Machinery Management System

Abstract

This invention provides a work machine management system that can detect abnormalities caused by hydraulic fluid leaks, regardless of the operating status of the work machine. [Solution] The work machine management system comprises a work machine 2 and a management server 3 that receives data from the controller 29 of the work machine 2 via a communication network 1. The management server 3 uses an estimation model that has as parameters the rotational speed of the prime mover 17 corresponding to the discharge flow rate of the main pump 18, the capacity of the main pump 18, multiple pilot pressures corresponding to the opening degrees of multiple control valves 20 to 23, and the hydraulic pressure of multiple hydraulic actuators 8, 12 to 14, which are included in the data, to estimate the speed of any one of the multiple hydraulic actuators 8, 12 to 14, and calculates and outputs the difference between the estimated speed and the actual speed.

Description

Technical Field

[0001] The present invention relates to a work machine management system.

Background Art

[0002] A hydraulic excavator, which is one of work machines, includes a hydraulic circuit. This hydraulic circuit includes a hydraulic pump, a plurality of hydraulic actuators driven by hydraulic oil discharged from the hydraulic pump, and a plurality of control valves that control the flow of hydraulic oil from the hydraulic pump to the plurality of hydraulic actuators. Each control valve controls the flow rate of the hydraulic oil supplied to the hydraulic actuator according to the operation amount of an operation member (for example, an operation lever) by the operator. Thereby, the speed of the hydraulic actuator is controlled. As the operating time of the hydraulic excavator elapses, if the components of the hydraulic circuit deteriorate, leakage of hydraulic oil may occur, and the speed of the hydraulic actuator may decrease.

[0003] Patent Document 1 discloses a method for detecting an abnormality due to leakage of hydraulic oil. In Patent Document 1, on the premise that only a single operation member is operated and its operation amount is maximum, as a condition for all of the hydraulic oil discharged from the hydraulic pump to be supplied to one hydraulic actuator. Then, the discharge flow rate of the hydraulic pump is calculated based on the current value and discharge pressure of the hydraulic pump, and the supply flow rate of the hydraulic cylinder is calculated based on the moving speed and pressure receiving area of the piston of the hydraulic cylinder. Then, it is determined whether there is an abnormality due to leakage of hydraulic oil based on whether the difference between the discharge flow rate of the hydraulic pump and the supply flow rate of the hydraulic actuator is greater than or equal to a predetermined threshold value.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As mentioned above, Patent Document 1 detects abnormalities due to hydraulic fluid leakage based on the premise that only a single operating member is operated and its operating amount is at its maximum. However, in actual hydraulic excavator operation, multiple operating members are frequently operated simultaneously, or even if only a single operating member is operated, its operating amount is not at its maximum. It is rare for only a single operating member to be operated and its operating amount to be at its maximum. Therefore, if the operator does not operate the operating members with the intention of detecting abnormalities due to hydraulic fluid leakage, there is a possibility of missing abnormalities over the long term.

[0006] The present invention has been made in view of the above matters, and its object is to provide a work machine management system that can detect abnormalities caused by hydraulic fluid leakage regardless of the operating state of the work machine. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a work machine management system comprising: a work machine equipped with a hydraulic pump, a plurality of hydraulic actuators driven by hydraulic fluid discharged from the hydraulic pump, a plurality of control valves that control the flow of hydraulic fluid from the hydraulic pump to the plurality of hydraulic actuators, and a controller that acquires data; and a management server that receives the data from the controller of the work machine via a communication network. The management server uses an estimation model, which includes parameters such as the discharge flow rate of the hydraulic pump or a corresponding state quantity, a plurality of state quantities corresponding to the opening degree of the plurality of control valves, and the hydraulic pressure of the plurality of hydraulic actuators, to estimate the speed of any one of the plurality of hydraulic actuators, calculates and outputs the difference between the estimated speed of the hydraulic actuator and the actual speed of the hydraulic actuator, or outputs the result of a calculation or determination using the difference. [Effects of the Invention]

[0008] According to the present invention, abnormalities caused by hydraulic fluid leakage can be detected regardless of the operating state of the work machine. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram illustrating the configuration of a work machine management system in one embodiment of the present invention. [Figure 2] This diagram shows the configuration of the drive system for a work machine in one embodiment of the present invention, specifically the configuration related to the driving of the slewing motor, boom cylinder, arm cylinder, and bucket cylinder. [Figure 3] This is a block diagram showing the functional configuration of the management server in one embodiment of the present invention, along with related equipment. [Figure 4] This is a flowchart illustrating the processing steps of the management server in one embodiment of the present invention. [Figure 5] This figure illustrates how to define the scope of application of an estimation model in one embodiment of the present invention. [Figure 6] This figure shows the display screen of a terminal in one modified example of the present invention. [Figure 7] This figure shows the display screen of a terminal in another modified example of the present invention. [Modes for carrying out the invention]

[0010] One embodiment of the present invention will be described with reference to the drawings.

