Working machine and control device for working machine

Abstract

A working machine comprises: a working machine body; an attachment on the working machine body; a working tool provided at the distal end of the attachment; and a control circuit. The control circuit is configured such that, when it is determined that a piston of a cylinder actuating the attachment has reached a predetermined range, and based on detection information regarding a lifting operation of the attachment after an object has been held in the working tool, it causes a measured result to vary the weight of the object according to a state of the working machine at the time the determination is made.

Description

TECHNICAL AREA The present disclosure relates to a working machine and a control device for the working machine. STATE OF THE ART When measuring the weight of an object, such as soil and sand, loaded by an excavator onto the loading platform of a dump truck or the like, a technique is known to suppress fluctuations in the weight measurement result due to disturbances. In particular, a technique is known for compensating the torque for rotating a boom based on at least one of the centrifugal force of an arm or the inertial force of an arm, and for measuring the weight of an object conveyed by a boom attachment based on the compensated torque. RELATED STATE OF THE ART PATENT DOCUMENTS Patent document 1: International Publication No. WO2022 / 124319 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION In the existing technique described above, the centrifugal force and inertial force of the arm are considered disturbances that cause fluctuations in the measured weight of an object. However, there are other disturbances that can also cause fluctuations in the measured weight of an object. The disclosed technique was developed in light of the above circumstances, and one of its aims is to improve the accuracy of measuring the weight of an object. MEANS TO SOLVENT THE PROBLEMS A working machine according to an embodiment of the present disclosure is a working machine comprising: a working machine body; an attachment piece mounted on the working machine body; a working tool provided at a distal end of the attachment piece; and a control circuit configured such that, when a determination is made, based on detection information relating to a lifting operation of the attachment piece, that a piston of a cylinder actuating the attachment piece has reached a predetermined range after an object has been held in the working tool, it causes a obtained measurement result of the weight of the object to differ according to a state of the working machine at a time when the determination is made. The working machine according to the embodiment of the present disclosure is a working machine comprising: a working machine body; an attachment piece mounted on the working machine body; and a working tool provided at a distal end of the attachment piece, wherein the working machine includes a control circuit configured such that, when a determination is made that a piston of a cylinder actuating the attachment piece has reached a predetermined range, it causes the obtained measurement result of a weight of the object to differ according to a state of the working machine at a time when the determination is made, based on detection information regarding a lifting operation of the attachment piece after an object has been held in the working tool, wherein the control circuit receives the weight of the object that is calculated.Based on the detection information regarding the lifting operation of the attachment, the control circuit receives the measurement result at the time the determination is made, if the state of the working machine at the time the determination is made is a state after the lifting operation of the attachment has started and the measurement result of the object's weight has not yet been obtained, and wherein, if the state of the working machine at the time the determination is made is a state after the lifting operation of the attachment has started and the measurement result of the object's weight has been obtained, the control circuit receives the measurement result that has been obtained as the measurement result of the object's weight at the time the determination is made, and if the state of the working machine at the time the determination is made is a state at the start of the lifting operation of the attachment, the control circuit does not receive the measurement result. The control device for a working machine according to the embodiment of the present disclosure is a control device for a working machine comprising: a working machine body; an attachment piece mounted on the working machine body; and a working tool provided at the distal end of the attachment piece, wherein the control device comprises a control circuit configured such that, based on detection information regarding a lifting operation of the attachment piece after an object has been held in the working tool, when a determination is made that a piston of a cylinder actuating the attachment piece has reached a predetermined range, it causes a obtained measurement result of the weight of the object to differ according to a state of the working machine at a time when the determination is made. ADVANTAGEOUS EFFECTS OF THE INVENTION The accuracy of measuring the weight of an object can be improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view of an excavator as an excavating machine according to the present embodiment; Fig. 2 is a schematic diagram illustrating an example of a drive system configuration of the excavator according to the present embodiment; Fig. 3 is a schematic diagram illustrating an example of a hydraulic system configuration of the excavator according to the present embodiment; Fig. 4A is a schematic diagram illustrating an example of components relating to an operating system of the excavator's hydraulic system according to the present embodiment; Fig. 4B is another schematic diagram illustrating an example of components relating to an operating system of the excavator's hydraulic system according to the present embodiment; Fig.Figure 4C is a further schematic diagram illustrating an example of components relating to an operating system of the excavator's hydraulic system according to the present embodiment; Figure 5 is a diagram illustrating an example of an electrical operating system configuration of the excavator according to the present embodiment; Figure 6 is a schematic diagram illustrating an example of components relating to an earth and sand loading detection function of the excavator according to the present embodiment; Figure 7 is a diagram illustrating an excavation and loading operation of the excavator; and Figure 8 is a flowchart illustrating an example of load weight determination processing. DETAILED DESCRIPTION OF THE INVENTION In the following, embodiments of the present disclosure are described with reference to the drawings. Furthermore, the embodiments described below are not intended to limit the invention, but are exemplary, and not all features or combinations thereof described in the embodiments are necessarily essential to the invention. In each of the drawings, the same or corresponding components are identified by the same or corresponding reference numerals, and their description may be omitted. [Overview of excavators] First, with reference to Fig. 1, an overview of an excavator (working machine) 100 according to the present embodiment is described. Fig. 1 is a side view of an excavator as an excavating machine according to the present embodiment. In Fig. 1, the excavator 100 is positioned on a horizontal plane facing a rising slope ES being constructed, and a rising cut slope BS (i.e., the daylight shape after construction for the rising slope ES), which is an example of a target construction area to be described below, is also shown. The rising slope ES to be constructed is provided with a cylindrical body (not illustrated) that indicates the direction normal to the rising cut slope BS, which is a target construction area. The excavator 100 according to the present embodiment is provided with a lower chassis 1, an upper pivoting body 3 which is mounted on the lower chassis 1 to rotate freely via a swivel 2, a boom 4, an arm 5 and a bucket 6, which are enclosed in an attachment (working machine), and a cab 10. The lower chassis 1 and the upper pivoting body 3 are enclosed in a working machine body. The lower undercarriage 1 drives the excavator 100 by means of a pair of left and right tracks, each hydraulically driven by drive hydraulic motors 1L and 1R (see Fig. 2, described below). That is, the pair of drive hydraulic motors 1L and 1R (an example of drive motors) drives the lower undercarriage 1 (track) as a driven part. The upper pivoting body 3 rotates relative to the lower drive body 1 by being driven by a pivoting hydraulic motor 2A (see Fig. 2, described below). That is, the pivoting hydraulic motor 2A is a pivoting drive section for driving the upper pivoting body 3 as a driven part, and the direction of the upper pivoting body 3 can be changed. The upper swivel body 3 can be electrically driven by an electric motor (hereinafter referred to as the "swivel motor") instead of the hydraulic swivel motor 2A. That is, like the hydraulic swivel motor 2A, the swivel motor is a swivel drive section for driving the upper swivel body 3 as a driven section, and the direction of the upper swivel body 3 can be changed. The boom 4 is rotatably mounted at the center of the front part of the upper pivoting body 3 in a tilting manner, the arm 5 is rotatably mounted at the tip of the boom 4 in a vertically rotatable manner, and the bucket 6, as an end piece, is rotatably mounted at the tip of the arm 5 in a vertically rotatable manner. The boom 4, the arm 5, and the bucket 6 are each hydraulically driven by a boom cylinder 7, an arm cylinder 8, and a bucket cylinder 9, respectively, as hydraulic actuators. It should be noted that the bucket 6 is an example of the end attachment and other end attachments, such as a slope bucket, a dredging bucket, a crusher, a lifting magnet, a grab, a fork, a harvesting machine including a chainsaw or the like, may be attached to the tip of the arm 5 instead of the bucket 6, according to the work content or the like. Cabin 10 is a driver's cab in which an operator rides and is provided on the front left side of the upper swivel body 3. [Excavator configuration] Next, with reference to Fig. 2, in addition to Fig. 1, a specific configuration of the excavator 100 according to the present embodiment is described. Fig. 2 is a schematic diagram illustrating an example of a bucket drive system configuration according to the present embodiment. In Fig. 2, a mechanical power system, a hydraulic oil line, a pilot line, and an electrical control system are indicated by double lines, solid lines, dashed lines, and dotted lines, respectively. The drive system of the excavator 100 according to the present embodiment comprises a motor 11, a controller 13, a main pump 14 and a control valve 17. The hydraulic drive system of the excavator 100 according to the present embodiment comprises hydraulic actuators such as the travel hydraulic motors 1L and 1R, the swing hydraulic motor 2A, the boom cylinder 7, the arm cylinder 8 and the bucket cylinder 9, in order to hydraulically drive the lower travel body 1, the upper swing body 3, the boom 4, the arm 5 and the bucket 6 respectively, as described above. The motor 11 is a primary power source in the hydraulic drive system and is mounted, for example, on the rear of the upper swivel body 3. Specifically, the motor 11 rotates at a predetermined target speed under direct or indirect control by a control unit 30 described below, driving the main pump 14 and a pilot pump 15. The motor 11 is, for example, a diesel engine that uses diesel fuel. Controller 13 controls the delivery rate of the main pump 14. For example, controller 13 adjusts the angle (tilt angle) of a swashplate of the main pump 14 according to a control command from controller 30. Controller 13 includes, for example, controllers 13L and 13R, as described below. The main pump 14, for example, is mounted on the rear of the upper swivel body 3 in the same manner as the motor 11 and supplies hydraulic oil to the control valve 17 via a high-pressure hydraulic line. The main pump 14 is driven by the motor 11, as described above. The main pump 14 is, for example, a variable displacement hydraulic pump, and, as described above, under the control of the controller 30, the tilt angle of the swashplate is adjusted by the governor 13, thereby adjusting the stroke length of a piston and controlling a delivery flow rate (delivery pressure). The main pump 14 includes, for example, main pumps 14L and 14R, as described below. The control valve 17, for example, is a hydraulic control device mounted in the center of the upper slewing body 3 and controls the hydraulic drive system in response to an operator's operation of a control device 26. As described above, the control valve 17 is connected to the main pump 14 via the high-pressure hydraulic line and selectively directs the hydraulic oil supplied by the main pump 14 to the hydraulic actuators (the travel hydraulic motors 1L and 1R, the slewing hydraulic motor 2A, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9) in response to an operating condition of the control device 26. Specifically, the control valve 17 includes control valves 171 to 176, which control the flow rate and direction of the hydraulic oil supplied by the main pump 14 to each of the hydraulic actuators.Furthermore, in particular, control valve 171 corresponds to the travel hydraulic motor 1L, control valve 172 corresponds to the travel hydraulic motor 1R, and control valve 173 corresponds to the slewing hydraulic motor 2A. Control valve 174 corresponds to the bucket cylinder 9, control valve 175 corresponds to the boom cylinder 7, and control valve 176 corresponds to the arm cylinder 8. Control valve 175 includes, for example, control valves 175L and 175R described below, and control valve 176 includes, for example, control valves 176L and 176R described below. Details of control valves 171 to 176 are described below. An operating system of the excavator 100 according to the present embodiment comprises the pilot pump 15 and the control device 26. The operating system of the excavator 100 includes a changeover valve 32 as a configuration with respect to a machine control function by the control 30 described below. The pilot pump 15, for example, is mounted on the rear of the upper swivel body 3 and supplies pilot pressure to the control device 26 via the pilot line. The pilot pump 15 is, for example, a fixed-displacement hydraulic pump and is driven by the motor 11, as described above. The control device (an example of a control element) 26 is located near the driver's seat of the cab 10. The control device 26 is an input device for an operator to operate various control elements (the lower travel body 1, the upper swing body 3, the boom 4, the arm 5, the bucket 6, etc.). In other words, the control device 26 is an input