After finalizing and testing all of the motor drivers and thrusters, we’ve begun work on assembling the navigation box and its components. The navigation box includes the DVL, the IMU (mounted directly onto the auto pilot board), and the depth sensor.
The first hurtle to tackle was realizing that we didn’t have all of the Fischer connectors which connect the DVL transducer head to its electronics box. We needed four right angle connectors (there are two cables), but we only had two. After a quick call to Fischer, we found out the lead time to get these connectors was 10 weeks. That option was out. The next call was to Teledyne RDI. They had the connectors in stock but they were very expensive and out of our budget. Left with a Fischer connector dilemma, we decided to get gutsy and create a solution on our own. The first step, open the electronics box, figure out whats going on and see if we can remove the Fischer connectors from the loop all together. At a cost of $20,000 per DVL, we can’t afford to make any mistakes here.
We realized that we could build our own cables with Molex connectors to link the DVL head to the electronics box without the use of the unobtainable Fischer connectors. The following madness pursued.
After 2 days of destroying fischer bulkheads, double checking pinouts, crimping, and soldering, the we finished the 3 transmit and receive cables which link the DVL transducer head and the electronics box. It looked great.
But, the $20,000 question of the day: Did it still work? We booted up the DVL, and talked to the box over DB-9. We ran all of the communication tests to validate that the electronics box could talk to the head and all of the tests passed successfully. Bingo.
The pressure sensor was then installed and the depth sensor micropic board was installed and programmed. Next up, programming the auto pilot gumstix board to get all of the sensors communicating and dumping their data into the kalman filter. Then pool time to calibrate and align the sensors later this week.
Here’s a photo of the whole navigation box in its current state.
