JP2024127331A - Work Machine - Google Patents

Abstract

[Problem] To accurately calculate the ZMP of a work machine whose load changes weight. [Solution] A work machine (100) including a vehicle body, a front work machine (104, 105, 106) attached to the vehicle body, a controller (110), attitude detection sensors (S1, S2, S3, S4), and a display (21), further including load sensors (S7R, S7B) for acquiring load parameters indicating the load of the front work machine, the controller including a ZMP calculation unit (220) for calculating the ZMP, which is the dynamic center of gravity position of the vehicle body and the front work machine, based on the detection results of the attitude detection sensor and the load sensor, and a support polygon calculation unit (230) for calculating a support polygon surrounded by a plurality of contact points between the vehicle body and the ground based on the detection results of the attitude detection sensor, and the ZMP is superimposed on the support polygon and displayed on the display. [Selected Figure] Figure 1

Description

The present invention relates to a work machine, and in particular to the calculation of the zero moment position (ZMP), which is the dynamic position of the center of gravity.

Patent Document 1 discloses a tip-over prevention device that "calculates the ZMP of a construction machine based on joint angle θ, angular velocity θ', angular acceleration θ", and tilt angle β. When the current ZMP is located outside a safety area D2, a search unit searches for a tilt direction in which the rate at which distance Lp decreases with respect to the current angular acceleration is maximized in a first function F1 that indicates distance Lp between a boundary B2 of the safety area D2 and an arbitrary ZMP in terms of angular acceleration θ", and searches for an angular acceleration at which distance Lp becomes zero or less by changing the angular acceleration along the searched tilt direction. (Summary excerpt)"

Patent Document 2 also discloses a parts discrimination device that includes: "an image input unit that inputs imaging data obtained by imaging a part using a camera; a division unit that divides the imaging data into first imaging data and second imaging data such that each data includes at least one characteristic part of the part; a specification identification unit that uses the first imaging data to identify the specification of the characteristic part in the first imaging data and thereby identify the type of part; and a specification correctness determination unit that uses the second imaging data to determine whether the specification of the characteristic part in the second imaging data is the same as the specification of the type identified by the specification identification unit (summary excerpt)."

JP 2018-21416 A JP 2020-149578 A

In work machines such as excavators, wheel loaders, and cranes, the ZMP can change depending on the weight of the load. However, in Patent Document 1, the load from the load is not taken into account when calculating the ZMP, which means that an accurate ZMP cannot be calculated. In Patent Document 2, while it is possible to identify parts, the ZMP is not taken into account. In this way, since the ZMP is not always calculated accurately, the operator cannot completely trust the displayed ZMP position.

The objective of the present invention is to provide the operator with an accurate ZMP of the work machine even if the weight of the load changes.

In order to solve the above problems, the present invention provides a work machine including a vehicle body, a front work implement attached to the vehicle body, a posture detection sensor that detects the posture of the vehicle body and the front work implement, a display, and a controller, further including a load sensor that acquires a load parameter that indicates the load on the front work implement, and the controller includes a ZMP calculation unit that calculates a ZMP, which is the dynamic center of gravity position of the vehicle body and the front work implement, based on the detection results of the posture detection sensor and the load sensor, a support polygon calculation unit that calculates a support polygon surrounded by multiple contact points between the vehicle body and the ground based on the detection results of the posture detection sensor, and a display control unit that superimposes the ZMP on the support polygon and displays it on the display.

According to the present invention, it is possible to show the operator the ZMP of the work machine with high accuracy even if the weight of the load changes. Objectives, configurations, and effects other than those described above will become clear from the description of the following embodiments.

