A method for automatically controlling vehicle speeds of a track-based work vehicle may include monitoring, with a computing device, a load transmitted through a pivot pin of a track assembly of the work vehicle and determining, with the computing device, a speed limit setting for the work vehicle based on the monitored load, wherein the speed limit setting is associated with maintaining an operating temperature of a track of the track assembly below a predetermined temperature threshold. In addition, the method may include automatically limiting, with the computing device, a vehicle speed of the work vehicle based on the determined speed limit setting.

A construction machine includes an engine, a load estimation unit that estimates a pump power absorption, a regeneration/powering power demand calculation unit that calculates a regeneration/powering power demand according to a state of charge in an electrical storage device, an engine power demand calculation unit that calculates an engine power demand based on the power absorption and regeneration/powering power demand, and a motor generator control unit that performs rotational speed control or torque control. The control unit includes a control switching unit that switches the rotational speed and the torque control according to the engine power demand and the rotational speed of the engine. The control switching unit switches from the torque control to the rotational speed control when during performance of the torque control, the engine power demand increases and the rotational speed of the engine becomes lower than a predetermined rotational speed.

The present disclosure relates to a hydraulic drive system having a hydraulic circuit architecture operable in first and second modes. In a first mode, a main hydraulic pump (22) is used to drive a hydraulic actuator (24) via a closed hydraulic circuit, and a charge pump (42) provides charge flow to the closed hydraulic circuit. In a second mode the main pump set to zero displacement and the charge pump (42) is used to drive the hydraulic actuator (24).

The disclosure relates to a method for controlling a road finishing machine with a material bunker for receiving paving material, a screed for compressing the paving material, a drivable rear wheel and a drivable front wheel. A rotational speed of the rear wheel of the road finishing machine is measured. Moreover, a travel speed of the road finishing machine is measured. A target driving torque of the front wheel of the road finishing machine is calculated based on the measured rotational speed of the rear wheel and the measured travel speed of the road finishing machine. Then, an actual driving torque of the front wheel is adjusted to the calculated target driving torque. The disclosure also relates to a road finishing machine.

A rollover alarming system, a rollover risk prediction method, and a rollover alarming method. An axle housing strain measurement unit measures strain values on both sides of an axle housing of a vehicle body. A roll angle measurement unit measures a roll angle of the vehicle body. A collection control unit is configured to collect the strain values on both sides of the axle housing of the vehicle body and the roll angle of the vehicle body, calculate a strain difference between the strain values according to the strain values on both sides of the axle housing of the vehicle body, and output a corresponding alarm control signal according to the strain difference between both sides of the axle housing of the vehicle body and the roll angle of the vehicle body. An alarm unit is configured to output a corresponding alarm signal according to the received alarm control signal.

The power-transmission device has an input shaft, an output shaft, a gear mechanism, and a motor. The gear mechanism includes a plurality of planetary gear mechanisms and a mode-switching mechanism, and transmits the rotations of the input shaft to the output shaft. The mode-switching mechanism selectively switches the drive-power transmission path of the power-transmission device between a plurality of modes. The motor is connected to the rotating elements of the planetary gear mechanisms. A target-input-torque determination unit determines the target input torque, which is a target value for the torque to be inputted to the power-transmission device. The target-output-torque determination unit determines the target output torque, which is a target value for the torque to be outputted from the power-transmission device. The command-torque determination unit uses the torque balance information to determine torque commands to the motor from the target input torque and the target output torque.

A method for mitigating powertrain abuse on a grade can include determining the grade a machine is on, the machine including an impeller clutch located between an engine and a powertrain so as to connect and disconnect engine power from the powertrain; and if the grade is over a threshold, a controller ignores any operator input to the impeller clutch such that machine speed retarding is utilized to keep the machine at a proper speed.

The present invention relates to an apparatus for controlling a cascaded hybrid construction machine system and a method therefor, which apparatus includes: a control part for controlling an electric motor for driving an actuator differently according to whether or not the actuator performs a recovery action and whether or not an energy storage device can be recharged; and a motor driver for driving or stopping the electric motor by switching under the control of the control unit, wherein when the actuator performs a recovery action for both the overcharged state and the failure state of the energy storage device, the motor for driving the actuator is temporarily stopped by the switching of the motor driver so as to restrain the recovery energy generated, thus protecting the hybrid power source system and keeping the operator safe as well as resolving the problem of the working time being increased due to the system's shutting off.

An exemplary embodiment suggested in the present specification provides an apparatus and a method of controlling a voltage of a direct current terminal of construction machinery equipped with a motor, which are capable of improving energy efficiency of a power conversion apparatus, such as an inverter and a converter by changing a voltage of the direct current terminal to an optimum voltage size in consideration of operation conditions of a swing motor, an engine auxiliary motor, and an energy storage apparatus.

This invention is a hydraulic work machine having an electric assist motor coupled to an engine and a hydraulic pump, in the hydraulic work machine of which, a rotational speed and torque of the engine are controlled so that an operating point of the engine moves along a predetermined route for yielding a combustion state of the engine under a transient state that the engine changes in speed and torque. A target speed and torque of the engine 7 are set so that the rotational speed and torque of the engine 7 will change along a predetermined route F in a running region of the engine, respective rates of change of the target rotational speed and torque of the engine 7 are limited, and the engine 7 is controlled to yield the target engine speed. In addition, torque of the assist motor 10 is controlled to yield the target torque of the engine.