Information processing device, excavator, method, and program for estimating the volume of soil in an excavator bucket from the angles of the boom and arm.

Abstract

An information processing device (1) comprises: a center-of-gravity position calculation unit (152) that determines respective center-of-gravity positions of a boom of a shovel, an arm attached to one end of the boom, and a bucket attached to a tip of the arm on the basis of a first angle, which is an angle of the boom relative to a horizontal plane, and a second angle, which is an angle of the arm relative to the horizontal plane; a moment calculation unit (153) that finds a gravity moment generated around the rotation center of a boom rotation shaft for rotating the boom by gravity from the respective masses and the respective center-of-gravity positions of the boom, the arm, and the bucket, and finds a pressure moment of the pressure of a boom cylinder for vertically driving the boom; and an amount-of-soil calculation unit (154) that finds the amount of soil in the bucket on the basis of the gravity moment and the pressure moment.

Description

Technical Field

[0001] The present invention relates to an information processing device, an excavator, a method, and a program for estimating the amount of soil in the bucket of an excavator from the angles of the boom and the arm.

Background Art

[0002] Excavators are often used to load soil into dump trucks. In order to load within the maximum load capacity of the dump truck, the mass of the soil loaded into the bucket of the excavator is calculated and accumulated, and the operation is adjusted so that the accumulated value is not more than the maximum load capacity. The mass of the soil is calculated during the operation of lifting the soil after excavation. For example, Patent Document 1 discloses a technique for calculating the weight of a conveyed object such as earth and sand lifted by a bucket based on the output values of angle sensors attached to the boom, the arm, and the bucket, and a boom bottom pressure sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The angle sensor attached to the bucket is necessary for obtaining the center of gravity position of the bucket and the conveyed object such as earth and sand. In addition, the angle sensor attached to the bucket can detect the movement of the bucket from the output angle, and for example, it can be used to determine the presence or absence of an earth-discharging operation of dropping the conveyed object such as earth and sand into the dump truck to be loaded. However, the angle sensor attached to the bucket often comes into contact with earth and sand during excavation, including the attached cable. Therefore, there is a problem that the rate of damage to the angle sensor attached to the bucket due to the impact during contact with earth and sand during excavation is higher than that of other angle sensors attached to the boom, the arm, etc.

[0005] This invention has been made in view of the above circumstances, and aims to enable the determination of the mass of soil loaded into a bucket even when an angle sensor is not attached to the bucket. [Means for solving the problem]

[0006] To achieve the above objective, the information processing apparatus according to the present invention is: A center of gravity calculation unit that determines the center of gravity positions of the boom, the arm, and the bucket attached to the tip of the arm based on a first angle, which is the angle of the shovel boom with respect to the horizontal plane, and a second angle, which is the angle of the arm attached to one end of the boom with respect to the horizontal plane. A moment calculation unit that determines the gravitational moment generated around the center of rotation of the boom rotation axis for rotating the boom due to gravity, based on the respective masses and center of gravity positions of the boom, the arm, and the bucket, and the pressure moment of the pressure of the boom cylinder for driving the boom up and down, A soil volume calculation unit that determines the amount of soil in the bucket based on the gravity moment and the pressure moment, Equipped with picture, The soil volume calculation unit determines the amount of soil loaded by the shovel based on the soil volume value obtained from the period when the calculated soil volume exceeds a predetermined first threshold and then falls below a predetermined second threshold. . [Effects of the Invention]

[0007] According to the present invention, the mass of soil loaded into a bucket can be determined even without attaching an angle sensor to the bucket. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram showing an overview of a shovel according to an embodiment of the present invention. [Figure 2] Diagram showing the configuration of the information processing system according to the embodiment. [Figure 3] A diagram showing the hardware configuration of the information processing device according to the embodiment. [Figure 4]A diagram illustrating the coordinates of the boom, arm, bucket connection point, and center of gravity of the excavator according to the embodiment. [Figure 5] A diagram illustrating the moments of the boom, arm, and bucket of the shovel according to the embodiment. [Figure 6] A diagram illustrating the measurement and soil removal condition determination method according to the embodiment. [Figure 7] Flowchart showing the operation of the earthwork volume estimation process according to the embodiment. [Figure 8] Flowchart showing the operation of the earthwork volume calculation process according to the embodiment. [Modes for carrying out the invention]

[0009] The information processing device according to an embodiment of the present invention is a device that can determine the mass of soil loaded into a bucket based on angles obtained from angle sensors attached to the boom and arm of an excavator and the cylinder hydraulic pressure of the boom. The information processing device, method, and program according to this embodiment will be described in detail below with reference to the drawings.

[0010] First, Figure 1 shows an overview of an excavator 4 equipped with an information processing device 1 according to an embodiment of the present invention. The excavator 4 comprises a boom 41, a boom cylinder 42, an arm 43, a bucket 44, a cabin 45, a drive unit 46, a base 47, a rotating unit 48, and caterpillar tracks 49. The boom 41 has an arm connection part 411 at one end for connecting the arm 43, and a boom rotation shaft 412 at the other end that is connected to the drive unit 46. The boom cylinder 42 is a cylinder for moving the boom 41 up and down. One end of the boom cylinder 42 is connected to the center of the boom 41 by a rod-side cylinder connection part 421, and the other end is connected to the drive unit 46 by a bottom-side cylinder connection part 422. A boom sensor 21 for measuring the bending angle of the boom 41 is located near the rod-side cylinder connection part 421.

