In this paper,a multi-loop internal model control(IMC) scheme in conjunction with feed-forward strategy based on the dynamic partial least squares(DyPLS) framework is proposed.Unlike the traditional methods to decoupl...In this paper,a multi-loop internal model control(IMC) scheme in conjunction with feed-forward strategy based on the dynamic partial least squares(DyPLS) framework is proposed.Unlike the traditional methods to decouple multi-input multi-output(MIMO) systems,the DyPLS framework automatically decomposes the MIMO process into a multi-loop system in the PLS subspace in the modeling stage.The dynamic filters with identical structure are used to build the dynamic PLS model,which retains the orthogonality among the latent variables.To address the model mismatch problem,an off-line least squares method is applied to obtain a set of optimal filter parameters in each latent space.Without losing the merits of model-based control,a simple and easy-tuned IMC structure is readily carried over to the dynamic PLS control framework.In addition,by projecting the measurable disturbance into the latent subspace,a multi-loop feed-forward control is yielded to achieve better performance for disturbance rejection.Simulation results of a distillation column are used to further demonstrate this new strategy outperforms conventional control schemes in servo behavior and disturbance rejection.展开更多
We propose a medium access control(MAC) protocol for uplink transmissions in wireless local area networks(WLANs),where both stations and access points(APs) are equipped with multiple antennas. The protocol solves some...We propose a medium access control(MAC) protocol for uplink transmissions in wireless local area networks(WLANs),where both stations and access points(APs) are equipped with multiple antennas. The protocol solves some common problems in utilizing multiple input multiple output(MIMO) under the 802.11 protocol,e.g.,how to deploy preamble(training sequence) used for channel estimation and how to enable simultaneous data transmissions,and facilitates two simultaneous uplink data transmissions via a cross-layer approach. Furthermore,we develop a 3D discrete-time Markov model to analyze the per-formance of the proposed WLAN scheme. The analytical results are verified by simulation,and numerical results show that the system throughput can be significantly improved by our proposed scheme as compared with conventional schemes.展开更多
基金Supported by the National Natural Science Foundation of China（60574047） the National High Technology Research and Development Program of China（2007AA04Z168 2009AA04Z154） the Research Fund for the Doctoral Program of Higher Education in China（20050335018）
文摘In this paper,a multi-loop internal model control(IMC) scheme in conjunction with feed-forward strategy based on the dynamic partial least squares(DyPLS) framework is proposed.Unlike the traditional methods to decouple multi-input multi-output(MIMO) systems,the DyPLS framework automatically decomposes the MIMO process into a multi-loop system in the PLS subspace in the modeling stage.The dynamic filters with identical structure are used to build the dynamic PLS model,which retains the orthogonality among the latent variables.To address the model mismatch problem,an off-line least squares method is applied to obtain a set of optimal filter parameters in each latent space.Without losing the merits of model-based control,a simple and easy-tuned IMC structure is readily carried over to the dynamic PLS control framework.In addition,by projecting the measurable disturbance into the latent subspace,a multi-loop feed-forward control is yielded to achieve better performance for disturbance rejection.Simulation results of a distillation column are used to further demonstrate this new strategy outperforms conventional control schemes in servo behavior and disturbance rejection.
基金supported by the National Natural Science Foundation of China (No. 60832008)the Research Grants Council Joint Research Scheme National Natural Science Foundation of China (No. 60731160013)
文摘We propose a medium access control(MAC) protocol for uplink transmissions in wireless local area networks(WLANs),where both stations and access points(APs) are equipped with multiple antennas. The protocol solves some common problems in utilizing multiple input multiple output(MIMO) under the 802.11 protocol,e.g.,how to deploy preamble(training sequence) used for channel estimation and how to enable simultaneous data transmissions,and facilitates two simultaneous uplink data transmissions via a cross-layer approach. Furthermore,we develop a 3D discrete-time Markov model to analyze the per-formance of the proposed WLAN scheme. The analytical results are verified by simulation,and numerical results show that the system throughput can be significantly improved by our proposed scheme as compared with conventional schemes.
