Accel/Brake Assist via Gyros?

[InfiniteWheelie]

Many wheels have accel/brake assist which tilts the pedals forward during acceleration, and back during braking. Of course it still requires the rider to provide all the shift in weight (lean), it just makes it significantly easier for the rider to do so.

However, what if you used active gyros instead? Similar to current accel/brake assist, it could be a percentage you set but instead of tilting the pedals it would directly amplify your lean force. For example when set to 100% it would exactly match the force you are applying, giving you twice the “lean power”.

This would mean, for example, that you wouldn’t need to be an expert rider to perform emergency braking. In addition, wouldn’t this also make traction control possible? For example if you had a very powerful wheel capable skidding while braking, the wheel could detect that and use the gyros and motor to end the skid.

What do you think of the idea? Would it be possible, practical, or even desirable?

Edited July 22 by InfiniteWheelie

[rcgldr]

There is no accel/brake assist. The rider exerts a torque onto the EUC, and the EUC responds by having the motor exert the same torque onto the wheel+tire, and a reverse torque with the same magnitude onto the EUC, canceling out the torque exerted by the rider to hold the EUC vertical and balanced. In a soft mode, the motor outputs a bit less torque while allowing the EUC to tilt, but once the EUC is tilted, the motor torque is increased to hold the EUC's current tilt angle.

Lower pedals offer some assist. The rider's mass reacts to accel/brake with a horizontal force at the pedals. This results in a "positive" torque relative to the axle, and a "negative" torque relative to the tire's contact path. Lower pedals will increase the "positive" torque and decrease the "negative" torque. If using pedals only, the "positive" torque applied to the pedals is limited by the distance from middle of pedals to front/back edge of pedals. Power pads increase the amount of "positive" torque the rider can apply to an EUC, because the distance from pedals to power pads is much greater than half the length of the pedals.

[InfiniteWheelie]

@rcgldr

You're basically explaining how regular accel/brake assist works, which I also acknowledged in my post. I'm discussing a different kind of accel/brake assist using gyros. This would be the "real" assist which doesn't currently exist.

If you want to see an example of how this works look at Lit Motors. Their 2 wheeled concept vehicle uses gyros to balance itself in the left/right orientation. This would work essentially the same way, but instead apply force in the forward/backward orientation to provide additional acceleration and braking.

Edited July 22 by InfiniteWheelie

[Mono]

9 hours ago, InfiniteWheelie said:

What do you think of the idea?

Looks quite ambitious. (BTW, it may not be clear for everyone what "active gyro" means, I found this vid for some context explanations).

9 hours ago, InfiniteWheelie said:

Would it be possible,

I suspect it should be.

9 hours ago, InfiniteWheelie said:

practical,

probably not

9 hours ago, InfiniteWheelie said:

or even desirable?

probably yes, it would in particular allow larger wheel diameters to be more usable. The wheel weight remains the recurrent problem though.

Edited July 22 by Mono

[rcgldr]

16 hours ago, InfiniteWheelie said:

I'm discussing a different kind of accel/brake assist using gyros. This would be the "real" assist which doesn't currently exist.

Adding gyros would complicate the forwards | backwards balancing algorithm. The gyros would have to be counter-rotating so that there would be zero net torque needed to maintain their speed, and if the friction is not exactly equal, then there is a net torque needed to overcome the friction difference, which could only be countered by accelerating or decelerating the EUC to get the rider a bit off balance in order to compensate for any net internal torque.

16 hours ago, InfiniteWheelie said:

2 wheeled concept vehicle

On a 2 wheel vehicle, the front tire is twisted left | right to steer, mostly independent of lean angle (lean angle affects turning radius for a given steering angle). On an EUC, the primary method to steer at normal speeds is to tilt the EUC which will steer due to camber effect. If gyros were being used to balance left | right, how would the EUC detect the difference between intended and unintended tilt angles? For both bikes and EUCs, but due to different physics, at sufficient speed, they become self-balancing left | right if riding in a straight line on smooth pavement. On my V8F and 18XL, this occurs around 8 mph, and I can essentially stand still without having to make any balance corrections (I became aware of this the first time I reached 8 mph on my V8F, during my second 30 minute learning session). There is the issue of counter-steering: in order to initiate a lean, the rider has to steer the bike or EUC outwards from under the rider to lean the rider inwards. On an EUC, this is somewhat automatic as the same Newton third law torque pair that leans the rider inwards also leans the EUC outwards. Once leaned, counter-steering still applies, steer more to lean less, steer less to lean more.

Edited July 22 by rcgldr

[Mono]

30 minutes ago, rcgldr said:

If gyros were being used to balance left | right, how would the EUC detect the difference between intended and unintended tilt angles?

Doesn't seem prohibitively difficult to do, but it's also unrelated to the OP.

[rcgldr]

10 hours ago, Mono said:

Doesn't seem prohibitively difficult to do, but it's also unrelated to the OP.

Unlike that 2 wheel vehicle, an EUC exert a significant amount of left | right torque onto the rider, especially if the rider is only touching the pedals, which is what I and many other riders do when riding, except for turns where a rider has to hang off and apply inwards pressure on the outside upper pad.

Back to the OP's premise, assume that the gyros somehow avoid running out of headroom (excessive rpm), and that they match the torque generated by the rider so that the motor can generate twice the torque onto the wheel+tire that the rider exerts onto the EUC. The increase in accel/brake assist would require the rider to lean further than currently, and the riders are already close to the limits of how far they can lean:

https://www.youtube.com/shorts/r9qrpG38wks

 

 

[Mono]

2 hours ago, rcgldr said:

the riders are already close to the limits of how far they can lean

right, that would be kinda exactly the point of this acceleration assistance: the rider needs less forward/backward displacement (of the CoG impacting the wheel) over the pedals to make acceleration happen and can just "normally" lean according to the acceleration that does happen.

Edited July 23 by Mono

[rcgldr]

22 hours ago, Mono said:

right, that would be kinda exactly the point of this acceleration assistance: the rider needs less forward/backward displacement (of the CoG impacting the wheel) over the pedals to make acceleration happen and can just "normally" lean according to the acceleration that does happen.

Assume a  better rider can pull 1/2 g on an EUC, which is about 26.6°, and additional lean need to exert the same torque onto the EUC, that the motor exerts onto the wheel+tire to achieve 1/2 g acceleration.  Say this is a ET max, 100 lb, 20 in tire, and rider with gear weigh  200 lbs, center of mass 3 feet above feet. For the 1/2 g acceleration, the 26.6° translates into center of mass 1.34 feet ahead of the axle for the 1/2 g + 0.625 feet ahead of the axle to exert 125 fl lb of torque for a total of 41° lean angle. If somehow a gyro assist increase this to 1 g, then it's 45° => 2.1 feet ahead for 1 g + 0.625 feet for 125 fl lb of torque = 66.3°, which probably isn't possible for acceleration. It might be possible for braking if sitting back and down and leaning back (bent back at the knees with almost no bend at the hips).

Then consider how much weight gyro(s) for assist will add to the weight. Also the gyros would have a limited range of +/- rpm, what happens if they reach a max rpm? If there is any net friction from the gyros, that would translate into a constant torque that would require the rider to lean forwards or backwards just to maintain a steady speed. These would be factors that would complicate a balancing algorithm.

Edited July 24 by rcgldr