Real-time measurement system and method for load mass of electric shovel based on dynamic calculation of moment of inertia

Abstract

This invention discloses a real-time measurement system and method for the load mass of an electric shovel based on dynamic calculation of rotational inertia, belonging to the field of mining excavating machinery. Specifically, it includes the following steps: real-time acquisition of the driving torque and angular acceleration on the output shaft of the rotary motor, and simultaneously acquisition of the real-time extension and tilt angle of the boom; obtaining the effective driving torque and angular acceleration acting on the center of rotation through rotational parameter conversion; calculating the variable and fixed rotational inertia under no-load conditions through no-load calibration; calculating the total rotational inertia under load through loaded operation; combining the variable and fixed rotational inertia under no-load conditions to calculate the load rotational inertia, and then calculating and outputting the material mass under load. Therefore, this invention effectively solves the technical problem of the difficulty of real-time and accurate monitoring of the load mass of an electric shovel using traditional methods, providing reliable data support for precise production measurement, operational efficiency optimization, and intelligent management in mines.

Description

Technical Field

[0001] This invention relates to a real-time measurement system and method for the load mass of an electric shovel based on dynamic calculation of rotational inertia, applicable to large mining electric shovels, and belonging to the field of mining excavation machinery. Background Technology

[0002] As a key piece of equipment in large-scale open-pit mining, the real-time and accurate measurement of the material load in the bucket of an electric shovel is of great significance for mine production measurement, operation efficiency optimization, and intelligent equipment management.

[0003] Currently, common methods for measuring the load capacity of electric shovels mainly rely on static calculations based on electrical signals (such as motor current) and mechanical geometric parameters of the lifting or pressing mechanism. A typical example is estimating material weight using the principle of lever arm and torque balance. However, due to the complex structure of the electric shovel's working device, the inconsistent efficiency of each transmission link, and the fact that the mechanism is constantly in a state of dynamic adjustment during operation, these methods suffer from problems such as large model simplification errors, significant signal fluctuations, and difficulty in adapting to changing working conditions. The measurement results often deviate significantly from the actual values, failing to meet the accuracy and real-time requirements of engineering applications. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a real-time measurement system and method for the load mass of electric shovels based on dynamic calculation of rotational inertia. It eliminates the need for expensive dedicated weighing sensors, utilizing only the existing drive motor control parameters of the electric shovel's slewing mechanism and the attitude detection equipment of the working device. By dynamically identifying changes in the rotational inertia of the entire slewing system, it calculates the mass of the material in the bucket in real time and non-contactly. The technical solution adopted in this invention is to establish a decomposition model of the rotational inertia of the upper shovel slewing system and perform dynamic inversion calculations based on the rigid body fixed-axis rotation law to obtain and output the material mass under load. Therefore, this invention is adaptable to various complex operating conditions of electric shovels, effectively solving the technical problem of the difficulty of real-time and accurate monitoring of the load mass of electric shovels using traditional methods, and providing reliable data support for precise production measurement, operational efficiency optimization, and intelligent management in mines.

[0005] To achieve the above-mentioned technical objectives, the present invention will adopt the following technical solution:

[0006] A method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia includes the following steps:

[0007] Data acquisition steps: Real-time acquisition of the drive torque on the output shaft of the rotary motor. and angular acceleration Simultaneously, the real-time elongation of the boom is collected. and pole tilt angle ;

[0008] Rotation parameter conversion steps: Based on the reducer transmission ratio of the electric shovel rotary transmission system External gear meshing transmission ratio , will drive torque and angular acceleration The rotation is shifted to the center of rotation of the slewing platform, thus obtaining the effective driving torque acting on the center of rotation. and angular acceleration ;

[0009] No-load calibration procedure: With the electric shovel in no-load condition, the effective driving torque acting on the center of rotation is used to calibrate the shovel. and angular acceleration Calculate the total unloaded moment of inertia in the current pose. Simultaneously, based on the inherent structural parameters of the mining electric shovel, the unloaded variable moment of inertia under the current posture is calculated. Furthermore, based on the calculated total moment of inertia under no-load conditions... and unloaded variable moment of inertia Calculate the fixed moment of inertia of the mining electric shovel. ;

[0010] Calculation steps for loaded operation: During the slewing start-up phase of loaded operation of the mining electric shovel, the driving torque on the output shaft of the real-time slewing motor is collected in real time. and angular acceleration Calculate the total moment of inertia under load. ;

[0011] Based on the calculated fixed moment of inertia Unloaded variable moment of inertia and total moment of inertia under load To calculate the moment of inertia of the load. Then, the mass of the material under load can be calculated in real time using the following formula. And output:

[0012] ;

[0013] It is the distance from the center of mass of the unloaded bucket to the center of rotation of the central pivot of the electric shovel.

