Diagnostic device, work machine, and diagnostic system

Abstract

This diagnostic device is provided with: a first processor that, on the basis of a travel feature amount representing the travel state of a travel device attached to the vehicle body of a work machine, diagnoses an abnormality in the travel device; and an output device that outputs the result of diagnosis by the first processor. The first processor: acquires an inclination feature amount indicating the inclination state of the vehicle body; calculates, on the basis of the inclination feature amount, a correction amount for cancelling out the influence of the inclination state of the vehicle body on the travel feature amount of the travel device; calculates a corrected travel feature amount by correcting the travel feature amount on the basis of the correction amount; calculates an abnormality determination evaluation value on the basis of the corrected travel feature amount; determines whether there is an abnormality in the travel device on the basis of the abnormality determination evaluation value; and outputs the determination result to the output device if it has been determined that there is an abnormality.

Description

Diagnostic device, working machine, and diagnostic system

[0001] The present invention relates to a diagnostic device, a working machine equipped with the diagnostic device, and a diagnostic system.

[0002] Patent Document 1 discloses a work machine equipped with a control device that controls the capacity of a first hydraulic pump and a second hydraulic pump in response to operation of a travel operating device. The work machine's control device calculates an abnormality determination evaluation value based on the differential pressure between the pressure of the first hydraulic pump and the pressure of the second pump, and determines that an abnormality has occurred in either the left or right traveling device based on the results of comparing this abnormality determination evaluation value with a predetermined determination reference value.

[0003] Japanese Patent Application Laid-Open No. 2019-049102

[0004] However, the pressure of the first hydraulic pump and the pressure of the second hydraulic pump used to determine whether or not there is an abnormality are affected by the slope of the road surface on which the vehicle is traveling. Therefore, the invention described in Patent Document 1 may erroneously detect an abnormality in the traveling device when the road surface on which the vehicle is traveling is sloped.

[0005] An object of the present invention is to prevent erroneous detection of an abnormality in the traveling device when traveling on a sloped road surface and to properly detect an abnormality in the traveling device.

[0006] A diagnostic device according to one aspect of the present invention includes a first processor that diagnoses an abnormality in a traveling device attached to a body of a work machine based on a traveling feature amount that indicates the traveling state of the traveling device, and an output device that outputs the results of the diagnosis by the first processor. The first processor acquires a tilt feature amount that indicates the tilt state of the body, calculates a correction amount based on the tilt feature amount to offset the effect that the tilt state of the body has on the traveling feature amount of the traveling device, calculates a corrected traveling feature amount by correcting the traveling feature amount based on the correction amount, calculates an abnormality determination evaluation value based on the corrected traveling feature amount, determines whether or not there is an abnormality in the traveling device based on the abnormality determination evaluation value, and if there is an abnormality, outputs the determination result to the output device.

[0007] According to the present invention, it is possible to prevent erroneous detection of an abnormality in the traveling device when traveling on a sloped road surface, and to appropriately detect an abnormality in the traveling device.

[0008] FIG. 1 is a side view of a hydraulic excavator according to a first embodiment of the present invention. FIG. 2 is a see-through perspective view of the undercarriage shown in FIG. 1. FIG. 3 is a schematic configuration diagram of a hydraulic drive unit mounted on the hydraulic excavator shown in FIG. 1. FIG. 4 is a diagram showing a traveling drive system of the hydraulic excavator. FIG. 5 is a diagram showing the vehicle body coordinate system of the hydraulic excavator and the rotation angle of the hydraulic excavator (undercarriage). FIG. 6 is a schematic rear view of the hydraulic excavator, illustrating a case where the traveling road surface is a horizontal road surface parallel to the horizontal direction. FIG. 7 is a schematic rear view of the hydraulic excavator, illustrating a case where the traveling road surface is an inclined road surface inclined with respect to the horizontal direction. FIG. 8 is a diagram showing the characteristics of the roll angle φ and the loads FL and FR applied to the left and right traveling units. FIG. 9 is a rear view of the hydraulic excavator, illustrating the mounting positions of the tilt angle detection devices. FIG. 10 is a functional block diagram of a controller according to the first embodiment. FIG. 11 is a diagram explaining the details of the correction logic implemented by the differential pressure value calculation unit and the correction amount calculation unit. FIG. 12 is a flowchart showing an example of the flow of an abnormality determination process executed by the controller according to the first embodiment. FIG. 13 is a functional block diagram of a controller according to a second embodiment. FIG. 14 is a diagram illustrating an allowable load difference and an allowable roll angle range. FIG. 15 is a flowchart illustrating an example of the flow of an abnormality determination process executed by the controller according to the second embodiment. FIG. 16 is a schematic diagram illustrating the inclination angle (roll angle φtrv and pitch angle θtrv) of the lower traveling body and the inclination angle (roll angle φswg and pitch angle θswg) of the upper rotating body. FIG. 17 is a graph illustrating the relationship between the swing angle ψ and the roll angle φtrv of the lower traveling body and the relationship between the swing angle ψ and the pitch angle θtrv of the lower traveling body when the roll angle φswg of the upper rotating body is 10°. FIG. 18 is a functional block diagram of a controller according to a third embodiment. FIG. 19 is a flowchart illustrating an example of the flow of an abnormality determination process executed by the controller according to the third embodiment. FIG. 20 is a diagram illustrating the configuration of a diagnosis system according to a fourth embodiment. FIG. 21 is a functional block diagram of a diagnosis system according to the fourth embodiment. FIG. 22 is a conceptual diagram illustrating calculation of data by downsampling after applying a filter for characteristic extraction.Fig. 23 is a flowchart showing an example of the flow of an abnormality determination process executed by a controller according to Modification 1. Fig. 24 is a flowchart showing an example of the flow of an abnormality determination process executed by a controller according to Modification 2.

[0009] Hereinafter, a hydraulic excavator will be described as an example of a hydraulic working machine according to an embodiment of the present invention with reference to the drawings. In each drawing, the same reference numerals are used to designate the same components, and duplicated explanations will be omitted where appropriate.

[0010] First Embodiment FIG. 1 is a side view of a hydraulic excavator 100 according to a first embodiment of the present invention.

[0011] 1 , the hydraulic excavator 100 includes a lower traveling body 101, an upper rotating body 102 that is rotatably provided relative to the lower traveling body 101, and a working device 103 that is attached to the front side of the upper rotating body 102. The lower traveling body 101 and the upper rotating body 102 constitute a vehicle body 107 of the hydraulic excavator 100.

[0012] The working device 103 comprises a boom 104 attached to the front right part of the upper rotating body 102 so as to be rotatable in the vertical direction, an arm 105 attached to the tip of the boom 104 so as to be rotatable in the vertical and longitudinal directions, a bucket 106 attached to the tip of the arm 105 so as to be rotatable in the vertical and longitudinal directions, a boom cylinder 33 as a hydraulic actuator that drives the boom 104, an arm cylinder 34 as a hydraulic actuator that drives the arm 105, and a bucket cylinder 35 as a hydraulic actuator that drives the bucket 106.

[0013] A cab 110 is provided at the front left side of the upper rotating body 102. The cab 110 is equipped with left and right travel lever devices 6 and 7 (see FIG. 4 ) as travel operation devices for operating the lower traveling body 101, and left and right operation lever devices 8 and 9 (see FIG. 4 ) as work operation devices for operating the upper rotating body 102 and the work device 103.

[0014] Behind the operator's cab 110, there is provided a building (engine room) in which hydraulic equipment such as a first hydraulic pump 11 and a second hydraulic pump 21 (see FIG. 3) and the engine 1 (see FIG. 3) are installed.

[0015] As shown in Figure 4, the left travel lever device 6 has a left travel lever 6a for operating the left travel motor 31. The right travel lever device 7 has a right travel lever 7a for operating the right travel motor 32. The left operating lever device 8 has a left operating lever 8a for operating the arm cylinder 34 and the swing motor 36 (see Figure 3). The right operating lever device 9 has a right operating lever 9a for operating the boom cylinder 33 and the bucket cylinder 35.

[0016] FIG. 2 is a perspective view of the lower traveling body 101 shown in FIG.

[0017] 2, the lower traveling body 101 includes a track frame 41 and left and right traveling devices 50, 60 provided on the left and right sides of the track frame 41. The left and right traveling devices 50, 60 include left and right traveling drive devices 51, 61, left and right crawler belts (track links and shoes) 52, 62 driven by the left and right traveling drive devices 51, 61, left and right front idlers 53, 63 that support the left and right crawler belts 52, 62, and left and right upper and lower rollers (not shown).

[0018] The left traveling drive unit 51 includes the left traveling motor 31 (see FIG. 3) made up of a hydraulic motor, a traveling speed reducer 54 (see FIG. 3) that reduces the rotation of the left traveling motor 31 and transmits it to the crawler, and a brake valve 55 (see FIG. 4) that brakes the left traveling motor 31. Similarly, the right traveling drive unit 61 includes the right traveling motor 32 (see FIG. 3) made up of a hydraulic motor, a traveling speed reducer 64 (see FIG. 3) that reduces the rotation of the right traveling motor 32 and transmits it to the crawler, and a brake valve 65 (see FIG. 4) that brakes the right traveling motor 32.

[0019] A slewing ring 42 for rotatably connecting the upper rotating body 102 is provided on the upper part of the track frame 41. A center joint 43 for circulating pressure oil between the lower traveling body 101 and the upper rotating body 102 is disposed at the center of the slewing ring 42. The left and right traveling drive devices 51, 61 and the center joint 43 are connected by piping 44.

[0020] FIG. 3 is a schematic diagram of the hydraulic drive system 200 mounted on the hydraulic excavator 100 shown in FIG.

[0021] As shown in FIG. 3 , the hydraulic drive system 200 includes an engine 1 as a prime mover, a first hydraulic pump 11 driven by the engine 1, a second hydraulic pump 21 driven by the engine 1, a first control valve unit 12 that controls the flow of hydraulic oil supplied from the first hydraulic pump 11 to a plurality of hydraulic actuators including the left travel motor 31 (the left travel motor 31, the arm cylinder 34, the swing motor 36, and the attachment actuator 37), and a second control valve unit 22 that controls the flow of hydraulic oil supplied from the second hydraulic pump 21 to a plurality of hydraulic actuators including the right travel motor 32 (the right travel motor 32, the boom cylinder 33, and the bucket cylinder 35).

[0022] The first control valve unit 12 and the second control valve unit 22 are each a multiple directional control valve having a plurality of directional control valves. The first control valve unit 12 has a left traveling directional control valve 12a that controls the flow of pressure oil between the first hydraulic pump 11 and the left traveling motor 31. The second control valve unit 22 has a right traveling directional control valve 22a that controls the flow of pressure oil between the second hydraulic pump 21 and the right traveling motor 32.

[0023] FIG. 4 is a diagram showing the traveling drive system of the hydraulic excavator 100.

[0024] 4 , the travel drive system of the left traveling device (hereinafter also referred to as the left traveling device) 50 includes a left traveling motor 31 driven by pressure oil supplied from a first hydraulic pump 11, a left traveling direction control valve 12a that controls the flow of pressure oil supplied from the first hydraulic pump 11 to the left traveling motor 31, and a left brake valve 55 provided in an oil line connecting the left traveling direction control valve 12a and the left traveling motor 31. The travel drive system of the right traveling device (hereinafter also referred to as the right traveling device) 60 includes a right traveling motor 32 driven by pressure oil supplied from a second hydraulic pump 21, a right traveling direction control valve 22a that controls the flow of pressure oil supplied from the second hydraulic pump 21 to the right traveling motor 32, and a right brake valve 65 provided in an oil line connecting the right traveling direction control valve 22a and the right traveling motor 32.

[0025] The first hydraulic pump 11 and the second hydraulic pump 21 are variable displacement hydraulic pumps. The first hydraulic pump 11 is equipped with a pump regulator 11a for adjusting the discharge capacity (displacement volume per rotation) of the first hydraulic pump 11. The second hydraulic pump 21 is equipped with a pump regulator 21a for adjusting the discharge capacity (displacement volume per rotation) of the second hydraulic pump 21.

[0026] The hydraulic excavator 100 includes a first pressure sensor 13, a second pressure sensor 23, a work operation sensor 3, a swing operation sensor 4, a travel operation sensor 5, and a controller 2. The first pressure sensor 13 is provided in an oil passage connecting the first hydraulic pump 11 and the first control valve unit 12. The first pressure sensor 13 detects a first pump pressure P1, which is the discharge pressure of the first hydraulic pump 11, and outputs a signal (sensor value) representing the detection result to the controller 2. The second pressure sensor 23 is provided in an oil passage connecting the second hydraulic pump 21 and the second control valve unit 22. The second pressure sensor 23 detects a second pump pressure P2, which is the discharge pressure of the second hydraulic pump 21, and outputs a signal (sensor value) representing the detection result to the controller 2. The first pump pressure P1 is a travel state quantity representing the travel state (travel drive force) of the left traveling device 50, and the second pump pressure P2 is a travel state quantity representing the travel state (travel drive force) of the right traveling device 60. Therefore, the first pressure sensor 13 and the second pressure sensor 23 function as a running state detection device that detects the running state of the running devices 50 and 60.

[0027] The work operation sensor 3 detects the operation (work operation) of the boom cylinder 33, arm cylinder 34, and bucket cylinder 35 by the operator, and outputs a work operation signal representing the detection result to the controller 2. The swing operation sensor 4 detects the operation (swing operation) of the swing motor 36 by the operator, and outputs a swing operation signal representing the detection result to the controller 2. The travel operation sensor 5 detects the operation (travel operation) of the left and right travel motors 31, 32 by the operator, and outputs a travel operation signal representing the detection result to the controller 2.

[0028] The controller 2 is composed of a computer equipped with a processor 2a such as a CPU (Central Processing Unit), MPU (Micro Processing Unit), or DSP (Digital Signal Processor), a non-volatile memory 2b such as a ROM (Read Only Memory), flash memory, or hard disk drive, a volatile memory 2c called RAM (Random Access Memory), an input interface 2d, an output interface 2e, and other peripheral circuits. These hardware components work together to run software and realize multiple functions. The controller 2 may be composed of a single computer or multiple computers. The processor 2a may be an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or the like.

[0029] The nonvolatile memory 2b stores programs capable of executing various calculations. In other words, the nonvolatile memory 2b is a storage medium (storage device) from which the programs that realize the functions of this embodiment can be read. The volatile memory 2c is a storage medium (storage device) that temporarily stores the results of calculations performed by the processor 2a and signals input from the input interface 2d. The processor 2a is a device that loads the programs stored in the nonvolatile memory 2b into the volatile memory 2c and executes the calculations, and performs predetermined calculations on data taken from the input interface 2d, the nonvolatile memory 2b, and the volatile memory 2c in accordance with the programs.

