Safety device for construction machine

Abstract

Provided is a safety device capable of stably performing safety control relating to a construction machine. The security device includes a position information acquisition unit and a control unit. The position information acquisition unit periodically acquires position information relating to the position of an object to be detected in the vicinity of the construction machine. The control unit performs safety control corresponding to this information when this information, which is the position information acquired this time, is changed in the direction of approaching the construction machine compared to last information, which is the position information acquired last time, and performs safety control corresponding to this information when a change suppression condition is satisfied. The control unit executes control change suppression that suppresses a change in the security control corresponding to a change in the position information, and cancels the control change suppression at a point in time at which a predetermined time has elapsed after the start of the control change suppression, the change suppression conditions including that the current information is less than the previous information, and the current information is less than the previous information. And changing towards the direction far away from the engineering machinery.

Description

Technical Field

[0001] The invention relates to a safety device for engineering machinery. Background Art

[0002] Conventionally, there is a known device that detects a detection object existing around a construction machine such as a hydraulic excavator and performs safety control. For example, Patent Document 1 discloses a device that determines the relative position of an obstacle with respect to a virtual boundary surface set around an upper rotating body of the construction machine; the smaller the distance from the virtual boundary surface to the obstacle, the greater the degree of limiting the movement speed of the upper rotating body.

[0003] Control based on the position information of such a detection object (an obstacle in Patent Document 1) is prone to become unstable. Specifically, the position of the detection object is determined by using a measurement value obtained by a distance sensor such as an infrared depth sensor or a millimeter wave radar, or by processing image data obtained by an imaging device (camera). The position information obtained in this way is easily confused by the performance or characteristics of the sensor or camera, or external factors such as the shaking of the vehicle body. In particular, when using the imaging device, the detection result may be temporarily greatly affected by the state or posture of the detection object, or the surrounding conditions. For example, it is possible that although the detection object actually exists, it temporarily becomes an undetected state, or although the position of the detection object has not changed, its detection result (for example, the distance from the construction machinery to the detection object) changes. Safety control performed based on unstable position information is prone to become unstable.

[0004] Prior art

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6819462 Summary of the invention

[0007] An object of the present invention is to provide a device capable of stably performing safety control related to construction machinery.

[0008] The provided safety device performs safety control of a construction machine, and the safety device includes a position information acquisition unit and a control unit. The position information acquisition unit periodically acquires position information related to the position of a detection object around the construction machine. When the position information acquired this time, i.e., this time information, changes in a direction closer to the construction machine compared to the position information acquired last time, i.e., last information, the control unit performs safety control corresponding to the current information, and when a change suppression condition is satisfied, performs control change suppression to suppress the change of the safety control corresponding to the change of the position information, the change suppression condition including: the current information changes in a direction away from the construction machine compared to the last information. The control unit releases the control change suppression at a time point after a specified time has passed since the start of the control change suppression, for example, at a time point when the position information has been acquired a specified number of times. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a side view showing a hydraulic excavator which is an example of a construction machine according to an embodiment of the present invention.

[0010] Figure 2 is a top view of the hydraulic excavator.

[0011] Figure 3 It is a block diagram showing a hydraulic circuit, a controller, etc. mounted on the hydraulic excavator.

[0012] Figure 4 is a block diagram showing the main functions of the controller.

[0013] Figure 5 is a flowchart showing the speed limit control executed by the controller.

[0014] Figure 6 This is a graph showing a first example of the time change of the distance value obtained by the hydraulic excavator, that is, an example in which the detection of the detection object is interrupted for a specific period of time.

[0015] Figure 7 This is a graph showing the time changes of each swing restriction command when the control change suppression is not performed and when the control change suppression is performed in the first example when the change suppression condition is satisfied.

[0016] Figure 8 This is a graph showing the time change of the swing pilot pressure when the control change suppression is not performed in the first example.

[0017] Fig. 9 2 is a graph showing a second example of the time change of the distance value obtained by the hydraulic excavator, that is, an example in which the distance value temporarily increases.

[0018] Fig.10 This is a graph showing the time changes of each swing restriction command when the control change suppression condition is satisfied and when the control change suppression is performed in the second example.

[0019] Fig.11 This is a graph showing the time change of the distance value when the moving average of the distance value is used in the second example.

[0020] Fig.12 This is a graph showing an example of processing in which the rate of change of the swing limiting command is limited.

[0021] Fig.13 It is a top view showing another example of the monitoring area set around the construction machine.

[0022] Fig.14 This is a graph showing the relationship between the monitoring area set around the construction machine and the indicated current value of the inverse proportional valve. DETAILED DESCRIPTION

[0023] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

[0024] Figure 1 and Figure 2 1 shows a hydraulic excavator, which is a construction machine equipped with a control device according to an embodiment of the present invention. The hydraulic excavator includes a lower traveling body 10 that can travel on a ground G, an upper revolving body 12 mounted on the lower traveling body 10, a working device 14 mounted on the upper revolving body 12, and a working drive device.

[0025] The lower traveling body 10 includes a pair of right crawler tracks 11R and left crawler tracks 11L disposed on the right and left sides, respectively. The right crawler tracks 11R and the left crawler tracks 11L are respectively operated so that the lower traveling body 10 travels on the ground G.

[0026] The upper revolving body 12 includes a revolving frame 16 and a plurality of elements mounted on the revolving frame 16 . The plurality of elements include an engine room 17 accommodating an engine, a cab or a driver's cabin 18 , and a counterweight 19 constituting a rear end portion of the upper revolving body 12 .

[0027] The working device 14 includes a boom 21, an arm 22, and a bucket 24. The boom 21 is supported at the front end of the revolving frame 16 so as to be able to rise and fall. The arm 22 is connected to the distal end of the boom 21 so as to be able to rotate in the vertical direction relative to the boom 21. The bucket 24 is a distal attachment for performing excavation work, etc., and is mounted on the distal end of the arm 22 so as to be able to rotate in the vertical direction relative to the arm 22.

[0028] Figure 3 The hydraulic circuit, multiple object detectors, an alarm 62, a display device 64, and a controller 70 mounted on the hydraulic excavator are shown. The controller 70 is composed of, for example, a microcomputer, and controls the operation of each element included in the hydraulic circuit. On the other hand, the controller 70 is electrically connected to the multiple object detectors, the alarm 62, the display device 64, and together with these parts, constitutes a safety device.

[0029] The hydraulic circuit includes a pump unit 30 , a plurality of hydraulic actuators, a plurality of control valves, an operating device, a plurality of operating valves, and a plurality of pilot pressure sensors.

[0030] The pump unit 30 includes a plurality of hydraulic pumps including at least one main pump and a pilot pump. The plurality of hydraulic pumps are connected to an engine (not shown) as a driving source and are driven by power output from the engine to discharge hydraulic oil.

[0031] Each of the plurality of hydraulic actuators is a hydraulic actuator that operates a movable portion of the hydraulic excavator by receiving the supply of hydraulic oil from the pump unit 30 , and includes a plurality of working hydraulic cylinders, a swing motor 32 , a right travel motor 33 , and a left travel motor 34 .

