DEVELOPMENT OF THE MULTIBODY MODEL OF A TWO-UNIT IN-PIPE ROBOT FOR EVALUATION OF ITS CAPABILITY TO MOVE THROUGH A PIPELINE

Abstract

The ability of a multi-unit in-pipe robot to drive through curved sections of a pipeline is an important
indicator of its capability to move through the pipeline. At the design stage, this indicator
cannot be verified without mathematical simulation of the robot spatial movement and interaction of
its running gear with the pipeline. The objective of this work is to create a dynamical model for evaluation
of the two-link in-pipe wheeled robot capability to drive through a pipeline. The model was
developed in the Universal Mechanism multibody system simulation program with the use of its
standard elements of the mechanical system modeling and a special-purpose wheel – pipeline contact
model developed by the authors. The wheel – pipeline contact model was created in MATLAB and
compiled as a DLL. The developed multibody model was verified by the robot behavior during its
motion through a bent section of the pipeline and by the time histories of the indicators of its capability
to drive through the pipeline. Two directions of the pipeline bend were studied. The minimum
distance from the extruding electric motors of the robot actuators to the internal surface of the pipeline
has been offered as an indicator of the robot ability to move through the pipeline. The analysis of
the simulation results has proved the adequacy of the model behavior and showed that the developed
multibody model can be used for the evaluation of the robot capability to move through the pipeline
at the early design stages before fabrication of its prototype.