FIG. 2 is a left side view showing the configuration of the hydraulic excavator. FIG. 4 is a diagram showing mounting positions of sensors that detect parameters required for calculating a ZMP in the hydraulic excavator in the first embodiment. FIG. 2 is a block diagram showing a hardware configuration of the hydraulic excavator according to the first embodiment. FIG. 2 is a functional block diagram of a controller mounted on the hydraulic excavator according to the first embodiment. 5 is a flowchart showing a flow of a ZMP calculation process in the hydraulic excavator according to the first embodiment. 13A and 13B are diagrams showing examples of screen displays, in which (a) is a diagram in which a ZMP is superimposed on an example of a support polygon when the lower running body is established on the ground surface, and (b) is a diagram in which a ZMP is superimposed on an example of a support polygon when the lower running body is jacked up by a front work machine. 1A and 1B are diagrams showing the attachment positions of the two-dimensional codes on the arm and bucket, where FIG. 1A shows the arm and bucket as viewed from the rear of the hydraulic excavator, and FIG. 1B is an enlarged view of the ventral side of the arm and the underside of the bucket. 1A and 1B are diagrams showing the attachment positions of two-dimensional codes on a bucket, a cab, and a truck, in which (a) is a diagram showing the hydraulic excavator from the front, and (b) is an enlarged view of the ventral side of the boom, the top surface of the cab, and the top surface of the truck. 1A and 1B are diagrams showing the counterweight two-dimensional code attachment position, in which (a) is a top view of the upper rotating body, and (b) is an enlarged view of the counterweight two-dimensional code attachment position. FIG. 11 is a diagram showing mounting positions of sensors that detect parameters necessary for calculating a ZMP and cameras that read part information in a hydraulic excavator in a second embodiment. FIG. 11 is a block diagram showing a hardware configuration of a hydraulic excavator according to a second embodiment. FIG. 11 is a functional block diagram of a controller mounted on a hydraulic excavator according to a second embodiment. 13 is a flowchart showing a flow of a ZMP calculation process in a hydraulic excavator according to a second embodiment.

The following describes in detail an embodiment of the present invention with reference to the drawings. In all drawings used to explain the embodiment, components having the same function are given the same or related reference numerals, and repeated explanations are omitted.

In the following embodiment, a hydraulic excavator will be described as an example of a work machine, but the work machine is not limited to a hydraulic excavator as long as it can carry a load on a front work mechanism that can rotate relative to the vehicle body. For example, a wheel loader or a bulldozer may also be used.

Figure 1 is a left side view showing the configuration of a hydraulic excavator.

The hydraulic excavator 100 shown in FIG. 1 comprises a lower traveling body 101, an upper rotating body 102 supported on the traveling body so as to be freely rotatable via a rotating mechanism 107, a cab 103 attached to the upper rotating body 102, and a front working machine connected to the upper rotating body 102 so as to be able to be tilted up and down. The lower traveling body 101 and the upper rotating body 102 are collectively referred to as the vehicle body.

The front work machine includes a boom 104 supported on the upper rotating body 102 so that it can be raised and lowered, an arm 105 supported on the boom 104 so that it can swing up and down, and a bucket 106 supported on the arm 105 so that it can rotate.

The hydraulic excavator 100 also has hydraulic actuators such as hydraulic motors and hydraulic cylinders for forward and backward movement using the lower traveling structure 101, rotation of the upper rotating structure 102, and elevation, swinging, and rotation of the boom 104, arm 105, and bucket 106. The hydraulic motor is provided for rotation and the like, and the hydraulic cylinder is provided for elevation, swinging, and rotation of the boom 104 and the like. Note that although a hydraulic system is assumed here, this is not restrictive and an electric system such as an electric motor or linear actuator may also be used. The lower traveling structure 101 has a left crawler 101L and a right crawler 101R (see Figure 8(a)). The left crawler 101L and the right crawler 101R each have a sprocket 101s at the front of their inner circumferential surface and an idler 101i at the rear. The left crawler 101L and the right crawler 101R are circulated by the rotation of the sprocket 101s.

1, the ZMP (zero moment point) is the dynamic center of gravity position of the hydraulic excavator 100, and is displayed on the display 21 as coordinates in a two-dimensional coordinate system with the center of rotation of the upper rotating body as the origin. Note that the ZMP can be calculated using known conventional techniques (for example, the following formulas (1) and (2)).

First Embodiment
In the first embodiment, the ZMP is calculated by following the load of the load. Fig. 2 is a diagram showing the mounting positions of sensors that detect parameters necessary for calculating the ZMP in the hydraulic excavator in the first embodiment. The point of this embodiment is that the value of mass M necessary for calculating the ZMP is the sum of the mass Mmachine of the hydraulic excavator 100 and the mass Wload of the load in the bucket, as shown in the following formula (3).

