KR102031369B1

KR102031369B1 - Method for diagnosing excavator and apparatus thereof

Info

Publication number: KR102031369B1
Application number: KR1020120151769A
Authority: KR
Inventors: 이택진; 김동목; 신행재; 유승범; 장계봉
Original assignee: 두산인프라코어 주식회사
Priority date: 2012-12-24
Filing date: 2012-12-24
Publication date: 2019-10-11
Also published as: KR20140083105A

Abstract

One embodiment presented herein provides a method of diagnosing excavator failure (or failure). The diagnostic method comprises the steps of measuring the position of the boom, arm and bucket of the excavator through one or more sensors; Measuring the discharge pressure of the main pump for driving the boom, the arm and the bucket through a pressure sensor while individually operating the boom, the arm and the bucket; After the operation, measuring the position of the boom, arm and bucket with at least one sensor; Comparing the moving distance calculated using the difference between the measured positions and the moving distance of the boom, the arm and the bucket theoretically calculated based on the discharge pressure; Based on the comparison result, it may include determining whether each of the boom, the arm and the bucket is normal or abnormal.

Description

Excavator diagnostic method and apparatus {METHOD FOR DIAGNOSING EXCAVATOR AND APPARATUS THEREOF}

The present invention relates to an excavator.

In general, a work vehicle using hydraulic pressure is used for a work requiring a large force such as construction or civil engineering. Hydraulic work vehicles include excavators, cranes and so on.

The excavator is widely used because it can perform a variety of operations, such as excavation, excavation, land leveling, rock breaking, wood clamping, concrete dismantling, transport and unloading of scrap metal.

1 is a side view illustratively showing one side of an excavator.

The excavator has a boom cylinder (2) and a boom (4), arm cylinder (6) installed to rotate from the upper body, as shown in Figure 1 and thereby arm pivotally connected from the boom (4) Arm 8, and bucket cylinder 10 and thereby a bucket 12 mounted to pivot from the arm.

In order to perform the excavation work using the excavator, the boom, the arm, the bucket should be controlled at the same time, the bucket 12 or the arm 8 should be controlled to move in a constant trajectory.

In order to facilitate such control, the boom 4, the arm 8, the boom cylinder 2 driving the bucket 12, the arm cylinder 6 and the bucket cylinder 10 may be implemented as hydraulic cylinders. However, when the linear movement amount of the piston is variable according to the hydraulic pressure inside the hydraulic cylinder, the rotational movement amount of the boom 4, the arm 8, and the bucket 12 is variable.

The excavator may further include a prime mover and a main pump to supply pressure oil as a power source to each of the cylinders. The pressurized oil is supplied to the cylinder head side of the boom cylinder 2 by the main pump, and the boom 4 is raised, and the boom is configured to be lowered by the self-weight of the boom 4 or the hydraulic oil supplied to the rod side of the cylinder.

In detail, when the pumped oil is supplied from the main pump, the boom cylinder 2, the arm cylinder 6, and the bucket cylinder 10 are telescopically operated, and each of these cylinders 2, 6 ( According to the stretching operation of the 10) the boom 2 and the arm 6 and the bucket 10 will move in a state of performing a joint motion is a predetermined operation is made.

On the other hand, Figure 2 is an exemplary view showing a hydraulic circuit for controlling each cylinder shown in FIG.

2, the control unit 21, the control valve 22, the pressure sensor 23 and the angle sensor 24, the spool 25, the hydraulic tank 26 and the hydraulic pump 27, The throttle 28 is shown.

The controller 21 reads the output values of the pressure sensor 23 and the angle sensor 24 to read the rotation angle of the work machine driven by the hydraulic cylinder 29, and the angle sensor 24 is a hydraulic pump ( The rotation angle of the adjustment plate 28 of the 27 and the pressure sensor 23 is to detect the hydraulic pressure supplied from the hydraulic pump 27 to the hydraulic cylinder (29).

The control unit 21 determines the target rotation angle of the hydraulic pump control plate 28, the boom while the hydraulic pressure supplied to each cylinder (2, 6, 10) in accordance with the target angle of the hydraulic pump control plate 28 The angle of rotation of the arm and the bucket is changed.

