Working machinery

Abstract

To provide a work machine that prevents contact with a suspended load when performing load suspending work using the work machine.SOLUTION: A work machine 100 comprises a work machine body 101 that suspends a suspended load 99, a manipulation device 33 that operates the work machine body 101 by manipulation by an operator, an external sensor 40 that acquires peripheral environmental information of the suspended load 99 and the work machine body 101, a swinging detection unit 64 that calculates a swinging direction of the suspended load 99 on the basis of the peripheral environmental information acquired by the external sensor 40, a determination unit 66 that determines whether the swinging direction calculated by the swinging detection unit 64 is a determination reference direction, and an operation unit 71 that operates the work machine body 101 by limiting the operation of the work machine body 101 by the manipulation device 33 when the determination of the determination unit 66 is affirmative determination.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a working machine.

Background Art

[0002] Patent Document 1 discloses a crane-specification hydraulic excavator. When this excavator operates in the automatic horizontal pulling mode, an angle detector detects the angles of the arm and boom of the crane-specification hydraulic excavator, a detector detects the length of the rope, and a controller calculates the position of the suspended load based on the output signals of these detectors and determines the presence or absence of a risk of contact between the suspended load and the cab. If there is a risk of contact between the suspended load and the cab, a buzzer alerts the operator and the operation of the automatic horizontal pulling is stopped.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the suspended load is moved by the excavator, the suspended load may sway. If the presence or absence of a risk of contact is determined based on the position of the swaying suspended load, even if the operation of the automatic horizontal pulling is stopped, there is still a risk that the suspended load may contact the cab.

[0005] Therefore, in view of the above problems, an object is to prevent contact of the suspended load when performing a load lifting operation using a working machine such as an excavator.

Means for Solving the Problems

[0006] To achieve the above object, a working machine main body for suspending a suspended load, an operating device for operating the working machine main body, An external sensor that acquires information about the surrounding environment of the suspended load and the main body of the work machine, A sway detection unit calculates the direction of sway of the suspended load based on the surrounding environment information acquired by the external sensor, A determination unit that determines whether the direction of vibration calculated by the vibration detection unit is the direction of the determination criterion, If the determination unit determines that the determination unit is positive, the operation of the work machine body by the operating device is restricted, and the operation unit that operates the work machine body is... A work machine equipped with the following is provided. [Effects of the Invention]

[0007] According to the present invention, contact with suspended loads can be prevented. [Brief explanation of the drawing]

[0008] [Figure 1] This is a side view of the work machine. [Figure 2] This is a block diagram of the work machine. [Figure 3] This is a flowchart illustrating the processing flow performed by the controller of a work machine. [Modes for carrying out the invention]

[0009] Embodiments will be described below with reference to the drawings. However, the scope of the present invention is not limited to the embodiments disclosed below. The drawings are provided for illustrative purposes only, and therefore the scope of the present invention is not limited to the examples shown in the drawings.

[0010] <<Overview of the work machine>> Figure 1 is a side view of the work machine 100. Figure 2 is a block diagram of the work machine 100.

[0011] The work machine 100 is a construction machine, more specifically a self-propelled excavator. The work machine 100 is typically used for excavating the ground. The work machine 100 is also used for lifting loads.

[0012] As shown in Figure 1, the work machine 100 includes a work machine body 101 for performing excavation and lifting operations. The work machine body 101 is the shovel body. The work machine body 101 includes a lower traveling body 1, a slewing mechanism 2, an upper slewing body 3, a boom 4, an arm 5, a bucket 6, a boom cylinder 7, an arm cylinder 8, a bucket cylinder 9, a cabin 10, and a hook 13. As shown in Figure 2, the work machine body 101 includes hydraulic motors 11L, 11R, 12, an engine 21, a main pump 22, a regulator 23, and a control valve 24.

[0013] Furthermore, the work machine 100 is equipped with an operating system for manually controlling the work machine body 101 according to the operator's commands. As shown in Figure 2, the operating system includes a pilot pump 31, a hydraulic control valve 32, and an operating device 33. Furthermore, the work machine 100 has a control system for controlling the work machine body 101. As shown in Figure 2, the control system includes a boom angle sensor 41, an arm angle sensor 42, a bucket angle sensor 43, a slewing angle sensor 44, a machine tilt sensor 45, a safety switch 46, a display device 50, and a controller 60.

[0014] <<Main body of the work machine>> The main body of the work machine 101 will be described in detail with reference to Figure 1.

[0015] The lower travel body 1 includes, for example, a pair of left and right crawlers. The lower travel body 1 moves when the crawlers of the lower travel body 1 are driven by hydraulic motors 11L and 11R, respectively, as shown in Figure 2.