[0014] Preferably, in the no-load calibration step, the no-load variable moment of inertia is calculated using the following formula. :

[0015] ;

[0016] In the above formula: Indicates the mass of the boom; Indicates the real-time elongation of the boom; Indicates the distance from the outer end of the stick to the starting point of the push rack. Axis projection distance; Indicates the angle of inclination of the boom; From the central pivot point of the electric shovel to the pushing axis Horizontal distance between points; Indicates the total length of the pole; This indicates the mass of the bucket when it is unloaded. The distance from the bucket's center of mass A to the starting point of the pushing rack. Axis projection distance.

[0017] Preferably, in the rotation parameter conversion step, the effective driving torque acting on the center of rotation... and angular acceleration Calculate using the following formulas respectively:

[0018] ;

[0019] ;

[0020] In the above formula: This indicates the driving torque on the output shaft of the rotary motor; Indicates the loss torque; This indicates the gear ratio of the reducer in the electric shovel's rotary drive system; This indicates the external gear meshing transmission ratio of the electric shovel's rotary drive system; This represents the angular acceleration on the output shaft of the rotary motor.

[0021] Preferably, in the no-load calibration step, the no-load total moment of inertia is... Fixed moment of inertia Calculate using the following formulas respectively:

[0022] ;

[0023] ;

[0024] In the above formula: This represents the effective driving torque acting on the center of rotation; This represents the angular acceleration acting on the center of rotation; The real-time elongation of the boom is indicated as The angle of the boom is The variable moment of inertia under no-load conditions.

[0025] Preferably, in the calculation step for loaded operations, the moment of inertia of the load is... The distance from the center of gravity of the unloaded bucket to the center of rotation of the electric shovel's central pivot. Solve using the following formulas respectively:

[0026] ;

[0027] ;

[0028] In the above formula: This represents the total moment of inertia under load; Indicates a fixed moment of inertia; The real-time elongation of the boom is indicated as The angle of the boom is Unloaded variable moment of inertia at that time; Indicates the quality of the material; The distance from the center of mass of the unloaded bucket to the center of rotation of the central pivot of the electric shovel; , These represent the driving torque and angular acceleration on the output shaft of the rotary motor during the slewing start-up phase of a mining electric shovel under load. The distance from the bucket's center of mass A to the starting point of the pushing rack. Axis projection distance; From the central pivot point of the electric shovel to the pushing axis The horizontal distance between points.

[0029] Preferably, during the no-load calibration step, the electric shovel is controlled in several different typical working positions. The no-load rotary start was performed, and multiple candidate values ​​of fixed moment of inertia were calculated. The average value is then taken as the final fixed moment of inertia calibration value. .

[0030] Preferably, after the load operation calculation step, a correction and error correction step is also included to adjust the calculated material mass. Make corrections:

[0031] ;

[0032] In the above formula: Indicates the corrected material quality; This represents the calibration coefficient.

[0033] Preferably, calibration coefficient Obtained through the following method: periodically using known weights. The standard load was measured to calculate the material mass in the loading operation steps. The calculation formula yields the corresponding material mass calculation value. Calibration coefficient The following formula is used to calculate:

[0034] .

[0035] Another technical objective of this invention is to provide a real-time measurement system for the load capacity of an electric shovel, used to implement the above-mentioned real-time measurement method for the load capacity of an electric shovel based on dynamic calculation of rotational inertia, comprising:

[0036] The torque and speed detection unit, installed on the output shaft of the rotary motor, is used to collect the driving torque. and angular acceleration The displacement and tilt angle detection unit installed at the boom is used to collect the boom elongation r and the boom tilt angle θ.

[0037] The data processing and control unit is configured to receive the acquired drive torque. angular acceleration The system stores the boom extension r and boom tilt angle θ; it also stores the inherent structural parameters of the electric shovel; it performs the rotation parameter conversion, no-load calibration, and loaded operation calculation steps; and it outputs the material mass calculated in real time. .

[0038] Another technical objective of the present invention is to provide a mining electric shovel, comprising the above-mentioned real-time measurement system for the load capacity of the electric shovel.