[0011] The boom cylinder 42 is a hydraulic cylinder and is equipped with a first boom hydraulic sensor 23 for measuring the hydraulic pressure on the rod side and a second boom hydraulic sensor 24 for measuring the hydraulic pressure on the bottom side. The first boom hydraulic sensor 23 is built into the vicinity of the rod-side cylinder connection portion 421 of the boom cylinder 42. The second boom hydraulic sensor 24 is built into the vicinity of the bottom-side cylinder connection portion 422 of the boom cylinder 42.

[0012] The arm 43 is connected at one end to the arm connection portion 411 of the boom 41. The arm 43 also has a bucket connection portion 441 at the other end for connecting the bucket 44. An arm sensor 22 for measuring the bending angle of the arm 43 is positioned near the arm connection portion 411 of the boom 41. The boom sensor 21 and the arm sensor 22 can be configured, for example, using an inertial measurement unit (IMU). An inertial measurement unit is a device that can detect three-dimensional inertial motion (translational motion and rotational motion in three orthogonal axes) at the part to which it is attached. The boom sensor 21 is an example of a first angle sensor in the claims. The arm sensor 22 is an example of a second angle sensor in the claims.

[0013] The cabin 45 is where the user who operates the shovel 4 gets in. In this embodiment, the information processing device 1 is mounted in the cabin 45. The drive unit 46 drives various parts such as the boom 41, boom cylinder 42, rotating part 48, and caterpillar tracks 49. The boom rotation axis 412 of the boom 41 and the bottom cylinder connection part 422 of the boom cylinder 42 are connected to the drive unit 46. As the drive unit 46 moves the boom rotation axis 412, the boom cylinder 42 moves up and down. This allows the boom 41 to move up and down. Therefore, the center of the boom rotation axis 412 becomes the center of rotation of the boom 41. Also, as the boom cylinder 42 moves up and down, the hydraulic pressure values ​​measured by the first boom hydraulic pressure sensor 23 and the second boom hydraulic pressure sensor 24 change.

[0014] The pedestal 47 mounts the boom 41, the cab 45, and the drive unit 46. The rotating part 48 can rotate left and right. The rotating part 48 is connected to the pedestal 47, and by rotating, it can move the positions of the boom 41, the cab 45, etc. attached to the pedestal 47 left and right. The caterpillar 49 moves the excavator 4.

[0015] The excavator 4 can lift the soil F loaded in the bucket 44 when the rotational axis moment Ma generated around the boom rotation axis 412 of the boom 41 and the hydraulic moment Mh due to the hydraulic pressure of the boom cylinder 42 are in balance. The rotational axis moment Ma is a moment generated by gravity from the respective masses and respective center of gravity positions of the boom 41, the arm 43, the bucket 44, and the soil F loaded in the bucket 44. Also, the hydraulic moment Mh is a moment calculated from the differential pressure between the hydraulic pressure at the rod - side cylinder connection part 421 of the boom cylinder 42 and the hydraulic pressure at the bottom - side cylinder connection part 422. Note that the rotational axis moment Ma is an example of the gravitational moment in the claims. Also, the hydraulic moment Mh is an example of the pressure moment in the claims.

[0016] When the soil F is loaded into the bucket 44 of the excavator 4 and the bucket 44 is in the lifted posture 44', the value of the rotational axis moment Ma generated around the boom rotation axis 412 of the boom 41 also changes according to the angle of the boom 41 and the angle of the arm 43.

[0017] Furthermore, when soil F is loaded into the bucket 44 of the shovel 4 and the bucket 44 is lifted to position 44', the hydraulic pressure values ​​at the rod-side cylinder connection 421 and the bottom-side cylinder connection 422 of the boom cylinder 42 change due to the respective masses of the boom 41, arm 43, bucket 44, and soil F, as well as gravity. When the hydraulic pressure value changes, the hydraulic moment Mh also changes. Therefore, in this embodiment, the mass of soil F loaded into the bucket 44 is estimated by utilizing the balance between the rotational axis moment Ma, which changes with the change in angle of the boom 41 and arm 43, and the hydraulic moment Mh, which changes with the change in hydraulic pressure of the boom cylinder 42. Hereafter, the mass of soil F loaded into the bucket 44 will be referred to as the soil volume.

[0018] Figure 2 shows an overview of the information processing system 100, including the information processing device 1. As shown in Figure 2, the information processing device 1 comprises an operation input unit 11, a communication unit 12, a display unit 13, a storage unit 14, and a control unit 15. The operation input unit 11 receives various operations from the user. The communication unit 12 sends and receives various data to and from the outside. The display unit 13 displays data entered by the user, data obtained by the control unit 15, etc.

