Tonnage monitoring method, electronic device, and computer-readable storage medium

Abstract

This application discloses a tonnage monitoring method, electronic device, and computer-readable storage medium. The method includes: acquiring the torque and rotational speed of a motor; obtaining the tangential force of a crankshaft based on the motor torque and rotational speed; acquiring a first angle and a second angle, and obtaining a first force exerted by a connecting rod on a slider in a first direction based on the tangential force of the crankshaft, the first angle, and the second angle; acquiring the acceleration of the slider, and obtaining the processing pressure of the slider based on the first force and acceleration. This method allows for tonnage monitoring of a servo punch press without relying on a tonnage sensor.

Description

Technical Field

[0001] This application relates to the field of servo motor technology, and in particular to a tonnage monitoring method, electronic device, and computer-readable storage medium. Background Technology

[0002] Currently, servo tonnage monitoring requires measurement using tonnage sensors. On the one hand, the installation design of tonnage sensors requires special design, which increases design costs. On the other hand, even after installation, tonnage sensors need regular maintenance to avoid inaccurate tonnage monitoring, which increases maintenance costs. Therefore, a new solution is urgently needed for servo tonnage monitoring. Summary of the Invention

[0003] This application provides a tonnage monitoring method, electronic device, and computer-readable storage medium that can complete tonnage monitoring without relying on a tonnage sensor.

[0004] This application provides a tonnage monitoring method applied to a frequency converter, the frequency converter controlling a servo punch press, the servo punch press including a motor, a crankshaft, a connecting rod, and a slider, the gear of the motor meshing with the gear of the crankshaft, the connecting rod connecting the slider and the crankshaft to cause the slider to slide along a first direction, the first direction being the direction of the line connecting the center of the crankshaft and the center of the slider, the method including: acquiring the torque of the motor and acquiring the rotational speed of the motor; obtaining the tangential force of the crankshaft based on the torque of the motor and the rotational speed; acquiring a first angle and a second angle, and obtaining the position of the connecting rod based on the tangential force of the crankshaft, the first angle, and the second angle. A first force is applied to the slider in the first direction; the first angle is the angle between the second direction and the first direction; the second angle is the angle between the extension direction of the connecting rod and the first direction and is less than 90 degrees; the second direction is the line connecting the center of the crankshaft and the target connection point; the target connection point is the connection point between the crankshaft and the connecting rod; both the first angle and the second angle are within the target triangle; the target connection point, the center point of the crankshaft, and the intersection point of the first direction and the extension direction of the connecting rod are all vertices of the target triangle; the acceleration of the slider is obtained, and the processing pressure of the slider is obtained based on the first force and the acceleration.

[0005] In one embodiment, the step of obtaining the tangential force of the crankshaft based on the torque and rotational speed of the motor includes: obtaining the rotational speed of the motor and differentiating the rotational speed of the motor to obtain the angular acceleration of the motor; obtaining a first moment of inertia and calculating the product of the first moment of inertia and the angular acceleration of the motor to obtain the angular momentum of the motor; obtaining the torque of the motor and calculating the difference between the torque of the motor and the angular momentum of the motor to obtain the torque acting on the motor; and determining the ratio of the torque acting on the motor to the gear radius of the motor as the tangential force of the crankshaft.

[0006] In one embodiment, the step of obtaining the first force exerted by the connecting rod on the slider in the first direction based on the tangential force of the crankshaft, the first angle, and the second angle includes: calculating the sum of the first angle and the second angle to obtain a third angle; calculating the ratio of the tangential force of the crankshaft to the sine of the third angle to obtain the force exerted by the crankshaft along the connecting rod direction; and obtaining the first force based on the product of the force exerted by the crankshaft along the connecting rod direction and the cosine of the second angle.

[0007] In one embodiment, the steps of obtaining the first angle and the second angle include: obtaining the angle of the crankshaft by sampling through the encoder of the crankshaft; calculating the absolute value of the difference between the angle of the crankshaft and 180 degrees to obtain the first angle; obtaining the length of the connecting rod and the eccentric radius of the crankshaft, and using the sine theorem, obtaining the second angle based on the length of the connecting rod, the eccentric radius of the crankshaft, and the first angle.

