JP2019002242A - Overturn preventing device and work machine - Google Patents

Abstract

To prevent overturn of a work machine, considering a danger of collapse in ground surface around a work machine.SOLUTION: A region setting section 253 detects a collapse danger region based on distance image data of terrain around a work machine 1 measured by a distance measuring sensor, and moves: at least sides interposed between the collapse danger region and a center of a support polygon among four sides constituting a warning line B1; and at least sides interposed between the collapse danger region and a center of a support polygon among four sides constituting a control line B2, respectively toward the center of the support polygon. An overturn preventing control portion 254 warns to notify a danger of collapse when a center of gravity G is positioned outside of the warning line B1, and performs an overturn preventing control when the center of gravity G is positioned outside of the control line B2.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fall prevention device and a work machine that prevent the fall of a work machine including one or more movable parts.

  2. Description of the Related Art Conventionally, in work machines such as power shovels and cranes, measures have been taken to prevent the body from falling over. For example, the following patent documents are known.

  Patent Literature 1 calculates the center of gravity of the entire demolition work machine based on the angle signals of the boom and arm in order to inform the operator of the demolition work machine during operation, and calculates the center of gravity and disassembly Calculate the distance between the front stable fulcrum and the rear stable fulcrum of the work equipment, and calculate the support force of each of the front stable fulcrum and the rear stable fulcrum based on the calculated distance and the calculated center of gravity. Is disclosed.

  Patent Document 2 gives a tipping warning when the ZMP of the working machine is included in the tipping warning area formed outside the safety area formed inside the supporting polygon of the working machine and inside the supporting polygon. Disclose the technology to issue. In this work machine, when it is detected from the information input by the operator, the tilt angle of the upper turning body, and the detection information of the attitude sensor that the work machine is working on an inclined ground, the valley side has a higher risk of falling than the mountain side. The width of the fall warning area is set to be wide.

Japanese Patent No. 2871105 Japanese Patent No. 541516

  By the way, in the case of actual work machine overturn accidents, many cases have been reported in which the shoulder of the shoulder is collapsed due to the load of the work machine applied to the end of the shoulder (the uppermost end of the slope) and the work machine falls. ing. According to the accident case studies described in the construction industry health and safety yearbook for the past five years, about 20% of the fall accidents are reported to be caused by the collapse of the scaffolding.

  Therefore, it is important to prevent the work machine from falling over in consideration of the collapse of the ground around the work machine.

  However, neither of the techniques of Patent Documents 1 and 2 describes the collapse of the shoulder scaffold and the collapse of the scaffold due to the softness of the ground.

  Patent Document 2 discloses that when the work machine is working on an inclined ground, the width of the fall warning area on the valley side is widened. However, the topography and hardness of the ground around the work machine are Since it has not been detected, it is not possible to prevent the fall from taking into account the collapse of the scaffold.

  An object of the present invention is to provide a fall prevention device and a work device that prevent the fall of the work machine in consideration of the danger of collapse of the ground around the work machine.

A fall prevention device according to an aspect of the present invention is a fall prevention device for a work machine including at least one movable part,
A center-of-gravity calculation unit that calculates the center of gravity of the work machine based on the posture of the movable unit;
An area setting unit for setting a safety area and a warning area surrounding the safety area inside a support polygon determined from a plurality of contact points with the ground of the work machine;
When the center of gravity is located in the warning area, the fall prevention control unit performs at least one of a warning for notifying the danger of the fall and a fall prevention control for restricting the operation of the movable part so as to avoid the fall. When,
An area specifying unit that specifies a collapse danger area that is likely to collapse on the surrounding ground based on ground information about the ground around the work machine;
The area setting unit, when the collapse risk area is specified by the area specifying unit, between at least the center of the support polygon and the collapse risk area of the boundary line between the safety area and the warning area. The boundary line interposed between the support polygon and the support polygon is moved in the center direction.

  According to this aspect, when the collapse risk area having the risk of collapse is identified on the ground around the work machine from the ground information on the ground, and the collapse risk area is identified, the boundary line between the safety area and the warning area is identified. Among them, at least a boundary line interposed between the center of the support polygon and the collapse risk area is moved in the direction of the center of the support polygon. As a result, the operator's operation through the warning or the fall prevention control restricts the movement of the center of gravity of the work machine to the collapse risk area side, restricts the load of the work machine on the ground on the collapse risk area side, and causes work due to the collapse. The machine can be prevented from overturning.

In the above aspect, the ground information includes terrain information indicating the terrain of the ground around the work machine,
It is preferable that the area specifying unit specifies the collapse risk area based on the terrain information.

  According to this aspect, since the collapse risk area is specified based on the terrain information indicating the terrain of the ground around the work machine, the fall of the work machine working near the cliff or on the shoulder is a common example of a fall accident. Can be prevented.

In the above aspect, the ground information includes hard soil information indicating the hardness of the ground around the work machine,
It is preferable that the area specifying unit specifies the collapse risk area based on the hard soil information.

  According to this aspect, since the collapse danger area is specified based on the hard soil information indicating the hardness of the ground around the work machine, it is possible to prevent the work machine that is working near the soft ground from falling. . Further, when the collapse risk area is specified by combining the hard soil information of this aspect with the above-described topographic information, it is possible to more reliably prevent the work machine working near the cliff where the ground is soft or on the shoulder.

  In the above aspect, the region specifying unit preferably includes the inclined surface in the collapse risk region when the topographic information indicates that there is an inclined surface around the area.

  According to this aspect, if there is an inclined surface around the work machine, the inclined surface is included in the collapse risk area, so that it is possible to prevent the work machine working near the cliff and shoulders as a fall accident case from falling. .

  In the above aspect, when the hard soil information indicates that there is a ground region having a ground strength lower than a reference value in the surroundings, the region specifying unit preferably includes the region in the collapse risk region.

  According to this aspect, if there is a region where the ground strength is lower than the reference value around the work machine, the region is included in the collapse risk region, and thus it is possible to prevent the work machine working over the region where the ground is soft from falling. .

  In the above aspect, the area setting unit calculates a collapse index value indicating the level of possibility of the collapse of the collapse risk area based on the ground information, and the object to be moved increases as the collapse index value increases. It is preferable to increase the amount of movement of the boundary line.

  According to this aspect, the amount of movement of the boundary line to be moved increases as the collapse index value indicating the likelihood of collapse of the collapse risk area increases. It can be set to an appropriate value according to the height.