[0032] The plurality of hydraulic cylinders for operation include Figure 1 The boom cylinder 26, the arm cylinder 27, and the bucket cylinder 28 are shown. The boom cylinder 26 receives the supply of hydraulic oil so that the boom 21 is extended and retracted relative to the upper revolving body 12 in a manner of rising and falling. The arm cylinder 27 receives the supply of hydraulic oil so that the arm 22 is extended and retracted relative to the boom 21 in a manner of rotating. The bucket cylinder 28 receives the supply of hydraulic oil so that the bucket 24 is extended and retracted relative to the arm 22 in a manner of rotating.

[0033] The rotary motor 32 includes a pair of right and left rotary ports, and is operated by supplying hydraulic oil to one of the right and left rotary ports to rotate the upper rotary body 12 in a direction corresponding to the port (right or left).

[0034] The right travel motor 33 includes a pair of right forward ports and right reverse ports, and is operated by supplying hydraulic oil to one of the right forward ports and the right reverse ports, so that the right crawler 11R moves in the direction corresponding to the port (forward direction or reverse direction). Similarly, the left travel motor 34 includes a pair of left forward ports and left reverse ports, and is operated by supplying hydraulic oil to one of the left forward ports and the left reverse ports, so that the left crawler 11L moves in the direction corresponding to the port (forward direction or reverse direction).

[0035] The plurality of control valves are valves that can perform opening and closing actions in a manner capable of controlling the actions of each of the plurality of hydraulic actuators. The plurality of control valves include Figure 3 The swing control valve 36, the right travel control valve 37 and the left travel control valve 38 are shown.

[0036] The swing control valve 36 is interposed between the pump unit 30 and the swing motor 32, and performs an opening and closing action to change the direction and flow rate (swing flow rate) of the working oil supplied from the pump unit 30 to the swing motor 32. The swing control valve 36 is composed of a pilot-operated directional switching valve including a right swing pilot port and a left swing pilot port. If a pilot pressure is input to the right swing pilot port, the swing control valve 36 opens in a manner that allows the working oil to be supplied to the right swing port of the swing motor 32 at a flow rate (right swing flow rate) corresponding to the magnitude of the pilot pressure. On the contrary, if a pilot pressure is input to the left swing pilot port, the swing control valve 36 opens in a manner that allows the working oil to be supplied to the left swing port of the swing motor 32 at a flow rate (left swing flow rate) corresponding to the magnitude of the pilot pressure.

[0037] The right travel control valve 37 is interposed between the pump unit 30 and the right travel motor 33, and performs an opening and closing action to change the direction and flow rate (right travel flow rate) of the working oil supplied from the pump unit 30 to the right travel motor 33. The right travel control valve 37 is composed of a pilot-operated direction switching valve including a right forward pilot port and a right reverse pilot port. If a pilot pressure is input to the right forward pilot port, the right travel control valve 37 opens in a manner that allows the working oil to be supplied to the right forward port of the right travel motor 33 at a flow rate (right forward flow rate) corresponding to the magnitude of the pilot pressure. On the contrary, if a pilot pressure is input to the right reverse pilot port, the right travel control valve 37 opens in a manner that allows the working oil to be supplied to the right reverse port of the right travel motor 33 at a flow rate (right reverse flow rate) corresponding to the magnitude of the pilot pressure.

[0038] The left travel control valve 38 is interposed between the pump unit 30 and the left travel motor 34, and performs an opening and closing action to change the direction and flow rate (left travel flow rate) of the working oil supplied from the pump unit 30 to the left travel motor 34. The left travel control valve 38 is composed of a pilot-operated direction switching valve including a left forward pilot port and a left reverse pilot port. If a pilot pressure is input to the left forward pilot port, the left travel control valve 38 opens in a manner that allows the working oil to be supplied to the left forward port of the left travel motor 34 at a flow rate (left forward flow rate) corresponding to the magnitude of the pilot pressure. On the contrary, if a pilot pressure is input to the left reverse pilot port, the left travel control valve 38 opens in a manner that allows the working oil to be supplied to the left reverse port of the left travel motor 34 at a flow rate (left reverse flow rate) corresponding to the magnitude of the pilot pressure.

[0039] The plurality of control valves further include a boom control valve, an arm control valve, and a bucket control valve (not shown) provided for the boom cylinder 26 , the arm cylinder 27 , and the bucket cylinder 28 , respectively.

[0040] The operating device is an operating device that receives an operation for operating the hydraulic excavator and inputs an operation signal to the controller 70. The operating device includes a plurality of operators corresponding to the plurality of control valves. Each of the plurality of operators is constituted by a so-called remote control valve connected to the pilot pump, and opens the valve in a manner that allows a pilot pressure corresponding to the operation applied to the remote control valve to be applied to the corresponding control valve.

[0041] The operation applied to the operating device includes a plurality of control object operations that are the objects of safety control. In the present embodiment, the plurality of control object operations include a swivel operation for swivel the upper swivel body 12 relative to the lower traveling body 10, and a right walking operation and a left walking operation for respectively moving the right crawler 11R and the left crawler 11L, and the right walking operation and the left walking operation are equivalent to a walking operation for moving the lower traveling body 10.

[0042] Figure 3 The slewing operator 42, the right travel operator 43, and the left travel operator 44 to which the control object operation is applied are shown among the plurality of operators.

[0043] The swing operator 42 includes a swing rod and a swing pilot valve connected to the swing rod. The swing pilot valve opens to supply a pilot pressure corresponding to the magnitude of the swing operation to the pilot ports corresponding to the direction of the swing operation applied to the swing rod, among the right swing pilot port and the left swing pilot port of the swing control valve 36. The right travel operator 43 includes a right travel rod and a right travel pilot valve connected to the right travel rod. The right travel pilot valve opens to supply a pilot pressure corresponding to the magnitude of the right travel operation to the pilot ports corresponding to the direction of the right travel operation applied to the right travel rod, among the right forward pilot port and the left forward pilot port of the right travel control valve 37. Similarly, the left travel operator 44 includes a left travel rod and a left travel pilot valve connected to the left travel rod. The left travel pilot valve opens to supply a pilot pressure corresponding to the magnitude of the left travel operation to the left forward pilot port of the left travel control valve 38 and the pilot port in the left forward pilot port corresponding to the direction of the left travel operation applied to the left travel rod.

[0044] The plurality of operators include a boom operator, an arm operator, and a bucket operator in addition to the swing operator 42, the right travel operator 43, and the left travel operator 44. The boom operator is subjected to a boom operation for moving the boom 21 and allows a pilot pressure to be supplied to the boom control valve. The arm operator is subjected to an arm operation for moving the arm 22 and allows a pilot pressure to be supplied to the arm control valve. The bucket operator is subjected to a bucket operation for moving the bucket 24 and allows a pilot pressure to be supplied to the bucket control valve. Although the boom operation, the arm operation, and the bucket operation are all operations for moving the working device 14, they are excluded from the control object operation in the present embodiment.

[0045] The multiple operating valves are respectively disposed between the swing operator 42, the right travel operator 43, the left travel operator 44, and the swing control valve 36, the right travel control valve 37, and the left travel control valve 38 corresponding to these operators, so that the swing pilot pressure and the right travel pilot pressure and the left travel pilot pressure can be limited by the controller 70. Specifically, the multiple operating valves are each composed of an electromagnetic pressure reducing valve, which limits the pilot pressure to a degree corresponding to the value of the limiting instruction, i.e., the indicated current, input to the pressure reducing valve. The pressure reducing valves involved in this embodiment are each electromagnetic inverse proportional pressure reducing valves, and the larger the limiting instruction, the greater the degree to which the pressure reducing valve limits the pilot pressure. The pressure reducing valve may also be an electromagnetic proportional pressure reducing valve.