[0011] Figure 1 is a schematic diagram showing the configuration of the work machine management system in this embodiment.

[0012] The work machine management system of this embodiment comprises work machines 2, a management server 3, and a terminal 4 that can communicate with each other via a communication network 1. The communication network 1 is composed of, for example, multiple wireless communication devices. The management server 3 is owned by an administrator who manages the work machines 2, and the terminal 4 is owned by a worker who performs maintenance work on the work machines 2.

[0013] The work machine 2 is, for example, a hydraulic excavator, and comprises a mobile body 5, a slewing body 6 rotatably mounted above the mobile body 5 (upper side in Figure 1), and a work device 7 connected to the front side of the slewing body 6 (left side in Figure 1). The mobile body 5 moves by the drive of a travel motor (not shown), and the slewing body 6 rotates by the drive of a slewing motor 8 (see Figure 2, described later).

[0014] The working device 7 comprises a boom 9 rotatably connected to the front of the slewing body 6, an arm 10 rotatably connected to the tip of the boom, and a bucket 11 rotatably connected to the tip of the arm 10. The boom 9 rotates by the drive of the boom cylinder 12, the arm 10 rotates by the drive of the arm cylinder 13, and the bucket 11 rotates by the drive of the bucket cylinder 14.

[0015] The slewing body 6 has a driver's cab 15 where the operator sits. Inside the driver's cab 15 are an operating device (not shown) that the operator operates to instruct the movement of the traveling body 5, an operating device 16A (see Figure 2 below) that the operator operates to selectively instruct the slewing body 6 to rotate and the arm 10 to rotate, and an operating device 16B (see Figure 2 below) that the operator operates to selectively instruct the boom 9 to rotate and the bucket 11 to rotate.

[0016] The work machine 2 is equipped with a drive system that drives multiple hydraulic actuators (specifically, the travel motor, slewing motor 8, boom cylinder 12, arm cylinder 13, and bucket cylinder 14 described above) in response to the operation of multiple operating devices. Figure 2 is a diagram showing the configuration of the drive system of the work machine 2 in this embodiment, specifically the configuration related to the driving of the slewing motor 8, boom cylinder 12, arm cylinder 13, and bucket cylinder 14. Note that Figure 2 does not show the configuration related to the driving of the travel motor, and its explanation is omitted.

[0017] The drive device of the working machine 2 includes a variable displacement main pump (hydraulic pump) 18 driven by a prime mover 17 (for example, an engine or an electric motor), a regulator 19 that controls the capacity of the main pump 18 (specifically, the tilt angle of the swash plate or swash shaft), a swing motor 8, a boom cylinder 12, an arm cylinder 13, and a bucket cylinder 14 driven by the hydraulic oil discharged from the main pump 18, a swing control valve 20 that controls the flow of hydraulic oil from the main pump 18 to the swing motor 8, a boom control valve 21 that controls the flow of hydraulic oil from the main pump 18 to the boom cylinder 12, an arm control valve 22 that controls the flow of hydraulic oil from the main pump 18 to the arm cylinder 13, and a bucket control valve 23 that controls the flow of hydraulic oil from the main pump 18 to the bucket cylinder 14.

[0018] The drive device of the working machine 2 includes a pilot pump 24 driven by the prime mover 17, swing solenoid valves 25A, 25B that generate the pilot pressure of the swing control valve 20 based on the discharge pressure of the pilot pump 24, boom solenoid valves 26A, 26B that generate the pilot pressure of the boom control valve 21 based on the discharge pressure of the pilot pump 24, arm solenoid valves 27A, 27B that generate the pilot pressure of the arm control valve 22 based on the discharge pressure of the pilot pump 24, bucket solenoid valves 28A, 28B that generate the pilot pressure of the bucket control valve 23 based on the discharge pressure of the pilot pump 24, and a controller 29 that controls the solenoid valves 25A, 25B to 28A, 28B according to the operations of the operation devices 16A, 16B. The controller 29 has a processor that executes processing according to a program, a memory that stores programs and data, and the like.

