Design of Adaptive Sensor Coupling-Based Upper Limb 7-DOF Exoskeleton for Smooth Human Motion Tracking: ASC-EXO

The conventional sensor coupling of the sensor in an exoskeleton robot suffers from inaccurate human motion tracking due to irregular inertial loading on the sensor axis. It may cause sensor axis misalignment and performance degradation and damage the sensor permanently, especially in the multiple degrees of freedom (DOFs) exoskeleton robot. In this article, we proposed a novel design of an adaptive sensor coupling-based 7-DOF exoskeleton (ASC-EXO) for motion tracking and telemanipulation. The adaptive sensor coupling (ASC) mechanism has been designed based on the flexure structure cantilever with a slew ring, which suppresses irregular inertial loading on the sensor and is stiff enough along the sensor rotation in the
${z}$
-axis and compliant on the other axes. The slew ring allows smooth joint rotation. Furthermore, the sensor values are improved by a Butterworth filter. As a result, the ASC suppressed the sensor noise 20 times more than the conventionally coupled sensor with the robot joint. Finally, we developed a prototype of the 7-DOF exoskeleton (ASC-EXO) using ASC for smooth human motion tracking. The performance evaluation of ASC and human motion tracking is presented. In addition, we demonstrated the smooth control of the secondary robot (KUKA) using the exoskeleton (ASC-EXO) as a primary device. Video:
https://youtu.be/HBmAb2FBaBw
.