Methods and system are described for changing a driveline gear range from a higher gear range to a lower gear range. The driveline may include two electric machines and four clutches in a four wheel drive configuration. The methods and systems permit a driveline to change from a higher gear range to a lower gear range without stopping a vehicle.

A method of controlling an automatic transmission connected to an engine in a motor vehicle includes receiving an input signal generated via an application of force by a switch inside the vehicle. The switch has a predetermined travel and is configured to request a transmission speed-ratio change via an output signal indicative of the received input signal. The output signal is received via a controller programmed with a permitted engine speed range. The transmission is commanded to execute a change from a currently selected speed-ratio to another speed-ratio if the requested speed-ratio change would generate an engine speed within the permitted engine speed range. The switch is commanded to execute full travel under the application of force if the speed-ratio change in the transmission was commanded. Alternatively, the switch is commanded to execute partial travel under the application of force if the speed-ratio change in the transmission was not commanded.

A control device of a continuously variable transmission has at least an automatic shift mode and a temporary manual mode. The control device includes an insufficient drive force determination unit, a first insufficient acceleration determination unit, and a downshift control unit. The insufficient drive force determination unit determines whether drive force insufficiency occurs if acceleration is performed in the current transmission gear. The first insufficient acceleration determination unit determines whether there is an acceleration request made by the driver of the vehicle. The downshift control unit downshifts from the current transmission gear to a transmission gear at a lower speed side in a case where, in the temporary manual mode, the insufficient drive force determination unit determines that a drive force insufficiency occurs and the first acceleration request determination unit determines that there is an acceleration request.

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 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 method to control a road vehicle for the execution of a multiple downshift in a drivetrain provided with a servo-assisted transmission; the control method comprises the steps of: detecting a condition of slowing down of the road vehicle and, simultaneously, detecting a driver's request for a multiple downshift; carrying out, in succession, a plurality of downshifts while the road vehicle is slowing down and in an autonomous manner regardless of further interventions of the driver; determining a duration of a shift time interval; and carrying out each downshift following a first downshift when said shift time interval has exactly elapsed since the previous downshift.

A control unit is provided for an automatic transmission of a vehicle. The vehicle has a gear selection operating element which allows a user of the vehicle to set different gear stages of the transmission by actuating the gear selection operating element, and the vehicle has at least one setting operating element which allows the user to change the value of a parameter of a function of the vehicle by actuating the setting operating element when the function of the vehicle is activated. The control unit is designed to detect an actuation of the gear selection operating element for a period of time which is equal to or longer than a minimum duration and to determine that the function of the vehicle is deactivated. In response thereto, the control unit is additionally designed to allow a manual change of the transmission gear by actuating the at least one setting operating element.

A shift mode control system includes a control apparatus that controls a shift mode of a vehicle, a first operation device that receives a first operation to switch an automatic mode to a manual mode, and a second operation device that receives a second operation to switch the manual mode to the automatic mode. The control apparatus includes a processor that calculates a speed ratio change amount that is a difference between a first speed ratio set when the automatic mode is switched to the manual mode in accordance with the first operation and a second speed ratio set when the manual mode is switched to the automatic mode in accordance with the second operation. The processor updates the speed ratio change amount set as a switching condition for automatically switching the manual mode to the automatic mode to the speed ratio change amount calculated by the processor.

A shift mode control system includes a control apparatus that controls a shift mode of a vehicle, a first operation device that receives a first operation to switch an automatic mode to a manual mode, and a second operation device that receives a second operation to switch the manual mode to the automatic mode. The control apparatus includes a processor that calculates a speed ratio change amount that is a difference between a first speed ratio set when the automatic mode is switched to the manual mode in accordance with the first operation and a second speed ratio set when the manual mode is switched to the automatic mode in accordance with the second operation. The processor updates the speed ratio change amount set as a switching condition for automatically switching the manual mode to the automatic mode to the speed ratio change amount calculated by the processor.

A control unit is provided for an automatic transmission of a vehicle. The vehicle has a gear selection operating element which allows a user of the vehicle to set different gear stages of the transmission by actuating the gear selection operating element, and the vehicle has at least one setting operating element which allows the user to change the value of a parameter of a function of the vehicle by actuating the setting operating element when the function of the vehicle is activated. The control unit is designed to detect an actuation of the gear selection operating element for a period of time which is equal to or longer than a minimum duration and to determine that the function of the vehicle is deactivated. In response thereto, the control unit is additionally designed to allow a manual change of the transmission gear by actuating the at least one setting operating element.