[0016] The upper rotating body 3 is mounted on the lower traveling body 1 via a rotation mechanism 2, and the rotation mechanism 2 connects the upper rotating body 3 to the lower traveling body 1 so that it can rotate. The upper rotating body 3 is driven by a hydraulic motor 12 as shown in Figure 2, causing the upper rotating body 3 to rotate relative to the lower traveling body 1. The cabin 10 is mounted on the upper rotating body 3. The cabin 10 is the cockpit where the operator sits.

[0017] The base end of the boom 4 is rotatably connected to the front center of the upper revolving body 3, and the boom 4 is provided so as to be able to pitch with its base end as a fulcrum. A boom cylinder 7 is connected between the upper revolving body 3 and the boom 4, and the boom 4 is driven by the boom cylinder 7.

[0018] The base end of the arm 5 is rotatably connected to the tip of the boom 4, and the arm 5 is provided so as to be able to undulate in the vertical direction with its base end as a fulcrum. An arm cylinder 8 is connected between the boom 4 and the arm 5, and the arm 5 is driven by the arm cylinder 8.

[0019] The base end of the bucket 6 is rotatably connected to the tip of the arm 5, and the bucket 6 is provided so as to be able to undulate in the vertical direction with its base end as a fulcrum. A bucket cylinder 9 is connected between the bucket 6 and the arm 5, and the bucket 6 is driven by the bucket cylinder 9.

[0020] The hook 13 is rotatably connected to the connecting portion between the arm 5 and the bucket 6. When the working machine body 101 performs an excavation operation, the hook 13 is stored between the two bucket links at the tip of the bucket cylinder 9, and when the working machine body 101 performs a load lifting operation, the hook 13 is deployed from between the two bucket links.

[0021] When the working machine body 101 performs a load lifting operation, the suspended load 99 is suspended from the hook 13. The suspended load 99 is moved by the pitching of the boom 4, the undulation of the arm 5, and the rotation of the upper revolving body 3. When the boom 4 pitches, the arm 5 undulates, or the upper revolving body 3 rotates, especially when the pitching speed of the boom 4, the undulation speed of the arm 5, or the rotation speed of the upper revolving body 3 changes, the suspended load 99 swings. Even if the swing of the suspended load 99 occurs, this working machine 100 is able to suppress contact between the suspended load 99 and the working machine body 101 or the obstacle 98.

[0022] Referring to Figure 2, the drive system of the work machine body 101, namely the boom cylinder 7, arm cylinder 8, bucket cylinder 9, hydraulic motors 11L, 11R, 12, engine 21, main pump 22, regulator 23, and control valve 24, will be described.

[0023] Engine 21 is the prime mover and the main power source in the hydraulic drive system. Engine 21 is, for example, a diesel engine that uses light oil as fuel. The output shaft of engine 21 is connected to the main pump 22 and the pilot pump 31 via a transmission or the like. Under direct or indirect control by the controller 60 described later, engine 21 rotates at a preset target rotational speed to drive the main pump 22 and the pilot pump 31.

[0024] The main pump 22 is, for example, a variable displacement hydraulic pump. The main pump 22 is connected to the control valve 24 via a high-pressure hydraulic line. The main pump 22 supplies hydraulic fluid to the control valve 24 by being driven by the engine 21. The regulator 23 is located on the main pump 22. The regulator 23 is controlled by the controller 60. Under the control of the controller 60, the regulator 23 adjusts the tilt angle of the swash plate of the main pump 22. By adjusting the tilt angle of the swash plate of the main pump 22, the discharge pressure and discharge flow rate of the main pump 22 are controlled.

[0025] The control valve 24 is located in the hydraulic line between the boom cylinder 7, arm cylinder 8, bucket cylinder 9, and hydraulic motors 11L, 11R, and 12 and the main pump 22. The control valve 24 selectively supplies hydraulic fluid supplied from the main pump 22 to the boom cylinder 7, arm cylinder 8, bucket cylinder 9, and hydraulic motors 11L, 11R, and 12. The control valve 24 has multiple valves, each of which controls the flow rate and direction of the hydraulic fluid supplied to the boom cylinder 7, arm cylinder 8, bucket cylinder 9, and hydraulic motors 11L, 11R, and 12. As a result, the boom cylinder 7 drives the boom 4, the arm cylinder 8 drives the arm 5, the bucket cylinder 9 drives the bucket 6, the hydraulic motor 11L drives the left crawler of the lower traveling body 1, the hydraulic motor 11R drives the right crawler of the lower traveling body 1, and the hydraulic motor 12 drives the upper slewing body 3.

[0026] <<Operation system>> Referring to Figure 2, the operating system of the work machine 100 will be described in detail.

[0027] The pilot pump 31 supplies pilot pressure to the hydraulic control valve 32 and the control valve 24 via the pilot hydraulic line.

