Hitachi Construction Machinery Co., Ltd.

Teruki Igarashi

Akihiro Narazaki

Yusuke Suzuki

Shuuichi Meguriya

Shiho Izumi

Hiroaki Tanaka

Ryu Narikawa

Hiroki Takeuchi

Ryohei Fukuchi

Hiroshi Sakamoto

Hisami Nakano

Kento Kumagai

Yasuhiko Kanari

Masamichi Ito

Mitsuhiko Kanehama

Masamichi Itou

Masamichi Itoh

When a bucketis grounded on soil, an operation signal is outputted or corrected such that a relative angle of the bucketwith respect to a target surface is maintained if a distance D between the bucketand the target surfaceis equal to or less than a preset first threshold value D. When the bucketis not grounded on soil, the operation signal is outputted or corrected such that the relative angle of the bucketwith respect to the target surfaceis maintained if the distance between the bucketand the target surfaceis equal to or less than a preset second threshold value Dset smaller than the first threshold value D. As a result, control to maintain an angle of a work tool can be suitably started.

Work machine assisting operation of operator by performing semi-automatic control

A work machine includes a work device having a boom, an arm, and work equipment and a controller that sets a target surface, and calculates a work equipment-to-target surface distance on the basis of signals from a position sensor and a posture sensor, and carries out control to decelerate the arm to keep the work equipment from excavating ground beyond the target surface when the work equipment-target surface distance has become shorter than a predetermined distance. The controller determines whether there is a possibility that the work equipment enters the target surface when operation of the arm is carried out based on the set target surface and the position sensor and posture sensor signals, and does not carry out the deceleration control when the work equipment-to-target surface distance is shorter than the predetermined distance and it is determined there is no possibility that the work equipment enters the target surface.

Work machine

A work machine includes a swing structure, a work device, a position sensor, a posture sensor and a controller that performs machine control on the basis of a target surface set on the basis of target shape data, the position information of the swing structure, and the information about the posture of the work machine. When the controller becomes unable to obtain the position information of the swing structure, the controller stores swing angle information of the swing structure, the swing angle information being sensed by the posture sensor at that time. The controller prohibits execution of the machine control when the swing structure is positioned outside a swing range; and permits the execution of the machine control when the swing structure is positioned inside the swing range and when the swing structure is positioned inside the swing range again after being positioned outside the swing range.

The invention of the present application intends to provide a work machine that can improve the work performance by keeping the work state of work equipment conforming to the intention of an operator in machine control for causing the work equipment to follow an excavation target surface. For this purpose, a controller determines the work state of the work equipment on the basis of an operation input amount inputted from an operation input device and the posture of the work equipment with respect to the target surface, computes a range of an action command value of actuators in which the work state determined is kept, and corrects, within the range, the action command value of the actuators to make the distance between the work equipment and the target surface small.

A work machine includes a flow control valve that controls the flow rate of a hydraulic operating fluid supplied from a hydraulic pump to a hydraulic cylinder, a solenoid valve that generates an operation pressure for operating the flow control valve, and a controller. The controller executes learning processing of changing in a stepwise manner the operation pressure generated by the solenoid valve, sensing the pressure of the hydraulic cylinder, and storing the operation pressure when the pressure of the hydraulic cylinder has become a reference value, as a learning result operation pressure. The controller calculates a differential pressure across the flow control valve and computes a target opening area of the flow control valve on the basis of the differential pressure across the flow control valve and a target flow rate of the hydraulic operating fluid that passes through the flow control valve. The controller computes a target value of the operation pressure generated by the solenoid valve, on the basis of an opening characteristic table, the target opening area, and the learning result operation pressure, and controls the solenoid valve on the basis of the target value of the operation pressure.

