Electronically controlled mechanical resistance device for rowing machines

A device for a rowing machine which mainly provides mechanical resistance to simulated rowing comprising:

• a multiphase BLDC motor;
• a transmission means comprising a one way acting clutch, wherein:
• an inner cylindrical surface of the clutch drivingly engages said motor's shaft;
• an outer cylindrical surface of the clutch is press fitted into a timing pulley or a sprocket, wherein:
• said pulley or said sprocket drivingly engages a rower's handle through a tensioned timing belt or a chain, attached to a middle of said rower handle's length;
• said clutch drivingly engages said rower's handle to said motor's shaft during a drive phase of a stroke and decouples the two during an idle phase of a stroke;
• a motor control means mainly controlling said motor shaft's resistance to rotation and comprising:
• a multiphase diode rectifier, used to rectify and sum said motor's induced currents into a common direct current;
• a filter to smooth said rectified direct current;
• a power transistor used to short and open the circuit comprising said rectified direct current;
• a microcontroller controllably engaged to said transistor's gate, wherein:
• a signaling technique from said microcontroller to said gate is pulse width modulation (PWM), wherein:
• one PWM cycle switches the transistor's gate fully ‘on’ and then fully ‘off’;
• wherein said PWM signal is configured to control a counter torque, resisting the rotation on said motor's shaft and therefore resisting the rower handle's motion during the drive phase of a stroke, wherein allowed torque settings range from:
• the maximum, wherein said PWM fully ‘on’ portion of a cycle is at hundred percent and fully ‘off’ portion of a cycle is at zero percent;
• and
• the minimum, wherein said PWM fully ‘off’ portion of a cycle is at one hundred percent and fully ‘on’ portion is at zero percent;
• a plurality of motion sensors attached to said microcontroller, wherein said sensors:
• detect a position of said timing belt pulley or said sprocket, henceforth detecting a position and a motion direction of the rower's handle, also allowing said microcontroller to derive information regarding said handle's velocity and acceleration;
• detect a position of said motor's shaft, also allowing said microcontroller to derive information about said motor shaft's velocity and acceleration;
• a set of algorithms on said microcontroller comprising instructions that:
• at the instance following a dead stop between an end of the drive phase and a beginning of the idle phase of a rowing stroke, attempt to stop said motor shaft's rotation, with the goal of completely stopping it before the beginning of the drive phase of the subsequent stroke wherein:
• stopping of the motor's shaft causes it to synchronize its velocity to that of the rower's handle at the beginning of the drive phase of the subsequent stroke;
• and
• wherein said synchronization is configured to avoid backlash between the motions of the rower's handle and said motor's shaft;
• set said motor shaft's torque relatively high at the beginning of the drive phase of a stroke for the purpose of avoiding said backlash;
• throughout a first part of the drive phase of a rowing stroke, eases the torque on the motor's shaft as the velocity of the rower's handle suddenly increases from zero;
• throughout the majority of the drive phase of a rowing stroke, increases the torque on the motor's shaft as the velocity of the rower's handle gradually increases;
• a means to connect said microcontroller to another computer;
• and
• a means for collecting and storing electric charge induced in said motor's windings, comprising at least one capacitor wherein:
• said charge collecting means connect in parallel to said power transistor's source and drain pins;
• charge is mostly collected during said PWM ‘off’ cycle portions;
• collected charge is used to:
• power said motor control means;
• and
• potentially power or charge at least one more auxiliary power draining device.