COMPUTER MODELING OF ADHESION AND TRACTION FORCESOF A SHIP MOBILE ROBOT

Abstract

The article addresses the scientific and practical problem of developing a computer simulation model of a ship mobile robot (SMR) to further automate maintenance processes for ships and port infrastructure facilities (pipelines, storage tanks, floating docks). Based on a review of existing solutions, the advantages of all-wheel drive wheeled platforms over tracked and legged counterparts in terms of manoeuvrability and energy efficiency are substantiated. A lack of research on the dynamics of wheeled SMRs equipped with elastic airless tyres with variable contact zone geometry is identified.A comprehensive spatial mathematical model of a four-wheeled SMR with an electromagnetic adhesion system has been developed. A distinctive feature of the proposed model is its focus on the synthesis of automatic control systems (ACS). It accounts for individual dynamic load transfer (normal support reactions) at each of the four wheels, depending on the heading angle, surface inclination, linear acceleration, and disturbances from technological operations. The mathematical description also accounts for the specific nature of rolling resistance occurring in a deformed elastic wheel under the action of magnetic adhesion A computer model of the locomotion system has been created in the MATLAB/Simulink environment using the derived mathematical apparatus. The boundaries of the critical zone (where movement is physically impossible due to resistance exceeding the maximum adhesion limit), the transitional critical zone (where movement is theoretically possible subject to structural modification of the robot), and the normal operating zone of the system have been determined and visualized according to the simulation results. The distribution of the required traction forces of the drive wheels during movement on an inclined ferromagnetic surface with changing spatial orientation has been investigated. The results quantitatively demonstrate the necessity of implementing traction distribution control systems (as opposed to a standard uncontrolled drive) to prevent wheel slip on locally unloaded wheels. The created model is an effective tool for the further development and verification of ACS algorithms for the main motion coordinates of the SMR.