CRUISE: fault tolerant Control for highly Redundant multirotor Unmanned aerIal vehicle using Sliding modEs

Lead Research Organisation: University of Exeter
Department Name: Engineering Computer Science and Maths

Abstract

Recent reports by the EU and House of Lords on the civilian use of unmanned aerial vehicles (UAVs) have highlighted examples of UAV applications for civil and commercial applications, which include search & rescue, inspection and filming. In fact recent media coverage highlighted prominent companies such as Amazon, DHL and Google which are seriously considering, and testing, small UAVs for delivery services.

Despite the huge potential impact of small UAVs on civil life and commercial practices, an increase in reported UAV-related incidents (e.g. a collision with a bridge, near collisions with large passenger aircraft, and injury to an athlete) has been a major concern for regulators worldwide. At present, the commercial use of small UAVs is currently heavily restricted and regulated in the UK. Some incidents occurred due to operator shortcomings, but raise serious concerns about the safety of UAVs, especially when one considers the presence of a large number of civil and commercial UAVs flying autonomously in heavily populated areas. Therefore, there is an urgent need to develop control technologies which will compensate for faults and failures, and enable the safe operation of autonomous UAVs. In fact, it is envisaged that small UAVs will embrace and implement advanced state-of-the-art fault tolerant control schemes before their manned aircraft counterparts could, partly due to their versatility and the fundamental need to ensure safety for civil and commercial applications.

This project will therefore: (1) help improve safety, resilience and survivability of small multirotor unmanned aerial vehicles in the event of in-flight faults and failures, and (2) bridge the gap between the theory and application of sliding mode control, thus encouraging adoption of sliding mode control in industry, particularly aerospace. Flight control systems will be developed for a small, highly redundant UAV for commercial and civil applications. A resilient control system, typically known as fault tolerant control (FTC), will be built based on sliding mode control (SMC) schemes. The fault tolerant schemes will initially be simulated with realistic faults/failures using a simulation tool developed in this project, then followed by hardware implementation and rigorous evaluation on a highly redundant UAV.

An important aspect of this proposal is the partnership with Bristol Robotics Laboratory (BRL) and Blue Bear Systems Research Ltd (BBSR). Driven by industrial challenges and supported by BRL and BBSR, a rigorous assessment and evaluation campaign will be undertaken to highlight the maturation of the control schemes developed during the project. By demonstrating an increase in technology readiness level (TRL), the project will promote the adoption of these technologies in industry.

Planned Impact

Economic impact:

Recent reports from Innovate UK acknowledged that the UK is 'well placed in the soaring UAV market' to unlock the extensive use of UAVs for commercial and civil applications. In formal reports on the civilian use of UAVs, the House of Lords and the European Union have estimated potential growth in the commercial UAVs market of $8.3bn by 2018, with the creation of 150,000 jobs across Europe. The reports also highlight the use of UAVs in civil and commercial applications is envisaged to become an intrinsic part of public life by 2020. Some industries, e.g. filming and leisure, have already embraced the technology, but concerns over safety remain.

This project will tackle challenges, which currently restrict full utilisation of UAVs for civil and commercial applications. Research into fault tolerant control for UAVs is rapidly expanding due to its potential to transform businesses, protect the environment and safeguard our wellbeing. By addressing current safety and technological issues associated with UAVs, this project will facilitate the civil and commercial employment of small UAVs in the UK and Europe, enabling growth of the small UAVs market, thereby solidifying the UK's position as a global leader in this rapidly expanding industry.

Industrial impact:

The technology developed during the project will be valuable to the aerospace sector by addressing UAV safety issues, which are critical for realising the potential of civil and commercial UAV applications in populated areas. Close collaboration with Blue Bear System Research Ltd (BBSR) will allow the company to rapidly access the technological advances developed through this project, thus giving them a strategic lead in the market. Furthermore, the activities in this project will highlight the maturation of the control scheme considered and promote its adoption in industry (e.g. Airbus, Deimos, Qinetiq and QuestUAV), by demonstrating an increase in technology readiness level (TRL). Additionally, the control schemes developed in this project will ultimately benefit areas beyond the UAV application considered in this project, for example: automotive, healthcare and renewable energies (e.g. wind and marine).

Societal impact:

Small UAVs are popular among younger generations, film-makers and tech enthusiasts. Therefore, this project promotes public awareness of the safety hazards associated with UAVs, particularly among commercial and 'emerging leisure users'. This project will also help enable the safe use and applications of civil and commercial UAVs (e.g. search and rescue service) and foster public confidence in the adoption of UAV technology, i.e. safety, security, privacy and data protection. Furthermore, the research in this project has the potential to attract the attention of regulators, and thereby influence UAV safety legislation across the globe.

The project will also inspire younger generations about UAVs, and other engineering topics, e.g. aerospace and coding/programming. Students across the South West of England will be the immediate beneficiaries through outreach, public engagement, open days and summer schools. A wider outreach initiative to inspire the researchers of the future will also be possible through a dedicated webpage created for the project and the University's media service. The webpage will feature the latest news and exciting developments in the field of small UAVs in general such as 'drone racing' and nature-inspired UAV designs (e.g. bats, moths and birds).

Publications

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