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Comment by TaylorAlexander | Hacker News Reader

If any of y’all like this, I am building an open source 3D printed off road robot with in wheel motors and transmissions, and I post regular updates on the project on YouTube. The transmission is currently an 11:1 two stage planetary gearbox that is almost entirely 3D printed (aside from some bearings, screws, and metal pins). I recently drove 2.2 kilometers with it but I’m shooting for 20km and hopefully 50+kms between gearbox services. Can be made on a $1k printer and it’s all CC0 open source. Code is python on Raspberry Pi.

Please check it out if that sounds cool!

https://youtu.be/cU_0M1_TvD0

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I myself have some interest in the software side of this. I see the robot is remote controlled - but I think a large degree of autonomy would be required for a 50Km trip.

The current self driving technology relies on a trunk full of Nvidia cards sucking data in from a few dozen cameras, lidars or radars all working to create a coherent world view, the whole system drawing hundreds of watts of power.

I wonder if it's possible to capture 90% of the performance of that system with simple hardware that can fit such minimal hardware and other applications where failure is an option and has limited consequences.

A thing I'm thinking about lately are lightweight, electric self driving bikes (or more exactly, trikes) running on existing, dedicated bike infrastructure, augmented with some embedded instrumentation. As long as the speed does not exceed 15Km/h and they are guaranteed to never run a red light or run over any object crossing the path, they could be as safe as a human driven bikes.

Why would you want a self-driving bicycle? It’s not like you can relax and read a book during the ride, and it’s not very autonomous either (unless it can stand upright without moving).

That's the idea, to relax for the bulk of the trip on dedicated infrastructure, then pedal the last mile to your final destination: https://www.coroflot.com/hadley/enclosed-bike

With solar panels and the right weather, it barley needs to recharge.

Ah, so the bicycle is just a legal term; in common speech, this would sooner be called a one person tiny car.

Is the windscreen the defining feature of a car? It can be replaced with a plastic, zipper tarpaulin. I see the distinction more as a weight-power-danger thing.

For me it’s closed vs open, and less so stable vs unstable (although 3-wheel motorcycles break that pattern).

It's a distinct category of human powered vehicle: https://en.m.wikipedia.org/wiki/Velomobile

That's not a bicycle, it's a tricycle. I guess you've solved the problem of balancing but I don't think many bicyclists would be happy with your design.

Well, I did say trike in the original post above. I think the relationship with the bicyclist community depends on the safety and weight/speed of the vehicle and how well it suits their own needs. Trikes and electric trikes are allowed on bicycle tracks depending on jurisdiction, an example upper ceiling of power is 250W.

'Get a horse!'

Not sure how relevant, but it appears he has the code for Rover's control on Github:

https://github.com/tlalexander/rover_control

Yes autonomy is super important for a robot like this! I build rover as a platform for autonomy research, as smaller robots I’ve built in the past didn’t have enough room for a high powered compute and an array of sensors.

I’m particularly interested in camera only navigation, localization, and obstacle avoidance, and I hope to get an NVIDIA Xavier board and multiple cameras to use as the sensing system. I’m trying to get myself in a position where I finally have to learn machine learning, and Rover is the project for that!

Wow. Another awesome open source project that I will hopefully be replicating. What's the remote control that you're using? I see flutter support in your code and am unfamiliar with flutter.

EDIT: Nvm. https://codeduino.com/news/hardware/flutter-the-wireless-ard...

http://flutterwireless.com/index.php?route=product/manufactu...

All products out of stock.

Thank you!

Yeah, I’m using Flutter. I’m the person who made Flutter so I have a lot of them. I used to have bluetooth control from iPhone but I wanted a physical interface. Any remote is trivially easy to add though - the remote is a standalone python program that sends GRPC commands to the motors. I recently got a PS4 remote and may add support for that!

I liked that part of the DARPA-demo the best for sure. It seems obvious that vehicle suspension should be dynamically controlled by software anticipating the terrain. (Maybe cars already have this technology to some extent? I'm not sure.) What's the soft tech in your robot?

There’s been at least two attempts at active suspension I’m aware of. One is quite old. It came up in discussion on HN recently. Back shortly with a link.

Update: link as promised https://news.ycombinator.com/item?id=17108828

there are electric sway bars https://www.youtube.com/watch?v=zVNHkGq9fDc

bose electromagnetic suspension: https://www.youtube.com/watch?v=WOR8eKBLwXQ

student project: https://www.youtube.com/watch?v=IQ1eKddstxM

> Maybe cars already have this technology to some extent?

It was banned in F1, that combined with the skirts for downforce meant for insane low ground clearances with grip off the scales. You could see cornering speeds going up seemingly without end.

context: https://www.racefans.net/2007/05/17/banned-active-suspension...

Even non-computer aided active suspension was banned. Good readup: https://www.autosport.com/f1/news/127638/f1-latest-suspensio...

some F1 cars had it briefly in the 1970s and it was outlawed. Cars would lean into the turns, nose up when braking, nose down when acclerating. crazy stuff.

Hello! I’m not sure I understand the phrase “soft tech”, but Rover uses some large springs for suspension and has big foam tires. I could build active suspension but it dramatically increases the cost and complexity of the robot, which goes counter to my goals. Some low cost active suspension would be helpful though! Right now I’m just focused on keeping the thing reliable. :)

Nicely done.

If the wheels were bigger, it could be double-sided / flippable (no "this side up").

Nice project! What kind of 3d printer are you using?

Thanks! I use a modified Monoprice Maker Select V2 and a modified TEVO Black Widow (which I don’t recommend due to assembly effort). The CR-10 and especially the 400mm version is what I recommend for building Rover!

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