[0030] The input interface 2d converts signals input from various devices (pressure sensors 13, 23, operation sensors 3, 4, 5, etc.) into data that can be calculated by the processor 2a. The output interface 2e generates an output signal according to the calculation result of the processor 2a and outputs the signal to various devices (pump regulators 11a, 21a, etc.).

[0031] The controller 2 calculates target discharge flow rates for the first hydraulic pump 11 and the second hydraulic pump 21 based on the detection results of the work operation sensor 3, the swing operation sensor 4, and the travel operation sensor 5. The controller 2 calculates target volumes (target discharge capacities) for the first hydraulic pump 11 and the second hydraulic pump 21 based on the calculated target discharge flow rates, and outputs command signals corresponding to the calculated target volumes to the pump regulators 11a, 21a. As a result, the discharge flow rates of the first hydraulic pump 11 and the second hydraulic pump 21 are controlled to match the respective target discharge flow rates. For example, the controller 2 increases the target volume of the first hydraulic pump 11 as the operation amount of the left travel lever device 6 increases. Furthermore, the controller 2 increases the target volume of the second hydraulic pump 21 as the operation amount of the right travel lever device 7 increases, for example.

[0032] In this embodiment, the hydraulic excavator 100 is equipped with a diagnostic device 80 that diagnoses abnormalities in the traveling gears 50, 60. The diagnostic device 80 is configured to include a controller 2 that is equipped with the hydraulic excavator 100 and output devices (a display device 91 and a communication device 92). The controller 2 diagnoses abnormalities in the left and right traveling gears 50, 60 when the hydraulic excavator 100 is in a predetermined operating state, based on the operation amounts detected by the operation sensors 3 to 5, the first pump pressure P1 detected by the first pressure sensor 13, and the second pump pressure P2 detected by the second pressure sensor 23. The results of the diagnosis are output by the display device 91 and the communication device 92, which serve as output devices.

[0033] The first pump pressure P1 and the second pump pressure P2 used in the abnormality diagnosis are affected by the slope of the road surface. The reason why the first pump pressure P1 and the second pump pressure P2 are affected by the slope of the road surface will be explained below.

[0034] FIG. 5 is a diagram showing the vehicle body coordinate system of the hydraulic excavator 100 and the rotation angle of the hydraulic excavator 100 (undercarriage 101).

[0035] As shown in Fig. 5, for example, a vehicle body coordinate system, which is a coordinate system based on the undercarriage 101, is set in the hydraulic excavator 100. The vehicle body coordinate system is defined as a right-handed coordinate system with the origin being any point on the swing center line, which is the rotation axis of the upper swing body 102. In the vehicle body coordinate system, the forward direction of the undercarriage 101 is defined as the positive direction of the X axis. In the vehicle body coordinate system, the vertically upward direction along the swing center line is defined as the positive direction of the Z axis. In the vehicle body coordinate system, the leftward direction of the undercarriage 101, which is perpendicular to both the X axis and the Z axis, is defined as the positive direction of the Y axis.

[0036] Rotation in the X-Z plane perpendicular to the Y axis is called pitching, and the angle of rotation is represented by the pitch angle θ. Rotation in the X-Y plane perpendicular to the Z axis is called yawing, and the angle of rotation is represented by the yaw angle ψ. Rotation in the Y-Z plane perpendicular to the X axis is called rolling, and the angle of rotation is represented by the roll angle φ. The X axis is an axis along the direction of travel of the lower running structure 101, and the roll angle φ with the X axis as the axis of rotation corresponds to the left-right tilt angle of the lower running structure 101 with respect to the horizontal plane. Here, the horizontal plane refers to an imaginary plane perpendicular to the direction of gravity (vertical direction).

[0037] 6 and 7 are schematic rear views of the hydraulic excavator 100. In the figures, the load acting on the hydraulic excavator 100 is schematically indicated by arrows. FIG. 6 shows a case where the travel road surface 109 is a horizontal road surface 109a parallel to the horizontal direction, while FIG. 7 shows a case where the travel road surface 109 is an inclined road surface 109b inclined with respect to the horizontal direction. The horizontal direction is the direction perpendicular to the direction of gravity (vertical direction). In other words, the roll angle φ is 0° (φ=0).

[0038] As shown in FIG. 6 , when the hydraulic excavator 100 travels on a horizontal road surface 109a, a load (reaction force) acts equally on each of the left traveling gear 50 and the right traveling gear 60 from the ground. In other words, the load FL acting on the left traveling gear 50 and the load FR acting on the right traveling gear 60 are equal. Furthermore, the loads FL and FR acting on the traveling gears 50 are half the weight F of the hydraulic excavator 100 (FL = FR = ½ × F). As shown in FIG. 6 , the posture of the hydraulic excavator 100 when it is not tilted is referred to as the horizontal posture. Furthermore, the intersection of the swing center axis of the hydraulic excavator 100 and the traveling road surface 109 in the horizontal posture is defined as a reference point O.

[0039] As shown in Figure 7, when the hydraulic excavator 100 travels on an inclined road surface 109b while tilting to the left or right, the load (reaction force) that the left traveling device 50 receives from the ground surface and the load (reaction force) that the right traveling device 60 receives from the ground surface are different in magnitude (FL ≠ FR). The loads acting on the hydraulic excavator 100 will be described in detail with reference to Figure 7.

[0040] The roll angle φ of the undercarriage 101 traveling on the sloped road surface 109b is not 0° (φ≠0). In the example shown, the left traveling device 50 is positioned lower than the right traveling device 60. In other words, the height of the left traveling device 50 is lower than the height of the right traveling device 60. Here, the height refers to the vertical distance from a horizontal reference plane to the traveling devices 50, 60. Furthermore, as shown in FIG. 7 , the posture of the hydraulic excavator 100 when it is tilted to the left or right is referred to as a tilted posture.

[0041] In the horizontal posture shown in Fig. 6 , the position of the center of gravity G of the hydraulic excavator 100 is located near the center line in the left-right width direction of the hydraulic excavator 100. In the inclined posture shown in Fig. 7 , the position of the center of gravity G of the hydraulic excavator 100 moves toward the left traveling device 50, which is lower in height than the left and right traveling devices 50, 60, compared to the horizontal posture (see Fig. 6 ). Specifically, the position of the center of gravity G is located to the left of the reference point O. As a result, the load FL acting on the left traveling device 50 becomes larger than the load FR acting on the right traveling device 60.

[0042] The load FR acting on the right traveling gear 60 is calculated by the following formula (1). The load FL acting on the left traveling gear 50 is calculated by the following formula (2). FR = (½ - h / B × tan φ) × F (1) FL = (½ + h / B × tan φ) × F (2) F is the gravity acting on the hydraulic excavator 100. The roll angle φ is the inclination angle of the traveling road surface 109 from the horizontal plane (reference plane). B is the distance from the center of the crawler (track) of the left traveling gear 50 to the center of the crawler (track) of the right traveling gear 60, hereinafter referred to as the crawler width. h is the height from the traveling road surface 109 to the center of gravity position G (h > 0). In other words, the height h corresponds to the distance from the center of gravity position G to the traveling road surface 109 along a perpendicular line drawn from the center of gravity position G to the traveling road surface 109.

[0043] The crawler width B, height h, and roll angle φ satisfy the relationship of the following equation (3): −B / 2h≦tanφ≦B / 2h (3) When the traveling road surface 109 is inclined, the load acting on traveling devices that are in a higher position is smaller than when the traveling road surface 109 is horizontal. Conversely, the load acting on traveling devices that are in a lower position is larger.

[0044] FIG. 8 is a diagram showing the characteristics of the loads FL and FR applied to the left and right traveling devices 50 and 60 as a function of the roll angle φ.

[0045] As shown in FIG. 8 , when the hydraulic excavator 100 is in a horizontal position, the roll angle φ is 0°. When the hydraulic excavator 100 is in an inclined position with the left traveling gear 50 positioned on the lower side and the right traveling gear 60 positioned on the upper side, the roll angle φ is a positive value. When the hydraulic excavator 100 is in an inclined position with the right traveling gear 60 positioned on the lower side and the left traveling gear 50 positioned on the upper side, the roll angle φ is a negative value. As the roll angle φ increases from 0°, the load FL acting on the left traveling gear 50 increases and the load FR acting on the right traveling gear 60 decreases. Conversely, as the roll angle decreases from 0° (increases in the negative direction), the load FR acting on the right traveling gear 60 increases and the load FL acting on the left traveling gear 50 decreases.

[0046] When the hydraulic excavator 100 travels in an inclined posture, as described above, the loads acting on the left and right travel units 50, 60 change from those in the horizontal posture. As a result, the loads acting on the drive units, sliding units, and other components of the travel drive units 51, 61 change from those in the horizontal posture. In an inclined posture, frictional forces and travel resistance (loss forces) with the ground change from those in the horizontal posture, and the drive force required to drive the hydraulic excavator 100 changes. For example, in an inclined posture in which the left travel unit 50 is positioned lower than the right travel unit 60, the left travel unit 50 sinks more deeply into the ground than in the horizontal posture. As a result, the road surface resistance acting on the left travel unit 50 from the ground is also greater than in the horizontal posture. In other words, in an inclined posture, the drive force required to drive the left travel unit 50 is greater than in the horizontal posture. As a result, the drive pressure of the left travel motor 31 (the discharge pressure of the first hydraulic pump 11) is greater than in the horizontal posture.

[0047] In this way, the driving force required for driving the vehicle may change due to a change in the load acting on the left and right traveling devices 50, 60. Therefore, in this embodiment, in order to properly diagnose abnormalities in the traveling devices 50, 60, the parameters used for abnormality diagnosis are corrected according to the tilt state of the vehicle body 107.

[0048] FIG. 9 is a rear view of the hydraulic excavator 100, showing the mounting position of the inclination angle detection device 76.

[0049] In this embodiment, in order to grasp the inclination state of the vehicle body 107, as shown in FIG. 9 , an inclination angle detection device 76 is attached to the track frame 41 of the lower traveling structure 101. The inclination angle detection device 76 detects a roll angle φ, which is the lateral inclination angle of the lower traveling structure 101 with respect to a horizontal plane, and outputs a signal (sensor value) representing the detection result to the controller 2. The controller 2 can grasp the inclination state (roll state) of the hydraulic excavator 100 based on the detection result of the inclination angle detection device 76. The inclination angle detection device 76 may be an IMU (Inertial Measurement Unit) that acquires angular velocity and acceleration about three orthogonal axes as information regarding the attitude of the lower traveling structure 101, calculates the roll angle φ of the lower traveling structure 101 based on this information, and outputs a signal representing the roll angle φ to the controller 2. The roll angle φ is an inclination state quantity that represents the inclination state of the vehicle body 107 with respect to the horizontal plane. Therefore, the inclination angle detection device 76 functions as an inclination state detection device that detects the inclination state of the vehicle body 107 with respect to the horizontal plane.

[0050] FIG. 10 is a functional block diagram of the controller 2.

[0051] The controller 2 is connected to a display device 91 such as a liquid crystal monitor installed in the cab 110 and a communication device 92 installed on the exterior of the cab 110, for example. The display device 91 is an output device controlled by the controller 2 and outputs the calculation results of the controller 2 as an image. The communication device 92 is a wireless communication device capable of wireless communication with a wireless base station connected to a communication line, and has a communication interface including a communication antenna with a sensitivity band of, for example, the 2.1 GHz band. The communication device 92 exchanges information with a server 40, for example, via the communication line. The communication device 92 is an output device controlled by the controller 2 and outputs communication data representing the calculation results of the controller 2. The server 40 is installed, for example, in a management facility away from the work site of the hydraulic excavator 100. A vehicle manager or a service technician can manage various vehicles (hydraulic excavators, etc.) working at the work site based on the operation information of various vehicles (hydraulic excavators, etc.) displayed on a display device such as a liquid crystal monitor connected to the server 40.

[0052] The controller 2 includes a differential pressure value calculation unit 81, an effective differential pressure value extraction unit 82, a correction amount calculation unit 83, a state determination unit 70, and an abnormality determination unit 90. The processor 2a of the controller 2 realizes these functions by executing programs stored in the non-volatile memory 2b. The state determination unit 70 determines whether or not a single driving operation is being performed based on the driving operation signal from the driving operation sensor 5, the work operation signal from the work operation sensor 3, and the turning operation signal from the turning operation sensor 4.

[0053] The state determination unit 70 determines whether the hydraulic excavator 100 is traveling straight or not based on a first tilting command value that is a tilting command value for the first hydraulic pump 11 and a second tilting command value that is a tilting command value for the second hydraulic pump 21. The state determination unit 70 determines that the hydraulic excavator 100 is traveling straight when the difference between the first tilting command value and the second tilting command value is equal to or smaller than the volume difference threshold. The state determination unit 70 determines that the hydraulic excavator 100 is not traveling straight when the difference between the first tilting command value and the second tilting command value is greater than the volume difference threshold.

[0054] The first tilt command value and the second tilt command value are calculated based on the travel operation signal from the travel operation sensor 5, the work operation signal from the work operation sensor 3, and the swing operation signal from the swing operation sensor 4. The first hydraulic pump 11 and the second hydraulic pump 21 are controlled, for example, so that their volumes increase as the operation amounts of the left and right travel levers 6a, 7a and the left and right operating levers 8a, 9a increase. This type of control is called positive control. However, the control method for the hydraulic pumps 11, 21 is not limited to this.

[0055] The state determination unit 70 determines whether the vehicle is in a sole driving operation and traveling straight. If the state determination unit 70 determines that the vehicle is in a sole driving operation and traveling straight, it determines that the diagnostic conditions are met and sets the state to an effective mode in which the parameters used for abnormality diagnosis are effective. If the state determination unit 70 determines that the vehicle is not in a sole driving operation and traveling straight, it determines that the diagnostic conditions are not met and sets the state to an ineffective mode in which the parameters used for abnormality diagnosis are invalid. Note that in this embodiment, a method for calculating the corrected differential pressure value ΔPc, which is a parameter used for abnormality diagnosis (abnormality determination evaluation value), will be described later.

[0056] The differential pressure value calculation unit 81 calculates a differential pressure value ΔP by subtracting the second pump pressure (pressure value) P2 detected by the second pressure sensor 23 from the first pump pressure (pressure value) P1 detected by the first pressure sensor 13 (ΔP = P1 - P2). In this way, the differential pressure value calculation unit 81 calculates the differential pressure value ΔP as a driving characteristic quantity of the driving devices 50, 60 based on the sensor values ​​indicating the driving state detected by the first pressure sensor 13 and the second pressure sensor 23. The differential pressure value calculation unit 81 corrects the differential pressure value ΔP with the correction amount Pc calculated by the correction amount calculation unit 83, and calculates a corrected differential pressure value ΔPc, which is the corrected differential pressure value. In other words, the differential pressure value calculation unit 81 calculates the corrected differential pressure value ΔPc as the corrected driving characteristic quantity by correcting the driving characteristic quantity (differential pressure value ΔP) based on the correction amount Pc.