In the above aspect, the warning area surrounds the safety area, the warning area is given when the center of gravity is located, and the fall prevention control is performed around the warning area and the center of gravity is located. Control area,
The area setting unit, when the collapse risk area is specified by the area specifying unit, at least a center of the support polygon and the collapse risk area of the first boundary line between the safety area and the warning area. A boundary line interposed therebetween is moved toward the center of the support polygon, and at least between the center of the support polygon and the collapse risk area among the second boundary lines of the warning area and the control area. It is preferable to move the boundary line interposed in the center of the support polygon.

  According to this aspect, when the collapse risk area is specified, the boundary line interposed between at least the center of the support polygon and the collapse risk area among the first boundary lines between the safety area and the warning area is the support polygon. Of the second boundary line between the warning area and the control area, and at least the boundary line interposed between the center of the support polygon and the collapse risk area is moved toward the center of the support polygon. The As a result, the operator's operation through the warning or the fall prevention control restricts the movement of the center of gravity of the work machine to the collapse risk area side, restricts the load of the work machine on the ground on the collapse risk area side, and causes work due to the collapse. The machine can be prevented from overturning.

In the above aspect, a weather information acquisition unit that acquires weather information related to the surrounding weather;
A risk determination unit that determines whether there is a risk of the work machine falling over based on the weather information;
Preferably, the area setting unit moves a boundary line between the safety area and the warning area in the center direction of the support polygon when the risk determination section determines that there is a risk of falling. .

  According to this aspect, for example, when the weather information indicates that the wind is strong and there is a risk that the work machine may fall down due to the strong wind, the boundary line between the safety area and the warning area is the center of the support polygon. Therefore, it is possible to prevent the work machine from overturning.

  According to the present invention, it is possible to prevent the work machine from falling over in consideration of the risk of collapse of the ground around the work machine.

1 is an external view of a work machine according to the present invention. It is a figure for demonstrating the basic composition of the working machine concerning this invention. It is a block diagram which shows the structure of the working machine which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the distance image data acquired because the ranging sensor measured the ground. In Embodiment 1, it is a figure which shows an example of a change of a warning line and a control line. 3 is a flowchart showing processing of the work machine according to the first embodiment. FIG. 6 is a block diagram illustrating a configuration of a work machine according to a second embodiment. It is a figure explaining a surface wave search method. In Embodiment 2, it is a figure which shows an example of a change of a warning line and a control line. In Embodiment 2, it is a figure which shows another example of a change of a warning line and a control line. 10 is a flowchart showing processing of the work machine according to the second embodiment. FIG. 6 is a block diagram illustrating a configuration of a work machine 1 according to a third embodiment. FIG. 6 is a block diagram illustrating a configuration of a work machine 1 according to a fourth embodiment.

(Embodiment 1)
[Work machine]
FIG. 1 is an external view of a work machine 1 according to the present invention. The work machine 1 is a work machine including an upper swing body 3 such as a power shovel or a crane. In FIG. 1, the + x direction indicates the front of the work machine 1, and the −x direction indicates the rear of the work machine 1. The front and rear are collectively referred to as the front-rear direction (x direction). The + z direction indicates the upper side of the work machine 1, and the −z direction indicates the lower side of the work machine 1. The upper part and the lower part are collectively referred to as the vertical direction (z direction). The + y direction indicates the left when the work machine 1 is viewed from the rear to the front, and the -y direction indicates the right when the work machine 1 is viewed from the rear to the front. The right side and the left side are collectively referred to as the left-right direction.

  The work machine 1 is a work machine that includes at least one movable part that rotates around a rotation axis or expands and contracts in the longitudinal direction. A work machine 1, a crawler type lower traveling body 2, an upper revolving body 3 that is turnable on the lower traveling body 2, and a work device 4 that is attached to the upper revolving body 3 are provided.

  The work device 4 includes a boom 41 attached to the upper swing body 3 so as to be able to move up and down, an arm 42 attached so as to be swingable with respect to a distal end portion of the boom 41, and a swing relative to the distal end portion of the arm 42. And a bucket 43 movably attached thereto.

  In addition, the working device 4 swings the boom 43 with respect to the upper swing body 3, the arm cylinder 52 with which the arm 42 swings with respect to the boom 41, and the bucket 43 with respect to the arm 42. And a bucket cylinder 53 to be operated.

  In the example of the power shovel shown in FIG. 1, the movable portion is configured by the upper swing body 3 in addition to the boom 41, the arm 42, and the bucket 43 that constitute the work device 4. Thus, the movable part employs a component of the work machine 1 that affects the center of gravity of the work machine 1 by changing the posture. For example, a jib of a hydraulic crane may be the movable part. Further, an attachment other than the bucket 43 may be a movable part. On the other hand, for example, a component (for example, nibler) of the work machine 1 that has a very low influence on the center of gravity of the work machine 1 is omitted from the movable part even if the component changes in posture.

[Basic configuration]
FIG. 2 is a diagram for explaining the basic configuration of the work machine 1 according to the present invention. The work machine 1 sets a warning line B1, a control line B2, and a limit line B3. The limit line B3 is a boundary line obtained by continuously connecting the outermost boundary portion from the center of the work machine 1 on the ground plane of the work machine 1. A region surrounded by the limit line B3 is a support polygon. When the center of gravity G of the work machine 1 protrudes outside the limit line B3, the work machine 1 rotates about the limit line B3 on the protruding side as a central axis, and the vehicle body on the side opposite to the protruding side starts to float and eventually falls. To do. Therefore, it is important for preventing the work machine 1 from toppling over so that the center of gravity G does not protrude outward from the limit line B3.

  A warning line B1 and a control line B2 surrounding the warning line B1 are set inside the limit line B3. Either one of the warning line B1 and the control line B2 may be omitted. The warning line B1 is set in the support polygon at a fixed distance d1 from the limit line B3, and the control line B2 is set in the support polygon at a fixed distance d2 (<d1) from the limit line B3. In the example of FIG. 2, the limit line B3 is a quadrangle, so the warning line B1 and the control line B2 are each a quadrangle similar to the limit line B3 whose center is located at the center of the support polygon. However, this is an example, and if the limit line B3 is a polygon other than a quadrangle such as a triangle, the warning line B1 and the control line B2 have the same shape as the polygon indicated by the limit line B3.

  A rectangular area surrounded by the warning line B1 is a safety area D1. A region between the warning line B1 and the control line B2 is a warning region D2 where a warning described later is issued when the center of gravity G enters. A region between the control line B2 and the limit line B3 is a control region D3 in which a fall prevention control described later is performed when the center of gravity G enters. The warning area D2 surrounds the safety area D1, and the control area D3 surrounds the warning area D2. The warning area D2 and the control area D3 are examples of a warning area.