On the other hand, it is difficult to determine which part is a problem when an abnormality occurs in each cylinder (2, 6, 10) of the excavator and the hydraulic components of the hydraulic line.

To solve this problem, a technique for determining abnormalities of the control system and hydraulic components using the position sensor and the pressure sensor has been developed (Japanese Patent Laid-Open No. 4-344638). Brief descriptions of the fault diagnosis method of this technology are as follows.

3 is a flowchart illustrating a method for determining an abnormality (failure) of a hydraulic component.

First, in order to determine the abnormality of the boom and the bucket to give an operation command to the boom and the bucket (S10).

When receiving the operation command, the current position and the pressure of the cylinder is measured before operating the boom and the bucket (S11).

The output current value and output time of the electromagnetic proportional valve for operating the boom and the bucket are calculated based on the measured position and the pressure information of the cylinder (S12).

The current is output to the electromagnetic proportional valve for the calculated time to operate the boom and the bucket and measure the position again (S13).

Subsequently, it is determined whether the boom and the bucket are moved as much as the received command at the target position (S14).

If it does not reach the target position, it is determined that the electromagnetic proportional valve for flowing the flow rate so that the boom and the bucket operates (S15).

However, if the target position is reached, the position is measured again after waiting for a predetermined time without additional operation command (S16).

Subsequently, it is determined whether the boom and the arm remain in the target position or are largely out of the target position (S17) or out of the target position (S17).

If the boom and the arm remain in the target position, it is determined as a normal state (S18).

However, if the boom and the arm is still in the target position, if it is far from the target position, it is determined that the hydraulic or mechanical parts are abnormal (S19).

As described above, the method shown in FIG. 3 determines that the electronic proportional valve is broken if the boom does not reach the target position within the time limit even though the control signal is normally supplied to the electromagnetic proportional valve. If the boom reaches the target position and the position is reconfirmed after a certain time without additional operation command and the position is largely out of the target position, it is determined that the hydraulic or mechanical parts are out of order.

That is, the method shown in FIG. 3 diagnoses an abnormality by giving an operation command and then confirming whether the commanded part has normally reached the target position.

However, this method has a limitation in that it is applicable only to excavators using electromagnetic proportional valves. In addition, there is a disadvantage in that a position sensor and a pressure sensor must be attached to each part in order to diagnose an abnormality of the boom or bucket.

Therefore, an object of the present specification is to propose a method for more accurately and economically determining a failure location.

In order to achieve the above object, one embodiment presented herein provides a method for diagnosing excavator failure (or failure). The diagnostic method comprises the steps of measuring the position of the boom, arm and bucket of the excavator through one or more sensors; Measuring the discharge pressure of the main pump for driving the boom, the arm and the bucket through a pressure sensor while individually operating the boom, the arm and the bucket; After the operation, measuring the position of the boom, arm and bucket with at least one sensor; Comparing the moving distance calculated using the difference between the measured positions and the moving distance of the boom, the arm and the bucket theoretically calculated based on the discharge pressure; Based on the comparison result, it may include determining whether each of the boom, the arm and the bucket is normal or abnormal.

On the other hand, in order to achieve the above object, another embodiment provided herein provides an excavator failure diagnosis apparatus. The excavator fault diagnosis apparatus includes one or more sensors for measuring the position of the boom, arm and bucket of the excavator; A pressure sensor for measuring a pressure discharged from a main pump for supplying pressure oil to a cylinder for driving each of the boom, the arm and the bucket; First, the position of the boom, the arm and the bucket is measured through the one or more sensors, and then the discharge pressure of the main pump is measured through the pressure sensor while operating the boom, the arm and the bucket individually, and the operation After completion, the boom, arm and bucket are re-measured by the one or more sensors to calculate the actual travel distance, while calculating the theoretically movable distance based on the discharge pressure measured by the pressure sensor. By comparing with the calculated actual travel distance, it may include a control unit for determining whether each of the boom, arm and bucket is normal or abnormal.

