Pedal sensitivity versus rider effort

[rcgldr]

16 hours ago, InfiniteWheelie said:

It seems to follow some kind of torque curve where the more tilted the wheel already is, the more torque the rider must apply to tilt the wheel further.

A rider can't apply more forwards torque until the rider is leaning more forwards, and that requires the EUC to accelerate less so that the rider briefly falls forwards, increasing rider lean, then the rider can switch to applying more forwards torque onto the EUC frame and the EUC increases acceleration with the self-balancing keeping the increased lean angle stable (to prevent the rider from fully falling forwards). In what I call "counter-tilting" (similar to counter-steering), the rider exerts less forwards torque to lean more and exerts more forwards torque to lean less (or return to vertical). If initially vertical, the initial torque is in the opposite direction. Since this is very similar to how people balance while standing on solid ground, a rider can just focus on adjusting lean angle similar to standing on solid ground.

In a hard pedal setting, since the EUC remains near vertical, the rider exerts about the same amount of torque as the motor during transitions. In a hair trigger like soft mode, the EUC would tilt and lean the rider rapidly during transitions, but I'm not aware of any EUC that has that rapid of a response in soft mode, since it could present a rider control issue. Some EUCs do have a fairly rapid tilt back that creates an issue for some riders.

Edited January 13, 2023 by rcgldr

[Funky]

One can simply apply more force with one foot. To go faster without even leaning forwards.. I time to time like to ride like that. Feels like i'm pressing down gas pedal.  

It's not always about the lean.. One can be standing completely straight/upright. Simply pressing down with fingertips.  Heels not touching the pedals even.

 

Or even better option - when you have smooth, long, straight road ahead.. You can move 1/3 of your feet over pedals. (Fingertips hanging over the pedals quit a bit, more than usually..) That way the wheel will go forwards without even need of a lean. You will be standing upright completely (same as standing on ground), but wheel will go forwards. Ofc same time the breaking gets dramatically reduced. < This right here is zero effort needed from the rider, because you are standing completely straight.

I personally do that and enjoy it.

 

Ankles and EUC "L" hangers...

If your ankles are behind "L" hangers, you will need to lean more - to go forwards/faster. (More effort.)

If your ankles are past "L" hangers. You will go forwards/faster, without much of a lean needed. (Less effort.)

It's all about how you position your feet on pedals. More forwards or backwards.. (If you move forwards/backwards more - your weight is also moved in front or back more.) You get more powerful braking vs more easy acceleration going forwards.

Someone who doesn't need to brake often - he should position their feet more forwards. It will be more comfortable, less effortless ride. But same time you will reduce the braking power. (You will need to lean way, way more backwards to get braking power - because your feet are more forwards.)

Edited January 13, 2023 by Funky

[rcgldr]

3 hours ago, Funky said:

go faster without even leaning forwards.

If an EUC started accelerating forwards and the rider was not leaning forwards, the rider would fall backwards, except that the self-balancing would detect the backwards falling rider and decelerate to re-balance the rider to prevent the rider from falling. 

As I posted before, in most cases on level pavement, only part of a rider's lean is related to torque exerted onto an EUC, most of the lean is due to acceleration or braking. If riding at higher speeds, a rider needs to lean forwards into the wind. Shifting feet forwards will reduce torque related lean, but acceleration | deceleration related lean remains the same.

Edited January 14, 2023 by rcgldr

[novazeus]

On 1/10/2023 at 7:23 PM, level9 said:

My S22 setup which fixes the torque issues - leg is just behind the center point of the wheel.

- pedals in the forward position
- grizzla flow pads + fairing plate

Everything is velcro attached, even the fairing plate and baby bumper pads for maximum adjustability.

Also have the 3d printed calf saver installed - highly recommended. It's a very comfy ride now.

 

a couple of things, first off thank u so much for ur picture. ur right, out of the box the pedals sb moved forward, esp on the s22 and pro!

the other thing is, i have a new t-handle allen wrench set i bought just for wheels, and since they aren't plastic junk anymore, more like rc helis, it wax much fun to get done on the floor and wrestle with it stoned. but i got it done and found some broken pieces up above the pedal hangers that u have to reverse so the set screw on the shaft indentation lines up. anyway, idk what these broken pieces did except rattle so just a heads up.

since i had to remove everything, i opted for the lower pedal position, woo woo, a good decision. it gives me more control with my leg and lowers the center of gravity. 

i tried it inside and it feels great.

for what i'm doing now on my little road, i don't need pads, but once i go in the pasture they might be handy. 

thanks again. really weird haven ur whole foot utilizing the whole pedal without toe hangover. cadillacing!

