A dead penguin, a dead seal, and a calibration mission

November 6, 2009

We ran a mission today to get data that allows us to calibrate our  navigation instruments so we can quantify the error between the robot’s estimate of its pose and the ground truth (which we obtain by tracking the robot with a radio beacon and marking its GPS position). We also saw some obstacles in the limno-hut region where the fiber had gotten snagged  last year in our new visualizer.


A dead penguin (between the two rocks). Emma had seen it some time back and told us about it. We stopped on our way to work today to see it.


We also saw a seal skeleton. Myself and Chris.


Chris, Rachel and Kristof.


A thin layer of ice freezes over the melt-hole every night that needs to be cleared before we can run any missions. Emma helped us chip ice from the melt-hole today morning. Emma was clearly delighted to do this.


Mission control. Myself, Kristof and Chris.


The bot sees things in water!

November 6, 2009

November 5

We had some more difficulties today. While going through the mission start checklist, I found that data from 3 of the 6 thrusters was being received only intermittently. Chris first thought that is was some problem with a driver card in the motor housing and we will have to open the motor pod to fix this. Bart decided to take a look at the screen-shot of the sensor state that we save at the beginning of every mission and realized that one battery had tripped off at night and did not get charged. This all took about an hour to figure out, and we all heaved a sigh of relief when we found that there was no major problem.

We also found that the forward-looking housing had water in it. This was because a fault with the sealing O-ring. Bill, Bart and Vickie were able to fix this without too much difficulty.


Kristof found that the forward-looking camera housing had water in it. Kristof and Bill inspecting the housing.

We finally put the bot down the melt-hole and went on a mission. The objective of this missions was to figure out whether we could use a forward-mounted multi-beam sonar for detecting obstacles. We hung three different obstacles from the melt-hole – an ice-chipper bar, a weight bag suspended from a cable and a PVC pipe. We were able to see all the three objects in the visualizer that was written by people at UIC visualization lab and built-upon by Chris. All in all, it turned out to be a useful day.

Three Objects at 15m 11-05-09

A screenshot of the visualizer that displays the returns from the forward looking vertical multi-beam sonar. The dense red dots at the top are the ice surface of the lake. The objects that we suspended from the melt-hole are clearly visible. Photo courtesy Chris and Bill.