Persistence through Reliable Perching (PEP)

Small Unmanned Aerial Systems (SUAS), enjoying the advantage of small size and low-weight, can be easily carried by end-users and rapidly deployed into different scenarios. However, multi-rotor, battery powered SUAS usually have the endurance of around 20 mins. In contrast, a common request for SUAS is the persistence of hours or more. Swarm Systems is developing a product for the growing market need of flying binoculars based on a Nano quadrotor platform (under 200g). Customers are specifically asking for a perch and stare capability to achieve persistence. However, perching using existing technology is very hit and miss. This Persistence through Reliable Perching (PEP) proposal has a goal of achieving greater than 99% reliability in perching on unprepared, outdoor locations in challenging weather conditions and taking off again. The PEP research approach includes: adding new passive and active sensors, creating soft sensors from combinations of existing sensors, researching a novel automatic abort using 'disturbance from internal model' techniques and innovating undercarriage design including multi-surface gripping. In particular, the Loughborough team will be responsible to develop the novel 'abort' flight control function to enable the SUAS to recover from unsuccessful perching in the presence of external disturbances such as wind gusts or contact with obstacles. A disturbance observer based on the quadrotor's internal model will be designed as a 'soft' sensor to provide estimates on abnormal external forces acting on the airframe together with normal sensors. The estimates will then be fed into a decision-maker to trigger the 'abort' flight mode, where a dedicated flight controller will be designed and optimised to perform this maneuver.

PEP project management will be led by an analysis of perching ground types and weather conditions. The final 1/3 of the project will be focused on improving where testing proves that reliability is poor. The Loughborough team will use its world leading indoor flight test facility (using Vicon system) to verify its algorithm and help the system integration of different algorithms into Swarm System's Nano quadrotor. A commercial goal is to add a key new capability to Swarm Systems product, enabling it to win export orders.

The direct beneficiaries of this project will be participators in UAV communities. This project is able to provide a new control design tool for UAVs, which are often subject to external disturbances and need agile manoeuvres. We also believe that the effective dissemination of the research outcomes and methods of this project will pave the way for wide applications of the proposed control method in different domains (e.g. robotics, maritime vessels and general industrial control applications), which in turn will bring long term impact.

On the other hand, by closely working with the project partner Swarm Systems Ltd (SSL), it is envisaged that the following impact will be made through the company:

Customers: Presently, the utility of a Small Unmanned Aerial Vehicle (SUAS) is limited to around 20mins in all applications. With the proposed project, that utility can be expanded to many hours outdoors, which can extensively expand the range of applications. Furthermore, with solar re-charging, a new era in which SUASs can be outdoors for many days and weeks becomes possible.

Supply chain: SSL has a largely British supply chain. Manufacturing, assembly and dispatch takes place at Adapt EMS in the region of Hitchin, Herts. SSL licenses IP from some of its subcontractors. If sales grow rapidly, then more R&D will be subcontracted to companies and universities throughout the UK.

Imports: The MoD placed their first Flying Binoculars procurement with a Norwegian company. If SSL, with new capability such as PEP, wins the next MoD procurement then approximately £20m of equipment imports will be substituted.

Social impact: some jobs that are dull, dangerous and dirty will be substituted by a perching SUAS. Productivity will increase as mundane work is automated.

Environmental: PEP will contribute to their being higher safety levels in autonomous SUASs.