Exercise device
A control system and method for exercise equipment and the like provides a way to simulate a physical activity in a manner that takes into account the physics of the physical activity being simulated to provide an accurate simulation. According to one aspect of the present invention, the control system and method takes into account the physics of the corresponding physical activity to generate a virtual or predicted value of a variable such as velocity, acceleration, force, or the like. The difference between the virtual or expected physical variable and a measured variable is used as a control input to control resistance forces of the exercise equipment in a way that causes the user to experience forces that are the same or similar to the forces that would be encountered if the user were actually performing the physical activity being simulated rather than using the exercise equipment.
1. A stationary exercise bike, comprising:
a support structure;
a flywheel rotatably mounted to the support structure and defining a rotational velocity;
a pair of input members movably interconnected with the support structure, wherein the input members are operably connected to the flywheel such that movement of the input members resulting from application of an input force to the input members by a user causes the flywheel to rotate;
a force-generating device having a movable flywheel-engaging portion that provides a resistance force that varies upon movement of the flywheel-engaging portion relative to the flywheel, and wherein the resistance force tends to reduce the rotational velocity of the flywheel, and wherein the force-generating device includes a powered actuator that moves the flywheel-engaging portion relative to the flywheel to thereby vary the resistance force provided by the force-generating device;
a first sensor that measures the resistance force provided by the force-generating device to provide a measured force;
a second sensor that provides at least one of a velocity and a position of the flywheel;
a controller that utilizes the measured force from the first sensor to determine a user input and a velocity difference between a measured velocity determined from data provided by the second sensor, and a virtual velocity that is determined utilizing a mathematical bike model that determines the effects of inertia with respect to a resistance force that would be experienced by a rider on a non-stationary bicycle if the user were riding on a non-stationary bicycle, and wherein the controller causes the powered actuator to adjust the resistance force according to the mathematical bike model.
2. The stationary exercise bike of claim 1 , wherein:
one of the flywheel and the flywheel-engaging portion is magnetized such that movement of the flywheel relative to the flywheel-engaging portion causes eddy currents that generate a resistance force tending to slow the flywheel.
3. The stationary exercise bike of claim 2 , wherein:
the flywheel defines a circular outer peripheral edge surface and opposite side surfaces;
the flywheel-engaging portion includes first and second portions that extend along the opposite side surfaces of the flywheel.
4. The stationary exercise bike of claim 3 , wherein:
the flywheel-engaging portion defines an elongated channel that receives the peripheral edge surface of the flywheel.
5. The stationary exercise bike of claim 1 , wherein:
the flywheel-engaging portion of the force-generating device includes a friction pad that contacts a surface of the flywheel to generate a resistance force.
6. The stationary exercise bike of claim 5 , wherein:
the flywheel defines a generally cylindrical outer peripheral surface, and the friction pad defines a concave cylindrical surface that corresponds to the cylindrical outer surface.
7. The stationary exercise bike of claim 1 , wherein:
the powered actuator comprises a solenoid having a coil and a moving member that extends and retracts when electrical current is supplied to the coil, and wherein the flywheel-engaging portion is connected to the moving member.
8. The stationary exercise bike of claim 7 , wherein:
the force-generating device includes a linear guide that movably supports the moving member.
9. The stationary exercise bike of claim 1 , wherein:
the force-generating device includes a structure that elastically deforms in response to a resistance force that is applied to the flywheel-engaging portion, and wherein a strain gauge is attached to the structure to provide a strain measurement that can be utilized to determine the resistance force.
10. The stationary exercise bike of claim 1 , wherein:
the base of the force-generating device comprises a bracket configured to permit the force-generating device to be mounted to a frame member of a stationary bike.
11. The stationary exercise bike of claim 1 , wherein:
the force-generating device includes an electrical generator having an input member that engages the flywheel, and wherein the input member is biased into engagement with the flywheel.