Immune-system inspired approach for decentralized multi-agent control

This paper contains the first steps towards the development of a fully decentralized system framework. The novel approach that has been taken is derived from the inherent properties of the immune system. An assessment of the proposed control architecture has been performed by comparison with a more typical approach under a search and suppress kind of mission for an unmanned fleet

Verifying collision avoidance behaviours for unmanned surface vehicles using probabilistic model checking

Collision avoidance is an essential safety requirement for unmanned surface vehicles (USVs). Normally, its practical verification is non-trivial, due to the stochastic behaviours of both the USVs and the intruders. This paper presents the probabilistic timed automata (PTAs) based formalism for three collision avoidance behaviours of USVs in uncertain dynamic environments, which are associated with the crossing situation in COLREGs. Steering right, acceleration, and deceleration are considered potential evasive manoeuvres. The state-of-the-art prism model checker is applied to analyse the underlying models. This work provides a framework and practical application of the probabilistic model checking for decision making in collision avoidance for USVs

Airport connectivity optimization for 5G ultra-dense networks

The rapid increase of air traffic demand and complexity of radio access network motivate developing scalable wireless communications by adopting system intelligence. The lack of adaptive reconfiguration in radio transmission systems may cause dramatic impacts on the traffic management concerning congestion and demand-capacity imbalances driving the industry to jointly access licensed and unlicensed bands for improved airport connectivity. Therefore, intelligent system is embedded into fifth generation (5G) ultra-dense networks (UDNs) to provision dense and irregular deployments that maintain extended coverage and also to improve the energy-efficiency for the entire airport network providing high speed services. To define the technical aspects of this solution, this paper addresses new intelligent technique that configures the coverage and capacity factors of radio access network considering the changes in air traffic demands. This technique is analysed through mathematical models that employ power consumption constraints to support dynamic traffic control requirements to improve the overall network capacity. The presented problem is formulated and exactly solved for medium or large airport air transportation network. The power optimization problem is solved using linear programming with careful consideration to latency and energy efficiency factors. Specifically, an intelligent pilot power method is adopted to maintain the connectivity throughout multi-interface technologies by assuming minimum power requirements. Numerical and system-level analysis are conducted to validate the performance of the proposed schemes for both licenced macrocell Long-Term Evolution (LTE) and unlicensed wireless fidelity (WiFi) topologies. Finally, the insights of problem modelling with intelligent techniques provide significant advantages at reasonable complexity and brings the great opportunity to improve the airport network capacit

Modelling and Verification of Multiple UAV Mission Using SMV

Model checking has been used to verify the correctness of digital circuits, security protocols, communication protocols, as they can be modelled by means of finite state transition model. However, modelling the behaviour of hybrid systems like UAVs in a Kripke model is challenging. This work is aimed at capturing the behaviour of an UAV performing cooperative search mission into a Kripke model, so as to verify it against the temporal properties expressed in Computation Tree Logic (CTL). SMV model checker is used for the purpose of model checking

Cooperative control for multiple interceptors to maximize collateral damage

In this paper, a cooperative control method to satisfy the relative interception angle constraints in multi-to-one engagement case is proposed. In this study, we consider the relative interception angle constraints of the multiple interceptors, which is intended to enhance the survivability of the multiple interceptors against a defense system of high value target as well as to maximize the collateral target damage. The proposed cooperation control can reduce the total control energy required while satisfying the given interception angle constraints. This characteristic allows to increase the change of mission in the multi-to-on engagement scenario. In this paper, the numerical simulations are conducted to verify the feasibility of proposed concept

Fuzzy logic based equivalent consumption optimization of a hybrid electric propulsion system for unmanned aerial vehicles

This paper presents an energy management strategy for a hybrid electric propulsion system designed for unmanned aerial vehicles. The proposed method combines the Equivalent Consumption Minimization Strategy (ECMS) and fuzzy logic control, thereby being named Fuzzy based ECMS (F-ECMS). F-ECMS can solve the issue that the conventional ECMS cannot sustain the battery state-of-charge for on-line applications. Furthermore, F-ECMS considers the aircraft safety and guarantees the aircraft landing using the remaining electrical energy if the engine fails. The main contribution of the paper is to solve the deficiencies of ECMS and take into consideration the aircraft safely landing, by implementing F-ECMS. Compared with the combustion propulsion system, the hybrid propulsion system with F-ECMS at least reduces 11% fuel consumption for designed flight missions. The advantages of F-ECMS are further investigated by comparison with the conventional ECMS, dynamic programming and adaptive ECMS. In contrast with ECMS and dynamic programming, F-ECMS can accomplish a balance between sustaining the battery state-of-charge and electric energy consumption. F-ECMS is also superior to the adaptive ECMS because there are less fuel consumption and lower computational cost

Fuzzy physical programming for Space Manoeuvre Vehicles trajectory optimization based on hp-adaptive pseudospectral method

In this paper, a fuzzy physical programming (FPP) method has been introduced for solving multi-objective Space Manoeuvre Vehicles (SMV) skip trajectory optimization problem based on hp-adaptive pseudospectral methods. The dynamic model of SMV is elaborated and then, by employing hp-adaptive pseudospectral methods, the problem has been transformed to nonlinear programming (NLP) problem. According to the mission requirements, the solutions were calculated for each single-objective scenario. To get a compromised solution for each target, the fuzzy physical programming (FPP) model is proposed. The preference function is established with considering the fuzzy factor of the system such that a proper compromised trajectory can be acquired. In addition, the NSGA-II is tested to obtain the Pareto-optimal solution set and verify the Pareto optimality of the FPP solution. Simulation results indicate that the proposed method is effective and feasible in terms of dealing with the multi-objective skip trajectory optimization for the SMV

Condition based maintenance optimization of an aircraft assembly process considering multiple objectives

The Commercial Aircraft Cooperation of China (COMAC) ARJ21 fuselage's final assembly process is used as a case study. Thefocus of this paper is on the condition based maintenance regime for the (semi-) automatic assembly machines and how theyimpact the throughput of the fuselage assembly process. The fuselage assembly process is modeled and analyzed by using agentbased simulation in this paper.The agent approach allows complex process interactions of assembly, equipment, and maintenanceto be captured and empirically studied. In this paper, the built network ismodeled as the sequence of activities in each stage, whichare parameterized by activity lead time and equipment used. A scatter search is used to find multiobjective optimal solutions forthe CBM regime, where the maintenance related cost and production rate are the optimization objectives. In this paper, in orderto ease computation intensity caused by running multiple simulations during the optimization and to simplify a multiobjectiveformulation,multipleMin-Max weightings are used to trace Pareto front. The empirical analysis reviews the trade-offs between theproduction rate and maintenance cost and how sensitive the design solution is to the uncertainties

A comparison between guidance laws for AUVs using relative kinematics

This paper presents a comparison between three popular guidance laws for path following of autonomous underwater vehicles: switching enclosure-based Line-Of-Sight (LOS), lookahead-based LOS, and vector field guidance laws. The equations of motion employ the concept of the relative kinematics, and a nonlinear controller is applied together with the guidance systems during path-following. The optimal tuning values for each guidance are selected using the Pareto efficiencies from multiple simulations in terms of providing low cross-track error and control effort. Performance analysis are carried out for a waypoint following scenario both with and without significant constant and irrotational ocean currents as disturbances. Simulation results are also presented using the model of an AUV