Qualitative Evaluation of Computer-Aided Teleopearation

Abstract—Computer-aided teleoperation (CAT) is investigated for extending human eye-hand motion coordination and dexterity. A telerobotic system consisting of a master arm and a slave arm interconnected by a computer network is designed. The proposed system is evaluated using a set of experiments which are (1) operating drawers, (2) pouring of water, and (3) wirewrapping. The non deterministic behavior of force contact favor a qualitative evaluation of teleoperation methodology. Direct teleoperation is evaluated using following schemes: (1) direct bilateral master-slave (DBMS) with stereo vision, (2) DBMS with vision and force feedback, and (3) BDMS with vision and active compliance. CAT tools used are space indexing, scalability, and selective scalability (blocking). Stereo vision is critical resource for teleoperation even with highly coordinated tool motion but it is not efficient alone to avoid excessive contact force and to shorten task time. Slave compliance continuously searches to nullify the external forces by correcting the tool position and orientation based on measured contact force. Space indexing is essential to maintain tele-operation in operator dexterity. Selective scalability is frequently used to linearly block some motion directions while keeping other directions under direct operator control. Mapping of operator hand motion and force to a dynamically computed tool point proved to reduce operator’s cognitive load and task time and ease of understanding of force feedback. This greatly reduces the number of task iterations because the tool DOFs become decoupled, i.e. varying one likely not to affect the others

Kinesthetic Haptics Sensing and Discovery with Bilateral Teleoperation Systems

In the mechanical engineering field of robotics, bilateral teleoperation is a classic but still increasing research topic. In bilateral teleoperation, a human operator moves the master manipulator, and a slave manipulator is controlled to follow the motion of the master in a remote, potentially hostile environment. This dissertation focuses on kinesthetic perception analysis in teleoperation systems. Design of the controllers of the systems is studied as the influential factor of this issue. The controllers that can provide different force tracking capability are compared using the same experimental protocol. A 6 DOF teleoperation system is configured as the system testbed. An innovative master manipulator is developed and a 7 DOF redundant manipulator is used as the slave robot. A singularity avoidance inverse kinematics algorithm is developed to resolve the redundancy of the slave manipulator. An experimental protocol is addressed and three dynamics attributes related to kineshtetic feedback are investigated: weight, center of gravity and inertia. The results support our hypothesis: the controller that can bring a better force feedback can improve the performance in the experiments