  As the center of gravity G moves toward the limit line B3, the risk of falling increases. Therefore, as the center of gravity G approaches the warning line B1 → the control line B2 → the limit line B3, the possibility of the work machine 1 falling is increased.

  Therefore, when the center of gravity G is positioned outside the warning line B1, the work machine 1 issues a warning for notifying the operator of the work machine 1 of a sound or an image indicating the risk of falling. In addition, when the center of gravity G is positioned on the outer side of the control line B2, the work machine 1 is about to fall, and thus performs a fall prevention control for avoiding the work machine 1 from falling. The fall prevention control includes, for example, control for forcibly stopping the work machine 1 or moving the center of gravity G from the limit line B3 to the inside of the work machine 1 regardless of the operation of the operator.

[Change boundary based on topographic information]
However, the basic configuration above assumes that the ground around the support polygon is a solid ground that does not collapse. The risk of falling is increased.

  When there is a steep slope that is in danger of collapsing when the work machine 1 approaches, the risk of falling in the vicinity increases. That is, when the center of gravity G moves to the steep slope side, a part of the ground collapses, and the risk of the work machine 1 falling is increased. As one of important information useful for preventing the work machine 1 from falling, there is terrain information indicating the topography of the ground around the work machine 1, and from this terrain information, it can be detected that there is a steep slope around the work machine 1.

  Therefore, in the first embodiment, for example, a steep slope is specified from the topographic information around the work machine 1 as a collapse risk area having a risk of collapse, and the positions of the warning line B1 and the control line B2 are based on the identified collapse risk area. The risk of falling is reduced by flexibly changing. Hereinafter, the working machine of Embodiment 1 will be described in detail.

[Block Diagram]
FIG. 3 is a block diagram showing the configuration of the work machine 1 according to the first embodiment of the present invention. In FIG. 3, the flow of hydraulic oil is indicated by a thick line, and the flow of control signals is indicated by a thin line.

  The work machine 1 includes an actuator 21, a control valve 22, a hydraulic pump 23, an engine 24, a controller 25, an operation unit 26, an angle sensor 27, a distance measuring sensor 28, and a notification unit 29. Note that the fall prevention device according to the present invention includes a controller 25, an operation unit 26, an angle sensor 27, a distance measurement sensor 28, and a notification unit 29.

  The actuator 21 includes, for example, a boom cylinder 51, an arm cylinder 52, a bucket cylinder 53, and a turning motor that turns the upper turning body 3 shown in FIG. However, this is only an example, and a travel motor that travels the lower traveling body 2 may be employed.

  The hydraulic pump 23 is connected to the drive shaft 24 </ b> X of the engine 24 and discharges hydraulic oil when driven by the power of the engine 24.

  The control valve 22 includes, for example, a hydraulic pilot switching valve interposed between the hydraulic pump 23 and the actuator 21 and an electromagnetic valve that adjusts the pilot pressure input to the hydraulic pilot switching valve. The hydraulic pilot valve opens at an opening corresponding to the pilot pressure input thereto, and supplies hydraulic oil from the hydraulic pump 23 to the actuator 21 at a flow rate corresponding to the opening. The controller 25 inputs a command signal to the solenoid valve, thereby changing the pilot pressure to control the operating speed of the actuator 21.

  The engine 24 is composed of, for example, a diesel engine.

  The controller 25 includes, for example, a computer including a CPU, a RAM, and a ROM, and includes a center-of-gravity calculation unit 251, a region specifying unit 252, a region setting unit 253, a fall prevention control unit 254, and a storage unit 255.

  The center-of-gravity calculation unit 251 calculates the ZMP of the work machine 1 based on the rotation angle θ, the angular velocity θ ′, and the angular acceleration θ ″, and calculates the calculated ZMP as the center of gravity of the work machine 1. However, this is an example. In this case, the center-of-gravity calculation unit 251 obtains the center of gravity of each movable part from the rotation angle θ, and calculates the average value thereof. The rotational angle θ is a parameter indicating the attitude of the movable part, and the angular velocity θ ′ and the angular acceleration θ ″ are parameters indicating the movement of the movable part.

  The center-of-gravity calculation unit 251 calculates the angular velocity θ ′ by first-order differentiation of the rotation angle θ detected by the angle sensor 27 and calculates the angular acceleration θ ″ by second-order differentiation of the rotation angle θ when calculating the ZMP. Alternatively, if an angular velocity sensor that detects the angular velocities of the boom 41, the arm 42, and the bucket 43 is provided, the center-of-gravity calculation unit 251 acquires the angular velocity detected by the angular velocity sensor. This is the same when an angular acceleration sensor is provided.

  The area specifying unit 252 specifies a collapse risk area from the distance image data of the terrain around the work machine 1 measured by the distance measuring sensor 28. Here, if the area | region identification part 252 includes the area | region which shows a steep slope in distance image data, what is necessary is just to identify the area | region as a collapse risk area. Here, the steep slope includes, for example, a slope that is an artificial slope created by cutting or embankment. The slope made by cutting is weak because the natural ground that was originally stable was cut. In addition, the slope created by embankment is not yet stable after the embankment construction, and the ground is weak. Therefore, the slope is characterized by frequent collapse due to changes in conditions such as heavy rain. A natural slope may be adopted as the steep slope.

  FIG. 4 is a diagram illustrating an example of distance image data acquired by the distance measuring sensor 28 measuring the ground. In the example of FIG. 4, a slope E3 created by cutting is located behind the work machine 1 diagonally to the left, and the work machine 1 is working on the shoulder E31 of the slope E3. Since the shoulder E31 is more likely to collapse than the normal ground, the slope E3 collapses as the gravity center G of the work machine 1 approaches the slope E3, and the risk of the work machine 1 falling is increased.

  Further, there is a slope E1 by embankment in front of the work machine 1, and the work machine 1 is working in a place immediately below the slope E1. Like the slope E1, the slope E1 has a weak ground. Therefore, when the work machine 1 rides on the slope E1, the slope E1 collapses and there is a risk that the work machine 1 falls.

  Therefore, in the present embodiment, the danger of falling is reduced by moving the warning line B1 and the control line B2 toward the center of the support polygon under such circumstances.

