An excavator material weighing system and method

Abstract

The application discloses a kind of excavator material weighing system and method, belong to engineering machinery intelligentization measurement field;System is composed of excavator body, inclination sensor, pressure sensor and controller;Inclination sensor is installed in bucket rod and bucket, pressure sensor is installed in bucket cylinder two cavities, controller posture, pressure, handle and main pump signal are collected, and weighing calculation is carried out in the relative static time when unloading before digging is completed, and bucket is not moved.The mechanical model is established only by using bucket parameters, the complex parameters of swing arm and bucket rod are omitted, and the calibration difficulty and external interference are reduced.The center of gravity of material, the weight of bucket is corrected in real time by force analysis of bucket and cylinder output calculation, and the weighing accuracy is significantly improved.The application solves the problems of existing technology, such as complicated calibration, easy to be affected by machine parameters, large dynamic error, has the advantages of simple calculation, high stability, strong adaptability, accurate weighing, and is suitable for various types of excavator online material measurement operation.

Description

Technical Field

[0001] This invention belongs to the field of intelligent metering technology for construction machinery, specifically relating to a material weighing system and method for excavators. Background Technology

[0002] Excavator weighing technology is a key component of intelligent and digital construction machinery. By using hydraulic sensing and dynamic modeling, it enables rapid online measurement of materials and allows the bucket to be used directly as a weighing device, significantly improving loading and unloading efficiency and the level of precision in construction management.

[0003] Current excavator weighing technologies generally employ a DH (Hyper-Hyper) model of the boom, stick, and bucket as a whole to calculate material weight. This requires comprehensive consideration of numerous structural, hydraulic, and kinematic parameters of the boom, stick, bucket, and their attachments. This method has significant drawbacks: First, the pre-weighing calibration process is complex and labor-intensive; second, changes in the parameters of components such as the boom and stick can significantly interfere with the weighing results, leading to low weighing accuracy and poor stability; third, the dynamic weighing process is greatly affected by vibration, acceleration, and motion damping, making it difficult to meet the requirements of high-precision measurement.

[0004] To address the aforementioned issues, this invention provides an excavator material weighing system and method based solely on bucket parameters, combined with working status judgment and parameter correction. This simplifies the calibration and calculation process, reduces external interference, and improves weighing accuracy. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an excavator material weighing system and method, which simplifies the weighing model, reduces calibration difficulty, minimizes interference between boom and stick parameters, and improves weighing accuracy.

[0006] The present invention adopts the following technical solution: an excavator material weighing system, comprising: an excavator body, an tilt sensor, a pressure sensor and a controller;

[0007] The tilt sensor is installed on the stick and the bucket to collect the attitude angle signals of the stick and the bucket;

[0008] The pressure sensor is installed in the rodless chamber and the rod chamber of the bucket cylinder to collect cylinder pressure signals;

[0009] The controller is electrically connected to the tilt sensor, pressure sensor, excavator handle, and main pump signal terminal, respectively, and is used for:

[0010] The working status of the excavator is determined by the value of the handle action and the pressure of the main pump, and the weighing time is locked when the excavation is completed and before unloading, and the bucket is not moving.

[0011] The bucket tilt angle is calculated and the force analysis is performed based on the tilt sensor signal; the bucket cylinder output force is calculated based on the pressure sensor signal.

[0012] The weight is estimated based on the bucket parameters, and the parameters of the material's center of gravity and bucket weight are corrected to output the material weight.

[0013] Furthermore, the controller determines the weighing timing based on the following conditions: the excavator is in the pre-unloading stage after excavation is completed, and the bucket handle signal is less than a set threshold.

[0014] Furthermore, the tilt sensor is used to detect the stick tilt angle α and the bucket tilt angle β. The controller calculates the bucket tilt angle θ based on the stick tilt angle α and the bucket tilt angle β to determine the loading and unloading status.

[0015] Furthermore, the pressure sensor collects the pressure in the rodless chamber of the bucket cylinder. Rod chamber pressure The controller is based on the formula Calculate the output force of the hydraulic cylinder, where The effective area of ​​the rodless cavity, This represents the effective area of ​​the rod cavity.

