Development of bilateral remote controller “Armrest Joystick” (Design of controller mechanism with weight compensation)

Abstract

Remotely operated mobile robots are demanded in many disaster fields, such as Nuclear/Biological/Chemical(NBC) terrorist attacks, earthquake and tsunami, and even in minefields, to assure safety for the human workers. It is a common choice to use commercial game controllers with joysticks and buttons to control such robots, but many complex manipulation tasks require much higher operability only achieved by Master-Slave systems. In this research, we propose a new bilateral remote controller called “Armrest Joystick” which has Master-Slave function and also presents high operability characteristics. It consists of : (i) a 3DOF position arm mechanism which is attached to a foldable portable chair, and the foremost link part acts as an armrest to support the operator's arm; (ii) a 3DOF wrist posture mechanism whose rotation centers were carefully designed to match the human hand; (iii) a gripper mechanism which has good follow-up performance for fingers. Furthermore, all 7 joints (axes) are equipped with electrical motors and are actuated to give the operator Force Feedback. In this paper, we report the basic concept and explain in detail the mechanism design of the Armrest Joystick, and then show the experiments to check basic performance, specially about the armrest, and which we conducted using an actual rescue robot as “slave”. The results verify the validity of the mechanical design, and show that the Armrest Joystick can be more intuitively used than the former commercial game controllers.

Keywords

• robot
• rescue
• controller
• master-slave
• operability
• force-feedback
• weight-compensation
• emg