A method of filtering a target transmission ratio of a continuously variable transmission of a vehicle includes: controlling, by a controller, a vehicle speed filter configured to filter a speed signal of a vehicle distorted due to vibration of the vehicle; controlling, by the controller, a target driving pulley speed memory configured to output a target driving pulley speed signal of the continuously variable transmission based on an output value of an acceleration pedal sensor and the filtered speed signal of the vehicle; and controlling, by the controller, a transmission calculator configured to calculate a target transmission ratio of the continuously variable transmission that is a stable value based on the target driving pulley speed signal of the continuously variable transmission and the filtered speed signal of the vehicle, wherein the vehicle speed filter increases filtering capability and a response speed of the vehicle speed filter and decreases the speed signal of the vehicle to a value that makes the target transmission ratio of the continuously variable transmission stable.

Disclosed is lateral pressure control of a continuously variable transmission (CVT) with a transmission ratio changed by changing groove widths of a drive pulley and a driven pulley, a drive force from a drive source being transmitted to a wheel. A control part controlling respective lateral pressures of the drive pulley and the driven pulley is provided. The control part sets an increase correction amount of the lateral pressure of the drive pulley to a first lateral pressure increase correction amount if the CVT is not in an in-gear state or a shift position is consistent with a traveling direction of the vehicle, and, sets said amount to a second lateral pressure increase correction amount smaller than the first lateral pressure increase correction amount if the CVT is in the in-gear state and the shift position is not consistent with the traveling direction of the vehicle.

A belt-type continuously variable transmission includes a primary pulley, a secondary pulley, and a belt wound around the primary pulley and the secondary pulley. A controller performs a process, when performing a low speed position return shift to shift a transmission ratio toward a lowermost speed position while a vehicle is decelerating. The process includes: calculating a primary pressure actual lower limit, at which the belt actually starts to slip, based on the transmission ratio and a deceleration of the vehicle; setting a lower limit of a setpoint of the primary pressure to the primary pressure actual lower limit; setting the primary pressure actual lower limit higher with a locking tendency of a vehicle wheel detected than that without the locking tendency detected; and setting the primary pressure actual lower limit with the locking tendency detected to increase as the transmission ratio varies toward the lowermost speed position.

A control system for a vehicle uses one or more inputs of a velocity request, a brake request, a speed request, travel direction indication, engine speed, and vehicle speed to determine a control strategy for a continuously variable transmission. A target engine speed is selected based upon the inputs, and the engine and continuously variable transmission ratio are controlled to achieve the target engine speed while controlling the vehicle according to the inputs. In some embodiments, the control strategy further selects the target engine speed according to accessory system demands, such as a hoist or lift system.

The control method for the continuously variable transmission in the present invention detects a magnitude of an acceleration request, and when the acceleration request exceeds a preset threshold value, the control method controls a transmission ratio by switching from a first shift mode, in which a target transmission ratio is changed steplessly, to a second shift mode, which includes a stepwise change in the target transmission ratio. Then, when executing the second shift mode, a target engine rotation speed is set according to the magnitude of the acceleration request, and a step-down shift, in which the target transmission ratio is lowered stepwise according to the target engine rotation speed, is executed at an acceleration start time, and the target engine rotation speed after executing the step-down shift is retained for a predetermined period.

A method of filtering a target transmission ratio of a continuously variable transmission of a vehicle includes: controlling, by a controller, a vehicle speed filter configured to filter a speed signal of a vehicle distorted due to vibration of the vehicle; controlling, by the controller, a target driving pulley speed memory configured to output a target driving pulley speed signal of the continuously variable transmission based on an output value of an acceleration pedal sensor and the filtered speed signal of the vehicle; and controlling, by the controller, a transmission calculator configured to calculate a target transmission ratio of the continuously variable transmission that is a stable value based on the target driving pulley speed signal of the continuously variable transmission and the filtered speed signal of the vehicle, wherein the vehicle speed filter increases filtering capability and a response speed of the vehicle speed filter and decreases the speed signal of the vehicle to a value that makes the target transmission ratio of the continuously variable transmission stable.

A tidal current energy converter including an infinitely variable transmission (IVT) control system and a hybrid vertical axis wind (or water) turbine (VAWTs) apparatus. The hybrid VAWT apparatus includes a modified-Savonius (MS) rotor in the central region and a straight bladed H-type Darrieus rotor in the surrounding annular region. The IVT control system includes a nonlinear closed-loop control combined with an integral time-delay feedback control to adjust a speed ratio of the IVT. A speed ratio control for an IVT system involves a forward speed controller and/or 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 control system for a vehicle uses one or more inputs of a velocity request, a brake request, a speed request, travel direction indication, engine speed, and vehicle speed to determine a control strategy for a continuously variable transmission. A target engine speed is selected based upon the inputs, and the engine and continuously variable transmission ratio are controlled to achieve the target engine speed while controlling the vehicle according to the inputs. In some embodiments, the control strategy further selects the target engine speed according to accessory system demands, such as a hoist or lift system.

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.