An Exoskeleton Master Hand for Controlling DLR/HIT Hand

In order to eliminate the drawbacks of conventional force feedback gloves, a new type of master hand has been developed. By utilizing three "four-bar mechanism joint" in series and wire coupling mechanism, the master finger transmission ratio is kept exact 1:1.4:1 in the whole movement range and it can make active motions in both extension and flexion direction. Additionally, to assure faster data transmission and near zero delay in master-slave operation, a digital signal processing/field programmable gate array (DSP/FPGA-FPGA) structure with 200 mu s cycle time is designed. The operating modes of the master hand can be contact or non-contact, which depends on the motion states of slave hand, 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 hand, an master-slave control experiment based on Force-Position control method between the master hand and DLR/HIT hand is conducted. The results demonstrate this new type master hand can augment telepresence.