Position and rate control modes are the two common modes for controlling remote manipulators with joysticks or hand controllers. Generally, position mode is easier for teleoperation than rate mode, when the manipulation work space is small or comparable to the human operator's control space.
When the telemanipulator's work space is very large, human operator's control motion range must be large to allow telemanipulator's full range of motion resulting poor control resolution. One way to solve the poor resolution problem is to use indexing. However, rate mode can provide any higher degree of resolution without use of indexing. If two modes are mixed, master controller will be more convenient. The mixed mode algorithm, changes operating mode from position mode to rate mode or vise versa using fuzzy logic. The fuzzy logic algorithm, which has been designed to recognize the teleoperator's intended motion properly, provides an intelligence to a master controller.
