Wednesday, September 30, 2020

Ocean Startup Challenge Win!


 The pitch in the Ocean Startup Challenge seemed to go OK last week, and fortunately the judges did not ask any really difficult questions. I wasn't expecting to be one of the top 10 companies, but was still kind of eager to find out the results. On Monday evening my phone rang while I was driving into town to pickup Kirsten from cross country practice. I pulled over and took the call, and was quite excited to find out that In Nature Robotics was one of the winners! As I found out just today when the official announcement was made, there were actually 14 winners chosen, so probably good for me that they decided to pick 40% extra! For a video and list of the winners, check out this link: https://www.oceanstartupchallenge.ca/announcements/. I also did a telephone interview with a fisheries / ocean tech journalist who writes for https://www.saltwire.com/, so there should be a story about me, In Nature Robotics, and AMOS appearing there soon. (EDIT: Here is the link to the story: https://www.saltwire.com/business/local-business/video-cod-collagen-project-and-a-boat-called-amos-east-coast-entrepreneurs-among-winners-of-ocean-startup-challenge-504940/)

The funding from the contest will be used to build a 4th prototype version of AMOS that will be a hybrid between the previous catamaran and surfboard versions. This time I would like to first make a silicone mold and then try using a two-part foam with that. I would also like to construct it so that the electronics boxes are mostly hidden away within the hull, in order to cut down on wind resistance as much as possible, and make things look a bit neater. I would also like to get some other people using and testing AMOS, to get their feedback and criticisms, and last I'm hoping to do a bit of R&D to work on adding some tech for discrete sample collection and underwater video.

I'll find out more details about the Ocean Startup program and funding next week. In the mean time I'm working on creating a 3D-printed container to house a small solenoid valve. It would be used for collecting physical water samples at different depths. I would like to fit a BLE (Bluetooth Low Energy) module, some batteries, and a microcontroller in there to allow AMOS to communicate with it wirelessly and tell it to open its inlet valve after a certain length of time. Then AMOS could lower the bottle into the water on a rope to the required depth and wait for the valve to open for a few seconds before pulling the bottle up again. A fancier version might also include a pressure sensor to allow the valve to open at a pre-determined depth. 


Tuesday, September 22, 2020

Foggy False Obstacles

This past week has been mostly filled with preparations for my upcoming pitch in the Ocean Startup Challenge this Thursday (the 24th), but I did find a bit of time to get out for a quick test on Monday morning. The air temperature was quite cold that morning (a low of 0 °C the night before) so there was a lot of fog on the water when AMOS was starting out:


Similar to what happened a couple of years ago on a foggy day (although with a different LiDAR model) AMOS was detecting a number of false obstacles due to the laser light from the LiDAR reflecting back from the water vapour. AMOS would turn in place until it found a "fog-free" direction and then proceed for a while before changing direction again. This slowed things down a bit at first, but soon the sun burned the fog away and AMOS sped from one end of Kelly's Creek to the other, a distance of almost 6 km in about 80 minutes:


I had to work pretty hard to tow AMOS back to the van in order to get back home in time for lunch and work at Measurand.

My slides and presentation are ready for the pitch on Thursday, although I'm meeting with some people tomorrow to get their feedback, so they might still need a bit more modification. Anyone who is interested can view the slides and speaking notes here:

https://drive.google.com/drive/u/0/folders/1NDSK35QObOzhbu_-wzTQwxbSCig7iita



Tuesday, September 15, 2020

More Capacitors = More Speed

 Work this week continued on efforts to re-wire the electronic speed controller (ESC) behind the propeller motor. This took way longer than I had planned, and involved swapping out the motor, swapping out the electronic speed controller, re-soldering all of the connections, re-calibrating the ESC, learning what all the ESC beeps meant and modifying the calibration software to be able to adjust all of the parameters according to those beeps. No matter what I tried though, the motor was always very choppy when run at medium to high speed. With nothing left to try, I resorted to Google, which fortunately came up with this web site that had a good discussion about some of the problems that can result with an ESC if your cables delivering DC power from the battery are too long: https://www.rcgroups.com/forums/showthread.php?952523-too-long-battery-wires-will-kill-ESC-over-time-precautions-solutions-workarounds

By positioning the ESC outside the box and behind the propeller, I had lengthened the cables delivering the 12 VDC power to the ESC by about a foot or so. The problem is not the extra bit of resistance that this adds, but rather the extra inductance that it adds. The inductance results in voltage spikes at the ESC, which can apparently result in erratic performance of the motor. The solution is to add extra capacitance at the ESC to help smooth out the voltage fluctuations. There is already a 30V 220 μF capacitor on the ESC, but the rule of thumb specified in the above website is to add an additional 220 μF capacitor for each additional 10 cm of power wire length. I added three 330 μF capacitors in parallel over the voltage inputs to the ESC. They were only rated for 25 V, but they seemed to improve things quite a bit, and were able to allow the motor to run at a normal speed.  I also tried adding an additional 330 μF capacitor to see if it might allow the speed to increase further, and it did a little bit, although not quite as much as I had hoped. 