The position sensor may include a first sensor measuring an angle of the boom, a second sensor measuring an angle of the arm, and a third sensor measuring an angle of the bucket.

The controller calculates an error of each of the boom, arm, and bucket by comparing the difference between the calculated actual traveled distance and the theoretically calculated traveled distance, and determines whether each of the calculated errors is greater than an allowable error. Through it, it is possible to determine whether each of the boom, the arm and the bucket is normal or abnormal.

If the calculated error of the boom, the error of the arm and the bucket error are all greater than the allowable error, the controller determines that all of the boom, the arm and the bucket are abnormal, and only the calculated error of the boom and the error of the arm When it is larger than this tolerance, it is determined that the boom and the arm are abnormal, and when only the error of the calculated boom and the bucket is larger than the tolerance, it is determined that the boom and the bucket is abnormal and the calculated If only the error of the arm and the error of the bucket is larger than the tolerance, it is determined that the arm and the bucket is abnormal, and if only the error of the calculated boom is larger than the tolerance, it is determined that only the boom is abnormal, the calculated If only the error of the arm is greater than the tolerance, it is determined that only the arm is abnormal, and if only the error of the calculated bucket is greater than the tolerance, the Only the bucket can be judged abnormal.

Tolerance of each of the boom, arm and bucket can be obtained from a storage medium or downloaded and obtained through a server having a tolerance value for each excavator product.

According to one embodiment presented herein, repair time and cost is reduced first when an error occurs. In other words, in the past, when an error occurs in the hydraulic parts of the front part, it is often difficult to identify which part is a problem, and thus a lot of time and money are required for repair. By using the method proposed in the present specification, it is possible to check which part of the hydraulic component of the boom, the arm, the bucket is abnormal, so that the repair time can be shortened and the cost consumed can be reduced.

Second, abnormal diagnosis is possible with a small number of sensors. That is, the conventional abnormal diagnosis technology requires a total of six position sensors and three pressure sensors, respectively, to diagnose an abnormality of the boom, arm, and bucket. On the other hand, the proposed method can be diagnosed with only 3 position sensors and 1 pressure sensor, which has the advantage of low additional cost when implementing the function.

Third, it can be applied regardless of the MCV method. That is, the conventional anomaly diagnosis technology can only diagnose in a vehicle to which an electromagnetic proportional valve is applied, but the proposed method has an advantage that it can be applied to all construction machinery using hydraulic pressure regardless of the type of valve.

Fourth, the diagnosis results can be reflected in product improvement by making a database. That is, since the diagnosis result is not only notified to the user through the display device but also transmitted to the manufacturer using communication, the manufacturer can improve the performance by improving the product based on the abnormal diagnosis information.

1 is a side view illustratively showing one side of an excavator.
2 is an exemplary view showing a hydraulic circuit for controlling each cylinder shown in FIG.
3 is a flowchart illustrating a method for determining an abnormality (failure) of a hydraulic component.
4 is a block diagram schematically illustrating a circuit unit for diagnosing an excavator error.
5 is a block diagram schematically showing the hydraulic circuit of the excavator.
6 is a flowchart illustrating a method for determining an abnormality (failure) according to an embodiment of the present invention.

It is to be noted that the technical terms used herein are merely used to describe particular embodiments, and are not intended to limit the present invention. In addition, the technical terms used in the present specification should be interpreted as meanings generally understood by those skilled in the art unless they are specifically defined in this specification, and are overly inclusive. It should not be interpreted in the sense of or in the sense of being excessively reduced. In addition, when the technical terms used herein are incorrect technical terms that do not accurately represent the spirit of the present invention, it should be replaced with technical terms that can be understood correctly by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or according to the context before and after, and should not be interpreted in an excessively reduced sense.

Also, the singular forms used herein include the plural forms unless the context clearly indicates otherwise. In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components, or various steps described in the specification, wherein some of the components or some of the steps It should be construed that it may not be included or may further include additional components or steps.

In addition, the suffixes "module" and "unit" for the components used herein are given or mixed in consideration of ease of specification, and do not have meanings or roles that are distinguished from each other.

