Model Based Teleoperation to Eliminate Feedback Delay NSF Grant BCS89-01352 - 3rd Report

We are conducting research in the area of teleoperation with feedback delay. Significant delays occur when performing space teleoperation from the earth as well as in subsea teleoperation where the operator is typically on a surface vessel and communication is via acoustic links. These delays make teleoperation extremely difficult and lead to very low operator productivity. We have combined computer graphics with manipulator programming to provide a solution to the delay problem. A teleoperator master arm is interfaced to a graphical simulation of the remote environment. Synthetic fixtures are used to guide the operators motions and to provide kinesthetic feedback. The operator\u27s actions are monitored and used to generate symbolic motion commands for transmission to, and execution by, the remote slave robot. While much of a task proceeds error free, when an error does occur, the slave system transmits data back to the master environment where the operator can then experience the motion of the slave manipulator in actual task execution. We have also provided for the use of tools such as an impact wrench and a winch at the slave site. In all cases the tools are unencumbered by sensors; the slave uses a compliant instrumented wrist to monitor tool operation in terms of resulting motions and reaction forces

Teleprogramming: Remote Site Research Issues: (Dissertation Proposal)

This document proposes the development of the remote site workcell for teleoperation with significant communication delays (on the order of one to 20 seconds). In these situations, direct teleoperation becomes difficult to impossible due to the delays in visual and force feedback. Teleprogramming has been developed in order to overcome this problem. In teleprogramming, the human operator interacts in real time with a graphical model of the remote site, which provides for real time visual and force feedback. The master arm and the manipulator/model interactions, given predefined criteria of what types of motions are to be expected. These commands are then sent via a communication link, which may delay the signals, to the remote site. Based upon a remote world model, predefined and possibly refined as more information is obtained, the slave carries out commanded operations in the remote world and decides whether each step has been executed correctly. The remote site receives commands sent via the delayed communication link. These commands must be parsed and translated into the local robot control language, which includes insertion of dynamic parameters that are not generated by the master system. The commands are then executed by the hybrid position/force controller, and the resulting motions monitored for errors. This proposal addresses the following remote site issues: low level manipulator control using an instrumented compliant wrist for sensory feedback, higher level command execution implementing dynamic parameters, and remote manipulator tool usage and control

Model Based Teleoperation to Eliminate Feedback Delay NSF Grant BCS89-01352 Second Report

We are conducting research in the area of teleoperation with feedback delay. Delay occurs with earth-based teleoperation in space and with surface-based teleoperation with untethered submersibles when acoustic communication links are involved. The delay in obtaining position and force feedback from remote slave arms makes teleoperation extremely difficult leading to very low productivity. We have combined computer graphics with manipulator programming to provide a solution to the problem. A teleoperator master arm is interfaced to a graphics based simulator of the remote environment. The system is then coupled with a robot manipulator at the remote, delayed site. The operator\u27s actions are monitored to provide both kinesthetic and visual feedback and to generate symbolic motion commands to the remote slave. The slave robot then executes these symbolic commands delayed in time. While much of a task proceeds error free, when an error does occur, the slave system transmits data back to the master environment which is then reset to the error state from which the operator continues the task

ROTEX-TRIIFEX: Proposal for a joint FRG-USA telerobotic flight experiment

The concepts and main elements of a RObot Technology EXperiment (ROTEX) proposed to fly with the next German spacelab mission, D2, are presented. It provides a 1 meter size, six axis robot inside a spacelab rack, equipped with a multisensory gripper (force-torque sensors, an array of range finders, and mini stereo cameras). The robot will perform assembly and servicing tasks in a generic way, and will grasp a floating object. The man machine and supervisory control concepts for teleoperation from the spacelab and from ground are discussed. The predictive estimation schemes for an extensive use of time-delay compensating 3D computer graphics are explained