So now there is an ugly cluster of capacitors and an ESC mounted behind the propeller. These would need to be weatherproofed with some silicone or other material if used outdoors on a consistent basis. Better positioning of the solar charge controller would also allow me to shorten the wire leads that power the ESC. Really the only reason for positioning the ESC behind the propeller is to keep it cool. Having it inside the electronics enclosure risks having it heat up to 110 °C on hot days, at which point the ESC firmware immediately cuts its output power by 50%. This sort of thing was happening occasionally back in August when the weather was sunny and the outdoor temperature was close to 30 °C.

Cluster of capacitors are shown here circled in red.

On the weekend I took AMOS and its new capacitors downtown for a test run, and was happy that it beat its old record for going up and down the downtown section of river by 5 minutes: from 47 minutes to 42 minutes. The dissolved O2 levels were good too - I guess those are going back up again now that the water is cooling again:




Tuesday, September 8, 2020

Ocean Startup Challenge!

 There was a big announcement today for In Nature Robotics: we were one of 31 companies out of 158 applicants to be picked for the next round of the Ocean Startup Challenge: http://www.oceanstartupchallenge.ca/announcements/. Starting this Friday, there will be a week of presentations and workshops to get ready for a final pitch presentation, sometime between September 22 and September 24. The 31 companies will be competing for 10 prizes of $25k plus in-kind support. It seems sort of similar to what we went through back in May for the Volta competition; except more of an overall ocean theme. 

I took a couple of days off from AMOS this week to go on a fun family camping trip at Spednic Lake. It would have been nice to try out AMOS there, but the van was packed tightly to the roof with camping supplies, so it wasn't possible. I did manage to get some 3D models of the new WeatherBox put together and tested for water-tightness though. Here is a picture of the component parts (no more little nuts or bolts required!!!) and a picture of the put-together unit (minus the interior locking piece):



The only thing that needs to be modified is that the camera board is recessed a bit too far inside the enclosure, so that you can see tiny smudges of black (from the enclosure) in the corners of the field of view:

(Please ignore the terrible state of this lawn. 😀)

To fix this, I can try to either (i) elevate the level of the camera board inside the enclosure, or (ii) trim down the thickness of the enclosure a bit. 

I have also been working on re-wiring the electronic speed controller (ESC) to situate it behind the propeller. Unfortunately though, I think I may have broken one or more of the wires going into either the ESC or the propeller motor today, as it was functioning sporadically, depending on how I moved the wire around. I'll try a replacement motor tomorrow, and if that doesn't work I'll try replacing the ESC.



Tuesday, September 1, 2020

Back From The Wilderness

 Avid readers of the blog may have noticed that there was no entry last week; that was the first time in over 2.5 years that the weekly update was missed! Without going into too many details, a long 15 hour bike ride through New Brunswick trails and back roads turned into an even longer 24+ bike ride due to some navigation errors that resulted from poor preparation (forgot 1 phone charger and the other 2 chargers that were brought were not charged, did not bring a printed map (only printed directions), and did not bring proper equipment to change a bike tire, which turned out to be necessary for the last 50 km or so). After being rescued and returned to safety, I was in no condition to think about the blog, and thereby felt justified in skipping a week to catch up on some sleep. Many thanks to Kelly and Dad for searching for us and rescuing us after this misadventure. 

The last time I had AMOS out for a test run was on August 22 at Kelly's Creek. One thing I happened to notice around the middle of this test was that the air propeller motor would sometimes audibly switch down to a lower speed, resulting in a somewhat lesser thrust. Going with the wind the reduction in thrust was not an issue, but on the return trip it was. Some testing in the backyard the next day revealed that the electronic speed controller (ESC) board output power became significantly less when it overheated. Currently, the ESC is sitting in the bottom of the back electronics enclosure, with the battery and a bunch of other electronics, so it makes sense that it could get pretty hot, especially if the weather outside is sunny and warm. By positioning the ESC outside the box, behind the propeller in the airflow however, the output power remained stable, presumably because the ESC was sufficiently cooled. Apparently drone makers know this already; there are instructions available on the Internet for applying a silicone conformal coating to the ESC board to protect it against moisture. The weather is starting to get cooler here, so I might not notice the overheating effect in future tests, but I think I'll re-wire things to put the board outside behind the propeller anyway. 

 Efforts are currently underway to re-design the WeatherBox (i.e. the waterproof enclosure for the camera on AMOS). I would like to get rid of the nuts and bolts and just have a window cap that screws directly onto the enclosure. This would make assembly a whole lot easier, and should look better too. Here are 3D printed versions of the base enclosure piece and an initial window cap (without the plexiglass window) screwed together:



This past week was Jata's last as an intern at In Nature Robotics. One of her projects was an online 3D modeling / ordering tool for AMOS. I have been trying to teach myself 3D modeling using TinkerCAD and other 3D tools to continue her work, but so far have not had much luck. Importing and exporting with these tools tends to do unexpected things to the models. Possibly it is just user error though!