i am interseted in how they achieve compilance and detect collision in servo without the use of sensors. so any one please explain briefly
It's explained on the video description:
In this research, a methodology for sensor-less full body active compliance was used on a 6-DOF RSS (Rotary-Spherical-Spherical) parallel manipulator. The manipulator can detect and comply with the external forces on any part of its body without using any explicit force/torque sensor at the joint or the end-effector. This was done by utilizing the estimated joint torque based actuator current feedback only. A three-layer cascaded impedance controller for active compliance and reaction to various human interactions was used. The proposed design and unique methodology for compliance exhibits an effective and inexpensive yet reliable alternative to be used in safe human-robot interactions and force controlled manufacturing applications.
Collision / Compliant motion is detected by the current draw increase of the motor.
This was done by utilizing the estimated joint torque based actuator current feedback only