IMU

An Inertial Measurement Unit combines accelerometers and gyroscopes (and sometimes magnetometers) to measure a body's specific force, angular rate, and magnetic field. IMUs are essential for legged robot balance, drone stabilization, and mobile robot odometry. 6-axis (3 accel + 3 gyro) and 9-axis (+ magnetometer) are common configurations. Sensor fusion algorithms convert raw IMU data into orientation estimates.