scholarly journals Cooperative Midcourse Guidance Law with Communication Delay

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Zihao Wu ◽  
Quanbin Ren ◽  
Zhiqing Luo ◽  
Yangwang Fang ◽  
Wenxing Fu
Keyword(s):  
Numerical Simulations ◽  
Initial Conditions ◽  
Communication Delay ◽  
Distributed Consensus ◽  
Consensus Protocol ◽  
Network Nodes ◽  
Guidance Law ◽  
Communication Topology ◽  
Midcourse Guidance ◽  
Terminal Guidance

The initial conditions of the cooperative terminal guidance law, which are the terminal conditions of the cooperative midcourse guidance, have a greater impact on its cooperation and guidance precision, so it is worthy of investigating the cooperative midcourse guidance. In addition, the problem of communication delay between the network nodes is inevitable and has a greater impact on the cooperative guidance law. To solve the above problems, a novel distributed cooperative midcourse guidance (DCMG) law with communication delay is proposed by combining the cooperative term with a distributed consensus protocol including communication delay under the directed communication topology. Firstly, a DCMG law with communication delay is designed by combining the trajectory shaping guidance with the distributed protocol including communication delay under the directed communication topology; secondly, the consensus of the proposed DCMG law with communication delay under the directed graph is proved; finally, the effectiveness and superiority of the proposed DCMG law are verified by numerical simulations.

scholarly journals The Impact of Initial Conditions in N-Body Simulations of Debris Discs

2015 ◽  
Vol 32 ◽  
Author(s):  
E. Thilliez ◽  
S. T. Maddison
Keyword(s):  
Numerical Simulations ◽  
Initial Conditions ◽  
Parent Body ◽  
Dust Trapping ◽  
Physical Context ◽  
Disc Width ◽  
Wide Range ◽  
Belt Width ◽  
New Generation ◽  
The Impact

AbstractNumerical simulations are a crucial tool to understand the relationship between debris discs and planetary companions. As debris disc observations are now reaching unprecedented levels of precision over a wide range of wavelengths, an appropriate level of accuracy and consistency is required in numerical simulations to confidently interpret this new generation of observations. However, simulations throughout the literature have been conducted with various initial conditions often with little or no justification. In this paper, we aim to study the dependence on the initial conditions of N-body simulations modelling the interaction between a massive and eccentric planet on an exterior debris disc. To achieve this, we first classify three broad approaches used in the literature and provide some physical context for when each category should be used. We then run a series of N-body simulations, that include radiation forces acting on small grains, with varying initial conditions across the three categories. We test the influence of the initial parent body belt width, eccentricity, and alignment with the planet on the resulting debris disc structure and compare the final peak emission location, disc width and offset of synthetic disc images produced with a radiative transfer code. We also track the evolution of the forced eccentricity of the dust grains induced by the planet, as well as resonance dust trapping. We find that an initially broad parent body belt always results in a broader debris disc than an initially narrow parent body belt. While simulations with a parent body belt with low initial eccentricity (e ~ 0) and high initial eccentricity (0 < e < 0.3) resulted in similar broad discs, we find that purely secular forced initial conditions, where the initial disc eccentricity is set to the forced value and the disc is aligned with the planet, always result in a narrower disc. We conclude that broad debris discs can be modelled by using either a dynamically cold or dynamically warm parent belt, while in contrast eccentric narrow debris rings are reproduced using a secularly forced parent body belt.

Suboptimal mid-course guidance algorithm for accelerating missiles

2016 ◽  
Vol 231 (11) ◽  
pp. 2032-2047 ◽  
Author(s):  
Min-Guk Seo ◽  
Min-Jea Tahk
Keyword(s):  
Performance Enhancement ◽  
Feedback Form ◽  
Velocity Change ◽  
Guidance Law ◽  
Burn Out ◽  
Homing Performance ◽  
Guidance Algorithm ◽  
Midcourse Guidance ◽  
Missile System ◽  
Loop Form

This paper deals with the closed-loop form of mid-course guidance law design for accelerating missile system, whose acceleration is approximately constant. A midcourse guidance algorithm of feedback form is proposed to satisfy the engagement geometry conditions at the burn-out time for terminal homing performance enhancement. The effect of velocity change due to missile acceleration is explicitly considered in the derivation of the guidance law. The terminal constraint update algorithm is proposed under the assumption that the target trajectory is predicted precisely. Simulation results are provided to show the performance and characteristics of the proposed algorithm.

