Feedback control of machine startup for energy-efficient manufacturing in Bernoulli serial lines

Effective control of production operations is considered as one of the most economical methods to improve energy efficiency in manufacturing systems. This paper investigates energy consumption reduction in Bernoulli serial lines with buffer stripping, i.e., with the buffers that must be depleted at the end of each shift. This buffer depletion activity is widely used in automotive paint shops and other production systems with perishable products to avoid quality deterioration. Clearly, to reduce energy consumption in such systems, the startup schedule of the machines downstream of the depleted buffers should be controlled properly at the beginning of each shift. In this paper, using transient analysis of the systems at hand, performance evaluation formulas are derived and system-theoretic properties are analyzed. In addition, effective controllers for machine startup schedule are proposed. The efficacy and practical implications of these controllers are demonstrated using numerical investigation. Finally, insights for obtaining the optimal controllers are provided.