Patent Application
20220097621
The present invention relates to a work machine that makes it possible to measure a work-target-object weight during a haulage step in loading work for a haulage machine.
Work machines represented by hydraulic excavators perform loading work of making the cargo bed of a certain haulage machine (e.g. a dump truck) full of a work target object by repeatedly loading the work target object onto the cargo bed of the haulage machine, in some cases. Loading work by a hydraulic excavator having a work arm (work implement) to which a bucket is attached at its tip is mentioned here as an example. The loading work includes a plurality of loading cycles, and each loading cycle includes the following three steps: an excavation step of excavating a work target object, and filling the inside of the bucket with the work target object; a haulage step of swinging an upper swing structure after the excavation step, and moving the bucket to a position above the cargo bed of a haulage machine; and a loading step of releasing the work target object onto the cargo bed of the haulage machine, and thereafter moving the bucket to a position where the excavation step is to be started. Note that loading work for each haulage machine onto which a work target object is loaded can be distinguished from that for other haulage machines.
Regarding such loading work, there are some work machines that include a controller (controller) that measures a work-target-object weight (also referred to as a hauled weight) during a haulage step at each loading cycle, and integrates all the hauled weights measured during loading work for a certain haulage machine, to thereby calculate an amount of a load having been loaded onto the certain haulage machine (also referred to as a loaded weight). By measuring and recording loaded amounts of haulage machines, a manager of a work site can grasp the amount of a work target object carried by the haulage machines out from the work site, and it becomes possible to monitor the amount of production of the work site.
In order to appropriately monitor the amount of production of a work site, it is necessary to manage, in association with each other, a loaded amount of a haulage machine calculated by a work machine, and information about the haulage machine onto which a work target object has been loaded.
As a work-amount monitoring system for a work machine, Patent Document 1 discloses a system in which a weight (loaded amount) integrated by a work machine is transmitted to a haulage machine and system terminal equipment of a work site via a wireless communication system that is capable of bidirectional communication.
Patent Document 1: JP-2010-89633-A
In the work-amount monitoring system of Patent Document 1, the transmission of the loaded amount from the work machine to the haulage machine or the system terminal equipment of the work site, or the resetting of the loaded amount at the time when the work proceeds to loading work for the next haulage machine are performed through manual operation by an operator of the work machine. Accordingly, at a work site where loading work is performed continuously for a plurality of haulage machines, the operator easily forgets to perform the manual operation, makes mistakes in the manual operation, and so on, because haulage machines come and go frequently, and there is a problem that it is difficult to correctly calculate a loaded amount of each haulage machine.
An object of the present invention is to provide a work machine that makes it possible to accurately calculate a loaded amount of a haulage machine.
In order to solve such a problem, a work machine according to the present invention includes: a machine body; a work arm that has, on one end side of the work arm, a work device that performs loading of a work target object onto a haulage machine, and is, on another end side of the work arm, attached to the machine body; a posture sensor that senses a posture of the work arm including the work device; a load sensor that senses a load acting on the work arm; a notification device for giving notification of a work instruction to the haulage machine; and a controller that determines, on the basis of the posture and the load, that a haulage step of hauling the work target object onto the haulage machine has been performed by the work arm, measures a weight of the work target object during the haulage step, and determines, on the basis of the posture or the load, that a loading step of performing loading of the work target object onto the haulage machine has been performed by the work arm. The controller is configured to: sense the work instruction via the notification device; determine a start of loading work for the haulage machine, and an end of the loading work on a basis of an operation state of the work machine at a time of the sensing of the work instruction; integrate the weight of the work target object that has been measured from the start of the loading work until the end of the loading work, and calculate a loaded amount of the haulage machine; and output the loaded amount to an external terminal at the end of the loading work.
According to the present invention, it becomes possible to accurately calculate a loaded amount of a haulage machine.
In the following, embodiments of the present invention are explained by using the figures. In the following cases explained, a hydraulic excavator is used as a loading machine included in a weight measurement system of a work machine, and dump trucks are used as haulage machines.
Work machines (loading machines) which are target machines of the present invention are not limited to hydraulic excavators having buckets as attachments (work devices), but also include hydraulic excavators having grapples, lifting magnets or the like that are capable of holding/releasing work target objects. In addition, the present invention can also be applied to wheel loaders and the like including work arms not having swing functionalities unlike hydraulic excavators.
The front work implement 12 includes: a boom 13 pivotably provided on the upper swing structure 11; an arm 14 pivotably provided at the tip of the boom 13; and a bucket (attachment) 15 pivotably provided at the tip of the arm 14. In addition, as actuators to drive the front work implement 12, the front work implement 12 includes: a boom cylinder 16 that is a hydraulic cylinder to drive the boom 13; an arm cylinder 17 that is a hydraulic cylinder to drive the arm 14; and a bucket cylinder 18 that is a hydraulic cylinder to drive the bucket 15.
A boom-angle sensor 24, an arm-angle sensor 25, and a bucket-angle sensor 26 that are posture sensors are attached to the pivot axes of the boom 13, the arm 14, and the bucket 15, respectively. Angles of pivot motion of the boom 13, the arm 14 and the bucket 15 can be acquired from these angle sensors 24, 25 and 26, respectively. In addition, a swing-angular-velocity sensor (e.g. a gyroscope) 27 and an inclination angle sensor 28 are attached to the upper swing structure 11, and are configured to be able to acquire the swing angular velocity of the upper swing structure 11, and the forward/backward-direction inclination angle of the upper swing structure 11, respectively. Postural data to identify the posture of the front work implement 12 can be acquired from sensed values of the angle sensors 24, 25, 26, 27, and 28.
A boom-bottom-pressure sensor 29 and a boom-rod-pressure sensor 30, and an arm-bottom-pressure sensor 31 and an arm-rod-pressure sensor 32 that are load sensors are attached to the boom cylinder 16 and the arm cylinder 17, respectively, and are each configured to be able to acquire the pressure inside a hydraulic cylinder. Driving force data to identify a thrust of each cylinder 16 or 18, that is, a driving force applied to the front work implement 12, and load data to identify a load on each cylinder 16 or 18 can be acquired from sensed values of the pressure sensors 29, 30, 31 and 32. Note that similar pressure sensors may be provided also on the bottom side and rod side of the bucket cylinder 18, and driving force data and load data about the bucket cylinder 18 may be acquired to be used for various types of control.