Scaling Membership of Byzantine Consensus

2020 ◽  
Vol 38 (3-4) ◽  
pp. 1-31
Author(s):  
Burcu Canakci ◽  
Robbert Van Renesse
Keyword(s):  
Fault Tolerant ◽  
Initial Conditions ◽  
Low Latency ◽  
Energy Costs ◽  
Prior Work ◽  
Improve Performance ◽  
Consensus Protocol ◽  
Normal Case ◽  
Network Topologies ◽  
And Performance

Scaling Byzantine Fault Tolerant (BFT) systems in terms of membership is important for secure applications with large participation such as blockchains. While traditional protocols have low latency, they cannot handle many processors. Conversely, blockchains often have hundreds to thousands of processors to increase robustness, but they typically have high latency or energy costs. We describe various sources of unscalability in BFT consensus protocols. To improve performance, many BFT protocols optimize the “normal case,” where there are no failures. This can be done in a modular fashion by wrapping existing BFT protocols with a building block that we call alliance . In normal case executions, alliance can scalably determine if the initial conditions of a BFT consensus protocol predetermine the outcome, obviating running the consensus protocol. We give examples of existing protocols that solve alliance. We show that a solution based on hypercubes and MAC s has desirable scalability and performance in normal case executions, with only a modest overhead otherwise. We provide important optimizations. Finally, we evaluate our solution using the ns3 simulator and show that it scales up to thousands of processors and compare with prior work in various network topologies.

scholarly journals Study on project trajectory of air-to-ground missile with strapdown seeker under multi constraints

2021 ◽  
Vol 39 (1) ◽  
pp. 141-147
Author(s):  
Junmin Zhao ◽  
Cong Nie ◽  
Guannan Chang ◽  
Meibo Lyu ◽  
Xinguo Li
Keyword(s):  
Good Condition ◽  
Field Of View ◽  
Small Field ◽  
Target Acquisition ◽  
Moving Targets ◽  
Proportional Navigation ◽  
Terminal Stage ◽  
Guidance Law ◽  
Terminal Guidance ◽  
Small Field Of View

The air-to-ground missile with strapdown seeker may have the problems, including small field of view(FOV), limited overload, and fall angle constraint. To solve the above mentioned problem, a phased guidance scheme is proposed. In this scheme, the attack trajectory is divided into the following six stages, including glided stage, fall angle constraint stage, target acquisition and adjustment stage, terminal guidance stage and blind zone stage. The glided stage is designed to increase range, the terminal fall angle is attained ahead of time at fall angle constraint stage. The aim of target acquisition and adjustment stage is to adjust the missile attitude, so that the target will fall within the FOV of the seeker. It creates good condition to capture the target for strapdown seeker. In the terminal stage, the guidance law of proportional navigation and attitude track are used to fit the needs of FOV constraint and attack accuracy. The simulation result shows that the project trajectory can solve the application of attacking moving targets for air-to-ground missile with strapdown seeker under multi constraints.

scholarly journals A Nonlinear Consensus Protocol of Multiagent Systems Considering Measuring Errors

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaochu Wang ◽  
Kaichun Zhao ◽  
Zheng You ◽  
Lungui Zheng
Keyword(s):  
Multiagent Systems ◽  
Energy Cost ◽  
Additional Condition ◽  
Consensus Protocol ◽  
Communication Topology ◽  
Measurement Uncertainties ◽  
Theoretical Analyses ◽  
Theoretical Results

In order to avoid a potential waste of energy during consensus controls in the case where there exist measurement uncertainties, a nonlinear protocol is proposed for multiagent systems under a fixed connected undirected communication topology and extended to both the cases with full and partial access a reference. Distributed estimators are utilized to help all agents agree on the understandings of the reference, even though there may be some agents which cannot access to the reference directly. An additional condition is also considered, where self-known configuration offsets are desired. Theoretical analyses of stability are given. Finally, simulations are performed, and results show that the proposed protocols can lead agents to achieve loose consensus and work effectively with less energy cost to keep the formation, which have illustrated the theoretical results.

Design and Instruction Solution of an Optimal Guidance Law for Ship-Air Missile beyond Visual Range

2012 ◽  
Vol 433-440 ◽  
pp. 3831-3836
Author(s):  
Yong Tao Zhao ◽  
Yun An Hu
Keyword(s):  
Control Variable ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Guidance Law ◽  
The Earth ◽  
Optimal Guidance ◽  
Quadratic Optimal Control ◽  
Simulation Results ◽  
Visual Range ◽  
Terminal Guidance

For the case of ship-air missile intercepting the low target beyond visual range by ship-ship coordination, the instruction solution model was presented and an optimal guidance law was designed considering the effect of the curvature of the earth. In the midcourse and terminal guidance segment, the optimal guidance law was designed through applying the concept of the pseudo control variable and the theory of the linear quadratic optimal control. The information of the target was described in the launch coordinates through coordinate transformation to realize the instruction solution for the designed guidance law. The simulation results show that the model of the instruction solution is correct and the designed guidance law is feasible.

Sign in / Sign up

Export Citation Format

Share Document