Unified numerical predictor-corrector guidance based on characteristic model

Aerocapture is one of the key technologies for low-cost transportation,with high demands of autonomy,accuracy,and robustness of guidance and control,due to its high reliability requirements for only one chance of trying.A unified numerical predictor-corrector guidance method based on characteristic models for aerocapture is proposed.The numerical predictor-corrector guidance method is used to achieve autonomy and high accuracy,and the characteristic model control method is introduced to achieve robustness.At the same time,by transforming path constraints,characteristic model equations including apogee deviation and altitude differentiation are established.Based on the characteristic model equations,a unified guidance law which can satisfy path constraints and guidance objectives simultaneously is designed.In guidance problems,guidance deviation is not directly obtained from the output of the dynamics at present,but is calculated through integral and algebraic equations.Therefore,the method of directly discretizing differential equations cannot be used to establish characteristic models,which brings great difficulty to characteristic modeling.A method for characteristic modeling of guidance problems is proposed,and convergence analysis of the proposed guidance law is also provided.Finally,a joint numerical simulation of guidance and control considering navigation deviation and various uncertainties is conducted to verify the effectiveness of the proposed method.The proposed unified method can be extended to general aerodynamic entry guidance designs,providing theoretical and methodological support for them.

Tri-level programming model for combined urban traffic signal control and traffic flow guidance

In order to balance the temporal-spatial distribution of urban traffic flow, a model is established for combined urban traffic signal control and traffic flow guidance. With consideration of the wide use of fixed signal control at intersections, traffic assignment under traffic flow guidance, and dynamic characteristics of urban traffic management, a tri-level programming model is presented. To reflect the impact of intersection delay on traffic assignment, the lower level model is set as a modified user equilibrium model. The middle level model, which contains several definitional constraints for different phase modes, is built for the traffic signal control optimization. To solve the problem of tide lane management, the upper level model is built up based on nonlinear 0-1 integer programming. A heuristic iterative optimization algorithm(HIOA) is set up to solve the tri-level programming model. The lower level model is solved by method of successive averages(MSA), the middle level model is solved by non-dominated sorting genetic algorithm II(NSGA II), and the upper level model is solved by genetic algorithm(GA). A case study is raised to show the efficiency and applicability of the proposed modelling and computing method.

Aero-thermal heating constrained midcourse guidance using state-constrained model predictive static programming method

This paper proposes a multiple-constraints-guaranteed midcourse guidance law for the interception of the hypersonic targets. In traditional midcourse law design, the constraints of the aero-thermal heating are rarely taken into consideration. The performance of the infrared detection system may be degraded and the instability of the flight control system may be induced.To address this problem, a state-constrained model predictive static programming method is introduced such that both terminal constraints(position and angle) and optimal energy consumption can be ensured. As a result, a sub-optimal midcourse guidance,guaranteeing the aforementioned multiple-constraints to be never violated, is synthesized. Simulation results demonstrate the effectiveness of the proposed method.

Comparative analysis of different iterative model for exoatmospheric autonomous iterative guidance method

Space applications have raised the demand on autonomy, security and reliability for current transportation vehicle, which require guidance technology of vehicle must have strong robustness and adaptability. Therefore, it is needed to research exoatmospheric autonomous iterative guidance method with stronger adaptivity and higher accuracy. Based on preliminary research results, two new iterative models with performance index of maximum terminal energy for exoatmospheric autonomous iterative guidance method are proposed in this paper. Then comparative analysis between preliminary research iterative model and two new iterative models proposed is performed. The results demonstrate that the inner update iterative model proposed is the least sensitive to initial values and have the best convergence and performance in the three iterative models.

Factors associated with intention to undergo specific health guidance among Japanese workers using health belief model

Objectives: To examine the factors associated with the intention to undergo “specific health guidance”. Methods: Self-reported questionnaire data were collected from 4861 health insurance union members of a company in Japan from August to September 2010. The information gathered included the intention to undergo “specific health guidance,” the Health Belief Model (HBM) subcomponents (perceived severity, susceptibility, benefit, and barriers), other factors related to undergoing specific health guidance, sex, and age. Perceived threat and net benefit were the main HBM components. Bivariate and multivariate logistic regression analyses were used to assess the associations between intention and the main HBM components, i.e., perceived threat and net benefit. We used two models with intention as the dependent variable;Model 1 used four HBM subcomponents, and Model 2 used perceived threat and net benefit as independent variables. Results: A total of 3457 individuals answered all variables (response rate;71.1%). Perceived severity (OR: 1.83, 95%CI: 1.59 - 2.10), benefit (OR: 6.91, 95%CI: 5.94 - 8.04), barriers (OR: 0.11, 95%CI: 0.09 - 0.13), perceived threat (OR: 1.52, 95%CI: 1.31 - 1.76), and net benefit (OR: 11.28, 95%CI: 9.60 - 13.25) were related to intention (all p < 0.01). Multivariate analysis showed that net benefit (OR: 11.23, 95%CI: 9.55 - 13.20) had a stronger correlation with intention than did perceived benefit (OR: 4.67, 95%CI: 3.95 - 5.51) and barriers (OR: 0.15, 95%CI: 0.13 - 0.18) (all p < 0.01). Conclusions: The results suggested that the main HBM components may predict health behavior better than the subcomponents. These results may effectively promote the benefits of, and reduce barriers to, programs aiming to increase participation in specific health guidance.

