strategies to improve the stability of perovskite layers in PSCs,and important strategies are highlighted.We analyze in-depth the influence of each site ion on perovskite structural stability and summarize the important progress of these structures showing superior stability.We then summarize the use of additives to regulate perovskite crystallization and defect passivation and elaborate the related mechanisms.Furthermore,the pros and cons of different interface treatment methods used in perovskite solar cells are discussed。展开更多
文摘在嵌入式平台下,高像素摄像头驱动的开发受到嵌入式处理器速度有限和系统资源有限的限制.为了更好地解决这一问题,本文基于PXA270嵌入式平台,使用Q u ick Capture接口技术,采用DMA描述符链的数据传送方式和双RAM池策略,并采用内存共享设计思想,降低了数据行走路径,在提高了数据传送速率的同时充分利用嵌入式系统的有限内存资源,降低了内存占用率,保证了获取高分辨率图像的要求.最终在YL-E270开发板上实现了分辨率为400万的CMO S摄像头驱动,通过实际测试,结果表明本文设计的高像素摄像头驱动程序具有良好的稳定性和性能,与低像素摄像头采集的文字图像相比,文字识别的正确率可提高17.5%,采用内存共享机制可减少21.5%内存占用率.
基金Projects(51076027,51036002) supported by the National Natural Science Foundation of ChinaProject(20090092110051) supported by the Doctoral Fund of Ministry of Education of China
文摘Solid oxide fuel cells (SOFCs) are considered to be one of the most important clean,distributed resources. However,SOFCs present a challenging control problem owing to their slow dynamics,nonlinearity and tight operating constraints. A novel data-driven nonlinear control strategy was proposed to solve the SOFC control problem by combining a virtual reference feedback tuning (VRFT) method and support vector machine. In order to fulfill the requirement for fuel utilization and control constraints,a dynamic constraints unit and an anti-windup scheme were adopted. In addition,a feedforward loop was designed to deal with the current disturbance. Detailed simulations demonstrate that the fast response of fuel flow for the current demand disturbance and zero steady error of the output voltage are both achieved. Meanwhile,fuel utilization is kept almost within the safe region.
文摘This work presents a novel coordinated control strategy of a hybrid photovoltaic/battery energy storage(PV/BES) system. Different controller operation modes are simulated considering normal, high fluctuation and emergency conditions. When the system is grid-connected, BES regulates the fluctuated power output which ensures smooth net injected power from the PV/BES system. In islanded operation, BES system is transferred to single master operation during which the frequency and voltage of the islanded microgrid are regulated at the desired level. PSCAD/EMTDC simulation validates the proposed method and obtained favorable results on power set-point tracking strategies with very small deviations of net output power compared to the power set-point. The state-of-charge regulation scheme also very effective with SOC has been regulated between 32% and 79% range.
文摘Control of clarifier in the activated sludge process is critical for ensuring effective wastewater treatment. This paper is to study appropriate control strategies for a clarifier in an industrial wastewater treatment plant. Five control strategies are proposed, implemented and evaluated in a simulation software （West ＋＋）. The sludge blanket height and the effluent suspended solids concentration were proposed as the measured variable. The manipulated variable was the quantity of polymer added to the system. The strategies were evaluated in terms of their ability to maintain the sludge blanket height below 1.5m, their polymer requirements, their sensitivity to poor tuning and the required control action.
文摘A hybrid automaton modeling approach that incorporates state space partitioning, phase dynamic modeling and control law synthesis by control strategy is utilized to develop a hybrid automaton model of molten carbonate fuel cell (MCFC) stack shutdown. The shutdown operation is divided into several phases and their boundaries are decided according to a control strategy, which is a set of specifications about the dynamics of MCFC stack during shutdown. According to the control strategy, the specification of increasing stack temperature is satisfied in a phase that can be modeled accurately. The model for phase that has complex dynamic is approximated. The duration of this kind of phase is decreased to minimize the error caused by model approximation.
基金supported by the National Key Research and Development Program of China (2016YFA0204000)the National Natural Science Foundation of China (U1632118, 21571129)+2 种基金Shanghai Tech Start-Up Funding1000 Young Talent program,Science and Technology Commission of Shanghai Municipality (16JC1402100, 16520720700)
文摘Controlling the nucleation and growth of organic-inorganic hybrids perovskite is of key importance to improve the morphology and crystallinity of perovskite films. However, the growth mechanism of perovskite films based on classical crystallization theory is not fully understood. Here, we develop a supersaturation controlled strategy(SCS) to balance the nucleation and crystal growth speeds. By this strategy, we are able to find an ideal supersaturation region to realize a balance of nucleation and crystal growth, which yields highly crystallized perovskite films with micrometer-scale grains. Besides, we provide a thoughtful analysis of nucleation and growth based on the fabrication of the perovskite films. As a result, the highest photovoltaic power conversion efficiencies(PCE) of 19.70% and 20.31% are obtained for the planar and the meso-superstructured devices, respectively. This strategy sheds some light for understanding the film growth mechanism of high quality perovskite film, and it provides a facile strategy to fabricate high efficiency perovskite solar cells.
基金supported by the National Key Research and Development Program of China (2021YFA0715502)the National Natural Science Foundation of China (61935016, 92056119, and 22175118)+1 种基金the Double First-Class Initiative Fund of Shanghai Tech Universitythe Science and Technology Commission of Shanghai Municipality (20XD1402500 and 20JC1415800)
文摘Perovskite is rising as the most promising material for the next generation of solar cells,due to its high efficiency,low cost,and convenient fabrication.However,the stability of perovskite solar cells remains to be a challenge towards large-scale application.Perovskite materials play a key role in improving the stability of PSCs,and tremendous efforts have been committed to stabilizing the perovskite materials,including composition regulation,crystallization control,and interface optimization.Herein we review the state-of-the-art strategies to improve the stability of perovskite layers in PSCs,and important strategies are highlighted.We analyze in-depth the influence of each site ion on perovskite structural stability and summarize the important progress of these structures showing superior stability.We then summarize the use of additives to regulate perovskite crystallization and defect passivation and elaborate the related mechanisms.Furthermore,the pros and cons of different interface treatment methods used in perovskite solar cells are discussed。