[0057] The correction amount calculation unit 83 calculates the roll angle φ as a tilt characteristic amount based on the sensor value indicating the tilt angle (tilt state) detected by the tilt angle detection device 76. The correction amount calculation unit 83 also calculates a correction amount Pc based on the roll angle φ and correction amount parameters (a loss torque coefficient C and a load characteristic table T, which will be described later) previously stored in the nonvolatile memory 2b. The method of calculating the correction amount Pc by the correction amount calculation unit 83 will be described in detail later.

[0058] When the valid mode is set by the state determination unit 70 (when the vehicle is in sole driving operation and traveling straight ahead), the effective differential pressure value extraction unit 82 extracts the corrected differential pressure value ΔPc from the differential pressure value calculation unit 81 as an abnormality determination evaluation value and outputs it to the abnormality determination unit 90. When the invalid mode is set by the state determination unit 70 (when the vehicle is not in sole driving operation or traveling straight ahead), the effective differential pressure value extraction unit 82 outputs the abnormality determination evaluation value to the abnormality determination unit 90 as 0 (zero).

[0059] The abnormality determination unit 90 determines whether or not an abnormality exists in either the left traveling device 50 or the right traveling device 60 based on the result of comparing the abnormality determination evaluation value (the corrected differential pressure value ΔPc in the effective mode) from the effective differential pressure value extraction unit 82 with the determination reference value ΔP0. Here, the determination reference value ΔP0 is an empirically determined value and is stored in advance in the non-volatile memory 2b. Note that the controller 2 is preferably configured to be able to change the determination reference value ΔP0 based on an operation on an input device by an operator or the like.

[0060] The abnormality determination unit 90 outputs the determination result to the display device 91 and the communication device 92. The display device 91 displays an image representing the determination result of the abnormality determination unit 90 on its screen. The communication device 92 transmits the determination result of the abnormality determination unit 90 to the server 40. A display device, a printing device, etc. are connected to the server 40. The server 40 outputs the received determination result to the display device or printing device connected to the server 40. This allows the operator, vehicle manager, and serviceman to quickly grasp any abnormalities in the traveling devices 50, 60 of the hydraulic excavator 100.

[0061] Next, a method for calculating correction amounts Pc1 and Pc2 for the pressure difference value ΔP that takes into account the inclination state of the road surface 109 will be described. First, the relationship between pump pressure and driving force will be described. In order for the conditions for diagnosing an abnormality in the traveling devices 50 and 60 to be met, the vehicle must be traveling straight. During straight traveling, the pump pressure acts as driving pressure on the traveling motors 31 and 32. Therefore, the traveling motors 31 and 32 generate driving force due to the pump pressure.

[0062] The left traveling drive force TmotL, which is the traveling drive force produced by the left traveling motor 31, and the right traveling drive force TmotR, which is the traveling drive force produced by the right traveling motor 32, are expressed by the following equations (4) and (5). TmotL=P1×q1 / (2π)×Ratio (4) TmotR=P2×q2 / (2π)×Ratio (5) Here, P1 is the discharge pressure (first pump pressure) of the first hydraulic pump 11, and P2 is the discharge pressure (second pump pressure) of the second hydraulic pump 21. q1 is the displacement volume of the left traveling motor 31, and q2 is the displacement volume of the right traveling motor 32. Ratio is the reduction ratio of the traveling reducers 54, 64 of the traveling motors 31, 32. During straight-ahead driving, the displacement volume q1 of the left traveling motor 31 is equal to the displacement volume q2 of the right traveling motor 32. Therefore, the displacement volume q1 of the left traveling motor 31 and the displacement volume q2 of the right traveling motor 32 will hereinafter also be referred to as motor volume q (q = q1 = q2).

[0063] The driving force of the left traveling reducer 54 is expressed by the following equation (6), and the driving force of the right traveling reducer 64 is expressed by the following equation (7). TmotL=P1×q / (2π)×Ratio=TtrvL+TlossL (6) TmotR=P2×q / (2π)×Ratio=TtrvR+TlossR (7) Here, TtrvL is the torque that is effectively used for driving the left traveling motor 31 for traveling (left traveling driving effective torque), and TtrvR is the torque that is effectively used for driving the right traveling motor 32 for traveling (right traveling driving effective torque). TlossL is loss torque such as drag resistance force during traveling operation of the left traveling motor 31, and will be referred to as left loss torque hereinafter. TlossR is a loss torque such as a drag resistance force during driving operation in the right driving motor 32, and will be referred to as right loss torque hereinafter.

[0064] When the hydraulic excavator 100 is traveling straight ahead in a horizontal position, the left loss torque and the right loss torque are approximately equal (TlossL ≈ TlossR). Therefore, from equations (6) and (7), the effective torque difference ΔT, which is the difference between the left traveling drive force and the right traveling drive force, is expressed as the following equation (8): ΔT = TtrvL - TtrvR = q / (2π) × Ratio × (P1 - P2) ... (8) It can be seen from equation (8) that the effective torque difference ΔT during traveling drive can be determined from the differential pressure value ΔP (= P1 - P2) between the first pump pressure P1 and the second pump pressure P2.

[0065] However, when the hydraulic excavator 100 is traveling straight in an inclined attitude, it is expected that the loss torques TlossL and TlossR acting on the traveling devices 50, 60 may differ greatly. For this reason, when equation (7) is subtracted from equation (6) when the hydraulic excavator 100 is traveling straight in an inclined attitude, the left loss torque TlossL and the right loss torque TlossR remain without canceling each other out, as expressed in the following equation (9): q / (2π)×Ratio×(P1−P2)=TtrvL−TtrvR+TlossL−TlossR (9) For this reason, in order to perform abnormality diagnosis using the differential pressure value ΔP, correction must be made taking the loss torques TlossL and TlossR into consideration.

[0066] Next, the correction method will be described in detail. As described above, when the vehicle body 107 is tilted to the left or right, the loads acting on the left and right traveling devices 50, 60 are different, as shown in FIG. 8 . If the loss torque during traveling is assumed to be a force (loss torque) corresponding to the load, such as a frictional force, the estimated value of the left loss torque (hereinafter referred to as the left loss torque estimated value) TlossL_est and the estimated value of the right loss torque (hereinafter referred to as the right loss torque estimated value) TlossR_est are expressed by the following equations (10) and (11). TlossL_est = C1 × FL (10) TlossR_est = C2 × FR (11) Here, FL is the load acting on the left traveling device 50, and FR is the load acting on the right traveling device 60. C1 is the loss torque coefficient (corresponding to the friction coefficient) of the left traveling device 50, and C2 is the loss torque coefficient (corresponding to the friction coefficient) of the right traveling device 60. The loss torque coefficients C1 and C2 can basically be considered to be almost equivalent because the left and right traveling devices 50 and 60 have equivalent configurations. For this reason, hereinafter, the loss torque coefficients C1 and C2 will also be referred to as loss torque coefficient C (C = C1 = C2). The loss torque coefficients C1 and C2 are determined based on design values, past measurement data, knowledge, etc., and are stored in advance in the non-volatile memory 2b.

[0067] The controller 2 corrects the differential pressure value ΔP by the amount of change in the differential pressure value ΔP due to the tilt, and corrects the differential pressure value ΔP so as to suppress (cancel) the influence of the tilt state (the difference between the left loss torque TlossL and the right loss torque TlossR).

[0068] Specifically, as shown in equation (12), the influence of the tilt state can be canceled by subtracting (TlossL-TlossR) on the right side of equation (9) from (TlossL_est-TlossR_est). q / (2π)×Ratio×(P1-P2)=TtrvL+TlossL-TlossL_est-(TtrvR+TlossR-TlossR_est) (12) Here, if there is little error in the loss torque estimated values ​​TlossL_est, TlossR_est with respect to the loss torques TlossL, TlossR, the following equation (13) can be obtained. q / (2π)×Ratio×(P1-P2)=TtrvL-TtrvR (13) When formula (13) is rearranged in terms of pressure units, formula (14) is obtained. P1-P2=(2π) / (q×Ratio)×(TtrvL-TtrvR) (14) According to this, even when the load acting on the traveling devices 50, 60 differs when the traveling device is in an inclined posture, changing the traveling loss torque, the inclination state can be detected, the loss torque can be estimated from the acting load, and the differential pressure value can be corrected based on the estimation result, thereby determining the effective driving force difference excluding the influence of the inclination state.

[0069] FIG. 11 is a diagram illustrating the details of the correction logic by the differential pressure value calculation unit 81 and the correction amount calculation unit 83.

[0070] 11, the correction amount calculation unit 83 refers to the load characteristics table T and calculates the load FL acting on the left traveling device 50 and the load FR acting on the right traveling device 60 based on the roll angle φ of the undercarriage 101 detected by the tilt angle detection device 76. The load characteristics table T is a data table that defines the relationship between the roll angle φ and the loads FL, FR described with reference to FIG. 8. The load characteristics table T is stored in advance in the non-volatile memory 2b.

[0071] The correction amount calculation unit 83 calculates a left loss torque estimated value TlossL_est by multiplying the calculated load FL acting on the left traveling device 50 by the loss torque coefficient C. The correction amount calculation unit 83 calculates a right loss torque estimated value TlossR_est by multiplying the calculated load FR acting on the right traveling device 60 by the loss torque coefficient C.

[0072] The correction amount calculation unit 83 calculates a first correction amount Pc1 by converting the calculated left loss torque estimated value TlossL_est into a unit of pressure using the motor volume q and the reduction ratio Ratio. The correction amount calculation unit 83 also calculates a second correction amount Pc2 by converting the calculated right loss torque estimated value TlossR_est into a unit of pressure using the motor volume q and the reduction ratio Ratio. The first correction amount Pc1 and the second correction amount Pc2, which are pressure correction amounts, are expressed by the following equations (15) and (16). Pc1 = (2π) / (q × Ratio) × TlossL_est... (15) Pc2 = (2π) / (q × Ratio) × TlossR_est... (16) The correction amount calculation unit 83 outputs the first correction amount Pc1 and the second correction amount Pc2 calculated using equations (15) and (16) to the differential pressure value calculation unit 81.

[0073] The first correction amount Pc1 corresponds to the change in the first pump pressure P1 in the inclined posture relative to the first pump pressure P1 in the horizontal posture (the difference between the first pump pressure P1 in the horizontal posture and the first pump pressure P1 in the inclined posture). The first correction amount Pc1 increases as the height of the left traveling device 50 decreases and the height of the right traveling device 60 increases in the inclined posture. The first correction amount Pc1 also decreases as the height of the left traveling device 50 increases and the height of the right traveling device 60 decreases in the inclined posture. The second correction amount Pc2 corresponds to the change in the second pump pressure P2 in the inclined posture relative to the second pump pressure P2 in the horizontal posture (the difference between the second pump pressure P2 in the horizontal posture and the second pump pressure P2 in the inclined posture). The second correction amount Pc2 decreases as the height of the left traveling device 50 decreases and the height of the right traveling device 60 increases in the inclined posture. Furthermore, the second correction amount Pc2 increases as the height of the left traveling device 50 increases and the height of the right traveling device 60 decreases in the inclined posture.

[0074] The differential pressure value calculation unit 81 calculates a differential pressure value ΔP by subtracting the second pump pressure P2 detected by the second pressure sensor 23 from the first pump pressure P1 detected by the first pressure sensor 13. The differential pressure value calculation unit 81 corrects the differential pressure value ΔP using the first correction amount Pc1 and the second correction amount Pc2. Specifically, the differential pressure value calculation unit 81 subtracts the first correction amount Pc1 from the differential pressure value ΔP and adds the second correction amount Pc2 to calculate a corrected differential pressure value ΔPc, which is the differential pressure value after correction. The corrected differential pressure value ΔPc is output to the effective differential pressure value extraction unit 82. Note that when the vehicle is traveling straight in a horizontal position, the load FL and the load FR are equal. In other words, the first correction amount Pc1 and the second correction amount Pc2 are equal. Therefore, the correction amount Pc (= second correction amount Pc2 - first correction amount Pc1) added to the differential pressure value ΔP becomes 0 (zero), and the differential pressure value ΔP (= ΔPc) in the case where no correction is actually made is output to the effective differential pressure value extraction unit 82.

[0075] In this way, the controller 2 according to this embodiment calculates a correction amount Pc (=Pc2-Pc1) for offsetting the effect of the tilt state of the lower running structure 101 on the first pump pressure P1 and the second pump pressure P2, based on the tilt angle (roll angle φ) of the lower running structure 101 detected by the tilt angle detection device 76. The correction amount Pc corresponds to a fluctuation in the differential pressure value ΔP (the difference between the differential pressure value in the horizontal posture and the differential pressure value in the inclined posture) caused by an increase in the load acting on one of the left running device 50 and the right running device 60 and a decrease in the load acting on the other of the left running device 50 and the right running device 60 due to the lower running structure 101 tilting in the left-right direction. The controller 2 calculates the corrected differential pressure value ΔPc by offsetting, with the correction amount Pc, the fluctuation in the differential pressure value ΔP calculated in the inclined posture when the horizontal posture is used as the reference.

[0076] Fig. 12 is a flowchart showing an example of the flow of an abnormality determination process executed by the controller 2. The flowchart shown in Fig. 12 is started, for example, when the ignition switch is turned on, and is repeatedly executed at a predetermined control period.

[0077] In step S2, the differential pressure value calculation unit 81 calculates a differential pressure value ΔP by subtracting the second pump pressure P2 from the first pump pressure P1.

[0078] In the next step S4, the correction amount calculation unit 83 refers to the load characteristics table T and calculates the load FL of the left traveling device 50 and the load FR of the right traveling device 60 based on the roll angle φ of the lower traveling structure 101 detected by the tilt angle detection device 76. The correction amount calculation unit 83 calculates a first correction amount Pc1 and a second correction amount Pc2 based on the loads FL and FR.

[0079] In the next step S6, the differential pressure value calculation unit 81 calculates the corrected differential pressure value ΔPc by adding the correction amount Pc (second correction amount Pc2 - first correction amount Pc1) calculated in step S4 to the differential pressure value ΔP calculated in step S2.

[0080] In the next step S10, the state determination unit 70 determines whether or not a work operation is being performed based on the work operation signal from the work operation sensor 3. If it is determined in step S10 that a work operation is not being performed (Yes), the process proceeds to step S20, and if it is determined in step S10 that a work operation is being performed (No), the invalid mode is set and the process shown in Fig. 12 for this control cycle ends. That is, the process proceeds to step S2 of the next control cycle.

[0081] In step S20, the state determination unit 70 determines whether or not a turning operation is being performed based on the turning operation signal from the turning operation sensor 4. If it is determined in step S20 that a turning operation is not being performed (Yes), the process proceeds to step S30, and if it is determined in step S20 that a turning operation is being performed (No), the invalid mode is set and the process shown in Fig. 12 for this control cycle ends.