[0008] In one embodiment, the force on the slider further includes the resistance force on the slider, the balancing force of the slider, and the gravity of the slider.

[0009] In one embodiment, the step of obtaining the acceleration of the slider and obtaining the processing pressure of the slider based on the first force and the acceleration includes: obtaining the acceleration of the slider and the mass of the slider, and calculating the resultant force on the slider; obtaining the resistance force on the slider, the balancing force of the slider, and the weight of the slider, and calculating the sum of the first force, the resistance force on the slider, the balancing force of the slider, the weight of the slider, and the resultant force of the slider according to Newton's second law, to obtain the processing pressure of the slider.

[0010] In one embodiment, the step of obtaining the acceleration of the slider includes: obtaining the displacement of the slider in a first direction, and taking the second derivative of the displacement of the slider in the first direction to obtain the acceleration of the slider.

[0011] In one embodiment, the step of obtaining the torque of the motor includes: determining the torque of the motor based on the current of the motor.

[0012] A second aspect of this application provides an electronic device including a processing circuit and a memory, the processing circuit being configured to execute a computer program stored in the memory to implement the tonnage monitoring method as described in any of the above embodiments.

[0013] A third aspect of this application provides a computer-readable storage medium storing a computer program that can be executed by a processor to implement the steps of the method as described in any of the above embodiments.

[0014] The beneficial effects are: This application obtains the tangential force of the crankshaft by acquiring the torque and speed of the motor, and obtains the first angle and the second angle. The first angle is the angle between the second direction and the first direction, and the second angle is the angle between the extension direction of the connecting rod and the first direction and is less than 90 degrees. Based on the tangential force of the crankshaft, the first force applied by the connecting rod to the slider in the first direction is obtained, and the acceleration of the slider is further obtained to calculate the processing pressure of the slider. Thus, the tonnage of the servo punch press can be monitored without relying on a tonnage sensor. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0016] Figure 1 This is a flowchart illustrating one embodiment of the tonnage monitoring method of this application;

[0017] Figure 2 This is a schematic diagram of one embodiment of the servo punch press of this application;

[0018] Figure 3 yes Figure 1 A flowchart illustrating one embodiment of step S200;

[0019] Figure 4 yes Figure 1 A flowchart illustrating one embodiment of step S300;

[0020] Figure 5 yes Figure 1 A flowchart illustrating another embodiment of step S300;

[0021] Figure 6 yes Figure 1 A flowchart illustrating one embodiment of step S400;

[0022] Figure 7 This is a schematic diagram of the structure of one embodiment of the electronic device of this application;

[0023] Figure 8 This is a schematic diagram of one embodiment of the computer-readable storage medium of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0025] It should be noted that the terms "first" and "second" in this application are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0026] Please see Figure 1 and Figure 2 This application provides a tonnage monitoring method, which is applied to a frequency converter. The frequency converter controls a servo punch press 10. The servo punch press 10 includes a motor 110, a crankshaft 120, a connecting rod 130, and a slider 140. The gear of the motor 110 meshes with the gear of the crankshaft 120. The connecting rod 130 connects the slider 140 and the crankshaft 120 so that the slider 140 slides along a first direction X. The first direction X is the direction of the line connecting the center of the crankshaft 120 and the center of the slider 140.

[0027] The method of this application includes:

[0028] Step S100: Obtain the torque of motor 110 and the speed of motor 110.

[0029] Specifically, the torque of the motor 110 can be measured by a torque sensor or calculated by real-time electrical parameters of the motor 110; the speed of the motor 110 can be measured by an encoder sampling in the motor 110 or by a tachometer.

[0030] In one embodiment, the step of obtaining the torque of the motor 110 in step S100 includes determining the torque of the motor 110 based on the current of the motor 110.

[0031] Specifically, the current of motor 110 can be directly measured by an ammeter, and this current is a real-time current. Based on the type of motor 110, the torque of motor 110 can be calculated.

[0032] In a specific application scenario, motor 110 is a surface-mount motor, and the formula for obtaining the torque of motor 110 is as follows:

[0033]

[0034] Among them, T e This is the torque of motor 110, and p is the magnetic pole pair. is the magnetic flux of the magnetic poles, and i is the current of motor 110.

