Komatsu Corporation

Shogo Miyazaki

Kenichi Yamada

Shota Yamawaki

Akira Takeno

Hiroshi Monden

Tatsuro Nohara

Shunsuke Miyamoto

Shinya Kawakita

Naoki Uchida

Ryota Enomoto

Shinobu Shimanaka

Koshiro Kodo

A control device of a work vehicle includes a required output torque determination unit that determines a required output torque of the power transmission device based on an operation amount of the operation device and a traveling speed of the work vehicle, a traveling load estimation unit that estimates a traveling load torque related to a traveling load on the work vehicle, a required output torque correction unit that corrects the required output torque such that the required output torque is included in an allowable output torque range including an estimated traveling load torque, and a drive source control unit that outputs a control signal for the drive source based on a corrected required output torque.

Control device and control method for controlling output of drive source of work vehicle

A control device of a work vehicle includes a braking force function determination unit and a required braking force function determination unit. The braking force function determination unit determines at least one of an offset and an inclination for a required braking force in a braking force function which indicates a relationship between a rotational speed of an output shaft of a transmission and the required braking force and in which the required braking force monotonically increases with respect to the rotational speed such that the smaller a stage number of a selected speed stage which is input into a traction force instruction device, the larger an absolute value of at least one of the offset and the inclination. The required braking force function determination unit determines the required braking force based on the rotational speed of the output shaft of the transmission and the braking force function.

Control device and control method for determining required braking force of work vehicle

A work machine includes a boom, a work tool configured to drive with respect to the boom, an actuator configured to drive the work tool, a sub-link attached to the boom, and a control section. The sub-link is configured to transmit driving force of the actuator to the work tool. The control section is configured to control the actuator based on a posture of the sub-link with respect to the boom. A method of controlling a work machine includes controlling an actuator based on a posture of a sub-link with respect to a boom, the sub-link being configured to transmit driving force of the actuator to a work tool configured to drive with respect to the boom.

Work machine and method for controling work machine

A power transmission device includes an input shaft, an output shaft, a differential device, a continuously variable transmission unit, and a control device. The differential device includes a first rotation element connected to the input shaft, a second rotation element connected to the output shaft, and a third rotation element. The continuously variable transmission unit includes a conversion unit configured to convert rotational power of the third rotation element into an other power, and a reconversion unit configured to reconvert the converted other power into the rotational power and supply the reconverted rotational power to the output shaft. The control device includes a continuously variable transmission control unit configured to generate a control signal of the continuously variable transmission unit such that the other power generated by the conversion unit exceeds the other power input to the reconversion unit.

Control device of power transmission device, power transmission device, and control method for power transmission device

A control device for a power machine includes a target circuit pressure specifying unit configured to specify a target circuit pressure of the hydrostatic continuously variable transmission, a measurement value acquisition unit configured to acquire an actual circuit pressure of the hydrostatic continuously variable transmission, a brake torque determination unit configured to determine a brake torque based on the target circuit pressure and the actual circuit pressure, and a pump control unit configured to control the hydraulic pump based on the brake torque. The brake torque is a torque consumed by the hydraulic pump.

Work vehicle, and control device and control method for power machine

A control method for a work vehicle, includes: calculating a speed ratio indicating a ratio between a rotation speed of an input shaft connected to an engine and a rotation speed of an output shaft connected to a traveling device; and outputting a capacity command for changing at least one of a capacity of a first hydraulic pump motor and a capacity of a second hydraulic pump motor based on correlation data indicating a relationship between the speed ratio and the capacities of the first and second hydraulic pump motors, wherein the correlation data is set so that both the capacity of the first hydraulic pump motor and the capacity of the second hydraulic pump motor are changed with a change in the speed ratio in a predetermined speed ratio range between a first speed ratio and a second speed ratio higher than the first speed ratio.

Work vehicle and control method for work vehicle

A work machine includes a main body, a boom to drive with respect to the main body, a work tool connecting to the boom, the work tool to drive with respect to the boom, an actuator connecting to the main body and the work tool, the actuator to drive the work tool, and a sub-link to transmit drive of the actuator to the work tool. A method for calibrating the work machine includes outputting a detection value to detect an angle of the sub-link with respect to the boom in a predetermined posture of the boom and a work tool posture, converting the detection value as a measurement angle of the sub-link with respect to the boom based on a conversion value, and calibrating the conversion value based on a relationship between the measurement angle and an actual angle in the work tool posture which is specified.

Method for calibrating work machine, controller for work machine, and work machine

A power transmission includes first and second clutches for switching a transmission path for a driving force therein. A clutch controlling unit provided for a work vehicle is configured to switch the transmission path from one to the other of first and second modes when a speed ratio parameter reaches a mode switching threshold. The clutch controlling unit is configured to keep setting the transmission path in the other mode even when the speed ratio parameter again reaches the mode switching threshold until a switching prohibition period having a predetermined initial value expires as long as a period of time elapsed after mode switching is included in the switching prohibition period. A trigger detecting unit provided for the work vehicle is configured to make the switching prohibition period expire when detecting a predetermined operation in the switching prohibition period.

Work vehicle and method of controlling work vehicle

A power transmission includes first and second clutches for switching a transmission path for a driving force. A work vehicle includes a clutch controlling unit and an engine controlling unit. The clutch controlling unit is configured to determine which of first and second modes the transmission path is switched into based on which of a range of greater than or equal to a mode switching threshold and a range of less than or equal to the mode switching threshold a speed ratio parameter falls into, and is configured to output a clutch command signal causing one of the first and second clutches to be engaged corresponding to the determined mode. The engine controlling unit is configured to apply an offset to a rotational speed of an input shaft such that after switching into the determined mode, the speed ratio parameter deviates from the mode switching threshold in the switched mode.

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Hiratsuka, Japan

Shogo Miyazaki