[0082] In step S30, the state determination unit 70 determines whether or not a driving operation is being performed based on the driving operation signal from the driving operation sensor 5. If it is determined in step S30 that a driving operation is being performed (Yes), the process proceeds to step S40, and if it is determined in step S30 that a driving operation is not being performed (No), the invalid mode is set and the process shown in FIG. 12 for this control cycle ends.

[0083] In step S40, it is determined whether the vehicle is traveling straight based on the first tilt command value and the second tilt command value. The state determination unit 70 calculates the first tilt command value and the second tilt command value based on the work operation signal, the turning operation signal, and the traveling operation signal. Note that the state determination unit 70 may also obtain the first tilt command value and the second tilt command value calculated by a hydraulic pump control unit (not shown).

[0084] When the first tilt command value and the second tilt command value are equal during sole travel operation, the flow rates supplied from the first hydraulic pump 11 and the second hydraulic pump 21 to the left and right travel motors 31, 32 are equal. At this time, the rotation speeds of the left and right travel motors 31, 32 are equal, and the left and right travel devices 50, 60 travel straight. Therefore, it is possible to determine whether the vehicle is traveling straight based on whether the first tilt command value and the second tilt command value are equal. Specifically, taking into account manufacturing errors of the first hydraulic pump 11, the second hydraulic pump 21, the left and right travel motors 31, 32, etc., it is determined that the left and right travel devices 50, 60 are traveling straight when the difference between the first tilt command value and the second tilt command value is equal to or less than a predetermined threshold.

[0085] If it is determined in step S40 that the vehicle is traveling straight ahead (Yes), the valid mode is set and the process proceeds to step S50. If it is determined in step S40 that the vehicle is not traveling straight ahead (No), the invalid mode is set and the process shown in FIG. 12 for this control cycle ends.

[0086] In step S50, the effective differential pressure value extractor 82 extracts the corrected differential pressure value ΔPc calculated in step S6 of this control cycle as an abnormality determination evaluation value to be used for abnormality determination. The abnormality determination evaluation value is a feature amount for evaluating the abnormality symptom state of the traveling devices 50, 60.

[0087] In the next step S60, the abnormality determination unit 90 determines whether the corrected differential pressure value ΔPc extracted as the abnormality determination evaluation value is equal to or less than a predetermined upper limit value Pu. A determination reference value (positive value) ΔP0 is used as the predetermined upper limit value Pu. The determination reference value ΔP0 is determined in advance taking into consideration pressure detection errors, manufacturing errors, etc., and is stored in the non-volatile memory 2b. The manufacturing errors include, for example, manufacturing errors of the first hydraulic pump 11, the second hydraulic pump 21, and the left and right traveling units 50, 60. The predetermined upper limit value Pu is a threshold value for determining whether an abnormality exists in the left traveling unit 50.

[0088] For example, when traveling straight on the horizontal road surface 109a and the loss torques of the left and right traveling devices 50, 60 are approximately the same, the left and right traveling motors 31, 32 are driven equally by the first hydraulic pump 11 and the second hydraulic pump 21. As a result, the first pump pressure P1 and the second pump pressure P2 become approximately the same, and the corrected differential pressure value ΔPc becomes equal to or less than the predetermined upper limit value Pu (ΔPc≦Pu). Note that when traveling on the horizontal road surface 109a, the corrected differential pressure value ΔPc corresponds to the differential pressure value ΔP. On the other hand, when traveling straight on the horizontal road surface 109a and the loss torque of the left traveling device 50 is greater than the loss torque of the right traveling device 60, the first pump pressure P1 becomes greater than the second pump pressure P2, and the corrected differential pressure value ΔPc (>0) becomes greater than the predetermined upper limit value Pu (>0) (ΔPc>Pu).

[0089] When the hydraulic excavator 100 travels on a sloped road surface 109b, the effect of the pressure difference between the first pump pressure P1 and the second pump pressure P2 caused by the inclined posture is canceled by the correction. Therefore, even when the hydraulic excavator 100 is traveling on a sloped road surface 109b, it is possible to determine that the pressure difference between the first pump pressure P1 and the second pump pressure P2 has increased due to an abnormality in the traveling devices 50, 60 by comparing the corrected differential pressure value ΔPc with the upper limit value Pu, just as when the hydraulic excavator 100 is traveling on a horizontal road surface 109a.

[0090] If it is determined in step S60 that the corrected differential pressure value ΔPc is greater than the predetermined upper limit value Pu (No), the process proceeds to step S70, and if it is determined in step S60 that the corrected differential pressure value ΔPc is equal to or less than the predetermined upper limit value Pu (Yes), the process proceeds to step S80.

[0091] In step S70, the abnormality determination unit 90 determines that there is an abnormality in the left traveling device 50, and the process proceeds to step S110.

[0092] In step S80, the abnormality determination unit 90 determines whether the corrected differential pressure value ΔPc extracted as the abnormality determination evaluation value is equal to or greater than a predetermined lower limit value Pl. The predetermined lower limit value Pl is set to the determination reference value ΔP0 multiplied by -1 (-ΔP0). The predetermined lower limit value Pl is a threshold value for determining whether an abnormality exists in the right traveling device 60. Note that the absolute value of the lower limit value Pl and the absolute value of the upper limit value Pu are not limited to being the same. The absolute value of the lower limit value Pl and the absolute value of the upper limit value Pu may also be different.

[0093] For example, when traveling straight on the horizontal road surface 109a, if the loss torques of the left and right traveling devices 50, 60 are approximately the same, the left and right traveling motors 31, 32 are driven equally by the first hydraulic pump 11 and the second hydraulic pump 21. As a result, the first pump pressure P1 and the second pump pressure P2 become approximately the same, and the corrected differential pressure value ΔPc becomes equal to or greater than the predetermined lower limit value Pl (ΔPc ≧ Pl). Note that when traveling on the horizontal road surface 109a, the corrected differential pressure value ΔPc corresponds to the differential pressure value ΔP. On the other hand, when traveling straight on the horizontal road surface 109a, if the loss torque of the right traveling device 60 is greater than the loss torque of the left traveling device 50, the second pump pressure P2 becomes greater than the first pump pressure P1, and the corrected differential pressure value ΔPc (< 0) becomes smaller than the predetermined lower limit value Pl (< 0) (ΔPc < Pl).

[0094] When the hydraulic excavator 100 travels on an inclined road surface 109b, the effect of the pressure difference between the first pump pressure P1 and the second pump pressure P2 caused by the inclined posture is canceled by the correction. Therefore, even when the hydraulic excavator 100 is traveling on an inclined road surface 109b, it is possible to determine that the pressure difference between the first pump pressure P1 and the second pump pressure P2 has increased due to an abnormality in the traveling devices 50, 60 by comparing the corrected differential pressure value ΔPc with the lower limit value Pl, just as when the hydraulic excavator 100 is traveling on a horizontal road surface 109a.

[0095] If it is determined in step S80 that the corrected differential pressure value ΔPc is smaller than the predetermined lower limit value Pl (No), the process proceeds to step S90, and if it is determined in step S80 that the corrected differential pressure value ΔPc is greater than or equal to the predetermined lower limit value Pl (Yes), the process proceeds to step S100.

[0096] In step S90, the abnormality determination unit 90 determines that an abnormality exists in the right traveling device 60, and the process proceeds to step S110.

[0097] In step S100, the abnormality determination unit 90 determines that there is no abnormality in the left and right traveling devices 50, 60 (i.e., that they are normal), and the process proceeds to step S110.

[0098] In step S110, the abnormality determination unit 90 outputs the determination result obtained in step S70, S90, or S100 to the display device 91 and the communication device 92. The display device 91 displays an image (icon, etc.) representing the determination result on its display screen. That is, the controller 2 notifies the operator of the determination result via the display device 91. The communication device 92 transmits the determination result to the server 40. The server 40 outputs the received determination result to a display device within the management facility. The display device within the management facility displays an image (icon, etc.) representing the determination result on its display screen. That is, the controller 2 notifies the vehicle manager or serviceman within the management facility of the determination result via communication via the communication device 92. When the determination result output process (step S110) is completed, the process shown in FIG. 12 for this control cycle ends.

[0099] As described above, in this embodiment, the controller 2 calculates a correction amount Pc for the differential pressure value ΔP based on the roll angle (inclination angle) φ of the undercarriage 101, and uses the correction amount Pc to calculate a corrected differential pressure value ΔPc as an abnormality determination evaluation value used for abnormality determination. The corrected differential pressure value ΔPc corresponds to a differential pressure value in which fluctuations due to the influence of inclination have been offset. Therefore, even in cases where a driving force difference occurs due to inclination, the influence of the inclination state is canceled. As a result, a differential pressure value ΔP equivalent to that when the vehicle is traveling straight on a horizontal plane is calculated as the corrected differential pressure value ΔPc. This improves the accuracy of monitoring the state of the traveling system regardless of the inclination state.

[0100] According to the above-described first embodiment, the following advantageous effects are achieved.

[0101] (1) The diagnostic device 80 includes a processor (first processor) 2a that diagnoses abnormalities in the traveling devices 50, 60 based on a traveling feature quantity (differential pressure value ΔP) that represents the traveling state of the traveling devices 50, 60 attached to the vehicle body 107 of the hydraulic excavator (work machine) 100, and an output device (a display device 91 and a communication device 92) that outputs the results of the diagnosis by the processor 2a. The processor 2a acquires a tilt feature quantity (roll angle φ) that represents the tilt state of the vehicle body 107. The processor 2a calculates a correction quantity Pc based on the tilt feature quantity (roll angle φ) to offset the effect of the tilt state of the vehicle body 107 on the traveling feature quantity (differential pressure value ΔP) of the traveling devices 50, 60. The processor 2a calculates a corrected traveling feature quantity (corrected differential pressure value ΔPc) by correcting the traveling feature quantity (differential pressure value ΔP) based on the correction quantity Pc. The processor 2a calculates an abnormality determination evaluation value (corrected differential pressure value ΔPc in the valid mode) based on the corrected driving characteristic amount (corrected differential pressure value ΔPc). The processor 2a determines whether or not an abnormality exists in the driving device 50, 60 based on the abnormality determination evaluation value, and if it determines that an abnormality exists, outputs the determination result to the output device.

[0102] For example, the display device 91 as an output device outputs a notification image to notify an operator that an abnormality has occurred, and the communication device 92 as an output device outputs notification information to the server 40 to notify a vehicle manager or a service person that an abnormality has occurred.

[0103] This configuration makes it possible to provide a diagnostic device 80 that can prevent erroneous detection of abnormalities in the traveling devices 50, 60 when traveling on a sloped road surface and can properly detect abnormalities in the traveling devices 50, 60.

[0104] (2) In the first embodiment, the hydraulic excavator 100 is equipped with the diagnostic device 80. The hydraulic excavator 100 includes a vehicle body 107, a working device 103 attached to the vehicle body 107, a first hydraulic pump 11 and a second hydraulic pump 21 provided on the vehicle body 107, a left traveling device 50 having a left traveling motor 31 driven by pressure oil supplied from the first hydraulic pump 11, a right traveling device 60 having a right traveling motor 32 driven by pressure oil supplied from the second hydraulic pump 21, and a traveling lever device (travel operation device) 6 that instructs the operation of the left traveling device 50 and the right traveling device 60. , 7, a processor (first processor) 2a that controls the capacity (displacement volume) of the first hydraulic pump 11 and the second hydraulic pump 21 in response to operation of the travel lever devices 6, 7, a first pressure sensor 13 that detects a first pump pressure P1 that is the discharge pressure of the first hydraulic pump 11, a second pressure sensor 23 that detects a second pump pressure P2 that is the discharge pressure of the second hydraulic pump 21, and an inclination angle detection device (inclination state detection device) 76 that detects the inclination angle (inclination state) of the vehicle body 107 with respect to the horizontal plane. The vehicle body 107 has a lower traveling body 101 that is equipped with a left traveling device 50 and a right traveling device 60, and an upper rotating body 102 that is rotatable relative to the lower traveling body 101.

[0105] The processor 2a calculates, as a traveling characteristic quantity, a differential pressure value ΔP between the first pump pressure P1 and the second pump pressure P2. The processor 2a calculates, as an inclination characteristic quantity, a roll angle φ, which is the inclination angle in the left-right direction of the vehicle body 107, based on a sensor value indicating the inclination angle (inclination state) detected by the inclination angle detection device 76. The processor 2a calculates, based on the roll angle (inclination angle) φ of the lower traveling structure 101, a correction amount Pc (second correction amount Pc2−first correction amount Pc1) for offsetting the influence of the inclination state of the lower traveling structure 101 constituting the vehicle body 107 on the first pump pressure P1 and the second pump pressure P2.

[0106] The processor 2a calculates the fluctuation in the differential pressure value ΔP caused by the load acting on one of the left running device 50 and the right running device 60 increasing and the load acting on the other of the left running device 50 and the right running device 60 decreasing due to the lower running body 101 tilting in the left-right direction as a correction amount Pc.

[0107] The processor 2a calculates a corrected differential pressure value ΔPc as a corrected travel characteristic quantity by correcting the calculated differential pressure value ΔP based on the correction amount Pc. The processor 2a calculates an abnormality determination evaluation value based on the calculated corrected differential pressure value ΔPc. In the present embodiment, the corrected differential pressure value ΔPc is used as the abnormality determination evaluation value. The processor 2a determines whether or not an abnormality exists in either the left traveling device 50 or the right traveling device 60 based on the calculated corrected differential pressure value ΔPc as the abnormality determination evaluation value. If the processor 2a determines that an abnormality exists, it outputs the determination result to the output device (the display device 91 and the communication device 92). This configuration makes it possible to prevent erroneous detection of an abnormality in the traveling devices 50, 60 when the hydraulic excavator 100 equipped with hydraulically driven traveling devices 50, 60 is traveling on an inclined road surface. According to the present embodiment, it is possible to appropriately diagnose the presence or absence of an abnormality in the traveling devices 50, 60 even when the hydraulic excavator 100 is traveling while tilting left or right.

[0108] (3) The processor 2a determines whether the left traveling device 50 and the right traveling device 60 are traveling straight when it determines that they are traveling straight. When the undercarriage 101 is traveling left or right and turning left or right due to the difference in speed between the left and right traveling devices 50, 60, it may not be possible to accurately detect an abnormality in the traveling devices 50, 60. In contrast, in this embodiment, an abnormality is determined when the vehicle is traveling straight. Therefore, it is possible to accurately detect an abnormality in the left and right traveling devices 50, 60.

[0109] (4) The processor 2a determines an abnormality when it determines that the working device 103 and the upper rotating body 102 are not being operated. When at least one of the working device 103 and the upper rotating body 102 is operating, the left and right load balance of the vehicle body 107 changes due to that operation, and there is a risk that an abnormality in the traveling devices 50, 60 cannot be accurately detected. In contrast, in this embodiment, an abnormality is determined when the working device 103 and the upper rotating body 102 are not being operated. Therefore, an abnormality in the left and right traveling devices 50, 60 can be accurately detected.

