The flight simulator has a flexible modular architecture, which enables the flight model, the displays, the flight control laws and the visual system to be re-programmed for a wide range of applications.
Recent research projects on the simulator include studies in sensors, flight guidance, weather modelling, flight control system design and air traffic management systems.
- Synthetic vision - projecting 3D symbology in the visual system to provide flight guidance.
- Air accident investigation of a light aircraft accident to reconstitute a flight path from observations and evidence recovered from the accident.
- Modelling of a forward-looking radar - to develop a real-time radar image, based on a physical model of a radar system, which can be projected in the HUD.
- Sensor fusion for sensor failure detection for synthetic vision - failure detection of a synthetic vision system to give flight crew timely warnings of sensor failures.
- Real-time wake vortex modelling - deriving a real-time wake vortex model from very large datasets generated from CFD models.
- Visualisation - showing the interaction between an aircraft and a vortex flow field in real-time.
Recent Research Programmes
This section outlines recent research activities in the flight simulation group. Two specific achievements are reported:
- Development of a detailed real-time radar model using off-the-shelf image generation hardware and an industry standard visual database - this is believed to be the first real-time model of a radar receiver to run at 25 Hz on a PC.
- Development of a real-time model of a wake vortex – this is believed to be the first model of a wake vortex that explicitly exploits detailed CFD modelling data and runs at 50 Hz on a PC.
Real-time Modelling and Sensor Fusion for a Synthetic Vision System
This research was undertaken as part of an EPSRC grant GR/R43020/02 ‘Feature Extraction in Enhanced Vision Systems for Civil Aircraft’. A forward-looking radar was developed by BAE Systems which penetrates cloud and rain for 4-8 Km to provide a radar image in a Head-Up Display (HUD) to enable flight crews to proceed with a landing after reaching the 200 feet decision point of an ILS approach. The thesis describes the development of a real-time radar model which can be parameterised to model specific radar receiver properties. The model uses a standard OpenFlight database, modified to include radar properties of the terrain. SGI Performer provides the 3D imaging of the radar display in the HUD which is augmented with real-time software to incorporate the correct radar characteristics in the image. By combining outputs from a radar tracker (used to locate the runway image in a cluttered image) and an inertial navigation system (INS), a Kalman Filter is used to smooth abrupt changes in the tracking loop and eliminate bias in the INS measurements. The performance of the Kalman Filter is monitored to detect errors and to alert pilots to system failure if a threshold is exceeded.
Wake Vortex Modelling
This research was undertaken as part of an EPSRC grant GR/R84047/01 ‘Real-time Simulation of the Effects of Wake Vortices on Civil Transport Aircraft’. Wake vortex models used in flight simulation are currently based on simplified analytic models to generate a disruptive flow field in the form of flows in a simple conic volume. The work reported focuses on the derivation of a complex flow field derived from CFD studies. The resultant flows include many of the dynamic features found in wake vortices, including the build up of Crow instabilities. Some 30G bytes of raw CFD data is generated for a typical wake vortex, taking approximately 15 days to compute on a processing cluster. This information is then reorganised and accessed in real-time to extract the flow field data close to an aircraft as it encounters the vortex. These values are combined with the aircraft motion to provide the appropriate disturbances across the complete airframe of an aircraft. In addition, the structural loads during the vortex encounter are computed and can be visualised in real-time. This is believed to be first real-time model of a wake vortex derived from detailed CFD data and updates at 50 Hz on a standard PC workstation.
For futher details, visit the wakesim website.
Distributed Methods for Conflict Resolution in ATM Environments
This research programme has been undertaken in collaboration with Boeing. In future air traffic environments, aircraft may communicate their position and trajectory information regularly, where the detection and resolution of conflicts will be computed in real-time in each aircraft. This research programme involves the development of an ATM model, (including wind) to enable conflict resolution algorithms to be developed. Currently, the system is capable of resolving conflicts for up to 50 aircraft in an airspace 50nm by 50 nm at a rate in excess of 1 Hz. The software is a mixture of Java and Matlab and further work is underway to link the flight simulator to traffic models running at Boeing via an Iridium link. The aim of the next phase of the programme is to develop and evaluate future displays to enable flight crews to operate safely and effectively in highly autonomous airspace, where responsibility for conflict resolution is distributed among aircraft in the network.