Optimal Object Placement using a Virtual Axis
This addresses a fundamental requirement in robotic cell design for manufacturing, offering a solution to a known bottleneck in iterative optimization methods.
The paper tackles the problem of ensuring a robot can reach all process positions when placing an object in a robotic production cell, by introducing a virtual prismatic joint that guarantees reachability and enables the use of higher-order nonlinear programming algorithms for optimal placement.
A basic task in the design of a robotic production cell is the relative placement of robot and workpiece. The fundamental requirement is that the robot can reach all process positions; only then one can think of further optimization. Therefore an algorithm that automatically places an object into the workspace is very desirable. However many iterative optimzation algorithms cannot guarantee that all intermediate steps are reachable, resulting in complicated procedures. We present a novel approach which extends a robot by a virtual prismatic joint - which measures the distance to the workspace - such that any TCP frames are reachable. This allows higher order nonlinear programming algorithms to be used for placement of an object alone as well as the optimal placement under some differentiable criterion.