Guide to Comparing Gyro/IMU Technology

fiber optic gyro, camera stabilization
Gyros are essential for stabilizing camera platforms mounted on vehicles that produce significant vibration. KVH's DSP-1750 FOGs are utilized in the GSS C520 camera stabilization platform in use on this helicopter.

Knowing the many choices available to applications engineers and integrators when they are designing systems for everything from payload stabilization platforms to driverless cars, KVH offers a resource for choosing the right technology: “A Guide to Comparing Gyro and IMU Technologies”.

When considering the technology options, the initial challenge is simply identifying which performance parameters are most critical to the success of the design.

With a focus on the leading gyro technologies capable of delivering industrial and tactical grade performance – primarily Fiber Optic Gyros (FOGs), and silicon or quartz Micro-Electro-Mechanical Systems (MEMS) gyros – the paper provides a straightforward method of evaluating gyros and inertial measurement units (IMUs) based on five key performance factors:

  1. Angle Random Walk (ARW)
  2. Bias Offset Error
  3. Bias Instability
  4. Temperature Sensitivity
  5. Shock and Vibration Sensitivity

While there are other significant differences that may affect design decisions between MEMS and FOG gyros and IMUs, such as size and cost, the focus on the above criteria is due to the fact that they are critical to success in industrial and tactical grade applications.

fiber optic gyro, camera stabilization
Gyros are essential for stabilizing camera platforms mounted on vehicles that produce significant vibration. KVH’s DSP-1750 FOGs are utilized in the GSS C520 camera stabilization platform in use on this helicopter.

An overview of the technology behind MEMS and FOG gyros and IMUs provides insights into the performance capabilities of the technologies, as well as their comparative limitations. Consumer-grade applications typically utilize MEMS gyros and IMUs, as this technology delivers acceptable performance at a low price and small size for consumer applications such as smartphones, video game controllers, and some automotive systems applications. FOGs deliver a much higher performance grade and tend to dominate more demanding industrial and tactical grade applications such as remote weapons systems, precision agriculture, payload stabilization platforms, surface and subsurface mining and mapping, autonomous vehicles, and driverless car applications.

As engineers continue to search for the right mix of critical performance factors matched with size and target price to solve their navigation, stabilization, and precision pointing challenges, manufacturers of both MEMS and FOG gyros and IMUs continue to push to improve performance, reduce size, and improve cost versus performance value.

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About Pam Cleveland 27 Articles
Manager, Inertial Navigation Marketing and Global Proposals

2 Comments

  1. Among your chosen key performance factors I would have expected to see cross-axis sensitivity. That’s actually a dominant error source in many operations. For decades I’ve been trying to get that point across. Success has been modest but, within the past decade, I’ve finally been able to dissuade others from approving plans for free-inertial coast over extended periods including a major change in direction. A website blog — http://jameslfarrell.com/error-propagation/gyro-mounting-misalignment explains that and takes the subject far beyond.

  2. You are right, cross axis is a very important factor such as gyro-g for MEMS or even magnetic sensitivity for FOGs.

    In our tests, we have demonstrated that it’s difficult to get better than 0.03 deg residual cross-axis over temperature and over time!

    Hopefully to further improve this, if the gyros a low noise enough, we estimate the cross-axis error when GPS is available!

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