[0028] The hydraulic control valves 32 are provided in correspondence with the boom cylinder 7, arm cylinder 8, bucket cylinder 9, and hydraulic motors 11L, 11R, and 12, respectively. Under the control of the controller 60, the hydraulic control valves 32 apply pilot pressure corresponding to the controller 60's control to the control valve 24 via the pilot hydraulic line. Therefore, the controller 60 operates the lower traveling body 1, upper slewing body 3, boom 4, arm 5, and bucket 6 through the control valve 24, hydraulic motors 11L, 11R, and 12, boom cylinder 7, arm cylinder 8, and bucket cylinder 9 by directly controlling the hydraulic control valves 32. There are two types of operation for the lower traveling body 1, upper slewing body 3, boom 4, arm 5, and bucket 6 by the controller 60: manual operation and automatic operation. Manual operation means that the controller 60 operates the lower traveling body 1, upper slewing body 3, boom 4, arm 5, and bucket 6 based on the output signal of the operating device 33. Automatic control refers to the controller 60 operating the lower vehicle 1, upper slewing body 3, boom 4, arm 5, and bucket 6 regardless of the output signal of the control device 33, or limiting the operating speed of the lower vehicle 1, upper slewing body 3, boom 4, arm 5, and bucket 6 and operating them based on the output signal of the control device 33. Safety control is a type of automatic control, which will be described later.

[0029] The control device 33 is installed inside the cabin 10 near the driver's seat. The control device 33 is a means of operation that allows the operator to control the driven parts of the work machine body 101, namely the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6. The control device 33 has controls corresponding to the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6. Controls refer to levers or pedals. The controls are used to control the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6. In other words, these controls are used to drive the hydraulic motors 11L, 11R, 12, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, respectively.

[0030] The operating device 33 is electrically operated. That is, when operated by an operator, the operating device 33 outputs an electrical signal to the controller 60 corresponding to the operation. In the case of manual operation, the controller 60 controls the hydraulic control valve 32 according to the electrical signal input from the operating device 33. Therefore, by operating the operating device 33, the operator can control the driven parts of the work machine body 101, namely the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6.

[0031] The operating device 33 may also be hydraulically pilot operated. In this case, in addition to the hydraulic control valve 32, a second hydraulic control valve and a shuttle valve are provided in the pilot hydraulic line, the operating device 33 is connected to the second hydraulic control valve, and the second hydraulic control valve and hydraulic control valve 32 are connected to the control valve 24 via the shuttle valve. In the case of manual operation, the controller 60 controls the second hydraulic control valve to high pressure, so that the shuttle valve shuts off the first hydraulic path from the hydraulic control valve 32 to the control valve 24 and connects the operating device 33 and the second hydraulic path from the second hydraulic control valve to the control valve 24. Therefore, when the operating device 33 is operated by the operator, it supplies pilot pressure to the control valve 24 via the second hydraulic control valve and the shuttle valve. Thus, the operator can operate the lower traveling body 1, the upper slewing body 3, the boom 4, the arm 5, and the bucket 6 by operating the operating device 33. In the case of automatic operation, the controller 60 controls the second hydraulic control valve to a low pressure, thereby connecting the first hydraulic path from the hydraulic control valve 32 to the control valve 24 via the shuttle valve, and shutting off the operating device 33 and the second hydraulic path from the second hydraulic control valve to the control valve 24.

[0032] If the operating device 33 is hydraulically pilot-operated, an operating pressure sensor is provided on the operating device 33. The operating pressure sensor detects the pilot pressure applied by the operating device 33 to each of the hydraulic motors 11L, 11R, and 12, the boom cylinder 7, the arm cylinder 8, and the bucket cylinder 9, and outputs the detected signal to the controller 60. In other words, the output signal of the operating pressure sensor corresponds to the electrical signal of an electrically operated operating device 33.

[0033] <<Control System>> The boom angle sensor 41 detects the elevation angle of the boom 4 and outputs a signal related to the elevation angle of the boom 4 to the controller 60. The controller 60 recognizes the elevation angle and elevation speed of the boom 4 based on the output signal from the boom angle sensor 41. The boom angle sensor 41 may include one or more of the following: a rotary encoder, an acceleration sensor, an angular velocity sensor, a six-axis sensor, and an IMU (Inertial Measurement Unit). The boom angle sensor 41 may also include a sensor that detects the extension and retraction length of the boom cylinder 7.

[0034] The arm angle sensor 42 detects the elevation angle of the arm 5 and outputs a signal related to the elevation angle of the arm 5 to the controller 60. The controller 60 recognizes the elevation angle and elevation speed of the arm 5 based on the output signal of the arm angle sensor 42. The arm angle sensor 42 may include one or more of the following: a rotary encoder, an acceleration sensor, an angular velocity sensor, a six-axis sensor, and an IMU. The arm angle sensor 42 may also include a sensor that detects the extension and retraction length of the arm cylinder 8.