Model Predictive Control Based Defensive Guidance Law in Three-Body Engagement

Model predictive control(MPC)has been widely used in process industry,but its appli-cations to missile guidance law are relatively rare.In this paper,MPC is introduced to design defen-sive guidance law in a three-body engagement,where a defending missile(i.e.,defender)is employed to protect a target aircraft from an attacking missile.Based on nonlinear kinematic equa-tions,an explicit linear discrete-time model is derived as the predictive model.Then the defensive guidance problem is formulated as a quadratic programming problem,and a fast algorithm for the MPC guidance law is developed.The advantages of the MPC guidance law include the applicabil-ity to scenarios with unknown guidance strategy of attacking missile,nonlinear kinematics and mul-tiple constraints.Another key feature is that the proposed approach does not require alteration in the target maneuver.Simulation results show that the MPC guidance law works well and can meet real-time requirements.

Research on Korf Ball Athletes Selecting Model under the Background of High Level Athletes Data Guidance

In this paper, we conduct research on the Korf ball athlete basic selecting model under the background of high level athlete data guidance. Athletes selecting closely related to the ultimate goal of training for many years. So, naturally, great athletes become references, the structure model of the excellent athlete competitive ability become athletes selecting targeting. Based on abundant literature, discusses the selection of the targeting of athletes, in an effort to at the same time, the rich athletes selecting theory provides a new perspective for the material practice. Our paper integrates the basic information of the high level athlete data to construct the novel paradigm for further promotion.

Head Pursuit Variable Structure Guidance Law for Three-dimensional Space Interception

This article aims to develop a head pursuit （HP） guidance law for three-dimensional hypervelocity interception, so that the effect of the perturbation induced by seeker detection can be reduced. On the basis of a novel HP three-dimensional guidance model, a nonlinear variable structure guidance law is presented by using Lyapunov stability theory. The guidance law positions the interceptor ahead of the target on its tlight trajectory, and the speed of the interceptor is required to be lower than that of the target, A numerical example of maneuvering ballistic target interception verifies the rightness of the guidance model and the effectiveness of the proposed method.

A User-Centric Approach to Activity Recognition and Guidance in Semantic Smart Home

Wireless smart home system is to facilitate people's lives and it trend to adopt a more intelligent way to provide services. It is very desirable in the recent SH market for the system to recognize users' behaviors and automatically response the corresponding activities to satisfy users' actual demands. However, activity models in the existing approaches are usually defined separately through knowledge-driven methods. These approaches cause that the activity models can't be matched with the services dynamically. To address the problem, we develop the semantic association model and a novel approach of activity recognition and guidance is presented. In our approach, the smart devices and users' requirements are described by semantic models. When the requirements are detected and understood, smart gateway can provide appropriate services, achieving activity assistance. The semantic association model allows all related elements in smart home connect with each other logically. The approach has been implemented and the results show that the success rate of the approach based on semantic association model is higher than 33% at average as compared to the approach based on predefined models. The proposed approach can effectively help people who are in trouble with learning or remembering in the common life.

A New Optimal Guidance Law For Intercepting Maneuvering Objects

In order to achieve a new minimum energy interception of an arbitrarily maneuvering vehicle a nonlinear modal is first approximated by a series of local linear models using an on-line linearizing method for some state variables, and then from the derived local linear models a new optimal strategy is developed using the receding horizon concept and associated techniques. That evader maneuvering in a small scope can be dealt with by the correspoding local linear model, and its maneuverring in a large scope is handled by model switching among a series of local linear models. Simulation results show that tile system designed in this way can intercept a randomly maneuvering evader.