[InfiniteWheelie]

@rcgldrThe point I'm making is LeaperKim wheels don't seem to just slowly tilt forward/back for a few degrees before hitting a hard mode. Like I said, that would probably be preferable since it would allow you to initially tilt forward/back easily, but with the safety of a hard tilt limit.

Instead of hitting hard mode after a few degrees, it simply becomes progressively harder to tilt, requiring more and more force to tilt it. But unfortunately you can indeed keep forcing it lower which is dangerous when applying hard acceleration or braking,

 

Edited January 14, 2023 by InfiniteWheelie

[rcgldr]

3 hours ago, InfiniteWheelie said:

The point I'm making is LeaperKim wheels don't seem to just slowly tilt forward/back for a few degrees before hitting a hard mode.

Inmotion EUCs off-road mode limits the amount of tilt, while commuter mode allows more tilt if in a softer (lower pedal sensitivity) setting. In hard 100% mode, it doesn't make any noticeable difference.

3 hours ago, InfiniteWheelie said:

Instead of hitting hard mode after a few degrees, it simply becomes progressively harder to tilt, requiring more and more force to tilt it. But unfortunately you can indeed keep forcing it lower which is dangerous when applying hard acceleration or braking,

If accelerating on level pavement and leaned forwards, if the rider wants to return to a vertical position and stop accelerating, the rider has to exert more forwards torque on the EUC, which coexists with a backwards torque exerted by the EUC onto the rider, but most of the decrease in rider lean angle is due to stronger acceleration of the EUC causing it to accelerate back under the rider's center of mass. Tilt back accelerates enough to lean the rider backwards and tilt the EUC backwards, without rider input. If trying to increase lean angle, the rider has to initially exert less torque onto the EUC, which reduces acceleration, causing the rider to lean further forwards. Then with the increased lean angle, the rider can then exert more forwards torque onto the EUC for more acceleration while holding the increased lean angle. 

Excessive pedal tilt can lead to pedal scrape, especially if riding off road. This is why Inmotion off-road setting limits tilt.

[mrelwood]

 

On 1/14/2023 at 9:26 AM, rcgldr said:

if the rider wants to return to a vertical position and stop accelerating, the rider has to exert more forwards torque on the EUC

This is what I tried to explain to people when they were worried that a tilt-back uses power that the wheel might not have near the top speed: The wheel would need about the same amount of power for the rider to start braking himself!

On 1/14/2023 at 9:26 AM, rcgldr said:

Excessive pedal tilt can lead to pedal scrape, especially if riding off road. This is why Inmotion off-road setting limits tilt.

I don’t think pedal scrape is an issue they worry about with the modern Inmotions. What the off-road mode gains is the stability when going over rocks and roots. In Commuter mode the wheel can feel as if it were struggling to go over the roots when the firmware is waiting for more tilt to create enough torque to climb over the root. In off-road mode the wheel requires less tilt to create the required climbing torque, resulting in a more stable ride.

 Though I do think the off-road mode could be improved by a lot. Currently setting the sensitivity to softer values creates a slack at the center position, yet the pedals feel very hard on both sides of the slack. I would make it ramp up the output power in an exponential curve, without the slack. Nobody will use the off-road mode with softer sensitivity anyway because of said slack.

[rcgldr]

5 hours ago, mrelwood said:

I don’t think pedal scrape is an issue they worry about with the modern Inmotions.

I got the impression from your video that off-road setting limits the tilt. I assumed this was done for pedal clearance from low off-road obstacles. 

5 hours ago, mrelwood said:

What the off-road mode gains is the stability when going over rocks and roots. In Commuter mode the wheel can feel as if it were struggling to go over the roots when the firmware is waiting for more tilt to create enough torque to climb over the root. In off-road mode the wheel requires less tilt to create the required climbing torque, resulting in a more stable ride.

