Dr Nadjim Horri

I am a lecturer (assistant professor) in aerospace control and currently the course director of the MSc Aerospace Engineering at the University of Leicester. I am a member of the aerospace research group and an associate member of the green energy and transportation research group within the school of engineering. My current research activities are in the guidance, navigation and control (GNC) of manned and unmanned aircraft and I also work closely with Space Park Leicester on satellite attitude and orbit control systems (AOCS) and related aspects of space mission analysis and design.

Before joining the University of Leicester, I was an assistant professor at Coventry University, where I worked on an EU ERFD project on hybrid UAV avionics, Innovate UK project Assured CAV parking and simulation based flight incident investigation consultancies. I also led the MSc Aerospace Engineering course and taught real time control, avionics, flight dynamics and UAV related modules. Before that, I worked as a research fellow for 5 years at the Surrey Space Centre, University of Surrey on EU project ASTRONET, EPSRC project AAReST (cubesat formation flight and reconfiguration) and STFC project STRaND-2 (In-orbit inspection). In surrey, I also led the guidance, navigation and control module and supported the spacecraft dynamics and propulsion modules. My PhD from University of Surrey was on the attitude control of underactuated spacecraft, with in-orbit implementation on SSTL satellites UoSat-12 and UK-DMC1.

Research interests

1. The development of safe, resilient and energy efficient GNC for aircraft (including UAV and eVTOL with hybrid aircraft configurations)
2. Motion, fault and disturbance estimation for aircraft or spacecraft using estimation approaches from observers and Kalman filters to particle filters. This includes aircraft parameter estimation and system identification, fault detection, isolation and recovery (FDIR) under sensor and actuator faults. This also extends to secure estimation for enhanced protection from cyberattacks on sensing (e.g. GPS spoofing) or on actuation
3. UAV path following, including enhanced formulations of pure pursuit, carrot chasing, vector field-based and other guidance methods to enable applications requiring high accuracy such as precision agriculture. This includes the Coordinated control of formations of collaborative UAVs
4. Optimal UAV coverage path planning using multi-objective optimisation, graph-based, sampling-based or machine learning (ML)-based approaches
5. Wind disturbance rejection using feedforward, adaptive or increasingly model predictive control (MPC) approaches to exploit forecasts and wind preview.
6. Spacecraft attitude and orbit control systems (AOCS), including forward motion compensation (FMC) and other attitude control modes under actuator constraints or faults, satellite attitude determination and formation flight for in-orbit maintenance or assembly and debris removal
7. Multimode GNC, including mode switching control and hybrid (continuous, discrete) systems, reconfigurable GNC systems, mode switching stability, multimode navigation with sensor fusion and optimal control allocation.
8. Flight simulation and hardware-in-the-loop (HIL) implementations for flight incident investigations (e.g. icing, pilot induced oscillations)
9. Constrained flight control including flight envelope protection (FEP), the handling of actuator constraints, reference governor for the handling of output constraints, gain-scheduling and Optimal control, including MPC. 
10. Adapting robustness settings to the severity of disturbances in adaptive robust control for improved disturbance resilience or fault tolerance and robust control with finite or fixed-time convergence
11. Allowing aircraft to "learn to fly" using AI-enhanced control, including trustworthy machine learning (ML) for GNC
12. Future applications of connecting UAVs to the internet-of-things (IoT) for rescue and other applications including collaborative UAVs or UAV-UGV collaboration.

Funded research

At University of Leicester, I am currently contributing to the development of collaboration networks for research on the autonomous guidance, navigation and control for UAV, eVTOL, spacecraft and autonomous vehicles more generally. I have secured PhD funding for a project on the coverage path planning and model predictive UAV control using wind forecasts. I am also currently developing the satellite attitude and orbit control systems (AOCS) design and analysis for a funded multi-U cubesat science mission using specialised software. I currently co-supervise and contribute to research on the estimation, control and path planning for different types of UAVs to efficiently deal with actuator faults, wind disturbance including wind gusts, turbulence and icing and other challenges affecting the safety, performance and resilience of aircraft/UAVs. 

At Coventry University, I worked on externally funded research projects, including the avionics/GNC design for a ducted fan UAV project funded by the European Union regional fund (Pii project), Innovate UK project Assured CAV Parking with Horiba Mira and consultancies including a tailplane stall investigation consultancy for AIBN (Accident Investigation Board Norway). 