[0046] Specifically, the plurality of operating valves include Figure 3The illustrated valves include a right swing operation valve 46R and a left swing operation valve 46L, a right forward travel operation valve 47F and a right reverse travel operation valve 47B, and a left forward travel operation valve 48F and a left reverse travel operation valve 48B.

[0047] The right swing operation valve 46R is interposed between the swing operator 42 and the right swing pilot port of the swing control valve 36, and operates in such a manner that the right swing pilot pressure input from the swing operator 42 to the right swing pilot port is limited to a degree corresponding to the right swing restriction command input from the controller 70 to the right swing operation valve 46R. Similarly, the left swing operation valve 46L is interposed between the swing operator 42 and the left swing pilot port of the swing control valve 36, and operates in such a manner that the left swing pilot pressure input from the swing operator 42 to the left swing pilot port is limited to a degree corresponding to the left swing restriction command input from the controller 70 to the left swing operation valve 46L.

[0048] The right forward travel operation valve 47F is interposed between the right travel operator 43 and the right forward pilot port of the right travel control valve 37, and operates in such a manner that the right forward pilot pressure inputted from the right travel operator 43 to the right forward pilot port is limited to a degree corresponding to the right forward travel restriction instruction inputted from the controller 70 to the right forward travel operation valve 47F. Similarly, the right reverse travel operation valve 47R is interposed between the right travel operator 43 and the right reverse pilot port of the right travel control valve 37, and operates in such a manner that the right reverse pilot pressure inputted from the right travel operator 43 to the right reverse pilot port is limited to a degree corresponding to the right reverse travel restriction instruction inputted from the controller 70 to the right reverse travel operation valve 47R.

[0049] The left forward travel operation valve 48F is interposed between the left travel operator 44 and the left forward pilot port of the left travel control valve 38, and operates in such a manner that the left forward pilot pressure inputted from the left travel operator 44 to the left forward pilot port is limited to a degree corresponding to the left forward travel restriction command inputted from the controller 70 to the left forward travel operation valve 48F. Similarly, the left reverse travel operation valve 48R is interposed between the left travel operator 44 and the left reverse pilot port of the left travel control valve 38, and operates in such a manner that the left reverse pilot pressure inputted from the left travel operator 44 to the left reverse pilot port is limited to a degree corresponding to the left reverse travel restriction command inputted from the controller 70 to the left reverse travel operation valve 48R.

[0050] Each of the plurality of pilot pressure sensors is an operation amount detector that detects the magnitude (operation amount) of each of the swing operation, the right travel operation, and the left travel operation. Specifically, each of the plurality of pilot pressure sensors is composed of a pressure sensor, detects the pilot pressures respectively input to the swing control valve 36, the right travel control valve 37, and the left travel control valve 38, and inputs a detection signal corresponding to the magnitude of the pilot pressure, that is, a detection signal corresponding to the object operation amount, to the controller 70. Specifically, the plurality of pilot pressure sensors include a right swing pilot pressure sensor 52R that detects the right swing pilot pressure, a left swing pilot pressure sensor 52L that detects the left swing pilot pressure sensor, a right forward pilot pressure sensor 53F that detects the right forward pilot pressure, a right reverse pilot pressure sensor 53B that detects the right reverse pilot pressure, a left forward pilot pressure sensor 54F that detects the left forward pilot pressure, and a left reverse pilot pressure sensor 54B that detects the left reverse pilot pressure.

[0051] In the hydraulic circuit, the swing motor 32, the swing control valve 36, the right swing operation valve 46R, and the left swing operation valve 46L together with the pump unit 30 constitute a swing drive circuit for swinging the upper swing body 12. Similarly, the right travel motor 33, the right travel control valve 37, the right forward travel operation valve 47F, and the right backward travel operation valve 47B together with the pump unit 30 constitute a right travel drive circuit for actuating the right crawler 11R, and the left travel motor 34, the left travel control valve 38, the left forward travel operation valve 48F, and the left backward travel operation valve 48B together with the pump unit 30 constitute a left travel drive circuit for actuating the left crawler 11L.

[0052] The plurality of object detectors are respectively arranged at specific locations of the hydraulic excavator, detect detection objects existing around the hydraulic excavator, and generate detection signals that can obtain position information related to the detection objects, and input the detection signals to the controller 70. The position information includes the object distance, which is the distance from the specific location to the detection object. In the present embodiment, the plurality of object detectors are each composed of an imaging device such as a single-lens camera or a stereo camera, and generate a captured image including the detection object.

[0053] Specifically, the plurality of object detectors according to the present embodiment are arranged on the upper rotating body 12, including Figure 2The right object detector 60R, the left object detector 60L, and the rear object detector 60B are shown. The right object detector 60R is arranged at the right side of the upper rotating body 12 so that it can detect at least the detection object located on the right side of the upper rotating body 12. The left object detector 60L is arranged at the left side of the upper rotating body 12 so that it can detect at least the detection object located on the left side of the upper rotating body 12. The rear object detector 60B is arranged at the rear end of the upper rotating body 12 so that it can detect at least the detection object located behind the upper rotating body 12.

[0054] When the alarm command is input from the controller 70 to the alarm 62, the alarm 62 sounds an alarm. The alarm 62 may be an alarm that sounds an alarm, such as a buzzer, or an alarm that sounds an alarm using light, such as an alarm lamp.

[0055] The display device 64 has a screen that can display an image of the surroundings including the detection object, and is disposed in the cockpit 18 so that the operator can see the screen. The display device 64 displays an image corresponding to a display instruction signal input from the controller 70 .

[0056] The controller 70 determines whether there is a detection object around the hydraulic excavator based on the image signals input from the object detectors 60R, 60L, and 60B, and determines the detection distance when the detection object exists, and performs safety control when the detection distance is less than a preset allowable distance. The detection distance is the distance from the reference position to the detection object, that is, the detected object distance. In this embodiment, the reference position is the position where the object detectors 60R, 60L, and 60B are respectively arranged, that is, the position of the specific part. Therefore, the detection distance involved in this embodiment is the object distance from the object detectors 60R, 60L, and 60B to the detection object detected by the object detectors 60R, 60L, and 60B.

[0057] In the present embodiment, the safety control includes speed limit control, alarm control and display control. The speed limit control is a control for limiting the speed of a pre-set restricted object action in the action of the hydraulic excavator according to the detection distance, and may also include a control for setting the speed to 0, that is, a stop control for forcibly stopping the restricted object action. In the present embodiment, the restricted object action at least includes the rotation action of the upper rotating body 12 relative to the lower walking body 10, and according to the situation, also includes the walking action performed by the right crawler 11R and the left crawler 11L. Alternatively, the restricted object action may also include the action of the working device 14, for example, including the ups and downs action of the boom 21 and the rotation action of the arm 22. The alarm control is a control for causing the alarm device 62 to issue the alarm based on the detection of the detection object. The display control is a control for causing the display device 64 to display a warning image based on the detection of the detection object. The warning image is, for example, a captured image captured by the object detectors 60R, 60L, and 60B, that is, a peripheral image of the detection object.

[0058] The controller 70 has the following features: Figure 4 The plurality of functions shown in the figure are used to perform the safety control, and the plurality of functions include a position information generating unit 72, a safety control determining unit 74, a swing restriction command unit 76, a travel restriction command unit 78, an alarm command unit 82, and a display command unit 84. For example, a CPU (Central Processing Unit) included in the controller 70 executes a program pre-stored in a memory included in the controller 70, thereby realizing these functions.

