CEA-Leti scientists, working with researchers at Politecnico di Milano, have developed the world’s first high-performance gyroscope for operating in severe environments, such as industrial and aeronautic equipment and automobiles. The breakthrough proves it is possible to detect minute rotational movement even among system vibrations.
Common in everyday objects, inertial sensors must be designed to meet ever-increasing constraints of miniaturization and cost, as well as requirements for performance and robustness. For certain automotive, industrial and military applications, gyroscopes must be able to detect a variation of one degree per hour, i.e. a speed of rotation about ten times slower than that of the earth, in environments that are subjected to strong, consistent vibrations.
Low-power MEMS gyroscopes are used in multiple fields because of their small footprint and low power consumption. They can monitor and control device position, orientation, direction, angular motion and rotation. Their integration into automobiles improves vehicle stability through an electronic stability-control system. They also can be used for dead reckoning – the determination of a car, ship or aircraft position without the aid of celestial observations – in driverless cars. Their integration into smartphones allows detection of unit rotation and twist (gesture-recognition functions), indoor navigation when GPS is disabled and mixed reality, among other functions.
The devices operate at a given resonant frequency.Parasitic mechanical vibrations rarely exceed 40 kHz. But today, there is no high-performance MEMS gyroscope with a resonant frequency >>20 kHz, above the frequency band of parasitic vibrations.When this frequency is close to that of the vibrations of the environment, mechanical disturbances can distort the measurements. In collaboration with Politecnico di Milano, CEA-Leti researchers overcame this distortion by developing a gyroscope that operates at frequencies in the order of 50 kHz, which is more than two times higher than the capability of conventional MEMS gyroscopes and beyond the frequencies of vibrations common even in severe automotive, industrial and aeronautic settings.
The breakthrough was reported in a paper titled “50kHz MEMS gyroscopes based on NEMS sensing with 1.3 mdps/√Hz ARW and 0.5°/h stability” at IEEE SENSORS 2020.