  Here, the area specifying unit 252 has, for example, a fixed angle (for example, 10 degrees, 20 degrees, 30 degrees, 40 degrees, etc.) within a certain range (for example, a radius of 5 m or 10 m) with reference to the work machine 1. ) If there is a region indicating a slope having an area equal to or larger than a certain area in the distance image data, the region may be detected as a steep slope, that is, a collapse risk region. Here, the region setting unit 253 may detect the steep slope as a collapse risk region only when the work machine 1 is located above the steep slope, or may be when the work machine 1 is located below the steep slope. Alternatively, the steep slope may be detected as a collapse risk area, or even if the steep slope is located within the steep slope, the steep slope may be detected as a collapse risk area.

  Returning to FIG. When the region specifying unit 252 specifies that there is a collapse risk region around the work machine 1, the region setting unit 253 at least supports many of the sides constituting the warning line B1 (an example of the first boundary line). The side interposed between the center of the square and the collapse risk area is moved toward the center of the support polygon, and at least the center of the support polygon among the sides constituting the control line B2 (an example of the second boundary line) And the side interposed between the falling danger area and the center of the support polygon is moved.

  FIG. 5 is a diagram illustrating an example of a change between the warning line B1 and the control line B2 in the first embodiment. FIG. 5A shows a scene in which the upper swing body 3 turns from the front to the left diagonally forward and the center of gravity G moves to the left diagonally forward from (a) to (b).

  In FIG. 5, the slope 501 is located on the left side of the work machine 1, and the work machine 1 is working with the shoulder of the slope 501. Since the slope 501 has a weak ground, the slope 501 tends to collapse as it goes from (a) to (b), and the risk of the work machine 1 falling is high.

  Therefore, the region setting unit 253 sets the side HL1 (here, the left side) interposed between the center of the support polygon and the slope 501 among the four sides constituting the warning line B1 from the default position to the center of the support polygon. The side HL2 (here, the left side) interposed between the center of the support polygon and the slope 501 among the four sides constituting the control line B2 is moved to the center of the support polygon from the default position. Let

  As a result, the distance d11 between the side HL1 and the support polygon (limit line B3) is larger than the default distance d1, so that the timing when the center of gravity G enters the warning area D2 is the default in the scene shown in FIG. Compared to faster. Therefore, in this scene, the warning to the operator is issued earlier, and the operator can be prompted to cancel the left turn at an early stage. As a result, the risk of the work machine 1 falling due to the slope 501 collapse can be reduced.

  Similarly, since the distance d21 between the side HL2 and the limit line B3 is larger than the default distance d2, the timing at which the center of gravity G enters the control region D3 is earlier in this scene than in the default case. Thereby, in this scene, the operation timing of the fall prevention control can be advanced, and the risk of the work machine 1 falling due to the collapse of the slope 501 can be reduced.

  On the other hand, of the four sides constituting each of the warning line B1 and the control line B2, the distances between the three sides that are not interposed between the center of the support polygon and the slope 501 are the default distances d1 and d2. Maintained. Therefore, in a scene where the center of gravity G does not move in the direction of the slope 501, it is possible to prevent warnings from being issued frequently and the overturn prevention control to operate excessively, thereby ensuring operability.

  In the example of FIG. 5, since the boundary line 501a of the slope 501 is parallel to the side closest to the slope 501 among the four sides constituting the limit line B3, the sides HL1 and HL2 are in the center direction of the support polygon. Has been moved to. However, this is an example. For example, as shown in FIG. 5A, if the boundary line of the slope 501 is the boundary line 501b, the side interposed between the center of the support polygon and the slope 501 among the four sides of the warning line B1 is the side HL1. , HF1 and two sides of the control line B2 between the center of the support polygon and the slope 501 are two sides HL2 and HF2. In this case, the region setting unit 253 may move the sides HL1, HF1, HL2, and HF2 toward the center of the support polygon. Alternatively, the area setting unit 253 moves the upper left vertex in the direction of the center of the support polygon with respect to each of the warning line B1 and the control line B2, thereby providing a side parallel to the boundary line 501b. And the control line B2 may be changed.

  Here, the area setting unit 253 calculates a collapse index value indicating the likelihood of collapse in the collapse risk area from the distance image data when the area identification unit 252 identifies the collapse risk area, and calculates the collapse The distance d11 and the distance d21 may be set larger as the index value increases. Here, the collapse index value is calculated from, for example, at least one of the inclination angle of the collapse risk area, the height of the collapse risk area, and the area of the collapse risk area. For example, assuming that the inclination angle of the collapse risk area is parameter Pr1, the height of the collapse risk area is parameter Pr2, and the area of the collapse risk area is parameter Pr3, the collapse index value is the collapse index value = α1 · Pr1 + α2 · Pr2 + α3 · Pr3. Calculated. Α1, α2, and α3 are coefficients for normalizing the parameters Pr1, Pr3, and Pr3.

  Returning to FIG. When the gravity center G calculated by the gravity center calculation unit 251 is positioned outside the warning line B1, the fall prevention control unit 254 issues a warning for notifying the danger of falling. Further, the fall prevention control unit 254 performs the fall prevention control when the center of gravity G is located outside the control line B2.

  The operation unit 26 includes, for example, an operation lever that receives an operation for changing the posture of the work device 4, and outputs an operation amount corresponding to the tilt amount of the operation lever to the controller 25.

  The angle sensor 27 is, for example, four angle sensors that detect the rotation angle θ1 of the boom 41, the rotation angle θ2 of the arm 42, the rotation angle θ3 of the bucket 43, and the rotation angle θ4 of the upper swing body 3 respectively. Composed. The rotation angle θ1 indicates the amount of undulation of the boom 41 with respect to the upper swing body 3. The rotation angle θ <b> 2 indicates the swing amount of the arm 42 with respect to the boom 41. The rotation angle θ <b> 3 indicates the swing amount of the bucket 43 with respect to the arm 42. The rotation angle θ4 indicates the turning amount of the upper swing body 3 with respect to the lower traveling body 2. When the rotation angles θ1 to θ4 are collectively referred to, they are represented as the rotation angle θ. The angle sensor 27 is composed of, for example, a resolver or a potentiometer.

  The distance measuring sensor 28 is composed of, for example, a depth sensor or a stereo camera, and distance image data (an example of terrain information) indicating the terrain of the surrounding ground is time-sequentially at a predetermined frame rate (for example, about 5 to 50 fps). get.

  As the depth sensor, for example, a time of flight (TOF) method that measures the distance distribution of the surrounding ground by measuring the time until the irradiated infrared light is reflected by the object and returns. Can be used. A stereo camera is a distance measuring sensor that measures the distance distribution of the surrounding ground by, for example, obtaining parallax between corresponding points in a plurality of images captured by a plurality of cameras.

