Force feedback controller based on fuzzy-rules emulated networks and Hertzian contact with ultrasound

In this paper, a novel force controller which combines a neuro-fuzzy algorithm and a contact ultrasonic probe is presented. The fuzzy rules emulated network (FREN) has a control algorithm structure based on fuzzyIF–THEN rules. The contact probe is constructed of an ultrasonic transducer and a force sensor integrated on a semi-spherical head controlled by a robotic system of four degrees of freedom. The experimental results show that the proposed system exhibits high sensitivity to initial instantaneous contact and it could provide an estimation of reaction force and elastic modulus of the test material by analyzing loading/unloading cycles. The system was tested on samples with different mechanical properties.

► A force controller which combines a neuro-fuzzy algorithm and a contact ultrasonic probe.
► High sensitivity to initial contact.
► Estimation of reaction force and elastic modulus of the test material by analyzing loading/unloading cycles.