A power split transmission structure has at least three interfaces to direct driving power from a drive to at least one output in order to supply the driving power to connected consumers. It comprises at least two variator paths which each comprise a summation gearbox communicating with an electric or hydraulic machine via a mechanical and a non-mechanical path in order to modify torque, speed or both of the driving power. A control device regulates the summation gearbox of each of the variator paths. A power electronics system or hydraulic control device is connected to the electric or hydraulic machine of each of the variator paths. The transmission structure directs the driving power via the variator paths such that the electric or hydraulic machine of each variator path is operable in a generator or motor mode in order to compensate for a power shortfall or a power oversupply at at least one outlet of the transmission structure.

A power split transmission structure has at least three interfaces to direct driving power from a drive to at least one output in order to supply the driving power to connected consumers. It comprises at least two variator paths which each comprise a summation gearbox communicating with an electric or hydraulic machine via a mechanical and a non-mechanical path in order to modify torque, speed or both of the driving power. A control device regulates the summation gearbox of each of the variator paths. A power electronics system or hydraulic control device is connected to the electric or hydraulic machine of each of the variator paths. The transmission structure directs the driving power via the variator paths such that the electric or hydraulic machine of each variator path is operable in a generator or motor mode in order to compensate for a power shortfall or a power oversupply at at least one outlet of the transmission structure.

A nonlinear closed-loop control combined with an integral time-delay feedback control is disclosed to adjust a speed ratio of an infinitely variable transmission (IVT) system. A speed ratio control for an IVT system involves a forward speed controller and a crank length controller for different speed ranges. The time-delay control is designed to reduce speed fluctuations of the output speed of an IVT with an accurate speed ratio. The speed ratio of an IVT with the disclosed control strategy can achieve an excellent tracking response for the desired constant output speed and reduce speed fluctuations of the output speed of an IVT by the time-delay feedback control.

A nonlinear closed-loop control combined with an integral time-delay feedback control is disclosed to adjust a speed ratio of an infinitely variable transmission (IVT) system. A speed ratio control for an IVT system involves a forward speed controller and a crank length controller for different speed ranges. The time-delay control is designed to reduce speed fluctuations of the output speed of an IVT with an accurate speed ratio. The speed ratio of an IVT with the disclosed control strategy can achieve an excellent tracking response for the desired constant output speed and reduce speed fluctuations of the output speed of an IVT by the time-delay feedback control.

A continuously variable transmission capable of operating in a forward direction or reverse direction may be controlled in the reverse direction by providing an initial skew angle in a first skew direction, followed by a set or sequence of skew angle adjustments in an opposite direction to prevent runaway or other unintended consequences. A continuously variable transmission may include a timing plate to maintain all planets at an angle or within a range of an angle in forward and reverse operations.

A continuously variable transmission capable of operating in a forward direction or reverse direction may be controlled in the reverse direction by providing an initial skew angle in a first skew direction, followed by a set or sequence of skew angle adjustments in an opposite direction to prevent runaway or other unintended consequences. A continuously variable transmission may include a timing plate to maintain all planets at an angle or within a range of an angle in forward and reverse operations.

An electronic controller for a variable ratio transmission and an electronically controllable variable ratio transmission including a variator or other CVT are described herein. The electronic controller can be configured to receive input signals indicative of parameters associated with an engine coupled to the transmission. The electronic controller can also receive one or more control inputs. The electronic controller can determine an active range and an active variator mode based on the input signals and control inputs. The electronic controller can control a final drive ratio of the variable ratio transmission by controlling one or more electronic solenoids that control the ratios of one or more portions of the variable ratio transmission.

An electric power generation controller for use in an aircraft is a controller of an electric power generating system configured such that: a manual transmission changes speed of rotational power of an aircraft engine; a continuously variable transmission changes the speed of the rotational power which has been changed in speed by the manual transmission; and the continuously variable transmission transmits the rotational power to an electric power generator. The electric power generation controller includes: a manual transmission control section configured to, when a predetermined shift condition is satisfied, control the manual transmission to switch a gear stage of the manual transmission; and a continuously variable transmission control section configured to, when the shift condition is satisfied, control the continuously variable transmission to such a side that fluctuation of an output rotational frequency of the manual transmission by the switching of the gear stage of the manual transmission is canceled.

A control system for a power transmission unit configured to shift an operating mode smoothly by manipulating engagement devices, and to simplify a structure of the power transmission unit. The control system is configured to reduce a speed difference between an axially stationary engagement element and a reciprocatable engagement element of a second engagement device when shifting from a first continuously variable mode to a second continuously variable mode by engaging the second engagement device. After the second engagement device has been engaged completely, a first engagement device is disengaged.

A control system for a power transmission unit configured to shift an operating mode smoothly by manipulating engagement devices, and to simplify a structure of the power transmission unit. The control system is configured to reduce a speed difference between an axially stationary engagement element and a reciprocatable engagement element of a second engagement device when shifting from a first continuously variable mode to a second continuously variable mode by engaging the second engagement device. After the second engagement device has been engaged completely, a first engagement device is disengaged.