Aligning the Forces-Eliminating the Misalignments in IMU Arrays

• Ultralow-cost single-chip inertial measurement units (IMUs) combined into IMU arrays are opening up new possibilities for inertial sensing. However, to make these systems practical for researchers, a simple calibration procedure that aligns the sensitivity axes of the sensors in the array is needed. In this paper, we suggest a novel mechanical-rotation-rig-free calibration procedure based on blind system identification and a Platonic solid printable using a contemporary 3-D printer. The IMU array is placed inside the Platonic solid, and static measurements are taken with the solid subsequently placed on all sides. The recorded data are then used together with a maximum-likelihood-based approach to estimate the interIMU misalignment and the gain, bias, and sensitivity axis nonorthogonality of the accelerometers. The effectiveness of the method is demonstrated with calibration results from an in-house developed IMU array. MATLAB scripts for the parameter estimation and production files for the calibration device (solid) are provided.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Signalbehandling (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Signal Processing (hsv//eng)

Keyword

Accelerometers

calibration

gyroscopes

inertial navigation

maximum likelihood estimation

sensor array

Publication and Content Type

ref (subject category)

art (subject category)