Caterpillar Inc.

Caterpilliar Inc.

Abhishek Awana

Christopher Lewis Wynkoop

Matthew Michael Tinker

Jeremy Dean Folkerts

Aaron Y Ho

Shanmugahari Murugesan

Robert Nicholas Harper

Ethan V Ferguson

Michael K Schallhorn

Mariappan Paramasivan

The present disclosure relates to a method of controlling gear selection in a transmission of a vehicle in response to a directional shift requested by an operator and to a control system for controlling gear selection to manage directional shifts in vehicles, from a first direct to a second direction (e.g. forward to reverse). The method compares the current transmission output speed with a predetermined direction shift threshold transmission output speed. If the current transmission output speed is less than or equal to the predetermined direction shift threshold transmission output speed, the transmission is caused to execute a direction shift from the initial first direction gear to the same second direction gear, or a next highest second direction gear if there is no second direction gear which corresponds to the initial first direction gear. If the current transmission output speed is greater than the predetermined direction shift threshold transmission output speed, the direction shift is inhibited until the current transmission output speed slows to less than or equal to the predetermined direction shift threshold transmission output speed.

Directional shift control in vehicles

A method for controlling powertrain of a machine not having a torque converter output speed sensor during a direction change of the machine is provided. The method includes retrieving a first desired engine speed value and a second desired engine speed value based on a detection of the direction change by a control module. The second desired engine speed value is determined based on a current gear setting of a gear shift lever and a desired gear setting of the gear shift lever. The method further includes determining the desired engine speed value based on a comparison between the first desired engine speed value and the second desired engine speed value by the control module. The control module is configured to identify a lower value of the first desired engine speed value and the second desired engine speed value as the desired engine speed value.

System and method to control powertrain during directional shift

A transmission control system for a machine is disclosed. The transmission control system may determine whether engine speed regulation during gear shift is enabled or disabled for the machine. The transmission control system may select a speed threshold, for inhibiting a high speed directional shift of the machine, based on whether the engine speed regulation during gear shift is enabled or disabled for the machine. The transmission control system may compare a speed of the machine and the speed threshold, and may selectively inhibit the high speed directional shift for the machine based on comparing the speed of the machine and the speed threshold.

Inhibiting high speed directional shifts based on whether controlled throttle shifting is enabled or disabled

A method for controlling an engagement of a lock-up clutch (LUC) of a torque converter of a machine is disclosed. The method includes detecting a pedal tap of a pedal, wherein the pedal tap is detected when the pedal is depressed from a position corresponding to a pedal displacement less than a first threshold displacement to a position corresponding to a pedal displacement greater than a second threshold displacement, and then released to a position corresponding to a pedal displacement less than the first threshold displacement within a threshold time duration. The method further includes causing the LUC to move to the LUC unlocked position if the pedal tap is detected.

Retarding system and lock-up clutch engagement control

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Dunlap, IL, United States of America

Abhishek Awana