Exercise apparatus with automatically adjustable foot motion

Abstract

An elliptical exercise apparatus includes a frame, a pair of footpads, and a linkage coupling the footpads to the frame and for guiding the footpads in closed paths when a user's feet apply forces to the footpads. The linkage, which includes a rotatable member having an angular position indicative of the positions of the footpads within their closed paths, responds to input control signals by adjusting length and height dimensions of the closed paths. A control system senses the angular position of the rotatable member, senses the forces the user applies to the footpads, and generates the control signals to increase or decrease the path dimensions when it senses particular combinations of angular position and user forces, thereby permitting the user to control the path dimensions by controlling the forces applied to the footpads.

1 . An exercise apparatus comprising:
 a frame;   a footpad for supporting a user's foot;   a linkage for coupling the footpad to the frame and for guiding the footpad in a closed path in response to a force applied to the footpad by the user's foot, the linkage including a rotatable member having an angular position indicative of a position of the footpad within the closed path, wherein the linkage adjusts a dimension of the closed path in response to an electrical control signal supplied as input to the linkage; and   a control system for monitoring the angular position of the rotatable member, for monitoring the force applied to the footpad, and for generating the control signal such that the linkage adjusts the dimension as a function of the monitored force on the footpad and of the angular position of the rotatable member.   
     
     
         2 . The exercise apparatus in accordance with  claim 1  wherein the control system generates the control signal to cause the linkage to increase and decrease the path dimension when it senses particular combinations the force and the angular position, thereby permitting the user to control the path dimension by controlling the force applied to the footpad. 
     
     
         3 . The exercise apparatus in accordance with  claim 2   wherein the control system controls the control signal such that the linkage alters the dimension when a magnitude of the force is outside a magnitude range while the angular position of the rotatable member is within a position range,   such that the linkage refrains from adjusting the dimension when the magnitude of the force is outside the magnitude range, and   such that the linkage refrains from adjusting the dimension when the angular position of the rotatable member is outside the position range.   
     
     
         4 . The exercise apparatus in accordance with  claim 1  further comprising:
 a strain gauge coupled between the footpad and the linkage for generating a force indicating signal indicative of the magnitude of the force, 
 wherein the control system monitors the force by monitoring the force indicating signal. 
 
     
     
         5 . The exercise apparatus in accordance with  claim 1  wherein the force and the dimension are in substantially parallel directions. 
     
     
         6 . The exercise apparatus in accordance with  claim 1  wherein the control system monitors the force by monitoring a rotational velocity of the rotatable member, and based on the monitored rotational velocity, determining a rotational acceleration of the rotatable member that is indicative of the magnitude of the force when the angular position of the rotatable member is within the position range. 
     
     
         7 . The exercise apparatus in accordance with  claim 1  wherein the dimension of the closed path defines a stride length of the user's foot. 
     
     
         8 . The exercise apparatus in accordance with  claim 1  wherein the dimension of the closed path defines a stride height of the user's foot. 
     
     
         9 . An exercise apparatus comprising
 a frame;   a footpad for supporting a user's foot;   a linkage for coupling the footpad to the frame and for guiding the footpad in a closed path in response to first and second forces applied in first and second directions, respectively, to the footpad by the user's foot, wherein the linkage includes a rotatable member having an angular position that changes with a position of the footpad within the closed path, and wherein the linkage adjusts first and second dimensions of the closed path in response to electrical control signals supplied as inputs to the linkage; and   a control system for monitoring the angular position of the rotatable member, for monitoring magnitudes of first and second forces, and for generating the control signals such that the linkage adjusts the first and second dimensions as functions of the monitored first and second forces and of the monitored angular position of the rotatable member.   
     
     
         10 . The exercise apparatus in accordance with  claim 9  wherein the control signals cause the linkage to increase and decrease the path dimensions when it senses particular combinations of the angular position and first and second forces, thereby permitting the user to control the path dimensions by controlling the force applied to the footpad. 
     
     
         11 . The exercise apparatus in accordance with  claim 10   wherein the control system controls the first and second control signals such that the linkage alters the first dimension when a magnitude of the first force is outside a first magnitude range while the angular position of the rotatable member is within a first position range, such that the linkage refrains from adjusting the first dimension when the magnitude of the first force is outside the first magnitude range, and such that the linkage refrains from adjusting the first dimension when the angular position of the rotatable member is outside the first position range, and   such that the linkage alters the second dimension when a magnitude of the second force is outside a second magnitude range while the angular position of the rotatable member is within a second position range, such that the linkage refrains from adjusting the second dimension when the magnitude of the second force is outside the second magnitude range, and such that the linkage refrains from adjusting the second dimension when the angular position of the rotatable member is outside the second position range.   
     