[0039] Based on the above-mentioned technical objectives, the present invention has the following advantages compared with the prior art:

[0040] 1. Simplified principle and improved accuracy: The complex static balance problem of multiple mechanisms is transformed into the dynamic moment of inertia identification problem of a single rotating mechanism, which reduces the modeling complexity and improves the calculation accuracy and reliability in principle.

[0041] 2. Non-contact measurement with strong adaptability: There is no need to install fragile weighing sensors on the bucket or working device. Measurement can be achieved using existing electronic control and attitude detection systems, making it suitable for the harsh and variable working environment of electric shovels.

[0042] 3. Good real-time performance: Calculations can be performed using dynamic data from the slewing start-up process, and a quality measurement can be completed within seconds, meeting the needs of real-time operation monitoring.

[0043] 4. Low cost and easy to implement: No large-scale structural modifications to electric shovels or the installation of expensive special equipment are required. The modification is simple and cost-effective, making it easy to promote and apply to existing electric shovels.

[0044] 5. High robustness: The fixed moment of inertia, which includes complex factors such as friction and efficiency, is obtained through no-load calibration. System errors are corrected through filtering and calibration measures, which enhances the engineering applicability and measurement stability of the method. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of a mining electric shovel.

[0046] Figure 2 This is a schematic diagram of the electric shovel rotation transmission system of the electric shovel rotation mechanism.

[0047] Figure 3 This is a flowchart of the real-time measurement system for the load mass of an electric shovel based on dynamic calculation of rotational inertia, as described in this invention. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specifically stated, the relative arrangement, expressions, and values ​​of components and steps set forth in these embodiments do not limit the scope of the present invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0049] I. System Structure and Parameter Definitions:

[0050] See Figure 1 The mining electric shovel mainly consists of a lower platform, an upper platform, and a working device. The working device includes a bucket, stick, pushing mechanism, and lifting mechanism. The extension, retraction, and pitch of the stick and bucket are achieved through the coordinated drive of the pushing and lifting mechanisms. The upper platform and its working device are driven by a slewing mechanism, rotating around a central pivot. During operation, the upper platform, along with its working device, rotates around the central pivot under the drive of the slewing mechanism to transport materials. During this rotation, the driving torque directly output by the slewing motor 1 is transmitted through multiple stages, including the slewing reducer 2 and the external gear meshing mechanism (formed by the meshing of the driving pinion 3 and the driven large gear), ultimately driving the entire machine to rotate. (See reference...) Figure 2 .

[0051] To establish a model for calculating the moment of inertia (used to calculate the fixed moment of inertia J1, the unloaded variable moment of inertia J2, and the loaded moment of inertia J3 respectively), the following key parameters are defined:

[0052] Establish a coordinate system XOY with the push axis (saddle rotation center) as the origin O, and the X-axis pointing outward along the stick direction towards the outside of the bucket. The axis is counterclockwise and perpendicular to axis.

[0053] Point A is the center of mass of the bucket (unloaded), and its mass is... .

[0054] The total length of the boom (excluding the bucket) is l, and its mass is [missing information]. .

[0055] r represents the real-time extension (stroke) of the boom.

[0056] d0 is the X-axis projection distance (fixed value) from the outer end of the stick to the starting point C of the push rack.

[0057] d1 is the X-axis projection distance (fixed value) from the center of mass of the bucket A to the starting point C of the pushing rack.

[0058] d2 is the horizontal distance (fixed value) from the rotation center of the electric shovel's central pivot to the pushing axis O.

[0059] θ is the boom tilt angle, which represents the real-time angle between the boom and the vertical direction (Y-axis).

[0060] i1 and i2 are the transmission ratio and external gear meshing transmission ratio of the rotary reducer, respectively.

[0061] In the XOY coordinate system, the horizontal coordinate of the outer end of the boom is... The horizontal coordinates of point A, the center of mass of the bucket .

[0062] The above parameters , , , , , , , These are all known inherent structural parameters of mining electric shovels, which can be obtained through design drawings or actual measurements.

[0063] II. Constructing the decomposition model of rotational inertia:

[0064] When the electric shovel is operating under load, this invention measures the total moment of inertia of the upper platform (including the working device) of the electric shovel rotating around the central pivot. Decomposed into fixed moment of inertia Unloaded variable moment of inertia and the moment of inertia of the load ,in:

[0065] Fixed moment of inertia This refers to the moment of inertia of all components of the upper platform (including the platform structure, cab, counterweight, and parts above the slewing bearing) about the center of rotation, excluding the working devices (bucket and boom). This part is considered a system constant, but it contains complex friction and transmission efficiency factors and needs to be obtained through overall no-load calibration.