[0035] Continue reading Figure 1 Step S100 is followed by:

[0036] Step S200: Based on the torque and speed of motor 110, obtain the tangential force of crankshaft 120.

[0037] Specifically, the motor 110 and the crankshaft 120 are meshed through gears, so when the motor 110 rotates, it also drives the crankshaft 120 to rotate. Figure 2 The description focuses on the motor 110 rotating counterclockwise to drive the crankshaft 120 to rotate clockwise. However, in other embodiments, the motor 110 can also rotate clockwise to drive the crankshaft 120 to rotate counterclockwise. Due to the meshing relationship between the motor 110 and the crankshaft 120, the tangential force on the crankshaft 120 can be obtained by analyzing the torque and speed of the motor 110 and the forces acting on the crankshaft 120 and the motor 110.

[0038] In one embodiment, see Figure 2 and Figure 3 The step S200 above, which involves obtaining the tangential force of the crankshaft 120 based on the torque and speed of the motor 110, includes:

[0039] S210: Obtain the rotational speed of motor 110, and differentiate the rotational speed of motor 110 to obtain the angular acceleration of motor 110.

[0040] Specifically, the rotational speed of motor 110 can be sampled from the encoder of motor 110, and the angular acceleration of motor 110 can be obtained by differentiating the sampled rotational speed with respect to time.

[0041] S220: Obtain the first moment of inertia and calculate the product of the first moment of inertia and the angular acceleration of the motor 110 to obtain the angular momentum of the motor 110.

[0042] Specifically, since the rotation of motor 110 drives the crankshaft 120 to rotate, and the rotation of motor 110 is affected by crankshaft 120, the moment of momentum of motor 110 should be calculated by including not only the moment of inertia of motor 110 itself but also the moment of inertia of crankshaft 120. Both the moment of inertia of motor 110 and crankshaft 120 are known quantities. The first moment of inertia is obtained from the moment of inertia of motor 110 and crankshaft 120. Therefore, the moment of momentum of motor 110 can be obtained by multiplying the first moment of inertia by the angular acceleration of motor 110.

[0043] S230: Obtain the torque of motor 110, calculate the difference between the torque of motor 110 and the angular momentum of motor 110, and obtain the torque on motor 110.

[0044] Specifically, based on the relationship between the torque of motor 110, the torque acting on motor 110, and the angular momentum of motor 110, the torque acting on motor 110 is obtained by subtracting the angular momentum of motor 110 from its torque. The torque of motor 110 can be obtained according to the embodiments described above.

[0045] S240: The ratio of the torque on motor 110 to the gear radius of motor 110 is determined as the tangential force of crankshaft 120.

[0046] Specifically, since motor 110 is only affected by the rotation of crankshaft 120, the torque on motor 110 originates from crankshaft 120. The tangential force on crankshaft 120 can be obtained by dividing the torque on motor 110 by the gear radius of motor 110. In one application scenario, the tangential force F of crankshaft 120 is obtained using the following formula. t :

[0047]

[0048] Among them, T e R is the torque of motor 110, r1 is the gear radius of motor 110, and J is the first moment of inertia. It is the derivative of the rotational speed ω1 of motor 110 with respect to time t.

[0049] Specifically, the formula for obtaining the crankshaft tangential force can be found in the following derivation.

[0050] Based on the force analysis between the motor 110 and the crankshaft 120, and the force F exerted by the motor 110 on the crankshaft 120 12 The reaction force F of crankshaft 120 on motor 110 21 The following formula can be established: F 12 =F 21 .

[0051] Based on the rotational relationship between the motor 110 and the crankshaft 120, as well as the rotational speed ω1 of the motor 110, the rotational speed ω2 of the crankshaft 120, the gear radius r1 of the motor 110, and the gear radius R2 of the crankshaft 120, the following formula ② can be established: ω1×r1=ω2×R2.

