Navigation and Control of the PRISMA Formation： In-Orbit Experience

This paper presents flight results and lessons learned from the Spaceborne Autonomous Formation Flying Experiment （SAFE） conducted by the German Space Operations Center in the frame of the Swedish PRISMA technology demonstration mission. PR1SMA involves two fully autonomous formation-flying spacecraft which have been launched in June 2010 in a dawn/dusk orbit at an altitude of 750 km. SAFE represents one of the first demonstrations in low Earth orbit of an advanced guidance, navigation and control system for dual-spacecraft formations. Innovative techniques based on carrier-phase differential GPS （Global Positioning System）, relative eccentricity/inclination vectors and impulsive maneuvering are validated and tuned in orbit to achieve centimeter accurate real-time relative navigation, reliable formation keeping at the meter level and flexible formation reconfiguration capabilities. The technologies demonstrated within SAFE are considered as key precursors of future distributed satellite systems for unrivaled remote sensing and space exploration.

Air and Missile Defense Under Spatial Grasp Technology

A novel control ideology and technology for solving tasks in large distributed networked systems will be briefed. Based on active scenarios self-navigating and self-matching distributed spaces in a highly organized super-virus mode, it can effectively establish global control over large systems of any natures. The technology can use numerous scattered and dissimilar facilities in an integral and holistic way, allowing them to work together in goal-driven supercomputer mode. The approach can be useful for advanced air and missile defense in a variety of ways which is described and explained in this paper.

A Study on Missile Reentry Control Based on the Method of Feedback Linearization

In the process of missile large attack angle reentry,there exist nonlinear,strong coupling uncertainty and multi-input-multi-output(MIMO)in the movement equations,so the traditional small disturbance faces difficulties.For such situations,the method of feedback linearization is adopted to control the complex system,and the control method based on the fuzzy adaptive nonlinear dynamic inversion decoupling control of missile is proposed in the paper.According to the principle of time-scale separation,the system is separated into fast loop and slow loop,the method of dynamic inversion is applied to them,and the method of adaptive fuzzy approach is adopted to compensate for the uncertainty of the fast loop.The simulation results denote the control method in the paper has a better tracing characteristic and robustness.

Saturation attack based route planning and threat avoidance algorithm for cruise missiles

According to the characteristic of cruise missiles,navigation point setting is simplified,and the principle of route planning for saturation attack and a concept of reference route are put forward.With the help of the shortest-tangent idea in route-planning and the algorithm of back reasoning from targets,a reference route algorithm is built on the shortest range and threat avoidance.Then a route-flight-time algorithm is built on navigation points.Based on the conditions of multi-direction saturation attack,a route planning algorithm of multi-direction saturation attack is built on reference route,route-flight-time,and impact azimuth.Simulation results show that the algorithm can realize missiles fired in a salvo launch reaching the target simultaneously from different directions while avoiding threat.

Impact Point Prediction and Lateral Correction Analysis of Two-dimensional Trajectory Correction Projectiles

Compared with the one-dimensional trajectory correction technology which adjusts longitudinal range, not only does the two-dimensional trajectory correction technology adjust the force in velocity direction, but also need to modulate the lateral force or trajectory (perpendicular to the vertical plane of fire direction). Therefore, the structure of control cabin of two-dimensional trajectory correction projectile (TDTCP) is more complicated than that of one-dimensional trajectory correction projectile (ODTCP). To simplify the structure of control cabin of TDTCP and reduce the cost, a scheme of adding a damping disk to the control cabin of ODTCP has been developed recently. The damping disk is unfolded at the right moment during its flight to change the ballistic drift of spin stabilized projectile. For this technical scheme of TDTCP, a fast and accurate impact point prediction method based on extended Kalman filter is presented. An approximate formula for predicting the ballistic drift and trajectory correction quantity is deduced. And the lateral correction capability for different fire angles and its influencing factors are analyzed. All the work is valuable for further research.

Research on SINS Error Recursive Model of Ballistic Missile

The strap-down inertial navigation system (SINS) error of ballistic missile is generated by the mutual influence of gyroscope and accelerometer, and the recursive model is completely different from that of gimbaled INS. In the paper, a discrete error recursive model was obtained by studying the applied SINS error model of ballistic missile, and the discrete Kalman filtering simulation based on the model was carried out. The simulated results show that the model can depict the SINS error exactly and provide the advantages for research on integrated guidance and improved hit accuracy.