[0019] The memory unit 14 stores various programs for determining the amount of soil loaded into the bucket 44, a measurement start threshold 141, and a soil discharge determination threshold 142. The measurement start threshold 141 is a threshold for determining the timing to start measuring the amount of soil. The soil discharge determination threshold 142 is a threshold for determining whether the soil F loaded into the bucket 44 has been loaded into a dump truck or the like. The measurement start threshold 141 is an example of a first threshold in the claims. The soil discharge determination threshold 142 is an example of a second threshold in the claims.

[0020] The control unit 15 includes a data acquisition unit 151, a center of gravity position calculation unit 152, a moment calculation unit 153, an earth volume calculation unit 154, a determination unit 155, and a display control unit 156. The data acquisition unit 151 acquires angle data from a boom sensor 21 mounted on the boom 41 and an arm sensor 22 mounted on the arm 43. The data acquisition unit 151 also acquires hydraulic data from a first boom hydraulic sensor 23 built near the rod-side cylinder connection part 421 of the boom cylinder 42 and a second boom hydraulic sensor 24 built near the bottom-side cylinder connection part 422.

[0021] The center of gravity calculation unit 152 calculates the center of gravity of the boom 41, arm 43, and bucket 44 from angle data obtained from the boom sensor 21 and arm sensor 22. In this embodiment, it is assumed that the center of gravity of the soil F coincides with the center of gravity of the bucket 44. The moment calculation unit 153 uses the center of gravity of the boom 41, arm 43, and bucket 44 calculated by the center of gravity calculation unit 152 to calculate the rotational axial moment Ma generated around the rod-side cylinder connection part 421 of the boom cylinder 42. The moment calculation unit 153 also calculates the hydraulic moment Mh due to the hydraulic pressure of the boom cylinder 42 from hydraulic pressure data obtained from the first boom hydraulic pressure sensor 23 and the second boom hydraulic pressure sensor 24.

[0022] The soil volume calculation unit 154 calculates the amount of soil loaded into the bucket 44 from the rotational axis moment Ma and the hydraulic moment Mh. The determination unit 155 determines the timing of soil volume measurement. The display control unit 156 displays various data, such as characters and figures, on the display unit 13.

[0023] Each function in the control unit 15 of the information processing device 1 is realized by executing various programs. An example of hardware for executing various programs is shown in Figure 3. The information processing device 1 comprises a processor 31, a main memory 32, an auxiliary memory 33, an input device 34, an operating device 35, a display controller 36, a display device 37, a communication device 38, and a bus 39 that connects these elements to each other.

[0024] The processor 31 processes data according to various programs. The processor 31 can be composed of processing units such as a CPU (Central Processing Unit) and an MPU (Micro-processing Unit). The main memory 32 functions as the work area of ​​the processor 31. The main memory 32 can be composed of, for example, RAM (Random Access Memory). The auxiliary storage device 33 stores various programs executed by the processor 31, fixed data, etc. The auxiliary storage device 33 can store data for a long period of time. The auxiliary storage device 33 functions as the storage unit 14 of the information processing device 1 shown in Figure 2. The auxiliary storage device 33 can be composed of, for example, flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc.

[0025] The input device 34 accepts various data inputs. For example, the input device 34 accepts data inputs from the boom sensor 21, arm sensor 22, first boom hydraulic sensor 23, and second boom hydraulic sensor 24 shown in Figure 2. The operation device 35 accepts various operations from the user. The operation device 35 can be composed of devices such as a keyboard or touch panel. The operation device 35 functions as the operation input unit 11 of the information processing device 1 shown in Figure 2.

[0026] The display controller 36 outputs video signals to the display device 37 for displaying display data consisting of characters and images. The display controller 36 can be configured using, for example, a video signal output device such as a video card, a GPU (Graphics Processing Unit), or a graphics board. The display device 37 is a display device that functions as the display unit 13 of the information processing device 1 shown in Figure 2. The display device 37 can be configured using, for example, a display interface device such as an LCD (Liquid Crystal Display) or an organic EL (Electro-Luminescence) panel.

[0027] The communication device 38 communicates with other devices and sends and receives various types of data. The communication device 38 functions as the communication unit 12 shown in Figure 2. The communication device 38 can be composed of devices using various communication methods such as wireless LAN (Local Area Network), Bluetooth (registered trademark), and Wi-Fi (registered trademark).

[0028] Next, the methods for calculating the rotational axis moment Ma and the hydraulic moment Mh will be explained below with reference to Figures 4 and 5. As mentioned above, the rotational axis moment Ma is the moment generated by gravity from the respective masses and center of gravity positions of the boom 41, arm 43, bucket 44, and the soil F loaded into the bucket 44. The hydraulic moment Mh is, as mentioned above, the moment calculated from the differential pressure between the hydraulic pressure at the rod-side cylinder connection part 421 of the boom cylinder 42 and the hydraulic pressure at the bottom-side cylinder connection part 422.

