Hmmm - could you possibly squeeze in an optional OC alarm output - maybe with a nearby pad for customer-installed pull-up? This is Gilding the Lily, but a hook to open up the possibility of passing along alerts to other (signaling) devices might be nice... :wink:justin_le said:
Cycle Analyst V3 preview and first beta release
- Thread starter justin_le
- Start date
NeilP
1 GW
Doctorbass said:
Let me guess...will the power figures have few more Zeros on the end
So one of the things that was really useful in the RC-CA thread was discussions about throttle mapping. In the original RC-CA, there device was setup only as a current throttle, and the input throttle range was limited over a 3V span via the AuxInput function. In the setup menu for the V3 CA's input throttle, you can specify both minimum and maximum input range allowing you to dial in just where the start and end zones are for the throttle motion, regardless of whether you have a potentiometer or a hall effect throttle type.
The output throttle range is similarly settable. One thing we've noticed is that many newer controllers run the hall throttles off a 4.3V supply rather than a 5V supply, and so instead of the usual 0.9-4.2V input range, they see a 0.9-3.6V range, with full throttle being at about 3.4V and with a 4V signal being considered a fault condition. So this way the CA's output can be adjusted to match properly with what the controller expects:
View attachment 4
And of course, you can select whether the output throttle is a voltage signal as per ebike controllers, or a servo pulse signal as used by RC controllers
In the RC output mode, there is no need to change any hardware on the CA, the same green wire in the 6-pin CA-DP connector will supply either a steady voltage or the pulse stream, and the min and max output ranges are then displayed in units of mS:
Back to the input throttle, there is a selection menu to now choose what the throttle controls, so you have the option of ignoring the input throttle, or treating it as a current throttle, a speed throttle, or now a Pass-Thru throttle. In pass-thru mode, the CA basically takes the input throttle within the input throttle range, and maps it over to the output throttle range. So this way if you don't want the CA's feedback loops to come into the picture, you can have it pass your own command throttle straight to the controller. But with the remapping capability of the input/output ranges, it means you can use potentiometer throttle on a controller expecting a hall input, a hall throttle on a potentiometer controller, or any throttle with an RC controller etc.
View attachment 5
And finally to give more of a soft start feeling to the ebike, and especially to reduce gear and clutch failures in geared drives, there is a throttle output rate limit that regardless of all other settings puts a firm clamp on how rapidly the throttle output of the CA can change:
View attachment 2
Some people like the instant kick of an instant throttle, while others find it disconcerting and prefer the power to ease in smoothly, and so with the rate limit this can be set to the user's preference.
The output throttle range is similarly settable. One thing we've noticed is that many newer controllers run the hall throttles off a 4.3V supply rather than a 5V supply, and so instead of the usual 0.9-4.2V input range, they see a 0.9-3.6V range, with full throttle being at about 3.4V and with a 4V signal being considered a fault condition. So this way the CA's output can be adjusted to match properly with what the controller expects:
View attachment 4
And of course, you can select whether the output throttle is a voltage signal as per ebike controllers, or a servo pulse signal as used by RC controllers
In the RC output mode, there is no need to change any hardware on the CA, the same green wire in the 6-pin CA-DP connector will supply either a steady voltage or the pulse stream, and the min and max output ranges are then displayed in units of mS:
Back to the input throttle, there is a selection menu to now choose what the throttle controls, so you have the option of ignoring the input throttle, or treating it as a current throttle, a speed throttle, or now a Pass-Thru throttle. In pass-thru mode, the CA basically takes the input throttle within the input throttle range, and maps it over to the output throttle range. So this way if you don't want the CA's feedback loops to come into the picture, you can have it pass your own command throttle straight to the controller. But with the remapping capability of the input/output ranges, it means you can use potentiometer throttle on a controller expecting a hall input, a hall throttle on a potentiometer controller, or any throttle with an RC controller etc.
View attachment 5
And finally to give more of a soft start feeling to the ebike, and especially to reduce gear and clutch failures in geared drives, there is a throttle output rate limit that regardless of all other settings puts a firm clamp on how rapidly the throttle output of the CA can change:
View attachment 2
Some people like the instant kick of an instant throttle, while others find it disconcerting and prefer the power to ease in smoothly, and so with the rate limit this can be set to the user's preference.
teklektik said:
Thanks Teklektik. It indeed started turning into something of a patchwork piece last fall, and so that's part of why there was such a long lapse from then to now figuring out how to get everything tidily integrated in this package in a way that makes sense. I'm glad you can see and appreciate that!
