Management method and system for monitoring and diagnosis of numerical control equipment

Abstract

The invention discloses a management method and system for monitoring and diagnosis of numerical control equipment, and relates to the technical field of numerical control equipment diagnos.The method comprises the steps that main shaft output power of the numerical control equipment is obtained, and main shaft output power consumption is obtained based on the main shaft output power and output time; the rotating speed of the main shaft and the corresponding main shaft no-load output power are obtained, and the mass, radius and cutting force of an object driven by the main shaft are obtained; according to the management method and system for monitoring and diagnosis of the numerical control equipment, whether a main shaft rotating part and a driving part such as a motor are abnormal or not and whether the cutting process is abnormal or not are judged by comparing and judging the output energy consumption during rotation of the main shaft of the numerical control equipment with the output energy consumption under historical corresponding conditions in sequence; after it is judged that the cutting process is abnormal, whether a workpiece rotates around the mass center or not and whether a tool is abraded or not during turning can be judged by researching the relation between the output energy consumption of the main shaft and the cutting position.

Description

Technical Field

[0001] The present invention relates to the technical field of numerical control equipment diagnosis, and in particular to a management method and system for numerical control equipment monitoring and diagnosis. Background Art

[0002] CNC equipment refers to equipment that uses computers to implement digital program control technology. CNC equipment is mainly composed of CNC system (CNC), servo system, mechanical part, cutting tool, cooling system, automation system, sensor and detection device and electrical system.

[0003] CNC equipment usually requires high-precision processing and manufacturing, so CNC equipment has high requirements for its own working conditions. The equipment needs to be monitored to ensure the status of the CNC equipment, thereby ensuring the accuracy of the CNC equipment's production and processing.

[0004] CNC equipment mainly uses the spindle to drive the workpiece or tool to rotate for turning or milling. In order to ensure high precision and service life of processing, it is necessary to reduce vibration during construction and keep the tool sharp. When the workpiece rotates, the deviation of the center of mass from the rotation axis will increase the vibration of the CNC equipment and accelerate equipment wear. Therefore, how to judge whether the object rotates around the center of mass is a problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a management method and system for monitoring and diagnosing numerical control equipment to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solution: a management method for monitoring and diagnosing numerical control equipment, comprising the following steps:

[0007] S1. Obtaining the spindle output power of a numerical control device, and obtaining the spindle output power consumption based on the spindle output power and output time, wherein the spindle of the numerical control device is used to drive a tool to rotate for milling, or to drive a workpiece to rotate for turning;

[0008] S2. Obtain the spindle speed and the corresponding no-load output power of the spindle, and obtain the mass, radius, and cutting force of the spindle-driven object, wherein the spindle speed is represented by angular velocity in radians per second, and the spindle-driven object may be a tool or a workpiece to be turned;

[0009] S3. Based on the mass, radius and rotation speed of the spindle driven object, the rotational kinetic energy of the spindle driven object is calculated; wherein the rotational kinetic energy formula is: Where I is the moment of inertia of the object, ω is the angular velocity of the object. When the object is a disk, Where m is the mass of the object and r is the radius of the object.

[0010] S4. Based on the cutting force and the rotation radius of the cutting position, the cutting force work is calculated; wherein the cutting force work can be calculated by the following formula: W = Fωr F t, where F is the cutting force, ω is the angular velocity of the cutting position, r F is the turning radius of the cutting position.

[0011] S5. Compare the obtained spindle no-load output power with the historical spindle no-load output power to determine whether the spindle no-load rotation is normal. If not, check and maintain the CNC equipment. The energy consumption of the spindle no-load rotation is abnormal. The possible reason is that the spindle friction and other resistances are too high, the spindle drive components are worn, the spindle motor is abnormal, etc.

[0012] S6. Based on the spindle output power, spindle no-load output power, output time, rotational kinetic energy of the spindle-driven object and cutting force work, the additional energy consumed by the first spindle is calculated; wherein, the additional energy consumed by the first spindle = spindle output power*output time-spindle no-load output power*output time-rotational kinetic energy of the spindle-driven object-cutting force work.

[0013] S7. Compare the extra energy consumption of the first spindle with the corresponding historical extra energy consumption of the first spindle to determine whether the cutting process is normal. If not, inspect and maintain the cutting tool and object. The extra energy consumption of the first spindle is abnormal, which may be because the center of mass of the object driven by the spindle to rotate deviates from the set position, or the tool does not match, the tool is worn, etc.

