Contents I. Introduction
During the past decades, the demand for robot assistance in human robot interaction has been more and more popular in various fields, from industry (e.g. manufacturing and assembly and disassembly) to service robotics (e.g. robot waiter). Many dangerous jobs were carried out by people themselves, such as the rescue of natural disasters like fire, flood and earthquake, or the demolition of dangerous goods like mines and bombs. With the development of science and technology, more and more robots have been developed and putted into these dangerous jobs, trying to replace people to enter these dangerous areas to carry out tasks. But because of the complexity of the tasks to be performed, these robots always need human's assistance to finish the task. In the past, if you wanted to control a robot manually, you had to be familiar with a large number of buttons on the controller. The more powerful the robot, the more buttons there were, thus increasing the difficulty of control.
