The technology deployed for lithium-ion battery state of charge(SOC)estimation is an important part of the design of electric vehicle battery management systems.Accurate SOC estimation can forestall excessive charging...The technology deployed for lithium-ion battery state of charge(SOC)estimation is an important part of the design of electric vehicle battery management systems.Accurate SOC estimation can forestall excessive charging and discharging of lithium-ion batteries,thereby improving discharge efficiency and extending cycle life.In this study,the key lithium-ion battery SOC estimation technologies are summarized.First,the research status of lithium-ion battery modeling is introduced.Second,the main technologies and difficulties in model parameter identification for lithium-ion batteries are discussed.Third,the development status and advantages and disadvantages of SOC estimation methods are summarized.Finally,the current research problems and prospects for development trends are summarized.展开更多
Magnetically steerable guidewires show significant advantages in vascular intervention surgery by enabling precise and minimally invasive navigation.Guidewires with embedded magnetic materials are widely studied.Howev...Magnetically steerable guidewires show significant advantages in vascular intervention surgery by enabling precise and minimally invasive navigation.Guidewires with embedded magnetic materials are widely studied.However,when an external magnetic field directly acts on the distal tip,it often experiences high acceleration,which leads to unpredictable motion and potential vessel injury.In contrast,coil-based magnetic guidewires allow precise adjustment of magnetic forces and torques through current,and immediate de-energization eliminates this risk.Nevertheless,single-coil designs provide limited deflection angles,which restrict their steering performance in complex vessels.To address these issues,this paper presents a dual-coil magnetic guidewire(DCMG)that achieves dual-attraction,dual-repulsion,and spoon-shaped modes under an external magnetic field.These three modes provide adaptable curvature control,that is,the dual-attraction/repulsion mode enhances bending range and axial force transmission,and the spoon-shaped mode facilitates compliant and safe navigation in tortuous vessels.Thermal characterization under static and flow conditions confirms safe operating temperatures under continuous energization.Furthermore,the deflection characteristics are experimentally measured under different current inputs.Steering performance is evaluated in a 90°glass channel under three actuation modes and validated through in vitro navigation experiments in a 3D heart aortic arch phantom.The results demonstrate that the DCMG achieves smooth curvature steering and controllable navigation,showing strong potential for future clinical application in vascular intervention surgeries.展开更多
Memristor is introduced as the fourth basic circuit element.Memristor exhibits great potential for numerous applications,such as emulating synapse,while the mathematical model of the memristor is still an open subject...Memristor is introduced as the fourth basic circuit element.Memristor exhibits great potential for numerous applications,such as emulating synapse,while the mathematical model of the memristor is still an open subject.In the linear-drift model,the boundary condition of the device is not considered.This paper proposes an extended linear-drift model of the memristor.The extended linear-drift model keeps the linear characteristic and simplicity of the linear-drift model and considers the boundary condition of the device.A piecewise linear approximation model of the extended linear-drift model is given.Both models are suitable for describing the memristor.展开更多
In order to recover a signal from its compressive measurements, the compressed sensing theory seeks the sparsest signal that agrees with the measurements, which is actually an l;norm minimization problem. In this pape...In order to recover a signal from its compressive measurements, the compressed sensing theory seeks the sparsest signal that agrees with the measurements, which is actually an l;norm minimization problem. In this paper, we equivalently transform the l;norm minimization into a concave continuous piecewise linear programming,and propose an optimization algorithm based on a modified interior point method. Numerical experiments demonstrate that our algorithm improves the sufficient number of measurements, relaxes the restrictions of the sensing matrix to some extent, and performs robustly in the noisy scenarios.展开更多
This paper works on a heuristic algorithm with determinacy for the global optimization of Continuous PieceWise Linear(CPWL) programming. The widely applied CPWL programming can be equivalently transformed into D.C. pr...This paper works on a heuristic algorithm with determinacy for the global optimization of Continuous PieceWise Linear(CPWL) programming. The widely applied CPWL programming can be equivalently transformed into D.C. programming and concave optimization over a polyhedron. Considering that the super-level sets of concave piecewise linear functions are polyhedra, we propose the Hill Tunneling via Weighted Simplex Centroid(HTWSC) algorithm, which can escape a local optimum to reach the other side of its contour surface by cutting across the super-level set. The searching path for hill tunneling is established via the weighted centroid of a constructed simplex. In the numerical experiments, different weighting methods are studied first, and the best is chosen for the proposed HTWSC algorithm. Then, the HTWSC algorithm is compared with the hill detouring method and the software CPLEX for the equivalent mixed integer programming, with results indicating its superior performance in terms of numerical efficiency and the global search capability.展开更多
This paper works on a modified simplex algorithm for the local optimization of Continuous Piece Wise Linear（CPWL） programming with generalization of hinging hyperplane objective and linear constraints. CPWL programm...This paper works on a modified simplex algorithm for the local optimization of Continuous Piece Wise Linear（CPWL） programming with generalization of hinging hyperplane objective and linear constraints. CPWL programming is popular since it can be equivalently transformed into difference of convex functions programming or concave optimization. Inspired by the concavity of the concave CPWL functions, we propose an Objective Variation Simplex Algorithm（OVSA）, which is able to find a local optimum in a reasonable time. Computational results are presented for further insights into the performance of the OVSA compared with two other algorithms on random test problems.展开更多
基金supported by research on value model and technology application of patent operation of science and technology project(52094020000U)National Natural Science Foundation of China(52177193).
