State Estimation Moving Window Gradient Iterative Algorithm for Bilinear Systems Using the Continuous Mixed p-norm Technique

This paper studies the parameter estimation problems of the nonlinear systems described by the bilinear state space models in the presence of disturbances.A bilinear state observer is designed for deriving identification algorithms to estimate the state variables using the input-output data.Based on the bilinear state observer,a novel gradient iterative algorithm is derived for estimating the parameters of the bilinear systems by means of the continuous mixed p-norm cost function.The gain at each iterative step adapts to the data quality so that the algorithm has good robustness to the noise disturbance.Furthermore,to improve the performance of the proposed algorithm,a dynamicmoving window is designed which can update the dynamical data by removing the oldest data and adding the newestmeasurement data.A numerical example of identification of bilinear systems is presented to validate the theoretical analysis.

Additive manufacturing of prototype elements with process interfaces for continuously operating manufacturing lines

Rapid prototyping based on in silico design and 3D printing enables fast customization of complex geometries to multiple needs. This study utilizes, additive manufacturing for rapid prototyping of elements for continuously operating mixing geometries including interfaces with process analytical technology(PAT) tools, to show that 3D printing can be used for prototyping of both parts of production line and PAT interfacing solution. An additional setup was designed for measuring the dynamic calibration samples for a semi-quantitative near infrared(NIR) spectroscopic model. The powder was filled in a small calibration chamber and in-line NIR spectra of calibration samples were collected from moving material while mimicking the powder flow dynamics in a typical continuous mixer. This dynamic powder mixing system was compared with a static powder calibration model where the NIR probe was placed at different positions on a static sample. Principal component analysis(PCA) revealed that the 3D printed device with dynamic measurement of the NIR spectra had more potential for quantitative analysis. With the prototype continuous mixer, two differently placed process interfaces for NIR spectroscopic monitoring of the powder mixing were evaluated. With this approach, the importance of positioning the process analytical tools to assess the blend uniformity could be demonstrated. It was also observed that with the longer mixing geometry, a better mixing result was achieved due to a larger hold up volume and increased residence time.

A robust subband adaptive filter algorithm for sparse and block-sparse systems identification

This paper presents a new subband adaptive filter(SAF)algorithm for system identification scenario under impulsive interference,named generalized continuous mixed p-norm SAF(GCMPN-SAF)algorithm.The proposed algorithm uses a GCMPN cost function to combat the impul-sive interference.To further accelerate the convergence rate in the sparse and the block-sparse system identification processes,the proportionate versions of the proposed algorithm,the L0-norm GCMPN-SAF(L0-GCMPN-SAF)and the block-sparse GCMPN-SAF(BSGCMPN-SAF)algorithms are also developed.Moreover,the convergence analysis of the proposed algorithm is provided.Simulation results show that the proposed algorithms have a better performance than some other state-of-the-art algorithms in the literature with respect to the convergence rate and the tracking capability.

燃气管网的混合整数规划建模及其等价连续化

燃气网络优化问题涉及到如何低成本的使用压缩机,同时满足燃气网络的所有约束.此问题一般情况下被建模为一个混合整数非线性优化问题.基于网络约简和分段线性近似的技术,得到一个混合整数线性优化问题.由于模型中整数变量的存在导致问题难以求解,因此通过连续化方法将表示压缩机开关的0-1变量通过一个非线性等式约束表示为[0,1]区间上的连续变量,并证明了问题的等价.将该方法应用于具有循环网络拓扑结构的中国西部天然气管网系统特例,数值结果显示相较于使用上述方法之前,该管网的燃气消耗量减少了133.85 m^(3)/d.

Microwave photonic notch filter with complex coefficient based on four wave mixing

A microwave photonic notch filter with a complex coefficient is proposed and demonstrated based on four wave mixing(FWM). FWM effect of two single-frequency laser beams occurs in a highly nonlinear fiber(HNLF), and multi-wavelength optical signals are generated and used to generate the multi-tap of microwave photonic filter(MPF). The complex coefficient is generated by using a Fourier-domain optical processor(FD-OP) to control the amplitude and phase of the optical carrier and phase modulation sidebands. The results show that this filter can be changed from bandpass filter to notch filter by controlling the FD-OP. The center frequency of the notch filter can be continuously tuned from 5.853 GHz to 29.311 GHz with free spectral range(FSR) of 11.729 GHz. The shape of the frequency response keeps unchanged when the phase is tuned.