Control device for revolving work machine

Abstract

Provided is a device capable of appropriately performing a control for inhibiting a turning body of a work machine and a monitoring object from mutual approach with a simple configuration. The device including a position information acquisition unit that acquires position information about a monitoring object and a control unit performing inhibition control for inhibiting mutual approach of the monitoring object and a turning body (12). During the rightward turning of the turning body (12), the control unit performs inhibition control only when the monitoring object is located in a rightward turning monitoring area (91, 92, 90) set so as to turn rightward integrally with the turning body (12) and suspends inhibition control when the monitoring object is not located in the rightward turning monitoring area. During the leftward turning of the turning body (12), the control unit performs the inhibition control only when the monitoring object is located in a leftward turning monitoring area, which is different from the rightward turning monitoring area and is set so as to turn leftward integrally with the turning body (12) and suspends the inhibition control when the monitoring object is not located in the leftward turning monitoring area.

Description

Technical Field

[0001] The present invention relates to a control device for a turning-type work machine.Background Art

[0002] Conventionally known is a device which performs a control, in a work machine with a turning body, such as a hydraulic excavator, for preventing the turning body from being brought into contact or proximity with a monitoring object around the work machine by the turning motion of the turning body. For example, it is described in Patent Literature 1 to activate a safety function when a monitoring object is detected in a predetermined area around an excavator. The safety function includes a notification function and a motion restriction function.

[0003] It is preferable that the activation of the safety function based on the detection of the monitoring object is performed only when it is necessary, for useless activation causes inconvenience. For example, frequent issues of alarm even in unnecessary case lowers the effect of the alarm, specifically, the effect of urging an operator or the like to alert. Besides, the excessive restriction of the motion of the work machine significantly lowers workability.

[0004] To inhibit such useless performance of safety function, it is described in Patent Document 1 to activate a safety function only when the monitoring object is present in the traveling direction of the vehicle for the traveling operation of the excavator and to prevent the safety function from being activated when the monitoring object is present in the direction opposite to the traveling direction (FIG. 7, FIG. 8A and FIG. 8B thereof). Patent Literature 1, however, indicates no disclosure about an appropriate control for preventing the turning body and the monitoring object from being brought into contact or proximity with each other by the turning motion of the turning body. It is unpreferable to employ complicated operations or large-scale equipment for achieving such control.Citation List Patent Literature

[0005] Patent Literature 1: Japanese Unexamined Patent Publication No. 2020-183624 (paragraphs

[0033] to

[0035] )Summary of Invention

[0006] It is an object of the present invention to provide a control device capable of appropriately performing a control for inhibiting a turning body of a work machine and a monitoring object from approaching each other with a simple configuration.(Means for Solving Problem)

[0007] Provided is a device for controlling a turning motion in a work machine including a support body and a turning body supported by the support body capably of the turning motion. The device includes: a position information acquisition unit that acquires position information on a relative position of a monitoring object to the turning body; and a control unit that performs an inhibition control for inhibiting the monitoring object and the turning body from approaching each other based on the position information. During a rightward turning of the turning body, the control unit performs the inhibition control only when the monitoring object is located in a rightward turning monitoring area that is set so as to turn rightward integrally with the turning body and suspends the inhibition control when the monitoring object is not located in the rightward turning monitoring area. During a leftward turning of the turning body, the control unit performs the inhibition control only when the monitoring object is located in a leftward turning monitoring area that is set so as to turn leftward integrally with the turning body and suspends the inhibition control when the monitoring object is not located in the leftward turning monitoring area.Brief Description of Drawings

[0008] FIG. 1 is a side view showing a hydraulic excavator, which is an example of a work machine according to an embodiment of the present invention. FIG. 2A is a plan view showing a rightward turning monitoring area that is set around the upper turning body of the hydraulic excavator. FIG. 2B is a plan view showing a leftward turning monitoring area that is set around the upper turning body of the hydraulic excavator. FIG. 3 is a block diagram showing a hydraulic circuit and a controller installed on the hydraulic excavator. FIG. 4 is a block diagram showing the main functions of the controller. FIG. 5 is a flowchart showing processing to be executed by the controller. FIG. 6 is a plan view showing another example of a rightward turning monitoring area and a leftward turning monitoring area that are set around the upper turning body. Detailed Description

[0009] Preferred embodiments of the present invention will be described with reference to the drawings.

[0010] FIG. 1, FIG. 2A and FIG. 2B show a work machine on which a control device according to an embodiment of the present invention is installed. The work machine illustrated therein is a hydraulic excavator, including a lower traveling body 10 capable of traveling on the ground G, an upper turning body 12 mounted on the lower traveling body 10, a work device 14 mounted on the upper turning body 12 and a work driving device.

[0011] The lower traveling body 10, which is an example of a support body, includes a pair of right crawlers 11R and a left crawler 11L disposed on the right and left, respectively. Each of the right and left crawlers 11R and 11L make motions so as to cause the lower traveling body 10 to travel on the ground G.

[0012] The upper turning body 12, which is an example of a turning body, is supported by the lower traveling body 10 capably of turning motion around a vertical turning axis 13. The upper turning body 12 includes a turning frame 16 and a plurality of elements mounted thereon. The plurality of elements include an engine room 17 that accommodates an engine, and a cab 18. The cab 18 is an example of an operation room that allows an operator to get thereon, and the operation room may be, for example, a canopy type in which at least a part of side walls are omitted. The turning motion includes a rightward turning motion of turning rightward and a leftward turning motion of turning leftward when viewed from an operator in the cab 18.

[0013] The work device 14 includes a boom 21, an arm 22, and a bucket 24. The boom 21 is supported by a front end of the turning frame 16 capably of derricking motion. The arm 22 is connected to the distal end of the boom 21 capably of vertically rotational motion with respect to the boom 21. The bucket 24 is a tip attachment for performing excavation work or the like, attached to the distal end of the arm 22 capably of vertically rotational motion with respect to the arm 22.

[0014] FIG. 3 shows a hydraulic circuit installed on the work machine, a plurality of object detectors, an operation lock device 61, an alarm device 62, a display device 64 and a controller 70. The controller 70 is composed of, for example, a microcomputer to control respective operations of the elements included in the hydraulic circuit. Meanwhile, the controller 70 is electrically connected to the plurality of object detectors, the alarm device 62 and the display device 64, constituting a control device in association therewith.

[0015] The hydraulic circuit includes a pump unit 30, a plurality of hydraulic actuators, a plurality of control valves, an operation device, a plurality of operation valves and a plurality of pilot pressure sensors.

[0016] The pump unit 30 includes a plurality of hydraulic pumps, which include at least one main pump and a pilot pump. The plurality of hydraulic pumps are connected to a non-illustrated engine as a drive source to be driven by power that is output by the engine to thereby discharge hydraulic fluid.

[0017] The plurality of hydraulic actuators receive the supply of hydraulic fluid from the pump unit 30 to thereby actuate respective movable parts of the work machine, including: a plurality of work hydraulic cylinders shown in FIG. 1, namely, a boom cylinder 26, an arm cylinder 27 and a bucket cylinder 28; and a turning motor 32, a right traveling motor 33 and a left traveling motor 34 which are shown in FIG. 3.

[0018] The boom cylinder 26 is expanded and contracted by the supply of hydraulic fluid thereto, so as to make the boom 21 perform the derricking motion with respect to the upper turning body 12. The arm cylinder 27 is expanded and contracted by the supply of hydraulic fluid thereto, so as to bring the arm 22 into vertically rotational motion with respect to the boom 21. The bucket cylinder 28 is expanded and contracted by the supply of hydraulic fluid thereto, so as to bring the bucket 24 into vertically rotational motion with respect to the arm 22.

[0019] The turning motor 32 includes a pair of rightward turning port and a leftward turning port, to one of which hydraulic fluid is supplied to thereby operate the turning motor 32 to turn the upper turning body 12 in a direction corresponding to the port to which the hydraulic fluid is supplied (a rightward turning direction or a leftward turning direction).

