An Improved Method of Control Law Design at High Angle of Attack Based on Wind Tunnel Test Data

Yongxi Lyu,Yuyan Cao,Weiguo Zhang,Jingping Shi,Xiaobo Qu 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

This paper presents an improved dynamic inversion (DI) based method, which is further successfully applied to the high angle of attack flight control of the aircraft under the influence of unsteady aerodynamics. On the basis of large oscillation wind tunnel test data, the accurate unsteady aerodynamic model is established by the sequential minimal optimization - support vector regression (SMO-SVR) method. The nonlinear longitudinal aircraft model is created by considering engine model, atmospheric model, actuator model, and so on. In order to solve the problem of large control error and control delay caused by the unsteady aerodynamics, the improved DI method is proposed. The integral is added in the pitch angle rate control, and the control law of angle of attack is designed combining lag correction. The daisy chain allocation method is utilized to obtain the deflections of the control surfaces and the engine vector nozzle. Numerical simulation of Cobra maneuver is employed to demonstrate the advantages and potential practical application of the proposed improved control law design method.

The Effects of Fiber Source on Organ Weight, Digesta pH, Specific Activities of Digestive Enzymes and Bacterial Activity in the Gastrointestinal Tract of Piglets

Ma, Yongxi,Li, Defa,Qiao, S.Y.,Huang, C.H.,Han, In K. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.10

The aim of this study was to explore the effects of fiber sources on gut development and bacterial activity in the gastrointestinal tract of piglets. Eighteen crossbred (Duroc${\times}$Landrace${\times}$Yorkshire) barrows were fed a basal diet based on corn plus soybean meal or similar diets in which a portion of the corn and soybean was replaced by 5% wheat bran or 5% sugar beet pulp. The results indicate that pigs fed diets containing 5% wheat bran or 5% sugar beet pulp had lower liver weights than control pigs (p<0.01). The relative weight of the pancreas in pigs fed diets containing 5% sugar beet pulp was greater than that of control pigs or pigs fed diets containing 5% wheat bran (p<0.05). The pH of the ileal digesta of pigs fed the diet containing 5% wheat bran was higher than that of control pigs or pigs fed the diet containing 5% sugar beet pulp (p<0.05). The lipase activity in the distal jejunum, proximal, and distal ileum of pigs fed the control diet was higher than that of pigs fed the diets containing 5% wheat bran or 5% sugar beet pulp (p<0.05). The concentration of volatile fatty acids anterior to the caecum was greater for the pigs fed the diet containing 5% sugar beet pulp, while the concentration of volatile fatty acids posterior to the ileum was greater for the pigs fed the diet containing 5% wheat bran. This means that sugar beet pulp increased the bacterial fermentation precaecum, while wheat bran increased the bacterial fermentation post-ileum. The concentration of bacterial nitrogen and bacterial protein/total protein in ileal digesta of pigs fed the control diet was higher (p<0.05) than that of pigs fed the diets contained either fiber source. Bacterial protein/total protein in the feces of pigs fed the diet containing 5% sugar beet pulp was higher than that of pigs fed the control diet. This means that inclusion of 5% wheat bran or sugar beet pulp in diets influenced the development of the digestive tract of piglet. The mechanism by which dietary fiber reduced specific activity of lipase needs further consideration. Dietary fiber influenced the bacterial activity in the digestive tract of piglets, sugar beet pulp increased the fermentation in the upper gastrointestinal tract, and while wheat bran increased the fermentation in the lower gastrointestinal tract.