文摘The technology deployed for lithium-ion battery state of charge(SOC)estimation is an important part of the design of electric vehicle battery management systems.Accurate SOC estimation can forestall excessive charging and discharging of lithium-ion batteries,thereby improving discharge efficiency and extending cycle life.In this study,the key lithium-ion battery SOC estimation technologies are summarized.First,the research status of lithium-ion battery modeling is introduced.Second,the main technologies and difficulties in model parameter identification for lithium-ion batteries are discussed.Third,the development status and advantages and disadvantages of SOC estimation methods are summarized.Finally,the current research problems and prospects for development trends are summarized.
基金supported in part by the National Natural Science Foundation of China(Grant 62473213)in part by the Sustainable Development Science and Technology Special Project of Shenzhen(Grant KCXFZ20230731100900002)+1 种基金in part by the Beijing Tianjin Hebei Basic Research Cooperation Special Project(Grant 24JCZXJC00060)in part by the Shenzhen Science and Technology Program(Grant KQTD20210811090143060).
文摘Magnetically steerable guidewires show significant advantages in vascular intervention surgery by enabling precise and minimally invasive navigation.Guidewires with embedded magnetic materials are widely studied.However,when an external magnetic field directly acts on the distal tip,it often experiences high acceleration,which leads to unpredictable motion and potential vessel injury.In contrast,coil-based magnetic guidewires allow precise adjustment of magnetic forces and torques through current,and immediate de-energization eliminates this risk.Nevertheless,single-coil designs provide limited deflection angles,which restrict their steering performance in complex vessels.To address these issues,this paper presents a dual-coil magnetic guidewire(DCMG)that achieves dual-attraction,dual-repulsion,and spoon-shaped modes under an external magnetic field.These three modes provide adaptable curvature control,that is,the dual-attraction/repulsion mode enhances bending range and axial force transmission,and the spoon-shaped mode facilitates compliant and safe navigation in tortuous vessels.Thermal characterization under static and flow conditions confirms safe operating temperatures under continuous energization.Furthermore,the deflection characteristics are experimentally measured under different current inputs.Steering performance is evaluated in a 90°glass channel under three actuation modes and validated through in vitro navigation experiments in a 3D heart aortic arch phantom.The results demonstrate that the DCMG achieves smooth curvature steering and controllable navigation,showing strong potential for future clinical application in vascular intervention surgeries.
基金supported by the National Natural Science Foundation of China(Nos.61074118 and 61134012)the National Key Basic Research and Development(973)Program of China(No.2012CB720505)
文摘Memristor is introduced as the fourth basic circuit element.Memristor exhibits great potential for numerous applications,such as emulating synapse,while the mathematical model of the memristor is still an open subject.In the linear-drift model,the boundary condition of the device is not considered.This paper proposes an extended linear-drift model of the memristor.The extended linear-drift model keeps the linear characteristic and simplicity of the linear-drift model and considers the boundary condition of the device.A piecewise linear approximation model of the extended linear-drift model is given.Both models are suitable for describing the memristor.
基金supported by the National Natural Science Foundation of China(Nos.61473165 and 61134012)the National Key Basic Research and Development(973)Program of China(No.2012CB720505)
文摘In order to recover a signal from its compressive measurements, the compressed sensing theory seeks the sparsest signal that agrees with the measurements, which is actually an l;norm minimization problem. In this paper, we equivalently transform the l;norm minimization into a concave continuous piecewise linear programming,and propose an optimization algorithm based on a modified interior point method. Numerical experiments demonstrate that our algorithm improves the sufficient number of measurements, relaxes the restrictions of the sensing matrix to some extent, and performs robustly in the noisy scenarios.
基金jointly supported by the National Key Basic Research and Development (973) Program of China (No. 2012CB720505)the National Natural Science Foundation of China (Nos. 61473165 and 61134012)
文摘This paper works on a heuristic algorithm with determinacy for the global optimization of Continuous PieceWise Linear(CPWL) programming. The widely applied CPWL programming can be equivalently transformed into D.C. programming and concave optimization over a polyhedron. Considering that the super-level sets of concave piecewise linear functions are polyhedra, we propose the Hill Tunneling via Weighted Simplex Centroid(HTWSC) algorithm, which can escape a local optimum to reach the other side of its contour surface by cutting across the super-level set. The searching path for hill tunneling is established via the weighted centroid of a constructed simplex. In the numerical experiments, different weighting methods are studied first, and the best is chosen for the proposed HTWSC algorithm. Then, the HTWSC algorithm is compared with the hill detouring method and the software CPLEX for the equivalent mixed integer programming, with results indicating its superior performance in terms of numerical efficiency and the global search capability.
基金supported by the National Natural Science Foundation of China (Nos. 61473165 and 61134012)the National Key Basic Research and Development (973) Program of China (No. 2012CB720505)
文摘This paper works on a modified simplex algorithm for the local optimization of Continuous Piece Wise Linear（CPWL） programming with generalization of hinging hyperplane objective and linear constraints. CPWL programming is popular since it can be equivalently transformed into difference of convex functions programming or concave optimization. Inspired by the concavity of the concave CPWL functions, we propose an Objective Variation Simplex Algorithm（OVSA）, which is able to find a local optimum in a reasonable time. Computational results are presented for further insights into the performance of the OVSA compared with two other algorithms on random test problems.
