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Development of axial extension actuator for narrow pipe inspection endoscopic robot

We have developed an earthworm-type 25A pipe inspection robot using a pneumatic drive. However, the developed robot had a low locomotion speed. This was due to the fact that the contraction amount of the pneumatic artificial muscle used for driving the actuator of the robot was small. To resolve the problem and increase the amount of movement of the robot, an extension actuator to extend in the axial direction was developed. The developed actuators was tested in an experiment that measured the extension amount. At that time, it was confirmed that the actuator largely extended while bending. Therefore, an experiment was performed to verify the bending of actuators and to confirm the extent of the bending. Test results confirmed that the movement tracing of extension actuator with tension springs on both the inside and outside (actuator2) was straighter than that of extension actuator that used the tension spring only on the inside (actuator1). In addition, the developed actuator was tested in an experiment that measured pushing force and pulling force. It was also verified that the extension actuator satisfied the force requirements for the robot.