System and method for simulated flywheel training

Abstract

A control system for simulating flywheel training includes processing circuitry. The processing circuitry is programmed to obtain sensor data indicating movement of an end effector of fitness equipment. The processing circuitry is also programmed to operate an electric motor of the fitness equipment, based on the movement of the end effector, to exert a force on the end effector. The force on the end effector is determined based on a result of a physics-based simulation of a virtual flywheel in order to provide a flywheel training experience for a user without requiring a flywheel physically coupled to the end effector.

What is claimed is: 
     
         1 . Fitness equipment, comprising:
 an electric motor;   a tensile member coupled with an output shaft of the electric motor;   an end effector coupled to the electric motor through the tensile member and configured for interaction with a user during performance of a flywheel training exercise by the user, wherein the electric motor is operable to provide a force to the end effector through the tensile member;   a sensor configured to obtain at least one of a position, a velocity, or an acceleration of the end effector; and   a controller programmed to cause the electric motor to operate to exert the force on the end effector during the interaction with the user by generating motor controls by simulating rotation of a virtual flywheel using the at least one of the position, the velocity, or the acceleration of the end effector.   
     
     
         2 . The fitness equipment of  claim 1 , wherein the controller is further programmed to:
 during a wind-out phase of the flywheel training exercise:
 determine a first force to be exerted on the end effector based on the acceleration of the end effector and a characteristic of a simulated flywheel using a first model of the simulated flywheel; 
 track a speed of the simulated flywheel; and 
 cause the electric motor to operate to exert the first force on the end effector, the first force exerted on the end effector in a direction opposing a first direction of motion of the end effector during the wind-out phase of the flywheel training exercise. 
   
     
     
         3 . The fitness equipment of  claim 2 , wherein the controller is further programmed to:
 during a wind-in phase of the flywheel training exercise:
 determine a second force to be exerted on the end effector based on a comparison between a speed of the end effector and the speed of the simulated flywheel using a second model of the simulated flywheel; and 
 cause the electric motor to operate to exert the second force on the end effector, the second force exerted on the end effector in the direction that is the same as a second direction of motion of the end effector during the wind-out phase of the flywheel training exercise and opposing a force exerted by the user on the end effector in the first direction. 
   
     
     
         4 . The fitness equipment of  claim 3 , wherein the second model of the simulated flywheel is different than the first model of the simulated flywheel, the second model comprising a monotonically increasing function of the comparison between the speed of the end effector and the speed of the simulated flywheel. 
     
     
         5 . The fitness equipment of  claim 1 , wherein the controller is further programmed to:
 determine whether to transition a simulator of a virtual flywheel out of a wind-out state corresponding to the wind-out phase of the flywheel training exercise and into a wind-in state corresponding to the wind-in phase of the flywheel training exercise responsive to at least one of (i) a position of the end effector exceeding a maximum allowable position corresponding to an end of the wind-out phase, or (ii) a simulated payout of the virtual flywheel returning to an intermediate position of the end effector after passing the maximum allowable position; and   determine whether to transition the simulator of the virtual flywheel out of the wind-in state and into the wind-out state responsive to at least one of (i) the position of the end effector being less than or equal to a minimum allowable position corresponding to an end of the wind-in phase, or (ii) a speed of the virtual flywheel being less than or equal to zero.   
     
     
         6 . The fitness equipment of  claim 1 , wherein the controller is programmed to implement a calibration phase before the flywheel training exercise by:
 operating a display screen of the fitness equipment to prompt the user to perform one or more repetitions of the flywheel training exercise;   record a first position of the end effector at which the end effector is fully retracted;   record a second position of the end effector at which the end effector is fully extended; and   use the first position and the second position of the end effector to transition a simulator of a virtual flywheel between a wind-out state corresponding to the wind-out phase of the flywheel training exercise and a wind-in state corresponding to the wind-in phase of the flywheel training exercise.   
     
     
         7 . The fitness equipment of  claim 1 , wherein the controller is programmed to:
 operate a user interface of the fitness equipment to prompt the user to enter a user input indicating a characteristic of a virtual flywheel for the flywheel training exercise; and   based on the characteristic of the virtual flywheel, cause the electric motor to operate to exert the force on the end effector during interaction with by the user to simulate the flywheel training exercise across both the wind-out phase and the wind-in phase of the flywheel training exercise.   
     
     
         8 . The fitness equipment of  claim 1 , further comprising a gearbox and a spool, wherein the output shaft of the electric motor is coupled with the gearbox, and the gearbox is coupled with the spool, the spool configured to take-up and let-out the tensile member responsive to movement of the end effector. 
     
