An FPGA-Based Modified Adaptive PID Controller for DC/DC Buck Converters

Lv, Ling,Chang, Changyuan,Zhou, Zhiqi,Yuan, Yubo The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.2

On the basis of the conventional PID control algorithm, a modified adaptive PID (MA-PID) control algorithm is presented to improve the steady-state and dynamic performance of closed-loop systems. The proposed method has a straightforward structure without excessively increasing the complexity and cost. It can adaptively adjust the values of the control parameters ($K_p$, $K_i$ and $K_d$) by following a new control law. Simulation results show that the line transient response of the MA-PID is better than that of the adaptive digital PID because the differential coefficient $K_d$ is introduced to changes. In addition, experimental results based on a FPGA indicate that the MA-PID control algorithm reduces the recovery time by 62.5% in response to a 1V line transient, 50% in response to a 500mA load transient, and 23.6% in response to a steady-state deviation, when compared with the conventional PID control algorithm.

An FPGA-Based Modified Adaptive PID Controller for DC/DC Buck Converters

Ling Lv,Changyuan Chang,Zhiqi Zhou,Yubo Yuan 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.2

On the basis of the conventional PID control algorithm, a modified adaptive PID (MA-PID) control algorithm is presented to improve the steady-state and dynamic performance of closed-loop systems. The proposed method has a straightforward structure without excessively increasing the complexity and cost. It can adaptively adjust the values of the control parameters (Kp, Ki and Kd) by following a new control law. Simulation results show that the line transient response of the MA-PID is better than that of the adaptive digital PID because the differential coefficient Kd is introduced to changes. In addition, experimental results based on a FPGA indicate that the MA-PID control algorithm reduces the recovery time by 62.5% in response to a 1V line transient, 50% in response to a 500mA load transient, and 23.6% in response to a steady-state deviation, when compared with the conventional PID control algorithm.

Modeling and coupling characteristics for an airframe-propulsion-integrated hypersonic vehicle

Lv, Chengkun,Chang, Juntao,Dong, Yilei,Ma, Jicheng,Xu, Cheng Techno-Press 2020 Advances in aircraft and spacecraft science Vol.7 No.6

To address the problems caused by the strong coupling of an airbreathing hypersonic vehicle's airframe and propulsion to the integrated control system design, an integrated airframe-propulsion model is established, and the coupling characteristics between the aircraft and engine are analyzed. First, the airframe-propulsion integration model is established based on the typical nonlinear longitudinal dynamical model of an air-breathing hypersonic vehicle and the one-dimensional dual-mode scramjet model. Thrust, moment, angle of attack, altitude, and velocity are used as transfer variables between the aircraft model and the engine model. The one-dimensional scramjet model can accurately reflect the working state of the engine and provide data to support the coupling analysis. Second, owing to the static instability of the aircraft model, the linear quadratic regulator (LQR) controller of the aircraft is designed to ensure attitude stability and height tracking. Finally, the coupling relationship between the aircraft and the engine is revealed through simulation examples. The interaction between vehicle attitude and engine working condition is analyzed, and the influence of vehicle attitude on engine safety is considered. When the engine is in a critical working state, the attitude change of the aircraft will not affect the engine safety without considering coupling, whereas when coupling is considered, the attitude change of the aircraft may cause the engine unstart, which demonstrates the significance of considering coupling characteristics.

Investigation on the influence of number of blades on flow-induced noise optimization design of a centrifugal pump

Chang Guo,Feiran Lv,Ming Gao,Wei Wei,Shen Cheng 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10

Aiming at the quiet centrifugal pump design, the effect of number of blades on the flow-induced noise is explored. The results show that the sound pressure fluctuation is generated due to the influence of sound source fluctuation and adjacent spatial locations, and the fluctuation ranges of sound source and sound pressure at the same location change little with the change in the number of blades. Additionally, the total sound source intensity increases along the flow direction in the volute under the same rotational radius, while it increases slowly and even decreases near the outlet of the impeller, which causes similar evolution characteristics of noise. Besides, the volume-weighted standard deviation of sound source (V-STDSS) is proposed to characterize the overall sound intensity, and the V-STDSS proportion of impeller is more than 0.6. The impeller with an even number of blades has a better sound performance, while the noise induced by volute with an odd number of blades is lower. Generally, the centrifugal pumps with an even number of blades have a better sound performance. This research can guide the noise control and optimization design of centrifugal pumps.

