Dynamic Modeling of Autonomous Robot Movement for Inspection of Pipelines in Different Geometric Conditions

In the current study, with the help of Adams and MATLAB software, a seven-degree-of-freedom wheeled autonomous robot with a mechanism of adaptation to the passive pipe diameter and benefiting from a fuzzy controller to guide the movement path was designed and simulated. The control system of this robot consists of two inputs, which are the difference between the desired speed and the actual speed of the robot (error) and its rate of change (acceleration) and an output, which is the voltage of direct current motors. In this research, the dynamic simulation of robot movement in different geometrical conditions such as straight and vertical pipes, elbows, pipes with reducer, sediments and corrosion was investigated through the design of the fuzzy controller, and the obtained results show that the modeled robot was able to Standard pipes with a diameter of 20-32 inches, as well as pipes with a diameter change or a 90-degree bend with a radius of curvature between 408-763 mm can pass successfully. In addition, the use of a spring instead of a motor in the design of this robot, in order to adapt to the diameter of the pipe, has been a solution to reduce production costs. Therefore, instead of using a motor and two separate controllers (one to adjust the adaptation mechanism to the diameter of the pipe and the other to supply the torque of the robot's wheels), this robot was able to advance its movement using only one controller and from this point of view, it has shown the economic potentials for making real samples, product commercialization and responding to the needs of some industries in the country.