  Reference is again made to FIG. In the present embodiment, the distance measuring sensor 28 includes four distance measuring sensors 281, 282, 283, and 284 provided on the front surface, rear surface, left side surface, and right side surface of the upper swing body 3. The distance measuring sensors 281 to 284 are respectively installed in the upper swing body 3 so that the optical axis faces the ground. The distance measuring sensors 281, 282, 283, and 284 have fan-shaped measurement ranges A 1, A 2, A 3, and A 4, respectively. The measurement ranges A1 to A4 are overlapped with the adjacent measurement ranges A1 to A4, respectively. Thereby, the distance measuring sensors 281 to 284 can measure the terrain in all directions around the work machine 1 and obtain distance image data indicating the measured terrain.

  As described above, the method of grasping the surrounding terrain using the distance measuring sensor 28 is capable of grasping the terrain that changes in real time by work such as excavation or the like, so that it is possible to prevent the collapse risk area from being overlooked. It is valid. Note that the method of grasping the surrounding terrain using the distance measuring sensor 28 is an example. For example, the area specifying unit 252 may specify a collapse risk area using wide-area terrain information measured in advance using a drone or the like. In this case, the area specifying unit 252 acquires the position of the work machine 1 using a GPS sensor attached to the work machine 1, and collates the acquired position with the wide-area terrain information, thereby surrounding the work machine 1. It is also possible to detect a collapse risk area.

  Returning to FIG. The storage unit 255 stores in advance the default position information of each of the default warning line B1, the control line B2, and the limit line B3. Here, as the default position information, the coordinates of the four vertices of the warning line B1, the control line B2, and the limit line B3 in the local coordinate system with the center of the work machine 1 as the origin can be adopted. Here, since the warning line B1, the control line B2, and the limit line B3 are set on the ground, the coordinates of the four vertices of the warning line B1, the control line B2, and the limit line B3 are local coordinates. In the system, it is set on a plane representing the ground.

  The notification unit 29 includes a display device and a speaker. When the fall prevention control unit 254 determines that the center of gravity G is located in the warning region D2, the notification unit 29 notifies the operator of the risk of the fall under the control of the fall prevention control unit 254. To do. Here, the notification unit 29 may output a voice message or warning sound for notifying the risk of falling from a speaker, or displaying a message or warning lamp for notifying the risk of falling on a display device. May be.

  Next, a ZMP calculation method in the gravity center calculation unit 251 will be briefly described.

<Calculation of ZMP>
The center-of-gravity calculation unit 251 may calculate ZMP using, for example, the following formulas (1) and (2).

  In the formulas (1) and (2), as shown in FIG. 2, the x axis and the y axis are set on the ground on which the work machine 1 is in contact, and the z axis is set vertically above the ground. . In the expressions (1) and (2), p on the left side represents ZMP. p is composed only of x and y components, and the z component is zero. This is because ZMP is a point on the support polygon set on the ground.

  The total mass M is a constant. The gravitational acceleration g (gx, gy, gz) is, for example, x, y, z components of the gravitational acceleration of the work machine 1 and can be detected by, for example, a gravity sensor that detects an inclination angle of the work machine 1. The total center-of-gravity position c (cx, cy, cz) is the center of gravity of the entire work machine 1 and is a variable depending on the rotation angle θ of the work machine 1. The total momentum P and the total angular momentum L are the vector sum of the momentum and angular momentum of each movable part.

  The total momentum P and the total angular momentum L are variables that depend on the rotation angle θ, the angular velocity θ ′, and the angular acceleration θ ″. Therefore, by adjusting the total momentum P and the total angular momentum L, the ZMP can be arranged at a target location. .

  Thus, the calculation of ZMP requires the total center of gravity position c, the total momentum P, and the total angular momentum L of the work machine 1. These physical quantities are kinematically determined from the rotation angle θ, the angular velocity θ ′, and the angular acceleration θ ″ of the work machine 1. Therefore, the equations (1) and (2) are expressed by the rotation angle θ, the angular velocity θ ′, And the angular acceleration θ ″.

  The rotation angle θ is a vector having a component corresponding to the degree of freedom. Since the working machine 1 in FIG. 1 has four degrees of freedom, the rotation angle θ is represented by a vector composed of four components of θ1, θ2, θ3, and θ4.

  Therefore, if the number of degrees of freedom is n, the rotation angle θ is represented by a vector composed of n components shown in Expression (3).

[flowchart]
FIG. 6 is a flowchart showing processing of the work machine 1 according to the first embodiment. This flowchart is executed at a predetermined sampling period. First, the distance measuring sensor 28 acquires distance image data of the ground around the work machine 1 as terrain information (S601).

  Next, the area specifying unit 252 specifies a collapse danger area around the work machine 1 from the distance image data, and sets a warning line B1 and a control line B2 according to the specifying result (S602). Here, if there is no collapse danger area around the work machine 1, the area specifying unit 252 sets the distance between the warning line B1 and the limit line B3 to the default distance d1 as shown in FIG. The distance between B2 and the limit line B3 is set to the default distance d2. On the other hand, if there is a collapse risk area around the work machine 1, the area specifying unit 252 is a distance between the side HL1 and the limit line B3 interposed between the center of the support polygon and the collapse risk area as shown in FIG. Is set to a distance d11 larger than the default distance d1, and the distance between the side HL2 and the limit line B3 interposed between the center of the support polygon and the collapse risk area is set to a distance d21 larger than the default distance d2. To do.

  Next, the center of gravity calculation unit 251 calculates the center of gravity G of the work machine 1 from the rotation angle θ detected by the angle sensor 27.

  Next, if the gravity center G calculated by the gravity center calculation unit 251 is positioned outside the warning line B1 (YES in S604), the fall prevention control unit 254 issues a warning to the operator (S605). On the other hand, if the gravity center G is not located outside the warning line B1 (NO in S604), the fall prevention control unit 254 returns the process to S601 because the gravity center G is in the safety region D1.

  Next, if the gravity center G is located outside the control line B2 (YES in S606), the fall prevention control unit 254 performs the fall prevention control. On the other hand, if the center of gravity G is located inside the control line B2 (NO in S606), the process returns to S601. In the flowchart of FIG. 6, if the center of gravity G is located outside the control line B2 (YES in S604 and YES in S606), the warning and the fall prevention control are performed, but the present invention is not limited to this. Instead, only the fall prevention control may be performed.