[0066] Unloaded variable moment of inertia The moment of inertia refers to the rotational inertia of the rigid connection consisting of the bucket and stick about the center of rotation under no-load conditions. Its value varies in real time with the stick elongation *r* and the stick tilt angle *θ*, and can be calculated based on its mass distribution and geometric relationships. The expression is:

[0067] .

[0068] Moment of inertia of the load This refers to the increment of rotational inertia caused by the material loaded in the bucket about the center of rotation. It is the target quantity to be determined by this method, and it is related to the material mass mload and the distance L from its center of mass to the center of rotation. In engineering practice, it is reasonably assumed that the center of mass of the material coincides with the center of mass A of the empty bucket. Then, the distance L satisfies: And there are .

[0069] III. Specific steps of the measurement method:

[0070] Combination Figure 3 The flowchart illustrates the real-time measurement method for the load mass of an electric shovel based on dynamic calculation of rotational inertia, as described in this invention. Specifically, it includes the following steps:

[0071] Step S0: Obtaining known structural parameters:

[0072] This step is fundamental to all subsequent calculations; it involves identifying and inputting the known intrinsic parameters: , , , , , , , .in: Indicates the mass of the boom; This indicates the mass of the bucket when it is unloaded. Indicates the total length of the pole; Indicates the distance from the outer end of the stick to the starting point of the push rack. Axis projection distance; The distance from the bucket's center of mass A to the starting point of the pushing rack. Axis projection distance; From the central pivot point of the electric shovel to the pushing axis The horizontal distance between the points; i1 and i2 are the transmission ratio of the rotary reducer and the external gear meshing transmission ratio, respectively.

[0073] S1. Data Acquisition:

[0074] This step is fundamental to all calculations and aims to obtain high-precision, real-time raw data. Two types of signals are simultaneously acquired through a sensor system integrated into the electric shovel body:

[0075] Electrodynamic signal: The drive torque on the output shaft of the rotary motor is acquired in real time via the motor driver or an additional torque / speed sensor. and angular acceleration These signals directly reflect the output characteristics of the drive system.

[0076] Mechanical geometric attitude signal: The real-time elongation of the boom is measured by displacement sensors (such as high-precision encoders). And the real-time angle between the boom and the vertical direction is measured by an angle sensor. included angle This refers to the stick tilt angle. These parameters define the spatial orientation of the working device and are key inputs for calculating the variable moment of inertia.

[0077] S2. Calculation of overall rotation parameters of the upper part:

[0078] This step aims to transfer the measured values ​​from the motor end to the rotation center of the rotary platform.

[0079] Considering factors such as stationary friction and mechanical losses, the torque on the actual rotary motor output shaft cannot be fully used to drive the upper rotary platform to rotate, resulting in torque loss. ,therefore:

[0080] Effective driving torque: ;

[0081] Since the direct measurement concerns the physical quantities of the motor shaft, while the rotational laws apply to the rotation center of the entire upper platform, parameter conversion is necessary, based on the design of the electric shovel's rotational drive system (e.g., ...). Figure 2 As shown, the system includes a rotary motor 1, a reducer 2, a driving pinion 3, and a driven gear 4. The transmission ratio between the driving pinion 3 and the driven gear 4 is denoted as the external gear meshing transmission ratio. Given the transmission ratio of the reducer External gear meshing transmission ratio Based on the transmission relationship, the following conversion can be performed:

[0082] The effective driving torque transmitted to the center of rotation is amplified, thus the effective driving torque at the center of rotation is... Represented as:

[0083] .

[0084] Correspondingly, the angular acceleration at the center of rotation is reduced, and the angular acceleration at the center of rotation... Represented as:

[0085] .

[0086] This step converts the measured values ​​at the motor end into an equivalent physical quantity acting on the entire rotary platform, providing accurate input for subsequent calculations of the rotational inertia based on the overall system.