Note that the boom-angle sensor 24, the arm-angle sensor 25, the bucket-angle sensor 26, the inclination angle sensor 28, and the swing-angular-velocity sensor 27 can be replaced with other sensors as long as those sensors can sense physical quantities from which postural data about the front work implement 12 can be computed. For example, each of the boom-angle sensor 24, the arm-angle sensor 25, and the bucket-angle sensor 26 can be replaced with an inclination angle sensor or an inertial measurement unit (IMU). In addition, the boom-bottom-pressure sensor 29, the boom-rod-pressure sensor 30, the arm-bottom-pressure sensor 31, and the arm-rod-pressure sensor 32 can be replaced with other sensors as long as those sensors can sense physical quantities from which data about thrusts generated by the boom cylinder 16 and the arm cylinder 17, that is, a driving force applied to the front work implement 12, and load data about each cylinder 16 and 17 can be computed. Furthermore, instead of or in addition to sensing of thrusts, driving forces, and loads, operation velocities of the boom cylinder 16 and the arm cylinder 17 may be sensed by stroke sensors, or operation velocities of the boom 13 and the arm 14 may be sensed by IMUs, to thereby sense operation of the front work implement 12.
A monitor (display device) 23 that displays results of calculations by the controller 21 (e.g. a hauled weight which is the weight value of a work target object 4 in the bucket 15 calculated by a weight calculating section 50 mentioned below, and a loaded amount of a haulage machine which is an integrated value of the hauled weight), and the like, and the operation lever 22 for giving instructions about operation of the front work implement 12, and the upper swing structure 11 are installed inside the operation room 20. An external communication device 42 used by the controller 21 for communicating with a terminal such as an external computer (e.g. a controller mounted on a dump truck 2 (see
The monitor 23 according to the present embodiment has a touch panel, and functions also as an input device used by an operator to input information to the controller 21. For example, a liquid crystal display having a touch panel can be used as the monitor 23.
The operation lever 22 has: a first lever (not illustrated) for giving instructions about raising/lowering of the boom 13 (expansion/contraction of the boom cylinder 16), and dumping/crowding of the bucket 15 (expansion/contraction of the bucket cylinder 18); and a second lever (not illustrated) for giving instructions about dumping/crowding of the arm 14 (expansion/contraction of the arm cylinder 17), and left/right swings of the upper swing structure 11 (left/right turns of the hydraulic motor 19). The first and second levers are dual combined multi-functionality operation levers. Forward/backward operation of the first lever corresponds to raising/lowering of the boom 13, and left/right operation of the first lever corresponds to crowding/dumping of the bucket 15. Forward/backward operation of the second lever corresponds to dumping/crowding of the arm 14, and left/right operation of the second lever corresponds to left/right turns of the upper swing structure 11. If a lever is operated in a diagonal direction, two corresponding actuators are operated simultaneously. In addition, operation amounts of the first and second levers determine operation velocities of the actuators 16 to 19.
In addition, the upper swing structure 11 further includes: a horn 41 that is a notification device for giving notification of work instructions by cues using horn sounds to haulage machines (dump trucks) 2 (more specifically, stop instructions to the haulage machines 2 accompanying starts of loading work, and departure instructions to the haulage machines 2 accompanying ends of the loading work); the external communication device 42 that is one of communication devices for exchanging data (hauled weights and loaded amounts) related to a weight of the work target object 4 with a machine other than the hydraulic excavator 1, and also is a haulage-machine-data acquiring device for exchanging data about operation or positions related to the haulage machine 2; and an antenna (positional-measurement data acquiring device) 43 for receiving signals from a plurality of GNSS satellites. The inside of the operation room 20 further includes a horn switch (work instruction switch) 40 that operates the horn 41 when triggered by operation of the switch 40.
Note that cues used for work instructions are not limited only to sound generation of horn sounds by the horn 41 mentioned above, but any configuration, like the flashing of light or buzzer signals via the external communication device 42, may be adopted as long as it is possible to notify operators of the haulage machines 2 whether or not there are cues. In addition, the horn switch 40 may be other hardware as long as it is configured as an interface by which it is possible to give instructions as to whether or not there is a cue, like a switch attached onto the operation lever 22, or a foot switch attached onto the floor surface of the operation room 20.
—Controller 21—
The controller 21 includes a calculation processing device (e.g. a CPU), a storage device (e.g. a semiconductor memory such as a ROM or a RAM), and an interface (input/output device), and executes a program (software) stored in advance on the storage device by using the calculation processing device. On the basis of set values defined in the program, and signals input through the interface, the calculation processing device performs a calculation process, and outputs a signal (calculation result) through the interface.
The inside of the controller 21 in
—Processes Performed by Loading Period Determining Section 54—
In the method explained next by using
At each haulage step, the controller 21 (weight calculating section 50) calculates a weight value (hauled weight) of the work target object 4 being hauled by the bucket 15. Then, every time loading work for one haulage machine 2 ends, the controller 21 (loaded amount calculating section 51) transmits the loaded amount of the haulage machine 2 obtained by integrating the hauled weight of the work target object 4 to an unillustrated computer installed in the management building 5 via the external communication device 42 provided to the hydraulic excavator 1, and a communication antenna 44 for management provided at the management building 5. At this time, if a hauled weight other than the work target object 4 loaded onto one haulage machine 2 is integrated mistakenly (e.g. not only a hauled weight for the current haulage machine, but also a hauled weight in loading work for the previous haulage machine is integrated mistakenly), the loaded amount becomes inaccurate, and it becomes impossible to correctly output the loaded amount. That is, the controller 21 is supposed to integrate only the weight of the work target object 4 at loading steps having been implemented for one haulage machine. With the configuration of the hydraulic excavator 1 mentioned earlier, and the method explained below, the present invention makes it possible to easily integrate only a weight having been loaded onto a haulage machine 2.
Each step in
When the flowchart illustrated in
At Step S102, the controller 21 (weight calculating section 50) resets a hauled weight M that is calculated at Step S108 mentioned below, and is retained on the memory to 0, and proceeds to Step S103.
