Region-based Route Instructions for Pedestrians

In guiding wayfinders along a route, it is necessary to determine the location of way-finders in relation to the route. Instead of using a Boolean operation that determines whether wayfinders are on- or off-route, we use SOCs to derive a qualitative distance measure of closeness, which can be used to adapt route instructions. This closeness measure is expressed by the topological SOCs of two CSEPs (Wuersch and Caduff, 2005), one being the wayfinder and one constructed on the route’s edge. Figure 2 shows how the changing location of a wayfinder triggers different instructions.
While not close to a region, the instructions guide wayfinders back until they are very close or inside the region. At that point wayfinders are considered to be on-route and the instruction points in the general direction of the route. Further instructions are only trig-gered if wayfinders move away from the region.

Fig. 2:    Different route instructions i based on the location of a wayfinder in relation to a route determined by SOCs between the wayfinder w and the CSEP c (c is on edge e with radius of the buffer width b).

Conclusions and Future Work

We have presented an approach that allows deriving route instructions for pedestrians not only based on a network-like structure, but also on a region-based definition of a route. This approach significantly increases applicability, usability, and reliability of PNSs, as the generation of instructions is no longer tied to a network, but is adapted to the pedestrian’s real environment and, therefore, frees wayfinders from route instruc-tions that are too persistent. Another benefit of this approach is that it considers positional inaccuracies and incorporates these in the route directions. We are currently working on a prototype implementation of the system, which will answer questions re-lated to feasibility and efficiency, and will provide further insights in the requirements of PNSs.

References

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