[0087] S3. Calibration of unloaded moment of inertia and fixed moment of inertia Acquisition:

[0088] This step is the core preprocessing step for achieving high precision in this invention, aiming to fix the system's inherent parameters and moment of inertia when the bucket is unloaded. The calibration process includes the following steps:

[0089] S3.1. When the electric shovel is unloaded, control it to perform a smooth slewing start process;

[0090] S3.2 Utilize the effective driving torque at the rotation center obtained from step S2. and angular acceleration According to the rotation law, the current pose can be calculated. Total moment of inertia under no-load conditions: ;

[0091] S3.3. Based on the decomposition model of the moment of inertia, the fixed moment of inertia can be calculated. The expression:

[0092] ;

[0093] ;

[0094] To increase the fixed moment of inertia The calibration accuracy can be achieved by repeating the above no-load measurement and calculation under multiple different typical working postures, and finally taking a fixed moment of inertia. The average value is used as the system's calibration value.

[0095] S4. Calculation of moment of inertia of load and mass of material:

[0096] This step is the core of the online real-time measurement in this invention, and it is performed during normal operation of the electric shovel under load. Specifically, it includes the following steps:

[0097] Step S4.1: When the electric shovel is operating under load, during its rotation start-up phase, measure and calculate the total moment of inertia under load in the current state:

[0098] ;

[0099] Step S4.2: Based on the rotational inertia decomposition model, calculate the rotational inertia of the load. (That is, the increase in rotational inertia generated by the material when it is under load).

[0100] Based on the rotational inertia decomposition model, the total rotational inertia under load can be determined. With a fixed moment of inertia Unloaded variable moment of inertia and the moment of inertia of the load It consists of three parts: Among them, the fixed moment of inertia The unloaded variable moment of inertia has been calibrated in step S3. It can be calculated based on the real-time pose. Therefore, the moment of inertia of the load. The following formula can be used to solve it:

[0101] .

[0102] Step S4.3: Under reasonable engineering assumptions (i.e., the center of mass of the material coincides with the center of mass of the empty bucket), the moment of inertia of the loaded load. With material quality The relationship is: ,in Let be the distance from the center of mass to the axis of rotation, and its calculation formula is: Therefore, the mass of the material under load can be calculated in real time using the following formula. :

[0103] .

[0104] S5. Calibration and Error Correction:

[0105] To address various interference factors in real-world industrial environments and further improve the reliability and accuracy of measurements, this step provides a complete post-processing and calibration solution.

[0106] Data filtering processing: raw electrical signals (especially torque at startup) and acceleration The collected torque may contain high-frequency noise and transient impacts. This invention employs digital filtering algorithms (such as moving average filtering or low-pass filtering) to process the collected torque. and acceleration The data is smoothed to filter out abnormal values ​​caused by motor starting current surges and mechanical transmission clearances, ensuring that the values ​​used for calculation are stable and reliable.

[0107] Systematic error calibration: To address systematic errors arising from theoretical model simplifications (such as the centroid assumption and neglecting transmission efficiency variations), this invention corrects them through calibration experiments under specific operating conditions (such as during regular maintenance). The specific method is as follows:

[0108] Using known weight By loading and measuring the standard load (optional standard weights or materials) and following the steps in S4, the corresponding material mass value can be calculated. Then calculate the material mass value. With true quality Compare and calculate a calibration coefficient. :

[0109] .

[0110] In practical applications, the calculated material mass Multiplying by this calibration factor yields the final corrected mass. : .

[0111] For cases with a large measurement range, a piecewise interpolation algorithm can be used to establish a more accurate calibration curve.

[0112] Through the above comprehensive measures, the error of the entire measurement system can be effectively controlled and stabilized within the acceptable range of ±5% for engineering applications.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A real-time measurement method of a load mass of an electric shovel based on dynamic calculation of rotational inertia, characterized by, Includes the following steps: Data acquisition step: real-time acquisition of driving torque on the output shaft of the rotary motor and angular acceleration , while collecting the real-time elongation of the boom and the boom inclination angle ; Rotating parameter conversion step: based on the reducer transmission ratio of the electric shovel slewing transmission system and external tooth meshing transmission ratio , the driving torque and angular acceleration is converted to the slewing center of the slewing platform, to obtain the effective driving torque and angular acceleration acting on the slewing center; Idle calibration step: in the idle state of the electric shovel, the effective driving torque acting on the rotation center is calculated and angular acceleration , the total moment of inertia in the current pose is calculated ; Meanwhile, according to inherent structural parameters of the mining shovel, the variable moment of inertia under the current pose is calculated ; and further according to the calculated variable moment of inertia under the current pose and the total moment of inertia under the current pose , the fixed moment of inertia of the mining shovel is calculated ; The belt load operation calculation step comprises: in the slewing starting stage of the belt load operation of the mine shovel, the driving torque on the output shaft of the slewing motor is collected in real time and the angular acceleration , and the total moment of inertia of the belt load is calculated ; based on the calculated fixed moment of inertia , the unloaded variable moment of inertia and the total moment of inertia with load to calculate the moment of inertia with load and to calculate the mass of the material in real time with load by the following formula and output: ； It is the distance from the center of mass of the unloaded bucket to the center of rotation of the central pivot of the electric shovel.

