Smart Tooling: A New Approach to Remote Operations
Smart Tooling is a radical new approach to remote tool design focusing on fusing actuation, sensing and control with tool design. The conventional approach to remote operation consists of combining a general teleoperated manipulator with fixtured tools. However, our experience shows that while functional, this approach to remote operations suffers in terms of tool wear, operator fatigue, task completion time and success rates. This degradation in performance can be traced back to a mismatch between the manipulators performance (dexterity, accuracy, resolution), the task requirements (force regulation, constrained operations, precision) and operator feedback (haptic fidelity, visual and acoustic cues). Smart tooling is formal methodology to tool design based upon a constrained optimization algorithm that identifies optimal sensory feedback and actuation (if needed) based on task requirements and manipulator performance. As a preliminary example, we explored metal cutting with a plasma torch using a conventional hydraulic manipulator. The task requires regulation of the tip from the cutting surface between 1/8"and 3/8"and a constant speed of 1 in/sec. However, the resolution of the arm (due to joint sensory feedback) is between 1/4" and 3/8". In addition, the kinematics of the arm dramatically limit the ability to arbitrarily configure the tool with respect to the environment. Our analysis showed that to achieve these objectives, the tool would require two additional degrees of freedom (rotation and translation) with at least three proximity sensors. Clearly, the resulting system becomes redundant. We exploit a new redundancy resolution methodology, developed at ORNL, that enables a closed form solution to reconfigurable systems (e.g. the solution is automatically generated during tool exchange).
Plasma torch with fixture.
"Smart" plasma torch.
Metal cutting with commercial arm.
Smart tooling can impact a large variety of application areas from medical tool design, forestry and construction equipment, to remote bomb disposal and operations in hazardous environments. The motivation for this work is directed towards applications that require cost effective dexterous remote manipulation. This can apply to telerobotic tasks in hazardous environments that are executed once or only a few times as well as to highly repetitive tasks in manufacturing assembly where the imprecision of the robot manipulator requires extensive tuning and tweaking of a taught program to coax the manipulator into successful completion of the desired task. Precise positioning is required; however costs must be minimized. Smart tooling can be used to finesse task execution past the level of performance of the manipulator either by enabling tasks that could not reasonably be completed remotely or by reducing the cost of the delivery system by permitting the use of a lower precision cheaper manipulator.
In FY-2001/2002 the deactivation and decommissioning (D&D) product line of the DOE EM-50 Robotics Crosscutting Program initiated an investigation of ways to facilitate telerobotic execution of tasks difficult for remote systems. This led to the concept of smart tooling whereby the tool itself carries the appropriate additional actuation and sensing that the deployment system lacks. The D&D focus was specifically for in situ systems working in unstructured and uncalibrated environments. The specific application presented was plasma torch cutting of carbon steel structural members (see above). The advantage of the plasma torch is the low tool wear and rapid cutting. However, the operational requirements included controlled tip standoff and velocity control of the tip with respect to the environment. The operational constraints proved too difficult for the conventional teleoperation approach. A new Smart Plasma Torch tool was designed and tested. The inclusion of actuation and sensing relaxed the operational constraints and enabled complex cutting on multiple surfaces in unstructured environments using a commercial teleoperated system designed for payload rather than precision operation.
Future Development Requirements
The demonstration of Smart
tooling with the plasma torch illustrated the potential for this basic concept.
There are many other examples that can benefit from this approach. Drilling,
bolt removal and assembly, to name a few, require constrained motion along specific
axes with respect to the task. Smart tooling using strategic force and displacement
measurement coupled with actuation and control can enable remote execution of
complex tasks in unstructured environments. The objective of this proposed program
is to identify a class of problems that can benefit from the smart tooling concept.
Research will focus on the design, sensing and control of this class of tools
to enable a flexible, reliable, low cost, high performance remote operation
system that can be deployed on any low cost remote manipulation system.
For further information, contact Mark W. Noakes.
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Last Updated: June 1, 2009