When multiple targets are within the same radar antenna beam and cannot be separated in the range dimension, the conventional imaging methods cannot be directly used to obtain a focused radar image. In this study, a n...
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When multiple targets are within the same radar antenna beam and cannot be separated in the range dimension, the conventional imaging methods cannot be directly used to obtain a focused radar image. In this study, a new joint estimation algorithm for multi-targets' motion parameters is proposed. In this method, the first-order Keystone transform is first applied to correct the range walk of multiple targets simultaneously, and then the Lv's transform is used to estimate the motion parameters of targets including velocity and acceleration. The signal-to-noise ratio threshold for the proposed method is also given. The proposed method is fast and can obtain the accurate parameter estimation without knowing the number of targets and their motion information. Experimental results demonstrate the performance of the proposed algorithm. Comparisons between the proposed method and other methods, the maximum-likelihood method, fractional Fourier transform and discrete polynomial transform, are performed, which show that the proposed method can efficiently obtain the accurate parameter estimation with low computational burden.
Lithium-ion batteries play a pivotal role in diverse applications, necessitating the precise estimation of their parameters for safe and efficient energy utilization. In the context of ternary lithium-ion battery rese...
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Lithium-ion batteries play a pivotal role in diverse applications, necessitating the precise estimation of their parameters for safe and efficient energy utilization. In the context of ternary lithium-ion battery research, this study introduces the cosine control whale optimization (CCWO) method to real-time optimization of the forgetting factor. Concurrently, an innovative multi-scale error feedforward extended double Kalman filter (EFDKF) algorithm, featuring model error feedforward, is presented for dynamic optimization of the state noise covariance matrix. This approach diminishes reliance on the model while jointly estimating the state of charge (SOC) and state of health (SOH). The algorithm's feasibility is validated under varied operational conditions, encompassing both normal and low temperatures. The maximum absolute errors of SOC and SOH estimation are 1.09% and 3.16% at normal temperature, and 3.46% and 4.96% at low temperature, respectively. The results affirm the algorithm's enhanced precision in joint SOC and SOH estimation, heightened robustness, and superior convergence. This contribution introduces a novel methodology for lithium-ion battery state estimation.
Having a proper and real-time process monitoring and control requires accurate and frequent measurement of process variables. However, using a particular sensor for an important variable has high cost and low precisio...
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Having a proper and real-time process monitoring and control requires accurate and frequent measurement of process variables. However, using a particular sensor for an important variable has high cost and low precision limitations. In such cases, laboratory analyses are an excellent choice for their high precision, but as their measurements are obtained manually and infrequently, they are not practical for every application in industries. This study presents an advanced soft sensor for a highly non-linear continuous stirred-tank reactor (CSTR) system which is observed with multiple sensors with different sampling rates under the assumption that there are different kinds of non-idealities in data acquisition for sensors. Some rules are assigned in order to vanquish these non-idealities in joint estimation algorithm. Therefore, the problem of simultaneous state and parameter estimation based on data fusion technique and unscented Kalman filter (UKF) is presented, and the effectiveness of the proposed method is investigated. Moreover, the proposed method is such that the effects of the inaccurate sensor on the parameter estimation are reduced. Simulation results on the estimation of four states and two parameters in a typical CSTR process show the proficiency of the proposed approach.
To apply polarisation information of radar signal in radar reconnaissance equipment, a joint estimation algorithm of the radar signal direction of arrival (DOA) and polarisation parameters based on dual-polarisation a...
