Work support system

Abstract

We provide a work support system that can accurately calculate the angle of the bucket. [Solution] A work support system 1 that assists work performed by a work machine, the work machine comprising a boom 4 connected to a machine body 3 so as to be able to be raised and lowered, an arm 5 connected to the tip of the boom 4 so as to be able a raised and lowered, an arm 5 that has been connected to the tip of the boom 4 so as to be able to be connected to the tip of the

Description

[Technical Field]

[0001] This disclosure relates to a work support system. [Background technology]

[0002] In recent years, work support systems have been developed that assist work performed by machinery through machine guidance functions and other means (see, for example, Patent Document 1). These types of work support systems attach attitude sensors to each movable part of the work machine and calculate the angle and position of each movable part based on the angles detected by these attitude sensors. For example, the angles of the boom and arm of a hydraulic excavator (backhoe) are calculated by directly attaching attitude sensors to the boom and arm and using the detected angles. On the other hand, since directly attaching an attitude sensor to the bucket of a hydraulic excavator carries a very high risk of damage, an attitude sensor is attached to a link between the arm and the bucket, and the angle of the bucket is indirectly calculated based on the detected angle. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-61455 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, because there are inherent errors and play in the link and bucket, and these errors and play can change over time, it is difficult to accurately calculate the bucket angle.

[0005] Therefore, this disclosure aims to provide a work support system that can accurately calculate the angle of a bucket. [Means for solving the problem]

[0006] In one respect, it offers the following solutions: A work support system that assists work performed by work machines, The aforementioned work machine is A boom that is attached to the aircraft in a manner that allows for elevation control, An arm is rotatably connected to the tip of the boom, The arm comprises a bucket that is rotatably connected to the tip of the arm via a link, The aforementioned work support system is The invention is characterized by comprising a relational expression calculation means that, during the rotation operation of the bucket, acquires the detection angle of a first attitude sensor attached to the link and the detection angle of a second attitude sensor attached to the bucket multiple times, and calculates a relational expression between the angle of the link and the angle of the bucket based on the acquired detection angles of the first and second attitude sensors. [Effects of the Invention]

[0007] This disclosure makes it possible to provide a work support system that can accurately calculate the angle of a bucket. [Brief explanation of the drawing]

[0008] [Figure 1] This diagram shows a hydraulic excavator with a work support system applied. [Figure 2] This is a block diagram showing the configuration of the work support system. [Figure 3] This is a flowchart showing the bucket calibration procedure. [Figure 4] This diagram shows the position sensor being moved from the boom to the bucket. [Figure 5] This is a diagram showing the app screen of a mobile device. [Figure 6] This diagram shows the relationship between the angle of the attitude sensor attached to the bucket and the angle of the bucket. [Figure 7] This is a diagram showing the range of motion of the bucket. [Figure 8]It is a diagram showing the relationship between the detection angle of the attitude sensor attached to the link and the detection angle of the attitude sensor attached to the bucket. [Figure 9] It is a diagram showing the replacement of the attitude sensor from the bucket to the boom. [Figure 10] It is a flowchart showing the calculation procedure of the bucket angle.

Best Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

[0010] (Work Machine) FIG. 1 is a diagram showing a hydraulic excavator 2 to which the work support system 1 is applied. The work support system 1 supports the work of an operator who operates the hydraulic excavator 2, which is a work machine (construction machine), by functions such as machine guidance.

[0011] The hydraulic excavator 2 includes a self-propelled machine body 3, a boom 4 that is connected to the machine body 3 so as to be able to perform a lifting operation, an arm 5 that is rotatably connected to the tip of the boom 4, and a bucket 7 that is rotatably connected to the tip of the arm 5 via a link 6.

[0012] The boom 4 rises and falls according to the hydraulic expansion and contraction operation of a boom cylinder (not shown) provided between the machine body 3 and the boom 4. The arm 5 rotates according to the hydraulic expansion and contraction operation of an arm cylinder (not shown) provided between the boom 4 and the arm 5. The bucket 7 rotates according to the hydraulic expansion and contraction operation of a bucket cylinder (not shown) provided between the arm 5 and the link 6. Note that the work support system 1 is not limited to the hydraulic excavator 2, and can be widely applied to various work machines used in work such as civil engineering, construction, agriculture, and transportation.

