[Gabriel]

Keep in mind that dead reckoning is only as good as the hardware platform its on. In software everything should always be constant - the real world never works that way. Motors behave differently in different environments for example. You can calibrate your software fairly precisely, but it will probably degrade over time. If you're going to use dead reckoning you need something that will make sure it stays accurate. You can use rotation counters on your wheels for example but those have their own problems.