At the University of Surrey, I worked on the real time implementation of low computational optimal spacecraft attitude control on an air bearing platform and on satellite simulators of Surrey Satellite Technology Ltd (SSTL) as part of the FP6 ASTRONET EU funded Marie Curie network/consortium. I also led the guidance, navigation and control part of EPSRC project AAReST (reconfigurable space telescope) and was also co-I during my time in Surrey for STFC funded project STRaND-2 with a focus on the relative attitude and orbit control for a satellite formation, including in-orbit inspection.

Selected publications:

[1] Mafaz, M.A., Horri, N., Lu, Q., England, M., Robust Auto-Tuning Control of a Delivery Quadcopter with Motor Faults, Mass and Inertia Estimation, IFAC Modeling, Estimation, and Control Conference (MECC), October 2024.

[2] Ebirim, K.E., Horri, N.M., Prempain, E., A 2DoF Twin Rotor MIMO System for Teaching and Research, IFAC workshop on aerospace control education (WACE) 2024 Conference, IFAC-PapersOnLine, 58 (16), 6-11, 2024.

[3] Horri, N., Holderbaum, W., Giulietti, F., Challenges in the Guidance, Navigation and Control of Autonomous and Transport Vehicles, Applied Sciences 14 (15), 6635, 2024.

[4] Dahia, K., Horri, N., Musso, C., Merlinge, N., Gyroless satellite attitude determination using a SVD-Laplace Particle Filter, Acta Astronautica, Volume 207, Pages 33-46, 2023.

[5] MA Bromfield, N Horri, K Halvorsen, K Lande, Loss of control in flight accident case study: icing-related tailplane stall, The Aeronautical Journal, Volume 127 (1315), Pages 1554-1573, 2023.

[6] Zyadat Z, Horri N, Innocente M, Statheros T. Observer-Based Optimal Control of a Quadplane with Active Wind Disturbance and Actuator Fault Rejection. Sensors, 23(4):1954, 2023.

[7] Ugwueze, O., Statheros, T., Bromfield, M.A., Horri, N., Trends in eVTOL aircraft development: the concepts, enablers and challenges

AIAA Scitech 2023 forum, 2096.

[8] Tai, J.J., Wong, J., Innocente, M., Horri, N., Brusey, J., Phang, S.K., PyFlyt--UAV Simulation Environments for Reinforcement Learning Research, arXiv e-prints, arXiv: 2304.01305, 2023. 

[9] Ugwueze, O., Statheros, T., Horri, N., Bromfield, M., Simo, J., A Mission-based Sizing Method for Electric VTOL Aircraft Conceptual Design, Aerospace, 1975544, 2023.

[10] Horri N, Pietraszko M. A Tutorial and Review on Flight Control Co-Simulation Using Matlab/Simulink and Flight Simulators. Automation, 3(3), 2022.

[11] Ugwueze, O., Statheros, T., Horri, N., Innocente, M., Bromfield, M., Investigation of a Mission-based Sizing Method for Electric VTOL Aircraft Preliminary Design, AIAA Scitech 2022 Forum, San Diego, USA, Jan 2022.

[12] Horri, N., Haas, O., Wang, S., et al. Mode Switching Control Using Lane Keeping Assist and Waypoints Tracking for Autonomous Driving in a City Environment, Transportation Research Record: Journal of the Transportation Research Board, Vol. 2676, Issue 3, 2022.

[13] Iglésis, E., Horri, N., Dahia, K., Brusey, J. & Piet-Lahanier, H., Nonlinear Estimation of Sensor Faults With Unknown Dynamics for a Fixed Wing Unmanned Aerial Vehicle, IEEE 2021 International Conference on Unmanned Aircraft Systems (ICUAS), p. 404-412, July 2021.

[14] Iglésis, E., Horri, N., Brusey, J., Dahia, K. & Piet-Lahanier, Simultaneous Actuator and Sensor Faults Estimation for Aircraft Using a Jump-Markov Regularized Particle Filter, 2021 IEEE International Conference on Prognostics and Health Management, ICPHM 2021. Detroit, USA, June 2021.

[15] Bromfield, M., Holvorsen, K., Horri, N., Lande, K., Tailplane or main wing stall? LOC-I event due to suspected icing, FORUM, journal of the International Society of Air Safety Investigators (ISASI), Pages 18-23, 2021.

[16] Iglésis, E., Dahia, K., Piet-Lahanier, H., Merlinge, N., Horri, N., Brusey, J., Markov Regularized Particle Filter for the estimation of

ambiguous sensor faults, 21st IFAC World Congress, Berlin, Germany, July 2020.