At Step S103, the controller 21 (weight calculating section 50) determines whether or not the excavation flag Fdig retained on the memory is ON, the output PrevPam (last arm-bottom pressure) of the arm-bottom-pressure sensor 31 in the previous sampling instance is higher than a threshold Th_Pam_cry that is set in advance on the memory, and the current output Pam (current arm-bottom pressure) of the arm-bottom-pressure sensor 31 is lower than the threshold Th_Pam_cry. As illustrated in the graph of the arm-cylinder bottom pressure Pam in
At Step S105, the controller 21 (weight calculating section 50) determines whether or not the haulage flag Fcry is ON. When the haulage flag Fcry has not been set to ON, the process skips to Step S109. When the haulage flag Fcry is ON, the process proceeds to Step S106.
At Step S106, the controller 21 (weight calculating section 50) determines whether or not the time tpl that has elapsed since the haulage flag Fcry has been set to ON is equal to or longer than a time threshold Th_tpl. When the time tpl is not longer than the time threshold Th_tpl, the process proceeds to Step S107.
At Step S107, the controller 21 (weight calculating section 50) calculates an instantaneous weight (work-target-object weight) Ml of the work target object 4, and records the work-target-object weight Ml in chronological order. The instantaneous work-target-object weight Ml is calculated according to a known method. For example, as illustrated in
Fcyl=A1·Pbm1−A2·Pbm2 (1)
Torque Tbm generated by the boom cylinder 16 is computed according to the following Formula (2) where the length of a line segment linking the boom pivot axis, and the point of action of the thrust of the boom cylinder 16 is Lbm, the thrust of the boom cylinder 16 is Fcyl, and the angle formed between the line segment Lbm and the direction of the thrust is θcyl.
Tbm=Fcyl·Lbm·sin(θcyl) (2)
Torque Tgfr generated by gravity of the front work implement 12 is computed according to the following Formula (3) where the centroid weight of the front work implement 12 is Mfr, the gravitational acceleration is g, the length in the forward/backward direction from the boom pivot axis to the front-implement centroid is Lfr, the angle formed between the horizontal plane and a line segment linking the boom pivot axis and the front-implement centroid is θfr.
Tgfr=Mfr·g·Lfr·cos(θfr) (3)
Torque Tcfr generated to the front work implement 12 by a swing centrifugal force is computed according to the following Formula (4) where the length in the forward/backward direction from the swing center of the upper swing structure 11 to the front-implement centroid is Rfr, and a swing angular velocity is co.
Tcfr=Mfr·Rfr·ω
2
·Lfr·sin(θfr) (4)
Note that Mfr, Lfr, Rfr, and θfr are computed from the preset length, centroid position and weight of each of the upper swing structure 11, the boom 13, the arm 14, and the bucket 15, and angle signals output from the boom-angle sensor 24, the arm-angle sensor 25, and the bucket-angle sensor 26. Torque Tgl generated to the work target object by gravity is computed according to the following Formula (5) where the work-target-object weight is Ml, the length in the forward/backward direction from the boom pivot axis to the bucket centroid is Ll, and the angle formed between the horizontal plane and a line segment linking the boom pivot axis and the centroid of the work target object is θl.
Tgl =Ml·g·Ll·cos(θl) (5)
Torque Tcl generated to the work target object by a swing centrifugal force is computed according to following Formula (6) where the length in the forward/backward direction from the swing center of the upper swing structure 11 to the bucket centroid is Rl.
Tcl=Ml·Rl·ω
2
·Llsin(θl) (6)
By modifying the balance of each type of torque acting around the pivot axis of the boom 13 illustrated in Formulae (2) to (6), and expanding them for the work-target-object weight Ml, the work-target-object weight Ml is computed according to the following Formula (7).
Ml=(Tbm−Tgfr−Tcfr)/(Ll·(g·cos(θl)+Rl·ω2·sin(θl))) (7)
In the calculation of the work-target-object weight according to Formulae (1) to (7), the work-target-object weight Ml always fluctuates, and does not become a constant value due to noise of sensors, characteristic of hydraulic circuits and the like. Accordingly, the average of the instantaneous work-target-object weight Ml recorded at Step S107 until the time tpl reaches the time threshold Th_tpl is determined to be used as the hauled weight M.
Meanwhile, when, at Step S106, the time tpl that has elapsed since the haulage flag Fcry has been set to ON is longer than the time threshold Th_tpl stored in advance on the memory, the process proceeds to Step S108.
At Step S108, the controller 21 (weight calculating section 50), on the basis of the record of the instantaneous work-target-object weight Ml, calculates the hauled weight M which is the average of the instantaneous work-target-object weight Ml by dividing the total of the instantaneous work-target-object weight Ml by the time tpl that has elapsed since the haulage flag Fcry has been set to ON, outputs the hauled weight M, and proceeds to Step S109.
At Step S109, the controller 21 (weight calculating section 50) determines whether or not the haulage flag Fcry is ON, an arm-bucket relative angle Prevθbk (last bucket angle) which is an output of the bucket-angle sensor 26 in the previous sampling instance is smaller than a preset threshold Th_θbk_load, and a current output θbk (current bucket angle) of the bucket-angle sensor 26 is larger than the threshold Th_θbk_load. As illustrated in the graph of the relative angle θbk between the arm 14 and bucket 15 in
When it is not determined at Step S109 that a loading step has started, the process skips to Step S113. Conversely, when it is determined at Step S109 that a loading step has started, the process proceeds to Step S110, the controller 21 (loaded amount calculating section 51) sets the loading flag Fload to ON, and sets the haulage flag Fcry to OFF, and the process proceeds to Step S111. Note that the example about the threshold Th_θbk_load illustrated in
At Step S111, the controller 21 (loaded amount calculating section 51) determines whether or not the loading in-progress flag Flw is ON. When the loading in-progress flag Flw is ON, it is determined that the hydraulic excavator 1 is implementing loading work for the haulage machine 2, and, at Step S112, the hauled weight M calculated at Step S108 is added to a weight integrated value Mtotal. On the other hand, when, at Step S111, the loading in-progress flag is OFF, the process skips Step S112, and proceeds to Step S113.
At Step S113, the controller 21 (work instruction sensing section 53) determines whether or not there has been a work instruction Fhorn to the haulage machine 2 via the horn switch 40 (horn 41). When there has not been a work instruction (Fhorn is OFF), the process returns to Step S100, and the program inside the controller 21 operates such that the calculations at and after Step S100 are executed again. When there has been a work instruction (Fhorn is ON), the process proceeds to Step S114.
