An Intelligent Integrated Navigation and Autopilot System for Uninhabited Surface Vehicles

Lead Research Organisation: University of Plymouth
Department Name: Sch of Marine Science & Engineering

Abstract

Global positioning systems (GPSs) are very useful navigational aids for both civilian and military vehicular systems. However, owing to the weakness of the radio signals from the satellites they are susceptible to signal loss when operations are being conducted in confined areas such as rivers, mountains and canyons, and are extremely exposed to being deliberately jammed by terrorists or aggressors during times of extreme tension or conflict. Thus given the vulnerability of GPSs to signal loss, it is prudent not to be totally reliant upon them in the design of navigation subsystems for autonomous vehicles (AVs). One solution to this problem is to enhance the subsystem with an algorithm based on simultaneous localization and mapping (SLAM) techniques. SLAM being the process of simultaneously building a feature based map of the operating environment and utilizing it to estimate the location of an AV. To further improve the capability and performance envelope of an AV it is appropriate to combine a SLAM reinforced navigation subsystem with an adaptive control subsystem thereby transforming them into one fully integrated system.This research proposal aims to design and build a new advanced intelligent integrated navigation and autopilot (IINA) system with adaptive capabilities for uninhabited surface vehicles (USVs). The existing intelligent navigation (IN) subsystem will be complemented with a SLAM algorithm which will be newly designed and also capable of interfacing with other types of more traditional navigation system. The new improved IN subsystem will be benchmarked against the existing navigation subsystem and a navigation system enhanced with an inertial measurement unit supplied by Atlantic Inertial Systems (AIS) who are the industrial collaborator for this project. Whilst the intelligent integrated system will be designed and developed for a marine application, the technology evolved will be able to be transferred and used in other types of AV.A common feature with many SLAM algorithms is the reliance upon extended Kalman filters to act as the information data collection mechanism. In this research proposal an interval Kalman filter (IKF) which uses interval calculus in its design will be employed instead and enhanced using artificial intelligence techniques to construct a fuzzy IKF (FIKF). Scene information extraction for SLAM can be from visual or non-visual sources. Visual SLAM has the benefit of selecting and using robust features gained from video imagery of the local scene. A novel aspect of this work will be the design of a feature-matching algorithm (FMA) that will be capable of operating in night-time conditions. Thus, an information data collection mechanism based on a FIKF will be integrated with the FMA to form the overall SLAM enhancement algorithm.Whilst there are a number of methods for introducing adaptability into an autopilot design, in this research project the approach to be taken will be based on a combination of on-line closed loop identification and model predictive control. Thus the methodology described herein represents a new conceptual framework for the design of marine autopilots. It should also be noted that, to date, all uninhabited marine vehicle system identification trials have been performed in the open loop. Upon the successful completion of the design of the adaptive autopilot, it will be merged with the SLAM enhanced IN subsystem to form the IINA system.

