Relative Position Control in an Electro-Hydraulic Forklift

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The purpose of this research is to utilize the excellent control capabilities of modern electric drives in electro-hydraulic systems such as forklifts, create direct drive position control for the forklift fork and verify the results by measurements. The drive consists of a Direct Torque Control (DTC) electric servo motor directly running a reversible hydraulic pump. The position of a hydraulic cylinder is controlled by a Permanent Magnet Synchronous Machine (PMSM) drive with a single feedback from motor rotor angle resolver. A fairly accurate lifting height sensorless control could be used e.g. as a base for a new automatic warehouse system. The system equipped with e.g. a simple proximity switch should be able to serve as an automated height control system for a warehouse.
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Permanent Magnet Machines; Energy Efficiency; Energy Recovery; Forklift; Electric Servo Drive; Hydraulics; Position Control; Potential Energy Regeneration (PERS)

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