This may be a subject for custom firmware, but there are two difficulties with a fixed rate of change.justin_le said:
- It is probably most useful to only have it apply only in the throttle-up direction so throttle-down response will not suffer (brakes-NOW!).
- Dead-start or at-speed clutch re-engagement is where the gears and clutch take a beating. A fixed rate in all cases can address these two situations but also will make general throttle response sluggish.
EDIT - hmmmm - okay - the criteria for initiating and terminating the behavior for (2) is problematic. Scratch that.
teklektik said:
Right, I should have clarified that as currently implemented it is just a ramp-up rate limit. Ramp down is still instant. If it's not this way then yes it's disconcerting when you brake, or stop pedalling in PAS mode, and it takes a while before the assist dies off.
As for 2, I'm exploring a different idea that would maybe address this pretty well. You are right that if you are already travelling at speed, the ramp rate can cause an annoying lag before you feel anything from the motor. However, if the CA was programmed to know the motor KV in V/kph, then it could rapidly move the throttle up to a value it knows is just below the speed of the bike, and then only at that point would the slower rate limit come into effect. That should in principle provide the smooth engagement of throttle ramping without the long latency when you are already moving. It's fairly high on the to-do agenda to try this out.
-Justin
I hear you there, but you know what kills a lot of systems in these here parts? Leaving the system powered on when unattended. Arguably unsafe, and quiescent draw sucks the batteries dry. I'd favor a 10-minutes-no-activity "nagger" alarm.justin_le said:
izeman
1 GW
buaaaahhhh ... i just ordered a CA yesterday. would i have know that there will be a V3 ...
will we see some of the screen updates in the "old" CA versions as well? or will it be hardware dependent?
will we see some of the screen updates in the "old" CA versions as well? or will it be hardware dependent?
johnrobholmes
10 MW
The throttle mapping is just icing on the cake! I can use them for any controllers now, what a great piece of kit.
Ever get any farther on integrating a watt controlled throttle or integrating amp limiting with speed limiting throttle types?
Ever get any farther on integrating a watt controlled throttle or integrating amp limiting with speed limiting throttle types?
GCinDC
100 MW
Awesome, Justin!
I loved hearing about the history of the CA, as well as the new features in the CA (04:20-13:44), during our podcast interview (mp3 download).
Parts II and III to be released soon here.
I can't wait for the beta release of the motor!
I loved hearing about the history of the CA, as well as the new features in the CA (04:20-13:44), during our podcast interview (mp3 download).
Parts II and III to be released soon here.
I can't wait for the beta release of the motor!
tfahrner said:
Well, having first hand dealt with dozens if not upwards of a hundred cases of batteries that have suffered this fate, I can't exactly disagree with the sentiment! But, the onus to solve this is really in the battery BMS board designers. They absolutely have to make it so that after a low voltage cutoff, the bms quiescent current falls to no more than a few uA, and the pack could continue to sit for over a year without issue. The present situation where the BMS quiescent current will kill a pack a month or two after LVC is really ridiculous.
But, I still can't get myself to embrace an alarm. It reminds me of the story from one of the bike stores here in Vancouver that deals heavily with BionX. The BionX batteries would do a very intermittent beep like every 10 minutes when at low voltage. The shop naturally had dozens of batteries scattered about, some on bikes, some in boxes, some on shelves, and so had an infuriating situation where a pack from somewhere would beep. But the noise was too high pitched and short to locate where it came from, and too infrequent between beeps to wait around for the next occurrence. It drove the proprietor mildly crazy (as it would myself too).
Awesome work. Now when are you releasing your controller
The temperature based limiting is the feature I've wanted most. Thank you!
Will your motors becoming with temps sensors stock? I heard some of the new crystals have temp sensors from the factory.
The temperature based limiting is the feature I've wanted most. Thank you!
Will your motors becoming with temps sensors stock? I heard some of the new crystals have temp sensors from the factory.
Justin your a genious!! this sounds to be just what is needed right now with more people building higher powered ebikes, the throttle mapping would be a god send!
Any idea on time scales, when we will be able to get our hands on them, i could use one right now, cant wait to explore the throttle options.
Simon.
