A control device of a vehicle includes between an engine and an automatic transmission a fluid transmission device transmitting power from a pump impeller coupled to the engine via a fluid to a turbine impeller coupled to the automatic transmission. The control device determines occurrence of a lost-drive state of the fluid transmission device based on an increase amount of a rotation speed of the engine after a predetermined time during start of the engine.

A powertrain for a machine includes an internal combustion engine, an aftertreatment system including a selective catalytic reduction (SCR) catalyst for treating exhaust gases from the internal combustion engine, and a continuously variable transmission operatively coupled to the internal combustion engine. An electronic controller can measure a catalyst temperature of the SCR catalyst and can inversely adjust an engine speed and a CVT output to selectively regulate a catalyst temperature of the SCR catalyst. In an embodiment, the CVT may be a hydro-mechanical transmission including a hydrostatic transmission and a mechanical transmission.

A gear shift control device for a continuously variable transmission of a vehicle is configured to steplessly and continuously change and output a rotation speed of an engine. The gear shift control device includes a gear shift control unit and a torque control command unit. The gear shift control unit is configured to implement a pseudo-stepped upshift control to change a gear shift ratio in steps when upshifting the continuously variable transmission. The torque control command unit is configured to output a torque reduction command so as to reduce an engine torque in conjunction with the pseudo-stepped upshift control so that reduction of the engine torque starts before a point in time when an actual gear shift ratio starts changing in response to an upshift command.

A speed change control system for a vehicle configured to reduce uncomfortable feeling of a driver when shifting an operating mode via the fixed mode. When a required drive force to propel the vehicle is increased, a controller shifts the operating mode from a first continuously variable mode to a second continuously variable mode via a fixed mode. In this case, the controller increases an engine speed to a first target speed from a point when shifting from the fixed mode to the second continuously variable mode, and further increase the engine speed to a second target speed calculated based on the required drive force. In addition, the controller reduces the first target speed with an increase in at least any one of a first elapsed time and a second elapsed time.

A process for determining a setpoint rotational speed of a work machine engine, having a continuously variable transmission, based on operation of power hydraulics. The setpoint rotational speed for highly productive operation is determined, without knowledge current operation of the power hydraulics, by a basic engine speed setting. With knowledge of the current operating state, the setpoint rotational speed is determined by the basic speed settings and low or high engine speed settings. The low speed setting alone determines setpoint rotational speeds that are lower than the basic speed setting or a combination of the low and basic speed settings. The high speed setting alone determines setpoint rotational speeds that are higher than the basic speed setting or a combination of the basic and high speed settings. The speed settings can comprise a setpoint rotational speed range of above a reciprocal transmission range of the variable transmission.

Methods and systems are provided for controlling a vehicle engine to deliver desired torque to a power take off device coupled to the engine. In one example, the method may include, learning a filtered PTO torque demand during vehicle acceleration, and steady state operation, and during transition in engine states using the learned PTO torque demand to adjust engine speed in order to deliver a desired engine torque output for optimal operation of the PTO device.

A control device of a vehicle includes between an engine and an automatic transmission a fluid transmission device transmitting power from a pump impeller coupled to the engine via a fluid to a turbine impeller coupled to the automatic transmission. The control device determines occurrence of a lost-drive state of the fluid transmission device based on an increase amount of a rotation speed of the engine after a predetermined time during start of the engine.

A vehicle control method is provided for controlling a vehicle in which a clutch provided on a power transmission path between an engine and a drive wheel is disconnected when a shift range is a non-driving range and the clutch is connected when the shift range is a driving range. The vehicle control method controls the engine to a prescribed idling speed, controls engine torque to a negative torque by delaying an ignition timing of the engine; and causes the prescribed idling speed to drop within a prescribed amount of time needed for the clutch to switch from being disconnected to being connected when the shift range is switched from the non-driving range to the driving range.

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 for the operation of a vehicle drive-train of a working machine having a drive motor, a transmission whose transmission ratio can be varied continuously, and a drive output. A rotational speed (nmot) of the drive motor can be varied by the driver, by the driver's actuation of a first control element (50), within a rotational speed range (53) delimited by an upper characteristic line (nmoto) and a lower characteristic line (nmotu). The characteristic lines (nmoto, nmotu) are functions of a reciprocal transmission ratio (irez) of the transmission. Furthermore, the rotational speed (nmot1) of the drive motor that can be set by the driver by way of the first control element (50), can be influenced by the driver's actuation of a second control element (51) and as a function of an operating condition of the working machine.