Pipelines play an important role in delivering fluids such as drinking water

Pipelines play an important role in delivering fluids such as drinking water, sewage water, oils, and gases. Many a times inconvenience is caused by deterioration of pipe, corrosion, crevice, and other damages which leads to a loss of the transported medium and can also affect the environment. Hence continuous inspection, maintenance, and cleaning are strongly demanded. To overcome such problems implementation of robots appears to be the most viable solutions. Robots are designed to reduce human factor as they can operate in environment unreachable for humans. Robots can be remotely controlled to tackle the inspection and even sometimes maintenance operations.
Most of previous research work have employed conventional robots such as electric motors, pneumatic actuator etc. Kurata et al. 1 developed a prototype which imitates the gesture of spirochetes, driven by motors and pulleys. It keeps the inner wall of pipe intact as it does not haul its body but may get confined in the pipe in case of malfunctioning of the mechanism. Osuka et al. 2 developed a pipe inspection robot, SPRING that can move along the gas pipes. Experimental results revealed a problem that the robot retards when accessing its path through a valve in the pipe network. Kim et al. 3 presented an inspection robot compelling wall force and actuated by DC motor. It consists of a driving module having three links placed mutually at an angle of 120° consisting of three caterpillar track wheels and a control module comprising of microcontroller, motor driver and sensor interface. It has the disadvantage of skidding. Also, the inner surface of the pipe may get vandalize because of high friction. A prototype of pipe inspection robot trigerred with the help of compressed air was developed by Yoon et al. 4. This prototype is capable of operating both on a plane and in the fluid but difficult in bending pipes. Fjerdingen et al. 5 proposed a robot having articulated transport mechanism consisting of successive identical modules linked together with the help of two rotational joints on either side of the modules. Wheels at each module give onward and reverse thrust. It is energy efficient with the disadvantage of the wheel getting embedded if there is a cavity in the pipe. Suzomori et. al 6 fabricated an inspection robot for pipelines of 1-inch diameter that provides adequate maneuverability and is acceptable for practical applications. The prototype bears a camera which provides resolution for minute cracks in the inner wall of the pipe. It carries a dual-hand system which has six degree of freedom for controlling and retrieving small objects.