A Geometric Approach For Pose and Velocity Estimation Using IMU and Inertial/Body-Frame Measurements
Sifeddine Benahmed, Soulaimane Berkane, Tarek Hamel
TL;DR
This work tackles robust pose and velocity estimation for a rigid body using an IMU and generic inertial/body-frame measurements. It builds a nonlinear geometric observer on the higher-dimensional Lie group $\\mathrm{SE}_5(3)$ by introducing an auxiliary state to decouple attitude and translation, enabling fusion of diverse sensor outputs and Kalman-filter–like gain design via a Riccati equation. Under uniform observability, the approach guarantees almost global asymptotic stability of the estimation error, with a proof structure that separates attitude ISS and translation GES dynamics. Simulations on stereo- and GPS-aided INS demonstrate accurate convergence and effective noise rejection, highlighting the method’s generality and practical applicability to a wide range of sensing configurations.
Abstract
This paper addresses accurate pose estimation (position, velocity, and orientation) for a rigid body using a combination of generic inertial-frame and/or body-frame measurements along with an Inertial Measurement Unit (IMU). By embedding the original state space, $\so \times \R^3 \times \R^3$, within the higher-dimensional Lie group $\sefive$, we reformulate the vehicle dynamics and outputs within a structured, geometric framework. In particular, this embedding enables a decoupling of the resulting geometric error dynamics: the translational error dynamics follow a structure similar to the error dynamics of a continuous-time Kalman filter, which allows for a time-varying gain design using the Riccati equation. Under the condition of uniform observability, we establish that the proposed observer design on $\sefive$ guarantees almost global asymptotic stability. We validate the approach in simulations for two practical scenarios: stereo-aided inertial navigation systems (INS) and GPS-aided INS. The proposed method significantly simplifies the design of nonlinear geometric observers for INS, providing a generalized and robust approach to state estimation.
