Method of controlling an electromechanical drive mechanism

Abstract

There is provided a method of controlling a pedal cycle and a pedal cycle incorporating the same. The pedal cycle has an electro-mechanical drive arrangement including a continuously variable ratio transmission system having an input which is mounted to rotate about the axis and an output connected to rotate with a hub member, the transmission system comprising an epicyclic gear set including a sun gear in mesh with a plurality of planet gears mounted to rotate about respective planet shafts carried by a common carrier, which is mounted to rotate with the input about the axis, the planet gears being in mesh with an annulus gear, which is connected to rotate with the hub member. Only the sun gear may be connected to rotate a rotor of an electrical machine or an additional machine may be provided. The electrical connections of the stator of the electrical machine are connected to a controller; the method may include the step of applying a time division multiplexed control algorithm to the electrical machine, wherein the time division multiplexed control algorithm alternates between a first control mode in which current generated by the electrical machine is monitored to infer torque applied to the crank arms of the cycle and a second control mode in which the current in the input electrical machine is controlled using the inferred torque.