device with which an operator can actuate hydraulic actuators (that is, the travel hydraulic motors 1L and 1R, the swing hydraulic motor 2A, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, and the like) to drive the respective control elements. The operating device 26 is connected directly to the control valve 17 via the pilot line on a secondary side or indirectly via the changeover valve 32 provided in the pilot line on the secondary side. Thus, a pilot pressure corresponding to the operating state of the lower carriage 1, the upper slewing body 3, the boom 4, the arm 5, the bucket 6, and the like in the operating device 26 can be input into the control valve 17. Therefore, the control valve 17 can actuate the respective hydraulic actuators according to the operating state in the operating device 26. The operating device 26 includes, for example, a lever device for actuating the arm 5 (arm cylinder 8). The operating device 26 also includes, for example, lever devices 26A to 26C for actuating the boom 4 (boom cylinder 7), the bucket 6 (bucket cylinder 9) and the upper swivel body 3 (swivel hydraulic motor 2A) (see Fig. 4). The operating device 26 also includes, for example, a lever device and a pedal device for actuating the pair of left and right tracks (drive hydraulic motors 1L and 1R) of the lower drive body 1. The changeover valve 32 comprises two inlet ports and one outlet port. The changeover valve 32 discharges hydraulic oil to the outlet port at a higher pilot pressure than the pilot pressure applied to the two inlet ports. One of the two inlet ports of the changeover valve 32 is connected to the control device 26, and the other is connected to a proportional valve 31. An outlet port of the changeover valve 32 is connected via the pilot line to a pilot port of a corresponding control valve in the control valve 17 (see Fig. 4 for details). Therefore, the changeover valve 32 can cause the pilot pressure, which is higher than the pilot pressure generated by the control device 26 or the pilot pressure generated by the proportional valve 31, to act on the pilot port of the corresponding control valve.This means that by causing the proportional valve 31 to output a higher pilot pressure than the secondary-side pilot pressure output by the operating device 26, the control unit 30 described below can control the corresponding control valve and the operation of various operating elements without being dependent on an operator operating the operating device 26. The changeover valve 32 includes, for example, the changeover valves 32AL, 32AR, 32BL, 32BR, 32CL, and 32CR described below. The control system of the excavator 100 according to the present embodiment comprises the control unit 30, a discharge pressure sensor 28, an operating pressure sensor 29, the proportional valve 31, a display device 40, an input device 42, an audio output device 43, a storage device 47, a boom angle sensor S1, an arm angle sensor S2, a bucket angle sensor S3, a machine body tilt sensor S4, a rotation state sensor S5, an imaging device S6, a positioning device P1 and a communicator T1. The control unit 30 (an example of a control device) is located, for instance, in cabin 10 and controls the drive of the excavator 100. The control unit 30 can be implemented using any hardware, software, or a combination thereof. For example, the control unit 30 essentially comprises a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), a non-volatile auxiliary storage device, and a microcomputer including various input / output interfaces and the like. The control unit 30 implements various functions, for example, by executing different programs stored in the ROM and the non-volatile auxiliary storage device on the CPU. For example, the controller 30 sets a target speed based on an operating mode or the like, which has been preset by a predetermined operation performed by an operator or the like, and performs drive control to rotate the motor 11 at a constant speed. Furthermore, the controller 30, for example, when necessary, issues a control command to the regulator 13 to change the delivery rate of the main pump 14. Furthermore, the control unit 30, for example, performs control with respect to a machine guidance function to guide the manual operation of the excavator 100 by an operator via the control device 26. Furthermore, the control unit 30, for example, performs control with respect to the machine control function to automatically support the manual operation of the excavator 100 by an operator via the control device 26. That is, the control unit 30 includes a machine guidance section 50 as a functional section with respect to a machine guidance function and the machine control function. The control unit 30 includes an earth and sand loading processor 60. The earth and sand loading processor 60 of the present embodiment determines whether the piston of the boom cylinder 7 has reached a predetermined range during an excavation and loading process described below. The predetermined range is a buffer zone where a buffer function is activated. When it is determined that the piston of the boom cylinder 7 has reached the predetermined range, the earth and sand loading processor 60 causes a measurement result of the obtained earth and sand weight to differ according to the condition of the excavator 100 at the time when the determination is made. This section describes the buffer function. The buffer function reduces the piston speed of a hydraulic cylinder as it approaches the end of its stroke. This buffer function mitigates the impact of the hydraulic cylinder piston as it reaches the end of its stroke. Specifically, when the boom cylinder 7 is extended (boom-up operation) and the piston reaches the buffer zone, the pressure in the rod-side oil chamber (boom rod pressure) of the boom cylinder 7 increases, and the piston speed decreases. At this time, the weight of the earth and sand cannot be accurately calculated due to the influence of the increasing boom rod pressure. The buffer function is achieved, for example, by a method of reducing the flow rate of the hydraulic oil by controlling a control valve, or by a method in which a hydraulic cylinder is configured so that the flow rate of the hydraulic oil decreases when the piston reaches the buffer area. In the present embodiment, when it is determined that the piston of the boom cylinder 7 has reached the predetermined range, a value to be used as a measurement result is caused to differ according to the state of the excavator 100 at that time. Therefore, according to the present embodiment, the weight of earth and sand, calculated in a state where the influence of the piston of the boom cylinder 7, which has reached the predetermined range, is suppressed, can be obtained as a measurement result. Furthermore, according to the present embodiment, if the earth and sand weight calculated during the period from the start of the lifting operation of the boom 4 until the piston of the boom cylinder 7 has reached a predetermined range is determined as a measurement result, this earth and sand weight can be obtained as a measurement result. Therefore, according to the present embodiment, a range in which the earth and sand weight can be measured with high accuracy can be maximized. Details of the earth and sand loading processor 60 are described below. It should be noted that some of the functions of controller 30 can be achieved by another controller (control device). That is, the functions of controller 30 can be achieved by several controllers in a distributed manner. For example, the machine guidance function and the machine control function can be achieved by a dedicated controller (control device). The discharge pressure sensor 28 detects the discharge pressure of the main pump 14. A detection signal corresponding to the discharge pressure detected by the discharge pressure sensor 28 is received by the controller 30. The discharge pressure sensor 28 includes, for example, the discharge pressure sensors 28L and 28R described below. As described above, the control pressure sensor 29 detects the pilot pressure on the secondary side of the control device 26, that is, the pilot pressure corresponding to the operating state (for example, control content such as direction and amount) of each control element (i.e., the hydraulic actuator) in the control device 26. Detection signals of the pilot pressures corresponding to the operating states of the lower carriage 1, the upper swing body 3, the boom 4, the arm 5, the bucket 6, and the like in the control device 26 are received by the operating pressure sensor 29 and transmitted to the control unit 30. The operating pressure sensor 29 includes, for example, the operating pressure sensors 29A to 29C described below. Instead of the operating pressure sensor 29, another sensor may be provided which is able to detect the operating state of each control element in the operating device 26, for example an encoder or a potentiometer which is able to detect the amount of operation (inclination amount) or the inclination direction of the lever devices 26A to 26C and the like. The proportional valve 31 is provided in the pilot line connecting the pilot pump 15 and the changeover valve 32 and is configured to modify a flow path area (cross-sectional area through which the hydraulic oil can flow) of the pilot line. The proportional valve 31 operates in response to a control command input from the controller 30. Thus, even when the operating device 26 (in particular the lever devices 26A to 26C) is not being actuated by an operator, the controller 30 can supply the hydraulic oil delivered by the pilot pump 15 to the pilot port of the corresponding control valve in the control valve 17 via the proportional valve 31 and the changeover valve 32. The proportional valve 31 includes, for example, the proportional valves 31AL, 31AR, 31BL, 31BR, 31CL, and 31CR described below. The display device 40 is located in cabin 10 at a position clearly visible to a seated operator and displays various information images below the control unit 30. The display device 40 can be connected to the control unit 30 via an onboard communication network, such as a Controller Area Network (CAN), or via a dedicated one-to-one leased line. The input device 42 is located within reach of the seated operator in cabin 10, receives various operator inputs from the operator, and outputs a corresponding signal to the control unit 30. The input device 42 comprises a touch panel mounted on a display unit for showing various information images, a rotary knob switch located at the tip of a lever section of the lever devices 26A to 26C, a push-button switch located around the display unit 40, a lever, a toggle switch, a rotary knob, and the like. The signal corresponding to the contents of an operation performed on the input device 42 is received by the control unit 30. The audio output device 43 is, for example, located in cabin 10, connected to the control unit 30, and outputs audio under the control of the control unit 30. The audio output device 43 is, for example, a loudspeaker or a buzzer. In response to an audio output command from the control unit 30, the audio output device 43 outputs various types of information acoustically. The storage device 47 is located, for example, in cabin 10 and stores various types of information under the control of the controller 30. The storage device 47 is, for example, a non-volatile storage medium such as a semiconductor memory. The storage device 47 can store information output by various devices during the operation of the excavator 100, or it can store information received by various devices before the excavator 100 started operating. For example, the storage device 47 can store data relating to a target construction area received via the communicator T1 or the like, or set via the input device 42 or the like. The target construction area can be set (stored) by the operator of the excavator 100 or by a site manager or the like. The boom angle sensor S1 is mounted on the boom 4 and detects an inclination angle (hereinafter referred to as the "boom angle") of the boom 4 relative to the upper pivoting body 3, for example, an angle formed in a side view by a straight line connecting the pivot points at both ends of the boom 4 with respect to a plane of rotation of the upper pivoting body 3. The boom angle sensor S1 may, for example, comprise a rotary encoder, an accelerometer, a 6-axis sensor, an inertial measurement unit (IMU), or the like. The boom angle sensor S1 may also include a potentiometer using a variable resistance, a cylinder sensor for detecting the stroke of a hydraulic cylinder (boom cylinder 7) according to the boom angle, and the like. The same applies to the arm angle sensor S2 and the bucket angle sensor S3.A detection signal corresponding to the boom angle detected by the boom angle sensor S1 is received by the controller 30. The arm angle sensor S2 is attached to the arm 5 and detects a rotation angle (hereinafter referred to as the "arm angle") of the arm 5 with respect to the boom 4, for example, an angle formed by a straight line connecting the pivot points at both ends of the arm 5 with respect to a straight line connecting the pivot points at both ends of the boom 4 in a side view. A detection signal corresponding to the arm angle detected by the arm angle sensor S2 is received by the controller 30. The blade angle sensor S3 is attached to the blade 6 and detects a rotation angle (hereinafter referred to as the "blade angle") of the blade 6 with respect to the arm 5, for example, an angle formed by a straight line connecting the pivot point and the tip (claw tip) of the blade 6 with respect to a straight line connecting the pivot points at both ends of the arm 5 in a side view. A detection signal corresponding to the blade angle detected by the blade angle sensor S3 is received by the controller 30. The machine body tilt sensor S4 detects the tilt state of the machine body (the upper swing body 3 or the lower travel body 1) relative to the horizontal plane. For example, the machine body tilt sensor S4 is mounted on the upper swing body 3 and detects the tilt angles (hereinafter referred to as "forward-backward tilt angle" and "left-right tilt angle") of the excavator 100 (i.e., the upper swing body 3) about two axes in the forward-backward and left-right directions. The machine body tilt sensor S4 can, for example, include a rotary encoder, an accelerometer, a 6-axis sensor, an IMU, or the like. Detection signals corresponding to the tilt angles detected by the machine-body tilt sensor S4 (the front-back and left-right tilt angles) are received by the control unit 30. The rotation state sensor S5 outputs detection information regarding the rotation state of the upper swivel body 3. For example, the rotation state sensor S5 detects the angular velocity and the rotation angle of the upper swivel body 3. The rotation state sensor S5 can, for example, include a gyroscope, a resolver, a rotary encoder, or the like. Detection signals corresponding to the rotation angle and angular velocity of the upper swivel body 3 detected by the rotation state sensor S5 are received