Robust sensorless FCS-PCC control for inverter-based induction machine systems with high-order disturbance compensation

Wang, Junxiao,Wang, Fengxiang The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.5

Due to its theoretically fast dynamic response with unlimited bandwidth for direct switch-driven-based induction machines, the finite control set predictive current control (FCS-PCC) method has been verified to be an effective solution in recent years. However, dynamic limitations of the outer speed PI controller exist, especially with high-order time-varying disturbances. In addition, hardware cost can be reduced. Using the universal proportional integral observer (UPIO) method, a robust deadbeat-like encoderless-based FCS-PCC control scheme is investigated for induction machine systems in this paper. The encoder is avoided using the proposed sensorless method. In addition, the system response and disturbance attenuation are enhanced in presence of time-varying unknown load torque and uncertainties. The squared norm is adopted for the cost function design to ensure system stability. Experimental results illustrate that it has good performance such as fast dynamics, good low-speed steady-state accuracy, and robustness.

Robust Time Delay Compensation for DTC-Based Induction Machine Systems via Extended State Observers

Wang, Fengxiang,Wang, Junxiao,Yu, Li The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

This paper presents an extended state observer (ESO) based direct torque control (DTC) for use in induction motor systems to handle the issues of time delays, load torque disturbances and parameter uncertainties. Direct torque control offers an excellent torque response and it does not require a proportion integration (PI) controller in the current loop. However, a PI controller is still adopted in the outer speed loop to generate the torque reference value, which is a slow method. An ESO based compound control scheme is proposed to improve the response rate and accuracy of the torque reference signal, especially when load torque is injected. In addition, the time delay problem is analyzed and compensated for in this paper to reduce torque ripples. The proposed disturbance compensation technique based direct control scheme is shown to have good performance both in the transient and stable states via simulations and experimental results.

Reduced-order Generalized Proportional Integral Observer Based Continuous Dynamic Sliding Mode Control for Magnetic Levitation System with Time-varying Disturbances

Junxiao Wang,Lei Zhao,Li Yu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.1

In order to reduce the influence of time-varying disturbances for magnetic levitation system, we propose areduced-order generalized proportional integral observer (RGPIO) based continuous dynamic sliding mode controlscheme for magnetic levitation system in this paper. Unlike the popular extended state observer (ESO), it coulddeal with constant or slowing varying disturbances from theoretical point of view, the reduced-order generalizedproportional integral observer (RGPIO) is designed to estimate the time-varying disturbances and system states,then the dynamic sliding mode surface is developed and deduce a continuous sliding mode controller (CSMC) formagnetic levitation system. Compared with ESO based continuous sliding mode controller, the proposed method notonly ensures the position tracking accuracy, but also obtain better time-varying disturbance reject ability. Simulationand experimental results are also given to verify the effectiveness.

Cellular uptake mechanism and comparative in vitro cytotoxicity studies of monomeric LMWP-siRNA conjugate

Junxiao Ye,Xing Pei,Hui Cui,Zhili Yu,이혁진,Jian-Xin Wang,Xu Wang,Lu Sun,Huining He,Victor C. Yang 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.63 No.-

The covalent attachment of CPPs to siRNA molecules offers great potential for CPP-mediated siRNA delivery. We recently reported a concise and high-yield synthesis strategy of the cell-permeable, cytosol-dissociable LMWP-siRNA covalent conjugate. Herein, cell uptake mechanism and cellular toxicity studies of this conjugate were performed to evaluate the potential of LMWP-siRNA conjugate for clinical translation. Cellular uptake mechanism study indicated that the conjugate could be taken up by cells via multiple pathways, including direct penetration of the plasma membrane and clathrin- and caveolae-independent endocytosis. In vitro cytotoxicity study revealed that the conjugation promoted internalization in a low-toxic fashion.

Cellular uptake mechanism and comparative <i>in vitro</i> cytotoxicity studies of monomeric LMWP-siRNA conjugate

Ye, Junxiao,Pei, Xing,Cui, Hui,Yu, Zhili,Lee, Hyukjin,Wang, Jianxin,Wang, Xu,Sun, Lu,He, Huining,Yang, Victor C. THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.63 No.-