[0020] The right traveling motor 33 includes a pair of right advance ports and a right reverse port, to one of which hydraulic fluid is supplied to thereby operate the right traveling motor 33 to actuate the right crawler 11R in a direction corresponding to the port to which the hydraulic fluid is supplied (advance direction or reverse direction). Similarly, the left traveling motor 34 includes a pair of left advance ports and a left reverse port, to one of which hydraulic fluid is supplied to thereby operate the left traveling motor 34 to actuate the left crawler 11L in a direction corresponding to the port to which the hydraulic fluid is supplied (advance direction or reverse direction).

[0021] The plurality of control valves make respective opening and closing motions so as to enable respective movements of the plurality of hydraulic actuators to be controlled, respectively. The plurality of control valves include a turning control valve 36, a right traveling control valve 37 and a left traveling control valve 38 shown in FIG. 3.

[0022] The turning control valve 36 makes opening and closing motions so as to change the direction and flow rate (turning flow rate) of the hydraulic fluid supplied from the pump unit 30 to the turning motor 32. The turning control valve 36 is composed of a pilot-operated direction selector valve including a rightward turning pilot port and a leftward turning pilot port, configured to be opened by input of a pilot pressure to the rightward turning pilot port so as to allow hydraulic fluid to be supplied to the rightward turning port of the turning motor 32 at a flow rate (rightward turning flow rate) corresponding to the magnitude of the pilot pressure, and configured to be opened, reversely, by input of a pilot pressure to the leftward turning pilot port so as to allow hydraulic fluid to be supplied to the leftward turning port of the turning motor 32 at a flow rate (leftward turning flow rate) corresponding to the magnitude of the pilot pressure.

[0023] The right traveling control valve 37 makes opening and closing motions so as to change the direction and flow rate (right traveling flow rate) of the hydraulic fluid supplied from the pump unit 30 to the right traveling motor 33. The right traveling control valve 37 is composed of a pilot-operated direction selector valve including a right advance pilot port and a right reverse pilot port, configured to be opened by input of a pilot pressure to the right advance pilot port so as to allow hydraulic fluid to be supplied to the right advance port of the right traveling motor 33 at a flow rate (right advance flow rate) corresponding to the magnitude of the pilot pressure, and configured to be opened, reversely, by input of a pilot pressure to the right reverse pilot port so as to allow hydraulic fluid to be supplied to the right reverse port of the right traveling motor 33 at a flow rate (right reverse flow rate) corresponding to the magnitude of the pilot pressure.

[0024] The left traveling control valve 38 makes opening and closing motions so as to change the direction and flow rate (left traveling flow rate) of the hydraulic fluid supplied from the pump unit 30 to the left traveling motor 34. The left traveling control valve 38 is composed of a pilot-operated direction selector valve including a left advance pilot port and a left reverse pilot port, configured to be opened by input of a pilot pressure to the left advance pilot port so as to allow hydraulic fluid to be supplied to the left advance port of the left traveling motor 34 at a flow rate (left advance flow rate) corresponding to the magnitude of the pilot pressure, and configured to be opened, reversely, by input of a pilot pressure to the left reverse pilot port so as to allow hydraulic fluid to be supplied to the left reverse port of the left traveling motor 34 at a flow rate (left reverse flow rate) corresponding to the magnitude of the pilot pressure.

[0025] In addition to them, the plurality of control valves include a boom control valve, an arm control valve and a bucket control valve, which are provided for the boom cylinder 26, the arm cylinder 27 and the bucket cylinder 28, respectively.

[0026] The operation device is configured to receive an operation for moving the work machine and input an operation signal to the controller 70, including a plurality of operation units corresponding to the plurality of control valves, respectively. Each of the operation units is composed of a so-called remote control valve connected to the pilot pump, and configured to be opened so as to allow a pilot pressure corresponding to the operation applied to the remote control valve to be imparted to the corresponding control valve.

[0027] FIG. 3 shows a turning operation unit 42, a right traveling operation unit 43 and a left traveling operation unit 44, which are included in the plurality of operation units.

[0028] The turning operation unit 42 includes a turning lever and a turning pilot valve connected to the turning lever, and the turning pilot valve is opened so as to cause a pilot pressure having a magnitude corresponding to the magnitude of a turning operation applied to the turning lever to be supplied to the pilot port corresponding to the direction of the turning operation among the rightward turning and the leftward turning pilot ports of the turning control valve 36. The right traveling operation unit 43 includes a right traveling lever and a right traveling pilot valve connected to the right traveling lever, and the right traveling pilot valve is opened so as to cause a pilot pressure having a magnitude corresponding to the magnitude of a right traveling operation applied to the right traveling lever to be supplied to the pilot port corresponding to the direction of the right traveling operation among the right advance and the left advance pilot ports of the right traveling control valve 37. Similarly, the left traveling operation unit 44 includes a left traveling lever and a left traveling pilot valve connected to the left traveling lever, and the left traveling pilot valve is opened so as to cause a pilot pressure having a magnitude corresponding to the magnitude of a left traveling operation applied to the left traveling lever to be supplied to the pilot port corresponding to the direction of the left traveling operation among the left advance and the left advance pilot ports of the left traveling control valve 38.

[0029] The plurality of operation units include a boom operation unit, an arm operation unit and a bucket operation unit, in addition to the turning operation unit 42 and the right traveling and the left traveling operation units 43, 44. The boom operation unit receives a boom operation for moving the boom 21 to allow a pilot pressure to be supplied to the boom control valve. The arm operation unit receives an arm operation for moving the arm 22 to allow a pilot pressure to be supplied to the arm control valve. The bucket operation unit receives a bucket operation for moving the bucket 24 to allow a pilot pressure to be supplied to the bucket control valve. Either of the boom operation, the arm operation and the bucket operation is an operation for moving the work device 14.

[0030] The ones illustrated in FIG. 3 among the plurality of operation valves are interposed between the operation units including the turning operation unit 42, the right traveling operation unit 43 and the left traveling operation unit 44, and the control valves corresponding to the illustrated operation units, namely, the turning control valve 36, the right traveling control valve 37 and the left traveling control valve 38, respectively, enabling the turning pilot pressure and the right and left traveling pilot pressures to be limited by the controller 70. Specifically, each of the operation valves is composed of a solenoid pressure-reducing valve, which limits the pilot pressure at a degree corresponding to a limitation command input to the pressure-reducing valve. Each of the pressure-reducing valves is, for example, a solenoid reverse-proportional pressure-reducing valve (inverse proportional valve), which limits the pilot pressure at a degree increased with an increase in the limiting command (exciting current). The pressure reducing valve, alternatively, may be a solenoid proportional pressure reducing valve (proportional valve).

[0031] Specifically, the plurality of operation valves include, as shown in FIG. 3, a pair of rightward turning operation valve 46R and a leftward turning operation valve 46L, a pair of right advance traveling operation valve 47F and a right reverse traveling operation valve 47B, and a pair of left advance traveling operation valves 48F and a left reverse traveling operation valve 48B.

[0032] The rightward turning operation valve 46R is interposed between the turning operation unit 42 and the rightward turning pilot port of the turning control valve 36, and operates to limit the rightward turning pilot pressure to be input from the turning operation unit 42 to the rightward turning pilot port at a degree corresponding to a rightward turning restriction command input to the rightward turning operation valve 46R from the controller 70. Similarly, the leftward turning operation valve 46L is interposed between the turning operation unit 42 and the leftward turning pilot port of the turning control valve 36, and operates to limit the leftward turning pilot pressure to be input from the turning operation unit 42 to the leftward turning pilot port at a degree corresponding to a leftward turning restriction command input to the leftward turning operation valve 46L from the controller 70.

[0033] The right advance traveling operation valve 47F is interposed between the right traveling operation unit 43 and the right advance pilot port of the right traveling control valve 37, and operates to limit the right advance pilot pressure to be input from the right traveling operation unit 43 to the right advance pilot port at a degree corresponding to a right advance traveling restriction command input from the controller 70 to the right advance traveling operation valve 47F. Similarly, the right reverse traveling operation valve 47R is interposed between the right traveling operation unit 43 and the right reverse pilot port of the right traveling control valve 37, and operates to limit the right reverse pilot pressure to be input from the right traveling operation unit 43 to the right reverse traveling pilot port at a degree corresponding to a right reverse traveling restriction command input from the controller 70 to the right reverse traveling operation valve 47R.

