Control of an Energy Efficient Hydraulic Cylinder Drive with Multiple Pressure Lines

Abstract

This paper concerns a novel energy efficient hydraulic cylinder drive concept, consisting of three pressure lines used to supply a hydraulic cylinder(s). The proposed concept allows for reduced throttling losses compared to conventional solutions, while maintaining accurately cylinder control. One application where the concept shows great potential is as the actuation system for life tests of large mechanical structures, where structure deflections is made through cylinder force control. This work contributes to the development and control of this hydraulic concept, where the purpose is to obtain a high energy efficiency and an accurate cylinder force control. The final concept design is implemented in simulation models, where the performance of the developed control system is investigated to verify that the control performance is satisfactory. Furthermore, the energy efficiency is compared to a conventional hydraulic concept to verify the feasibility. Through simulation models, control performance similar to a conventional hydraulic concept has been obtained with the proposed control structure, while reducing the hydraulic energy consumption by up to 50 %. Based on the findings in this paper it is assessed that the concept is ready for experimental validation.

Energy Efficient Drive System With Digital Hydraulic Cylinder for Construction and Agricultural Machinery

“…Pedersen proposed an energy-efficient hydraulic cylinder concept with three pressure lines, which allows reducing throttling losses compared to conventional solutions while maintaining accuracy and control. The final design of the concept was implemented in simulation models to investigate the performance of the developed control system (Pedersen et al, 2018).…”

Energy efficient throttling control of a multi-pressure system using a genetic algorithm and model predictive control

“…Some researchers 12–14 have utilised the multi-pressure concept along with multi-chamber cylinders to improve the force resolution and to decrease switching losses by adding a medium pressure line. Furthermore, Pedersen et al 18 have presented a force control application, where a standard two-chamber cylinder is fed from three pressure lines. A three-pressure system capable of throttling control, called STEAM, has been studied by Vukovic and colleagues.…”