[0014] Furthermore, the method further comprises the following steps:

[0015] Obtain the spindle output power when the spindle drives the object to rotate, and obtain the drive output power;

[0016] Based on the spindle output power, the drive output power and the corresponding output time, the rotational kinetic energy of the object driven by the corresponding spindle and the additional energy consumption of the first spindle, the additional energy consumption of the second spindle is calculated;

[0017] Compare the extra energy consumed by the second main axis with the extra energy consumed by the second main axis of the object driven by the main axis with the same mass and radius in history, and determine whether the rotation of the object is normal;

[0018] If not, based on the extra energy consumption of the second main axis and the angular kinetic energy calculation formula, the center of mass deviation distance of the object is calculated, and the center of mass deviation distance is the perpendicular distance between the center of mass of the object and the axis of rotation of the object.

[0019] Furthermore, in S2, when obtaining the cutting force of the spindle driving the object, the cutting force during the cutting process is measured by a force sensor.

[0020] Further, in S2, when obtaining the cutting force of the spindle-driven object, the cutting force is calculated by cutting data, wherein the cutting data includes a cutting force constant, a cutting area, a feed rate, and a cutting depth. The cutting force can be calculated based on a calculation formula of the cutting force and the obtained cutting data. The cutting force formula is:

[0021] F = K·S,

[0022] Where K is the cutting force constant and S is the cutting area;

[0023] When plane milling is used, S = f·d, where f is the feed depth and d is the cutting width;

[0024] When turning, S = π·d·f, d is the cutting depth and f is the feed speed.

[0025] Further, the S7 comprises the following steps:

[0026] Based on the change of the rotation radius of the cutting position during cutting, the corresponding extra energy consumption of the first spindle is collected to obtain a corresponding extra energy consumption change curve of the first spindle, wherein the extra energy consumption change curve of the first spindle is a curve of the extra energy consumption of the first spindle as the rotation radius of the cutting position changes;

[0027] The extra energy consumption change curve of the first spindle is compared with the corresponding extra energy consumption curve of the first spindle in history to determine whether the error exceeds the set first threshold. If so, the cutting is abnormal; if not, the cutting is normal and the step ends. The corresponding extra energy consumption curve of the first spindle in history is the extra energy consumption curve of the first spindle in history when the same type of tool is used to cut objects of the same material, mass and radius.

[0028] Furthermore, the S7 further comprises the following steps:

[0029] Determine whether the cutting is turning, that is, determine whether the object driven by the spindle is the workpiece being cut;

[0030] If yes, then draw a curve of the rotational kinetic energy variation of the spindle-driven object, wherein the curve of the rotational kinetic energy variation of the spindle-driven object is a curve of the rotational kinetic energy variation of the spindle-driven object with the rotation radius of the cutting position;

[0031] Regression analysis is performed on the extra energy consumption change curve of the first spindle and the rotational kinetic energy change curve of the spindle-driven object to obtain the extra energy consumption change formula of the first spindle and the rotational kinetic energy change formula of the spindle-driven object;

[0032] Determine whether the error of the difference between the first spindle additional energy consumption change formula and the spindle driven object rotational kinetic energy change formula exceeds a set error second threshold, if so, the center of mass of the spindle driven object is not on the rotation axis;

[0033] Based on the curve of the change of the extra energy consumption of the first spindle and the formula for the change of the extra energy consumption of the first spindle, the distance between the center of mass of the spindle-driven object and the axis of rotation is calculated. This can help determine that during turning, there may be problems with the accuracy of the workpiece clamping mechanism, which causes the center of mass of the workpiece to be not on the axis of rotation when it rotates, resulting in increased vibration and loss during rotation.

[0034] A management system for monitoring and diagnosing numerical control equipment, comprising a data acquisition module, an information input module, a database, and a diagnosis module;

[0035] The data acquisition module is used to connect with the numerical control device to obtain the spindle output power, spindle speed and cutting position of the numerical control device in real time, wherein the cutting position when starting cutting can be determined by the cutting position obtained in real time and the rate of change of the spindle output power;

[0036] The information input module is used to manually set the cutting method, cutting data, and cutting object data, wherein the cutting object data includes the material, mass, and diameter of the cutting object;

[0037] The database is used to store data acquired by the data acquisition module and the information input module;

[0038] The diagnostic module is used to execute a management method for monitoring and diagnosing numerical control equipment as described in any one of claims 6 to determine whether the numerical control equipment is operating normally, and to output an abnormal location in case of an abnormality.