Effects of American Ginseng Cultivation on Bacterial Community Structure and Responses of Soil Nutrients in Different Ecological Niches

( Fan Chang ),( Fengan Jia ),( Rui Lv ),( Min Guan ),( Qingan Jia ),( Yan Sun ),( Zhi Li ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.4

American ginseng (Panax quinquefolium L.) is a perennial herbaceous plant widely cultivated in China, Korea, the United States, and Japan due to its multifunctional properties. In northwest China, transplanting after 2-3 years has become the main mode of artificial cultivation of American ginseng. However, the effects of the cultivation process on the chemical properties of the soil and bacterial community remain poorly understood. Hence, in the present study, high-throughput sequencing and soil chemical analyses were applied to investigate the differences between bacterial communities and nutrition driver factors in the soil during the cultivation of American ginseng. The responses of soil nutrition in different ecological niches were also determined with the results indicating that the cultivation of American ginseng significantly increased the soluble nutrients in the soil. Moreover, the bacterial diversity fluctuated with cultivation years, and 4-year-old ginseng roots had low bacterial diversity and evenness. In the first two years of cultivation, the bacterial community was more sensitive to soil nutrition compared to the last two years. Proteobacteria, Actinobacteria, Gemmatimonadetes, Acidobacteria, Firmicutes, and Bacteroidetes dominated the bacterial community regardless of the cultivation year and ecological niche. With the increase of cultivation years, the assembly of bacterial communities changed from stochastic to deterministic processes. The high abundance of Sphingobium, Novosphingobium, and Rhizorhabdus enriched in 4-years-old ginseng roots was mainly associated with variations in the available potassium (AK), total phosphorus (TP), total potassium (TK), and organic matter (OM).

Expression analysis of HSP70 gene in response to environmental stress in Spodoptera frugiperda (Lepidoptera: Noctuidae)

Zhou Lv,Meng Jian-Yu,Ruan Hong-Yun,Zhang Chang-Yu 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.3

This study aimed to investigate the role of heat shock proteins in the response of Spodoptera frugiperda to environmental stress. Four Hsp70 genes of S. frugiperda were cloned using reverse transcription–polymerase chain reaction (RT-PCR) and their sequence characteristics were characterized using bioinformatics analysis. RTqPCR was used to detect Hsp70 at different developmental stages, in different tissues, and under varying environmental stresses (45 ◦ C, 36 ◦ C, 4 ◦ C, ultraviolet-A, and emamectin benzoate) to quantify the relative expression of this gene. Four Hsp70 genes were obtained by cloning, namely SfHsp70-1, SfHsp70-2, SfHsp70-3, and SfHsp70-like, which encode 653, 686, 638, and 627 amino acids, respectively, and all contain the three Hsp70 family signature sequences. Neighbor-joining (NJ) method was used to construct phylogenetic tree, and four Hsp70 of the S. frugiperda species were clustered with Lepidoptera. The results of real-time PCR showed that the SfHsp70s gene was specifically expressed in different tissues at different developmental stages and its expression increased considerably under nearly all environmental stresses in adults. This study shows that the SfHsp70 gene contributes to a large extent to the resistance of S. frugiperda to environmental stress.

Genome-wide identification of the ARRs gene family in tobacco (Nicotiana tabacum)

Jing Lv,Chang-bo Dai,Wei-feng Wang,Yu-he Sun 한국유전학회 2021 Genes & Genomics Vol.43 No.6

Background The growth of axillary buds determines the shoot branching and morphology of plants, and its initiation and development are regulated by a series of hormonal signals, such as cytokinin. Arabidopsis response regulators (ARRs) can regulate the growth and development, disease resistance and stress resistance of plants by participating in cytokinin signaling. Objective To explore the distribution and expression pattern of ARR members in tobacco. Methods The identifcation, isoelectric points, molecular weights, protein subcellular localization prediction, multiple sequence alignment, phylogenetic analysis, protein motifs and structures, chromosome distributions of deduced ARR proteins were conducted. The gene expression profling of various tissues in response to topping, low temperature and drought were analyzed by RNA-seq and qRT-PCR. Results 59 ARR genes from cultivated tobacco (Nicotiana tabacum) were identifed, namely NtARRs, including 21 type A NtARRs and 38 type B NtARRs. The 59 NtARRs were expressed mainly in all organs except the fruits. Some representative NtARRs may participate in axillary bud initiation and development, as well as in stress resistance through cytokinin signal transduction. Conclusion Understanding the roles of NtARRs in the molecular mechanisms responsible for axillary bud growth and stress tolerance could aid in targeted breeding in crops.

