MEMS gyros can measure Earth's rate of rotation

According to a study carried out by the Department of Computer Systems at Tampere University of Technology in Finland, VTI's MEMS gyros are so accurate that they can detect and measure the Earth's rate of rotation.

There are different methods to measure the Earth's rotation - for example for navigation purposes.

Until recent advances in MEMS technology, only very high-quality - and very expensive - gyros, such as ring laser gyros (RLGs), were accurate enough to be used for this application.

'These gyros are smaller in size, they consume less power and, most importantly, they are much more cost efficient than, for example, ring laser gyros,' said Ville Nurmiainen, VTI product manager and a specialist in gyroscopes.

The study consisted of an improved method of computing the Earth's rotation rate using a gyroscope.

'The key findings showed that, by compensating the non-stationary bias errors via a sequence of rotations and Kalman filter implementation, and by reducing the effect of external factors such as temperature and g-sensitivity, it is possible to detect and measure very small angular rates, such as the Earth's rotation,' added Nurmiainen.

This level of accuracy can be achieved with the VTI SCC1300 combined sensor.

He continued: 'The core of the gyroscope is the sensor element based on VTI's 3D MEMS technology that, together with a state-of-the-art ASIC [application-specific integrated circuit], results in a very stable, low-noise and accurate gyro.

'The SCC1300 combines this gyro with a high-accuracy three-axis accelerometer in the same package and offers interesting opportunities in various applications.

'The results of this study are good news for many device, instrument and equipment manufacturers.

'In navigation applications, in particular, the gyro has to be small in size and cost efficient - but as high in accuracy as traditional RLGs.

'There is a growing number of emerging applications for this high level of gyro accuracy, such as pedestrian navigation and gyrocompasses,' said Nurmiainen.