[0039] Compared with the prior art, the present invention provides a management method and system for monitoring and diagnosing CNC equipment, which compares and judges the output energy consumption of the CNC equipment spindle during rotation with the output energy consumption of corresponding historical situations, and determines whether there are abnormalities in the spindle rotating parts and driving parts such as motors, and whether there are abnormalities in the cutting process.

[0040] Compared with the prior art, the present invention provides a management method and system for monitoring and diagnosing CNC equipment. After determining that the cutting process is abnormal, the relationship between the spindle output energy consumption and the cutting position is studied, so as to determine whether the workpiece rotates around the center of mass during turning and whether the tool is worn. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0042] Figure 1 A method step diagram provided for an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of the system structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0045] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Example embodiments will be described more fully below with reference to the accompanying drawings, but the example embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. On the contrary, the purpose of providing these embodiments is to make the present disclosure thorough and complete and to enable those skilled in the art to fully understand the scope of the present disclosure.

[0047] In the absence of conflict, the various embodiments of the present disclosure and the various features therein may be combined with each other.

[0048] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0049] The terms used herein are only used to describe specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It will also be understood that when the terms "comprising" and / or "made of" are used in this specification, the presence of the features, wholes, steps, operations, elements and / or components is specified, but the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or groups thereof is not excluded.

[0050] The embodiments described herein may be described with reference to plan views and / or cross-sectional views by means of idealized schematic diagrams of the present disclosure. Therefore, the example illustrations may be modified according to manufacturing techniques and / or tolerances. Therefore, the embodiments are not limited to the embodiments shown in the accompanying drawings, but include modifications of the configurations formed based on the manufacturing process. Therefore, the regions illustrated in the accompanying drawings have schematic properties, and the shapes of the regions shown in the figures illustrate the specific shapes of the regions of the elements, but are not intended to be limiting.

[0051] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted as having an idealized or overly formal meaning unless explicitly defined as such herein.

[0052] See also Figure 1-Figure 2 , a management method for monitoring and diagnosing numerical control equipment, comprising the following steps:

[0053] S1. Obtain the spindle output power of the CNC device, and obtain the spindle output power consumption based on the spindle output power and output time, wherein the spindle of the CNC machine device is used to drive the tool to rotate for milling, or to drive the workpiece to rotate for turning;

[0054] S2. Obtain the spindle speed and the corresponding no-load output power of the spindle, and obtain the mass, radius, and cutting force of the spindle-driven object, wherein the spindle speed is represented by angular velocity in radians per second, and the spindle-driven object may be a tool or a workpiece to be turned; in one embodiment, when obtaining the cutting force of the spindle-driven object, a force sensor is used to measure the cutting force during the cutting process.

[0055] In another embodiment, when obtaining the cutting force of the spindle-driven object, the cutting force is calculated by cutting data. The cutting data includes a cutting force constant, a cutting area, a feed rate, and a cutting depth. The cutting force can be calculated based on a calculation formula of the cutting force and the obtained cutting data. The cutting force formula is:

[0056] F = K·S,

[0057] Where K is the cutting force constant and S is the cutting area;

[0058] When plane milling is used, S = f·d, where f is the feed depth and d is the cutting width;

[0059] When turning, S = π·d·f, d is the cutting depth and f is the feed speed.

[0060] S3. Based on the mass, radius and rotation speed of the spindle driven object, the rotational kinetic energy of the spindle driven object is calculated; wherein the rotational kinetic energy formula is: Where I is the moment of inertia of the object, Iω2 is the angular velocity of the object. When the object is a disk, Where m is the mass of the object and r is the radius of the object.

[0061] S4. Based on the cutting force and the rotation radius of the cutting position, the cutting force work is calculated; wherein the cutting force work can be calculated by the following formula: W = Fωr F t, where F is the cutting force, Iω 2 is the angular velocity of the cutting position, r F is the turning radius of the cutting position.

[0062] S5. Compare the obtained spindle no-load output power with the historical spindle no-load output power to determine whether the spindle no-load rotation is normal. If not, check and maintain the CNC equipment. The energy consumption of the spindle no-load rotation is abnormal. The possible reason is that the spindle friction and other resistances are too high, the spindle drive components are worn, the spindle motor is abnormal, etc.

[0063] S6. Based on the spindle output power, the spindle no-load output power, the output time, the rotational kinetic energy of the spindle-driven object and the work done by the cutting force, the additional energy consumed by the first spindle is calculated; wherein, the additional energy consumed by the first spindle = spindle output power*output time-spindle no-load output power*output time-rotational kinetic energy of the spindle-driven object-cutting force work.

