A mobile work machine has a drive unit for driving at least one drive element and/or a working element. The drive unit is hydromechanical drive unit with at least one internal combustion engine and hydraulic energy transmission unit with at least one hydraulic pump and a hydraulic motor. In normal operation, the motor shaft of the internal combustion engine rotates at a normal speed (n_0). Conversely, in a limit temperature operation in which a sensed actual operating temperature of the internal combustion engine or another part of the drive unit is higher than or equal to a target limit temperature (T_limit), an electrical control unit and/or electronic control unit controls the internal combustion engine in such a way that the motor shaft of the internal combustion engine rotates at a first speed (n_target) that is higher than the normal speed (n_0) of the motor shaft in normal operation.

An exemplary method generally involves determining a hazard parameter for a tracked vehicle including a ground interface assembly. The ground interface assembly generally includes a track and a drive wheel operable to move the track to thereby propel the tracked vehicle. A load sensor senses a load carried by the tracked vehicle, and a speed sensor senses a vehicle speed of the tracked vehicle. A control system in communication with the load sensor, the speed sensor, and a temperature sensor determines the hazard parameter based upon the load, the vehicle speed, and an ambient temperature in a vicinity of the tracked vehicle. The control system compares the hazard parameter to a threshold parameter, and performs an action based upon the comparison.

Methods and systems are provided for operating a driveline of a hybrid vehicle during conditions when a temperature of a motor/generator is increasing. In one example, a method is provided that adjusts engine speed as a function of motor/generator temperature while maintaining engine power output when driver demand wheel power is constant.

An example method includes making a first determination that a load of a cooling system of a vehicle is expected to increase and become greater than a capacity of the cooling system; operating, in response to making the first determination, the vehicle in a first mode where a combustion engine and an electric motor operate such that a charge level of a power supply of the vehicle increases or is maintained above a threshold charge level; making, after operating the vehicle in the first mode, a second determination that the load of the cooling system has become greater than the capacity of the cooling system; and operating, in response to making the second determination, the vehicle in a second mode where the combustion engine and the electric motor operate such that the charge level of the power supply decreases or is maintained below the threshold charge level.

A control method for a hybrid vehicle is provided. The hybrid vehicle includes: a generator configured to charge a battery by using power of an engine; an electric motor configured to drive a driving wheel by electric power of the battery; and a particulate filter configured to collect particulate matter contained in exhaust gas from the engine. In the control method, the engine is driven to raise a temperature of the particulate filter when a first temperature rise condition is satisfied in which a first predetermined amount or more of the particulate matter is accumulated in the particulate filter and the temperature of the particulate filter is equal to or lower than a predetermined temperature. Drive of the engine is prohibited, when a predetermined first condition that a driver does not intend to drive the engine is satisfied.

A system and method for controlling a hybrid vehicle having an engine, a traction motor, and an automatic step-ratio transmission having a plurality of selectable discrete gear ratios, a torque converter, and sharing a common cooling fluid or oil with the traction motor, include a controller configured to shift the automatic step-ratio transmission to neutral in response to vehicle speed being below a threshold with the engine idling while temperatures of at least two of: the traction battery, the electric machine, and the transmission are above associated thresholds to reduce heat generation by the torque converter due to oil shear with the torque converter stalled. The controller may shift the transmission to drive in response to release of a brake pedal. A neutral shift may also be performed in response to high-voltage accessory loads or on-board generator loads exceeding a threshold.

To curb temperature rises in a control device for a supercharger and extend the life of the control device for the supercharger, a work vehicle includes a variable geometry supercharger with variable boost pressure, and a working device driven by pressure oil discharged from a working hydraulic pump, the work vehicle further including: a supercharger control device adapted to control the supercharger; a temperature detection device adapted to detect temperature of the supercharger control device; and a main control device adapted to limit at least one of maximum rotational speed of an engine and maximum vehicle speed of the work vehicle in case the temperature of the supercharger control device is above a predetermined temperature as compared to case the temperature of the supercharger control device is below the predetermined temperature.

An apparatus including a transmission mechanism in a power transfer path between a drive source and wheels; an oil pressure control device supplying lubricating oil to the transmission mechanism; and a control part outputting an electrical instruction to increase a flow rate of the supplied lubricating. When the control part outputs an electrical instruction to the oil pressure control device to increase a flow rate of lubricating oil supplied to the transmission mechanism, and determines that the flow rate of lubricating oil supplied to the transmission mechanism from the oil pressure control device does not increase as indicated by the electrical instruction (time t1), the control part considers that the oil pressure control device is in an abnormal state, and can impose a limitation that an absolute value of torque of the transmission mechanism transferred between the wheels and the drive source be reduced (time t1-t5).

A transmission is subject to thermal management to prevent damage or failure due to overheating. Sensors can be employed to capture characteristics of a transmission, such as fluid temperature or pressure. Further, a predictive model can be invoked to predict characteristics based on current and future conditions. Characteristics can be compared with a threshold for intervention. A thermal mitigation strategy can be generated and initiated when characteristics satisfy the threshold. The thermal mitigation strategy can specify various actions to dissipate heat, including altering shift control logic and triggering mechanical devices that can increase airflow, reduce air temperature, or both surrounding the transmission.

A method and device for vehicle speed control when towing a heavy load trailer are disclosed. The method includes determining whether a vehicle is in a trailer towing mode; determining whether the vehicle is in a slope-climbing situation or not using a G sensor based road gradient value when the vehicle is determined to be in the trailer towing mode; calculating a difference between the G sensor based road gradient value and a torque-based road gradient value, and determining whether a towed trailer is a heavy load trailer on the basis of the calculated difference, when it is determined the vehicle is in the slope-climbing situation; and performing shift control using a heavy load trailer dedicated shift map when the towed trailer is determined to be a heavy load trailer.