As shown in FIG. 2, the hydraulic excavator 100 is equipped with a boom angle sensor S1, an arm angle sensor S2, and a bucket angle sensor S3 that detect the rotation angles of the boom 104, the arm 105, and the bucket 106, and a vehicle body inclination angle sensor S4 that detects the inclination angle of the vehicle body relative to the horizontal plane. The angles of the boom 104, the arm 105, and the bucket 106 are determined from the sensor outputs of the boom angle sensor S1, the arm angle sensor S2, and the bucket angle sensor S3, so that the posture of the front working equipment can be detected. Furthermore, the inclination posture of the vehicle body can be detected from the detected angle of the vehicle body inclination angle sensor S4. Therefore, the boom angle sensor S1, the arm angle sensor S2, the bucket angle sensor S3, and the vehicle body inclination angle sensor S4 correspond to posture detection sensors.

The hydraulic excavator 100 further includes boom pressure sensors S7R and S7B in the hydraulic cylinder of the boom 104. The boom pressure sensors S7R and S7B measure the load that the hydraulic excavator 100 receives from the load loaded on the bucket 106. In other words, the boom pressure sensors S7R and S7B function as load sensors. The sensor output of the boom pressure sensors S7R and S7B is an example of a load parameter. A method for calculating the mass Wload of the load using a load sensor may use a known technique such as the method described in JP 2020-165259 A. Other examples of the load parameter may include a measured value obtained by directly measuring the weight of the soil, or a strain amount of the pin or an estimated value obtained by estimating the load amount from the strain amount, and are not limited to the above examples.

Figure 3 is a block diagram showing the hardware configuration of the hydraulic excavator according to the first embodiment.

The controller 110 includes a processor 111 consisting of a CPU (Central Processing Unit) etc., a RAM (Random Access Memory) 112, a ROM (Read Only Memory) 113, a storage device 114, an input I/F 115, and an output I/F 116, which are connected to each other via a bus 117.

The storage device 114 can be any type of device that can store data non-volatilely, such as a hard disk drive (HDD) or a solid state drive (SSD).

Operation signals from the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, vehicle body inclination angle sensor S4, boom pressure sensors S7R and S7B, and the operation lever 22 are input to the input I/F 115. The operation signal from the potentiometer, which converts the signal into an electrical signal corresponding to the amount of operation of the operation lever 22 and outputs it, drives the solenoid valve 23 via the controller 110, and the hydraulic actuator is operated by the pilot pressure output from this solenoid valve 23.

The output I/F 116 is connected to the display 21 and the solenoid valve 23.

Figure 4 is a functional block diagram of the controller installed in the hydraulic excavator according to the first embodiment.

The controller 110 includes a main control unit 210, a ZMP calculation unit 220, and a support polygon calculation unit 230. It may further include an alarm unit 240 that issues an alarm based on the position of the ZMP, a display control unit 250 when the calculated ZMP is visualized, and an operation control unit 260 when the calculated ZMP is used for tip-over prevention processing.

Figure 5 is a flowchart showing the flow of the ZMP calculation process in the hydraulic excavator 100 according to the first embodiment.

When the engine of the hydraulic excavator 100 starts, the hydraulic excavator 100 acquires sensor outputs from the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, vehicle body tilt angle sensor S4, and boom pressure sensors S7R and S7B (S01). The sensor outputs from the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, vehicle body tilt angle sensor S4, and boom pressure sensors S7R and S7B become ZMP calculation parameters.

The ZMP calculation unit 220 obtains the tilt angle of the work machine with respect to gravity, and the angle, angular velocity, and angular acceleration of the movable part with respect to the rotation axis based on the sensor outputs of the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, vehicle body tilt angle sensor S4, and boom pressure sensors S7R and S7B, and calculates the ZMP, which is the dynamic center of gravity position (S02).

The ZMP calculation unit 220 outputs the calculated ZMP according to the intended use (S03). For example, if the purpose is to alert the operator of the hydraulic excavator 100, the display control unit 250 may display on the display 21 an image in which a mark indicating the ZMP is superimposed on an icon of the hydraulic excavator 100. Furthermore, if the purpose is to prevent the hydraulic excavator 100 from tipping over, the operation control unit 260 may perform operation control such as suppressing movement of the operating lever 22 in the direction away from the ZMP as the ZMP moves away from a predetermined home position.

