MEMS IMU: Short Term High Accuracy Estimation of Position

Thread Starter

Psycho-look

Joined Jan 29, 2018
1
Hey,

I am measuring movements using an IMU with 6DOF with 3-axis acceleromter and gyroscope. But i lack a bit accuracy with my current setup. My goal is to measure short term precision in relative position, in relation to my first movement.

I have to accurately measure for about 1 sec and i can calibrate for temperature and other non-optimal factors, as my data is processed after the measuring and not in real time.

Currently my angular data is quite accurate, but the acceleromter data is dragging my position of limits due to the accuracy of my IMU. So here comes my initial question,

Are there MEMS IMUs that have more then 16-bit resolution, it has to be capable of measuring +/- 2g or more and have a resolution/sensitivity of somewhere around 0.005mg per LSB i think. Leading to an IMU with at least 20-bits, where every bit is quite accurate, not an IMU with lots of bits and terrible accuracy. Also, it has to be quite lite and therefore ''has to be'' a MEMS IMU. In addition, the gyro has to be accurate but if the acceleromter is accurate the gyro should not be a problem i would assume, from a short time perspective. It needs to be able to run on batteries and not be to heavy, preferably already in a complete HW setup so i can use it out of the box. When it comes done to price well, accuracy > price, the main objective is not how much it cost but how good it can measure!

I have to be able to measure about 0.1mm change in position for movements of about 2 - 10mm for 1 sec, in relative position.

Are there any IMUs on the marked that have the capability of this kind of accuracy?

Any input is highly appreciated and if I left out any essential information I can elaborate more!

Hopefully there is a good answer to this, either good or bad news are appreciated!
 

GopherT

Joined Nov 23, 2012
8,012
I have to be able to measure about 0.1mm change in position for movements of about 2 - 10mm for 1 sec, in relative position.

Are there any IMUs on the marked that have the capability of this kind of accuracy?
It is not possible to answer your question without more information on the system, the operating environment and the exact model number and datasheet of your devices.

In general, external position sensors are used (encoders, proximity (Hall effect, light, etc) ) are used to get the precision you are talking about. I am sure someone will come in with an example but, I suggest you discuss with manufacturer of MEMs device to discuss detail. Their tech support teams are very open to discussing specific applications.
 

OBW0549

Joined Mar 2, 2015
3,019
I know of three MEMS units that come (somewhat) close to meeting your requirements: the MS9000 from Colibrys, the AXO215 from Tronic’s Microsystems S.A., and the SDI-1525 from Silicon Designs. Those three, as far as I know, are about the best MEMS units available although I don't believe any of them will quite meet the requirements you stated.
 
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