Tow test today to test sensor extensions and modified T-foil. Sensor extensions were not stiff enough. We returned to the shop and stiffened them by bonding half-circular carbon tube to the inside of the sensors with methacrylate, for testing later today. We also practiced shooting video from the quadcopter. Joe’s dad, Jim Brock, joined us on this test.
We took K2 out early today to test the new sensor gearing adjustors. Initial towing went well, so we continued on to Treasure Island to launch the 18 sqm kite. We kited at mid-twenties speeds northeast of the island for a couple of hours before heading to the west side to check out the America’s Cup races. We, along with many other boats, watched Oracle’s amazing comeback, and then returned to the back side of Treasure Island. The wind began to pick up, and our best speed of the day was 32+ knots with 4 crew. Overall, the sensor gear adjustors were very effective in creating a smoother, although lower, ride. We did have some trouble on the tow home […more]
Some quick clips of the line angle sensor on K2 today.
Today was a beautiful day to test our wind sensor, Paul Larkin’s headsets, and our new GoPro Hero3 cameras. We also performed a brief kite test using the new 18 sqm kite. Paul’s friend John Bond joined us on this test.
First, we compared our primary wind sensor, an ultrasonic model, to a standard cup-and-vane sensor. In the past, we have seen suspicious readings in true wind speed and direction that we attributed to compass miscalibration or poor alignment of the sensor with the boat. In the last test, however, we collected data that showed that any compass or alignment errors that exist are far smaller than the discrepancies that we have seen. This data indicates that the basic apparent […more]
Today we performed a series of tests as part of our effort to improve our measurement of the kiteboat’s performance versus true wind angle (TWA), which is the angle between the wind direction and the heading of the boat. This information is ultimately used to produce polar plots, which are a standard method of showing the expected speed of a boat at different TWA. We are approaching this goal from several directions, which include adding a real-time update of the boat TWA to the boat mobile device displays and updating the KAIView software, as well as checking that the wind sensor readings are accurate. Today we towed K2 to calibrate the compass for this purpose. We additionally towed the boat […more]
Kite Inflator Specification
[This document is a work in progress.]
The kite inflator is a device that monitors and sets the inflation pressure of the kite. It will also serve as a general purpose data logger and transmitter for sensors such as an altimeter, temperature sensor, and GPS.
Physical, Environmental, Performance
1. max size: ?
2. max weight: ?
3. kite attachment method: ?
4. splashproof, but not submersible
5. external power switch and on/off display
6. normal use constitutes the motor valve operating for 25% of the time
7. must run for 12 hours of normal use on a full charge
8. reliable radio range of 100m on the water