by the controller 30. The boom angle sensor S1, the arm angle sensor S2, the blade angle sensor S3, the machine body tilt sensor S4, and the rotation state sensor S5 are integrated into position sensors. The position sensors detect not only the claw tip position of the blade 6, but also the boom angle, boom rotation speed, boom rotation acceleration, etc. The imaging device S6, as a spatial detection device, captures images of the surroundings of the excavator 100. The imaging device S6 comprises a front camera S6F, configured to image the front of the excavator 100, a left camera S6L, configured to image the left side of the excavator 100, a right camera S6R, configured to image the right side of the excavator 100, and a rear camera S6B, configured to image the rear of the excavator 100. The front camera S6F, for example, is mounted on the ceiling of cabin 10, i.e., inside cabin 10. The front camera S6F can also be mounted outside cabin 10, such as on the roof of cabin 10 or on a side surface of the boom 4. The left camera S6L is mounted on the left end of the top of the upper swivel body 3, the right camera S6R is mounted on the right end of the top of the upper swivel body 3, and the rear camera S6B is mounted on the rear end of the top of the upper swivel body 3. The imaging device S6 (cameras S6F, S6B, S6L and S6R) is, for example, a monocular wide-angle camera with a very large field of view. The imaging device S6 can be a stereo camera, a distance imaging camera, or the like. The image captured by the imaging device S6 is received by the control unit 30 via the display device 40. The imaging device S6, acting as a spatial detection device, can function as an object detection device. In this case, the imaging device S6 can detect an object located around the excavator 100. The object to be detected could be, for example, a person, an animal, a vehicle, construction equipment, a building, a hole, and the like. Furthermore, the imaging device S6 can calculate the distance from the imaging device S6 or the excavator 100 to the detected object. The imaging device S6, acting as an object detection device, could, for example, include a stereo camera, a distance image sensor, and the like. The spatial detection device could, for example, be a monocular camera that includes an image sensor such as a CCD or CMOS sensor and outputs a captured image to the display device 40.Furthermore, the spatial detection device can be configured to calculate a distance from the spatial detection device or the excavator 100 to the detected object. Additionally, besides the imaging device S6, another object detection device, such as an ultrasonic sensor, millimeter-wave radar, a light detection and ranging (LiDAR) system, an infrared sensor, or the like, can be provided as a spatial detection device. If a millimeter-wave radar, an ultrasonic sensor, a laser radar, or the like is used as the spatial detection device, a large number of signals (laser light or the like) can be transmitted to the object, and the reflected signals can be received to detect the object's distance and direction. It should be noted that the imaging device S6 can be directly connected to the control unit 30 in order to be able to communicate with each other. A boom rod pressure sensor S7R, a boom base pressure sensor S7B, and a boom cylinder stroke sensor S7C are mounted on boom cylinder 7. A boom rod pressure sensor S8R, a boom base pressure sensor S8B, and a boom cylinder stroke sensor S8C are mounted on boom cylinder 8. A bucket rod pressure sensor S9R, a bucket base pressure sensor S9B, and a bucket cylinder stroke sensor S9C are mounted on bucket cylinder 9. The boom rod pressure sensor S7R, the boom base pressure sensor S7B, the boom rod pressure sensor S8R, the boom base pressure sensor S8B, the bucket rod pressure sensor S9R, and the bucket base pressure sensor S9B are collectively referred to as "cylinder pressure sensors." The boom cylinder stroke sensor S7C, the boom cylinder stroke sensor S8C, and the bucket cylinder stroke sensor S9C are also referred to as "cylinder stroke sensors." The boom rod pressure sensor S7R detects the pressure (boom rod pressure) of a rod-side oil chamber of boom cylinder 7. A boom bottom pressure sensor S7B detects the pressure (boom bottom pressure) of a bottom-side oil chamber of boom cylinder 7. A boom cylinder stroke sensor S7C detects the stroke amount (boom stroke amount) of boom cylinder 7. The arm rod pressure sensor S8R detects the pressure (arm rod pressure) of the rod-side oil chamber of the arm cylinder 8. The arm bottom pressure sensor S8B detects the pressure (arm bottom pressure) of the bottom-side oil chamber of the arm cylinder 8. The arm cylinder stroke sensor S8C detects the stroke (arm stroke amount) of the arm cylinder 8. The bucket rod pressure sensor S9R detects the pressure (bucket rod pressure) of the rod-side oil chamber of bucket cylinder 9. The bucket bottom pressure sensor S9B detects the pressure (bucket bottom pressure) of the bottom-side oil chamber of bucket cylinder 9. The bucket cylinder stroke sensor S9C detects the stroke amount (bucket stroke amount) of bucket cylinder 9. The positioning device P1 measures the position and direction of the upper swivel body 3. The positioning device P1 is, for example, a compass of a global navigation satellite system (GNSS) and detects the position and direction of the upper swivel body 3. Upon detection, a detection signal corresponding to the position and direction of the upper swivel body 3 is received by the controller 30. Furthermore, the function of detecting the direction of the upper swivel body 3 can be replaced by an orientation sensor attached to the upper swivel body 3 within the functions of the positioning device P1. The communicator T1 communicates with an external device via a predetermined network comprising a mobile network, a satellite communications network, an internet network, and the like, which includes a base station as an end device. The communicator T1 is, for example, a mobile communications module compliant with a mobile communications standard such as Long Term Evolution (LTE), 4th generation (4G), 5th generation (5G), or the like, or a satellite communications module for connecting to a satellite communications network. The machine control section 50 controls the excavator 100 with respect to the machine control function. The machine control section 50 transmits work information, such as the distance between the target work surface and the tip of the attachment, in particular the working section of the end attachment, to the operator via the display device 40, the audio output device 43, and the like. The data relating to the target work surface are previously stored, for example, as described above, in the storage device 47. The data relating to the target work surface are expressed, for example, in a reference coordinate system. The reference coordinate system is, for example, the geodetic world system.The geodetic world system is a three-dimensional orthogonal XYZ coordinate system with its origin at the Earth's center of mass, an X-axis in the direction of the intersection of the Greenwich Meridian and the equator, a Y-axis in the direction of 90 degrees east longitude, and a Z-axis in the direction of the North Pole. The operator can set any position on the construction site as the reference point and adjust the target work area according to its relative position to the reference point using the input device 42. For example, the working section of the bucket 6 is the tip of the bucket 6, the back of the bucket 6, or the like. If, for example, a crusher is used as the end piece instead of the bucket 6, the tip of the crusher corresponds to the working section.The machine control section 50 communicates the work information to the operator via the display device 40, the audio output device 43 or the like, and controls the operation of the excavator 100 by the operator via the control device 26. The machine control section 50 controls the excavator 100 for the machine control function. The machine control section 50 can, for example, automatically actuate at least one of the boom 4, arm 5, or bucket 6 so that the target construction area coincides with the tip position of the bucket 6 when the operator performs the excavation operation manually. The machine control section 50 receives information from the boom angle sensor S1, the arm angle sensor S2, the blade angle sensor S3, the machine body tilt sensor S4, the rotation state sensor S5, the imaging device S6, the positioning device P1, the communication device T1, the input device 42, and the like. The machine control section 50 calculates, for example, the distance between the blade 6 and the target building surface based on the received information, notifies the operator of the degree of distance between the blade 6 and the target building surface by means of the audio output device 43 and the image displayed on the display device 40, and automatically controls the operation of the attachment so that the tip (in particular a working section such as the claw tip or the back of the blade 6) of the attachment coincides with the target building surface.The machine guidance section 50 includes a position computer 51, a distance computer 52, an information transmitter 53, a control circuit 54 and a rotary angle computer 55 as detailed functional configurations with respect to the machine guidance function and the machine control function. The position calculator 51 calculates the position of a predetermined positioning object. For example, the position calculator 51 calculates a coordinate point in the reference coordinate system of the tip of the attachment, in particular a working section such as the claw tip or the back of the bucket 6. Specifically, the position calculator 51 calculates the coordinate point of the working section of the bucket 6 from the inclination angles (boom angle, arm angle and bucket angle) of the boom 4, the arm 5 and the bucket 6. The distance calculator 52 calculates the distance between the two positioning objects. For example, the distance calculator 52 calculates the distance between the tip of the attachment, in particular the working section such as the claw tip or the back of the bucket 6, and the target surface. The distance calculator 52 can also calculate the angle (relative angle) between the back of the bucket 6, as the working section, and the target surface. The information transmitter 53 transmits (reports) various types of information to the operator of the excavator 100 via predetermined notification means such as the display device 40 and the audio output device 43. The control circuit 54 individually adjusts the pilot pressure applied to the control valves (in particular the control valve 173, the control valves 175L and 175R and the control valve 174) according to the several hydraulic actuators (in particular the swing hydraulic motor 2A, the boom cylinder 7 and the bucket cylinder 9) according to the manual operation of the excavator 100 by the operator via the control device 26. Thus, the control circuit 54 can achieve the operation of the hydraulic actuators according to the operation carried out by the operator. The rotation angle calculator 55 calculates the rotation angle of the upper slewing body 3. This allows the controller 30 to specify the current direction of the upper slewing body 3. The rotation angle calculator 55 calculates the angle of the front-back axis of the upper slewing body 3 relative to a reference direction as the rotation angle, for example, based on the output signal of the GNSS compass included in the positioning device P1. The rotation angle calculator 55 can also calculate the rotation angle based on the detection signal of the rotation state sensor S5. If the reference point is set at the construction site, the rotation angle calculator 55 can further specify the direction in which the reference point is viewed from a rotation axis as the reference direction. The rotation angle specifies the direction in which an attachment operating surface extends with respect to the reference direction. The attachment operating surface is, for example, an imaginary plane extending along the attachment in the front-to-back direction and perpendicular to the plane of rotation. The plane of rotation is, for example, an imaginary plane encompassing the underside of a rotary frame perpendicular to the axis of rotation. If, for example, the controller 30 (machine guide section 50) determines that the attachment operating surface encompasses the line normal to the target build surface, the controller 30 determines that the upper swivel body 3 faces the target build surface. The rotation angle calculated by the rotation angle calculator 55 can be displayed as visual information on the display device 40 by the information transmitter 53. Furthermore, the rotation angle can be used as a condition for the earth and sand loading processor 60 to measure the earth and sand weight (for example, to determine whether the upper swivel body 3 has rotated or not). The swivel hydraulic motor 2A comprises a first port 2A1 and a second port 2A2. A hydraulic sensor 21 detects the hydraulic oil pressure at the first port 2A1 of the swivel hydraulic motor 2A. A hydraulic sensor 22 detects the hydraulic oil pressure at the second port 2A2 of the swivel hydraulic motor 2A. Detection signals corresponding to the output pressures detected by the hydraulic sensors 21 and 22 are received by the controller 30. The first port 2A1 is connected to a hydraulic oil tank via a relief valve 23. The relief valve 23 opens when the pressure on one side of the first port 2A1 reaches a predetermined relief pressure and releases the hydraulic oil from that side of the first port 2A1 to the hydraulic oil tank. Similarly, the second port 2A2 is connected to the hydraulic oil tank via a relief valve 24. The relief valve 24 opens when the pressure on one side of the second port 2A2 reaches a predetermined relief pressure and releases the hydraulic oil from that side of the second port 2A2 to the hydraulic oil tank. [Excavator hydraulic system] Next, a hydraulic system of the excavator 100 according to the present embodiment will be described with reference to Fig. 3. Fig. 3 is a schematic diagram illustrating an example of a hydraulic system configuration for the excavator according to the present embodiment. In Fig. 3, the mechanical power system, the hydraulic oil line, the pilot line, and the electrical control system, as in Fig. 2 and the like, are indicated by double lines, solid lines, dashed lines, and dotted lines, respectively. The hydraulic system realized by the hydraulic circuit illustrated in Fig. 3 circulates the hydraulic oil from the main pumps 14L and 14R driven by the motor 11 via central bypass oil paths C1L and C1R as well as parallel oil paths C2L and C2R to the hydraulic oil tank. The central bypass oil path C1L starts at the main pump 14L and passes successively through the control valves 171, 173, 175L and 176L arranged in the control valve 17 to reach the hydraulic oil tank. The central bypass oil path C1R starts at the main pump 14R and passes successively