[0052] Based on the torque relationship of motor 110 itself, and the torque T of motor 110 e The reaction force F of crankshaft 120 on motor 110 21 The gear radius r1 of motor 110, the moment of inertia J1 of motor 110, the rotational speed ω1 of motor 110, and the time t can be established by the following formula ③:

[0053] in, It is the derivative of the rotational speed ω1 of motor 110 with respect to time t.

[0054] Based on the torque relationship of the crankshaft 120 itself, and the force F applied by the motor 110 to the crankshaft 120 12 The gear radius R2 of crankshaft 120, and the tangential force F of crankshaft 120. t The moment of inertia J2 of crankshaft 120, the rotational speed ω2 of crankshaft 120, and the time t can be established by the following formula ④:

[0055] in, It is the derivative of the crankshaft rotational speed ω2 with respect to time t.

[0056] Based on the above formulas ①, ②, ③, and ④, the following relationship is derived:

[0057]

[0058] Among these, the gear radius r1 of motor 110, the gear radius R2 of crankshaft 120, the moment of inertia J1 of motor 110, and the moment of inertia J2 of crankshaft 120 are known quantities. Therefore, a first moment of inertia can be defined. The formula obtained after sorting is as follows:

[0059]

[0060] Continue reading Figure 1 Step S200 is followed by:

[0061] Step S300: Obtain the first angle α and the second angle β, and determine the tangential force F of the crankshaft 120. t The first angle α and the second angle β are used to obtain the first force F exerted by the connecting rod 130 on the slider 140 in the first direction X. T The first angle α is the angle between the second direction Y and the first direction X. The second angle β is the angle at which the extension direction of the connecting rod 130 intersects the first direction X and is less than 90 degrees. The second direction Y is the direction of the line connecting the center of the crankshaft 120 and the target connection point A. The target connection point A is the connection point between the crankshaft 120 and the connecting rod 130. The first angle α and the second angle β are both located in the target triangle. The target connection point A, the center point B of the crankshaft, and the intersection point C of the first direction X and the extension direction of the connecting rod 130 are all vertices of the target triangle.

[0062] Specifically, as the crankshaft 120 rotates clockwise, it drives the connecting rod 130 to oscillate, further causing the slider 140 to slide in the first direction X. The target triangle formed by the target connection point A, the center point B of the crankshaft, and the intersection point C of the first direction X and the extension direction of the connecting rod 130 changes during the rotation of the crankshaft 120 due to the continuous change in the second direction Y. Consequently, the first angle α and the second angle β within the target triangle also change. Although the target triangle is constantly changing, it is fixed at a given moment. Therefore, it can be determined based on the tangential force F of the crankshaft 120. t Based on the first angle α and the second angle β, force analysis yields the first force F exerted by the connecting rod 130 on the slider 140 in the first direction X. T .

[0063] In one embodiment, see Figure 2 and Figure 4 The steps in step S300 above for obtaining the first angle α and the second angle β include:

[0064] S310: The angle of crankshaft 120 is obtained by sampling through the encoder of crankshaft 120.

[0065] Specifically, the crankshaft 120 can be defined with its end away from the slider 140 along the first direction X as the top dead center U, and its end closer to the slider 140 along the first direction X as the bottom dead center D. The top dead center U is used as the starting point for the rotation of the crankshaft 120, and the angle δ of the crankshaft 120 can be obtained by sampling through the encoder of the crankshaft 120.

[0066] S320: Calculate the absolute value of the difference between the crankshaft angle and 180 degrees to obtain the first angle α.

[0067] Specifically, from Figure 2As can be seen from the diagram, the first angle α is based on the line connecting the bottom dead center D and the center B of crankshaft 120, while the angle δ of crankshaft 120 is based on the line connecting the top dead center U and the center B of crankshaft 120. The angle δ of crankshaft 120 differs from the first angle α by 180 degrees, or they can be added together to obtain 180 degrees. Therefore, the absolute value of the difference between the crankshaft angle and 180 degrees is taken to obtain the first angle α.

[0068] Of course, preferably, the first angle α can be directly calculated using the following formula:

[0069] α = |δ - 180|.

[0070] S330: Obtain the length of connecting rod 130 and the eccentric radius of crankshaft 120. Using the sine theorem, based on the length of connecting rod 130, the eccentric radius of crankshaft 120, and the first angle α, obtain the second angle β.