Any idea on time scales, when we will be able to get our hands on them, i could use one right now, cant wait to explore the throttle options.
Simon.
el_walto
10 kW
I'm interested in the Torque Sensors. Would be nice if i could build pedal and go ebikes for my parents. Not sure if there is going to be anything decent available from ebikes.ca torque sensor wise to go with the CA.
Excellent!justin_le said:
Excellent as well - thanks for the clarification.justin_le said:
Can we look forward to user-installable firmware updates from you of the platform? I know this opens up all sorts of really evil ball-and-chain support issues with sunset hardware that drain resources in the future, but I have to ask :wink:
adrian_sm
1 MW
Fantastic work Justin. Great list of new features. Especially like the automatic battery gauge, and the whole concept of making the CA the central brain that can work with any controller.
Couple of questions/requests
1) Torque Limit
If you have a constant power limit, torque drops as speed increases. Some systems may benefit from being able to set a maximum "torque" based on Volts*Current / Speed. This makes sense to me as most drive trains are torque rather than power limit.
2) Throttle Rate Limit
I am a bit of a special case, but I actually use a separate rate limit for throttle down. It smooths the disengagement of my friction drive. Would be nice if this option was possible on the CA.
3) Large Screen vs Small Screen
Are you only offering the large screen CA in the future? Has the smaller screen version been permanently discontinued?
4) Temp Limit
Have you decided on how you will be implementing any limitting features baseed on the temperature sensor input?
- Adrian
Couple of questions/requests
1) Torque Limit
If you have a constant power limit, torque drops as speed increases. Some systems may benefit from being able to set a maximum "torque" based on Volts*Current / Speed. This makes sense to me as most drive trains are torque rather than power limit.
2) Throttle Rate Limit
I am a bit of a special case, but I actually use a separate rate limit for throttle down. It smooths the disengagement of my friction drive. Would be nice if this option was possible on the CA.
3) Large Screen vs Small Screen
Are you only offering the large screen CA in the future? Has the smaller screen version been permanently discontinued?
4) Temp Limit
Have you decided on how you will be implementing any limitting features baseed on the temperature sensor input?
- Adrian
dodjob
1 kW
- Joined
- Jun 30, 2010
- Messages
- 320
Really nice improvements there!
In Europe we have the legal possibility to have a "push/start-help" 'til 6Km/h (without the PAS signal) after this speed a PAS signal is needed to reach "full" speed. Any infos If this could be inplemented or if it eventually already the case? ^^
I deal with heavy ebikes and such option would reaaally helps
Gruß,
H.
In Europe we have the legal possibility to have a "push/start-help" 'til 6Km/h (without the PAS signal) after this speed a PAS signal is needed to reach "full" speed. Any infos If this could be inplemented or if it eventually already the case? ^^
I deal with heavy ebikes and such option would reaaally helps
Gruß,
H.
johnrobholmes said:
Yes I actually have a watt throttle in the code but commented it out for now since I hadn't implemented the feedback loop yet. But the combined function throttle is still on the items to explore list.
I had another idea though which might be the best option for systems that have a hard time getting closed-loop current control working smoothly, but that would still have the overall benefits of a current throttle in that the full range of the throttle motion is useful regardless of your speed. This would again require the CA knowing the Kv of the motor in kph/V. The throttle output of the CA would countinously scale upwards with the vehicle speed, such that (based on Kv) the no-throttle motor RPM is slightly less than the RPM of the wheel. Then the throttle motion moves the output voltage above this point.
So in equation format it would be something like:
Throttle Output = K1*(vehicle speed / motor Kv) + K2*(user throttle)
Where the contant K1 would be figured out by the CA from the battery voltage and the throttle output range, while K2 would be a parameter that the user could set. There are a lot of advantages to running open-loop in this manner, since you wouldn't have to tune any feedback parameters and it would better cope with controllers that have response lags and latencies.
-Justin
johnrobholmes
10 MW
Seems like a really slick way of getting around the surging issues. I'm sure there would be other methods of open loop control too, but I can't really think of anything simpler than using the motor KV combined with wheel speed to get things ramped up without slamming the driveline.
I'm really excited to try one out. I just placed an order for some regular versions for the store and had Ben send an beta unit my way at the same time
I'm really excited to try one out. I just placed an order for some regular versions for the store and had Ben send an beta unit my way at the same time
GMUseless
100 W
Justin:
The V3 sounds like there's so many new features many of us won't be able to resist upgrading. But, since I own two large screen CA's allready I hate to have them go idle. Since it's the same physical platform, have you thought about an update program where perhaps we can ship you our V2 CA's to be upgraded? Would that even perserve any significant value from the consumer or production side?