through the control valves 172, 174, 175R and 176R arranged in the control valve 17 to reach the hydraulic oil tank. The control valve 171 is a spool valve for supplying the hydraulic oil delivered by the main pump 14L to the drive hydraulic motor 1L and for delivering the hydraulic oil delivered by the drive hydraulic motor 1L to the hydraulic oil tank. The control valve 172 is a spool valve for supplying the hydraulic oil delivered by the main pump 14R to the drive hydraulic motor 1R and for delivering the hydraulic oil delivered by the drive hydraulic motor 1R to the hydraulic oil tank. The control valve 173 is a spool valve for supplying the hydraulic oil delivered by the main pump 14L to the swivel hydraulic motor 2A and for delivering the hydraulic oil delivered by the swivel hydraulic motor 2A to the hydraulic oil tank. The control valve 174 is a slide valve for supplying the hydraulic oil delivered by the main pump 14R to the bucket cylinder 9 and for delivering the hydraulic oil in the bucket cylinder 9 to the hydraulic oil tank. The control valves 175L and 175R are spool valves for supplying the hydraulic oil delivered by the main pumps 14L and 14R to the boom cylinder 7 and for delivering the hydraulic oil from the boom cylinder 7 into the hydraulic oil tank. The control valves 176L and 176R are spool valves for supplying the hydraulic oil delivered by the main pumps 14L and 14R to the arm cylinder 8 and for delivering the hydraulic oil from the arm cylinder 8 into the hydraulic oil tank. The control valves 171, 172, 173, 174, 175L, 175R, 176L and 176R respectively adjust the flow rate of the hydraulic oil supplied to and from the hydraulic actuator and switch the flow direction according to the pilot pressure to be applied to the pilot port. Parallel oil path C2L supplies hydraulic oil from the main pump 14L to control valves 171, 173, 175L, and 176L in parallel with the central bypass oil path C1L. Specifically, parallel oil path C2L branches off from the central bypass oil path C1L upstream of control valve 171 and is configured to supply hydraulic oil from the main pump 14L to control valves 171, 173, 175L, and 176R in parallel. Thus, parallel oil path C2L can supply hydraulic oil to the control valve located further downstream if the flow of hydraulic oil through the central bypass oil path C1L is restricted or blocked by one of the control valves 171, 173, or 175L. Parallel oil path C2R supplies hydraulic oil from the main pump 14R to control valves 172, 174, 175R, and 176R in parallel with the central bypass oil path C1R. Specifically, parallel oil path C2R branches off from the central bypass oil path C1R upstream of control valve 172 and is configured to supply hydraulic oil from the main pump 14R to control valves 172, 174, 175R, and 176R in parallel. Thus, parallel oil path C2R can supply hydraulic oil to the control valve located further downstream if the flow of hydraulic oil through the central bypass oil path C1R is restricted or blocked by one of the control valves 172, 174, or 175R. The controllers 13L and 13R adjust the delivery quantities of the main pumps 14L and 14R by adjusting the tilt angles of the swashplates of the main pumps 14L and 14R under the control of the controller 30. The 28L discharge pressure sensor detects the discharge pressure of the main pump 14L. Upon detection, a corresponding detection signal is received by the controller 30. The same applies to the 28R discharge pressure sensor. Thus, the controller 30 can control the regulators 13L and 13R according to the discharge pressures of the main pumps 14L and 14R. A negative control orifice (hereinafter referred to as a "negative control throttle") 18L is provided in the central bypass oil path C1L between the furthest downstream control valve 176L and the hydraulic oil tank. Similarly, a negative control orifice 18R is provided in the central bypass oil path C1R between the furthest downstream control valve 176R and the hydraulic oil tank. Thus, the hydraulic oil flows delivered by the main pumps 14L and 14R are restricted by the negative control throttles 18L and 18R. The negative control throttles 18L and 18R generate control pressure (hereinafter referred to as "negative control pressure") to control the governors 13L and 13R. Negative control pressure sensors 19L and 19R detect the negative control pressure. A detection signal corresponding to the negative control pressure detected by negative control pressure sensors 19L and 19R is received by the control unit 30. The controller 30 can control the governors 13L and 13R according to the discharge pressures of the main pumps 14L and 14R detected by the discharge pressure sensors 28L and 28R, in order to adjust the discharge rates of the main pumps 14L and 14R. For example, the controller 30 can control governor 13L in response to an increase in the discharge pressure of the main pump 14L, adjusting the tilt angle of the swashplate of the main pump 14L and thus reducing the discharge rate. The same applies to governor 13R. Therefore, the controller 30 can control the total power (horsepower) of the main pumps 14L and 14R so that the power (horsepower) absorbed by the main pumps 14L and 14R, represented by the product of discharge pressures and discharge rates, does not exceed the output horsepower of the engine 11. The controller 30 can control the regulators 13L and 13R according to the negative control pressures detected by the negative control pressure sensors 19L and 19R in order to adjust the delivery rates of the main pumps 14L and 14R. For example, the controller 30 reduces the delivery rates of the main pumps 14L and 14R when the negative control pressures increase, and increases the delivery rates of the main pumps 14L and 14R when the negative control pressures decrease. Particularly in a standby state (state as illustrated in Fig. 3), in which none of the hydraulic actuators of the excavator 100 are actuated, the hydraulic oil delivered by the main pumps 14L and 14R flows through the central bypass oil passages C1L and C1R to reach the negative control throttles 18L and 18R. The flow of hydraulic oil delivered by the main pumps 14L and 14R increases the negative control pressure generated upstream of the negative control throttles 18L and 18R. As a result, the control unit 30 reduces the delivery rates of the main pumps 14L and 14R to a permissible minimum delivery rate and suppresses pressure loss (pump loss) when the delivered hydraulic oil flows through the central bypass oil passages C1L and C1R. In contrast, when one of the hydraulic actuators is actuated by the control device 26, the hydraulic oil delivered by the main pumps 14L and 14R flows through the control valve corresponding to the hydraulic actuator being actuated into the hydraulic actuator being actuated. The flow of hydraulic oil delivered by the main pumps 14L and 14R reduces or prevents the amount reaching the negative control throttles 18L and 18R and reduces the negative control pressure generated upstream of the negative control throttles 18L and 18R. As a result, the control unit 30 increases the delivery rates of the main pumps 14L and 14R, circulates sufficient hydraulic oil to the hydraulic actuator being actuated, and reliably drives the hydraulic actuator being actuated. [Details of the excavator's machine control function configuration] Next, details of the configuration of the machine control function of the excavator 100 are described with reference to Figures 4A to 4C. Figures 4A to 4C are diagrams that schematically illustrate an example of a component relating to an operating system in the hydraulic system of the excavator according to the present embodiment. In particular, Fig. 4A is a diagram illustrating an example of a control circuit for applying pilot pressure to the control valves 175L and 175R for hydraulically controlling the boom cylinder 7. Fig. 4B is a diagram illustrating an example of a control circuit for applying pilot pressure to the control valve 174 for hydraulically controlling the bucket cylinder 9. Fig. 4C is a diagram illustrating an example of the control circuit for applying pilot pressure to the control valve 173 for hydraulically controlling the slewing hydraulic motor 2A. As illustrated in Fig. 4A, the lever device 26A is used by an operator or the like to actuate the boom cylinder 7 in accordance with the boom 4. The lever device 26A, using hydraulic oil supplied from the pilot pump 15, transmits a pilot pressure to the secondary side corresponding to the operator's input. The changeover valve 32AL comprises two inlet ports, each connected to a secondary pilot line of the lever device 26A and a secondary pilot line of the proportional valve 31AL, corresponding to an operation (hereinafter referred to as "boom-high operation") in a lifting position of the boom 4, and an outlet port connected to a right pilot port of the control valve 175L and a left pilot port of the control valve 175R. The changeover valve 32AR comprises two inlet ports, each connected to the secondary pilot line of the lever device 26A and the secondary pilot line of the proportional valve 31AR, corresponding to an operation (hereinafter referred to as "boom-down operation") in a downward direction of the boom 4, and one outlet port connected to a right-hand pilot port of the control valve 175R. This means that the lever device 26A causes a pilot pressure corresponding to the operating parameters (e.g., the direction of operation and the amount of operation) to be applied via the changeover valves 32AL and 32AR to the pilot ports of the control valves 175L and 175R. Specifically, when the boom is raised, the lever device 26A outputs a pilot pressure corresponding to the amount of operation to an inlet port of the changeover valve 32AL and causes the pilot pressure to be applied via the changeover valve 32AL to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. When the boom is lowered, the lever device 26A outputs a pilot pressure corresponding to the amount of operation to an inlet port of the changeover valve 32AR and causes the pilot pressure to be applied via the changeover valve 32AR to the right pilot port of the control valve 175R. The proportional valve 31AL operates in response to a control current input from the controller 30. Specifically, using hydraulic oil supplied by the pilot pump 15, the proportional valve 31AL outputs a pilot pressure corresponding to the control current input from the controller 30 to the other inlet port of the changeover valve 32AL. Thus, the proportional valve 31AL can adjust the pilot pressure applied via the changeover valve 32AL to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. The proportional valve 31AR operates in response to the control flow input from the controller 30. Specifically, using hydraulic oil supplied by the pilot pump 15, the proportional valve 31AR outputs a pilot pressure corresponding to the control flow input from the controller 30 to the other inlet port of the changeover valve 32AR. Thus, the proportional valve 31AR can adjust the pilot pressure applied via the changeover valve 32AR to the right pilot port of the control valve 175R. This means that the proportional valves 31AL and 31AR can adjust the pilot pressure output to the secondary side so that the control valves 175L and 175R can be adjusted to the desired valve positions independently of the operating state of the lever device 26A. Similar to the proportional valve 31AL, a proportional valve 33AL functions as a control valve for machine control. The proportional valve 33AL is arranged in a line connecting the operating device 26 and the shuttle valve 32AL and is configured so that the flow path of the line can be changed. In the present embodiment, the proportional valve 33AL operates in response to a control command issued by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic oil supplied by the operating device 26 and supply the reduced pressure via the shuttle valve 32AL to the pilot port of the corresponding control valve in the controller 17, regardless of the operator's operation of the operating device 26. Similarly, a proportional valve 33AR functions as a control valve for the machine control system. The proportional valve 33AR is arranged in a line connecting the operating device 26 and the changeover valve 32AR and is configured so that the flow path of the line can be changed. In the present embodiment, the proportional valve 33AR operates in response to a control command issued by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic oil supplied by the operating device 26 and supply the reduced pressure via the changeover valve 32AR to the pilot port of the corresponding control valve in the controller 17, regardless of whether the operator is operating the operating device 26. The operating pressure sensor 29A detects the user's input on the lever device 26A in the form of pressure (operating pressure). A detection signal corresponding to the operating pressure detected by the operating pressure sensor 29A is received by the controller 30. Thus, the controller 30 can monitor the user input on the lever device 26A. The control unit 30 can supply the hydraulic oil delivered by the pilot pump 15, via the proportional valve 31AL and the changeover valve 32AL, to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R, independently of the operator's operation of the boom-raising lever device 26A. The control unit 30 can also supply the hydraulic oil delivered by the pilot pump 15, independently of the operator's operation of the lever device 26A, to the right pilot port of the control valve 175R via the proportional valve 31AR and the changeover valve 32AR. This means that the control unit 30 can automatically control the raising and lowering of the boom 4. The control unit 30 can also forcibly stop the operation of the hydraulic actuator corresponding to the specific operating device 26, even if the specific operating device 26 is currently being operated. The proportional valve 33AL operates in response to a control command (current command) issued by the controller 30. The pilot pressure is then reduced by the hydraulic oil supplied by the pilot pump 15 via the lever assembly 26A, the proportional valve 33AL, and the changeover valve 32AL to the right pilot port of the control valve 175L and the left pilot port of the control valve 175R. The proportional valve 33AR operates in response to a control command (current command) issued by the controller 30. The pilot pressure is then reduced by the hydraulic oil supplied by the pilot pump 15 via the lever assembly 26A, the proportional valve 33AR, and the changeover valve 32AR to the right pilot port of the control valve 175R. The proportional valves 33AL and 33AR can adjust the pilot pressure so that the control valves 175L and 175R can be adjusted to the desired valve positions. With this configuration, the controller 30 can forcibly stop the closing operation of the boom 4 by reducing the pilot pressure applied to the pilot port on the upward side of the control valve 175 (the left pilot port of control valve 175L and the right pilot port of control valve 175R) as needed, even if the boom-raising