The rider still needs to be leaned a bit forwards in order to generate more torque, but encountering rock or root or ... , is likely going to decelerate the EUC, leaning the rider forwards, in which case self-balancing would have to generate more torque to prevent the rider from falling forwards. The logic would be similar to the auto-lean that occurs on a transition to an incline, but with a faster response.

It's still not clear to me (and most youtubers) what the actual difference is between commuter and off-road settings are. A lot of reviews state that at 100% pedal sensitivity, there's no perceptible difference. Since I worry about overlean on my V8F, I don't lean much. I'll accelerate moderately from 5 to 12 mph, and back off as I approach 15 mph, since current increases a more than linearly with increase in speed (due to voltage sag). Due to my conservative riding on the V8F, I don't feel much difference between 0% and 100% sensitivity. With pedal sensitivity at 0%, maybe there is a bit more tilt on inclines or declines, but I mostly notice this on declines as opposed to inclines, and it's probably more related to the auto-lean than auto-tilt, or maybe it's just not working on my V8F. At 12 to 15 mph, I lean more to the side for making turns than I'm willing lean forwards, since the turning isn't significantly power restricted. The V8F and most EUCS seem to be able to brake harder than they can accelerate without issue. One exception seems to be early versions of V12, where the firmware apparently was limiting the braking. I don't know if this was fully resolved.

Edited January 16, 2023 by rcgldr

[mrelwood]

On 1/16/2023 at 7:41 PM, rcgldr said:

I got the impression from your video that off-road setting limits the tilt. I assumed this was done for pedal clearance from low off-road obstacles. 

A forward tilt rarely affects clearance on modern wheels. On suspension wheels the pedals are significantly higher.

On 1/16/2023 at 7:41 PM, rcgldr said:

The rider still needs to be leaned a bit forwards in order to generate more torque, but encountering rock or root or ... , is likely going to decelerate the EUC, leaning the rider forwards, in which case self-balancing would have to generate more torque to prevent the rider from falling forwards. The logic would be similar to the auto-lean that occurs on a transition to an incline, but with a faster response.

Exactly. When the wheel slows down behind a larger obstacle, the first thing the rider has to consider is whether the wheel can make it or should the rider bail. The shorter the time it takes to climb over the obstacle and the shallower the required tilt, the more confident and stable the experience. In soft mode (on some wheels) the wheel can slow down to a halt and feel overpowered for a short while behind every obstacle, while a hard mode can feel like smooth sailing.

On 1/16/2023 at 7:41 PM, rcgldr said:

It's still not clear to me (and most youtubers) what the actual difference is between commuter and off-road settings are.

Commuter is the normal mode. The more the wheel tilts, the more it accelerates. Sensitivity determines the ratio between input and output. High sensitivity reacts already to the slightest tilt, and is practically impossible to tilt further. Low sensitivity lets the wheel tilt a lot until it catches up.

On Off-Road mode at 100% it's indeed difficult to notice a difference to the Commuter Mode, but at lower sensitivity the behavior is vastly different. There is a small area in the middle where the wheel feels completely loose, and the wheel doesn't seem to react to changes between say -2 and +2 degrees of tilt. But beyond those limits it behaves like a hard mode with +/- 2 degrees of calibration, and the pedals are very hard to tilt any further.

My gripe with the Off-Road mode is the overly sharp transition between the loose area in the middle and the hard areas beyond the threshold. I can't see the completely loose middle area of being any good for any situation, and lowering the sensitivity doesn't soften the behavior much beyond the threshold, which is what I would've hoped.

On 1/16/2023 at 7:41 PM, rcgldr said:

Due to my conservative riding on the V8F, I don't feel much difference between 0% and 100% sensitivity.

If I remember correctly, your max power usage was indeed very low. I can see how that can hide the differences in ride mode settings. Another thing is that the V8F doesn't have the instant power required for a modern hard mode, so the scale of settings is narrower than it is on more powerful wheels.

 

I made another video on the ride mode settings, where I concentrate in explaining why the hard mode (in modern wheels) is not necessarily the best way to go:

 

[rcgldr]

5 hours ago, mrelwood said:

The more the wheel tilts, the more it accelerates.

For constant acceleration | deceleration, the torque the rider exerts onto the EUC frame is the same as the torque the motor exerts onto the wheel+tire. The EUC will make corrective changes to the motor torque to keep the rider balanced while holding a lean angle. Pedal sensitivity | EUC tilt isn't a factor for constant acceleration | deceleration.

