Cycle time analysis in reentrant robotic cells with swap ability

International Journal of Production Research

Gunawan

Ibrahim

2014

Self Cite

Automated material handling systems are usually characterised by robotic cells that result in the improvement of the production rate. The main purpose of this research is to study the scheduling of a rotationally arranged robotic cell with the multi-function robot (MFR). This special class of industrial robot is able not only to transfer the part between two adjacent processing stages but also to perform a special operation in transit. Considering MFR for material handling and operation, the objective function of the research here is the maximisation of production rate, or equivalently the minimisation of the steady-state cycle time for identical part production. This problem is modelled as a travelling salesman problem to give computational benefits with respect to the existing solution methods. Then, the lower bound for the cycle time is deduced in order to measure the productivity gain of two practical production permutations, namely uphill and downhill permutations. As a design problem, a preliminary analysis initially identifies the regions where the productivity gain of a regular multi-function robotic cell is more than that of the corresponding single-function robotic cell for both small-and large-scale cells. The conclusion shows the suggested topics for future research.

Section: Literature Review For Transporting Sfrsmentioning

confidence: 99%

Scheduling rotationally arranged robotic cells served by a multi-function robot

International Journal of Production Research

Gunawan

Ibrahim

2014

Self Cite

“…In another study, Jolai et al [11] summarized an approach for finding optimal cycle of two-machine flexible SFRCs with swap ability. The two-machine reentrant SFRCs composed of a SFR with temporary buffer was investigated in [12]. Zarandi et al [13] considered twomachine SFRC scheduling problem with sequencedependent setup times.…”

Section: Introductionmentioning

confidence: 99%

Cyclic production for robotic cells served by multi-function robots with resumable processing regime

2013 IEEE International Conference on Industrial Engineering and Engineering Management

Ibrahim

Gunawan

2013

This paper addresses the problem of finding the optimal robot move cycle to minimise the cycle time of twomachine cells. The earlier robot's function was mainly moving parts between machines in a manufacturing process. We lift this assumption on robot tasks and assumed a special robot, namely multi-function, which performs a unique operation in transit. This robot starts performing this operation after unloading a part from input buffer and finishes it before loading the part to the output buffer. The processing mode on robot is ''stop resume''. Thus, regardless of the gap interrupts during the operation, the robot continues processing on part when it is reloaded to the robot without any loss in time. The focus of this study is on one-unit cycles since they are very popular in industry. The cycle time of two possible one-unit cycles is obtained, and the optimality condition of them is determined.

“…The robot with swap ability is International Journal of Computer Integrated Manufacturing 203 able to transfer at most one part at any given moment, but the dual gripper robot has a capacity for transferring two parts at any given time. Their results were then extended to the reentrant robotic cell case by Foumani and Jenab (2012). A real-world example of a four-machine robotic cell, a sheet metal spinning cell that predominantly manufactured viscous torsional vibration damper cases for heavy-duty diesel engines of various diameters, was presented in their case study.…”

Section: Introductionmentioning

confidence: 99%

Analysis of flexible robotic cells with improved pure cycle

International Journal of Computer Integrated Manufacturing

Jenab²

2013

Self Cite

In this paper, we study the robotic cell scheduling problem with two machines and identical parts. It is assumed that there are flexibility in the robot type, the pickup category, and the cell layout. Also, the objective is to find the robot move sequence that minimizes the cycle time. One of the assumptions in the pertaining literature is that the occupied robot cannot load a part into an occupied machine. In contrast, the authors consider the robot has the swap ability, so the busy robot will be able to load concurrently a part into an occupied machine. It is also presumed that each part can entirely be processed by one computer numerical control (CNC) machine. A wide range of m-unit cycles named pure cycles has been well documented in the literature. However, a new class of the pure cycles which can produce less than m parts is defined in this study. We prove that the improved pure cycles always dominate pure cycles. The performance of these improved pure cycles for linearly and circularly configured robotic cells, based on free-pickup and no-wait categories are examined. Also, the number of machines which should be idle or busy to obtain an optimal cycle is determined. The novelty of this research is the introduction of the improved pure cycles that increase the long run average throughput rate and also reduce the number of machines.