At Step S114, the controller 21 (loading period determining section 54) determines whether or not the haulage flag Fcry is ON, and an angle θab (hereinafter, referred to as a “bucket absolute angle θab” in some cases) of an opening section of the bucket 15 relative to the horizontal plane calculated from outputs of the sensor 24 to the sensor 28 is equal to or larger than an angle threshold Th_θab recorded in advance on the memory. Note that the bucket absolute angle θab can be calculated by adding together all the outputs of the sensor 24 to the sensor 28, for example. In this document, the crowding direction of the bucket 15 (the direction in which the bucket 15 is folded toward the operation room 20) is defined as the positive direction. As illustrated in
When, at Step S114, the haulage flag Fcry is ON, and the bucket absolute angle θab is equal to or larger than the threshold Th_θab, the controller 21 (loading period determining section 54) determines that loading work starts, and the process proceeds to Step S115. At Step S115, the loading in-progress flag Flw is set to ON, it is determined thereby that the loading work has started, and the process returns to Step S100. On the other hand, when the condition is not satisfied at Step S114 (i.e. a situation where loading work is in progress or the loading work ends), the process proceeds to Step S116.
At Step S116, the controller 21 (loading period determining section 54) determines whether or not the loading flag Fload is ON, and the bucket absolute angle θab is smaller than an angle threshold THh_θab recorded in advance on the memory. As illustrated in (b) in
At Step S117, after the controller 21 (loading period determining section 54) sets the loading in-progress flag Flw to OFF, and determines thereby that the loading work has ended, the controller 21 (output information generating section 52) transmits a loaded amount Mtotal via the external communication device 42 (Step S118), the controller 21 (loaded amount calculating section 51) resets the loaded amount Mtotal (Step S119), and the process returns to Step S100. Note that if the condition is not satisfied at Step S116, the process returns to Step S100.
As illustrated in
As illustrated in the screen at the upper section in
—Operation/Advantages—
When loading work is started by the thus-configured hydraulic excavator 1, the result of the determination by the controller 21 at Step S100 becomes YES at the timing of an excavation step at the initial loading cycle, and the controller 21 sets the excavation flag to ON (Step S101), and resets the hauled weight M to zero (Step S102). Subsequently, the result of the determination by the controller 21 at Step S103 becomes YES at the timing of a haulage step at the initial loading cycle, and the controller 21 sets the haulage flag to ON (Step S104), and measures the elapsed time tpl that has elapsed since a time at which the haulage step has started. Until the time tpl reaches the threshold Th_tpl, the controller 21 calculates the instantaneous weight Ml repeatedly (Step S107), and, when the time tpl reaches the threshold Th_tpl, calculates the average value of the instantaneous weight Ml, and uses the average value as the hauled weight M (Step S108). At this time, as illustrated in (a) in
Thereafter, upon the arrival of the haulage machine 2, the operator of the hydraulic excavator 1 outputs a cue to stop (work instruction) by sounding the horn 41. When the work instruction by the horn 41 is sensed, the controller 21 proceeds to Step S114 from Step S113, the result of the determination at Step S114 by the controller 21 becomes YES, and the controller 21 sets the loading in-progress flag to ON (Step S115). When the hydraulic excavator 1 performs dumping operation of the bucket 15 to start loading of the work target object onto the cargo bed of the haulage machine 2 (i.e. a loading step at the initial loading cycle), the result of the determination by the controller 21 at Step S109 becomes YES, and the controller 21 sets the loading flag Fload to ON (Step S110). Since the loading in-progress flag Flw is ON in the determination at the subsequent Step S111, the process proceeds to Step S112, and the hauled weight M calculated at Step S108 is integrated with the loaded amount Mtotal (=zero).
From then on, a plurality of loading cycles are executed by the hydraulic excavator 1 until the cargo bed of the haulage machine 2 becomes full. At that time, the controller 21 calculates the hauled weight M at each haulage step (Step S108), and integrates the hauled weight M at each loading step, to calculate the loaded amount Mtotal.
Thereafter, when the cargo bed of the haulage machine 2 is made full of the work target object 4 as a result of a loading step at the last loading cycle as illustrated in (b) in
In the manner mentioned above, in the present embodiment, at Step S114, the step at the loading cycle at the time when a work instruction is output from the hydraulic excavator 1 to the haulage machine 2, and the operation state of the front work implement 12 are compared with each other. Thereby, it is possible to easily determine a start and end of loading work for one haulage machine 2, and it is possible to accurately calculate the loaded amount because the hauled weight M is integrated only between the start and end of the loading work.
Note that, in order to improve the precision of determinations about the loading-work start timing at Step S114 in
In addition, although the loaded amount Mtotal is transmitted to the external terminal at Step S118 in
Meanwhile, the method of determining a start and end of loading work illustrated in Step S114 to Step S119 in
In the present modification example, the controller 21 determines that the initial loading step in loading work for one haulage machine 2 has been performed (loading work has started) when the upper swing structure 11 has stopped in a haulage step at a loading cycle at which a work instruction has been sensed, and determines that the last loading step in the loading work for the one haulage machine 2 has been performed (the loading work has ended) when the upper swing structure 11 has not stopped (i.e. the upper swing structure 11 is swinging) in the haulage step at the loading cycle at which the work instruction has been sensed. In the following, details of this case are explained.
When it is confirmed at Step S105 in
Next, when it is determined at Step S113 in
Typically, the hydraulic excavator 1 immediately proceeds to a haulage step after an excavation step in order to increase the efficiency of loading work, and furthermore proceeds to a loading step without stopping a swing of the upper swing structure 11 having been input during the haulage step. When the count Cstop is larger than the threshold Th_Cstop (e.g. 1), it can be decided that the hydraulic excavator 1 has stopped a swing of the upper swing structure 11 during the haulage step, and has been waiting for an entrance of a haulage machine 2 without proceeding to a loading step.
In view of this, if the condition of Step S122 is satisfied, the controller 21 proceeds to Step S115 determining that loading work has started, and otherwise proceeds to Step S117 determining that the loading work has ended.