[0059] The position information generating unit 72 periodically (specifically, every time a preset sampling period passes) obtains the image signals inputted from the object detectors 60R, 60L, and 60B, respectively, and processes the image signals. Thus, the position information generating unit 72 determines whether there is a detection object within the imaging range of the object detectors 60R, 60L, and 60B, and determines a distance value corresponding to the detection distance when there is a detection object, and generates position information including the position of the detection object and the distance value. The detection distance is the object distance, and in the present embodiment, it is the distance from the position where the object detectors 60R, 60L, and 60B are respectively arranged to the detection object. In this way, the position information generating unit 72 and the object detectors 60R, 60L, and 60B together constitute a position information acquiring unit that periodically acquires the position information. The detection object preferably includes at least a person (operator), and may also include objects other than a person.

[0060] The safety control determination unit 74 determines whether the safety control needs to be performed and determines the content of the safety control based on the position information generated by the position information generation unit 72. Specifically, when the safety control is determined to be necessary, the safety control determination unit 74 of this embodiment determines the action to be speed-limited and determines the degree of speed limitation of the restricted object action corresponding to the detection distance. The speed limitation also includes forced stop.

[0061] The safety control determination unit 74 also stores a preset change suppression condition, and performs control change suppression only when the position information periodically generated by the position information generation unit 72 satisfies the change suppression condition. The change suppression condition is a condition preset in order to determine whether the control change suppression is required, and includes the following condition, namely, the current information changes in a direction away from the hydraulic excavator compared with the previous information. The current information is the position information obtained this time, and the previous information is the information obtained last time (in the previous sampling cycle) of the current information, that is, the position information obtained last time. That is, the change suppression condition involved in this embodiment includes: the detection distance increases. The control change suppression refers to suppressing the change of the safety control corresponding to the change of the position information (the increase of the detection distance), which contributes to the stabilization of the safety control. The control change suppression involved in this embodiment is to maintain the safety control based on the previous information regardless of the current information.

[0062] The safety control determination unit 74 further releases the control change suppression at a preset suppression release time point. The suppression release time point is a time point when a predetermined time has passed after the start of the control change suppression. In this embodiment, it is a time point when the position information has been acquired a predetermined number of times after the start of the control change suppression. Therefore, the predetermined time involved in this embodiment is a time obtained by multiplying the sampling period by the predetermined number of times.

[0063] The swing restriction instruction unit 76 generates a swing restriction instruction signal. The swing restriction instruction signal is a signal for executing the swing restriction control in the safety control determined by the safety control determination unit 74. Specifically, when the control for limiting the speed of the right swing action or the left swing action has been determined, it is a signal for limiting the speed (including forced stop) by the restriction degree determined for the restriction of the speed (swing speed). The swing restriction instruction unit 76 inputs the swing restriction instruction signal to the operating valve corresponding to the restricted object action among the right swing operation valve 46R and the left swing operation valve 46L (the right swing operation valve 46R when the right swing action is restricted).

[0064] The travel restriction instruction unit 78 generates a travel restriction instruction signal. The travel restriction instruction signal is a signal for executing the travel restriction control in the safety control determined by the safety control determination unit 74. Specifically, when the control for limiting the speed of the forward walking action or the backward walking action is determined, it is a signal for limiting the speed (including forced stop) by the restriction degree determined for the restriction of the speed (walking speed). The travel restriction instruction unit 78 inputs the swing restriction instruction signal to the operating valve corresponding to the restriction object action to be restricted among the right forward walking operation valve 47F, the right backward walking operation valve 47B, the left forward walking operation valve 48F and the left backward walking operation valve 48B (the right backward walking operation valve 47B and the left forward walking operation valve 48B when the backward walking action is restricted).

[0065] When the safety control determination unit 74 determines that the safety control is necessary, the alarm instruction unit 82 generates an alarm instruction signal and inputs the alarm instruction signal to the alarm device 62 , thereby causing the alarm device 62 to sound an alarm.

[0066] When the safety control determination unit 74 determines that the safety control is necessary, the display instruction unit 84 generates a display instruction signal and inputs the display instruction signal to the display device 64 , thereby causing the display device 64 to display the warning image.

[0067] Next, refer to Figure 5 The flowchart further specifically illustrates the content of the safety control performed by the controller 70.

[0068] Each time the preset sampling period (e.g., 50 ms) passes (step S1 is "yes"), the position information generating unit 72 of the controller 70 obtains the image signal input from the object detectors 60R, 60L, 60B, and obtains the position information including the current distance value LX based on the image signal (step S2). In detail, the position information generating unit 72 generates the position information of the detected object by processing the image signal. The current distance value LX is a value obtained by digitizing the position information generated this time, i.e., the detection distance included in the current information. When a plurality of object detectors among the object detectors 60R, 60L, 60B detect the detected object at the same time, a value corresponding to the distance detected by the object detector closest to the detected object among the plurality of object detectors is used as the current distance value LX. In other words, the minimum value among the values ​​corresponding to the respective detection distances is used as the current distance value LX.

[0069] The safety control determination unit 74 of the controller 70 determines whether the preset change suppression condition is satisfied based on the obtained current distance value LX (steps S3 and S4). The change suppression condition is a condition set to determine the necessity of control change suppression. Specifically, if the current distance value LX is used to perform safety control based on the current distance value LX, there may be problems as described in detail below. Therefore, it is necessary to suppress changes in safety control corresponding to changes in the distance value. The change suppression condition is a condition set based on this viewpoint. The change suppression condition involved in this embodiment requires that the following two conditions A and condition B are both met.

[0070] (Condition A) The current distance value LX is greater than the previous distance value LXp (LX>LXp: "Yes" in step S3). The previous distance value LXp is the distance value obtained last time.

[0071] (Condition B) The difference between the current distance value LX and the previous distance value LXp exceeds a preset allowable distance difference ΔLxo (LX-LXp>ΔLXo: step S4: YES).

[0072] In other words, when the change suppression condition is not satisfied, the safety control as generally described is performed. Specifically, it is as follows.

[0073] First, when the current distance value LX does not exceed the previous distance value LXp (step S3 is "No"), that is, when the distance value does not change in the increasing direction (when the position information of the detection object does not change in the direction away from the reference position), the controller 70 performs control based on the current distance value LX (step S6) after clearing the detection count value CT to 0 (step S5). The detection count value CT is a value set to count the number of detections in each of the sampling cycles after the control change suppression starts. "The current distance value LX does not exceed the previous distance value LXp" not only includes the case where the current distance value LX is less than the previous distance value LXp (LX≤LXp), but also includes the following cases CS1 and CS2. The situation CS1 is a situation where neither the last distance value LXp nor the current distance value LX is obtained, that is, the object detectors 60R, 60L, and 60B did not detect the existence of the detection object either last time or this time. The situation CS2 is a situation where the current distance value LX is obtained for the first time but the last distance value LXp is not obtained, that is, the following situation: when the position information was obtained last time, the object detectors 60R, 60L, and 60B did not detect the existence of the detection object, but when the position information was obtained this time, the existence of the detection object was detected for the first time.

