Passive programmable resistance device

Claim 2

A programmable resistance device comprising; (a) a hydraulic cylinder; (b) a piston mounted in said cylinder for movement by a force applied to the piston; (c) a control valve for controlling the flow of hydraulic fluid from said cylinder as said piston moves and thereby controlling the amount of resistance provided to movement of the piston; (d) means for measuring the pressure in said cylinder to provide a first output which is a function of force applied to said piston; (e) means for providing a second output which is a function of the position of the piston; (f) drive means for controlling said valve; and (g) programmable means having as inputs said first and second outputs and providing a third output coupled as a control input to said drive means, said programmable means including means to store an array of desired force values versus position; means responsive to said second output to select one of the stored values of force for comparison; and means to compare said selected value with said first output and to provide said third output in accordance with the difference therebetween.

Claim 3

The device of claim 1 where said drive means comprises a stepper motor.

Claim 4

The device of claim 1 wherein said drive means comprises a stepper motor which rotates in response to said control input to increase or decrease the rate at which hydraulic fluid flows out of said hydraulic cylinder.

Claim 5

A programmable resistance device comprising: (a) a hydraulic cylinder; (b) a piston mounted in said cylinder for movement by a force applied to the piston; (c) a control valve for controlling the fIow of hydraulic fluid from said cylinder as said piston moves and thereby controlling the amount of resistance provided to movement of the piston; (d) means for measuring the pressure in said cylinder to said piston; (e) means for providing a second output which is a function of the position of the piston; (f) drive means for controlling said valve; and (g) programmable means having as inputs said first and second outputs and providing a third output coupled as a control input to said drive means, said programmable means including means to store an array of desired velocity values as a function of position; means to derive from said second output a signal representative of velocity; means to select one of said stored values as a function of said second output; and means to compare said selected value with said signal and to provide a control output in accordance with the difference therebetween.

Claim 6

A programmable resistance device comprising: (a) a hydraulic cylinder; (b) a piston mounted in said cylinder for movement by a force applied to the piston; (c) a control valve for controlling the fIow of hydraulic fluid from said cylinder as said piston moves and thereby controlling the amount of resistance provided to movement of the piston; (d) means for measuring the pressure in said cylinder to said piston; (e) means for providing a second output which is a function of the position of the piston; (f) drive means for controlling said valve; and (g) programmable means having as inputs said first and second outputs and providing a third output coupled as a control input to said drive means, said programmable means including means to store an array of desired velocity values as a function of position; means to derive from said second output a signal representative of velocity; means to select one of said stored values as a function of said second output; and means to compare said selected value with said signal and to provide a control output in accordance with the difference therebetween.

Claim 7

A programmable resistance device comprising; (a) a hydraulic cylinder; (b) a piston mounted in said cylinder for movement by a force applied to the piston; (c) a control valve for controlling the flow of hydraulic fluid from said cylinder as said piston moves and thereby controlling the amount of resistance provided to movement of the piston; (d) means for measuring the pressure in said cylinder to provide a first output which is a function of force applied to said piston; (e) means for providing a second output which is a function of the position of the piston; (f) drive means for controlling said valve; and (g) programmable means having as inputs said first and second outputs and providing a third output coupled as a control input to said drive means, said programmable means including means to store an array of desired acceleration values as a function of position; means to derive from said second output a signal representative of acceleration; means to select one of said stored values as a function of said second output; and means to compare said selected value with said signal and to provide a control output in accordance with the difference therebetween.

Claim 8

A programmable resistance device comprising; (a) a hydraulic cylinder; (b) a piston mounted in said cylinder for movement by a force applied to the piston; (c) a control valve for controlling the flow of hydraulic fluid from said cylinder as said piston moves and thereby controlling the amount of resistance provided to movement of the piston; (d) means for measuring the pressure in said cylinder to provide a first output which is a function of force applied to said piston; (e) means for providing a second output which is a function of the position of the piston; (f) drive means for controlling said valve; and (g) programmable means having as inputs said first and second outputs and providing a third output coupled as a control input to said drive means, said programmable means including means to store an array of desired acceleration values as a function of position; means to derive from said second output a signal representative of acceleration; means to select one of said stored values as a function of said second output; and means to compare said selected value with said signal and to provide a control output in accordance with the difference therebetween.