A vehicle propulsion system includes an oncoming condition sensor that generates an oncoming condition signal, a continuously variable transmission with a variator assembly adapted to transfer torque between a first rotating member and a second rotating member through a flexible continuous device rotatably coupling the first rotating member to the second rotating member, one of the first rotating member and second rotating member including a clamping pulley adapted to controllably adjust a clamping force on the flexible continuous device, and a controller in communication with the oncoming condition sensor and the continuously variable transmission that is programmed to characterize an oncoming condition based upon the oncoming condition signal and to control the clamping pulley to adjust the clamping force based on the characterization of the oncoming condition.

A method is proposed to complete a power-on upshift while a vehicle encounters wheel slip conditions such as driving in loose sand. The wheels slip conditions may be detected based on a maximum rate of change of an output shaft exceeding a threshold. In response to the wheel slip conditions, one or more shift parameters may be adjusted to bias the shift toward a tie-up and decrease the chance of a flare. These modified shift parameters may include an increased stroke pressure, a delayed off-going clutch release timing, and an increased ratio change capacity.

An all-wheel-drive-vehicle controller includes: a drive gear coupled to a driving source; a driven gear meshed with the drive gear and coupled to main and sub driving-wheel axle shafts transmitting torques to main and sub driving wheels, respectively; a transfer clutch interposed between the driven gear and the sub-driving-wheel axle shaft and adjusting the torque transmitted to the sub driving wheel; a first determination unit determining whether a first condition in which a torque applied to the drive gear is substantially zero is satisfied; a second determination unit determining whether a second condition in which hydraulic pressure is applied to the transfer clutch and a torque applied to the driven gear is substantially zero is satisfied; and a control unit controlling a torque adjuster to adjust the torque applied to either one of the drive gear and the driven gear if the first and second conditions are satisfied.

A hydrostatic traction drive includes a first hydraulic machine that is coupled to a drive unit. The first hydraulic machine is hydraulically arranged in a hydraulic circuit with a second hydraulic machine. The second hydraulic machine has a drive shaft that is connected in a rotationally fixed fashion to a lockable differential. The traction drive has a control unit that is configured so as to control at least one measure for traction control as a function of a rotational speed of the second hydraulic machine. The at least one measure includes one or more of a measure for detecting a loss of traction and a measure for overcoming the loss of traction. A method for controlling the traction drive includes eliminating a loss of traction of the traction drive with use of the control unit as a function of the rotational speed of the second hydraulic machine.

A control device for a continuously variable transmission includes a belt type continuously variable transmission and a controller. The controller is configured to calculate an actual gear shift ratio based on rotation speed sensor values from a primary rotation speed sensor and a secondary rotation speed sensor, and to perform gear shift ratio control using feedback control to converge the actual gear shift ratio to a target gear shift ratio. The controller is further configured to stop calculation of the actual gear shift ratio when one of the rotation speed sensor values is less than a first threshold value determined based on a lower limit value of sensor detection accuracy, and stop calculation of the actual gear shift ratio even when one of the rotation speed sensor values is the first threshold value or greater, when a deceleration level of the drive wheel is a prescribed deceleration level or greater.

A method is provided for controlling a drivetrain of a vehicle, wherein the drivetrain comprises a multi-clutch transmission. The gear shift of the multi-clutch transmission is adapted to be performed either by power cut shift or by power shift dependent on predetermined vehicle shift conditions. The method includes detecting at least one of a plurality of indications of slippery road conditions and setting a slip risk factor, wherein the slip risk factor is dependent on the indication of slippery road conditions. If the slip risk factor is above a first predetermined threshold value the method further comprises controlling the multi-clutch transmission such that an upcoming gear shift is performed as a power-shift independently of if upcoming shift was determined to be performed as a power-cut shift or as a power shift.

A vehicle includes a transmission having input and output shafts and clutches engageable in combinations to create power-flow paths between the input and output shafts. The vehicle further includes wheels driven by the output shaft and a controller. The controller is programmed to engage one of the combinations, and, responsive to the wheels slipping and a desired engine torque reduction exceeding a threshold, command capacity to an additional one of the clutches to reduce torque of the output shaft.

A continuously variable transmission, a transmission control system, and a method is provided. The control system is configured to determine whether a predetermined condition is met for applying a clutch critical pressure to an applied clutch. The clutch critical pressure is less than line pressure and is a pressure at which the clutch may slip upon experiencing a predetermined torque disturbance level. The control system is configured to command the clutch critical pressure to be applied to the clutch if the predetermined condition is met. The control system is further configured to determine whether the clutch is slipping beyond a predetermined threshold, and if the clutch is slipping beyond the predetermined threshold, command a clutch slip control scheme to be applied to the clutch that is configured to bring a clutch slip of the clutch under the predetermined threshold.

A control apparatus for a vehicle drive-force transmitting apparatus including a gear mechanism and a continuously-variable transmission mechanism provided in respective first and second drive-force transmitting paths. The control apparatus sets a target gear ratio of the continuously-variable transmission mechanism during a switching control operation that is executed to switch between (i) a first state in which the first drive-force transmitting path is established and (ii) a second state in which the second drive-force transmitting path is established, such that, when drive wheels are not being slipped, the target gear ratio is set to a highest gear ratio of the continuously-variable transmission mechanism, and such that, when the drive wheels are being slipped, the target gear ratio is set to an actual gear ratio at a point of time at which the drive wheels start being slipped.

CVT controller has rotation speed sensors detecting driving and driven wheel rotation speed; driving and driven wheel speed difference detection unit detecting wheel speed difference vfr; and bad road judgment unit judging that road is bad road when vfr is first value vfr_br or greater. CVT controller further has first belt clamping force increase unit increasing belt clamping force in case where road is judged to be bad road, as compared with case where road is not judged to be bad road; vibration detection unit detecting vehicle speed vibration fvsp; and second belt clamping force increase unit increasing belt clamping force when vfr is second value vfr_psec or greater or when fvsp is third value fvsp_psec or greater in case where road is not judged to be bad road, as compared with case where vfr is less than vfr_psec and case where fvsp is less than fvsp_psec.