[0074] The "control based on the current distance value LX" (step S6) also includes a determination of whether safety control is required, which is based on the determination of whether the current distance value LX has been obtained. For example, when none of the object detectors 60R, 60L, and 60B detects the detection object, safety control is not performed. On the other hand, when the current distance value LX has been obtained and the current distance value LX is less than the previous distance value LXp, that is, when it is determined that the position of the detection object relative to the reference position has not changed or the detection object is close to the reference position, speed limit control, warning control, and display control based on the current distance value LX are performed.

[0075] Specifically, the safety control determination unit 74 stores, for example, relational information preset for the relationship between the distance value LX and the speed limit level in the form of a relational expression or a map, and determines the speed limit level corresponding to the distance value LX based on the relational information. In accordance with the speed limit level determined in the above manner, at least one of the swing limit instruction unit 76 and the travel limit instruction unit 78 of the controller 70 generates and outputs a limit instruction signal. The controller 70 may also be configured such that, even when the distance value LX is obtained, when the distance value LX exceeds the preset allowable distance value LXo, the speed limit is not performed. That is, the condition of LX>LXo may be set as the speed limit condition.

[0076] The safety control may be performed all the time when the distance value LX is obtained (i.e., when the detection object is detected), or the safety control may be performed only when the operation (slewing operation and traveling operation) detected by the pilot pressure sensors 52R, 52L, 53F, 53B, 54F, 54B is an operation in a direction that brings the hydraulic excavator closer to the detection object. Although the speed limit control may be performed for all the swing actions and the traveling actions, it is preferred to limit only the speed of the action that brings the upper swing body 12 (or the upper swing body 12 and the lower traveling body 11) closer to the detection object. For example, when Figure 2 In the posture shown, if only the right object detector 60R or the left object detector 60L detects the detection object, and the rear object detector 60B does not detect the detection object, the walking action may not be restricted. In this way, the action to be restricted is determined in consideration of the specific position of the detection object and the operation direction, which can suppress the reduction of workability caused by unnecessary action restrictions.

[0077] Even in the case where the distance value LX of this time is greater than the distance value LXp of the previous time, when the difference (=Lx-Lxp) is less than the allowable distance difference ΔLXo (step S4 is "No"), control based on the distance value LX of this time is still performed (step S6). That is, the control change suppression is not performed. The reason is that: when the difference is small, that is, when the change of the position information is small, even if the safety control based on the distance value LX of this time is performed, the change of the safety control is small, and no substantial problem (significant instability of the safety control) will occur. In other words, it is more desirable to set the allowable distance difference ΔLXo to a degree that does not cause such a problem. This can ensure the stability of the safety control and effectively suppress the decline in work efficiency.

[0078] On the other hand, when the change suppression condition is satisfied, that is, when the current distance value LX is greater than the previous distance value LXp (step S3 is "yes") and the difference (=LX-LXp) exceeds the allowable distance difference ΔLXo (step S4 is "yes"), the controller 70 performs the control change suppression until the acquisition of the position information in each sampling cycle is performed a prescribed number of times. Specifically, the controller 70 updates the value obtained by adding 1 to the detection count value CT as a new detection count value CT (self-increment of the detection count value CT: step S7), and performs control based on the previous distance value LXo until the detection count value CT updated in the above manner reaches a prescribed count value CTo (for example, 4) corresponding to the prescribed number of times (step S8 is "no" and step S9). For example, even if the distance value LX this time is significantly increased compared to the distance value LXo last time, that is, even if it is determined that the detection object has moved relatively significantly in a direction away from the reference position (that is, a safe direction) by considering only the position information obtained this time, the safety control based on the last distance value LXo corresponding to the position information obtained last time is continued. That is, the relaxation of the safety control is temporarily suspended. This can suppress the situation where the safety control becomes unstable due to the temporary confusion of the position information as described in detail below, and ensure higher safety.

[0079] At the time point when the detection times count value CT reaches the prescribed count value CTo (step S8 is "Yes"), that is, at the time point when the time obtained by multiplying the sampling period by the prescribed number of times has passed after the control change suppression started (suppression release time point), the controller 70 releases the control change suppression. Specifically, the controller 70 resets the detection times count value CT to 0 (step S5), and restarts the normal safety control based on the current distance value LX (step S6).

[0080] The effect of the control variation suppression will be described in more detail below.

[0081] The safety control is performed based on the periodically acquired position information as described above, but the position information is easily confused. In particular, when the object detectors 60R, 60L, and 60B are composed of relatively inexpensive imaging devices such as single-lens cameras, and the detection object is determined and the detection distance (the object distance from the reference position to the detection object) is measured by processing the image acquired by the imaging device, the possibility of confusion of the position information of the detection object becomes higher.

[0082] Specifically, the distance to the object is calculated based on the height and angle of the installation position of the single-lens camera and the position of the area in the captured image where the detection object is detected, or the distance to the object is calculated based on the position of a specific part of the detection object (such as the position of a person's feet), thereby realizing the distance measurement using the image processing of the camera. However, in either case, the measured value may have a large deviation. For example, in the distance measurement based on the position of a person's feet, the position of the foot may not be accurately extracted due to the influence of the ground or the background, resulting in a large deviation in the measurement result of the foot position. In addition, when a person's feet are hidden behind other objects and the position of the feet cannot be determined, the distance to the object is estimated based on the size of other parts of the human body (such as the head) and the position on the image. In this way, the estimated value is easily greatly affected by the relative relationship between the human body and the background or the orientation of the human body, and the deviation may further increase. Depending on the conditions, it is possible that the detection object is temporarily not detected even though it exists, or conversely, an object that does not exist is mistakenly detected.

[0083] In this way, the safety control that is implemented immediately and unconditionally in response to the position information that is prone to confusion is prone to become unstable. For example, in the case where the safety control includes the speed limit control, if the degree of speed restriction of the restricted object's movement changes in response to the confusion of the position information, the restricted object's movement is prone to become unsmooth. In addition, in the case where the safety control includes the alarm control or the display control, the warning action performed by the alarm or display may become discontinuous randomly. Moreover, when the object distance is erroneously detected as being in an increasing direction (a direction away from the reference position) even though the object distance has not changed or has decreased, the safety control may be inappropriately relaxed or interrupted.

[0084] Figure 6 The first example of the time change of the distance value LX obtained in the embodiment is shown. In the first example, the detection of the detection object is temporarily interrupted due to some reason due to an error in the specific period TL. In the first example, if the position information is temporarily confused due to the failure to detect the detection object as described above, and the speed limit control is performed according to the distance value LX, then Figure 7 As shown by the solid line in FIG. , during the specific period TL, no restriction instruction (in the same figure, a rotation restriction instruction) is temporarily generated, resulting in the following Figure 8 In the figure, the pilot pressure (rotation pilot pressure) shown in the figure is increased inappropriately, that is, the speed limit is not properly relaxed (accelerated). Figure 5 The safety control based on the last distance value LXp (step S9) shown in FIG. Figure 6The last distance value LXp shown by the dotted line in FIG. 1 can be independent of the temporary confusion of the position information, and Figure 7 Maintain the limit command (the rotation limit command in the same figure) as shown by the dotted line in the figure to prevent Figure 8 Inappropriate increase of the pilot pressure (swing pilot pressure) shown (inappropriate relaxation of the speed limit). In addition, when the safety control includes the alarm control or the display control, it is also possible to prevent the warning from being inappropriately interrupted due to confusion of the position information.

