Research On Master-slave Control Based On Force Feedback Glove And Hit/dlr Hand

It is difficult to design a autonomous robot due to the complex, dynamic,unknown environment and also the technology constraint of the computer, theintelligence and the mechanics. In this condition, combining the semi-autonomousrobot with the human intelligence would be a reasonable idea which makes thehuman become a part of the robot control system and extends the ability of humansenses and behaviors. Force feedback device is such an instrument, which is a keytechnology field for the effective control of dexterous robots. The aim of thisdissertation is to develop a new type exoskeletonforce feedback glove to overcomethe drawbacks of conventional force feedback glove, and to conduct a research onmaster-slave control based on the force feedback glove and HIT/DLR hand.To overcome the disadvantages of conventional force feedback gloves, such asthe departure between driving part and exoskeleton mechanism which makes thestructure bulk, characteristics which the gloves should be groundedto the segmentsof operator's finger and the interaction force can not be measured which affect thetelepresence seriously. A new modular multi-sensory high-integrated exoskeletontype force feedback glove has been designed in this thesis. The glove can makeactive motions in both flexion and extension directions like human finger based onfour-bar mechanism and coupling transmission mechanism. The glove canimplement force feedback in the two directions.Through comparison the advantages and disadvantages of all kinds of master-salve control method,the two channel force/position control method is employedto implement master-slave control in this thesis. In order to identify the contact andnon-contact mode in master-slave operation, the master is endowed with twocontrol methods. One is tip position control, the other is force tacking. Theoperating modes of the master hand depends on the motion states of HIT/DLR hand,free motion or constrained motion. The position control employed in non-contactmode ensures unconstrained motion and the force control adopted in contact modeguarantees natural contact sensation.In order to assure the stability of interaction between HIT/DLR hand andenvironment, an adaptive force based impedance controller in joint space is proposed. In view of nonlinear,friction and uncertainty exsisting in robot system,avelocity observer is designed for improving the quality of velocity and adisturbance observer is contrivedto estimate the disturbance and compensate it.Because the time delay has effect on the transparency and stability inteleoperation system, a smith predictor is integrated into force/position architectureto compensate the time delay. By analyze the transparency and stability of thesystem, a conclusion can be acquired, i.e., compared with the teleoperation systemdesigned by passivity approach, the system based on smith predictor can get bettertransparency and stability, and the stability is not depended on time delay. In viewof the smith predictor need linear model of the slave robot, but the actual model isdifficult and almost impossible to acquire, so an disturbance observer is designed tolinear the salve robot dynamics, which make the slave robot model easy toimplement in smith predictor.Finally, control experiments of master-slave and master-slave with time delayare conducted base on the developed exoskeleton force feedback glove andHIT/DLR dexterous hand. Experimental results prove the control methodsmentioned and designed in the dissertation are valid, and prove the force feedbackglove can augment telepresence.