When notifying the operator of the ZMP, the support polygon calculation unit 230 may calculate a support polygon surrounded by multiple contact points between the vehicle body and the ground, and display the ZMP superimposed on this support polygon. The support polygon calculation unit 230 refers to the sensor output of the attitude detection sensor to detect the ground contact state of the hydraulic excavator 100 and calculate the support polygon.

Figure 6 shows examples of screen displays, where (a) is a diagram in which the ZMP is superimposed on an example of a support polygon when the lower traveling body is upright on the ground surface, and (b) is a diagram in which the ZMP is superimposed on an example of a support polygon when the lower traveling body is jacked up by the front work machine. The example screen of Figure 6 is displayed on the display 21 (see Figure 4).

6A, when the hydraulic excavator 100 is upright on the ground surface, the support polygon calculation unit 230 calculates a shape of the support polygon L that is approximately equal to the planar shape of the lower running structure 101. Whether the hydraulic excavator 100 is upright on the ground surface can be determined by the support polygon calculation unit 230 determining, for example, that the closer the value (tilt angle) of the vehicle body tilt angle sensor S4 is to 0, the closer the hydraulic excavator 100 is to the upright state.

When the planar shape of the undercarriage 101 is rectangular, it may be defined as a rectangle with the line connecting the center points of the left and right sprockets 101s (known from the design value of the hydraulic excavator 100) as the front boundary line, the line connecting the center points of the left and right idlers 101i (known from the design value of the hydraulic excavator 100) as the rear boundary line, and the outer ends of the left and right crawlers 101c as the left and right boundary lines (known from the design value of the hydraulic excavator 100). Note that the front and rear boundaries may be the forwardmost ground contact point of the crawler 101c and the rearmost ground contact point of the rearmost crawler 101c (known from the design value of the hydraulic excavator 100).

When the lower body 101 is jacked up by the front working machine, the hydraulic excavator 100 comes into contact with the ground surface at the bucket 106 of the front working machine and the rear of the lower body 101 (when the front working machine is jacked up in front of the lower body 101), so the support polygon L becomes a polygon as shown in Figure 6 (b).

The support polygon calculation unit 230 may set the boundary K between the normal region J and the fall warning region N inside the support polygon L. Specifically, the boundary K may be set as a polygon in which the support polygon L is shrunk toward the center point according to a ratio determined according to the safety factor, or as a polygon in which the support polygon L is moved inward by a length determined according to the safety factor.

The alarm unit 240 may issue a warning when the ZMP crosses boundary K from the normal area J or remains in the tip-over warning area N. The operation control unit 260 may also restrict the operation of the vehicle body or front work equipment based on the results of comparing the ZMP with the support polygon L. More specifically, when the ZMP crosses boundary K from the normal area J, the operation may be restricted to prevent the vehicle from entering the tip-over warning area N, or the operation speed may be reduced.

While the hydraulic excavator 100 is operating (S04: Yes), new sensor output is acquired at a predetermined cycle (S05), and the ZMP calculation unit recalculates the ZMP based on the new ZMP sensor output (S02). This process is repeated while the hydraulic excavator is operating.

The "predetermined period" referred to here may be a period set by the operator as the timing for updating the ZMP, for example a period set to update every 10 seconds, or a period that matches the timing for updating the sensor output.

When the hydraulic excavator 100 stops operating (S04: No), the power to the controller 110 is also turned off, and the series of processes ends.

According to this embodiment, when calculating the ZMP, not only the mass Mmachine of the hydraulic excavator 100 but also the mass Wload of the load is taken into account, and the mass Wload of the load is changed to follow changes in the load. This makes it possible to calculate a ZMP that corresponds to changes in the load, even when the load is large or small, or when the moment changes depending on the operation or posture of the front work equipment, thereby improving the accuracy of the ZMP calculation.

Also, by making the predetermined period for updating the ZMP relatively short, the ZMP can be updated in real time. On the other hand, by making the predetermined period relatively long depending on the calculation performance of the controller 110, it is possible to achieve both a reduction in the calculation load on the controller 110 and ZMP tracking ability.

