A power system includes an engine; a sensor to determine an engine speed; and a transmission. The transmission includes an input element configured to receive the power from the engine as input torque; an output element configured to provide at least a portion the power from the engine as output torque; and a clutch arrangement to transform the input torque into output torque. The clutch arrangement includes at least one clutch selectively positionable between a fully engaged state, a partially engaged state in which a portion of the input torque is transformed into the output torque, and a fully disengaged state. A controller is coupled to the at least one clutch and configured to generate clutch commands based at least in part on the engine speed to position the at least one clutch into the fully engaged state, the partially engaged state, or the fully disengaged state.

Transmissions, control systems for transmissions, and methods of operating transmissions are disclosed herein. A transmission includes an input shaft, an output shaft, one or more clutches, and a control system. The input shaft is configured to receive rotational power supplied by a drive unit. The output shaft is coupled to the input shaft and configured to provide rotational power supplied to the input shaft to a load. The one or more clutches are coupled between the input shaft and the output shaft to selectively transmit rotational power between the input shaft and the output shaft in one or more operating modes of the transmission. Each of the one or more clutches is selectively engageable in response to one or more fluid pressures applied thereto. The control system is configured to control operation of the one or more clutches to select the one or more operating modes of the transmission.

Transmissions, control systems for transmissions, and methods of operating transmissions are disclosed herein. A transmission includes an input shaft, an output shaft, one or more clutches, and a control system. The input shaft is configured to receive rotational power supplied by a drive unit. The output shaft is coupled to the input shaft and configured to provide rotational power supplied to the input shaft to a load. The one or more clutches are coupled between the input shaft and the output shaft to selectively transmit rotational power between the input shaft and the output shaft in one or more operating modes of the transmission. Each of the one or more clutches is selectively engageable in response to one or more fluid pressures applied thereto. The control system is configured to control operation of the one or more clutches to select the one or more operating modes of the transmission.

An inching system for a vehicle having a hydrostatic transmission and an engine that drives the transmission. The transmission has a pilot pressure port with a pressure of hydraulic fluid at the pilot pressure port controlling a level of power from the transmission, a beginning of draining of the hydraulic fluid from the pilot pressure port defining an inching starting point. The system includes a brake pedal and an electrohydraulic valve coupled to the pilot pressure port of the transmission, the valve being configured to drain the hydraulic fluid at the pilot pressure port. A sensor is coupled to the pedal to detect an input from the operator, the sensor producing a signal indicative of the input from the operator. A controller receives the signal and a speed of the engine. The controller controls the electrohydraulic valve dependent upon the signal and the engine speed so that the inching starting point is unchanged regardless of the speed of the engine.

An inching system for a vehicle having a hydrostatic transmission and an engine that drives the transmission. The transmission has a pilot pressure port with a pressure of hydraulic fluid at the pilot pressure port controlling a level of power from the transmission, a beginning of draining of the hydraulic fluid from the pilot pressure port defining an inching starting point. The system includes a brake pedal and an electrohydraulic valve coupled to the pilot pressure port of the transmission, the valve being configured to drain the hydraulic fluid at the pilot pressure port. A sensor is coupled to the pedal to detect an input from the operator, the sensor producing a signal indicative of the input from the operator. A controller receives the signal and a speed of the engine. The controller controls the electrohydraulic valve dependent upon the signal and the engine speed so that the inching starting point is unchanged regardless of the speed of the engine.

Provided is a transmission control device which can improve drivability in an acceleration section even while taking a reduction of fuel consumption in a deceleration section into consideration. The transmission control device (transmission controller) which controls a transmission in a running control of a vehicle includes a shift timing calculation unit which determines an acceleration position at which the vehicle accelerates on the basis of a target speed pattern generated from external information, a target gear ratio calculation unit which determines a required gear ratio which is required at the acceleration position, and a gear ratio overwriting command unit which outputs a command of overwriting the gear ratio such that the gear ratio at the acceleration position approaches the required gear ratio. In the control of the transmission of the transmission controller, the gear ratio is set to the required gear ratio (target gear ratio) at a predetermined point after the vehicle exits the deceleration section and reaches the acceleration position.

A work vehicle includes an engine, a hydrostatic transmission, and a controller. The hydrostatic transmission includes a traveling pump driven by the engine, a hydraulic circuit connected to the traveling pump, and a traveling motor connected to the traveling pump via the hydraulic circuit. The controller is configured to control the traveling motor and the traveling pump, determine a target flow rate of the traveling motor or the traveling pump, determine a correction amount of the target flow rate from a hydraulic pressure of the hydraulic circuit, and determine a target displacement of the traveling motor or the traveling pump from the target flow rate and the correction amount.

A work vehicle includes an engine, a hydrostatic transmission, and a controller. The hydrostatic transmission includes a traveling pump driven by the engine, a hydraulic circuit connected to the traveling pump, and a traveling motor connected to the traveling pump via the hydraulic circuit. The controller is configured to control the traveling motor and the traveling pump, determine a target flow rate of the traveling motor or the traveling pump, determine a correction amount of the target flow rate from a hydraulic pressure of the hydraulic circuit, and determine a target displacement of the traveling motor or the traveling pump from the target flow rate and the correction amount.

An electronic control module (ECM) may obtain sensor information concerning an engine and may determine, based on the sensor information, a speed of the engine. The ECM may cause a swashplate of a hydraulic pump to adjust based on the speed of the engine.

An electronic control module (ECM) may obtain sensor information concerning an engine and may determine, based on the sensor information, a speed of the engine. The ECM may cause a swashplate of a hydraulic pump to adjust based on the speed of the engine.