When balancing a broomstick, to accelerate it to the left, at first the bottom has to be moved to the right to lean the broomstick left before it can be accelerated left, which I call counter-lean. Similarly if a rider is vertical, to lean forwards, the rider initially exerts a backwards torque on the EUC frame (this coexists with the EUC frame exerting a forwards torque onto the rider), which causes the EUC to decelerate from under the rider, leaning the rider forwards, which allows the rider to then exert a forwards torque onto the EUC frame, and the motor to exert the same forwards torque onto the wheel+tire to accelerate. In what I call counter-leaning, to adjust lean angle, the rider exerts more torque to lean less (or return to vertical) and less torque to lean more. Pedal tilt transitions only account for a small part of the exerted torque.

Pedal tilt reduces ankle bend, which can be more comfortable, but can mask how much a rider is leaning forwards or backwards. This is why most of the how to ride videos suggest beginners start off in hard | 100% sensitivity mode, until they develop a sense for lean angle independent of ankle bend. 

The rider initiates torque changes to command the EUC to accelerate or decelerate, while the EUC initiates torque changes to balance the rider, or to prevent over-speed with tilt-back, or in the case of Inmotion EUCs, auto-lean the rider for transitions onto incline | decline.

Tilt sensitivity - an EUC could multiply a rider's intended input. For example a rider initially exerts 10 lb ft backwards torque onto the EUC, but the EUC could respond by exerting 20 lb ft of forwards torque onto the rider (coexistent with the rider now exerting 20 lb ft of backwards torque onto the EUC frame due to momentum), and 20 lb ft of backwards torque onto the wheel+motor, rapidly leaning the rider forward to what initially was a small torque input command. Similar to auto-tilt, it would be an EUC initiated torque, and I don't know if any EUCs do this.

 

[mrelwood]

 

29 minutes ago, rcgldr said:

Pedal sensitivity | EUC tilt isn't a factor for constant acceleration | deceleration.

You’re right, I should’ve typed “The more the wheel tilts, the more power it gives to the motor.”

29 minutes ago, rcgldr said:

Tilt sensitivity - an EUC could multiply a rider's intended input. For example a rider initially exerts 10 lb ft backwards torque onto the EUC, but the EUC could respond by exerting 20 lb ft of forwards torque onto the rider

I’m not sure if I follow. Do you mean that the wheel would tilt back during acceleration, and tilt forward during braking? That would be the exact opposite of the current braking and acceleration assists that we see on some wheels. It would make the acceleration and braking harder and slower. I feel that the Begode firmware does something a bit like that though, as if it overcompensated for the lean a bit. Or then it just slowly recovers to horizontal, not sure. Either way, I dislike it. I don’t like it when the wheel specifically does something noticeable.

[rcgldr]

20 hours ago, rcgldr said:

Pedal sensitivity | EUC tilt isn't a factor for constant acceleration | deceleration.

 

18 hours ago, mrelwood said:

“The more the wheel tilts, the more power it gives to the motor.”

In hard or 100% sensitivity, the EUC could tilt a small amount momentarily, but return and hold the pedals level regardless of the amount of torque being used to accelerate | decelerate.  In your second video (the one above), you show this, a rider leaning forwards and accelerating with zero EUC tilt. The torque exerted by the rider onto the EUC frame is the same as the torque exerted by the motor onto the wheel+tire that results in acceleration | deceleration (regardless of tilt angle, as long as the tilt angle is not changing).  I did the math for this in my prior post:

https://forum.electricunicycle.org/topic/31318-pedal-sensitivity-versus-rider-effort/?do=findComment&comment=452675

20 hours ago, rcgldr said:

Tilt sensitivity - an EUC could multiply a rider's intended input. For example a rider initially exerts 10 lb ft backwards torque onto the EUC, but the EUC could respond by exerting 20 lb ft of forwards torque onto the rider

 

18 hours ago, mrelwood said:

Do you mean that the wheel would tilt back during acceleration, and tilt forward during braking?

