Closed-loop power dissipation control for cardio-fitness equipment

Abstract

Various embodiments of the present invention provide (a) an inexpensive apparatus enabling the measurement of power dissipated by the rider of a cardio-fitness station (or any other stationary bicycle) that does not depend on manufacturing tolerances or machine condition variations, and (b) a method of using the data measured by such an apparatus to improve the accuracy of exercise condition settings by implementing the invented apparatus into a closed-loop control system which improves the quality of the exercise experience and enhances the adoption of exercise on a cardio-fitness station employing this as a community activity.

1 . A system, comprising:
 a computer running a computer program;   a video monitor in communication with the computer;   a stationary exercise equipment including steerable handlebars and pedals, wherein the pedals are able to rotate around a first axis, the rotation of the pedals providing a first electrical signal to the computer;   a flywheel comprising conductive material, the flywheel able to rotate around a second axis, wherein the flywheel is mechanically coupled to the pedals such that pedal rotation causes flywheel rotation;   a first electromagnet mounted in proximity to the flywheel, the first electromagnet fixed to the stationary bicycle;   an electrical power supply coupled to the first electromagnet, the electrical power supply configured to deliver electric current to the electromagnet, wherein the magnitude of the electric current is controlled by the computer program; and   a torque-measuring module mechanically coupled to the pedals, the torque-measuring module measuring the torque exerted by pedals around the first axis, the torque-measuring module providing a second electrical signal to the computer;   wherein the first and the second electrical signals are used by the computer program to adjust the electrical current to the first electromagnet.   
   
   
       2 . The system of  claim 1 , wherein:
 the stationary bicycle further includes a heart-rate monitor, wherein the heart-rate monitor communicates electronically with the computer.   
   
   
       3 . The system of  claim 1 , wherein:
 the steerable handlebars are steered by the rider of the stationary exercise equipment,   wherein the steerable handlebars are mechanically coupled to a third electrical sensor and the third electrical sensor provides a third electrical signal to the computer when the steerable handlebars are steered.   
   
   
       4 . The system of  claim 1 , wherein:
 the computer program, upon execution by the computer, simulates a virtual bicycle riding through a computer simulated virtual landscape, wherein forward motion of the virtual bicycle through the computer simulated virtual landscape is controlled responsive to at least the first electrical signal, and the direction of the virtual bicycle within the computer simulated virtual landscape is determined responsive to the third electrical signal.   
   
   
       5 . The system of  claim 1 , further comprising:
 a second electromagnet mounted in the proximity of the flywheel, wherein the second electromagnet is fixed to the stationary exercise equipment.   
   
   
       6 . The system of  claim 1 , further comprising:
 a gear-shifting member fixed to the stationary bicycle, the motion of the gear-shifting member providing a fourth electrical signal to the computer; and   the first, the second, and the fourth electrical signals are used by the computer to adjust the magnitude of the electric current.   
   
   
       7 . The system of  claim 6 , further wherein:
 the first, the second, and the fourth electrical signals are used by the computer to adjust the magnitude of torque exerted by the pedals around the first axis; and   the magnitude of torque exerted by the pedals around the first axis is adjusted to a value determined by the computer depending on the motion of a virtual bicycle riding through a computer simulated virtual landscape.   
   
   
       8 . The system of  claim 1 , wherein the torque-measuring module comprises a strain gauge. 
   
   
       9 . A method of power level control, the method comprising:
 receiving a request indicating a a target power level;   determining a current power level based on identifying one or more of torque exerted on a flywheel and an angular velocity of the flywheel; and   adjusting an electric current to change a resistance to movement of the flywheel;   wherein the electric current is adjusted based on a difference between the target power level and the current power level; and   recomputing an updated current power level and adjusting the electric current such that the updated current power level substantially approaches the target power level.   
   
   
       10 . A machine-readable medium embodying instructions, the instructions, which when executed, causing a machine to perform a method comprising:
 receiving a request indicating a a target power level;   determining a current power level based on identifying one or more of torque exerted on a flywheel and an angular velocity of the flywheel;   adjusting an electric current to change a resistance to movement of the flywheel;   wherein the electric current to be adjusted based on a difference between the target power level and the current power level; and   recomputing an updated current power level and adjusting the electric current such that the updated current power level substantially approaches the target power level.   
   
   
       11 . A stationary exercise equipment, comprising:
 a frame;   a seat;   pedals, the pedals being able to rotate around an axis;   a magnetic resistance device including an electromagnet, the magnetic resistance device providing resistance to rotation of the pedals around the axis when the electromagnet is energized with an electric current; and   a torque-measuring device mechanically attached to and between the pedals and the magnetic resistance device, wherein the torque-measuring device provides a measure of torque exerted by the pedals around the axis.   
   
   
       12 . The stationary exercise equipment of  claim 11 , wherein:
 the measure of torque exerted on the pedals around the axis is used to adjust the electric current.   
   
   
       13 . The stationary exercise equipment of  claim 11 , wherein:
 the torque-measuring device comprises a magnetoelastic torque sensor.   
   
   
       14 . The stationary exercise equipment of  claim 12 , wherein:
 the torque-measuring device comprises a piezo-electric transducer.