Ignore readings less than the sensor's minimum range

[spmaniato]

If a LaserScan message contains range readings that are below the sensor's minimum range, Karto will still use them for mapping purposes, resulting in situations like the one in the screenshot below, where the red arrow is the robot's initial pose, [0 0 0] More details on this issue can be found here: http://answers.ros.org/question/232523

Even though Karto does have filtering capabilities:

inline const PointVectorDouble& GetPointReadings(kt_bool wantFiltered = false) const

they are not used. All calls to GetPointReadings are without wantFiltered = true. So, one way to address the issue would be to do pScan->GetPointReadings(true) in the function AddScan. However, since there's already some filtering logic in AddScan, I just added another condition to the if statement. (There is a slight difference between the two solutions. I went with the one that, imo, will have minimal side effects.)

[mikeferguson]

LGTM -- I'll leave open for a few days for any other comments and then merge

[jonbinney]

Makes sense; in the LaserScan message it says "# range data [m] (Note: values < range_min or > range_max should be discarded"

[mgruhler]

great catch. Was already starting to wonder if my config is bad ;-)

[EndlessLoops]

I met same the problem .