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Attitude, speed, and position of unmanned aerial vehicles are susceptible to wind disturbance. The types, characteristics, and mathematical models of the wind, which have great influence on unmanned aerial vehicle in the low-altitude environment, are summarized, including the constant wind, turbulent flow, many kinds of wind shear, and the propeller vortex. Combined with the mathematical model of the unmanned aerial vehicle, the mechanism of unmanned aerial vehicle movement in the wind field is illustrated from three different kinds of viewpoints including velocity viewpoint, force viewpoint, and energy viewpoint. Some simulation tests have been implemented to show the effects of different kinds of wind on unmanned aerial vehicle’s path and flight states. Finally, some proposals are presented to tell reader in which condition, which wind model should be added to simulation, and how to enhance the stability of unmanned aerial vehicle for different kinds of wind fields.

This article reviews remotely operated underwater vehicle (ROUV) and its different types focusing on the control systems. This study offers a brief introduction of unmanned underwater vehicle (UUV) together with ROUV. Underwater robots are designed to work as an alternative to humans because of a difficult and hazardous underwater environment. The applications and demand of marine robots are increasing with the passage of time. There are several research articles and publications available on these topics but, a complete review of old and recent research about this technology is still hard to find. This article also assesses some recently published research papers on underwater systems. It presents the comparison of different control systems and designs of underwater vehicles. There have been major developments in marine technology depending on the needs, applications and cost of different missions. Scientists design many remotely operated vehicles based on the educational or industrial purposes. This article is presented in order to help and assist the future researchers as a massive review of the field of remotely operated underwater vehicles and their possible future developments are presented.

To improve the performance of multi-unmanned aerial vehicle path planning in plateau narrow area, a control strategy based on Cauchy mutant pigeon-inspired optimization algorithm is proposed in this article. The Cauchy mutation operator is chosen to improve the pigeon-inspired optimization algorithm by comparing and analyzing the changing trend of fitness function of the local optimum position and the global optimum position when dealing with unmanned aerial vehicle path planning problems. The plateau topography model and plateau wind field model are established. Furthermore, a variety of control constrains of unmanned aerial vehicles are summarized and modeled. By combining with relative positions and total flight duration, a cooperative path planning strategy for unmanned aerial vehicle group is put forward. Finally, the simulation results show that the proposed Cauchy mutant pigeon-inspired optimization method gives better robustness and cooperative path planning strategy which are effective and advanced as compared with traditional pigeon-inspired optimization algorithm.

Pueraria thomsonii is a leguminous plant with high root yield and starch content. It is also a medicinal material in the Chinese pharmacopeia. However, the raw materials of P. thomsonii are often confused with some non-medicinal Pueraria plants. To enrich the genetic resources of P. thomsonii and guide its molecular identification, the complete chloroplast genome was sequenced and reported. The total genome of P. thomsonii is 153,434 bp in length. consisting of two inverted repeat regions (IR S , 25,640 bp each) separated by a large single-copy (LSC, 84,155 bp) and a small single-copy region (SSC, 17,999 bp). The overall GC content is 35.41%. It contains 130 genes, including 85 protein coding genes, 8 rRNA genes and 37 tRNA genes. Phylogenetic analysis showed that P. thomsonii could be distinguished from other plants and closely related to the legume Pachyrhizus erosus. This study enriches the genetic information of P. thomsonii and contributes to the screening of excellent germplasm.

In this paper, a novel multi-mode flight control strategy for unmanned helicopter, in presence of model uncertainty, atmospheric disturbances and handling qualities specification requirements (as in ADS-33E), based on multi-loop control structure combining robust H-infinity and PI control is presented. In inner loop H-infinity optimal control technique is utilized ensuring the stability of flight control system in case of change of helicopter dynamics, model uncertainties and eliminates effect of gust disturbance on helicopter states and collective/cyclic inputs. PI control in outer loop is used to improve the dynamic and static operation characteristics. Attitude control and attitude holding flight mode with satisfactory command response and decoupling characteristics is designed using the proposed control strategy. Analysis and simulation results show that Level 1 handling requirements as defined in ADS-33E are accomplished even when helicopter is under constant wind circumstance.