[0013] (Work Support System) FIG. 2 is a block diagram showing the configuration of the work support system 1. As shown in Figure 2, the work support system 1 comprises a plurality of posture sensors 11A to 11C, a relay unit 12, a notification unit 13, and a portable terminal 14.

[0014] (Posture sensor) The multiple attitude sensors 11A to 11C include a boom attitude sensor 11A (second attitude sensor), an arm attitude sensor 11B (third attitude sensor), and a link attitude sensor 11C (first attitude sensor). The boom attitude sensor 11A is attached to the boom 4 and detects the elevation angle of the boom 4. The arm attitude sensor 11B is attached to the arm 5 and detects the rotation angle of the arm 5. The link attitude sensor 11C is attached to the link 6 and indirectly detects the rotation angle of the bucket 7.

[0015] As shown in Figure 2, each attitude sensor 11A to 11C includes a detection unit 111 for detecting the attitude of the object to be detected, a calculation unit 112 for processing the detection information from the detection unit 111, a communication unit 113 for wirelessly transmitting the detection information as attitude information to the relay unit 12, and a battery (not shown) for supplying power to each unit. By operating on battery power and transmitting attitude information via wireless communication, each attitude sensor 11A to 11C can be easily installed in any location without the need to provide cables for power supply and data communication.

[0016] More specifically, the detection unit 111 is fitted with an IMU (INERTIAL MEASUREMENT UNIT) sensor, and the wireless communication in the communication unit 113 uses BLUETOOTH®.

[0017] Furthermore, each attitude sensor 11A to 11C includes a detection unit 111, a calculation unit 112, a communication unit 113, and a case 114 that houses the battery. The case 114 has, for example, a magnet (not shown) on its bottom surface, and is detachably attached to the boom 4, arm 5, or link 6 by the magnetic force of the magnet. Also, an arrow 115 (see Figure 6) indicating the mounting direction of each attitude sensor 11A to 11C is formed on the top surface of the case 114.

[0018] (Relay section) The relay unit 12 is attached to the aircraft 3 and collects attitude information acquired by each attitude sensor 11A to 11C through data communication with each attitude sensor 11A to 11C and outputs it to the mobile terminal 14. It also acquires data output from the mobile terminal 14 and outputs it to the notification unit 13.

[0019] (Notification Department) The notification unit 13 is configured to notify the operator of information to assist in the operator's operation in the operator's seat of the hydraulic excavator 2, and in this embodiment, it is formed by an image display device. Various types of information that can assist in the operator's operation can be applied to the information to assist in the operator's operation, such as the current construction position relative to the construction target, but in this embodiment, the angles of the boom 4, arm 5 and bucket 7 with respect to the reference direction (e.g., horizontal direction) are applied. The notification unit 13 may also notify the operator of information to assist in the operator's operation by voice or alarm sound, or it may be used in conjunction with a portable terminal 14.

[0020] (Mobile device) The mobile terminal 14 is a so-called smartphone or tablet device, and it calculates information to support the operator's operation based on attitude information obtained from attitude sensors 11A to 11C via the relay unit 12.

[0021] More specifically, the mobile terminal 14 comprises a display unit 141, an imaging unit 142, an operation unit 143, a calculation unit 144, and a communication unit 145. The display unit 141 is formed by an image display panel such as a liquid crystal display panel and displays various image information related to the mobile terminal 14. The operation unit 143 is formed by a touch panel or the like located on the display unit 141 and detects various operations of the operator. The imaging unit 142 acquires imaging results in accordance with the operator's operations under the control of the calculation unit 144. The communication unit 145 inputs and outputs attitude information, information to support the operator's operations, etc., to and from the relay unit 12 via wireless communication.

[0022] The calculation unit 144 is a calculation processing circuit that executes application software related to the work support system 1. It displays various image information on the display unit 141, switches various operations of the mobile terminal 14 according to the operation of the operation unit 143, and further switches the operation of the work support system 1.