[0029] As shown in Figure 4, the origin is defined as the center of rotation Po of the boom rotation axis 412 of the boom 41, with the horizontal direction being the x-direction and the vertical direction being the y-direction. The arm connection part 411 at the end of the boom 41 opposite the boom rotation axis 412 has its center of rotation as the center of rotation of the arm 43. The bucket connection part 441 at the end of the arm 43 opposite the arm connection part 411 has its center of rotation as the center of rotation of the bucket 44. The center of gravity of the boom 41 is Pbm, the center of gravity of the arm 43 is Pam, and the center of gravity of the bucket 44 is Pbt. The center of gravity of the soil F loaded into the bucket 44 is at the same position as the center of gravity Pbt of the bucket 44.

[0030] Let Lbm be the distance between the rotation center Po of the boom rotation axis 412 and the rotation center of the arm connection part 411. Let Lam be the distance between the rotation center of the arm connection part 411 and the rotation center of the bucket connection part 441. Let LHbt be the distance between the rotation center of the bucket connection part 441 and the center of gravity Pbt of the bucket 44. Let Pcy be the center position of the bottom cylinder connection part 422 of the boom cylinder 42. Let Lcy be the distance between the center position Pcy of the bottom cylinder connection part 422 and the rotation center Po of the boom rotation axis 412.

[0031] Let θbm be the angle with respect to the horizontal plane in the Lbm direction. Let θam be the angle with respect to the horizontal plane in the Lam direction. θbm is calculated based on the angle measured by the boom sensor 21 shown in Figure 4. Let θbt be the angle with respect to the horizontal plane in the LHbt direction. In this embodiment, since the bucket 44 is fixed in the lifting position 44' shown in Figure 1, θbt is a fixed value. Let θcy be the angle with respect to the horizontal plane in the Lcy direction. Since θcy is determined by the structure of the shovel 4, it is a fixed value.

[0032] Let LHbm be the distance between the intersection of the perpendicular from the center of gravity Pbm of the boom 41 to Lbm and the center of rotation Po of the boom rotation axis 412. Let LVbm be the distance from the center of gravity Pbm of the boom 41 to the intersection of the perpendicular from Pbm to Lbm. Let θam be the angle with respect to the horizontal plane in the Lam direction. θam is the pitch angle at the center of the arm connection part 411, measured by the arm sensor 22 attached to the arm 43. Note that θbm is an example of the first angle in the claims. Also, θam is an example of the second angle in the claims.

[0033] Let LHam be the distance between the intersection of the center of gravity of arm 43 and the perpendicular from Pam to Lam, and the center of rotation of arm connection part 411. Let LVam be the distance from the center of gravity of arm 43 Pam to the intersection of the perpendicular from Pam to Lam. Let LHbt be the distance between the center of rotation of bucket connection part 441 and the center of gravity of bucket 44 Pbt.

[0034] In this case, the coordinates (xPbm, yPbm) of the center of gravity Pbm of boom 41 can be expressed by the following equations (1) and (2). xPbm=LHbm·cosθbm-LVbm·sinθbm (1) yPbm=LHbm·sinθbm+LVbm·cosθbm (2)

[0035] Furthermore, the coordinates (xPam, yPam) of the center of gravity Pam of arm 43 can be expressed by the following equations (3) and (4). xPam=Lbm·cosθbm+LHam·cosθam+LVam·sinθam (3) yPam=Lbm·sinθbm-LHam·sinθam+LVam·cosθam (4)

[0036] Furthermore, the coordinates (xPbt, yPbt) of the centroid Pbt of bucket 44 can be expressed by the following equations (5) and (6). xPbt=Lbm·cosθbm+Lam·cosθam+LHbt·cosθbt (5) yPbt=Lbm·sinθbm-Lam·sinθam-LHbt·sinθbt (6)

[0037] Furthermore, the coordinates (xPcy, yPcy) of the center position Pcy of the bottom cylinder connection portion 422 of the boom cylinder 42 can be expressed by the following equations (7) and (8). xPcy = Lcy·cosθcy (7) yPcy = Lcy·sinθcy (8)

[0038] Here, as shown in Figure 5, Fbm is defined as gravity on the boom 41. Fbm' is defined as the component of Fbm perpendicular to the direction of the rotation center Po of the boom rotation axis 412 of the boom 41. Fam is defined as gravity on the arm 43. Fam' is defined as the component of Fam perpendicular to the direction of the rotation center Po of the boom rotation axis 412 of the boom 41. Fbt is defined as gravity on the bucket 44. Fbt' is defined as the component of Fbt perpendicular to the direction of the rotation center Po of the boom rotation axis 412 of the boom 41. Fsl is defined as gravity on the soil F. Fsl' is defined as the component of Fsl perpendicular to the direction of the rotation center Po of the boom rotation axis 412 of the boom 41.