operation is performed by the operator. The same applies in the case where the boom-lowering operation of the boom 4 is forcibly stopped if the boom-lowering operation is performed by the operator. Alternatively, the control unit 30 can forcibly stop the boom-raising operation of boom 4 by controlling the proportional valve 31AR, increasing the pilot pressure applied to the pilot port on the down side of control valve 175 (the right pilot port of control valve 175R), which is located on the opposite side from the pilot port on the up side of control valve 175, and forcibly returning control valve 175 to a neutral position if necessary, even if the operator is currently performing the boom-raising operation. In this case, the proportional valve 33AL can be omitted. The same applies to the case where the boom-lowering operation of boom 4 is forcibly stopped when the boom-lowering operation is being performed by the operator. As illustrated in Fig. 4B, the lever device 26B is used by the operator or the like to actuate the bucket cylinder 9 according to the bucket 6. The lever device 26B outputs the pilot pressure to the secondary side according to the operating commands using the hydraulic oil supplied by the pilot pump 15. The changeover valve 32BL comprises two inlet ports, each connected to the secondary pilot line of the lever device 26B and the secondary pilot line of the proportional valve 31BL, corresponding to an operation (hereinafter referred to as "blade closing operation") in one closing direction of the blade 6, and an outlet port connected to the left pilot port of the control valve 174. The changeover valve 32BR comprises two inlet ports connected to the secondary pilot line of the lever device 26B and the secondary pilot line of the proportional valve 31BR, each corresponding to one operation (hereinafter referred to as the "blade opening operation") in the opening direction of the blade 6, and one outlet port connected to the right pilot port of the control valve 174. This means that the lever device 26B causes a pilot pressure corresponding to the operating conditions to be applied to the pilot port of the control valve 174 via the changeover valves 32BL and 32BR. Specifically, when the bucket closing operation is performed, the lever device 26B outputs a pilot pressure corresponding to the input value to an inlet port of the changeover valve 32BL and causes the pilot pressure to be applied to the left pilot port of the control valve 174 via the changeover valve 32BL. When the bucket opening operation is performed, the lever device 26B outputs a pilot pressure corresponding to the input value to an inlet port of the changeover valve 32BR and causes the pilot pressure to be applied to the right pilot port of the control valve 174 via the changeover valve 32BR. The proportional valve 31BL operates in response to the control current input from the controller 30. Specifically, the proportional valve 31BL, using hydraulic oil supplied by the pilot pump 15, outputs a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the changeover valve 32BL. Thus, the proportional valve 31BL can adjust the pilot pressure applied via the changeover valve 32BL to the left pilot port of the control valve 174. The proportional valve 31BR operates in response to the control current input from the controller 30. Specifically, the proportional valve 31BR outputs a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the changeover valve 32BR, using hydraulic oil supplied by the pilot pump 15. Thus, the proportional valve 31BR can adjust the pilot pressure applied via the changeover valve 32BR to the right pilot port of the control valve 174. This means that the proportional valves 31BL and 31BR can adjust the pilot pressure output to the secondary side so that the control valve 174 can be adjusted to a desired valve position independently of the operating state of the lever device 26B. Similar to the proportional valve 31BL, a proportional valve 33BL functions as a control valve for machine control. The proportional valve 33BL is arranged in a line connecting the operating device 26 and the shuttle valve 32BL and is configured to change the flow path of the line. In the present embodiment, the proportional valve 33BL operates in response to a control command issued by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic oil supplied by the operating device 26 and supply the reduced pressure via the shuttle valve 32BL to the pilot port of the corresponding control valve in the controller 17, regardless of the operator's operation of the operating device 26. Similarly, a proportional valve 33BR functions as a control valve for machine control. The proportional valve 33BR is arranged in a line connecting the operating device 26 and the shuttle valve 32BR and is configured so that the flow path of the line can be changed. In the present embodiment, the proportional valve 33BR operates in response to a control command issued by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic oil supplied by the operating device 26 and supply the reduced pressure via the shuttle valve 32BR to the pilot port of the corresponding control valve in the controller 17, independently of the operator's operation of the operating device 26. An operating pressure sensor 29B detects the operation of the lever device 26B by the operator in the form of pressure (operating pressure). The detection signal corresponding to the operating pressure detected by the operating pressure sensor 29B is received by the control unit 30. Thus, the control unit 30 can record the operating contents of the lever device 26B. Control unit 30 can supply the hydraulic oil delivered by pilot pump 15 to the left pilot port of control valve 174 via proportional valve 31BL and changeover valve 32BL, independently of the operator's bucket closing operation of lever device 26B. Control unit 30 can also supply the hydraulic oil delivered by pilot pump 15 to the right pilot port of control valve 174 via proportional valve 31BR and changeover valve 32BR, independently of the operator's bucket opening operation of lever device 26B. This means that control unit 30 can automatically control the bucket closing or opening operation of bucket 6. Furthermore, control unit 30 can forcibly stop the operation of the hydraulic actuator corresponding to the specific operating device 26, even while the specific operating device 26 is being operated. It should be noted that the operation of the proportional valves 33BL and 33BR for the forced stopping of the operation of the bucket 6 when the bucket closing operation or the bucket opening operation is carried out by the operator is the same as the operation of the proportional valves 33AL and 33AR for the forced stopping of the operation of the boom 4 when the boom raising operation or the boom lowering operation is carried out by the operator, and therefore a description of it is omitted. As illustrated in Fig. 4C, the lever device 26C is used by an operator or the like to actuate the swivel hydraulic motor 2A, which corresponds to the upper swivel body 3 (rotary device 2). The lever device 26C, using hydraulic oil supplied by the pilot pump 15, transmits a pilot pressure to the secondary side corresponding to the operator's input. The changeover valve 32CL comprises two inlet ports, each connected to the secondary pilot line of the lever device 26C, which corresponds to a left-hand rotation (hereinafter referred to as "left-hand rotation") of the upper pivot body 3, and to the secondary pilot line of the proportional valve 31CL, and one outlet port connected to the left pilot port of the control valve 173. The changeover valve 32CR comprises two inlet ports, each connected to the secondary control line of the lever device 26C, which corresponds to a right-hand rotation (hereinafter referred to as "right-hand rotation") of the upper pivot body 3, and to the secondary control line of the proportional valve 31CR, and one outlet port connected to a right-hand control port of the control valve 173. This means that the lever device 26C causes a pilot pressure corresponding to the operating parameters in the left-right direction to be applied to the pilot port of the control valve 173 via the changeover valves 32CL and 32CR. Specifically, when the left-hand rotation is performed, the lever device 26C outputs a pilot pressure corresponding to the operating parameter to an inlet port of the changeover valve 32CL and causes the pilot pressure to be applied to the left pilot port of the control valve 173 via the changeover valve 32CL. When the right-hand rotation is performed, the lever device 26C outputs a pilot pressure corresponding to the operating parameter to an inlet port of the changeover valve 32CR and causes the pilot pressure to be applied to the right pilot port of the control valve 173 via the changeover valve 32CR. The proportional valve 31CL operates in response to a control current input from the controller 30. Specifically, by using hydraulic oil supplied by the pilot pump 15, the proportional valve 31CL outputs a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the changeover valve 32CL. Thus, the proportional valve 31CL can adjust the pilot pressure applied via the changeover valve 32CL to the left pilot port of the control valve 173. The proportional valve 31CR operates in response to the control current input from the controller 30. Specifically, the proportional valve 31CR outputs a pilot pressure corresponding to the control current input from the controller 30 to the other pilot port of the changeover valve 32CR by using hydraulic oil supplied by the pilot pump 15. Thus, the proportional valve 31CR can adjust the pilot pressure applied via the changeover valve 32CR to the right pilot port of the control valve 173. This means that the proportional valves 31CL and 31CR can adjust the pilot pressure output to the secondary side so that the control valve 173 can be adjusted to a desired valve position independently of the operating state of the lever device 26C. A proportional valve 33CL functions similarly to the proportional valve 31CL as a control valve for machine control. The proportional valve 33CL is arranged in a line connecting the operating device 26 and the shuttle valve 32CL and is configured so that the flow path of the line can be changed. In the present embodiment, the proportional valve 33CL operates in response to the control command issued by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic oil supplied by the operating device 26 and supply the reduced pressure via the shuttle valve 32CL to the pilot port of the corresponding control valve in the controller 17, regardless of the operator's operation of the operating device 26. Similarly, a proportional valve 33CR functions as a control valve for machine control. The proportional valve 33CR is arranged in a line connecting the operating device 26 and the shuttle valve 32CR and is configured so that the flow path of the line can be changed. In the present embodiment, the proportional valve 33CR operates in response to a control command issued by the controller 30. Therefore, the controller 30 can reduce the pressure of the hydraulic oil supplied by the operating device 26 and supply the reduced pressure via the shuttle valve 32CR to the pilot port of the corresponding control valve in the controller 17, regardless of the operator's operation of the operating device 26. An operating pressure sensor 29C detects the operating status of the lever device 26C as determined by the operator in the form of pressure (operating pressure). A detection signal corresponding to the operating pressure detected by the operating pressure sensor 29C is received by the controller 30. Thus, the controller 30 can detect the operating actions of the lever device 26C in the left-right direction. The control unit 30 can supply the hydraulic oil delivered by the pilot pump 15 to the pilot port on the left side of the control valve 173 via the proportional valve 31CL and the changeover valve 32CL, regardless of whether the operator is turning the lever 26C counterclockwise. The control unit 30 can also supply the hydraulic oil delivered by the pilot pump 15 to the pilot port on the right side of the control valve 173 via the proportional valve 31CR and the changeover valve 32CR, regardless of whether the operator is turning the lever 26C clockwise. This means that the control unit 30 can automatically control the left-right rotation of the upper swivel body 3. Furthermore, the control unit 30 can forcibly interrupt the operation of the hydraulic actuator corresponding to the specific operating device 26, even when the specific operating device 26 is being operated. The operation of the proportional valves 33CL and 33CR for the forced stopping of the operation of the upper slewing body 3 when the operator performs the rotary operation is the same as the operation of the proportional valves 33AL and 33AR for the forced stopping of the operation of the boom 4 when the operator performs the boom-up operation or the boom-down operation, and therefore a description of it is omitted. The excavator 100 can also be equipped with a configuration for automatically opening and closing the arm 5 and a configuration for automatically moving the lower undercarriage 1 forward and backward. In this case, the components of the hydraulic system relating to the operating system of the arm cylinder 8, the components relating to the operating system of the travel hydraulic motor 1L, and the components relating to the operating system of the travel hydraulic motor 1R can be configured similarly to the components relating to the operating system of the boom cylinder 7 and the like (see Figs. 4A to 4C). The excavator 100 can communicate indirectly or directly with an external device (not illustrated), for example using the communicator T1. The excavator 100 can be configured to be operated remotely from outside the excavator 10 (remote control) instead of being operated by an operator inside the cab 10. When the excavator 100 is remotely controlled, the interior of the cab 10 can be unmanned. The following description assumes that the operation performed by the operator includes at least one operation of the control device 26 by the operator inside the cab 10 or remote control by an external operator. The remote control includes, for example, a mode in which the excavator 100 is operated by an input to the excavator 100's actuator, which is carried out by a predetermined external device. In this case, the excavator 100 can, for example, transmit image information (captured image) output by the front camera S6F for capturing an image in front of the upper swing body 3 to the external device for remote control via the communicator T1 described below. The external device can display the received image information (captured image) on a display device provided in a separate device (hereinafter referred to as the "remote control display device").Furthermore, various information images (information screens) displayed on the display device 40 inside the cab 10 of the excavator 100 can be similarly displayed on the remote control display device of the