[0071] Specifically, using the law of sines, given the lengths of two sides (i.e., the length of connecting rod 130 and the eccentric radius of crankshaft 120), and the included angle corresponding to at least one known side (i.e., the first angle α), the included angle corresponding to the other side, i.e., the second angle β, can be calculated.

[0072] Of course, preferably, the second angle β can be directly calculated using the following formula:

[0073]

[0074] Where L is the length of connecting rod 130 and R is the eccentric radius of crankshaft 120.

[0075] In some other embodiments, the starting point for the rotation of the crankshaft 120 may be other positions, and the first angle and the second angle may be calculated accordingly; or they may be directly measured by an angle measuring instrument.

[0076] In one embodiment, see Figure 2 and Figure 5 In step S300 above, based on the tangential force F of crankshaft 120... t The first angle α and the second angle β are used to obtain the first force F exerted by the connecting rod 130 on the slider 140 in the first direction X. T The steps include:

[0077] S340: Calculate the sum of the first angle α and the second angle β to obtain the third angle θ.

[0078] Specifically, the sum of the first angle α and the second angle β is calculated according to the exterior angle theorem of a triangle to obtain the third angle θ.

[0079] S350: Calculate the tangential force F of crankshaft 120.t The ratio of the sine value of the third angle θ to the force F applied by the crankshaft 120 along the direction of the connecting rod 130 is obtained.

[0080] Specifically, during the rotation of crankshaft 120, a force is applied to connecting rod 130. The third angle θ is the angle between the line connecting target connection point A and the center point B of crankshaft 120 and the extending direction of connecting rod 130. Therefore, based on the tangential force F of crankshaft 120... t The force F applied by crankshaft 120 along the direction of connecting rod 130 can be calculated from the third angle θ.

[0081] S360: The first force F is obtained by multiplying the force F applied by crankshaft 120 along the direction of connecting rod 130 and the cosine of the second angle β. T .

[0082] Specifically, during the rotation of the crankshaft 120, the angle between the line connecting the slider 140 and the center point B of the crankshaft 120 and the connecting rod 130 is always the second angle β. Therefore, the first force F can be obtained by multiplying the force F applied by the crankshaft 120 along the direction of the connecting rod 130 by the cosine of the second angle β. T .

[0083] In one application scenario, the first force F can be calculated using the following formula. T :

[0084]

[0085] Continue reading Figure 1 and Figure 2 Step S300 includes the following:

[0086] Step S400: Obtain the acceleration 'a' of slider 140, and determine the acceleration based on the first force F. T And the acceleration a, to obtain the processing pressure F of slider 140. w .

[0087] Specifically, the forces acting on the slider in the first direction X can be analyzed, including the acceleration a of the variable slider 140 and the processing pressure F of the slider 140. w Therefore, in the actual measurement or calculation process, as long as the first force F at a certain moment is known... T And by calculating the acceleration 'a', the processing pressure F of slider 140 at that moment can be obtained. w This allows for tonnage monitoring without the need for sensors to measure processing pressure, as is the case with existing technologies. The acceleration 'a' of the slider 140 can be measured by an acceleration sensor or calculated from other parameters, as detailed in the following embodiments.

[0088] In one embodiment, the step of obtaining the acceleration of the slider 140 in step S400 above includes:

[0089] Obtain the displacement of slider 140 in the first direction X, and take the second derivative of the displacement of slider 140 in the first direction X to obtain the acceleration of slider 140.

[0090] Specifically, the displacement of slider 140 in the first direction X can be obtained by a displacement sensor or by other means. This application does not impose any restrictions. The acceleration of slider can be obtained by taking the second derivative of the displacement of slider 140 in the first direction X.

[0091] In one application scenario, the acceleration 'a' of slider 140 is calculated using the following formula:

[0092]

[0093] Where S is the displacement of slider 140 in the first direction X, v is the velocity of slider 140 in the first direction X, R2 is the gear radius of crankshaft 120, α is the first angle, λ is the ratio of the eccentric radius R of crankshaft 120 to the length L of connecting rod 130, and t is time. It is the derivative of the velocity v of slider 140 in the first direction X with respect to time t. It is the derivative of the displacement S of slider 140 in the first direction X with respect to time t.