[0034] The left advance traveling operation valve 48F is interposed between the left traveling operation unit 44 and the left advance pilot port of the left traveling control valve 38, and operates to limit a left advance pilot pressure to be input from the left traveling operation unit 44 to the left advance pilot port at a degree corresponding to a left advance traveling restriction command input to the left advance traveling operation valve 48F from the controller 70. Similarly, the left reverse traveling operation valve 48R is interposed between the left traveling operation unit 44 and the left reverse pilot port of the left traveling control valve 38, and operates to limit the left reverse pilot pressure to be input from the left traveling operation unit 44 to the left reverse traveling pilot port at a degree corresponding to a left reverse traveling restriction command input to the left reverse traveling operation valve 48R from the controller 70.

[0035] Each of the pilot pressure sensors is an operation amount detector for detecting the direction and size (operation amount) of each of the turning operation, the right traveling operation, and the left traveling operation. Specifically, the plurality of pilot pressure sensors, each composed of a pressure sensor, detect respective pilot pressures input to the turning control valve 36, the right traveling control valve 37, and the left traveling control valve 38 and input detection signals corresponding to the magnitude of the pilot pressures, that is, detection signals corresponding to respective target motion amounts, to the controller 70. Specifically, the plurality of pilot pressure sensors include: a rightward turning pilot pressure sensor 52R that detects the rightward turning pilot pressure, a leftward turning pilot pressure sensor 52L that detects the leftward turning pilot pressure, a right advance pilot pressure sensor 53F that detects the right advance pilot pressure, a right reverse pilot pressure sensor 53B that detects the right reverse pilot pressure, a left advance pilot pressure sensor 54F that detects the left advance pilot pressure, and a left reverse pilot pressure sensor 54B that detects the left reverse pilot pressure.

[0036] In the hydraulic circuit, the turning motor 32, the turning control valve 36, and the rightward turning and leftward turning operation valves 46R, 46L constitute a turning drive circuit for turning the upper turning body 12, in association with the pump unit 30. Similarly, the right traveling motor 33, the right traveling control valve 37 and the right advance and right reverse traveling operation valves 47F, 47B constitute a right traveling drive circuit for actuating the right crawler 11R, in association with the pump unit 30, and the left traveling motor 34, the left traveling control valve 38 and the left advance and left reverse traveling operation valves 48F, 48B constitute a left traveling drive circuit for moving the left crawler 11L, in association with the pump unit 30.

[0037] The plurality of object detectors are disposed on respective specific parts of the work machine, detecting a monitoring object present around the work machine, and generating a detection signal that enables position information containing a distance from the specific portion to the monitoring object to be acquired to input the detection signal to the controller 70. Each of the object detectors, composed of an imaging device such as a monocular camera or a stereo camera, generates a captured image including the monitoring object.

[0038] Specifically, in the example shown in FIG. 2, the plurality of object detectors include a right object detector 60R, a left object detector 60L and a rear object detector 60B, which are disposed on the upper turning body 12. The right object detector 60R is disposed on the right side part of the upper turning body 12 capably of detecting at least a monitoring object located on the right side of the upper turning body 12. The left object detector 60L is disposed on the left side part of the upper turning body 12 capably of detecting at least a monitoring object located on the left side of the upper turning body 12. The rear object detector 60B is disposed at a rear end part of the upper turning body 12 capably of detecting at least a monitoring object located on the rear side of the upper turning body 12.

[0039] The operation lock device 61 includes an operation lock lever and a command signal generator, which are not illustrated. The operation lock lever is, for example, a gate lock lever, which is provided so as to be shiftable between a close position (unlock position) for blocking the entrance of the cab 18, which is the operation room, and an open position (lock position) for opening the entrance. The command signal generator, which is composed of, for example, a lever position sensor that detects the position of the operation lock lever, generates an operation lock signal only when the operation lock lever is at the open position and inputs the operation lock signal to the controller 70. The operation lock signal is a signal for invalidating all the operations applied to the operation units, that is, disabling the motion of the work machine regardless of the presence or absence of the operation.

[0040] The alarm device 62 issues an alarm when an alarm command is input from the controller 70. The alarm is issued to an operator in order to inhibit the work machine and the monitoring object from approaching each other, as described in detail later. The alarm device 62 may be either a sound alarm, such as a buzzer, or a light alarm, such as a warning lamp.

[0041] The display device 64 has a screen capable of displaying a peripheral image including the monitoring object, disposed in the cab (driving chamber) 18 so as to allow an operator to visually recognize the screen. The display device 64 displays an image corresponding to a display command signal input from the controller 70.

[0042] The controller 70 makes judgment on the presence or absence of a monitoring object around the work machine and determination of the position of the monitoring object when the monitoring object is present, based on an image signal input from each of the object detectors 60R, 60L, 60B, and executes an inhibition control based on the determined position. The inhibition control is a control on a target motion to inhibit the work machine and the monitoring object from approaching each other (more specifically, preventing excessive approach). In the present embodiment, the target motion can include at least one of a traveling motion provided by the right crawler 11R and the left crawler 11L and a turning motion of the upper turning body 12 with respect to the lower traveling body 10.

[0043] The target motion, alternatively, may include the motion of the work device 14, for example, the derricking motion of the boom 21 and the rotational motion of the arm 22. Conversely, like the present embodiment, may be excluded the motion performed by the work device 14, in particular, the motion performed on the front side of the operation room (the cab 18 in the present embodiment) from the target motion. Thus suspending the work restriction control for inhibiting the mutual approach of the work device 14 and the monitoring object regardless of the presence or absence and the position of the monitoring object from being executed allows the frequency of the execution of control for restricting the motion of the work machine to be further lowered with securement of the safety of the work machine. The work restriction control includes not only a control for restricting the actual movement of the work device 14 but also, for example, a control for indirectly restricting the work motion by issuing an alarm to an operator to urge the operator to inhibit the work motion.

[0044] The position of the monitoring object detected by the object detectors 60R, 60L and 60B is, for example, the relative position of the monitoring object to a reference position set in the work machine. The reference position is, for example, each of the positions at which the object detectors 60R, 60L, 60B are disposed, respectively, that is, respective positions of the specific part.

[0045] The inhibition control according to the embodiment includes a forced stop control, an alarm control and a display control. The forced stop control is a control for forcibly stopping the target motion. The alarm control is a control for issuing an alarm for urging the inhibition of the target motion from the alarm device 62 to an operator. The display control is a control for making the display device 64 display a warning image based on the detection of the monitoring object.

[0046] The controller 70 includes a plurality of functions as shown in FIG. 4 for executing the inhibition control, the plurality of functions including a position information generation unit 72, an inhibition control judgment unit 74, a turning restriction command unit 76, a traveling restriction command unit 78, an alarm command unit 82, and a display command unit 84. The functions are provided by, for example, the execution of a program prestored in advance in the memory included in the controller 70 by the CPU included in the controller 70.

[0047] The position information generation unit 72 captures an image signal input from each of the object detectors 60R, 60L, 60B periodically (specifically, every time a preset sampling period has elapsed). The position information generation unit 72 processes the image signal to thereby make judgment on the presence or absence of the monitoring object within the imaging range of the object detectors 60R, 60L, 60B and determination of the relative position of the monitoring object to the reference position (i.e., respective positions at which the object detectors 60R, 60L, 60B are disposed in the present embodiment), that is, the relative position of the monitoring object to the work machine in the present embodiment, generating position information on the relative position. The position information generation unit 72, thus, constitutes a position information acquisition unit that acquires the position information in association with the object detectors 60R, 60L, 60B. The monitoring object preferably includes at least a person (worker) and may include an object other than a person.

[0048] The inhibition control judgment unit 74 judges the necessity of execution of the inhibition control based on the position information generated by the position information generation unit 72. Specifically, when judging the inhibition control to be necessary, the inhibition control judgment unit 74 determines a target motion to be the target of the inhibition control (at least one of the turning motion and the traveling motion in the present embodiment) and determines the control content corresponding to the target motion.