In addition, terms including ordinal numbers, such as first and second, as used herein may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

In addition, in describing the present invention, when it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easily understanding the spirit of the present invention and should not be construed as limiting the spirit of the present invention by the accompanying drawings.

4 is a block diagram schematically showing a circuit unit for diagnosing an excavator error, and FIG. 5 is a block diagram briefly showing a hydraulic circuit of an excavator.

First, as can be seen with reference to FIG. 4, the circuit unit for diagnosing an excavator error may include a controller 110, one or more sensors 160, and an output unit 190.

The one or more sensors 160 may include a boom position sensor 161, an arm position sensor 162, and a bucket position sensor 163, as shown. Meanwhile, the one or more sensors 160 may further include a main pump pressure sensor 164.

The control unit 110 is the position of the boom, arm, bucket cylinder and the boom position sensor 161, arm position sensor 162, bucket position calculated based on the pressure measured by the main pump pressure sensor 164 By comparing the actual measured position with the sensor 163 serves to determine the abnormal part of the boom, arm, bucket.

The output unit 190 may include a display device for displaying information on a portion of the boom, the arm, the bucket is abnormal. In addition, the output unit 190 may transmit information on the abnormal part to the manufacturer server or maintenance company server.

Meanwhile, referring to FIG. 5, the excavator lever pressure sensing unit 120, the main pump 130, the main control valve (MCV) 140, the boom cylinder 151, the arm cylinder 152, the bucket Cylinder 153 is shown.

When the excavator operator or the driver operates the lever to operate the boom, the arm, the bucket, the excavator lever pressure sensing unit 120 measures the degree of operation of the lever, and the discharged from the main pump 130 according to the measurement The flow rate passes through the main control valve (MCV) 140 and is transmitted to the boom cylinder 151, the arm cylinder 152, and the bucket cylinder 153. At this time, the main control valve (MCV) 140 serves to distribute the flow rate to the boom cylinder 151, the arm cylinder 152, the bucket cylinder 153 according to the measured lever operation degree. When the fluid passing through the main control valve (MCV) 140 moves any one or more of the boom cylinder 151, the arm cylinder 152, and the bucket cylinder 153, at least one of the corresponding boom, arm, and bucket. The above will work. In the present invention, the boom cylinder, the arm cylinder 152, the bucket cylinder 153 of the boom cylinder, 151, the bucket cylinder 153 for each operation based on the fluid discharge pressure of the main pump 130 measured after the individual operation of the boom, arm, bucket Calculate the distance traveled theoretically. After the individual operation, the position of the boom, arm, and bucket is measured by the position sensors 161, 162, and 163, and the actual distance traveled by the cylinders 151, 152, and 153 is calculated. Obtain If the error exceeds the preset allowable range, it is determined that there is an error in the cylinder hydraulic part. The allowable range is the value initially set for each product.

6 is a flowchart illustrating a method for determining an abnormality (failure) according to an embodiment of the present invention.

As can be seen with reference to Figure 6, according to an embodiment of the present invention, using the position sensor (161, 162, 163) and the pressure sensor 164 of the main pump mounted on the boom, arm, bucket Partial abnormalities can be diagnosed.

Specifically, first, through the position sensors (161, 162, 163) to measure the angle for each part before the boom, arm, bucket individual operation (S101).

Then, the position of the boom, arm, bucket cylinder before the operation is calculated based on the measured angle (S102).

Then, the individual operation is performed for each of the boom, the arm and the bucket (S103). In general, the compound operation is performed separately because the faulty part may affect the part in which it operates normally.

Next, the discharge pressure of the main pump 130 is measured in order to calculate the theoretical moving distances of the boom, the arm and the bucket cylinders 151, 152, and 153 (S104). The theoretical position values of the boom, arm, and bucket cylinders 151, 152, and 153 are calculated based on the discharge pressure information of the main pump 130 according to the individual operation (S105).