[0016] A method for weighing materials using an excavator, comprising the following steps:

[0017] 1) Obtain the handle signal and main pump pressure signal to determine that the excavator is in the unloading stage after digging is completed and the bucket is not moving;

[0018] 2) Collect the tilt angle signals of the boom and bucket, calculate the bucket tilt angle, and perform force analysis on the bucket;

[0019] 3) Collect the pressure signals of the rodless and rod chambers of the bucket cylinder, and calculate the cylinder output force after filtering;

[0020] 4) Based on the bucket parameters, combined with force analysis and cylinder output, estimate the total weight of the bucket and the material;

[0021] 5) Correct the parameters of the material's center of gravity and the actual weight of the bucket to obtain the accurate material weight.

[0022] Furthermore, in step 2), the bucket tilt angle θ is calculated based on the boom tilt angle α and the bucket tilt angle β. At the same time, the motion angles of each component can be calculated to prepare for the force analysis calculation. The bucket tilt angle θ satisfies the following conditions: θ < -90° when the bucket is loading and θ > -90° when the bucket is unloading.

[0023] Furthermore, in step 3)

[0024] When the bucket is not moving, calculate the force of the bucket cylinder to eliminate the interference of acceleration force and motion damping force;

[0025] When the bucket is in motion, this formula can be used to make a rough calculation, and the result can be used as a correction parameter.

[0026] Furthermore, the method for correcting the bucket's self-weight in step 5) is as follows: when the bucket is unloaded after unloading, repeat steps 1)-4) to calculate the bucket's working mass. Material quality = - ,in This is the corrected total mass.

[0027] Furthermore, if the bucket handle signal is less than the set value, it is determined that the bucket is not moving.

[0028] Furthermore, the force analysis is based on the torque balance of the bucket hinge point and the force balance of the bucket cylinder-connecting rod hinge point, using only the relevant geometric and mechanical parameters of the bucket, without introducing the structural and hydraulic parameters of the boom and stick.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1) Only bucket parameters are used for weighing calculation, simplifying the weighing model and calibration process, and greatly reducing the interference of boom, stick structure and hydraulic parameters on weighing accuracy;

[0031] 2) Combine the handle action with the main pump pressure to determine the working status, weigh under relatively static conditions, reduce dynamic interference such as acceleration, vibration, and motion damping, and improve weighing stability;

[0032] 3) By correcting the material center of gravity and the bucket weight in real time, it adapts to different working conditions such as full bucket rate and material adhesion, significantly improving the weighing accuracy in different working environments. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the excavator weighing system of the present invention;

[0034] Figure 2 This is a flowchart of the excavator weighing method of the present invention;

[0035] Figure 3 This is a schematic diagram of the attitude angle monitoring of the present invention;

[0036] Figure 4 This is a schematic diagram of the force analysis of the bucket of the present invention;

[0037] Figure 5 This is a flowchart of the material weighing process of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0040] like Figure 1 As shown, an excavator material weighing system includes: an excavator body, an tilt sensor, a pressure sensor, and a controller;

[0041] The tilt sensor is installed on the stick and the bucket to collect the attitude angle signals of the stick and the bucket;

[0042] The pressure sensor is installed in the rodless chamber and the rod chamber of the bucket cylinder to collect cylinder pressure signals;

[0043] The controller is electrically connected to the tilt sensor, pressure sensor, excavator handle, and main pump signal terminal, respectively, and is used for:

[0044] The working status of the excavator is determined by the value of the handle action and the pressure of the main pump, and the weighing time is locked when the excavation is completed and before unloading, and the bucket is not moving.

[0045] The bucket tilt angle is calculated and the force analysis is performed based on the tilt sensor signal; the bucket cylinder output force is calculated based on the pressure sensor signal.

[0046] The weight is estimated based on the bucket parameters, and the parameters of the material's center of gravity and bucket weight are corrected to output the material weight.

[0047] The controller determines the weighing timing based on the following conditions: the excavator is in the pre-unloading state after excavation, and the bucket handle signal is less than a set threshold; the tilt sensor detects the stick tilt angle α and bucket tilt angle β, and the controller calculates the bucket tilt angle θ based on the stick tilt angle α and bucket tilt angle β to determine the loading and unloading status; the pressure sensor collects the pressure in the rodless chamber of the bucket cylinder. Rod chamber pressure The controller is based on the formula Calculate the output force of the hydraulic cylinder, where The effective area of ​​the rodless cavity, This represents the effective area of ​​the rod cavity.