<P><B>Abstract</B></P> <P>The covalent attachment of CPPs to siRNA molecules offers great potential for CPP-mediated siRNA delivery. We recently reported a concise and high-yield synthesis strategy of the cell-permeable, cytosol-dissociable LMWP-siRNA covalent conjugate. Herein, cell uptake mechanism and cellular toxicity studies of this conjugate were performed to evaluate the potential of LMWP-siRNA conjugate for clinical translation. Cellular uptake mechanism study indicated that the conjugate could be taken up by cells via multiple pathways, including direct penetration of the plasma membrane and clathrin- and caveolae-independent endocytosis. <I>In vitro</I> cytotoxicity study revealed that the conjugation promoted internalization in a low-toxic fashion.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Robust Time Delay Compensation for DTC-Based Induction Machine Systems via Extended State Observers

Fengxiang Wang,Junxiao Wang,Li Yu 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

This paper presents an extended state observer (ESO) based direct torque control (DTC) for use in induction motor systems to handle the issues of time delays, load torque disturbances and parameter uncertainties. Direct torque control offers an excellent torque response and it does not require a proportion integration (PI) controller in the current loop. However, a PI controller is still adopted in the outer speed loop to generate the torque reference value, which is a slow method. An ESO based compound control scheme is proposed to improve the response rate and accuracy of the torque reference signal, especially when load torque is injected. In addition, the time delay problem is analyzed and compensated for in this paper to reduce torque ripples. The proposed disturbance compensation technique based direct control scheme is shown to have good performance both in the transient and stable states via simulations and experimental results.

Comparison of Clinical and Radiographic Outcomes Between Transforaminal Endoscopic Lumbar Discectomy and Microdiscectomy: A Follow-up Exceeding 5 Years

Xinyu Yang,Shijun Zhang,Junxiao Su,Sai Guo,Yakubu Ibrahim,Kai Zhang,Yonghao Tian,Lianlei Wang,Suomao Yuan,Xinyu Liu 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio. Conclusion: Both TELD and MD provide generally satisfactory long-term clinical outcomes for patients with LDH. TELD can be used as a reliable alternative to MD with less surgical trauma. Modic type II changes, decreased preoperative intervertebral height, and a high body mass index are predictors of a poor prognosis. Objective: To compare the long-term clinical and radiographic outcomes of transforaminal endoscopic lumbar discectomy (TELD) versus microdiscectomy (MD). Methods: The data of 154 patients with lumbar disc herniation (LDH) who underwent TELD (n = 89) or MD (n = 65) were retrospectively analyzed. The patients’ clinical outcomes were evaluated using visual analogue scales for leg and low back pain, the Japanese Orthopaedic Association (JOA) score, and the Oswestry Disability Index (ODI). The evolution of radiographic manifestations was observed during follow-up. Potential risk factors for a poor clinical outcome were investigated. Results: During a mean follow-up of 5.5 years (range, 5–7 years), the recurrence rate was 4.49% in the TELD group and 1.54% in the MD group. All scores significantly improved from preoperatively to postoperatively in both groups (p < 0.01). The improvement in the ODI and JOA scores was significantly greater in the TELD than MD group (p < 0.05). Forty-seven patients (52.8%) in the TELD group and 32 (49.2%) in the MD group had Modic changes before surgery, most of which showed no changes at the last follow-up. The degeneration grades of 292 discs (71.0%) were unchanged at the last follow-up, while 86 (20.9%) showed improvement, mostly at the upper adjacent segment. No significant difference was observed in the intervertebral height index or paraspinal muscle-disc ratio.

MiR-34a, miR-21 and miR-23a as potential biomarkers for coronary artery disease: a pilot microarray study and confirmation in a 32 patient cohort

Hui Han,Chenghua Han,Yu-Hong Wang,Ting-Ting Sun,Feng-Qing Li,Junxiao Wang,Shan-Shun Luo,Guang-Jin Qu 생화학분자생물학회 2015 Experimental and molecular medicine Vol.47 No.-

The aim of this study was to investigate the expression of circulating microRNAs (miRNAs) in apolipoprotein E (apoE) knockout mice (apoE− / −) and to validate the role of these miRNAs in human coronary artery disease (CAD). Pooled plasma from10 apoE− / − mice and 10 healthy C57BL/6 (B6) mice was used to perform the microarray analysis. The results showed that miR-34a, miR-21, miR-23a, miR-30a and miR-106b were differentially expressed in apoE− / − mice, and these expression changes were confirmed by real-time quantitative reverse-transcription PCR. Then, miR-34a, miR-21, miR-23a, miR-30a and miR-106b were detected in the plasma of 32 patients with CAD and of 20 healthy controls. Only miR-34a, miR-21 and miR-23a were significantly differentially expressed in the plasma of CAD patients (all Po0.01). In conclusion, miR-34a, miR-21 and miR-23a were elevated in CAD patients, which means that these miRNAs might serve as biomarkers of CAD development and progression.