Evaluation of an electromagnetic system with haptic feedback for control of untethered, soft grippers affected by disturbances

Current wireless, small-scale robots have restricted manipulation capabilities, and limited intuitive tools to control their motion. This paper presents a novel teleoperation system with haptic feedback for the control of untethered soft grippers. The system is able to move and open/close the grippers by regulating the magnetic field and temperature in the workspace. Users can intuitively control the grippers using a grounded haptic interface, that is also capable of providing compelling force feedback information as the gripper interacts with the environment. The magnetic closed-loop control algorithm is designed starting from a Finite Element Model analysis. The electromagnetic model used is validated by a measurement of the magnetic field with a resolution of 0.1 mT and sampling rate of 6.8×106 samples/m2. The system shows an accuracy in positioning the gripper of 0.08 mm at a velocity of 0.81 mm/s. The robustness of the control and tracking algorithms are tested by spraying the workspace with water drops that cause glares and related disturbances of up to 0.41 mm.