Note that the counter Cstop retained on the memory is reset to 0 simultaneously when the hauled weight M is reset to 0 at Step S102 in
Note that the determination about a stop during an excavation step mentioned above is not limited only to a determination based on the swing velocity of the upper swing structure 11, but obviously the velocity of a pivot motion of the bucket 15 resulting from a swing, an integrate value of an amount of swing operation through the operation lever 22, and the like may also be used.
In the present modification example, the controller 21 determines that the initial loading step has been performed (loading work has started) when a lowest point PrevHbk of a height Hbk of the bucket claw tip at a loading step at a loading cycle at which a work instruction has been sensed is lower than a predetermined height threshold TH_Hbk, and determines that the last loading step has been performed (loading work has ended) when the lowest point PrevHbk of the height of the bucket claw tip at the loading step at the loading cycle at which the work instruction has been sensed is higher than the height threshold TH_Hbk.
The flowchart in
At Step S131, the controller 21 calculates the height Hbk of the bucket claw tip. Hbk is calculated by using the dimensions of the hydraulic excavator 1 and the front work implement 12 recorded in advance on the memory of the controller 21, and signals of the boom-angle sensor 24, the arm-angle sensor 25, and the bucket-angle sensor 26. The height of the bottom surface of the lower travel structure 10 is defined as 0, and the upward direction of the hydraulic excavator 1 is defined as the positive direction.
After Hbk is calculated at Step S131, at Step S132, the controller 21 determines whether or not Hbk is smaller than PrevHbk retained on the memory at Step S133 mentioned below. An initial value (0 in the present embodiment) larger than the height threshold is determined for PrevHbk. When Hbk is higher than PrevHbk, the process skips to Step S113. When Hbk is lower than PrevHbk, at Step S133, PrevHbk retained on the memory is overwritten with Hbk, and the process proceeds to Step S113. In these processes at Step S132 and Step S133, as illustrated in
At Step S113, the controller 21 determines whether or not there has been the work instruction Fhorn from the horn switch 40 to the haulage machine 2. When there has been the work instruction, at Step S134, an instruction retention flag TempFhorn indicating that there has been the work instruction is set to ON, and otherwise the process proceeds to S135.
At Step S135, the controller 21 determines whether or not the instruction retention flag TempFhorn is ON. When the instruction retention flag TempFhorn is not ON, the process skips to Step S100, and when the instruction retention flag TempFhorn is ON, the process proceeds to Step S136.
At Step S136, the controller 21 determines whether or not the bucket absolute angle θab relative to the horizontal plane is larger than the threshold Th_θab_load recorded in advance on the memory. That is, it is determined whether or not operation of releasing the work target object 4 has ended. If the condition is not satisfied, the process skips to Step S100, and if the condition is satisfied, the process proceeds to Step S137.
At Step S137, the controller 21 determines whether or not PrevHbk retained on the memory during loading step is lower than the height threshold Th_Hbk recorded in advance on the memory. As illustrated in (a) in
When it is determined at Step S137 that PrevHbk is lower than the threshold Th_Hbk, that is, loading work has started, the process proceeds to Step S115, and the loading in-progress flag Flw is set to ON. Thereafter, Step S112 is executed, the hauled weight M is added to the loaded amount Mtotal, and the process proceeds to Step S138. Note that, in order to compensate for the fact that the timing at which the loading in-progress flag Flw is set to ON is delayed, and Step S111 in
On the other hand, when it is determined at Step S137 that PrevHbk is higher than the threshold Th_Hbk, that is, the loading work has ended, the process proceeds to Step S117, and the loading in-progress flag Flw is set to OFF. Subsequently, at Step S118, the loaded amount Mtotal is transmitted. At Step S119, the loaded amount Mtotal is reset to 0, and the process proceeds to Step S138.
At Step S138, the controller 21 sets the instruction retention flag TempFhorn to OFF, and resets PrevHbk to the initial value (=0), and the process returns to Step S100.
While, in the first embodiment, the work instruction (horn 41) to stop a haulage machine 2 is output at a haulage step, and the work command for a departure of the haulage machine 2 is output at a loading step, some operators of the hydraulic excavator 1 output the work instruction to stop a haulage machine 2 at a loading step subsequent to a haulage step, and output the work command for a departure of the haulage machine 2 at the haulage step before the loading step, in some cases. In such a case also, loaded amounts need to be calculated accurately.
(1) In view of this, the controller 21 according to the present embodiment determines that a haulage step at a first loading cycle is the initial loading step when a work instruction is sensed at the haulage step at the first loading cycle and the loaded amount Mtotal until a second loading cycle which is the previous cycle of the first loading cycle is smaller than a loading threshold Th_Mtotal, or when a work instruction is sensed at the haulage step at the first loading cycle and elapsed time tcry from the start of the haulage step at the first loading cycle until the time of the sensing of the work instruction is longer than a first time threshold Th_tcry (a route from Step S142 to Step S149 in
(2) In addition, the controller 21 according to the present embodiment integrates the hauled weight M calculated at a haulage step at a first loading cycle with the loaded amount Mtotal until a second loading cycle which is the previous cycle of the first loading cycle at a loading step at the first loading cycle, and calculates the loaded amount Mtotal of a haulage machine in a case in which: a work instruction is sensed at the haulage step at the first loading cycle, and the loaded amount Mtotal until the second loading cycle is equal to or larger than the loading threshold Th_Mtotal; and a work instruction is sensed at the haulage step at the first loading cycle, and the elapsed time tcry from the start of the haulage step at the first loading cycle until the time of the sensing of the work instruction is equal to or shorter than the first time threshold Th_tcry (a route from Step S142 to Steps S143 and S144 in
(3) In addition, the controller 21 according to the present embodiment determines that a loading step at a third loading cycle is the last loading step when a work instruction is sensed at the loading step at the third loading cycle and the hauled weight M calculated at a haulage step at the third loading cycle is larger than a weight threshold Th_M, or when a work instruction is sensed at the loading step at the third loading cycle and elapsed time tload from the start of a loading step at a fourth loading cycle which is the previous cycle of the third loading cycle until the start of the loading step at the third loading cycle is shorter than a second time threshold Th_tload (a route from Step S147 to Step S150 in
(4) In addition, the controller 21 according to the present embodiment integrates the hauled weight M calculated at a haulage step at a third loading cycle with the loaded amount Mtotal until a fourth loading cycle which is the previous cycle of the third loading cycle, and calculates the loaded amount Mtotal of a haulage machine 2 when a work instruction is sensed at a loading step at the third loading cycle and the hauled weight M calculated at the haulage step at the third loading cycle is equal to or smaller than the weight threshold Th_M, or when a work instruction is sensed at the loading step at the third loading cycle and the elapsed time Tload from the start of a loading step at the fourth loading cycle until the start of the loading step at the third loading cycle is equal to or longer than the second time threshold Th_tload (a route from Step S147 to Steps S148 and S149 in
In the following, details of the configuration of the controller 21 for realizing the control in (1) to (4) described above are explained.