[0019] The operating device 16A includes an operation lever (operation member) that can be operated by the driver in the front-rear direction and the left-right direction, a first potentiometer that generates and outputs an operation signal corresponding to the rear-side operation amount of the operation lever, a second potentiometer that generates and outputs an operation signal corresponding to the front-side operation amount of the operation lever, a third potentiometer that generates and outputs an operation signal corresponding to the right-side operation amount of the operation lever, and a fourth potentiometer that generates and outputs an operation signal corresponding to the left-side operation amount of the operation lever.

[0020] The operating device 16B includes an operation lever (operation member) that can be operated by the driver in the front-rear direction and the left-right direction, a fifth potentiometer that generates and outputs an operation signal corresponding to the rear-side operation amount of the operation lever, a sixth potentiometer that generates and outputs an operation signal corresponding to the front-side operation amount of the operation lever, a seventh potentiometer that generates and outputs an operation signal corresponding to the left-side operation amount of the operation lever, and an eighth potentiometer that generates and outputs an operation signal corresponding to the right-side operation amount of the operation lever.

[0021] The controller 29 generates a drive signal corresponding to the operation signal from the first potentiometer and outputs the generated drive signal to the swing electromagnetic valve 25A. The swing electromagnetic valve 25A generates a pilot pressure corresponding to the drive signal and outputs the generated pilot pressure to one pressure receiving portion of the swing control valve 20. As a result, the swing control valve 20 is switched to the switching position on the left side in the drawing, and the opening degree of the swing control valve 20 (specifically, the opening area of the center bypass passage, the opening area of the meter-in passage, and the opening area of the meter-out passage) is controlled. Then, hydraulic oil is supplied from the main pump 18 to one port of the swing motor 8 through the swing control valve 20, and the hydraulic oil is returned from the other port of the swing motor 8 to the tank through the swing control valve 20. As a result, the swing motor 8 rotates in one direction, and the swing body 6 swings to the left.

[0022] The controller 29 generates a drive signal corresponding to the operation signal from the second potentiometer and outputs the generated drive signal to the slewing solenoid valve 25B. The slewing solenoid valve 25B generates a pilot pressure corresponding to the drive signal and outputs the generated pilot pressure to the pressure receiving section on the other side of the slewing control valve 20. As a result, the slewing control valve 20 is switched to the switching position shown on the right side of the figure, and the opening degree of the slewing control valve 20 is controlled. Then, hydraulic fluid is supplied from the main pump 18 to the other port of the slewing motor 8 via the slewing control valve 20, and hydraulic fluid is returned to the tank from the port on one side of the slewing motor 8 via the slewing control valve 20. As a result, the slewing motor 8 rotates in the opposite direction, and the slewing body 6 sways to the right.

[0023] The controller 29 generates a drive signal corresponding to the operation signal from the third potentiometer and outputs the generated drive signal to the arm solenoid valve 27A. The arm solenoid valve 27A generates a pilot pressure corresponding to the drive signal and outputs the generated pilot pressure to the pressure receiving section on one side of the arm control valve 22. As a result, the arm control valve 22 is switched to the switching position shown on the left in the figure, and the opening degree of the arm control valve 22 is controlled. Then, hydraulic fluid is supplied from the main pump 18 to the bottom port of the arm cylinder 13 via the arm control valve 22, and the hydraulic fluid is returned to the tank from the rod port of the arm cylinder 13 via the arm control valve 22. As a result, the arm cylinder 13 extends and the arm 10 clouds.

[0024] The controller 29 generates a drive signal corresponding to the operation signal from the fourth potentiometer and outputs the generated drive signal to the arm solenoid valve 27B. The arm solenoid valve 27B generates a pilot pressure corresponding to the drive signal and outputs the generated pilot pressure to the pressure receiving section on the other side of the arm control valve 22. As a result, the arm control valve 22 is switched to the switching position shown on the right in the figure, and the opening degree of the arm control valve 22 is controlled. Then, hydraulic fluid is supplied from the main pump 18 to the rod-side port of the arm cylinder 13 via the arm control valve 22, and hydraulic fluid is returned to the tank from the bottom-side port of the arm cylinder 13 via the arm control valve 22. As a result, the arm cylinder 13 is retracted and the arm 10 is dumped.