Planned Impact

In summary, the research and technological advancements which will be made in this programme of work will result in the following: (1) Current feature trackers perform well on man-made structures in scenes. The highly repetitive textures that are characteristic of natural scenes require a new method to be researched and developed. We propose to assess existing techniques and compare to two new techniques. The ability to establish landmarks in highly difficult natural scenes including low light conditions will open up new opportunities for SLAM operation. The new feature detector will make a significant contribution to the wider machine vision community. (2) The HD video archive will be developed as a public data set to allow other researchers access to this difficult visual domain. Co-lateral data will be made available as well. This will ensure that concurrent with the video stream GPS and gyro data are made available. It is expected this to foster further co-operative work with related machine vision researchers. (3) An attractive alternative Kalman filter design that possesses excellent qualities in terms of adaptability, accuracy, robustness, reliability and stability. (4) A ubiquitously novel SLAM enhancement algorithm which will be capable of enhancing more conventional navigation systems and allow truly autonomous navigation to take place with a night-time operational capability. (5) A new adaptive marine autopilot that will possess a wide operational envelope and be compatible with a range of navigation systems. (6) A new conceptual paradigm for marine autopilot design. (7) An innovative intelligent integrated navigation and autopilot (IINA) system which is technically and practically superior to its predecessors in terms of accuracy, capability and robustness. The control and robotic academic and industrial communities will benefit greatly from the above research outputs. The approaches taken in the design of the Kalman filter, the feature tracking algorithm and the adaptive autopilot will be capable of being converted into design tools for use in a range of different waterborne and land applications. Also both the SLAM algorithm and the IINA system may be modified for usage in land and indoor mobile robots, and underwater robotic systems. Knowledge of the various research outcomes and their potential will be promulgated in number ways including journals and conference proceedings. Of particular note is the maintenance of a dedicated website that will contain all progress reports, trials data, photographs and videos, published papers and software listings, with links provided to/from the websites of co-researchers and related programmes/research centres within the UK, Europe and the rest of the world. The UP Knowledge Exploitation team in collaboration with AIS will create an exploitation proposal which will include a business plan and potential market opportunities. Product(s) based on the above will be commercially exploited in partnership with AIS possibly as stand alone items or as enhancements to their existing product line. Thus a route to the worldwide financially lucrative military and civilian market places for navigation and control systems hardware will be established which will increase the economic competitiveness of the UK in these particular industrial sectors. Clearly the IINA system has the potential for installation in land and waterborne robotic systems where they are required to operate in dense and cluttered environments without the aid of GPS for both military and civilian applications. Additionally, the IINA system by itself could be employed in the marine sector as an automatic control system for ships and large marine craft.
 
Description We have developed an integrated approach for navigation, guidance and control for unmanned surface vehicles where vehicles can adapt in a changing and GPS denied environment. Better and robust estimation of sensor's readings were also obtained by improving a basic Kalman filtering approach by an interval based Kalman filter. The algorithms were also tested both in simulation and real environment and can be used for other applications in air and land.
Exploitation Route The robust and efficient algorithms for navigation, guidance and control.
Sectors Aerospace, Defence and Marine,Transport

URL https://www.plymouth.ac.uk/research/autonomous-marine-systems
 
Description In this study, the design of a navigation, guidance and control (NGC) system for the Springer USV was based on the key criteria of adaptability, robustness and reliability. By using these criteria as a design philosophy it has been possible to produce a generic system which the general public can be confident in its usage with economic savings being made in the operational costs of this and similar vehicles. The adaptable nature of the NGC system is reflected in its autopilot (controller) being able to cope with sudden variations in payloads and a navigation subsystem capable of handling the loss of GPS signals thereby allowing missions to continue with minimum disruptions. Whereas the robustness of the system is seen by the ability of the guidance subsystem and autopilot to work together to minimize the effects of adverse environmental conditions whilst still producing better waypoint track paths than other more traditional NGC systems. Thus mission costs can be cut by the provision of shorter optimized paths. Also the interval Kalman filter approach used in the navigation system is more robust to drift and faults in the sensor suite compared to more conventional Kalman filter techniques. Furthermore, with regards to reliability, this has been tackled in two ways. Firstly, during the autopilot study amongst others a quantitative energy performance index based on control demand was employed in the design selection. As a consequence, the batteries in the vehicle had longer longevity which in turn impacts on longer mission durations. Also by taking into account controller action results in less wear in the actuators and hence less maintenance costs can achieved. Thus such considerations make a significant contribution to the sustainability aspects of the NGC system. Secondly, the project was enhanced by a study into the application of fault monitoring and diagnosis techniques in USVs. In particular, the study investigated such techniques in detecting damaged propeller blades of trolling motors typically used in the Springer propulsion system. The work being reported in a technical report and a recently submitted journal paper to the Proceedings of IMechE Part I. Clearly this work needs to be expanded to help long endurance autonomous missions to be conducted. The above prototype technology that has been developed and briefly outlined above is now mature enough to go to the commercialization stage with suitable entrepreneurial backing. The advantage of this technology is that it is generic and can easily be transferred into aerospace and land vehicle applications as well. Thus it has great potential to be a commercial success which will impact positively on the employment market and the economy. Throughout this project the Research Team has made a conscious decision to publish regularly their results in the press, trade magazines, on the television and radio, and at public engagement events in order to enlighten the public on the need for such technology and the latest advances made in the area. Information dissemination via technical reports, conference presentations and papers, and journal articles have been forthcoming and was considered vital in order to help lay the foundation for the development of a skilled workforce to support this growing and exciting highly technological area. Finally, it is worth remembering that the developed technology is aimed at improving the performance of unmanned craft which could see service in hazardous environments in place of manned vehicles where the personnel would be in life threatening situations. Thus any technology, as in this case, that has the potential to preserve life must be beneficial to society.
First Year Of Impact 2014
Sector Aerospace, Defence and Marine,Transport
Impact Types Economic,Policy & public services