Use of the Method of Guidance by a Required Velocity in Control of Spacecraft Attitude

We apply the method of guidance by a required velocity for solving the optimal control problem over spacecraft’s reorientation from known initial attitude into a required final attitude.We suppose that attitude control is carried out by impulse jet engines.For optimization of fuel consumption,the controlling moments are calculated and formed according to the method of free trajectories together with principle of iterative control using the quaternions for generating commands to actuators.Optimal solution corresponds to the principle“acceleration-free rotation-separate corrections-free rotation-braking”.Rotation along a hitting trajectory is supported by insignificant correction of the uncontrolled motion at discrete instants between segments of acceleration and braking.Various strategies of forming the correction impulses during stage of free motion are suggested.Improving accuracy of achievement of spacecraft's final position is reached by terminal control using information about current attitude and angular velocity measurements for determining an instant of beginning of braking(condition for start of braking based on actual motion parameters is formulated in analytical form).The described method is universal and invariant relative to moments of inertia.Developed laws of attitude control concern the algorithms with prognostic model,the synthesized control modes are invariant with respect to both external perturbations and parametric errors.Results of mathematical modeling are presented that demonstrate practical feasibility and high efficiency of designed algorithms.

Coupled dynamic model of state estimation for hypersonic glide vehicle

Aiming at handling complicated maneuvers or other unpredicted emergencies for hypersonic glide vehicle tracking,three coupled dynamic models of state estimation based on the priori information between guidance variables and aerodynamics are presented. Firstly, the aerodynamic acceleration acting on the target is analyzed to reveal the essence of the target’s motion.Then three coupled structures for modeling aerodynamic parameters are developed by different ideas: the spiral model with a harmonic oscillator, the bank model with trigonometric functions of the bank angle and the guide model with the changing rule of guidance variables. Meanwhile, the comparison discussion is concluded to show the novelty and advantage of these models.Finally, a performance assessment in different simulation cases is presented and detailed analysis is revealed. The results show that the proposed models perform excellent properties. Moreover, the guide model produces the best tracking performance and the bank model shows the second; however, the spiral model does not outperform the maneuvering reentry vehicle(MaRV) model markedly.

Multiple Model Filtering in the Presence of Gaussian Mixture Measurement Noises

A simplified multiple model filter is developed for discrete-time systems inthe presence of Gaussian mixture measurement noises. Theoretical analysis proves that the proposedfilter has the same estimation performance as the interacting multiple model filter at the price ofless computational cost. Numerically robust implementation of the filter is presented to meetpractical applications. An example on bearings-only guidance demonstrates the effect of the proposedalgorithm.

Cooperative interception with fast multiple model adaptive estimation

For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang-bang evasive maneuver with a random switching time.Combined Fast multiple model adaptive estimation(Fast MMAE)algorithm,the cooperative guidance law takes detection configuration affecting the accuracy of interception into consideration.Introduced the detection error model related to the line-of-sight(LOS)separation angle of two interceptors,an optimal cooperative guidance law solving the optimization problem is designed to modulate the LOS separation angle to reduce the estimation error and improve the interception performance.Due to the uncertainty of the target bang-bang maneuver switching time and the effective fitting of its multi-modal motion,Fast MMAE is introduced to identify its maneuver switching time and estimate the acceleration of the target to track and intercept the target accurately.The designed cooperative optimal guidance law with Fast MMAE has better estimation ability and interception performance than the traditional guidance law and estimation method via Monte Carlo simulation.

Primary safe criterion of earth-brushing flight for flying vehicle over digital surface model

In modern terrain-following guidance it is an important index for flight vehicle to cruise about safely and normally. On the basis of a constructing method of digital surface model (DSM), the definition, classification and scale analysis of an isolated obstacle threatening flight safety of terrain-following guidance are made. When the interval of vertical-and cross-sections on DSM is 12. 5 m, the proportion of isolated obstacles to the data amount of DSM model to be loaded is optimal. The main factors influencing the lowest flying height in terrain-following guidance are analyzed, and a primary safe criterion of the lowest flying height over DSM model is proposed. According to their test errors, the lowest flying height over 1:10 000 DSM model can reach 40. 5 m^45. 0 m in terrain-following guidance. It is shown from the simulation results of a typical urban district that the proposed models and methods are reasonable and feasible.

