Determination of Load Collective for Sizing of a Hydraulic Drive Network System Considering Simultaneity Between Actuator Loads

Designing and sizing the drive system for a multi-actuator machine controlled by a human driver, the drive system requirements are difficult to define. In this case it may be most sensible to size the drive system based on measurements from an existing and similar machine in the same size class, but possibly with a different drive topology. However, this poses two main challenges. First, the measurements likely contain dynamics from interactions with the surroundings. Secondly, the measured motion is influenced by the drive characteristics of the test machine as well as imperfect driver control by the human driver.

This paper proposes a method for determination of a load collective for design and sizing of an electro-hydraulic variablespeed drive network (VDN), seeking to account for the aforementioned effects by modifying measurements to create design load cycles constituting a load collective, while obtaining equal maximum actuator forces and speeds. The method is applied for the case of a knuckle boom crane, showcasing a significant impact on drive system size. This demonstrates the significance of properly defining a load collective when designing and sizing drive network systems.