[0049] In the present embodiment, to judge the necessity of the execution of the inhibition control on the turning motion, a rightward turning monitoring area shown in FIG. 2A and a leftward turning monitoring area shown in FIG. 2B are set in advance, and the controller 70 stores information on the monitoring areas. The rightward turning monitoring area is a monitoring area to be used when the upper turning body 12 performs a rightward turning motion as shown in FIG. 2A, being set so as to turn rightward integrally with the upper turning body 12. Similarly, the leftward turning monitoring area is a monitoring area used when the upper turning body 12 performs a leftward turning motion, as shown in FIG. 2B, being set so as to turn leftward integrally with the upper turning body 12. Thus, the relative position of the upper turning body 12 to the rightward turning monitoring area and the leftward turning monitoring area is always kept constant regardless of the turning motion of the upper turning body 12.

[0050] During the rightward turning motion shown in FIG. 2A, the inhibition control judgment unit 74 determines the execution of the inhibition control only when the monitoring object is located in the rightward turning monitoring area whereas the inhibition control judgment unit 74 suspends the execution of the inhibition control when the monitoring object is not located in the rightward turning monitoring area. Similarly, during the leftward turning motion shown in FIG. 2B, the inhibition control judgment unit 74 determines the execution of the inhibition control only when the monitoring object is located in the leftward turning monitoring area, whereas the inhibition control judgment unit 74 suspends the execution of the inhibition control when the monitoring object is not located in the leftward turning monitoring area.

[0051] As shown in FIG. 2A, the rightward turning monitoring area includes a right front area portion 91, a left rear area portion 92 and a rear area portion 90. Similarly, the leftward turning monitoring area includes a left front area portion 93, a right rear area portion 94, and the rear area portion 90, as shown in FIG. 2B. The rear area portion 90, thus, is shared by the rightward turning monitoring area and the leftward turning monitoring area.

[0052] Both the right front area portion 91 of the rightward turning monitoring area and the right rear area portion 94 of the leftward turning monitoring area are set within the detection range of the right object detector 60R. Specifically, the inner end of the detection range of the right object detector 60R (the end closer to the right side surface of the upper turning body 12), indicated by a two-dot chain line 66R in FIG. 2A, defines respective inner surfaces of the right front area portion 91 and the right rear area portion 94. Hence, the monitoring object located in either of the right front area portion 91 and the right rear area portion 94 can be detected by the common right object detector 60R.

[0053] Similarly, both the left front area portion 93 of the leftward turning monitoring area and the left rear area portion 92 of the rightward turning monitoring area are set within the detection range of the left object detector 60L. Specifically, the inner end of the detection range of the left object detector 60L (the end on the side closer to the left side surface of the upper turning body 12), indicated by a two-dot chain line 66L in FIG. 2B, defines respective inner surfaces of the left front area portion 93 and the left rear area portion 92. Hence, the monitoring object in either of the left front area portion 93 and the left rear area portion 92 can be detected by the common left object detector 60L.

[0054] The rear area portion 90 shared by the rightward turning monitoring area and the leftward turning monitoring area is set within the detection range of the rear object detector 60B. Specifically, the inner surface of the detection range of the rear object detector 60B (the end on the side closer to the rear end surface of the upper turning body 12), indicated by a two-dot chain line 66B in FIGS. 2A and 2B, defines the inner surface of the rear area portion 90. Hence, the monitoring object located in the rear area portion 90 can be detected by the rear object detector 60B during either of the rightward turning motion and the leftward turning motion.

[0055] The right front area portion 91 of the rightward turning monitoring area is an area portion set on the right side of the right front side surface of the upper turning body 12, the right side surface being a part of the right side surface of the upper turning body 12, the part located on the front side (upper side in FIG. 2A in FIG. 2A) of the turning axis 13 in the front-rear direction of the upper turning body 12. The right front area portion 91 is defined mainly by the inner side surface, a rear end surface 91a, and an outer peripheral surface 91b.

[0056] The rear end surface 91a is a plane along a turning center surface 15, which is a vertical surface extending in the left-right direction of the upper turning body 12 through the turning axis 13 as indicated by a chain line in FIG. 2A. "Along the turning center surface 15" encompasses not only a mode in which the rear end surface 91a is coincident with the turning center surface 15 but also a mode in which the rear end surface 91a extends substantially parallel to the turning center surface 15 in the vicinity of the turning center surface 15. Hence, the right front area portion 91 may include, in addition to the part located on the right side of the right front side surface of the upper turning body 12, a part protruding rearward beyond the part. Thus setting the rear end surface 91a can lower the frequency of the execution of the inhibition control by excluding the rightward turning motion in a situation where the monitoring object is located on the rear side of the turning center surface 15 with poor possibility of the mutual approach of the monitoring object and the right rear side surface from the target of the inhibition control, while effectively inhibiting the right front side surface of the upper turning body 12 and the monitoring object from approaching each other due to the rightward turning motion of the upper turning body 12.

[0057] The outer peripheral surface 91b is a curved surface arc-shaped with the turning axis 13 as a center in a plan view, and the outer peripheral surface 91b is located on the outer side, in the turning radius direction of the upper turning body 12, of the turning trajectory of the right front corner part 121 of the upper turning body 12 during the rightward turning of the upper turning body 12. The outer peripheral surface 91b, thus, has a radius larger than the turning radius of the right front corner part 121. This allows the right front corner part 121 and the monitoring object located in the right front area portion 91 to be more reliably inhibited from approaching each other.

[0058] The left rear area portion 92 of the rightward turning monitoring area is an area portion set on the left side of the left rear side surface of the upper turning body 12, the left rear side surface being a part of the left side surface of the upper turning body 12, the part located on the rear side (lower side in FIG. 2A) of the turning axis 13 in the front-rear direction of the upper turning body 12. The left rear area portion 92 is defined mainly by the inner side surface, a front end surface 92a, and an outer peripheral surface 92b.

[0059] The front end surface 92a is a plane along the turning center surface 15. "Along the turning center surface 15" encompasses not only a mode in which the front end surface 92a is coincident with the turning center surface 15 but also a mode in which the front end surface 92a extends substantially parallel to the turning center surface 15 in the vicinity of the turning center surface 15. Hence, the left rear area portion 92 may include, in addition to the part located sideward of the left rear side surface of the upper turning body 12, a part protruding frontward beyond the part. Thus setting the front end surface 92a can lower the frequency of execution of the inhibition control by excluding the rightward turning motion in a situation where the monitoring object is located on the front side of the turning center surface 15 with no possibility of the mutual approach of the monitoring object and the left front side surface from the target of the inhibition control, while effectively inhibiting the left rear side surface of the upper turning body 12 and the monitoring object from approaching each other due to the rightward turning motion of the upper turning body 12.

[0060] The outer peripheral surface 92b is a curved surface arc-shaped with the turning axis 13 as a center in a plan view, and the outer peripheral surface 92b is located on the outer side, in the turning radius direction of the upper turning body 12, of the turning trajectory of the left rear corner part 122 of the upper turning body during the rightward turning of the upper turning body 12. The outer peripheral surface 92b, thus, has a radius larger than the turning radius of the left rear corner part 122. This enables the left rear corner part 122 and the monitoring object located in the left rear area portion 92 to be more reliably inhibited from approaching each other.

[0061] The left front area portion 93 of the leftward turning monitoring area is an area portion set on the left side of the left front side surface of the upper turning body 12, the left front side surface being a part of the left side surface of the upper turning body 12, the part located on the front side (upper side in FIG. 2B) of the turning axis 13 in the front-rear direction of the upper turning body 12. The left front area portion 93 is defined mainly by the inner side surface, a rear end surface 93a, and an outer peripheral surface 93b.