[0035] The bucket angle sensor 43 detects the elevation angle of the bucket 6 and outputs a signal related to the elevation angle of the arm 5 to the controller 60. The controller 60 recognizes the elevation angle and elevation speed of the bucket 6 based on the output signal from the bucket angle sensor 43. The bucket angle sensor 43 may include one or more of the following: a rotary encoder, an acceleration sensor, an angular velocity sensor, a six-axis sensor, and an IMU. The bucket angle sensor 43 may also include a sensor that detects the extension and retraction length of the bucket cylinder 9.

[0036] The swivel angle sensor 44 detects the swivel angle of the upper swivel body 3 and outputs a signal related to the swivel angle of the upper swivel body 3 to the controller 60. The controller 60 recognizes the swivel angle and swivel speed of the upper swivel body 3 based on the output signal of the swivel angle sensor 44. The swivel angle sensor 44 may include one or more of the following: a potentiometer, a rotary encoder, and a resolver.

[0037] The aircraft tilt sensor 45 detects the tilt angle of the lower traveling body 1 or the upper rotating body 3, specifically the roll angle, pitch angle, or both, and outputs a signal related to the tilt angle of the lower traveling body 1 or the upper rotating body 3 to the controller 60. The aircraft tilt sensor 45 is mounted, for example, on the upper rotating body 3. The aircraft tilt sensor 45 may include one or more of the following: an acceleration sensor (tilt sensor), an angular velocity sensor, a six-axis sensor, and an IMU.

[0038] As shown in Figure 1, the two cameras 40 are mounted on the exterior of the cabin 10, facing forward. These two cameras 40 are positioned side by side with a gap between them, and there is a parallax between the viewpoint and line of sight of one camera 40 and the viewpoint and line of sight of the other camera 40. In other words, the imaging device consisting of the two cameras 40 is a so-called stereo camera. Note that the installation location of the cameras 40 is not limited to the cabin 10. For example, the cameras 40 may be mounted on the upper rotating body 3.

[0039] Camera 40 is an external sensor that captures images of the area in front of the upper rotating body 3 and acquires images as information about the surrounding environment of the suspended load 99 and the work machine body 101. If obstacles 98 around the work machine body 101 are within the field of view of camera 40, camera 40 will also capture images of the obstacles 98 in addition to the suspended load 99. As shown in Figure 2, camera 40 transmits the image signals captured by camera 40 to controller 60.

[0040] Camera 40 is used to prevent contact between the suspended load 99 and the work machine body 101 or an obstacle 98 due to the swaying of the suspended load 99. Therefore, when the work machine body 101 performs a load-lifting operation, camera 40 performs a shooting operation. Camera 40 may also perform a shooting operation when the work machine body 101 performs an excavation operation.

[0041] A display device 50 may be installed inside the cabin 10, and the video signal captured by the camera 40 may be transmitted to the display device 50 by the controller 60, and the video may be displayed on the display device 50.

[0042] The safety switch 46 is installed, for example, inside the cabin 10. When the operator lifts a load using the work machine 100, the operator turns on the safety switch 46. The safety switch 46 then transmits an ON signal to the controller 60, which causes the controller 60 to execute the computer program 62 described later. When the operator turns off the safety switch 46, the safety switch 46 transmits an OFF signal to the controller 60, which causes the controller 60 to terminate the execution of the computer program 62.

[0043] The changeover switch for switching between the lifting mode and the excavation mode may also serve as the safety switch 46. In this case, the user turns on the changeover switch, and the operating mode of the work machine 100 changes to the lifting mode, after which the controller 60 executes the computer program 62. When the operating mode of the work machine 100 changes to the lifting mode, the controller 60 changes the target rotational speed of the engine 21 to a low speed. Furthermore, the controller 60 operates the bucket 6 to close it and holds the bucket 6 in the closed position.

[0044] Alternatively, a safety switch 46 may be installed on the hook 13. In this case, when the hook 13 is retracted between the two bucket links at the tip of the bucket cylinder 9, the safety switch 46 is turned off by the hook 13, and when the hook 13 is unfolded from between the two bucket links, the safety switch 46 is turned on by the hook 13.

[0045] The controller 60 is mounted inside the cabin 10. The controller 60 is a computer equipped with a CPU, RAM, GPU, system bus, and storage device 61 as hardware. The storage device 61 of the controller 60 stores a computer program 62 that the CPU can execute. When the operator lifts a load using the work machine 100, the computer program 62 is executed by the CPU of the controller 60. For example, when the safety switch 46 outputs an ON signal to the controller 60, the controller 60 recognizes this and the CPU of the controller 60 executes the computer program 62. Then the controller 60 functions as a load detection unit 63, a sway detection unit 64, an obstacle detection unit 65, a first judgment unit 66, a first judgment criterion calculation unit 67, a second judgment criterion calculation unit 68, a second judgment unit 69, a third judgment criterion calculation unit 70, a safety autopilot unit 71, and a notification unit 72. The suspended load detection unit 63, the sway detection unit 64, the obstacle detection unit 65, the first determination unit 66, the first determination criterion calculation unit 67, the second determination criterion calculation unit 68, the second determination unit 69, the third determination criterion calculation unit 70, the safety autopilot unit 71, and the notification unit 72 are software modules implemented by the CPU executing the computer program 62.