[0110] <Modification of First Embodiment> In the first embodiment, an example was described in which the driving characteristic quantity is the differential pressure value ΔP, but the driving characteristic quantity is not limited to this. For example, the driving characteristic quantity may be a driving force difference, which is the difference between the driving force of the left driving device 50 and the driving force of the right driving device 60. With this configuration, the present invention can also be applied to driving devices driven by electric motors. The driving force of an electrically driven driving device may be calculated based on torque detected by a torque sensor, or may be estimated based on current and voltage detected by a current sensor and a voltage sensor.

[0111] Furthermore, in the first embodiment, an example in which the tilt feature quantity is the roll angle φ has been described, but the tilt feature quantity is not limited to this. For example, the tilt feature quantity may be a distance difference, which is the difference between the vertical distance of the left traveling device 50 from the reference plane and the vertical distance of the right traveling device 60 from the reference plane. Because the width of the traveling device (the distance between the left traveling device 50 and the right traveling device 60) is known, the distance difference can be considered a parameter representing the tilt state. Note that, in the following embodiment, as in the first embodiment, an example in which the traveling feature quantity is the differential pressure value ΔP and the tilt feature quantity is the roll angle φ will be described. However, as in this modified example, the traveling feature quantity may be any parameter that represents the traveling state, and the tilt feature quantity may be any parameter that represents the tilt state.

[0112] <Second embodiment> A hydraulic excavator 100 according to a second embodiment of the present invention will be described with reference to Figures 13 to 15. Note that the same reference symbols are used to designate components that are the same as or equivalent to those described in the first embodiment, and differences will be mainly described.

[0113] Fig. 13 is a functional block diagram of a controller 202 according to the second embodiment, similar to Fig. 10. The controller 202 has an inclination state determination unit 277 instead of the correction amount calculation unit 83 of the controller 2 according to the first embodiment. Moreover, the controller 202 has a differential pressure value calculation unit 281, an effective differential pressure value extraction unit 282, and an abnormality determination unit 290 instead of the differential pressure value calculation unit 81, the effective differential pressure value extraction unit 82, and the abnormality determination unit 90 of the controller 2 according to the first embodiment. The processor 2a of the controller 202 realizes these functions by executing programs stored in the nonvolatile memory 2b.

[0114] In the second embodiment, the correction of the differential pressure value described in the first embodiment is not performed. Therefore, when the difference ΔF between the loads FL, FR on the horizontal road surface 109a and the loads FL, FR on the inclined road surface 109b (hereinafter also referred to as the load difference due to inclination) is greater than a predetermined value (hereinafter also referred to as the allowable load difference) ΔFt, there is a risk that abnormality detection based on the differential pressure value ΔP cannot be performed accurately. Therefore, the controller 2 according to the second embodiment is configured not to perform abnormality determination based on the differential pressure value ΔP when the load difference ΔF due to inclination is greater than the allowable load difference ΔFt.

[0115] FIG. 14 is a diagram showing the allowable load difference and the allowable roll angle range.

[0116] As shown in FIG. 14 , in this embodiment, the magnitude of the roll angle φ of the lower traveling structure 101 (absolute value of the roll angle φ) when the ratio of the smaller of the loads FL and FR to the loads FL and FR on the horizontal road surface 109a is 90% is defined as the allowable roll angle φt. The allowable roll angle range is defined as a range equal to or greater than a lower limit angle (−φt) and equal to or less than an upper limit angle (+φt). The upper limit angle (+φt) corresponds to the allowable roll angle φt (positive value). The lower limit angle (−φt) corresponds to the value obtained by multiplying the allowable roll angle φt by −1. When the roll angle φ is within the allowable roll angle range shown in FIG. 14 , the accuracy of abnormality determination can be ensured.

[0117] FIG. 15 is a flowchart similar to FIG. 12 , illustrating an example of the flow of an abnormality determination process executed by the controller 202 according to the second embodiment. The flowchart of FIG. 15 omits steps S4 and S6 from the flowchart of FIG. 12 . That is, the differential pressure value calculation unit 281 shown in FIG. 13 outputs the calculated differential pressure value ΔP to the effective differential pressure value extraction unit 82 without correcting it. Furthermore, in the flowchart of FIG. 15 , steps S250, S260, and S280 are executed instead of steps S50, S60, and S80 from the flowchart of FIG. 12 . Furthermore, in the second embodiment, if a positive determination is made in step S40, a tilt state determination process (step S245) is executed.

[0118] As shown in FIG. 15 , if a positive determination is made in step S40, the process proceeds to step S245. In step S245, the tilt state determination unit 277 determines whether the roll angle φ detected by the tilt angle detection device 76 is within the allowable roll angle range. If the roll angle φ is equal to or greater than the lower limit angle (−φt) and equal to or less than the upper limit angle (+φt), the roll angle φ is determined to be within the allowable roll angle range. If it is determined that the roll angle φ is within the allowable roll angle range (Yes), the valid mode is set, and the process proceeds to step S250. If the roll angle φ is less than the lower limit angle (−φt) or greater than the upper limit angle (+φt), the roll angle φ is determined to be not within the allowable roll angle range. If it is determined that the roll angle φ is not within the allowable roll angle range (No), the invalid mode is set, and the process shown in FIG. 15 for this control cycle ends.

[0119] In step S250, the effective differential pressure value extracting unit 282 extracts the differential pressure value ΔP calculated in step S2 of this control cycle as an abnormality determination evaluation value to be used for abnormality determination.

[0120] In the next step S260, the abnormality determination unit 290 determines whether the differential pressure value ΔP extracted as the abnormality determination evaluation value is equal to or less than a predetermined upper limit value Pu. If it is determined in step S260 that the differential pressure value ΔP is greater than the predetermined upper limit value Pu (No), the process proceeds to step S70. If it is determined in step S260 that the differential pressure value ΔP is equal to or less than the predetermined upper limit value Pu (Yes), the process proceeds to step S280.

[0121] In step S280, the abnormality determination unit 290 determines whether the differential pressure value ΔP extracted as the abnormality determination evaluation value is equal to or greater than a predetermined lower limit value P1. If it is determined in step S280 that the differential pressure value ΔP is smaller than the predetermined lower limit value P1 (No), the process proceeds to step S90. If it is determined in step S280 that the differential pressure value ΔP is equal to or greater than the predetermined lower limit value P1 (Yes), the process proceeds to step S100.

[0122] As described above, in the second embodiment, when the absolute value of the roll angle φ of the lower traveling body 101 (the magnitude of the roll angle φ) is greater than the predetermined angle φt, the abnormality determination process is not executed because this would affect the abnormality determination process. The predetermined angle φt is a threshold value of the roll angle φ for determining whether the traveling device 50, 60 is in an inclination state that would affect the abnormality determination process. The predetermined angle φt corresponds to the roll angle φ when it is, for example, ±10% (in this embodiment, −10%) of the balanced load when there is no inclination (φ=0°). Therefore, the abnormality determination process is executed only when the load change due to the inclination is within ±10%.

[0123] According to the second embodiment described above, the following advantageous effects are achieved.

[0124] The processor 2a of the controller 202 calculates an abnormality determination evaluation value based on the differential pressure value ΔP between the first pump pressure P1 and the second pump pressure P2. In this embodiment, the differential pressure value ΔP is used as the abnormality determination evaluation value. The processor 2a of the controller 202 determines that an abnormality exists in either the left traveling device 50 or the right traveling device 60 when the absolute value |φ| of the roll angle (inclination angle of the vehicle body 107) φ of the undercarriage 101 is equal to or less than a predetermined angle φt and the absolute value |ΔP| of the differential pressure value ΔP as the abnormality determination evaluation value is greater than a determination reference value ΔP0. When the processor 2a of the controller 202 determines that an abnormality exists, it outputs the determination result to the output device (the display device 91 and the communication device 92). The processor 2a of the controller 202 does not determine that there is an abnormality in either the left traveling device 50 or the right traveling device 60 if the absolute value |φ| of the roll angle (tilt angle of the vehicle body 107) φ of the lower traveling body 101 is greater than a predetermined angle φt, or if the absolute value |ΔP| of the differential pressure value ΔP as an abnormality determination evaluation value is less than or equal to the determination reference value ΔP0.

[0125] According to this configuration, when the inclination angle of the inclined road surface 109b, i.e., the roll angle φ of the lower traveling unit 101, is equal to or less than the predetermined angle φt, the abnormality determination process is executed based on the differential pressure value ΔP. On the other hand, when the roll angle φ of the lower traveling unit 101 is greater than the predetermined angle φt, the abnormality determination process based on the differential pressure value ΔP is not executed. This makes it possible to suppress erroneous detection of an abnormality resulting from the execution of the abnormality determination process in a situation that is easily affected by the inclination angle of the inclined road surface 109b. In other words, similar to the first embodiment, the second embodiment can provide a hydraulic excavator 100 that can prevent erroneous detection of an abnormality in the traveling units 50, 60 when traveling on the inclined road surface 109b. According to this embodiment, the effect of the inclination on the abnormality determination process can be eliminated, and abnormalities in the traveling units 50, 60 can be accurately detected.

[0126] <Third embodiment> A hydraulic excavator 100 according to a third embodiment of the present invention will be described with reference to Figures 16 to 19. Note that the same reference symbols are used to designate components that are the same as or equivalent to those described in the second embodiment, and differences will be mainly described.

[0127] In the first and second embodiments, an example has been described in which the roll angle φ of the lower traveling structure 101 is detected by the inclination angle detection device 76 attached to the lower traveling structure 101. In contrast, in the third embodiment, the roll angle φ of the lower traveling structure 101 is indirectly detected based on the detection result of the rotating structure inclination angle sensor 376a attached to the upper rotating structure 102 and the rotation angle of the upper rotating structure 102 relative to the lower traveling structure 101. In other words, the rotating structure inclination angle sensor 376a and the rotation angle sensor 376b constitute the inclination angle detection device 376 of the lower traveling structure 101. The upper rotating structure 102 has a cab 110 and a building for storing the engine, etc., and is therefore easier to install sensors, etc., than the lower traveling structure 101. It also has excellent environmental resistance.

[0128] FIG. 16 is a schematic diagram showing the inclination angle (roll angle φtrv and pitch angle θtrv) of the lower traveling body 101 and the inclination angle (roll angle φswg and pitch angle θswg) of the upper rotating body 102.

[0129] As shown in Fig. 16 , for example, a traveling body reference coordinate system, which is a coordinate system based on the lower traveling body 101, and a rotating body reference coordinate system, which is a coordinate system based on the upper rotating body 102, are set in the hydraulic excavator 100. Fig. 16 schematically shows the relationship between the traveling body reference coordinate system and the rotating body reference coordinate system.

[0130] The running body reference coordinate system corresponds to the vehicle body coordinate system described in the first embodiment. The running body reference coordinate system is defined as a right-handed coordinate system with the origin being any point on the turning center line, which is the rotation axis of the upper rotating body 102. In the running body reference coordinate system, the forward direction of the lower running body 101 is defined as the positive direction of the Xtrv axis. In the running body reference coordinate system, the vertically upward direction along the turning center line is defined as the positive direction of the Z axis. In the running body coordinate system, the leftward direction of the lower running body 101, which is perpendicular to both the Xtrv axis and the Z axis, is defined as the positive direction of the Ytrv axis.

[0131] The rotating unit-referenced coordinate system is defined as a right-handed coordinate system with the origin being any point on the rotation centerline, which is the rotation axis of the upper rotating unit 102. In the rotating unit-referenced coordinate system, the forward direction of the upper rotating unit 102 is defined as the positive direction of the Xswg axis. In the rotating unit-referenced coordinate system, the vertically upward direction along the rotation centerline is defined as the positive direction of the Z axis. In the rotating unit-referenced coordinate system, the left direction of the upper rotating unit 102, which is perpendicular to both the Xswg axis and the Z axis, is defined as the positive direction of the Yswg axis.

[0132] The Z axis of the running body reference coordinate system and the Z axis of the rotating body reference coordinate system are common. The rotation angle in the Xtrv-Z plane perpendicular to the Ytrv axis is represented by the pitch angle θtrv of the lower running body 101. The rotation angle in the Xtrv-Ytrv plane perpendicular to the Z axis is represented by the yaw angle ψtrv of the lower running body 101. The rotation angle in the Ytrv-Z plane perpendicular to the Xtrv axis is represented by the roll angle φtrv of the lower running body 101. The Xtrv axis is an axis along the traveling direction of the lower running body 101, and the roll angle φtrv with the Xtrv axis as the rotation axis corresponds to the left and right tilt angle of the lower running body 101 with respect to the horizontal plane. The Ytrv axis is an axis parallel to the rotation axes of the traveling motors 31 and 32, and the pitch angle θtrv about the Ytrv axis corresponds to the inclination angle of the lower traveling body 101 in the front and rear directions relative to the horizontal plane.

[0133] The rotation angle in the Xswg-Z plane perpendicular to the Yswg axis is represented by the pitch angle θswg of the upper rotating body 102. The rotation angle in the Xswg-Yswg plane perpendicular to the Z axis is represented by the yaw angle ψswg of the upper rotating body 102. The rotation angle in the Yswg-Z plane perpendicular to the Xswg axis is represented by the roll angle φ of the upper rotating body 102. The Xswg axis is an axis along the front of the upper rotating body (in front of the cab 110), and the roll angle φ about the Xswg axis as the rotation axis corresponds to the left-right inclination angle of the upper rotating body 102 with respect to the horizontal plane. The Yswg axis is an axis parallel to the rotation axis of the boom 104, and the pitch angle θswg about the Yswg axis as the rotation axis corresponds to the front-to-rear inclination angle of the upper rotating body 102 with respect to the horizontal plane. The difference between the yaw angle ψtrv of the lower traveling body 101 and the yaw angle ψswg of the upper rotating body 102 corresponds to the swing angle ψ.

[0134] The upper rotating body 102 rotates relative to the lower traveling body 101. Therefore, if the orientation of the upper rotating body 102 and the orientation of the lower traveling body 101 do not match, the tilt angle of the upper rotating body 102 and the tilt angle of the lower traveling body 101 will not be equal. For example, when the roll angle φswg of the upper rotating body 102 is 10°, the relationship between the swing angle ψ and the roll angle φtrv of the lower traveling body 101 and the relationship between the swing angle ψ and the pitch angle θtrv of the lower traveling body 101 are represented by the graph shown in FIG.

[0135] The roll angle (hereinafter also referred to as the vehicle roll angle) φtrv of the lower traveling body 101 is expressed by equation (17). The pitch angle (hereinafter also referred to as the vehicle pitch angle) θtrv of the lower traveling body 101 is expressed by equation (18). φtrv=φswg×cos ψ+θswg×sin ψ (17) θtrv=φswg×sin ψ+θswg×cos ψ (18) As shown in Fig. 16 , φswg is the roll angle (hereinafter also referred to as the vehicle roll angle) of the upper rotating body 102, θswg is the pitch angle (hereinafter also referred to as the vehicle pitch angle) of the upper rotating body 102, and ψ is the rotation angle.

