We have developed a Radiation-proof Robot(called RaBOT) operated under the severe conditions such as gamma radiation. The robot has been operated from the operation desk with the master arm system. The master arm system is the armrest type 6 axes joystick with force feedback. However, the system has become large and complicated because the master arms have the same number of active joints as the slave manipulators; moreover, that provide not only the required sensory feedbacks on the operator but also uncomfortable constraints. This report examines the miniaturization and carriage ability for the master arm system and describes the basic performance test results.
