Low-Cost Gyroscope and Accelerometer Calibration with Free Fall Pendulum Motion: Results and Sensitivity

The calibration of an inertial measurement unit (IMU), which could have noisy and inaccurate output, is usually made with expensive mechanical platforms. In this paper, the calibration is performed by fixing the IMU to the extremity of a low-cost pendulum, driven by free-fall motion. The theoretical IMU motion is estimated by the pendulum motion, modeled with kinetic and viscous friction whose values are experimentally determined. The calibration procedure is easy and relatively fast, since possible assembly errors of the IMU on the pendulum are mitigated: the calibration parameters of sensors are not affected by orientation errors up to 10° between the IMU and the pendulum. The results of the proposed calibration approach are compared with the output of a commercial calibrated IMU, performing slow-rotation movements with a robotic arm. The results validate the proposed calibration method as a reliable and low-cost procedure.