Cooperative Navigation for Autonomous Underwater Vehicles Based on Estimation of Motion Radius Vectors

A cooperative navigation algorithm for a group of autonomous underwater vehicles is proposed on the basis of motion radius vector estimation.Combined the dead reckoning data with the mutual range data through an acoustic communication network among the group members, the relative positioning problem can be solved. A novel approach for solving the relative positioning is presented by using a recursive trigonometry technique and extended Kalman filter(EKF). Simulation results verify the correctness and effectiveness of this navigation method.

Design of Neural Network Variable Structure Reentry Control System for Reusable Launch Vehicle

A flight control system is designed for a reusable launch vehicle with aerodynamic control surfaces and reaction control system based on a variable-structure control and neural network theory.The control problems of coupling among the channels and the uncertainty of model parameters are solved by using the method.High precise and robust tracking of required attitude angles can be achieved in complicated air space.A mathematical model of reusable launch vehicle is presented first,and then a controller of flight system is presented.Base on the mathematical model,the controller is divided into two parts:variable-structure controller and neural network module which is used to modify the parameters of controller.This control system decouples the lateraldirectional tunnels well with a neural network sliding mode controller and provides a robust and de-coupled tracking for mission angle profiles.After this a control allocation algorithm is employed to allocate the torque moments to aerodynamic control surfaces and thrusters.The final simulation shows that the control system has a good accurate,robust and de-coupled tracking performance.The stable state error is less than 1°,and the overshoot is less than 5%.

Cooperative Search and Task Allocation Among Heterogeneous Teams of UAVs

A cooperative control method of multi-class UAV(unmanned air vehicle) team is investigated.During the mission,the UAVs perform search,classification,attack and battle damage assessment(BDA) tasks at various locations,which involves a combination of the team intelligence type of decision making combined with control,estimate and real-time trajectory optimization.The search-theoretic approach based on rate of return(ROR) maps is developed to get the cooperative search strategy.Templates are developed and views are combined to maximize the probability of correct target identification over various aspect angles.Monte Carle simulation runs for the scenario to evaluate the performance of the approach with various decision parameters,UAVs distributions and UAV team characteristics.Simulation results show that the cooperative behavior can significantly improve the operational effectiveness of UAV team,and the cooperative control allows for near optimal solution of the correlative behavior of a group of UAVs in battlefield.

Modeling and Simulation for Gliding Missile with Large Aspect Ratio

An improved STT (skid to turn) autopilot was developed to solve the problem of roll control saturation for the gliding missile with large aspect ratio. A lateral acceleration feedback was introduced in the roll channel of the autopilot to ensure that the roll angle could closely follow the lateral acceleration,so that the sideslip angle and the roll rudder deflection could be reduced,and the roll control saturation was avoided. A six-DOF ( degree of freedom) nonlinear simulation model was set up. The simulation results indicate that the model and the control scheme are effective.

Optimal Gliding Guidance of Vertical Plane for Standoff Released Guided Bomb Unit

Optimal gliding guidance for a guided bomb unit in the vertical plane is studied based on nonlinear dynamics and kinematics.The guidance law is designed under minimum energy loss index.To avoid the complexity in solving two-point-boundary-value problems,the steady-state solutions of the adjoint states in regular equations are suggested to be used.With these considerations,a quasi-closed,optimal gliding guidance law is obtained.The guidance law is described by the angle of attack in a simple nonlinear equation.An iterative computation method can be easily used to get the optimal angle of attack.The further simplified direct computation algorithm for the optimal angle of attack is also given.The guidance properties are compared with those of maximum lift-to-drag angle of attack control.The simulation results demonstrate that the quasi-closed,optimal gliding guidance law can improve the gliding phase terminal performance with significant increase in the altitude and much little decrease in the speed.

Relaxed Stable Stability Technology for an Air-to-air Missile

Relaxed Stable Stability （RSS） in an important part of the active control technology. It is a new way to raise the flying speed, distance and maneuverability of missile. Depth study of RSS technology plays an important role for the new concept missile design. This paper describes the detailed definition of RSS and its advantages, pres- ents the research status and prospects for its application in the design of new missiles.

