Self-rescue mechanism for screw drive in-pipe robots

This paper presents a self-rescue mechanism for a screw drive in-pipe robot, which only uses one DC motor. The robot has two working modes, Normal Working Mode and Self-rescue Mode. Under normal working mode, the robot propels itself in the pipe just as other classical screw drive robots. When the robot encounters the obstacle and gets jammed, the lock up mechanism and motion control mechanism of the robot are activated. Then, the robot changes from working mode to self-rescue mode and moves away in the reverse direction to avoid jamming in the pipe. The change of the working mode is determined by the characteristics of the mechanism. The proposed mechanism can be used as a safety protection method for the pipe robot. Experiments have been conducted to testify the proposed mechanism. Compared with those with screw drive mechanisms, robots with self-rescue mechanism are able to avoid jamming in the pipe.