[0062] The rear end surface 93a is a plane along the turning center surface 15. "Along the turning center surface 15" encompasses not only a mode in which the rear end surface 93a is coincident with the turning center surface 15 but also a mode in which the rear end surface 93a extends substantially parallel to the turning center surface 15 in the vicinity of the turning center surface 15. Hence, the left front area portion 93 may include, in addition to the part located sideward of the left front side surface of the upper turning body 12, a portion protruding rearward beyond the part. Thus setting the rear end surface 93a can lower the frequency of execution of the inhibition control by excluding the leftward turning motion in a situation where the monitoring object is located on the rear side of the turning center surface 15 with no possibility of the mutual approach of the monitoring object and the left rear side surface from the target of the inhibition control, while effectively inhibiting the left front side surface of the upper turning body 12 and the monitoring object from approaching each other due to the leftward turning motion of the upper turning body 12.

[0063] The outer peripheral surface 93b is a curved surface arc-shaped with the turning axis 13 as a center in a plan view, the outer peripheral surface 93b being located on the outer side, in the turning radius direction of the upper turning body 12, of the turning trajectory of the left front corner part 123 of the upper turning body during the leftward turning of the upper turning body 12. The outer peripheral surface 93b, thus, has a radius larger than the turning radius of the left front corner part 123. This enables the left front corner part 123 and the monitoring object located in the left front area portion 93 to be more reliably inhibited from approaching each other.

[0064] The right rear area portion 94 of the leftward turning monitoring area is an area portion set on the right side of the right rear side surface of the upper turning body 12, the right rear side surface being a part of the right side surface of the upper turning body 12, the part located on the rear side (lower side in FIG. 2A) of the turning axis 13 with respect to the front-rear direction of the upper turning body 12. The right rear area portion 94 is defined mainly by the inner side surface, a front end surface 94a, and an outer peripheral surface 94b.

[0065] The front end surface 94a is a plane along the turning center surface 15. "Along the turning center surface 15" encompasses not only a mode in which the front end surface 94a is coincident with the turning center surface 15 but also a mode in which the front end surface 94a extends substantially parallel to the turning center surface 15 in the vicinity of the turning center surface 15. Hence, the right rear area portion 94 may include, in addition to the part located sideward of the right rear side surface of the upper turning body 12, a part protruding frontward beyond the part. Thus setting the front end surface 94a can lower the frequency of execution of the inhibition control by excluding the leftward turning motion in a situation where the monitoring object is located on the front side of the turning center surface 15 with no possibility of the mutual approach of the monitoring object and the right front side surface from the target of the inhibition control, while effectively inhibiting the right rear side surface of the upper turning body 12 and the monitoring object from approaching each other due to the leftward turning motion of the upper turning body 12.

[0066] The outer peripheral surface 94b is a curved surface arc-shaped with the turning axis 13 as a center in a plan view, the outer peripheral surface 94b being located on the outer side, in the turning radius direction of the upper turning body 12, of the turning trajectory of the right rear corner part 124 of the upper turning body during the leftward turning of the upper turning body 12. The outer peripheral surface 94b, thus, has a radius larger than the turning radius of the right rear corner part 124. This enables the right rear corner part 124 and the monitoring object located in the right rear area portion 94 to be more reliably inhibited from approaching each other.

[0067] The rear area portion 90 included in either of the leftward turning monitoring area and the rightward turning monitoring area is an area portion set on the rear side of the rear end surface of the upper turning body 12, mainly defined by the inner side surface and an outer peripheral surface 90b. The outer peripheral surface 90b is a curved surface arc-shaped with the turning axis 13 as a center in a plan view, the outer peripheral surface 90b being located on the outer side, in the turning radius direction of the upper turning body 12, of the turning trajectory of the right rear corner part 124 and the left rear corner part 123 of the upper turning body 12 during each of the rightward turning and the leftward turning of the upper turning body 12. The outer peripheral surface 90b, thus, has a radius larger than the turning radius of each of the right rear corner part 124 and the left rear corner part 123. This enables the right rear corner part 124 or the left rear corner part 123 and the monitoring object located in the rear area portion 90 to be inhibited from approaching each other.

[0068] The turning restriction command unit 76 generates a turning restriction command signal when the inhibition control judgment unit 74 determines the execution of the inhibition control for the turning motion. The turning restriction command signal is a signal for decelerating the turning motion that is designated as the target of the inhibition control out of the rightward turning motion and the leftward turning motion. Specifically, the turning restriction command unit 76 inputs the turning restriction command signal to the operation valve corresponding to the turning motion in the direction to be the target of the forced stop control out of the rightward turning operation valve 46R and the leftward turning operation valve 46L (for example, the rightward turning operation valve 46R when the target is the rightward turning motion).

[0069] On the other hand, when judging that the traveling motion is included in the target motion of the inhibition control, the inhibition control judgment unit 74 determines the content of the inhibition control on the traveling motion. The judgment on the necessity of the execution of the inhibition control of the traveling motion and the content of the control are arbitrary. The necessity of the execution of the inhibition control may be, for example, judged either based on the presence or absence of a monitoring object in the monitoring area that is set for the traveling motion in the same manner as the rightward turning monitoring area and the leftward turning monitoring area (for example, an area extended from the lower traveling body 10 in the traveling direction) or simply based on the distance from the object detector that has detected the monitoring object among the object detectors 60R, 60L and 60B to the monitoring object. The inhibition control on the traveling motion preferably includes at least a part of the forced stop control, the warning control and the display control, or may include other controls.

[0070] The traveling restriction command unit 78 generates a traveling restriction command signal. When the inhibition control judgment unit 74 determines the execution of the forced stop control as the inhibition control on the traveling motion, the traveling restriction command unit 78 generates a traveling restriction command signal. The traveling restriction command signal, thus, is a signal for decelerating the traveling motion in the direction involving the mutual approach of the work machine and the monitoring object. Specifically, the traveling restriction command unit 78 inputs the traveling restriction command signal to the operation valve corresponding to the traveling motion that is the target of the forced stop among the right advance traveling operation valve 47F, the right reverse traveling operation valve 47B, the left advance traveling operation valve 48F and the left reverse traveling operation valve 48B.

[0071] When the inhibition control judgment unit 74 determines the execution of the alarm control as the inhibition control, the alarm command unit 82 generates an alarm command signal for the alarm control, and inputs the alarm command signal to the alarm device 62 to thereby make the alarm device 62 issue an alarm to an operator. The alarm control during the rightward turning motion and the alarm control during the leftward turning motion may be different from each other. For example, it may be done either to light different lamps in color during the rightward turning and the leftward turning, respectively, or to make a speaker constituting the alarm device 62 output a message with different voices.

[0072] The display command unit 84 generates a display command signal when the inhibition control judgment unit 74 judges the inhibition control to be necessary, and inputs the display command signal to the display device 64 to thereby make the display device 64 display a warning image. The warning image is, for example, a peripheral image that is a captured image provided by the object detectors 60R, 60L, and 60B, the image including the monitoring object. In the case of the target motion including the turning motion, it is preferable that the warning image includes the rightward turning monitoring area or the leftward turning monitoring area selectively according to the turning direction.

[0073] On the other hand, when the operation lock signal is input from the operation lock device 61, that is, when the operation lock lever is at the open position (lock position), the controller 70 makes the opening-closing valves that are interposed between the pilot pump and all the plurality of operation units including the turning operation unit 42, the right traveling operation unit 43, and the left traveling operation unit 44 shown in FIG. 3, respectively, closed, thereby invalidating all operations applied to the plurality of operation units. The controller 70, thus, forcibly disables the motion of the work machine.

[0074] Moreover, the inhibition control judgment unit 74 of the controller 70 is configured to suspend the execution of the inhibition operation regardless of the presence or absence of the detection of the monitoring object when the operation lock lever is at the open position and the operation lock signal is input from the operation lock device 61. When the operation lock signal is input, there is no effectiveness of the forced stop control because of the stop of the work machine; therefore, the substantial targets to be suspended in the inhibition control are the alarm control and the display control.

[0075] Next will be described more specifically the processing to be performed by the controller 70 with respect to the inhibition control on the turning motion, with reference to the flowchart of FIG. 5.

[0076] The position information generation unit 72 of the controller 70 captures an image signal (detection signal) input from the object detectors 60R, 60L, 60B every time a preset sampling period (for example, 50ms) has elapsed, and acquires position information based on the image signal (step S10). Specifically, the position information generation unit 72 processes the image signal to thereby generate position information about the monitoring object. The position information determines the relative position of the monitoring object to the upper turning body 12, allowing the presence or absence of the monitoring object in each of the rightward turning monitoring area and the leftward turning monitoring area to be judged.

