Monday, December 29, 2008

Making digital maps more current and accurate

European researchers have designed an innovative new system to help keep motorists on the right track by constantly updating their digital maps and fixing anomalies and errors. Now the partners are mapping the best route to market.

The ‘oddly enough’ sections of newspapers regularly feature amusing stories of GPS mayhem. For instance, one lorry driver in Poland had such confidence in his positioning device that he ignored several signs warning that a road had been closed to make way for an artificial reservoir and drove straight into the lake!

In addition to providing a cautionary tale about investing too much faith in technology, this amusing anecdote highlights a more mundane and daily challenge: how to reflect the constantly shifting topography of Europe’s road network.

A large number of digital maps used by onboard GPS navigation systems are stored on DVDs or hard disks, with periodic updates only available on replacement disks. In addition, advanced driver assistance systems (ADAS) - such as adaptive cruise control (ACC) and lane-keeping systems (LKS) - are beginning to make more extensive use of digital maps. Given the safety dimension of ADAS applications, it is crucial that digital maps are highly accurate.

Some interactive solutions have made it to market. One example is the EU-backed ActMAP project which developed mechanisms for online, incremental updates of digital map databases using wireless technology. The system helps to shorten the time span between updates significantly. Nevertheless, there is still room for improvement in terms of detecting map errors, changes in the real world, or monitoring highly dynamic events like local warnings automatically. Addressing these ever-changing realities requires a radical rethink of the applied methodology.

Ground-level input

The assumption behind ActMAP and other systems is that the supplier is responsible for all updates. However, this approach overlooks a valuable source of information: the motorists who use the navigation systems themselves. If anomalies found by road users could be automatically sent to the supplier, this could be used as a valuable supplementary source of information to iron out irregularities in maps and beam them back to the users.

This bottom-up approach is the basic premise of FeedMAP, which has been designed to work in a loop with ActMAP. This means that, when the reality on the ground does not correspond with the digital map in the system, these so-called map deviations are automatically compiled into a map deviation report which is picked up by roadside sensors and relayed back to the supplier. The driver can also report anomalies (s)he encounters manually.



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