Accelerometrie

Accelerometrie is the measurement of acceleration using accelerometers to quantify motion and orientation in space. It is used in fields ranging from biomechanics and sports science to medicine and consumer electronics to analyze how objects and people move.

Most accelerometers are microelectromechanical systems (MEMS) that measure acceleration along one or more axes. A tri-axial accelerometer can detect acceleration in the x, y, and z directions, expressed in meters per second squared (m/s^2) or g, where 1 g equals approximately 9.81 m/s^2. Accelerometers detect both dynamic acceleration (movement) and static acceleration (often gravity), allowing detection of tilt and orientation in addition to motion.

In practice, accelerometers are frequently combined with gyroscopes and sometimes magnetometers to form inertial measurement units (IMUs). Sensor fusion algorithms combine multiple sensors to estimate accurate motion, orientation, and velocity. Calibration is important to correct biases, scale factors, and cross-axis sensitivity, and temperature can influence readings.

Applications are diverse. In biomechanics and gait analysis, accelerometry helps quantify endpoints such as step length, posture, and activity level. In rehabilitation, sports science, and clinical monitoring, it tracks movement patterns and energy expenditure. Consumer devices, including smartphones and wearables, use accelerometers for activity recognition, sleep tracking, and user interface features.

Data from accelerometers are processed through filtering and feature extraction. Analysts often work with high-frequency raw data, applying time-domain and frequency-domain analyses, and addressing drift that arises when integrating acceleration to velocity or position. Limitations include noise, bias, environmental sensitivity, and the need for careful interpretation in context.