[0136] Fig. 18 is a functional block diagram of a controller 302 according to the third embodiment, similar to Fig. 13. The controller 302 has a tilt state determination unit 377 instead of the tilt state determination unit 277 of the controller 202 according to the second embodiment. The processor 2a of the controller 302 realizes these functions by executing programs stored in the nonvolatile memory 2b.

[0137] The inclination angle detection device (tilt state detection device) 376 has a revolving structure inclination angle sensor 376a, a swing angle sensor 376b, and an inclination calculation unit 378. The revolving structure inclination angle sensor 376a detects the inclination angle of the upper revolving structure 102 with respect to a reference plane (e.g., a horizontal plane) and outputs a signal representing the detection result to the inclination calculation unit 378. The swing angle sensor 376b is provided on the vehicle body 107 and detects a swing angle ψ, which is the rotation angle of the upper revolving structure 102 with respect to the undercarriage 101, and outputs a signal representing the detection result to the inclination calculation unit 378. The rotating unit inclination angle sensor 376a may be an IMU (Inertial Measurement Unit) that acquires angular velocities and accelerations of three orthogonal axes as information related to the attitude, calculates the inclination angles (rotating unit roll angle φswg and rotating unit pitch angle θswg) based on this information, and outputs a signal representing the inclination angles φswg and θswg to the inclination calculation unit 378. The inclination calculation unit 378 calculates the travel unit roll angle φtrv based on information representing the attitude of the upper rotating unit 102 (rotating unit roll angle φswg, rotating unit pitch angle θswg, and swing angle ψ). The inclination calculation unit 378 is configured by a microcomputer (arithmetic device) having a processor such as a CPU and memories such as a ROM and a RAM. The functions of the inclination calculation unit 378 may be provided by the controller 302, which is an arithmetic device.

[0138] Fig. 19 is a flowchart similar to Fig. 15, showing an example of the flow of an abnormality determination process executed by the controller 302 according to the third embodiment. In the flowchart of Fig. 19, the process of step S307 is added between step S2 and step S10 in the flowchart of Fig. 15.

[0139] 19 , when the differential pressure calculation process (step S2) ends, the process proceeds to step S307. In step S307, the tilt state determination unit 377 acquires the vehicle roll angle φ calculated by the tilt calculation unit 378. The tilt calculation unit 378 acquires the revolving unit roll angle φswg, the revolving unit pitch angle θswg, and the swing angle ψ detected by the tilt angle detection device 376 at a predetermined calculation cycle, calculates the vehicle roll angle φtrv, and outputs it to the controller 302.

[0140] According to the above-described third embodiment, in addition to the same effects as those of the second embodiment, the following effects are achieved.

[0141] The inclination angle detection device (inclination state detection device) 376 includes a rotating body inclination angle sensor 376a attached to the upper rotating body 102 and detecting the inclination angle (roll angle φswg and pitch angle θswg) of the upper rotating body 102 with respect to the horizontal plane, a swing angle sensor 376b detecting the swing angle ψ of the upper rotating body 102 with respect to the lower running body 101, and an inclination calculation unit (calculation device) 378 that calculates the roll angle φtrv, which is the left-right inclination angle of the lower running body 101 with respect to the horizontal plane, based on the inclination angles φswg, θswg of the upper rotating body 102 detected by the rotating body inclination angle sensor 376a and the swing angle ψ of the upper rotating body 102 detected by the swing angle sensor 376b. When the absolute value |φtrv| of the roll angle φtrv of the undercarriage 101 detected by the inclination angle detection device 376 is equal to or smaller than the predetermined angle φt and the absolute value |ΔP| of the differential pressure value ΔP as an abnormality determination evaluation value is larger than the determination reference value ΔP0, the processor 2a of the controller 302 determines that an abnormality exists in either the left traveling device 50 or the right traveling device 60. When the absolute value |φtrv| of the roll angle φtrv of the undercarriage 101 detected by the inclination angle detection device 376 is larger than the predetermined angle φt, or when the absolute value |ΔP| of the differential pressure value ΔP as an abnormality determination evaluation value is equal to or smaller than the determination reference value ΔP0, the processor 2a of the controller 302 does not determine that an abnormality exists in either the left traveling device 50 or the right traveling device 60.

[0142] The lower traveling structure 101 has a mechanism for rotatably connecting the upper rotating structure 102, and it is not easy to install a sensor or the like. In the third embodiment, there is no need to install the inclination angle detection device 76 on the lower traveling structure 101. This simplifies the configuration of the hydraulic excavator 100 and reduces manufacturing costs.

[0143] 20 and 21, a diagnostic system 410 according to a fourth embodiment of the present invention will be described. Note that the same reference symbols are used to designate components that are the same as or equivalent to those described in the first embodiment, and differences will be mainly described.

[0144] The hardware configuration of the hydraulic excavator 400 is similar to that of the hydraulic excavator 100 described in the first embodiment. In the first embodiment, an example has been described in which the diagnostic device 80 includes a controller 2 mounted on the hydraulic excavator 100 and output devices (a display device 91 and a communication device 92). In contrast, in the fourth embodiment, the diagnostic device 480 includes a server 440 provided in a management facility and output devices (a display device 462 and a communication device 498). In other words, in the fourth embodiment, the server 440 diagnoses abnormalities in the traveling gears 50, 60 of the hydraulic excavator 400 based on feature quantities acquired from one or more hydraulic excavators 100. For this reason, the controller 402 of the hydraulic excavator 400 has a function for calculating feature quantities but does not have a function for diagnosing abnormalities.

[0145] In the fourth embodiment, it is possible to simultaneously or in a composite manner handle processes such as collecting feature amounts from a plurality of hydraulic excavators 100 and analyzing, comparing, and judging them, thereby enabling data analysis and diagnosis with an overall overview.

[0146] FIG. 20 is a diagram showing the configuration of a diagnostic system 410 according to the fourth embodiment. The diagnostic system 410 includes one or more hydraulic excavators 400 that perform work at a work site and a diagnostic device 480 that is provided in a management facility. The management facility is provided in a location away from the work site. The hydraulic excavators 400 and the diagnostic device 480 are configured to be able to perform two-way communication via a communication line NT of a wide area network. In other words, the hydraulic excavators 400 and the diagnostic device 480 can send and receive information (data) via the communication line NT. The communication line NT may be a mobile phone communication network (mobile communication network) provided by a mobile phone carrier or the like, a satellite communication network, the Internet, or the like. The diagnostic device 480 is configured to include a server 440, an input device 461, a display device 462, and a communication device 498.

[0147] The controller 402 mounted on the hydraulic excavator 400 and the server 440 installed in the management facility are computers that include processors 402a, 440a such as CPUs, nonvolatile memories 402b, 440b, and volatile memories 402c, 440c that serve as storage devices (memories), similar to the controller 2 of the first embodiment. The controller 402 and the server 440 also include input interfaces 402d, 440d and output interfaces 402e, 440e. The controller 402 and the server 440 may each be configured as a single computer or multiple computers.

[0148] The server 440 collects feature amounts (travel feature amounts and slope feature amounts) from the hydraulic excavator 400 via the communication device 498 serving as a receiver. The server 440 analyzes the operation and deterioration trends of the hydraulic excavator 400 from the time-series behavior of the feature amounts, compares the feature amounts with thresholds, and makes various determinations. The server 440 also compares the feature amounts of a plurality of hydraulic excavators 400 to identify hydraulic excavators 400 that have transmitted feature amounts that deviate from the average feature amount, and performs various analyses based on the degree of deviation of the feature amounts. Furthermore, the server 440 can also make various determinations using other statistical analysis methods, etc.

[0149] The server 440 is connected to a display device 462 such as a liquid crystal monitor, an input device 461 such as a keyboard, and a communication device 498 that sends and receives information to and from each hydraulic excavator 400 via a communication line NT. The display device 462 is an output device that is controlled by the server 440 and outputs the calculation results of the server 440 as images. The communication device 498 is connected to the communication line NT and is an output device that outputs the calculation results of the server 440 to the hydraulic excavator 400.

[0150] In the first embodiment shown in FIG. 10 , the controller 2 may calculate an abnormality determination evaluation value (corrected differential pressure value ΔPc) from the first pump pressure P1, the second pump pressure P2, and the vehicle body roll angle φ, and transmit the abnormality determination evaluation value to the server 40 via the communication device 92. Furthermore, the server 40 according to the first embodiment may have an analysis function, such as storing, analyzing, comparing, and judging acquired data. If an abnormality is detected through the analysis, the server 40 displays information about the hydraulic excavator 100 in which the abnormality has been detected on a display device such as an LCD monitor. This allows the vehicle manager to easily identify the hydraulic excavator 100 in which the abnormality has occurred. Furthermore, the server 40 may transmit information notifying the occurrence of the abnormality to the hydraulic excavator 100 in which the abnormality has been detected, or may transmit information notifying the occurrence of the abnormality to the vehicle manager, operator, or the like using a notification means such as email. However, using such a system may make operation and management complicated.

[0151] For example, in the first embodiment, the abnormality determination evaluation value is compared with the determination reference value for each of the multiple hydraulic excavators 100 to determine whether or not an abnormality exists. Here, a correction amount Pc corresponding to the roll angle φ of the hydraulic excavator 100 is used to calculate the abnormality determination evaluation value. The coefficients (e.g., loss torque coefficient C) and load characteristics table T used to calculate the correction amount Pc may be determined in advance from design values ​​or trends in past measured data, as in the first embodiment, but it is preferable to adjust them by acquiring operation information of the actual hydraulic excavator 100. For this reason, the correction amount parameters (e.g., loss torque coefficient C and load characteristics table T) required to calculate the correction amount Pc may be reviewed while checking operation information from the initial stage of operation of the hydraulic excavator 100.

[0152] This revision of the correction amount parameters is beneficial because it allows an appropriate correction amount Pc to be obtained. However, in the first embodiment, calculation of the correction amount Pc and correction processing using the correction amount Pc are performed by the controller 2 of each hydraulic excavator 100. Therefore, modifying the correction amount parameters required to calculate the correction amount Pc or changing the correction logic (correction method) requires software modification (rewriting) for each of the multiple hydraulic excavators 100. For example, if it becomes necessary to modify the correction amount parameters for a certain model of hydraulic excavator 100, similar software modification work will be required for all of the corresponding hydraulic excavators 100, which will require a lot of work. Furthermore, it will be necessary to monitor the operation of the hydraulic excavator 100 whose correction amount parameters have been modified and check whether the modifications were appropriate for each of the multiple hydraulic excavators 100, which will require a lot of management work.

[0153] In contrast to this, in the diagnosis system 410 according to the fourth embodiment, it is possible to easily modify the correction amount parameters and change the correction logic (correction method), and furthermore, it is also possible to easily manage the modifications. This will be described in detail below.

[0154] FIG. 21 is a functional block diagram of a diagnostic system 410 according to the fourth embodiment. As shown in FIG. 21 , the controller 402 includes a state determination unit 70, a traveling state quantity calculation unit 495, a tilt state quantity calculation unit 496, and a feature quantity calculation unit 482. The processor 402a of the controller 402 executes programs stored in the nonvolatile memory 402b to realize these functions. The server 440 also includes a correction quantity calculation unit 483, a feature quantity correction unit 481, an analysis unit 490, and a correction unit 499. The processor 440a of the server 440 executes programs stored in the memory 440b to realize these functions.

[0155] The driving state quantity calculation unit 495 stabilizes the pressure sensor values ​​(sensor data representing the first pump pressure P1 and the second pump pressure P2) output from the first pressure sensor 13 and the second pressure sensor 23 using a stabilization filter or the like, and calculates a driving state quantity equivalent to the driving force based on the stabilized pressure sensor values.

[0156] The tilt state quantity calculation unit 496 stabilizes the tilt angle sensor value (sensor data representing the roll angle φ) output from the tilt angle detection device 76 using a stabilization filter or the like, and calculates a tilt state quantity equivalent to the roll angle φ of the vehicle body 107 based on the stabilized tilt angle sensor value.

[0157] The traveling state quantity and the tilt state quantity need to be synchronized. Therefore, the characteristics of the stabilization filters used in the traveling state quantity calculation unit 495 and the tilt state quantity calculation unit 496 have the same response characteristics. The traveling state quantity calculation unit 495 and the tilt state quantity calculation unit 496 output the traveling state quantity and the tilt state quantity in synchronization with each other.

[0158] The feature quantity calculation unit 482 calculates a driving feature quantity and a tilt feature quantity based on the driving state quantity calculated by the driving state quantity calculation unit 495, the tilt state quantity calculated by the tilt state quantity calculation unit 496, and the determination result by the state determination unit 70. The feature quantity calculation unit 482 extracts, as the driving feature quantity, the driving state quantity calculated at the time when the valid mode is set by the state determination unit 70. That is, in the fourth embodiment, the driving feature quantity refers to the driving state quantity that is to be transmitted to the server 440. Similarly, the feature quantity calculation unit 482 extracts, as the tilt feature quantity, the tilt state quantity calculated at the time when the valid mode is set by the state determination unit 70. That is, in the fourth embodiment, the tilt feature quantity refers to the tilt state quantity that is to be transmitted to the server 440.

[0159] The feature amount calculation unit 482 transmits feature amount data linking the travel feature amount and slope feature amount, the time when the sensor values ​​used in the calculation were acquired, and the vehicle ID for identifying the hydraulic excavator 400 to the server 440 via the communication device (transmitter) 92. The server 440 acquires the feature amount data from each hydraulic excavator 400 via the communication device (receiver) 498.

[0160] The travel feature amount may be the sensor data itself output from a travel condition detection device provided in the hydraulic excavator 400, or may be calculated data calculated based on the sensor data. Similarly, the tilt feature amount may be the sensor data itself output from the tilt condition detection device, or may be calculated data calculated based on the sensor data.

[0161] The correction amount calculation unit 483 calculates and outputs a correction amount for the driving characteristic amount from the tilt characteristic amount. When the tilt state amount and the tilt characteristic amount are the roll angle φ, the correction amount calculation unit 483 calculates the correction amount Pc in the same way as the correction amount calculation unit 83 of the first embodiment.

[0162] The feature quantity corrector 481 corrects and outputs the driving feature quantity based on the correction quantity Pc. When the driving state quantity and the driving feature quantity are the differential pressure value ΔP between the first pump pressure P1 and the second pump pressure P2, the feature quantity corrector 481 calculates the corrected differential pressure value ΔPc as an abnormality determination evaluation value in the same manner as the differential pressure value calculator 81 of the first embodiment.

