A transmission is subject to thermal management to prevent damage or failure due to overheating. Sensors can be employed to capture characteristics of a transmission, such as fluid temperature or pressure. Further, a predictive model can be invoked to predict characteristics based on current and future conditions. Characteristics can be compared with a threshold for intervention. A thermal mitigation strategy can be generated and initiated when characteristics satisfy the threshold. The thermal mitigation strategy can specify various actions to dissipate heat, including altering shift control logic and triggering mechanical devices that can increase airflow, reduce air temperature, or both surrounding the transmission.

A temperature estimation device for friction engaging elements including an execution device and a storage device is provided. The storage device stores mapping data that defines mapping. The mapping includes, as an input variable, a heat amount variable that is a variable indicating an amount of heat generated by the friction engaging elements during the shifting of the transmission and a shifting variable indicating the friction engaging elements to be engaged at the time of the shifting of the transmission, and, as an output variable, the temperature. The execution device executes an acquisition process of acquiring a value of the input variable and a calculation process of inputting the value of the input variable acquired by the acquisition process into the mapping to calculate a value of the output variable.

A controller for a vehicle drive device includes an engagement control part controlling an engagement state of a first engagement device based on an engagement control instruction; a hydraulic pressure information obtaining part obtaining hydraulic pressure information indicating first hydraulic pressure supplied to the first engagement device; an acceleration information obtaining part obtaining acceleration information indicating vehicle acceleration; and a determining part determining a state of the first engagement device, and when an input rotational speed is greater than zero, a state of a transmission is a drive transmission state in which drive power is transmitted, the engagement control instruction is a disengagement instruction brining the first engagement device into a disengaged state, the first hydraulic pressure is greater than a first threshold value, and the acceleration has a negative value smaller than a second threshold value, the determining part determines the first engagement device state is an engagement abnormality.

An engine lubrication system including: an oil pump configured to be driven by an engine; an oil jet mechanism configured to inject oil pressure-fed by the oil pump to a piston; and circuitry configured to set a target hydraulic pressure of the oil injected from the oil jet mechanism according to an operation state of the engine; determine a hydraulic pressure state of the oil injected from the oil jet mechanism; and change a gear stage of the automatic transmission to a lower gear stage in a case that a predetermined condition between the determined hydraulic pressure state and the target hydraulic pressure is satisfied.

An engine lubrication system including: an oil pump configured to be driven by an engine; an oil jet mechanism configured to inject oil pressure-fed by the oil pump to a piston; and circuitry configured to set a target hydraulic pressure of the oil injected from the oil jet mechanism according to an operation state of the engine; determine a hydraulic pressure state of the oil injected from the oil jet mechanism; and change a gear stage of the automatic transmission to a lower gear stage in a case that a predetermined condition between the determined hydraulic pressure state and the target hydraulic pressure is satisfied.

In one aspect, a method is provided or braking a work vehicle including an engine and a hydrostatic drive system including a hydraulic pump configured to be rotationally driven by the engine and a hydraulic motor fluidly coupled with the hydraulic pump through a closed hydraulic loop of the hydrostatic drive system. The hydraulic pump may be configured to fluidly drive the hydraulic motor. The method may include receiving an operator request to reduce a ground speed of the work vehicle. The method may include monitoring a fluid temperature of a hydraulic fluid associated with the closed hydraulic loop and automatically controlling at least one of a pump displacement of the hydraulic pump or a motor displacement of the hydraulic motor based on the operator request and the monitored fluid temperature to adjust hydrostatic braking of the work vehicle and thereby reduce the ground speed of the work vehicle.

In one aspect, a method is provided or braking a work vehicle including an engine and a hydrostatic drive system including a hydraulic pump configured to be rotationally driven by the engine and a hydraulic motor fluidly coupled with the hydraulic pump through a closed hydraulic loop of the hydrostatic drive system. The hydraulic pump may be configured to fluidly drive the hydraulic motor. The method may include receiving an operator request to reduce a ground speed of the work vehicle. The method may include monitoring a fluid temperature of a hydraulic fluid associated with the closed hydraulic loop and automatically controlling at least one of a pump displacement of the hydraulic pump or a motor displacement of the hydraulic motor based on the operator request and the monitored fluid temperature to adjust hydrostatic braking of the work vehicle and thereby reduce the ground speed of the work vehicle.

A method for operating a drive train of a motor vehicle, the drive train having at least one transmission (2) for carrying out different transmission gear ratios between an input shaft (21) and an output shaft (22) of the transmission (2) by selectively engaging hydraulically actuatable shift elements of the transmission (G), the drive train further having an electric machine as a drive source (1), and a hydraulically actuatable or bridgeable starting component (3) in the power path between the drive source (1) and the output shaft (22). The method includes performing a starting process of the motor vehicle driven solely by the drive source (1) with an engaged or bridged starting component (3). The method further includes limiting a drive source torque (1t) during the starting process to a maximum value dependent on a current system pressure (2p) of a hydraulic system of the transmission (2).

A hybrid system includes a transmission control module, a power source, a transmission, and a drive train. The transmission control module partially operates the hybrid system and receives operating information from various components of the system, calculates power losses in the drive train, and calculates the driving torque needed to reach a target power profile determined from a driver's input.

A hybrid vehicle includes an engine, a switching valve, and an electronic control unit. The electronic control unit configured to perform switching from the engine travel mode to the EV travel mode through a first stage to start the filling control when it is determined that the possibility is high that the engine stop condition will be established afterwards while the engine travel mode is selected, a second stage to start the clutch release control by switching the switching valve to the second state in response to establishment of the engine stop condition, and a third stage to stop operation of the engine after completion of the clutch release control.