Research Overview: Fault Tolerant Flight Control

The squeaking wheel doesn't always get the grease. Sometimes it gets replaced.
- Vic Gold

I've looked at two topics under the heading of 'Fault tolerance':

The first was during my master's thesis, in which I studied fault identification of hybrid systems and in particular hydraulic circuits. I haven't looked at this topic for many years now, but you can find details on the work in the publications section below.

The second was an investigation into reconfigurable flight control of civilian aircraft. In particular, we studied a Boeing 747 crash that happened in Amsterdam in 1994. In this incident, two of the engines fell off and took a goodly part of the wing surface with it. It makes an interesting case study, since the pilots were able to keep the aircraft in the air for a full 10 minutes before the crash, which is a reasonable amount of time for an online fault-tolerant system to take effect.

The approach that we took in this case is (not surprisingly) based on model-predictive control. Given a re-identified model of the damaged aircraft, we were able to control a simulated damaged aircraft through its final landing maneuvers. This work was done as an early part of the GARTEUR action group AG16 (which was just getting rolling as I completed my PhD). Many more interesting links and details on their work can be found here.

This is a simulation of the MPC-based fault-tolerant controller. The three planes are as follows: White: Functional airplane, standard controller Red : Damaged airplane, standard controller Green : Damaged airplane, fault-tolerant controller

Publications

J.M Maciejowski, C.N.Jones, MPC Fault-Tolerant Flight Control Case Study: Flight 1862, IFAC Safeprocess Conference, Washington DC., 9-11 June 2003

More details available here

C.N.Jones, Reconfigurable Flight Control - First Year Report, First year report, Cambridge University, 2002

More details available here

C.N.Jones, G.Bond, P.Lawrence, Consistency-Based Fault Isolation for Uncertain Systems with Applications to Quantitative Dynamic Models, 12th International Workshop on Principles of Diagnosis, 2002

C.N.Jones, Consistency-Based Fault Isolation for Hybrid Dynamic Systems, M.A.Sc Thesis, University of British Columbia, 2001

Further reading

• Some years ago I put together a bibliographic database of papers in the area. It's a bit out of date, as it was last updated in 2002, but may be a good starting point: FTC Bibliographic Database
• Jan Maciejowski's page on FTC