external device. Thus, the operator of the external device can remotely control the excavator 100 while, for example, confirming display content such as a captured image and an information screen depicting the status of the excavator 100 on the remote control display device. The excavator 100 can actuate an actuator according to a remote control signal, which represents the content of the remote control received by the external device via the communicator T1, in order to drive the driven elements such as the lower track 1 (left and right crawlers), the upper swing body 3, the boom 4, the arm 5, and the bucket 6. The remote control can, for example, include a mode in which the excavator 100 is operated externally by a person (e.g., a worker) around the excavator 100 via audio input, gesture input, or the like. Specifically, the excavator 100 recognizes a voice spoken by a worker nearby and a gesture performed by the worker via an audio input device (e.g., a microphone), a gesture input device (e.g., a display device), or the like mounted on the excavator 100. The excavator 100 can then actuate an actuator according to the content of the recognized voice, gesture, or the like to drive the driven elements, such as the lower undercarriage 1 (left and right tracks), the upper swing body 3, the boom 4, the arm 5, and the bucket 6. The control device 26 (including a left control lever, a right control lever, a left travel lever, and a right travel lever) can be of an electrical type, which outputs an electrical signal, instead of a hydraulic pilot type, which outputs a pilot pressure. In this case, the electrical signal from the control device 26 is input to the controller 30, and the controller 30 controls each of the control valves 171 to 176 in the control valve 17 according to the input electrical signal, thereby achieving the operation of the various hydraulic actuators according to the contents of the control commands with respect to the control device 26. For example, the control valves 171 to 176 in the control valve 17 can be electromagnetic spool valves, which are actuated by a command from the controller 30.Furthermore, for example, a solenoid valve, operating according to an electrical signal from the controller 30, can be arranged between the pilot pump 15 and the pilot port of each of the control valves 171 to 176. In this case, when manual operation is carried out using the electrical operating device 26, the controller 30 controls the solenoid valve according to an electrical signal corresponding to the operating amount (for example, a lever operating amount) to increase or decrease the pilot pressure, thereby actuating each of the control valves 171 to 176 according to the contents of the operation with respect to the operating device 26. Fig. 5 is a diagram illustrating an example of an electrical operating system configuration for the excavator according to the present embodiment. Here, the operating device 26 is an electromagnetic control lever, and the control unit 30 controls the pilot pressure applied to the control valve 17 (control valve 175) to suppress the vibration of the boom 4. When an electric operating system comprising an electric control lever is used, the controller 30 can easily perform an autonomous control function, unlike in a case where a hydraulic operating system comprising a hydraulic control lever is used. The electric operating system illustrated in Fig. 5 is an example of a boom operating system and essentially comprises the pilot-pressure-operated control valve 17, the lever assembly 26A as an electric control lever, the controller 30, a solenoid valve 160 for boom-up operation, and a solenoid valve 162 for boom-down operation. The electric operating system illustrated in Fig. 5 can be similarly applied to a boom operating system, a bucket operating system, and the like. Hereinafter, an electromagnetic control lever or an electric control lever will simply be referred to as an “electric lever.”The lever device 26A is an example of the electric lever. The pilot-operated control valve 17 comprises the control valve 175 (see Fig. 3) for the boom cylinder 7, the control valve 176 (see Fig. 3) for the arm cylinder 8, the control valve 174 (see Fig. 3) for the bucket cylinder 9, and the like. The solenoid valve 160 is configured to adjust the flow path range of a line connecting the pilot pump 15 to the upstream pilot port of the control valve 175. The solenoid valve 162 is configured to adjust the flow path range of a line connecting the pilot pump 15 to the downstream pilot port of the control valve 175. When manual operation is performed, the control unit 30 generates a boom-up operating signal (electrical signal) or a boom-down operating signal (electrical signal) corresponding to an operating signal (electrical signal) output by the operating signal generator of the lever device 26A. The operating signal output by the operating signal generator of the lever device 26A is an electrical signal that changes according to the amount and direction of operation of the lever device 26A. In particular, when the lever device 26A is actuated in the boom-up direction, the controller 30 outputs a boom-up operating signal (electrical signal) to the solenoid valve 160, corresponding to the lever's operating position. The solenoid valve 160 adjusts a flow path range according to the boom-up operating signal (electrical signal) and controls a pilot pressure as a boom-up operating signal (pressure signal), which is to be applied to the upward pilot port of the control valve 175. Similarly, when the lever device 26A is actuated in a boom-down direction, the controller 30 outputs a boom-down operating signal (electrical signal) to the solenoid valve 162, corresponding to the lever's operating position.The solenoid valve 162 adjusts a flow path range according to the boom-down operating signal (electrical signal) and controls a pilot pressure as the boom-down operating signal (pressure signal), which is to be applied to the downward-side pilot port of the control valve 175. When autonomous control is executed, the controller 30 generates, for example, a boom-up operating signal (electrical signal) or a boom-down operating signal (electrical signal) corresponding to a correction operating signal (electrical signal) instead of an operating signal (electrical signal) output by the operating signal generator of the lever device 26A. The correction operating signal can be an electrical signal generated by the controller 30 or an electrical signal generated by an external control device other than the controller 30. [Details of configuration of earth and sand loading detection function of excavator] Next, with reference to Fig. 6, details of the configuration of the earth and sand loading detection function of the excavator 100 according to the present embodiment are described. Fig. 6 is a schematic diagram illustrating an example of components relating to the earth and sand loading detection function of the excavator according to the present embodiment. In addition to the configuration described above, the control unit 30 includes an earth and sand load processor 60 as a functional section with respect to the function of detecting the load of earth and sand excavated by the bucket 6. The earth and sand loading processor 60 includes the determination condition evaluator 61, a range determiner 62, a loading weight calculator 63, a maximum loading amount detector 64, a loading summation calculator 65, a calculator 66 for remaining loading amount and a determiner 67 of received weight. Here, an example of an operation is described in which earth and sand (loaded object) are loaded onto a dump truck by the excavator 100 according to the present embodiment. First, the excavator 100 excavates earth and sand with the bucket 6 by controlling the attachment point at an excavation position (excavation operation). Next, the excavator 100 performs a boom-raising operation, in which the boom 4 is raised until the bottom of the bucket 6 reaches a desired height above the ground, rotates the upper swing body 3, and moves the bucket 6 from the excavation position to an unloading position (rotation operation). A dump truck bed is positioned below the unloading position. Next, the excavator 100 loads the earth and sand in the bucket 6 onto the dump truck bed by releasing the earth and sand in the bucket 6 by controlling the attachment point at the unloading position (unloading operation). Next, the excavator 100 rotates the upper swing body 3 and moves the bucket 6 from the unloading position to the excavation position (rotation operation).By repeating these operations, the excavator 100 loads the excavated earth and sand onto the loading platform of the dump truck. A determination condition evaluator 61 determines whether the state of the excavator 100 fulfills a predetermined condition (determination condition) in order to determine the weight of earth and sand (an example of an object) loaded into the bucket 6 as a measurement result. In the present embodiment, after the bucket 6 has been loaded with earth and sand, the determination condition evaluator 61 determines whether a detection signal (an example of detection information) relating to the lifting operation of the boom 4 fulfills several determination conditions. Furthermore, the determination condition evaluator 61 determines, in particular, whether a detection signal (an example of the detection information) with respect to the lifting operation of the boom 4 fulfills all of the several determination conditions, fulfills some of the several determination conditions, or fulfills none of the several determination conditions. The several determination conditions are the first to fourth conditions described below. The following describes a specific determination procedure using the determination condition evaluator 61. For example, the first condition among the several determining conditions defined by the determining condition evaluator 61 is a condition relating to boom-raising operation. Specifically, the determining condition evaluator 61 determines that the first condition is met when the boom-raising operation performed by the operator is stopped. The determining condition evaluator 61 can determine whether the boom-raising operation has been stopped or not based on the pilot pressure corresponding to the operating state of the boom 4. The second condition among the several conditions determined by the determining condition evaluator 61 is a condition relating to the height of the bucket 6. Specifically, the determining condition evaluator 61 determines that the second condition is met when the height of the bucket 6 reaches a predetermined height. The height of the bucket 6 is the distance from the ground to the underside of the bucket 6. The height of the bucket 6 can be calculated by the distance calculator 52. The third condition among the several conditions determined by the Determination-Condition Evaluator 61 is a condition relating to the lifting height of the boom 4. Specifically, the Determination-Condition Evaluator 61 determines that the third condition is met if the lifting height of the boom 4 is sufficient. The lifting height of the boom 4 is the difference in height between the height of the boom 4 when the excavation operation is complete and the current height of the boom 4. The fourth condition among the several conditions determined by the determining condition evaluator 61 is a condition relating to the acceleration with which the boom 4 moves. Specifically, the determining condition evaluator 61 determines that the fourth condition is satisfied if the acceleration with which the boom 4 moves lies within a predetermined range. The acceleration with which the boom 4 moves can be the angular acceleration about a foot bolt of the boom 4. Furthermore, the fourth condition can be a condition relating to the acceleration with which arm 5 moves. For example, the determining condition evaluator 61 can calculate the angular acceleration of arm 5 based on the arm angle detected by the arm angle sensor S2 and determine that the fourth condition is met if the angular acceleration of arm 5 is not less than a predetermined lower limit and not greater than a predetermined upper limit, and the acceleration with which arm 5 moves is within a predetermined range. The determination condition evaluator 61 determines the measurement accuracy of the soil and sand weight based on the determination condition that the detection signal indicates is fulfilled, among the multiple determination conditions. For example, if the determination condition evaluator 61 determines that all conditions are fulfilled under the multiple determination conditions, the measurement accuracy of the soil and sand weight can be determined to be the highest. The determination condition evaluator 61 can determine that the measurement accuracy of the soil and sand weight is average accuracy if the detection signal fulfills some of the determination conditions among the multiple determination conditions. When the determination condition evaluator 61 determines that the determination condition is met, the soil and sand load processor 60 determines the soil and sand weight, calculated on the basis of the detection signal by the load weight calculator 63, which is described below, as the measurement result. It should be noted that the determination condition evaluator 61 is not limited to a single detection signal and multiple detection signals can be used for the determination. The range determiner 62 determines whether the piston of the boom cylinder 7 is in the buffer zone at the start of the boom-raising operation. In other words, the range determiner 62 determines whether the piston of the boom cylinder 7 has reached the buffer zone at the start of the boom-raising operation. In particular, the range determiner 62 determines that the piston of the boom cylinder 7 is located in the buffer range at the start of boom-raising operation if a value measured by the boom ground pressure sensor S7B at the start of boom-raising operation is equal to or greater than a predetermined value. In the present embodiment, it is therefore possible to automatically determine whether the piston of the boom cylinder 7 is located in the buffer range at the start of boom-raising operation or not. Furthermore, the range determiner 62 determines whether the piston of the boom cylinder 7 has reached the range (buffer range) at which the buffer function is activated. In particular, the range determiner 62 can determine that the piston of the boom cylinder 7 has reached the buffer range if the boom angle detected by the boom angle sensor S1 is equal to or greater than a predetermined threshold. Furthermore, the range determiner 62 can, for example, determine that the piston of the boom cylinder 7 has reached the buffer range if a boom stroke detected by the boom cylinder stroke sensor S7C is equal to or greater than the predetermined threshold. Furthermore, the range determiner 62 can, for example, determine that the piston of the boom cylinder 7 has reached the buffer range when the amount of change in boom rod pressure detected by the boom rod