Hydraulic Cylinder Velocity Control With Energy Recovery: A Comparative Simulation Study

A valve configuration including a hydraulic accumulator for energy recovery is proposed for velocity control of hydraulic cylinders. A control design incorporating a low-level adaptive robust controller and high-level logic is presented. The benefits of independent cylinder pressure control, regeneration flows, and the proposed energy recovery system are compared. Simulation results show the proposed configuration provides significant energy savings compared to the other system configurations following the same velocity trajectory. An explanation of the advantages of the proposed configuration over previous configurations is given, showing why the proposed configuration makes increased recycling of system flows possible. Results for constant pressure source and a load-sensing pump show that different control objectives are appropriate for different supply pressure setups. Additional applications and further study of the proposed configuration are discussed.