[0039] Let Fcy be the differential pressure at both ends of the boom cylinder 42. Let Fcy' be the component of Fcy perpendicular to the direction of the rotation center Po of the boom rotation axis 412 of the boom 41. Here, FTcy is the hydraulic pressure at the rod-side cylinder connection part 421 of the boom cylinder 42, obtained from the first boom hydraulic sensor 23 shown in Figure 1. And FBcy is the hydraulic pressure at the bottom-side cylinder connection part 422 of the boom cylinder 42, obtained from the second boom hydraulic sensor 24 shown in Figure 1. In this case, Fcy can be expressed by the following equation (9). Fcy = |FTcy - FBcy| (9)

[0040] Based on the coordinates and differential pressure of the boom cylinder 42 calculated by equations (1) to (9) above, we create an equilibrium equation between the rotational axial moment Ma generated around the rotation center Po of the boom rotation axis 412 of the boom 41 and the hydraulic moment Mh calculated from the differential pressure at both ends of the boom cylinder 42. First, the rotational axial moment Ma is the sum of the moments due to gravity of the boom 41, arm 43, bucket 44, and soil F. Here, let Mbm be the moment due to gravity of the boom 41. Let Mam be the moment due to gravity of the arm 43. Let Mbt be the moment due to gravity of the bucket 44. Let Msl be the moment due to gravity of the soil F.

[0041] In this case, the moment Mbm of the boom 41 due to gravity can be expressed by the following equation (10). Mbm=Fbm'|PoPbm|=Fbm|xPbm| (10)

[0042] The moment Mam of arm 43 due to gravity can be expressed by the following equation (11). Mam=Fam'·|PoPam|=Fam·|xPam| (11)

[0043] The moment Mbt due to gravity in bucket 44 can be expressed by the following equation (12). Mbt=Fbt'|PoPbt|=Fbt|xPbt| (12)

[0044] The moment Msl due to gravity in soil F can be expressed by the following equation (13). Note that the center of gravity of soil F is at the same position as the center of gravity Pbt of bucket 44, as described above. Msl=Fsl'|PoPbt|=Fsl|xPbt| (13)

[0045] From the above, the rotational moment Ma can be expressed by the following equation (14). Ma = Mbm + Mam + Mbt + Msl (14)

[0046] Furthermore, the hydraulic moment Mh, calculated from the differential pressure at both ends of the boom cylinder 42, can be expressed by the following equation (15). Mh=Fcy'|PoPcy|=Fcy|xPcy| (15)

[0047] The equation for the balance between the rotational axial moment Ma and the hydraulic moment Mh can be expressed by the following equation (16). Ma=Mh =Mbm+Mam+Mbt+Msl (16)

[0048] From equation (16), the gravitational force of soil F can be expressed by the following equation (17). Fsl=(Fcy|xPcy|-Fbm|xPbm|-Fam|xPam|-Fbt|xPbt|) / |Pbt| (17) The gravitational force Fsl of soil F is 9.8 [m / s²]. 2 The volume of soil can be calculated by dividing by [ ].

[0049] In the calculation of soil volume shown in equations (1) to (17), the angle θbt of the bucket 44 is a fixed value because it is the angle of the lifting position 44'. For example, from before excavation of soil F, during excavation, and during soil removal, the position of the bucket 44 is different from the lifting position 44'. In this case, the soil volume value calculated before excavation, etc., will be different from the value calculated in the lifting position 44', resulting in a large error. Normally, when the shovel 4 loads soil onto a dump truck, the shovel 4 loads soil F into the bucket 44 and lifts it, then rotates the boom 41, arm 43, and bucket 44 to the dump truck bed while maintaining the lifting position 44'. During rotation, the position of the bucket 44 does not change from the lifting position 44', so the calculated soil volume has less error. Therefore, in this embodiment, the average value of the soil volume calculated during rotation is taken as the soil volume of soil F loaded into the bucket 44.

[0050] The timing of calculating the soil volume will be explained with reference to Figure 6. The graph in Figure 6 has the calculated soil volume on the vertical axis and time (t) on the horizontal axis, showing the calculated soil volume in chronological order. In the graph, the soil volume calculated using the above-mentioned equations (1) to (17) is shown as a solid line, and the true soil volume is shown as a dotted line.

[0051] After excavation, when the bucket 44 is lifted to position 44', a lifting force, which is a force in the opposite direction to gravity, is applied to the bucket 44. The bucket 44 can be lifted if the lifting force is greater than the gravitational force acting on the bucket 44 and the soil F. In this case, the gravitational force acting on the bucket 44 and the soil F will be a negative value, so the volume of soil calculated using equations (1) to (17) above will be a negative value.

[0052] As the bucket 44 approaches the required height for rotation, the lifting force gradually decreases, and the gravitational force on the bucket 44 and soil F changes from a negative value to a positive value. As a result, the calculated soil volume also changes from a negative value to a positive value. Then, when the bucket 44 reaches the required height for rotation, the shovel 4 rotates the bucket 44 to the dump truck bed. During rotation, the posture of the bucket 44 does not change from the lifted posture 44', so the calculated soil volume remains roughly constant. Then, when the shovel 4 discharges the soil F onto the dump truck bed, the amount of soil F on the bucket 44 decreases, and therefore the soil volume decreases.