Integrated control of an air-breathing hypersonic vehicle considering the safety of propulsion system

Chengkun, Lv,Juntao, Chang,Lei, Dai Techno-Press 2023 Advances in aircraft and spacecraft science Vol.10 No.1

This paper investigates the integrated control of an air-breathing hypersonic vehicle considering the safety of propulsion system under acceleration. First, the vehicle/engine coupling model that contains a control-oriented vehicle model and a quasi-one-dimensional dual-mode scramjet model is established. Next, the coupling process of the integrated control system is introduced in detail. Based on the coupling model, the integrated control framework is studied and an integrated control system including acceleration command generator, vehicle attitude control loop and engine multivariable control loop is discussed. Then, the effectiveness and superiority of the integrated control system are verified through the comparison of normal case and limiting case of an air-breathing hypersonic scramjet coupling model. Finally, the main results show that under normal acceleration case and limiting acceleration case, the integrated control system can track the altitude and speed of the vehicle extremely well and adjust the angle deflection of elevator to offset the thrust moment to maintain the attitude stability of the vehicle, while assigning the two-stage fuel equivalent ratio to meet the thrust performance and safety margin of the engine. Meanwhile, the high-acceleration requirement of the air-breathing hypersonic vehicle makes the propulsion system operating closer to the extreme dangerous conditions. The above contents demonstrate that considering the propulsion system safety will make integrated control system more real and meaningful.

Effectiveness of a home-based exercise program among patients with lower limb spasticity post-stroke: A randomized controlled trial

Chen Shaomin,Chang Lv,Wu Jiaozhen,Chengwei Zhou,Xiaolong Shui,Yi Wang 한국간호과학회 2021 Asian Nursing Research Vol.15 No.1

Purpose: To evaluate the effectiveness of advanced practice nurseeguided home-based rehabilitation exercise program (HREPro) among patients with lower limb spasticity post-stroke. Methods: This randomized controlled study recruited 121 patients with lower limb spasticity poststroke. Intervention (n = 59) and control (n = 62) groups underwent 12-month HREPro and conventional rehabilitation, respectively, after discharge. The FugleMeyer assessment of spasticity measurement, modified Ashworth scale of motor function, 10-Meter Walk Test of walking ability, and Barthel index of activities of daily living (ADL) were evaluated at 0, 3, 6, and 12 months after discharge. Results: Significant differences were found in spasticity degree, motor function, walking ability, and ADL at 6 and 12 months after discharge between the control and intervention groups. Lower limb spasticity and ADL in the intervention group were significantly improved. Conclusion: HREPro is effective for rehabilitation of patients with lower limb spasticity post-stroke and has favorable home application.

Susceptibility of Lung Cancer with Polymorphisms of CYP1A1, GSTM1, GSTM3, GSTT1 and GSTP1 Genotypes in the Population of Inner Mongolia Region

Jiang, Xue-Yan,Chang, Fu-Hou,Bai, Tu-Ya,Lv, Xiao-Li,Wang, Min-Jie,Wang, Guang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Background: To study the relationship of susceptibility to lung cancer with the gene polymorphisms of CYP1A1, GSTM1, GSTM3, GSTT1, GSTP1 and smoking status in Han and Mongolian populations of Inner Mongolia, an autonomous region of China. Materials and Methods: PCR-RFLP, allele-specific and multiplex PCR were employed to identify the genotypes of CYP1A1, GSTM1, GSTM3, GSTT1 and GSTP1 in a case-control study of 322 lung cancer patients diagnosed by bronchoscopy and 456 controls free of malignancy. Results: There is a significant difference in genotypic frequency of GSTT1 of healthy Mongolian and Han subjects. A statistically prominent association was found between CYP1A1 Msp1 (vt/vt) (OR=4.055, 95%CI:2.107-7.578, p=0.000), GSTM1 (-) (OR=2.290, 95%CI:1.467-3.573, p=0.000) and lung cancer in Mongolians. Similarly, in the Han population, CYP1A1 Msp1 (vt/vt) (OR=3.194, 95%CI:1.893-5.390, p=0.000) and GSTM1 (-) (OR=1.884, 95%CI:1.284-2.762, p=0.001) carriers also had an elevated risk of lung cancer. The smokers were more susceptible to lung cancer 2.144 fold and 1.631 fold than non-smokers in Mongolian and Han populations, respectively. The smokers who carried with CYP1A1 Msp1 (wt/vt+vt/vt), exon7 (Val/Val+Ile /Val), GSTM1 (-), GSTM3 (AB+BB), and GSTT1 (-) respectively were found all to have a high risk of lung cancer. Conclusions: CYP1A1 Msp1 (vt/vt) and GSTM1 (-) are risk factors of lung cancer in Han and Mongolian population in the Inner Mongolia region. The smokers with CYP1A1 Msp1 (wt/vt+vt/vt), CYP1A1 exon7 (Val/Val+Ile /Val), GSTM1 (-), GSTM3 (AB+BB), and GSTT1 (-) genotypes, respectively, are at elevated risk of lung cancer.