pressure sensor S7R or the amount of change in boom bottom pressure detected by the boom bottom pressure sensor S7B is equal to or greater than a predetermined threshold. In this case, the range determiner 62 does not necessarily need to be preset to a predetermined threshold for the change in boom rod pressure or boom base pressure. Instead, the range determiner 62 can determine that the boom cylinder 7 piston has reached the buffer zone when the change in boom base pressure suddenly exceeds the historical change in boom rod pressure or boom base pressure. This allows for automatic determination that the boom cylinder 7 piston has reached the buffer zone. The change in boom rod pressure and the change in boom ground pressure are the change rates per unit of time (i.e., derivative value). As described above, the boom angle sensor S1, the boom cylinder stroke sensor S7C, the boom rod pressure sensor S7R, and the boom ground pressure sensor S7B output detection signals related to the lifting operation of boom 4. The range determiner 62 can determine, using several determination methods among those described above, whether the piston of the boom cylinder 7 has reached the buffer zone or not. As described above, the accuracy of the determination can be improved by using several determination methods together. The area determiner 62 of the present embodiment determines by any of the determination methods described above whether the piston of the boom cylinder 7 has reached the buffer area or not. If the height of the bucket 6 is included in a measuring section for measuring the weight of the earth and sand loaded into the bucket 6, the load weight calculator 63 calculates the weight of the earth and sand in the bucket 6 based on the thrust force (values ​​measured by the boom rod pressure sensor S7R and the boom ground pressure sensor S7B) of the boom cylinder 7, derived from the detection signal of the cylinder pressure sensors, and the center of gravity of the earth and sand. The measuring section is a section provided in a vertical direction for calculating the weight of the earth and sand in the bucket 6 and is determined according to embodiments. The weight of the earth and sand is calculated, for example, by balancing the torque about the boom base of boom 4. Specifically, the thrust of boom cylinder 7 is increased by the earth and sand in the bucket 6, and the torque about the boom base of boom 4, calculated from the thrust of boom cylinder 7, is also increased. This increased torque corresponds to the torque calculated from the weight and center of gravity of the earth and sand. As described above, the load weight calculator 63 calculates the weight of the earth and sand based on the thrust of boom cylinder 7 (values ​​measured by the boom rod pressure sensor S7R and the boom ground pressure sensor S7B) and the center of gravity of the earth and sand derived from the detection signal. The center of gravity of the earth and sand is obtained experimentally beforehand and stored in the controller 30. Although the present embodiment describes an example of calculating the weight of soil and sand based on the thrust of the boom cylinder 7, the calculation method for the weight of soil and sand is not limited to the described method. The load weight calculator 63 according to the present embodiment can calculate the weight of soil and sand based on the detection signal detected as the operation of the attachment. For example, the load weight calculator 63 can calculate the weight of soil and sand based on the thrust of the boom cylinder 8 (values ​​measured by the boom rod pressure sensor S8R and the boom base pressure sensor S8B) or the weight of soil and sand based on the thrust of the bucket cylinder 9 (values ​​measured by the bucket rod pressure sensor S9R and the bucket base pressure sensor S9B). The maximum load detector 64 detects the maximum load of a dump truck to be loaded with soil and sand. For example, the maximum load detector 64 specifies a dump truck to be loaded with soil and sand based on an image captured by an imaging device S6. Next, the maximum load detector 64 detects the maximum load of the dump truck based on the image of the specified dump truck. For example, the maximum load detector 64 determines the vehicle type (size, etc.) of the dump truck based on the image of the specified dump truck. The maximum load detector 64 includes a table in which the vehicle type is linked to the maximum load and determines the maximum load of the dump truck based on the vehicle type determined from the image and the table.The maximum load amount, vehicle type or the like of the dump truck can be entered via the input device 42, and the maximum load amount detector 64 can determine the maximum load quantity of the dump truck based on the input information of the input device 42. The load summation calculator 65 calculates the weight of soil and sand loaded into the dump truck. That is, each time soil and sand are transferred from bucket 6 to the dump truck bed, the load summation calculator 65 adds the weight of soil and sand in bucket 6 calculated by the load weight calculator 63 to calculate a total load amount (total weight), which is the sum of the weights of soil and sand loaded onto the dump truck bed. When a new dump truck is loaded with soil and sand, the total load amount is reset. The determiner 67 of the adopted weight determines the earth and sand weight to be adopted as the measurement result according to the state of the excavator 100 at the time when the range determiner 62 determines that the piston of the boom cylinder 7 has reached the buffer range. In particular, if the measurement result of the weight of earth and sand is not determined (the excavator 100 does not meet the several determination conditions) at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer range, the determiner 67 of the adopted weight adopts the weight of earth and sand calculated at that time by the load weight calculator 63 as the measurement result. In other words, the determiner 67 of the adopted weight takes the earth and sand weight calculated by the load weight calculator 63 at the time when the piston of the boom cylinder 7 reached the buffer zone, as the measurement result when the excavator 100 is in boom-high operation after start-up and the earth and sand weight as the measurement result at the time when the piston of the boom cylinder 7 reached the buffer zone was not obtained. That is, the determiner 67 of adopted weight receives the earth and sand weight at the time when the piston of the boom cylinder 7 reached the buffer zone as the measurement result. It should be noted that the earth and sand weight obtained at this time by the determiner 67 from the assumed weight as the measurement result can be determined in such a way that the measurement accuracy of the earth and sand weight is low, since the condition of the excavator 100 does not meet any of the several determination conditions. If the measurement result of the earth and sand weight is determined at the time when the range determiner 62 determines that the piston of the boom cylinder 7 has reached the buffer range, the determiner 67 of the acquired weight adopts the determined earth and sand weight as the measurement result. In other words, if the excavator 100 is in the state of boom-high operation at the time the piston of boom cylinder 7 reaches the buffer range, and the earth and sand weight has been determined, the determiner 67 takes the determined earth and sand weight as the measurement result. In other words, the determiner 67 receives the determined earth and sand weight as the measurement result. In the present embodiment, by determining the earth and sand weight to be obtained as the measurement result, the earth and sand weight corresponding to the state of the excavator 100 at the time when the piston of the boom cylinder 7 has reached the buffer range can be used as the measurement result, and the accuracy of the measurement result can be improved. Furthermore, in the present embodiment, the earth and sand weight calculated by the load weight calculator 63 can be obtained as the measurement result before it is influenced by a reaction force in the buffer area, and the influence of the reaction force in the buffer area can be minimized. Furthermore, in the present embodiment, the load weight calculator 63 calculates the weight of the earth and sand until the piston of the boom cylinder 7 reaches the buffer zone. Therefore, in the present embodiment, the measuring range in which the weight of the earth and sand is measured can be extended to the maximum extent. The remaining load calculator 66 calculates the difference between the maximum load of the dump truck detected by the maximum load detector 64 and the current total load calculated by the load summation calculator 65 as the remaining load. The remaining load is the remaining weight of soil and sand that can be loaded into the dump truck. The display device 40 can display the earth and sand weight in the bucket 6 calculated by the load weight calculator 63, the maximum load amount of the dump truck detected by the maximum load amount detector 64, the total load amount of the dump truck calculated by the load summation calculator 65 (total weight of earth and sand loaded onto the loading platform), and the remaining load amount of the dump truck calculated by the remaining load amount calculator 66 (remaining weight of earth and sand that can be loaded). If the total load exceeds the maximum load, a warning can be displayed on display device 40. Similarly, if the calculated weight of earth and sand in bucket 6 exceeds the remaining load, a warning can be displayed on display device 40. This warning is not limited to display on display device 40 and can also be an audible alert via audio output device 43. This helps prevent the dump truck from being loaded with earth and sand beyond its maximum capacity. Next, with reference to Fig. 7, an example of the operation of the excavator 100 is described. Fig. 7 is a diagram to illustrate the excavation and loading operation of the excavator. First, as illustrated in (A) of Fig. 7, the operator lowers the boom. Then, the operator positions the tip of the bucket 6 at a desired height relative to the excavation object and gradually closes the bucket 6 from an open position, as illustrated in (B) of Fig. 7. At this time, the excavated earth and sand enter the bucket 6. Next, the operator raises the boom 4 to lift the bucket 6 into the position illustrated in (C) of Fig. 7, with the top edge of the bucket 6 being substantially horizontal. At this time, the operator can raise the boom 4 and close the arm 5. Furthermore, if, during the lifting operation of the boom 4, the angular acceleration about the base pin of the boom 4 is less than a first threshold value when the height of the boom 4 reaches the measuring section, and the time in which a change in the amount of change (difference value) of the cylinder thrust is determined to be less than a second threshold value is longer than a predetermined time, the load weight calculator 63 calculates the weight of the earth and sand in the bucket 6. If, furthermore, the condition for determining the weight of the earth and sand is not met, the information transmitter 53 can prompt the operator to perform an operation to meet the condition. Then, as illustrated in (D) of Fig. 7, the operator raises the boom 4 until the bottom of the bucket 6 reaches a desired height above the ground. The desired height is, for example, a height greater than or equal to the height of a DT dump truck (see (E) of Fig. 7, which is described below). Subsequently or simultaneously, the operator rotates the upper pivot body 3 as indicated by arrow AR1, moving the bucket 6 to a position for unloading soil and sand. The operation of the bucket during this time is referred to as the “boom-raise rotation operation,” and a section for the “boom-raise rotation operation” is referred to as a “boom-raise rotation section.” When the boom-raising slewing operation is complete, the operator opens the arm 5 and the bucket 6 to unload the earth and sand into the bucket 6, as illustrated in (E) of Fig. 7. The operation of the excavator 100 at this time is referred to as an unloading operation, and a section for the dumping process is referred to as an unloading operation section. During the unloading operation, the operator can only open the bucket 6 to unload the earth and sand. When the unloading operation is complete, the operator rotates the upper swing body 3, as illustrated by arrow AR2 in (F) of Fig. 7, and moves the bucket 6 directly above the excavation position. At the same time, the boom 4 is lowered simultaneously with the rotation to lower the bucket 6 to a desired height above the excavation object. The operation of the excavator at this time is referred to as the "boom-down-rotation operation," and a section for the boom-down-rotation operation is called a "boom-down-rotation operation." The operator continues the excavation and loading operation while repeating a cycle that includes the "excavation operation", the "boom-raising operation", the "unloading operation", and the "boom-lowering operation". Next, an example of load weight determination processing is described with reference to Fig. 8. Fig. 8 is a flowchart illustrating an example of load weight determination processing. The processing illustrated in Fig. 8 can be carried out mainly in the boom-high rotary operating section illustrated in (C) of Fig. 7. The excavator 100 scoops out earth and sand with bucket 6 and starts the boom-raising operation (step S801). When the height of bucket 6 reaches a lower end of the measuring section, the load weight calculator 63 of the control unit 30 starts calculating the weight of the earth and sand loaded in bucket 6. Subsequently, the earth and sand loading processor 60 uses the range determiner 62 to determine whether the piston of the boom cylinder 7 is in the buffer range or not when the boom-up operation is started (step S802). In other words, the range determiner 62 determines whether the state of the excavator 100 is at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer range, at the start of the boom-up operation. If, at step S802, it is determined that the piston of the boom cylinder 7 is within the buffer zone, the controller 30 waits until the piston of the boom cylinder 7 is outside the buffer zone. Therefore, at this time, no measurement result has been received from the determiner 67, and the measurement result is not obtained. If step S802 determines that the piston of the boom cylinder 7 is not in the buffer area, the area determiner 62 determines whether the piston of the boom cylinder 7 has reached the buffer area or not (step S803). If step S803 determines that the piston of the boom cylinder 7 has reached the buffer zone, the earth and sand loading processor 60 proceeds to step S809, which is described below. In contrast, if step S803 determines that the piston of the boom cylinder 7 has not reached the buffer zone, the determination condition evaluator 61 determines whether the detection signal regarding the lifting