Nordic Inertial’s motion sensing systems excel in accuracy. Yet, the sensors are not perfect. They have inaccuracies, such as noise, especially when it comes to microscale sensors.
The fusion algorithm is filtering noise to optimize the measuring results. You may have heard about white noise or pink noise, but what about random walk?
Noise Modeling
Nordic Inertial works hard to minimize the effect of noise when measuring movement with inertial sensors. We employ a statistical approach to noise modeling. The models, such as white noise, pink noise, brownian noise, also known as random walk, can be applied across a wide range of applications. For efficient filtering, noise models need to match with the actual measurement. At Nordic Inertial, we have different, application-specific filters for different purposes and situations.
– The purpose is to get as accurate information as possible about motion and its constraints in the application, and what kind of sensor noise is relevant. Modeling these efficiently, we get unprecedented results. When the application is modeled correctly, the filters work optimally, explains Jussi Collin, the CEO of Nordic Inertial.
Carouseling Sensors
Carouseling is a method used to mitigate the measurement errors of inertial sensors, particularly MEMS gyroscopes. The theoretical and experimental results show that carouseling reduces the contributions of additive bias, 1/f noise (pink noise), and rate random walk significantly compared to plain averaging. Interested to take a deeper look at the effects of carouseling on angular rate sensors? To learn more check out a study here.
– As the sensor develops and becomes more precise, there is less noise, which opens up new dimensions and possibilities, Collin continues furthermore.
1/f noise has been found in many systems that are completely unrelated, even in many types of music. Want to listen to gyro noise as sound? Listen to the clip below. Do you think it's as calming as 1/f noise is often told to be?
Do you know a thing or two about noise modeling? Curious to work at Nordic Inertial? Contact Jussi Collin at jussi.collin@nordicinertial.com and check out our website for more information.