Subsequently, after the individual operation, the angles of the boom, the arm and the bucket are measured through the position sensors 161, 162 and 163 (S106). Based on the measured angles, the positions of the boom, arm, and bucket cylinders 151, 152, and 153 are calculated, and the moving distances of the cylinders by the individual movements are obtained by comparing the positions of the cylinders before the individual movements (S107).

Next, an error between the theoretically calculated cylinder travel distance and the actual measured cylinder travel distance is calculated (S108). Then, the cylinder tolerance value initially set for each excavator product is received through the server or the value stored in the storage medium is read (S109).

Then, it is checked whether the error value of the boom cylinder is larger than the tolerance (S110). If the error value of the boom cylinder is larger than the tolerance, it is first determined that the hydraulic component is abnormal in the boom cylinder, and then the error value of the arm cylinder is compared with the tolerance (S111).

In addition, if the error value of the arm cylinder is larger than the tolerance when it is determined that there is an error in the hydraulic parts of the boom cylinder, the error value of the bucket cylinder is determined after the error of the hydraulic parts of the two parts of the boom and the arm cylinder. Comparison is made (S112). As such, when the error value of the bucket cylinder is larger than the allowable error in the state in which it is determined that there is an error in the boom and the arm cylinder, it is determined that there is an error in the hydraulic parts of the three parts of the boom, the arm and the bucket (S113). However, when it is determined that there is an error in the boom and the arm cylinder, if the error value of the bucket cylinder is smaller than the tolerance, it is determined that there is an error in the hydraulic parts of the boom and the arm.

In addition, if the error value of the arm cylinder is less than the tolerance in the state that it is determined that there is an error in the boom cylinder hydraulic components, it is determined that there is an error in the boom cylinder hydraulic components, and then the error value of the bucket cylinder is compared with the tolerance ( S114). As such, when the error value of the bucket cylinder is larger than the allowable error in the state in which the boom cylinder hydraulic component is determined to be abnormal, it is determined that the hydraulic component of the two parts of the boom and the bucket cylinder is abnormal (S115). However, if the error value of the bucket cylinder is smaller than the tolerance, it is determined that the hydraulic component of the boom cylinder is abnormal (S120).

On the other hand, if the error value of the boom cylinder is smaller than the tolerance, first determine that there is no abnormality in the hydraulic components in the boom cylinder, and then compares the error value of the arm cylinder with the tolerance (S117). As such, when the error value of the arm cylinder is larger than the tolerance in the state where it is determined that the boom cylinder hydraulic part is not abnormal, it is determined that the hydraulic part of the arm cylinder is abnormal and then the error value of the bucket cylinder is compared with the tolerance ( S118). As such, when the error value of the bucket cylinder is larger than the allowable error in the state in which the hydraulic component of the arm cylinder is determined to be abnormal, it is determined that the hydraulic component of both the arm and the bucket cylinder is abnormal (S119). However, if the error value of the bucket cylinder is smaller than the tolerance, it is determined that there is an error in the hydraulic component of the arm cylinder (S123).

On the other hand, if the error value of the arm cylinder is smaller than the tolerance, it is determined that there is no abnormality in the hydraulic parts of the two parts of the boom and the arm cylinder, and then the error value of the bucket cylinder is compared with the tolerance (S121). As such, when the error value of the bucket cylinder is larger than the allowable error in the state in which it is determined that there is no abnormality in the hydraulic parts of the two parts of the boom and the arm cylinder, it is determined that the hydraulic parts of the bucket cylinder are abnormal (S122). However, if the error value of the bucket cylinder is smaller than the tolerance, it is determined that the steady state (S124).

As described above, the present invention reduces the number of sensors used in the conventional abnormal diagnosis and enables diagnosis even in a vehicle in which the electronic proportional valve is not installed. In other words, the number of pressure sensors used is reduced by mounting the pressure sensors only on the main pump, not on the cylinders of the boom, arm and bucket. In addition, by comparing the position of main pump pressure with the position of boom, arm, and bucket in the state of performing a specific operation rather than giving output command to the solenoid proportional valve and confirming its position, it is possible to diagnose abnormality even in a vehicle other than the solenoid proportional valve. .