Second Embodiment
In the second embodiment, the ZMP is calculated taking into account the specifications of the components of the work machine in addition to the load of the loaded object.

The boom 104, arm 105, bucket 106, and track 101T (see FIG. 8(a)), counterweight 102c (see FIG. 10), and cab 103 that make up the hydraulic excavator 100 come in a variety of specifications, and the weight and center of gravity of the vehicle body change depending on how they are combined. Therefore, this embodiment is characterized in that it constantly grasps information related to the weight and center of gravity of the object to be controlled, and calculates the ZMP taking this information into account, thereby calculating the ZMP with high accuracy.

The bucket 106 is an example of an attachment that can be attached to the arm 105, and depending on the type of work, the bucket 106 can be replaced with a grapple, breaker, crusher, skeleton bucket, auger, bale gripper, rake, etc. Therefore, since the specifications such as shape and mass differ depending on the type of attachment, the ZMP is calculated taking into account what attachment is attached.

Therefore, in the second embodiment, a two-dimensional code indicating part information required to determine the specifications of the components of the hydraulic excavator 100 is attached to each part of the hydraulic excavator 100, and is read by a camera (described later) and used in the ZMP calculation process. Note that, although a two-dimensional code is used as image information indicating part information below, if a one-dimensional code is sufficient for the amount of information, such as when only part identification information is included as part information, a one-dimensional code may be used instead of a two-dimensional code.

Figure 7 shows the attachment positions of the two-dimensional codes on the arm and bucket, where (a) shows the arm and bucket as viewed from the rear of the hydraulic excavator 100, and (b) is an enlarged view of the ventral side of the arm and the underside of the bucket.

As shown in Figures 7(a) and (b), in this embodiment, an arm two-dimensional code 105Q is attached to the ventral side of the arm 105 (the surface visible from the cab 103), and a bucket two-dimensional code 106Q is attached to a portion of the underside of the bucket 106 that is visible from the cab 103. This allows the arm two-dimensional code 105Q and bucket two-dimensional code 106Q to be photographed by a cab front camera 1081 (see Figure 10) mounted with its lens facing forward from the cab 103. As a result, multiple two-dimensional codes can be read with one camera, and the number of cameras required can be fewer than the number of two-dimensional codes to be read.

Figure 8 shows the attachment positions of the two-dimensional codes on the bucket, cab, and truck, where (a) shows the hydraulic excavator 100 from the front, and (b) is an enlarged view of the ventral side of the boom, the top of the cab, and the top of the truck.

As shown in Figures 8(a) and 8(b), a boom two-dimensional code 104Q is attached to the ventral side of the boom 104, and a cab two-dimensional code 103Q is attached to the top surface of the cab 103.

The lower running structure 101 includes a left crawler 101L, a right crawler 101R, and a track 101T that rotatably supports the left crawler 101L and the right crawler 101R. A lower running structure two-dimensional code 101Q indicating part information of the lower running structure 101 is attached to the track 101T.

Figure 9 shows the counterweight two-dimensional code attachment position, where (a) is a top view of the upper rotating body and (b) is an enlarged view of the counterweight two-dimensional code attachment position.

As shown in Figures 9(a) and (b), a counterweight two-dimensional code 102Q indicating the specifications of the counterweight 102c is attached to the top surface of the counterweight 102c.

Figure 10 is a diagram showing the mounting positions of sensors that detect parameters required for calculating the ZMP and cameras that read part information in the hydraulic excavator 100 in the second embodiment.

In the hydraulic excavator 100 according to the second embodiment, a cab front camera 1081 is provided on the front side of the top surface of the cab 103. The cab front camera 1081 is attached in a direction that includes the front, more specifically, the ventral side (surface facing the ground) of the arm 105 and the bottom surface of the bucket 106 (surface facing the cab 103) in its angle of view. The cab front camera 1081 captures images of the arm two-dimensional code 105Q and the bucket two-dimensional code 106Q.

Furthermore, a cab rear camera 1082 is provided on the rear side of the top surface of the cab 103. The cab rear camera 1082 is mounted in an orientation that includes the counterweight 102c in its angle of view, and captures an image of the counterweight two-dimensional code 102Q.

