In-pipe Microrobot Driven by SMA Elements

The paper presents a microrobot designed for moving inside of pipelines, whose actuator is based on a strand made of Shape Memory Alloy (SMA). According to the accepted assumptions, a device of a simple structure has been elaborated; it consists of a possibly small number of members and employs a simple control system and power supply. Simplicity of the control system and the power supply was achieved owing to heating the SMA strand by means of an impulse DC supply. Movement within the pipeline is realized by a sequence of displacements of two members of the frame, and the resultant position is kept automatically due to interactions of the flat springs with the internal wall of the pipeline. A demonstrator of the robot was built and experimentally tested, mainly in order to determine its ability to transfer loads. Limitations pertaining to the realized concept are indicated, and solutions improving dynamics of operation of such robot are put forward.