[0046] The suspended load detection unit 63 periodically calculates the three-dimensional position and range of the suspended load 99 based on the video signals from the two cameras 40 using a three-dimensional surveying principle that utilizes parallax (this three-dimensional surveying principle is also known as the principle of a stereo camera). The three-dimensional position of the suspended load 99 is expressed by the X, Y, and Z coordinates of a Cartesian coordinate system (hereinafter referred to as the sensor coordinate system) defined by mutually orthogonal X, Y, and Z axes, representing the position of a representative point of the suspended load 99. The range of the suspended load 99 is expressed in X, Y, and Z coordinates as the range in which the suspended load 99 exists within the sensor coordinate system. In other words, the range of the suspended load 99 represents the dimensions of the suspended load 99 in the X-axis direction, Y-axis direction, and Z-axis direction, respectively. Periodic calculation refers to calculating the three-dimensional position and range of the suspended load 99 for each frame of the video captured by the camera 40, or calculating the three-dimensional position and range of the suspended load 99 every one or more frames of the video. Since the external sensor is the camera 70, the sensor coordinate system is also called the camera coordinate system. The origin of the sensor coordinate system is determined, for example, based on the position of the camera 40, and this origin follows the movement of the lower traveling body 1, the rotation of the upper rotating body 3, or both. Therefore, if the lower traveling body 1 moves or the upper rotating body 3 rotates, the obstacle 98 moves in the sensor coordinate system.

[0047] The vibration detection unit 64 periodically calculates the three-dimensional direction and velocity of the suspended load 99 in the sensor coordinate system based on the video signals from the two cameras 40, using a three-dimensional surveying principle that utilizes parallax. More specifically, the vibration detection unit 64 calculates the difference between the three-dimensional position of the suspended load 99 in a given frame and the three-dimensional position of the suspended load 99 in a subsequent frame. This difference is a vector consisting of components in the X-axis direction, the Y-axis direction, and the Z-axis direction, where the X-axis, Y-axis, and Z-axis components represent the direction of the suspension load 99's vibration. The magnitude of this vector corresponds to the vibration velocity.

[0048] The obstacle detection unit 65 periodically calculates the three-dimensional position and range of the obstacle 98 based on the video signals from the two cameras 40, using a three-dimensional surveying principle that utilizes parallax. The three-dimensional position of the obstacle 98 is expressed in terms of the X, Y, and Z coordinates of the sensor coordinate system, representing the position of a representative point of the obstacle 98. The range of the obstacle 98 is expressed in terms of the X, Y, and Z coordinates, representing the range in which the obstacle 98 exists within the sensor coordinate system.

[0049] The first determination unit 66 determines whether the three-dimensional swaying direction of the suspended load 99 calculated by the sway detection unit 64 is in the determination criterion direction. A determination that the three-dimensional swaying direction of the suspended load 99 is in the determination criterion direction is called an affirmative determination, and a determination that it is not is called a negative determination. The determination criterion direction may or may not have a range. The determination criterion direction refers to the direction from the suspended load 99 to the work machine body 101 (especially the cabin 10 or upper slewing body 3), or the direction from the suspended load 99 to the obstacle 98. The determination criterion direction is calculated by the first determination criterion calculation unit 67 or the second determination criterion calculation unit 68.

[0050] The first judgment criterion calculation unit 67 calculates the judgment criterion direction based on the position and range of the work machine body 101 (particularly the cabin 10 and upper slewing body 3) in the sensor coordinate system and the position and range of the suspended load 99 calculated by the suspended load detection unit 63. The judgment criterion direction calculated in this way is the direction from the suspended load 99 to the work machine body 101 (particularly the cabin 10 or upper slewing body 3). The position and range of the work machine body 101 (particularly the cabin 10 and upper slewing body 3) in the sensor coordinate system may be set in advance in the computer program 62, or the controller 60 may correct the setting based on the boom angle sensor 41, arm angle sensor 42, bucket angle sensor 43, slewing angle sensor 44 and machine tilt sensor 45.

[0051] The second judgment criterion calculation unit 68 calculates the judgment criterion direction based on the position and range of the obstacle 98 calculated by the obstacle detection unit 65 and the position and range of the suspended load 99 calculated by the suspended load detection unit 63. The judgment criterion direction calculated in this way is the direction from the suspended load 99 to the obstacle 98. The judgment criterion direction is not calculated by the judgment criterion calculation units 67 and 68, but may be a predetermined direction.

