A method is disclosed for controlling a drill-free curve-CVT including a ring wheel, a set of planet wheels, and a sun wheel, wherein the ring and sun wheel are clamped together. The normal forces between the ring and sun wheel on the one hand and the planet wheels on the other hand are well defined when the transmission ratio is constant. The normal forces for constant ratio are called the static values. The method is configured so that during a continuous increase or decrease of the transmission ratio, any force component added to the static values of the first and/or the second normal force is either zero or smaller than a predefined force component to maintain a microslip condition of the rolling contacts between the planet wheels and the ring and sun wheels. This control of the forces is applied regardless of the speed of the ratio change.

Systems and methods for controlling transmissions and associated vehicles, machines, equipment, etc., are disclosed. In one case, a transmission control system includes a control unit configured to use a sensed vehicle speed and a commanded, target constant input speed to maintain an input speed substantially constant. The system includes one or more maps that associate a speed ratio of a transmission with a vehicle speed. In one embodiment, one such map associates an encoder position with a vehicle speed. Regarding a specific application, an automatic bicycle transmission shifting system is contemplated. An exemplary automatic bicycle includes a control unit, a shift actuator, various sensors, and a user interface. The control unit is configured to cooperate with a logic module and an actuator controller to control the cadence of a rider. In one embodiment, a memory of, or in communication with, the control unit includes one or more constant cadence maps that associate transmission speed ratios with bicycle speeds.

A vehicle includes a transmission having a variator and a sub-transmission mechanism, a controller serving as a shift control unit adapted to, as shift of the transmission, shift the sub-transmission mechanism and the variator so that a through speed ratio becomes a target speed ratio, and an engine serving as a torque increasing portion adapted to increase a torque inputted to the transmission in association with the shift of the transmission. The controller has a torque setting unit adapted to make a magnitude of an inclination larger as an increase amount of the engine rotation speed in association with the shift of the transmission is larger.

A vehicle includes a transmission having a variator and a sub-transmission mechanism, a controller serving as a shift control unit adapted to, as shift of the transmission, shift the sub-transmission mechanism and the variator so that a through speed ratio becomes a target speed ratio, and an engine serving as a torque increasing portion adapted to increase a torque inputted to the transmission in association with the shift of the transmission. The controller has a torque setting unit adapted to make a magnitude of an inclination larger as an increase amount of the engine rotation speed in association with the shift of the transmission is larger.

Systems and methods for controlling transmissions and associated vehicles, machines, equipment, etc., are disclosed. In one case, a transmission control system includes a control unit configured to use a sensed vehicle speed and a commanded, target constant input speed to maintain an input speed substantially constant. The system includes one or more maps that associate a speed ratio of a transmission with a vehicle speed. In one embodiment, one such map associates an encoder position with a vehicle speed. Regarding a specific application, an automatic bicycle transmission shifting system is contemplated. An exemplary automatic bicycle includes a control unit, a shift actuator, various sensors, and a user interface. The control unit is configured to cooperate with a logic module and an actuator controller to control the cadence of a rider. In one embodiment, a memory of, or in communication with, the control unit includes one or more constant cadence maps that associate transmission speed ratios with bicycle speeds.

Methods and systems are provided for adapting a pressure to torque transfer function of a clutch of a dual clutch transmission. In one example, a method includes operating a first clutch of the dual clutch transmission at a selected capacity to change a speed of a first transmission input shaft to a desired speed, adjusting values of a torque transfer function of the first clutch based on a rate of the speed change, and maintaining driver demanded wheel torque during the adjusting via controlling torque output of an electric motor positioned in the driveline. In this way, the method may be used to adapt both positive and negative torque transfer functions.

A method is disclosed for controlling a drill-free curve-CVT including a ring wheel, a set of planet wheels, and a sun wheel, wherein the ring and sun wheel are clamped together. The normal forces between the ring and sun wheel on the one hand and the planet wheels on the other hand are well defined when the transmission ratio is constant. The normal forces for constant ratio are called the static values. The method is configured so that during a continuous increase or decrease of the transmission ratio, any force component added to the static values of the first and/or the second normal force is either zero or smaller than a predefined force component to maintain a microslip condition of the rolling contacts between the planet wheels and the ring and sun wheels. This control of the forces is applied regardless of the speed of the ratio change.

Disclosed is a control apparatus for a vehicular transmission comprising: a vehicle speed sensor; an accelerator opening angle sensor; and a gear-shift control section (8D) of a CVTECU 8. The vehicle speed sensor includes: an output shaft rotation speed sensor (90) configured to detect a rotation speed (rotation numbers) of an output shaft (41) of the automatic transmission; road wheel rotation speed sensors configured to detect rotation speeds (rotation numbers) of four road wheels (90B through 90E); and a vehicle speed calculating section (8B) of CVTECU 8 configured to calculate the vehicle speed from the information of the road wheel rotation speeds when a preset predetermined condition as a condition under which vertical variations of the rotation speed of the output shaft are generated is established and calculate the vehicle speed from the output shaft rotation speed information if the predetermined condition is not established.

A method of controlling a four wheel drive (4WD) low range shift in a vehicle is provided. The vehicle has a powertrain including a transmission that drives a transmission output shaft to provide drive torque to a driveline including a power transfer unit (PTU) that delivers torque to front drive wheels and a rear differential unit (RDU) that delivers torque to rear drive wheels. The PTU and RDU are selectively rotatably coupled to each other through a propeller (prop) shaft. The PTU and the RDU are commanded into a neutral position. A clutch at the RDU is commanded to selectively engage to a degree that communicates a desired amount of torque from the prop shaft to the RDU. A determination is made that an output speed of the transmission output shaft is synchronized to match a speed of the RDU and the RDU is commanded to shift into 4WD low.

Methods and systems are provided for adapting a pressure to torque transfer function of a clutch of a dual clutch transmission. In one example, a method includes operating a first clutch of the dual clutch transmission at a selected capacity to change a speed of a first transmission input shaft to a desired speed, adjusting values of a torque transfer function of the first clutch based on a rate of the speed change, and maintaining driver demanded wheel torque during the adjusting via controlling torque output of an electric motor positioned in the driveline. In this way, the method may be used to adapt both positive and negative torque transfer functions.