  Thus, according to the work machine 1 of the first embodiment, when the collapse risk area is specified from the map image data of the ground around the work machine 1, the four sides constituting the warning line B1 and the control line B2 are identified. Among these, at least the side interposed between the center of the support polygon and the collapse risk area is moved in the center direction of the support polygon.

  Thereby, the movement of the gravity center G of the work machine to the collapse danger area side is restricted by the operation of the operator through the warning or by the fall prevention control. As a result, the load of the work machine 1 applied to the ground on the collapse danger area side is limited, and the work machine 1 can be prevented from falling due to the collapse.

(Embodiment 2)
In addition to the topographic information, there is hard soil information indicating the hardness of the ground as information useful for preventing the work machine 1 from falling. In particular, when the work machine 1 approaches or enters a soft place on the ground, there is a risk that the ground is inclined or collapses, and the risk of the work machine 1 falling near the place increases. Therefore, in the second embodiment, the risk of falling is determined by specifying the collapse risk area using the solid soil information and flexibly changing the positions of the warning line B1 and the control line B2 based on the specified collapse risk area. Reduce. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

[Block Diagram]
FIG. 7 is a block diagram illustrating a configuration of the work machine 1 according to the second embodiment. The work machine 1 according to the second embodiment further includes a ground sensor 30 and a GPS sensor 31. The ground sensor 30 measures the ground strength of the ground around the work machine 1 using, for example, a surface wave exploration method. The GPS sensor 31 detects the current position of the work machine 1 by receiving a signal from a GPS satellite.

  FIG. 8 is a diagram for explaining the surface wave exploration method. In the surface wave exploration method, as shown in FIG. 8A, the surface waves W of various frequencies generated by the vibrator 81 are received by the receivers 82 and 83, and the velocity of the surface wave W is detected. This is a method for estimating the ground strength.

  In general, it is said that surface waves are slower as they are softer. When the frequency is high as shown in FIG. 8B, the surface wave W propagates through a relatively shallow portion of the ground E, and when the frequency is low as shown in FIG. The relatively deep part of Therefore, the ground strength according to the depth can be estimated by changing the frequency of the surface wave W. Note that the speed of the surface wave W is set, for example, by separating the receiver 82 and the receiver 83 on the ground E by a known distance L, and the receiver 82 on the side of the vibrator 81 detects the surface wave W. Then, the time T from when the receiver 83 detects the surface wave W is measured, and the distance L is divided by the time T. And the ground strength of the area | regions near the receivers 82 and 82 should just be calculated by inputting the speed of the calculated surface wave W into a predetermined function, for example.

  The ground sensor 30 may be composed of (i) only the receivers 82 and 83, (ii) only the exciter 81, or (iii) the receivers 82 and 83 and the exciter. 81 and both.

  In the case of (i), an exciter 81 is installed on the ground E, and the receivers 82 and 83 provided on the work machine 1 receive the surface wave W from the exciter 81, so that the ground sensor 30 What is necessary is just to calculate the speed of the wave W. In the case of (ii), the receivers 82 and 83 are installed on the ground E, and the ground waves are received by the receivers 82 and 83 by receiving the surface waves W from the vibrator 81 provided on the work machine 1. 30 may calculate the velocity of the surface wave W. Further, in the case of (iii), the ground wave sensor 30 receives the surface wave W by causing the receivers 82 and 83 provided in the work machine 1 to receive the surface wave W from the vibration generator 81 provided in the work machine 1. What is necessary is just to calculate the speed of. In the case of (iii), if the receiver 82 is installed at a position away from the vibrator 81 by a known distance, the receiver 82 outputs the surface wave W after the vibrator 81 outputs the surface wave W. Since the speed of the surface wave W can be detected by measuring the time until reception, the receiver 83 may be omitted.

  In the present embodiment, the area specifying unit 252 performs the above-described ground strength measurement using the ground sensor 30 at a plurality of positions on the work site, and obtains the distribution of the ground strength on the work site. And the area | region specific part 252 should just memorize | store in the memory | storage part 255 beforehand the distribution of the obtained ground strength as solid soil information.

  Note that the region specifying unit 252 may acquire the solid soil information using the following method in addition to the above method.

  For example, the region specifying unit 252 may acquire the hard soil information by applying a high-density surface exploration method that has been practically used in recent years to the work site, and may store it in the storage unit 255 in advance. In the high-density surface exploration method, humans are struck by using a hammer or the like to ground the ground on which several tens of receivers are placed, and surface waves W are received at once by the receivers. This is a method for estimating the distribution of the two-dimensional ground strength.

  Or the area | region specific | specification part 252 calculates | requires distribution of N value in a work site by implementing the Swedish sounding test which measures N value which is the hardness of a ground directly in a work site, and is memory | storage part 255 as hard soil information. You may memorize in advance.

  Alternatively, the area specifying unit 252 acquires the distribution of ground strength at the work site from a database (country land information search site: Ministry of Land, Infrastructure, Transport and Tourism, etc.) in which the distribution of ground strength measured by the Swedish sounding test is aggregated. The acquired ground strength distribution may be stored in advance in the storage unit 255 as hard soil information.

  Returning to FIG. For example, the area specifying unit 252 acquires the current position of the work machine 1 using the GPS sensor 31, and collates the acquired current position with the solid soil information of the work site stored in the storage unit 255. The collapse risk area around the machine 1 is specified.

  Here, for example, the region specifying unit 252 may specify a certain range of region including a position where the ground strength is lower than the reference value in the hard soil information as the collapse risk region. Then, if the region specifying unit 252 specifies that there is a collapse danger region around the work machine 1, the region setting unit 253 uses the same method as in the first embodiment to generate the warning line B1 and the control line B2. Should be set.

  FIG. 9 is a diagram illustrating an example of a change between the warning line B1 and the control line B2 in the second embodiment. FIG. 9 shows a scene in which the upper swing body 3 turns from the front toward the left diagonally backward from (a) to (b), and the center of gravity G moves from the center to the diagonally backward left.

  In FIG. 9, the collapse danger area 901 with low ground strength is located behind the work machine 1, and therefore, the fall danger area 901 tends to collapse from (a) to (b). The risk of falls increases.