Yes for tilt back, such as a rider accelerating and triggering tilt-back due to speed, where the EUC accelerates more than rider commanded, momentarily unbalancing the rider to lean the rider backwards due to a combination of the increased forwards acceleration and increased backwards torque exerted onto the rider. The EUC would use some of the motor torque to tilt-back the EUC. For Inmotion EUCs, during a transition onto an incline | decline, the EUC leans the rider as needed without rider input.

As for acceleration or deceleration on level ground, the self-balancing logic results in the EUC increasing or decreasing torque as needed to balance the rider, without rider input, but these are typically small adjustments.

In theory an EUC could magnify the riders input during normal riding. For example, the rider intends to lean gently, but the EUC aggressively leans the rider, effectively a response sensitivity > 100%, but I doubt any actual EUC would be programmed to do this.  

Edited February 2, 2023 by rcgldr

[Uras]

mrelwood - thanks for the awesome video. I can understand that  and it's really quite logical.

[mrelwood]

 

7 hours ago, rcgldr said:

In your second video (the one above), you show this, a rider leaning forwards and accelerating with zero EUC tilt.

Very little tilt actually…

 

7 hours ago, rcgldr said:

The torque exerted by the rider onto the EUC frame is the same as the torque exerted by the motor onto the wheel+tire that results in acceleration | deceleration (regardless of tilt angle, as long as the tilt angle is not changing).

Except the wheel has no method of sensing the amount of torque exerted to the pedals or the shell. It only senses the tilt angle by the MEMS sensors on the mainboard. Hence, the wheel won’t accelerate if the pedals are truly dead level. Only when they are tilted, even just a fraction of a degree.

 

7 hours ago, rcgldr said:

The EUC would use some of the motor torque to tilt-back the EUC.

What would be the point of such function during acceleration, other than to get the wheel to accelerate in front of the rider and slow them down (= traditional tilt-back)?

 

7 hours ago, rcgldr said:

In theory an EUC could magnify the riders input during normal riding. For example, the rider intends to lean gently, but the EUC aggressively leans the rider, effectively a response sensitivity > 100%, but I doubt any actual EUC would be programmed to do this.  

It’s the other way around. If the rider wants to tilt forward gently, the only way to make them tilt more is to let the gravity to draw them further down. This is a low sensitivity in the wheel’s upright attempting algorithm. Which is exactly what the soft mode is!

An over correcting sensitivity would do the opposite, it is called the tilt-back.

[rcgldr]

11 hours ago, mrelwood said:

Except the wheel has no method of sensing the amount of torque exerted to the pedals or the shell. 

An EUC can sense the torque from the motor as well as tilt, but I don't know if or what it uses the torque sensing for.

11 hours ago, mrelwood said:

Hence, the wheel won’t accelerate if the pedals are truly dead level. Only when they are tilted, even just a fraction of a degree.

An EUC responds to changes in tilt angle, not to actual tilt angle. My V8F allows me to set default pedal tilt angle from -5 to +5 degrees. Riders doing a range test can continue to ride and accelerate mildly despite tilt back due to low battery or if a mild tilt-back is used as a warning that the EUC is close to its top speed. Under normal circumstances, once a rider is leaning forwards on an EUC, the riders forward torque on the EUC initially tilts the EUC forwards a small amount, which responds with a forwards torque on the motor to accelerate and balance the rider to hold the lean angle, and there's no reason the EUC can't use some of that torque to return the pedals back to zero tilt while accelerating. The EUC can continue to accelerate with zero tilt (or any fixed tilt angle within reason) until it senses a change in the tilt angle.

11 hours ago, mrelwood said:

If the rider wants to tilt forward gently, the only way to make them tilt more is to let the gravity to draw them further down. This is a low sensitivity in the wheel’s upright attempting algorithm. Which is exactly what the soft mode is! An over correcting sensitivity would do the opposite, it is called the tilt-back.

If a rider is in a vertical position, gravity is pulling straight down at the riders center of mass, the pedals are pushing straight up through the rider's center of mass, and the rider isn't going to lean due to gravity. In order to initiate a forwards lean, the rider has to exert a backwards torque onto the EUC frame, coexistent with the EUC frame exerting a forwards torque onto the rider. The EUC will also decelerate in response, leaning the rider further forwards. How fast the rider is leaned further forwards depends on how hard the EUC decelerates. During transitions, the EUC is not correcting | balancing the rider; it is causing or allowing the rider's lean angle to change. The rider stops the forwards rate of lean by exerting a forwards torque onto the EUC, coexistent with the EUC frame exerting a backwards torque onto the rider, and the EUC will accelerate in response, which also exerts a backwards torque onto the rider, to balance the rider against the pull of gravity. All this can happen regardless of the actual tilt angle.

