Electronically controlled mechanical resistance device for rowing machines

Abstract

This invention offers a rowing machines' mechanical resistance device which comprises an electric motor and a programmable control. While it simulates the beneficial responses of a mechanical resistance imparting device comprising a fluid pump and a flywheel, it simultaneously eliminates the compromising effect of backlash. Said backlash exists on commonly used, state of the art rowing machines between the idling and the pulling phases of a rowing stroke. By eliminating backlash, this invention allows rowers to achieve better rowing form and avoid injury.

1 . A device for a rowing machine which provides mechanical resistance comprising:
 an electric motor;   a motor control means comprising a means for managing said motor's resistance to rotation and a microprocessor, wherein said microprocessor's programmed algorithm causes said motor to produce the mechanical responses of a simulated device comprising a flywheel and an adjustable fluid pump;   a plurality of motion sensors attached to said motor control means, wherein said sensors detect the position of said motor's shaft and the position of the rowing machine's handle to which an embodiment of this invention is attached to; and   a transmission means, wherein said transmission means drivingly engage said motor to said rowing machine's user's handle.   
     
     
         2 . A unit, according to  claim 1 , wherein said motor control means further comprises:
 a means for collecting and storing electric charge induced in said motor windings, wherein collected charge is used to power said motor control means, and power or charge at least one more auxiliary power draining device;   a means to connect said microprocessor to another computer;   a means for charging said computer using said collected charge; and   a switching means, wherein said switching means selectively engage said motor with said means for managing said motor's resistance to rotation and said means to collect and store electric charge.   
     
     
         3 . A unit, according to  claim 2 , wherein said motor control means stops said motor at the instance of the dead stop between the idling and the power phase of a rowing stroke. 
     
     
         4 . A unit, according to  claim 3 , wherein said microprocessor's programmed algorithm comprises:
 an algorithm simulating said simulated device during the idling phase of a rowing stroke;   an algorithm simulating said simulated device during the initial piece of a rowing stroke's power phase;   an algorithm simulating said simulated device during the final piece of a rowing stroke's power phase.   
     
     
         5 . A unit, according to  claim 4 , wherein said fluid is air, and wherein said flywheel and said adjustable fluid pump comprising said simulated device are assumed to rotate in unison. 
     
     
         6 . A unit, according to  claim 5 , wherein said microprocessor's programmed algorithm related to said idling phase of a rowing stroke is dω old =Kn*ω old   2 *dt/J old , wherein:
 said dω old  represents the drop of said simulated device's rotating components' angular velocity; 
 said dt represents the interval between said microprocessor's calculations, ranging from 0.1 to 200 milliseconds; 
 said J old  represents the angular moment of inertia of said simulated device's rotating components; 
 said Kn represents the drag coefficient related to said air pump's adjustable air flow settings; and 
 said ω old  represents the angular velocity of said simulated device's rotating components. 
 
     
     
         7 . A unit, according to  claim 6 , wherein said microprocessor's algorithm related to said initial piece of a rowing stroke's power phase comprises:
 an equation, dω old =Kn*ω old   2 *dt/J old ;   a condition, (ω old −dω old )>(ω new *T multiplier ), wherein:
 said ω new  represents the angular velocity of said motor's shaft, and ω new  is derived from measurements related to said motor's shaft position sensors; 
 said T multiplier  represents a torque multiplier related to the gearing ratio in said transmission means; 
   an equation, P strokePower =Kn*ω old   3 +ω old *(J old −J new /T multiplier   2 )*(dω old /dt), wherein:
 said P strokePower  represents the calculated power response of said simulated device corresponding to said ω old ; 
 said hew represents the angular moment of inertia of said motor's rotor; 
   an equation, P beginStroke =C*(P max *((ω old −dω old )−ω new *T multiplier )/(ω old −dω old )+P strokePower *( 1 −((ω old −dω old )−ω new *T multiplier ) (ω old −dω old ))), wherein:
 said P beginStroke  represents the actual power response implemented on said motor; 
 said P max  represents the maximum power response of an embodiment of this invention; 
 said C represents a catch factor ranging from 0.1 to 1, and wherein C shall be used to simulate lighter or heavier boat's oar riggings; and 
   a condition, P beginStroke <P strokePower , wherein:
 if said condition is satisfied, the algorithm shall override any other related equations from this claim and set P beginStroke  according to P beginStroke =P strokePower . 
   
     
     
         8 . A unit, according to  claim 7 , wherein said microprocessor's algorithm related to said final piece of a rowing stroke's power phase comprises:
 an equation, dω old =Kn*ω old   2 *dt/J old ;   a condition, (ω new *T multiplier )>=(ω old −dω old ), wherein:
 if said condition is satisfied, ω old  in subsequent equation shall be calculated according to ω old =ω new *T multiplier ; 
   an equation, P strokePower =Kn*ω old   3 +ω old *(J old −J new /T multiplier   2 )*(dω old /dt); and   a condition, (ω new *T multiplier )<(ω old −dω old ), wherein:
 if said condition is satisfied, the algorithm shall override any other related equations from this claim and set P strokePower  according to P strokePower =0; 
   
     
     
         9 . A unit, according to  claim 8 , wherein said Kn drag coefficient value changes during exercise, wherein
 said Kn drag coefficient values relate to simulating different wind and water stream speed conditions when rowing real boats.   
     
     
         10 . A unit, according to  claim 9 , wherein said microprocessor's algorithm related to the final piece of a rowing stroke's power phase alternates between the algorithm described in  claim 8  and an algorithm causing said motor to produce a constant torque response, wherein said motor's constant torque response is related to simulating light weight lifting. 
     
     
         11 . A unit, according to  claim 3 , wherein for the purpose of calibrating an embodiment of this invention, via using said means for managing said motor's resistance to rotation, said motor control means controllably releases tension between said motor and a retracting cord comprising a rowing machine to which said embodiment of this invention is attached to, wherein:
 said controllable release of tension is used to establish a tension map of said retracting cord; and   said tension map is used to augment calculations related to rower's power consumption when rowing on said rowing machine.   
     
     
         12 . A unit, according to  claim 3 , wherein said motor control means further comprises a means to control said motor drivingly. 
     
     
         13 . A unit, according to  claim 12 , wherein means to control said motor drivingly engage said motor during the idle phase of a rowing stroke. 
     
     
         14 . A unit, according to  claim 3 , wherein said transmission means comprises a one way clutch. 
     
     
         15 . A unit, according to  claim 3 , wherein the method of said means for managing said motor's resistance to rotation is to controllably short said motor windings.