Night Cowboy Posted October 19, 2020 Share Posted October 19, 2020 Do unicycles require calibration after they're shipped to a different location? A gyroscope calibrated for china would show up as the wrong direction in another country. It seems that gyroscopes are unaffected by manual calibration for this reason. Are the gyroscopes in a wheel calibrated throughout riding? Does anyone have insight about these automatic calibration processes that they would like to share? Quote Link to comment Share on other sites More sharing options...
meepmeepmayer Posted October 20, 2020 Share Posted October 20, 2020 The gyro sensor is calibrated when the wheel is produced, and there's no need for you to ever recalibrate unless you have a gyro-related problem (pedal dipping in curves, or a totally off calibration aka badly tilted pedals). These things just measure the pitch/jaw/roll and (a bit) the corresponding accelerations. Same thing as in smartphones. Doesn't matter where on Earth (or the moon) you are All a new calibration does is zero in on which direction gravity points. 1 hour ago, Night Cowboy said: Do unicycles require calibration after they're shipped to a different location? No. 1 hour ago, Night Cowboy said: A gyroscope calibrated for china would show up as the wrong direction in another country. No. Why would it? 1 hour ago, Night Cowboy said: Are the gyroscopes in a wheel calibrated throughout riding? No. But they can slowly drift over time because they are not very precise, and if they develop issues (e.g. pedal dipping in curves), you can reset them with a new calibration. 1 hour ago, Night Cowboy said: Does anyone have insight about these automatic calibration processes that they would like to share? There are no automatic calibration processes. 1 Quote Link to comment Share on other sites More sharing options...
Dgar Posted October 20, 2020 Share Posted October 20, 2020 Quote 15 hours ago, meepmeepmayer said: But they can slowly drift over time because they are not very precise, and if they develop issues (e.g. pedal dipping in curves), you can reset them with a new calibration. To clarify, when you say calibration, is that making sure the pedals are at 0 degrees (or whatever you set them at) or is there a different calibration required? My KS14 has been dipping quite a bit when I turn lately. I have recalibrated the angle of the pedals several times with no positive results. eWheels sent me a firmware upgrade which I just applied this last weekend and it seems to be marginally better but still seems to dip when turning corners and randomly when riding in general. I'm just wondering if there is another calibration I am not aware of. Quote Link to comment Share on other sites More sharing options...
meepmeepmayer Posted October 20, 2020 Share Posted October 20, 2020 (edited) 32 minutes ago, Dgar said: I'm just wondering if there is another calibration I am not aware of. No there is not. Just the one you described. It's important to not have the wheel tilted sideways when calibrating (front/back does not matter, this is just how you can set the pedal angle), and also it should be still (don't hold it in your hand, lean it as upright as possible against a wall). Pedal dipping is just from a bad calibration, then tilting the wheel sideways (like in curves) throws the sensor off and what it thinks is down isn't exactly down, hence the dipping. Sometimes it's a game of luck if a calibration is good, and if the sensor on your board is more or less prone to dipping (these things really aren't high-end). You can try an intentionally bad calibration (wheel heavily tilted sideways + crazy pedal angle) and after that a good one and see if that changes anything. Anything to coax your sensor to behave... Edited October 20, 2020 by meepmeepmayer 1 Quote Link to comment Share on other sites More sharing options...
Dgar Posted October 20, 2020 Share Posted October 20, 2020 Thanks. I was not aware that the side-to-side was as important to pay attention to since the stabilization happens front to back. I have been holding it steady but have concentrated mostly on front to back, so the side-to-side may have drifted a degree or two. I will try it again and stabilize it against something instead of holding it. If that doesn't work I'll try a bad setting and then recalibrate back to true. Quote Link to comment Share on other sites More sharing options...
meepmeepmayer Posted October 20, 2020 Share Posted October 20, 2020 It doesn't have to be super upright. Just it turned out that not being upright can produce a bad calibration. As well as the wheel not being still. The calibration also may end up to take a few cryptic beeps longer than you think it does, so keep the wheel in place until everything is definitely over. Quote Link to comment Share on other sites More sharing options...
null Posted October 20, 2020 Share Posted October 20, 2020 (edited) Pedal dip correction (when turning) also depends of proper sideways calibration I believe. Calibrate it leaning against a wall might give weird results when turning. If you have to use a wall try to make it as vertical as possible. Edited October 21, 2020 by null Quote Link to comment Share on other sites More sharing options...
MrRobot Posted October 21, 2020 Share Posted October 21, 2020 (edited) Calibrate it against a wall with a bubble level on the pedal/pedal hanger. Perfect calibration every time. Edited October 21, 2020 by MrRobot Quote Link to comment Share on other sites More sharing options...
Night Cowboy Posted October 22, 2020 Author Share Posted October 22, 2020 (edited) Thanks for your responses. It seems that I was experiencing a misconception, that an orientation can be determined by a gyroscopic sensor directly. To determine its orientation, the wheel must have a correct accelerometer calibration and then it must perform a calculation using both accelerometer and gyroscopic sensor data. It's clear that the functions used by most wheels have their pitfalls, which we experience as pedal tilt, but they're otherwise pretty great. To answer my own question: Calibration is the wrong term to use however, the angle of orientation determined by the wheel is calculated constantly and is not always perfect. The perceived angle can drift from the real angle but will converge on the real angle whenever gravity is the primary force acting on the wheel. Edited October 22, 2020 by Night Cowboy Quote Link to comment Share on other sites More sharing options...
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