[0048] like Figure 2 As shown, a method for weighing materials using an excavator includes the following steps:

[0049] 1) The controller acquires the handle signal and the main pump pressure signal to determine that the excavator is in the state before unloading after digging and the bucket is not moving (the bucket signal of the handle is less than the set value).

[0050] Among them, the excavation status judgment:

[0051] When the following three conditions are met simultaneously: the bucket retraction signal controlled by the handle to adjust the stick angle α is greater than or equal to the set value, the action time is greater than or equal to the set value, and the main pump pressure is greater than or equal to the set value, the digging state is established.

[0052] When only one of the following two conditions is met: the bucket retraction signal controlled by the handle to tilt the stick α is less than the set value, or the main pump pressure is less than the set value, the digging state is exited, that is, the digging is completed.

[0053] Before unloading, if the excavation status is determined to be completed and the bucket tilt angle θ is less than the set value, it is considered to be in the pre-unloading state.

[0054] 2) The controller uses tilt sensors to collect the boom tilt angle α and bucket tilt angle β to calculate the bucket tilt angle θ and performs force analysis on the bucket;

[0055] like Figure 3 As shown, the tilt angle θ of the bucket is an important parameter for measuring the loading and unloading state of the bucket. When the bucket is loading, θ < -90°, and when the bucket is unloading, θ > -90°. The tilt angle θ of the bucket is calculated by tilt sensors installed on the boom and rocker arm. At the same time, the motion angle of each component can be calculated to prepare for force analysis calculation.

[0056] (1)

[0057] In the formula: α and β are the values ​​detected by the tilt sensor (counterclockwise is positive), and the values ​​of each length and part of the fixed angle are known quantities (which can be obtained by measurement);

[0058] also, middle:

[0059] cylinder length ,

[0060] ;

[0061] , middle:

[0062] ,

[0063] .

[0064] like Figure 4 As shown, force analysis:

[0065] Force analysis was performed on the bucket couple and the bucket cylinder-connecting rod hinge point, respectively, and the results were obtained.

[0066] (2)

[0067] In the formula: The force of the bucket and the weight of the material. , The power outputs are respectively from the connecting rod and the bucket cylinder. , The torque from the material's weight and the connecting rod force to the bucket hinge point. , .

[0068] 3) Collect the pressure signals of the rodless and rod chambers of the bucket cylinder, and calculate the cylinder output force after filtering;

[0069] The pressure signal from the bucket cylinder is filtered, and the cylinder output is calculated.

[0070]

[0071] In the formula: For rodless chamber pressure, For rod chamber pressure, The force-bearing area of ​​the rodless cavity. The area of ​​the rod cavity subjected to force;

[0072] When the bucket is not moving (the bucket handle signal is less than the set value), the bucket cylinder force is calculated to eliminate interference from acceleration force, motion damping force and other factors, and improve the calculation accuracy.

[0073] When the bucket is in motion, this formula can be used to make a rough calculation, and the result can be used as a correction parameter.

[0074] 4) Based on the bucket parameters, combined with force analysis and cylinder output, estimate the total weight of the bucket and the material;

[0075] Based on steps 1) to 3) above, given the default center of gravity position, the total weight of the bucket and the material is calculated. .

[0076] 5) such as Figure 5 As shown, the material's center of gravity position and the actual weight of the bucket are corrected to obtain the accurate material weight;

[0077] Based on the estimated total weight of the bucket and material obtained in step 4) After correcting the center of gravity, a relatively accurate total weight of the bucket and material is calculated. Repeat this process again to calculate a more accurate weight of the bucket and the material under the quasi-weight-quasi-center of gravity parameters. ;

[0078] To obtain accurate material excavation quality, the bucket weight also needs to be adjusted (material may stick together during loading of a standard weight bucket, causing a significant increase in bucket weight). Therefore, the working weight of the bucket needs to be calculated using steps 1) to 5) when the bucket is empty after unloading. ;

[0079] By calculating the mass of materials = - The final material quality is obtained .