\u3cem\u3eGRASP News\u3c/em\u3e, Volume 6, Number 1

A report of the General Robotics and Active Sensory Perception (GRASP) Laboratory, edited by Gregory Long and Alok Gupta

Flight telerobot mechanism design: Problems and challenges

Problems and challenges of designing flight telerobot mechanisms are discussed. Specific experiences are drawn from the following system developments: (1) the Force Reflecting Hand Controller, (2) the Smart End Effector, (3) the force-torque sensor, and a generic multi-degrees-of-freedom manipulator

Operating Interaction and Teleprogramming for Subsea Manipulation

The teleprogramming paradigm has been proposed as a means to efficiently perform teleoperation in the subsea environment via an acoustical link. In such a system the effects of both limited bandwidth channels and delayed communications are overcome by transmitting not Cartesian or joint level information but rather symbolic, error-tolerant, program instructions to the remote site. The operator interacts with a virtual reality of the remote site which provides immediate visual and kinesthetic feedback. The uncertainty in this model can be reduced based on information received from the slave manipulator\u27s tactile contact with the environment. It is suggested that the current state of the model be made available to the operator via a graphical display which shows not only the position of objects at the remote site but also, through the use of color clues, the uncertainty associated with those positions. The provision of uncertainty information is important since it allows the operator to compromise between speed and accuracy. An additional operator aid, which we term synthetic fixturing, is proposed. Synthetic fixtures provide the operator of the teleprogramming system with the teleoperation equivalent of the snap commands common in computer aided design programs. By guiding the position and/or orientation of the master manipulator toward specific points, lines or planes the system is able to increase both the speed and precision with which the operator can control the slave arm without requiring sophisticated hardware

Robotic Exploration of Surfaces With a Compliant Wrist Sensor

This paper presents some results of an ongoing research project to investigate the components and modules that are necessary to equip a robot with exploratory capabilities. Of particular interest is the recovery of certain material properties from a surface, given minimal a priori information, with the intent to use this information to enable a robot to stand and walk stably on a surface that is unknown and unconstrained. To this end, exploratory procedures (ep\u27s) have been designed and implemented to recover penetrability, material hardness and surface roughness by exploring the surface using a compliant wrist sensor. A six degree-of-freedom compliant wrist sensor, which combines passive compliance and active sensing, has been developed to provide the necessary flexibility for force and contact control, as well as to provide accurate position control. This paper describes the compliant wrist and sensing mechanism design along with a hybrid control algorithm that utilizes the sensed information from the wrist to adjust the apparent stiffness of the end-effector as desired

Servomotor-Linked Articulated Versatile End Effector (SLAVE2)

A strategy is presented for the design and construction of a large master/slave-controlled, five-finger robotic hand. Each of the five fingers will possess four independent axes each driven by a brushless DC servomotor and, thus, four degrees-of-freedom. It is proposed that commercially available components be utilized as much as possible to fabricate a working laboratory model of the device with an anticipated overall length of approximately three feet (0.9 m). The fingers are to be designed to accommodate proximity, tactile, or force/torque sensors imbedded in their structure. In order to provide for the simultaneous control of the operator wears a specially instrumented glove which produces control signals corresponding to the finger configuration and which is capable of conveying sensor feedback signals to the operator. Two dexterous hand master devices are currently commercially available for this application with both undergoing continuing development

A Distributed System for Robot Manipulator Control, NSF Grant ECS-11879 Fourth Report

This is the fourth annual report representing our last year\u27s work under the current grant. This work was directed to the development of a distributed computer architecture to function as a force and motion server to a robot system. In the course of this work we developed a compliant contact sensor to provide for transitions between position and force control; developed an end-effector capable of securing a stable grasp on an object and a theory of grasping; developed and built a controller which minimizes control delays; explored a parallel kinematics algorithms for the controller; developed a consistent approach to the definition of motion both in joint coordinates and in Cartesian coordinates; developed a symbolic simplification software package to generate the dynamics equations of a manipulator such that the calculations may be split between background and foreground