A hydraulic actuator includes a control valve unit that controls a flow of a hydraulic fluid supplied from a hydraulic pump to a plurality of hydraulic actuators, a plurality of control lever devices that output a pilot pressure actuating the control valve unit, with use of a discharged pressure from a pilot pump as a source pressure, a solenoid valve unit including a plurality of solenoid pressure reducing valves connected between the plurality of control lever devices and the control valve unit, and a controller configured to calculate velocity limits for the plurality of hydraulic actuators on the basis of signals from a plurality of posture sensors and control openings of the solenoid pressure reducing valves, in which the controller is configured to control the openings of the solenoid pressure reducing valves for arm crowding and arm dumping to be larger than an opening based on the velocity limits while a boom raising operation signal is being output from the control lever devices.

Hydraulic excavator

A work machine includes: a work device including a plurality of hydraulic actuators and a plurality of driving target members; a posture sensor that senses posture information of the work device; a control valve unit that controls flows of hydraulic operating fluid supplied from the hydraulic pump to the plurality of hydraulic actuators; a plurality of solenoid valves that generate pilot pressure for driving the control valve unit; and a controller that computes a command value of the pilot pressure to be generated by the solenoid valves, and outputs a control signal corresponding to the command value to the solenoid valves. The controller computes a gravitational direction component of an action direction vector of the driving target members on the basis of the posture information sensed by the posture sensor, corrects the command value of the pilot pressure on the basis of the gravitational direction component of the action direction vector when the command value exceeds a predetermined pressure, and outputs the control signal corresponding to the command value after the correction to the solenoid valves.

Provided is a remote control system for work machine capable of enhancing the stability and efficiently improving the operability. A remote control system for a work machine having a plurality of actuatorscorrects all command signals for the actuatorsbeing operated when a communication delay time occurs during operation with the actuators. This limits the operation of the actuatorswhile keeping the ratio of the command signals (operation signals) of the actuators

Remote control system for work machine

An articulated-type front work implement has a boom, an arm, and a bucket that are driven members coupled to each other; a boom cylinder, an arm cylinder and a bucket cylinder that are hydraulic actuators each of which drives a corresponding one of the plurality of driven members on the basis of an operation signal; a plurality of operation members each outputting the operation signal to one of the hydraulic actuators; and a controller that outputs the operation signal to at least one of the plurality of hydraulic actuators or executes area limiting control of correcting the output operation signal such that the front work implement moves on a target surface preset for a work target of the front work implement or within an area above the target surface, and corrects the operation signal on the basis of information related to operation of the hydraulic actuator.

A hydraulic excavator includes a controller having an actuator control section that executes machine control of operating a work implement in accordance with a predetermined condition in a case in which a work implement is positioned in a deceleration area, and that does not execute machine control in a case in which the work implement is positioned in a non-deceleration area. The controller further includes an operation deciding section that decides operation of the work implement on the basis of an operation amount of an operation device, and a display control section that displays, on a display device, a positional relationship among the work implement, a target surface and a boundary line between the deceleration area and the non-deceleration area. The actuator control section executes machine control while changing the position of the boundary line depending on a result of the decision by the operation deciding section, and the display control section changes the display position of the boundary line on the display device, depending on the result of the decision by the operation deciding section.

A controller outputs a first velocity (first limiting velocity) as a limiting velocity for a boom cylinder when a boom lowering operation amount is smaller than a first operation amount, and outputs a second velocity when the boom lowering operation amount is equal to or larger than the first operation amount. The first velocity is set to decrease according to a decrease in a target surface distance. The second velocity is defined by a weighted average of the first velocity and a third velocity (second limiting velocity) set to change according to one of the target surface distance and the boom lowering operation amount of the operation device, and is set such that an increase in the boom lowering operation amount reduces a weight for the first velocity while increasing a weight for the third velocity.

A controller for a hydraulic excavator includes a first speed computation section that calculates a first speed of an arm cylinder from a value detected by an operation amount sensor; a second speed computation section that calculates a second speed from a value detected by a posture sensor and a third speed computation section calculates a third speed that is used as the speed of the arm cylinder in an actuator control section adapted to execute MC (machine control). The third speed computation section calculates the first speed as the third speed during the period between the detection of an input of operation for an arm by the operation amount sensor and predetermined time to, the third speed as a speed calculated from the first speed and the second speed during the period between tand time t, and the second speed as the third speed at and after time t

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Tsuchiura, Japan

Teruki Igarashi