[0085] Fig. 9 A second example of the time change of the distance value obtained in the embodiment is shown. In the second example, the distance value temporarily increases erroneously during a plurality of periods. In the second example, if the position information is temporarily confused due to the erroneous measurement of the distance to the object, and the speed limit control is performed in accordance with the distance value LX, then Fig.10 As shown by the solid line in , the limit command (the swing limit command in the same figure) will temporarily decrease (that is, the speed limit will be relaxed), which may cause an inappropriate increase in the pilot pressure (the swing pilot pressure in the same figure) as in the first example. In contrast, by executing the control change suppression as described above, it is possible to temporarily increase the distance value LX regardless of the temporary increase in the distance value LX. Fig.10 The limit instruction (the rotation limit instruction in the same figure) is kept fixed as shown by the dotted line in the figure to prevent inappropriate relaxation of the speed limit (i.e., acceleration). In addition, when the safety control includes the warning control, inappropriate interruption of the warning action can also be prevented as in the first example.

[0086] On the other hand, when the change suppression condition is not satisfied, in particular, when the current distance value LX is less than the previous distance value LXp ( Figure 5 If step S3 is "No", that is, if it is judged based on the previous information and the current information that the relative position of the detection object relative to the reference position has not changed or is closer to the reference position, the normal safety control based on the current distance value LX is performed (step S6), thereby ensuring high safety.

[0087] The instability of safety control caused by the confusion of position information as described above can also be solved by Fig.11 The distance value LX shown by the dotted line in FIG. 1 is smoothed (in the example of the same figure, it is a moving average) to suppress it, but in this case, it is difficult to ensure the safety obtained by the original safety control. Specifically, in Fig.11In the example shown, when the actual distance value LX shown by the solid line is LX1, the smoothed distance value shown by the dotted line becomes a value greater than the distance value LX1 by the amount indicated by the arrow A1 in the figure, and the safety control is accordingly relaxed. In addition, the timing of determining that the distance value LX has decreased to the value LX1 is delayed by a time T1 due to the moving average, which may cause the detection object to be closer to the construction machine accordingly. In contrast, the control change suppression is performed only when the change suppression condition is satisfied, which can ensure high safety ensured by the safety control and stabilize the safety control.

[0088] The present invention is not limited to the above-described embodiment. The present invention includes, for example, the following aspects.

[0089] (1) Regarding control change suppression

[0090] The control change suppression involved in the present invention is not limited to the control change suppression of the safety control based on the last distance value LX (last information) as described above, that is, it is not limited to the control change suppression of the last information. For example, in the case where the safety control includes the speed limit control, the control change suppression may be based on the position information obtained by weakening the change of the position information from the last information to the current information, thereby indirectly weakening the relaxation of the speed limit, or directly weakening the relaxation of the speed limit corresponding to the change from the last information to the current information.

[0091] Fig.12 An example of applying a so-called rate limiter that limits the rate of change of the swing limit instruction is shown as an example of directly weakening the relaxation of the speed limit itself. In the same figure, in the period TA when the swing limit instruction decreases with the passage of time and satisfies the change suppression condition, the time reduction rate of the swing limit instruction is suppressed below a fixed reduction rate, thereby smoothing the change of the swing limit instruction and suppressing the reduction of the swing limit instruction itself, thereby suppressing the relaxation of inappropriate restrictions. On the other hand, in the period TB when the swing limit instruction increases and does not satisfy the change suppression condition, the swing limit instruction calculated based on the acquired position information (this time information) is applied to the speed limit as it is, thereby ensuring high safety. Only when the change suppression condition is satisfied (only when the change suppression condition is satisfied) Fig.12 During the period TA in the example shown), other smoothing means are applied to the rotation restriction instruction, such as Fig.11 The moving average shown in FIG. 1 can thereby obtain the same effect as described above, or the position information (for example, Figure 6 , Fig. 9The distance value LX) shown is smoothed, thereby achieving the same effect as above.

[0092] Furthermore, the period during which the control change suppression is performed may not be a period set based on the number of detections as in the above-described embodiment, but may be a period set by time itself.

[0093] (2) Change suppression conditions

[0094] The change suppression conditions involved in the present invention only need to include at least the condition that the current information changes in the direction away from the reference position compared with the previous information (the condition A in the embodiment), and other conditions can be omitted or set arbitrarily. For example, the change suppression conditions can also include: the position information about the detection object related to the current information has been obtained more than a preset number of times, and this condition can be used instead of the condition B (the difference between the current distance value LX and the previous distance value LXp exceeds the allowable distance difference ΔLXo), or this condition can be added to the condition B. This can prevent the control change suppression from being inappropriately performed when the presence of the detection object is temporarily erroneously detected.

[0095] (3) Location Information and Location Information Acquisition Unit

[0096] The position information involved in the present invention can be any information related to the relative position of the detection object relative to the reference position set for the construction machinery, and may include only information related to the distance from the reference position to the detection object, i.e., the distance of the object, or other information. For example, a rotation angle sensor for detecting the rotation angle of the upper rotating body 12 relative to the lower traveling body 10 may be provided, and the position coordinates of the detection object may be determined based on the rotation angle detected by the rotation angle sensor.

[0097] The reference position is not necessarily the location where the object detector is installed. That is, the object distance is not necessarily the distance from the object detector to the detection object. The reference position may also be a position in the construction machinery that deviates from the location where the object detector is installed, or a position set around the construction machinery. For example, based on the detection signal generated by the object detector, the part of the construction machinery closest to the detection object may be determined, and the position of the part may be set as the reference position. That is, the reference position may also be set in a manner that always calculates the shortest distance as the object distance.

[0098] The object detector constituting the position information acquisition unit involved in the present invention is not limited to the object detector including the camera device. For example, in the case where the detection object is not particularly limited (that is, in the case where it is not necessary to determine the detection object), the object detector may also be a distance detector such as an infrared depth sensor or a millimeter wave radar. Alternatively, the object detector may not be a single-lens camera, but a camera device that can generate three-dimensional information, such as a stereo camera. However, in the case where the position information acquisition unit includes a combination of the camera device and image processing as described above, although there is an advantage of using an inexpensive camera device and being able to identify the detection object, on the other hand, confusion of the position information is easily generated. Therefore, it is more effective to apply the safety control and the control change suppression involved in the present invention.

[0099] (4) Speed ​​limit control

[0100] When speed limiting control is performed in the present invention, the specific means for performing the speed limiting control is not limited. For example, the swing operator 42 or the travel operator 43, 44 is an electric control lever device, that is, a device that generates an electric signal corresponding to the operation input by the operator and inputs the electric signal to the controller, and the controller operates the solenoid valves respectively between the pilot hydraulic source and the control valve (for example, the swing control valve 36 and the travel control valves 37, 38) based on the electric signal. In the construction machinery constructed in this way, the speed limiting (that is, suppressing the actual speed to a speed below the speed corresponding to the operation) can also be performed by changing the command input to the solenoid valve.

[0101] In the above embodiment, the speed limit control to be executed is determined based only on the object distance from the reference position to the detection object. However, in the present invention, the control unit may be configured in such a way that a monitoring area of ​​an arbitrary shape including a speed limit area is set around the construction machine, and the speed limit control is executed only when it is determined that the detection object exists in the speed limit area. In this case, the control unit may also maintain the safety control performed in the detection state in the monitoring area as the control change suppression when the detection object is detected in the monitoring area.

