Vertical Orientation Sensors

by Web FishJun 18, 2013 @ 11:03am

In order to operate normally (or at least efficiently) within the current design concept, the central micro-controller will need to be able to determine which side of the boat is currently facing down. This allows the power and control to be routed to the proper set of motor pods and rudders. This might sound like a trivial task, but under open sea conditions it gets complicated by the constant forces acting on the vessel. Assuming the surface of the water was (near) perfectly still, you can rely on the accelerometer reading to determine the current position relative to the earth center of gravity (or "down"). This is how most cellphone / tablet firmware operates. Ideally one would want to deploy a 3-axis gyroscope to get an accurate reading on orientation. We are trying to get away without one, so currently testing these mechanical tilt-switch sensors for overall vessel orientation. They add an inertial component to the accelerometer readings - hoping to develop an algorithm that relies on a combination of both sensor types to determine with sufficient accuracy the actual vertical orientation of the boat on the water. We don't need precise vertical orientation - just Side A vs. Side B currently down. We will still rely on compass readings for fine readings in the horizontal plane.