An arm camera 1083 is also provided on the ventral side (the side facing the ground) of the arm 105. The arm camera 1083 is attached in a direction that includes the top surface of the truck 101T, the ventral side of the boom 104, and the top surface of the cab 103 in its angle of view. The arm camera 1083 captures images of the lower vehicle two-dimensional code 101Q, the boom two-dimensional code 104Q, and the cab two-dimensional code 103Q.

In this way, in the hydraulic excavator 100 according to the second embodiment, cameras are placed in three locations, and the specifications of each part, such as the front working implement and the counterweight 102c, are identified by image recognition. The cameras are attached in positions that allow the viewing of parts whose mass changes significantly when they are replaced.

Figure 11 is a block diagram showing the hardware configuration of a hydraulic excavator according to the second embodiment.

The hydraulic excavator 100 according to the second embodiment differs from the first embodiment in that a cab front camera 1081, a cab rear camera 1082, and an arm camera 1083 are connected to the controller 110. The other hardware configurations are the same as those in the first embodiment, so duplicated explanations will be omitted.

Figure 12 is a functional block diagram of a controller installed in a hydraulic excavator according to the second embodiment.

The controller 110 includes an image analysis unit 270 and a part specification information storage unit 280 in addition to the configuration of the first embodiment. The image analysis unit 270 is realized by a processor such as a CPU loading a program into RAM and executing it. The part specification information storage unit 280 is formed by a storage area for part specification information in the storage device 114.

Figure 13 is a flowchart showing the flow of the ZMP calculation process in the hydraulic excavator according to the second embodiment.

When the engine of the hydraulic excavator 100 starts, it acquires sensor outputs from the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, vehicle body inclination angle sensor S4, and boom pressure sensors S7R and S7B (S01), and also acquires images captured by the cab front camera 1081, cab rear camera 1082, and arm camera 1083 (S11).

The image analysis unit 270 acquires captured images from each camera and analyzes the two-dimensional code captured in each image (S12). If the two-dimensional code contains part specifications (S13: Yes), the image analysis outputs the part specifications obtained as a result of the image analysis to the ZMP calculation unit 220.

If the two-dimensional code only contains information about the part type (S13: No), the image analysis unit 270 searches the part specification information storage unit 280, reads out the specifications corresponding to the part type (S14), and outputs them to the ZMP calculation unit 220.

The ZMP calculation unit 220 acquires the tilt angle of the work machine, the angle of the movable part relative to the rotation axis, the angular velocity and angular acceleration, and the load based on the sensor outputs of the vehicle body tilt angle sensor, the angle sensor, and the boom pressure sensor serving as a load sensor, and further calculates the ZMP, which is the dynamic center of gravity position, by adding the specification information of the parts (S02). At this time, the ZMP calculation unit 220 uses the following formula (4) to calculate the mass Mmachine of the hydraulic excavator 100 from the above formula (3). Mi represents the mass of each part read by the two-dimensional code.

Ｍｉは上記と同様二次元コードによって読みこまれたそれぞれの部品の質量を表し、ciは二次元コードによって読みこまれたそれぞれの部品のx軸方向およびy軸方向の重心の位置を示す。 Furthermore, the following equation (5) is used to determine the position of the center of gravity of the hydraulic excavator 100 in the x-axis and y-axis directions.

As above, Mi indicates the mass of each part read by the two-dimensional code, and ci indicates the position of the center of gravity in the x-axis and y-axis directions of each part read by the two-dimensional code.

The subsequent processing is the same as in the first embodiment, so a duplicate explanation will be omitted.

According to this embodiment, a two-dimensional code or one-dimensional code indicating part information for obtaining specification information for each part is attached to each part of the hydraulic excavator 100, the part information is read by a camera to determine the specifications of each part, and the ZMP is calculated taking these specifications into account. This allows the ZMP to be calculated taking into account the specifications of parts that may be replaced on-site in addition to the load, improving the accuracy of the ZMP calculation.

