Provided is a microtrencher having a utility avoidance system that detects objects buried under the roadway, identifies whether the buried object is a utility and determines whether the buried utility is in the path of the cutting wheel. If the buried utility is in the path of the cutting wheel, an alert is sent to the operator, the vehicle is stopped, and/or the cutting wheel is raised in relation to the roadway. Also provided is a method of using the microtrencher to cut a microtrench in a roadway and to avoid cutting a buried utility in the path of the cutting wheel.

A hydraulic excavator (1) including a controller (21) having a load computing section (52) configured to compute a load of a work target material on the basis of thrust information about a boom cylinder (16) during the period when a front work implement (12) is performing a transporting operation of a work target material, the controller (21) further including: a velocity limiting value computing section (55) configured to compute a limiting value (Vlim) of a velocity of a boom cylinder (16) on the basis of posture information about the work implement (12) at a time of starting the transporting operation; a velocity command correction section (50) configured to correct a velocity command in such a manner that the velocity of the boom cylinder is equal to the limiting value (Vlim) when the velocity of the boom cylinder exceeds the limiting value and output the corrected velocity command; and a drive signal generation section (51) configured to generate and output a drive signal for the boom cylinder on the basis of the velocity command output from a velocity command correction section.

A hydraulic drive unit of a hydraulic excavator is configured to include a first hydraulic pump (P1) that discharges a hydraulic oil for activating a boom cylinder (36) and the like, a first electric motor (M1) that drives the first hydraulic pump (P1), a hydraulic pump for revolution (P2) that discharges a hydraulic oil for activating a revolution motor (26), a second electric motor (M2) that drives the hydraulic pump for revolution (P2), and a motor control device (150) that controls the rotation of the first electric motor (M1) and that of the second electric motor (M2). The motor control device (150) is configured such that when the revolution of the revolving body is not activated by the revolution motor (26), control to deactivate the second electric motor (M2) is performed.

A hydraulic drive unit of a hydraulic excavator is configured to include a first hydraulic pump (P1) that discharges a hydraulic oil for activating a boom cylinder (36) and the like, a first electric motor (M1) that drives the first hydraulic pump (P1), a hydraulic pump for revolution (P2) that discharges a hydraulic oil for activating a revolution motor (26), a second electric motor (M2) that drives the hydraulic pump for revolution (P2), and a motor control device (150) that controls the rotation of the first electric motor (M1) and that of the second electric motor (M2). The motor control device (150) is configured such that when the revolution of the revolving body is not activated by the revolution motor (26), control to deactivate the second electric motor (M2) is performed.

A method, system, and machine for controlling the output of an engine of a machine includes calculating the difference between a measured track slip based on track speed and ground speed and a calculated target track slip depending on track speed and chassis pitch, inputting the difference into a controller to determine a propulsion engine torque limit, and limiting the engine toque to the propulsion engine torque limit plus a steering system input torque.

A work machine includes a prime mover, a hydraulic pump to be operated by the prime mover to output an operation fluid, a hydraulic device to be operated by the operation fluid, a measurement sensor to measure a first temperature and a second temperature, the first temperature being a temperature of the operation fluid at starting of the prime mover, the second temperature being a temperature of the operation fluid after the starting of the prime mover, and a controller including a determiner to determine an upper limit revolution speed based on the first temperature, the upper limit revolution speed being an upper limit of a revolution speed of the prime mover, and a changer to change the upper limit revolution speed based on the second temperature.

Provided is a microtrencher having a utility avoidance system that detects objects buried under the roadway, identifies whether the buried object is a utility and determines whether the buried utility is in the path of the cutting wheel. If the buried utility is in the path of the cutting wheel, an alert is sent to the operator, the vehicle is stopped, and/or the cutting wheel is raised in relation to the roadway.

Power machines, control systems and methods that adjust engine speed based upon actuation of user input controls that control other power machine functions such as travel functions and lift arm functions. By controlling engine speed at least partially in response to the user input devices controlling other machine functions, more optimal engine speeds can be achieved.

A cooling control system includes a prime mover, a fan to be rotated under rotational power of an output shaft of the prime mover, a housing to which the fan is attached, a rotor to be rotated under rotational power of the prime mover, the rotor and the housing, under the agency of a fluid, rotating together, a fluid setting circuit to determine an injection quantity of the fluid to be introduced into the gap, a fan rotation detection device to detect a fan actual rotation speed, a target rotation obtaining circuit to obtain a fan target rotation speed. The integral controlling circuit does not execute the integral control with a difference between the fan actual rotation speed and a fan target rotation speed being greater than or equal to a threshold, and executes the integral control with the difference being less than the threshold.

A work vehicle (1) according to an aspect of the present invention is configured to shift, in a transmission unit (17), a speed of a driving force from an engine (5) mounted on a traveling body (2) and to transfer the shifted driving force to a traveling unit (3, 4) and a work unit (70). The work vehicle (1) includes: a mode shift switch (303) that is configured to shift a maximum vehicle speed by the traveling unit (3, 4) or a maximum number of revolutions of the engine (5), the maximum vehicle speed and the maximum number of revolutions being set for each of a plurality of modes; and a work unit operation lever (51) that is configured to be used for operating the work unit (70). The work unit operation lever (51) is provided with the mode shift switch (303).