[0053] In this embodiment, in Figure 6, the period in which the calculated soil volume exceeds the measurement start threshold indicated by the dashed line and becomes a constant value is considered to be the period during which the bucket 44 is rotating, and the average value of this period is taken as the soil volume. Furthermore, if the soil volume calculated after rotation decreases to less than the soil discharge determination threshold indicated by the double dashed line, it is determined that the soil has been discharged, and the soil volume determined during rotation is considered to have been loaded into the dump truck. The measurement start threshold is stored as the measurement start threshold 141 in the storage unit 14 shown in Figure 2, and the soil discharge determination threshold is stored as the soil discharge determination threshold 142 in the storage unit 14.

[0054] A user loading soil F into a dump truck with shovel 4 can estimate the volume of soil in bucket 44 by executing a soil volume estimation program stored in the memory unit 14 of the information processing device 1 shown in Figure 2 during the operation. The soil volume estimation program is linked to, for example, an icon displayed on the screen of the display unit 13 of the information processing device 1 shown in Figure 2, and is activated when the user selects the icon using the operation input unit 11. The processing flow of the soil volume estimation program will be explained below with reference to the soil volume estimation flowchart shown in Figure 8.

[0055] The data acquisition unit 151 included in the control unit 15 of the information processing device 1 shown in Figure 2 initializes the total soil volume and counter N (step S101). The data acquisition unit 151 of the control unit 15 acquires various data (step S102). Specifically, the data acquisition unit 151 acquires the measurement start threshold 141 and the soil removal determination threshold 142 from the storage unit 14 of the information processing device 1 shown in Figure 2. The data acquisition unit 151 also acquires various values ​​such as Lbm and Lam of the shovel 4 shown in Figure 4 from the storage unit 14.

[0056] The centroid position calculation unit 152, included in the control unit 15 of the information processing device 1 shown in Figure 2, performs the earthwork volume calculation process (step S103). The earthwork volume calculation process will be explained below with reference to the flowchart shown in Figure 8.

[0057] The center of gravity position calculation unit 152 obtains the angles of the boom 41, arm 43, and bucket 44 (step S201). Specifically, the center of gravity position calculation unit 152 calculates the angle θbm of the boom 41 based on the angle measured by the boom sensor 21 shown in Figure 1. The center of gravity position calculation unit 152 obtains the angle θa of the arm 43 from the arm sensor 22 shown in Figure 1. The center of gravity position calculation unit 152 obtains the fixed value angle θbt of the bucket 44 from the storage unit 14.

[0058] The center of gravity calculation unit 152 calculates the coordinates of each part (step S202). Specifically, the center of gravity calculation unit 152 calculates the coordinates of the center of gravity of the boom 41, arm 43, and bucket 44 using equations (1) to (6) described above. The center of gravity calculation unit 152 also calculates the coordinates of the center position Pcy of the bottom cylinder connection part 422 of the boom cylinder 42 using equations (7) and (8) described above.

[0059] The moment calculation unit 153 included in the control unit 15 of the information processing device 1 shown in Figure 2 calculates the rotational axis moment Ma and the hydraulic moment Mh (step S203). Specifically, the moment calculation unit 153 calculates the rotational axis moment Ma using equations (10) to (14) described above. The moment calculation unit 153 also calculates the hydraulic moment Mh using equations (9) and (15) described above.

[0060] The soil volume calculation unit 154 included in the control unit 15 of the information processing device 1 shown in Figure 2 calculates the gravity of the soil F (step S204). Specifically, the soil volume calculation unit 154 calculates the gravity of the soil F using the above-mentioned equations (16) and (17). The soil volume calculation unit 154 calculates the soil volume (step S205). Specifically, the soil volume calculation unit 154 calculates the gravity of the soil F calculated in step S204 as 9.8 [m / s²]. 2 The volume of soil is calculated by dividing by [ ]. The volume of soil calculation unit 154 then terminates the volume of soil calculation process.

[0061] Now, let's return to Figure 7. The determination unit 155 included in the control unit 15 of the information processing device 1 shown in Figure 2 determines whether the value of the soil volume calculated in step S103 is greater than the measurement start threshold (step S104). If the value of the soil volume is greater than the measurement start threshold (step S104; YES), the determination unit 155 determines whether the difference between the soil volume calculated last time and this time is less than a predetermined threshold (step S105). Here, as shown in Figure 6, the calculated value of the soil volume is constant during rotation. Therefore, the difference between the soil volume calculated last time and this time is small, and the value of the difference is smaller than the predetermined threshold. Also, when not rotating, the calculated value of the soil volume is not constant. Therefore, the difference between the soil volume calculated last time and this time is large, and the value of the difference is larger than the predetermined threshold.

[0062] If the difference is not less than a predetermined threshold (step S105; NO), the determination unit 155 returns to step S103. Also, if the difference is less than a predetermined threshold (step S105; YES), the determination unit 155 adds the amount of soil calculated this time to the total amount of soil (step S106). The determination unit 155 adds 1 to the counter (step S107). The determination unit 155 returns to step S103.

[0063] Furthermore, in step S104, if the value of the soil volume is not greater than the measurement start threshold (step S104; NO), the determination unit 155 determines whether the previously calculated value of the soil volume is greater than the currently calculated value (step S108). If the previously calculated value of the soil volume is not greater than the currently calculated value (step S108; NO), the determination unit 155 returns to step S103. Also, if the previously calculated value of the soil volume is greater than the currently calculated value (step S108; YES), the determination unit 155 determines whether the currently calculated value of the soil volume is less than the soil removal measurement threshold (step S109).