The flowchart in
When, at Step S113 in
At Step S141, the controller 21 determines whether or not the bucket absolute angle θab is larger than the threshold Th_θab recorded in advance on the memory. When the bucket absolute angle θab relative to the horizontal plane is larger than the threshold Th_θab, the process proceeds to Step S142, and otherwise the process proceeds to Step S154.
Meanwhile, at Step S140 and Step S141, similarly to Step S114 in
—Problem 1—
Meanwhile, at some work sites, at the end of loading work, expecting the time required for an operator of a haulage machine 2 to make the haulage machine 2 depart after the operator notices a work instruction, the work instruction is output before an operator of the hydraulic excavator 1 starts a loading step, that is, during a haulage step, in some cases. In that case, the work instruction 3 is input before it is determined that the loading 4 is in progress, and the loading flag Fload is set to ON as represented by the work instruction 3 in the middle section in
—Solution 1—
In view of this, at Step S142, the controller 21 (loading period determining section 54) in the present embodiment determines whether or not the loaded amount Mtotal is smaller than the threshold Th_Mtotal recorded in advance on the memory in the controller 21, or the time tcry that has elapsed since the haulage flag Fcry has been set to ON is longer than the threshold Th_tcry recorded in advance on the memory. As represented by the work instruction 3 in the bottom section in
If, the condition of Step S142 is not satisfied, that is, when it is determined that a work instruction has been given before a loading step is implemented at the end of loading work, the controller 21 (loading period determining section 54) waits until the loading flag Fload is set to ON at Step S143, without performing other processes. That is, the determination at Step S108 in
If the condition is satisfied at Step S142, the controller 21 (loading period determining section 54) determines that loading work has started, proceeds to Step S149, and sets the loading in-progress flag to ON similarly to the process at Step S115 in
When the haulage flag Fcry is OFF at Step S140, the controller 21 (loading period determining section 54) proceeds to Step S145, and, at Step S145, determines whether or not the loading flag Fload is ON. When the loading flag Fload is ON, the process proceeds to Step S146, and otherwise the process proceeds to Step S144.
At Step S146, the controller 21 (loading period determining section 54) determines whether or not the bucket absolute angle θab relative to the horizontal plane is smaller than the threshold Th_θab recorded in advance on the memory. When the bucket absolute angle θab relative to the horizontal plane is smaller than the threshold Th_θab, the process proceeds to Step S147, and otherwise the process proceeds to Step S154.
At Step S145 and Step S146, similarly to Step S116 in
—Problem 2—
Meanwhile, at some work sites, at the start of loading work, in order to reduce the time during which the hydraulic excavator 1 is waiting for a haulage machine 2 as much as possible, loading work is started while the haulage machine 2 is moving, that is, a work instruction is output during a loading step, in some cases. In that case, the work instruction 2 is input after it is determined that the loading 1 is in progress, and the loading flag Fload is set to ON as represented by the work instruction 2 in the middle section in
—Solution 2—
In view of this, at Step S147, the controller 21 (loading period determining section 54) in the present embodiment determines whether or not the loaded amount Mtotal is larger than the threshold Th_M recorded in advance on the memory, or the time tload that has elapsed since the loading flag Fload has been set to ON last time until the loading flag Fload is set to ON this time is shorter than the threshold Th_tload recorded in advance on the memory. As represented by the work instruction 2 in the bottom section in
If the condition of Step S147 is not satisfied, that is, when it is determined that a work instruction has been given after a loading step has started at the beginning of loading work, the controller 21 (loading period determining section 54) proceeds to Step S148. At Step S148, the controller 21 (loaded amount calculating section 51) adds the hauled weight value M to the loaded amount Mtotal, and proceeds to Step S149.
If the condition is satisfied at Step S147, the controller 21 (loading period determining section 54) determines that the loading work has ended, proceeds to Step S150, sets the loading in-progress flag Flw to OFF similarly to the process in
When the process has proceeded to Step S153, a warning and a screen for confirming whether the loading in-progress flag should be set to ON or OFF are output to the monitor 23. By determining that a work instruction has been output at a timing other than the start or end of loading work in the determinations at Step S140 to Step S142, and Step S145 to Step S147, and leaving the decision to an operator of the hydraulic excavator 1, it is possible to prevent a loaded amount from being calculated mistakenly due to a false determination.
Note that the threshold Th_tload, which is a time-related threshold, is set to any value by which whether or not a haulage machine 2 is being waited for can be determined, within a range equal to or longer than average time required for one excavation step, excavation step or loading step or one instance of reaching work performed by the hydraulic excavator 1. The threshold Th_tcry is set to any value by which whether or not a haulage machine 2 is being waited for can be determined, within a range equal to or longer than average time of an excavation step performed by the hydraulic excavator 1. In addition, the haulage threshold Th_M, which is a hauled-weight-related threshold, is set to any value by which it can be determined that loading work has started, within a range equal to or smaller than an average loaded amount (hauled weight) of a load on a haulage machine 2 loaded by the hydraulic excavator 1 at one loading step. The loading threshold Th_Mtotal is set to any value by which it can be determined that loading work has ended, within a range equal to or larger than an average loaded amount of a load of a haulage machine 2 loaded by the hydraulic excavator 1 at one loading step, and equal to or smaller than an average loaded amount of a load on the haulage machine 2 loaded by the hydraulic excavator 1 in one instance of loading work. By making determinations based on the start time of each type of work in loading work in this way, it is possible to easily make determinations about a start and end of loading work, and accurately calculate the loaded amount even at a site where the timing of output of a work instruction is early or late.