[0094] Specifically, the acceleration 'a' of slider 140 can be obtained by differentiating the velocity 'v' of slider 140 in the first direction X with respect to time t, i.e. The velocity v of slider 140 in the first direction X can be obtained by differentiating the displacement S of slider 140 in the first direction X with respect to time t, that is... The displacement S of slider 140 in the first direction X can be obtained directly from the existing crankshaft trajectory equation, for example:

[0095] Of course, in some other embodiments, the displacement S of the slider 140 in the first direction X can be based on the existing crankshaft trajectory equation or other methods, and this application does not impose any restrictions.

[0096] In one embodiment, see Figure 2 The force on slider 140 further includes the resistance F acting on the slider. f The balancing force F of the slider p And the weight G of the slider.

[0097] Specifically, force analysis shows that slider 140 is subjected to the first force F. Tand processing pressure F w In addition, the forces acting on the slider also include the resistance force F. f The balancing force F of the slider p And the weight G of the slider, substituting these into the formula can increase the final processing pressure F. w The accuracy.

[0098] Of course, in some other implementations, the forces in the above implementations can be disregarded, and other forces can be counteracted by balancing forces, or the magnitude of other forces can be ignored when they are not significant compared to the processing pressure.

[0099] In one embodiment, see Figure 2 and Figure 6 The step S400 above, which involves obtaining the acceleration of the slider and determining the processing pressure of the slider based on the first force and the acceleration, includes:

[0100] S410: Obtain the acceleration and mass of slider 140, and calculate the net force acting on slider 140.

[0101] Specifically, based on the force on slider 140, the resultant force on slider 140 can be obtained by measuring the acceleration and mass of slider 140. The mass of slider 140 can be pre-measured and set in the program.

[0102] S420: Obtain the resistance force, the balancing force, and the weight of slider 140. According to Newton's second law, calculate the sum of the first force, the resistance force, the balancing force, the weight, and the resultant force of slider 140 to obtain the processing pressure of slider 140.

[0103] Specifically, the resistance experienced by slider 140 can be measured by a force sensor, the balancing force of slider 140 is a set value, and the weight of slider 140 can be pre-measured and set in the program. Using Newton's second law, the processing pressure can be calculated based on the forces acting on slider 140. In one application scenario, the processing pressure F of slider 140 can be obtained using the following formula. w :

[0104] F w =F T -F f +GF p +m×a.

[0105] Among them, F T It is the first force, F f G is the resistance force on slider 140, G is the weight of slider 140, and F is the resistance force on slider 140. pis the balancing force of slider 140, m is the mass of slider 140, and a is the acceleration of slider 140.

[0106] According to one embodiment of this application, please refer to Figure 7 , Figure 7 This is a schematic diagram of the structure of an embodiment of the electronic device of this application. This application provides an electronic device 50 including a memory 502 and a processing circuit 500. The processing circuit 500 is used to execute a computer program stored in the memory 502 to implement any of the tonnage monitoring methods described above. Specifically, the electronic device 50 includes, but is not limited to, desktop computers, laptops, tablets, servers, etc., and is not limited thereto. Furthermore, the processing circuit 500 can also be referred to as a CPU (Center Processing Unit). The processing circuit 500 may be an integrated circuit chip with signal processing capabilities. The processing circuit 500 can also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The general-purpose processor can be a microprocessor or any conventional processor. Additionally, the processing circuit can be implemented using integrated circuit chips.

[0107] According to one embodiment of this application, please refer to Figure 8 , Figure 8 This is a schematic diagram illustrating the structure of one embodiment of the computer-readable storage medium of this application. This application provides a computer-readable storage medium 60 storing program data 600, which, when executed by a processor, implements the steps of the method as described in any of the above embodiments.

[0108] It is understood that the program data 600 stored in the computer-readable storage medium 60 in this embodiment is used to execute a method similar to the tonnage monitoring method provided in the above embodiments, and its principle and steps are the same, so they will not be described again here.