     
         12 . The exercise apparatus in accordance with  claim 9  further comprising:
 a first strain gauge coupled between the footpad and the linkage for generating a first force indicating signal indicative of the magnitude of the first force, and 
 a second strain gauge coupled between the footpad and the linkage for generating a second force indicating signal indicative of the magnitude of the second force, 
 wherein the control system monitors the first and second forces by monitoring the first and second force indicating signals. 
 
     
     
         13 . The exercise apparatus in accordance with  claim 9  wherein the first dimension of the closed path defines a stride length of the user's foot, and
 wherein the second dimension of the closed path defines a stride height of the user's foot. 
 
     
     
         14 . A method for controlling an exercise apparatus having a frame, a footpad for supporting a user's foot, and a linkage for coupling the footpad to the frame and for guiding the footpad in a closed path in response to a force applied to the footpad by the user's foot, wherein the linkage includes a rotatable member having an angular position that changes with a position of the footpad within the closed path, and wherein the linkage adjusts a dimension of the closed path in response to an electrical control signal supplied as input to the linkage, the method comprising the steps of
 a. monitoring the angular position of the rotatable member,   b. monitoring a magnitude of the force, and   c. controlling the control signal such that the linkage adjusts the dimension as a function of the monitored force on the footpad and of the monitored angular position of the rotatable member.   
     
     
         15 . The method in accordance with  claim 14  wherein the control signals cause the linkage to increase and decrease the path dimension when it senses particular combinations of the monitored angular position and the monitored force, thereby permitting the user to control the path dimension by controlling the force applied to the footpad. 
     
     
         16 . The method in accordance with  claim 14   wherein the exercise apparatus includes a strain gauge coupled between the footpad and the linkage for generating a force indicating signal indicative of the magnitude of the force, and   wherein step b comprises monitoring the force indicating signal.   
     
     
         17 . The method in accordance with  claim 14   wherein step c comprises controlling the control signal   such that the linkage alters the dimension when a magnitude of the force is outside a magnitude range while the angular position of the rotatable member is within a position range,   such that the linkage refrains from adjusting the dimension when the magnitude of the force is outside the magnitude range, and   such that the linkage refrains from adjusting the dimension when the angular position of the rotatable member is outside the position range.   
     
     
         18 . The method in accordance with  claim 17  wherein the force and the dimension are in substantially parallel directions. 
     
     
         19 . The method in accordance with  claim 14  wherein step b comprises the substeps of:
 b1. monitoring a rotational velocity of the rotatable member, and 
 b2. based on the monitored rotational velocity, determining a rotational acceleration of the rotatable member indicative of the magnitude of the force when the angular position of the rotatable member is within the position range. 
 
     
     
         20 . The exercise apparatus in accordance with  claim 14  wherein the dimension of the closed path defines a stride length of the user's foot. 
     
     
         21 . The method in accordance with  claim 14  wherein the dimension of the closed path defines a stride height of the user's foot. 
     
     
         22 . A method for controlling an exercise apparatus having a frame, a footpad for supporting a user's foot, and a linkage for coupling the footpad to the frame and for guiding the footpad in a closed path in response to first and second forces applied in differing directions to the footpad by the user's foot, wherein the linkage includes a rotatable member having an angular position that changes with a position of the footpad within the closed path, and wherein the linkage adjusts first and second dimensions of the closed path in response to a plurality of electrical control signals supplied as inputs to the linkage, the method comprising the steps of
 a. monitoring the angular position of the rotatable member,   b. monitoring magnitudes of first and second forces, and   c. controlling the control signals such that the linkage adjusts the first and second dimensions as functions of the monitored first and second forces and the monitored angular position of the rotatable member.   
     
     
         23 . The method in accordance with  claim 22  wherein the control signals cause the linkage to increase and decrease the path dimensions when it senses particular combinations of the monitored angular position and first and second forces, thereby permitting the user to control the path dimensions by controlling the force applied to the footpad. 
     
     
         24 . The method in accordance with  claim 22   wherein the exercise apparatus includes a first strain gauge coupled between the footpad and the linkage for generating a first force indicating signal indicative of the magnitude of the first force,   wherein the exercise apparatus includes a second strain gauge coupled between the footpad and the linkage for generating a second force indicating signal indicative of the magnitude of the second force, and   wherein step b comprises monitoring the first and second force indicating signals.   
     