In the manner mentioned above, determinations about a start and end of loading work do not have to be made on the basis of only the absolute angle θbk of the bucket 15 relative to the horizontal plane, and may be made by using other conditions such as the posture and operation state of the hydraulic excavator 1, or the start time of each type of work, or by combining conditions, in other possible configurations.
In a procedure explained in the present embodiment by using
The controller 21 according to the present embodiment receives identification data and positional data about the plurality of haulage machines 2 output from the plurality of haulage machines 2, chooses one haulage machine from the plurality of haulage machines that has been in a predetermined area around the work machine for the longest time from the initial loading step until the last loading step in a certain instance of loading work, on the basis of the received identification data and positional data about the plurality of haulage machines, and outputs, to an external terminal, the loaded amount calculated about the certain instance of loading work as the loaded amount of the chosen haulage machine. In the following, details of the configuration of the controller 21 for realizing the control are explained. Note that it is assumed that a calculation of the loaded amount Mtotal is performed similarly to that in the first embodiment (including the modification examples) or the second embodiment, and an explanation thereof is omitted here.
Each step in
Subsequently, at Step S161, it is determined whether or not there is a haulage machine 2 whose relative distance PrevLt in the previous sampling instance is longer than a threshold Th_Lt set in advance on the memory, and whose current relative distance Lt is shorter than the threshold Th_Lt. Here, as illustrated in
At Step S163, the controller 21 (haulage-machine loading-period estimating section 57) determines whether or not there is a haulage machine 2 whose relative distance Lt in the previous sampling instance is equal to or shorter than the threshold Th_Lt set in advance on the memory, and whose current relative distance Lt is longer than the threshold Th_Lt. When there is a haulage machine 2 that satisfies the condition, at Step S164, the haulage-machine identifying section 58 erases a buffer Buf(IDtruck) of the haulage machine IDtruck that satisfies the condition on the memory. Thereby, only a buffer Buf(IDtruck) of a haulage machine 2 whose relative distance Lt is equal to or shorter than the threshold Th_Lt always exists on the memory. When there are no haulage machines 2 that satisfy the condition at Step S163, the process proceeds to Step S165 with no other processes being performed.
The controller 21 (haulage-machine-data acquiring section 55) has acquired the positional data Ptruck(IDtuck) about the plurality of haulage machines 2A to 2C as illustrated in
At Step S165, the controller 21 (haulage-machine identifying section 58) determines whether or not the loading in-progress flag Flw is ON. When the loading in-progress flag Flw is ON, the process proceeds to Step S166, and otherwise the process skips to Step S169. At Step S166, it is determined whether or not a loading in-progress flag PrevFlw in the previous sampling instance is OFF, and the number of Buf(IDtruck) reserved on the memory is one. That is, in combination with the condition at Step S165, it is determined whether or not the number of Buf(IDtruck) at the moment when the loading in-progress flag has been switched from OFF to ON is one. If the condition is satisfied, at Step S167, a haulage machine 2 having the corresponding IDtruck is set as a haulage machine for which loading is being performed. Since the moment at which the loading period determining section 54 has determined that loading work has started is extracted at Step S166, and it is estimated that the haulage machine 2A is the only haulage machine for which loading is started at the time when the loading is started as represented by a start of loading 1 in
At Step S168, 1 is added to all of Buf(IDtruck) reserved on the memory in the controller 21, and thereafter the process proceeds to Step S169.
At Step S169, it is determined whether or not the loading in-progress flag PrevFlw in the previous sampling instance is ON, and the current loading in-progress flag Flw is OFF. If the condition is satisfied, that is, if the moment when the loading in-progress flag is switched from ON to OFF is sensed, the process proceeds to Step S170, and otherwise the process returns to Step S160.
At Step S170, IDtruck with the largest value is extracted from a plurality of Buf(IDtruck). That is, one haulage machine 2 in the plurality of haulage machines 2 that has stayed for the longest time within the predetermined area (threshold Th_Lt) from the hydraulic excavator 1 during a period from the initial loading step to the last loading step in loading work for a certain haulage machine 2 is chosen. At the end of loading 1 in
At Step S171, it is determined whether or not the number of extracted IDtruck is larger than 1. If the condition is satisfied, the process proceeds to Step S172, and otherwise the process skips to Step S174.
At Step S172, it is determined that a plurality of haulage machines 2 happened to be identified. Accordingly, a screen for displaying identification data IDtruck about corresponding haulage machines 2, and for selecting a haulage machine 2 as a loaded amount calculation target is displayed on the monitor 23, and an operator of the hydraulic excavator 1 is prompted to select a haulage machine 2 for which loading has been performed. At the subsequent Step S173, identification data IDtruck selected by the operator of the hydraulic excavator 1 is acquired, and the process proceeds to Step S174.
At Step S174, it is instructed to transmit the extracted IDtruck and a loaded amount Mtotal via the output information generating section 52 and the external communication device 42, and the process proceeds to Step S175.
At Step S175, a buffer area Buf(IDtruck) on the memory corresponding to the extracted IDtruck is erased. At the end of loading 1 in
By comparing a loading period determined by the work machine (hydraulic excavator) 1 with loading periods estimated on a basis of data about haulage machines 2 in this way, a haulage machine 2 for which loading has been performed can be identified precisely, and a loaded amount and the haulage machine 2 for which loading has been performed can be associated with each other. Accordingly, a loaded amount of each haulage machine 2 can be managed precisely.
Note that the method of identifying a haulage machine 2 is not limited to the method mentioned above, but may be a different identification method. For example, obviously the method performed by the haulage-machine loading-period estimating section 57 to estimate loading periods needs not be based on only positional-measurement data about the hydraulic excavator 1 and haulage machines 2. For example, RF tags may be attached to haulage machines 2, the hydraulic excavator 1 may include an RF reader, and it may be detected that a haulage machine 2 is approaching by using an RG tag and the RG reader, in another possible configuration. A gate-type identifying machine may be provided at the entrance/exit of a work site, and data about the times of entrances/exits of haulage machines acquired at the gate may be able to be acquired by the hydraulic excavator 1 via a network, in still another possible configuration.
