Jeremy Ruhland

Jeremy Ruhland

Electrical Engineering Technology

WWU Marine Technology Club

May 06, 2014 — Jeremy Ruhland

2013: Aegir I

Working on the ROV at the 2013 regionals in Federal Way, Washington

ROV prepped for testing

ROV during initial underwater testing

ROV electronics system installed inside waterproof case

During the 2013 competition year our ROV used a vectored thrust design. Pulse width modulation of the four outer motors allowed the vehicle to translate in any direction. Unfortunately the tradeoff between agility and thrust proved too much and left us with a vastly underpowered system.

As head of electrical engineering I designed the motor control H-bridges (small purple PCBs) and the motherboard for our TI Stellaris microcontroller (large red PCB). These electronics were shielded from water within a large aluminum pipe.

Aegir I suffered from a number of failures, our high PWM switching frequency caused excessive head dissipation within our H-bridges, limiting operational time. Also, due to the mass of the ROV a large amount of foam was required for buoyancy control. Although this worked well in our tests, once at operational depth the pressure proved too much for the weak foam which compressed and destroyed its air cells.

Design lessons from the 2013 competition were carried on and applied in the 2014 build season.

More information is available here on my blog.

2014: Draugr

Kids playing with Draugr during Back2Bellingham spring faire

Testing buoyancy in the WWU pool

Assembly and testing

Using Draugr to collect trash in Red Square fountian

The 2014 ROV was much lighter than the 2013 model and had much better performance. As a collaborative effort, the society for mechanical engineers designed the frame and I designed the electronics system.

The electronics system contained a package of h-bridges and sensors which communicated with a USB hub shared with waterproofed USB webcameras. This bus was tied to the surface with an extended range USB cable.

2014 WWU Marine Tech ROV Demo from Jeremy Ruhland on Vimeo.