Finding True North with a MEMS Gyroscope
ABSTRACT
While navigating, it's essential to know the position and heading, which can be critically important especially when starting a route.
A MEMS gyroscope can be used to determine true north for heading detection. There can be differences between the true north and magnetic north based on the location. Also, MEMS gyroscope is not affected by the disturbances from presence of magnetic metals and electric currents in urban environment.
Earth rotates at a leisurely pace of 360 degrees every 24 hours which equals roughly to 0.004 degrees per second. For a long time, this subtle motion was considered too small to be detected by MEMS gyroscopes, which typically measure accuracy within a range of a few dps to hundreds of dps. Either the sensor noise performance or the bias stability has not been in a sufficient level to achieve such accuracy. Murata’s new MEMS technology takes a big leap forward. The new SCH16T series gyro has achieved noise levels as low as 0.0005dps/sqHz enabling accurate measurement of the Earth’s rotation.
Murata’s new Gyro Compass demo using 4pcs of SCH16T series sensors can find true north with ± 1° (1σ) target accuracy in less than 1 min using earth’s rotation instead of the magnetic field. The fast and relatively inexpensive solution will enhance autonomous cars but will also make it possible to navigate and position accurately in completely new applications. North Finder could also be used in underground applications, such as mining or tunneling equipment. It could also be useful above ground with heavy-duty machines, antenna positioning, and others which need precise location information.
BIOGRAPHY
Suvi Rauhamaa is a Business Development Manager for Murata Electronics North America. Her role is to support customers in North America in Automotive and Industrial markets with their IMU challenges in the measurement, integration and manufacturing in autonomous and other designs.
Suvi has 20 years of both technical and business experience with MEMS acceleration and angular rate sensors and solutions. She has MSc in Engineering focusing on Semiconductors from the Helsinki University of Technology (Finland).