On Demand Displacement Control of Hydraulic Power System

摘要

A method and apparatus for controlling a hydraulic power system is provided that includes a hydraulic motor and a hydraulic pump configured to supply hydraulic fluid to the hydraulic motor. A relief valve is provided that is configured to release hydraulic fluid from a location between the hydraulic pump and the hydraulic motor when a pressure of the hydraulic fluid exceeds a predetermined relief pressure. Above a predetermined threshold pressure for the system, the displacement of the pump is adjusted to at least a minimum displacement that is based on a total demanded flow for the system that includes a desired flow of hydraulic fluid across the relief valve and a first hydraulic fluid flow consumed by the motor.