[0163] The analysis unit 490 acquires and analyzes the corrected differential pressure value ΔPc, which is the corrected traveling characteristic quantity. For example, the analysis unit 490 performs abnormality determination using a method similar to that of the abnormality determination unit 90 described in the first embodiment. If the analysis unit 490 determines that an abnormality has occurred in the traveling devices 50, 60, it outputs the vehicle ID of the hydraulic excavator 400 that is equipped with the traveling devices 50, 60 and notification information notifying that an abnormality has occurred in the traveling devices 50, 60 to the display device 491 and the sound output device 492.

[0164] The display device 491 displays a notification screen informing the user that an abnormality has occurred. The notification screen includes the vehicle ID of the hydraulic excavator 400 in which the abnormality has occurred and information about the traveling device in which the abnormality has occurred (the left traveling device 50 or the right traveling device 60). The notification screen may also include information about traveling feature amounts and slope feature amounts. The sound output device 492 is, for example, a speaker that outputs the notification information as sound. Note that the sound output device 492 may also be a device that outputs an alarm sound in a predetermined output pattern according to the notification information.

[0165] This allows the vehicle manager to quickly identify the hydraulic excavator 400 in which an abnormality has occurred. The analysis unit 490 may be configured to transmit notification information via the communication device 498 to the hydraulic excavator 400 in which an abnormality has occurred or to an information terminal (for example, a tablet terminal, a smartphone, or a laptop PC) carried by the operator of the hydraulic excavator 400.

[0166] The correction unit 499 determines whether or not the correction amount parameters need to be corrected based on the driving feature amount, the slope feature amount, the current correction amount parameters, and the analysis results. If the correction unit 499 determines that the correction amount parameters need to be corrected, it corrects the correction amount parameters. For example, if the correction unit 499 determines that the analysis results deviate to a certain extent based on the appropriateness of the analysis results, it determines that the correction amount parameters need to be modified or adjusted, and performs an adjustment process for the correction amount parameters. For example, by increasing the data parameter or recalculating the characteristics of the driving feature amount and the slope feature amount, it is possible to obtain characteristics that are closer to the true values ​​and that match the actual situation.

[0167] As a result, when correction of the correction amount parameters is necessary, this can be achieved by correcting the software of the server 440. As a result, there is no need to carry out work such as software correction for each of the multiple hydraulic excavators 400, and the correction amount parameters can be easily corrected on the server 440 side. Furthermore, by simply partially correcting the software of the server 440, it is possible to accommodate all of the hydraulic excavators 400 that are the targets of diagnosis, which is advantageous as it does not require rewriting management for each hydraulic excavator 400.

[0168] Although the above description has been given of an example in which the server 440 automatically corrects the correction amount parameters, the vehicle manager or a service person may manually correct the correction amount parameters using the input device 461 as necessary.

[0169] As described above, the diagnosis device 480 according to the fourth embodiment includes the server 440 having a processor (first processor) 440a that diagnoses abnormalities in the traveling devices 50, 60 based on a traveling feature quantity (differential pressure value ΔP) that represents the traveling state of the traveling devices 50, 60 attached to the vehicle body 107 of the hydraulic excavator 400, and an output device (display device 462, communication device 498) that outputs the results of the diagnosis by the processor 440a. The processor 440a acquires a tilt feature quantity (roll angle φ) that represents the tilt state of the vehicle body 107. The processor 440a calculates a correction amount Pc based on the tilt feature quantity (roll angle φ) to offset the effect of the tilt state of the vehicle body 107 on the traveling feature quantity (differential pressure value ΔP) of the traveling devices 50, 60. The processor 440a corrects the traveling feature quantity (differential pressure value ΔP) based on the correction amount Pc to calculate a corrected traveling feature quantity (corrected differential pressure value ΔPc). The processor 440a calculates an abnormality determination evaluation value based on the corrected driving characteristic quantity (corrected differential pressure value ΔPc). The processor 440a determines whether or not an abnormality exists in the driving devices 50, 60 based on the abnormality determination evaluation value. If the processor 440a determines that an abnormality exists, it outputs the determination result to the output device (display device 462).

[0170] According to this diagnostic system 410, the server 440 diagnoses abnormalities in the hydraulic excavator 400, and an image showing the diagnosis results is output by the display device (output device) 462. This allows the vehicle manager to easily identify the hydraulic excavator 400 in which an abnormality has occurred, and to quickly and appropriately formulate a maintenance plan to resolve the abnormality.

[0171] A diagnostic system 410 according to the fourth embodiment includes a diagnostic device 480 and a hydraulic excavator (work machine) 400. The diagnostic device 480 is equipped with a communication device (receiver) 498 and a server 440. The communication device 498 receives a traveling characteristic quantity (differential pressure value ΔP) and a tilt characteristic quantity (roll angle φ) transmitted from the hydraulic excavator 400. The server 440 has a processor (first processor) 440a that diagnoses an abnormality in the traveling devices 50, 60 of the hydraulic excavator 400 based on the traveling characteristic quantity and the tilt characteristic quantity received by the communication device 498, and a nonvolatile memory (memory) 402b that stores correction amount parameters (loss torque coefficient C and load characteristic table T) used to calculate the correction amount Pc. The hydraulic excavator 400 includes a traveling condition detection device (first pressure sensor 13 and second pressure sensor 23) that detects the traveling condition of the traveling devices 50, 60, an inclination condition detection device (inclination angle detection device 76) that detects the inclination condition of the vehicle body 107, a processor (second processor) 402a that calculates a traveling characteristic quantity (differential pressure value ΔP) based on sensor values ​​that represent the traveling condition detected by the traveling condition detection device and calculates a tilt characteristic quantity (roll angle φ) based on sensor values ​​that represent the inclination condition detected by the inclination condition detection device, and a communication device (transmitter) 92 that transmits the traveling characteristic quantity (differential pressure value ΔP) and the tilt characteristic quantity (roll angle φ) calculated by the processor 402a to a server 440. The processor 402a calculates the traveling characteristic quantity (differential pressure value ΔP) and the tilt characteristic quantity (roll angle φ) in synchronization with each other. The processor 440a calculates the correction amount Pc based on the correction amount parameters (loss torque coefficient C and load characteristic table T) stored in the nonvolatile memory 402b and the tilt characteristic amount (roll angle φ).

[0172] In this configuration, a service technician can easily modify the correction amount parameters because the correction amount parameters are stored in the server 440. In other words, in this embodiment, a service technician does not need to modify the correction amount parameters for each of a plurality of hydraulic excavators.

[0173] <Modification of Fourth Embodiment> In this modification of the fourth embodiment, a configuration for a case where the data communication cycle is slow will be described. Various types of data communication cycles are assumed depending on the data. For example, when transmitting data in real time, the data communication cycle is set to about several tens of Hz. Furthermore, when transmitting daily report data, the data communication cycle is set to one day. In this modification of the fourth embodiment, an example suitable for a case where the data transmission cycle of the hydraulic excavator 400 is long will be described.

[0174] In monitoring and diagnosing the vehicle body condition, such as diagnosing abnormalities in the traveling gear of the hydraulic excavator 400, the vehicle body condition can be adequately represented even by grasping the condition in a daily report format once a day, since this is familiar to routine inspections of the vehicle body 107. When the data communication cycle is about once a day, the amount of communication can be significantly reduced compared to when data is transmitted in real time. For example, when transmitting data as a daily report, data is thinned to one data item per day and transmitted once a day. In this case, the communication cycle from the communication device (transmitter) 92 to the communication device (receiver) 498 is one day (24 hours), and the data on the server 440 side is downsampled every day.

[0175] On the other hand, there is a demand for statistical processing and filtering by the analysis unit 490 of the server 440 to analyze the behavior and trends of acquired data, such as feature quantities. However, the sampling frequency of the data can have adverse effects (the effect of aliasing). Specifically, when sampling a signal, the Nyquist frequency must be taken into consideration, and there is a restriction that "only frequencies up to half the sampling frequency can be reproduced." Therefore, for characteristics that include a restricted band, filtering (equivalent to an anti-aliasing filter) to suppress the effects must be performed before downsampling. An anti-aliasing filter is a low-pass filter that attenuates frequencies exceeding half the sampling frequency with high attenuation characteristics. Sampling a signal that has passed through an anti-aliasing filter prevents aliasing.

[0176] FIG. 22 is a conceptual diagram illustrating how data is calculated by downsampling after applying a filter for characteristic extraction. The feature amount calculation unit 482 (see FIG. 21 ) downsamples after appropriately calculating the output value of the filter, etc. The feature amount calculation unit 482 downsamples the output value at three different periods. As shown in FIG. 22 , the three periods are a first period (hereinafter, short-term) S, a second period (hereinafter, medium-term) M, and a third period (hereinafter, long-term L), and the magnitude relationship between the three periods is short-term S < medium-term M < long-term L.

[0177] 22, dynamic responses for feature extraction from the original data are generated and output by a dynamic filter that acquires short-term S, medium-term M, and long-term L trends. Each of these output values ​​is downsampled as a daily report and output to the server 440. According to the configuration of the modification of the fourth embodiment, appropriate values ​​can be calculated for, for example, relatively short-term behavior and used for analysis.

[0178] The controller 402 according to the modification of the fourth embodiment calculates driving feature amounts based on sensor data sampled at each of short-term S, medium-term M, and long-term L periods according to the dynamic response characteristics required for analysis, and transmits each calculated value to the server 440. Note that, since the slope data is also treated as an explanatory variable, slope feature amounts having similar response characteristics are calculated so that the responses are synchronized, and similarly transmitted as a daily report. In other words, the controller 402 calculates slope feature amounts based on sensor data sampled at each of short-term S, medium-term M, and long-term L periods, and transmits each calculated value to the server 440.

[0179] The controller 402 calculates the driving feature amounts and slope feature amounts that are synchronized in the short term S and transmits them to the server 440. The controller 402 also calculates the driving feature amounts and slope feature amounts that are synchronized in the medium term M and transmits them to the server 440. The controller 402 also calculates the driving feature amounts and slope feature amounts that are synchronized in the long term L and transmits them to the server 440.

[0180] This allows the analysis unit 490 of the server 440 to use driving features and slope features with the desired response characteristics in a synchronized manner, so that the features can be used as good features without causing phase shifts between the data.

[0181] As described above, in the modification of the fourth embodiment, the processor (second processor) 402a of the excavator 400 calculates the traveling feature amount and the slope feature amount for each of a plurality of periods (short term S, medium term M, and long term L). The processor (first processor) 440a of the server 440 can calculate the abnormality determination evaluation value for each of a plurality of periods (short term S, medium term M, and long term L) based on the traveling feature amount and the slope feature amount for each of the plurality of periods (short term S, medium term M, and long term L).

[0182] According to this configuration, it is possible to diagnose an abnormality using an abnormality determination evaluation value calculated based on a driving feature amount and a slope feature amount having desired response characteristics, thereby improving the usability of the diagnosis device 480.

[0183] With the configurations according to the fourth embodiment and the modified example of the fourth embodiment, the condition determination logic can be performed on the server side, so that the feature values ​​can be calculated and updated regardless of the tilt condition, and correction amount parameters can be easily adjusted while checking the state of the feature values. Furthermore, there is no need to rewrite the software of the controller 402, and the work of modifying and maintaining the vehicle body is significantly reduced.

[0184] Moreover, since it is possible to collect travel feature amounts and inclination feature amounts of a plurality of hydraulic excavators 400 and analyze the behavior of these feature amounts, it is possible to appropriately and easily set correction conditions such as whether or not correction amount parameters or correction logic (correction method) need to be corrected, and the amount of correction of the correction parameters, etc. Furthermore, by monitoring the behavior of the collected travel feature amounts and inclination feature amounts after the correction conditions have been set, it is also possible to easily determine the appropriateness of the setting of the correction conditions.

[0185] The following modified examples are also within the scope of the present invention, and it is possible to combine the configuration shown in the modified example with the configuration described in the above embodiment, to combine the configurations described in the different embodiments above, or to combine the configurations described in the different modified examples below.

[0186] <Modification 1> In the first embodiment, correction was performed to determine whether the traveling devices 50, 60 were abnormal, regardless of the roll angle φ of the lower traveling body 101. However, if the roll angle φ is too large, there is a risk that the abnormality determination cannot be performed accurately even if correction is performed. Therefore, in Modification 1, the correction process described in the first embodiment is performed only when the tilt angle is within a predetermined angle range, and an abnormality determination is performed on the traveling devices 50, 60 based on the corrected differential pressure value ΔPc as the abnormality determination evaluation value. Modification 1 corresponds to an example that combines the first and second embodiments.

[0187] Fig. 23 is a flowchart similar to Fig. 12 and Fig. 15, showing an example of the flow of abnormality determination processing executed by the controller 2 according to Modification 1. In the flowchart shown in Fig. 23, the processing of step S245 of the flowchart of Fig. 15 is added between steps S40 and S50 of the flowchart of Fig. 12. The processing of steps S2 to S40 and S50 to S110 is the same as in the first embodiment, and the processing of step S245 is the same as in the second embodiment.

[0188] The processor 2a of the controller 2 according to the first modification determines that an abnormality exists in either the left traveling device 50 or the right traveling device 60 when the absolute value |φ| of the roll angle φ of the undercarriage 101 detected by the inclination angle detection device 76 is equal to or less than a predetermined angle φt and the absolute value |ΔPc| of the corrected differential pressure value ΔPc serving as an abnormality determination evaluation value is greater than the determination reference value ΔP0. The processor 2a of the controller 2 does not determine that an abnormality exists in either the left traveling device 50 or the right traveling device 60 when the absolute value |φ| of the roll angle φ of the undercarriage 101 detected by the inclination angle detection device 76 is greater than the predetermined angle φt or when the absolute value |ΔPc| of the corrected differential pressure value ΔPc serving as an abnormality determination evaluation value is equal to or less than the determination reference value ΔP0. This configuration makes it possible to more appropriately prevent erroneous detection of an abnormality in the traveling devices 50, 60.

[0189] <Modification 2> In the second embodiment, an example in which the inclination angle detection device 76 is provided on the lower traveling body 101 has been described. However, the upper rotating body 102 may be provided with the rotating body inclination angle sensor 376a described in the third embodiment, and the inclination angle detection device 76 on the lower traveling body 101 may be omitted. If the orientation (e.g., the front-to-rear direction) of the upper rotating body 102 and the orientation (e.g., the front-to-rear direction) of the lower traveling body 101 are substantially the same, the roll angle φswg detected by the rotating body inclination angle sensor 376a on the upper rotating body 102 can be regarded as the roll angle φtrv of the lower traveling body 101.

[0190] Fig. 24 is a flowchart similar to Fig. 15, showing an example of the flow of abnormality determination processing executed by the controller 202 according to Modification 2. In the flowchart shown in Fig. 24, processing of step S543 is added between step S40 and step S245 of the flowchart in Fig. 15.