The aforementioned method can be implemented through various means. For example, embodiments of the present invention may be implemented by hardware, firmware, software, or a combination thereof.

In the case of a hardware implementation, the method according to embodiments of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs). Field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, the method according to the embodiments of the present invention may be implemented in the form of a module, a procedure, or a function that performs the functions or operations described above. The software code may be stored in a memory unit and driven by a processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various known means.

110: control unit
120: excavator lever pressure detection unit
130: main pump
140: main control valve
151: boom cylinder
152: arm cylinder
153: bucket cylinder
160: sensor
161: boom position sensor
162: arm position sensor
163: bucket position sensor
164: main pump pressure sensor
190: output unit

Claims

Measuring the position of the boom, arm, and bucket of the excavator through one or more sensors;
Measuring the discharge pressure of the main pump for driving the boom, the arm and the bucket through a pressure sensor while individually operating the boom, the arm and the bucket;
After the operation, measuring the position of the boom, arm and bucket with at least one sensor;
Comparing the moving distance calculated using the difference between the measured positions and the moving distance of the boom, the arm and the bucket theoretically calculated based on the discharge pressure;
And determining whether the cylinder operation for driving each of the boom, the arm, and the bucket is normal or abnormal based on the comparison result.

One or more sensors for measuring the position of the boom, arm and bucket of the excavator;
A pressure sensor for measuring a pressure discharged from a main pump for supplying pressure oil to a cylinder for driving each of the boom, the arm and the bucket;
First, the position of the boom, the arm and the bucket is measured through the one or more sensors, and then the discharge pressure of the main pump is measured through the pressure sensor while operating the boom, the arm and the bucket individually, and the operation After completion, the boom, arm and bucket are re-measured by the one or more sensors to calculate the actual travel distance, while calculating the theoretically movable distance based on the discharge pressure measured by the pressure sensor. And a controller for determining whether cylinder operation for driving each of the boom, arm, and bucket is normal or abnormal by comparing with the calculated actual traveled distance.

The method of claim 2, wherein the position sensor
Excavator failure diagnosis apparatus comprising a first sensor for measuring the angle of the boom, a second sensor for measuring the angle of the arm, and a third sensor for measuring the angle of the bucket.

The method of claim 2, wherein the control unit
By comparing the difference between the calculated actual traveled distance and the theoretically calculated traveled distance, the error of each of the boom, arm and bucket is calculated,
Excavator abnormality diagnosis apparatus characterized in that it is determined whether the cylinder operation for driving each of the boom, arm and bucket is normal or not by determining whether the calculated error is greater than the tolerance.

The method of claim 4, wherein the control unit
When the calculated error of the boom, the error of the arm and the error of the bucket are all larger than the allowable error, it is determined that each cylinder for driving the boom, the arm and the bucket is all abnormal,
If only the error of the calculated boom and the error of the arm is larger than the allowable error, it is determined that each cylinder for driving the boom and the arm is abnormal,
If only the error of the calculated boom and the error of the bucket is larger than the allowable error, it is determined that each cylinder for driving the boom and the bucket is abnormal,
If only the error of the calculated arm and the error of the bucket is larger than the allowable error, it is determined that each cylinder for driving the arm and the bucket is abnormal,
If only the error of the calculated boom is larger than the allowable error, it is determined that only each cylinder for driving the boom is abnormal,
If only the error of the calculated arm is larger than the tolerance, it is determined that only each cylinder for driving the arm is abnormal,
If only the error of the calculated bucket is larger than the allowable error, excavator failure diagnosis apparatus, characterized in that it is determined that each cylinder for driving the bucket is abnormal.

The method of claim 4, wherein
The tolerances of each of the booms, arms and buckets are obtained from storage media or
Download and acquire through the server having the tolerance value per excavator product,
An output unit capable of displaying information of cylinders determined to be abnormal among cylinders for driving each of the booms, arms and buckets, and transmitting the information of the cylinders determined to be abnormal to a server of a manufacturer or a maintenance company.
Excavator abnormality diagnosis device further comprising.