[0064] The method further comprises the following steps:

[0065] Obtain the spindle output power when the spindle drives the object to rotate, and obtain the drive output power;

[0066] Based on the spindle output power, the drive output power and the corresponding output time, the rotational kinetic energy of the object driven by the corresponding spindle and the additional energy consumption of the first spindle, the additional energy consumption of the second spindle is calculated;

[0067] Compare the extra energy consumed by the second spindle with the extra energy consumed by the second spindle of the historical spindle-driven object with the same mass and radius to determine whether the rotation of the object is normal;

[0068] If not, the center of mass deviation distance of the object is calculated based on the additional energy consumption of the second main axis and the angular kinetic energy calculation formula. The center of mass deviation distance is the perpendicular distance between the center of mass of the object and the axis of rotation of the object.

[0069] S7. Compare the extra energy consumption of the first spindle with the corresponding historical extra energy consumption of the first spindle to determine whether the cutting process is normal. If not, inspect and maintain the cutting tool and object. The extra energy consumption of the first spindle is abnormal, which may be because the center of mass of the object driven by the spindle to rotate deviates from the set position, or the tool does not match, the tool is worn, etc.

[0070] S7 includes the following steps:

[0071] Based on the change of the rotation radius of the cutting position during cutting, the corresponding extra energy consumption of the first spindle is collected to obtain a corresponding extra energy consumption change curve of the first spindle, where the extra energy consumption change curve of the first spindle is a curve of the extra energy consumption of the first spindle changing with the rotation radius of the cutting position;

[0072] The extra energy consumption change curve of the first spindle is compared with the corresponding extra energy consumption curve of the first spindle in history to determine whether the error exceeds the set first threshold. If so, the cutting is abnormal; if not, the cutting is normal and the step ends. The corresponding extra energy consumption curve of the first spindle in history is the extra energy consumption curve of the first spindle in history when the same type of tool is used to cut objects of the same material, mass and radius.

[0073] S7 also includes the following steps:

[0074] Determine whether the cutting is turning, that is, determine whether the object driven by the spindle is the workpiece being cut;

[0075] If yes, then draw a curve of the rotational kinetic energy variation of the spindle-driven object, which is a curve of the rotational kinetic energy variation of the spindle-driven object with the rotation radius of the cutting position;

[0076] Regression analysis is performed on the extra energy consumption change curve of the first spindle and the rotational kinetic energy change curve of the spindle-driven object to obtain the extra energy consumption change formula of the first spindle and the rotational kinetic energy change formula of the spindle-driven object;

[0077] Determine whether the error of the difference between the first spindle additional energy consumption change formula and the spindle driven object rotational kinetic energy change formula exceeds a set error second threshold, if so, the center of mass of the spindle driven object is not on the rotation axis;

[0078] Based on the curve of the change of the extra energy consumption of the first spindle and the formula for the change of the extra energy consumption of the first spindle, the distance between the center of mass of the spindle-driven object and the axis of rotation is calculated. This can help determine that during turning, there may be problems with the accuracy of the workpiece clamping mechanism, which causes the center of mass of the workpiece to be not on the axis of rotation when it rotates, resulting in increased vibration and loss during rotation.

[0079] The present invention also provides a management system for monitoring and diagnosing numerical control equipment, comprising a data acquisition module, an information input module, a database, and a diagnosis module;

[0080] The data acquisition module is used to connect with the CNC equipment to obtain the spindle output power, spindle speed and cutting position of the CNC equipment in real time. The cutting position at the start of cutting can be determined by the cutting position obtained in real time and the change rate of the spindle output power.

[0081] The information input module is used to manually set the cutting method, cutting data, and cutting object data. The cutting object data includes the material, mass, and diameter of the cutting object.

[0082] The database is used to store the data acquired by the data acquisition module and the information input module;

[0083] The diagnosis module is used to execute a management method for monitoring and diagnosing numerical control equipment provided by the present invention, determine whether the numerical control equipment operates normally, and output the abnormal position when an abnormality occurs.

