Ausarbeitung/preliminaries.tex

   1 \chapter{Preliminaries}
   2 This chapter describes the preliminary topics. \todo .
   3
   4 \section{Dead reckoning}
   5 The process of \definition{dead reckoning} describes an inexpensive method for
   6 relative positioning by computing a vehicle's position from an initial
   7 starting position and the covered distance and course it has moved. In the case
   8 of mobile robots, the covered distance can be simply computed in real time from
   9 the revolution of its wheels, or by accelerometers the robot may be equipped
  10 with. However, since the vehicle's current position is based on its previous
  11 position, and the distance measurement may be imprecise, dead reckoning has the
  12 disadvantage that errors in position calculation can cumulate and the error
  13 of the calculated position grows with time.
  14
  15 Another approach to determine a vehicle's position is absolute positioning, for
  16 example satellite-based, over navigation beacons or by map matching. Still,
  17 these techniques are rather expensive to deploy, cannot (yet) be used in real
  18 time, or are even impreciser than relative approaches\cite{umbmark}, so dead
  19 reckoning can still be useful for the time being.
  20
  21 In the following, the iRobot Roomba serves as an example of an autonomous,
  22 mobile agent, which can be used to implement dead reckoning for lack of either
  23 built-in absolute positioning and other relative approaches.
  24
  25 \input{roomba}
  26 \input{wiselib}