Simulating Sailing Robots

Abstract

This paper outlines our experiences in simulating sailing robots. It focuses on efforts to simulate a sailing robot, both in pure software and a “Hardware in the Loop” (HIL) simulation and compares these results with sailing a similar course using an actual robot. The software simulator is built upon an open source sailing game called Tracksail. This is based on a highly simplistic physics model and makes no attempt to simulate the actions of waves, currents or tides. The target robot to be simulated is BeagleB, a 3.65 m long boat based upon a MiniJ dinghy equipped with a 2m high wing sail. To provide a more realistic simulation of this boat a “Hardware in the Loop” simulator was constructed using nearly identical electronics attached to a trolley table. Sensor inputs can either be provided by a Tracksail simulation or from sensors on the table. Sailing of an identical course in the Tracksail, the HIL System and on BeagleB showed similar results in all cases. This suggests these simulations are a reasonable approximation of real world robot performance. Although they are no substitute for actually sailing a robot they are a sufficient for testing software, testing hardware and developing control strategies.