  Therefore, the region setting unit 253 sets the distance between the side HB1 (here, the lower side) interposed between the collapse danger region 901 and the center of the support polygon among the four sides constituting the warning line B1 to the limit line B3 as a default. The distance d11 is set to be larger than the distance d1, and the side HB1 is moved toward the center of the support polygon. Further, the region setting unit 253 sets the distance between the limit line B3 and the side HB2 (here, the lower side) interposed between the collapse risk region 901 and the center of the support polygon among the four sides constituting the control line B2 as a default. The distance d21 is set to be greater than the distance d2, and the side HB2 is moved toward the center of the support polygon. As a result, in the scene shown in FIG. 9, the warning issuance timing and the fall prevention control operation timing are advanced, and the fall of the work machine 1 due to the fall of the fall danger area 901 can be prevented.

  FIG. 10 is a diagram illustrating another example of a change between the warning line B1 and the control line B2 in the second embodiment. FIG. 10 shows a scene in which the upper swing body 3 turns from the front toward the left diagonally backward from (a) to (b), and the center of gravity G moves from the center to the diagonally backward left.

  In FIG. 10, since the collapse danger area 1101 is located in all the front, rear, left, and right directions of the work machine 1, the direction of the center of gravity G moves, including the movement of the center of gravity G to the left diagonally rear as shown in (b). Even so, the collapse risk area 1101 is easily collapsed, and the risk of the work machine 1 falling is increased.

  Therefore, the region setting unit 253 sets the distance between the four sides constituting the warning line B1 and the limit line B3 to a distance d11 larger than the default distance d1, and sets each of the four sides to a support polygon more than the default position. Move toward the center of. Further, the region setting unit 253 sets the distance between the four sides constituting the control line B2 and the limit line B3 to a distance d21 larger than the default distance d2, and sets each of the four sides to a support polygon than the default position. Move toward the center of.

  Thereby, in the scene where the center of gravity G moves outward in all directions of the work machine 1, including the scene shown in FIG. 10, the warning timing and the fall prevention control operation timing are advanced, The risk of falling of the work machine 1 due to the collapse of the collapse danger area 1101 can be reduced.

  In addition, the area setting unit 253, when the area specifying unit 252 specifies that there is a collapse danger area around the work machine 1, the possibility of collapse so that the value increases as the ground strength decreases. May be set, and the distance d11 and the distance d21 may be set larger as the calculated collapse index value increases.

  FIG. 11 is a flowchart showing processing of the work machine 1 according to the second embodiment. In FIG. 11, the same processes as those in FIG. 6 are denoted by the same reference numerals. First, the area specifying unit 252 acquires hard soil information from the storage unit 255 (S1101). Next, the area specifying unit 252 specifies whether or not there is a collapse risk area around the work machine 1 by collating the hard soil information with the current position of the work machine 1 obtained from the GPS sensor 31. Based on the specific result, the warning line B1 and the control line B2 are set (S1102). The details of the setting of the warning line B1 and the control line B2 are the same as in S602. Hereinafter, the process of S603-S607 demonstrated in FIG. 6 is performed, and the measure which reduces the risk of the fall of the working machine 1 is taken.

  As described above, according to the work machine 1 according to the second embodiment, the collapse risk area is identified from the solid soil information around the work machine 1, and if there is a collapse risk area, as in the first embodiment, The warning line B1 and the control line B2 are moved toward the center of the support polygon. Thereby, the fall of the working machine 1 due to collapse can be prevented.

(Embodiment 3)
A work machine 1 according to the third embodiment is a combination of the first embodiment and the second embodiment. FIG. 12 is a block diagram illustrating a configuration of the work machine 1 according to the third embodiment.

  The work machine 1 includes both a distance measuring sensor 28 and a ground sensor 30. The area specifying unit 252 specifies the collapse risk area using both the distance image data acquired by the distance measuring sensor 28 and the hard soil information created in advance using the ground sensor 30. For example, if there is at least one of the steep slope region and the region where the ground strength is equal to or less than the reference value around the work machine 1, the region specifying unit 252 may detect the region as a collapse risk region.

  In this case, the region setting unit 253 includes (i) a region having a steep slope but having a ground strength greater than a reference value, (ii) a region not having a steep slope but having a ground strength of a reference value or less, and (iii) a steep slope and ground strength being a reference. The collapse index value may be calculated by dividing the pattern into three patterns below the value, and the warning line B1 and the control line B2 may be changed.

  For example, the area setting unit 253 determines that the case (iii) has the largest collapse index value, and then the order of the cases (i) and (ii), or the cases (ii) and (i) next. The collapse index value may be calculated so that the values increase in the order of. Then, the region setting unit 253 increases the warning line B1 so that the distance d11 between the warning line B1 and the limit line B3 and the distance d21 between the control line B2 and the limit line B3 increase as the collapse index value increases. The control line B2 may be set.

  Alternatively, when the area setting unit 253 detects the collapse risk area, the slope angle of the collapse risk area is the parameter Pr1, the height of the collapse risk area is the parameter Pr2, the area of the collapse risk area is the parameter Pr3, and the ground of the collapse risk area If the strength is the parameter Pr4, the collapse index value may be calculated by α1 · Pr1 + α2 · Pr2 + α3 · Pr3 + α4 · Pr4. Α1, α2, α3, and α4 are coefficients for normalizing the parameters Pr1 to Pr4.

  As described above, according to the work machine 1 of the third embodiment, the collapse risk area is specified from the map image data around the work machine 1 and the ground strength, so the work is performed on a soft cliff or shoulder. The fall of the work machine 1 can be prevented more reliably.

(Embodiment 4)
In the first to third embodiments, the risk of the work machine 1 toppling is determined based on at least one of the topographic information and the hard soil information. However, the work machine 1 according to the fourth embodiment provides the weather information. Further, the risk of the work machine 1 toppling over is taken into consideration.

  FIG. 13 is a block diagram showing a configuration of work machine 1 according to Embodiment 4 of the present invention. The work machine 1 further includes a weather information acquisition unit 32 and a risk determination unit 256. The weather information acquisition unit 32 is composed of, for example, an anemometer, and detects the wind speed and the wind direction around the work machine 1.

  The risk determination unit 256 determines the risk of the work machine 1 falling over from the wind speed and the wind direction detected by the weather information acquisition unit 32.

  The area setting unit 253 moves the warning line B1 and the control line B2 in the center direction of the support polygon when the risk determination unit 256 determines that there is a risk of falling. In this case, the risk determination unit 256 may determine that there is a risk of falling if the wind speed is equal to or higher than the reference value.

  When the risk determination unit 256 determines that there is a risk of falling, the region setting unit 253 sets the leeward region around the work machine 1 as the falling risk region, and sets the warning line B1 and the control line B2 What is necessary is just to move the edge | side which interposes at least the fall danger area and the center of a support polygon among the 4 sides which comprise to the center side of the working machine 1. FIG.

