Sophisticated MEMS capacitive sensors combined with advanced electronics are replacing traditional geophones or seismometers for different types of seismic measurements. Numbers of applications outside the traditional strong motion earthquake monitoring are using these seismic motion sensors for their extreme low noise, high resolution and large dynamic range. These applications are characterized by low amplitude signals produced by natural (earthquake, volcano, subsidence or even wind) or human-induced (explosions, shock, constructions) movements.
Inertial navigation is the process of calculating the position and velocity of a body (such as an aircraft) from self-contained accelerometers and gyroscopes. Attitude and Heading Reference Systems, better known as AHRS, are multi-axis sensors that provide heading, attitude and yaw information for aircraft or any subject moving in free space.
AHRS are designed to replace traditional mechanical gyroscopic flight instruments and provide superior reliability and accuracy. They consist of either solid-state or MEMS gyroscopes, accelerometers and magnetometers on all three axes. Some AHRS use GPS receivers to improve long-term stability of the gyroscopes. A Kalman filter is typically used to compute the solution from these multiple sources.
The Sensor of Choice for Unmanned Monitoring
Unattended Ground Sensors (UGS) are unmanned monitoring stations often used for military surveillance, troop movement detection, and target identification. It can also be used for perimeter security or border and access control. This demanding application requires a compact, rugged and high-performance sensor. Compared to conventional coil-and-magnet based velocity transducers, the Si-Flex line of accelerometers offers several key benefits for battlefield monitoring and homeland security.
Some new technologies such as Extended Area Protection & Survivability (EAPS) are being developed to counter incoming enemy attacks. These programs require increasing utilization of long-range artillery and can represent an unacceptably high risk of civilian causalities. Therefore, more precise artillery systems, smart munitions and smart missiles are increasingly required and accuracy of ammunitions must be enhanced to meet "Smart Artillery" performances independently of any GPS control.
Such projectiles also integrate independent, reliable and redundant self-destruct mechanism that can also be based on sensors such as accelerometers that have to perform not only after the initial shock but also after impact. If a target is not detected or not attained, the weapon either self-destructs, eliminating the threat to civilian from explosive remnant or render itself inert. Note that increased accuracy means also that fewer rounds are needed, resulting in a big reduction in the logistics tail of artillery units..
Mid accuracy navigation systems (IMU), AHRS and control systems require gyros and accelerometers to predict the position of a moving object in free space. Accelerometers are used to perform initial leveling and to correct the gyro drift on the move.
In this whitepaper we compare the main parameters of the ±10g Colibrys accelerometers MS9010.D and RS9010.A currently under development, to support the system designers and as a guideline for optimum selection of an accelerometer. Four main parameters are compared including bias repeatability, scale factor, axis misalignment and vibration rectification error. MS9010.D has a long term bias repeatability of better than 5mg while first result on RS9010.A samples is better than 1.5mg. The scale factor repeatability of MS9010.D is 400ppm whilst the value for RS9010.A is 150ppm. In addition, the vibration rectification error of RS9010.A has a potential to be better than 100µg/g².