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Comment by sandworm101 | Hacker News Reader

Lol, a self-driving motorcycle isn't anywhere near possible atm. Driving a car is to riding a motorcycle as walking is to ballet. There are all manner of strange physics (Google "countersteering"). Add to this the vast differences in threat profiles, the regular need for evasive maneuvers, serious judgment calls re emergency braking in corners, the weight-shifting of the rider, the potential 'bail out' decision, the lowside v highside decision (laydowns) ... I haven't heard even a passing joke about an autodrive two-wheeler. Even automatic transmissions are near fantasy beyond small 2-gear scooters.

Any sudden, unexpected, movement by an autodrive motorcycle would probably see the drive thrown free, or at least result in a weight shift great enough to down the entire package.

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I meant it as a little joke, but since you bring it up - no, I actually think that autodrive motorcycle is not only feasible, it's not that harder than a self-driving car. Why?

Because all those "ballet-like" things is basic feedback control issues, the kind of which you learn about on control theory 101 in college. You can pretty much convert the problem of steering the self-driving motorcycle into the problem of self-driving car by adding a module that accepts car-like inputs and translates them to dynamic balance control. We've solved the basics with segways, which are smart-high-schooler level electronics projects.

Also, generally, whatever you can do on your vehicle a machine can do the same using the same control inputs, only better. Manual gear shift included.

I take it you haven't driven a motorcycle. I can ride one, at speed and around corners, without touching the controls. Remember that the rider may represent 30+% of the vehicle mass. Moving your weight around on the bike has as much control over direction as the handlebars. Unless you are going to strap the rider into a seat (ie make it a car) attach him to a hydraulic arm, or install a 200lb gyro, no machine can take directional control.

This all comes to a head at the transition point of countersteering, where the controls reverse around 20ish mph. The rider's balance controls whether turning the handlebars right means right or left. If the rider isn't in sync with the autodrive, everyone is in the ditch.

I'm genuinely curious, as an occasional motorcyle enthusiast myself, whether it's physically possible to counter the movements of the rider in addition to and counter to their movements, which represent a large portion of the vehicle mass. My gut feeling based on the segway is, yes, it's possible. But I'd love to hear any analyses to the negative.

My guess is, you could put a 1m vertical pole behind the driver with some mass attached to the top end of it and motors controlling it at the bottom. That should give you enough angular control to compensate for whatever rider is doing.

Given the close interaction between the rider and the bike, I'm not sure how comfortable would such a vehicle be. It may turn out to be nausea-inducing.

I wonder if a "feet first" design would be once solution. The lower centre of gravity should be easier to stabilise. I don't know whether the riding style of an FF makes the same use of the rider shifting their weight as with a regular bike.

It's probably possible to some extent. It's like having a anxious pillion rider on your bike. I remember when I first took my little sister along on my motorcycle, she'd lean the wrong way in the curves because she was scared the bike might fall over or something. Made controlling the bike harder, but not impossible.

(That experience taught me to always tell people to lean into the curve if they've never sat on a motorcycle before)

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