Schisandrin A ameliorates MPTP‑induced Parkinson’s disease in a mouse model via regulation of brain autophagy

Yinghao Zhi,Yongxi Jin,Lulu Pan,Aiguo Zhang 대한약학회 2019 Archives of Pharmacal Research Vol.42 No.11

Schisandrin A (Sch A) is one of the principalbioactive lignans isolated from Fructus schisandrae. In thisstudy, we demonstrated its protective effect and biochemicalmechanism of action in a 1-methyl-4-phenyl-1, 2, 3,6-tetrahydropyridine-induced mouse model of Parkinson’sdisease. Sch A significantly ameliorated behavioural abnormalitiesand increased the number of nigral dopaminergicneurons detected by tyrosine hydroxylase immunohistochemistry. Pre-treatment with Sch A significantly decreasedthe levels of the inflammatory mediators IL-6, IL-1β, andTNF-α and markedly improved antioxidant defences byinhibiting the activity of MDA and increasing that of SOD. Furthermore, Sch A activated expression of the autophagyrelatedproteins LC3-II, beclin1, parkin, and PINK1 andincreased mTOR expression. Taken together, these findingsindicate that Sch A has neuroprotective effects against thedevelopment of Parkinson’s disease via regulation of brainautophagy.

A Coordinated Control Method of Thrust Vector and Aerodynamic Surfaces Based on Control Allocation Technology

Shi Jingping,Lv Yongxi,Qu Xiaobo,Shi Jing 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

As one of the most important technologies of the advanced fighter, thrust vector technology can greatly increase the range of controlled angle of attack, and make the fighter easily realize the post stall maneuver. However currently thrust vector technology is achieved by manually manipulating the additional vector stick, which greatly increases the burden on pilots. Thus how to bring the thrust vector control into the automatic control system to reduce the pilot operation burden has become an important engineering problem to be solved. A dynamic inverse design method based on daisy chain allocation method is proposed, which integrates the thrust vector into the automatic control system, thus eliminating the thrust vector manipulating mechanism and reducing the pilot`s operating burden. In addition, the method maximizes the use of the control surface and reduces the use time of the thrust vector, thus effectively reducing the maintenance cost of the engine. The simulation results of vector cylinder maneuver shows that this method can effectively achieve the coordinated control of thrust vector.

Effects of vitamin K supplementation on reproductive performance and bone metabolism-related biochemical markers in lactation sows

Huakai Wang,Yu Zhang,Yongxi Ma Asian Australasian Association of Animal Productio 2023 Animal Bioscience Vol.36 No.10

Objective: This study was conducted to evaluate the effects of vitamin K (VK) supplementation on reproductive performance and bone metabolism-related biochemical markers in sows. Methods: Twenty-four Large White×Landrace sows (mean parity 4.04) were randomly assigned to two dietary treatments (NC diet, a basal diet with 0.5 mg/kg of VK₃; VK diet, a basal diet with 5 mg/kg of VK₃) with twelve replicates per treatment and one sow per replicate according to parity. The experiment started on day 107 of gestation and lasted until day 21 of lactation (weaning). Results: We observed that there were no differences (p>0.05) in average daily feed intake, backfat loss of sows, live piglet number at birth and weaning, average birth weight, average weaning weight, and average daily gain of piglets between two treatments. The apparent total tract digestibility of phosphorus was increased (p<0.05) in VK sows compared with NC sows. The serum bone alkaline phosphatase, osteocalcin, type I procollagen amino-terminal peptide, and type I procollagen carboxyl-terminal peptide on day of farrowing were higher (p<0.05) in VK sows than in NC sows. The serum phosphorus, parathyroid hormone, tartrate-resistant acid phosphatase, and tumor necrosis factor-alpha on day of weaning were lower (p<0.05) in VK sows compared with NC sows. Conclusion: Therefore, the overall results suggested that increasing dietary VK₃ (0.5 to 5 mg/kg) during lactation improved the apparent total tract digestibility of phosphorus and serum bone metabolism biochemical markers in sows.

Finite-time Observer Based Predefined-time Aircraft Attitude Tracking Control

Yunhao Fu,Jingping Shi,Yongxi Lyu 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.11

This paper investigates the attitude tracking issue of the fixed-wing unmanned aerial vehicle (UAV) with model uncertainty and external disturbance using contemporary predefined-time stability theory and disturbance observer. Firstly, by using a time-varying tuning function with the expected settling time, composite state tracking errors are introduced to the design process of dynamic surface control, which is named dynamic surface based predefined time control (DSPTC). Then, the lumped disturbances are estimated by finite time extended states observer (FTESO). It is proved that all of signals in the aircraft attitude system are globally uniformly ultimately bounded. Finally, a set of simulations is implemented to validate the availability of the proposed controller.

