Description
An Inertial Measurement Unit (IMU) is a MEMS sensor combining 3-axis accelerometer + 3-axis gyroscope (6-axis) and optionally a 3-axis magnetometer (9-axis / MARG). IMUs are the core of smartphone motion sensing and the canonical pairing for Pedestrian Dead Reckoning (PDR) baselines that fuse with BLE / Wi-Fi RSSI for indoor localization. In the thesis, IMU signals from smartphones during BLE-calibration campaigns provide trajectory ground truth — accelerometer alone is rarely enough, the gyro contributes orientation that corrects RSSI heading bias.
Specs / capabilities
- Accelerometer (accelerometer): 3-axis linear, ±2 to ±16 g
- Gyroscope: 3-axis angular rate, ±125 to ±2000 dps
- Magnetometer (9-axis): 3-axis flux, ±4 to ±16 gauss
- Combined sample rates 100-1000 Hz typical
- I²C / SPI digital output
Used by (papers)
- PDR baselines (sensor fusion with BLE / Wi-Fi)
- Wearable-HAR datasets paired with CSI