# Mychron Gyro, Force sensors Discussion

Continuing on the topic discussed in a separate topic.

How do they filter out steering movement though?

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That is a problem of mounting the device on the steering wheel. I know that was a problem a year ago but thought they would have corrected it by now.

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@KartingIsLife the gyro

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Do you beleive acelerometer data are more accurate than GPS data?

So the lat and long sensors are in a gyro? I’ve never heard one spin up inside mine, maybe it’s super small?

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The gyro is electronic.

Great point about the sensor being in a circuit board that is mounted to the steering which rotates and that is on a vehicle which is rotating and it is the vehicle rotation that we are interested in. I need to think about this… give me a day or so.

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Gyro in this sense is not the same as a gyroscopic stabilizer. It is an accelerometer that specifically measures rotational acceleration. If you track the three rotational axes, you can perfectly correct for the steering wheel (and the kart) rotating.

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Assuming they are able to correct ‘perfectly’ for steering rotation when calculating Lat/long data from the onboard accelerometer, then why wouldn’t they also use that data to create a “steering angle” data field? I don’t believe that is a datapoint the Mychron offers. My understanding is that the only way to get steering angle data is to buy the external steering sensor AIM sells.

I would also think the correction algorithm would somehow need to know the circumference of the arc the Mychron will travel as the driver turns the wheel which would vary depending on the steering wheel size or mychron mount being used. Perhaps also the angle the Mychron is mounted to relative to a vertical plane.

I’m no engineer or math guy so I could be making some incorrect assumptions about what would be necessary in order to implement the correction calculations. But, I am doubtful they are actually correcting for steering angle effects on the onboard lat/long accelerometers or the GPS latAcc/longAcc data points.

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It cannot distinguish steering rotation from kart rotation, so it just knows rotation.

I did ESC software for motorsports, so you can trust me on the math.

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I’d like to but I’m not sure what mathematical statement you are making? Your previous comment which I was responding to sounded theoretical. Do you know if AIM is actually correcting for steering angle effect on the device’s onboard accelerometer data and its GPS accelerometer values?

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The only reason to go through the expense of adding the gyro vs a basic three-axis accelerometer is to measure and correct rotations

Edit to expand: when doing a chassis-mounted accelerometer, you have the luxury of assuming the sensor does not rotate relative to the chassis, so lateral is always lateral. When mounted to a steering wheel, the lateral channel can become longitudinal with enough steering input on a vertical steering column, so, even though our columns aren’t vertical, you still get the components of acceleration mixed up when it turns the wheel. You must use either the gyro to figure out your compensation or GPS wizardry, but then you are limited by GPS accuracy. Having the hardware do the compensation is far faster.

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why you can’t have an external sensor that communicates with the mychron via a port and is hard mounted to the chassis or something. Or, how about a watch that can serve as the channel for that data like a garmin or Apple Watch type thing?

Could you sorta use two data sources and combine somehow in rs3? Data from watch (or whatever) and data from mychron?

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You can I believe. Could probably use CANBUS for it. If there’s no commercial unit you could probably up rig something up with an STM32 board and sensors.

I haven’t looked to see if I can import data from my RaceBox Pro yet.

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Does the Mychron5 support one of their external GPS antennas like the GPS09? Having that fixed to the chassis seems like it could just eliminate the variables of being mounted to the steering wheel.

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Alternatively, you could mount something like the RaceBox Mini S to your chassis and utilize that for analysis without the variable of the steering wheel.

https://www.racebox.pro/products/racebox-mini-s

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They already account for the rotation of wheel by using the gyro. If they used a simpler triax accelerometer, then, yes, they’d need additional hardware. Using the 6-axis gyro/accelerometer combo is the simplest way to do that since there’s no extra wiring needed like an external sensor.

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Could you please provide a source for claiming they are actually accounting for the rotation of the wheel? I get that it is technically possible, but I am not sure how you can definitely claim they are without having that confirmed by AIM.

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I’ll see if I can find a concrete source, but coming from the industry, it is certainly the industry standard. There’s just no other reason to waste money on the extra hardware and then advertise the hardware you aren’t using.

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I might split this topic up since I’ve inadvertently derailed it

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