Re-entry Attitude Double-loop SMC of the Spacecraft and Its Logic Selection

A spacecraft re-entry attitude control method using sliding mode control (SMC) theory is developed. The controller utilizes double-loop SMC scheme and provides the robust, de-coupled tracking of both the angular velocity and the shuttle orientation angles. In accordance with the hybrid-controlling characteristics of the aerodynamic surfaces and reaction control system of the spacecraft, the control torque commands are allocated into the actuators such as the aerodynamic surfaces and reaction control system by using the optimal control selection allocation algorithm. The simulation of the spacecraft re-entry attitude controlling demonstrates the robust, de-coupled tracking performance of the proposed method and its validity.

Research on Robust Control of Nonlinear Fuzzy VSS for Spacecraft

The nonlinear dynamic system of spacecraft with uncertainty and coupling is analyzed and its general dynamical equation is given.The decoupling-ability and controllability are proved.Aiming at this system,a new nonlinear decoupling controlling method is put forward by synthetically using the variable structure and fuzzy theory.The simulation results show that this method is effective in tracking performances under the existence of uncertainty and outer disturbance.

Research on Airborne Electro-Optical Tracking and Sighting System Based on Fuzzy PID and H_∞ Control

Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance,and its control system consists of stabilizing and tracking components.Stabilizing control is applied to track angular velocity order and control multi-disturbance under airborne condition,and its robustness should be very good;tracking control is applied to compensate tracking error of angular position.A mathematical model is established by taking the control of yaw loop as example.H∞ stabilizing controller is designed by taking the advantage of H∞ control robustness and combining with Kalman filter.A fuzzy control is introduced in general PID control to design a decoupled fuzzy Smith estimating PID controller for tracking control.Simulation research shows that the control effect of airborne electro-optical tracking and sighting system based on fuzzy PID and H∞ control is good,especially when the model parameters change and the multi-disturbance exists,the system capability has little fall,but this system still can effectively track a target.

5G通信技术在船舶电气控制系统中的应用

文章探讨了5G通信技术在船舶电气控制系统中的应用。5G通信技术凭借其高带宽、低时延以及高可靠性,显著提升了船舶电气系统的实时监控、远程控制以及智能电网管理能力。同时,5G通信技术在自主航行与避障系统、船岸一体化通信中发挥着关键作用。通过优化能耗管理,提升系统的灵活性和适应性,5G通信技术为船舶电气系统的智能化发展提供了重要支持。

智能割草机自主导航关键技术的研究综述

首先介绍了智能割草机市场规模和发展前景,然后概述了国内外主流智能割草机产品的功能和使用技术。随后对智能割草机采用的全球导航卫星系统导航(GNSS)、机器视觉导航、激光雷达导航和多传感器融合定位导航等4类导航技术的研究现状进行了介绍,并对它们的优势和不足进行了概括分析。研究结果显示,多传感器融合定位导航是智能割草机未来导航发展的方向。接下来介绍了智能割草机所采用的PID控制和纯跟踪算法控制等2种导航策略的研究现状。最后对智能割草机存在的问题和未来发展方向进行了总结和展望。

跨介质无人机的技术问题与解决方案分析

阐述跨介质无人机作为一种能够在不同介质(水体、空气)中自由切换的多功能飞行器,受到广泛关注。分析跨介质无人机所面临的机械结构、能源与动力系统、导航与控制系统方面的技术问题,提出相应解决方案。通过优化机械结构、改进能源系统和升级导航控制系统的措施,有效地解决跨介质无人机的技术挑战,推动其在各个应用领域的发展。

内河码头污染防治技术应用分类模型研究

本文构建了基于规则分类方法的内河码头污染防治技术分类模型,提出了基于政策标准要求、技术适用性、应用基础条件、污染防治效果和成本费用5个分类属性及相应的分类标准,通过建立20个分类关系规则,将不同污染防治技术划归为“应、宜、可、严禁、不提倡”5种分类标签,最后以易扬尘货物堆存粉尘防治技术为代表进行了方案应用案例分析。该分类模型可促使内河码头从更深层次、更广范围,以更高要求采取有效的污染防治措施,实现码头污染防治精准治理。

电子信息技术在无人机领域的应用

介绍了电子信息技术在无人机领域的应用情况,分析了导航与控制、通信与数据传输、传感器技术、机器视觉与图像处理技术、人工智能与机器学习、地理信息系统(GIS)等在无人机领域的具体应用,提出了电子信息技术在无人机领域的应用,提高了无人机的性能和功能。分析认为,电子信息技术为无人机在各个行业的应用提供了技术支持。