In this method, two pipes (the warning pipe and the safe pipe) are automatically generated from 3D reference path in real time.
In Section 3, we introduce the dynamic adjustment algorithm of the safe pipe and the warning pipe. In Section 4, we report the experiment results of two control modes.
The second pipe is the early warning pipe. It gives a real-time warning once there was any muscles jitter of the operators during the robot controlling.
The outer one is a safe pipe and the inner one is an early warning pipe. Formula (8) can be a reference to the generation algorithm of safe pipe.
When the robot EE strays from the path, the early warning pipe needs to adjust itself accordingly, so that it can give a real-time warning when the robot EE crosses safe pipe.
In the experiment, we drew a safe path from the EE to the center of the hole, and then the system created two pipes automatically: the safe pipe and the warning pipe. The safe pipe could expand until the safe pipe collided with the edge of the hole and the warning pipe would adjust the radius of itself.
The safe pipe was designed to detect the potential collision and the warning pipe constrained the robot EE to follow the referenced path.
The purpose of the warning pipe was to detect the deviation from the reference path.