[0052] The second determination unit 69 determines whether the swaying speed of the suspended load 99, calculated by the swaying detection unit 64, exceeds the judgment standard speed. A determination that the swaying speed of the suspended load 99 exceeds the judgment standard speed is called an affirmative determination, and a determination that does not is called a negative determination. The judgment standard speed may be a predetermined constant or a variable. If the judgment standard speed is a variable, it is calculated by the third judgment standard calculation unit 70.

[0053] The third judgment criterion calculation unit 70 calculates the judgment criterion speed based on the range of the suspended load 99 recognized by the suspended load detection unit 63. Specifically, the third judgment criterion calculation unit 70 calculates a smaller judgment criterion speed as the range of the suspended load 99 recognized by the suspended load detection unit 63 widens. Therefore, as the range of the suspended load 99 recognized by the suspended load detection unit 63 widens, it becomes easier for the second judgment unit 69 to determine that the swinging speed of the suspended load 99 exceeds the judgment criterion speed. Thus, as the range of the suspended load 99 recognized by the suspended load detection unit 63 widens, the judgment by the second judgment unit 69 becomes stricter.

[0054] If the first determination unit 66 makes a positive determination, or if both the first determination unit 66 and the second determination unit 69 make positive determinations, the safety autopilot unit 71 and the notification unit 72 are activated. The safety autopilot unit 71 restricts manual operation of the lower traveling body 1, upper slewing body 3, boom 4, and arm 5 based on the output signal of the operating device 33, and performs automatic safety operation of the lower traveling body 1, upper slewing body 3, boom 4, or arm 5. Automatic safety operation of the lower traveling body 1, upper slewing body 3, boom 4, or arm 5 means stopping the manually operated lower traveling body 1, upper slewing body 3, boom 4, or arm 5, reversing the movement of the manually operated upper slewing body 3, boom 4, or arm 5, or limiting and reducing the speed of the manually operated upper slewing body 3, boom 4, or arm 5. More specifically, it is as follows (1) to (5).

[0055] (1) When the operator operates the control device 33 and the controller 60 is controlled to swing down the boom 4 or arm 5, if the determination of the first determination unit 66 is a positive determination, or if the determinations of both the first determination unit 66 and the second determination unit 69 are positive determinations, then the positive determination means that the swinging suspended load 99 is likely to come into contact with the work machine body 101 (especially the cabin 10 or the upper slewing body 3). In this case, the safety autopilot unit 71 ignores the output signal of the control device 33 and either stops the boom 4 or arm 5, limits and reduces the speed of the boom 4 or arm 5, or controls the boom 4 or arm 5 to swing up and then stops the boom 4 or arm 5. This prevents the suspended load 99 from coming into contact with the work machine body 101.

[0056] (2) When the operator operates the control device 33 and the controller 60 is controlled to swing up the boom 4 or arm 5, if the determination of the first determination unit 66 is a positive determination, or if the determinations of both the first determination unit 66 and the second determination unit 69 are positive determinations, then the positive determination means that the swinging suspended load 99 is likely to come into contact with the obstacle 98 in front of the work machine body 101. In that case, the safety autopilot unit 71 ignores the output signal of the control device 33 and either stops the boom 4 or arm 5, limits and reduces the speed of the boom 4 or arm 5, or controls the boom 4 or arm 5 to swing down and then stops the boom 4 or arm 5. This prevents the suspended load 99 from coming into contact with the obstacle 98.

[0057] (3) When the operator operates the control device 33 and the controller 60 is directed to rotate the upper slewing body 3 to the left, if the determination of the first determination unit 66 is a positive determination, or if the determinations of both the first determination unit 66 and the second determination unit 69 are positive determinations, then the positive determination means that the swinging suspended load 99 is likely to come into contact with the obstacle 98 to the left of the work machine body 101. In that case, the safety automatic control unit 71 ignores the output signal of the control device 33 and either stops the upper slewing body 3, limits and reduces the speed of the upper slewing body 3, or directs the upper slewing body 3 to rotate to the right and then stops the upper slewing body 3. This prevents the suspended load 99 from coming into contact with the obstacle 98.

[0058] (4) When the operator operates the control device 33 and the controller 60 is directed to rotate the upper slewing body 3 to the right, if the determination of the first determination unit 66 is a positive determination, or if the determinations of both the first determination unit 66 and the second determination unit 69 are positive determinations, then the positive determination means that the swinging suspended load 99 is likely to come into contact with the obstacle 98 to the right of the work machine body 101. In that case, the safety automatic control unit 71 ignores the output signal of the control device 33 and either stops the upper slewing body 3, limits and reduces the speed of the upper slewing body 3, or directs the upper slewing body 3 to rotate to the left and then stops the upper slewing body 3. This prevents the suspended load 99 from coming into contact with the obstacle 98.

