Synthesis of Optimal Control for Cooperative Collision Avoidance in a Close Proximity Encounter: Special Cases

2011 ◽  
Vol 44 (1) ◽  
pp. 9775-9781 ◽  
Author(s):  
Tanya Tarnopolskaya ◽  
Neale L. Fulton
Keyword(s):  
Optimal Control ◽  
Collision Avoidance ◽  
Special Cases ◽  
Close Proximity

Automatic Control of Underway Replenishment Maneuvers in a Random Sea

1978 ◽  
Vol 22 (01) ◽  
pp. 20-28
Author(s):  
Reidar Alvestad
Keyword(s):  
Computer Simulation ◽  
Automatic Control ◽  
Collision Avoidance ◽  
Nonlinear Interaction ◽  
Interaction Forces ◽  
Random Seas ◽  
Close Proximity ◽  
Controller Performance ◽  
Hybrid Computer ◽  
Avoidance Problem

This paper describes a hybrid computer simulation of two ships performing replenishment operations in random seas. Such operations present collision hazards due to the nonlinear interaction forces and moments which result from close proximity maneuvering while underway. Maneuvers are simulated to demonstrate automatic controller performance during station-keeping, station-changing, and the approach and breakaway phases of typical underway replenishment (UNREP) operations. Results indicate that automatic control should be considered as a possible solution to the UNREP collision avoidance problem.

Optimal control of arrivals to multiserver queues in a random environment

1984 ◽  
Vol 21 (3) ◽  
pp. 602-615 ◽  
Author(s):  
Werner E. Helm ◽  
Karl-Heinz Waldmann
Keyword(s):  
Optimal Control ◽  
Random Environment ◽  
Cost Structure ◽  
Control Limit ◽  
Inductive Approach ◽  
Multiserver Queues ◽  
Special Cases ◽  
Actual Environment

We study the problem of optimal customer admission to multiserver queues. These queues are assumed to live in an extraneous environment which changes in a semi-Markovian way. Arrivals, service mechanism and random reward/cost structure may all depend on these surroundings. Included as special cases are SM/M/c queues, in particular G/M/c queues, in a random environment. By a direct inductive approach we establish optimality of a generalized control-limit rule depending on the actual environment. Particular emphasis is laid on different applications that show the versatility of the proposed setup.

The Uncertainty and Uncoordination of Mariners' Behaviour in Collision Avoidance at Sea

1995 ◽  
Vol 48 (3) ◽  
pp. 425-435 ◽  
Author(s):  
J. Zhao ◽  
W. G. Price ◽  
P. A. Wilson ◽  
M. Tan
Keyword(s):  
Decision Making ◽  
Simulation Model ◽  
Collision Avoidance ◽  
Simulation Models ◽  
Fuzzy Programming ◽  
Assessment Model ◽  
The Other ◽  
Entropy Theory ◽  
Close Proximity ◽  
Decision Making Model

It is well known that many collisions occur because one ship turns right whilst the other turns left when in close proximity to one another. Little is known as to why this occurs and, although some simulation models have been established using entropy theory, the problem remains unsolved.In this paper, an assessment model for uncertainty is reviewed briefly. The concepts of uncertainty and uncoordination of mariners' behaviour in collision avoidance are discussed. A simulation model in conjunction with a DCPA (distance to the closest point of approach) decision-making model using fuzzy programming is introduced to discuss coordination.

scholarly journals Analysis of Collision Threat Parameters and Criteria

2015 ◽  
Vol 68 (5) ◽  
pp. 887-896 ◽  
Author(s):  
Andrzej S. Lenart
Keyword(s):  
Collision Avoidance ◽  
Safe Distance ◽  
Dangerous Situation ◽  
Special Cases

In this paper collision threat parameters such as the distance at closest point of approach and time to the closest point of approach are derived and analysed for special cases and features; collision criteria are analysed for limitations. A new collision threat parameter - time to safe distance - is proposed and its different applications to collision avoidance are presented. Time to safe distance can replace time to the closest point of approach, as it gives a safer time in a dangerous situation. It can be applied in Automatic Radar Plotting Aids (ARPAs) to detect dangerous objects and to display possible evasive manoeuvres.

scholarly journals Gradient Optimal Control of the Bilinear Reaction–Diffusion Equation

2021 ◽  
Author(s):  
El Hassan Zerrik ◽  
Abderrahman Ait Aadi
Keyword(s):  
Optimal Control ◽  
Diffusion Equation ◽  
Minimization Problem ◽  
Reaction Diffusion ◽  
Numerical Approach ◽  
Time Dependent ◽  
Reaction Diffusion Equation ◽  
Energy Term ◽  
Bounded Controls ◽  
Special Cases

In this chapter, we study a problem of gradient optimal control for a bilinear reaction–diffusion equation evolving in a spatial domain Ω⊂Rn using distributed and bounded controls. Then, we minimize a functional constituted of the deviation between the desired gradient and the reached one and the energy term. We prove the existence of an optimal control solution of the minimization problem. Then this control is characterized as solution to an optimality system. Moreover, we discuss two special cases of controls: the ones are time dependent, and the others are space dependent. A numerical approach is given and successfully illustrated by simulations.

scholarly journals Visual Flight Rules-Based Collision Avoidance Systems for UAV Flying in Civil Aerospace

Robotics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Hamid Alturbeh ◽  
James F. Whidborne
Keyword(s):  
Decision Making ◽  
Optimal Control ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Real Time ◽  
Collision Avoidance ◽  
Inverse Dynamics ◽  
Guidance System ◽  
Visual Flight Rules ◽  
Decision Making System

The operation of Unmanned Aerial Vehicles (UAVs) in civil airspace is restricted by the aviation authorities, which require full compliance with regulations that apply for manned aircraft. This paper proposes control algorithms for a collision avoidance system that can be used as an advisory system or a guidance system for UAVs that are flying in civil airspace under visual flight rules. A decision-making system for collision avoidance is developed based on the rules of the air. The proposed architecture of the decision-making system is engineered to be implementable in both manned aircraft and UAVs to perform different tasks ranging from collision detection to a safe avoidance manoeuvre initiation. Avoidance manoeuvres that are compliant with the rules of the air are proposed based on pilot suggestions for a subset of possible collision scenarios. The proposed avoidance manoeuvres are parameterized using a geometric approach. An optimal collision avoidance algorithm is developed for real-time local trajectory planning. Essentially, a finite-horizon optimal control problem is periodically solved in real-time hence updating the aircraft trajectory to avoid obstacles and track a predefined trajectory. The optimal control problem is formulated in output space, and parameterized by using B-splines. Then the optimal designed outputs are mapped into control inputs of the system by using the inverse dynamics of a fixed wing aircraft.

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