Robust Path Following Controller for Unmanned Aerial Vehicle Based on Carrot Chasing Guidance Law Using Dynamic Inversion

Ehab Safwat,Weiguo Zhang,Mei Wu,Yongxi Lyu,Qianlei Jia 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

This paper focuses on autonomous path-following flight under uncertainty and external disturbances. Integrated UAV waypoints guidance scheme based on carrot chasing guidance law is presented. In order to follow a desired path a Virtual Track Point (VTP) is introduced on the path and make the UAV chase it. The UAV updates its heading direction toward the VTP. As time progresses, the UAV will move toward the path and asymptotically follow the path. Nonlinear Dynamic Inversion (NDI) awards the flight control system researchers a straight forward method of deriving control laws for nonlinear systems. The control inputs are used to cancel unwanted terms in the equations of motion using negative feedback of these terms. The two-timescale assumption that separates the fast dynamics which are the three angular rates of the aircraft from the slow dynamics which include the angle of attack, side-slip angle, and bank angle is adopted. NDI control law is designed for the fast variables using the deflection of aerodynamic control surfaces as inputs. Next, NDI is applied to the control of the slow states using the outputs of the fast loop as inputs. Simulation results for the nonlinear flight control system are given to illustrate the effectiveness of the technique. The validation of the designed flight system controller is demonstrated through real flight test.

Adaptive Back-stepping Neural Control for an Embedded and Tiltable Vtail Morphing Aircraft

Fuxiang Qiao,Jingping Shi,Xiaobo Qu,Yongxi Lyu 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.2

This paper presents an adaptive back-stepping neural control (ABNC) method for the coupled nonlinear model of a novel type of embedded surface morphing aircraft. Based on a large number of aerodynamic data for different V-tail configurations, the longitudinal and lateral aerodynamic characteristics of the aircraft are analyzed, and a nonlinear model with six degrees-of-freedom is established. To avoid the problem of “differential explosion,” the controller is designed using the traditional back-stepping control (TBC) method with a first-order filter. Radial basis function neural networks are introduced to estimate the uncertainty and external disturbance of the model, and a controller based on the ABNC method is designed. The stability of the proposed ABNC controller is proved using Lyapunov theory, and it is shown that the tracking error of the closed-loop system converges uniformly within specified bounds. Simulation results show that the ABNC controller works well, with better tracking performance and robustness than the TBC controller.

Sequence Analysis and Molecular Characterization of Wnt4 Gene in Metacestodes of Taenia solium

Junling Hou,Xuenong Luo,Shuai Wang,Cai Yin,Shaohua Zhang,Xueliang Zhu,Yongxi Dou,Xuepeng Cai 대한기생충학열대의학회 2014 The Korean Journal of Parasitology Vol.52 No.2

Reconfigurable Flight Control System Design for Blended Wing Body UAV Based on Control Allocation

Xiaobo Qu,Jingping Shi,Haijun Zhou,Ling Zuo,Yongxi Lyu 제어로봇시스템학회 2018 제어로봇시스템학회 국제학술대회 논문집 Vol.2018 No.10

The aircraft control surface fault reconfigurable scheme based on control allocation is an active approach to achieve fault-tolerant in flight control. It has obvious advantages such as the structure and parameters of the control law does not need to be redesigned as deflector failures occurs. The attainable moment subset and allocation efficiency with typical control allocation algorithms are evaluated. A modular scheme reconfigurable flight control system (FCS) of a miniature tailless Blended Wing Body UAV is studied by utilizing weighted pseudo-inverse, direct control, and fixed-point control allocation methods. The performance of the reconfigurable FCS is tested and verified with the simulation including typical failure modes such as deflector floating, loss-of-effectiveness and lock-in-place. Results validate that the reconfigurable FCS based on control allocation has preferable ability to handle deflector failures, improve the safety and reliability of aircraft. And the modular scheme proposed in the article demonstrates a good application prospect in the field of aviation and aerospace engineering.