In a method explained in the present embodiment by using
The controller 21 according to the present embodiment measures required time from the last loading step for a certain haulage machine 2 until the initial loading step for another haulage machine which is the loading target next to the certain haulage machine, and, when the required time exceeds a prestored set value, it is determined that the work efficiency of the hydraulic excavator 1 has deteriorated, and a result of the determination is output to an external terminal. In the following, details of the configuration of the controller 21, and a system including the controller 21 for realizing the control are explained. Note that it is assumed that a calculation of the loaded amount Mtotal is performed similarly to that in the first embodiment, and an explanation thereof is omitted. It is needless to say that the control can be applied also to the modification examples of the first embodiment, and the second embodiment.
When it is determined at Step S114 that loading work has started, and the loading in-progress flag Flw is set to ON at Step S115, at Step S180, the controller 21 (haulage-machine-replacement-time measuring section) 60 stores a time t_lw_on at which the loading in-progress flag Flw is set to ON.
When it is determined at Step S116 that loading work has ended, and the loaded amount Mtotal is reset at Step S119, at Step S182, the controller 21 (haulage-machine-replacement-time measuring section 60) stores a time t_lw_off at which the loading in-progress flag Flw is set to OFF.
Subsequently, at Step S181, the difference between the current time and the time t_lw_off stored at Step S182 is calculated as haulage-machine replacement time t_wxtruck. In addition, at Step S183, the difference between the current time and the time t_lw_on stored at Step S180 is calculated as loading-work time t_lcycle, and the process proceeds to Step S184.
At S184, the controller 21 (work-suspension-time determining section 61) determines whether or not a step haulage-machine replacement time t_extruck is longer than a threshold Th_t_extruck recorded in advance on the memory. When the step haulage-machine replacement time t_extruck is longer, at Step S185, the lengthy-haulage-machine-replacement-time count Nl_truck retained on the memory is increased by 1, and the process proceeds to Step S186. When the step haulage-machine replacement time t_extruck is shorter, the process proceeds to Step S186 with no other processes being performed.
At the subsequent Step S186, the controller 21 determines whether or not the loading-work time t_lcycle is longer than a threshold Th_t_lcycle recorded in advance on the memory. When the loading-work time t_lcycle is longer, at Step S187, the lengthy-loading-work-time count Nl_cycle is increased by 1, and the process proceeds to Step S188. When the loading-work time t_lcycle is shorter, the process proceeds to Step S188 with no other processes being performed.
At Step S188, the controller 21 determines whether or not the lengthy-haulage-machine-replacement-time count Nl_truck is larger than a threshold Th_Nlong recorded in advance on the memory. When the lengthy-haulage-machine-replacement-time count Nl_truck is larger, the process proceeds to Step S189, and otherwise the process proceeds to Step S190.
At Step S189, the controller 21 determines whether or not the lengthy-loading-work-time count Nl_cycle is larger than the threshold Th_Nlong recorded in advance on the memory. When at Step S189 the count is larger, the process proceeds to Step S191, and otherwise the process proceeds to Step S192.
At Step S190, the controller 21 determines whether or not the lengthy-loading-work-time count Nl_cycle is larger than the threshold Th_Nlong recorded in advance on the memory. When at Step S190 the count is larger, the process proceeds to Step S193, and otherwise the process returns to Step S100 with no other processes being performed.
At Step S191, the controller 21 outputs a warning that both the replacement time of haulage machines 2 and the work time required for loading work are lengthy to the monitor 23 of the hydraulic excavator 1 and the management monitor 45 (see
Note that the threshold Th_t_extruck, which is time-related threshold, is set to any value within a range from the average of time required for an excavation step and an excavation step performed by the hydraulic excavator 1 to time required for one instance of loading work, and the threshold Th_t_lcycle is set to any value within a range equal to or longer than the average of time required for one instance of loading work performed by the hydraulic excavator 1. In addition, the threshold Th_Nlong, which is a threshold of a loading-work count, is set to any value within a range equal to or smaller than the average count of instances of loading work performed by the hydraulic excavator 1 per day.
In
If determinations of loading periods by the loading period determining section 54 is used in the manner mentioned above, time required for loading work for one haulage machine 2 and time required for replacement of haulage machines can be measured, and it becomes possible to precisely grasp time in which the hydraulic excavator 1 is actually performing work in the overall work time, and time in which the hydraulic excavator 1 is waiting for haulage machines 2 in the overall work time. Thereby, it is possible to estimate factors that have led to an increase in work time, and a manager of a work site can manage machines at the work site in more detail.
Note that the present invention is not limited to the embodiments described above, and includes various modification examples within the scope not deviating from the gist of the present invention. For example, the present invention is not limited to those including all the configurations explained in the embodiments described above, but also includes those from which some of the configurations are eliminated. In addition, some of configurations related to an embodiment can be added to or be replaced with configurations related to another embodiment.
For example, while the hydraulic excavator 1 used in the explanation of each embodiment described above has the upper swing structure 11, the boom 13, the arm 14, and the bucket 15, the configuration of a work implement is not limited to this, but may be a work implement such as a lifting magnet machine having a different form.
Determinations at steps by the weight calculating section 50 are not limited to those according to the method using the arm-cylinder bottom pressure and the bucket angle as mentioned above. For example, in a case of a work machine like a lifting magnet machine, it is easy to make determinations about a haulage step and a loading step on the basis of an ON/OFF signal about magnetic attraction.
In addition, data input and output through the external communication device 42 is not limited to a loaded amount and positional data about a haulage machine 2, and obviously, for example, a target loading amount of a haulage machine 2 may be output, in other possible configurations.
Calculations of hauled weights are not limited to those according to calculation formulae based on the model illustrated in
In addition, each configuration related to the controller (controller) 21 described above, and the functionality, execution process, and the like of each configuration may be partially or entirely realized by hardware (e.g. designing logic to execute each functionality in an integrated circuit). In addition, configurations related to the controller 21 described above may be a program (software) that is read out/executed by a calculation processing device (e.g. a CPU) to thereby realize each functionality related to the configurations of the controller 21. Data related to the program can be stored on, for example, a semiconductor memory (a flash memory, an SSD, and the like), a magnetic storage device (a hard disk drive, and the like), and a recording medium (a magnetic disk, an optical disk, and the like).
In addition, although control lines and information lines that are deemed to be necessary for the explanation of each embodiment are illustrated in the explanation of the embodiment described above, all control lines and information lines related to products are not necessarily illustrated. It may be considered that actually almost all configurations are connected mutually.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-035847 | Feb 2019 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/005894 | 2/14/2020 | WO | 00 |
