A work vehicle control system includes: a hydraulic device configured to adjust a supply state of hydraulic fluid supplied to a hydraulic cylinder configured to cause a work tool to operate; and a control device configured to control the hydraulic device. The control device includes: an operation data acquisition unit configured to acquire operation data indicating an operation state of an operating device operated in order to cause a work tool to perform dumping and tilting movements; and a control command unit configured to output, based on the operation data, a control command to control the hydraulic device; an operating condition determination unit configured to determine, based on the operation data, whether the operating device is operated under prescribed operating conditions; and a limit command unit configured to output a limit command to limit the control command when the operating device is determined to be operated under the operating conditions.

An object of the present invention is to provide a construction machine that has a hydraulic closed-circuit system mounted therein and capable of selectively connecting some of a plurality of hydraulic pumps driven by two engines to any one of a plurality of hydraulic actuators and that can downsize the engines while maintaining high work efficiency. A controller 80 includes an actuator/engine allocation computing section F6 that, at the time of connecting closed-circuit pumps that are not connected to any of the hydraulic actuators 1, 3, 5, and 7 to any one of the hydraulic actuators, allocates closed-circuit pumps driven by a right engine 9b to the one hydraulic actuator in a case in which an estimated maximum load on a left engine 9a is heavier than an estimated maximum load on the right engine, and allocates closed-circuit pumps driven by the left engine to the one hydraulic actuator in a case in which the estimated maximum load on the right engine is heavier than the estimated maximum load on the left engine.

An opening and closing motion control section controls an optional control valve so as to reduce opening degree of the optional control valve in a case where a first opening reduction condition is satisfied that a slewing operation detection section detects an operation amount equal to or more than a reference operation amount set in advance so that the reference operation amount is larger than a minimum operation amount of a slewing operation member for causing slewing motion of an upper slewing body and that an optional operation detection section detects operation received by an optional operation member.

A work vehicle includes a vehicle body, a work implement attached to the vehicle body, an operating device configured to operate the work implement, a controller configured to drive the work implement at a driving speed corresponding to an operation amount of the operating device, and an input device. The controller is further configured to execute an automatic drive control in order to automatically drive the work implement as far as a predetermined position at a driving speed set in response to an operation amount of the operating device when the controller has received an input from the input device while the operating device is operated.

A shovel includes a lower traveling body, an upper turning body turnably mounted on the lower traveling body, an attachment including a boom attached to the upper turning body, an arm attached to an end of the boom, and an end attachment attached to an end of the arm, wherein a motion of the arm or the end attachment is corrected according to a stability of a body of the shovel.

A hydraulic pump supplies hydraulic energy to a hydraulic system load. A vehicle controller establishes a commanded rotor speed for the motor or electric machine based on a target pump rotational speed of a pump rotor or pump shaft for operation of the hydraulic pump at a set point or within an operational region consistent with the hydraulic system load or estimated work task of the vehicle for one or more sampling intervals, where the set point or operational region is defined by a hydraulic pump flow rate versus head characterization curve and where the target pump rotational speed can be independent of a rotational speed of the engine shaft (e.g., in a first mode).

In a control method for construction machinery, an operation performed by the construction machinery is divided into a plurality of subordinate works. A current subordinate work currently performed by the construction machinery is determined. A maximum absorbing torque of a hydraulic pump is adjusted according to the determined subordinate work. An engine speed change map is adjusted according to the determined subordinate work.

An electronic control unit to control an engine control module of an engine is disclosed. The electronic control unit may receive, from a load monitoring device, power command information associated with a load of an engine. The electronic control unit may determine, based on the power command information, a total power command of the engine. The electronic control unit may determine, based on the total power command, a target engine speed for the engine. The electronic control unit may cause an engine control module to control the engine to operate in association with the target engine speed.

A hydraulic system for a working vehicle includes a first hydraulic pump to deliver pilot fluid to a control valve for a hydraulic actuator whose highest load pressure acts on a first fluid passage, and a second hydraulic pump to deliver hydraulic fluid whose pressure acts on a second fluid passage. A hydraulic controller is operable to control a load-sensing (LS) differential pressure between the highest load pressure and a delivery pressure of the hydraulic fluid from the second hydraulic pump. A third fluid passage to which the second hydraulic pump delivers the hydraulic fluid branches to a fourth fluid passage for flow of the pilot fluid. A solenoid valve is operable to change a pilot pressure of the pilot fluid for the hydraulic controller, and a controller is configured or programmed to control the solenoid valve to adjust the pilot pressure to change the LS differential pressure.

A work machine includes an elevating cab and processing circuitry. The processing circuitry is configured to detect the position of the elevating cab and to maintain a travel speed at low speed when a traveling operation is performed while the detected position of the elevating cab is higher than a predetermined height.