operation of the boom 4 fulfills all, some, or none of the determination conditions. If, at step S804, it is determined that the detection signal regarding the lifting operation of the boom 4 fulfills all of the several determination conditions, the earth and sand loading processor 60 determines the earth and sand weight calculated at that time as the measurement result of the earth and sand weight (step S805). Since all determination conditions are fulfilled here, the measurement accuracy of the determined earth and sand weight is high. The soil and sand loading processor 60 then notifies the operator that the determination conditions have been met (step S806). In particular, the soil and sand loading processor 60 displays the measurement accuracy determined by the determination condition evaluator 61 and the soil and sand weight calculated by the loading weight calculator 63 on the display unit 40 via the information transmitter 53. The earth and sand loading processor 60 then determines whether the state of the excavator 100 meets a measuring end condition (step S807). The measuring condition means that the earth and sand in bucket 6 are unloaded onto the loading platform of the dump truck in the excavator 100 and the earth and sand weight in bucket 6 calculated by the load weight calculator 63 is added to the total load amount (total weight), which is the total weight of the earth and sand loaded onto the loading platform of the dump truck. If step S807 determines that the measurement end condition is met, the earth and sand loading processor 60 terminates processing. If step S807 determines that the measurement end condition is not met, the earth and sand loading processor 60 returns to processing step S802. If, at step S804, it is determined that the detection signal with respect to the lifting operation of the boom 4 fulfills some of the multiple determination conditions, the earth and sand loading processor 60 determines the earth and sand weight calculated at this point as the measurement result of the earth and sand weight (step S808) and proceeds to step S806. Since some of the multiple determination conditions are fulfilled here, the determined earth and sand weight has a medium accuracy (medium accuracy level). Furthermore, the soil and sand loading processor 60 can compare the accuracy of the measurement result of the retained soil and sand weight with the accuracy when the soil and sand weight is determined at step S808, and determine the measurement result with higher accuracy than the measurement result of the soil and sand weight. In particular, the soil and sand loading processor 60 can, for example, compare the number of fulfilled determination conditions when determining the retained soil and sand weight with the number of fulfilled determination conditions when determining the soil and sand weight at step S808, and determine the soil and sand weight that fulfills the greater number of determination conditions than the measurement result. Furthermore, in the present embodiment, the priority of each determination condition is given in advance, and the soil and sand loading processor 60 can, for example, compare the priority of the determination condition that is fulfilled when the retained soil and sand weight is determined with the priority of the determination condition that is fulfilled when the soil and sand weight is determined at step S808. The soil and sand loading processor 60 can determine as the measurement result the soil and sand weight that has the higher priority of the fulfilled determination condition. Furthermore, if the measurement result of the retained soil and sand weight and the soil and sand weight calculated at step S808 change beyond a predetermined range, the soil and sand loading processor 60 can determine a new soil and sand weight as the measurement result. If, at step S804, it is determined that the detection signal relating to the lifting operation of the boom 4 does not meet any of the multiple determination conditions, the earth and sand loading processor 60 returns to the processing at step S802. If, in step S803, it is determined that the piston of the boom cylinder 7 has reached the buffer range, the range determiner 62 determines whether the determiner 67 has determined the earth and sand weight from the received weight or not (step S809). In other words, the determiner 67 of assumed weight determines whether the condition of the excavator 100 during a period from the start of the excavation and loading operation until the determination at step S803 that the piston of the boom cylinder 7 has reached the buffer range satisfies several or some of the several determination conditions or not. If, in step S809, it is determined that the soil and sand weight has been determined, the determiner 67 of the adopted weight adopts the already determined soil and sand weight as the measurement result (step S810). If, in step S809, it is determined that the earth and sand weight was not determined, the determiner 67 adopts the calculated earth and sand weight, which was calculated by the load weight calculator 63 at the time when, in step S803, it was determined that the piston of the boom cylinder 7 had reached the buffer zone, as the measurement result (step S811). In this case, the adopted measurement result for the earth and sand weight has low measurement accuracy because the condition of the excavator 100 does not meet any of the several determination conditions. As described above, in the present embodiment, when it is determined that the piston of the boom cylinder 7 has reached the buffer area, the value obtained as the measurement result differs depending on the state of the excavator 100 at the time when the determination is made. In particular, in the present embodiment, if the state of the excavator 100 at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer zone is the start of the boom-raising operation (when the measurement of the earth and sand weight is started), a blank value is output as the measurement result. In other words, in the present embodiment, if the state of the working machine at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer zone is the start of the attachment lifting operation, the measurement result is not obtained. In the present embodiment, it is possible to prevent the calculated earth and sand weight from being determined as the measurement result in a state where an error occurs in the torque around the boom base of the boom 4 due to entering the buffer zone. At this time, the earth and sand loading processor 60 can display a message on the display device 40 or the like, indicating that the measurement will be repeated after lowering the boom 4. Furthermore, in the present embodiment, if the state of the excavator 100 at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer area is a state in which the excavation and loading operation has already started and the earth and sand weight has been determined, the already determined earth and sand weight is adopted as the measurement result and the determined earth and sand weight is not updated. In other words, in the present embodiment, if the state of the working machine at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer area is a state in which the lifting operation of the attachment has been started and the measurement result of the weight of the object has been obtained, the already determined earth and sand weight is adopted as the measurement result, and the determined earth and sand weight is not updated. Therefore, according to the present embodiment, it is possible to prevent the earth and sand weight, which was calculated in a state where an error occurs in the torque around the boom base of boom 4 due to entering the buffer zone, from being adopted as the measurement result, thereby improving the accuracy of the measurement of the earth and sand weight. Furthermore, in the present embodiment, if the condition of the excavator 100 at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer range is a condition in which the earth and sand weight has not been determined since the start of the excavation and loading operation, the earth and sand weight calculated by the load weight calculator 63 is adopted as the measurement result at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer range in order to forcibly determine the earth and sand weight. In other words, in the present embodiment, if the state of the working machine at the time when it is determined that the piston of the boom cylinder 7 has reached the buffer area is a state in which the lifting operation of the attachment has been started and the measurement result of the weight of the object has not been obtained, the earth and sand weight calculated by the load weight calculator 63 is adopted as the measurement result at the time when it is determined that the earth and sand weight is to be determined by force. Therefore, according to the present embodiment, a measuring range for measuring the earth and sand weight can be provided to a maximum extent in a state in which the earth and sand weight is not influenced by reaching the buffer zone by the piston of the boom cylinder 7. Furthermore, in the present embodiment, when the piston of the boom cylinder 7 has reached the buffer area, the earth and sand weight that is not affected by the piston entering the buffer area is taken as the measurement result, so that the earth and sand weight carried out by a cycle of excavation and loading operation can be maintained in order to have constant accuracy. In the present embodiment, the weight of the loaded object, such as soil, sand, and waste material, which is loaded onto the loading platform of a dump truck or trailer, can be measured with high accuracy as described above, and the accuracy of calculating the remaining loadable amount can be improved. Therefore, according to the present embodiment, rework and manual adjustments to the weighing can be reduced, and work efficiency at the loading site can be improved. Furthermore, this can also contribute to improved transport efficiency and the suppression of road damage caused by overloading. REFERENCE MARK LIST 100 Excavator 30 Control unit 60 Earth and sand loading processor 61 Determination condition evaluator 62 Area determiner 63 Load weight calculator 64 Maximum load amount detector 65 Load summation calculator 66 Calculator for remaining load amount 67 Determiner of transferred weight

Claims

Working machine comprising: a working machine body; an attachment piece mounted on the working machine body; a working tool provided at a distal end of the attachment piece; and a control circuit configured such that, when a determination is made that a piston of a cylinder actuating the attachment piece has reached a predetermined range, based on detection information regarding a lifting operation of the attachment piece after an object has been held in the working tool, it causes a obtained measurement result of the weight of the object to differ according to a state of the working machine at a time when the determination is made. Working machine according to claim 1, wherein the control circuit receives the weight of the object calculated on the basis of the detection information regarding the lifting operation of the attachment as the measurement result at the time at which the determination is made, if the state of the working machine at the time at which the determination is made is a state after the lifting operation of the attachment has been started and the measurement result of the weight of the object has not been obtained. Working machine according to claim 1, wherein: if the state of the working machine at the time at which the determination is made is a state after the lifting operation of the attachment has been started, and the measurement result of the weight of the object has been obtained, the control circuit receives the measurement result, which is the measurement result of the weight of the object at the time at which the determination was made. Working machine according to claim 1, wherein the control circuit determines, on the basis of a change in the cylinder pressure of the cylinder, whether the piston of the cylinder has reached the predetermined range or not. Working machine according to claim 1, wherein the control circuit does not receive the measurement result if the state of the working machine at the time the determination is made is a state at the start of the lifting operation of the attachment piece. Working machine according to claim 5, wherein the control circuit determines that the state of the working machine is in the state at the start of the lifting operation of the attachment piece when a ground pressure on a bottom of the cylinder at the start of the lifting operation of the attachment piece is equal to or greater than a predetermined value. Working machine comprising: a working machine body; an attachment piece mounted on the working machine body; a working tool provided at a distal end of the attachment piece; and a control circuit configured such that, when a determination is made that a piston of a cylinder actuating the attachment piece has reached a predetermined range, based on detection information regarding a lifting operation of the attachment piece after an object has been held in the working tool, the control circuit causes a obtained measurement result of the weight of the object to differ according to a state of the working machine at a time when the determination is made, wherein the control circuit obtains the weight of the object, calculated on the basis of the detection information regarding the lifting operation of the attachment piece, as the measurement result at the time when the determination is made.If the state of the working machine at the time the determination is made is a state after the lifting operation of the attachment has started, and the measurement result of the object's weight has not been obtained, the measurement result is obtained as the measurement result of the object's weight at the time the determination is made, if the state of the working machine at the time the determination is made is a state after the lifting operation of the attachment has started, and the measurement result of the object's weight has been obtained, and the measurement result is not obtained, if the state of the working machine at the time the determination is made is a state at the start of the lifting operation of the attachment. Control device for a working machine, comprising: a working machine body; an attachment on the working machine body; and a working tool provided at a distal end of the attachment, wherein the control device comprises a control circuit configured such that, when a determination is made that a piston of a cylinder actuating the attachment has reached a predetermined range, based on detection information regarding a lifting operation of the attachment after an object has been held in the working tool, it causes a measured result of the weight of the object to differ according to a state of the working machine at a time when the determination is made.

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