[0025] The controller 29 generates a drive signal corresponding to the operation signal from the fifth potentiometer and outputs the generated drive signal to the boom solenoid valve 26A. The boom solenoid valve 26A generates a pilot pressure corresponding to the drive signal and outputs the generated pilot pressure to the pressure receiving section on one side of the boom control valve 21. As a result, the boom control valve 21 is switched to the switching position shown on the left in the figure, and the opening degree of the boom control valve 21 is controlled. Then, hydraulic fluid is supplied from the main pump 18 to the bottom port of the boom cylinder 12 via the boom control valve 21, and hydraulic fluid is returned to the tank from the rod port of the boom cylinder 12 via the boom control valve 21. As a result, the boom cylinder 12 extends and the boom 9 rises.

[0026] The controller 29 generates a drive signal corresponding to the operation signal from the sixth potentiometer and outputs the generated drive signal to the boom solenoid valve 26B. The boom solenoid valve 26B generates a pilot pressure corresponding to the drive signal and outputs the generated pilot pressure to the pressure receiving section on the other side of the boom control valve 21. As a result, the boom control valve 21 is switched to the switching position shown on the right in the figure, and the opening degree of the boom control valve 21 is controlled. Then, hydraulic fluid is supplied from the main pump 18 to the rod-side port of the boom cylinder 12 via the boom control valve 21, and hydraulic fluid is returned to the tank from the bottom-side port of the boom cylinder 12 via the boom control valve 21. As a result, the boom cylinder 12 is retracted and the boom 9 is lowered.

[0027] The controller 29 generates a drive signal corresponding to the operation signal from the seventh potentiometer and outputs the generated drive signal to the bucket solenoid valve 28A. The bucket solenoid valve 28A generates a pilot pressure corresponding to the drive signal and outputs the generated pilot pressure to the pressure receiving section on one side of the bucket control valve 23. As a result, the bucket control valve 23 is switched to the switching position shown on the left in the figure, and the opening degree of the bucket control valve 23 is controlled. Then, hydraulic fluid is supplied from the main pump 18 to the bottom port of the bucket cylinder 14 via the bucket control valve 23, and hydraulic fluid is returned to the tank from the rod port of the bucket cylinder 14 via the bucket control valve 23. As a result, the bucket cylinder 14 extends and the bucket 11 clouds.

[0028] The controller 29 generates a drive signal corresponding to the operation signal from the eighth potentiometer and outputs the generated drive signal to the bucket solenoid valve 28B. The bucket solenoid valve 28B generates a pilot pressure corresponding to the drive signal and outputs the generated pilot pressure to the pressure receiving section on the other side of the bucket control valve 23. As a result, the bucket control valve 23 is switched to the switching position shown on the right in the figure, and the opening degree of the bucket control valve 23 is controlled. Then, hydraulic fluid is supplied from the main pump 18 to the rod-side port of the bucket cylinder 14 via the bucket control valve 23, and hydraulic fluid is returned to the tank from the bottom-side port of the bucket cylinder 14 via the bucket control valve 23. As a result, the bucket cylinder 14 is retracted and the bucket 11 is dumped.

[0029] The controller 29 controls the capacity of the main pump 18 via the regulator 19 according to the maximum value of the operation signals from the first to eighth potentiometers (in other words, the maximum value of the operation amount of the multiple operation levers).

[0030] The drive unit of the work machine 2 includes a main relief valve 30 that returns a portion of the hydraulic fluid on the discharge side of the main pump 18 to the tank when the discharge pressure of the main pump 18 exceeds a predetermined upper limit; a pilot relief valve 31 that returns a portion of the hydraulic fluid on the discharge side of the pilot pump 24 to the tank when the discharge pressure of the pilot pump 24 exceeds a predetermined upper limit; slewing relief valves 32A, 32B that return a portion of the hydraulic fluid of the slewing motor 8 to the tank when the hydraulic pressure of the slewing motor 8 exceeds a predetermined upper limit; boom relief valves 33A, 33B that return a portion of the hydraulic fluid of the boom cylinder 12 to the tank when the hydraulic pressure of the boom cylinder 12 exceeds a predetermined upper limit; arm relief valves 34A, 34B that return a portion of the hydraulic fluid of the arm cylinder 13 to the tank when the hydraulic pressure of the arm cylinder 13 exceeds a predetermined upper limit; and bucket relief valves 35A, 35B that return a portion of the hydraulic fluid of the bucket cylinder 14 to the tank when the hydraulic pressure of the bucket cylinder 14 exceeds a predetermined upper limit.

