As high-performance inertial MEMS products continue to advance in their noise/stability performance, they are serving as feedback sensing elements in a growing number of closed-loop stabilization systems, some of which would traditionally use higher-cost IMU solutions. When used as the feedback sensing element in this type of system, the sensor's frequency response (magnitude/phase) has a direct impact on loop response and stability. Early understanding of these behaviors feed the control loop design process that seeks to optimize response time while maintaining loop stability. This can be particularly tricky for the system that has been optimized around a lower-bandwidth solution and is now trying to take advantage of the cost/performance associated with a product like the ADIS16485. Without adjustments to the controller, a wider bandwidth sensor can introduce instability for the loop.
In addition to loop stability, the frequency response of an inertial sensor system can influence its response to vibration as well. Understanding and predicting this response can provide conditions for optimizing mechanical and electrical filter designs.
For this reason, we published an article to share analysis techniques that enable the system designer to estimate the frequency response for parameters that can influence their designs. This article is in last month's (July, 2012) Analog Dialogue and carries the following title: Analyzing Frequency Response of Inertial MEMS in Stabilization Systems
We hope that this article helps you and would encourage you to post your comments or feedback. Has it helped you in your design? Is there additional on this topic, which would help you?