Notes on feasibility and optimality conditions of small-scale multifunction robotic cell scheduling problems with pickup restrictions
- Authors: Foumani, Mehdi , Gunawan, Indra , Smith-Miles, Kate , Ibrahim, Yousef
- Date: 2015
- Type: Text , Journal article
- Relation: IEEE Transactions on Industrial Informatics Vol. 11, no. 3 (2015), p. 821-829
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- Description: 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. ©2014 IEEE.
Stochastic scheduling of an automated two-machine robotic cell with in-process inspection system
- Authors: Foumani, Mehdi , Smith-Miles, Kate , Gunawan, Indra , Moeini, Ashgar
- Date: 2015
- Type: Text , Conference proceedings
- Relation: 45th International Conference on Computers and Industrial Engineering, CIE 2015; Universite de Lorraine, LCOMS Metz; France; 28th-30th October 2015. In Proceedings - CIE 45: 2015 International Conference on Computers and Industrial Engineering
- Full Text: false
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- Description: This study is focused on the domain of a two-machine robotic cell scheduling problem. Particularly, we propose the first analytical method for minimizing the partial cycle time of such a cell with a PC-based automatic inspection system to make the problem more realistic. It is assumed that parts must be inspected in one of the production machines, and this may result in a rework process. The stochastic nature of the rework process prevents us from applying existing deterministic solution methods for the scheduling problem. This study aims to develop an in-line inspection of identical parts using multiple contact/non-contact sensors. Initially, we present a heuristic method that converts a multiple-sensor inspection system into a single-sensor inspection system. Then, the expected sequence times of two different cycles are derived based on a geometric distribution, and finally the maximum expected throughput is pursued for each individual case.