[0031] The drive unit of the work machine 2 includes a main check valve 36 that supplies a portion of the hydraulic fluid returned to the tank from a hydraulic actuator, etc., to the discharge side of the main pump 18 when the discharge pressure of the main pump 18 is below a predetermined lower limit; slewing check valves 37A, 37B that supply a portion of the hydraulic fluid returned to the tank from other hydraulic actuators, etc., to the slewing motor 8 when the hydraulic pressure of the slewing motor 8 is below a predetermined lower limit; boom check valves 38A, 38B that supply a portion of the hydraulic fluid returned to the tank from other hydraulic actuators, etc., to the boom cylinder 12 when the hydraulic pressure of the boom cylinder 12 is below a predetermined lower limit; arm check valves 39A, 39B that supply a portion of the hydraulic fluid returned to the tank from other hydraulic actuators, etc., to the arm cylinder 13 when the hydraulic pressure of the arm cylinder 13 is below a predetermined lower limit; and bucket check valves 40A, 40B that supply a portion of the hydraulic fluid returned to the tank from other hydraulic actuators, etc., to the bucket cylinder 14 when the hydraulic pressure of the bucket cylinder 14 is below a predetermined lower limit.

[0032] The drive system of the work machine 2 includes a rotation speed sensor 41 for detecting the rotation speed of the prime mover 17, a capacity sensor 42 for detecting the capacity of the main pump 18 (specifically, the tilt angle of the swash plate or oblique axis), and a discharge pressure sensor 43 for detecting the discharge pressure of the main pump 18. The rotation speed of the prime mover 17 and the capacity of the main pump 18 are state variables corresponding to the discharge flow rate of the main pump 18.

[0033] The drive unit of the work machine 2 includes pilot pressure sensors 44A and 44B for detecting the pilot pressure of the slewing control valve 20, pilot pressure sensors 45A and 45B for detecting the pilot pressure of the boom control valve 21, pilot pressure sensors 46A and 46B for detecting the pilot pressure of the arm control valve 22, and pilot pressure sensors 47A and 47B for detecting the pilot pressure of the bucket control valve 23. The pilot pressure of the slewing control valve 20 is a state variable corresponding to the opening degree of the slewing control valve 20, the pilot pressure of the boom control valve 21 is a state variable corresponding to the opening degree of the boom control valve 21, the pilot pressure of the arm control valve 22 is a state variable corresponding to the opening degree of the arm control valve 22, and the pilot pressure of the bucket control valve 23 is a state variable corresponding to the opening degree of the bucket control valve 23.

[0034] The drive unit of the work machine 2 includes hydraulic sensors 48A and 48B for detecting the hydraulic pressure of the slewing motor 8, hydraulic sensors 49A and 49B for detecting the hydraulic pressure of the boom cylinder 12, hydraulic sensors 50A and 50B for detecting the hydraulic pressure of the arm cylinder 13, and hydraulic sensors 51A and 51B for detecting the hydraulic pressure of the bucket cylinder 14.

[0035] The drive system of the work machine 2 includes a speed sensor 52 for detecting the speed (actual speed) of the slewing motor 8, a speed sensor 53 for detecting the speed (actual speed) of the boom cylinder 12, a speed sensor 54 for detecting the speed (actual speed) of the arm cylinder 13, and a speed sensor 55 for detecting the speed (actual speed) of the bucket cylinder 14.

[0036] The controller 29 of the work machine 2 transmits to the management server 3 a set of data consisting of the detection results from the rotation speed sensor 41, capacity sensor 42, discharge pressure sensor 43, pilot pressure sensors 44A, 44B to 47A, 47B, hydraulic sensors 48A, 48B to 51A, 51B, and speed sensors 52 to 55, where the detection times are the same. Based on the data received from the controller 29 of the work machine 2, the management server 3 calculates the difference between the estimated speed and the actual speed of each hydraulic actuator as an indicator for detecting abnormalities due to hydraulic fluid leakage. The details of this process will be explained using Figures 3 and 4.

