Design and Configuration of Folded Platonic Strapdowns of Biaxial MEMS Accelerometers

The authors report on the design, configure, and test of isotropic accelerometer strapdowns for high-precision inertial measurement unit (IMU) and folded MEMS configuration. The biaxial low-g MEMS accelerometers are based on the Platonic solids. A Platonic strapdown is integrated into an embedded system for acceleration-array signal acquisition targeting rigid-body pose-and-twist estimation. The electromechanical properties for dynamic sensitivity are tested on a haptic manipulator, which shows that the position estimation matches reasonably well the encoder readouts. The Platonic strapdown is promising in folded MEMS IMU with chip-level miniaturization and high estimation precision.

Isotropic Accelerometer Strapdowns and Related Algorithms for Rigid-Body Pose and Twist Estimation

A novel design of accelerometer strapdown, intended for the estimation of the rigid-body acceleration and velocity fields, is proposed here. The authors introduce the concept of isotropic-polyhedral layout of simplicial biaxial accelerometers (SBA), in which one SBA is rigidly attached at the centroid of each face of the polyhedron. By virtue of both the geometric isotropy of the layout and the structural planar isotropy of the SBA, the point tangential relative acceleration is decoupled from its centripetal counterpart, which is filtered out, along with the angular velocity. The outcome is that the rigid-body angular acceleration can be estimated independent of the angular velocity, thereby overcoming a hurdle that mars the estimation process in current accelerometer strapdowns. An estimation algorithm, based on the extended Kalman filter, is included. Simulation results show an excellent performance of the proposed strapdowns in estimating the acceleration and velocity fields of a moving object along with its pose.

Design of Isotropic Accelerometer Strapdowns for Rigid-Body Pose-and-Twist Estimation

Coupling of tangential and centripetal acceleration components occurs in the estimation of rigid-body pose and twist with current accelerometer strapdowns. To address this shortcoming and its pernicious effects, a novel design of biaxial accelerometer strapdown is proposed. By virtue of its inherent isotropy, point tangential acceleration is decoupled from its centripetal counterpart, thereby realizing a straightforward and accurate acceleration estimation. The algorithm associated with the strapdown is validated by means of a numerical example, which shows the precision of the strapdown in estimating rigid-body pose and twist.