An example of Linear Generator motored compression ratio testing at our facilities in Sheffield, using Libertine's intelliGEN platform.

In this video a single-cylinder opposed free piston module is motored from compression ratio 9:1 through to 24:1 and back down.

Throughout this test, Libertine's software maintains tight piston synchronisation by making fine cycle-by-cycle adjustments to the target motion profile of each mover. These changes compensate in real-time for subtle differences in the build and operation of each of the two linear electrical machines and their respective bounce chambers.

The result: Very tight compression ratio control (coefficient of variation is significantly less than 1%) and near-zero vibration. Despite the fact that during every cycle each of the bounce chambers generate well over a tonne of gas force using stored energy from the expansion stroke to return the movers back towards the centre of the machine on the compression stroke, synchronisation ensures these forces cancel out, and our tell-tale coin remains standing.