[0191] As shown in FIG. 24 , if a positive determination is made in step S40, the processing proceeds to step S543. In step S543, the controller 202 determines whether the swing angle ψ detected by the swing angle sensor 376b is within a predetermined swing angle range. When the hydraulic excavator 100 is in the reference posture, the swing angle ψ is 0°. The reference posture corresponds to a posture in which the orientation of the lower traveling structure 101 and the orientation of the upper swing structure 102 match. When the upper swing structure 102 swings right from the reference posture, the swing angle ψ increases from 0° to 180° in response to the swing. When the upper swing structure 102 swings left from the reference posture, the swing angle ψ decreases from 0° to −180° in response to the swing (the absolute value increases).

[0192] The predetermined swing angle range is set to an angle range that does not cause erroneous detection of an abnormality in the traveling devices 50, 60 when the roll angle φswg of the upper swing body 102 is set to the roll angle φtrv of the lower traveling body 101. In other words, the predetermined swing angle range is set to determine whether the posture is the reference posture, and is set to, for example, not less than −10° and not more than +10°.

[0193] As described above, the hydraulic excavator 100 according to the second modification includes a swing angle sensor 376b that detects the swing angle ψ of the upper rotating body 102 relative to the lower traveling body 101, and a swing body inclination angle sensor (tilt state detection device, inclination angle detection device) 376a that is attached to the upper rotating body 102 and detects the roll angle (tilt angle) φ of the upper rotating body 102 relative to the horizontal plane. When the orientations of the upper rotating body 102 and the lower traveling body 101 are the same, the roll angle φswg of the upper rotating body 102 matches the roll angle φtrv of the lower traveling body 101. The processor 2a of the controller 202 determines whether the swing angle ψ detected by the swing angle sensor 376b is within a predetermined swing angle range (-ψt≦ψ≦ψt), which includes the swing angle (0°) at which the orientations of the lower traveling body 101 and the upper rotating body 102 match. If the swing angle ψ is within a predetermined swing angle range, the absolute value |φ| of the roll angle (tilt angle) φ of the upper swing body 102 detected by the swing body tilt angle sensor 376a is equal to or less than a predetermined angle φt, and the absolute value |ΔP| of the differential pressure value ΔP serving as an abnormality determination evaluation value is greater than the determination reference value ΔP0, the processor 2a of the controller 202 determines that there is an abnormality in either the left traveling device 50 or the right traveling device 60. If the swing angle ψ is not within the predetermined swing angle range or if the absolute value |φ| of the roll angle φ of the upper swing body 102 is greater than the predetermined angle φt, the processor 2a of the controller 202 does not determine that there is an abnormality in either the left traveling device 50 or the right traveling device 60.

[0194] According to this configuration, the roll angle φswg of the upper rotating body 102 can be regarded as the roll angle φtrv of the lower traveling body 101 to perform abnormality determination for the traveling devices 50, 60, and therefore there is no need to perform the calculation process for the traveling body roll angle φtrv based on the tilt angle (φswg, θswg) and the swing angle ψswg of the upper rotating body 102 described in the third embodiment. Therefore, it is possible to appropriately perform abnormality determination for the traveling devices 50, 60 while reducing the calculation load.

[0195] <Modification 3> In the first embodiment, as described in the third embodiment, the tilt calculation unit 378 may calculate the travelling body roll angle φ based on the rotating body roll angle φswg, the rotating body pitch angle θswg, and the swing angle ψ.

[0196] In the present modified example 3, the inclination angle detection device (tilt state detection device) 376 includes a rotating body inclination angle sensor 376a attached to the upper rotating body 102 and detecting the inclination angle (roll angle φswg, pitch angle θswg) of the upper rotating body 102 with respect to a horizontal plane, a swing angle sensor 376b detecting the swing angle ψ of the upper rotating body 102 with respect to the lower traveling body 101, and an inclination calculation unit (computing device) 378 that calculates a roll angle φtrv, which is the lateral inclination angle of the lower traveling body 101 with respect to the horizontal plane, based on the inclination angle (roll angle φswg, pitch angle θswg) of the upper rotating body 102 detected by the rotating body inclination angle sensor 376a and the swing angle ψ of the upper rotating body 102 detected by the swing angle sensor 376b. The processor 2a of the controller 2 calculates the correction amount Pc based on the roll angle φtrv of the lower traveling body 101.

[0197] According to this configuration, in addition to the same effects as those of the first embodiment, by omitting the installation of an inclination angle detection device on the lower traveling body 101, the configuration of the hydraulic excavator 100 can be simplified and manufacturing costs can be reduced.

[0198] <Modification 4> In the above embodiments, examples have been described in which the differential pressure value (second and third embodiments) or the corrected differential pressure value (first and fourth embodiments) is used as the abnormality determination evaluation value. However, the present invention is not limited to this. An integrated value of the differential pressure values ​​or an integrated value of the corrected differential pressure values ​​may also be used as the abnormality determination evaluation value. For example, in the second embodiment, after the process of step S2 in FIG. 15 , the controller 202 adds the differential pressure value calculated in step S2 to the multiple differential pressure values ​​calculated in previous steps S2 to calculate an integrated value of a fixed number (e.g., N) of differential pressure values. In step S250, the controller 202 extracts the integrated value of the differential pressure values ​​as the abnormality determination evaluation value. Note that the determination reference value ΔP0′ to be compared with the integrated value of the differential pressure values ​​is set to a value (ΔP0×N) obtained by multiplying the determination reference value described in the second embodiment by a fixed number (e.g., N) (ΔP0′=ΔP0×N). The upper limit value Pu corresponds to ΔP0′ (Pu=ΔP0′), and the lower limit value P1 corresponds to −ΔP0′ (P1=−ΔP0′).

[0199] By using the differential pressure integrated value as the abnormality determination evaluation value, it is possible to appropriately detect abnormalities in the left and right traveling devices 50, 60 while eliminating the influence of road surface conditions.

[0200] <Modification 5> A low-pass filter process may be performed on the first pump pressure P1 detected by the first pressure sensor 13 and the second pump pressure P2 detected by the second pressure sensor 23, and an abnormality determination evaluation value may be calculated based on the differential pressure value between the first pump pressure P1 and the second pump pressure P2 after the low-pass filter process. The low-pass filter process removes pressure fluctuations in the first pump pressure P1 and the second pump pressure P2 that occur when the left and right traveling devices 50, 60 accelerate, and one example of this is moving average processing.

[0201] The controller applies low-pass filtering to each pressure value from the first pressure sensor 13 and the second pressure sensor 23, thereby removing transient fluctuation components contained in each pressure value, thereby maintaining the accuracy of abnormality detection for the left and right running devices 50, 60 during non-steady driving conditions such as acceleration.

[0202] <Modification 6> In the above embodiment, an example has been described in which the work machine is the hydraulic excavator 100, but the present invention is not limited to this. The present invention can be applied to various work machines that are equipped with a hydraulically driven or electrically driven left traveling device 50 and right traveling device 60.

[0203] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0204] 1...engine, 2...controller, 2a...processor (first processor), 2b...non-volatile memory (memory), 3...work operation sensor, 4...swing operation sensor, 5...travel operation sensor, 6...travel lever device (travel operation device), 11...first hydraulic pump, 13...first pressure sensor (travel state detection device), 21...second hydraulic pump, 23...second pressure sensor (travel state detection device), 31...left travel motor (hydraulic motor, hydraulic actuator), 32...right travel motor (hydraulic motor, hydraulic actuator), 33...boom cylinder (hydraulic actuator), 3 4...Arm cylinder (hydraulic actuator), 35...Bucket cylinder (hydraulic actuator), 36...Swing motor (hydraulic actuator), 37...Attachment actuator (hydraulic actuator), 50...Left traveling device, 51...Travel drive device, 60...Right traveling device, 61...Travel drive device, 70...Status determination unit, 76...Tilt angle detection device (tilt state detection device), 80...Diagnostic device, 81...Differential pressure value calculation unit, 82...Effective differential pressure value extraction unit, 83...Correction amount calculation unit, 90...Abnormality determination unit, 91...Display device (output device), 92...Communication device (output device, transmission 100...hydraulic excavator (work machine), 101...lower traveling body, 102...upper rotating body, 103...working device, 107...vehicle body, 110...operator's cab, 200...hydraulic drive unit, 202...controller, 277...tilt state determination unit, 281...differential pressure value calculation unit, 282...effective differential pressure value extraction unit, 290...abnormality determination unit, 302...controller, 376...tilt angle detection device, 376a...rotating body tilt angle sensor (tilt state detection device, tilt angle detection device), 376b...rotation angle sensor, 377...tilt state determination unit, 378...tilt calculation unit (arithmetic device), 400...hydraulic excavator, 4 02...controller, 402a...processor (second processor), 410...diagnostic system, 440...server, 440a...processor (first processor), 440b...non-volatile memory (memory), 461...input device, 462...display device (output device), 480...diagnostic device, 481...feature amount correction unit, 482...feature amount calculation unit, 483...correction amount calculation unit, 490...analysis unit, 491...display device (output device), 492...sound output device (output device), 495...traveling state amount calculation unit, 496...tilt state amount calculation unit, 498...communication device (output device, receiver), FL,FR...load, G...center of gravity position, P1...first pump pressure, P2...second pump pressure, Pc...correction amount, Pc1...first correction amount, Pc2...second correction amount, Pl...lower limit value (negative judgment reference value), Pu...upper limit value (positive judgment reference value), ΔP...differential pressure value (abnormality judgment evaluation value), ΔP0...judgment reference value, ΔPc...corrected differential pressure value (abnormality judgment evaluation value), θ, θtrv...traveling body pitch angle, θswg...rotating body pitch angle, φ, φtrv...traveling body roll angle, φswg...rotating body roll angle, ψ...rotation angle, φt...allowable roll angle (predetermined angle), ψ...rotation angle,

Claims

1. A diagnostic device comprising: a first processor that diagnoses abnormalities in a traveling device based on traveling characteristics representing the traveling state of a traveling device attached to the body of a work machine; and an output device that outputs the results of the diagnosis by the first processor, The first processor is, Obtain a tilt feature quantity that represents the tilt state of the vehicle body, A correction amount is calculated based on the tilt characteristics to offset the influence of the vehicle body's tilt state on the running characteristics of the running device. By correcting the aforementioned driving characteristics based on the aforementioned correction amount, the corrected driving characteristics are calculated. Based on the corrected driving characteristics, an abnormality judgment evaluation value is calculated, Based on the aforementioned abnormality determination evaluation value, it is determined whether or not there is an abnormality in the traveling device. If an abnormality is detected, the detection result is output to the output device. A diagnostic device characterized by the following features.

2. A work machine equipped with the diagnostic device described in claim 1, The aforementioned work machine is The aforementioned vehicle body and, A work device attached to the vehicle body, A first hydraulic pump and a second hydraulic pump are provided on the vehicle body, A travel control device that instructs the operation of the aforementioned travel device, The left travel device is a travel device having a left travel motor driven by pressurized oil supplied from the first hydraulic pump, The right travel device is a travel device having a right travel motor driven by pressurized oil supplied from the second hydraulic pump, The first processor controls the capacity of the first hydraulic pump and the second hydraulic pump in accordance with the operation of the travel control device, A first pressure sensor for detecting the first pump pressure, which is the discharge pressure of the first hydraulic pump, A second pressure sensor for detecting the second pump pressure, which is the discharge pressure of the second hydraulic pump, It includes a tilt state detection device that detects the tilt state of the vehicle body with respect to the horizontal plane, The first processor is, As the aforementioned driving characteristic, the differential pressure value between the first pump pressure and the second pump pressure is calculated, Based on the sensor value representing the tilt state detected by the tilt state detection device, the roll angle, which is the tilt angle in the left-right direction of the vehicle body, is calculated as the tilt feature quantity. A correction amount to offset the effect of the vehicle body's tilt on the first and second pump pressures is calculated based on the vehicle body's roll angle. By correcting the differential pressure value based on the correction amount, the corrected differential pressure value is calculated as the corrected driving characteristic quantity. Based on the corrected differential pressure value, the abnormality determination evaluation value is calculated. Based on the aforementioned abnormality determination evaluation value, it is determined whether or not there is an abnormality in either the left travel device or the right travel device. If an abnormality is detected, the detection result is output to the output device. A work machine characterized by the following features.

3. In the work machine described in claim 2, The first processor calculates the change in the differential pressure value as the correction amount, which is caused by the vehicle body tilting in the left-right direction, resulting in an increase in the load acting on one of the left or right running gears and a decrease in the load acting on the other of the left or right running gears. A work machine characterized by the following features.

4. In the work machine described in claim 2, The first processor determines that there is an abnormality in either the left travel device or the right travel device if the roll angle is less than or equal to a predetermined angle and the abnormality determination evaluation value is greater than the determination criterion value. A work machine characterized by the following features.

5. In the work machine described in claim 2, The aforementioned vehicle body is A lower traveling body equipped with the left traveling device and the right traveling device, It has an upper slewing body that is rotatably mounted relative to the lower traveling body, The tilt state detection device is, A tilt angle sensor attached to the upper rotating body detects the tilt angle of the upper rotating body with respect to the horizontal plane, A slewing angle sensor for detecting the slewing angle of the upper slewing body relative to the lower traveling body, The system includes a calculation device that calculates the roll angle, which is the left-right inclination angle of the lower traveling body with respect to the horizontal plane, based on the inclination angle of the upper rotating body detected by the rotating body inclination angle sensor and the rotation angle of the upper rotating body detected by the rotation angle sensor. The first processor calculates the correction amount based on the roll angle of the lower traveling body. A work machine characterized by the following features.

6. A diagnostic system comprising the diagnostic device described in claim 1 and the work machine, The diagnostic device is A receiver that receives the travel characteristics and the inclination characteristics transmitted from the work machine, The system comprises a first processor that diagnoses abnormalities in the travel device of the work machine based on the travel characteristics and tilt characteristics received by the receiver, and a server that stores correction amount parameters used in calculating the correction amount. The aforementioned work machine is A running state detection device for detecting the running state of the aforementioned running device, A tilt state detection device for detecting the tilt state of the vehicle body, A second processor calculates the driving feature quantity based on the sensor value representing the driving state detected by the driving state detection device, and calculates the tilt feature quantity based on the sensor value representing the tilt state detected by the tilt state detection device. The system includes a transmitter that transmits the driving characteristics and the gradient characteristics calculated by the second processor to the server, The second processor synchronously calculates the driving feature quantity and the gradient feature quantity, The first processor calculates the correction amount based on the correction amount parameter stored in the memory and the slope feature quantity. A diagnostic system characterized by the following features.

7. In the diagnostic system described in claim 6, The second processor of the aforementioned work machine calculates the travel characteristics and the slope characteristics at multiple cycle intervals, The first processor of the server is capable of calculating the abnormality judgment evaluation value for each of the multiple periods based on the driving characteristics and the gradient characteristics for each of the multiple periods. A diagnostic system characterized by the following features.

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