[0077] Only when the operation lock signal is not input from the operation lock device 61 (NO in step S11) and the turning operation (rightward turning operation or leftward turning operation) is applied to the turning operation unit 42 (YES in step S12), the inhibition control judgment unit 74 of the controller 70 performs the processing of step S14 and the steps following it, that is, the election of the monitoring area in accordance with the turning direction corresponding to the turning operation and the execution of inhibition control based on the elected monitoring area (rightward turning monitoring area or leftward turning monitoring area). The presence or absence of the turning operation and the turning direction is allowed to be judged by the detection signals input from each of the turning pilot pressure sensors 52R and 52L.

[0078] When the operation lock signal is input from the operation lock device 61 (YES in step S11), the inhibition control judgment unit 74 suspends the processing of step S14 and the steps following it, the processing including the inhibition control. This prevents the inhibition control from being executed in a state of no possibility of the performance of the turning motion regardless of the presence or absence of the turning operation, thereby allowing the frequency of the execution to be appropriately lowered. In particular, the suspension of the execution of the alarm control is effective for preventing the alarm control from being frequently executed to reduce the effect of the alarm.

[0079] When the turning operation is performed and the performed turning operation is a rightward turning motion (YES in each of step S12 and step S14), the inhibition control judgment unit 74 judges whether or not a monitoring object is located in the rightward turning monitoring area (step S16R). In the present embodiment, the judgement is made on whether or not the monitoring object is located in any of the right front area portion 91, the left rear area portion 92 and the rear area portion 90 shown in FIG. 2A. Only when judging that the monitoring object is located in the rightward turning monitoring area (YES in step S16R), the inhibition control judgment unit 74 determines execution of the inhibition control on the rightward turning motion (step S18R). According to the determination, the inhibition control on the rightward turning motion is executed. Specifically, a rightward turning restriction command signal is input from the turning restriction command unit 76 to the rightward turning operation valve 46R; an alarm command signal is input from the alarm command unit 82 to the alarm device 62; and a display command signal is input from the display command unit 84.

[0080] When judging that the monitoring object is not located in the rightward turning monitoring area (NO in step S16R), the inhibition control judgment unit 74 suspends the execution of the inhibition control on the rightward turning motion. The cases where the monitoring object is not located in the rightward turning monitoring area include not only a case where no monitoring object is detected but also cases where a monitoring object is detected but the detected monitoring object is not located in the rightward turning monitoring area, the latter cases including a case where the monitoring object is located in the leftward turning monitoring area but not located in the rightward turning monitoring area, for example, a case where the monitoring object is located in the left front area portion 93 or the right rear area portion 94.

[0081] When the turning operation is not a rightward turning operation (NO in step S14) but a leftward turning operation, the inhibition control judgment unit 74 judges whether or not a monitoring object is located in the leftward turning monitoring area (step S16L). The judgment, in the present embodiment, is made on whether or not the monitoring object is located in any of the left front area portion 93, the right rear area portion 94 and the rear area portion 90 which are shown in FIG. 2B. Only when judging that the monitoring object is located in the leftward turning monitoring area (YES in step S16L), the inhibition control judgment unit 74 determines execution of the inhibition control on the leftward turning motion (step S18L). In accordance with this determination, the inhibition control on the leftward turning motion is executed. Specifically, a leftward turning restriction command signal is input from the turning restriction command unit 76 to the leftward turning operation valve 46L; an alarm command signal is input from the alarm command unit 82 to the alarm device 62; and a display command signal is input from the display command unit 84.

[0082] When judging that the monitoring object is not located in the leftward turning monitoring area (NO in step S16L), the inhibition control judgment unit 74 suspends the execution of the inhibition control on the leftward turning motion. The cases where the monitoring object is not located in the leftward turning monitoring area include not only a case where no monitoring object is detected but also cases where a monitoring object is detected but the detected monitoring object is not located in the leftward turning monitoring area, the latter cases including a case where the monitoring object is located in the rightward turning monitoring area but not located in the leftward turning monitoring area, for example, a case where the monitoring object is located in the right front area portion 91 or the left rear area portion 92.

[0083] The judgment on the necessity of the execution of the inhibition control as described above allows the inhibition of the turning motion to be executed only in a situation with high possibility of mutual approach of the upper turning body 12 and the monitoring object and suspended in a situation with poor possibility of the approach, with a simple configuration of electing the area corresponding to the turning direction of the upper turning body 12 from among the preset rightward turning monitoring area and the leftward turning monitoring area and judging whether or not a monitoring object is located in the elected monitoring area. For example, in the case where the monitoring object is detected at the position P1 shown in FIG. 2A and FIG. 2B, the inhibition control on the rightward turning motion is executed because the position P1 is in the right front area portion 91 of the rightward turning monitoring area whereas the inhibition control on the leftward turning motion is suspended because the position P1 is outside the leftward turning monitoring area; in fact, the right front side surface of the upper turning body 12 is made go away from the position P1 by the leftward turning motion. Similarly, in the case where the monitoring object is detected at the position P2 shown in FIG. 2A and FIG. 2B, the inhibition control on the leftward turning motion is executed because the position P2 is in the left front area portion 93 of the leftward turning monitoring area whereas the inhibition control on the rightward turning motion is suspended because the position P2 is outside the rightward turning monitoring area; in fact, the left front side surface of the upper turning body 12 is made go away from the position P2 by the rightward turning motion. Thus, the judgment on the necessity of execution of the inhibition control based on the rightward turning monitoring area and the leftward turning monitoring area is matched to the level of the possibility of the approach corresponding to the turning direction of the upper turning body 12.

[0084] Besides, in the present embodiment, where the rightward turning monitoring area and the leftward turning monitoring area share the rear area portion 90, the inhibition control is executed when the monitoring object is located on the rear side of the upper turning body 12, regardless of the turning direction, to inhibit the monitoring object and the rear end portion of the upper turning body 12 from approaching each other.

[0085] In the present invention, the specific shape and size of the rightward turning monitoring area and the leftward turning monitoring area are not limited but allowed to be arbitrarily set according to the specific shape and size of the turning body (the upper turning body 12 in FIG. 2) and the detection range of the object detector. For example, the hydraulic excavator shown in FIG. 6 is designed to be a rear small turning type in which the rear end of the upper turning body 12 is arc-shaped with the turning axis 13 as a center in a plan view to reduce the protruding amount of the rear end, having a margin in the vicinity of the rear part in comparison with the upper turning body 12 shown in FIGS. 2A and 2B, whereas the radiuses of respective outer peripheral surfaces 92b, 94b and 90b of the left rear area portion 92, the right rear area portion 94 and the rear area portion 90 which are set correspondingly to the rear part are set to be equal to the radiuses of respective outer peripheral surfaces 91b, 93b of the right front area portion 91 and the left front area portion 93 which are set correspondingly to the front part of the upper turning body 12. The radiuses of the outer peripheral surfaces 92b, 94b and 90b, conversely, may be set to be smaller than the radiuses of the outer peripheral surfaces 91b and 93b (for example, may be set to radiuses decreased toward the rear of the upper turning body 12).

[0086] While the auxiliary weight 19 in the upper turning body 12 shown in FIG. 6 protrudes rearward at the rear end of the upper turning body 12, respective radiuses of the outer peripheral surfaces 92b, 94b, 90b of the left rear area portion 92, the right rear area portion 94 and the rear area portion 90 may be set based on the rear end surface of the auxiliary weight 19 in the case where the protruding amount of the auxiliary weight 19 is enough large to be dominant.

[0087] Besides, the present invention encompasses the following aspects as examples.(1) Inhibition control

[0088] The inhibition control according to the present invention only has to satisfy the condition of inhibiting the target motion when the monitoring object is located in the rightward turning monitoring area that is set during the rightward turning or the leftward turning monitoring area that is set during the leftward turning, allowed to be freely within the condition. For example, only a part of the forced stop control, the alarm control, and the display control according to the embodiment may be elected as the inhibition control, or another control, for example, a speed inhibition control of rendering the actual speed of the target motion smaller than the speed corresponding to the magnitude of the operation (operation amount) applied by the operator, may be included in the inhibition control.

