Movement simulator

A movement-simulator, comprising:

• at least one support frame;
• a subframe movable relative to the support frame;
• a variable element having a first end connected to the support frame and a second end connected to the subframe;
• first and second acceleration transducers, the first acceleration transducer attached to the second end of the variable element, the second acceleration transducer attached between the first and second ends of the variable element, the first and second acceleration transducers being aligned in space;
• a first difference circuit electrically connected to the first and second acceleration transducers, the first and second acceleration transducers producing output signals generated with respect to an effective mass, said acceleration signals which are received by said first difference circuit, wherein the output signals are subtracted from each other for forming an acceleration signal;
• a correction circuit electrically connected to the first difference circuit, the correction circuit receiving the acceleration signal from the difference circuit;
• a computer electrically connected to the correction circuit for controlling the correction circuit;
• a second difference circuit electrically connected to the correction circuit and the computer, such that output from the correction circuit is received by the second difference circuit and output of a nominal acceleration from the computer is received by the second difference circuit;
• and
• a first integrator electrically connected to the second difference circuit and to the variable element for converting output from the second difference circuit to a velocity signal and for providing the velocity signal to control the variable element.

A movement-simulator, comprising:

• at least one support frame;
• at least one hydraulic cylinder having a cylinder housing, a plunger, and a piston, the plunger having first and second ends, the piston attached to the second end of the plunger, the cylinder housing having top and bottom ends, the bottom end of the cylinder housing connected to the support frame;
• a subframe connected to the first end of the plunger of the hydraulic cylinder;
• a position transducer attached to the cylinder housing;
• a first acceleration transducer connected to the first end of the plunger;
• a second acceleration transducer connected to a lateral surface of the cylinder housing at the top end, the first and second acceleration transducers being aligned in space;
• a first difference circuit electrically connected to the first and second acceleration transducers;
• a correction circuit electrically connected to the first difference circuit for receiving output from the first difference circuit;
• a computer electrically connected to the correction circuit for controlling the correction circuit;
• a second difference circuit electrically connected to the correction circuit for receiving output from the correction circuit, the second difference circuit electrically connected to the computer for receiving a nominal acceleration signal from the computer;
• a multiplier electrically connected to the correction circuit and the computer for receiving and multiplying an actual acceleration signal from the correction circuit and an actual effective mass from the computer;
• a first integrator electrically connected to the correction circuit for receiving the actual acceleration signal from the correction circuit;
• a second integrator electrically connected to the first integrator for receiving a velocity signal from the first integrator;
• a third difference circuit electrically connected to the second integrator for receiving a position signal from the second integrator, and to the position transducer for receiving a position signal;
• a summing circuit electrically connected to the third difference circuit for providing an acceleration signal, the summing circuit electrically connected to the first integrator for receiving a velocity signal from the first integrator, the summing circuit electrically connected to the second difference circuit for receiving a position signal from the second difference circuit, the summing circuit electrically connected to the multiplier for receiving an acceleration signal from the multiplier;
• and
• a control valve attached to the lateral surface at the bottom end of the cylinder housing to the hydraulic cylinder, the control valve electrically connected to the summing circuit for providing a control signal from the summing circuit to the control valve.