Guaranteed Performance of Dynamic Behaviour of Multiple Unmanned Aerial Vehicles

Lead Research Organisation: Imperial College London
Department Name: Chemical Engineering

Abstract

The use of multiple unmanned aerial vehicles (MUAVs) can provide significant reductions in manpower and risk to humans for critical security and defence roles. In particular, MUAVs potentially offer: 1) enhancements of the coverage of large areas by improvement in latency and accuracy of information gathering; 2) increase in the mission success rate; 3) enabling new tasks and operations by increasing autonomy; 4) robustness and benign degradetion in performance. A key utility feature of a single UAV is that it is a mobile sensor platform. MUAVs offer a magnification of the sensing capability by creating an airborne, relocatable multi-sensor. This capability offers new opportunities for surveillance and reconnaissance missions which provide the practical context of the proposed research.A key issue which must be addressed in order for the potential benefits to become real is guaranteed performance of the dynamic behaviour of MUAVs. In particular, coordinating flight dynamics of MUAVs in a predictable and verifiable way is crucial for their certification in the airspace and acceptance for safety-critical missions. therefore, the main focus of this proposal is to develop and validate a rigorous, analytical framework for deriving and accesing guaranteed dynamic and kinematic performance of MUAVs. The dynamic behaviour of MUAVs constitutes an interconnected dynamical system depending on the individual dynamics and on the nature of the vehicle-vehicle and environment-vehicle interactions. The representation of this dynamical system as a distinct entity and the optimisation of its performance is a challenging study. Despite the recent advances, an actual operation of a group of MUAVs has not been fully realised yet.The main thrust of the proposed project is to develop a rigorous, analytical framework that determines in detail the number and characteristics of the vehicles, the interactions between the vehicles and their embedded guidance and control schemes. This framework will be used to predict MUAVs behaviour in two multitask mission scenarios, and assess the resulting performance through simulations and ground vehicle experiments. The framework is expressed in terms of a hierarhical character of co-operative controller of multiple UAVs; the hierarchy comprises three layers. Co-mission/tasks. Layer 1 decision-making results in generation of co-operative trajectories in Layer 2, realising coordinated guidance for the UAVs acting as a group. The coordinated guidance produces co-operating trajectories. Each reference trajectory (guidance demand) generated in Layer 2 is then followed by the individual controllers of the UAVs, with the cooperation decided on Level 1, and defined by the trajectory tracking requirements in Level 2. The centrel design issue is how to design each layer and their interaction, so that the individual and group performance can be guaranteed.The programme of this research work will ivolve both the study of each of three layers of cooperative control and the integration of them for two example scenarios. Two PhD students and two post doctoral research associates (RA) will develop new solutions for both scanarios. Cranfield's PhD student will develop new algorithms for coordinated guidance, while Imperial's PhD student will focus on the use of Mixed-Integer Optimization and Parametric Programming methods to express dynamics of the vehicles. Cranfield's post-doc RA will focus on the interogation of planning (Layer 1) and guidance (Layer 2). imperial's RA will focus on the integration of guidance (Layer 2) and tracking control (Layer 3).

Publications

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Description The outcomes of this research project are novel theoretical and algorithmic methods for the integrated path-generation, guidance and control of unmanned air vehicles (UAVs). More specifically, the developments of this research are the following



A. Novel explicit/multi-parametric robust control methods for the low-level control and guidance of UAVs.

B. A framework for the offline design and validation/testing of explicit/multi-parametric MPC controllers for the tracking control of UAVs.

C. A framework for the simultaneous design of constrained Moving Horizon Estimation (MHE) and robust explicit/multi-parametric MPC relevant to the guidance and control of UAVs.

D. Improvement of existing linear dynamic models for UAV to capture the effect of the wind.

E. Investigation of the implementation of modern estimation methods (such as MHE) for wind estimation in UAVs.

F. Novel methods for multi-parametric Mixed-Integer Linear Programming (mp-MILP) relevant to the path-generation and guidance.

G. A framework for the integration of the path-generation, guidance and low-level control levels of the co-operative control of UAVs.



In addition, a number of case studies were performed for evaluating the developed methodologies. In these case studies the developed frameworks for explicit/multi-parametric robust control, simultaneous design of moving horizon estimators and explicit controllers and the integration framework for the path-planning, guidance and control levels were evaluated on a small UAV system. Additional case studies from the area of process and energy systems were also contacted to evaluate the developed control methodologies and demonstrate their potential use in other engineering areas.
Exploitation Route The research may be used by the defence industry and potential use growing number of civil applications such as civilian aerial surveillance and oil and gas exploration and production (e.g. monitoring of the integrity of oil and gas pipelines and related installations, geomagnetic surveys)
Findings are thoughts to be relevant for the following applications:



- defence industry

- security/surveillance (

- exploration and production for mining and oil and gas (geomagnetic surveys)

- scientific research (e.g. aerosondes used to track huricanes)

- search and rescue

- environment monitoring
Sectors Aerospace, Defence and Marine