Making a torque throttle instead of a speed throttle for a cheap controller

[Woosh]

what is the advantage of maintaining constant current versus constant speed? When you ride on throttle,you just push more to go faster, intuitively. The bike reacts immediately with the change in the throttle's output then settles to higher speed. If you turn the throttle to current proportional, you'd need to fiddle with the throttle all the time because the road's gradient and environment changes to maintain your speed, like following the vehicle in front.

 

[vfr400]

You don't notice the difference so much on low power bikes, but on high power ones, current throttles are more or less essential. Also, current throttles work better on crank drive bikes because of the high torque they make in ghe low gears.

 

[danielrlee]

It becomes more pertinent running at increased power levels, where granular control is almost impossible at low speed over varying terrain with rapid changes to motor loading. It's difficult to describe, but I think it might be down to the fact that even better speed throttle controllers struggle to dampen constant changes to power delivery due to lacking the proper PID feedback.

EDIT: TUFKAD beat me to it!

 

[AviatorTrainman]

Shoot, just realized I forgot to update this thread after rebuilding my battery. I'm running on 44v now, which is alright, I just need a new BMS and charger so I don't have to check the voltage every few minutes while charging. In any case, using the code given above, and tweaking a few of the throttle voltage values to more precisely match my throttle, I am happy with the project as it stands. I have been using this to go everywhere for some time now, and I can happily say I have found no glitches, and it works just fine. The shutoff is instant, and power up is as fast as the built-in soft start will allow. I would recommend this project to anybody looking to have some of the functionality of a CA, with a far lower cost. My all-in cost for this project was $5 for the Arduino (an Amazon clone of the real thing), $17 for the contactless current sensor, and some wires, resistors, and a capacitor I had just laying about, so a total of $22-25, depending on your part sources. I might yet make some more refinements, and if I do, I'll make sure to post them here, but I believe this can stand on its own as a fully complete project. It would, in theory, be possible to implement a bunch of other functions, I just don't have any use for them right now. The Arduino has 4 more analog inputs available, and 13 more digital input/outputs, with the capability to run a basic LCD, so it should be quite possible to make something with more functionality than this project.

 

[Alibro]

Shoot, just realized I forgot to update this thread after rebuilding my battery. I'm running on 44v now, which is alright, I just need a new BMS and charger so I don't have to check the voltage every few minutes while charging. In any case, using the code given above, and tweaking a few of the throttle voltage values to more precisely match my throttle, I am happy with the project as it stands. I have been using this to go everywhere for some time now, and I can happily say I have found no glitches, and it works just fine. The shutoff is instant, and power up is as fast as the built-in soft start will allow. I would recommend this project to anybody looking to have some of the functionality of a CA, with a far lower cost. My all-in cost for this project was $5 for the Arduino (an Amazon clone of the real thing), $17 for the contactless current sensor, and some wires, resistors, and a capacitor I had just laying about, so a total of $22-25, depending on your part sources. I might yet make some more refinements, and if I do, I'll make sure to post them here, but I believe this can stand on its own as a fully complete project. It would, in theory, be possible to implement a bunch of other functions, I just don't have any use for them right now. The Arduino has 4 more analog inputs available, and 13 more digital input/outputs, with the capability to run a basic LCD, so it should be quite possible to make something with more functionality than this project.

Hi and thank you for this great project. I have a 1500W ebike kit and it is pretty brutal in the power delivery so I am going to give this a go. The kit I bought was very cheap so I'm not surprised and have enjoyed doing small upgrades to it. I have ordered the parts you listed so will have to wait for a couple of weeks for them to arrive.
One other thing I'm very keen to do is to upgrade the cadence control as it's so poor as to be useless. I was looking for a way to do this with an Arduino and thought it might be something you could add to your project.

 

[Cavimine]

can anyone tell me what current the contacles current sensor should measure?

 

[AncientMariner]

can anyone tell me what current the contacles current sensor should measure?

I've been working on and off on this device, tried to contact the Author without success. I need proper torque control for my projects and plan to get stuck in again this week, so if your still interested, would be happy to compare observations. Oh yes, regarding the current sunsor, it implies it is sensing motor current but I,ve been thinking of trying sensing battery current which may be more stable.

 

[vfr400]

Most controllers have a shunt in them to measure current. You could easily use that rather than add another device to measure the current. There's normally a shunt in the battery's BMS that you could use too.

 

[AncientMariner]

I'm seeking assistance from someone who has experience in programming an Arduino. The attached program for a torque throttle, when switched on, ramps the output voltage to the controller to 3.81V and just stayes there. Sorry to say I've run out of ideas.

 

[AncientMariner]

Reference my request for assistance programming an Arduino, prblem solved, reason too embarrassing to admit in Public!

 

[Saabman]

Reference my request for assistance programming an Arduino, problem solved, reason too embarrassing to admit in Public!

Just stumbled onto this thread while researching converting my speed control to Torque control as well- you problem was it related to your code or wiring?

Also the link to the Current sensor the OP posted right back at the begining is no longer valid. Any one that has a had a go at this have any further in formation ?