The V3 sounds like there's so many new features many of us won't be able to resist upgrading. But, since I own two large screen CA's allready I hate to have them go idle. Since it's the same physical platform, have you thought about an update program where perhaps we can ship you our V2 CA's to be upgraded? Would that even perserve any significant value from the consumer or production side?
johnrobholmes
10 MW
It is a big hardware upgrade, not just updates on the firmware. I would suggest you sell the units on the forum, I bet they would get snatched up pretty dang fast. V1 and V2 units will still be extremely valuable kit.
adrian_sm said:
Hey Adrian, nice work on completing the tidy Brainbox too btw! It's no small feat to go from a concept/prototype into a first small scale production run like that,,, i would know
Yes, I think this might have come up in the RC-CA thread as well. Torque limit also works best from the perspective of protecting controller mosfets and motor phase wires and connectors. IF the throttle output of the CA is mapped properly and the controller takes the throttle signal as a direct control of the PWM duty cycle, then the CA should be able to estimate the motor current from
Motor Current ~= Battery Current / (Act Throttle Output / Full Throttle Output)
And hence could set up a limit accordingly. Doing it as Volts*Current / Speed is an interesting approach but it wouldn't reflect the torque at lower speeds well where the efficiency of the motor is poor. It's looking at input power / speed, while what we'd want to be looking at (for motor torque / phase current) is output power / speed.
Duly noted!
We still keep the small screen LCD's and membrane overlays on hands for OEMs (like the stealth bomber), and if anyone wants to take on doing a small form factor enclosure for these and offering it that would be great. The actual footprint of the small LCD PCB is just 80mm x 36mm, and we made sure that the V3 CA boards would fit within this boundary. So in principle you could make a fairly small box around it. The old hammond enclosures we used to machine for the application were 100mm x 50mm.
Right now you set a threshold temp and a maximum temp:
The current limit automatically starts to scale linearly downwards when you hit the thresh temp, until it reaches 0 amps when you reach MaxTemp. I don't think anything more than this is really needed for effective overtemp protection, but if you have other ideas I'd be curious. I don't personally push many items to their thermal limit in my own ebike usage.
-Justin
johnrobholmes said:
Ha, spoken like a true businessman JRH! Indeed this is a complete hardware change and has an especially more tedious set of wiring and connector harnesses to make up and solder. So the plan is that we will be keeping the V2 CA's in full production as they are still perfectly suitable for tons of users who don't need these new features, and also for people who don't want any additional wiring clutter on their ebikes. It's a bit early to say for sure since we haven't started production in quantity, but the V3 CA's will probably be in at the ~$160 price range, versus $120 for the CA V2's. So the CA V2's aren't going to become obsolete, we're just making a more 'deluxe' model for those who want it.
-Justin
johnrobholmes
10 MW
Mmm, deluxe model 8)
I just call it like I see it, but you have me pegged :lol: If you stopped v2 production I bet there would be a mad scramble on the forum of people swapping out units!
I just call it like I see it, but you have me pegged :lol: If you stopped v2 production I bet there would be a mad scramble on the forum of people swapping out units!
Just a note that I'm about to take off my first distance trip using a CA V3 with torque sensing pedalec mode and so may be absent for this thread for a couple days though I haven't finished writing about all the V3 details yet. I'm travelling from the eZee factory to visit Cell_Man in another part of Shanghai. So far all the testing has been of the around-the-block variety so it'll be fun to take this on a real distance run which is where the pedalec mode should really shine.
Here's the rig that I put together. It has two hub motors installed for a dual drive, but I'm only connected to the front motor at the moment:
Cell_Man, if you don't here from me by sunset, I've emailed you my cell number which hopefully will work. China roads and traffic are a little crazy. Trusting that the google maps "pedestrian" route is a safe one!
-Justin
Here's the rig that I put together. It has two hub motors installed for a dual drive, but I'm only connected to the front motor at the moment:
Cell_Man, if you don't here from me by sunset, I've emailed you my cell number which hopefully will work. China roads and traffic are a little crazy. Trusting that the google maps "pedestrian" route is a safe one!
-Justin
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