Analog Devices
 

Now that the season is over does anyone know if Analog devices will be selling the IMU and if so where we can buy one

Re: Analog Devices
 

Please clarify, to which IMU are you referring?

Re: Analog Devices
 

the 10 DOF ADI IMU board from analog devices that was in FIRST choice this year. You can see them on here http://www.analog.com/en/landing-pages/001/FIRST.html

I was told that they were not selling them due to some contract with FIRST and would only be available this year in FIRST choice.

Re: Analog Devices
 

I spoke (very briefly) with an Analog Devices employee this weekend, and he said the issue is that if they sold the IMU it would be over the $400 limit for an individual component on the robot. Thus they provided them via FIRST Choice, making it a KOP item.

I do not know whether they have plans to sell them or not.

Re: Analog Devices
 

That is disappointing. Really wish i would have saw them on FIRST choice.

Maybe they will be around next year for testing. Any chance anyone on here has a spare one for sale?

Re: Analog Devices
 

Unfortunately, the module will not be sold to teams outside of FIRST Choice. The IMUs were donated by Analog Devices to FIRST, so FIRST owns the stock currently in FIRST Choice. That being said, I'm very confident the remaining stock shown in FIRST Choice will be made available next year. ADI may donate additional IMUs to FIRST Choice next season, so I would check back in a few months!

Re: Analog Devices
 

Strange, as I understand it, KOP items are exempt from the $400 limit. e.g. the $435 RoboRio...

Re: Analog Devices
 

And I know many teams will not use an item if they can get only one. I certainly won't go to competition without a spare.

Re: Analog Devices
 

There was no limit on the IMUs. We got spares, and really enjoyed using them.

Re: Analog Devices
 

That's right! Shameless plug, I just updated the IMU driver to drastically reduce CPU usage in LabVIEW! Let me know if anyone has issues with it!

https://github.com/juchong/ADIS16448-RoboRIO-Driver

Re: Analog Devices
 

Juan,
First off, thank you for continuing to support this device!

We were fortunate enough to receive two of the ADIS16448 boards via FIRST Chiose. Based on this thread we chose to only use the gyro output data and not the Kalman filtered data for our headings.

Now that you are updating drivers..... Any chance you will be addressing this issue in Java code?

Re: Analog Devices
 

The ADIS16448 retails for $850-$900 in single item quantities depending on where you source it, as far as I can tell. Is this what others see? Very nice that Analog Devices provided it in FIRST Choice this year. Given that there are other IMUs with similar functionality for less cost (AdaFruit breakout for 10-DoF IMU part #1604, at $30 and has the baro, for example ... no affiliation), what is special about the ADIS16448?

The technical specifications are difficult to directly compare, as they are not standardized across companies. Does anyone have the typical gyro drift rate for the ADIS16448?

For those teams that used the ADIS16448 this year, what do you think is distinctive about its performance? Did you use a sensor fusion algorithm to improve performance (such as Juan Chong's above, or other)?

I found the Bosch BNO055 IMU, which has integrated sensor fusion, to have good performance (no drift, good magnetic disturbance rejection). Cost about $35, or free from Digi-Key using this year's KoP voucher. Is this a higher performing product for the cost, or are there other considerations (output data rate appears a bit faster for the AD device, no baro or flash on BNO005)?

Has anyone performed side-to-side comparison between these IMUs? With the navX MXP?

Re: Analog Devices
 

Did you notice real world issues, or were you just being careful?

For autonomous, the drift is low enough without the filter that you won't have seen an issue. Probably for an entire match as well. The gyro in the ADIS16448 has noise properties of the ADXRS450, which would put it at 25 degrees/hr of drift.

Playing with the ADIS16448 properly is on my list of things to do this summer. Juan also recommended looking at the ADIS16460, which looks even more awesome. 6 degrees/hr of drift, and more dynamic range. I've been working through how to get a ground truth measurement (I think I can borrow a pair of GPS units and use those with drtk to get an accurate position) so we can try various algorithms and benchmark performance.

The ADIS16448 let us add some pretty cool features this year. We wrote a "down estimator" which estimated the direction of gravity using a gyro and 2 accelerometer axis. We used this in auto mode to detect when we crossed the defenses, and also to compensate our shot angle for the robot not being flat on the ground.

Re: Analog Devices
 

Yep, just an over abundance of caution.

Agreed, we never had an issue in autonomous related to drift.

We do not have the programming resources to do this type of testing, thus we rely on the work and generosity of others. Therefore, I look forward to hearing what you find out.

Re: Analog Devices
 

Austin - Did you conduct the user calibration process or simply accept the factory calibration values?

Did you make use of the magnetometer?

The ADIS16480 has embedded sensor fusion, running an on-board Extended Kalman Filter. This puts it functionally on par with the Bosch BNO055. These 'Orientation Sensors', with embedded fusion algos, have ready low (or no) drift orientation outputs as well as stabilized gravity vector outputs - making for simpler/faster integration. (However, the ADI device appears to retail > $2k.)