[0037] Figure 3 is a block diagram showing the functional configuration of the management server 3 in this embodiment, along with related equipment.

[0038] The management server 3 has a functional configuration that includes a data extraction unit 56, a data storage unit 57, a model construction unit 58, a model storage unit 59, a speed estimation unit 60, and a difference calculation unit 61.

[0039] Figure 4 is a flowchart illustrating the processing performed by the management server 3 in this embodiment. The processing shown in Figure 4 is performed at predetermined intervals or after a predetermined number of receptions.

[0040] In step S1, the data extraction unit 56 of the management server 3 extracts diagnostic data from the data received from the work machine 2 and stores it in the data storage unit 57. More specifically, in order to determine whether at least one of the operating devices 16A and 16B is being operated, the data extraction unit 56 determines whether at least one of the pilot pressures of the slewing control valve 20, boom control valve 21, arm control valve 22, and bucket control valve 23 is above a predetermined threshold. In addition, in order to determine whether the main relief valve 30 and the main check valve 36 are closed, the unit determines whether the discharge pressure of the main pump 18 is below a predetermined upper limit and above a predetermined lower limit. Furthermore, in order to determine whether the slewing relief valves 32A, 32B and the slewing check valves 37A, 37B are closed, the unit determines whether the hydraulic pressure of the slewing motor 8 is below a predetermined upper limit and above a predetermined lower limit. Furthermore, in order to determine whether the boom relief valves 33A, 33B and the boom check valves 38A, 38B are in a closed state, it is determined whether the hydraulic pressure of the boom cylinder 12 is below a predetermined upper limit and above a predetermined lower limit. Furthermore, in order to determine whether the arm relief valves 34A, 34B and the arm check valves 39A, 39B are in a closed state, it is determined whether the hydraulic pressure of the arm cylinder 13 is below a predetermined upper limit and above a predetermined lower limit. Furthermore, in order to determine whether the bucket relief valves 35A, 35B and the bucket check valves 40A, 40B are in a closed state, it is determined whether the hydraulic pressure of the bucket cylinder 14 is below a predetermined upper limit and above a predetermined lower limit. The data extraction unit 56 extracts data that satisfies the above conditions and stores it in the data storage unit 57.

[0041] In step S2, the model building unit 58 of the management server 3 determines whether an estimation model for estimating the speed of each hydraulic actuator has been built. If an estimation model has not been built, the process proceeds to step S3. In step S3, the model building unit 58 determines whether the number of data sets stored in the data storage unit 57 is equal to or greater than a predetermined value. Initially, the number of data sets stored is less than the predetermined value, so the process ends. Step S1 described above is repeated until the number of data sets stored is equal to or greater than the predetermined value, at which point the process proceeds to step S4.

[0042] In step S4, the model building unit 58 constructs an estimation model to estimate the speed of each hydraulic actuator. More specifically, the model building unit 58 randomly classifies the data stored in the data storage unit 57 into training data, validation data, and test data. The model building unit 58 uses the aforementioned training data (specifically, the rotational speed of the prime mover 17 corresponding to the discharge flow rate of the main pump 18 and the capacity of the main pump 18, the pilot pressure corresponding to the opening degree of the slewing control valve 20, the pilot pressure corresponding to the opening degree of the boom control valve 21, the pilot pressure corresponding to the opening degree of the arm control valve 22, the pilot pressure corresponding to the opening degree of the bucket control valve 23, the hydraulic pressure of the slewing motor 8, the hydraulic pressure of the boom cylinder 12, the hydraulic pressure of the arm cylinder 13, the hydraulic pressure of the bucket cylinder 14, and the actual speed of at least one hydraulic actuator among the slewing motor 8, boom cylinder 12, arm cylinder 13, and bucket cylinder 14) to perform regression learning using a multilayer neural network to construct an estimation model that estimates the speed of the slewing motor 8, boom cylinder 12, arm cylinder 13, or bucket cylinder 14.

[0043] Furthermore, at each stage of learning, the model building unit 58 uses the verification data mentioned above to calculate the error between the estimated speed of the hydraulic actuator calculated by the estimation model and the actual speed. If the aforementioned error shows an increasing trend, it determines that overfitting has occurred and stops learning.

