108
C.1
C.1 Description
The Safety Tow Float is a 3-pound, 20-inch long waterproof capsule that houses an acoustic pinger, microprocessor,
and reusable buoyancy. It is attached to the EcoMapper by a specialized Kort Nozzle and two-foot long cable and
pulled by the AUV. The EcoMapper powers and communicates with the Safety Tow Float via the two-pin connection at
the base of the GPS antenna.
Users specify conditions in the EcoMapper UVC’s Safety Rules that signal an emergency condition to the Safety Tow
Float. Once the float recognizes the emergency condition it enters a user-specified “bag delay time” that signals the
float to deploy after the delay time. Should the vehicle recognize that it is no longer in danger and the safety rule
has disengaged, the Safety Tow Float will exit the bag delay time and resume normal operation. In the event of an
emergency condition, the Safety Tow Float deploys its buoyancy bag to pull the AUV to the surface.
The Safety Tow Float will deploy the buoyancy bag in an additional two situations regardless even if the float disarmed
and no safety rule has been triggered..
1. If the float is submerged at or below the “Limit Depth” (defined in the user interface, Section C.25), the bag
will deploy.
2. If the float is submerged below the armed depth longer than the time specified as the “Time Limit” (set in
the user interface in section XXXX) continuously, the bag will deploy.
The buoyancy bag can also be manually deployed at the end of a mission (via a user-specified setting in VectorMap)
to increase vehicle visibility and assist the user in recovery. The acoustic pinger is also a valuable recovery aid should
the vehicle become difficult to locate.
The Safety Tow Float body consists of a buoyancy bag chamber, magnetic activation area, CO
2
cartidge chamber, and
electronics sections. The electronics section is comprised of a sonar pinger, depth sensor, LED indicatiors, audio
indicator (buzzer), and microprocessor. The user connects to the Safety Tow Float via a Bluetooth
TM
Dongle (a small
USB drive). Once connected, the user programs the Float with a simple laptop HyperTerminal interface.
Magnetic Activation
Area
Buoyancy Bag
Chamber
CO
2
Cartidge
Chamber
Electronics
Section
Depth Sensor
LED Indicators