[0102] For example, the safety control determination unit 74 may be configured as follows: Figure 2The surroundings (rear and left and right sides) of the hydraulic excavator shown are set as right side areas AR1, AR2, rear areas AB1, AB2 and left side areas AL1, AL2 as shown by double-dotted lines corresponding to the detection ranges of the object detectors 60R, 60L, and 60B, respectively, and the action (rotating action or walking action) to which the speed should be limited (or should be forced to stop) is determined based on in which area the detection object exists.

[0103] Specifically, it is more ideal that, among the areas AR1, AR2, AB1, AB2, AL1, AL2, the areas AR1, AB1, AL1 which are the inner areas, i.e., the areas on the side close to the upper rotating body 12, are set as the stop areas Asp, and the areas AR2, AB2, AL2 which are the outer areas, i.e., the areas on the side away from the upper rotating body 12, are set as the speed limit areas Alm.

[0104] Or, if Fig.13 As shown in FIG. 1 , a single stop area Asp may be set around the hydraulic excavator, and a single speed limit area Alm may be set outside the stop area Asp.

[0105] In either case, it is desirable that the controller 70 stops in the stop area Asp (in Figure 2 When the detection object is detected in any one of the areas AR1, AB1, and AL1, a forced stop control is executed, i.e., a control for forcibly stopping the movement of the restricted object is performed as the safety control, and when the speed limit area A1m (in any one of the areas AR1, AB1, and AL1) is detected, a forced stop control is performed, i.e., a control for forcibly stopping the movement of the restricted object is performed as the safety control, and Figure 2 When the detection object is detected in any one of the areas AR2, AB2, and AL2), the speed limit control is performed as the safety control.

[0106] Fig.14 The example of the inverse proportional valve indicated current value corresponding to the stop area and the speed limit area set in the above manner is shown. The inverse proportional valve indicated current value is a limit instruction, i.e., an indicated current value, input from the controller 70 to each target inverse proportional valve, which is a valve that constitutes the plurality of operating valves ( Figure 3 The electromagnetic inverse proportional pressure reducing valve of the operating valve 46R, 46L, 47F, 47B, 48F, 48B) shown in the figure is used for Figure 2 or Fig.13 The operating valve shown is arranged to restrict the movement of the hydraulic excavator (construction machine).

[0107] like Fig.14As shown, in order to force the control object action of the engineering machinery to stop in the stop area Asp, the inverse proportional valve indicated current value is set to the maximum value. In order to limit the speed of the restricted object action to a greater extent as the object distance is smaller in the speed limit area Alm, in other words, in order to relax the speed limit of the restricted object action as the object distance increases, the inverse proportional valve indicated current value is set in such a way that the inverse proportional valve indicated current value gradually decreases from the maximum value as the object distance increases. In addition, in order to release the speed limit of the control object action in the area further outside than the monitoring area, the inverse proportional valve indicated current value is set to the minimum value.

[0108] In this example, it is desirable that the controller 70 also suppresses the relaxation of the speed limit of the restricted object action corresponding to the change from the previous information to the current information as the control change suppression. For example, it is desirable that, according to the previous information, the detection object is detected in the speed limit area A1m, and according to the current information, the object distance of the detection object increases compared with the previous information. In this case, the speed limit corresponding to the previous information is maintained as the control change suppression. In addition, it is desirable that, according to the previous information, the detection object is detected in the stop area Asp, and according to the current information, it has transitioned to a state where the detection object is not detected (including a state where the detection object is detected in the speed limit area A1m or a state where the detection object is detected outside the monitoring area). In this case, the control object action is continued to be forcibly stopped.

[0109] Furthermore, in either case, it is more desirable that the change suppression condition for executing the control change suppression includes: a difference between the object distance involved in the current information and the object distance involved in the previous information exceeds a preset allowable difference.

[0110] As described above, according to the present invention, a device capable of stably performing safety control related to construction machinery is provided. The provided safety device performs safety control of construction machinery, and the safety device includes a position information acquisition unit and a control unit. The position information acquisition unit periodically acquires position information related to the position of a detection object around the construction machinery. When the position information acquired this time, i.e., this time information, changes in a direction closer to the construction machinery compared to the position information acquired last time, i.e., last information, the control unit performs safety control corresponding to the current information, and when a change suppression condition is satisfied, performs control change suppression to suppress the change of the safety control corresponding to the change of the position information, the change suppression condition including: the current information changes in a direction away from the construction machinery compared to the last information. The control unit releases the control change suppression at a time point after a specified time has passed since the start of the control change suppression, for example, at a time point when the position information has been acquired a specified number of times.

[0111] When the change suppression condition is satisfied, the control change suppression is performed, so that even when the position information is not stably obtained, the safety of the construction machinery can be ensured and the stable safety control can be performed. For example, when the detection object is not detected temporarily despite the fact that the detection object actually exists, or when the position information temporarily changes in the direction of moving away despite the fact that the detection object is not actually away, the control unit does not unconditionally perform the safety control immediately corresponding to the change, but performs the control change suppression to suppress the change of the safety control (mitigate the change in the direction of the safety control) when the change suppression condition is satisfied, thereby stabilizing the safety control. Moreover, at a time point after a predetermined time has passed, for example, at a time point when the position information is obtained a predetermined number of times after the control change suppression starts, the control change suppression is released, thereby preventing the safety control based on the previous information from being excessively continued. On the other hand, when the position information changes in the direction of approaching the construction machinery, the safety control based on the current information is performed, thereby ensuring the high safety of the construction machinery.

[0112] Preferably, the safety control includes speed limit control. The speed limit control is a control for limiting the speed of the pre-set restricted object action in the action of the engineering machinery to a greater extent as the object distance is within a pre-set speed limit range, and the object distance is the distance from the reference position set for the engineering machinery to the detection object. The speed limit control may also include a control for setting the speed of the restricted object action to 0, that is, a stop control for forcibly stopping the restricted object action. The control change suppression corresponding to the speed limit control prevents the speed limit from being unnecessarily relaxed due to temporary confusion of the position information obtained, thereby suppressing the instability of the action of the engineering machinery and further improving safety. The control change suppression is to suppress the relaxation of the speed limit of the restricted object action corresponding to the change from the previous information to the current information.

[0113] It is more ideal that, when the engineering machinery includes a hydraulic circuit for performing the movement of the restricted object, and the hydraulic circuit is constructed in a manner so as to limit the movement of the restricted object according to a restriction instruction input into the hydraulic circuit, the control unit, when performing the speed limit control, generates the restriction instruction, inputs the restriction instruction into the hydraulic circuit, and suppresses changes in the restriction instruction as the control change suppression.

[0114] More specifically, it may be that, when the engineering machinery includes a lower traveling body and an upper rotating body rotatably mounted on the lower traveling body, and the hydraulic circuit includes a circuit for rotating the upper rotating body, the position information acquired by the position information acquisition unit includes information related to the distance to an object, the object distance is the distance from a reference position set for the upper rotating body to the detected object, the restricted object action includes at least the rotation action of the upper rotating body, and the restriction instruction includes a rotation restriction instruction for limiting the rotation action.

[0115] Alternatively, the safety control may be a control for causing an alarm device included in the safety device to sound an alarm. In this aspect, the control change suppression may also prevent the alarm from being inappropriately interrupted due to confusion in the acquired position information.

[0116] For the control change suppression, for example, it is effective to continue the safety control based on the previous information regardless of the current information, that is, to hold the previous information as the position information for determining the safety control.

