Efficient actuation is an important requirement in electromechanical designs. Although hydraulic actuators are used extensively when high-magnitude forces are present in heavy machinery, they are not very energy-efficient. This paper aims to increase the efficiency of electro-hydraulic servo systems after introducing a controllable supply pressure and six mode of operation for different condition. This process allows for the system to have very low energy consumption whenever its environmental force agrees with its position reference signal. For this purpose, first, the electrohydraulic servo systems is modeled and a robust H∞ controller is designed for each mode of operation. The resulting control system works based on applying each mode strategy at right time to save energy. The effectiveness of this method is tested by conducting experiments on a hydraulic test rig and presenting the experimental results.
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