  In addition, when the risk determining unit 256 determines that there is a risk of falling, the region setting unit 253 determines a falling index value indicating the magnitude of the possibility of falling from the wind speed, and the falling index value increases. Accordingly, the movement amount of the warning line B1 and the control line B2 may be increased.

  Further, when the region setting unit 253 detects both the fall risk region and the collapse risk region, at least both regions and the center of the support polygon among the four sides constituting each of the warning line B1 and the control line B2. You may move the edge | side which intervenes in the center direction of a support polygon.

  In this case, the area setting unit 253 has a higher risk of falling than the area where the fall risk area and the fall risk area overlap each other in the area where the fall risk area and the fall risk area overlap. Can be determined. Then, the region setting unit 253 moves in the direction toward the center of the support polygon of the side interposed between the overlapping region and the center of the support polygon among the four sides constituting each of the warning line B1 and the control line B2. The amount may be larger than the amount of movement of the non-superimposed region.

  Thus, according to the working machine 1 which concerns on Embodiment 4, the fall of the working machine 1 based on weather information, such as a wind direction, can be prevented.

  In addition, the weather information acquisition part 32 may be comprised with the communication apparatus which acquires the weather information around the working machine 1 from the weather server which provides the weather information on the internet, for example. In this case, the weather information acquisition unit 32 may acquire the weather information around the work machine 1 from the current position of the work machine 1 acquired from the GPS sensor 31.

(Modification 1)
The area setting unit 253 may move all the sides of the warning line B1 and the control line B2 in the center direction of the support polygon regardless of the position of the collapse danger area with respect to the work machine 1.

(Modification 2)
When the center of gravity G moves in the direction of the limit line B3 in the control region D3 and in the region interposed between the collapse risk region and the center of the support polygon, the fall prevention control unit 254 has a remaining region in the control region D3. In comparison with the case where the center of gravity G moves in the direction of the limit line B3, the strength of the overturning prevention control may be increased. In this case, for example, the fall prevention control unit 254 may increase the strength of the fall prevention control by increasing the torque applied to the movable part in order to return the center of gravity G toward the center of the work machine 1.

(Modification 3)
In the second embodiment, the area specifying unit 252 detects the collapse risk area by referring to the hard soil information created in advance. However, the present invention is not limited to this, and the ground sensor 30 performs the ground strength in real time. May be used to identify the collapse risk area. In this case, for example, the region specifying unit 252 installs the ground sensors 30 on the front, rear, left, and right sides of the work machine 1, and if the ground strength in at least one of the front, rear, left, and right directions of the work machine 1 is equal to or less than a reference value. What is necessary is just to determine with the fall danger area in the direction.

(Modification 4)
The work machine 1 may be jacked up or work on a slope. In this case, the support polygon may change from a quadrangle to a shape other than a quadrangle such as a triangle. Therefore, the region setting unit 253 determines which representative point of the plurality of representative points is installed on the ground from the detection values of the plurality of load sensors provided at the plurality of representative points of the lower traveling body. A support polygon may be set by connecting representative points. In this case, it is only necessary that the default positions of the warning line B1 and the control line B2 are set so as to be similar to the support polygon.

B1 warning line B2 control line B3 limit line D1 safety area D2 warning area D3 control area G center of gravity 1 work machine 2 lower traveling body 3 upper turning body 4 work device 25 controller 26 operation unit 27 angle sensors 28, 281, 282, 283 284 Ranging sensor 29 Notification unit 30 Ground sensor 251 Center of gravity calculation unit 252 Region determination unit 253 Region setting unit 254 Fall prevention control unit 255 Storage unit 901, 1101 Collapse risk region

Claims (9)

A fall prevention device for a work machine comprising at least one movable part,
A center-of-gravity calculation unit that calculates the center of gravity of the work machine based on the posture of the movable unit;
An area setting unit for setting a safety area and a warning area surrounding the safety area inside a support polygon determined from a plurality of contact points with the ground of the work machine;
When the center of gravity is located in the warning area, the fall prevention control unit performs at least one of a warning for notifying the danger of the fall and a fall prevention control for restricting the operation of the movable part so as to avoid the fall. When,
An area specifying unit that specifies a collapse danger area that is likely to collapse on the surrounding ground based on ground information about the ground around the work machine;
The area setting unit, when the collapse risk area is specified by the area specifying unit, between at least the center of the support polygon and the collapse risk area of the boundary line between the safety area and the warning area. The fall prevention device which moves the boundary line which intervenes in the central direction of the support polygon. The ground information includes terrain information indicating the terrain of the ground around the work machine,
The fall prevention device according to claim 1, wherein the area specifying unit specifies the collapse risk area based on the terrain information. The ground information includes hard soil information indicating the hardness of the ground around the work machine,
The fall prevention device according to claim 1 or 2, wherein the region specifying unit specifies the collapse risk region based on the hard soil information.   The fall prevention device according to claim 2, wherein the region specifying unit includes the inclined surface in the collapse risk region when the topographic information indicates that there is an inclined surface around the area.   The fall prevention device according to claim 3, wherein when the hard soil information indicates that there is a ground area whose ground strength is lower than a reference value, the area specifying unit includes the area in the collapse risk area. .   The area setting unit calculates a collapse index value indicating the likelihood of the collapse of the collapse risk area based on the ground information, and as the collapse index value increases, a boundary line to be moved The fall prevention device according to any one of claims 1 to 5, wherein the amount of movement of the tip is increased. The warning area surrounds the safety area, and a warning area where the warning is performed when the center of gravity is located; a control area which surrounds the warning area and where the fall prevention control is performed when the center of gravity is located; Including
The area setting unit, when the collapse risk area is specified by the area specifying unit, at least a center of the support polygon and the collapse risk area of the first boundary line between the safety area and the warning area. A boundary line interposed therebetween is moved toward the center of the support polygon, and at least between the center of the support polygon and the collapse risk area among the second boundary lines of the warning area and the control area. The fall prevention device according to any one of claims 1 to 6, wherein a boundary line interposed in the center is moved in a center direction of the support polygon. A weather information acquisition unit for acquiring weather information about the surrounding weather;
A risk determination unit that determines whether there is a risk of the work machine falling over based on the weather information;
The area setting section moves a boundary line between the safety area and the warning area in the center direction of the support polygon when the risk determination section determines that there is a risk of falling. The fall prevention device in any one of -7. The fall prevention device according to any one of claims 1 to 8,
A work machine comprising at least one movable part.

Images