Free piston assembly and method for controlling a free piston assembly

A free piston assembly comprising:

• at least one piston accommodating device;
• at least one piston device having a first piston surface and a second piston surface facing away from said first piston surface which is moveable in a linear manner in the corresponding piston accommodating device;
• an expansion space which is arranged in the piston accommodating device and delimited by the first piston surface;
• wherein the piston device is arranged to be driven by the action of a medium which expands in the expansion space;
• a resilience space arranged in the at least one piston accommodating device, said resilience space being delimited by the second piston surface;
• wherein the resilience space is connected to at least one pre-compression chamber in fluidic manners;
• and
• at least one linearly moveable active element that is connected to the piston device;
• wherein the at least one piston accommodating device comprises a side from which there is guided out the at least one linearly moveable active element;
• wherein the at least one active element is guided through the at least one pre-compression chamber;
• wherein at least one channel, which has a first opening and a second opening, is arranged on the at least one active element;
• wherein the position of the first opening and the second opening in relation to the resilience space and a pre-compression space of the pre-compression chamber is dependent on the position of the at least one active element;
• and
• wherein the pre-compression space and the resilience space are connected together in fluidic manner via the channel in one or more positions of the piston device.