In this article, a novel hybrid control scheme is proposed for controlling the position of a three-phase brushless direct current (BLDC) motor. The hybrid controller consists of discrete time sliding mode control (SMC) with model free adaptive control (MFAC) to make a new data-driven control (DDC) strategy that is able to reduce the simulation time and complexity of a nonlinear system. The proposed hybrid algorithm is also suitable for controlling the speed variations of a BLDC motor, and is also applicable for the real time simulation of platforms such as a gimbal platform. The DDC method does not require any system model because it depends on data collected by the system about its Inputs/Outputs (IOS). However, the model-based control (MBC) method is difficult to apply from a practical point of view and is time-consuming because we need to linearize the system model. The above proposed method is verified by multiple simulations using MATLAB Simulink. It shows that the proposed controller has better performance, more precise tracking, and greater robustness compared with the classical proportional integral derivative (PID) controller, MFAC, and model free learning adaptive control (MFLAC).

Hepatitis B virus (HBV) infection is the most common cause of liver disease and liver cancer in Singapore, being endemic despite availability of an efficacious vaccine. To assess the factors associated with HBV screening and vaccination. Using mixed methods analysis, focus group discussions were conducted alongside a cross-sectional study amongst 784 Singapore Citizens and Permanent Residents aged 25–69 residing in Housing and Development Board (HDB) flats. Amongst the respondents, 50.6% were screened and 37.8% were vaccinated. The self-reported prevalence of HBV infection was 3.4% and that of HBsAg seropositivity among those screened was 4.3%. Routine health screening was the most common reason cited for screening (32.9%) while doctors’ recommendation was the most common reason for vaccination (42.7%). For both screening and vaccination, knowledge and cost were the top facilitators and barriers respectively. Multivariable regression models revealed the most significant predictors for not undergoing screening to be poor knowledge (p < 0.001), the presence of stigma (p = 0.040) and not being employed in a healthcare sector (p = 0.022), while factors associated with not undergoing vaccination are that of having not undergone screening (p < 0.001) and the lack of importance placed on the knowledge of the possibility of HBV being a silent killer (p = 0.006). Several facilitators and barriers are seen to regulate health-seeking behaviour towards HBV infection. Public initiatives including education and financial relief targeting specific population groups should be considered to increase the uptake of HBV screening and vaccination.

For attitude control system, based on decentralized fault-tolerant control framework, actuators damage and stuck fault detection and identification unit are designed for the flight control system. The observer-based auxiliary system unit is also designed. The auxiliary system implies control surface damage faults and disturbances information. Firstly, the researchers give the attitude control system under actuator stuck, lose of effectiveness, and control surface damages faults. Secondly, a multi-observer is designed for actuator fault detection and identification using a decision-making mechanism to determine current actuator failure modes. Then, an adaptive sliding mode observer is designed for implicit control surface damages and interference information. The reconfigurable controller can achieve fault tolerant using the information of adaptive sliding mode observer. Finally, the simulation results show the effectiveness of the proposed method.

For spacecraft attitude control system, we consider the aircraft's control surface deflection position saturation and rate constraints. Based on the dynamic control allocation method, we put forward redistribution method in the event of actuator stuck and damage failure. Firstly, because of the system modeling error caused by uncertainty and external disturbance, under actuator stuck and damage failure, we put forward the attitude control system mathematical model of angular rate control. We design actuator stuck fault diagnosis device and an adaptive sliding mode observer, respectively. The hidden failures and interference information feedback to the controller and the dynamic control allocation algorithm, in order to realize the fault tolerant control of actuator stuck and damage failure.

For attitude control system, based on instruction filter back-stepping techniques, a robust fault-tolerant control method is proposed. Firstly, attitude control system mathematical model is given, on this basis, the attitude control system under the modeling errors caused by uncertainty, external disturbances and control surfaces faults are considered. The fault tolerant control design involves two main units: one is auxiliary system design, and the other is controller design using the auxiliary system. Finally, the simulation results show that the proposed method can make the tracking performance for flight control system.