Author: betsy

Electronic Kite Inflator

1/6/12

The electronic kite inflator, which we sometimes refer to as the kite Inflation Management System (IMS), is now ready for additional field testing. The device is designed to monitor and regulate the pressure of inflated kites. A Zigbee radio link is used to transmit pressure and status to the ground and to receive pressure setpoint commands. The inflator is integrated into the web-based logger interface, which allows us to monitor and control the kite pressure from any smartphone.

The latest version of the inflator uses a smaller and more robust PCB, and has a pressure release valve. Previously, the device could only inflate the kite, and had no way to release air if necessary. With the new release valve, the […more]

Logger Web Interface

1/6/12

We have made progress in creating a usable web interface to the kiteboat and Kite Assist logging systems. The basic idea is that the logger acts as a wireless router and web server. Any wifi-enabled device with a browser can connect to view the logger status, monitor the realtime data stream, and to send control commands to the device network.

Pictured are two Android mobile devices, which are connected to the kiteboat logger and showing realtime telemetry. The phone on the left is displaying the boat speed, line load, and kite inflation pressure. The larger tablet has a “kite” screen selected, which shows the current kite inflation pressure, the target inflation (with +/- pressure adjustment controls), and the battery voltage […more]

Kiteboat kite with ribs

12/19/11
Bottom skin

Dudu and Don are working on a new kiteboat kite design that will feature a single leading edge with a partial lower skin to fair the entry. Plastic ribs, location at the stations where there is no strut to connect the top and bottom skins, will keep the geometry stable.

Shown in the photos is a sample section of this design. The tip sections on a whole kite will be held taut by the leading edge–the final shape should resemble the shape in the photos where Dudu holds the kite, and not the shape shown at the bottom. Black airfoil shape is a plastic rib–there are three in this sample section. Photo of Dudu holding the kite cross-wise shows the […more]

K2 tow test – Dec 14

12/14/11

We tow-tested K2 today to show Jim Antrim, a naval architect and our newest consultant, around the platform. We towed out to Treasure Island and inflated the 30 sqm high aspect ratio kite to demonstrate how the mast worked. Jamie rode on K2 for the first time, in order to operate his new logging equipment.

K2 tow test – Nov 22

11/22/11

Today we towed K2 around the bay to test new logger updates. We hoped also to try our new 50 sqm high-aspect-ratio kite, but the wind was too low. Damon’s father-in-law joined us on the Protector. Joe and Vincent also tried out brand-new drysuits, and Gabe’s father visited the shop.

from Jamie:
For the first time on K2, we are now recording the kitearm angle and the rudder pitch angle. We are particularly interested in relating the rudder pitch to the boat speed, since this is an important manual adjustment that could be automated in the future. Currently, the helmsman must adjust the pitch of the rudder to keep the boat level as the boat speed changes. An example […more]

New 50 sqm kite

11/21/11

We received our new 40 sqm and 50 sqm high-aspect-ratio kites from China. Today Don and Joe set up the 50 sqm in the shop. We hope to test it tomorrow on K2 if the wind is strong enough.

Kite Inflation Maintenance System

11/15/11

Jamie has augmented our kite inflation controller, which monitors a kite’s inflation levels and maintains a designated psi by inflating the kite further, in case of a leak or temperature change, for example. The new electronics add precise pressure measurement, a radio link to the ground, and remote pressure control. In the photos, the system is inflating a kite section to 8 psi. Our smaller kites take higher inflation pressures, up to 9 psi, whereas the larger kites take lower pressures, 2-3 psi. This system is splashproof, but not waterproof, which is sufficient now that our launch and retrieval procedures largely keep the kite out of the water.

The graph shows the pressure as the small kite section is inflated […more]