[0023] (Functional configuration of mobile devices) The mobile terminal 14 includes a functional configuration realized through the cooperation of hardware and software, comprising multiple calibration means and multiple angle calculation means. The multiple calibration means include a boom calibration means, an arm calibration means, and a bucket calibration means (relational formula calculation means). The multiple angle calculation means also include a boom angle calculation means, an arm angle calculation means, and a bucket angle calculation means.

[0024] (Overview of calibration means and angle calculation means) When the calibration means receives a calibration instruction from the operator, it calculates the mounting angle error of the attitude sensors 11A to 11C relative to the reference mounting angle and registers a relational formula or correction data for correcting the attitude information (detected angle) of the attitude sensors 11A to 11C. The angle calculation means also corrects the attitude information input from the relay unit 12 based on the registered relational formula or correction data and sends out the corrected attitude information as information to support the operator's operation.

[0025] For example, when the arm calibration means starts processing, it instructs the operator to take an image of the arm attitude sensor 11B via the display unit 141 and records the image information of the imaging result obtained via the imaging unit 142. At this time, the arm calibration means instructs the acquisition of imaging results that include the rotation axes at both ends of the arm 5.

[0026] Next, the arm calibration means calculates the direction of the arm 5 and the mounting direction of the arm attitude sensor 11B relative to the arm 5 based on the acquired imaging results. For example, the direction of the arm 5 is calculated by recognizing the positions of the pivot axes at both ends of the arm 5 from the imaging results and using the direction of a virtual straight line connecting the pivot axes at both ends. The mounting direction of the arm attitude sensor 11B is calculated by recognizing the arrow 115 formed on the case 114 of the arm attitude sensor 11B and using the direction of the arrow 115.

[0027] The arm calibration means then calculates a relational expression or correction data to obtain the angle of arm 5 from the detected angle of arm attitude sensor 11B, based on the calculated direction of arm 5 and the mounting direction of arm attitude sensor 11B. Note that the boom calibration means uses a similar method to the arm calibration means, so a detailed explanation is omitted.

[0028] (Bucket calibration means and bucket angle calculation means) Since the angle of the bucket 7 is calculated indirectly based on the detected angle of the link attitude sensor 11C, the bucket calibration means acquires relational formulas or correction data using a different method than the arm calibration means and boom calibration means.

[0029] Specifically, when performing bucket calibration, the bucket calibration means instructs the operator to reattach the boom attitude sensor 11A to the side of the bucket 7 and then rotate the bucket 7. The bucket calibration means then acquires the detection angle of the link attitude sensor 11C attached to the link 6 and the detection angle of the boom attitude sensor 11A attached to the bucket 7 at approximately the same time while the bucket 7 is rotating, and repeats this multiple times. Subsequently, the bucket calibration means calculates a relationship between the angle of the link 6 (hereinafter referred to as the link angle as appropriate) and the angle of the bucket 7 (hereinafter referred to as the bucket angle as appropriate) based on the acquired detection angles of the link attitude sensor 11C and the boom attitude sensor 11A.

[0030] This bucket calibration method allows for obtaining a relationship between the link angle and the bucket angle that takes into account aircraft-specific errors and play, making it possible to accurately calculate the angle of the bucket 7 based on the angle detected by the link attitude sensor 11C.

[0031] Furthermore, the bucket calibration means corrects the relational expression based on the mounting angle of the boom attitude sensor 11A relative to the bucket 7. This prevents a decrease in the accuracy of bucket angle calculation due to variations in the mounting angle of the boom attitude sensor 11A relative to the bucket 7.

[0032] Furthermore, when the bucket calibration means acquires the detection angles of the link attitude sensor 11C and the boom attitude sensor 11A, it also records the detection angle of the arm attitude sensor 11B attached to the arm 5. This allows the difference between the arm angle at the time of calibration and the current arm angle (detection angle of the arm attitude sensor 11B) to be calculated when calculating the angle of the bucket 7 based on the detection angle of the link attitude sensor 11C and the relational formula. By correcting the relational formula based on this difference, a decrease in the accuracy of the bucket angle calculation due to the arm angle can be prevented.

[0033] (Bucket calibration procedure) Next, the specific procedure for bucket calibration to implement the bucket calibration means described above will be explained with reference to Figures 3 to 9. Note that boom calibration and arm calibration may be performed before or after bucket calibration.