2. The method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia according to claim 1, characterized in that, During the no-load calibration step, the no-load variable moment of inertia is calculated using the following formula. : ； In the above formula: Indicates the mass of the boom; Indicates the real-time elongation of the boom; Indicates the distance from the outer end of the stick to the starting point of the push rack. Axis projection distance; Indicates the angle of inclination of the boom; From the central pivot point of the electric shovel to the pushing axis Horizontal distance between points; Indicates the total length of the pole; This indicates the mass of the bucket when it is unloaded. The distance from the bucket's center of mass A to the starting point of the pushing rack. Axis projection distance.

3. The method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia according to claim 2, characterized in that, During the rotation parameter conversion step, the effective driving torque acting on the center of rotation and angular acceleration Calculate using the following formulas respectively: ； ； In the above formula: This indicates the driving torque on the output shaft of the rotary motor; Indicates the loss torque; This indicates the gear ratio of the reducer in the electric shovel's rotary drive system; This indicates the external gear meshing transmission ratio of the electric shovel's rotary drive system; This represents the angular acceleration on the output shaft of the rotary motor.

4. The method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia according to claim 3, characterized in that, In the no-load calibration step, the total moment of inertia under no-load conditions... Fixed moment of inertia Calculate using the following formulas respectively: ； ； In the above formula: This represents the effective driving torque acting on the center of rotation; This represents the angular acceleration acting on the center of rotation; The real-time elongation of the boom is indicated as The angle of the boom is The variable moment of inertia under no-load conditions.

5. The method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia according to claim 4, characterized in that, In the calculation steps for loaded operations, the moment of inertia of the load... The distance from the center of gravity of the unloaded bucket to the center of rotation of the electric shovel's central pivot. Solve using the following formulas respectively: ； ； In the above formula: This represents the total moment of inertia under load; Indicates a fixed moment of inertia; The real-time elongation of the boom is indicated as The angle of the boom is Unloaded variable moment of inertia at that time; Indicates the quality of the material; The distance from the center of mass of the unloaded bucket to the center of rotation of the central pivot of the electric shovel; , These represent the driving torque and angular acceleration on the output shaft of the rotary motor during the slewing start-up phase of a mining electric shovel under load. The distance from the bucket's center of mass A to the starting point of the pushing rack. Axis projection distance; From the central pivot point of the electric shovel to the pushing axis The horizontal distance between points.

6. The method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia according to claim 1, characterized in that, During the no-load calibration step, the electric shovel is controlled in several different typical working positions. The no-load rotary start was performed, and multiple candidate values ​​of fixed moment of inertia were calculated. The average value is then taken as the final fixed moment of inertia calibration value. .

7. The method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia according to claim 1, characterized in that, Following the calculation step for the loaded operation, a correction and error adjustment step is also included to adjust the calculated material mass. Make corrections: ； In the above formula: Indicates the corrected material quality; This represents the calibration coefficient.

8. The method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia according to claim 7, characterized in that, Calibration coefficient Obtained through the following method: periodically using known weights. The standard load was measured to calculate the material mass in the loading operation steps. The calculation formula yields the corresponding material mass calculation value. Calibration coefficient The following formula is used to calculate: 。 9. A real-time measurement system for the load capacity of an electric shovel, characterized in that, A method for real-time measurement of the load mass of an electric shovel based on dynamic calculation of rotational inertia as described in any one of claims 1-8, comprising: The torque and speed detection unit, installed on the output shaft of the rotary motor, is used to collect the driving torque. and angular acceleration The displacement and tilt angle detection unit installed at the boom is used to collect the boom elongation r and the boom tilt angle θ. The data processing and control unit is configured to receive the acquired drive torque. angular acceleration The system stores the boom extension r and boom tilt angle θ; it also stores the inherent structural parameters of the electric shovel; it performs the rotation parameter conversion, no-load calibration, and loaded operation calculation steps; and it outputs the material mass calculated in real time. .

10. A mining electric shovel, characterized in that, It includes the real-time measurement system for the load capacity of the electric shovel as described in claim 9.

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