[0064] If the calculated soil volume is not smaller than the soil removal measurement threshold (step S109; NO), the determination unit 155 returns to step S103. If the calculated soil volume is smaller than the soil removal measurement threshold (step S109; YES), the soil volume calculation unit 154 of the control unit 15 shown in Figure 2 calculates the average soil volume (step S110). Specifically, the soil volume calculation unit 154 divides the total soil volume by the value of the counter.

[0065] The volume calculation unit 154 clears the total volume and counter (step S111). The determination unit 155 of the control unit 15 determines whether or not the worker has given an instruction to finish (step S112). For example, if the user inputs an instruction to finish from the operation input unit 11 of the information processing device 1 shown in Figure 2, the volume estimation process is terminated. If the user has not input an instruction to finish from the operation input unit 11, the volume estimation process is continued.

[0066] If the worker does not give an instruction to finish (step S112; NO), the determination unit 155 returns to step S103. If the worker gives an instruction to finish (step S112; YES), the determination unit 155 terminates the soil volume estimation process.

[0067] As described above, the information processing device 1 according to this embodiment can estimate the mass of soil F loaded into the bucket 44 by utilizing the balance between the rotational axis moment Ma, which changes with the change in angle of the boom 41 and arm 43, and the hydraulic moment Mh, which changes with the change in hydraulic pressure of the boom cylinder 42. This makes it possible to determine the mass of soil loaded into the bucket even when an angle sensor is not attached to the bucket.

[0068] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are, of course, possible without departing from the spirit of the invention.

[0069] In the above embodiment, as shown in Figure 1, the information processing device 1 is placed inside the cabin 45 of the shovel 4. However, the information processing device 1 may be a separate unit and placed outside the cabin 45.

[0070] Furthermore, in the above embodiment, the bucket 44 of the shovel 4 is assumed to consist of one bucket 44 as shown in Figure 1. However, it is not limited to this, and a clamshell bucket specification bucket 44A, which combines two buckets 44, may also be used. In the clamshell bucket specification bucket 44A, when lifting soil F, the bucket 44A is closed and suspended. In this case, by setting θbt = 90°, the volume of soil can be calculated using equations (1) to (17) described above in the embodiment.

[0071] Furthermore, in the above embodiment, the hydraulic pressure on the rod-side cylinder connection portion 421 of the boom cylinder 42 is measured by the first boom hydraulic pressure sensor 23, and the hydraulic pressure on the bottom-side cylinder connection portion 422 of the boom cylinder 42 is measured by the second boom hydraulic pressure sensor 24, and the differential pressure of the measured hydraulic pressures is calculated using equation (9). However, the embodiment is not limited to this, and a hydraulic pressure sensor that outputs the differential pressure of the hydraulic pressures measured by the first boom hydraulic pressure sensor 23 and the second boom hydraulic pressure sensor 24 as the hydraulic pressure of the boom cylinder 42 may also be provided. Note that this hydraulic pressure sensor, or the first boom hydraulic pressure sensor 23 and the second boom hydraulic pressure sensor 24, are examples of pressure sensors within the scope of the claims.

[0072] Furthermore, the part referred to as "angle with the horizontal plane" in the above embodiment may be replaced with an angle made with respect to a line or plane in a predetermined direction, such as "angle with the vertical line."

[0073] Furthermore, a computer capable of realizing each of the above-described functions of the information processing device 1 may be configured by distributing programs for realizing each of the functions of the information processing device 1 in a storage medium such as a computer-readable CD-ROM (Compact Disc Read Only Memory) or DVD-ROM (Digital Versatile Disc Read Only Memory), and installing these programs on a computer. In cases where each function is realized through a division of labor between the OS (Operating System) and applications, or through cooperation between the OS and applications, only the applications may be stored on the storage medium.

[0074] The present invention allows for various embodiments and modifications without departing from the broad spirit and scope of the invention. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of the invention. In other words, the scope of the invention is indicated by the claims, not by the embodiments. Various modifications made within the scope of the claims and the equivalent significance of disclosure are considered to be within the scope of the invention. [Industrial applicability]

[0075] The present invention can be suitably used in an information processing system including an information processing device, a shovel, and an information processing device. [Explanation of symbols]

[0076] 1 Information processing device, 4 Shovel, 11 Operation input unit, 12 Communication unit, 13 Display unit, 14 Memory unit, 15 Control unit, 21 Boom sensor, 22 Arm sensor, 23 First boom hydraulic sensor, 24 Second boom hydraulic sensor, 31 Processor, 32 Main memory, 33 Auxiliary memory, 34 Input device, 35 Operation device, 36 Display controller, 37 Display device, 38 Communication device, 39 Bus, 41 Boom, 42 Boom cylinder, 43 Arm, 44, 44A Bucket, 44' Lifting position, 45 Cabin, 46 Drive unit, 47 Base, 48 Rotating unit, 49 Caterpillar, 100 Information processing system, 151 Data acquisition unit, 152 Center of gravity position calculation unit, 153 Moment calculation unit, 154 Soil volume calculation unit, 155 Judgment unit, 156 Display control unit, 411 Arm connection part, 412 boom rotation axis, 421 rod-side cylinder connection part, 422 bottom-side cylinder connection part, 441 bucket connection part.