[0034] Figure 3 is a flowchart showing the bucket calibration procedure. The bucket calibration means performs bucket calibration while instructing the operator on the app screen of the mobile terminal 14 to perform predetermined tasks and operations. First, the bucket calibration means instructs the operator to remove the boom attitude sensor 11A from the boom 4 and install it on the side of the bucket 7 (S11, see Figure 4).

[0035] Next, the bucket calibration means instructs the operator to use the mobile terminal 14 to take a picture from directly beside the link 6 and the bucket 7 so that the sides are visible, and acquires images as shown in Figures 5 and 6. At this time, the bucket calibration means may automatically recognize the position of the bucket pin 71, which is the pivot axis of the bucket 7, and the position of the bucket cutting edge 72 in the acquired images, or it may allow the operator to select them.

[0036] The bucket calibration means calculates the angle Br of the bucket 7 (direction of the straight line passing through the bucket pin 71 and the bucket cutting edge 72) and the mounting angle Bs of the boom attitude sensor 11A installed on the side of the bucket 7 (direction of arrow 115) from the acquired image. Subsequently, the bucket calibration means calculates the difference ΔB (=Bs - Br) between the angle Br of the bucket 7 and the mounting angle Bs of the boom attitude sensor 11A (S12, see Figure 6).

[0037] Next, the bucket calibration means instructs the operator to rotate the bucket 7 to its maximum open and maximum closed positions (see Figure 7). At this time, since the bottom of the bucket 7 is in close contact with the ground when the hydraulic excavator 2 is not performing excavation work, it is necessary to move the boom 4 and arm 5 to a predetermined position (for example, upward) so that the bottom of the bucket 7 is lifted a certain distance from the ground.

[0038] Next, the bucket calibration means rotates the bucket 7 to its maximum open position and then instructs the operator to press the recording start button (not shown) displayed on the mobile terminal 14. At this time, the boom 4 and arm 5 are kept stopped, and only the bucket 7 and link 6 are operated.

[0039] Next, the bucket calibration means rotates the bucket 7 to its maximum closed position and then instructs the operator to press the intermediate record button (not shown) displayed on the mobile terminal 14. At this time, the boom 4 and arm 5 are kept stopped, and only the bucket 7 and link 6 are operated.

[0040] Next, the bucket calibration means rotates the bucket 7 to its maximum open position and then instructs the operator to press the recording end button (not shown) displayed on the mobile terminal 14. At this time, the boom 4 and arm 5 are kept stopped, and only the bucket 7 and link 6 are operated.

[0041] The bucket calibration means acquires and records the detected angles of the link attitude sensor 11C and the boom attitude sensor 11A at approximately the same timing during the bucket opening and closing operation described above for one round trip, and repeats this multiple times. Then, the bucket calibration means calculates equation 1, the relationship between the link angle and the bucket angle, from the combination of the recorded detected angles of the link 6 and the bucket 7 (S13). Note that the reciprocating motion of the bucket 7 is not limited to one round trip, but can be any number of round trips, as long as it is 0.5 round trips or more.

[0042] For example, let Y be the detection angle of the boom attitude sensor 11A attached to the bucket 7, and X be the detection angle of the link attitude sensor 11C attached to the link 6, and let Xn and Yn be n arbitrary detection angles. In this case, the combinations of detection angles are (X1, Y1), (X2, Y2), ..., (Xn, Yn), and relation 1 can be obtained, for example, by the least squares method or cubic approximation. In the case of cubic approximation, as shown in Figure 8, Y = a × X 3 +b×X 2 +c × X 1 +d×X 0 It can be expressed as follows.

[0043] Also, when the recording end button is pressed, the bucket calibration means records the angle Zi of the arm 5 (the detected angle of the arm posture sensor 11B) (S14).

[0044] Next, the bucket calibration means instructs the operator to return the boom posture sensor 11A installed on the side surface of the bucket 7 to the original position of the boom 4 (see FIG. 9).

