Controlling an e-bike is pretty straightforward. If you want to just let it rip, it’s a no-brainer — or rather, a one-thumber, as a thumb throttle is the way to go. Or, if you’re still looking for a bit of the experience of riding a bike, sensing when the pedals are turning and giving the rider a boost with the motor is a good option.
But what if your e-conveyance is more of the aquatic variety? That’s an interface design problem of a different color, as [Braden Sunwold] has discovered with his DIY e-kayak. We’ve detailed his work on this already, but for a short recap, his goal is to create an electric assist for his inflatable kayak, to give you a boost when you need it without taking away from the experience of kayaking. To that end, he used the motor and propeller from a hydrofoil to provide the needed thrust, while puzzling through the problem of building an unobtrusive yet flexible controller for the motor.
His answer is to mount an inertial measurement unit (IMU) in a waterproof container that can clamp to the kayak paddle. The controller is battery-powered and uses an nRF link to talk to a Raspberry Pi in the kayak’s waterproof electronics box. The sensor also has an LED ring light to provide feedback to the pilot. The controller is set up to support both a manual mode, which just turns on the motor and turns the kayak into a (low) power boat, and an automatic mode, which detects when the pilot is paddling and provides a little thrust in the desired direction of travel.
The video below shows the non-trivial amount of effort [Braden] and his project partner [Jordan] put into making the waterproof enclosure for the controller. The clamp is particularly interesting, especially since it has to keep the sensor properly oriented on the paddle. [Braden] is working on a machine-learning method to analyze paddle motions to discern what the pilot is doing and where the kayak goes. Once he has that model built, it should be time to hit the water and see what this thing can do. We’re eager to see the results.
That’s a really cool project and nice engineering.
And it reminds me to get the Kayaks from the garage attic and bring them to a nice stream, again.
To be fair, this project is doing the AI hyping. Why do you need ai machine learning to turn on and off a motor? You don’t. A couple cent button would do it and be reliable.
“Why do you need $UNUSUAL_HACK?”
The “You don’t.” answer applies to pretty much every project on HaT.
“A couple cent button would do it and be reliable.”
In a marine environment? Which couple of cent button are you recommending? Does it meet IP69 (or better, IP69k)? Would it get trigger if a wave broke over it, or it was submerged a few feet?
I have an e-boat throttle I’ve been working on and switches for it are not cheap. So I am looking forward to your recommendation.
AI? No.
1. Put strain gauge on paddle blade.
2. When strain goes on way, because the blade flexes when you use it, turn motor on.
3. When strain goes away, motor off.
Bonus round, make it run backwards when you paddle backwards.
Done.
No IMUs.
No ML.
No dumb solutions to non-existent problems.
The not so “non-existent” problem is the side to side turning motion of rowing a kayak. Your solution just augments it. There are paddling techniques to reduce it and go straighter, that’s what the ML is attempting to detect and replicate. The question is how significant of an efficiency loss are we looking at but I bet it’s significant at higher assist modes.
Certainly in California any motorized craft must be registered. But this is not true everywhere.
I believe the maker is in WA, and there regulations are significantly different.
From boat.wa.gov:
blah blah blah need title and registration, except when…
– a canoe or kayak, OR not propelled by a motor or sail
– less then 16ft an has a motor of 10hp or less (and used in non-federal waters)
That seems to exclude kayaks without any exception (i.e. motor or sail ok with a kayak). Also seems to depend on the waterway being used. If nothing else it is ambiguous.
“DO NOT FUCK THIS UP FOR US.”
What is it are worried about (even if that you’re say was true)? Plenty of people believing in a “small government” are out there breaking these types of rules all the time….
Perhaps you can also not fuck this us for the rest of us, by not being a rulez nazi and going around shouting and hassling people with made up rules? Maybe?