 
Description Ministry of Education Academic Research Fund, Singapore
Geographic Reach Europe 
Policy Influence Type Participation in advisory committee
 
Description China Scholarship Council grant
Amount £20,700 (GBP)
Organisation University of Leeds 
Department China Scholarship Council
Sector Academic/University
Country United Kingdom
Start 11/2014 
End 04/2016
 
Title Adaptive Autopilot based on MPC 
Description An Adaptive Autopilot based on MPC was developed and tested in real time which is capable of coping with sudden changes in the USV's payload. This is the first application of this technique in the marine environment. 
Type Of Material Computer model/algorithm 
Year Produced 2014 
Provided To Others? Yes  
Impact Several journal and conference publications. 
 
Title Interval Kalman Filtering 
Description It is considered that in this study it is the first time an Interval Kalman filter has been used as a navigation subsystem and implemented in a real time. 
Type Of Material Computer model/algorithm 
Year Produced 2014 
Provided To Others? Yes  
Impact Several publications in esteemed journals and conference proceedings. 
 
Title Visual SLAM 
Description Visual SLAM techniques which are mostly used for land applications were tested for the first time in cluttered marine environments with modified algorithms. 
Type Of Material Computer model/algorithm 
Year Produced 2014 
Provided To Others? Yes  
Impact UTCAS, our industrial partner in this project demonstrated these techniques during their defence bid. 
 
Description Collaborative partners 
Organisation UTCAS Trastornos de la Conducta Alimentaria
Country Spain 
Sector Charity/Non Profit 
PI Contribution Technical knowledge obtained from SLAM were used by UTCAS in a defence technical bid. Two PhD interns from UCL were seconded for 3 months to the project and trained on multi-sensor-data-fusion and path planning techniques.
Collaborator Contribution UTCAS supplied their kind support by attending technical meetings and providing expert advice on sensor and instrumentation related matters. They also provided their commercial IMU worth of £5000 for benchmarking purposes. Oxford rovided advice on SLAM and Girona on both SLAM and system identification techniques.
Impact 1) UTCAS - Sensor integration and benchmarking (Aerospace, Marine and Mechanical) 2) Oxford - Expert advice on SLAM algorithms development (Engineering Science and Computing and Electronics) 3) Girona - Expert advice on SLAM and system identification (Aerospace, Marine, Mechanical, Computing and Electronics) 4) UCL - Interim training on multi-sensor-data-fusion and path planning techniques - Technical reports and one journal paper submitted to Proc M: IMechE (Mechanical and Marine)
Start Year 2011
 
Description Collaborative partners 
Organisation University College London
Country United Kingdom 
Sector Academic/University 
PI Contribution Technical knowledge obtained from SLAM were used by UTCAS in a defence technical bid. Two PhD interns from UCL were seconded for 3 months to the project and trained on multi-sensor-data-fusion and path planning techniques.
Collaborator Contribution UTCAS supplied their kind support by attending technical meetings and providing expert advice on sensor and instrumentation related matters. They also provided their commercial IMU worth of £5000 for benchmarking purposes. Oxford rovided advice on SLAM and Girona on both SLAM and system identification techniques.
Impact 1) UTCAS - Sensor integration and benchmarking (Aerospace, Marine and Mechanical) 2) Oxford - Expert advice on SLAM algorithms development (Engineering Science and Computing and Electronics) 3) Girona - Expert advice on SLAM and system identification (Aerospace, Marine, Mechanical, Computing and Electronics) 4) UCL - Interim training on multi-sensor-data-fusion and path planning techniques - Technical reports and one journal paper submitted to Proc M: IMechE (Mechanical and Marine)
Start Year 2011
 
