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Using digital twin technology as the medium, this paper understands modern space equipment digitalization driven by the digital twin technology thoroughly from the three perspectives of data, model and process. Based on the above three perspectives, it analyzes the system composition, feature system and key technologies of the entire equipment digital twin. Then, by combing the application of digital twin technology in some space equipment, the paper discusses the role and advantages of digital twin technology in the design and manufacture of space equipment, and analyzes the application prospect of digital twin in the field of space equipment in the future. Finally, from the above three perspectives of data, model and process, this paper summarizes the current difficulties faced by the digi-tal transformation construction of space equipment research and development, as well as the main contradictions faced by the development of digital twin of equipment. It puts forward new ideas to find possible breakthrough points and solutions to explore a new path to promote the digital transformation of space equipment research and development.

Game guidance can handle dynamic problems involving multi-party cooperation and competition in complex systems, which is conducive to maximizing the value of information on intelligent battlefields and promoting the intelligent development of precision guided weapons. This article summarizes the basic classification and modeling methods of game guidance, and proposes key issues of aircraft game guidance from the perspectives of terminal constraints, time constraints, overload constraints, and terminal speed constraints. Two typical game model solving frameworks, matrix game and differential game are constructed, and the algorithm solutions of game guidance are sorted out from the perspectives of analytical solutions, numerical solutions, and intelligent algorithms. Finally, the future development trends of aircraft game guidance are discussed and summarized from the perspectives of nonlinear differential game solving methods, incomplete information game algorithms, multi aircraft collaboration under unbalanced and asymmetric information, and multi type weapon system games.

Objective To investigate the rules of gout patients attending the hospital by analyzing their time series data, and to provide a reference for the prevention and treatment of gout in medical and health departments. Methods Time series data were collected from the gout patients who attended a grade A tertiary hospital in Qingdao from 2013 to 2018, and a descriptive analysis was performed for the data including the time of patients attending the hospital, age, and sex. An Autoregressive Integra-ted Moving Average (ARIMA) model was established based on the time series data of gout patients in 2013—2018, and the data of gout patients from January to October, 2019, were used for the extrapolation validation of this model. The X-11 method was used to analyze seasonal factors, long-term trends, and random fluctuations. Results Among the gout patients attending the hospital in 2013—2018, male patients accounted for 94.68% and female patients accounted for 5.32%; in terms of age composition, the patients aged 30-39 years, 40-49 years, 50-59 years, and >60 years accounted for 21.50%, 21.67%, 19.74%, and 23.32%, respectively. The ARIMA model established based on time series data of the gout patients in 2013—2018 was ARIMA(0,1,1)×(0,1,1)12, with an AIC value of 674.89 and an SBC value of 679.05, and the extrapolation verification of the predictive effect of this model showed an MAE value of 86.28 and an MAPE value of 7.64%. The X-11 method for seasonal stability (F=27.81,P0.05) showed that the time series of gout patients had stable seasonality and was not affected by time. The number of patients attending the hospital in July and August each year was higher than the mean value, and that in February was lower than the mean value; the number of patients was stable in the other months. Conclusion The ARIMA model is effective with stable prediction results, and combined with the seasonal factors and long-term trend extracted by the X-11 method, it can better explain the rules of gout patients attending the hospital and thus provide a reference for health authorities and medical institutions to formulate the prevention and control policies for gout, conduct health education, and allocate human resources.

Cooperative guidance is an important research direction in the field of missile guidance in recent years. Based on the classification criteria such as mission requirements, communication structure, constraints, etc., this paper classifies and summarizes the current multi-missile cooperative terminal guidance strategies, and combs the research status of time cooperative guidance law, spatial cooperative guidance law, and spatial-time cooperative guidance law. It analyzes the key issues for cooperative guidance at this stage, such as the estimation problem of remaining flight time, the cooperative interception problem of maneuvering targets, the information registration problem of closed-loop cooperative guidance, the communication problem of closed-loop cooperative missile, etc. Finally, this paper proposes four research directions of the future multi-missile cooperative terminal guidance technologies: cooperative interception technology for large maneuvering targets, robust cooperative guidance technology for real scenes, intelligent autonomous cooperative guidance technology, and parallel interactive design technology for cooperative operations.