Furthermore, the part information is captured by a camera, and the image analysis unit 270 analyzes the captured image, obtains the specification information of the part from the part information, and outputs it to the ZMP calculation unit 220, so the operator of the hydraulic excavator 100 does not have to input the specification information of the part. This makes it possible to improve the accuracy of ZMP calculation without increasing the operational burden on the operator.

In the second embodiment, a hydraulic excavator is also used as an example, but the present invention is not limited to hydraulic excavators and may be applied to any work machine that includes components that can be replaced after shipment from the factory, such as a wheel loader or a bulldozer.

The above embodiment is not intended to limit the present invention, and various modifications are also included in the present invention. For example, the mounting position and number of cameras are not limited to those described above.

Also, it may be configured so that only the part type and part-specific information are obtained from the two-dimensional code or one-dimensional code, and the controller 110 makes an inquiry to a server connected to the communication network and obtains part specification information from the server. In this case, the part specification information storage unit 280 is not required.

The front cab camera, rear cab camera, and arm camera may also be used as an on-board camera (surroundings monitoring device) to detect obstacles around the hydraulic excavator 100. This reduces the cost of additional parts.

21: Display 22: Operation lever 23: Solenoid valve 100: Hydraulic excavator 101: Lower traveling body 101L: Left crawler 101Q: Lower traveling body two-dimensional code 101R: Right crawler 101T: Track 101c: Crawler 101i: Idler 101s: Sprocket 102: Upper rotating body 102Q: Counterweight two-dimensional code 102c: Counterweight 103: Cab 103Q: Cab two-dimensional code 104: Boom 104Q: Boom two-dimensional code 105: Arm 105Q: Arm two-dimensional code 106: Bucket 106Q: Bucket two-dimensional code 107: Swing mechanism 110: Controller 111: Processor 114: Storage device 115: Input I/F
116: Output I/F
117: Bus 210: Main control unit 220: ZMP calculation unit 230: Support polygon calculation unit 240: Alarm unit 250: Display control unit 260: Operation control unit 270: Image analysis unit 280: Part specification information storage unit 1081: Cab front camera 1082: Cab rear camera 1083: Arm camera J: Normal area K: Boundary L: Support polygon N: Tip-over warning area S1: Boom angle sensor S2: Arm angle sensor S3: Bucket angle sensor S4: Vehicle body inclination angle sensor S7R, S7B: Boom pressure sensor

Claims (8)