[0109] The computer-readable storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0110] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A tonnage monitoring method, characterized in that, The method is applied to a frequency converter, which controls a servo punch press. The servo punch press includes a motor, a crankshaft, a connecting rod, and a slide block. The gear of the motor meshes with the gear of the crankshaft. The connecting rod connects the slide block and the crankshaft, causing the slide block to slide along a first direction, where the first direction is the direction of the line connecting the center of the crankshaft and the center of the slide block. The method includes: The torque of the motor and the speed of the motor are obtained; The tangential force of the crankshaft is obtained based on the torque of the motor and the rotational speed. Obtain a first angle and a second angle, and based on the tangential force of the crankshaft, the first angle, and the second angle, obtain the first force exerted by the connecting rod on the slider in the first direction. The first angle is the angle between the second direction and the first direction, the second angle is the angle between the extension direction of the connecting rod and the first direction and is less than 90 degrees, the second direction is the direction of the line connecting the center of the crankshaft and the target connection point, the target connection point is the connection point between the crankshaft and the connecting rod, the first angle and the second angle are both within the target triangle, and the target connection point, the center point of the crankshaft, and the intersection point of the first direction and the extension direction of the connecting rod are all vertices of the target triangle. The acceleration of the slider is obtained, and the processing pressure of the slider is obtained based on the first force and the acceleration. The step of obtaining the tangential force of the crankshaft based on the torque and rotational speed of the motor includes: Obtain the rotational speed of the motor, and differentiate the rotational speed to obtain the angular acceleration of the motor; Obtain the first moment of inertia and calculate the product of the first moment of inertia and the angular acceleration of the motor to obtain the angular momentum of the motor; Obtain the torque of the motor, calculate the difference between the motor torque and the motor angular momentum, and obtain the torque acting on the motor; The ratio of the torque acting on the motor to the radius of the motor gear is determined as the tangential force of the crankshaft; The steps of obtaining the first angle and the second angle include: The angle of the crankshaft is obtained by sampling through the encoder of the crankshaft; The first angle is obtained by calculating the absolute value of the difference between the crankshaft angle and 180 degrees; The length of the connecting rod and the eccentric radius of the crankshaft are obtained. Using the law of sine, the second angle is obtained based on the length of the connecting rod, the eccentric radius of the crankshaft, and the first angle.

2. The tonnage monitoring method according to claim 1, characterized in that, The step of obtaining the first force exerted by the connecting rod on the slider in the first direction based on the tangential force of the crankshaft, the first angle, and the second angle includes: Calculate the sum of the first angle and the second angle to obtain the third angle; Calculate the ratio of the tangential force on the crankshaft to the sine value of the third angle to obtain the force applied by the crankshaft along the connecting rod direction; The first force is obtained by multiplying the force applied by the crankshaft along the connecting rod direction and the cosine of the second angle.

3. The tonnage monitoring method according to claim 1, characterized in that, The forces acting on the slider further include the resistance force acting on the slider, the balancing force of the slider, and the weight of the slider.

4. The tonnage monitoring method according to claim 3, characterized in that, The step of obtaining the acceleration of the slider and determining the processing pressure of the slider based on the first force and the acceleration includes: Obtain the acceleration and mass of the slider, and calculate the net force acting on the slider; Obtain the resistance force, the balancing force, and the weight of the slider. Based on Newton's second law, calculate the sum of the first force, the resistance force, the balancing force, the weight, and the resultant force of the slider to obtain the processing pressure of the slider.

5. The tonnage monitoring method according to claim 4, characterized in that, The step of obtaining the acceleration of the slider includes: The displacement of the slider in the first direction is obtained, and the second derivative of the displacement of the slider in the first direction is taken to obtain the acceleration of the slider.

6. The tonnage monitoring method according to claim 4, characterized in that, The step of obtaining the torque of the motor includes: The torque of the motor is determined based on the motor's current.

7. An electronic device, characterized in that, The electronic device includes a processing circuit and a memory, the processing circuit being used to execute a computer program stored in the memory to implement the tonnage monitoring method as described in any one of claims 1-6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that can be executed by a processor to implement the steps of the method as described in any one of claims 1-6.

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