When IR thermometers are used to measure surface temperature they can potentially sense all three kinds of energy, therefore all thermometers have to be adjusted to read Emitted energy only. Measuring errors are often caused by IR energy being reflected by light sources.
Other units have a fixed, pre-set Emissivity of 0.95, which is the Emissivity value for most organic materials and painted or oxidized surfaces. If you are using a thermometer with a fixed Emissivity to measure the surface temperature of a shiny object you can compensate by covering the surface to be measured with masking tape or flat black paint.
hillzofvalp wrote:It would be epic if we cold program the CA To change the watts limit on the fly based on speed. That would solve a lot of the instant wheelie problems at low speed with a high power setup. I suppose it would have to be implemented in a safe way so that to arent suddenly launched when you are on a borderline limit. Maybe a buffer if some sort would be appropriate... Or maybe like this:
ohzee wrote:Here's to hoping you put up some more videos of your travels to China and to see cell_man.. I very much enjoyed
all the other videos I have seen.
1JohnFoster wrote:Hi Justin,
Congrats! Looks very well thought out, all those features carefully packed in.
Does it protect the pack by dropping the output throttle to keep pack voltage above a minimum?
Can it be programmed to "bog" the output throttle when it estimates low remaining capacity, say the last ~25%. So that idiots like me who drive along going "wheeeeee" and ignore all gauges will get seat of the pants feedback that I'm running out of juice?
dodjob wrote:justin_le wrote:dodjob wrote: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? ^^
Yes, at present I have almost the opposite. There is a "Start Speed" setting which gives a minimum speed that you need to attain before there is any output power to the motor.
This is there mostly for sensorless RC type setups that have issues with starting from a dead stop. There's no reason not to have a "PAS Threshold Speed" that requires pedalling above a certain speed but allows throttle only power below that. I'll probably fit this setting in with the PAS setup menu, but haven't implemented it yet.
Is it only germany that has this legislation passed or is it europe wide?
justin_le wrote:hillzofvalp wrote:It would be epic if we cold program the CA To change the watts limit on the fly based on speed. That would solve a lot of the instant wheelie problems at low speed with a high power setup. I suppose it would have to be implemented in a safe way so that to arent suddenly launched when you are on a borderline limit. Maybe a buffer if some sort would be appropriate... Or maybe like this:
A watts limit based on speed _is_ basically a torque limit! Which is what me and Adrian were discussing a few posts back. Doing it this way (as opposed to discrete power limit steps as you suggest) would achieve what you are suggesting and would be the smoothest approach for sure..
justin_le wrote: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 continuously 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 content 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.
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.
oatnet wrote:It would be interesting to have a mode in setup that would display the throttle voltage the CA is receiving.
gensem wrote:+1 Oatnet, the throttle lower and upper value is a killer feature, you can virtually use anything you like as a throttle without having to play with pots and resistors.
So to keep this on topic, I've looked at the websites for the torque sensors you mentioned, and this led me to wonder if you think I could use the torque sensor signal from my I2C 350 watt BionX with the CA V3? I think DocBass did a little testing of the relationship between torques and signal output but did not really fully characterize it. Perhaps you know if it would be suitable- eg is it linear, etc?
My goal is to use the BionX torque sensor with my own battery/BMS and a third party controller along with the CA V3 all routing back to and driving the BIonX motor.
BTW, I was riding in China last week and was told in Macau that ebikes are completely illegal there!
liveforphysics wrote:My friend, it would seem to me that if you have the voltage off the strain sensor on the rear axle, and a single hall signal, and the number of poles is known, than you have all that is needed to know human added pedal torque regardless of gearing or gearing compensations.
This is because you have both the human torque applied (regardless of RPM, the torque and RPM will vary inversely to stay in balance), and the RPM of the motor at which this human added torque is being applied.
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