A control device for an automatic transmission includes a continuously variable transmission mechanism, a torque converter, a target transmission ratio calculation unit, a feedback control unit, and a phase compensation unit. The torque converter has a lock-up clutch. The target transmission ratio calculation unit is configured to calculate a target transmission ratio based on a travelling state. The feedback control unit is configured to perform feedback control based on an actual value indicative of a state of the continuously variable transmission mechanism. The phase compensation unit is configured to perform phase lead compensation of the feedback control based on the travelling state. The phase compensation control unit is configured to halt the phase lead compensation when an unstable travelling state of a vehicle is detected. The phase compensation control unit is further configured to release the lock-up clutch when the phase lead compensation is halted.

For a hybrid vehicle including an engine, a motor generator, and a belt-type continuously variable transmission, a controller performs a low speed position return expediting control in response to a downshift request accompanying deceleration. During the low speed position return expediting control, the controller increases a differential pressure between a primary pressure and a secondary pressure and cause a downshift toward a lowest speed position transmission ratio by reducing the primary pressure, and further reduces the primary pressure when the secondary pressure becomes greater than or equal to a trigger threshold value during the downshift; and terminates the low speed position return expediting control when an actual secondary pressure decreases to a secondary pressure minimum level. The controller further sets a secondary pressure lower limit higher than the secondary pressure minimum level during the low speed position return expediting control.

A belt-type continuously variable transmission includes an actual gear ratio calculation unit for calculating an actual gear ratio based on the rotation speed of a drive pulley and the rotation speed of a driven pulley, a reference gear ratio calculation unit for calculating a reference gear ratio by modifying the actual gear ratio based on an input torque and a driven pulley hydraulic pressure, and a condition determination unit for, in a case where the target gear ratio is an overdrive gear ratio, determining that at least part of rings of a belt is missing when the reference gear ratio is greater than or equal to a predetermined gear ratio and a drive pulley hydraulic pressure is greater than or equal to a predetermined hydraulic pressure.

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 belt-type continuously variable transmission includes an actual gear ratio calculation unit for calculating an actual gear ratio based on the rotation speed of a drive pulley and the rotation speed of a driven pulley, a reference gear ratio calculation unit for calculating a reference gear ratio by modifying the actual gear ratio based on an input torque and a driven pulley hydraulic pressure, and a condition determination unit for, in a case where the target gear ratio is an overdrive gear ratio, determining that at least part of rings of a belt is missing when the reference gear ratio is greater than or equal to a predetermined gear ratio and a drive pulley hydraulic pressure is greater than or equal to a predetermined hydraulic pressure.

A vehicle includes an engine, a continuously variable transmission including an endless belt to output a power from the engine, and a transmission to which the power from the continuously variable transmission is transmitted. If the vehicle travel speed is not smaller than a first threshold value and an accelerator opening degree is not smaller than a second threshold value, a controller determines that the continuously variable transmission is being used in a belt high-load situation. If a travel distance in the belt high-load situation is not smaller than a third threshold value, the controller determines that the endless belt is deteriorated or deterioration thereof is in an advanced stage, and a deterioration message about the endless belt is displayed on a display based on an instruction from the controller. A situation in which a speed changing ratio of the continuously variable transmission is not greater than a fourth threshold value may be determined as the belt high-load situation.

A vehicle with continuously variable transmission operational modes is provided. The vehicle includes a motor to provide engine torque; a driveline; a continuously variable transmission (CVT), an actuator, a memory and a controller. The CVT is configured to couple torque between the motor and the driveline. The actuator is in operational communication with the CVT to selectively set operating characteristics of the CVT. The memory stores operating instructions including operational mode. The controller is in communication with the memory and the actuator. The controller configured to control the actuator based on one or more of the operational modes.

A vehicle control apparatus for a vehicle provided with an engine, a continuously variable transmission (CVT) coupled to an output shaft of the engine, a motor coupled to a wheel, and an output clutch that transmits power from an output shaft of the CVT and the motor to the wheel includes a controller that is able to switch and execute either of an EV mode that allows, upon disengagement of the output clutch, power outputted from the motor to drive the wheel, and an HEV mode that allows, upon engagement of the output clutch, power outputted from the engine and the motor to drive the wheel, and that, in an adjustment of a gear ratio of the CVT during the EV mode, engages the output clutch and adjusts the gear ratio of the CVT, and thereafter disengages the output clutch before the gear ratio reaches a target gear ratio.

An automatic transmission is provided, which includes a variator having a first pulley, a second pulley and a belt wound around the first and second pulleys, a first motor configured to give a pulley thrust force for shifting the variator to the first or second pulley, a second motor configured to cause a belt clamping force to be generated in the variator, and a power transmission mechanism provided between the second motor and the variator, to transmit an output torque of the second motor to the variator. The power transmission mechanism includes a cycloid decelerator configured to decelerate an input torque from the second motor, and transmit the decelerated input torque to the variator.