[17] Horri, N., Book review of “Spacecraft Modeling, Attitude Determination and Control: Quaternion-Based Approach” by Yang Yaguang, The Aeronautical Journal, December 2020.

[18] Merlinge, N. J. A., Horri, N., Dahia, K., Brusey, J. & Piet-Lahanier, H., Box Particle Control for Aerospace Vehicles Guidance Under Failure Probability Constraints1 Nov 2018, 2018 UKACC 12th International Conference on Control (CONTROL) . IEEE, p. 75-80 6 p.

[19] Milward, T. O., Bromfield, M., Horri, N., Ali, R. & Scott, S., 10 Sep 2018, (Submitted) AIAA SciTech 2019 Proceedings. American Institute of Aeronautics & Astronautics, Vol. (In-Press). AIAA 2019-1540 Multi-point Angle of Attack Sensing for Avoidance of Loss of Control in Flight

[20] Merlinge, N. J. A., Dahia, K., Piet-Lahanier, H., Brusey, J. & Horri, N., A Box Regularized Particle Filter for state estimation with severely ambiguous and non-linear measurements, In : Automatica. 104, Pages 102-110, June 2019.

[21] Merlinge, N. J. A., Brusey, J., Horri, N., Dahia, K. & Piet-Lahanier, H., Enhanced cooperative navigation by data fusion from IMU, ambiguous terrain navigation, and coarse relative states, 2017 IEEE 56th Annual Conference on Decision and Control (CDC), p. 375-380, 2017.

[22] Horri, N., Book review of “Book review of "Spacecraft and Payload Pointing” by Geoffrey N. Smit, The Aeronautical Journal, June 2016.

[23] Inumoh, L. O., Forshaw, J. L. & Horri, N. M., Tilted Wheel Satellite Attitude Control with Air-Bearing Table Experimental Results, Sep 2015, In : Acta Astronautica. 117, Article 5550, p. 414-429 16 p, 2015.

[24] N Horri, P Palmer, Relative Navigation, Book chapter from "Distributed Space Missions for Earth System Monitoring", pp. 331-344, Springer, 2012.

[25] Horri, N.M., Dahia, K., “Model predictive lateral control of a UAV formation using a virtual structure approach”, International Journal of unmanned systems engineering (IJUSENG), Volume 2, No. 3, 2014.

[26] Inumoh., D., Horri,N.M., Forshaw, J., Pechev, A., "Bounded Gain-Scheduled LQR Satellite Control using a Tilted Wheel", IEEE Transactions on Aerospace and Electronic systems, Volume 50, Issue 3, August 2014.

[27] Horri, N.M., Palmer, P.L., “Practical implementation of attitude control algorithms for an underactuated satellite”, AIAA Journal of Guidance, Control and Dynamics, Volume 31, No1, Pages 40-50, Jan-Feb 2012. (18 citations on Scopus)

[28] Horri, N.M., Palmer, P.L., Roberts, R.M.,"Gain scheduled inverse optimal satellite attitude control", IEEE Transactions on Aerospace and Electronic systems, final acceptance received, Volume 48, No 3, July 2012.

[29] Horri, N.M., Palmer, P.L., Roberts, R.M.," Energy Optimal spacecraft attitude control with convergence rate constraints", IFAC Journal of Control Engineering Practice, Volume 19, Issue 11, Pages 1297-1314, November 2011.

[30] Horri, N.M., Kristiansen, K., Palmer, P.L., Roberts, R.M, “Relative attitude dynamics and control for a satellite inspection mission”, Acta Astronautica, Volume 71, Pages 109-118, February-March 2012.

[31] Horri, N.M., Palmer, P.L., Roberts, R.M.," Design and validation of geometric optimisation software for the attitude control of microsatellites", Acta Astronautica, Volume 69, Issues 11-12, Pages 997-1006, December 2011.

[32] Biggs, J., Horri, N.M. “Single slew re-pointing for spin-stabilized spacecraft”, Systems and control letters, Volume 61, Issue 4, pp. 609-616, 2012.

[33] Horri, N.M., Hodgart, M.S., “Novel Developments in the Attitude Control of an Underactuated satellite using two wheels”, WSEAS Transactions on systems, Issue 1, Volume 3, pp.328-334, January 2004.

