In this Grin Tech video
They discuss a clever new way of engaging and variably controlling regen braking. There's not a lot of detail, but essentially:
There isn't an electronic control over the variable regen, it is entirely mechanical. The disc rotor connects not to the shell, but to the planet carrier. So when you engage the mechanical disc brake on that wheel, it prevents the carrier from rotating (or adds drag to it if you aren't fully engaging the brake), and causes the clutch to engage as if the motor was spinning, causing the wheel rotation to backfeed into the motor.
This image from their page shows the standee with the images too)
![FullyCharged1[1].jpg](https://endless-sphere.com/sphere/data/attachments/205/205268-8f403a5e062f6ae448b1d0f13840d3ac.jpg "FullyCharged1[1].jpg")
![FullyChargedBoothCorner[1].jpg](https://endless-sphere.com/sphere/data/attachments/205/205269-75d2344360305585a62aaeac49b24849.jpg "FullyChargedBoothCorner[1].jpg")
Stuff not covered in the video:
Since you wouldn't normally have the motor operating while you're braking, it would then just be creating voltage as a generator, feeding current back to the battery if the voltage is higher than the battery voltage, using the controller FETS as a 3-phase rectifier. The more force you apply with the lever (which you will get natural normal mechanical feedback for, as you are simply using a standard disc brake as-designed),
If a controller could be designed to be able to detect that braking is occurring via this generated voltage and then perform switching operations it could increase this braking force, or alter the curve it is applied with, etc. (you could install some form of position sensor on the caliper that provides a variable output to do this, but that defeats the point of the system not requiring any sensors or wiring for this, and changes the feedback to control the braking to electronic instead of mechanical).
It's an interesting system I wish I had thought of.
It should be possible to alter an existing geared hubmotor to work this way, although the ones I've personally opened up have the planetary carrier and clutch on the pedal drive side, not the brake side, so it would take some mechanical rearrangement of the casing and internals to do this that would be easier on a front motor than a rear.
I am going to take a look at the old bafang Jump Bike motors I've got to see if this is a possible mod with the capabilities I have here, when at some point in the future I have time/etc to try.
There isn't an electronic control over the variable regen, it is entirely mechanical. The disc rotor connects not to the shell, but to the planet carrier. So when you engage the mechanical disc brake on that wheel, it prevents the carrier from rotating (or adds drag to it if you aren't fully engaging the brake), and causes the clutch to engage as if the motor was spinning, causing the wheel rotation to backfeed into the motor.
This image from their page shows the standee with the images too)
Stuff not covered in the video:
Since you wouldn't normally have the motor operating while you're braking, it would then just be creating voltage as a generator, feeding current back to the battery if the voltage is higher than the battery voltage, using the controller FETS as a 3-phase rectifier. The more force you apply with the lever (which you will get natural normal mechanical feedback for, as you are simply using a standard disc brake as-designed),
If a controller could be designed to be able to detect that braking is occurring via this generated voltage and then perform switching operations it could increase this braking force, or alter the curve it is applied with, etc. (you could install some form of position sensor on the caliper that provides a variable output to do this, but that defeats the point of the system not requiring any sensors or wiring for this, and changes the feedback to control the braking to electronic instead of mechanical).
It's an interesting system I wish I had thought of.
It should be possible to alter an existing geared hubmotor to work this way, although the ones I've personally opened up have the planetary carrier and clutch on the pedal drive side, not the brake side, so it would take some mechanical rearrangement of the casing and internals to do this that would be easier on a front motor than a rear.
I am going to take a look at the old bafang Jump Bike motors I've got to see if this is a possible mod with the capabilities I have here, when at some point in the future I have time/etc to try.
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