[0089] The present invention is also applicable to a work machine without the operation lock device 61 shown in FIG. 3; besides, also in a work machine including the operation lock device 61, the presence or absence of the input of the operation lock signal may be separated from the judgment on the necessity of execution of the inhibition control. Specifically, the control unit according to the invention may be configured to execute the inhibition control, regardless of whether or not the operation lock signal is input, when the monitoring object is located in the rightward turning monitoring area and the leftward turning monitoring area during the rightward turning and the leftward turning, respectively.(2) Rightward turning monitoring area and leftward turning monitoring area

[0090] The rightward turning monitoring area and the leftward turning monitoring area according to the present invention only has to be different from each other in at least respective parts of them; therefore, a mode including an area portion shared by both monitoring area such as the rear area portion 90 shown in FIG. 2A, FIG. 2B, and FIG. 6 is not excluded. The part thus shared by the rightward turning monitoring area and the leftward turning monitoring area is not limited to the rear area portion 90, and only has to be an area to be alert during both the rightward turning and the leftward turning.

[0091] While the radiuses of the outer peripheral surfaces 91b and 93b of the right front area portion 91 and the left front area portion 93 in FIGS. 2A and 2B are set based on the right and left front corner parts 121 and 123 of the upper turning body 12, the radius of each of the outer peripheral surfaces 91b and 93 of the right front area portion 91 and the left front area portion 93 may be enlarged to the turning radius of a monitoring-target part set in the work device 14 in consideration with a dead angle, if it is present, behind the work device 14 when viewed from an operator in the cab 18 (in the example shown in FIG. 2A and FIG. 2B). Besides, such specific shape and size of the rightward turning monitoring area and the leftward turning monitoring area can be freely set according to the type of the working machine to be applied (for example, an excavator, a crane, a crusher, and a high lift work vehicle).(3) Position information and position information acquisition unit

[0092] The position information according to the present invention only has to be information about the relative position of the monitoring object to the work machine to allow the relative positional relationship of the monitoring object to the rightward turning monitoring area and the leftward turning monitoring area. For example, a turning angle sensor may be provided to detect the turning angle of the upper turning body 12 with respect to the lower traveling body 10 to allow the position coordinates of the monitoring object to be determined based on the turning angle detected by the turning angle sensor and the detection result provided by the object detector mounted on the upper turning body 12.

[0093] The object detector constituting the position information acquisition unit according to the present invention is not limited to one including an imaging device. For example, in the case of no special limitation on the monitoring object (that is, the case of no necessity of identifying the monitoring object), the object detector may be a distance detector such as an infrared depth sensor or a millimeter wave radar. Alternatively, it may be an imaging device capable of generating three-dimensional information differently from a monocular camera, for example, a stereo camera.

[0094] As has been described, according to the present invention is provided a control device capable of performing control for inhibiting a turning body of a work machine and a monitoring object from approaching each other, at a proper frequency, with a simple configuration.

[0095] Provided is a device for controlling a turning motion of a work machine including a support body and a turning body supported by the support body capably of the turning motion. The device includes: a position information acquisition unit that acquires position information on a relative position of a monitoring object to the turning body; and a control unit that performs an inhibition control for inhibiting the monitoring object and the turning body from approaching each other based on the position information. During a rightward turning of the turning body, the control unit performs the inhibition control only when the monitoring object is located in a rightward turning monitoring area that is set so as to turn integrally with the turning body and suspends the inhibition control when the monitoring object is not located in the rightward turning monitoring area. During a leftward turning of the turning body, the control unit performs the inhibition control only when the monitoring object is located in a leftward turning monitoring area that is set so as to turn integrally with the turning body and suspends the inhibition control when the monitoring object is not located in the leftward turning monitoring area.

[0096] The device makes it possible to appropriately lower the frequency of execution of the control while inhibiting the turning body of the work machine and the monitoring object from approaching each other by simple control only including electing the monitoring area corresponding to the turning direction of the turning body between the rightward turning monitoring area and the leftward turning monitoring area which are prepared in advance and judging whether or not a monitoring object is located in the elected monitoring area. For example, during the rightward turning, judging the necessity of execution of the inhibition control based on whether or not a monitoring object is located in the rightward turning monitoring area set for the rightward turning allows the inhibition control to be prevented from being executed during the rightward turning despite that a monitoring object is located at a position where the monitoring object has to be watched cautiously during the leftward turning but does not have to be watched cautiously during the rightward turning.

[0097] Specifically, it is preferable that the rightward turning monitoring area includes a right front area portion set on a right side of a right front side surface, which is a part of a right side surface of the turning body and is located on a front side of a turning center of the turning body, and a left rear area portion set on a left side of a left rear side surface, which is a part of a left side surface of the turning body and is located on a rear side of the turning center of the turning body, and that the leftward turning monitoring area includes a left front area portion set on a left side of a left front side surface, which is a part of a left side surface of the turning body and is located on a front side of the turning center of the turning body, and a right rear area portion set on a right side of a right rear side surface, which is a part of a right side surface of the turning body and is located on a rear side of the turning center of the turning body. The rightward turning monitoring area including the right front area portion and the left rear area portion allows the right front side surface and the left rear side surface of the turning body to be inhibited from approaching the monitoring object due to the rightward turning of the turning body, and, similarly, the leftward turning monitoring area including the left front area portion and the right rear area portion allows the left front side surface and the right rear side surface of the turning body to be prevented from approaching the monitoring object due to the leftward turning of the turning body.

[0098] The "right front area portion set on a side of the right front side surface" may include not only a first portion located sideward of the right front side surface but also a second portion protruding rearward beyond the first portion. This is the same for the left rear area portion, the left front area portion and the right rear area portion.

[0099] More specifically, it is preferable that the right front area portion has a rear end surface along a turning center surface and the left rear area portion has a front end surface along the turning center surface. The turning center surface is a vertical surface extending in a left-right direction of the turning body through the turning center. This enables the execution of the monitoring object to be suspended during the rightward turning in which the monitoring object is located sideward of the left front side surface and the right rear side surface to involve a poor possibility of mutual approach of the turning body and the monitoring object, while inhibiting each of the right front side surface and the left rear side surface from approaching the monitoring object.

[0100] Similarly, it is preferable that the left front area portion has a rear end surface along the turning center surface and the right rear area portion has a front end surface along the turning center surface. This enables the execution of the monitoring object to be suspended during the leftward turning in which the monitoring object is located sideward of the right front side surface and the left rear side surface to involve a poor possibility of mutual approach of the turning body and the monitoring object, while inhibiting each of the left front side surface and the right rear side surface from approaching the monitoring object.

[0101] The "rear end surface along the turning center surface" and the "front end surface along the turning center surface" include not only a surface coincident with the turning center surface but also a surface extending substantially parallel to the turning center surface in the vicinity of the turning center surface.

[0102] Preferably, the position information acquisition unit includes a right object detector that is disposed on a right side part of the turning body to detect a monitoring object located on the right side of the turning body, and both the right front area portion of the rightward turning monitoring area and the right rear area portion of the leftward turning monitoring area are set within a detection range of the right object detector. This allows the common right object detector to detect both a monitoring object located in any of the right front area portion and the right rear area portion.

[0103] Similarly, it is preferable that the position information acquisition unit includes a left object detector that is disposed on a left side part of the turning body to detect a monitoring object located on a left side of the turning body, and both the left rear area portion of the rightward turning monitoring area and the left front area portion of the leftward turning monitoring area are set within a detection range of the left object detector. This allows the common left object detector to detect a monitoring object located in any of the left front area portion and the left rear area portion.

[0104] Preferably, the right front area portion has an outer peripheral surface arc-shaped with the turning center as a center in a plan view, and the outer peripheral surface is located on an outer side, in the turning radius direction of the turning body, of a turning trajectory of a right front corner part of the turning body during the rightward turning of the turning body. This allows the right front corner part of the turning body and the monitoring object to be effectively inhibited from approaching each other due to the rightward turning of the turning body.

