A control device for an automatic transmission includes: a first engagement control section configured to bring the lockup clutch to a full engagement state after a rotation of the internal combustion engine is increased in a slip engagement state while a torque transmission capacity of the lockup clutch is increased, and a second engagement control section configured to add a predetermined capacity to the increased torque transmission capacity when the torque judging section judges an increase of the output torque of the internal combustion engine in a state where a sensed rotation speed difference in the slip engagement state of the engagement state of the first engagement control is increased to be equal to or greater than a first predetermined value, and then decreased to be equal to or smaller than a second predetermined value smaller than the first predetermined value.

The present invention is a control device for an automatic transmission, the control device being adapted to control the automatic transmission including a torque converter and a stepped transmission mechanism provided on a power transmission route from the torque converter to drive wheels, wherein while a non-driving range of the automatic transmission is selected, determination on interlock in the stepped transmission mechanism is executed on the basis of deceleration of an output shaft of the stepped transmission mechanism and a change in the torque converter.

An actual slip amount (S) of a torque converter is calculated by subtracting an actual input shaft rotational speed (Nr) of an automatic transmission from an engine rotational speed (Ne), which is the rotational speed of a crankshaft. Then, an engine rotational speed for display (Nd) is calculated by adding a slip amount adjusted for display (Sp), which is obtained by applying a predetermined correction process to the actual slip amount (S) to the actual input shaft rotational speed (Nr). The above described correction process may be a first-order-lag filter processing, for example. Thus, even when the actual slip amount (S) temporarily increases or decreases, a temporary increase or decrease in the engine rotational speed for display (Nd) may be suppressed. In other words, fluctuation or variation in the engine rotational speed for display (Nd) is suppressed. Further, Further, it is possible to provide the driver with a visually excellent direct-feeling display of engine speed Nd without impairing the drivability.

A control device for an automatic transmission includes: a transmission gear ratio control section configured to control the transmission gear ratio so that a rotation speed of the output element rapidly becomes closer to a rotation speed of the internal combustion engine, a first engagement control section configured to perform a first engagement control to be brought to the full engagement state after the rotation of the internal combustion engine is increased in the slip engagement state while a torque transmission capacity of the lockup clutch is increased when the lockup clutch is switched through the slip engagement state to the full engagement state by an ON operation of an accelerator of the vehicle, the transmission gear ratio control being prohibited during the first engagement control by the first engagement control section.

A system for determining a torque converter clutch is stuck in an engaged position includes a control module, an engine speed sensor, and a transmission speed sensor. The control module evaluates the torque converter clutch by determining a value of a torque converter clutch command. The torque converter clutch command indicates a position of the torque converter clutch. In response to determining that the value of the torque converter clutch command indicates the disengaged position, the control module calculates accumulated slip based on the transmission speed and the engine speed during an evaluation time. In response to determining the evaluation time is complete, the control module compares the accumulated slip with a calibrated threshold of slip. In response to the accumulated slip being less than or equal to the calibrated threshold of slip, the control module determines the torque converter clutch is stuck in the engaged position.

A loader backhoe work machine in which a power unit is coupled to a power train through a torque convertor. The torque convertor incorporates a lock up clutch to enable more efficient operation of the work machine in a transport mode while retaining the torque multiplication feature during the loading and/or backhoe operations. The control system for the lock up clutch senses selected engine and system operating parameters to engage the lock up clutch only when those sensors indicate a transport operating condition.

The present disclosure includes a system for improving the perceived ease of operation in a work vehicle with an internal combustion engine. According to an aspect of the present disclosure, the system comprises a torque converter coupled at one end to the internal combustion engine and is coupled to a transmission at an opposite end via at least a transmission input shaft. The system also comprises at least two governors coupled to the internal combustion engine, wherein the governors are configured to adjust an operating parameter of the internal combustion engine. In addition, the system comprises a vehicle control unit communicatively coupled to the governors wherein the vehicle control unit is configured to receive a first and a second speed signal. This vehicle control unit commands the engine control unit to enable to at least one of the governors when a ratio of the first speed signal to the second speed signal exceeds a first predetermined threshold.

A method of controlling a transmission includes providing an input, an output, a controller, a control system, a hydrostatic unit, and a geartrain. The geartrain includes a direct drive pivot clutch and a steer drive geartrain. The method also includes receiving a pivot command by the controller from a shift selector, where the command indicates the shift selector is in a pivot position. The method further includes engaging the direct drive pivot clutch, decoupling the hydrostatic unit from a torque path defined between the input and the output, and coupling the input and the output to one another via a second torque path. The second torque path is defined through the direct drive pivot clutch and the steer drive geartrain. The transmission is controllable in a direct drive steer operation.

Techniques modeling and controlling a torque converter of a vehicle include accessing a look-up table relating (i) various K-factors of a turbine of the torque converter to (ii) various K-factors of an impeller of the torque converter, speed ratios of the torque converter, and torque ratios of the torque converter, calculating a K-factor of the turbine based on the set of parameters, determining a speed ratio and a torque ratio of the torque converter based on the calculated turbine K-factor using the look-up table, determining a target speed and a target torque for the impeller based on the determined speed and torque ratios of the torque converter, and controlling a torque generating system including the torque converter to achieve the target impeller speed and torque to thereby achieve the torque request at a driveline and mitigate or eliminate noise/vibration/harshness (NVH).

The present disclosure includes a system for improving the perceived ease of operation in a work vehicle with an internal combustion engine. According to an aspect of the present disclosure, the system comprises a torque converter coupled at one end to the internal combustion engine and is coupled to a transmission at an opposite end via at least a transmission input shaft. The system also comprises at least two governors coupled to the internal combustion engine, wherein the governors are configured to adjust an operating parameter of the internal combustion engine. In addition, the system comprises a vehicle control unit communicatively coupled to the governors wherein the vehicle control unit is configured to receive a first and a second speed signal. This vehicle control unit commands the engine control unit to enable to at least one of the governors when a ratio of the first speed signal to the second speed signal exceeds a first predetermined threshold.