## 5 Conclusions  
The choice of power generation architecture of a hydraulic system has a very large impact on the energy efficiency and operating costs. All the architectures considered provide a significant reduction in active power consumption compared to the standard architecture, ranging from 50.5% to 64.3%. The hourly cost of electricity absorption is also significantly reduced, with percentages ranging from 47.1% to 70.1%. This shows the importance of the architecture of the system. Moreover, the comparative study of the most common hydraulic architectures used to drive an industrial process with time-varying speeds and work forces has highlighted the differences between the various solutions in quantitative terms and provided objective comparative data that was not available in the literature. Comparing the values of energy savings with those reported in the literature for different approaches, it can be observed that the values obtained for the considered architectures are consistent with the best ones reported in Table 1. Moreover, it can be deduced that even with a simple and low-cost solution such as regeneration, significant and larger energy savings can be achieved than with the more complex solutions reported in the literature. The modern hydraulic architecture with drive-controlled pump and DCV with regeneration--A hybrid, limited to the category of industrial processes, is a very efficient solution in terms of energy consumption and economy. It has been shown that the dynamic phenomena, often overlooked in the sizing, have a significant impact on the total energy absorption. The oleo-hydraulic architectures studied represent a significant part of the state of the art in hydraulic technology for the actuation of industrial machinery, but not its entirety. Other solutions characterized by high energy efficiency include architectures with high-efficiency square-case induction motors or architectures with a brushless synchronous electric motor and an internally geared pump. Another oleo-hydraulic architecture that could be explored, but which is a poor fit for the industrial process example, involves the use of an accumulator installed in parallel with a fixed-displacement pump. Furthermore, from an economic point of view, the analysis could be complemented by an analysis of the initial investment costs required for each architecture considered. However, it can be concluded that energy-conscious decisions for the power architecture of a hydraulic axis can benefit from the presented analysis. **Funding:** This research received no external funding. **Acknowledgments:** Acknowledgement of the valuable technical contribution of the engineers [PERSON], [PERSON], and [PERSON]. **Conflicts of Interest:** The authors declare no conflict of interest. **Abbreviations**  
The following abbreviations are used in this manuscript: \begin{tabular}{l l} ERS & Energy regeneration system \\ SI & Single-valve independent control \\ SMISMO & Separate meter in and separate meter out control \\ DP & Dual valve parallel control \\ DCP & Direct-driven pump-controlled hydraulic system \\ DCV & Directional control valve \\ CDS & Combined drive system \\ HIMMs & Hydraulic injection molding machines \\ FC & Force control \\ EHVDPS & Electro-hydraulic variable-displacement pump system \\ LSC & Load-sensing control \\ CSPC & Constant supply pressure control \\ VDP & Variable-displacement pump \\ QD & Quick descent \\ B & Blanking \\ E & Expulsion \\ QR & Quick rise \\ TR & Table rotation \\ \end{tabular}   
**Nomenclature**  
The following mathematical symbols are used in this manuscript: