Parallel Systems and Structural Frames Realignment Planning and Actuation Strategy

Abstract

Parallel structural systems and assemblies are challenging to erect, align and plumb on construction sites due to their complex geometries and current heuristic realignment strategies. Examples of parallel systems include complicated pipe modules and pipe racks in the industrial construction sector. This paper presents a generalized approach analogous to robotics and inverse kinematics for building parallel systems’ realignment planning, introduced using a series approach. In addition to the calculation of a realignment strategy, feasible applications of such a strategy are also investigated in this paper. The framework for realigning parallel systems has two primary steps: (1) as-built status identification by capturing the geometric state of construction assemblies using three-dimensional (3D) imaging theories, and (2) realignment calculation and actuation based on degrees of freedom (DOFs) defined during the development of the kinematics chains of assemblies. A Quasi-Newton-Raphson (QNR) method is employed for solving the kinematics equation of the inverse kinematics analogy. Experimental results show that the developed algorithms are sufficiently accurate to capture any incurred geometrical discrepancies in parallel construction assemblies and proactively calculate and plan for efficient realignment strategies. Generalization of realignment calculation for parallel systems and realignment actuation are the key contributions of this work.