Online Kinematic and Dynamic-State Estimation for Constrained Multibody Systems Based on IMUs

Abstract

This article addresses the problems of online estimations of kinematic and dynamic states of a mechanism from a sequence of noisy measurements. In particular, we focus on a planar four-bar linkage equipped with inertial measurement units (IMUs). Firstly, we describe how the position, velocity, and acceleration of all parts of the mechanism can be derived from IMU signals by means of multibody kinematics. Next, we propose the novel idea of integrating the generic multibody dynamic equations into two variants of Kalman filtering, i.e., the extended Kalman filter (EKF) and the unscented Kalman filter (UKF), in a way that enables us to handle closed-loop, constrained mechanisms, whose state space variables are not independent and would normally prevent the direct use of such estimators. The proposal in this work is to apply those estimators over the manifolds of allowed positions and velocities, by means of estimating a subset of independent coordinates only. The proposed techniques are experimentally validated on a testbed equipped with encoders as a means of establishing the ground-truth. Estimators are run online in real-time, a feature not matched by any previous procedure of those reported in the literature on multibody dynamics.

Real-Time Multibody Model-Based Heads-Up Display Unit of a Tractor

“…Solution of multibody equations of motion can be synchronized to real-time as shown in [32], [35] and [36]. Moreover, virtual sensors can be built using a multibody model such as in [37], [38].…”

Entropic Measure of Epistemic Uncertainties in Multibody System Models by Axiomatic Design

“…verify the design statement at step m th (12) For example, D evolves from N to P, as described in Figure 3. In N, there is general information and unclassified information, whereas in P there is accurate information, classified, and quantified information.…”

“…Several examples of such complex systems can be found in industrial engineering applications [11][12][13][14][15][16][17][18][19][20]. The complexity of the dynamic behavior of such constrained mechanical systems requires the development of advanced analysis and modelling tools for performing virtual prototyping in a multibody framework [21][22][23][24][25][26][27][28].…”

Evaluation of Uncertainties in the Design Process of Complex Mechanical Systems

“…Multibody systems are the class of mechanical systems composed of rigid and/or flexible bodies interconnected by kinematic joints [1][2][3][4][5][6][7][8][9][10]. They are subjected to nonlinear external force fields and undergo large, finite translations and rotations [11][12][13][14][15]. Examples of multibody systems can be found in several engineering applications [16][17][18][19][20].…”