     
         25 . The method in accordance with  claim 22   wherein step c comprises controlling the first and second control signal   such that the linkage alters the first dimension when a magnitude of the first force is outside a first magnitude range while the angular position of the rotatable member is within a first position range, such that the linkage refrains from adjusting the first dimension when the magnitude of the first force is outside the first magnitude range, and such that the linkage refrains from adjusting the first dimension when the angular position of the rotatable member is outside the first position range, and   such that the linkage alters the second dimension when a magnitude of the second force is outside a second magnitude range while the angular position of the rotatable member is within a second position range, such that the linkage refrains from adjusting the second dimension when the magnitude of the second force is outside the second magnitude range, and such that the linkage refrains from adjusting the second dimension when the angular position of the rotatable member is outside the second position range.   
     
     
         26 . The method in accordance with  claim 22  wherein the first and second forces are applied to the footpad in substantially orthogonal directions. 
     
     
         27 . The method in accordance with  claim 22  wherein the first and second dimensions are in substantially orthogonal directions. 
     
     
         28 . The method in accordance with  claim 22  wherein the first dimension of the closed path defines a stride length of the user's foot, and
 wherein the second dimension of the closed path defines a stride height of the user's foot. 
 
     
     
         29 . An exercise apparatus comprising:
 a frame,   a right footpad for supporting a user's right foot,   a left footpad for supporting the users left foot,   a linkage for coupling the right and left footpads to the frame and for guiding the right and left footpads in a closed pats in response to forces applied to the right and left footpads by the user's right and left feet, the linkage including a rotatable member having an angular position indicative of positions of the right and left footpads within their closed paths, wherein the linkage adjusts dimensions of the closed paths of the right and left footpads in response to electrical control signals supplied as inputs to the linkage, and   a control system for monitoring the angular position of the rotatable member, for monitoring the forces applied to the right and left footpads, and for generating the control signals such that the linkage adjusts at least one dimension of the right footpad as a function of monitored force on the right footpad and of the angular position of the rotatable member, and independently adjusts at least one dimension of the left foot pad as a function of monitored force on the left footpad and of the angular position of the rotatable member.   
     
     
         30 . The exercise apparatus in accordance with  claim 29  wherein the control system generates the control signals to cause the linkage to increase and decrease the path dimensions of the right and left footpads when it senses particular combinations the angular position and the monitored forces, thereby permitting the user to independently control the dimensions of the paths followed by the right and left footpads by controlling the forces applied to the right and left footpads. 
     
     
         31 . The exercise apparatus in accordance with  claim 30   wherein the control system controls the control signals such that the linkage alters the dimension of the closed path of the right footpad when a magnitude of the force on the right footpad is outside a first magnitude range while the angular position of the rotatable member is within a first position range and otherwise refrains from adjusting the dimension of the closed path of the right footpad; and   such that the linkage alters the dimension of the closed path of the left footpad when a magnitude of the force on the left footpad is outside a second magnitude range while the angular position of the rotatable member is within a second position range and otherwise refrains from adjusting the dimension of the closed path of the left footpad,   
     
     
         32 . A method for controlling an exercise apparatus having
 a frame,   a right footpad for supporting a user's right foot,   a left footpad for supporting the users left foot, and   a linkage for coupling the right and left footpads to the frame and for guiding the right and left footpads in a closed pats in response to forces applied to the right and left footpads by the user's right and left feet, the linkage including a rotatable member having an angular position indicative of positions of the right and left footpads within their closed paths, wherein the linkage adjusts dimensions of the closed paths of the right and left footpads in response to electrical control signals supplied as inputs to the linkage,   the method comprising the steps of   a. monitoring the angular position of the rotatable member,   b. monitoring the forces applied to the right and left footpads, and   c. generating the control signals such that the linkage adjusts at least one dimension of the right footpad as a function of monitored force on the right footpad and of the angular position of the rotatable member, and independently adjusts at least one dimension of the left foot pad as a function of monitored force on the left footpad and of the angular position of the rotatable member.   
     
     
         33 . The method in accordance with  claim 1  wherein the control signals cause the linkage to increase and decrease the path dimensions of the right and left footpads when in response to particular combinations the angular position and the monitored forces, thereby permitting the user to independently control the dimensions of the paths followed by the right and left footpads by controlling the forces applied to the right and left footpads. 
     
     
         34 . The method in accordance with  claim 33   wherein the control signals cause the linkage alter the dimension of the closed path of the right footpad when a magnitude of the force on the right footpad is outside a first magnitude range while the angular position of the rotatable member is within a first position range and otherwise to refrain from adjusting the dimension of the closed path of the right footpad, and   wherein the control signals cause the linkage alter the dimension of the closed path of the left footpad when a magnitude of the force on the left footpad is outside a second magnitude range while the angular position of the rotatable member is within a second position range and otherwise to refrain from adjusting the dimension of the closed path of the left footpad.