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To apply polarisation information of radar signal in radar reconnaissance equipment, a joint estimation algorithm of the radar signal direction of arrival (DOA) and polarisation parameters based on dual-polarisation antenna array has been researched in this study. The mathematical model of dual-polarised circular array has been given, and the jointestimation method of DOA and polarisation parameters for radar signal based on multiple signal classification (MUSIC) algorithm has been analysed. To overcome the shortcomings such as high calculation cost for the MUSIC algorithm, the DOA-matrix algorithm has been presented. DOA-matrix algorithm can effectively distinguish the radar signals with different polarisation states in the same direction by use of eigen-decomposition of the DOA-matrix. Through matrix correlation calculation, spectral peak search has been avoided, and the computational cost and algorithm complexity are greatly reduced. Finally, the feasibility of the DOA-matrix algorithm has been simulated and analysed. The simulation results show that the DOA-matrix algorithm can effectively complete the jointestimation of DOA and polarisation parameters for radar signal. The running time reaches millisecond level, which has a strong application value in engineering.
The problem of CDMA multiuser detection in the presence of a small residual carrier offset is considered, with subspace-based approaches being employed for channel estimation and signal demodulation. The channel respo...
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The problem of CDMA multiuser detection in the presence of a small residual carrier offset is considered, with subspace-based approaches being employed for channel estimation and signal demodulation. The channel response and the carrier offset are estimated separately to avoid the complicated computation in the jointestimation of two parameters. The simulation results show that the separate estimation approach results in lower BER than does a previous subspace-based joint estimation algorithm for a large range of carrier offsets that are generally considered in practical applications. Adaptive channel estimation in a time-variant channel is also considered. A novel adaptive algorithm for subspace estimation, namely the NOOja algorithm, is used to track the channel variations. The NOOja algorithm offers a set of advantages as compared to similar algorithms in the literature;in particular, it can be used for both signal and noise subspace estimation and has a very low computational complexity as compared to the batch eigendecomposition techniques.
The classical ambiguity function (AF) in radar signal processing often has a low and fixed resolution in the presence of adjacent multi-targets. The frequency-domain exponential ambiguity function (FEAF) was previousl...
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The classical ambiguity function (AF) in radar signal processing often has a low and fixed resolution in the presence of adjacent multi-targets. The frequency-domain exponential ambiguity function (FEAF) was previously presented with a variable exponent p introduced in the frequency-domain expression of the AF whose range resolution and output signal-to-noise ratio can be mutually replaced by controlling the exponent p. However, the FEAF mainly improves the range resolution of reference signals, but it cannot improve its velocity resolution. In this study, on the basis of symmetry theory in the time and frequency domains, a time-domain exponential ambiguity function (TEAF) was defined by indexing the time-domain expression of AF. The time-frequency properties of the defined TEAF are similar and symmetric to those of the FEAF. On the basis of the combination of the FEAF and TEAF with multi-exponents and a modified CLEAN algorithm for stepwise elimination and estimation of targets, the authors proposed a new joint estimation algorithm for delays and Doppler shifts of multi-targets. Simulation experiments indicated that the proposed estimationalgorithm achieves higher accuracies in delay and Doppler shift estimation in comparison with the traditional AF-based estimationalgorithm and the FEAF-based estimationalgorithm.
In order to solve the problems of high complexity and absence of adaptability with the jointestimation for time delay (TD) and angle of arrival (AOA) in coherent multipath environments, a fast estimationalgorithm ba...
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In order to solve the problems of high complexity and absence of adaptability with the jointestimation for time delay (TD) and angle of arrival (AOA) in coherent multipath environments, a fast estimationalgorithm based on orthogonal frequency division multiplexing (OFDM) technique is proposed. First, we combine OFDM signal characteristics with array features to obtain extended arrays. Then, we obtain the channel frequency domain response covariance matrices for TD and AOA estimation separately by smoothing preprocessing in the spatial and frequency domains, respectively. Finally, we estimate the TD values by a one-dimensional (1-D) spectral peak search, as well as determine the closed-form solution for AOA by Unitary-ESPRIT. In comparison with previous work, the proposed algorithm not only improves the adaptability in correlated or mixed multipath environments but also significantly reduces the complexity. The simulation results show the effectiveness and robustness of the proposed joint estimation algorithm.
Lithium ion batteries are popularly used in various energy storage systems. Accurate battery's State of Charge (SoC) and State of Health (SoH) estimate is essential for energy storage system's safety. This man...
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