Page 259 - Introduction to Autonomous Mobile Robots
P. 259

244























                           Figure 5.34                                                    Chapter 5
                           Kalman filter estimation of the new robot position: By fusing the prediction of robot position (thin)
                           with the innovation gained by the measurements (thick) we get the updated estimate p ˆ k k(  )   of the
                           robot position (very thick).




                           to enable finding the best matches while eliminating all other remaining observed and pre-
                           dicted unmatched features.


                           5. Estimation. Applying the Kalman filter results in a final pose estimate corresponding
                           to the weighted sum of (figure 5.34)
                           • the pose estimates of each matched pairing of observed and predicted features;

                           • the robot position estimation based on odometry and observation positions.

                           5.7  Other Examples of Localization Systems

                           Markov localization and Kalman filter localization have been two extremely popular strat-
                           egies for research mobile robot systems navigating indoor environments. They have strong
                           formal bases and therefore well-defined behavior. But there are a large number of other
                           localization techniques that have been used with varying degrees of success on commercial
                           and research mobile robot platforms. We will not explore the space of all localization sys-
                           tems in detail. Refer to surveys such as [5] for such information.
                             There are, however, several categories of localization techniques that deserve mention.
                           Not surprisingly, many implementations of these techniques in commercial robotics
   254   255   256   257   258   259   260   261   262   263   264