[0044] The process proceeds to step S5, where the model building unit 58 determines whether the accuracy of the estimation model built in step S4 is sufficient. More specifically, the model building unit 58 uses the test data described above to calculate the error between the estimated speed of the hydraulic actuator calculated by the estimation model and the actual speed. If the aforementioned error is below a predetermined threshold, the unit determines that the accuracy of the estimation model is sufficient and proceeds to step S6.

[0045] In step S6, the model building unit 58 defines the scope of application of the estimation model. More specifically, as shown in Figure 5(a), the model building unit 58 selects k sets of training data from a large number of training data represented in a coordinate space with coordinate axes of number k parameters (for convenience, k=3 in Figure 5), which are close to each set of test data, and calculates the average distance between each set of test data and the k sets of training data. Then, as shown in Figure 5(b), it sets a threshold for the distribution of average distances in multiple sets of test data, with the average distance corresponding to 80% of the total number of sets being used. The condition that the average distance is less than or equal to the threshold is then defined as the scope of application of the estimation model. Subsequently, the process proceeds to step S7, where the model storage unit 59 of the management server 3 saves the estimation model built in step S4 and the scope of application defined in step S6 (specifically, the training data used to calculate the average distance and the threshold for the average distance).

[0046] If the estimation model has already been built in step S2, the process proceeds to step S8. In step S8, the speed estimation unit 60 of the management server 3 determines whether the new data extracted by the data extraction unit 56 is within the scope of the estimation model. More specifically, it selects k sets of training data close to the new data from among a large number of training data represented in a coordinate space with coordinate axes of number k parameters, and calculates the average distance between the new data and the k sets of training data. Then, it determines whether the data is within the scope of the estimation model based on whether the calculated average distance is below a threshold. If the new data is within the scope of the estimation model, the process proceeds to step S9.

[0047] In step S9, the speed estimation unit 60 uses an estimation model into which new data (specifically, the rotational speed of the prime mover 17 corresponding to the discharge flow rate of the main pump 18 and the capacity of the main pump 18, the pilot pressure corresponding to the opening degree of the slewing control valve 20, the pilot pressure corresponding to the opening degree of the boom control valve 21, the pilot pressure corresponding to the opening degree of the arm control valve 22, the pilot pressure corresponding to the opening degree of the bucket control valve 23, the hydraulic pressure of the slewing motor 8, the hydraulic pressure of the boom cylinder 12, the hydraulic pressure of the arm cylinder 13, and the hydraulic pressure of the bucket cylinder 14) is substituted to estimate the speed of the slewing motor 8, boom cylinder 12, arm cylinder 13, or bucket cylinder 14.

[0048] The process proceeds to step S10, where the difference calculation unit 61 of the management server 3 calculates the difference between the speed of the swing motor 8, boom cylinder 12, arm cylinder 13, or bucket cylinder 14 estimated in step S9 and the actual speed included in the new data, and outputs it to the terminal 4.

[0049] Terminal 4 displays the difference between the estimated speed and the actual speed of each hydraulic actuator (in other words, the amount of speed reduction). This allows the operator to determine whether there is an abnormality due to a hydraulic fluid leak and whether maintenance work should be performed.

[0050] As described above, in this embodiment, abnormalities caused by hydraulic fluid leakage can be detected regardless of the operating state of the work machine 2.

[0051] In the above embodiment, the management server 3 was described as outputting the speed reduction amount of each hydraulic actuator to the terminal 4 as an example, but it is not limited to this. In one modified version of the present invention, the management server 3 calculates the trend of the speed reduction amount of each hydraulic actuator and outputs it to the terminal 4. More specifically, the management server 3 calculates statistical values ​​(e.g., average, maximum, or minimum) for each predetermined time period (e.g., one month) for one work machine 2, and a reference value obtained by averaging the statistical values ​​for each predetermined time period for multiple work machines 2, with respect to the speed reduction amount of each hydraulic actuator, and outputs them to the terminal 4. As shown in Figure 6, for example, the terminal 4 displays the trend of the speed reduction amount of each hydraulic actuator (solid line A), as well as the trend of the aforementioned reference value (dotted line B) and a maintenance judgment value (dotted line C) for determining whether maintenance work should be performed. This allows the operator to determine the timing of maintenance work.

