A force feedback master finger in exoskeleton type

In order to eliminate the drawbacks of conventional force feedback gloves,a new type of master finger has been developed.By utilizing three"four-bar mechanism joint"in series and wire coupling mechanism,the master finger transmission ratio is kept exactly 1:1.4:1 in the whole movement range and it can make active motions in both extension and flexion directions.Additionally,to assttre faster data transmission and near zero delay in the master-slave operation,a digital signal processing/field programmable gate array(DSP/FPGA-FPGA)structure with 200μs cycle time is designed.The operating modes of the master finger can be contact or non-contact,which depends on the motion states of a slave finger,free motion or constrained motion.The position control employed in non-contact mode ensures unconstrained motion and the force control adopted in contact mode guarantees natural contact sensation.To evaluate the performances of the master finger,an experiment between the master finger and a DLR/HIT dexterous finger is conducted.The results demonstrate that this new type master finger can augment telepresence.