Posted on Thursday 14th November 2013
By Professor Bob Stone, HIT Team Director and Chair in Multimedia Systems, School of Electronic, Electrical and Computer Engineering
Staff and students from the Human Interface Technologies Team of the School of Electronic, Electrical & Computer Engineering have taken to the road again, this time to test a new piece of technology designed to improve the quality of information obtained when conducting surveys of historical sites – especially those that are inaccessible due to challenging terrain or plant cover, or out of bounds due to conservation or health and safety restrictions. Building upon recent experiences whilst conducting heritage site surveys on Dartmoor (some of which were reported in the previous edition of this newsletter), what was once a hobby of one of the School’s latest PhD student recruits, Chris Bibb, has now become an important research tool, allowing sites to be investigated on detail from above, courtesy of a sophisticated hexacopter unmanned air platform. Chris’s hexacopter is unlike many of those seen on the Web or in recent news features. Costing a mere fraction of those being used by emergency services and the Armed Forces, yet delivering an impressively stable flight performance, the hexacopter allows an observer to view inaccessible sites using a head-controlled pan/tilt module or a gimbal-stabilised unit (supporting either a high-definition camera or a stereoscopic pair of cameras), relaying images to a variety of devices, from tablet computers and Smartphones to head-mounted displays.
The 6 fixed-pitch propellers of the hexacopter rotate in alternating clockwise and counter-clockwise directions with motion control achieved by altering the thrust of each motor to provide motion – vertical (including hover), forward/backward, left/right, and yaw. The platform is capable of fully autonomous flight including take-off, GPS way-point navigation, and auto-landing. The integrated sensors (3-axis gyro, accelerometer, magnetometer and barometer) provide auto-stabilisation and additional GPS and sonar subsystems allow altitude hold, position hold or loitering, way-point navigation and a return-to-launch function. The hexacopter can handle payloads of up to 1.2kg and uses a MAVlink telemetry connection for long-distance communication (up to 1km) from a ground control station (which can be configured for use with a range of popular gaming input devices). The hexacopter has already been used to good effect during surveys conducted within the Burrator Reservoir area, including establishing the proximity of the Devonport Leat to the abandoned GWR railway line and gaining aerial perspectives of the remains of Longstone Manor (also mentioned in the previous edition of this newsletter). More recently, the hexacopter has been flown in inclement weather – intermittent heavy showers and winds averaging 16 mph, gusting up to 31mph – over the gun emplacements of Whitesand Fort on the Cornish coast. Built between 1890 and 1894, this complex formed part of Lord Palmerston’s “Ring of Fire”, providing defence to the City of Plymouth and her naval assets.
An ambitious but highly challenging modification to the hexacopter is also being undertaken by one of Prof. Stone’s MEng students this year. Yousef Amar is investigating how relatively low-cost, off-the-shelf components can be exploited to develop a lightweight LIDAR (Light Detection and Ranging) system capable of generating real-time data enabling the construction of simple 3D terrain models, or models of the main structural components of heritage sites whilst in flight. The plan is to test the results of his research and development efforts using the HIT Team’s hexacopter sometime in early 2014, whn the team will return to Dartmoor to fly over locations such as Longstone Manor and the abandoned RAF airfield at Harrowbeer (mentioned in the previous Alumni Newsletter).
The HIT Team is also in early discussions with the Friends of Purton – custodians of the Purton Ships' Graveyard (the largest of its kind in the UK – see http://www.friendsofpurton.org.uk/) – to see if the Team’s hexacopter, Virtual and Augmented Reality technologies can be used to help preserve this unique maritime heritage site. The Purton Ships are the remains of around 80 vessels and barges which, from 1909 to 1963, were deliberately towed out of Sharpness Dock on the River Severn during high spring tides and then released to collide at speed with the riverbank. By subsequently drilling holes onto the side of the hulls, thus allowing silt to pour in over time, these abandoned vessels were used to strengthen the constantly shifting riverbank, thus protecting the route of the Gloucester & Sharpness Canal.
Stay in touch with the HIT Team’s Virtual and Augmented Reality research, plus ongoing developments using the hexacopter, by downloading the brochures and reading the news reports on Professor Stone’s website (www.birmingham.ac.uk/stone).