     
         9 . A method of simulating a flywheel training exercise, the method comprising:
 providing exercise equipment comprising a motor and an end effector operably coupled with the motor;   obtaining a user input indicating a desired characteristic of a virtual flywheel, the desired characteristic determining an amount of resistance to be exerted on the end effector by the motor during the flywheel training exercise;   obtaining calibration data indicating a first position and a second position of the end effector corresponding to a range of motion of the flywheel training exercise;   during a wind-out phase in which the end effector is moved in a first direction, determining a first force to be exerted on the end effector using a simulation of a flywheel based on acceleration of the end effector, and operating the motor to exert the first force on the end effector; and   during a wind-in phase in which the end effector is moved in a second direction, determining a second force to be exerted on the end effector using the simulation of the flywheel based on speed of the end effector, and operating the motor to exert the second force on the end effector.   
     
     
         10 . The method of  claim 9 ,
 wherein determining the first force during the wind-out phase of the flywheel training exercise comprises determining the first force based on an acceleration of the end effector and the desired characteristic of the virtual flywheel; and   wherein determining the second force during the wind-in phase of the flywheel training exercise comprises determining the second force based on a monotonically increasing function of a difference between a speed of the end effector and a simulated speed of the virtual flywheel.   
     
     
         11 . The method of  claim 10 , wherein the simulated speed of the virtual flywheel is updated based on a previously determined simulated speed of the virtual flywheel and a force exerted by a user on the end effector. 
     
     
         12 . The method of  claim 9 , wherein the calibration data is obtained by at least one of:
 prompting a user to perform a repetition of the flywheel training exercise and recording the first position and the second position of the end effector;   predicting the first position and the second position of the end effector based on one or more characteristics of the user; or   predicting the first position and the second position of the end effector based on a first position and a second position of the end effector for a different exercise.   
     
     
         13 . The method of  claim 9 , further comprising:
 determining whether to transition the simulation of the virtual flywheel out of a wind-out state corresponding to the wind-out phase of the flywheel training exercise and into a wind-in state corresponding to the wind-in phase of the flywheel training exercise responsive to at least one of (i) a position of the end effector exceeding the first position, or (ii) a simulated payout of the virtual flywheel returning to an intermediate position of the end effector after passing the second position.   
     
     
         14 . The method of  claim 9 , further comprising:
 determining whether to transition the simulation of the virtual flywheel out of a wind-in state and into a wind-out state responsive to at least one of (i) the position of the end effector being less than or equal to a minimum allowable position corresponding to an end of the wind-out phase, or (ii) a speed of the virtual flywheel being less than or equal to zero.   
     
     
         15 . The method of  claim 9 , wherein the first force is determined in the wind-out phase during a concentric portion of a repetition of the flywheel training exercise, and the second force is determined in the wind-in phase during an eccentric portion of the repetition of the flywheel training exercise. 
     
     
         16 . The method of  claim 9 , wherein the speed of the end effector and the acceleration of the end effector are determined based on sensor data from a position sensor and inertial measurement data obtained from an inertial measurement unit positioned within the end effector. 
     
     
         17 . A control system for simulating flywheel training, the control system comprising:
 processing circuitry programmed to:
 obtain sensor data indicating movement of an end effector of fitness equipment; and 
 operate an electric motor of the fitness equipment, based on the movement of the end effector, to exert a force on the end effector, the force on the end effector determined based on a result of a physics-based simulation of a virtual flywheel in order to provide a flywheel training experience for a user without requiring a flywheel physically coupled to the end effector. 
   
     
     
         18 . The control system of  claim 17 , wherein a size of the virtual flywheel for the physics-based simulation is user adjustable to adjust a behavior of the virtual flywheel and the force exerted on the end effector responsive to movement of the end effector. 
     
     
         19 . The control system of  claim 17 , wherein the processing circuitry is further programmed to:
 prior to the operation of the electric motor to simulate the flywheel training experience, operate a display screen of the fitness equipment to prompt the user to perform a plurality of repetitions of the flywheel training exercise with the end effector;   record minimum and maximum positions of the end effector while performing the plurality of repetitions; and   implement the physics-based simulation of the virtual flywheel using the minimum and maximum positions to determine when to transition between a wind-in state and a wind-out state of the virtual flywheel.   
     
     
         20 . The control system of  claim 17 , wherein the sensor data comprises position data obtained from a position sensor operably coupled with an output shaft of the electric motor, wherein the movement of the end effector comprises a speed and an acceleration of the end effector, the speed and the acceleration of the end effector determined by the processing circuitry using numerical differentiation of the position data and a filter. 
     
     
         21 . One or more non-transitory computer-readable media storing program instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:
 obtain data indicating movement of an end effector of fitness equipment;   determine a target force for a motor of the fitness equipment by:
 during a first phase of an exercise, determining the target force based on an acceleration of the end effector; and 
 during a second phase of the exercise, determining the target force based on a simulated speed of a virtual mass; and 
   control the motor based on the target force.   
     
     
         22 . The one or more non-transitory computer-readable media of  claim 21 , wherein the virtual mass is a virtual flywheel.