[0105] Besides, it is preferable that the left rear area portion has an outer peripheral surface arc-shaped with the turning center as a center in a plan view, and the outer peripheral surface is located on an outer side, in the turning radius direction of the turning body, of a turning trajectory of a left rear corner part of the turning body during the rightward turning of the turning body. This allows the left rear corner part of the turning body and the monitoring object to be effectively inhibited from approaching each other due to the rightward turning of the turning body.

[0106] Similarly, it is preferable that the left front area portion has an outer peripheral surface arc-shaped with the turning center as a center in a plan view, and the outer peripheral surface is located on an outer side, in the turning radius direction of the turning body, of a turning trajectory of a left front corner part of the turning body during the leftward turning of the turning body. This allows the left front corner part of the turning body and the monitoring object to be effectively inhibited from approaching each other due to the leftward turning of the turning body.

[0107] Besides, it is preferable that the right rear area portion has an outer peripheral surface arc-shaped with the turning center as a center in a plan view, and the outer peripheral surface is located on an outer side, in the turning radius direction of the turning body, of a turning trajectory of a right rear corner part of the turning body during the leftward turning of the turning body. This allows the left rear corner part of the turning body and the monitoring object to be effectively inhibited from approaching each other due to the leftward turning of the turning body.

[0108] The rightward turning monitoring area and the leftward turning monitoring area only has to be different from each other in at least a part of each of the rightward turning monitoring area and the leftward turning monitoring area; hence, a common portion may be included in both monitoring areas. For example, the rightward turning monitoring area and the leftward turning monitoring area may share a rear area portion set on a rear side of the turning body. This makes it possible to effectively inhibit the monitoring object located on the rear side of the turning body and the turning body from approaching each other during both the rightward turning and the leftward turning.

[0109] The inhibition control, for example, preferably includes an alarm control for issuing an alarm from an alarm device to an operator. Since the excessive frequency of the issue of the alarm decreases the efficiency of the alarm, the control of the frequency of execution of the inhibition control by the setting of the rightward turning monitoring area and the leftward turning monitoring area keeps the alarm with high effectiveness.

[0110] On the other hand, it is preferable that the control unit is configured to suspend the inhibition control (at least the alarm control) regardless of the presence or absence of the monitoring object when an operation lock signal for invalidating an operation applied for a motion of the work machine is input. This prevents the inhibition control from being executed in a situation where the operation lock signal is input to eliminate the possibility of the performance of the turning motion regardless of the presence or absence of the turning operation, thereby allowing the frequency of execution of the inhibition control to be appropriately controlled.

[0111] In the case where the turning body includes an operation room that allows an operator to get thereon and the work machine further includes a work device mounted on the turning body capably of performing a work motion on a front side of the operation room, the control unit may be configured to suspend a work restriction control for restricting the work motion in order to inhibit the approach of the work device and the monitoring object, regardless of the presence or absence and the position of the monitoring object. Thus suspending the execution of the work restriction control for inhibiting the approach of the work device and the monitoring object, that is, the control for restricting the work motion, with respect to a work motion that can be visually recognized by an operator riding in the operation room makes it possible to further lower the frequency of execution of the control for restricting the operation of the work machine with high safety secured. The work restriction control encompasses not only a control for restricting the actual motion of the work device but also a control for indirectly restricting the work motion by issuing an alarm to an operator to urge inhibition of the work motion.

Claims

1. A turning-type work machine control device for controlling a turning motion in a work machine including a support body and a turning body supported by the support body capably of the turning motion, comprising: a position information acquisition unit that acquires position information on a relative position of a monitoring object to the turning body; and a control unit that performs an inhibition control for inhibiting the monitoring object and the turning body from approaching each other based on the position information, wherein the control unit performs the inhibition control, during a rightward turning of the turning body, only when the monitoring object is located in a rightward turning monitoring area that is set so as to turn rightward integrally with the turning body and suspends the inhibition control when the monitoring object is not located in the rightward turning monitoring area, and the control unit performs the inhibition control, during a leftward turning of the turning body, only when the monitoring object is located in a leftward turning monitoring area that is set so as to turn leftward integrally with the turning body and suspends the inhibition control when the monitoring object is not located in the leftward turning monitoring area.

2. The turning-type work machine control device according to claim 1, wherein: the rightward turning monitoring area includes a right front area portion set on a right side of a right front side surface, which is a part of a right side surface of the turning body and is located on a front side of a turning center of the turning body, and a left rear area portion set on a left side of a left front side surface, which is a part of a left side surface of the turning body and is located on a rear side of the turning center of the turning body; and the leftward turning monitoring area includes a left front area portion set on a left side of a left front side surface, which is a part of a left side surface of the turning body and is located on a front side of the turning center of the turning body, and a right rear area portion set on a right side of a right rear side surface, which is a part of a right side surface of the turning body and is located on a rear side of the turning center of the turning body.

3. The turning-type work machine control device according to claim 2, wherein the right front area portion has a rear end surface along a turning center surface and the left rear area portion has a front end surface along the turning center surface, the turning center surface being a vertical surface extending in a left-right direction of the turning body through the turning center.

4. The turning-type work machine control device according to claim 2, wherein the left front area portion has a rear end surface along a turning center surface and the right rear area portion has a front end surface along the turning center surface, the turning center surface being a vertical surface extending in a left-right direction of the turning body through the turning center.

5. The turning-type work machine control device according to claim 2, wherein the position information acquisition unit includes a right object detector that is disposed on a right side part of the turning body to detect a monitoring object located on a right side of the turning body, and both the right front area portion of the rightward turning monitoring area and the right rear area portion of the leftward turning monitoring area are set within a detection range of the right object detector.

6. The turning-type work machine control device according to claim 2, wherein the position information acquisition unit includes a left object detector that is disposed on a left side part of the turning body to detect a monitoring object located on a left side of the turning body, and both the left rear area portion of the rightward turning monitoring area and the left front area portion of the leftward turning monitoring area are set within a detection range of the left object detector.

7. The turning-type work machine control device according to claim 2, wherein the right front area portion has an outer peripheral surface arc-shaped with the turning center as a center in a plan view, and the outer peripheral surface is located on an outer side, in a turning radius direction of the turning body, of a turning trajectory of a right front corner part of the turning body during the rightward turning of the turning body.

8. The turning-type work machine control device according to claim 2, wherein the left rear area portion has an outer peripheral surface arc-shaped with the turning center as a center in a plan view, and the outer peripheral surface is located on an outer side, in a turning radius direction of the turning body, of a turning trajectory of a left rear corner part of the turning body during the rightward turning of the turning body.

9. The turning-type work machine control device according to claim 2, wherein the left front area portion has an outer peripheral surface arc-shaped with the turning center as a center in a plan view, and the outer peripheral surface is located on an outer side, in a turning radius direction of the turning body, of a turning trajectory of a left front corner part of the turning body during the leftward turning of the turning body.

10. The turning-type work machine control device according to claim 2, wherein the right rear area portion has an outer peripheral surface arc-shaped with the turning center as a center in a plan view, and the outer peripheral surface is located on an outer side, in a turning radius direction of the turning body, of a turning trajectory of a right rear corner part of the turning body during the leftward turning of the turning body.

11. The turning-type work machine control device according to claim 2, wherein the rightward turning monitoring area and the leftward turning monitoring area share a rear area portion set on a rear side of the turning body.

12. The turning-type work machine control device according to claim 1, wherein the inhibition control includes an alarm control for issuing an alarm from an alarm device to an operator.

13. The turning-type work machine control device according to claim 12, wherein the control unit is configured to suspend the inhibition control, regardless of presence or absence of the monitoring object, when an operation lock signal for invalidating an operation applied for a motion of the work machine is input.

14. The turning-type work machine control device according to claim 1, wherein the turning body includes an operation room that allows an operator to get thereon, the work machine further including a work device mounted on the turning body capably of performing a work motion on a front side of the operation room, and the control unit is configured to suspend a work restriction control for restricting the work motion in order to inhibit the work device and the monitoring object from approaching each other, regardless of the presence or absence of the monitoring object and the position of the monitoring object.

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