Endurance tests of a linear peristaltic actuator

Pneumatic actuators are typically discarded for applications where fine motion control is required, mainly due to the nonlinearities caused by friction effects between piston and rod seals. Conventional control laws are unable to counteract this phenomenon, and thus, conventional actuators find limited applicability in servo control systems. Recently, the use of an alternative solution, a pneumatic linear peristaltic actuator (PLPA), was proposed to overcome this problem. In its present embodiment, a PLPA comprehends two rollers pressing a hose and thereby defining two separate chambers. The use of a PLPA has several potential advantages over conventional or low friction actuators, but its endurance is yet to be known as no studies on this topic can be found in literature. This paper tries to fill this gap by presenting an experimental characterization of some mechanical properties of three different hoses, which are subsequently used in experimental endurance tests. This paper also presents a detailed description of the failure causes found and an analysis on how different parameters may influence its longevity. Finally, possible solutions to increase the life of PLPAs are envisaged.