[0045] Thereafter, the bucket calibration means calculates the relational expression 2 based on the above-described difference ΔB and the relational expression 1 (S15). That is, when the angle of the arm 5 is Zi, if the detected angle of the link posture sensor 11C at an arbitrary timing is Xt, the angle of the bucket 7 at that time is Yt = a×Xt 3 +b×Xt 2 +c×Xt 1 +d×Xt 0 which can be expressed as. However, since the actual angle of the bucket 7 is deviated by the difference ΔB, the relational expression 2 considering the difference ΔB is Yt = ΔB + a×Xt 3 +b×Xt 2 +c×Xt 1 +d×Xt 0 and becomes.

[0046] (Bucket Angle Calculation Procedure) Next, a specific calculation procedure of the bucket angle for realizing the above-described bucket angle calculation means will be described with reference to FIG. 10.

[0047] FIG. 10 is a flowchart showing the calculation procedure of the bucket angle. As shown in FIG. 10, when calculating the angle of the bucket 7, the bucket angle calculation means first obtains the current arm angle Zt (the detected angle of the arm posture sensor 11B) (S21).

[0048] Next, the bucket angle calculation means calculates the difference ΔZ (=Zt-Zi) between the current arm angle Zt and the arm angle Zi calculated using relational equations 1 and 2 (S22), and then calculates relational equation 3 based on the difference ΔZ and relational equation 2 (S23). In other words, if the arm angle is anything other than Zi, the change in the arm angle of arm 5 is added to or subtracted from the link angle Xt, so it is necessary to add or subtract the difference ΔZ from the arm angle Zt at any given time to Xt. Therefore, the bucket angle calculation means calculates Yt, which does not include the change in arm 5, and then adds the difference ΔZ to Yt to obtain the bucket angle Yt' at any given time. Relational equation 3 is Yt'=ΔZ+Yt=ΔZ+ΔB+[a×(Xt-ΔZ)] 3 +b × (Xt - ΔZ) 2 +c × (Xt - ΔZ) 1 +d×(Xt―ΔZ) 0 ]

[0049] Subsequently, the bucket angle calculation means calculates the angle of the bucket 7 by substituting the current link angle (the angle detected by the link attitude sensor 11C) into relational equation 3 (S24).

[0050] Although each embodiment has been described in detail above, the invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope described in the claims. Furthermore, it is possible to combine all or more of the components of the embodiments described above. [Explanation of Symbols]

[0051] 1. Work support system 2 Hydraulic Excavator 3 aircraft 4 Boom 5 Arms 6 links 7 buckets 71 Bucket Pin 72 Bucket cutting edge 11A Boom attitude sensor 11B Attitude sensor for arm 11C Link Attitude Sensor 111 Detection Unit 112 Arithmetic section 113 Communications Department 114 cases 115 Arrow 12 Relay section 13 Notification Department 14 Mobile devices 141 Display section 142 Imaging Unit 143 Operation section 144 Arithmetic section 145 Communications Department

Claims

1. A work support system that assists work performed by work machines, The aforementioned work machine is A boom that is attached to the aircraft in a manner that allows for elevation control, An arm is rotatably connected to the tip of the boom, The arm comprises a bucket that is rotatably connected to the tip of the arm via a link, The aforementioned work support system is A work support system comprising: a means for calculating a relational expression that, during the rotation operation of the bucket, acquires the detection angle of a first attitude sensor attached to the link and the detection angle of a second attitude sensor attached to the bucket multiple times, and calculates a relational expression between the angle of the link and the angle of the bucket based on the acquired detection angles of the first and second attitude sensors.

2. The work support system according to claim 1, wherein the second attitude sensor is a boom attitude sensor that is normally attached to the boom, and is switched to the bucket only when calculating the relational expression.

3. The work support system according to claim 1, wherein the relational expression calculation means corrects the relational expression based on the mounting angle of the second attitude sensor with respect to the bucket.

4. The work support system according to claim 1, wherein the relational expression calculation means records the detection angle of a third attitude sensor attached to the arm when acquiring the detection angles of the first attitude sensor and the second attitude sensor.

5. The bucket angle calculation means further comprises substituting the current detected angle of the first attitude sensor into the relational expression to calculate the current angle of the bucket, The work support system according to claim 4, wherein the bucket angle calculation means corrects the calculated angle of the bucket based on the difference between the current detected angle of the third attitude sensor and the detected angle of the third attitude sensor recorded by the relational expression calculation means.

Images