Description Collaborative partners 
Organisation University College Oxford
Country United Kingdom 
Sector Academic/University 
PI Contribution Technical knowledge obtained from SLAM were used by UTCAS in a defence technical bid. Two PhD interns from UCL were seconded for 3 months to the project and trained on multi-sensor-data-fusion and path planning techniques.
Collaborator Contribution UTCAS supplied their kind support by attending technical meetings and providing expert advice on sensor and instrumentation related matters. They also provided their commercial IMU worth of £5000 for benchmarking purposes. Oxford rovided advice on SLAM and Girona on both SLAM and system identification techniques.
Impact 1) UTCAS - Sensor integration and benchmarking (Aerospace, Marine and Mechanical) 2) Oxford - Expert advice on SLAM algorithms development (Engineering Science and Computing and Electronics) 3) Girona - Expert advice on SLAM and system identification (Aerospace, Marine, Mechanical, Computing and Electronics) 4) UCL - Interim training on multi-sensor-data-fusion and path planning techniques - Technical reports and one journal paper submitted to Proc M: IMechE (Mechanical and Marine)
Start Year 2011
 
Description Collaborative partners 
Organisation University of Girona
Country Spain 
Sector Academic/University 
PI Contribution Technical knowledge obtained from SLAM were used by UTCAS in a defence technical bid. Two PhD interns from UCL were seconded for 3 months to the project and trained on multi-sensor-data-fusion and path planning techniques.
Collaborator Contribution UTCAS supplied their kind support by attending technical meetings and providing expert advice on sensor and instrumentation related matters. They also provided their commercial IMU worth of £5000 for benchmarking purposes. Oxford rovided advice on SLAM and Girona on both SLAM and system identification techniques.
Impact 1) UTCAS - Sensor integration and benchmarking (Aerospace, Marine and Mechanical) 2) Oxford - Expert advice on SLAM algorithms development (Engineering Science and Computing and Electronics) 3) Girona - Expert advice on SLAM and system identification (Aerospace, Marine, Mechanical, Computing and Electronics) 4) UCL - Interim training on multi-sensor-data-fusion and path planning techniques - Technical reports and one journal paper submitted to Proc M: IMechE (Mechanical and Marine)
Start Year 2011
 
Description BBC Spotlight News Programme and BBC Devon Radio (18 Sep 2014) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact BBC Spotlight and BBC Devon Radio broadcasted the application of the Springer USV undertaking surveying tasks using a side-scan sonar at Roadford Reservoir, Devon, UK. See the link below for the BBC Spotlight broadcast:
https://dl.dropboxusercontent.com/u/74315540/Spotlight_-_19_09_2014.mpg

Met Office (Exeter) contacted us with a view to collaborate in a TSB call.
Year(s) Of Engagement Activity 2014
 
Description Marine Science and Technology Showcase 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Nearly 300 school children attended this event and were presented with advanced techniques in a simple and easy to understand language to stimulate their interest in marine robotics systems.

A high number of prospective students at our Open Days and enquired about the research and related courses.
Year(s) Of Engagement Activity 2012
 
Description Newspaper articles 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Several newspapers and online organisation as listed below showed interest in this research and approached us from time to time to publish outcomes for general dissemination.
1) Maritime Journal (2011)
2) Western Morning News (2011)
3) The Herald (2014)
4) Devon and Cornwall News (2014)

Local schools and colleges expressed their desire to see the vehicle and to know about the project in more details.
Year(s) Of Engagement Activity 2011,2012,2014
 
Description Workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact 40 people from leading UK academia and the marine industry attended this workshop and participated in the event which resulted in a roadmap for future research activities in this area.

An EPSRC research proposal has been recently submitted based on the outcomes from this workshop. A bid is also in preparation to establish an EPSRC Marine Autonomous Systems Technology Network at Plymouth.
Year(s) Of Engagement Activity 2013