[0059] (5) When the suspended load 99 is being lowered from the hook 13, the movement of the work machine body 101 is prohibited. If the operator accidentally operates the control device 33, the controller 60 will move the lower travel body 1. In such a case, if the first determination unit 66 makes a positive determination, or if both the first determination unit 66 and the second determination unit 69 make positive determinations, that positive determination means that the swinging suspended load 99 is likely to come into contact with the work machine body 101 or an obstacle 98 in front of it. In that case, the safety autopilot unit 71 can prevent the suspended load 99 from coming into contact with the work machine body 101 by ignoring the output signal of the control device 33 and stopping the lower travel body 1. Alternatively, the safety autopilot unit 71 can prevent the suspended load 99 from coming into contact with the work machine body 101 by operating the boom 4 or arm 5 to swing it up and then stopping the boom 4 or arm 5. Alternatively, if the safety autopilot unit 71 stops the boom 4 or arm 5 after operating it to swing it down, contact of the suspended load 99 with the obstacle 98 in front of the work machine body 101 is prevented.

[0060] The notification unit 72 outputs a video signal for notification to the display device 50, which acts as a notification device, causing the display device 50 to display, for example, a video indicating the risk of contact. This allows the operator to detect the risk of contact with the suspended load 99 while remaining inside the cabin 10. Alternatively, a notification device such as a speaker, lamp, or flashing light may be provided inside the cabin 10, and the notification unit 72 may cause the notification device to perform a notification operation.

[0061] <<Controller Processing Flow>> When the operator uses the work machine 100 to lift a load, and the operator turns on the safety switch 46, the controller 60 performs the following processing according to the computer program 62. While the computer program 62 is running, the operator operates the control device 33 to manually control the work machine body 101, causing the load 99 to be lifted and moved by the work machine body 101.

[0062] First, the controller 60 operates the two cameras 40 (step S1) and continuously receives video signals from the two cameras 40.

[0063] Next, the controller 60, acting as a suspended load detection unit 63, calculates the three-dimensional position and range of the suspended load 99 based on the video signals from the two cameras 40 (step S2). Next, the controller 60, acting as a vibration detection unit 64, calculates the three-dimensional direction and velocity of the suspension load 99 based on the video signals from the two cameras 40 (step S3). Next, the controller 60, acting as an obstacle detection unit 65, periodically calculates the three-dimensional position and range of the obstacle 98 based on the video signals from the two cameras 40 (step S4). Note that the order of steps S2 to S4 may be changed.

[0064] Next, the controller 60, acting as the first judgment criterion calculation unit 67, calculates the judgment criterion direction based on the position and range of the work machine body 101 (particularly the cabin 10 and the upper slewing body 3) in the sensor coordinate system and the position and range of the suspended load 99 calculated in step S2 (step S5). The judgment criterion direction thus calculated is the direction from the suspended load 99 to the work machine body 101.

[0065] Furthermore, the controller 60, which acts as the second judgment criterion calculation unit 68, calculates the judgment criterion direction based on the position and range of the obstacle 98 calculated in step S4 and the position and range of the suspended load 99 calculated in step S2 (step S5). The judgment criterion direction calculated in this way is the direction from the suspended load 99 to the obstacle 98.

[0066] Next, the controller 60, acting as the first determination unit 66, determines whether the three-dimensional swaying direction of the suspended load 99 calculated in step S3 is in the determination criterion direction (step S6). If this determination is positive, the controller 60 proceeds to step S7 (step S6: YES). If this determination is negative, the controller 60 returns to step S2 (step S6: NO). If this determination is positive, the controller 60 may proceed to step S8.

[0067] In step S7, the controller 60, acting as the second determination unit 69, determines whether the three-dimensional swaying velocity of the suspended load 99 calculated in step S3 exceeds the determination criterion velocity. The determination criterion velocity may be a predetermined constant, or it may be calculated by the controller 60, acting as the third determination criterion calculation unit 70, based on the range of the suspended load 99 calculated in step S6.

[0068] If the determination in step S7 is positive, the controller 60 proceeds to step S8 (step S7: YES). If the determination in step S7 is negative, the controller 60 returns to step S2 (step S7: NO).

[0069] In step S8, the controller 60, acting as a safety autopilot unit 71, restricts manual operation of the lower travel body 1, upper slewing body 3, boom 4, and arm 5 based on the output signals of the operating device 33, and performs automatic safety operation of the lower travel body 1, upper slewing body 3, boom 4, or arm 5. This prevents the suspended load 99 from coming into contact with the work machine body 101 or an obstacle 98.

[0070] Next, the controller 60, acting as the notification unit 72, outputs a video signal for notification to the display device 50, causing the notification video to be displayed on the display device 50 (step S9).