[0084] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A management method for monitoring and diagnosing numerical control equipment, characterized in that: The following steps are involved: S1. Obtain the spindle output power of the numerical control device, and obtain the spindle output power consumption based on the spindle output power and output time; S2. Obtain the spindle speed and the corresponding no-load output power of the spindle, and obtain the mass, radius, and cutting force of the spindle-driven object; S3, calculating the rotational kinetic energy of the spindle-driven object based on the mass, radius and spindle speed of the spindle-driven object; S5. Compare the obtained spindle no-load output power with the historical spindle no-load output power to determine whether the spindle no-load rotation is normal. If not, check and maintain the CNC equipment. S6. Calculate the additional energy consumption of the first spindle based on the spindle output power, the spindle no-load output power, the output time, the rotational kinetic energy of the spindle-driven object, and the work done by the cutting force; S7. Compare the extra energy consumed by the first spindle with the corresponding historical extra energy consumed by the first spindle to determine whether the cutting process is normal. If not, inspect and maintain the cutting tool and object.

2. A management method for monitoring and diagnosing numerical control equipment according to claim 1, characterized in that: The method further comprises the following steps: Obtain the spindle output power when the spindle drives the object to rotate, and obtain the drive output power; Based on the spindle output power, the drive output power and the corresponding output time, the rotational kinetic energy of the object driven by the corresponding spindle and the additional energy consumption of the first spindle, the additional energy consumption of the second spindle is calculated; Compare the extra energy consumed by the second main axis with the extra energy consumed by the second main axis of the object driven by the main axis with the same mass and radius in history, and determine whether the rotation of the object is normal; If not, based on the extra energy consumption of the second main axis and the angular kinetic energy calculation formula, the center of mass deviation distance of the object is calculated, and the center of mass deviation distance is the perpendicular distance between the center of mass of the object and the axis of rotation of the object.

3. A management method for monitoring and diagnosing numerical control equipment according to claim 1, characterized in that: In S2, when obtaining the cutting force of the spindle driving the object, the cutting force during the cutting process is measured by a force sensor.

4. A management method for monitoring and diagnosing numerical control equipment according to claim 1, characterized in that: In S2, when obtaining the cutting force of the spindle-driven object, the cutting force is calculated through cutting data, and the cutting data includes a cutting force constant, a cutting area, a feed speed, and a cutting depth.

5. A management method for monitoring and diagnosing numerical control equipment according to claim 1, characterized in that: The S7 comprises the following steps: Based on the change of the rotation radius of the cutting position during cutting, the corresponding extra energy consumption of the first spindle is collected to obtain a corresponding extra energy consumption change curve of the first spindle, wherein the extra energy consumption change curve of the first spindle is a curve showing the extra energy consumption of the first spindle changes with the rotation radius of the cutting position; The first spindle extra energy consumption change curve is compared with the corresponding historical first spindle extra energy consumption curve to determine whether the error exceeds the set first threshold. If so, the cutting is abnormal, if not, the cutting is normal and the step ends.

6. A management method for monitoring and diagnosing numerical control equipment according to claim 5, characterized in that: The S7 further comprises the following steps: Determine whether the cutting is turning; If yes, then draw a curve of the rotational kinetic energy variation of the spindle-driven object, wherein the curve of the rotational kinetic energy variation of the spindle-driven object is a curve of the rotational kinetic energy variation of the spindle-driven object with the rotation radius of the cutting position; Regression analysis is performed on the extra energy consumption change curve of the first spindle and the rotational kinetic energy change curve of the spindle-driven object to obtain the extra energy consumption change formula of the first spindle and the rotational kinetic energy change formula of the spindle-driven object; Determine whether the error of the difference between the first spindle additional energy consumption change formula and the spindle driven object rotational kinetic energy change formula exceeds the set error second threshold, if so, the center of mass of the spindle driven object is not on the rotation axis; Based on the first spindle extra energy consumption variation curve and the first spindle extra energy consumption variation formula, the distance between the center of mass of the spindle driven object and the rotation axis is calculated.

7. A management system for monitoring and diagnosing numerical control equipment, applicable to a management method for monitoring and diagnosing numerical control equipment as claimed in any one of claims 1 to 6, characterized in that: It includes data acquisition module, information input module, database and diagnosis module; The data acquisition module is used to connect with the numerical control equipment to obtain the spindle output power, spindle speed and cutting position of the numerical control equipment in real time; The information input module is used to manually set the cutting method, cutting data, and cutting object data, wherein the cutting object data includes the material, mass, and diameter of the cutting object; The database is used to store data acquired by the data acquisition module and the information input module; The diagnostic module is used to execute a management method for monitoring and diagnosing numerical control equipment as described in any one of claims 1 to 6, to determine whether the numerical control equipment is operating normally, and to remind and output the abnormal position when an abnormality occurs.

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