The car body and
A front working machine attached to the vehicle body;
a posture detection sensor for detecting the postures of the vehicle body and the front work implement;
A display and
A working machine including a controller,
a load sensor for acquiring a load parameter indicating a load of the front working implement,
the controller includes a ZMP calculation unit that calculates a ZMP, which is a dynamic center of gravity position of the vehicle body and the front working implement, based on a detection result of the attitude detection sensor and a detection result of the load sensor;
a support polygon calculation unit that calculates a support polygon surrounded by a plurality of contact points between the vehicle body and the ground based on a detection result of the attitude detection sensor;
A display control unit that displays the ZMP on the display by superimposing the ZMP on the support polygon.
A work machine characterized by: The car body and
A front working machine attached to the vehicle body;
a posture detection sensor for detecting the posture of the vehicle body and the front work implement;
A display and
A working machine including a controller,
a load sensor for acquiring a load parameter indicating a load of the front working implement,
the controller includes a ZMP calculation unit that calculates a ZMP, which is a dynamic center of gravity position of the vehicle body and the front working implement, based on a detection result of the attitude detection sensor and a detection result of the load sensor;
a support polygon calculation unit that calculates a support polygon surrounded by a plurality of contact points between the vehicle body and the ground based on a detection result of the attitude detection sensor;
and a motion control unit that limits a motion of the vehicle body or the front working implement based on a comparison result between the ZMP and the support polygon.
A work machine characterized by: 2. The work machine according to claim 1,
A one-dimensional code or two-dimensional code indicating part information for determining the specifications of the component parts is added,
The vehicle body is further provided with a camera that reads the one-dimensional code or the two-dimensional code,
The controller further includes an image analysis unit that analyzes the captured image read by the camera,
The ZMP calculation unit calculates the ZMP taking into account the specifications of the component parts analyzed by the image analysis unit.
A work machine characterized by: 4. The working machine according to claim 3,
The work machine is a hydraulic excavator,
The hydraulic excavator includes a lower traveling body, an upper rotating body mounted on the lower traveling body via a rotating mechanism, a boom connected to the front of the upper rotating body so as to be able to be raised and lowered, an arm connected to a tip of the boom so as to be able to rotate, and a bucket rotatably attached to the tip of the arm,
The upper rotating body includes a cab in which an operator of the hydraulic excavator sits, and a counterweight provided behind the cab,
the lower traveling body includes a left crawler and a right crawler, and a track that rotatably supports the left crawler and the right crawler,
A boom two-dimensional code indicating part information of the boom is provided on a ventral side surface of the boom facing the ground,
a two-dimensional arm code indicating part information of the arm is provided on a ventral surface of the arm facing the ground,
A two-dimensional code indicating part information of the bucket is provided on the back surface of the bucket,
A cab two-dimensional code indicating part information of the cab is provided on the upper surface of the cab,
A two-dimensional code indicating part information of the undercarriage is provided on the upper surface of the truck,
A counterweight two-dimensional code indicating part information of the counterweight is provided on the upper surface of the counterweight;
A cab front camera is mounted on the upper surface of the cab in a direction that includes the front in its angle of view, and a cab rear camera is mounted in a direction that includes the counterweight in its angle of view.
An arm camera is provided on the ventral side of the arm,
The cab front camera reads the arm two-dimensional code and the bucket two-dimensional code,
The cab rear camera reads the counterweight two-dimensional code,
The arm camera reads the boom two-dimensional code, the cab two-dimensional code, and the vehicle two-dimensional code.
A work machine characterized by: 2. The work machine according to claim 1,
The load sensor detects new load parameters at a predetermined period,
When the ZMP calculation unit acquires new load parameters from the load sensor, the ZMP calculation unit re-calculates the ZMP at the predetermined period.
A work machine characterized by: 3. The work machine according to claim 2,
A one-dimensional code or two-dimensional code indicating part information for determining the specifications of the component parts is added,
The vehicle body is further provided with a camera that reads the one-dimensional code or the two-dimensional code,
The controller further includes an image analysis unit that analyzes the captured image read by the camera,
The ZMP calculation unit calculates the ZMP taking into account the specifications of the component parts analyzed by the image analysis unit.
A work machine characterized by: 7. The work machine according to claim 6,
The work machine is a hydraulic excavator,
The hydraulic excavator includes a lower traveling body, an upper rotating body mounted on the lower traveling body via a rotating mechanism, a boom connected to the front of the upper rotating body so as to be able to be raised and lowered, an arm connected to a tip of the boom so as to be able to rotate, and a bucket rotatably attached to the tip of the arm,
The upper rotating body includes a cab in which an operator of the hydraulic excavator sits, and a counterweight provided behind the cab,
the lower traveling body includes a left crawler and a right crawler, and a track that rotatably supports the left crawler and the right crawler,
A boom two-dimensional code indicating part information of the boom is provided on a ventral side surface of the boom facing the ground,
a two-dimensional arm code indicating part information of the arm is provided on a ventral surface of the arm facing the ground,
A two-dimensional code indicating part information of the bucket is provided on the back surface of the bucket,
A cab two-dimensional code indicating part information of the cab is provided on the upper surface of the cab,
A two-dimensional code indicating part information of the undercarriage is provided on the upper surface of the truck,
A counterweight two-dimensional code indicating part information of the counterweight is provided on the upper surface of the counterweight;
A cab front camera is mounted on the upper surface of the cab in a direction that includes the front in its angle of view, and a cab rear camera is mounted in a direction that includes the counterweight in its angle of view.
An arm camera is provided on the ventral side of the arm,
The cab front camera reads the arm two-dimensional code and the bucket two-dimensional code,
The cab rear camera reads the counterweight two-dimensional code,
The arm camera reads the boom two-dimensional code, the cab two-dimensional code, and the vehicle two-dimensional code.
A work machine characterized by: 3. The work machine according to claim 2,
The load sensor detects new load parameters at a predetermined period,
When the ZMP calculation unit acquires new load parameters from the load sensor, the ZMP calculation unit re-calculates the ZMP at the predetermined period.
A work machine characterized by:

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