The integrated guidance and control (IGC) problem for hypersonic vehicles in dive phase is reviewed from the perspective of model construction and method design in this paper. Firstly, this paper summarizes model construction of IGC in dive phase. In the sequence of integration improving degree, it introduces IGC model of individual channels, coupling full state high-order IGC model, improved integrated low-order IGC model, and analyzes and summarizes the characters of hypersonic vehicles system and design models, then points out typical problems of system faced in method design. Secondly, with respect to design difficulties of IGC system in dive phase, this paper reviews design methods from views of robust control under strong uncertainties, control methods under high-order mismatched uncertainties and control methods with multiple constraints. It points out the current development and existing problems of related theories at home and abroad. Finally, the IGC for hypersonic vehicles in dive phase is forecasted.

The essence of direct force/aerodynamic force compound control is to improve the maneuverability and rapidity of controlled aircraft by using the fast response speed of direct force, which can effectively compensate the slow response of aerodynamic control caused by insufficient aerodynamic force. This paper describes the characteristics and key problems of direct force/aerodynamic force compound control system, and introduces the modeling method of direct force/aerodynamic force compound control system from three aspects: the configuration of engine, the existing research of direct force modeling at home and abroad, and the disturbance modeling of direct force control.The direct force/aerodynamic force compound control method is introduced from three aspects: the control method, the existing research of direct force/aerodynamic force compound control method at home and abroad, and the ignition algorithm of pulse engine. The feasible direct force/aerodynamic force compound system stability analysis method is given, the future development trend of direct force/aerodynamic force compound control is prospected, and its key technologies are summarized.

The moving mass technology uses the movement of the internal masses to change the position of the mass center of vehicles. It can avoid thermal ablation, rudder flutter, and high fuel consumption caused by traditional manners such as aerodynamic rudder and reaction control system. It is of high control efficiency and advantageous to maintain a good aerodynamic configuration for vehicles. Based on the connotation of moving mass control, this paper summarizes the characteristics of the two forms of moving mass configuration. The research progress of three moving mass control modes, including roll control, trim control and compound control, is sorted out. Finally, key problems faced by the moving mass technology, such as complex multi-body dynamics modeling, strong coupling and strong nonlinear control, design and development of high dynamic and high performance actuator, are discussed. By looking forward to the new scenarios of moving mass control application, the future research direction is pointed out.

In order to rebuild its long-term absolute superiority, the United States proposed the concept of mosaic warfare. It has become the focus of attention of the world’s military powers. Based on the concept of mosaic warfare, this paper analyzes the background, design concept and actual combat characteristics of mosaic warfare. Combined with the concept of cooperative combat, the connotation of current cooperative combat technology is summarized, and the technical challenges faced by cooperative combat under mosaic warfare are analyzed.

This paper investigates the issue of integrated guidance and control (IGC) design for an unmanned aerial vehicle with an unknown control coefficient, approach angle constraint, and field-of-view limitations. Different from the existing methods, the proposed approach integrates the approach angle and field-of-view requirements into a single reference to satisfy the constraints simultaneously, and meanwhile guarantees the successful mission despite the unknown control coefficient. Based on the established IGC model, a novel sliding mode strategy is generated to ensure that the approach angle and field-of-view constraints can be obeyed once the designed reference is tracked precisely. Then, the IGC issue are transformed into a tracking problem under an unknown control direction, and the periodic sliding mode control technique is introduced to construct the IGC law. The stability of the closed-loop system is analyzed in detail. The effectiveness of the proposed method is verified by numerical simulations. [ABSTRACT FROM AUTHOR]