Accelerometer advice please

[Dan Robbins]

Hi,

We are looking to expand the equipment in our lab to include the use of accelerometers, ideally with the option of setting up a system that has potential to work independently (i.e. in a field setting with a laptop) and synchronously (i.e. in a lab with simultaneous EMG and 3D motion systems). We have been looking at sensors capable of operating on 0-30g, >2KHz data acquisition range.
As we only have limited knowledge of accelerometers it would be very helpful if members could advise us on a few questions we have been considering during our “pre-purchase research”

• Is there a particular brand or company that is better than others?
• What is the difference between AC and DC systems? (And is one better than the other?)
• Is it practical to try and obtain accelerometers that can work in stand alone and synchronous settings as
described above?
• Are there any issues with increased cable length? i.e. would we need amplifiers or preamplifiers?
• Are there any issues with wireless systems? E.g. are there issues with accounting for lag times due to
delayed signal transmission?
• How reliable are systems that include a gyro? To date we have only seen sensors that have a lower range
(e.g. >10g), are there systems with gyro’s that operate at higher forces?

I appreciate any help or advice you can offer.
Many thanks
Dan

[Dustyn Roberts]

Re: Accelerometer advice please

See this Accelerometer and Gyro buying guide from Sparkfun Electronics: http://www.sparkfun.com/tutorials/167
This is more of a DIY place but the advantage is you have control over what you do with the raw data, rather than trusting the "proprietary algorithm" of a commercial sensor. My lab is working with a Motion Node IMU and that part still makes me a little nervous.

Dustyn Roberts, PE, PhD candidate
Applied Dynamics & Optimization Lab
NYU-Poly

Hi,

We are looking to expand the equipment in our lab to include the use of accelerometers, ideally with the option of setting up a system that has potential to work independently (i.e. in a field setting with a laptop) and synchronously (i.e. in a lab with simultaneous EMG and 3D motion systems). We have been looking at sensors capable of operating on 0-30g, >2KHz data acquisition range.
As we only have limited knowledge of accelerometers it would be very helpful if members could advise us on a few questions we have been considering during our “pre-purchase research”

• Is there a particular brand or company that is better than others?
• What is the difference between AC and DC systems? (And is one better than the other?)
• Is it practical to try and obtain accelerometers that can work in stand alone and synchronous settings as
described above?
• Are there any issues with increased cable length? i.e. would we need amplifiers or preamplifiers?
• Are there any issues with wireless systems? E.g. are there issues with accounting for lag times due to
delayed signal transmission?
• How reliable are systems that include a gyro? To date we have only seen sensors that have a lower range
(e.g. >10g), are there systems with gyro’s that operate at higher forces?

I appreciate any help or advice you can offer.
Many thanks
Dan

[Neil Schell]

Re: Accelerometer advice please

Hi Dan,

Is there a particular reason you are searchnig only for accelerometer based sensors? Depending on what specifically you intend to measure, you may also want to consider magnetic tracking. Magnetic tracking provides true 6DOF measurement, and has zero drift (unlike accelerometers) and no ambient light or line-of-sight occlusion (unlike camera based systems). If you'd like more details, please contact me or visit, www.polhemus.com.

Sincerely,
Neil Schell
Polhemus

[Kieran Moran]

Re: Accelerometer advice please

Hi Dan

I am now faced with the exact same question almost as the one you raised last year. Would you be able to answer your own questions at this stage? I am going to be looking at impacts in running and therefore will play it safe and get a 30g or 50g accelerometer. Any help you could offer would be most appreciated

Kieran

Hi,

We are looking to expand the equipment in our lab to include the use of accelerometers, ideally with the option of setting up a system that has potential to work independently (i.e. in a field setting with a laptop) and synchronously (i.e. in a lab with simultaneous EMG and 3D motion systems). We have been looking at sensors capable of operating on 0-30g, >2KHz data acquisition range.
As we only have limited knowledge of accelerometers it would be very helpful if members could advise us on a few questions we have been considering during our “pre-purchase research”

• Is there a particular brand or company that is better than others?
• What is the difference between AC and DC systems? (And is one better than the other?)
• Is it practical to try and obtain accelerometers that can work in stand alone and synchronous settings as
described above?
• Are there any issues with increased cable length? i.e. would we need amplifiers or preamplifiers?
• Are there any issues with wireless systems? E.g. are there issues with accounting for lag times due to
delayed signal transmission?
• How reliable are systems that include a gyro? To date we have only seen sensors that have a lower range
(e.g. >10g), are there systems with gyro’s that operate at higher forces?

I appreciate any help or advice you can offer.
Many thanks
Dan

[Jonathan Williams]

Re: Accelerometer advice please

Hi Dan (and others)

You indeed raise some interesting questions and the follow up posts are also of interest. Have you considered a bespoke solution. ThetaMetrix.co.uk offer off the shelf stand alone accelerometers, both wired and wireless but also ones that could be tailored for your spec (i.e. 10g etc.). Furthermore if interested they could discuss the options of including a rate gyro board and a magnetometer (inertial sensor) depending on the specifics of your application. Issues of synchronising with other outputs could also be included as could MatLab code writing if necessary. Contact Dr Robinson at hrobinson@thetametrix.co.uk if interested.