Rowing exercise machines having a configurable rowing feel
Among other things, a rowing exercise machine includes a movable inertial element, an eddy current brake coupled to the movable inertial element, a rowing grip coupled to the movable inertial element, and control circuitry coupled to the eddy current brake to cause a resistance to motion of the rowing grip during part of a rowing stroke. The resistance to motion of the rowing grip during the drive phase of the rowing stroke conforms to a target feel for a rower. The target feel corresponds to a feel for a rower of a target other rowing exercise machine or other target feel of interest.
1. Two or more rowing exercise machines, each of the rowing exercise machines comprising
a movable inertial element,
an eddy current brake coupled to the movable inertial element,
a rowing grip coupled to the movable inertial element, and
control circuitry coupled to the eddy current brake and comprising a control loop to cause a resistance to motion of the rowing grip during a drive phase of the rowing stroke to track a target resistance to motion of the rowing grip, the causing of the resistance to track the target resistance comprising adjusting one or more parameters of a control model of the rowing exercise machine as part of the control loop based on changing characteristics of the rowing exercise machine over time,
the tracking of the target resistance to motion by the two or more rowing exercise machines being collectively within a predetermined degree of precision and a predetermined accuracy,
the control circuitry of the respective two or more rowing exercise machines being configured to adjust the one or more parameters of the control models of the respective two or more rowing exercise machines differently based on different changing characteristics of the respective two or more rowing exercise machines over time, and
the control circuitry included in each rowing exercise machine storing a torque table usable by the control circuitry to determine a current to be applied to the eddy current brake.
2. The two or more rowing exercise machines of claim 1 in which the movable inertial element comprises a flywheel and the eddy current brake is coupled to the flywheel to cause the resistance to motion of the rowing grip during part of the rowing stroke.
3. The two or more rowing exercise machines of claim 1 in which the rowing grip comprises a handle coupled to the movable inertial element through a flexible elongated element.
4. The two or more rowing exercise machines of claim 1 in which the control circuitry comprises a sensor to measure a position or velocity or both of the movable inertial element.
5. The two or more rowing exercise machines of claim 1 in which the resistance to motion of the rowing grip caused by the control circuitry is based on one or more parameter values, and the parameter values comprise one or more of: position of the rowing grip, velocity of the rowing grip, ambient temperature, timing in relation to a training schedule, heart rate of a user, skin resistance of a user, and intervention by an observer.
6. The two or more rowing exercise machines of claim 1 all being of a common design or model.
7. The two or more rowing exercise machines of claim 1 in which the control circuitry of each of the rowing exercise machines comprises storage for information representing the target resistance to motion and relationships among velocities of the movable inertial element, currents applied to the eddy current brake, and amounts of resistance to motion of the rowing grip.
8. The two or more rowing exercise machines of claim 7 in which the information contained in the storage is not changeable.
9. The two or more rowing exercise machines of claim 7 in which the information contained in the storage is changeable to information received at the rowing exercise machine through the Internet.
10. The two or more rowing exercise machines of claim 7 in which the information contained in the storage is changeable in response to inputs from user interface controls of a user interface.
11. The two or more rowing exercise machines of claim 1 in which the target resistance to motion is the same for all of the rowing exercise machines.
12. The two or more rowing exercise machines of claim 1 in which the target resistance to motion is based on one or more parameter values and corresponds to a resistance to motion caused by a target other rowing exercise machine based on one or more corresponding parameter values.
13. The two or more rowing exercise machines of claim 12 in which the target other rowing exercise machine comprises an identified model of a mechanical rowing exercise machine.
14. The two or more rowing exercise machines of claim 1 in which the accuracy for each of the rowing exercise machines is independent of the target resistance to motion of the rowing grip.
15. The two or more rowing exercise machines of claim 1 in which the target resistance to motion of the rowing grip of each of the rowing exercise machines comprises a profile of resistance to motion of the rowing grip during part or all of a drive phase of the rowing stroke.
16. The two or more rowing exercise machines of claim 1 in which the control circuitry of each of the rowing exercise machines is configured to maintain the resistance to motion of the rowing grip during the drive phase within a pre-specified amount of error relative to the target resistance to motion of the rowing grip.
17. The two or more rowing exercise machines of claim 1 comprising storage in each of the rowing exercise machines for information representing the target resistance to motion of the rowing grip and an eddy current brake model.
18. The two or more rowing exercise machines of claim 1 in which the control circuitry is configured to maintain the resistance to motion of the rowing grip during the drive phase within a pre-specified amount of accuracy relative to the target resistance to motion of the rowing grip.
19. The two or more rowing exercise machines of claim 1 in which the target resistance to motion comprises a resistance to motion of an existing model or design of a mechanical ergometer.
20. The two or more rowing exercise machines of claim 1 in which the target resistance to motion is the same as the target resistances to motion of other rowing exercise machines of a given model or design.
21. The two or more rowing exercise machines of claim 1 in which the target resistance to motion applies to all of the successive strokes during a rowing session of a rower.
22. The two or more rowing exercise machines of claim 1 in which the one or more parameters of the control model of the rowing exercise machine comprise one or a combination of two or more of a torque gain, a current gain, and a speed gain.
23. The two or more rowing exercise machines of claim 1 in which the one or more parameters are adjusted during motion of the rowing grip so as to decrease a difference between the resistance to motion of the rowing grip and the target resistance to motion of the rowing grip.
24. The two or more rowing exercise machines of claim 1 in which the torque table is recomputed during motion of the rowing grip so as to decrease a difference between the resistance to motion of the rowing grip and the target resistance to motion of the rowing grip.