[0071] <<Technically advantageous effects>> Even if the suspended load 99 swings when the operator controls the work machine body 101 via the control device 33, it is possible to prevent the suspended load 99 from coming into contact with the work machine body 101 or an obstacle 98. Therefore, the lifting operation can be performed safely.

[0072] The larger the suspended load 99, the lower the threshold speed for judgment. Therefore, the larger the suspended load 99, the more likely the automatic control by the safety automatic control unit 71 is to be activated. Thus, even with large suspended loads, the lifting operation can be performed safely.

[0073] <<Variation>> In the above-described embodiment, the external sensor is a camera 40. However, a three-dimensional distance measuring sensor may be used instead of the camera 40. The three-dimensional distance measuring sensor periodically measures the distance and direction from the sensor to the suspended load 99 and obstacles 98 around the work machine body 101 by irradiating waves such as laser light, electromagnetic waves, infrared rays, or ultrasonic waves. The three-dimensional distance measuring sensor may employ LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) or a three-dimensional scanner. The suspended load detection unit 63 periodically calculates the three-dimensional position and range of the suspended load 99 based on the output signal of the three-dimensional distance measuring sensor. The sway detection unit 64 periodically calculates the three-dimensional sway direction and sway velocity of the suspended load 99 in the sensor coordinate system based on the output signal of the three-dimensional distance measuring sensor. The obstacle detection unit 65 periodically calculates the three-dimensional position and range of the obstacles 98 based on the output signal of the three-dimensional distance measuring sensor.

[0074] In the above-described embodiment, the work machine body 101 is an excavator body. However, the work machine body is not limited to an excavator body as long as it is capable of lifting loads. For example, the work machine body may be a mobile crane body or a fixed crane body. A mobile crane body refers to, for example, a crawler crane body, a wheel crane body, a truck crane body, etc. A fixed crane body refers to, for example, a port crane body, an overhead crane body, a gantry crane body, and an unloader body, etc. The work machine body may be a construction machine body other than an excavator, as long as it has a jib, arm, boom, etc. [Explanation of Symbols]

[0075] 1. Lower running body 3. Upper rotating body 4 Boom 5 Arms 40 Cameras (external sensor) 60 Controllers 63. Suspended load detection unit 64. Shake detection unit 65 Obstacle detection unit 66 1st judgment part 67 1st judgment criterion calculation section 68 Second judgment criterion calculation section 69 Second judgment part 71 Safety Autopilot Unit 100 working machines 101 Main body of the work machine

Claims

1. The main body of the work machine that lifts the load, An operating device that controls the main body of the work machine by being operated by an operator, An external sensor that acquires information about the surrounding environment of the suspended load and the main body of the work machine, A sway detection unit calculates the direction of sway of the suspended load based on the surrounding environment information acquired by the external sensor, A determination unit that determines whether the direction of vibration calculated by the vibration detection unit is the direction of the determination criterion, If the determination unit determines that the determination unit is positive, the operation of the work machine body by the operating device is restricted, and the operation unit that operates the work machine body is... A work machine equipped with the following features.

2. It is further equipped with a second determination unit, The vibration detection unit calculates the vibration speed of the suspended load based on the surrounding environment information acquired by the external sensor. The second determination unit determines whether the vibration speed calculated by the vibration detection unit exceeds the determination speed, The control unit restricts the operation of the work machine body by the operating device when the determination unit's determination is positive and the second determination unit's determination is positive, thereby controlling the work machine body. The work machine according to claim 1.

3. The operation of the work machine body by the control unit is to reduce the speed of the work machine body's movement, to stop the work machine body's movement, or to reverse the direction of the work machine body's movement. The work machine according to claim 1 or 2.

4. A load detection unit calculates the position of the suspended load based on the surrounding environment information acquired by the external sensor, An obstacle detection unit calculates the location of obstacles around the main body of the work machine based on the surrounding environment information acquired by the external sensor, A judgment criterion calculation unit calculates the direction from the position of the suspended load calculated by the suspended load detection unit to the position of the obstacle calculated by the obstacle detection unit, as the judgment criterion direction. The work machine according to claim 1 or 2, comprising:

5. A load detection unit calculates the position of the suspended load based on the surrounding environment information acquired by the external sensor, A judgment criterion calculation unit calculates the direction from the position of the suspended load to the work machine as the judgment criterion direction, based on the position of the suspended load calculated by the suspended load detection unit. The work machine according to claim 1 or 2, comprising:

6. The aforementioned work machine is an excavator body having a lower traveling body, an upper rotating body mounted on the lower traveling body and rotating, a boom connected to the upper rotating body and raising and lowering, and an arm connected to the tip of the boom and raising and lowering. The aforementioned load is suspended from the tip of the arm, The operation of the work machine body by the aforementioned operating device and the operation of the work machine body by the aforementioned control unit are the rotation of the upper rotating body, the elevation of the boom, and the raising and lowering of the arm. The work machine according to claim 3.

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