Various methods and systems are provided for a shift assembly for a vehicle transmission. In one example, a shift assembly for a transmission includes a first barrel cam including a first cam track; a second barrel cam arranged coaxially with the first barrel cam and including a second cam track; a first motor configured to drive the first barrel cam independent of the second barrel cam; and a second motor configured to drive the second barrel cam independent of the first barrel cam.

A variable speed control system includes a multiple-speed transmission which changes a speed of an engine output in multiple stages based on a change in meshing state of a dog clutch which is caused in association with an operation of a change pedal connected mechanically, a pedal load detection device which detects an operation load of the change pedal, and a control unit which suppresses or shuts off an engine output to the multiple-speed transmission and permits a speed change action of the multiple-speed transmission by the change pedal when a detected pedal load exceeds a pedal load threshold. The variable speed control system further includes an engine revolution speed detection sensor which detects an engine revolution speed. The control unit changes the pedal load threshold according to the engine revolution speed detected. Such variable speed control system can realize a stable speed change action irrespective of running conditions.

A method of controlling a transmission for a vehicle may include performing deceleration intention determination, by a controller, of determining an intention of a driver for deceleration based on whether a brake pedal signal is received by the controller, upon determining that the driver intends to decelerate, performing downshift determination, by the controller, of determining an intention of the driver to use engine braking based on whether manual downshift of a shifter is performed by the driver, upon determining that the driver intends to use the engine braking, performing continuous shifting determination, by the controller, of determining whether the driver intends to implement maximum engine braking through continuous shifting, and upon determining that the driver has the intention to implement the maximum engine braking, performing continuous shifting, by the controller, of implementing maximum engine braking by shifting to a lowest gear implementable under a current driving condition.

A method to control a road vehicle provided with a clutch, which connects an internal combustion engine to drive wheels and is arranged upstream of a servo-assisted transmission; the control method comprises the steps of: checking whether the tyres of the drive wheels are close to a grip limit; and opening the clutch so that the clutch transmits a torque to the drive wheels with a slip of the clutch that is constant and other than zero when the tyres of the drive wheels are close to the grip limit.

A recreational vehicle is provided including a power source, such as an engine or an electric motor, and a transmission having a variable gear ratio. A sub-transmission coupled to an output of the transmission includes a plurality of selectable gear configurations including at least one of a forward gear, a neutral gear, a reverse gear, and a park gear. An electronic controller is operative to electronically control the gear configuration of the sub-transmission.

A transmission system configured to perform a gear change based on a shift operation by an operator is provided, which includes a power transmission system including a transmission and configured to transmit an engine driving force to wheels, a shift operation detecting module, and a transmission controlling module adapted to be executable of a manual rotation synchronizing mode having first and second steps. In the first step, when a first shift operation for changing the transmission to a lower-speed side is detected, the transmission controlling module sends a control signal to a connecting-and-disconnecting mechanism provided to the power transmission system to suspend the transmission of the driving force. In the second step, when a second shift operation is detected, the transmission controlling module sends a control signal to the connecting-and-disconnecting mechanism to resume the transmission of the driving force while the transmission is switched to the lower-speed side.

A slip control method and arrangement for a drivetrain including a continuously variable transmission, forward-reverse clutch arrangement and an optional three-speed gearbox is described herein. The forward-reverse clutch arrangement includes a clutch that is so controlled as to slip when a torque higher than the usable torque attempts to pass through. Accordingly, the clutch prevents the prime mover from stalling.

A control system for a work vehicle includes a power source with an engine and at least one motor configured to generate power; a transmission including a plurality of clutches configured for selective engagement to transfer the power to drive an output shaft of a powertrain of the work vehicle; and a controller coupled to the power source and the transmission. The controller has a processor and memory architecture configured to: initiate a transition for the transmission between a first transmission mode and a second transmission mode at a first shift point associated with an engine throttle shift function; determine a current engine speed; and generate and execute an engine speed command for the engine such that a commanded engine speed is a function of the current engine speed in accordance with the engine throttle shift function upon the transition of the transmission at the first shift point.

A transmission system configured to perform a gear change based on a shift operation by an operator is provided, which includes a power transmission system including a transmission and configured to transmit an engine driving force to wheels, a shift operation detecting module, and a transmission controlling module adapted to be executable of a manual rotation synchronizing mode having first and second steps. In the first step, when a first shift operation for changing the transmission to a lower-speed side is detected, the transmission controlling module sends a control signal to a connecting-and-disconnecting mechanism provided to the power transmission system to suspend the transmission of the driving force. In the second step, when a second shift operation is detected, the transmission controlling module sends a control signal to the connecting-and-disconnecting mechanism to resume the transmission of the driving force while the transmission is switched to the lower-speed side.

A control device for an automatic transmission arranged between an engine and a drive wheel, the automatic transmission including a torque converter having a lock-up clutch, and a transmission mechanism. The control device includes a shift control unit configured to perform shift control of the transmission mechanism. The shift control unit includes a forced downshift control processing unit configured to implement forced downshift when an accelerator foot release operation is performed during auto-upshift in a power-on state with the lock-up clutch engaged. The forced downshift control processing unit is configured to start the forced downshift before an engine rotation speed that has decreased due to the auto-upshift reaches a lock-up release rotation speed.