Abstract:
A system and method for regulating torque transmitted via a torque converter can include providing a lock up clutch between a crankshaft and transmission of a vehicle. A position sensor can output data indicative of at least one of an engaged position of the lock-up clutch, a transitional position of the lock-up clutch, and a disengaged position of the lock-up clutch. An engine speed sensor can output data indicative of rotational speed of the crankshaft. A controller can be placed in electrical communication with the engine speed sensor and the position sensor and configured to determine when actuation of the lock-up clutch is desired. The controller can be configured to determine a torque reduction target based on certain variables, for example, engine acceleration. The controller can then signal the engine to output torque substantially equal to the torque reduction target when conditions exist that warrant torque reduction.
Abstract:
A vehicle drivetrain can include various structures, such as a multi-ratio transmission, a two-speed final drive assembly connected in series with the multi-ratio transmission and including a low speed final drive ratio and a high speed final drive ratio, a pair of front driveshafts driven by the two-speed final drive assembly, a pair of rear driveshafts, a rear differential assembly connected to the two-speed final drive assembly, and a control assembly including. The control assembly can include a controller in electrical communication with portions of the rear differential assembly, such as a variable displacement pump and purge valve. An input array can be in electrical communication with the controller and can include a plurality of sensors, and at least one switch accessible to an operator of the vehicle. Various related methods can also be executed for control and operation of such a drivetrain. The methods can incorporate a number of variables in order to control the drivetrain, and the variables can include but are not limited to road grade, vehicle acceleration, vehicle speed, presence of towing apparatus, road surface conditions, switch condition(s), etc.
Abstract:
A vehicle anti-rollback system and method can be incorporated into a vehicle that includes a pair of front wheels, a pair of rear wheels, a power unit, and a transmission connecting the power unit to at least one wheel of the front and rear wheels. The transmission can include a plurality of forward drive ratios and at least one reverse drive ratio and a two speed final drive ratio transmission configured to select between a high range drive ratio and a low range drive ratio when the transmission is in one of the plurality of forward drive ratios. A controller can be provided that senses a vehicle rollback condition. When the rollback condition is detected, the controller can decrease torque distributed from the power unit of the vehicle to the at least one wheel, and can actuate a brake. While the vehicle is braked and torque transfer is reduced, the controller can execute drive ratio changeover in a stable manner from the high range drive ratio to the low range drive ratio.