Edited February 3, 2023 by rcgldr

[techyiam]

2 hours ago, rcgldr said:

rider isn't going to lean due to gravity. In order to initiate a forwards lean, the rider has to exert a backwards torque onto the EUC frame

You are assuming the human body is a rigid body, which it isn't. 

[rcgldr]

4 hours ago, rcgldr said:

If a rider is in a vertical position, gravity is pulling straight down, and the rider isn't going to lean due to gravity.

 

2 hours ago, techyiam said:

You are assuming the human body is a rigid body, which it isn't. 

To clarify, the rider is vertical implies that the EUC pedals are pushing upwards through the riders center of mass, and gravity is pulling down at the riders center of mass, so there is zero torque, and the rider remains vertical. The rider has to exert a torque or a force that results in a torque to offset the riders center of mass relative to the pedals so that there is an offset between the upwards force exerted by the pedals and the downwards force exerted by gravity, which results in a torque that leans the rider. 

For comparison, imagine a person standing on solid ground, and balanced so that the person is not leaning. In order to lean forwards, the person initially presses more with the heels, which coexists with the ground pushing up more at the heels, behind the person's center of mass, creating a torque that leans the person forwards. Once leaned forwards, there is a forwards torque on the person, and the person presses more with the toes to counter that torque and control the lean angle.

[techyiam]

37 minutes ago, rcgldr said:

For comparison, imagine a person standing on solid ground, and balanced so that the person is not leaning. In order to lean forwards, the person initially presses more with the heels, which coexists with the ground pushing up more at the heels, behind the person's center of mass, creating a torque that leans the person forwards. Once leaned forwards, there is a forwards torque on the person, and the person presses more with the toes to counter that torque and control the lean angle.

Or, since the human body is not rigid, the person can move his center mass forward horizontally, and exert an equal reaction backwards horizontally.

[mrelwood]

20 minutes ago, techyiam said:

Or, since the human body is not rigid, the person can move his center mass forward horizontally, and exert an equal reaction backwards horizontally.

The only way to do that though is by balancing the weight distribution between one's heels and toes (or balls of feet to be precise). Starting to move the CoM forward requires an opposite force, which manifests in a weight distribution towards one's heels (compared to the starting point of the CoM).

Edited February 2, 2023 by mrelwood

[rcgldr]

On 1/16/2023 at 9:41 AM, rcgldr said:

With my V8F ... I don't feel much difference between 0% and 100% sensitivity.

 

On 2/1/2023 at 12:56 AM, mrelwood said:

If I remember correctly, your max power usage was indeed very low. I can see how that can hide the differences in ride mode settings. Another thing is that the V8F doesn't have the instant power required for a modern hard mode, so the scale of settings is narrower than it is on more powerful wheels.

I've since discovered that although I hear the beep when changing pedal sensitivity, I have to power my V8F off and back on for the pedal sensitivity to change. I did some rocking back and forth as a test to confirm the need to power cycle the V8F. Since switching to hiking boots solved my calf muscle issues, I haven't tried different sensitivity settings. I can test this wearing an old pair of tennis shoes with thin, flexible soles that give a good feel of the pedals.

Update - I did a quick test at 50% and 10% (setting to 0% ends up at 10% after power cycle) with my old tennis shoes. The issue is most of my riding is at 12 to 15 mph, very little acceleration or braking, so it's not making much difference. When stopping, I can feel the tilt back during braking, and there may be a bit more tilt on inclines and declines (there's a 6 degree slope on a street next to my home). 

 

Edited February 3, 2023 by rcgldr

[mrelwood]

6 hours ago, rcgldr said:

I've since discovered that although I hear the beep when changing pedal sensitivity, I have to power my V8F off and back on for the pedal sensitivity to change.

On most Inmotion wheels the pedal sensitivity changes right away, even while riding, but one needs to press the lift switch for it to change between Commuter and Off-road ride modes. Maybe that’s the case for the V8 as well?