A gearbox (100) includes an input shaft (105), which is connected to a drive source, and a first and a second proportionally controllable shift element (A-F). A method (200) for open-loop control of the gearbox (100) includes: determining (210) an absolute torque demand (330) on the drive source on the basis of a profile controlled by way of an open-loop system (340) and a profile controlled by way of a closed-loop system (345); determining (220) whether the absolute torque demand (330) threatens to exceed a predetermined threshold value (335); and, in response, reducing (225) the portion controlled by way of the closed-loop system (345).

A power transmission system of a vehicle and a gear-shift control method are provided. The power transmission system includes a first drive assembly (101) and a second drive assembly (102). The first drive assembly includes a first automatic transmission (2) and a first motor (1) connected with the first automatic transmission (2) for outputting power to two wheels of the vehicle. The second drive assembly (102) includes a second automatic transmission (2000) and a second motor (1000) connected with the second automatic transmission (2000) for outputting power to the other two wheels of the vehicle. The first and second automatic transmission are configured to be shifted to a preset gear or a gear adjacent to the preset gear, such that when one of the first and second automatic transmission is shifted to the preset gear, the other one of the first and second automatic transmission is shifted to the preset gear or the gear adjacent to the preset gear.

A power transmission system of a vehicle and a gear-shift control method are provided. The power transmission system includes a first drive assembly (101) and a second drive assembly (102). The first drive assembly includes a first automatic transmission (2) and a first motor (1) connected with the first automatic transmission (2) for outputting power to two wheels of the vehicle. The second drive assembly (102) includes a second automatic transmission (2000) and a second motor (1000) connected with the second automatic transmission (2000) for outputting power to the other two wheels of the vehicle. The first and second automatic transmission are configured to be shifted to a preset gear or a gear adjacent to the preset gear, such that when one of the first and second automatic transmission is shifted to the preset gear, the other one of the first and second automatic transmission is shifted to the preset gear or the gear adjacent to the preset gear.

A control device that includes an electronic control unit that is configured to, in a case where a request to start the internal combustion engine is made while a downshift for changing a speed ratio of the speed change device so that the speed ratio after shifting is higher than the speed ratio before shifting is being performed in the electric drive state, perform the first start control after the downshift is completed.

A control device that includes an electronic control unit that is configured to, in a case where a request to start the internal combustion engine is made while a downshift for changing a speed ratio of the speed change device so that the speed ratio after shifting is higher than the speed ratio before shifting is being performed in the electric drive state, perform the first start control after the downshift is completed.

A method for evaluating a transmission device using various characteristic values, wherein said characteristic values can be determined by means of variable or constant parameters.

A method for evaluating a transmission device using various characteristic values, wherein said characteristic values can be determined by means of variable or constant parameters.

An electronic control unit is configured to set a target torque phase time which is used in torque phase control based on an output shaft torque difference. The electronic control unit sets the target torque phase time to be longer when the output shaft torque difference is large than when the output shaft torque difference is small. Accordingly, since the target torque phase time can be appropriately set, it is possible to achieve both of preventing a sudden change in driving force and torsion vibration of an output shaft and preventing a decrease in drivability due to hesitation at the same time. Sudden change in driving force and torsion vibration of the output shaft occur when the difference in driving force between before and after a gear shift is large. Hesitation occurs when the difference in driving force between before and after the gear shift is small.

An electronic control unit is configured to set a target torque phase time which is used in torque phase control based on an output shaft torque difference. The electronic control unit sets the target torque phase time to be longer when the output shaft torque difference is large than when the output shaft torque difference is small. Accordingly, since the target torque phase time can be appropriately set, it is possible to achieve both of preventing a sudden change in driving force and torsion vibration of an output shaft and preventing a decrease in drivability due to hesitation at the same time. Sudden change in driving force and torsion vibration of the output shaft occur when the difference in driving force between before and after a gear shift is large. Hesitation occurs when the difference in driving force between before and after the gear shift is small.

A wheel loader includes a forward clutch, an accelerator pedal, a brake pedal, and a controller configured to control hydraulic pressure of hydraulic oil supplied to the forward clutch. The controller performs clutch hydraulic pressure control for reducing the hydraulic pressure of the hydraulic oil supplied to the forward clutch according to an operation amount of the brake pedal on condition that at least the brake pedal is operated while the accelerator pedal is being operated. The controller continues the clutch hydraulic pressure control even after the clutch shifts from a complete engagement state to a semi-engagement state by the clutch hydraulic pressure control.