萨提亚模式团体辅导在大学生自杀意念干预中的应用效果

目的探讨萨提亚模式团体辅导对大学生自杀意念的干预效果,为大学生自杀行为的防控提供依据。方法采用随机整群抽样方法选取某高校大二年级的20个班的学生作为调查对象,随机分为干预组和对照组,每组10个班,干预组采用萨提亚模式团体辅导进行干预,对照组不采取任何干预。随访干预3个月,对2组大学生的自杀意念、生命意义及自我和谐进行比较分析。结果干预后,干预组的自杀意念检出率(6.13%)低于对照组(10.31%)及干预前(11.74%)(P<0.05);干预组对自杀行为的态度、对自杀者的态度、对自杀者家属的态度和对安乐死的态度得分分别为(2.98±0.56)分、(2.81±0.45)分、(2.97±0.36)分和(2.95±0.61)分,均高于对照组及干预前自身得分(P<0.05);干预组生命意义得分和寻求意义得分分别为(25.15±3.12)分和(26.82±3.63)分,均高于对照组得分(P<0.05);干预组自我与经验的不和谐、自我的灵活性和自我的刻板性得分分别为(45.32±8.21)、(47.81±8.27)和(16.03±3.92)分,与对照组相比差异均有统计学意义(P<0.05)。结论萨提亚模式团体辅导对大学生自杀意念有着积极的干预作用,值得在高校推广。

注意力引导的多尺度红外行人车辆实时检测

红外成像技术通过捕捉目标热辐射特征进行成像,能实现复杂道路场景下的目标监测和道路冗杂信息滤除。针对红外行人和车辆目标检测模型参数量大、依赖高性能GPU资源和检测速度慢等问题,提出了一种注意力引导的多尺度红外行人车辆实时检测模型。首先,为精确匹配校准红外行人和车辆目标尺度与锚框尺寸,利用K-Means++算法对红外行人和车辆目标尺度进行先验框预置参数重聚类生成,并设计128×128精细尺度检测层;其次,设计注意力引导广域特征提取模块增强模型特征提取能力和空间及通道信息聚焦能力;随后,构建跨空间感知模块引入空间信息感知,强化不同尺度空间下的目标的特征表达能力;最后,针对资源受限设备,通过4倍通道剪枝方法降低模型参数量,增强移动端算法部署适应性。实验结果表明:所提IRDet算法与基准方法相比,模型平均检测精度提升4.3%,达到87.4%,模型权重值压缩60.4%,降至5.7 MB。

生涯教育视角下普通高中选科指导实践模式的建构及检验

新高考改革将选择权交还给学生,不仅带来选择空间的放大和决策时间的前置,而且引发高中生对未来愿景的更多期许。选科指导成为兼及学生当下选择与长远发展的重要契机和有力抓手。基于生涯教育的视角建构涵盖选科指导目标之“谐和”、内容之“融和”、路径之“通和”、评价之“正和”为一体的“4和”模式,并通过实践运用检验其效用和价值,旨在回应时代关切。研究结果表明,该模式能显著降低学生选科过程中的决策困难,提升学生生涯发展的成熟度,加深其对高中学习意义的理解,促进由表层学习动机向深层学习动机的转化。实验结果一方面验证了生涯教育视角对于选科指导具有正向作用,另一方面也在操作层面检验了“4和”实践模式的可借鉴性。

基于动态哈夫模型及双边匹配的电动汽车充电引导策略

由于充电站中充电桩数目有限且电动汽车充电耗时长,陆续产生充电需求的各电动汽车用户存在对充电站资源的竞争。这不仅增加了用户排队概率,降低了充电站收益和利用率,而且使得用户在充电站规模、价格、评价等方面的个性化需求得不到充分满足。为此,提出了一种动态哈夫模型与双边匹配方法相结合的电动汽车充电引导策略。首先,对充电站客流、充电订单和充电桩详情等真实数据集进行大数据挖掘,分析公共充电站用户的充电站选择偏好和充电行为特征;然后,基于动态哈夫模型,结合用户充电站选择偏好量化不同区域用户前往不同充电站的概率,并生成充电站推荐列表;最后,将前景理论与双边匹配策略相结合,进行充电引导。算例分析表明,所提策略大幅降低了用户的排队概率,在满足用户个性化充电需求的同时,保障了充电站利益。

信息加工视角下地铁导视系统设计策略研究

目的对地铁导视系统设计现状进行梳理,旨在从信息加工视角出发,探究地铁导视系统设计策略,以提升乘客的寻路体验。方法通过文献和现状调研分析现阶段地铁导视系统设计存在的问题,论述信息加工模型切入的可行性,构建地铁导视信息加工模型。以武汉地铁为例,通过定性和定量对当前导视系统效力进行评估并确定痛点,基于模型从感知处理、记忆储存、决策执行三个层面对地铁导视系统痛点进行分类分析。结论构建了地铁导视信息加工模型,提出了以感知为基础的表现层设计、以记忆为依托的结构层设计、以决策为主线的行为层设计三条策略。从信息加工视角审视地铁导视系统设计,不仅可以提升乘客的寻路体验,还能有效提高地铁系统的整体运行效率。