Good Production Cycles for Circular Robotic Cells

In this paper, we study cyclic production for throughput optimization in robotic flow-shops. We are focusing on simple production cycles. Robotic cells can have a linear or a circular layout: most classical results on linear cells cannot be extended to circular cells, making it difficult to quantify the potential gain brought by the latter configuration. Moreover, though the problem of finding the best one part production cycle is polynomial for linear cells, it is NP-hard for circular cells. We consider the special case of circular balanced cells. We first consider three basic production cycles, and focus on one which is specific to circular cells, for which we establish the expression of the cycle time. Then, we provide a counterexample to a classical conjecture still open in this configuration. Finally, based on computational experiments, we make a conjecture on the dominance of a family of cycle, which could lead to a polynomial algorithm for finding the best 1-cycle for circular balanced cells

Development of a remote trauma care assist robot

Abstract-In typical teleoperated surgeries, skilled staff are still necessary in the remote surgical room to change manipulator tooling and to manage surgical supply delivery and removal. This paper describes the development of a nurse robot to provide automated support to a teleoperated surgical manipulator system in environments where the presence of skilled surgical support staff may not be practical. The tools must be inserted precisely into a compliant manipulator in a timely manner, and the supplies are diverse in nature. To support experimental investigations and evaluations, a seven degrees-of-freedom commercially available manipulator was selected. The design of novel end-effecters, tool grasping and supply holding features, and tool auto-loading systems for optimum surgical tool changing and supply delivery in minimum time is presented. A novel approach for calibration of the nurse robot among compliant and rigid subsystems and for managing forces during subsystem interaction is described and experimental results using this force management approach are presented. Overall experimental performance data for the nurse robot system during tool changing and supply delivery tasks is also presented to illustrate the feasibility of performing these functions in a remote medical or trauma care-assist cell

Notes on feasibility and optimality conditions of small-scale multifunction robotic cell scheduling problems with pickup restrictions

Optimization of robotic workcells is a growing concern in automated manufacturing systems. This study develops a methodology to maximize the production rate of a multifunction robot (MFR) operating within a rotationally arranged robotic cell. An MFR is able to perform additional special operations while in transit between transferring parts from adjacent processing stages. Considering the free-pickup scenario, the cycle time formulas are initially developed for small-scale cells where an MFR interacts with either two or three machines. A methodology for finding the optimality regions of all possible permutations is presented. The results are then extended to the no-wait pickup scenario in which all parts must be processed from the input hopper to the output hopper, without any interruption either on or between machines. This analysis enables insightful evaluation of the productivity improvements of MFRs in real-life robotized workcells.Mehdi Foumani, Indra Gunawan, Kate Smith-Miles, M. Yousef Ibrahi