Raymarine introduces Hydro-Balance™ technology for Evolution™ autopilotsDate March 2, 2014
By Hudson Marine Electronics
Raymarine has announced the addition of new Hydro-Balance™ technology to its multiple award-winning Evolution™ autopilot line. This new patent-pending technology brings an even higher level of autopilot steering performance to boats with hydraulic steering systems. Specifically designed for hydraulic steering systems which have no rudder reference fitted, Hydro-Balance™ is particularly effective on boats with outboard engines.
Evolution™ Hydro-Balance™ technology adapts to your boat’s steering system
Evolution’s new Hydro-Balance™ technology actively compensates for hydraulic system elasticity caused by air bubbles trapped in the steering system, flex in hose and piping, and variable valve performance. Elasticity is a variable factor that can degrade autopilot performance over time. Experienced captains instinctively feel and compensate for system elasticity when steering by hand, but an autopilot needs to learn how to detect and compensate for it when it is in control of the boat. Until now, conventional marine autopilots without rudder angle sensors were unable to detect this condition.
Left unchecked, an autopilot steering a boat with excessive steering system elasticity will show symptoms of hunting and oscillation; the boat’s heading may swing through a few degrees or the outboard motors may hunt as the pilot struggles to keep the boat on course. With autopilot hunting, the pilot drives the outboards back and forth over a few degrees, trying to sense why the boats heading is falling off. Often it’s just not possible to correct the condition as conventional autopilot systems do not have the precision heading reference or smart sensor built-in to exclude hydraulic system elasticity.
Raymarine’s Evolution™ autopilots with Hydro-Balance™ technology adjusts for elasticity in the system and compensates automatically to prevent steering oscillation. Under autopilot control, the result is precise course-keeping and no drive-unit hunting.
Hydro-Balance™ technology keeps Prop-Walk in check
Another common issue with high-powered outboard engine vessels is asymmetrical torque steer, commonly known as “prop walk.” Essentially, the torque of the turning propellers creates a minor side-force that acts like a tyre gripping the road. In addition to propelling the boat forward or aft, the side-force causes the boat’s bow to veer off to port or starboard (depending on the direction of rotation of the propellers.) Asymmetry also causes boats to turn more tightly in one direction than the other. At low autopilot speeds, asymmetry can impact the natural motion of baits and jigs while trolling. During rapid acceleration, asymmetry can cause the boat’s heading to pull to one side even though the helm is straight. Hydro-Balance™ technology detects asymmetry and then teaches the Evolution™ autopilot to eliminate it through smart adaptive algorithms. The result is straight-as-an-arrow course keeping at all speeds.