|
摘要(英) |
Currently, the accuracy of traffic accident on-site sketchs is
limited to the measuring tools, like tapes or walking measuring
wheels, because the measurements is made on the distances for
those objects in an accident. Without measuring the relative
angles between objects, the validity of traffic accident on-site
sketch is often challenged. In Taiwan, two common measuring
methods for drawing a traffic accident on-site sketch: one is
trilateration method, and another one is offset method. Both
methods have their limits. Trilateration can cause significant
errors without aiming at the target. As for the offset method,
it would have wrong positions if the angle is not 90 degrees.
This research focuses on evaluating the accuracies of
trilateration and offset methods. In this research, two accident
scenes are setup: one is on the flat road, and another one is on
the hill. In addition to trilateration and offset method with
tapes and walking measuring wheels, a total station is employed
to measuring angles and distances. With the measured angles and
distances, the correct positions are calculated with the
geometric principles. After comparing the results, we find out
that the results got from offset method is close to the results
got form the measurements with a total station. We also find out
that the results measured by a tape are better than that
measured by a walking measuring wheel. At last, if extra
geometric constraints are given, the accuracy can be
significantly increased. |