Claims

1. A center of gravity calculation unit that determines the center of gravity positions of the boom, the arm, and the bucket attached to the tip of the arm based on a first angle, which is the angle of the shovel boom with respect to the horizontal plane, and a second angle, which is the angle of the arm attached to one end of the boom with respect to the horizontal plane. A moment calculation unit that determines the gravitational moment generated around the center of rotation of the boom rotation axis for rotating the boom due to gravity, based on the respective masses and center of gravity positions of the boom, the arm, and the bucket, and the pressure moment of the pressure of the boom cylinder for driving the boom up and down, A soil volume calculation unit that determines the amount of soil in the bucket based on the gravity moment and the pressure moment, Equipped with, The soil volume calculation unit determines the amount of soil loaded by the shovel based on the soil volume value during the period when the calculated soil volume value exceeds a predetermined first threshold and then falls below a predetermined second threshold. Information processing device.

2. The system further includes a determination unit that determines whether to start measuring the amount of soil in the bucket if the value of the amount of soil in the bucket obtained by the soil volume calculation unit is greater than the first threshold. The information processing apparatus according to claim 1.

3. The determination unit determines that the amount of soil in the bucket has been removed if the value of the amount of soil in the bucket obtained by the soil volume calculation unit is less than the second threshold. The information processing apparatus according to claim 2.

4. A first angle sensor is provided on the boom for measuring the first angle, The arm is equipped with a second angle sensor for measuring the second angle, The boom cylinder is provided with a pressure sensor for measuring the pressure of the boom cylinder, and further comprises An information processing apparatus according to any one of claims 1 to 3.

5. The first angle sensor and the second angle sensor are inertial measuring devices that detect three-dimensional inertial motion at the part to which they are attached. The pressure sensor is a hydraulic sensor that outputs the differential pressure between the hydraulic pressure measured by a first boom hydraulic pressure sensor located on the rod side of the boom cylinder and the hydraulic pressure measured by a second boom hydraulic pressure sensor located on the bottom side of the boom cylinder as the hydraulic pressure of the boom cylinder. The information processing apparatus according to claim 4.

6. The soil volume calculation unit determines the amount of soil loaded by the shovel based on the average value of the soil volume in the bucket from the time the calculated soil volume in the bucket exceeds the first threshold until it falls below the second threshold. An information processing apparatus according to any one of claims 1 to 3.

7. The boom and A first angle sensor fixed to the boom measures a first angle with respect to the horizontal plane, An arm rotatably supported at one end of the boom, A second angle sensor fixed to the aforementioned arm and measuring a second angle with respect to the horizontal plane, A pressure sensor is fixed to the boom cylinder for driving the boom up and down, and measures the pressure of the boom cylinder. A bucket rotatably supported at the tip of the aforementioned arm, A shovel equipped with, By inputting the measured first angle, second angle, and boom cylinder pressure into the information processing device, the information processing device is instructed to estimate the volume of soil in the bucket. Based on the estimated volume of soil from the point where the estimated volume exceeds a predetermined first threshold until it falls below a predetermined second threshold, the amount of soil loaded by the shovel is estimated. Shovel.

8. A method executed by an information processing device, Based on a first angle, which is the angle of the shovel boom with respect to the horizontal plane, and a second angle, which is the angle of the arm attached to one end of the boom with respect to the horizontal plane, the center of gravity positions of the boom, the arm, and the bucket attached to the tip of the arm are determined. The gravitational moment generated around the center of rotation of the boom rotation axis for rotating the boom due to gravity, based on the respective masses and center of gravity positions of the boom, the arm, and the bucket, and the pressure moment of the pressure in the boom cylinder for driving the boom up and down are determined. Based on the gravity moment and the pressure moment, the volume of soil in the bucket is determined, and based on the value of the determined volume of soil from the time it exceeds a predetermined first threshold until it falls below a predetermined second threshold, the volume of soil loaded by the shovel is determined. method.

9. On the computer, A process to determine the center of gravity positions of the boom, the arm, and the bucket attached to the tip of the arm, based on a first angle which is the angle of the boom of the shovel with respect to the horizontal plane, and a second angle which is the angle of the arm attached to one end of the boom with respect to the horizontal plane. A process for determining the gravitational moment generated around the center of rotation of the boom rotation axis for rotating the boom due to gravity, based on the respective masses and center of gravity positions of the boom, the arm, and the bucket, and the pressure moment of the pressure of the boom cylinder for driving the boom up and down. A process to determine the volume of soil in the bucket based on the gravity moment and the pressure moment, and to determine the volume of soil loaded by the shovel based on the value of the soil volume from when it exceeds a predetermined first threshold until it falls below a predetermined second threshold. A program to execute.

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