[34] Horri, N. & Dahia, K., Model Predictive Lateral Control of a UAV Formation Using a Virtual Structure Approach 2014, In : International Journal of Unmanned Systems Engineering . 2, 3, p. 1-11 11 p.

[35] Horri, N.M., Palmer, P.L., Giffen, A., “Spacecraft attitude control mechanisms”, Encyclopedia of Aerospace Engineering, 9 Volume Set, DOI: 10.1002/9780470686652.eae299, John Wiley and Sons, Article number Part 26:265, December 2010.

[36] Horri, N.M., Palmer, P.L., “Technological challenges: relative navigation”, IAA book on Distributed Space Missions for Earth System Monitoring, Springer Verlag, 2012.

[37] Horri, N.M., Dahia, K., “Optimal coordinated lateral control of a UAV formation using a virtual structure approach”, World congress on unmanned systems engineering, Oxford, UK, 2014.

[38] Horri, N.M., Rihan, A., Palmer, P., “Optimal coordinated attitude control of multiple satellites in a formation”, 5th international conference on spacecraft formation flying missions and technologies, Munich, Germany, May 2013.

[39] Bridges, C., Taylor, B., Horri, N., Underwood, C., “STRaND-2: Visual inspection, proximity operations & nanosatellite docking”, 2013 IEEE aerospace conference, Montana, 2013.

[40] Yusuf Acar, Horri, N., “Optimal Momentum Unloading of Reaction Wheels in the Presence of Attitude Control Errors”, AIAA Guidance, Navigation, and Control (GNC) Conference, August 2013.

[41] Underwood, C., Pellegrino, S., Taylor, B., Chhaniyara, S., Horri, N., “Autonomous Assembly of a Reconfigurable Space Telescope(AAReST) Rendezvous and Docking on a 2D Test-bed”, 9th IAA Symposium on Small Satellites for Earth Observation Berlin, Germany, April 2013.

[42] Underwood, C., Pellegrino, S., Lappas, V., Bridges, C., Taylor, B., Chhaniyara, S., Theodorou, T., Shaw, P., Horri, N.M., Baker, J., Arya, M., Breckinridge, J., Hogstrom, K., “Autonomous Assembly of a Reconfigurable Space Telescope(AAReST) – A CubeSat/Microsatellite Based Technology Demonstrator”, 27th Annual AIAA/USU Conference on Small Satellites, August 2013.

[43] Inumoh, L. O., Horri, N., Forshaw, J. L. & Pechev, A., Bounded gain-scheduled LQR satellite control using a tilted wheel, 2014, In : IEEE Transactions on Aerospace and Electronic Systems. 50, 3, p. 1726 – 1738

[44] Inumoh, Y., Horri, N.M., "Real time demonstration of three-axis attitude control using a tilted wheel methodology ", AIAA conference on Guidance, Navigation and Control, Minneapolis, Minnesota, USA, August 2012.

[45] Inumoh, O., Horri, N.M., Pechev, A., "Tilted Wheel for Three-Axis Attitude Control of A Rigid Satellite", 1st IAA Conference on Dynamics and Control of Space Systems, Porto, Portugal, March 19-21, 2012.

[46] Inumoh, D., Horri, N.M., Pechev, A. “Hybrid attitude control of an underactuated satellite”, 62nd IAC (International Astronautical Congress), Cape Town, 03-07 October, 2011.

[47] Sharmila, K., Horri, N.M. Tekinalp, O., Ozgoren, K., “Gain scheduled inverse optimal control for fine pointing of a spacecraft camera”, Recent advances in space technology, Istanbul, Turkey, paper accepted, 09-11 June 2011.

[48] Horri, N.M.,Palmer, P.L., Roberts, R.M., “Design and validation of geometric optimisation software for the attitude control of microsatellites”, proceedings of the 61st IAC (International Astronautical Congress), Prague, Czech republic, September 27th – October 1st, 2010.

[49] Horri, N.M., Palmer, P.L., Roberts, R.M., “Optimal satellite attitude control: A geometric approach”, proceedings of the 2009 IEEE aerospace conference, 11 pages, ISBN: 978-1-4244-2621-8, Big Sky, Montana, USA, March 7-14, 2009.

[50] Horri, N.M., Palmer, P.L., Roberts, R.M., “Practical implementation of inverse optimal satellite attitude control techniques”, 21st International Symposium on Space Flight Dynamics, Toulouse, France, September 28th –October 2nd, 2009.

