US 12,068,704 B2
Method and system for controlling a free piston mover
Samuel Edward Cockerill, York (GB); and Matthew Viele, Florissant, CO (US)
Assigned to Libertine FPE Ltd, York (GB)
Appl. No. 17/416,214
Filed by LIBERTINE FPE LTD, York (GB)
PCT Filed Dec. 20, 2019, PCT No. PCT/GB2019/053667
§ 371(c)(1), (2) Date Jun. 18, 2021,
PCT Pub. No. WO2020/128515, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 1821016 (GB), filed on Dec. 21, 2018.
Prior Publication US 2022/0085743 A1, Mar. 17, 2022
Int. Cl. G05B 13/04 (2006.01); H02K 7/18 (2006.01); H02P 25/06 (2016.01)
CPC H02P 25/06 (2013.01) [G05B 13/042 (2013.01); H02K 7/1884 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method of controlling a Free Piston Mover, the method comprising the steps of:
generating a Control Parameter Set for closed loop control of a Target Control Variable, this set comprising a Target Control Variable Function together with one or more of:
a Stroke Threshold Function;
a Feed Forward Current Function;
a Feedback Terms Function;
Control Parameter Set Transition Conditions;
transmitting the Control Parameter Set to an In-Stroke Controller in advance of the start of a Stroke to be controlled;
modifying one or more of the constituents of the Control Parameter Set for any-Future Stroke of the Free Piston Mover using a Future-Stroke Controller;
transmitting the modified Control Parameter Set to the In-Stroke Controller for the control of any Future Stroke;
sampling a Base Variable indicative of Free Piston Mover performance during a Stroke following the generation of the Control Parameter Set;
generating at least one Target Control Variable using the measured Base Variable with reference to a Target Control Variable Function;
determining at least one Control Variable Error using the measured Control Variable and the Target Control Variable;
generating a Current Demand output which is input to a Current Controller using the Control Variable Error;
sampling a second Base Variable indicative of a second Free Piston Mover performance;
generating at least one second Target Control Variable using the measured second Base Variable with reference to a second Target Control Variable Function;
determining at least one second Control Variable Error using the measured second Control Variable and the second Target Control Variable;
generating a Current Demand output which is input to a second Current Controller using the second Control Variable Error; and
modifying the second Target Control Variable Function for a future stroke of the Free Piston Mover using a Future-Stroke Controller which may affect the next stroke or any future stroke.