[0052] In another modification of the present invention, the management server 3 determines whether there is an abnormality based on the amount of speed reduction of each hydraulic actuator (for example, whether it is above a predetermined threshold), and outputs an alarm command to the terminal 4 if an abnormality is determined. The terminal 4 displays an alarm screen (see Figure 7) in response to the alarm command.

[0053] In the above embodiment, the estimation model was described using the example of a case where the rotational speed of the prime mover 17 and the capacity of the main pump 18, which correspond to the discharge flow rate of the main pump 18, as parameters, but it is not limited to this. The estimation model may have the discharge flow rate of the main pump 18 as a parameter instead of the rotational speed of the prime mover 17 and the capacity of the main pump 18. That is, the controller 29 of the work machine 2 may calculate using the rotational speed of the prime mover 17 and the capacity of the main pump 18, or it may transmit the discharge flow rate of the main pump 18 detected by the flow sensor to the management server 3.

[0054] Furthermore, in the above embodiment, the estimation model was described using the example of having multiple pilot pressures corresponding to the opening degrees of multiple control valves 20 to 23 as parameters, but it is not limited to this. The estimation model may have multiple state quantities other than multiple pilot pressures (for example, the operating amounts of multiple operating levers, multiple operating signals, or multiple drive signals) as parameters, as long as they correspond to the opening degrees of multiple control valves 20 to 23. In other words, the controller 29 of the work machine 2 may transmit the aforementioned multiple state quantities to the management server 3.

[0055] Furthermore, although not specifically described in the above embodiment, the estimation model may also include the temperature of the hydraulic fluid as a parameter to improve estimation accuracy. That is, the controller 29 of the work machine 2 may transmit the temperature of the hydraulic fluid detected by the temperature sensor to the management server 3.

[0056] Furthermore, although the above embodiment was described using the example of a case where the work machine 2 is equipped with multiple speed sensors 52 to 55 for detecting the speeds of multiple hydraulic actuators, it is not limited to this. The work machine 2 may be equipped with multiple sensors for detecting the amount of movement of multiple members driven by multiple hydraulic actuators, and the controller 29 may calculate the speed of each hydraulic actuator by differentiating the amount of movement of each member.

[0057] Furthermore, although the above embodiment described an example in which the management server 3 constructs an estimation model using data received from the controller 29 of the work machine 2, it is not limited to this. The management server 3 may also store pre-constructed estimation models. [Explanation of Symbols]

[0058] 1. Communication Network 2. Working Machines 3. Management Server 8. Swivel motor (hydraulic actuator) 12. Boom Cylinder (Hydraulic Actuator) 13. Arm Cylinder (Hydraulic Actuator) 14. Bucket cylinder (hydraulic actuator) 18. Main pump (hydraulic pump) 20 Swivel control valve 21 Boom control valve 22 Control valve for arm 23 Control valve for buckets 29 Controllers

Claims

1. A work machine comprising a hydraulic pump, a plurality of hydraulic actuators driven by hydraulic fluid discharged from the hydraulic pump, a plurality of control valves that control the flow of hydraulic fluid from the hydraulic pump to the plurality of hydraulic actuators, and a controller that acquires data, A work machine management system comprising a management server that receives the data from the controller of the work machine via a communication network, The aforementioned management server Using an estimation model that includes the discharge flow rate of the hydraulic pump or a corresponding state quantity, a plurality of state quantities corresponding to the opening degrees of the plurality of control valves, and the hydraulic pressure of the plurality of hydraulic actuators as parameters, the speed of one of the plurality of hydraulic actuators is estimated. A work machine management system characterized by calculating and outputting the difference between the estimated speed of the hydraulic actuator and the actual speed of the hydraulic actuator, or outputting the result calculated or determined using the difference.

2. In the work machine management system according to claim 1, The work machine management system is characterized in that the management server constructs the estimation model using the following data: the discharge flow rate of the hydraulic pump or a corresponding state quantity, a plurality of state quantities corresponding to the opening degrees of the plurality of control valves, the hydraulic pressure of the plurality of hydraulic actuators, and the actual speed of at least one of the plurality of hydraulic actuators.

3. In the work machine management system according to claim 1, The aforementioned management server is characterized by calculating and outputting the trend of the difference, thereby providing a machine management system.

4. In the work machine management system according to claim 1, The aforementioned management server determines whether there is an abnormality based on the difference, and outputs an alarm command if it determines that there is an abnormality, thereby providing a machine management system.

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