[51] Horri, N.M., Palmer, P.L., Roberts, R.M., “Inverse optimal satellite attitude control from a geometric viewpoint”, proceedings of the 11th IASTED conference on Control and Applications, Cambridge, UK, also chair of the nonlinear systems session, July 13-15, 2009.

[52] Horri, N.M., Palmer, P.L., Roberts, R.M., “Optimal satellite attitude control with low implementation complexity”, 7th IAA symposium on small satellites for earth observation, Berlin, Germany, May 04-08, 2009. ISBN: 3-89685-571-9.

[53] Horri, N.M., Palmer, P.L., Roberts, R.M.," Optimal spacecraft attitude control with convergence rate constraints", International Conference on Space Technology, Thessaloniki, Greece, August 23-27, 2009. ISBN: 978-1-901725-38-4.

[54] Horri, N.M., Hodgart, M.S., “Attitude stabilisation of an underactuated small satellite using two wheels”, Proceedings of the 2003 IEEE AEROSPACE CONFERENCE, ISSN: 1095-323X, Big Sky , Montana, USA, volume 6, pages 6_2629 - 6_2635, March 07/15 , 2003.

[55] Horri, N.M., Hodgart, M.S., “Large angle manoeuvre of an underactuated small satellite using two wheels”, 4th IAA (International Academy of Astronautics) symposium on small satellites for earth observation, Berlin, Germany, April 07/11, 2003.

[56] Horri, N.M., Hodgart, M.S., “Novel Developments in the Attitude Control of an Underactuated satellite using two wheels”, proceedings of the 3rd WSEAS Int. Conf. on Instrumentation, Measurement, Control, Circuits And Systems, Malta, September 1-3, 2003.

7 successful PhD completions so far, mostly on the guidance, navigation and control (GNC) of UAV and spacecraft, including 3 international collaborations. Currently co-supervising 3 PhDs with other Universities. My aircraft and spacecraft GNC interests include the use of optimisation or machine learning in GNC systems, fault tolerance including FDIR, disturbance estimation and rejection, sensor fusion, control allocation, advances in adaptive, robust or low computational optimal control, constrained control including flight envelope protection, collaborative control for formation flight, and mission planning.

New Fully Funded PhD opportunity (in UAV control) with application deadline on 31/1/2025

Eligibility: UK students or settled/pre-settled EU Students (4 years UK fee waiver + 4 years studentship, EPSRC DLA funding)

I am also happy to discsuss being a supervisor for self-funded PhDs in line with the student's research interests, ideally in the fields of autonomous guidance, navigation and control (GNC) for aircraft (including UAV and eVTOL), spacecraft or autonomous vehicles. Always happy to discuss research ideas from enthusiastic students.

• EG7042: Robust Control (MSc)

I have contributed to BBC articles and BBC interviews about eVTOLs (electric vertical takeoff and landing) aircraft for urban air mobility and drones, as well as the UK's Future of Flight Action Plan, for example:

• https://theaccratimes.com/uk-government-aims-for-flying-taxis-to-soar-in-2-years/
• https://www.bbc.co.uk/news/technology-68597045

I am more generally happy to dicsuss with the press/media about:

- The progress and challenges, including the public acceptance, for eVTOLs (urban air mobility), drones, electric aircraft, crewed aircraft with increased levels of autonomy and the future prospects of developing autonomous UAV formation flight and swarming. I have strong links with industry and academia in these fields. I am particularly interested in the development of software and systems to improve the safety of these vehicles.

- The progress in challenging spacecraft/satellite missions requiring in-orbit servicing and repair, in-orbit assembly, in-orbit inspection of other satellites, debris recovery including the reentry of defunct satellites, in-orbit rendezvous and docking and formation flight of multiple satellites for mission reconfigurability. I have highly relevant work experience at the Surrey Space Centre (reconfigurable space telescope mission AAReST, satellite formation project STRaND-2) and current collaborations with Space Park Leicester (improving Earth observation for small satellites and multi-U cubesats using more intelligent software).

- Improved resilience (including fault tolerance and safety) for autonomous drones and spacecraft using fault/tolerant and robust intelligent software and systems.

Associate editor for the Drones and Sensors journals (Q1)

Reviewer for Automatica, Aerospace Science and Technology, IEEE Transactions on robotics and automation, AIAA journal of guidance, control and dynamics, Acta Astronautica, control engineering practice, systems and control letters, scientific reports, RAeS and Wiley book reviews, etc.