[0080] The force analysis is based on the moment balance of the bucket hinge point and the force balance of the bucket cylinder-connecting rod hinge point. It only uses the relevant geometric and mechanical parameters of the bucket and does not introduce the structural and hydraulic parameters of the boom and stick.

[0081] This invention simplifies the weighing model, optimizes the weighing timing, and adds parameter correction to achieve high-precision, low-interference, and easily calibrated excavator material weighing, which is suitable for various earthwork projects, mines, ports and other operation scenarios.

Claims

1. A material weighing system for an excavator, characterized in that, include: Excavator body, tilt sensor, pressure sensor and controller; The tilt sensor is installed on the stick and the bucket to collect the attitude angle signals of the stick and the bucket; The pressure sensor is installed in the rodless chamber and the rod chamber of the bucket cylinder to collect cylinder pressure signals; The controller is electrically connected to the tilt sensor, pressure sensor, excavator handle, and main pump signal terminal, respectively, and is used for: The working status of the excavator is determined by the value of the handle action and the pressure of the main pump, and the weighing time is locked when the excavation is completed and before unloading, and the bucket is not moving. The bucket tilt angle is calculated and the force analysis is performed based on the tilt sensor signal; the bucket cylinder output force is calculated based on the pressure sensor signal. The weight is estimated based on the bucket parameters, and the parameters of the material's center of gravity and bucket weight are corrected to output the material weight.

2. The excavator material weighing system according to claim 1, characterized in that, The controller determines the weighing timing based on the following conditions: the excavator is in the pre-unloading stage after excavation is completed, and the bucket handle signal is less than the set threshold.

3. The excavator material weighing system according to claim 1, characterized in that, The tilt sensor is used to detect the stick tilt angle α and the bucket tilt angle β. The controller calculates the bucket tilt angle θ based on the stick tilt angle α and the bucket tilt angle β to determine the loading and unloading status.

4. The excavator material weighing system according to claim 1, characterized in that, The pressure sensor collects the pressure in the rodless chamber of the bucket cylinder. Rod chamber pressure The controller is based on the formula Calculate the output force of the hydraulic cylinder, where The effective area of ​​the rodless cavity, This represents the effective area of ​​the rod cavity.

5. A method for weighing materials using an excavator, characterized in that, Includes the following steps: 1) Obtain the handle signal and main pump pressure signal to determine that the excavator is in the unloading stage after digging is completed and the bucket is not moving; 2) Collect the tilt angle signals of the boom and bucket, calculate the bucket tilt angle, and perform force analysis on the bucket; 3) Collect the pressure signals of the rodless and rod chambers of the bucket cylinder, and calculate the cylinder output force after filtering; 4) Based on the bucket parameters, combined with force analysis and cylinder output, estimate the total weight of the bucket and the material; 5) Correct the parameters of the material's center of gravity and the actual weight of the bucket to obtain the accurate material weight.

6. The method for weighing materials in an excavator according to claim 5, characterized in that, Step 2) The bucket tilt angle θ is calculated based on the boom tilt angle α and the bucket tilt angle β. At the same time, the motion angles of each component can be calculated to prepare for the force analysis calculation. The bucket tilt angle θ satisfies the following conditions: θ < -90° when the bucket is loading and θ > -90° when the bucket is unloading.

7. The method for weighing materials in an excavator according to claim 5, characterized in that, Step 3) When the bucket is not moving, calculate the force of the bucket cylinder to eliminate the interference of acceleration force and motion damping force; When the bucket is in motion, this formula can be used to make a rough calculation, and the result can be used as a correction parameter.

8. The method for weighing materials in an excavator according to claim 5, characterized in that, The method for correcting the bucket's self-weight in step 5) is as follows: When the bucket is unloaded after unloading, repeat steps 1)-4) to calculate the working mass of the bucket. Material quality = - ,in This is the corrected total mass.

9. A method for weighing materials in an excavator according to claim 5, characterized in that, If the signal of the bucket handle is less than the set value, it is determined that the bucket is not moving.

10. A method for weighing materials in an excavator according to claim 5, characterized in that, The force analysis is based on the moment balance of the bucket hinge point and the force balance of the bucket cylinder-connecting rod hinge point. It only uses the relevant geometric and mechanical parameters of the bucket and does not introduce the structural and hydraulic parameters of the boom and stick.

Images