[0117] Alternatively, when the safety control is the speed limit control, the control change suppression may limit the speed of the restricted object action based on the position information obtained by weakening the change from the previous information to the current information, or may directly weaken the relaxation of the speed limit of the restricted object action corresponding to the change from the previous information to the current information. For example, in a method in which the control unit inputs the restriction instruction to the hydraulic circuit, the control change suppression may be a limitation of the time change rate of the restriction instruction.

[0118] The change suppression condition may also include: the change from the previous information to the current information is large, specifically, the difference between the current information and the previous information exceeds a preset allowable difference. In other words, when the current information changes in a direction closer to the construction machinery than the previous information but the change is small, that is, when the safety control is changed with the change and the stability of the safety control is not greatly affected, the control change suppression may be temporarily suspended. This can prevent the decrease in operating efficiency caused by frequent control change suppression, i.e., the relaxation suppression of the safety control.

[0119] The change suppression condition may further include: the position information of the detection object related to the current information has been acquired a predetermined number of times or more. This can prevent the control change suppression from being inappropriately performed when the presence of the detection object is temporarily erroneously detected.

[0120] In the present invention, although the specific structure of the position information acquisition unit is not limited, it is particularly effective when the position information acquisition unit includes a camera device that generates a captured image including the detection object and a position information generation unit that generates the position information by processing the captured image. The position information acquired by processing the captured image generated by the camera device is prone to become unstable due to various factors, so the control change suppression that can perform stable safety control regardless of the instability of the position information becomes particularly effective.

[0121] The control unit may also execute the safety control when the detection object is detected in the monitoring area set around the engineering machine. In this case, it is more desirable that the control unit, when transitioning from the in-area detection state in which the detection object is detected in the monitoring area to the in-area non-detection state in which the detection object is not detected in the monitoring area, maintains the safety control performed in the in-area detection state as the control change suppression. This will suppress the safety control from being inappropriately stopped when the detection object is temporarily not detected in the monitoring area due to confusion in the acquired position information.

[0122] Specifically, it is more desirable that the monitoring area includes a stop area and a speed limit area, and when the detection object is detected in the stop area, the control unit performs a forced stop control as the safety control, and when the detection object is detected in the deceleration control area, the control unit performs a speed limit control as the safety control. The forced stop control is a control that forcibly stops the action of the restricted object set in advance in the action of the engineering machinery, and the control unit, the speed limit control is a control that limits the speed of the restricted object action to a greater extent as the object distance is smaller, and the object distance is the distance from the reference position set for the engineering machinery to the detection object. In this case, it may be that the control change suppression includes: suppressing the relaxation of the speed limit of the restricted object action corresponding to the change from the previous information to the current information.

[0123] In this case, preferably, the change suppression condition further includes: a difference between the object distance involved in the current information and the object distance involved in the previous information exceeds a preset allowable difference.

Claims

1. A safety device for engineering machinery, for safety control of engineering machinery, characterized in that include: a position information acquisition unit that periodically acquires position information related to the position of a detection target object around the construction machine; as well as Control unit, wherein The control unit, when the position information obtained this time, i.e., this information, changes in a direction closer to the construction machinery compared to the position information obtained last time, i.e., last information, performs the safety control corresponding to the information this time, and when a change suppression condition is satisfied, executes control change suppression for suppressing the change of the safety control corresponding to the change of the position information, and releases the control change suppression at a time point of a specified time after the start of the control change suppression, the change suppression condition including: the information this time changes in a direction away from the construction machinery compared to the last information.

2. The safety device for construction machinery according to claim 1, characterized in that: The control unit releases the control change suppression at a time when the position information is acquired a predetermined number of times after the control change suppression is started.

3. The safety device for construction machinery according to claim 1, characterized in that: The safety control includes speed limit control, wherein when the object distance is within a preset speed limit range, the smaller the object distance is, the greater the speed of the preset restricted object movement in the movement of the construction machine is limited, wherein the object distance is the distance from a reference position set for the construction machine to the detection object. The control change suppression includes suppressing relaxation of the speed restriction of the restriction target action corresponding to a change from the previous information to the current information.

4. The safety device for construction machinery according to claim 3, characterized in that: The construction machine includes a hydraulic circuit for performing the movement of the restriction object, wherein the hydraulic circuit restricts the movement of the restriction object according to a restriction command input into the hydraulic circuit. The control unit generates the limit command when performing the speed limit control, inputs the limit command to the hydraulic circuit, and suppresses a change in the limit command as the control change suppression.

5. The safety device for construction machinery according to claim 4, characterized in that: The construction machine includes a lower traveling body and an upper rotating body rotatably mounted on the lower traveling body. The hydraulic circuit includes a circuit for rotating the upper rotating body, the position information acquired by the position information acquisition unit includes information related to the distance of the object, the object distance is the distance from the reference position set for the upper rotating body to the detection object, the restricted object action includes at least the rotating action of the upper rotating body, and the restriction instruction includes a rotation restriction instruction for limiting the rotating action.

6. The safety device for construction machinery according to claim 1, characterized in that Also includes: Siren, where The safety control includes a control for causing the alarm to sound an alarm.

7. The safety device for construction machinery according to claim 1, characterized in that: The control change suppression is to continue the safety control based on the previous information regardless of the current information.

8. The safety device for engineering machinery according to claim 3, characterized in that: The control change suppression limits the speed of the restriction object action based on the position information obtained by reducing the change from the previous information to the current information.

9. The safety device for construction machinery according to claim 3, characterized in that: The control change suppression directly weakens the relaxation of the speed restriction of the restricted action corresponding to the change from the previous information to the current information.

10. The safety device for construction machinery according to claim 1, characterized in that: The change suppression condition further includes: a difference between the current information and the previous information exceeds a preset allowable difference.

11. The safety device for construction machinery according to claim 1, characterized in that: The change suppression condition further includes that the position information of the detection target object with respect to the current information has been acquired a predetermined number of times or more.

12. The safety device for construction machinery according to claim 1, characterized in that: The position information acquisition unit includes: an imaging device that generates a captured image including the detection target object; and a position information generation unit that generates the position information by processing the captured image.

13. The safety device for engineering machinery according to claim 1, characterized in that: The control unit executes the safety control when the detection object is detected in a monitoring area set around the construction machinery, and when transitioning from a detection state in which the detection object is detected in the monitoring area to a non-detection state in which the detection object is not detected in the monitoring area, maintains the safety control performed in the detection state in the area as the control change suppression.

14. The safety device for engineering machinery according to claim 13, characterized in that: The monitoring area includes a stop area and a speed limit area. When the detection object is detected in the stop area, the control unit performs forced stop control as the safety control, wherein the forced stop control is a control for forcibly stopping a movement of a predetermined restricted object in the movement of the construction machine. When the detection object is detected in the deceleration control area, the control unit performs speed limit control as the safety control, wherein the speed limit control is a control for limiting the speed of the restricted object movement to a greater extent as the object distance is smaller, the object distance being the distance from a reference position set for the construction machine to the detection object, The control change suppression includes suppressing relaxation of the speed restriction of the restriction target action corresponding to a change from the previous information to the current information.

15. The safety device for construction machinery according to claim 14, characterized in that: The change suppression condition further includes: a difference between the object distance involved in the current information and the object distance involved in the previous information exceeds a preset allowable difference.

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